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Cancer-associated fibroblasts are positively correlated with metastatic potentialof human gastric cancers
Journal of Experimental & Clinical Cancer Research 2010, 29:66 doi:10.1186/1756-9966-29-66
Kangkang Zhi ([emailprotected])Xiaojun Shen ([emailprotected])
Hao Zhang ([emailprotected])Jianwei Bi ([emailprotected])
Article type Research
Submission date 8 February 2010
Acceptance date 8 June 2010
Publication date 8 June 2010
Article URL http://www.jeccr.com/content/29/1/66
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Cancer-associated fibroblasts are positively correlated with metastatic
potential of human gastric cancers
Kangkang Zhi 1, Xiaojun Shen
1, Hao Zhang
1, Jianwei Bi
1. Department of General Surgery, the Second Military Medical University affiliated
Changhai hospital, Shanghai 200433, China
§ Corresponding author: Jianwei Bi; Department of General Surgery, the Second
Military Medical University affiliated Changhai hospital, No.168 Changhai Road, Yangpu
district, Shanghai 200433, China; Email: [emailprotected]
Kangkang Zhi : [emailprotected]
Xiaojun Shen: [emailprotected]
Hao Zhang: [emailprotected]
Jianwei Bi: [emailprotected]
The prognosis of gastric cancer patients is difficult to predict because of defects in
establishing the surgical-pathological features. Cancer-associated fibroblasts (CAFs)
have been found to play prominent role in promoting tumor growth, invasion and
metastasis. Thus raises the hypothesis that the extent of CAFs prevalence may help to
establish the prognosis of gastric cancer patients.
Immunochemistry and realtime-PCR experiments were carried out to compare the
expression of proteins which are specific markers of CAFs or secreted by CAFs in the
tumor and normal tissue specimens. The extent of CAFs’ prevalence was graded
according to immunochemical staining, and correlation was further analyzed between
CAFs’ prevalence and other tumor characteristics which may influence the prognosis
of gastric cancer patients.
Nearly 80 percent of normal gastric tissues were negative or weak positive for CAFs
staining, while more than 60 percent of gastric cancer tissues were moderate or strong
positive for CAFs staining. Realtime-PCR results also showed significant elevated
expression of FAP, SDF-1 and TGF-β1 in gastric cancer tissues compared to normal
gastric tissues. Further analysis showed that CAFs’ prevalence was correlated with
tumor size, depth of the tumor, lymph node metastasis, liver metastasis or peritoneum
Reactive cancer associated fibroblasts (CAFs) were frequently accumulated in gastric
cancer tissues, and the prevalence of CAFs was correlated with tumor size, depth of
the tumor and tumor metastasis, thus give some supports for establishing the
prognosis of the gastric cancer patients.
Gastric cancer is the second leading cause of cancer-related death worldwide .
Substantial geographic variations exist in the incidence of gastric cancer and it
represents the most common cancer in China . More and more gastric cancer
patients have been diagnosed in recent years with changing diet and lifestyle as well
as developing diagnostic procedures. Although surgical treatment has shown to be
effective for some early gastric cancers, including total gastrectomy and extended
radical gastrectomy, the prognosis of these patients is poor due to the recurrence after
surgery, in the form of lymphatic spread, blood-borne metastasis, or peritoneal
The prognosis of patient with gastric cancer has been shown to be influenced by
several established surgical-pathological features, such as the pathological stage, the
location of the tumor and the histological type and grade of the tumor . While
Aurello et al.  have indicated that the number of nodes necessary to conclude N0
may vary according to the depth of tumor invasion (T), the TNM classification
requires the retrieval and analysis of at least 15 lymph nodes for accurate staging.
However, in most cases, the number of nodes dissected is smaller and only 20 to 30%
of the patients have the recommended minimum dissection of 15 nodes. Accessorial
indicators which can provide further information of the prognosis of gastric cancer
patients are needed.
Cancer-associated fibroblast (CAF), one of the important stromal cells comprising
solid tumors, has been found to play prominent role in promoting tumor growth and
progression . In contrast to resting fibroblasts, CAFs possess an activated
phenotype and can be identified by their expression of fibroblast-specific protein 1
(FSP1), vimentin, desmin, and α-smooth-muscle actin . CAFs communicate among
themselves as well as with cancer cells and inflammatory and immune cells directly
through cell contact and indirectly through paracrine/exocrine signaling, proteases,
and modulation of the extracellular matrix (ECM). This complex communications
network is pivotal to providing the appropriate microenvironment to support
tumorigenesis, angiogenesis, and metastasis [8, 9]. Additionally, compared to
transformed tumor cells, CAFs are more genetically homogeneous  and it has
been demonstrated by Gastavo et al that reactive stroma can act as a predictor of
recurrence in prostate cancer , thus represent an attractive predictor and
therapeutic target for tumor patients.
In this study, we collected 100 cases of surgical resection specimens of primary
gastric cancer as well as normal gastric tissues (more than 5cm far from tumor tissue)
from January 2007 to June 2007 in the Second Military Medical University affiliated
Changhai hospital (Shanghai, China). Immunochemistry and RT-PCR experiments
were carried out to compare the expression of proteins which are specific markers of
CAFs or secreted by CAFs in the tumor and normal tissue specimens. The extent of
CAFs’ prevalence was graded according to immunochemical staining, and correlation
was further analyzed between CAFs’ prevalence and other tumor characteristics
which may influence the prognosis of gastric cancer patients.
One hundred cases of primary gastric cancer patients were enrolled from January
2007 to June 2007 in the Second Military Medical University affiliated Changhai
hospital. All patients have provided a written informed consent. Entry criteria for this
study include: (a) no preoperative chemotherapy treatment; (b) pathologically or
cytologically validated gastric-adenocarcinoma; (c) aged between 18-85 years; (d)
expected life>3 months; (e) WBC>3.5×109/L; PLT>10
11/L; Hb>100g/L; Serum
creatinine no more than 1.25 times of normal upper limit; GPT and ALP no more than
1.25 times of normal upper limit; Total bilirubin no more than 1.5 times of normal
upper limit; PT<12s; and (f) no severe CNS disease.
