Mingchuan Zhao

MiR-138 Inhibits Tumor Growth Through Repression of EZH2 in Non-Small Cell Lung Cancer

Background/Aims: MicroRNAs (miRNAs) play important roles in tumorigenesis. We investigated the roles and mechanisms of miR-138 in human non-small cell lung cancer (NSCLC). Methods: The expression of miR-138 was first examined in NSCLC cell lines and tumourtissues by real-time PCR The in vitro and in vivo functional effect of miR-138 was examined further. A luciferase reporter assay was conducted to confirm target association between miR-138 and the enhancer of zeste homolog 2 (EZH2). Results: miR-138 was frequently downregulated in NSCLC cells and tissues. Overexpression of miR-138 inhibited proliferation of NSCLC cells in vitro and tumor growth in vivo. The EZH2 oncogene, which is often overexpressed in various human cancers and acts as an important regulator of cell growth and tumor invasion, was identified as a novel target of miR-138. miR-138 can bind to the 3′ untranslated region (3′ UTR) of EZH2 and suppress the expression of EZH2 at both mRNA and protein levels. Furthermore, knockdown of EZH2 phenocopied the tumor suppressive effects of miR-138 in cell models, whereas ectopic expression of EZH2 rescued the suppressive effects of miR-138. Conclusion: These findings define a tumor suppressor function for miR-138 in NSCLC and further suggest that miR-138 may represent a potential therapeutic target for NSCLC patients.

Transforming growth factor-β1 promotes lung adenocarcinoma invasion and metastasis by epithelial-to-mesenchymal transition

Lung cancer is a highly malignant carcinoma, and most deaths of lung cancer are caused by metastasis. The alterations associated with epithelial-to-mesenchymal transition (EMT) may be related to the cancer cell metastasis. Nevertheless, the mechanism of lung cancer metastasis remains unclear. We conducted a study in vitro to investigate whether transforming growth factor-β1 (TGF-β1) could induce changes of, such as cell morphology, expression of relative protein markers, and cellular motile and invasive activities. In this research, the changes of cell morphology were first investigated under a phase contrast microscope, then western blotting was employed to detect the expression of E-cadherin, vimentin, and fibronectin, and finally cell motility and invasion were evaluated by cell wound-healing as well as invasion assays. The data indicated that human lung adenocarcinoma cell lines, A-549 and PC-9 cells of epithelial cell characteristics, were induced to undergo EMT by TGF-β1. Following TGF-β1 treatment, cells showed dramatic morphological changes assessed by phase contrast microscopy, accompanied by decreased epithelial marker E-cadherin and increased mesenchymal markers vimentin and fibronectin. More importantly, cell motility and invasion were also enhanced in the EMT process. These results indicated that TGF-β1 may promote lung adenocarcinoma invasion and metastasis via the mechanism of EMT.

Microarray expression profile of long non-coding RNAs in EGFR-TKIs resistance of human non-small cell lung cancer

The application of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is limited by drug resistance in non-small cell lung cancer (NSCLC). Long non-coding RNAs (lncRNAs) are known to be involved in tumor development and metastasis, as well as chemotherapy resistance. To gain insight into the molecular mechanisms of EGFR-TKIs resistance, EGFR-TKIs‑sensitive and ‑resistant human lung cancer cells were analyzed by lncRNA microarray. In the present study, we found a total of 22,587 lncRNAs expressed in lung cancer cells. Of these, the expression level of 1,731 lncRNAs was upregulated >2-fold compared with gefitinib-sensitive cells while that of 2,936 was downregulated. Bioinformatics analysis (GO and pathway analyses) revealed that some classical pathways participating in cell proliferation and apoptosis were aberrantly expressed in these cells (P-value cut-off was 0.05). Enhancer-like lncRNAs and their nearby coding genes were analyzed. Six lncRNAs were identified as potential enhancers. Several lncRNAs were validated in lung cancer cell lines using RT-qPCR. To the best of our knowledge, the results showed for the first time that differentially expressed lncRNAs responded to EGFR-TKIs resistance in NSCLC cells. LncRNAs may therefore be novel candidate biomarkers and potential targets for EGFR-TKIs therapy in the future.

Peripheral blood for epidermal growth factor receptor mutation detection in non-small cell lung cancer patients.

