Jialei Wang

Identification and Validation of Long Noncoding RNA Biomarkers in Human Non–Small-Cell Lung Carcinomas

Introduction: Dysregulation of long noncoding RNAs (lncRNAs) has been regarded as a primary feature of several human cancers. However, the genome-wide expression and functional significance of lncRNAs in non–small-cell lung carcinomas (NSCLC) remains unclear. The aim of this study was to identify novel lncRNAs that may play an important role in contributing to NSCLC pathogenesis. Methods: We performed an integrative analysis of two NSCLC microarray datasets comprising 165 and 90 patients, respectively. The candidate lncRNAs were identified using the GSE19188 dataset, and then confirmed in the GSE18842 dataset. In addition, an independent cohort of 73 clinical samples was analyzed to validate the selected lncRNAs by quantitative real-time polymerase chain reaction analysis. Results: With microarray gene expression analysis, we identified and validated a list of 64 lncRNAs significantly dysregulated in NSCLC tumors compared with normal lung tissues; and a panel of 181 lncRNAs that were specific to histological subtypes of NSCLC (adenocarcinoma, large-cell carcinoma, and squamous cell carcinoma). The quantitative real-time polymerase chain reaction analysis of six selected lncRNAs in clinical samples further confirmed the results of microarray analysis. Conclusions: We have identified and validated multiple novel lncRNAs associated with tumorigenesis and histological differentiation in human NSCLC. These lncRNAs could be further exploited for the development of useful biomarkers in diagnosis, prognosis, and treatment of NSCLC.

miR-196a2 C allele is a low-penetrant risk factor for cancer development

Published data on the association between miR-196a2 T/C polymorphism and cancer susceptibility are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 21 studies including 10,441 cases and 12,353 controls were involved in this meta-analysis. Overall, significantly elevated cancer risk was associated with miR-196a2 C allele when all studies were pooled into the meta-analysis (TC vs. TT: OR=1.23, 95% CI=1.11-1.36; CC vs. TT: OR=1.30, 95% CI=1.14-1.48; dominant model: OR=1.25, 95% CI=1.13-1.38). In the subgroup analysis by ethnicity, significantly increased risks were found in Asains (TC vs. TT: OR=1.24, 95% CI=1.10-1.40; CC vs. TT: OR=1.31, 95% CI=1.13-1.52; dominant model: OR=1.26, 95% CI=1.12-1.41) but with bordline statistical significance in Caucasians (TC vs. TT: OR=1.15, 95% CI=1.00-1.31). In the subgroup analysis by cancer type, statistically significantly increased risks were found for breast cancer (TC vs. TT: OR=1.15, 95% CI=1.01-1.31; CC vs. TT: OR=1.30, 95% CI=1.01-1.68; dominant model: OR=1.22, 95% CI=1.00-1.50; and recessive model: OR=1.11, 95% CI=1.01-1.23) and lung cancer (CC vs. TT: OR=1.30, 95% CI=1.10-1.54; and recessive model: OR=1.18, 95% CI=1.02-1.36). When stratified by study design, statistically significantly elevated risk was found in hospital-based studies (TC vs. TT: OR=1.30, 95% CI=1.13-1.49; CC vs. TT: OR=1.37, 95% CI=1.14-1.66; dominant model: OR=1.32, 95% CI=1.15-1.53) and population-based studies (CC vs. TT: OR=1.19, 95% CI=1.06-1.35; dominant model: OR=1.13, 95% CI=1.01-1.25). Despite some limitations, this meta-analysis suggests that the miR-196a2 C allele is a low-penetrant risk factor for cancer development.

A phase II randomized trial evaluating gefitinib intercalated with pemetrexed/platinum chemotherapy or pemetrexed/platinum chemotherapy alone in unselected patients with advanced non-squamous non-small cell lung cancer

