Immunohistochemical study of epidermal growth factor and epidermal growth factor receptor in gastric carcinoma

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.

The challenge of targeted therapies for gastric cancer patients: the beginning of a long journey

INTRODUCTION

Despite significant improvements in systemic chemotherapy over the last two decades, the prognosis of patients with advanced disease remains dismal. Collaborative, high-quality research and advances in high-throughput technologies have contributed to elucidate molecular pathways underpinning disease progression and have stimulated many clinical studies testing target therapies in the advanced disease setting. Although progress has been made thanks to trastuzumab in HER2 positive tumours, antiangiogenic drugs have produced conflicting results and EGFR-inhibitors have failed to show major improvements.

AREAS COVERED

While commenting on the results of many key Phase III randomized trials, the Authors discuss the most promising classes of novel targeted agents and present the current challenges toward a customized treatment.

EXPERT OPINION

Palliative chemotherapy became the worldwide standard of care for patients with advanced gastric cancers, producing significant life prolongation and improvement of life quality. Nevertheless, long-term outcomes of those patients remain poor. Because of the encouraging advancement in novel targeted therapies, such a disappointing scenario is now evolving. While results serve as a springboard for future research, more comprehensive efforts are needed to clarify the biological mechanisms underpinning cancer progression and help clinicians to develop new effective treatments.

New targeted therapies for gastric cancer

INTRODUCTION

Inhibitors targeting oncogenic kinases, especially receptor tyrosine kinases (RTKs), are being vigorously developed, and some have been demonstrated to be effective in clinical settings. The amplification of certain RTKs (ErbB2, c-Met and FGFR2) is associated with gastric cancer progression, but the only recently approved inhibitor is trastuzumab, ErbB2-targeting antibody. Other well-known oncogenic kinases (PI3K and RAF) are also activated in a small portion of gastric cancers. Drugs targeting these kinases are promising and should be approved in an appropriate and expeditious way.

AREAS COVERED

This article reviews novel inhibitors emerging in the field of advanced gastric cancer, based on basic research concerning altered oncogenes and the clinical trials of drugs targeting these oncogenes.

EXPERT OPINION

Promising inhibitors of gastric cancer may be found in not only new investigative agents but also agents currently being used against other malignancies. The appropriate design for clinical trials of molecularly targeted therapeutic agents is also important. Targeted therapies tailored to individual genomic profiles would provide a more personalized treatment for advanced gastric cancer.

Apoptosis signal-regulating kinase 1 and cyclin D1 compose a positive feedback loop contributing to tumor growth in gastric cancer

Mitogen-activated protein kinase (MAPK) pathways regulate multiple cellular functions and are highly active in many types of human cancers. Apoptosis signal-regulating kinase 1 (ASK1) is an upstream MAPK involved in apoptosis, inflammation, and carcinogenesis. This study investigated the role of ASK1 in the development of gastric cancer. In human gastric cancer specimens, we observed increased ASK1 expression, compared to nontumor epithelium. Using a chemically induced murine gastric tumorigenesis model, we observed increased tumor ASK1 expression, and ASK1 knockout mice had both fewer and smaller tumors than wild-type (WT) mice. ASK1 siRNA inhibited cell proliferation through the accumulation of cells in G1 phase of the cell cycle, and reduced cyclin D1 expression in gastric cancer cells, whereas these effects were uncommon in other cancer cells. ASK1 overexpression induced the transcription of cyclin D1, through AP-1 activation, and ASK1 levels were regulated by cyclin D1, via the Rb-E2F pathway. Exogenous ASK1 induced cyclin D1 expression, followed by elevated expression of endogenous ASK1. These results indicate an autoregulatory mechanism of ASK1 in the development of gastric cancer. Targeting this positive feedback loop, ASK1 may present a potential therapeutic target for the treatment of advanced gastric cancer.

Study of growth factors and receptors in carcinoma ex pleomorphic adenoma

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignant salivary gland tumor derived from a pre-existing pleomorphic adenoma. It is a good model to study the evolution of carcinogenesis, starting with in situ areas to frankly invasive carcinoma. Growth factors are associated with several biological and neoplastic processes by transmembrane receptors. In order to investigate, by immunohistochemistry, the expression of some growth factors and its receptors [EGF receptor, fibroblast growth factor, fibroblast growth factor receptor 1, fibroblast growth factor receptor 2, hepatocyte growth factor, c-Met, transforming growth factor (TGF) beta1, TGFbetaR-II and insulin-like growth factor receptor 1] in the progression of CXPA, we have used ten cases of CXPA in several degrees of invasion- intracapsular, minimally and frankly invasive carcinoma- with only epithelial component. Slides were qualitatively and semi-quantitatively evaluated according to the percentage of stained tumor cells from 0 to 3 (0 = less than 10%; 1 = 10-25%; 2 = 25-50%; 3 = more than 50% of cells). Malignant epithelial cells starting with in situ areas showed stronger expression than luminal cells of pleomorphic adenoma for all antibodies. Most of the intracapsular, minimally and frankly invasive CXPA presented score 3. However, score 2 was more evident in the frankly invasive one. In small nests of invasive carcinoma, negative cells were observed probably indicating that the proliferative process is replaced by the invasive mechanism. Altogether this data infers that these factors may contribute to cell proliferation during initial phases of the tumor.

