Immunohistochemical study of epidermal growth factor and transforming growth factor-beta in the penetrating type of early gastric cancer

Utilising network pharmacology to explore the underlying mechanism of Wumei Pill in treating pancreatic neoplasms

Background

Wumei Pill (WMP), a famous herbal formula, has been widely used to treat digestive system diseases in clinical practice in China for centuries. We have found a correlation between the indications of WMP and the typical symptoms of pancreatic neoplasms. However, the pharmacological mechanisms of WMP still remain unknown.

Methods

In the present work, we used a network pharmacological method to predict its underlying complex mechanism of treating pancreatic neoplasms. Firstly, we obtained relative compounds of WMP based on TCMSP database, TCM database@Taiwan and TCMID database and collected potential targets of these compounds by target fishing. Then we built the pancreatic neoplasms target database by CTD, TTD, PharmGKB. Based on the matching results between WMP potential targets and pancreatic neoplasms targets, we built a PPI network to analyze the interactions among these targets and screen the hub targets by topology. Furthermore, DAVID bioinformatics resources were utilized for the enrichment analysis on GO_BP and KEGG.

Results

A total of 80 active ingredients and 77 targets of WMP were picked out. The results of DAVID enrichment analysis indicated that 58 cellular biological processes (FDR < 0.01) and 17 pathways (FDR < 0.01) of WMP mostly participated in the complex treating effects associated with proliferation, apoptosis, inflammatory response and angiogenesis. Moreover, 17 hub nodes of WMP (PTGS2, BCL2, TP53, IL6, MAPK1, EGFR, EGF, CASP3, JUN, MAPK8, MMP9, VEGFA, TNF, MYC, AKT1, FOS and TGFB1) were recognized as potential targets of treatments, implying the underlying mechanisms of WMP acting on pancreatic neoplasms.

Conclusion

WMP could alleviate the symptoms of pancreatic neoplasms through the molecular mechanisms predicted by network pharmacology. This study proposes a strategy to elucidate the mechanisms of Traditional Chinese Medicine (TCM) at the level of network pharmacology.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2580-y) contains supplementary material, which is available to authorized users.

Influence of the HER receptor ligand system on sensitivity to cetuximab and trastuzumab in gastric cancer cell lines

Purpose

Gastric cancer remains a major health concern, and improvement of the therapeutic options is crucial. Treatment with targeted therapeutics such as the EGFR-targeting antibody cetuximab or the HER2-targeting antibody trastuzumab is either ineffective or moderately effective in this disease, respectively. In this study, we analysed the involvement of the HER receptor ligands amphiregulin (AREG), epidermal growth factor (EGF), heparin-binding epidermal growth factor (HB-EGF) and transforming growth factor alpha (TGFα) in the responsiveness of gastric cancer cell lines to cetuximab and trastuzumab.

Methods

A panel of 11 gastric cancer cell lines was characterized for cetuximab and trastuzumab sensitivity, ligand secretion and expression and activation of the HER receptors using WST-1 cell proliferation assays, ELISAs and Western blot analyses. We further investigated the effects of an exogenous ligand application on the cetuximab and trastuzumab sensitivity.

Results

We found no correlation between TGFα secretion and the sensitivity to cetuximab or trastuzumab. For AREG, we confirmed previous results indicating that this ligand is a positive predictor of cetuximab sensitivity. Exogenous HB-EGF was effective in rescuing sensitive cell lines from inhibition of cell proliferation by both, cetuximab and trastuzumab.

Conclusions

Our data indicate that HB-EGF may be a useful marker for the prediction of trastuzumab sensitivity in gastric cancer.

Electronic supplementary material

The online version of this article (doi:10.1007/s00432-016-2308-z) contains supplementary material, which is available to authorized users.

Transforming growth factor-beta signaling promotes hepatocarcinogenesis induced by p53 loss

Hepatocellular carcinoma (HCC) results from the accumulation of deregulated tumor suppressor genes and/or oncogenes in hepatocytes. Inactivation of TP53 and inhibition of transforming growth factor-beta (TGF-β) signaling are among the most common molecular events in human liver cancers. Thus, we assessed whether inactivation of TGF-β signaling, by deletion of the TGF-β receptor, type II (Tgfbr2), cooperates with Trp53 loss to drive HCC formation. Albumin-cre transgenic mice were crossed with floxed Trp53 and/or floxed Tgfbr2 mice to generate mice lacking p53 and/or Tgfbr2 in the liver. Deletion of Trp53 alone (Trp53(KO) ) resulted in liver tumors in approximately 41% of mice by 10 months of age, whereas inactivation of Tgfbr2 alone (Tgfbr2(KO) ) did not induce liver tumors. Surprisingly, deletion of Tgfbr2 in the setting of p53 loss (Trp53(KO) ;Tgfbr2(KO) ) decreased the frequency of mice with liver tumors to around 17% and delayed the age of tumor onset. Interestingly, Trp53(KO) and Trp53(KO) ;Tgfbr2(KO) mice develop both HCC and cholangiocarcinomas, suggesting that loss of p53, independent of TGF-β, may affect liver tumor formation through effects on a common liver stem cell population. Assessment of potential mechanisms through which TGF-β signaling may promote liver tumor formation in the setting of p53 loss revealed a subset of Trp53(KO) tumors that express increased levels of alpha-fetoprotein. Furthermore, tumors from Trp53(KO) mice express increased TGF-β1 levels compared with tumors from Trp53(KO) ;Tgfbr2(KO) mice. Increased phosphorylated Smad3 and ERK1/2 expression was also detected in the tumors from Trp53(KO) mice and correlated with increased expression of the TGF-β responsive genes, Pai1 and Ctgf.

CONCLUSION

TGF-β signaling paradoxically promotes the formation of liver tumors that arise in the setting of p53 inactivation.