All specimens including tumor tissues and normal gastric tissues which was more
than 5cm far from tumor tissues were fixed in 10% formalin within 30 minutes after
surgical resection. Paraffin embedded serial sections (4 µm) were prepared. Tumor
differentiation was characterized according to WHO classification (2000) while the
TNM classification was done according to International Union Against Cancer, fifth
Antibody used in this procedure includes rabbit anti-FSP1 polyclonal antibody
(Abcam, 1:50), mouse anti-α-SMA monoclonal antibody (Sigma, 1A4, 1:200), rat
anti-procollagen I monoclonal antibody (Chemicon, Mab1912, 1:500),
biotin-conjugated rat anti-mouse IgG polyclonal antibody (ebioscience, 13-4013,
1:100), biotin-conjugated mouse anti-rat IgG polyclonal antibody (ebioscience,
13-4813, 1:100) and biotin-conjugated mouse anti-rabbit IgG polyclonal antibody
(BD PharMingen, C101-167, 1:100). Immunochemistry analysis was performed as
previously described . Briefly, paraffin sections were de-paraffinized in xylene
and a series of graded alcohol solutions. The sections were then treated with 0.3%
hydrogen peroxide (H2O2) in water for 10 minutes to quench any endogenous
peroxidase activity within the tissue, and the nonspecific binding sites were blocked
with 0.5% bovine serum albumin (BSA) for 10 minutes at room temperature. Next,
the sections were incubated for 15 minutes in the presence of the primary antibody,
and then the slides were washed in phosphate buffered saline (PBS) containing 0.1%
Tween 20 (PBS/Tween) for 15 minutes while changing the solution 3 times before the
application of the secondary biotinylated antibody. The slides were incubated with the
secondary antibody for 15 minutes at room temperature before being washed for 15
minutes in PBS/Tween that was changed 3 times. The sections were then incubated
for 15 minutes with an avidin-biotinylated horseradish peroxidase complex, and the
reaction visualized using 0.02% 3,3’-diaminobenzidine tetrahydrochloride as a
chromogen in a Tris-HCl buffer, pH 7.6, containing 0.03% H2O2. Hematoxylin was
used to counterstain the nuclei.
To evaluate the level of FSP1, α-SMA and procollagen-I expression, the percentage of
positive-staining cells were graded on a scale of 0-3, with less than 5%
positive-staining cells as grade 0, 5-25% as grade 1, 26-50% as grade 2, and more
than 50% as grade 3. And the intensity of staining also graded on a scale of 0-2, with
negative to weak intensity as grade 0, weak to moderate intensity as grade 1, and
moderate to strong intensity as grade 2. Ten high-power fields were selected randomly
for each slides and analyzed by two pathologists independently. For each marker, the
score of percentage and intensity was multiplied and the scores for these three
markers was added when these markers was analyzed conjointly. And the final score
between 0-6 was determined as negative (-), score between 7-9 was determined as
weak positive (+), score between 10-12 was determined as moderate positive (++),
and score higher than 13 was determined as strong positive (+++).
Total RNA was extracted from tumor or normal tissues by Trizol reagent (invitrogen)
and first-strand cDNA was synthesized using RevertAid First Strand cDNA Synthesis
Kit (Fermentas, USA) as described previously . Realtime PCR was carried out
using LightCycler DNA Master SYBR Green I Kit (Roche Diagnostics, Mannheim,
Germany) according to the manufacturer’s instructions. The copies of target cDNA
were normalized by GAPDH expression. Primers for FAP, SDF-1, TGF-β1 and
GAPDH were listed as follows:
FAP F: 5’-TGGGAATATTACGCGTCTGTCTAC-3’
FAP R: 5’-GATAAGCCGTGGTTCTGGTCA-3’
SDF-1 F: 5’-CCGTCAGCCTGAGCTACA-3’
SDF-1 R: 5’-GAAGGGCACAGTTTGGAG-3’
TGF-β1 F: 5’-GCAACAATTCCTGGCGATAC-3’
TGF-β1 R: 5’-AAGGCGAAAGCCCTCAAT-3’
GAPDH F: 5’-ATCAAGTTGCGTGCTGTG-3’
GAPDH R: 5’-TGCGAAATGAAAGGAGTGT-3’
For each target cDNA, the copies of normal tissue samples is averaged, and the copies
of each tumor tissue sample is divided by the average, then the results of these three
target cDNA is added for each tumor tissue sample. If the sum is equal to or larger
than 8, then the tumor tissue is considered to be positive for CAFs.
Data are shown as means and standard deviations. Statistical analyses of the data were
analyzed with the two-tailed independent Student’s t test and χ2 analysis by SPSS 12.0.
The level of statistical significance was set at P<0.05.
Reactive tumor associated fibroblasts were prevalent in gastric cancer tissues
To determine the extent of CAFs’ prevalence in gastric cancer tissues, paraffin
embedded sections of tissue specimens were prepared and stained for FSP1, α-SMA
and procollagen I expression as described above. In addition, realtime-PCR was
carried out to determine the expression level of several proteins which was expressed
or secreted by reactive CAFs, such as FAP, SDF-1 and TGF-β1.
Results of immunochemistry staining showed that more reactive fibroblasts were
present in gastric cancer tissues than normal gastric tissues. Twenty four out of the
100 normal specimens were negative (-) for reactive fibroblasts staining and 55
normal specimens were weak positive (+). And the number of normal specimens
which were moderate (++) or strong positive (+++) were 21 and 0, respectively. While
concerning cancer tissues, there were 13, 26, 25 and 36 specimens which were
negative (-), weak positive (+), moderate positive (++) and strong positive (+++) for
fibroblast staining, respectively (Fig 1a and Fig 1b). And if tumor specimens graded
as negative or weak positive were regarded as negative, and moderate or strong
positive were regarded as positive, there was a significant difference between tumor
and normal tissues concerning the positive rate of CAFs (Fig 1c).