OBJECTIVE: It is important to analyze and track Epidermal Growth Factor Receptor (EGFR) mutation status for predicting efficacy and monitoring resistance throughout EGFR-tyrosine kinase inhibitors (TKIs) treatment in non-small cell lung cancer (NSCLC) patients. The objective of this study was to determine the feasibility and predictive utility of EGFR mutation detection in peripheral blood. METHODS: Plasma, serum and tumor tissue samples from 164 NSCLC patients were assessed for EGFR mutations using Amplification Refractory Mutation System (ARMS). RESULTS: Compared with matched tumor tissue, the concordance rate of EGFR mutation status in plasma and serum was 73.6% and 66.3%, respectively. ARMS for EGFR mutation detection in blood showed low sensitivity (plasma, 48.2%; serum, 39.6%) but high specificity (plasma, 95.4%; serum, 95.5%). Treated with EGFR-TKIs, patients with EGFR mutations in blood had significantly higher objective response rate (ORR) and insignificantly longer progression-free survival (PFS) than those without mutations (ORR: plasma, 68.4% versus 38.9%, P = 0.037; serum, 75.0% versus 39.5%, P = 0.017; PFS: plasma, 7.9 months versus 6.1 months, P = 0.953; serum, 7.9 months versus 5.7 months, P = 0.889). In patients with mutant tumors, those without EGFR mutations in blood tended to have prolonged PFS than patients with mutations (19.7 months versus 11.0 months, P = 0.102). CONCLUSIONS: EGFR mutations detected in blood may be highly predictive of identical mutations in corresponding tumor, as well as showing correlations with tumor response and survival benefit from EGFR-TKIs. Therefore, blood for EGFR mutation detection may allow NSCLC patients with unavailable or insufficient tumor tissue the opportunity to benefit from personalized treatment. However, due to the high false negative rate in blood samples, analysis for EGFR mutations in tumor tissue remains the gold standard.

Serum Levels of the Cancer-Testis Antigen POTEE and Its Clinical Significance in Non-Small-Cell Lung Cancer

Background POTEE (POTE ankyrin domain family, member E) is a newly identified cancer-testis antigen that has been found to be expressed in a wide variety of human cancers including cancers of the colon, prostate, lung, breast, ovary, and pancreas. Aim To measure the serum levels of POTEE in patients with non-small-cell lung cancer (NSCLC) and to explore the clinical significance of POTEE in NSCLC. Patients and Methods 104 NSCLC patients, 66 benign lung disease patients and 80 healthy volunteers were enrolled in this study from May 2013 to February 2014. Serum POTEE levels were measured using enzyme-linked immunosorbent assay (ELISA). Numerical variables were recorded as means ± standard deviation (SD) and analyzed by independent t tests. Categorical variables were calculated as rates and were analyzed using a χ2 test or Fisher’s exact test. Survival curves were estimated and compared using the Kaplan-Meier method and log-rank tests. Results Serum POTEE levels were significantly higher in NSCLC patients than in benign lung disease patients and healthy controls (mean ± SD [pg/ml], 324.38± 13.84 vs. 156.93 ± 17.38 and 139.09 ± 15.80, P<0.001) and were significantly correlated with TNM stage. Survival analysis revealed that patients with low serum POTEE had longer progression-free survival (PFS) than those with high serum POTEE (P=0.021). Cox multivariate analysis indicated that POTEE was an independent prognostic factor of progression-free survival (P =0.009, hazard ratio, 2.440). Conclusions Serum POTEE level in NSCLC patients is associated with TNM stage and is a potential prognostic factor.

Video-assisted thoracic surgery lobectomy for unexpected pathologic N2 non-small cell lung cancer

This study was performed to assess early and late outcomes of pathologic N2 disease unexpectedly detected in patients with non‐small cell lung cancer undergoing video‐assisted thoracic surgery (VATS) lobectomy for clinical stage I.

Feasibility and long-term efficacy of video-assisted thoracic surgery for unexpected pathologic N2 disease in non-small cell lung cancer

OBJECTIVES: This study compares early and late outcomes for treatment by video-assisted thoracic surgery (VATS) versus treatment by thoracotomy for clinical N0, but post-operatively unexpected, pathologic N2 disease (cN0-pN2). METHODS: Clinical records of patients with unexpected N2 non-small cell lung cancer (NSCLC) who underwent VATS were retrospectively reviewed, and their early and late outcomes were compared to those of patients undergoing conventional thoracotomy during the same period. RESULTS: VATS lobectomy took a longer time than thoracotomy (P < 0.001), but removal of thoracic drainage and patient discharge were earlier for patients in the VATS group (P < 0.001). There was no difference in lymph node dissection, mortality and morbidity between the two groups (P > 0.05). The median follow-up time for 287 patients (89.7%) was 37.0 months (range: 7.0-69.0). The VATS group had a longer survival time than for the thoracotomy group (median 49.0 months vs. 31.7 months, P < 0.001). The increased survival time of the VATS group was due to patients with a single station of N2 metastasis (P = 0.001), rather than to patients with multiple stations of N2 metastasis (P = 0.225). CONCLUSIONS: It is both feasible and safe to perform VATS lobectomy on patients with unexpected N2 NSCLC. VATS provides better survival rates for those patients with just one station of metastatic mediastinal lymph nodes.