Transforming growth factor-beta signaling promotes hepatocarcinogenesis induced by p53 loss

Hepatocellular carcinoma (HCC) results from the accumulation of deregulated tumor suppressor genes and/or oncogenes in hepatocytes. Inactivation of TP53 and inhibition of transforming growth factor-beta (TGF-β) signaling are among the most common molecular events in human liver cancers. Thus, we assessed whether inactivation of TGF-β signaling, by deletion of the TGF-β receptor, type II (Tgfbr2), cooperates with Trp53 loss to drive HCC formation. Albumin-cre transgenic mice were crossed with floxed Trp53 and/or floxed Tgfbr2 mice to generate mice lacking p53 and/or Tgfbr2 in the liver. Deletion of Trp53 alone (Trp53(KO) ) resulted in liver tumors in approximately 41% of mice by 10 months of age, whereas inactivation of Tgfbr2 alone (Tgfbr2(KO) ) did not induce liver tumors. Surprisingly, deletion of Tgfbr2 in the setting of p53 loss (Trp53(KO) ;Tgfbr2(KO) ) decreased the frequency of mice with liver tumors to around 17% and delayed the age of tumor onset. Interestingly, Trp53(KO) and Trp53(KO) ;Tgfbr2(KO) mice develop both HCC and cholangiocarcinomas, suggesting that loss of p53, independent of TGF-β, may affect liver tumor formation through effects on a common liver stem cell population. Assessment of potential mechanisms through which TGF-β signaling may promote liver tumor formation in the setting of p53 loss revealed a subset of Trp53(KO) tumors that express increased levels of alpha-fetoprotein. Furthermore, tumors from Trp53(KO) mice express increased TGF-β1 levels compared with tumors from Trp53(KO) ;Tgfbr2(KO) mice. Increased phosphorylated Smad3 and ERK1/2 expression was also detected in the tumors from Trp53(KO) mice and correlated with increased expression of the TGF-β responsive genes, Pai1 and Ctgf.

CONCLUSION

TGF-β signaling paradoxically promotes the formation of liver tumors that arise in the setting of p53 inactivation.

Current research in perineural invasion of cholangiocarcinoma

Background

Perineural invasion is a common path for cholangiocarcinoma (CCA) metastasis, and it is highly correlated with postoperative recurrence and poor prognosis. It is often an early event in a disease that is commonly diagnosed in advanced stages, and thus it could offer a timely therapeutic and diagnostic target if better understood. This article systematically reviews the progress of CCA neural invasion-related molecules.

Methods

Studies were identified by searching MEDLINE and PubMed databases for articles from January 1990 to December 2009, using the keywords "cholangiocarcinoma," "perineural invasion," "nerve growth factor"(NGF), "neural cell adhesion molecule" (NCAM), "matrix metalloproteinase"(MMP), "neurotransmitter," "acetylcholine" (Ach), and "transforming growth factor" (TGF)." Additional papers and book chapters were identified by a manual search of references from the key articles.

Results

From above we found that the molecules NGF, NCAM, MMP, Ach and TGF may have prognostic significance in, and offer clues to the mechanism of CCA neural invasion.

Conclusions

Cholangiocarcinoma's increasing worldwide incidence is especially poignant in view of both the lacking effective therapies, and the fact that it is commonly diagnosed in advanced stages. As CCA neural invasion often appears early, more complete characterization of its molecular pathology could lead to the identification of targets for the diagnosis and therapy of this devastating malignancy.

Expression of deleted in pancreatic carcinoma locus 4 and transforming growth factor-β1 in human colorectal carcinoma and their clinical significance

AIM: To investigate the expression of deleted in pancreatic carcinoma locus 4 (DPC4) and transforming growth factor-β1 (TGF-β1) in human colorectal cancer tissues and their clinical significances.

METHODS: Forty-eight samples of human colorectal carcinoma were collected from patients from January 2005 to December 2005. In situ hybridization and immunohistochemistry were used to detect DPC4/TGF-β1 mRNA and protein expression respectively.

RESULTS: The expression of DPC4 mRNA was lower in colorectal carcinoma specimens as compared with that in normal colorectal specimens (52.1% vs 72.9%, P < 0.01), while TGF-β1 mRNA expression was higher in carcinoma specimens (68.8% vs 41.7%, P < 0.01). The level of DPC4 protein expression in the cancer specimens was significantly lower than that in the normal specimens, while TGF-β1 protein level were higher in the carcinoma specimens. DPC4 expression was related with the tumor size, clinical stages, differentiation degree and lymph node metastasis, while TGF-β1 expression was related with the clinic stage, differentiation degree and lymph node metastasis. There existed a close correlation between DPC4 and TGF-β1 expression (χ² = 3.95, P < 0.05).

CONCLUSION: DPC4 and TGF-β1 are the capital factors in TGF-β transduction pathway. Low-expression of DPC4 and over-expression of TGF-β1 may serve as an index for unfavorable prognosis of colorectal carcinoma.

Expression of transforming growth factor β1 and its type I receptor in gastric cancer

AIM: To evaluate the significance of transforming growth factor-β1 (TGF-β1) and its β I type receptor (TGF-β R1) in the pathogenesis of gastric carcinoma.

METHODS: TGF-β1 and TGF-β R1 were detected by immunohistochemistry in and real-time PCR (RT-PCR) 50 cases of gastric carcinoma, 19 cases of atrophic gastritis and 18 cases of normal gastric mucosa.

RESULTS: Immunohistochemistry demonstrated that the positive expression rates of TGF-β1 and TGF-β R1 were significantly higher in gastric carcinoma (80.0% and 75.0%) than in normal gastric mucosa (33.3% and 27.8%) and atrophic gastritis (36.8% and 36.8%) (P < 0.01). The lower the differentiation of gastric carcinoma was, the higher the expression of TGF-β1 and TGF-β R1 was (r = 35.58, P < 0.01). Furthermore, the expression of TGF-β1 and TGF-β R1 mRNA was significantly higher in gastric carcinoma than in normal gastric mucosa and atrophic gastritis (TGF-β1: 4.20 ± 0.51 vs 9.15 ± 2.12, 8.22 ± 1.81; TGF-β R1: 1.28 ± 0.48 vs 5.55 ± 1.48, 4.19 ± 0.95).

CONCLUSION: High expression of TGF-β1 and TGF-β R1 is correlated with the development, biologic behavior and prognosis of gastric carcinoma.

