Overexpression of epidermal growth factor receptor (EGFR) is observed in many cancers, sometimes accompanied by gene amplification. Recently, several clinical therapies targeting EGFR were developed, but the eligibility criteria for these therapies is not fully established. To develop such eligibility criteria for esophageal squamous cell carcinoma (ESCC), we sought to clarify: (i) the exact frequency of EGFR overexpression, (ii) the relationship between protein overexpression and gene amplification, (iii) the relationship between gene amplification and specific gene mutations and (iv) the correlation between the status of EGFR and clinical or pathological features. Immunohistochemistry revealed that EGFR protein is overexpressed in 53 (50%) of the 106 ESCC examined. Fluorescence in situ hybridization (FISH) indicated clear EGFR gene amplification in 15 of the 53 tumors, somewhat higher EGFR copy in 32 cases, and no increase in 6 cases. Gene amplification was significantly associated with high level overexpression. Direct sequencing of exons 19 and 21 of EGFR revealed no mutations in 15 tumors exhibiting gene amplification, and no mutations in 25 tumors not exhibiting gene amplification. Overexpression of EGFR was significantly correlated with depth of invasion of the tumor.In conclusion, anti‐EGFR therapies may be appropriate for patients with ESCC. We assume that combined analyses by immunohistochemistry/FISH would clarify aberrations in protein and gene function, and could help to identify those patients who may benefit from anti‐EGFR therapy. © 2005 Wiley‐Liss, Inc.
Carcinomas of the biliary tract have a poor prognosis. It is important to understand the molecular genetic characteristics of these tumours in order to employ newer effective treatments and to improve patient prognosis. There is increasing evidence that overexpression of tyrosine kinase growth factor receptors such as ErbB-2, epidermal growth factor receptor (EGFR), and Met may play important roles in the development of biliary tract carcinomas. The aim of this study was to assess the potential for novel chemotherapies targeting these receptors. Overexpression of the tyrosine kinase receptor proteins was examined by immunohistochemistry in 221 biliary tract carcinomas, of which 28 were from the intrahepatic bile duct, 78 from the extrahepatic bile duct, 89 from the gall bladder, and 26 from the ampulla of Vater. Positively stained tumours were further examined for gene amplification by fluorescence in situ hybridization. Overexpression of ErbB-2 was found in 15.7%, 11.5%, and 5.1% of carcinomas of the gall bladder, ampulla of Vater, and extrahepatic bile duct, respectively, and gene amplification was present in 79% of these. Overexpression of EGFR was found in 8.1% of tumours with no predominant location and was also associated with gene amplification with high frequency (77%). Met overexpression, most frequent in intrahepatic bile duct carcinomas (21.4%), was not associated with gene amplification. It is proposed that the new adjuvant chemotherapies could be directed to carcinomas of the biliary tract in which ErbB-2 and EGFR are overexpressed.
Nasopharyngeal carcinoma (NPC) is known for its high-metastatic potential. Here we report the identification of the proteoglycan serglycin as a functionally significant regulator of metastasis in this setting. Comparative genomic expression profiling of NPC cell line clones with high-and low-metastatic potential revealed the serglycin gene (SRGN) as one of the most upregulated genes in highly metastatic cells. RNAi-mediated inhibition of serglycin expression blocked serglycin secretion and the invasive motility of highly metastatic cells, reducing metastatic capacity in vivo. Conversely, serglycin overexpression in poorly metastatic cells increased their motile behavior and metastatic capacity in vivo. Growth rate was not influenced by serglycin in either highly or poorly metastatic cells. Secreted but not bacterial recombinant serglycin promoted motile behavior, suggesting a critical role for glycosylation in serglycin activity. Serglycin inhibition was associated with reduced expression of vimentin but not other epithelial-mesenchymal transition proteins. In clinical specimens, serglycin expression was elevated significantly in liver metastases from NPC relative to primary NPC tumors. We evaluated the prognostic value of serglycin by immunohistochemical staining of tissue microarrays from 263 NPC patients followed by multivariate analyses. High serglycin expression in primary NPC was found to be an unfavorable independent indicator of distant metastasis-free and disease-free survival. Our findings establish that glycosylated serglycin regulates NPC metastasis via autocrine and paracrine routes, and that it serves as an independent prognostic indicator of metastasis-free survival and disease-free survival in NPC patients. Cancer Res; 71(8); 3162-72. Ó2011 AACR.
c-erb-2 amplification and overexpression are currently attracting a great deal of attention because a new adjuvant therapy using an antibody against the c-erbB-2 gene product, trastuzumab (Herceptin; Genentech, Inc., South San Francisco, CA), has proved effective in treating breast cancer with amplification and/or overexpression of c-erbB-2. Aberrations of c-erbB-2 have also been detected in ovarian, endometrial and gastric carcinomas at varied frequencies. Amplification of the c-erbB-2 locus (17q12-q21.32), overexpression of c-erbB-2 protein (p185) and serum levels of soluble c-erbB-2 protein fragments (p105) were examined in gastric cancer patients using fluorescence in situ hybridization (FISH), immunohistochemistry and enzyme-linked immunosorbent assay (ELISA), respectively. Overexpression of c-erbB-2 protein was found in 29 (8.2%) of the 352 gastric carcinomas analyzed. In FISH analysis, all tumors with 3؉ immunostaining and 1 of 5 tumors with 2؉ staining showed high-level amplification of c-erbB-2. Pre-operative serum p105 was quantified in serum specimens from 129 patients with gastric cancer and 28 patients with benign diseases. There were no significant differences in the serum p105 levels among 11 patients with c-erbB-2-overexpressing carcinomas, 118 patients with c-erbB-2 non-overexpressing carcinomas and 28 controls, although a single case of gastric carcinoma overexpressing c-erbB-2 with extensive liver metastasis had a higher level than the cut-off value. The mechanisms of overexpression of p185 and highlevel amplification of c-erbB-2 in gastric adenocarcinomas seem similar to those well-established in breast cancers. Patients having gastric adenocarcinoma with c-erbB-2 amplification are potential candidates for a new adjuvant therapy using humanized monoclonal antibody.
