Association of epidermal growth factor receptor (EGFR) gene polymorphism with lung cancer risk: a systematic review

Application of the conventional and novel methods in testing EGFR variants for NSCLC patients in the last 10 years through different regions: a systematic review

Variants in the epidermal growth factor receptor (EGFR) gene are recognized as predictors of therapy response and are correlated with progression-free and overall survival in non-small cell lung cancer (NSCLC) patients. Molecularly guided therapy needs precise and cost-effective molecular tests. This review focused primarily on screening or target methods for the EGFR variants detection with diagnostic and prognostic potential in the clinical research published papers. Concerning the inclusion and exclusion criteria, the search interval comprised available articles published from 2010 until 2020 in three electronic databases, ISI Web of Science, Pub Med, and Scopus. The analysis of eligible studies started with 5647 and obtained the final 987 full-text articles analyzed as clinical research. The regions comprised were Africa, America, Australia, Asia, Euro-Asia, Europe, or a consortium of different countries. All of the tested methods were applied prevalently in Asia. In clinical research, the polymerase chain reaction (PCR), followed by sequencing methods have been involved mostly over the years. The identified high-through output approaches evolved to improve the survival and quality of the NSCLC patient's life becoming more sensitive, specific, and cost-effective.

Association of HIF1-α gene polymorphisms with advanced non-small cell lung cancer prognosis in patients receiving radiation therapy

We investigated the association between single nucleotide polymorphisms (SNPs) in the HIF1A gene and the prognosis of advanced non-small cell lung cancer (NSCLC) patients undergoing radiation therapy. Patient overall survival (OS) and progression-free survival (PFS) were analyzed. The rs11549465 TT genotype was associated with poor PFS (P<0.001) and OS (P=0.001). The rs2057482 TT genotype was also associated with poor PFS (P=0.002) and OS (P=0.007). Stratified analyses revealed that these associations occurred in patients with a smoking history, squamous cell carcinoma, and stage IIIA disease, as well as those receiving radiation therapy a radiation dose of ≥70 Gy. We found associations between SNPs and PFS but not OS in patients without a smoking history, other histological types, and stage IIIB disease, as well as those undergoing chemoradiotherapy with a radiation dose of <70 Gy. No associations were observed between rs11549467 or rs110873142 and NSCLC prognosis. These results suggest that HIF1A polymorphisms can be used as independent prognostic biomarkers for NSCLC patients receiving radiation therapy.

miR-210-3p regulates the proliferation and apoptosis of non-small cell lung cancer cells by targeting SIN3A

Previous studies have indicated that microRNA (miR)-210-3p is upregulated in NSCLC, however, the specific mechanism underlying the role of miR-210-3p in NSCLC pathogenesis requires further investigation. The aim of the present study was to explore the roles of miR-210-3p in NSCLC and the associated mechanisms. A total of 30 NSCLC tissues and paired adjacent normal tissues were collected for study. Reverse transcription-quantitative polymerase chain reaction was performed to compare the expression of miR-210-3p in the 30 paired cancerous and adjacent normal tissues. Additionally, the expression of miR-210-3p in different NSCLC lines and normal human lung epithelial cell line BEAS-2B were also compared. Furthermore, A549 and H1299 NSCLC cells were cultured and transfected with miR-210-3p inhibitors, and MTT and propidium iodide/annexin V assays were performed to investigate the effects of miR-210-3p inhibition on the proliferation and apoptosis of the cells. RT-qPCR and western blot analyses were also performed to determine the effects of miR-210-3p on the expression levels of SIN3A, B-cell lymphoma 2 (Bcl-2) and Caspase-3. Finally, a reverse experiment was conducted by transfecting A549 cells with miR-210-3p inhibitor and SIN3A small interfering (si)RNA, and a dual-luciferase reporter assay was performed to confirm that SIN3A is a direct target of miR-210-3p. It was observed that miR-210-3p was significantly upregulated in NSCLC tissues compared with the levels in the adjacent normal tissues, and that the expression of miR-210-3p in patients with NSCLC was negatively correlated with the expression of SIN3A in NSCLC tissue. miR-210-3p was also significantly upregulated in different NSCLC cell lines compared with the levels in BEAS-2B cells. The transient downregulation of miR-210-3p in A549 cells led to a significant suppression of cell proliferation and markedly increased cell apoptosis, as well as increased the expression of SIN3A and Caspase-3 and decreased the expression of Bcl-2. On the other hand, co-transfection of miR-210-3p inhibitor and SIN3A siRNA partially blocked miR-210-3p inhibitor-induced pro-apoptotic effects. The results of the dual-luciferase reporter assay demonstrated that SIN3A is a direct target of miR-210-3p. Collectively, these findings indicate that can regulate the proliferation and apoptosis of NSCLC cells by targeting SIN3A. These results suggest that miR-210-3p has the potential to become a novel therapeutic target for the treatment of NSCLC.