Relation of neuroendocrine cells to transforming growth factor-alpha and epidermal growth factor receptor expression in gastric adenocarcinomas: prognostic implications

The presence of neuroendocrine (NE) cells in gastric adenocarcinoma (GCa) is well documented, however, their significance is controversial. There is no evidence in the literature concerning the possible effect of these cells on the expression of TGF-alpha and EGFR, which are believed to confer growth advantage to tumor cells. 101 partial or total gastrectomy specimens from patients operated for conventional gastric adenocarcinoma were included in the study. In each case immunohistochemistry was performed on sequential tissue sections for chromogranin A (ChrA), TGF-alpha and EGFR. Samples were graded based on the number of ChrA-positive cells (0-3). TGF-alpha and EGFR expressions were evaluated according to both the intensity (0-2) and quantification of the positively stained areas (0-3). Follow-up data was available in 54 patients. Twenty-seven patients died of disease, while 27 patients were alive with a follow-up of at least 15 months. ChrA expression was detected in 54.4% of the tumor specimens. TGF-alpha was stained positively in 42.6% and EGFR in 49.5% of the cases. NE cells in GCa was related to TGF-alpha (p<0.0001) and EGFR expression (p<0.05), and TGF-alpha/EGFR coexpression (p<0.001). Among histopathologic variables, the presence of NE cells was significantly related to grade, stage and lymph node status. Although the presence of NE cells had no effect on survival, the expression of EGFR (p<0.0001) and TGF-alpha (p=0.002) were related to survival. The results of our study suggest that the presence of NE cells may have an effect on the expression of TGF-alpha and EGFR in GCa, and the autocrine mechanism between TGF-alpha and EGFR plays an important role in the prognosis of gastric carcinoma.

Effect of surgical treatment on the cellular immune response of gastric cancer patients

Patients with gastric cancer have a variety of immunological abnormalities. In the present study the lymphocytes and their subsets were determined in the peripheral blood of patients with gastric cancer (N = 41) both before and after surgical treatment. The percent of helper/inducer CD4 T cells (43.6 +/- 8.9) was not different after tumor resection (43.6 +/- 8.2). The percent of the cytotoxic CD8+ T cell population decreased significantly, whether patients were treated surgically (27.2 +/- 5.8%, N = 20) or not (27.3 +/- 7.3%, N = 20) compared to individuals with inflammatory disease (30.9 +/- 7.5%) or to healthy individuals (33.2 +/- 7.6%). The CD4/CD8 ratio consequently increased in the group of cancer patients. The peripheral blood lymphocytes of gastric cancer patients showed reduced responsiveness to mitogens. The defective blastogenic response of the lymphocytes was not associated with the production of transforming growth factor beta (TGF- ) since the patients with cancer had reduced production of TGF- Beta1 (269 +/- 239 pg/ml, N = 20) in comparison to the normal individuals (884 +/- 175 pg/ml, N = 20). These results indicate that the immune response of gastric cancer patients was not significantly modified by surgical treatment when evaluated four weeks after surgery and that the immunosuppression observed was not due to an increase in TGF- 1 production by peripheral leukocytes.

Expression of transforming growth factor-beta1 and transforming growth factor-beta receptors in hepatocellular carcinoma and dysplastic nodules

In this study we analyzed by immunohistochemistry the expression of TGF-beta1 protein and TGF-beta receptors I and II in 4 low-grade dysplastic nodules, 2 high-grade dysplastic nodules, 6 early, 22 small, and 62 advanced hepatocellular carcinomas. The expression of TGF-beta1 protein by hepatocytes was decreased in advanced hepatocellular carcinoma compared with small or early hepatocellular carcinoma(P < .05). Frequent and intense staining of TGF-beta1 protein was noted in the sinusoidal endothelium of advanced hepatocellular carcinomas despite of its decreased staining in hepatocellular carcinoma cells. Reduced expression of TGF-beta receptors I and II compared with surrounding nontumorous tissue were noted from the early hepatocellular carcinoma stage suggesting that down-regulation of TGF-beta receptors is correlated with progression from premalignant to malignant phenotype. Reduced expression of both TGF-beta1 and TGF-beta receptor II in neoplastic hepatocytes were also significantly correlated with increased tumor size and increased proliferative activity(P < .05). These findings suggest that during hepatocarcinogenesis, the inhibitory effects of TGF-beta1 protein on hepatocellular carcinoma cells is outweighed by its effects on stromal elements, which, overall, contributes indirectly to a tumor growth stimulatory environment. Also, the growth-inhibitory effects of TGF-beta1 may have been further negated by reduced TGF-beta receptors on hepatocellular carcinoma cells.

Role of TGF-beta 1 and TGF-beta type II receptor in gastric cancer

BACKGROUND

TGF-beta is known as a cell growth inhibitory factor to suppress almost all cells, including the epithelial cell. Unlike normal cells, cancer cells are not affected by TGF-beta growth inhibitory action and the lack of TGF-beta receptor expression or mutation is being reported as its mechanism, which is rarely studied in Korea. Therefore, we investigated this study to clarify the role of TGF-beta I and TGF-beta II receptors in gastric cancer.

METHODS

23 cases that underwent operations for gastric cancer provided RNA collected from their carcinoma tissues and adjacent normal tissues. We investigated the level of TGF-beta 1 and T beta R-II mRNA expression with semi-quantitatively reverse transcription PCR and analyzed the correlation with prognostic factors, such as tumor size, depth of invasion, tumor differentiation and lymph-node metastasis.

RESULTS

(1) TGF-beta 1 and T beta R-II mRNA were expressed in all carcinoma tissues and adjacent normal tissues of the 23 cases without statistical difference in the level of the expression. (2) The level of TGF-beta 1 mRNA expression was higher in patients with gastric cancer invaded only at the mucosa and submucosa than in patients with gastric cancer invaded over muscular propria, and also higher in the patients without lymph-node metastasis or perineural invasion than in the patients with lymph-node metastasis or perineural invasion. There was no significant correlation between the level of T beta R-II mRNA expression and several parameters, such as age, gender, tumor size, location, differentiation, Lauren's classification and vascular invasion. (3) There was a significant correlation between the level of TGF-beta 1 and T beta R-II mRNA expression in carcinoma tissues.

CONCLUSION

It indicated that TGF-beta 1 mRNA expression in gastric cancer might concern the early stage of gastric carcinogenesis and, unlike the earlier reports, it was higher in patients with early gastric cancer, negative lymph-nodes or negative perineural invasion. Further studies are required to clarify the role of TGF-beta 1 in gastric carcinogenesis with more patients.

