Correlations between EGFR gene polymorphisms and pleural metastasis of lung adenocarcinoma

Identification of nine mutant genes and establishment of three prediction models of organ tropism metastases of non-small cell lung cancer

BACKGROUND

Most Non-small cell lung cancer (NSCLC) patients tend to have metastases at the initial diagnosis. However, limited knowledge has been established regarding which factors, are associated with its metastases. This study aims to identify more biomarkers associated with its organ tropism metastasis and to establish models for prediction of its metastatic organs.

METHODS

We performed targeted next-generation sequencing (NGS) to detect genes related to lung cancer in 272 patients with primary advanced NSCLC from Northeast China. We adopted Fisher test, multivariate logistic regression analysis to identify metastasis-related gene mutations and to establish prediction models.

RESULTS

Mutations of EGFR (p = 0.0003, OR = 2.554) (especially EGFR L858R [p = 0.02, OR = 2.009]), ATM (p = 0.008, OR = 11.032), and JAK2 (p = 0.009, OR = Inf) were positively and of TP53 exon4mut (p = 0.001, OR = 0.173) was negatively correlated with lung metastasis, and those of CSF1R (p = 0.01, OR = Inf), KIT (p = 0.03, OR = 4.746), MYC (p = 0.05, OR = 7.938), and ERBB2 (p = 0.02, OR = 2.666) were positively correlated with pleural dissemination; those of TP53 (p = 0.01, OR = 0.417) was negatively, while of SMAD4 (p = 0.03, OR = 4.957) was positively correlated with brain metastasis of NSCLC. Additionally, smoking history (p = 0.004, OR = 0.004) was negatively correlated with pleural dissemination of NSCLC. Furthermore, models for prediction of lung metastasis (AUC = 0.706), pleural dissemination (AUC = 0.651), and brane metastasis (AUC = 0.629) were established.

CONCLUSION

Taken together, this study revealed nine mutant genes and smoking history associated with organ tropism metastases of NSCLC and provided three models for the prediction of metastatic organs. This study enables us to predict the organs to which non-small cell lung cancer metastasizes before it does develop.

Polymorphisms in EGFR Gene Predict Clinical Outcome in Unresectable Non-Small Cell Lung Cancer Treated with Radiotherapy and Platinum-Based Chemoradiotherapy

For non-small cell lung cancer (NSCLC), radiotherapy (RT) and platinum-based chemotherapy (CHT) are among the main treatment options. On the other hand, radioresistance and cytotoxic drug resistance are common causes of failure. The epidermal growth factor receptor (EGFR) plays an important role in radioresponse and therapy resistance. We hypothesized that single nucleotide polymorphisms (SNPs) in the EGFR gene might affect individual sensitivity to these treatments, and thus, therapy outcome and prognosis. The association between functional EGFR SNPs and overall (OS), locoregional recurrence-free (LFRS), and metastasis-free (MFS) survival was examined in 436 patients with unresectable NSCLC receiving RT and platinum-based CHTRT. In a multivariate analysis, the rs712830 CC homozygotes showed reduced OS in the whole group (p = 0.039) and in the curative treatment subset (p = 0.047). The rs712829 TT genotype was strongly associated with decreased LRFS (p = 0.006), and the T-C haplotype was a risk factor for locoregional recurrence in our patients (p = 0.003). The rs2227983 GG alone and in combination with rs712829 T was an indicator of unfavorable LRFS (p = 0.028 and 0.002, respectively). Moreover, significant independent effects of these SNPs on OS, LRFS, and MFS were observed. Our results demonstrate that inherited EGFR gene variants may predict clinical outcomes in NSCLC treated with DNA damage-inducing therapy.

Ginsenoside Rg3 inhibits the migration and invasion of liver cancer cells by increasing the protein expression of ARHGAP9

Ginsenoside Rg3, a naturally occurring phytochemical, serves an important role in the prevention and treatment of cancer. In the present study, with the aim to reveal the molecular mechanism of Rg3 in liver cancer cell metastasis, the anti-migration and anti-invasion effects of Rg3 on liver cancer cells were investigated. It was demonstrated that Rg3 caused marked inhibition of cell migration and invasion of human liver cancer cells, HepG2 and MHCC-97L, in vitro, and the growth of HepG2 and MHCC-97L tumors in BABL/c nude mice. The protein expression of Rho GTPase activating protein 9 (ARHGAP9) was increased both in HepG2 and MHCC-97L cells. Following ARHGAP9 knockdown, the results of Transwell and tumorigenesis assays revealed that the anti-migration, anti-invasion and anti-tumor growth effects of Rg3 were impaired significantly. The increased expression of ARHGAP9 protein induced by Rg3 was remarkably suppressed. All results suggested that ARHGAP9 protein may be a vital regulator in the anti-metastatic role of Rg3. To the best of our knowledge, the present study is the first to report that Rg3 effectively suppressed the migration and invasion of liver cancer cells by upregulating the protein expression of ARHGAP9, indicating a novel natural therapeutic agent and a therapeutic target for the treatment of liver cancer.