The Association between Epidermal Growth Factor Receptor Single Nucleotide Polymorphisms and Radiochemotherapy Response in Cervical Cancer

Emerging data reveal that epidermal growth factor receptor (EGFR) single nucleotide polymorphisms (SNPs) can act as efficacy indicators for tumor treatment. Here, the association between EGFR R497K (rs11543848) and -216G/T (rs712829) SNPs and radiochemotherapy response in cervical cancer was investigated. EGFR R497K and -216G/T genotypes were analyzed by polymerase chain reaction-ligation detection reaction in 196 cervical cancer patients receiving radiotherapy alone, or in combination with chemotherapy. Compared with the 497G/G genotype, the A/A genotype significantly increased sensitivity to radiochemotherapy treatment (adjusted OR = 0.244, 95% CI = 0.087-0.680). Sensitivity to radiochemotherapy was not significantly different in carriers of the 'T' allele than that measured for the -216G/G genotype (adjusted OR = 2.412, 95% CI = 0.856-6.979). Additionally, the 497A/A genotype conferred a reduced risk of recurrence or metastasis than did the G/G genotype (adjusted OR = 0.248, 95% CI = 0.078-0.786, P < 0.05). Moreover, carriers of the 'T' allele did not have significantly modified risk of recurrence or metastasis compared with those with the -216G/G genotype (adjusted OR = 1.027, 95% CI = 0.324-3.253). Multivariate analysis revealed an association between clinical stage and treatment response (adjusted OR = 3.575, 95% CI = 1.662-7.692) and between age and the risk of recurrence or metastasis (adjusted OR = 0.319, 95% CI = 0.148-0.691). Our results show that, in patients with cervical cancer, the R497K polymorphism is correlated with treatment response and the risk of recurrence or metastasis. The R497K SNP might be a genetic marker for prediction of radiochemotherapy response and the risk of recurrence and/or metastasis in patients with cervical cancer.

Effects of miR‑138‑5p and miR‑204‑5p on the migration and proliferation of gastric cancer cells by targeting EGFR

GC (gastric cancer) remains one of the most lethal malignancies worldwide. EGFR (epidermal growth factor receptor) plays an important role in the malignant process of GC, therefore, the present study addressed the relationship between EGFR and its potential regulators and examined their regulatory mechanisms in GC. We examined differences in the expression levels of EGFR in GC and adjacent non‑cancerous tissues. Bioinformatics analyses and dual luciferase reporter assays were used to confirm the putative relationship between miR‑138 or miR‑204 and EGFR, and their relationship was further detected using western blotting, RT‑PCR, and a series of cell studies. EGFR proteins were abundantly expressed in GC tissues, however EGFR mRNA levels remained indistinctive. Consequently, EGFR was revealed as a putative target of miR‑138 and miR‑204 which bound to the 3'UTR of EGFR mRNA. Further analysis revealed that miR‑138 and miR‑204 were significantly downregulated in GC tissues and the overexpression of miR‑138 and miR‑204 in GC cell lines resulted in the significant inhibition of EGFR protein levels and GC cell proliferation and metastasis. Rescue experiments confirmed that the roles of the two microRNAs were specific to EGFR. EGFR is a pivotal oncogene in GC progression that may be regulated by miR‑138 and miR‑204.

Anti-proliferation effects, efficacy of cyasterone in vitro and in vivo and its mechanism

Cyasterone was demonstrated potential inhibition effect in mouse skin carcinoma cells in published report. However, the molecular mechanisms of the cyasterone on cells remain unknown. Herein, we investigated the effects of cyasterone-induced apoptosis in A549 and MGC823 cells in vitro. MTT assay showed that cyasterone caused a significantly decreasing of the proliferation of A549 and MGC823 cells in a time-and dose-dependent manner with IC₅₀ values of 38.50±3.73μg/mL on A549 cells and 32.96±1.24μg/mL on MGC823 cells at 48h, respectively. Hoechst staining and TUNEL staining results indicated the quintessential apoptosis features in immunofluorescence image. Apoptosis and cell cycle were determined by flow cytometry. Cyasterone treatment triggered inhibition of epidermal growth factor receptor- phosphatidylinositol 3 kinase/protein kinase B (EGFR-AKT) signaling pathways and activation of P38 pathways. Furthermore, cyasterone inhibited MGC823 cells xenografted tumor growth in vivo with few changes in body weights. In conclusion, our findings provide the evidence that cyasterone inhibits growth of A549 and MGC823 cells, via regulating EGFR signaling pathway. Our results indicated that cyasterone, a natural EGFR inhibitor, maybe a promising anti-cancer agent.