HER4 and its cytoplasmic isoforms are associated with progression-free survival of malignant melanoma

Prognostic value of receptor tyrosine kinases in malignant melanoma patients: A systematic review and meta-analysis of immunohistochemistry

Background

Substantial evidence suggests that receptor tyrosine kinases (RTKs) are overexpressed in tumors; however, few studies have focused on the prognostic value of RTKs in melanoma.

Objectives

The objective of this study is to evaluate the association between overexpression of RTKs and survival in melanoma patients based on immunohistochemistry (IHC) analysis.

Methods

Our review is registered on PROSPERO (http://www.crd.york.ac.uk/PROSPERO), registration number CRD42021261460. Seven databases were searched, and data were extracted. We used IHC to measure the association between overexpression of RTKs and overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), and clinicopathology in melanoma patients. Pooled analysis was conducted to assess the differences between Hazard Ratios along with 95% confidence intervals.

Results

Of 5,508 publications examined following the database search, 23 publications were included in this study, which included data from a total of 2,072 patients. Vascular endothelial growth factor receptor 2 (VEGF-R2) overexpression was associated with worse OS and DFS in melanoma. Furthermore, there was an association between OS and the expression of several RTKs, including epidermal growth factor receptor (EGFR), mesenchymal-epithelial transition factor (MET), vascular endothelial growth factor receptor 1 (VEGF-R1), and insulin-like growth factor 1 receptor (IGF-1R). There were no significant correlations between EGFR overexpression and worse DFS or PFS. EGFR overexpression was associated with worse OS cutaneous and nasal melanoma, but not uveal melanoma. However, MET overexpression was related to worse OS in both cutaneous and uveal melanoma. Furthermore, EGFR overexpression was associated with a worse OS in Europe compared to other geographic areas. Moreover, EGFR and MET overexpression showed significant prognostic value in patients with the cut-off “≥10% staining”.

Conclusions

Our findings build concrete evidence that overexpression of RTKs is associated with poor prognosis and clinicopathology in melanoma, highlighting RTK expression has the potential to inform individualized combination therapies and accurate prognostic evaluation.

A Network-Centric Framework for the Evaluation of Mutual Exclusivity Tests on Cancer Drivers

One of the key concepts employed in cancer driver gene identification is that of mutual exclusivity (ME); a driver mutation is less likely to occur in case of an earlier mutation that has common functionality in the same molecular pathway. Several ME tests have been proposed recently, however the current protocols to evaluate ME tests have two main limitations. Firstly the evaluations are mostly with respect to simulated data and secondly the evaluation metrics lack a network-centric view. The latter is especially crucial as the notion of common functionality can be achieved through searching for interaction patterns in relevant networks. We propose a network-centric framework to evaluate the pairwise significances found by statistical ME tests. It has three main components. The first component consists of metrics employed in the network-centric ME evaluations. Such metrics are designed so that network knowledge and the reference set of known cancer genes are incorporated in ME evaluations under a careful definition of proper control groups. The other two components are designed as further mechanisms to avoid confounders inherent in ME detection on top of the network-centric view. To this end, our second objective is to dissect the side effects caused by mutation load artifacts where mutations driving tumor subtypes with low mutation load might be incorrectly diagnosed as mutually exclusive. Finally, as part of the third main component, the confounding issue stemming from the use of nonspecific interaction networks generated as combinations of interactions from different tissues is resolved through the creation and use of tissue-specific networks in the proposed framework. The data, the source code and useful scripts are available at: https://github.com/abu-compbio/NetCentric.

A Review of HER4 (ErbB4) Kinase, Its Impact on Cancer, and Its Inhibitors

HER4 is a receptor tyrosine kinase that is required for the evolution of normal body systems such as cardiovascular, nervous, and endocrine systems, especially the mammary glands. It is activated through ligand binding and activates MAPKs and PI3K/AKT pathways. HER4 is commonly expressed in many human tissues, both adult and fetal. It is important to understand the role of HER4 in the treatment of many disorders. Many studies were also conducted on the role of HER4 in tumors and its tumor suppressor function. Mostly, overexpression of HER4 kinase results in cancer development. In the present article, we reviewed the structure, location, ligands, physiological functions of HER4, and its relationship to different cancer types. HER4 inhibitors reported mainly from 2016 to the present were reviewed as well.