Epidermal Growth Factor Receptor Gene in Non-Small-Cell Lung Cancer: The Importance of Promoter Polymorphism Investigation

Recently, epidermal growth factor receptor (EGFR) was a key molecule in investigation of lung cancer, and it was a target for a new therapeutic strategy, based on molecular analyses. In this review, we have summarized some issues considering the role of EGFR in lung cancer, its coding gene, and its promoter gene polymorphisms (SNPs) -216G/T and -191C/A in non-small-cell lung cancer (NSCLC). The position of the SNPs indicates their significant role in EGFR regulation. The accumulation of knowledge regarding SNPs lately suggests their significant and important role in the onset of carcinogenesis, the prediction of the onset of metastases, the response to therapy with TKI inhibitors, and the onset of toxic effects of the applied therapy. Based on this, we suggest further studies of the relationship of clinical significance to SNPs in patients with lung tumors.

The Impact of EGFR Gene Polymorphisms on the Risk of Alzheimer's Disease in a Chinese Han Population: A Case-Controlled Study

BACKGROUND The aim of this study was to investigate the association between polymorphisms of the epidermal growth factor receptor (EGFR) gene with the risk of Alzheimer's disease (AD) in a Chinese Han population. MATERIAL AND METHODS A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used to genotype 139 patients with AD and 152 healthy control individuals. The Hardy-Weinberg equilibrium (HWE) was analyzed using the chi-squared (χ²) test, and genotype and allele frequencies were compared between the two population groups, using the χ² test. The odds ratios (ORs) and corresponding 95% confidence intervals (CI) were calculated to express the degree of risk of AD resulting from polymorphisms in the EGFR gene. Linkage disequilibrium among EGFR polymorphisms was analyzed using the Haploview bioinformatics software. RESULTS The CC genotype and C allele frequencies of rs730437 were significantly lower in patients with AD compared with the controls (P=0.037), indicating that rs730437 was associated with a reduced risk of AD (CC vs. AA: OR=0.446, 95% CI=0.207-0.960) (C vs. A: OR=0.702, 95% CI=0.502-0.980). The presence of the TT genotype of rs1468727 significantly reduced the risk of AD (P=0.003; OR=0.333, 95% CI=0.160-0.691), and T allele carriers of rs1468727 had a 0.605-fold increased risk of AD. Haplotype A-C-C was significantly correlated with an increased risk of AD (OR=1.922, 95% CI=1.130-3.269). CONCLUSIONS In a Han Chinese population, EGFR gene polymorphisms, rs730437 and rs1468727 and haplotype A-C-C were shown to be possible protective factors for the development of AD.

Survival time following resection of intracranial metastases from NSCLC-development and validation of a novel nomogram

Background

Brain metastases (BM) from non-small cell lung cancer (NSCLC) are the most frequent intracranial tumors. To identify patients who might benefit from intracranial surgery, we compared the six existing prognostic indexes(PIs) and built a nomogram to predict the survival for NSCLC with BM before they intended to receive total intracranial resection in China.

Methods

First, clinical data of NSCLC presenting with BM were retrospectively reviewed. All of the patients had received total intracranial resection and were randomly distributed to developing cohort and validation cohort by 2:1. Second, we stratified the cohort using a recursive partitioning analysis(RPA), a score index for radiosurgery (SIR), a basic score for BM (BS-BM), a Golden Grading System (GGS), a disease-specific graded prognostic assessment (DS-GPA) and by NSCLC-RADES. The predictive power of the six PIs was assessed using the Kaplan–Meier method and the log-rank test. Third, univariate and multivariate analysis were explored, and the nomogram predicting survival of BMs from NSCLC was constructed using R 3.2.3 software. The concordance index (C-index) was calculated to evaluate the discriminatory power of the nomogram in the developing cohort and validation cohort.

Results

BS-BM could better predict survival of patients before intracranial surgery compared with other PIs. In the final multivariate analysis, KPS at diagnosis of BM, metachronous or synchronous BM and the histology of lung cancer appeared to be the independent prognostic predictors for survival. The C-index in the developing cohort and validation cohort were 0.75 and 0.71 respectively, which was better than the C-index of the other six PIs.

Conclusions

The new nomogram is a promising tool in further choosing the candidates for intracranial surgery among NSCLC with BM and in helping physicians tailor suitable treatment options before operation in clinical practice.

Intrapleural targeted therapies (anti-VEGF and anti-EGFR) in the model of malignant pleural effusion

Rationale

Malignant pleural effusion has few options of treatment and drugs administrated by different routes can lead to a less permissive microenvironment for the development of malignant pleural disease.

Objectives

To analyze therapies administered intrapleurally in malignant pleural disease and to study EGFR and KRAS mutations in adenocarcinoma.

Methods

Mice received LLC cells and were treated intrapleurally with anti-VEGF, anti-EGFR, anti-VEGF+anti-EGFR or saline. Animal survival, weight and mobility, volume, biochemistry and immunology of fluid, gene expression, KRAS and EGFR mutation were evaluated.

Results

All animals developed malignant effusion and presented progressive weight loss without difference between groups; however, groups treated with anti-EGFR were more active. No difference in mortality was observed. Temporal increase of volume and inflammatory markers was observed mainly in the untreated group. Gene expression in tumors was overexpressed in VEGF, EGFR and KRAS compared with normal tissue. Mutation in exon 2 of the KRAS gene was observed.

Conclusions

Intrapleural Anti-VEGF and/or anti-EGFR reduced volume and inflammatory mediators in pleural fluid. Anti-EGFR and anti-VEGF+anti-EGFR decreased morbidity although without impact on survival. LLC tumors presented KRAS mutation, this could have influenced the action of these therapies.