Overexpression of HER-2 and the epidermal growth factor receptor (EGFR) has been observed in many cancers, sometimes accompanied by gene amplification. To assess whether novel chemotherapies targeting these overexpressed proteins may be effective for the treatment of colorectal cancers, we examined the exact frequency of HER-2 and EGFR overexpression, the relationship between gene amplification and protein expression, and the heterogeneity of gene amplification within and between primary and metastatic tumors. We evaluated 244 colorectal cancers immunohistochemically. All tumors found to overexpress HER-2 or EGFR were further analyzed for gene amplification by fluorescent in situ DNA hybridization. Overexpression of HER-2 and EGFR was found in 8 (3%) and 19 (8%) of the 244 colorectal carcinomas, respectively. Gene amplification was observed in 100 and 58% of the tumors exhibiting HER-2 and EGFR overexpression, respectively. HER-2 amplification in cancer cells was characterized by clusters of hybridization signals, suggesting amplicons in homogeneously staining regions that were predominant in most primary and metastatic tumors. EGFR amplification, observed as scattered signals reminiscent of amplicons in double minute chromosomes, or coamplification of EGFR with the centromeric regions was observed as a minor population within primary tumors, and found in variety of populations in metastatic tumors. Overexpression of HER-2 and EGFR were observed in only a small fraction of colorectal carcinomas, but were frequently accompanied by gene amplification. The HER-2 gene is located on chromosomal region 17q11.2-q12 and the EGFR gene is located on 7p12. These encode 185 kDa (p185) and 170 kDa plasma membrane glycoproteins, respectively. They share approximately 50% overall homology and are composed of an N-terminus extracellular ligand-binding domain, a transmembrane lipophilic segment, and a C-terminus intracellular region containing a tyrosine kinase domain.
The authors' recent discovery that glycogen synthase kinase-3β β β β (GSK-3β β β β) participates in colon cancer cells' survival and proliferation prompted us to investigate whether GSK-3β β β β inhibition alters proliferation of colon cancer cells in vivo.
BACKGROUNDRecently, molecular therapies targeting epidermal growth factor receptor (EGFR) have been developed for clinical use. The current study was conducted to determine 1) the exact frequency of EGFR protein overexpression, 2) the correlation between protein overexpression and EGFR amplification, and 3) the correlation between the status of the genetic and clinicopathologic features in nonsmall cell lung carcinomas (NSCLC).METHODSIn total, 181 NSCLC samples were examined immunohistochemically using an antibody against EGFR, and tumor cells that exhibited overexpression were examined further for EGFR amplification by fluorescence in situ hybridization.RESULTSOverexpression of EGFR protein was found in 34% of the tumors. Among these, EGFR amplification was demonstrated in 74%. High‐level gene amplification was found exclusively in tumors cells with high protein expression. In most of these tumors, cells that exhibited EGFR overexpression and gene amplification were distributed heterogeneously, even within a single tumor nodule. Statistically, EGFR overexpression was correlated significantly with lymph node metastasis and with a more advanced pathologic stage. Moreover, in adenocarcinomas, gene amplification was correlated significantly with lymph node metastasis and tended to be correlated with a more advanced pathologic stage.CONCLUSIONSThe overexpression of EGFR in NSCLC was accompanied predominantly, but not exclusively, by gene amplification. It is important to evaluate not only protein overexpression but also the EGFR status to design adjuvant therapies for patients with NSCLC, because specimens that exhibit both protein overexpression and gene amplification may predict eventual lymph node metastasis and, possibly, aggressive tumor behavior. Cancer 2005. © 2005 American Cancer Society.
The utilisation of antitumour T cells induced by cancer vaccination with HER-2 peptides or antibodies (Herceptin) against HER-2, as immunotherapy for oesophageal cancer, is a novel and attractive approach. It is important to clarify the frequencies of HER-2 expression and gene amplification in patients with oesophageal squamous cell carcinoma (SCC) and to evaluate the relationship between HER-2 status and HLA haplotype, since the candidates for HER-2 peptide-based vaccination are restricted to a certain HLA haplotype. We determined the frequency of HER-2 expression using the HercepTestt for immunohistochemistry and HER-2 gene amplification by fluorescence in situ hybridisation (FISH) assay in oesophageal SCC (n ¼ 66). HER-2-positive tumours (1 þ /2 þ /3 þ ) analysed by a HercepTest were observed in 30.3% of all the patients and HER-2 gene amplification evaluated by FISH was observed in 11.0% of all the patients, in which all HercepTest (3 þ ) tumours were found to have gene amplification and three of six moderately positive (2 þ ) tumours showed gene amplification. Furthermore, HER-2-positive cells were present more diffusely and were larger within each tumour in the patients who were HercepTest 3 þ than those who were HercepTest 1 þ . Moreover, the survival rate in HER-2-positive group was significantly worse than that in HER-2-negative group. Also, the survival rate in the patients with HER-2 gene amplification was significantly worse than that without HER-2 gene amplification. In addition, oesophageal SCC patients with both HLA-A24-positive and HER-2-positive tumours (1 þ /2 þ /3 þ ) accounted for 26% of these cases, and both HLA-A2-and HER-2-positive tumours accounted for 18% of them.
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