HER4 promotes the progression of colorectal cancer by promoting epithelial‑mesenchymal transition

Colorectal cancer (CRC) remains one of the most common cancer types worldwide. A few previous studies have examined whether HER4 may promote the progression of CRC. The present study examined the associations among the expression levels of members of the HER family, and investigated the potential mechanism underlying the function of HER4 in CRC cells. Immunohistochemistry analysis was conducted to detect the expression levels of HER family members in patients with CRC. HER4 expression was knocked down using short hairpin RNA in HCT116 cells, and confirmed by quantitative PCR and western blotting. The proliferation and adhesion of CRC cells were analyzed by CCK-8 assays and adhesive assays, respectively. Flow cytometry was used to measure cell apoptosis. Western blotting and immunofluorescence staining in CRC cells were performed to identify proteins related to epithelial-mesenchymal transition. The proportion of patients with CRC presenting positive expression of the HER family members epidermal growth factor receptor (EGFR), HER2, HER3 and HER4 were 72.1, 45.2, 43.8 and 34.2%, respectively. No relationship was found between HER4 and EGFR, HER2 or HER3 expression. Higher expression of HER4 was positively associated with lymph node metastasis (P=0.039). In the present study, HER4 expression was found to be associated with an unfavorable clinical outcome in patients with CRC (P_logrank=0.020). Cell proliferation was inhibited, and apoptosis was increased following HER4 knockdown. Furthermore, HER4 knockdown increased the expression of E-cadherin and decreased the expressions of N-cadherin and vimentin (P<0.05). HER4 expression was found to be unrelated to other HER family members. In the present study, positive expression of HER4 promoted the progression of CRC through epithelial-mesenchymal transition.

Diverse roles of epidermal growth factors receptors in oral and cutaneous canine melanomas

BACKGROUND

The epidermal growth factor receptors participate in the physiological processes such as regulation of morphogenesis, proliferation and cell migration, but when overexpressed or overactivated they may play an important role in neoplastic progression. Melanoma is the most aggressive skin neoplasm and is characterized by elevated invasion and low survival rates in both humans and dogs. In human melanomas the overexpression of EGFR, HER3 or HER4 is associated with poor prognosis. In canine melanomas the epidermal growth factor receptors expression has not been evaluated. Therefore, this study evaluated the expression of epidermal growth factor receptors by immunohistochemistry and investigated their relationship with morphological characteristics and proliferative indices in cutaneous and oral canine melanoma.

RESULTS

In cutaneous melanoma an increased proliferative index was associated with increased cytoplasmic HER4 and reduced EGFR and HER3 protein expression. In oral melanomas, membranous HER2 protein expression correlated with occurrence of emboli, but ERBB2 gene amplification wasn't observed.

CONCLUSION

Thus, our work evidenced the relationship between HER4 and the stimulus to cell proliferation in cutaneous melanomas, in addition to the relationship between HER2 and the occurrence of emboli in oral melanomas.

Expressions and clinical significance of HER4 and CD44 in sinonasal mucosal malignant melanoma

Sinonasal mucosal malignant melanoma (SNMMM) is a rare disease. The aim of this study was to investigate the expressions of HER4 and CD44 in human SNMMM tissues and their relationship with the clinicopathological features and prognosis of patients. In total, 64 paraffin-embedded samples of SNMMM treated in our hospital from 29 December 1999 to 24 June 2011 were collected. HER4 and CD44 were detected in the tissues of SNMMM by immunohistochemistry. The differences in the HER4 and CD44 expressions in the tissues were evaluated and matched with clinicopathological parameters and the survival rate, respectively. The positive rates of the HER4 and CD44 expressions were 70.3 and 65.6%, respectively; the positive expression of HER4 was correlated with a positive expression of CD44 (P<0.05). The positive expression of HER4 was correlated with the prognosis of SNMMM patients (P<0.05). There was no significant correlation between a positive expression of CD44 and the prognosis of patients (P>0.05). The expressions of HER4 and CD44 were not significantly correlated with sex, age, pigment, tumor site, etc. (P>0.05). Our results further emphasize a correlation between HER4 and CD44 expressions in SNMMM tissues and point out that a positive HER4 expression might be an important factor in valuing the prognosis of patients with SNMMM.