Involvement of an Autocrine Stromal Cell–Derived Factor-1/CXCR4 System on the Distant Metastasis of Human Oral Squamous Cell Carcinoma

We have previously shown that a stromal cell-derived factor-1 (SDF-1; CXCL12)/CXCR4 system is involved in the establishment of lymph node metastasis, but not in that of distant metastasis, in oral squamous cell carcinoma (SCC). In this study, we investigated the role of the autocrine SDF-1/CXCR4 system, with a focus on distant metastasis in oral SCC cells. The immunohistochemical staining of SDF-1 and CXCR4 using primary oral SCCs and metastatic lymph nodes showed a significantly higher number of SDF-1-positive cases among the metastatic lymph nodes than among the primary oral SCCs, which was associated with a poor survival rate among those of the former group. The forced expression of SDF-1 in B88 cells, which exhibit functional CXCR4 and lymph node metastatic potential (i.e., the autocrine SDF-1/CXCR4 system), conferred enhanced cell motility and anchorage-independent growth potential onto the cells. Orthotopic inoculation of the transfectant into nude mice was associated with an increase in the number of metastatic lymph nodes and more aggressive metastatic foci in the lymph nodes. Furthermore, the SDF-1 transfectant (i.e., the autocrine SDF-1/CXCR4 system) exhibited dramatic metastasis to the lung after i.v. inoculation, whereas the mock transfectant (i.e., the paracrine SDF-1/CXCR4 system) did not. Under the present conditions, AMD3100, a CXCR4 antagonist, significantly inhibited the lung metastasis of the SDF-1 transfectant, ameliorated body weight loss, and improved the survival rate of tumor-bearing nude mice. These results suggested that, in cases of oral SCC, the paracrine SDF-1/CXCR4 system potentiates lymph node metastasis, but distant metastasis might require the autocrine SDF-1/CXCR4 system.

Expression of epidermal growth factor receptor in gastric carcinomas

BACKGROUND & AIMS

Epidermal growth factor receptor belongs to the family of type I receptor tyrosine kinases. Overexpression of epidermal growth factor receptor has been observed in a variety of cancers with or without amplification of the gene. Novel chemotherapies targeting receptor tyrosine kinases might be effective for the treatment of cancers in which overexpression of this protein is a feature. The aim of this study was to assess the potential efficacy of epidermal growth factor receptor-targeted therapy in gastric cancer. This was achieved by determining the frequency of increased epidermal growth factor receptor expression in gastric cancers and investigating the relationship between protein overexpression and gene amplification.

METHODS

Immunohistochemical evaluation of 413 gastric cancers was carried out by using a monoclonal antibody to the epidermal growth factor receptor. The intensity of reactivity was scored by using a 4-tier system (negative, 1+, 2+, and 3+). All positive staining (>1+) tumors overexpressing the protein were then analyzed for gene amplification by fluorescence in situ hybridization by using a gene-specific probe.

RESULTS

High levels of overexpression (2+ or 3+ staining) were found in 9 of 413 (2.2%) patients, whereas low levels of overexpression (1+) were found in 34 (8.2%) of the study cohort. Fluorescence in situ hybridization analysis showed that more than 10 copies of the gene were recognized in all 5 cancers with 3+ staining and in 2 of the 4 tumors with 2+ staining.

CONCLUSIONS

Although a high level of overexpression of epidermal growth factor receptor is uncommon in gastric carcinomas, it almost exclusively occurs by gene amplification.

Clinical implications of the EGF receptor/ligand system for tumor progression and survival in gastrointestinal carcinomas: evidence for new therapeutic options

The epidermal growth factor (EGF) receptor and its various ligands (EGF, TGF-alpha, amphiregulin, heparin-binding (HB)-EGF, heregulin, betacellulin) seem to be involved in the growth regulation of intestinal mucosa and might be related to the development and progression of gastrointestinal tumors. However, few quantitative data investigating the impact of tumor-EGF receptor levels in gastrointestinal carcinomas on tumor stage and prognosis are available. Therefore, EGF receptors were quantitatively determined in colorectal carcinomas in comparison to adjacent normal mucosa by 125I[EGF]-binding studies. EGFR capacity was increased in advanced invasive colorectal carcinomas (T1/2 vs. T3/4 tumors, p<0.001) and advanced UICC stages (UICC I vs. UICC II/III, p<0.001). These findings were confirmed with quantitative 125[I]EGF autoradiography performed on frozen tissue slides and analyzed by laser densitometry (p=0.020). EGF receptor analysis with immunohistochemistry with EGFR antibodies directed against the extracellular domain of the receptor was not correlated with tumor invasion or prognosis. mRNA-expression of EGFR ligands was investigated using semiquantitative RT-PCR amplification using specific primers. RT-PCR transcripts of EGFR ligands (EGF, TGF-alpha, HB-EGF, and amphiregulin) were detected in both carcinomas and normal mucosa, indicating that autocrine growth stimulation of colorectal carcinomas is mediated by coexpression of EGF receptor ligands and upregulation of EGF receptors. Survival of colorectal cancer patients with increased tumor EGF receptor levels was significantly reduced in comparison to patients with low/unchanged tumor EGF receptor levels (mean survival+/-SD, 36.2+/-4.0 vs. 46.8+/-4.3 months; p=0.017). Further studies investigating EGF receptor levels in gastric cancer patients have shown that increased tumor EGF receptor levels were associated with poor prognosis in gastric cancer patients with tumors localized distal from the cardia. Several specific EGF receptor tyrosine kinase inhibitors have recently entered clinical phase I-III studies, with promising antitumor effects in several tumors, including gastrointestinal cancer. Therefore, patients with invasive gastric or colorectal carcinomas might benefit from therapies specifically blocking EGFR-mediated signal transduction.

Expression and prognostic value of epidermal growth factor receptor, transforming growth factor-alpha, and c-erb B-2 in nephroblastoma

BACKGROUND

Wilms tumor is one of the most common solid tumors in children. A transforming growth factor-alpha (TGF-alpha)/epidermal growth factor receptor (EGF-R) autocrine loop plays an important role in tumor growth. Abnormal expression of TGF-alpha, EGF-R and c-erb B-2 has been demonstrated in several human malignancies.

