Serum levels of c-erbB-2 protein in digestive diseases

Recognition of HER2 expression in hepatocellular carcinoma and its significance in postoperative tumor recurrence

Background

The ERBB2 oncogene hypothesis is challenged in hepatocellular carcinoma (HCC) with the conflicting evidences of human epidermal growth factor receptor 2 (HER2) overexpression. HER2 could be a new target as a treatment option for HCC as well as tumor recurrence after surgery. HER2 in HCC biology needs further explorations.

Methods

Clinical and mRNA data of HCC patients were obtained from TCGA HCC cohort, GSE89377 and GSE115018. Western Blotting and immunohistochemistry were employed to test expression of HER2, E‐cadherin, and Vimentin. In HepG2, JM1, HER2‐transfected McA cells, and TGF‐β cocultured JM1 cells, HCC biology, including cell survival, proliferation, and epithelial‐to‐mesenchymal transition (EMT) phenotypes were evaluated.

Results

ERBB2 mRNA amplification was found in HCC datasets, and its expression was downregulated in high grade HCC with a worse overall survival. HER2 overexpression was identified in H4IIE, HepG2, JM1 cells, and 82% (14/17) HCC samples, and tumor stage was correlated with expression of HER2, E‐cadherin, and Vimentin (P < 0.05). Trastuzumab with the high concentrations suppressed proliferation of HER2‐positive hepatoma cells (P < 0.05); in the coculture model to induce EMT of JM1 cells, HER2 expression increased with downregulated E‐cadherin and upregulated Vimentin. Trastuzumab intravenous injection inhibited in vivo tumor size and metastases (P < 0.05). Signal analysis revealed that HER2 functioned through upregulation of β‐catenin and inhibition of SMAD3.

Conclusion

HER2 expression pattern is linked with tumor stage and overall survival; the transforming function of HER2 is found more relevant through β‐catenin and SMAD3. HER2‐targeted treatment is recommended to suppress the HER2‐mediated tumor growth during postoperative liver regeneration.

Survival and inflammation promotion effect of PTPRO in fulminant hepatitis is associated with NF-κB activation

Previous investigations demonstrated that protein tyrosine phosphatase, receptor type, O (PTPRO) acts as a tumor suppressor in liver cancer; however, little is known about its role in liver inflammation. Thus, we investigated the role of PTPRO in fulminant hepatitis (FH) using a Con A-induced mouse model. Significantly more severe liver damage, but attenuated inflammation, was detected in PTPRO-knockout (KO) mice, and PTPRO deficiency could confer this phenotype to wild-type mice in bone marrow transplantation. Moreover, hepatocytes with PTPRO depletion were more sensitive to TNF-α-induced apoptosis, and secretion of cytokines was significantly decreased in both T and NK/NKT cells and led to marked impairment of NF-κB activation. Intriguingly, wild-type and PTPRO-KO cells responded equally to TNF-α in activation of IKK, but NF-κB activation was clearly decreased in PTPRO-KO cells. PTPRO associated with ErbB2, and loss of PTPRO potentiated activation of the ErbB2/Akt/GSK-3β/β-catenin cascade. Increased β-catenin formed a complex with NF-κB and attenuated its nuclear translocation and activation. Importantly, in humans, PTPRO was much decreased in FH, and this was associated with enhanced β-catenin accumulation but reduced IFN-γ secretion. Taken together, our study identified a novel PTPRO/ErbB2/Akt/GSK-3β/β-catenin/NF-κB axis in FH, which suggests that PTPRO may have therapeutic potential in this liver disease.

Serial Serum HER2 Measurements for the Detection of Breast Cancer Recurrence in HER2-Positive Patients

Purpose

The measurement of serum human epidermal growth factor receptor 2 (HER2) extracellular domain levels is a well-established method for evaluating whether a metastatic HER2-positive breast cancer patient will respond to HER2-targeted treatment. However, little is known about the value of serum HER2 for detecting disease relapse following curative surgical treatment in breast cancer patients. The purpose of this study was to evaluate the sensitivity of serum HER2, carcinoembryonic antigen (CEA), and carcinoma antigen 15-3 (CA 15-3) for the detection of disease recurrence in postoperative breast cancer patients with a primary HER2-positive tumor.