Gefitinib or lapatinib with foretinib synergistically induce a cytotoxic effect in melanoma cell lines

Melanoma is an aggressive cancer type with a high mortality rate and an elevated resistance to conventional treatment. Recently, promising new tools for anti-melanoma targeted therapy have emerged including inhibitors directed against frequently overexpressed receptors of growth factors implicated in the progression of this cancer. The ineffectiveness of single-targeted therapy prompted us to study the efficacy of treatment with a combination of foretinib, a MET (hepatocyte growth factor receptor) inhibitor, and gefitinib or lapatinib, EGFR (epidermal growth factor receptor) inhibitors. We observed a synergistic cytotoxic effect for the combination of foretinib and lapatinib on the viability and proliferation of the examined melanoma cell lines. This combination of inhibitors significantly decreased Akt and Erk phosphorylation, while the drugs used independently were insufficient. Additionally, after treatment with pairs of inhibitors, cells became larger, with more pronounced stress fibers and abnormally shaped nuclei. We also noticed the appearance of polyploid cells and massive enrichment in the G2/M phase. Therefore, combination treatment was much more effective against melanoma cells than a single-targeted approach. Based on our results, we conclude that both EGFR and MET receptors might be effective targets in melanoma therapy. However, variation in their levels in patients should be taken into consideration.

HER4 isoform CYT2 and its ligand NRG1III are expressed at high levels in human colorectal cancer

The present study aimed to evaluate the expression of human epidermal growth factor receptor (HER4) isoforms and their ligand neuregulin 1 (NRG1) isoforms in human primary colorectal cancer (CRC). The mRNA expression of HER4 isoforms JM-a, JM-b, CYT1 and CYT2, and their ligand isoforms NRG1 I, II and III in CRC tissues and adjacent normal tissues were quantified by reverse transcription-quantitative polymerase chain reaction analysis. Univariate analysis and logistic regression analysis were performed to analyze the association between HER4 and NRG1 expression and lymph node metastasis in CRC. The expression levels of CYT1 (P=0.002), CYT2 (P=0.002) and NRG1 type III (P<0.001) were significantly higher in the CRC tissues than in the adjacent normal tissues. The expression of CYT2 was correlated with tumor stage (P=0.018), lymph node status (P=0.015) and tumor-node-metastasis (P=0.038) in CRC. The expression of NRG1III was correlated with lymph node metastasis, and the expression of CYT2 was associated with the expression of NRG1III (r=0.691, P<0.01). The logistic regression analysis indicated that expression of CYT2 >50 was a risk factor for lymph node metastasis in CRC. In conclusion the expression levels of CYT1, CYT2 and NRG1III were upregulated in CRC. An expression of CYT-2 >50 was identified as a risk factor for lymph node metastasis in CRC. Therefore, CY-2 and NRG1III may be involved in the progression of CRC.

Correlations of EGF G1380A, bFGF C754G and VEGF T460C polymorphisms with malignant melanoma susceptibility and prognosis: A case-control study

This case-control study aims to investigate the correlations of EGF G1380A, bFGF C754G and VEGF T460C polymorphisms with the susceptibility and prognosis of malignant melanoma. A total of 153 patients with multiple primary melanomas were collected as the case group and another 170 healthy individuals were selected as the control group. ELISA and PCR-RFLP were performed to test the serum level of VEGF and to analyze the genotype as well as allele frequencies of VEGF T460C, EGF G1380A, and bFGF C754G, respectively. The patients were assigned into complete remission (CR), partial remission (PR) and non-remission groups after treatment. HE and CD34 staining were conducted in tissue samples of CR and PR patients. Event-free survival (EFS) and overall survival (OS) were measured. AA genotype of EGF G1380A and GG genotype of bFGF C754G had higher frequency distribution in the case group than the control group. Patients with AA genotype of EGF G1380 and GG genotype of bFGF C754G had an elevated VEGF level in comparison to other genotypes. Patients with GA+GG genotypes of EGF G1380A and CG+CC genotypes of bFGF C754G had higher EFS and OS than those with AA genotype and those with GG genotype, respectively. According to the haplotype analysis, the case group had a notably higher frequency of TAG and CAG along with while lower frequency of TGG and CGC compared with the control group. Logistic regression analysis revealed that the polymorphisms of EGF G1380A and bFGF C754G as well as the haploid TAG increased the susceptibility of malignant melanoma. The results indicated that EGF G1380A and bFGF C754G gene polymorphisms were associated with the susceptibility and prognosis of malignant melanoma, and that the polymorphisms of EGF G1380A and bFGF C754G as well as the haploid TAG increased the susceptibility of malignant melanoma.