For mRNA expression of the proteins, results showed that the expression level of all
these proteins were elevated in tumor specimens compared to these in normal tissues.
Taking FAP as an example, the mRNA expression level of FAP in tumor specimens
was 4 times higher than that in normal tissues (Fig 2a). And there were also 3 times
elevation of mRNA expression level regarding SDF-1 (Fig 2b) or TGF-β1 (Fig 2c).
From these results, we can conclude that reactive CAFs were prevalent in gastric
tumor tissues and secret high level of proteins which have been demonstrated to be
essential for tumor growth, invasion and metastasis.
CAFs’ prevalence was closely related with invasive and metastatic properties of
To determine whether the grade of CAFs’ prevalence can be served as a predictor for
the prognosis of gastric cancer patients, correlation analysis was carried out between
the grade of CAFs’ prevalence and other clinicopathological parameters of gastric
cancers. Tumor specimens graded as negative or weak positive were regarded as
negative, and moderate or strong positive were regarded as positive in these analysis.
Patient and tumor characteristics were described in Table 1. We can also find in Table
1 that there was no correlation between CAFs’ prevalence and age, gender of the
patient or the location of the tumor. There was an increase of CAFs’ prevalence when
the tumor differentiation decreased from well-differentiated (43.75%) to
poorly-differentiated (64.00%), while the positive rate of CAFs in undifferentiated
gastric cancer is only 26.67%, much less than that in well or poorly differentiated
gastric cancers, thus we could not find the correlation between the CAFs’ prevalence
and tumor differentiation (P=0.56). While concerning tumor size, depth of the tumor
(T) and lymph node metastasis (N), there showed statistically significant correlation
between the prevalence of CAFs and these tumor characteristics, with higher positive
rate of CAFs in larger tumors, more invasive tumors and tumors with more lymph
node metastasis. Also we can find that the positive rate of CAFs was high in gastric
cancers with liver metastasis (P<0.01) or peritoneum metastasis (P<0.01).
In addition, in the situation of tumor metastasis, whatever lymph node metastasis,
distant metastasis or organ metastasis, the positive percentage for CAFs is much
higher than that in those without metastasis (71.93% vs 25.58%, P<0.01) (Fig 3).
And we also analyzed the correlation between the mRNA level of FAP, SDF-1 and
TGF-β1 and the gastric cancer stage. The level of these proteins were scored as
described in the methods and the tumor tissue samples were determined to be positive
if the score is equal to or larger than 8. It was found that the positive percentage is
much high in large tumors (>5 cm, 32/38) than that in small tumors (≤5cm, 20/62)
(p<0.05). And the positive percentage in tumor samples with TNM stage IA, IB, II,
IIIA, IIIB and IV are 33.3% (5/15), 42.9%(3/7), 52.6%(10/19), 60.9%(14/23),
73.3%(11/15) and 76.2(16/21), respectively, showing that the prevalence of CAFs is
closely correlated with the gastric cancer stages (p<0.01). These results strongly
suggested that CAFs’ prevalence could help to establish the gastric cancer stage and
could be used as a marker for the prognosis of gastric cancer patients.
Recent studies in molecular and cellular biology have shown that tumor growth and
metastasis are not determined by cancer cells alone but also by a variety of stromal
cells [14, 15]. The stroma actively provides continuous support to carcinoma cells
throughout the different pathophysiological processes that modulate tumor
progression. Fibroblasts are an important component of tumor stroma, which have
received increased attention because of their participation in tumor development,
including growth, invasion and metastasis, such as in prostate cancer [16, 17] or
breast cancer [18, 19]. It has also been demonstrated in a gastric cancer mice model
that activated fibroblasts promote tumor angiogenesis , and it is consistent with
out results that activated fibroblasts were accumulated in human gastric cancer
The term fibroblast encompasses a number of stromal cells with a broadly similar
phenotype. Most tumors incorporate an obvious biologically active, fibroblastic cell
type known variously as reactive fibroblasts, myofibroblasts, or simply
tumor-associated fibroblasts. Smooth muscle α-actin (α-SMA) is the most common
marker used to identify CAFs, while its expression can also be found in smooth
muscle cells and myoepithelial cells . So other markers should be used in
combination with α-SMA to identify CAFs. Fibroblast-specific protein 1 (FSP1,
S100A4), a member of the family of Ca2+ -binding S100 proteins, constitutively
expressed in the cytoplasm of tissue fibroblasts, and its expression is highly specific
for fibroblasts [22, 23]. It is widely accepted to combine a-SMA and FSP1 for the
identification of tumor-associated fibroblasts. And in our experiment, we also used a
third marker, procollagen I, to identify reactive CAFs with production of extracellular
We also detected the mRNA expression level of other proteins which is expressed or
secreted by CAFs. FAP is a type II transmembrane cell surface protein belonging to
the post-proline dipeptidyl aminopeptidase family, with dipeptidyl peptidase and
endopeptidase activity, including a collagenolytic activity capable of degrading
gelatin and type I collagen [24, 25]. FAP is expressed selectively by CAFs and
pericytes in more than 90% of human epithelial cancers examined [26-30] and
research has been reported in animal model showing a therapeutic effect by inhibiting
FAP expression or enzymatic activity . The next protein we selected to detect is
SDF-1, which is secreted by CAFs and stimulates tumor cells proliferation,
angiogenesis, invasion and metastasis through the CXCR4 receptor expressed by
tumor cells [32-34]. Another secreted protein we detected is TGF-β1, which is a
potent inducer for myofibroblasts differentiation , and may play a role in tumor
invasion-metastasis cascades . The results of the present study showed that these
proteins were up-regulated in gastric cancer tissues, suggesting their potential role in
promoting gastric cancer progression.
Gastric cancer is the second leading cause of cancer-associated mortality in the world.
Prognosis in patients with gastric cancer is difficult to establish because it is
commonly diagnosed when gastric wall invasion and metastasis have occurred.
Several groups attempted to find some biomarkers for the prognosis of gastric cancer.