Methods

Serial measurements were taken of serum HER2, CEA, and CA 15-3 levels in patients with primary invasive HER2-positive breast cancer who underwent curative surgical treatment between January 2008 and December 2010. Following treatment, serum HER2 levels were monitored every 6 months using a chemiluminescence immunoassay.

Results

Overall, 264 patients were analyzed in this retrospective study. The median follow-up period was 27.7 months, and 24 patients relapsed during follow-up. The sensitivity of serum HER2, CEA, and CA 15-3 for the detection of disease recurrence was 37.5%, 25.1%, and 12.5%, respectively. Sensitivity increased to 45.8% when all three tumor markers were combined in the analysis. In a subgroup of patients without liver disease, the sensitivity of serum HER2, CEA, and CA 15-3 was 57.1%, 21.4%, and 14.3%, respectively. Of the 264 patients in this study, 80 patients had chronic hepatitis, liver cirrhosis, or abnormal aspartate aminotransferase or alanine aminotransferase levels during the follow-up period. Following the exclusion of these patients, the sensitivity of serum HER2 for the detection of disease recurrence increased to 57.1%.

Conclusion

Serial serum HER2 measurement may be useful for the detection of disease relapse in patients with HER2-positive breast cancer. Abnormal liver function can result in elevated serum HER2 in the absence of disease recurrence.

Increased plasma concentrations of tumour markers in the absence of neoplasia

Tumour markers are a very heterogeneous group of molecules that are generally found in very small concentrations in the plasma and serum of healthy individuals. In the process of neoplastic differentiation the cell can synthesize, release, or induce synthesis of other cells, thus increasing their concentration in plasma and serum. These substances may also increase their plasma concentration in patients without cancer due to processes that increase the release or reduce catabolism, and so give rise to false positives. An understanding of the main physiopathological processes that increase the concentrations of these substances could improve our interpretation of tumour markers and their clinical application. In this study we review the physiopathological processes that may increase the plasma concentrations of tumour markers. We performed a bibliography review in PubMed, searching for causes of false positives for the following tumour markers: α-Fetoprotein, CA 125, CA 15-3, CA 19-9, CA 72-4, carcinoembryonic antigen, CYFRA 21-1, squamous cell carcinoma, prostatic specific antigen, β(2)-microglobulin, choriogonadotropin (β chain), chromogranin A, neuron specific enolase, HER2-neu, progastrin releasing peptide, S-100, and thyroglobulin. The results favour the use of tests which can identify pathological processes that may increase tumour marker concentrations.

Antiangiogenesis gene armed tumor-targeting adenovirus yields multiple antitumor activities in human HCC xenografts in nude mice

AIM

Gene therapy represents a promising therapeutic strategy for hepatocellular carcinoma (HCC). To improve the ratio of killing efficacy on tumor cells to side-effect on normal cells, we constructed an oncolytic adenovirus vector, AdSu-hE, expressing the human endostatin (hE) gene, in which the chimeric promoter of human epidermal growth factor receptor 2 enhancer and human telomerase reverse transcriptase promoter was used to control the adenoviral E1a gene.

METHODS

Tumor-selective replication of adenovirus AdSu-hE and its concomitant expression of endostatin were measured by 50% tissue culture infective dose method, fluorescent protein expression, Western blot and enzyme linked immunosorbent assay in cancer and normal cell lines. The antitumor efficacy was observed in nude mice bearing human HCCs.

RESULTS

The oncolytic adenovirus AdSu-hE replicated restrictedly in telomerase-positive cancer cells and resulted in oncolysis, but did not replicate in normal cell lines. Along with virus replication, AdSu-hE mediated 5-fold increased expression of endostatin in tumor cells compared with that in normal cells. Moreover, AdSu-hE expressed more endostatin in cancer cells than the non-replicative adenovirus vector Ad-hE. In vivo administration of the oncolytic adenovirus AdSu-hE into HCC-bearing nude mice produced a significant tumor reduction by synergistic effects of virus oncolysis and endostatin antiangiogenesis.