METHODS

The immunohistochemical expression of TGF-alpha, EGF-R, and c-erb B-2 was studied in paraffin material of 62 clinical Wilms tumors. Patients had a mean follow-up of 5.7 years.

RESULTS

Generally, TGF-alpha, EGF-R, and c-erb B-2 were expressed in tissue of the normal kidney and at variable levels in the three cell types of Wilms tumor, i.e., blastemal, epithelial, and stromal cells. Immunoreactive blastema cells were found in 48%, 44%, and 34% of tumors for TGF-alpha, EGF-R, and c-erb B-2, respectively. It was found that TGF-alpha, EGF-R, and c-erb B-2 blastemal and epithelial expression gradually increased from T1 to T3. The blastemal expression of TGF-alpha was statistically significantly correlated with clinicopathologic stages. Both univariate and multivariate analysis showed that blastemal TGF-alpha expression was indicative for clinical progression, but neither blastemal TGF-alpha, nor EGF-R or c-erb B-2 expression correlated with patients survival. Epithelial staining was of no prognostic value. The simultaneous expression of TGF-alpha/EGF-R was indicative for clinical progression at univariate level.

CONCLUSIONS

Increased expression of TGF-alpha in the blastemal part of Wilms tumor correlated with tumor classification and clinical progression. These findings suggest that significant expression of TGF-alpha and EGF-R may play a role in promoting transformation and/or proliferation of Wilms tumor, perhaps by an autocrine mechanism. Therefore, their expression may be of value in identifying patients at high risk of tumor recurrence.

The progression of invasiveness regarding the role of transforming growth factor beta receptor type II in gastric cancer

AIMS

Transforming growth factor beta (TGF beta) is a potent growth inhibitor of epithelial cells. The expression of TGF beta receptors is required for the effect of TGF beta. In this study, we used immunohistochemistry to demonstrate the roles of the expression of TGF beta type I (T beta R-I) and type II (T beta R-II) receptors in the progression of gastric carcinoma.

METHODS

To evaluate the potential prognostic value of T beta R-I and T beta R-II, 158 consecutive gastric cancer tissues specimens obtained over a 3-year period were examined.

RESULTS

A total of 50 (32%) and 28 (18%) patients had T beta R-I(+) and T beta R-II(+), respectively. The 5-year survival rates of the patients with T beta R-I(+) and those with T beta R-I(-) were 74% and 71%, respectively. In contrast, the 5-year survival rates of the patients with T beta R-II(+) and those with T beta R-II(-) were 57% and 75%, respectively, and the difference was statistically significant (P<0.05). The extent of T beta R-II was closely correlated to the macroscopic types based on the Borrmann classification (P<0.01), and curability (P<0.05). However, a significant difference between the 5-year survival rates of the patients with T beta R-II(+) and those with T beta R-II(-) was only obtained in advanced cases (P<0.05) not in either curative cases, non-curative cases, or early cases.

CONCLUSIONS

Our data suggest that when T beta R-II expression correlates with the progression of invasiveness in gastric cancer, it may lead to a non-curative resection and a poor prognosis.

Gastric cancer in pregnancy: do pregnancy, age or female sex alter the prognosis? Case reports and review

The coincidence of gastric cancer and pregnancy is a rare event. By literature research of the last three decades only 31 cases from outside Japan were identified including two own patients. The analysis of these and another 61 cases from Japan revealed the same predominance of poorly differentiated diffuse carcinomas with peritoneal and lymphatic metastases as in other young patients (<40 years). The survival rate is not obviously affected by pregnancy, young age or female sex. Experimental and epidemiological data suggest a protective effect of oestrogen against the induction of (intestinal) gastric cancer, while the cancer growth itself seems to be enhanced. Oestrogen receptors (ER) are found in about 22% of gastric cancer cells, especially in the poorly differentiated type. In contrast to target organs like the breast, ER in gastric cancer seem to be a sign of tumour adaptation involving e.g. the pathway of the epidermal growth factor. The results of treatment with anti-oestrogen are controversial in experimental and clinical settings. Due to the very common epigastric complaints early diagnosis of gastric cancer is even more difficult in pregnancy, so that early gastroscopy is advisable in patients on risk. Main effort should be given, however, to primary prevention.

Prognostic factors in gastric cancer

BACKGROUND

Despite gastric cancer being common, its prognosis has not been improved significantly in recent years. Now, greater insight has been gained into the biological properties of tumour cells, how they become malignant and what mechanisms they may use to invade and metastasize. This involves tumour-associated protease systems, loss or mutation of adhesion molecules and changes in genetics. The view of gastric cancer is changing: it is not only a solid tumour but also exhibits a minimal residual disease component even in the early stages of disease. Such biological tumour characteristics may provide new prognostic factors and also potential new therapeutic options.

METHODS

This is an update of prognostic factors in gastric cancer, emphasizing new biological features, some of which have been investigated by this group over the past few years. Current results are discussed in the light of 212 references obtained from the Medline database from 1979 to 1997.

RESULTS

There is high probability that some of the factors reviewed, such as c-erbB-2, individual course and phenotyping of disseminated tumour cells will become significant new prognostic variables. This is true also, to a lesser extent, of cathepsin D, matrix metalloproteinase 2 combined with activators or tissue inhibitor of metalloproteinases 2, CD44, E-cadherin, p53 and cripto. Plasminogen activator inhibitor 1 (PAI-1), a member of the urokinase-type plasminogen activator (uPA) system, can already be defined as an established new prognostic factor in gastric cancer.

CONCLUSION

PAI-1 should be considered prognostically in addition to established tumour classifications. Moreover, the uPA system is a target for future therapeutic concepts. Further analysis of factors describing tumour biology should lead to new, functionally orientated, tumour classifications in gastric cancer.

