Missense Mutations in Exons 18-24 of EGFR in Hepatocellular Carcinoma Tissues

LHPP suppresses proliferation, migration, and invasion in hepatocellular carcinoma and pancreatic cancer by inhibiting EGFR signaling pathway

Phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP) has been reported to be a new tumor suppressor with a significant inhibitory effect in various cancers. Although LHPP has been repeatedly shown to inhibit the progression of various tumors by inhibiting the phosphorylation of AKT, up to now, the studies on the function and mechanism of LHPP in tumors are insufficient. In this study, LHPP expression was found to be downregulated in both hepatocellular carcinoma (HCC) and pancreatic cancer (PC). Here, we found that LHPP could bind to epidermal growth factor receptor (EGFR) and inhibit its phosphorylation, which thereby inhibited the activation of EGFR downstream pathways ERK, AKT, and STAT3, and then weakening the ability to proliferate, invade, and migrate in HCC and PC. This paper showed a new physiological function of LHPP in inhibiting phosphorylation of EGFR and its potential anti-tumor mechanism and indicated that LHPP was a potential therapeutic target for HCC and PC.

The EGFR Polymorphism Increased the Risk of Hepatocellular Carcinoma Through the miR-3196-Dependent Approach in Chinese Han Population

Background

Previous studies have shown that epidermal growth factor receptor (EGFR) promotes cell proliferation through the PI3K-Akt-mTOR signaling pathway and participates in the occurrence and development of hepatocellular carcinoma (HCC). Here, we focused on the functional polymorphism of EGFR in the 3ʹ-untranslated region (UTR), aiming to reveal the potential mechanisms by which functional polymorphism is associated with the risk and development of HCC in the Han Chinese population.

Methods

This study was a hospital-based case-control study. A total of 600 patients were enrolled, and another 600 healthy volunteers served as controls. The miR-associated SNPs in EGFR were screened, and genotyping was performed by TaqMan allele differential analysis. In this study, genotyping, real-time PCR, cell transfection and double luciferase reporter gene were used for subsequent analysis.

Results

HBV/HCV infection instead of alcohol exposure, smoking exposure, hypertension or diabetes mellitus was associated with an increased risk of HCC. Compared with TT genotypes, TG and GG genotypes of EGFR rs884225 were significantly associated with reduced HCC risk. The stratified analysis of association between rs884225 and HCC subgroup feature reveal a highly correlation with tumor size. Furthermore, qRT-PCR confirmed that EGFR rs884225, TG and GG genotypes were more likely to bind to miR-3196 and down-regulate EGFR level in cells, thereby inhibiting cell proliferation.

Conclusion

This study suggested that EGFR rs884225 is associated with a reduced risk of liver cancer and may be a developing biomarker.

Systematically Exploring the Antitumor Mechanisms of Core Chinese Herbs on Hepatocellular Carcinoma: A Computational Study

Objective

Chinese herbs play a positive role in the management of hepatocellular carcinoma (HCC) in China. However, it is not clear which of Chinese herbs are critical for the treatment of HCC. Besides, mechanisms of CCHs in the treatment of HCC remain unclear. Hence, our goal is to identify the core Chinese herbs (CCHs) for treating HCC and explore their antitumor mechanism.

Methods

Firstly, clinical traditional Chinese medicine (TCM) prescriptions for HCC were collected from Chinese National Knowledge Infrastructure (CNKI) database, and then, data mining software was used to identify CCHs. After that, bioactive compounds and corresponding target genes of CCHs were obtained using three TCM databases, and target genes of HCC were acquired from MalaCards and OMIM. Subsequently, common target genes of CCHs and HCC were screened. Moreover, biological functions and pathways were analyzed, and Cytoscape plugin cytoHubba was used to identify hub genes. Finally, prognostic values of hub genes were verified by survival analysis, and the molecular docking approach was utilized to validate the interactions between targets and bioactive compounds of CCHs.

Results

Eight CCHs were determined from 630 prescriptions, and 100 bioactive compounds (e.g., quercetin and luteolin) and 126 common target genes were screened. Furthermore, common target genes of CCHs and HCC were mainly enriched in cancer-associated pathways, and six hub genes with statistical significance in survival analysis were selected as key target genes for molecular docking. Additionally, molecular docking showed that the bioactive compounds docked well with the protein receptors of key target genes.

Conclusion

By combining data mining, network pharmacology, molecular docking, and survival analysis methods, we found that CCHs may play a therapeutic role in HCC through regulating the target genes and pathways related to cancer occurrence and development, angiogenesis, metastasis, and prognosis.