Abnormal distribution of collagen type IV in extrahepatic bile duct carcinoma

The present study investigated the pathogenesis of desmoplastic stroma formation, which is characteristic of most bile duct carcinomas and other scirrhous carcinomas. Using immunohistochemical analysis, the expression of collagen types I and IV, laminin and TGF-beta1 was examined in human extrahepatic bile duct carcinoma and compared with gastric and colon carcinoma. In addition to delineating the basement membranes of carcinoma nests and blood vessels, collagen type IV was present along the thick bundles of collagenous fibers in the stroma of extrahepatic bile duct carcinoma and scirrhous gastric carcinoma. The immunoreactivity of collagen type IV was strong in the adjacent or surrounding interstitium of tumor cell nests, but was absent or weak in older, more central portions of the tumor that contained sclerotic collagen. In situ hybridization demonstrated active expression of collagen alpha1(IV) mRNA in extrahepatic bile duct carcinoma and scirrhous gastric carcinoma cells. These results suggest that, although collagen type IV is typically a component of the basement membrane, it is expressed in the interstitial stroma of extrahepatic bile duct carcinoma and scirrhous gastric carcinoma where it may play a role in desmoplastic stroma formation.

Endocervical cancer is associated with an increase in the ligands and receptors for transforming growth factor-beta and a contrasting decrease in p27(Kip1)

OBJECTIVE

The aim of this study was to investigate the relationship between the expression of the TGF-beta ligands and TGF-beta receptors to the expression of p27(Kip1), a TGF-beta-regulated gene, in endocervical cancer.

METHODS

To examine the expression of TGF-beta and p27(Kip1) in malignant transformation of the uterine endocervix, a panel of 23 formalin-fixed and paraffin-embedded human cervical specimens, including 8 with benign endocervical glands, 8 with cervical adenocarcinoma in situ, and 7 with cervical adenocarcinomas, was used. Tissues were immunostained with polyclonal antibodies that react specifically with TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-beta RI, TGF-beta RII, and p27(Kip1).

RESULTS

Immunostaining for TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-beta RI, TGF-beta RII, and p27(Kip1) was detected in normal endocervix, with the TGF-betas showing weak cytoplasmic staining, while p27(Kip1) showed strong nuclear staining. Expression of TGF-beta increased significantly upon neoplastic transformation with the TGF-beta ligands and receptors showing strong cytoplasmic staining in adenocarcinoma in situ compared to normal endocervix. Interestingly, expression of TGF-beta was lower in adenocarcinoma than in adenocarcinoma in situ, but still significantly higher than in normal endocervix. TGF-beta 2 and TGF-beta 3 showed higher levels of immunostaining than TGF-beta 1 in adenocarcinomas. In contrast, p27(Kip1) protein expression decreased with progressive malignancy, with lower p27(Kip1) protein levels detected in adenocarcinoma than in adenocarcinoma in situ, while normal endocervix showed the highest level of p27(Kip1) protein expression.

CONCLUSION

Elevated expression of the TGF-beta ligands and receptors is found in both cervical adenocarcinoma in situ and adenocarcinoma compared to normal endocervix. In contrast, a progressive decrease in p27(Kip1) occurs upon neoplastic transformation of the normal endocervix to cervical adenocarcinoma. These results suggest that neoplastic transformation of the endocervix may be related to dysregulation of TGF-beta and p27(Kip1) seen as an elevation of TGF-beta and a reduction of p27(Kip1) expression that may lead to loss of cell cycle control.

TGF-beta and cancer

The relationships between transforming growth factor-beta (TGF-beta) and cancer are varied and complex. The paradigm that is emerging from the experimental evidence accumulated over the past decade or so is that TGF-beta can play two different and opposite roles with respect to the process of malignant progression. During early stages of carcinogenesis, TGF-beta acts predominantly as a potent tumor suppressor and may mediate the actions of chemopreventive agents such as retinoids and nonsteroidal anti-estrogens. However, at some point during the development and progression of malignant neoplasms, bioactive TGF-betas make their appearance in the tumor microenvironment and the tumor cells escape from TGF-beta-dependent growth arrest. In many cases, this resistance to TGF-beta is the consequence of loss or mutational inactivation of the genes that encode signaling intermediates. These include the types I and II TGF-beta receptors, as well as receptor-associated and common-mediator Smads. The stage of tumor development or progression at which TGF-beta-resistant clones come to dominate the tumor cell population in different types of neoplasm remains to be defined. The phenotypic switch from TGF-beta-sensitivity to TGF-beta-resistance that occurs during carcinogenesis has several important implications for cancer prevention and treatment.

The expression of transforming growth factor-beta1 is significantly correlated with the expression of vascular endothelial growth factor and poor prognosis of patients with advanced gastric carcinoma

BACKGROUND

Transforming growth factors beta (TGFs beta) are involved in a variety of important cellular functions, including cell growth and differentiation, adhesion, migration, extracellular matrix formation, and immune function. Moreover, it has been reported that TGFs beta are correlated with angiogenesis. However, the role of TGF-beta as an angiogenic factor in gastric carcinoma is still unclear.

METHODS

TGF-beta1 expression was determined in 101 patients with gastric carcinoma by immunohistochemical procedures, and this expression was compared in the current study with both the expression of vascular endothelial growth factor (VEGF), which is thought to be the most potent angiogenic factor, and microvessel density, to evaluate the effect of TGF-beta1 on the angiogenesis of gastric carcinoma tissues.

RESULTS

TGF-beta1 expression was detected in 23 tumors (22.8%). TGF-beta1 expression was more frequent in differentiated than in undifferentiated gastric carcinoma. Furthermore, TGF-beta1 expression was significantly correlated with the depth of invasion and the stage of disease. There was a close correlation between TGF-beta1 expression and VEGF expression. There was no correlation between TGF-beta1 expression and microvessel density, whereas VEGF expression was significantly correlated with microvessel density. With regard to prognosis, the 5-year survival rate was 55.9% for patients with TGF-beta1 positive tumors and 67.0% in patients with TGF-beta1 negative tumors. Accordingly, the prognosis for patients with TGF-beta1 negative tumors was significantly better than that for patients with TGF-beta1 positive tumors. Multivariate analysis indicated that lymph node metastasis, tumor size, and TGF-beta1 expression were independent prognostic factors.

CONCLUSIONS

These results suggest that TGF-beta1 might be associated with tumor progression by indirectly stimulating angiogenesis through the up-regulation of VEGF expression in gastric carcinoma.