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.

Superficial spreading type of early gastric cancer

To determine the clinicopathological features of the superficial spreading type of early gastric cancer, which is defined as early gastric cancer in which the product of the longest diameter of the tumour and the diameter perpendicular to it is greater than 25 cm2, they were compared retrospectively with those of small-sized early gastric cancers, which are defined as tumours smaller than 2 x 2 cm2. The superficial spreading type accounted for 5.46% of all early gastric cancers. The distinguishing histopathological features of superficial spreading lesions were: a diffuse type of cancer, submucosal invasion and advanced lymph node involvement. Of the 32 patients with superficial spreading lesions, eight underwent an additional resection as a continuance of the first gastrectomy, because of an indistinct tumour margin. More extensive lymph node dissection was also performed on the group with superficial spreading lesions. There was no difference in 5 year survival rate between the two groups (superficial spreading type, 96.0% vs small-sized type, 95.1%). The most appropriate treatment for superficial spreading lesions is a wide surgical resection with extensive lymph node dissection.

Characterization of the mouse epidermal growth factor promoter and 5'-flanking region. Role for an atypical TATA sequence

As a step toward delineating mechanisms that regulate its activity, we have characterized the mouse epidermal growth factor (EGF) promoter. Primer extension and S1 nuclease analyses identified prominent (+1/+2) and minor (+28) transcription start sites, with the dominant +1/+2 site located 33 bases downstream from a TTTAAA sequence. A restriction fragment that spanned these start sites and contained 390 base pairs of 5'-flanking sequence directed transcription from the +1/+2 site in vitro in the presence of HeLa cell nuclear extracts. Additionally, it promoted expression of a coupled luciferase reporter gene in transfected cell lines. The inclusion of additional 5'-flanking sequence either stimulated or inhibited luciferase expression depending on the cell line. Approximately 2 kilobases of EGF 5'-flanking sequence was determined and found to contain several motifs with partial homology to steroid hormone response elements. Despite this fact and evidence that EGF expression might be regulated by androgens in vivo, EGF promoter-luciferase constructs were not steroid-responsive in cells cotransfected with steroid receptor expression vectors. An oligonucleotide containing the aforementioned TTTAAA sequence specifically bound TATA-binding protein and TFIIA in gel shift assays, and an EGF promoter-luciferase construct in which the core TA dinucleotide was mutated to CG was not active in transfected cells. These data suggest that the TTTAAA sequence functions as an atypical TATA box.

Increased estrogen receptor and epidermal growth factor receptor gene product co-expression in surgically resected gastric adenocarcinomas

BACKGROUND

Evidence exists that estrogens influence the action of epidermal growth factor (EGF) and its receptor (EGF-R) at multiple levels. Estrogen and antiestrogen action on gastric and other gastrointestinal malignancies has been evaluated by several groups with conflicting results, and EGF-R has been implicated in the current growth factor-mediated models for gastric cancer progression.

METHODS

ERs and EGF-Rs were detected immunohistochemically in a total of 53 advanced gastric carcinomas using monoclonal antibodies (mAbs) to human ERs and EGF-Rs.

RESULTS

ERs were expressed in 30 (56%) and EGF-Rs in 20 (38%) of the gastric tumors. ER(+) gastric tumors were closely associated with the intestinal type (P < 0.01), whereas EGF-R(+) tumors were significantly correlated with poor differentiation status and ER(+) expression (P < 0.01). Of EGF-R(+) tumors, 85% were also ER(+). EGF-R and ER co-expression was demonstrated in 17 tumors (32% of the group). These cases were significantly corelated with poor differentiation and large tumor size upon resection (P < 0.05).

CONCLUSIONS

ER and EGF-R co-expression indicates that a functional interaction between estrogens and EGF may exist in gastric cancer and that when such an interaction becomes operative, it may lead to dedifferentiation and increased tumor growth.

Are Japanese and European gastric cancer the same biological entity? An immunohistochemical study

To examine the suggested biological difference between Japanese and British gastric cancers, immunohistochemistry was used to demonstrate eight markers of biological activity in a matched series of 40 Japanese and 33 British cases. There were no differences in the proportions of Japanese and British tumours positive to epidermal growth factor, epidermal growth factor receptor, transforming growth factor alpha, cripto or p53. A significantly greater proportion of British tumours were positive to c-erbB-2 whilst a significantly greater proportion of Japanese tumours were positive to nm23. British tumours had a significantly greater mean proliferating cell nuclear antigen proliferation index than Japanese tumours. These differences could be clinically significant.

Concomitant and isolated expression of TGF-alpha and EGF-R in human hepatoma cells supports the hypothesis of autocrine, paracrine, and endocrine growth of human hepatoma

Single and double immunohistochemical staining for transforming growth factor (TGF)-alpha and epidermal growth factor-receptor (EGF-R) was done in order to identify the localization of TGF-alpha and EGF-R in human hepatocellular carcinoma (HCC). Single immunohistochemical staining for TGF-alpha showed immunoreactivity in the cytoplasm of hepatoma cells in 22 of 30 cases of HCC. The localization of TGF-alpha was heterogeneous from HCC cells to HCC cells. In the surrounding regenerative nodules, the hepatocytes were mildly to moderately positive for TGF-alpha. The proliferating bile ductules and peripheral nerves were also immunopositive for TGF-alpha. Single immunohistochemical staining for EGF-R demonstrated a linear localization of EGF-R along the cell membrane of the HCC cells in 21 of the 30 cases of HCC. In the regenerative nodules, the hepatocytes also showed linear staining along the cell membrane. Double staining for TGF-alpha and EGF-R in 12 cases of HCC showed a concurrent localization of TGF-alpha and EGF-R in some hepatoma cells and isolated localization of the two substances of other HCC cells. These combinations either abruptly moved around or intermingled with each other. These immunohistochemical results thus support the theory of an autocrine, paracrine, and endocrine mechanism of TGF-alpha and EGF-R on the proliferation of human hepatocellular carcinoma.