For example, the expression of several extracellular matrix metalloproteinases
(MMP-2, 7, 9) has been found to be elevated in gastric cancer tissues compared to
healthy gastric tissues. And the up-regulation of these MMPs in gastric cancer has
been associated with a poor prognosis and elevated invasive capacity . Another
example is insulin-like growth factor-1 receptor (IGF-1R), it was frequently expressed
in gastric cancers and was associated with tumor size, quantity of stroma, depth of
wall invasion, lymph node metastasis, TNM stages and differentiation status of gastric
cancer . And VEGF-C expression at tumor margins was also associated with
nodal metastasis, lymphatic vessel invasion, poor recurrence-free survival, and poor
overall survival, and could serve as an independent predictor for patients with gastric
carcinoma . We can find that these predictors are either proteins secreted by CAFs
or receptors expressed by tumor cells which bind the proteins secreted by CAFs, so
these clues may suggest that the prevalence of CAFs in gastric cancer tissues will be
an important predictor of gastric cancer patients. And our results confirmed that the
prevalence of CAFs was closely associated with the metastatic potential of gastric
cancer, and further work should be done to confirm the correlation between CAFs’
prevalence and survival of gastric cancer patients.
Our findings report here demonstrate that reactive cancer associated fibroblasts (CAFs)
were frequently accumulated in gastric cancer tissues, and the prevalence of CAFs
was correlated with tumor size, depth of the tumor and tumor metastasis as well as the
overall TNM stage, suggesting that CAFs were critical for tumor growth, invasion and
metastasis, thus give some supports for the prognosis of the gastric cancer patients.
CAFs tumor associated fibroblasts; FAP fibroblast activation protein; SDF-1
stromal-cell derived factor 1; TGF-β1 transforming growth factor beta 1; ECM
extracellular matrix; WBC white blood cell count; PLT platelet count; Hb hemoglobin;
GPT glutamic-pyruvic transaminase; ALP alkaline phosphatase; PT prothrombin time;
CNS central nerves system; α-SMA α-smooth-muscle actin; FSP1 fibroblast specific
protein 1; GAPDH glyceraldehyde phosphate dehydrogenase; MMP matrix
metalloproteinase;VEGF vascular endothelial growth factor.
The authors declare that there were no competing interests.
KK Zhi carried out the specimen collection and immunochemistry experiment. XJ
Shen dealed with RNA extraction and realtime PCR. H Zhang carried out the
statistical analysis. JW Bi designed the study and helped to draft the manuscript. All
authors have read and approved the final manuscript.
We want to thank Prof. Li Gao in the Department of pathology of Changhai Hospital
and Dr. Ni Zhu in the Central Lab of Changhai Hospital for their expert technical
supports for the experiments. This work was supported by The National Natural
Science Foundation of China (30672046).
1. Anderson C, Nijagal A, Kim J: Molecular markers for gastric adenocarcinoma: an
update. Mol Diagn Ther 2006, 10:345-352.
2. Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL: Sabiston Textbook of
Surgery 18th edition. Saunders, An Imprinter of Elsevier. Philadelphia; 2008.
3. Kim JW, Hwang I, Kim MJ, Jang SJ: Clinicopathological characteristics and
predictive markers of early gastric cancer with recurrence. J Korean Med Sci 2009, 24:
4. Miyahara R, Niwa Y, Matsuura T, Maeda O, Ando T, Ohmiya N, Itoh A, Hirooka Y,
Goto H: Prevalence and prognosis of gastric cancer detected by screening in a large
Japanese population: data from a single institute over 30 years. J Gastroenterol
Hepatol 2007, 22:1435-1442.
5. Aurello P, D'Angelo F, Rossi S, Bellagamba R, Cicchini C, Nigri G, Ercolani G, De
Angelis R, Ramacciato G: Classification of lymphnode metastases from gastric cancer:
comparison between N-site and N-number systems. Our experience and review of the
literature. Am Surg 2007, 73:359-366.
6. Kalluri R, Zeisberg M: Fibroblasts in cancer. Nat Rev Cancer 2006, 6: 392–401.
7. Mueller MM, Fusenig NE: Friends or foes - bipolar effects of the tumour stroma in
cancer. Nat Rev Cancer 2004, 4: 839–849.
8. Bhowmick NA, Neilson EG, Moses HL: Stromal fibroblasts in cancer initiation and
progression. Nature 2004, 432:332–337.
9. Tlsty TD, Coussens LM: Tumor stroma and regulation of cancer development.
Annu Rev Pathol 2006, 1:119–150.
10. Qiu W, Hu M, Sridhar A, Opeskin K, Fox S, Shipitsin M, Trivett M, Thompson
ER, Ramakrishna M, Gorringe KL, Polyak K, Haviv I, Campbell IG: No evidence of
clonal somatic genetic alterations in cancer-associated fibroblasts from human breast
and ovarian carcinomas. Nat Genet 2008, 40: 650-655.
11. Ayala G, Tuxhorn JA, Wheeler TM, Frolov A, Scardino PT, Ohori M, Wheeler M,
Spitler J, Rowley DR: Reactive stroma as a predictor of biochemical-free recurrence
in prostate cancer. Clin Cancer Res 2003, 9: 4792-4801.
12. Lee SJ, Kim JG, Sohn SK, Chae YS, Moon JH, Kim SN, Bae HI, Chung HY, Yu
W: No Association of Vascular Endothelial Growth Factor-A (VEGF-A) and VEGF-C
Expression with Survival in Patients with Gastric Cancer. Cancer Res Treat 2009, 41:
13. Olumi AF, Grossfeld GD, Hayward SW, Carroll PR, Tlsty TD, Cunha GR:
Carcinoma-associated fibroblasts direct tumor progression of initiated human
prostatic epithelium. Cancer Res 1999, 59: 5002-5011.
14. Bissell MJ, Radisky D: Putting tumours in context. Nat Rev Cancer 2001, 1:
15. Polyak K, Haviv I, Campbell IG: Co-evolution of tumor cells and their
microenvironment. Trends Genet 2009, 25: 30-38.