Role of transforming growth factor-beta1 and decorin in development of central fibrosis in pulmonary adenocarcinoma

Transforming growth factor-beta1 (TGF-beta1) is known as the growth factor that stimulates the synthesis of extracellular matrix. Recently, TGF-beta has been found to control the growth of cancer cells. Small chondroitin-dermatan sulfate (decorin) is an abundant extracellular matrix component. TGF-beta1 stimulates the synthesis of decorin, and decorin is considered to bind TGF-beta1. The activity of decorin in neutralizing TGF-beta1 activity suggests that decorin serves as a negative-feedback regulator of TGF-beta1 activity. To investigate the role and relationship of TGF-beta1 and decorin in the formation of central fibrosis in pulmonary adenocarcinoma, we performed an immunohistochemical study of TGF-beta1 and decorin in 61 cases of T1 pulmonary adenocarcinoma. Positive stainings for TGF-beta1 were shown in 40 cases and negative in 21 cases. Twenty-seven of 32 cases with central fibrosis were positive for TGF-beta1. Positive staining for TGF-beta1 was significantly related to the appearance of central fibrosis in pulmonary adenocarcinoma. When central fibrosis was composed of proliferative connective tissue with loose staining for decorin, cancer cells showed intense staining for TGF-beta1. When central fibrosis was composed of old fibrotic tissue with dense staining for decorin, cancer cells showed weak staining for TGF-beta1. Our results suggest that TGF-beta1 has an important role in the formation of central fibrosis in pulmonary adenocarcinoma, and decorin may play a role as a negative feedback regulator in the production of TGF-beta1 in pulmonary adenocarcinoma.

Role of transforming growth factor-beta 1 in invasion and metastasis in gastric carcinoma

PURPOSE

Transforming growth factor-beta1 (TGF-beta1) is a major modulator of cellular proliferation and extracellular matrix formation. We determined the role of TGF-beta1 in invasion and metastasis in gastric cancer.

MATERIALS AND METHODS

We detected TGF-beta1 expression in primary and lymph node metastatic lesions of gastric cancer, using an antibody and in situ hybridization. The plasma TGF-beta1 levels in the peripheral vein and in the tumor drainage vein were assayed.

RESULTS

In the cytoplasm of cancer cells, TGF- beta1 was immunostained in 35.9% (78 of 217) of primary gastric carcinomas, and this expression was confirmed by in situ hybridization. Of 59 gastric carcinomas with a TGF-beta1-negative primary tumor, metastatic lymph nodes were positive for TGF-beta1 staining in 32 cases (54.2%). Positive staining of TGF-beta1 in gastric cancer tissues was closely related to serosal invasion, infiltrative growth, and lymph node metastasis. Multivariate analysis showed that the expression of TGF-beta1 was an independent risk factor for serosal invasion and infiltrative growth of the tumor. The plasma level of TGF-beta1 did not differ between TGF-beta1-negative and -positive groups. There were also no differences in plasma TGF-beta1 levels among each tumor stage, between the peripheral and the tumor drainage veins, and between preoperative and postoperative testings.

CONCLUSION

Transforming growth factor-beta1 is closely related to the invasion and metastasis of gastric cancer, and production of TGF-beta1 in the tumor does not contribute to the total amount of TGF-beta1 in the blood circulation. We interpret our observations to mean that in a tumor microenvironment, TGF-beta1 alters the biologic behavior of the tumor.

Transforming growth factor beta1 (TGF-beta1) is a preoperative prognostic indicator in advanced gastric carcinoma

It has been generally accepted that transforming growth factor beta1 (TGF-beta1) has both negative and positive effects on tumour growth and progression. This study analysed the prognostic value of TGF-beta1 mRNA in advanced gastric carcinoma. A reverse transcriptase-polymerase chain reaction analysis (RT-PCR) was used for TGF-beta1 in endoscopic biopsy specimens from 42 advanced gastric carcinomas. Thirty specimens expressed TGF-beta1 mRNA while 12 specimens did not. The follow-up duration ranged from 4 to 37 months (mean 22.8 months). TGF-beta1-positive group demonstrated a shorter overall survival compared with the TGF-beta1 -negative group (P=0.0014). A significant correlation was also found in the 32 patients who underwent curative resection (P=0.0048). Significant correlations were found between TGF-beta1 mRNA expression and both stage (P=0.0015) and nodal involvement (P=0.0060). Multivariate analysis demonstrated that only TGF-beta1 mRNA expression (P=0.0306) was an independent prognostic factor. All of ten patients who underwent non-curative resection expressed TGF-beta1 mRNA. Expression of TGF-beta1 mRNA in gastric biopsy specimens may be an important preoperative prognostic variable for advanced gastric carcinoma.

Reduction in transforming growth factor-beta type II receptor in mouse lung carcinogenesis

Transforming growth factor-beta (TGF-beta) is a growth modulator that inhibits the proliferation of many epithelial cells through interaction with its receptors, the type I and type II receptors (TGF-beta RI and RII) by activating their serine/threonine kinase activities. Loss of growth inhibition by TGF-beta is thought to contribute to the development of many types of tumors. To examine the roles of TGF-beta1, -beta2, and -beta3 and TGF-beta RI and RII in chemically induced mouse lung tumorigenesis, we used immunohistochemical and in situ hybridization analyses to measure the expression of their proteins and mRNAs in A/J mice treated with the carcinogen urethane to induce lung adenomas. Immunostaining for the TGF-beta ligands and receptors was detected in the epithelia of the bronchioles of untreated and treated A/J mice at similar levels. Immunostaining for the TGF-beta ligands and receptors was also detected in adenomas by 2 mo. While immunostaining for TGF-beta1, -beta2, and -beta3 and TGF-beta RI in adenomas was detected at levels comparable to those in bronchioles, immunostaining for TGF-beta RII was less intense in adenomas than in bronchioles. Decreased immunostaining for TGF-beta RII in adenomas persisted for at least 8 mo after exposure to urethane, whereas immunostaining for TGF-beta1, -beta2, and -beta3 and TGF-beta RI persisted at levels comparable to those in normal bronchioles. In situ hybridization studies conducted with TGF-beta receptor riboprobes showed a corresponding reduction in expression of TGF-beta RII mRNA but not of TGF-beta RI mRNA in adenomas compared with expression in bronchioles. Expression of TGF-beta RII mRNA was also examined in non-tumorigenic and tumorigenic mouse lung cells; expression of TGF-beta RII mRNA was lower in the tumorigenic cells derived from urethane-induced lung tumors. These data suggest that a decrease in expression of TGF-beta RII may contribute to autonomous cell growth and may play an important role in mouse lung carcinogenesis induced by urethane.