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.

Establishment and characterization of TSGH9201, a human gastric carcinoma cell line that is growth inhibited by epidermal growth factor

A human signet ring gastric carcinoma cell line TSGH9201 was established in vitro. The cells grew in vitro as a monolayer with polygonal morphology and had a population doubling time of 34 hours. The cells secreted tumor markers CEA and CA 125. They were, however, not tumorigenic in athymic nude mice. Karyotypic analysis demonstrated a near tetraploidy with a modal chromosome number of 98. Northern blotting and immunocytochemical analysis revealed the expression of both transforming growth factor alpha and high levels of epidermal growth factor receptor. Cell growth was inhibited by the epidermal growth factor in vitro. The cell line may be a useful tool to study autocrine growth regulation through the epidermal growth factor receptor.

Stimulatory effect of EGF and inhibitory effect of sialoadenectomy on growth of an EGF receptor-hyperproducing human gastric cancer xenograft in nude mice

We recently established epidermal growth factor (EGF) receptor-hyperproducing human gastric cancer xenografts in nude mice. The present study was designed to examine whether the growth of a xenograft having 1,098 +/- 276 fmol/mg protein of EGF receptor would either be stimulated by the administration of EGF or inhibited by the removal of the submandibular glands (sialoadenectomy) which contain a large amount of EGF. A miniosmotic pump containing 2 micrograms or 20 micrograms of EGF was implanted on the back of the animals in the EGF stimulation experiments. The tumor growth was stimulated by the administration of EGF (P < 0.01), and the doubling time of the tumor was reduced relative to the controls (P < 0.01). Both the mitotic indices and the bromodeoxyuridine (BrdU)-labeling indices of the tumor were higher than those of the controls (P < 0.01). Tumor growth inhibited by the sialoadenectomy (P < 0.05) while the tumor doubling time was prolonged compared with the sham-operated mice (P < 0.05). These results suggest that the growth of a human gastric cancer xenograft may be modulated by EGF.

Expression of EGF, EGF-receptor, p53, v-erb B and ras p21 in colorectal neoplasms by immunostaining paraffin-embedded tissues

Immunohistochemical studies were performed to clarify the significance of the expression or overexpression of epidermal growth factor (EGF), EGF-receptor (EGFR), p53, v-erb B, ras p21 in 23 cases each of tubular adenoma and adenocarcinoma. The expression of EGF, EGFR, p53, v-erb B, and ras p21 in paraffin-embedded tissues, from 46 patients with colorectal tumors (adenoma: 23 cases; 14 mild dysplasia, six moderate dysplasia, three severe dysplasia, adenocarcinoma: 23 cases; 17 well differentiated, two moderately differentiated, three poorly differentiated, one mucinous carcinoma was analyzed immunohistochemically using anti-EGF, EGFR, p53, v-erb B and ras p21 antibodies. The EGF and ras p21 tended to express more strongly in carcinoma cases than in the adenoma cases, and in severe and moderate dysplasia than in mild dysplasia (EGF: stained positive in five adenomas [21.74%] and 17 adenocarcinomas [73.91%]; ras p21: stained positive in six adenomas [26.09%] and 14 adenocarcinomas [60.87%]. The EGFR stained positive in two adenomas (8.70%) and two adenocarcinomas (8.70%). The p53 and v-erb B showed positive staining only in the carcinoma cases (p53: stained positive in four cases [17.39%]; v-erb B: stained positive in eight cases [34.78%]). This study suggests that these factors seem to have some role in the progression of colon neoplasms. It suggests that genetic alteration is not always equal to the overexpression of protein products, but that it reflects them well, and that the staining makes some contribution to differential diagnosis in colorectal neoplasms.

Epidermal growth factor receptor expression in squamous cell lung carcinomas: an immunohistochemical and gene analysis in formalin-fixed, paraffin-embedded material

Epidermal growth factor (EGF) and its receptor (EGFr) constitute an important and well-characterized mitogenic system in various ectodermal tissues. We evaluated the expression of EGFr and examined possible EGFr gene alterations in 18 formalin-fixed, paraffin-embedded squamous cell lung carcinomas (SCLC) by an immunohistochemical assay, Southern blotting and differential polymerase chain reaction (DPCR). The immunohistochemical study employing the F4 and EGF-R1 monoclonal antibodies, directed against the intra- and extra-cellular portion of the receptor respectively, showed EGFr over-expression in 89% of the SCLC cases examined. All cases showed positive immunostaining for both antibodies, thus excluding the possibility of truncated receptors. In addition, analysis of the EGFr gene was carried out by Southern blotting and DPCR on paraffin extracted DNA from the same carcinoma cases. We found amplification of the EGFr gene in 5/18 (27%) SCLCs. All 5 positive cases showed EGFr over-expression, suggesting a possible correlation between the presence of EGFr gene amplification and over-expression of receptor protein. No correlation was observed among EGFr staining, EGFr gene amplification and differentiation of carcinomas. In addition, Southern blot analysis with HER-A2, a probe which hybridizes a sequence of the receptor's intracellular domain, revealed three novel EcoRI restriction fragment patterns. We suggest that these patterns correspond to EcoRI polymorphic sites of the receptor's tyrosine kinase domain.

Prognostic significance of transforming growth factor-alpha in human esophageal carcinoma. Implication for the autocrine proliferation

BACKGROUND

The authors recently used immunostaining to demonstrate that patients with epidermal growth factor receptor (EGFR) overexpression have poor survival after surgery. However, the clinical significance of transforming growth factor (TGF)-alpha, one of the ligands of EGFR, has not been demonstrated in esophageal carcinoma.