16. Hayward SW, Wang Y, Cao M, Hom YK, Zhang B, Grossfeld GD, Sudilovsky D,
Cunha GR: Malignant transformation in a nontumorigenic human prostatic epithelial
cell line. Cancer Res 2001, 61: 8135-8142.
17. Cheng N, Bhowmick NA, Chytil A, Gorksa AE, Brown KA, Muraoka R, Arteaga
CL, Neilson EG, Hayward SW, Moses HL: Loss of TGF-beta type II receptor in
fibroblasts promotes mammary carcinoma growth and invasion through upregulation
of TGF-alpha-, MSP- and HGF-mediated signaling networks. Oncogene 2005, 24:
18. Cheng N, Chytil A, Shyr Y, Joly A, Moses HL: Enhanced hepatocyte growth
factor signaling by type II transforming growth factor-beta receptor knockout
fibroblasts promotes mammary tumorigenesis. Cancer Res 2007, 67:4869-4877.
19. Noel A, De Pauw-Gillet MC, Purnell G, Nusgens B, Lapiere CM, Foidart JM:
Enhancement of tumorigenicity of human breast adenocarcinoma cells in nude mice
by matrigel and fibroblasts. Br J Cancer 1993, 68: 909-915.
20. Guo X, Oshima H, Kitmura T, Taketo MM, Oshima M: Stromal fibroblasts
activated by tumor cells promote angiogenesis in mouse gastric cancer. J Biol Chem
2008, 283: 19864-19871.
21. Gabbiani G, Kapanci Y, Barazzone P, Franke WW: Immunochemical identification
of intermediate-sized filaments in human neoplastic cells. A diagnostic aid for the
surgical pathologist. Am J Pathol 1981, 104: 206-216.
22. Strutz F, Okada H, Lo CW, Danoff T, Carone RL, Tomaszewski JE, Neilson EG:
Identification and characterization of a fibroblast marker: FSP1. J Cell Biol 1995, 130:
23. Iwano M, Fischer A, Okada H, Plieth D, Xue C, Danoff TM, Neilson EG:
Conditional abatement of tissue fibrosis using nucleoside analogs to selectively
corrupt DNA replication in transgenic fibroblasts. Mol Ther 2001, 3: 149-159.
24. Christiansen VJ, Jackson KW, Lee KN, McKee PA: Effect of fibroblast activation
protein and [alpha]2-antiplasmin cleaving enzyme on collagen types I, III, and IV.
Arch Biochem Biophys 2007, 457:177–186.
25. Aggarwal S, Brennen WN, Kole TP, Schneider E, Topaloglu O, Yates M, Cotter
RJ, Denmeade SR: Fibroblast activation protein peptide substrates identified from
human collagen I derived gelatin cleavage sites. Biochemistry 2008, 47:1076–1086.
26. Cohen SJ, Alpaugh RK, Palazzo I, Meropol NJ, Rogatko A, Xu Z, Hoffman JP,
Weiner LM, Cheng JD: Fibroblast activation protein and its relationship to clinical
outcome in pancreatic adenocarcinoma. Pancreas 2008, 37:154–158.
27. Garin-Chesa P, Old LJ, Rettig WJ: Cell surface glycoprotein of reactive stromal
fibroblasts as a potential antibody target in human epithelial cancers. PNAS 1990, 87:
28. Goscinski MA, Suo Z, Flørenes VA, Vlatkovic L, Nesland JM, Giercksky KE:
FAP-alpha and uPA show different expression patterns in premalignant and malignant
esophageal lesions. Ultrastruct Pathol 2008, 32:89–96.
29. Henry LR, Lee HO, Lee JS, Klein-Szanto A, Watts P, Ross EA, Chen WT, Cheng
JD: Clinical implications of fibroblast activation protein in patients with colon cancer.
Clin Cancer Res 2007, 13:1736–1741.
30. Scanlan MJ, Raj BK, Calvo B, Garin-Chesa P, Sanz-Moncasi MP, Healey JH, Old
LJ, Rettig WJ: Molecular cloning of fibroblast activation protein a, a member of the
serine protease family selectively expressed in stromal fibroblasts of epithelial cancers.
PNAS 1994, 91:5657–5661.
31. Santos AM, Jung J, Aziz N, Kissil JL, Puré E: Targeting fibroblast activation
protein inhibits tumor stromagenesis and growth in mice. J Clin Invest 2009, 119:
32. Orimo A, Gupta PB, Sgroi DC, Arenzana-Seisdedos F, Delaunay T, Naeem R,
Carey VJ, Richardson AL, Weinberg RA: Stromal fibroblasts present in invasive
human breast carcinomas promote tumor growth and angiogenesis through elevated
SDF-1/CXCL12 secretion. Cell 2005, 121:335-348.
33. Ao M, Franco OE, Park D, Raman D, Williams K, Hayward SW: Crosstalk
between paracrine-acting cytokine and chemokine pathways promotes malignancy in
benign human prostatic epithelium. Cancer Res 2007, 67: 4244-4253.
34. Vindrieux D, Escobar P, Lazennec G: Emerging roles of chemokines in prostate
cancer. Endocr Relat Cancer 2009, 16: 663-673.
35. Tuxhorn JA, McAlhany SJ, Yang F, Dang TD, Rowley DR: Inhibition of
transforming growth factor-beta activity decreases angiogenesis in a human prostate
cancer-reactive stroma xenograft model. Cancer Res 2002, 62: 6021-6025.
36. Shimoda M, Mellody KT, Orimo A: Carcinoma-associated fibroblasts are a
rate-limiting determinant for tumour progression. Semin Cell Dev Biol 2010, 21:
37. de la Peña S, L Sampieri C, León-Córdoba K: Matrix metalloproteases as
molecular markers in gastric cancer. Med Clin (Barc) 2010, 134: 123-126.