Systematic Elucidation of the Potential Mechanisms of Core Chinese Materia Medicas in Treating Liver Cancer Based on Network Pharmacology

Objective

In this study, the data mining method was used to screen the core Chinese materia medicas (CCMMs) against primary liver cancer (PLC), and the potential mechanisms of CCMMs in treating PLC were analyzed based on network pharmacology.

Methods

Traditional Chinese medicine (TCM) prescriptions for treating PLC were obtained from a famous TCM doctor in Shenzhen, China. According to the data mining technique, the TCM Inheritance Support System (TCMISS) was applied to excavate the CCMMs in the prescriptions. Then, bioactive ingredients and corresponding targets of CCMMs were collected using three different TCM online databases, and target genes of PLC were obtained from GeneCards and OMIM. Afterwards, common targets of CCMMs and PLC were screened. Furthermore, a network of CCMMs bioactive ingredients and common target gene was constructed by Cytoscape 3.7.1, and gene ontology (GO) and signaling pathways analyses were performed to explain the mechanism of CCMMs in treating PLC. Besides, protein-protein interaction (PPI) analysis was used to identify key target genes of CCMMs, and the prognostic value of key target genes was verified using survival analysis.

Results

A total of 15 high-frequency Chinese materia medica combinations were found, and CCMMs (including Paeoniae Radix Alba, Radix Bupleuri, Macrocephalae Rhizoma, Coicis Semen, Poria, and Curcumae Radix) were identified by TCMISS. A total of 40 bioactive ingredients (e.g., quercetin, kaempferol, and naringenin) of CCMMs were obtained, and 202 common target genes of CCMMs and PLC were screened. GO analysis indicated that biological processes of CCMMs were mainly involved in response to drug, response to ethanol, etc. Pathway analysis demonstrated that CCMMs exerted its antitumor effects by acting on multiple signaling pathways, including PI3K-Akt, TNF, and MAPK pathways. Also, some key target genes of CCMMs were determined by PPI analysis, and four genes (MAPK3, VEGFA, EGF, and EGFR) were found to be correlated with survival in PLC patients.

Conclusion

Based on data mining and network pharmacology methods, our results showed that the therapeutic effect of CCMMs on PLC may be realized by acting on multitargets and multipathways related to the occurrence and development of PLC.

HCC-derived EGFR mutants are functioning, EGF-dependent, and erlotinib-resistant

Background

Epidermal growth factor receptor (EGFR) has emerged as an important therapeutic target. Overexpression of EGFR is frequently observed in hepatocellular carcinoma (HCC) and EGFR activation has been proven to be a potential determinant of primary resistance of HCC cells to sorafenib. In our previous study, we found 13 missense mutations in EGFR exon 19-23 from hepatocellular carcinoma (HCC) tissues, but the functions of these mutations have not been determined. This study aims to determine the kinase activity and sensitivity to erlotinib, a 1st-generation EGFR-tyrosine kinase inhibitor (TKI), of seven HCC-derived mutants (K757E, N808S, R831C, V897A, P937L, T940A, and M947T).

Results

Using transduction of pBabe-puro retroviral vector with or without EGFR, we constructed and determined the function of EGFRs in NIH-3T3 cells stably harboring each of the seven mutants, as well as the erlotinib-sensitive L858R-mutant, the erlotinib-resistant T790M-mutant, and EGFR wild type (WT). Our results indicate that the seven mutants are functioning, EGF-dependent, EGFRs. Cells harboring six of the seven mutants could generate some level of EGFR phosphorylation in the absence of EGF, indicating some constitutive kinase activity, but all of the seven mutants remain primarily EGF-dependent. Our results demonstrate that erlotinib induces differential degree of apoptosis and autophagy among cells harboring different EGFRs: complete apoptosis and autophagy (cleavage of both caspase-3 and PARP, and marked LC3-II increment) in L858R-mutant; partial apoptosis and autophagy (only cleavage of caspase-3, and moderate LC3-II increment) in WT and HCC-derived mutants; and no apoptosis and minimal autophagy (no cleavage of caspase-3 and PARP, and minimal LC3-II increment) in T790M-mutant. The seven HCC-derived mutants are erlotinib-resistant, as treatment with erlotinib up to high concentration could only induce partial inhibition of EGFR phosphorylation, partial or no inhibition of AKT and ERK phosphorylation, and partial apoptosis and autophagy.

Conclusion

The seven HCC-derived EGFR mutants in this study are functioning, EGF-dependent, and erlotinib-resistant. Erlotinib induces differential degree of apoptosis and autophagy among cells harboring different EGFRs. The degree of inhibition of EGFR phosphorylation by erlotinib is the determining factor for the degree of apoptosis and autophagy amongst cells harboring EGFR mutants. This study paves the way for further investigation into the sensitivity of these HCC-derived mutants to the 3rd-generation irreversible EGFR-TKI, osimertinib.