METHODS

Immunohistochemical study for TGF-alpha and EGFR was performed on 57 esophageal squamous cell carcinomas using monoclonal antibodies.

RESULTS

TGF-alpha expression was positive in 35% of the tumors, and EGFR overexpression, defined as stronger staining in cancer cells than in normal epithelium, was positive in 43% of the tumors, according to the authors' arbitrary criteria. The incidence of TGF-alpha positivity was relatively higher in patients with the EGFR overexpression (EGFR+) than in the patients with non-overexpression (EGFR-). The survival rate was significantly lower in patients with TGF-alpha(+) than in those with TGF-alpha(-) (P < 0.01) and in patients with EGFR(+) than in patients with EGFR(-) (P < 0.01), respectively. Considering TGF-alpha and EGFR expression simultaneously, the survival rate of the patients with TGF-alpha(+)/EGFR(+) tumors was the lowest of the four subgroups, with statistically significant differences noted. These relationships between the immunoreactivities and survival curves were observed in the analysis within patients with node-positive disease. In addition, a multivariate statistical analysis demonstrated that TGF-alpha was the only significant variable, whereas EGFR and nodal status provided no additional information regarding postoperative survival.

CONCLUSION

The results presented suggest that TGF-alpha may act as an autocrine growth factor through hyperproducing EGFR and that its expression and EGFR overexpression may prove useful as a valuable prognostic indicator for patients with esophageal carcinoma.

Expression of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) in gastric and colorectal carcinomas. An immunohistological study of 63 cases

Immunohistochemical study for epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) was performed on paraffin-embedded tissue specimens from 39 colorectal and 24 gastric carcinomas. The carcinomas were placed in one of the following 3 groups: group 1, neither EGF nor EGFR was stained (11 gastric and 21 colorectal carcinomas); group 2, either EGF or EGFR was stained (4 gastric and 4 colorectal carcinomas); and group 3, both EGF and EGFR were stained (9 gastric and 14 colorectal carcinomas). Compared with the carcinomas in groups 1 and 2, those in group 3 had significantly higher rates of lymph node spread and serosal invasion of the gastrointestinal wall. In contrast, no significant differences were found between the EGF and/or EGFR expression and histological differentiation of carcinomas. These results suggest that gastrointestinal carcinomas expressing both EGF and EGFR display pathological features of more aggressive disease. Furthermore, the synchronous expression of EGF and EGFR indicates that these carcinomas may regulate their growth by an autocrine and/or paracrine mechanism.

The type 1 (EGFR-related) family of growth factor receptors and their ligands

This review considers the biology of the type 1 growth factor receptor family which is increasingly recognised as important in the control of normal cell proliferation and in the pathogenesis of human cancer. The family currently comprises three closely related members: the epidermal growth factor (EGF) receptor, c-erbB-2 and c-erbB-3, all of which show abnormalities of expression in various human tumours. The family of factors related to EGF has also expanded recently and now includes transforming growth factor alpha, heparin-binding EGF, amphiregulin, cripto and heregulin, as well as several other potential ligands for the c-erbB2-2 receptor. The involvement of these receptors and growth factors in human cancer has implications for the design of novel forms of therapy for cancer, and we review recent advances and future avenues for investigation.

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

We report that the penetrating type of early gastric cancer (PEN) is a specific type of early gastric cancer and that the poorly differentiated PEN type could be considered an initial lesion of linitis plastica-type cancer. We performed an immunohistochemical study to clarify the role of growth factors (epidermal growth factor [EGF] and transforming growth factor-beta [TGF-beta]) in the PEN type of early gastric cancer. The results indicated that the PEN type of early gastric cancer has a high growth capacity. Moreover, it was suggested that EGF was involved in its specific infiltrative growth and that both EGF and TGF-beta were involved in its specific scirrhous growth. From these findings, it was assumed that the immunohistochemical staining of EGF and TGF-beta in endoscopic biopsy specimens was useful for the diagnosis of the PEN type of gastric cancer and also for the diagnosis of the initial lesion of linitis plastica-type gastric cancer.

Clinicopathological significance of c-erbB-2 protein expression in human gastric carcinoma

One hundred seventy-nine primary human gastric tumors not associated with early cancer or noncurative resection were examined immunohistochemically for the expression of c-erbB-2 protein. Positive staining, regarded as an indication of gene amplification, was evident in 22(12%) of the tumors. Of various clinicopathological factors considered, a statistically significant difference in association with frequency of expression was noted only for histological differentiation, as follows: 39% positive staining in papillary, 17% in well differentiated, 5% in moderately differentiated, and 4% in undifferentiated adenocarcinomas (P greater than 0.01). The 5-year survival rates of patients with positive and negative c-erbB-2 staining were 57% and 59%, respectively. These findings indicate that, in the case of human gastric adenocarcinoma, expression of c-erbB-2 protein is correlated with tumor histological differentiation. Our results also suggest that the presence or absence of c-erbB-2 protein may not serve as a prognostic indicator, particularly in cases of adenocarcinoma of the stomach.

Transforming growth factor alpha expression in normal gastric mucosa, intestinal metaplasia, dysplasia and gastric carcinoma--an immunohistochemical study

Using a monoclonal antibody (GF10) and a standard immunohistochemical technique, immuno-expression of transforming growth factor alpha (TGF-alpha) was found consistently within the differentiated compartment of normal adult human gastric mucosa. In 70% of mucosal samples exhibiting intestinal metaplasia there was more or less uniform TGF-alpha immunoreactivity throughout the intestinalized mucosa. Similarly, 60% of cases of dysplasia and 60% of gastric carcinomas showed strong immunoreactivity in most of the cells. However, whereas 93% of intestinal-type cancers showed strong immunoreactivity only 30% of the diffuse type were stained and then only weakly. Transforming growth factor alpha expression is thus a fairly regular feature of several types of differentiated gastric epithelia (normal, metaplastic, dysplastic and intestinal-type carcinoma), while its relative absence may be a factor in the histogenesis of the diffuse type of gastric carcinoma.