38. Ge J, Chen Z, Wu S, Chen J, Li X, Li J, Yin J, Chen Z: Expression levels of
insulin-like growth factor-1 and multidrug resistance-associated protein-1 indicate
poor prognosis in patients with gastric cancer. Digestion 2009, 80: 148-158.
39. Gao P, Zhou GY, Zhang QH, Su ZX, Zhang TG, Xiang L, Wang Y, Zhang SL, Mu
K: Lymphangiogenesis in gastric carcinoma correlates with prognosis. J Pathol 2009,
Fig 1. Immunochemistry analysis of the grade of CAFs’ prevalence in tumor and
normal gastric tissues. Paraffin sections of surgically resected tumor and normal
tissues from the same gastric cancer patients (100 cases) were stained for FSP1,
α-SMA and procollagen-1 expression and CAFs prevalence was graded according to
the positive rate and intensity of the immunochemical staining. The number of tumor
or normal tissue specimens graded as -, +, ++ and +++ was compared (a). And the
distribution of these four grades of CAFs’ prevalence in the 100 tumor or normal
tissue specimens were analyzed (b). Grade – and + was regarded as negative, while
grade ++ and +++ was regarded as positive for CAFs prevalence, then the number of
the tumor or normal tissue specimens which was positive or negative for CAFs’
prevalence was compared (c).
Fig 2. Realtime-PCR analysis of secreted proteins by CAFs in tumor and normal
gastric tissues. Total RNA was extract and cDNA was prepared from surgically
resected tumor and normal tissues from the same gastric cancer patients (100 cases).
Realtime-PCR was carried out to compare the expression level of FAP (a), SDF-1 (b)
and TGF-β1 (c) in tumor and normal tissues, the first two lanes of the
electrophoretogram represented normal tissues and the last two lanes represented
tumor tissues. *:p<0.01.
Fig 3. The percentage of tumor specimens which was positive or negative for CAFs’
prevalence in the group of patients with or without tumor metastasis. The tumor
specimens were grouped according to whether or not the gastric cancer patients had
tumor metastasis (whatever lymph node metastasis, distant metastasis or organ
metastasis). And the percentage of the specimens which was positive (grade – or +
according to immunochemical staining) or negative (grade ++ or +++ according to
immunochemical staining) for CAFs’ prevalence was analyzed (a). And the
immunochemical staining of α-SMA was shown in normal gastric tissue, gastric
cancer tissue without metastasis and gastric cancer tissue with metastasis (b).
Table 1. Patient and tumor characteristics and their relationship with CAFs prevalence
Positive for CAFs
N (%) P value
Age (year) 2.77a
≤60 47 22 (46.81)
>60 53 29 (54.72)
Male 57 32 (56.14)
Female 43 19 (44.19)
Location of the tumor 1.35b
Proximal end of stomach (1/3) 13 9 (69.23)
Gastric body (1/3) 19 9 (47.37)
Remote end of stomach (1/3) 51 22 (43.14)
More than 1/3 of the stomach involved 17 11 (64.71)
Tumor differentiation 0.56b
Well differentiated 16 7 (43.75)
Moderate differentiated 44 24 (54.55)
Poorly differentiated 25 16 (64.00)
Undifferentiated 15 4 (26.67)
Tumor size 0.02a
≤5cm 62 16 (35.48)
>5cm 38 29 (76.32)
Depth of tumor (T) 0.03b
Tis 4 1 (25.00)
T1 13 5 (38.46)
T2 39 19 (48.72)
T3 26 15 (57.69)
T4 18 11 (61.11)
Lymph node metastasis (N) <0.01a
N0 46 16 (34.78)
N1-3 54 35 (64.81)
Liver metastasis <0.01a
Yes 12 9
No 88 42
Peritoneum metastasis <0.01a
Yes 9 7 (77.77)
No 91 44 (48.35)
TNM Stage <0.01b
IA 15 3 (20)
IB 7 2 (28.57)
II 19 6 (31.58)
IIIA 23 11 (47.83)
IIIB 15 8 (53.33)
IV 21 14 (66.67)
a: Fisher exact test; b: Chi-Square Tests
CAFs induce tumor growth
Among the stromal cells in the microenvironment surrounding the tumor, increasing evidence has reported that CAFs are targets and inducers of tumorigenic activation signals (31,32). CAFs produce autocrine and/or paracrine cytokines that promote the biological characteristics of tumors.
Components of the TME, such as cancer-associated fibroblasts (CAFs), which are activated fibroblasts in the tumor stroma, have been implicated in cancer malignancy and tumor progression . CAFs have been found to contribute to non-restricted growth, angiogenesis, invasion, metastasis, and therapy resistance .How are cancer-associated fibroblasts activated? ›
Within the tumor microenvironment, various inflammatory cytokines produced by cancer cells, host immune and stromal cells induce the activation of fibroblasts. These activated fibroblasts are termed cancer-associated fibroblasts (CAFs).How do CAFs promote metastasis? ›
CAFs secreted exosomes promote metastasis and chemotherapy resistance by enhancing cell stemness and epithelial-mesenchymal transition in colorectal cancer.What is the role of cancer-associated fibroblasts in cancer invasion and metastasis? ›
CAFs can promote cancer invasion and metastasis by inducing biochemical changes and regulating tumor-related signaling . Nevertheless, a fact related to CAFs that has been ignored by various studies is that CAFs exert a negative influence on malignant tumorigenesis and progression under certain conditions .Which protein controls cancer growth? ›
The Myc protein, depicted here, is mutated in more than half of all human cancers. A cancer-associated protein called Myc directly controls the expression of two molecules known to protect tumor cells from the host's immune system, according to a study by researchers at the Stanford University School of Medicine.Are cancer-associated fibroblasts heroes or villains? ›
It might be that fibroblasts begin as a tumour-suppressive cell type, but as the tumour develops it begins to influence the environment and transforms these fibroblasts into pro-tumoural factories. It is therefore conceivable that fibroblasts act as both heroes and villains.What are the different types of cancer fibroblasts? ›
A cancer-associated fibroblast (CAF) (also known as tumour-associated fibroblast; carcinogenic- associated fibroblast; activated fibroblast) is a cell type within the tumor microenvironment that promotes tumorigenic features by initiating the remodelling of the extracellular matrix or by secreting cytokines.What triggers fibroblasts? ›
These fibroblasts have the capacity to become activated by inflammatory cytokines to myofibroblasts that display up-regulated cellular migration, exaggerated ECM production, the endowment of a contractile apparatus, and increased chemical signaling secretion and responsiveness.What are breast cancer-associated fibroblasts? ›
Cancer-associated fibroblasts (CAF) are a major cellular component of epithelial tumors. In breast cancers in particular these stromal cells have numerous tumorigenic effects in part due to their acquisition of a myofibroblastic phenotype. Breast CAFs (bCAFs) typically express MCL-1.