EGFR-TKIs plus chemotherapy demonstrated superior efficacy than EGFR-TKIs alone as first-line setting in advanced NSCLC patients with EGFR mutation and BIM deletion polymorphism

BACKGROUND Non-small-cell lung cancer (NSCLC) patients with both epidermal growth factor receptor (EGFR) positive mutation and B-cell chronic lymphocytic leukemia/lymphoma-like 11 (BIM) deletion polymorphism had a poor clinical response to EGFR-tyrosine kinase inhibitors (TKIs). The current study aimed to investigate the clinical efficacy and tolerability of EGFR-TKIs plus chemotherapy versus EGFR-TKIs alone as first-line treatment in advanced NSCLC patients with EGFR mutations and BIM deletion polymorphism. METHODS A retrospective, non-randomized analysis was conducted. BIM deletion polymorphism was detected using polymerase chain reaction (PCR) analysis and direct sequencing of DNA from peripheral blood cells. Clinical characteristics, overall survival (OS), progress-free-survival (PFS), objective response rate (ORR) and treatment-related adverse events were compared between EGFR-TKIs alone versus EGFR-TKIs plus chemotherapy group. RESULTS 65 patients were enrolled. 36 of them received EGFR-TKIs and 29 received EGFR-TKIs plus chemotherapy. EGFR-TKIs plus chemotherapy had significantly higher ORR than TKIs alone (65.5% vs. 38.9%, P = 0.046). Median PFS was significantly longer in EGFR-TKIs plus chemotherapy group than in TKIs group (7.2 vs 4.7 m; P = 0.008). Median OS was numerically longer in EGFR-TKIs plus chemotherapy group than in TKIs alone (18.5 vs 14.2 m; P = 0.107). EGFR-TKIs plus chemotherapy was associated with more grade 3 or 4 hematological toxic effects than EGFR-TKIs alone. CONCLUSION EGFR-TKIs plus chemotherapy conferred a significantly higher ORR, prolonged PFS and numerically longer OS in advanced NSCLC patients with EGFR mutation and BIM deletion polymorphism. Further prospective studies are needed to validate these findings.

Analysis of Predictive Factors for Postoperative Survival for Non Small Cell Lung Carcinoma Patients with Unexpected Mediastinal Lymph Nodes Metastasis

OBJECTIVES To discuss the predictive factors of postoperative survival for non small cell lung carcinoma (NSCLC) patients with clinical N0 stage but postoperative pathological N2 stage (cN0-pN2). METHODS From January 1, 2005, to December 31, 2009, the clinical data of NSCLC patients with cN0-pN2 after radical surgery were retrospectively collected, and their survival information was collected through follow-up. The expiration date for follow-up was December 31, 2011. The predictive factors of postoperative survival for NSCLC patients with unexpected mediastinal lymph node metastasis were analyzed using Cox proportional hazards regression. RESULTS A total of 263 patients were enrolled. The follow-up rate was 91.63%. The overall 1-, 3-, and 5-year survival rates were 94.6, 55.2, and 26.3%, respectively. Video-assisted thoracotomy surgery (VATS; odds ratio [OR] 0.659; 95% confidence interval [CI] 0.469 to 0.927; p = 0.017), multiple stations of metastatic mediastinal lymph nodes (OR 1.605; 95% CI 1.180 to 2.183; p = 0.003), and no adjuvant chemotherapy (OR 1.576; 95% CI 1.105 to 2.246; p = 0.012) were independent predictive factors for unexpected N2 patients. The median survival after VATS was superior to that after thoracotomy for patients with a single station of metastatic mediastinal lymph node (48.45 m vs 37.34 m, p = 0.018). The median survival without any adjuvant chemotherapy was inferior to that after adjuvant chemotherapy for patients with multiple stations of metastatic mediastinal lymph nodes (20.32 m vs 31.55 m, p = 0.001). CONCLUSION The postoperative survival for NSCLC patients with cN0-pN2 was related to operational method, adjuvant chemotherapy, and the number of metastatic mediastinal lymph node stations. Patients with a single station of metastatic mediastinal lymph node are likely to benefit from VATS, whereas patients with multiple stations of metastatic mediastinal lymph nodes are likely to benefit from adjuvant chemotherapy.