Expression of transforming growth factor-alpha in gastric carcinoma and normal gastric mucosa cells

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.

Expression of transforming growth factor-alpha in hepatoblastoma

BACKGROUND

Transforming growth factor-alpha (TGF-alpha) is a potent stimulator of cell proliferation in the liver and in liver tumors; however, its significance and association with hepatocyte proliferation remains unclear.

METHODS

Expression of TGF-alpha and proliferation markers, such as proliferating cell nuclear antigen (PCNA) and cyclin A, were studied and correlated with each other in samples of tumor and surrounding liver tissue taken from nine patients with hepatoblastoma. An avidin-biotin-peroxidase immunohistochemical method was used for detection of TGF-alpha, PCNA, and cyclin A, and in situ hybridization was used to detect TGF-alpha mRNA.

RESULTS

Two types of tumor cells of epithelial origin were distinguished based on the expression of TGF-alpha protein and RNA. The more differentiated "fetal" phenotype had a high expression of TGF-alpha and correlated with a low expression of proliferation markers. The less differentiated "embryonal" phenotype had low TGF-alpha expression and high proliferation activity.

CONCLUSIONS

The expression of TGF-alpha is associated with a certain morphologic phenotype of tumor cells in hepatoblastoma; higher expression can be detected in more differentiated tumor cells. The negative correlation between the expression of TGF-alpha and proliferation markers suggests that the less differentiated embryonal cells do not depend on growth stimulation provided by TGF-alpha.

Ménétrier disease of childhood: role of cytomegalovirus and transforming growth factor alpha

OBJECTIVE

Because the role of cytomegalovirus in Ménétrier disease in children remains unclear and recent studies have implicated transforming growth factor alpha in the pathogenesis of this disease in adults, we investigated the possibilities that (1) cytomegalovirus is etiologic in Ménétrier disease in children and (2) transforming growth factor alpha mediates its development.

METHODS

The presence of a cytomegaloviral infection and the pattern of transforming growth factor alpha immunolocalization were determined in the gastric mucosa of four pediatric patients with Ménétrier disease, in control subjects (children with normal gastric mucosa, gastritis, or prostaglandin E1-induced antral hyperplasia), and in adults with Ménétrier disease.

RESULTS

Evidence of a cytomegaloviral infection was present only in the four children with Ménétrier disease. The pattern of transforming growth factor alpha immunostaining was identical in the specimens from pediatric and adult patients with Ménétrier disease. This pattern was distinct from that found in the pediatric control specimens.

CONCLUSIONS

These data strengthen the possibilities that cytomegalovirus is etiologic in children and that transforming growth factor alpha is involved in the pathogenesis of Ménétrier disease in both children and adults.

Molecular variants of epidermal growth factor in malignant astrocytoma

The present study has measured EGF levels in primary brain tumor tissues. EGF levels were measured by specific radioimmunoassay (RIA) and further analyzed by reversed-phase high performance liquid chromatography (RP-HPLC) followed by RIA and radioreceptor binding. The levels of EGF-like immunoreactivity (EGF-LI) in astrocytoma-IV tumors were fourfold greater than those in normal brain tissues. In astrocytoma-II and astrocytoma-III tumors, however, levels of EGF-LI were not different from those in normal brain. HPLC analysis of extracts from normal brain tissue and astrocytoma-II showed one peak of EGF-LI that coeluted with standard human EGF (retention time 22 min). Interestingly, EGF-LI in extracts of astrocytoma-IV tumors eluted in two distinct peaks with retention times of 24 and 26 min (Astro-A and Astro-B, respectively). Materials in both Astro-A and Astro-B peaks reduced the specific binding of [125I]hEGF to EGF receptors in human placental membranes. These studies demonstrate elevated levels of EGF-LI in malignant astrocytoma, but not in benign tumors. Furthermore, two different EGF-like molecules that are different from native EGF are present in malignant astrocytoma.

Preoperative staging of gastric cancer as precondition for multimodal treatment

Preoperative staging of gastric cancer plays a crucial role every multimodal treatment protocol. At present, staging intends to be far more than evaluation of the depth of tumor infiltration into the organ wall, that is, T stage, nodular status (N category), and the presence of distant metastases (M stage) according to UICC criteria. In modern surgical oncology it includes more often the evaluation of prognostic factors such as the RAS-protein, p53 tumor suppressor gene, growth factor receptors, cell adhesion molecules, proteolytic factors, and proliferation-associated antigens. Furthermore, evaluation of nodular status is possible by sophisticated computer programs. The conventional staging of gastric cancer using endoscopy and sonography, conventional ultrasonography, computed tomography, and magnetic resonance imaging is discussed. Possible improvements of staging in oncologic centers should include surgical laparoscopy, laparoscopic ultrasonography, and meticulous evaluation of an abdominal lavage including immunohistochemical detection of free tumor cells. The most promising tumor biology-related prognostic factors in gastric cancer are briefly discussed.