Quantitative Phosphoproteomics Analysis of ERBB3/ERBB4 Signaling

The four members of the epidermal growth factor receptor (EGFR/ERBB) family form homo- and heterodimers which mediate ligand-specific regulation of many key cellular processes in normal and cancer tissues. While signaling through the EGFR has been extensively studied on the molecular level, signal transduction through ERBB3/ERBB4 heterodimers is less well understood. Here, we generated isogenic mouse Ba/F3 cells that express full-length and functional membrane-integrated ERBB3 and ERBB4 or ERBB4 alone, to serve as a defined cellular model for biological and phosphoproteomics analysis of ERBB3/ERBB4 signaling. ERBB3 co-expression significantly enhanced Ba/F3 cell proliferation upon neuregulin-1 (NRG1) treatment. For comprehensive signaling studies we performed quantitative mass spectrometry (MS) experiments to compare the basal ERBB3/ERBB4 cell phosphoproteome to NRG1 treatment of ERBB3/ERBB4 and ERBB4 cells. We employed a workflow comprising differential isotope labeling with mTRAQ reagents followed by chromatographic peptide separation and final phosphopeptide enrichment prior to MS analysis. Overall, we identified 9686 phosphorylation sites which could be confidently localized to specific residues. Statistical analysis of three replicate experiments revealed 492 phosphorylation sites which were significantly changed in NRG1-treated ERBB3/ERBB4 cells. Bioinformatics data analysis recapitulated regulation of mitogen-activated protein kinase and Akt pathways, but also indicated signaling links to cytoskeletal functions and nuclear biology. Comparative assessment of NRG1-stimulated ERBB4 Ba/F3 cells revealed that ERBB3 did not trigger defined signaling pathways but more broadly enhanced phosphoproteome regulation in cells expressing both receptors. In conclusion, our data provide the first global picture of ERBB3/ERBB4 signaling and provide numerous potential starting points for further mechanistic studies.

Exosomal proteins as potential diagnostic markers in advanced non-small cell lung carcinoma

Background

Lung cancer is one of the leading causes of cancer-related death. At the time of diagnosis, more than half of the patients will have disseminated disease and, yet, diagnosing can be challenging. New methods are desired to improve the diagnostic work-up. Exosomes are cell-derived vesicles displaying various proteins on their membrane surfaces. In addition, they are readily available in blood samples where they constitute potential biomarkers of human diseases, such as cancer. Here, we examine the potential of distinguishing non-small cell lung carcinoma (NSCLC) patients from control subjects based on the differential display of exosomal protein markers.

Methods

Plasma was isolated from 109 NSCLC patients with advanced stage (IIIa–IV) disease and 110 matched control subjects initially suspected of having cancer, but diagnosed to be cancer free. The Extracellular Vesicle Array (EV Array) was used to phenotype exosomes directly from the plasma samples. The array contained 37 antibodies targeting lung cancer-related proteins and was used to capture exosomes, which were visualised with a cocktail of biotin-conjugated CD9, CD63 and CD81 antibodies.

Results

The EV Array analysis was capable of detecting and phenotyping exosomes in all samples from only 10 µL of unpurified plasma. Multivariate analysis using the Random Forests method produced a combined 30-marker model separating the two patient groups with an area under the curve of 0.83, CI: 0.77–0.90. The 30-marker model has a sensitivity of 0.75 and a specificity of 0.76, and it classifies patients with 75.3% accuracy.

Conclusion

The EV Array technique is a simple, minimal-invasive tool with potential to identify lung cancer patients.