Overexpression of autocrine TGF-beta 1 suppresses the growth of spindle epithelial cells in vitro and in vivo in the rat 4NQO model of oral carcinogenesis

We examined the effect of the stable transfection of latent TGF-beta 1 cDNA, under the control of a cytomegalovirus promoter in the expression vector pcDNA3, into a 4NQO-induced clonal rat oral keratinocyte cell line that formed undifferentiated spindle cell tumours following subcutaneous transplantation to athymic mice. Test cells containing latent TGF-beta 1 cDNA produced a 2.3-fold increase in TGF-beta 1 protein compared to pcDNA3 controls as demonstrated by ELISA. Neutralisation experiments indicated that the majority of the protein was in the latent form. Untransfected and transfected (containing either TGF-beta 1 cDNA or pcDNA3) cell lines were keratin negative and vimentin positive. Cells transfected with TGF-beta 1 were inhibited more than pcDNA3 controls when cultured in an anchorage dependent or independent environment. Subcutaneous transplantation of cells overproducing TGF-beta 1 resulted in tumours of significantly smaller volume than vector-only controls. Further, orthotopic transplantation of cells containing TGF-beta 1 cDNA to the floor of the mouth in athymic mice markedly inhibited the development of pulmonary metastases compared to vector-only controls. Both test and control cell lines in athymic mice formed undifferentiated tumours with a complete absence of keratin elaboration. Subcutaneous xenografts were recultured and cells containing the TGF-beta 1 cDNA produced a similar amount of TGF-beta 1 peptide as the cells containing pcDNA3 only. The production of TGF-beta 1 by both of the xenograft-derived cell lines was significantly less than the parent, pre-transplanted cell lines and the untransfected cell line. All of the cell lines were inhibited by exogenous TGF-beta 1. Our results demonstrate that autocrine TGF-beta 1 functions as a tumour suppressor in vitro and in vivo in 4NQO-induced spindle tumour cells that are growth inhibited by the ligand. Furthermore, tumour formation in athymic mice is associated with selection for a cell phenotype with diminished autocrine TGF-beta 1 production.

Surgically curable and incurable scirrhous carcinomas of the stomach

BACKGROUND AND OBJECTIVES

The purpose of this study was to identify a subgroup of patients with scirrhous carcinoma of the stomach who are more suitable for surgery by analysis of their clinicopathologic characteristics.

METHODS

Seventy-three patients with scirrhous gastric carcinoma who underwent gastrectomy between 1979 and 1994 were included in the study. Clinicopathological characteristics of 5-year survivors and nonsurvivors were compared. A multivariate analysis of various prognostic factors was performed.

RESULTS

The 5-year survival rate was 31.4%; 78% (28/36) of nonsurvivors died of malignant ascites and only 8% (3/36) died of hepatic or lung metastasis. When clinicopathologic parameters of 5-year survivors and nonsurvivors were compared, age, tumor size, macroscopic appearance, pT, pN, pM, stage, peritoneal lavage cytology, residual tumor, extent of gastric resection, operation time, volume of blood loss, and transfusion were significantly different. By the multivariate analysis, residual tumor, pathological depth of tumor infiltration, blood transfusion, and histological type were the independent prognostic factors.

CONCLUSIONS

The prognosis of scirrhous carcinoma of the stomach is mainly determined by the depth of penetration and curability. In order to obtain better survival, early detection of tumor while it is limited to T2 stage appeared most important. Aggressive surgery would be indicated for T3 tumors, but in the case of T4 tumors, extent of operation should be determined by other factors such as extent of nodal metastasis or presence of distant metastasis.

Clinical relevance of transforming growth factor-beta 1 in the urine of patients with hepatocellular carcinoma

To assess the clinical relevance of transforming growth factor-beta 1 (TGF-beta 1) in the urine of patients with hepatocellular carcinoma (HCC), TGF-beta 1 was measured, by radioimmunoassay, in 140 patients with HCC, 50 cirrhotic patients, 30 patients with chronic active hepatitis, and 50 healthy controls. The results indicate that there were significantly increased urinary TGF-beta 1 levels in patients with HCC. Raised TGF-beta 1 levels were associated, in a dose-related fashion, with increased risk for development of HCC (odds ratio, 1.05, 95% confidence interval, 1.03-1.07). HCC patients with raised TGF-beta 1 levels had shorter survival than those with normal TGF-beta 1 levels (p = 0.038). TGF-beta 1 levels decreased after successful anticancer therapy (p < 0.0001). There was an inverse correlation between TGF-beta 1 and serum alpha-fetoprotein (AFP) (r = -0.199, p < 0.04). Receiver operating characteristics (ROC) curve analysis indicated that parallel determination of TGF-beta 1 and AFP significantly increased the sensitivity and diagnostic accuracy, with a high specificity. In conclusion, raised urinary TGF-beta 1 was associated with HCC development. It is a predictor of poor prognosis, and a tumor marker for diagnosis and therapeutic follow-up of HCC.

Differential localization of transforming growth factor-beta isoforms in human gastric mucosa and overexpression in gastric carcinoma

Transforming growth factor beta (TGF-beta) isoforms comprise a family of multifunctional polypeptide growth factors that either inhibit or stimulate cell proliferation. We examined TGF-beta expression in normal human gastric mucosa and carcinoma. The distribution and expression of TGF-beta isoforms in 4 normal mucosa samples from organ donors, in 12 normal mucosa samples adjacent to gastric cancer and in 12 gastric carcinomas were examined using immunohistochemistry and Northern blot analysis. Because TGF-beta s regulate collagen expression, collagen type I alpha1 mRNA amounts were also examined. Immunohistochemical analysis of normal human gastric tissue samples indicated that TGF-beta1 localized principally in parietal cells but also in some surface mucus cells, TGF-beta2 was present exclusively in chief cells and TGF-beta3 was present in parietal, chief and mucus cells. In the gastric cancers, strong colocalization of TGF-beta1, -beta2 and -beta3 was evident in the cancer cells. Northern blot analysis indicated that, compared to normal gastric tissue, gastric cancers showed a 4.8- and 6-fold increase in mRNA amounts encoding TGF-beta1 and TGF-beta3, respectively. In contrast, TGF-beta2 mRNA amounts were comparable in both groups. Northern blot analysis showed a 10-fold increase in human collagen type I alpha1 mRNA amounts compared to normal gastric tissue. These findings imply a role forTGF-beta s in normal human gastric mucosa function, and raise the possibility that the aberrant colocalization and overexpression of all 3 TGF-beta isoforms in human gastric cancer cells in vivo may contribute to the pathobiology of gastric carcinoma.