Expression of c-erbB-2 oncoprotein in gastric carcinoma. Immunoreactivity for c-erbB-2 protein is an independent indicator of poor short-term prognosis in patients with gastric carcinoma

Correlations of c-erbB-2 protein expression with clinical outcomes of gastric carcinomas were studied in 189 gastric carcinomas. There were 23 (12.2%) carcinomas with evidence of c-erbB-2 protein in which the reaction was localized to the cell membrane. There was no significant association between c-erbB-2 staining and the macroscopic or histologic type of the carcinomas. c-erbB-2-stained tumors were more likely to be associated with serosal invasion, nodal involvement, and peritoneal metastasis, than c-erbB-2-unstained ones. In addition, c-erbB-2 was stained in none of early gastric carcinomas. The 5-year survival rates of the c-erbB-2 protein-positive and the protein-negative group were 11% and 50%, respectively. When the c-erbB-2 tissue status and seven clinicopathologic variables as conventional prognostic factors were entered simultaneously into the Cox regression model, serosal invasion, hepatic metastasis, peritoneal metastasis, nodal status, and c-erbB-2 tissue status emerged as independent prognostic variables. The results suggested that c-erbB-2 protein expression might be enhanced in advanced stages during the progression of gastric carcinoma. In this particular group of patients, immunoreactivity for c-erbB-2 protein is an indicator of poor short-term prognosis.

Immunohistochemical demonstration of epidermal growth factor receptor and ceruloplasmin in thyroid diseases

The expression of epidermal growth factor receptors (EGFR) and ceruloplasmin (CP) in thyroid diseases was investigated by immunohistochemical methods, and the results were compared with the expression of thyroglobulin (TG). Eighty-eight surgical specimens of thyroid diseases, including follicular carcinoma (7 cases), papillary carcinoma (20 cases), follicular adenoma (29 cases), adenomatous goiter (10 cases), diffuse hyperplasia (20 cases) and chronic thyroiditis (2 cases), were studied. All cases of follicular carcinoma and 18 cases (90%) of papillary carcinoma expressed the EGFR immunoreaction in the cytoplasm with a moderate to strong staining intensity. A weak immunoreaction for EGFR was noted in some benign thyroid diseases. CP showed various degrees of positivity in all cases of follicular carcinoma and 19 cases (95%) of papillary carcinoma. The benign thyroid lesions were consistently negative for this antigen, not counting one case of Hürthle cell adenoma. There was a positive correlation between EGFR and CP immunostaining intensity in thyroid carcinomas, representing higher expression of EGFR accompanied by a stronger staining intensity of CP. Except for two cases of papillary carcinoma, all cases showed immunoreaction for TG. The results indicate the enhanced expression of EGFR and CP in thyroid carcinomas. EGFR and CP thus appear to be valuable tools for differential diagnosis between benign and malignant thyroid neoplasms.

Immunohistochemical distribution patterns of epidermal growth factor receptor in malignant mesothelioma and non-neoplastic mesothelium

An immunohistochemical study of the epidermal growth factor (EGF) receptor in non-neoplastic pleural mesothelium (35 cases) and in human malignant mesothelioma (36 cases) was made, using a murine monoclonal antibody OM-11-951. All malignant mesotheliomas and non-neoplastic pleural biopsies exhibited a strong cytoplasmic immunoreactivity in mesothelial cells. Nuclear immunoreactivity was detected in mesothelial cells of all specimens of both malignant and non-neoplastic pleura. No statistically significant differences were found between malignant mesothelioma and non-neoplastic pleural mesothelium. There were differences, between the three subtypes of mesothelioma, in the number of cells that exhibited nuclear staining. Statistically significant differences were noted between the epithelial subtype and the mesenchymal subtype (P less than 0.005), epithelial subtype versus the mixed cell type (P less than 0.005) and between the mesenchymal component of the mixed cell type and the mesenchymal type (p less than 0.0005). We conclude that there is strong expression of EGF receptor in both malignant mesothelioma and in non-neoplastic pleural mesothelium. Different staining patterns are seen when comparing the different subtypes of mesotheliomas with each other. EGF receptor expression cannot be used to distinguish between malignant and benign mesothelium.

Quantitative assay of epidermal growth factor receptor in human squamous cell carcinomas of the oral region by an avidin-biotin method

A quantitative assay method for epidermal growth factor receptors (EGFRs) of human tumor tissues was established, based on enzyme-labeled avidin-biotin (LAB) interaction with anti-human EGFR monoclonal antibody 528IgG. A standard calibration curve for EGFR estimation in human tumor tissues was obtained with A431#8 cells cloned from A431 human epidermoid carcinoma cell line. The coefficient of variance for the standard curve was below 35% in the application to tumor tissues from nude mice implanted with human tumor cell lines. The minimum tissue amount required for the quantitative assay was around 0.1 g (wet weight). Using the LAB method, the correlation between the level of EGFR number and tumor malignancy was examined for 14 human squamous cell carcinomas (SCCs) from the oral region. Seven of the SCCs showed a more than two-fold higher EGFR number compared to normal gingival tissues. Three highly aggressive carcinomas with poor prognosis possessed five to ten times higher levels of EGFR number than normal tissues. The elevated EGFR level in the SCCs seems to correlate to increasing tumor size and the stage of SCCs as clinically classified according to the 1987 UICC TNM system.