CONCLUSION

The oncolytic virus with antiangiogenesis gene driven by the chimeric promoter has an improved killing efficacy on tumor cells, and may be useful for cancer gene therapy.

Increased expression of ErbB-2 in liver is associated with hepatitis B x antigen and shorter survival in patients with liver cancer

Hepatitis B x antigen, or HBxAg, contributes importantly to the pathogenesis of hepatocellular carcinoma (HCC). Given that HBxAg constitutively activates beta-catenin and that upregulated ErbB-2 promotes beta-catenin signaling in other tumor types, experiments were designed to ask whether HBxAg was associated with upregulated expression of ErbB-2. When HBxAg positive and negative HepG2 cells were subjected to proteomics analysis, ErbB-2 was shown to be upregulated in HepG2X but not control cells. ErbB-2 was also strongly upregulated in HB infected liver, and weakly in some HCC nodules, where it correlated with HBxAg expression. Among tumor bearing patients, strong ErbB-2 staining in the liver was associated with dysplasia, and a shorter survival after tumor diagnosis. This implies that elevated ErbB-2 is an early marker of HCC. Treatment of HepG2X cells with ErbB-2 specific siRNA not only reduced ErbB-2 expression, but also reduced the expression of beta-catenin, suggesting that ErbB-2 contributed to the stabilization of beta-catenin. ErbB-2 specific siRNA also partially blocked the ability of HBxAg to promote DNA synthesis and growth of HepG2 cells. These results suggest that ErbB-2/beta-catenin up-regulation contributes importantly to the mechanism of HBxAg mediated hepatocellular growth.

Value and Limitations of Measuring HER-2 Extracellular Domain in the Serum of Breast Cancer Patients

The human epidermal receptor-2 (HER-2) is overexpressed or amplified in 15% to 25% of breast cancers. Determination of HER-2 tumor status offers clinically useful information, as it selects patients who may benefit from treatment with trastuzumab, the monoclonal antibody against HER-2. Currently approved methods for HER-2 testing include immunohistochemistry or fluorescent in situ hybridization using tumor tissue. A fragment of HER-2 composed of its extracellular domain (ECD) can also be detected in the serum of some patients with breast cancer. As an easily accessible tumor marker, it could offer additional useful prognostic or predictive information. This review will briefly address the biology of the circulating HER-2 ECD and discuss the evidence to support the role, if any, for measuring HER-2 ECD levels in women with breast cancer. In particular, we focus on the value and limitations of serum ECD in both early and advanced breast cancer in the following clinical contexts: as a marker of HER-2 tumor tissue status; clinical implications of raised levels in women who have a tumor not overexpressing HER-2; as a prognostic indicator and as a predictor of response to treatment; and as a monitoring tool for early recurrence. On the basis of our review of the literature, we conclude that there is currently insufficient evidence to support the use of serum HER-2 ECD in the routine management of individual patients with breast cancer. This conclusion is in agreement with the 2007 American Society of Clinical Oncology guidelines on the use of biomarkers in breast cancer.

c-erbB-2 protein in serum of primary lung cancer patients

We determined c-erbB-2 protein level in serum of 86 primary lung cancer patients (78 non-small cell lung carcinomas (NSCLC), 3 small cell carcinomas, 5 not histologically defined) and in 61 controls. Aim of this study was to evaluate the clinical usefulness of c-erbB-2 as marker for lung cancer diagnosis. The protein was measured with a commercially available sandwich enzyme immunoassay. Mean levels of c-erbB-2 were 72.8 +/- 122.3 fmol/ml in lung cancers and 64.6 +/- 17.5 fmol/ml in controls (P = 0.2). No association was found between c-erbB-2 levels and histotype, tumor stage, sex and smoking habits. Among NSCLC, only four patients showed a c-erbB-2 concentration higher than the selected cut-off value of 99.6 fmol/ml. Subjects with levels higher than the 75th percentile in tumors (73 fmol/ml) had a shorter median survival than those with lower levels (6.3 months versus 10.0 months, P = 0.003). Our results indicated that serum c-erbB-2 protein is not a reliable diagnostic marker. There is, however, a suggestion of a possible clinical usefulness in terms of survival prediction.