Roles of the transforming growth factor beta 1 and its type I and II receptors in the development of a pulmonary adenocarcinoma: results of an immunohistochemical study

BACKGROUND

In the United States, pulmonary adenocarcinomas have recently replaced squamous cell carcinomas as the most frequent type of lung cancer encountered. The incidence of pulmonary adenocarcinoma continued to increase worldwide.

METHOD

To determine the roles of the transforming growth factor-beta 1 (TGF-beta 1), and TGF-beta type I receptor (T beta R-I), and the TGF-beta type II receptor (T beta R-II) in the progression of a pulmonary adenocarcinoma, their respective expressions have been immunohistologically studied in specimens from 120 pulmonary adenocarcinoma patients.

RESULT

The overall prognosis was significantly poorer for patients showing positive TGF-beta 1, T beta R-I, T beta R-II expressions than for patients who were negative to all three immunostainings (P < 0.01). Our multivariate analysis also revealed that a positive TGF-beta 1 response significantly affect prognosis (P < 0.05).

CONCLUSIONS

TGF-beta 1, T beta R-I, and T beta R-II play important roles in tumor progression, and a positive TGF-beta 1 expression can serve as a pulmonary adenocarcinoma marker. T beta R-I and T beta R-II expressions are necessary for TGF-beta signal transduction.

Expression of PDGF, IGF-II, bFGF and TGF-beta 1 in pulmonary adenocarcinoma

Effects of the expression of the platelet-derived growth factor (PDGF), insulin-like growth factor-II (IGF-II), basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta 1 were studied individually and in combinations with the clinicopathologic features and prognosis of pulmonary adenocarcinoma using paraffin embedded tissue specimens. Tumor sections from 90 patients with pulmonary adenocarcinoma were stained immunohistochemically for PDGF, IGF-II, bFGF and TGF-beta 1 by the ABC method. The survival rate was worse in patients in whom each of the four growth factors was expressed than in those where growth factors were not expressed. The reduced expression of the four growth factors correlated with less tumor aggressiveness and better prognosis of pulmonary adenocarcinoma.

Transforming growth factor beta 1 expression in human colorectal tumours: an independent prognostic marker in a subgroup of poor prognosis patients

Members of the transforming growth factor beta (TGF-beta family, in particular TGF-beta 1, are some of the most potent inhibitory growth factors in a variety of cell types. Resistance to TGF-beta 1-induced growth inhibition is frequently observed in colorectal carcinomas and is associated with tumour progression. Perturbations of TGF-beta 1 expression and function, therefore, may contribute to the loss of some constraints on tumour cell growth. In this study we have examined the expression of TGF-beta 1 and its precursor latency-associated peptide (LAP)-TGF-beta in human colorectal tumours using immunohistochemical techniques. In 86% of the tumours the LAP-TGF-beta complex was present in both the stromal and epithelial cells, whereas the mature TGF-beta 1 peptide was expressed in the glandular epithelium of 58.3% of these tumours. Intense staining for TGF-beta 1 was positively associated with advanced Dukes' stage. Furthermore, there was a significant correlation between the presence of TGF-beta 1 in the tumours and a shorter post-operative survival. This was most significant in a subgroup of patients who had received only a palliative operation. These results suggest that TGF-beta 1 expression may be useful as an independent prognostic indicator for a subgroup of patients who have a particularly poor prognosis.

Comparison between immunocytochemical and polymerase chain reaction techniques for detection of oestrogen receptor and transforming growth factor beta in breast cancer

The utility of the polymerase chain reaction (PCR) as a technique for determining the expression of transforming growth factor beta (TGF-beta) and of the oestrogen receptor (ER) in clinical breast cancer tissue was examined. PCR analysis was compared with immunocytochemical assays for TGF-beta and for ER. Seventy confirmed breast carcinoma samples were analysed for ER using both techniques with a statistically highly significant concordance (P < 0.001) between the two methods. Nineteen samples were observed to be ER positive and 46 samples were found to be ER negative by both techniques. Forty-eight samples were analysed for TGF-beta using both PCR and immunocytochemistry. Of the 24 samples observed to be positive for TGF-beta by immunocytochemistry, all were found to be positive for TGF-beta mRNA (PCR). Similarly, the 24 samples observed to be TGF-beta negative by immunocytochemistry were also negative for TGF-beta mRNA, indicating 100% specificity and 100% sensitivity of the PCR technique. PCR is therefore considered a viable technique for analysis of both ER and TGF-beta in small samples such as fine-needle aspirates.

Transforming growth factor-beta in GI neoplasia, wound healing and immune response

The last decade has been marked by tremendous advances in the biochemical and functional characterization of TGF-betas and their receptors in normal and transformed cells. TGF-betas have been shown to modulate proliferation, differentiation and motility of different cell types in a number of in vitro model systems and in some cases with some intriguing results. It is obvious that there is no simple pattern that explains the TGF-betas biological activity in vitro and their effects on cell behaviour need to be assessed in the context of an appropriate physiological cellular environment. Cell-cell and cell-matrix interactions, the differentiating status of the cell together with the functional activity of other soluble growth factors can influence how TGF-betas modulate cell behaviour. However, the overwhelming interest in this field shown by clinicians and basic scientists is rapidly increasing our understanding of how growth factors such as TGF-betas regulate the homeostasis of the GI mucosa and their role in gastrointestinal carcinogenesis.

Transforming growth factor-beta receptors and mannose 6-phosphate/insulin-like growth factor-II receptor expression in human hepatocellular carcinoma

OBJECTIVE

The authors examined the expression of transforming growth factor-beta receptor (TGF-beta r) types I and II and the mannose 6-phosphate/insulin-like growth factor-II receptor (M6-P/IGF-IIr) in human hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

Transforming growth factor-beta (TGF-beta) is part of a superfamily of peptide-signaling molecules that play an important role in modulating cell growth. It is secreted as a latent complex and therefore, must be activated to elicit a biological response. Bioactivation of the TGF-beta complex is facilitated by binding to the M6-P/IGF-IIr. Once activated, TGF-beta exerts its effects by binding to specific cell membrane TGF-beta receptors. The loss of responsiveness of hepatocytes to TGF-beta has been implicated in hepatocarcinogenesis and could result from a loss in the expression of either the TGF-beta receptors or the M6-P/IGF-IIr.