Afatinib, an EGFR inhibitor, decreases EMT and tumorigenesis of Huh‑7 cells by regulating the ERK‑VEGF/MMP9 signaling pathway

Transcatheter arterial embolization (TAE) therapy has been used in the treatment of inoperable hepatocellular carcinoma (HCC). However, tumor recurrence and metastasis are common in patients after TAE, and these processes may be caused by circulating tumor cells (CTCs). Epithelial-mesenchymal transition (EMT) serves important roles in CTCs, and abnormal expression and activation of epidermal growth factor receptor (EGFR) is common in cancer cells. Afatinib is an EGFR-tyrosine kinase inhibitor (TKI). The present study aimed to investigate the effects of afatinib on EMT and tumorigenesis in HCC cells. Western blot analysis suggested that afatinib was able to effectively suppress overactivation of EGFR. Moreover, the expression levels of EMT- and metastasis-associated genes were found to be modulated by afatinib through EGFR inhibition. In addition, Cell Counting Kit-8 and Transwell assays suggested that the viability, migration and invasion of HCC cells were inhibited by afatinib through EGFR inhibition. Furthermore, the activity of the ERK signaling pathway and the expression levels of vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP9) were decreased following treatment with afatinib in vitro. Collectively, the present results suggested that the inhibitory effects of afatinib on EMT and tumorigenesis may be associated with the ERK-VEGF/MMP9 signaling pathway. The present study provides new insights into understanding the mechanism underlying HCC and may facilitate the development of novel therapeutic strategies to treat HCC recurrence.

Immunohistochemical Expression of Epidermal Growth Factor Receptor in Hepatocellular Carcinoma

INTRODUCTION

Epidermal growth factor receptor (EGFR) signaling plays an important role in various cancers, including hepatocellular carcinoma (HCC). We aimed to evaluate immunoexpression of EGFR in HCC and surrounding non-tumor liver tissue and to correlate it to multiple clinicopathologic data.

MATERIAL AND METHODS

We analyzed 60 patients with HCC for multiple clinicopathologic characteristics and survival. Presence of the immunosignal and the percentage of positive tumor cells at the whole tumor tissue sample and adjacent cirrhotic liver tissue were semi-quantitatively determined.

RESULTS

Nineteen patients (31.67%) were female and 41 (68.33%) were male ranging in age from 31 to 85 years, median 61.88±10.51. Mean survival time for female patients was 8.86±1.76 months, for male 13.03±1.50 months and overall survival was 11.6051±1.19 months. The most patients had: T2 status (41.67%), no enlarged lymph nodes (90%), vascular invasion (63.33%) and well differentiated (43.33%) tumors. EGFR immunoexpression was determined in range from 0% to 100% in both tumor and non-tumor tissue with mean value of 39.58% in tumor and 86.86% in cirrhotic tissue (p<0.00). Higher percent of tumor EGFR positive cells were found in cases with higher T status, higher levels of AFP and poorly differentiated carcinoma, but not significantly. Lower percent of tumor EGFR positive cells were found in patients with vascular invasion and enlarged lymph nodes, but also not significantly. EGFR expression in tumor tissue significantly influenced survival of the patients (p<0.05).

CONCLUSION

The study showed that expression of EGFR in lower percentage of tumor cells was associated to favorable prognosis, making it a potential prognostic marker and therapeutic target.

FGF8 promotes cell proliferation and resistance to EGFR inhibitors via upregulation of EGFR in human hepatocellular carcinoma cells

Fibroblast growth factor 8 (FGF8), a member of the fibroblast growth factor (FGF) family, is upregulated in several human cancers, including HCC (HCC). Previous studies have demonstrated that FGF8 increased cell growth and invasion of tumor cells. In the present study we investigated whether FGF8 is involved in the cell proliferation and resistance to several drugs in human HCC cells. We stably overexpressed FGF8 by lentiviral transfection. In addition, we also added recombinant FGF8 instead of stably overexpressing FGF8 in human HCC cells. Stable overexpression of FGF8 or exogenous recombinant FGF8 resulted in significantly enhanced cell proliferation in human HCC cells. With the use of CellTiter-Glo assay for the determination of cell viability, we found that FGF8 increased the resistance to epidermal growth factor receptor (EGFR) inhibitors in human HCC cells. Additionally, the expression of EGFR was also upregulated by stably overexpressing FGF8 or exogenous recombinant FGF8. Yes-associated protein 1 (YAP1) was reported to upregulate the expression of EGFR. Moreover, we also found that FGF8 increased the expression of YAP1 and knockdown of YAP1 eliminated the upregulation of EGFR and the resistance to EGFR inhibition induced by FGF8. Our study provides evidence that FGF8 plays an important role in the resistance to EGFR inhibition of human HCC cells.