Cancer-associated fibroblasts (CAFs) orchestrate the resistance to chemoradiotherapies in the tumor microenvironment. CAFs secrete abundant chemokines, cytokines, growth factors, exosomes, and other factors.What are the four steps needed for the development of metastases? ›
Metastasis is facilitated by four essential steps: detachment, migration, invasion and adhesion. Cancer cells first detach from the primary tumor, undergo migration, invasion, and travel to different sites through blood and lymphatic vessels, then settle (adhesion) and grow.What is the most common site of metastasis of soft tissue sarcoma? ›
For patients with soft tissue sarcoma, the lungs are the most common site of metastatic disease.What is positive for metastasis? ›
Signs and symptoms that cancer has spread to the lungs include coughing, coughing up blood, chest pain, breathing problems, and fluid around the lungs. Contact your health care team if you experience any of the symptoms above. These can be signs of cancer metastasis or another health problem.What hallmark of cancer is activating invasion and metastasis? ›
Cancer cells invade local tissue and spread to distant sites via two distinct, but similar processes known as invasion and metastasis. Tissue invasion is the mechanism by which tumor cells expand into nearby environments.Do cancer cells activate fibroblasts? ›
Fibroblasts can be activated by a diverse set of factors secreted from cancer or immune cells. Not only growth factors such as TGF-β, PDGF, HGF and FGF but also interleukins, metalloproteinases and reactive oxygen species can promote activation.Why do cancer cells invade tissues? ›
Tumor cells spreading into the surrounding tissues and distant organs are known to reproduce the mechanisms and migration types characteristic of normal, non-tumor cells during physiological processes.What protein kills cancer cells? ›
Glutathione is needed for the ability of the T cells to kill the cancer cells. The more protein you eat, the better your chance of getting enough cysteine to make glutathione. Glutathione is just a 3 amino-acid peptide, and the critical amino acid in that peptide is cysteine.What foods inhibit cancer growth? ›
Phytochemicals are compounds found in plants that can help prevent chronic diseases like cancer. The list is usually topped with berries, broccoli, tomatoes, walnuts, grapes and other vegetables, fruits and nuts.
Tyrosine kinase inhibitors (TKIs) block chemical messengers (enzymes) called tyrosine kinases. Tyrosine kinases help to send growth signals in cells, so blocking them stops the cell growing and dividing. Cancer growth blockers can block one type of tyrosine kinase or more than one type.
The involvement of specific fibroblast lineages may have particular relevance to diseases characterized by excessive fibrosis and scarring such as scleroderma, keloids, graft-versus-host disease, and pulmonary fibrosis.What disease has fibroblast activation protein? ›
Fibroblast activation protein-α (FAP) is a type-II transmembrane serine protease expressed almost exclusively to pathological conditions including fibrosis, arthritis and cancer. Across most cancer types, elevated FAP is associated with worse clinical outcomes.Which of the 4 tissue types has fibroblasts? ›
The family of connective-tissue cells includes fibroblasts, cartilage cells, bone cells, fat cells, and smooth muscle cells.What creature is immune to cancer? ›
However, several species are known to be extremely cancer resistant. These include the naked mole rat, blind mole rat, elephant and bowhead whale.What proteins indicate cancer? ›
C-reactive protein (CRP) is a predominant protein of the acute phase response; its blood levels have long been used as a minimally invasive index of any ongoing inflammatory response, including that occurring in cancer.What are the most mutated proteins in cancer? ›
The most common tumor suppressor gene that mutates in people with cancer is p53 or TP53. This gene is missing or damaged in more than half of all cancers.Are cancer associated fibroblasts in ovarian cancer? ›
CAFs can regulate the growth, proliferation, and metastasis of ovarian cancer in different ways, including (a) secreting cytokines, (b) shaping the immune microenvironment, and (c) establishing metabolic crosstalk.What is the morphology of cancer associated fibroblasts? ›
Fibroblasts in cancer tissues are similar in morphology to myofibroblasts, which are large spindle-shaped cells that are activated during the wound healing process .What are the two types of fibroblast? ›
Types of Fibroblasts
Muscular fibroblasts: These contain three layers of fibroblasts (the endomysium, perimysium, and epimysium) that support skeletal muscles. Dermal fibroblasts: These play an essential role in wound healing. Several fibroblasts support the layers of skin and help in hair production.
The fibroblast is one of the most abundant cell types present in the stroma. It has a variety of functions and composes the basic framework for tissues and organs. Under homeostasis, this cell is responsible for maintaining the extracellular matrix (ECM).