METHODS

Human hepatocellular carcinomas and surrounding normal tissue were collected from operating room samples and snap-frozen in liquid nitrogen (n = 13). Tissues from two tumors were fixed in Omni-fix for sectioning and immunohistochemistry staining for the M6-P/IGF-IIr and TGF-beta 1. RNA was extracted from both normal and malignant liver tissue and analyzed using an RNase protection assay. SDS-PAGE of purified membrane hybridized with 125I-TGF-beta 1 and 125I-IGF-II was used to determine the TGF-beta type I (TGF-betarI) and type II (TGF-beta rII) receptors and M6-P/IGF-IIr protein levels, respectively. Gels were quantitated by phosphorimager, and a paired t test was used for statistical analysis.

RESULTS

In HCC, a 60% (p < 0.01) and 49% (p < 0.02) reduction in the mRNA levels for T beta rI and T beta rII, respectively, relative to the receptor levels in surrounding normal liver, was shown. A similar decrease in the receptor protein levels also was observed. The M6-P/IGF-IIr mRNA and protein levels were reduced in 7 of 11 hepatocellular carcinomas. Immunohistochemical staining demonstrated an absence of intracellular TGF-beta 1 and reduced M6-P/IGF-IIr in the hepatocellular carcinoma cells.

CONCLUSIONS

These results demonstrate that human HCCs have a significantly reduced expression of both the TGF-beta rI- and TGF-beta rII-signaling receptors for TGF-beta. This may provide a selective growth advantage to the HCC by allowing them to escape the mito-inhibitory effects of activated TGF-beta. Furthermore, in the subset of HCC in which the expression of the M6-P/IGF-IIr is downregulated, the bioactivation of TGF-beta also may be impaired.

Comparative clinicopathological and immunohistochemical study of ras and p53 in flat and polypoid type colorectal tumours

Mutations in oncogenes and tumour suppressor genes may have an important oncogenic role. Although flat type tumours have been frequently detected in recent years, ras and p53 expressions have not been studied in these tumours. Using a monoclonal and polyclonal antibody to the ras p21 and p53 product, paraffin wax embedded sections of 98 colorectal tumours (43 cases of the flat type colorectal tumour and 55 cases of polypoid type tumour) were stained using the immunoperoxidase technique. Staining was evaluated by light microscopic examination. Positive staining rate of ras p21 for the flat type was 0%; for the polypoid type, it was 60% in cancer with submucosal invasion, 82% in adenoma with high grade dysplasia, and 0% in adenoma with low grade dysplasia. The positive staining rate of p53 for the flat type was 50% in submucosal cancer, 9% in adenoma with high grade dysplasia, and 0% in adenoma with low grade dysplasia. For the polypoid type, it was 40% in submucosal cancer, 12% in adenoma with high grade dysplasia, and 0% in adenoma with low grade dysplasia. The intermediate staining rate of p53 in the polypoid type was 20% in submucosal cancer and 41% in adenoma with high grade dysplasia. It was seen that p53 was commonly expressed in both flat and polypoid lesions, p21 was not expressed in flat lesions, whereas it was commonly expressed in polypoid neoplasms. In the flat type cancer, a genetic change different from that of the polypoid type cancer is suggested.

Transforming growth factor beta 1 secreted from scirrhous gastric cancer cells is associated with excess collagen deposition in the tissue

To explore the mechanism of increased collagen deposition in scirrhous carcinoma of the stomach, an attempt was made to define the role of transforming growth factor beta 1 (TGF-beta 1), secreted from tumour cells, as a possible humoral factor which functions in a paracrine manner to stimulate the production of collagen in regional fibroblasts. Immunohistochemical staining revealed that tumour cells in scirrhous carcinomas were generally stained more intensively than those in other types of carcinomas. On Northern blot analysis the tumour cells established from scirrhous carcinoma (KATO-III, OCUM-1 and HSC-39) exhibited relatively strong signals compared with those from non-scirrhous carcinoma (MKN-28 and MKN-45). In the culture media of scirrhous carcinoma cells, the active form of TGF-beta 1 was detected, while in those of the non-scirrhous carcinoma cells the latent form was demonstrated by both colony and radioreceptor assays. The culture medium from KATO-III showed strong stimulating activity of collagen synthesis in fibroblasts, and this activity was partially neutralised by an anti-TGF-beta 1 antibody. These results suggest that tumour cells in scirrhous carcinoma produce more active-form TGF-beta 1 than does non-scirrhous carcinoma and thus is partially responsible for the observed enhanced collagen deposition in the region.

Enhanced expression of transforming growth factor beta isoforms in pancreatic cancer correlates with decreased survival

BACKGROUND

Transforming growth factor beta s (TGF-beta s) constitute a family of bifunctional polypeptide growth factors that either inhibit or stimulate cell proliferation. Perturbations in TGF-beta expression and function may lead to loss of negative constraints on cell growth. In this study, we examined TGF-beta expression in human pancreatic cancer.

METHODS

The distribution of TGF-beta isoforms in 60 human pancreatic cancers was examined using immunohistochemical, Northern blot, and in situ hybridization techniques.

RESULTS

Immunohistochemical analysis showed the presence of TGF-beta 1 (47% of tumors), TGF-beta 2 (42% of tumors), and TGF-beta 3 (40% of tumors) in the cancer cells. The presence of TGF-beta 2 was associated with advanced tumor stage (P < 0.05). Furthermore, there was a significant correlation between the absence of TGF-beta s in the tumors and longer postoperative survival. Northern blot analysis indicated that, by comparison with the normal pancreas, pancreatic adenocarcinomas showed 11- (P < 0.001), 7- (P < 0.05), and 9-fold (P < 0.001) increases in the messenger RNA (mRNA) levels encoding TGF-beta 1, TGF-beta 2, and TGF-beta 3, respectively. By in situ hybridization, these mRNA moieties colocalized with their respective proteins in the cancer cells.

CONCLUSIONS

These findings show that human pancreatic cancers show increased levels of TGF-beta isoforms and enhanced TGF-beta mRNA expression and suggest that the presence of TGF-beta s in pancreatic cancer cells may contribute to disease progression.