Immunohistochemical demonstration of epidermal growth factor and c-myc oncogene product in normal, benign and malignant thyroid tissues

The expression of epidermal growth factor (EGF) and c-myc oncogene product was studied immunohistochemically in 65 benign and malignant human thyroids. Normal thyroid tissues were usually negative with each antibody. Benign and malignant neoplastic thyroid tissues demonstrated a high percentage of stained cells. However, there was no significant difference in positivity between benign and malignant neoplastic tissues. In Graves' disease 25% of the cases were positive for EGF, and 100% for c-myc product. The effect of EGF or c-myc expression on prognosis was also examined in 42 patients with papillary thyroid carcinoma. When the cases were divided into two groups with regard to their EGF staining score (highly-expressed and poorly-expressed groups), the frequency of highly-expressed tumours was significantly higher in the recurrence-positive group compared with the recurrence-free group (86% vs 57%), but there was no significant difference between the groups in respect of c-myc expression.

Adenocarcinoma development in the trigone 34 years after trigonocolonic urinary diversion for exstrophy of the bladder

A case of adenocarcinoma development in the trigone 34 years after trigonosigmoidostomy for exstrophy of the bladder is presented. The need for lifelong surveillance is emphasized and endoscopy is recommended annually in patients with urinary diversion to a colonic segment.

Expression of epidermal growth factor receptor in normal colorectal mucosa, adenoma, and carcinoma

Using the monoclonal antibody EGF-R1, the expression of epidermal growth factor receptor (EGFR) was investigated immunohistochemically in normal colonic mucosa distant from and adjacent to colonic neoplasms, in 25 adenomas and in 144 unselected colorectal carcinomas. EGFR expression was an inconsistent phenomenon in each of these conditions. It was not expressed in 23/44 non-neoplastic mucosa specimens distant from and in 26/44 mucosae adjacent to colon tumours; 15/25 adenomas and 71 (49.3%) of the carcinomas failed to contain detectable amounts of EGFR. In contrast, large amounts of EGFR were found in 4 non-neoplastic mucosae at both locations, in 3 adenomas and in 11 (7.6%) carcinomas. The remaining cases showed complex patterns of EGFR-expression. In comparing mucosae close to and distant from a colonic tumour, only minor differences in EGFR content were observed. The intra-individual comparison of the mode of EGFR expression in non-neoplastic and neoplastic epithelium revealed an overexpression of EGFR in carcinomas in about one third of the 44 cases examined. One third showed no obvious differences, and one third showed lower levels of EGFR expression within the tumour. We conclude that the mode of EGFR expression in normal and neoplastic colon epithelium is variable and reflective of inter-individual constitutive differences rather than of abnormalities in gene regulation. Statistical analysis failed to reveal correlations between the mode of EGFR expression and tumour grade, type or Dukes stage.

The correlation of epidermal growth factor with invasion and metastasis in human gastric cancer

We examined the localization of epidermal growth factor (EGF) in 185 specimens of primary human gastric cancer using the avidin-biotin peroxidase complex immunohistochemical method on formalin-fixed paraffin-embedded sections. Thirty-four per cent of the gastric cancer specimens were positive for EGF, which was mainly located in the cytoplasm of the cancer cells and occasionally in the stromal cells, but was not detected in non-cancerous gastric epithelium. Moreover, the presence of EGF in gastric cancer was correlated with gastric wall invasion and lymph node metastasis. EGF was found more often in advanced cancers than in early ones (p less than 0.01), and also more often in cancers with lymph node metastasis than in those without (p less than 0.05). The five-year survival of patients with EGF-positive tumors was worse than that of patients with EGF-negative tumors (p less than 0.05). The presence of EGF in human gastric cancer may thus represent higher malignant potential.

Expression of human epidermal growth factor and its receptor in esophageal cancer

The expression of human epidermal growth factor (hEGF) was examined immunohistochemically in 86 esophageal cancer lesions, comprising 67 primary tumors and 19 metastatic lymph nodes. In the normal esophagus, the parabasal and intermediate cell layers showed a weak expression of hEGF, however, hEGF-positive tumor cells were detected in 62 (92.5 per cent) of the 67 primary esophageal carcinomas and in 18 (94.7 per cent) of the 19 metastatic lymph nodes. In this study, the immunoreactivity of hEGF was classified into 4 grades according to the number of stained tumor cells. A significant correlation was observed between the histologic type and the grade of hEGF immunoreactivity (Chi-square test, p less than 0.01). hEGF immunoreactivity in well differentiated squamous cell carcinomas was significantly higher than in other squamous cell carcinomas, although there were no correlations between other pathological findings and hEGF immunoreactivity. Patients with hEGF immunoreactivities of grades II or III had much worse prognoses than those with grades 0 or I (p less than 0.05). In 22 esophageal carcinomas and 10 normal esophageal mucosae, EGF receptor (EGFR) contents were measured by the competitive binding assay. The average EGFR content (101.3 +/- 35.7 fmol/mg protein, mean +/- SE) of the esophageal carcinomas was significantly higher than that (5.3 +/- 1.2) of the normal esophageal mucosae (p less than 0.05). Moreover, in hEGF negative tumors, EGFR contents were lower than in hEGF positive tumors. These results suggest that hEGF and EGFR show increased production in squamous cell carcinomas and could to be useful prognostic factors in patients with esophageal cancer.

Growth factors and oncogenes in human solid tumors: clinical aspects

Growth factors, growth factor receptors and oncogenes have been extensively studied in human tumors for some years. The purpose of this paper is to review the clinical results obtained in human cancers and their predisposing conditions or high risk groups as well as their relation with clinical, pathological characteristics and their prognosis.