Clinical significance of epidermal growth factor (EGF), EGF receptor, and c-erbB-2 in human gastric cancer

The EGF stimulation system for growth regulation is implicated in normal and neoplastic cell proliferation. The role of EGF, the EGF receptor, and c-erbB-2 in human gastric cancer is reviewed on the basis of several reports, which have been mainly oriented toward their clinical significance. EGF has been shown immunohistochemically to be present in 26% of gastric cancers (n = 395). The presence of EGF in gastric cancer is correlated with the degree of gastric wall invasion and lymph node metastasis. The 5-year survival of patients with EGF-positive tumors is worse than that of patients with EGF-negative tumors. The presence of EGF in human gastric cancer may therefore represent a higher malignant potential. Fifteen percent of gastric cancers (n = 352) were also shown to be positive for both EGF and the EGF receptor immunohistochemically, and the simultaneous occurrence of EGF and the EGF receptor suggests that these tumors grow in an autocrine fashion. Tumors exhibiting EGF and the EGF receptor simultaneously show a greater degree of local invasion and lymph node metastasis. Increased expression of EGF receptor protein in gastric cancer appears to be related to biologic aggressiveness, although gene amplification has occurred only to a small extent. Twelve percent of gastric cancers (n = 486) were found to be positive for c-erbB-2. This type of tumor has a frequent metastasis, and patients with c-erbB-2-positive cancer have a poorer prognosis than those with c-erbB-2-negative tumors. Selective blockade of the EGF receptor and c-erbB-2 from their ligands with monoclonal antibodies (MoAbs) inhibits the growth of human gastric cancer xenografts. These MoAbs may therefore be effective antitumor agents against gastric cancer showing overexpression of EGF receptors or c-erbB-2.

Developmental expression of transforming growth factor-alpha and epidermal growth factor receptor proteins in the human pancreas and digestive tract

This study was designed to localize transforming growth factor alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) expression in the developing human gastrointestinal tract and pancreas. Immunohistochemical techniques using specific antibodies against human TGF-alpha and EGFR were performed on digestive tissues of fetuses from 9 to 10 to 24 weeks of gestation, children and adults. In fetuses, TGF-alpha and EGFR proteins were expressed in all epithelial tissues studied with a good correlation and from an age as early as 9 to 10 weeks of gestation, except for TGF-alpha in the esophagus. The strongest TGF-alpha immunostaining was noted in the stomach and the proximal colon. Unexpectedly, immunoreactive gut endocrine cells were observed with the two antibodies used. Relatively numerous in fetuses, they decreased in number with age and were rare in adults particularly along the colon. Enteroglucagonsecreting cells were shown to express TGF-alpha, while some gastrin, somatostatin and pancreatic glucagon cells were immunostained with EGFR antibodies. The presence of TGF-alpha and its receptor in digestive tract epithelium and pancreatic tissues early in fetal life suggests a functional role for TGF-alpha during the developmental process of the digestive system. We demonstrate that TGF-alpha is also produced by endocrine cells and might have an additional mode of action other than paracrine, at least during fetal life.

Epidermal growth factor and transforming growth factor-alpha mRNA in rat small intestine: in situ hybridization study

The expression of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) mRNA in the small intestine of suckling and adult rats was examined by in situ hybridization. EGF mRNA was found mainly in the intestinal crypts in adult rats. Adult rats also exhibited a considerably stronger signal for EGF mRNA in comparison to suckling rats, where the signal was very low or absent. In contrast to EGF, very strong expression of TGF-alpha mRNA was observed in the small intestine of both adult and suckling rats. These data suggest the differences between the expression of EGF and TGF-alpha in the developing small intestine.

pS2 protein in gastric carcinoma and normal gastric mucosa: association with clincopathological parameters and patient survival

The presence of pS2 protein (pS2) was studied in a total of 120 consecutive patients with gastric carcinomas. This immunohistochemical study found pS2 expression in 48 per cent (n = 58) of carcinomas. pS2 expression was also detected in normal gastric mucosa in 95 per cent (n = 102) of specimens in upper antral mucopeptic glands and deep foveolar cells of the gastric pits but not in intestinal metaplasia. There was a significant statistical correlation between pS2 expression and extent of tumour growth (pT state) and expression of pepsinogen II by the tumours. There was no statistical correlation with clinical features such as patient age or sex or other pathological parameters (tumour stage, size, grade, and localization or growth pattern according to histological classification). There were no statistically significant differences in survival times between patients with pS2-positive and pS2-negative tumours. In contrast to findings concerning breast cancer, pS2 expression in gastric carcinomas had no influence on the patient's prognosis. On the other hand, strong expression of pS2 by surface epithelium of normal gastric mucosa may indicate that pS2 might play a role in physiological cell renewal of normal gastric mucosa.

Transforming growth factor alpha and epidermal growth factor in laryngeal carcinomas demonstrated by immunohistochemistry

Fifteen laryngeal squamous cell carcinomas were investigated for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) using immunohistochemical methods. In a recent study the same material was characterized for epidermal growth factor receptors (EGF receptors) which were confined predominantly to the undifferentiated cells. The expression of this growth factor system in malignant cells may play a role in carcinogenesis and/or tumour growth. All carcinomas were positive for TGF-alpha and 12 were positive for EGF. In moderately-to-well differentiated carcinomas, the immunoreactivity was mainly detected in the cytologically more differentiated cells. Nine sections included both laryngeal stratified squamous epithelium of normal appearance and carcinoma. The immunoreactivity was here again localized in the cytologically more differentiated cells above the basal cell layer. The present investigation and our previous results confirm the existence of EGF receptors, TGF-alpha and EGF in laryngeal carcinomas. In addition, we conclude that the conditions do exist for growth factors to act through an autocrine system in poorly differentiated tumours and through a paracrine system in the moderately-to-well differentiated tumours.