Prostaglandin E(2) inhibits fibroblast chemotaxis.Do fibroblasts cause inflammation? ›
Fibroblasts are a key source of inflammatory cytokines and chemokines in inflammatory diseases such as RA (13). In fact, fibroblasts may produce larger amounts of inflammatory factors than leukocytes, as they are the dominant source of inflammatory cytokines like IL-6 (61).What are the three biomarkers for breast cancer? ›
Three of the most important markers are estrogen receptor (ER), progesterone receptor (PR) and a receptor called HER2. The levels of these markers can influence how a person with breast cancer is treated in the clinic.What protein is a marker for breast cancer? ›
Tumor markers are typically proteins that are produced by cancer cells, many of which can be found in the blood. Some examples of such tumor markers in breast cancer are: CA 15-3 and CA 27.29: CA 15-3 and CA 27.29 are two related markers that are made in higher amounts by breast cancer cells.What three receptor types are most commonly associated with breast cancer development? ›
Breast tumors may be positive for estrogen receptors (ER+), progesterone receptors (PR+) or both (ER/PR+).What is the difference between adjuvant and metastatic cancer? ›
Adjuvant therapies are administered after surgical removal of a localized or regional cancer when there is no evidence of distant spread. Metastatic drugs are administered to patients with measurable tumors that have typically spread beyond the primary organ.Which highly metastatic type of skin cancer is resistant to chemotherapy? ›
Melanoma is a most dangerous and deadly type of skin cancer, and considered intrinsically resistant to both radiotherapy and chemotherapy.What are cancers that affect connective tissues called? ›
Soft tissue sarcomas are cancers that develop in the connective and supporting tissues in the body.Can Stage 4 metastasis be cured? ›
Stage 4 cancer usually can't be cured. In addition, because it's usually spread throughout the body by the time it's diagnosed, it is unlikely the cancer can be completely removed. The goal of treatment is to prolong survival and improve your quality of life.Does metastasis always mean stage 4? ›
Cancer that spreads from where it started to a distant part of the body is called metastatic cancer. For many types of cancer, it is also called stage IV (4) cancer. The process by which cancer cells spread to other parts of the body is called metastasis.
Metastasis is a multi-step process encompassing the (i) local infiltration of tumor cells into the adjacent tissue, (ii) transendothelial migration of cancer cells into vessels known as intravasation, (iii) survival in the circulatory system, (iv) extravasation and (v) subsequent proliferation in competent organs ...Where do sarcomas metastasize most often? ›
When sarcoma spreads to a different part of the body, it is called secondary or metastatic cancer. Sarcoma spreads most often to the lungs. It might also spread to the liver.What is the survival rate of soft tissue sarcoma metastasis? ›
Overall, the 5-year survival rate for soft tissue sarcomas is about 65%. The 5-year survival rate for cancer that has reached nearby organs or lymph nodes is about 50%. Once soft tissue sarcoma has spread to other parts of the body, the 5-year survival rate is about 18%.Where do most sarcomas start? ›
While sarcomas may arise anywhere in the body, they most often originate in the arms, legs, chest, or abdomen. Sarcomas are often not symptomatic until they are very large and may first be noticed as swelling or a painless lump.What is the tumor marker for metastasis? ›
Blood tumor marker tests.
For metastatic breast cancer, testing may be done for cancer antigen 15-3 (CA 15-3), cancer antigen 27.29 (CA 27.29), and/or carcinoembryonic antigen (CEA). These biomarkers may be found in the blood of people with breast cancer.
Which Type of Cancer Spreads the Fastest? The fastest-moving cancers are pancreatic, brain, esophageal, liver, and skin. Pancreatic cancer is one of the most dangerous types of cancer because it's fast-moving and there's no method of early detection.Has anyone survived metastasis? ›
In the past, many people did not live long with metastatic cancer. Even with today's better treatments, recovery is not always possible. But doctors can often treat cancer even if they cannot cure it. A good quality of life is possible for months or even years.What role do cancer associated fibroblasts have in manipulating the tumor microenvironment? ›
Cancer-associated fibroblasts (CAFs) are a key component of the tumour microenvironment with diverse functions, including matrix deposition and remodelling, extensive reciprocal signalling interactions with cancer cells and crosstalk with infiltrating leukocytes.Do cancer cells allow tumors to grow? ›
Unlike normal cells, cancer cells don't stop growing and dividing when there are enough of them. So the cells keep doubling, forming a lump (tumour) that grows in size.What cells promote tumor growth? ›
Regulatory T cells (Tregs) are normally required to suppress inflammatory responses and control autoimmunity. In the context of the TME, Tregs are ubiquitous and promote tumor development and progression by dampening antitumor immune responses.
It might be that fibroblasts begin as a tumour-suppressive cell type, but as the tumour develops it begins to influence the environment and transforms these fibroblasts into pro-tumoural factories. It is therefore conceivable that fibroblasts act as both heroes and villains.What are the subtypes of cancer-associated fibroblasts? ›
In tumor samples from human breast adenocarcinoma, Costa et al. identified four subtypes of CAFs, designated CAF-S1 to CAF-S4, based on the expression of six markers, including integrin β1 (ITGB1, a.k.a. CD29), αFAP, PDGFRβ, FSP-1, α-SMA and caveolin 1 (Cav1).What is the morphology of cancer-associated fibroblasts? ›
Fibroblasts in cancer tissues are similar in morphology to myofibroblasts, which are large spindle-shaped cells that are activated during the wound healing process .What starves cancer cells? ›
Researchers found in cells and in mice that a low-protein diet blocked the nutrient signaling pathway that fires up a master regulator of cancer growth.What cell kills tumor cells? ›
Killer T cells can be separated from other blood cells, grown in the laboratory, and then given to a patient to kill cancer cells. A killer T cell is a type of white blood cell and a type of lymphocyte. Also called cytotoxic T cell and cytotoxic T lymphocyte.What is a fast growing tumor called? ›
Glioblastoma (GBM), also referred to as a grade IV astrocytoma, is a fast-growing and aggressive brain tumor. It invades the nearby brain tissue, but generally does not spread to distant organs. GBMs can arise in the brain de novo or evolve from lower-grade astrocytoma.What kills tumor cells? ›
Oncolytic viruses kill individual cancer cells, but studies also suggest that they can boost the immune system's ability to recognize and kill a tumor. The viruses enter tumor cells specifically and replicate, eventually breaking the cells apart.What is fibroblast cancer called? ›
A cancer-associated fibroblast (CAF) (also known as tumour-associated fibroblast; carcinogenic- associated fibroblast; activated fibroblast) is a cell type within the tumor microenvironment that promotes tumorigenic features by initiating the remodelling of the extracellular matrix or by secreting cytokines.