Current pemetrexed/platinum chemotherapy does not produce a satisfactory therapeutic response in advanced lung cancer patients. The aim of this study was to determine whether the administration of gefitinib, a tyrosine kinase inhibitor (TKI), intercalated with pemetrexed/platinum could improve the efficacy in chemotherapy-naïve patients with advanced non-squamous NSCLC without subsequent gefitinib maintenance therapy. Treatment-naïve patients with stage IIIB or IV NSCLC were randomly assigned to receive pemetrexed (500 mg/m2 d1) and either cisplatin (75 mg/m2 d1) or carboplatin (AUC = 5 d1) plus gefitinib (250 mg/d on days 3 to 16 of a 3-week cycle) (PC-G) or pemetrexed–platinum (PC) alone. Randomization was stratified according to the tobacco smoking status and EGFR mutational status of the patients. The primary endpoint was the non-progression rate (NPR) at 12 weeks. Secondary endpoints included progression-free survival (PFS), overall response rate (ORR), overall survival (OS), and biosafety. The NPR at 12 weeks was 84.5% for the PC-G treatment arm and 83.1% for the PC treatment arm (P = 0.87). Median PFS was 7.9 months for the PC-G arm and 7.0 months for the PC arm (P = 0.57). The ORR was 50.0% for the PC-G arm and 47.4% for the PC arm (P = 0.78). Median survival was 25.4 mo for the PC-G arm and 20.8 mo for the PC arm (P = 0.54). The incidence of adverse events was similar between the two treatment arms, except for a higher incidence of skin rash with PC-G. Predefined subgroup analyses demonstrated that PC-G significantly increased the PFS compared with the PC regimen in patients with EGFR mutations (P = 0.017). Although gefitinib intercalated with pemetrexed/platinum chemotherapy did not improve the NPR at 12 weeks compared with chemotherapy, an improvement in the PFS for the intercalated treatment arm was seen in the subgroup of patients with EGFR mutations.

Decreased expression of RPS15A suppresses proliferation of lung cancer cells

Lung cancer is the leading cause of cancer-related death in the world. Previous report has identified ribosomal protein s15a (RPS15A) as a TGF-β-responsible gene in the lung adenocarcinoma cell line A549. In this study, we used specific si-RNA to downregulate RPS15A expression in A549 cells and found that decreased RPS15A expression significantly inhibited cell proliferation and survival, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays. Moreover, A549 cells were obviously accumulated in the G0/G1 phase in response to RPS15A knockdown, suggesting that RPS15A inhibition could induce a diminution of proliferation through cell cycle arrest. In addition, immunohistochemistry analysis further revealed that RPS15A was overexpressed in surgically resected lung cancer tissues. In conclusion, we identify RPS15A as a novel potential oncogenic gene involved in lung carcinogenesis. This study may provide a preliminary experimental basis for a gene therapy approach for treating lung cancer.

Lentivirus-Mediated Silencing of Myosin VI Inhibits Proliferation and Cell Cycle Progression in Human Lung Cancer Cells.

Myosin VI (MYO6) is a unique actin motor, which moves toward the pointed ends of actin filaments. In this study, we found that MYO6 is overexpressed in lung cancer tissues and associated with lung cancer progression, particularly lymph node metastasis. To investigate its functions in lung cancer cells, we generated recombinant lentivirus taking shRNA of MYO6. Using two lung cancer cell lines, A549 and 95D, we found that Lv‐shMYO6 could infect lung cancer cells with high efficiency and downregulate MYO6 on both mRNA and protein levels. After knockdown of MYO6, the proliferation rates of lung cancer cells were decreased significantly. The colony‐formation ability of MYO6‐silenced lung cancer cells was also impaired with reduced colony numbers and fewer cells per colony. Flow cytometry showed that cell cycle progression was stuck at the G0/G1 phase, especially at the sub‐G1 phase, which represents apoptotic cells. Moreover, knockdown of MYO6 downregulated the phosphorylation of ERK1/2. Further experiments using another shRNA of MYO6 confirmed the above results. These results suggest that MYO6 is crucial in maintaining cell cycle and cell growth of lung cancer cells. MYO6 may serve as a potential therapeutic target for lung cancer treatment.

PA-MSHA in combination with EGFR tyrosine kinase inhibitor: A new strategy to overcome the drug resistance of non-small cell lung cancer cells

The inhibition of epidermal growth factor receptor (EGFR) signaling by Gefitinib provides a promising treatment strategy for non-small cell lung cancer (NSCLC); however, drug resistance to Gefitinib and other tyrosine kinase inhibitors presents a major issue. Using NSCLC cell lines with differential EGFR status, we examined the potency of PA-MSHA (Pseudomonas aeruginosa-mannose-sensitive hemagglutinin) in combination with Gefitinib on proliferation, apoptosis, cell cycle arrest, EGFR signaling and tumor growth. PC-9, A549, and NCI-H1975 cells were treated with PA-MSHA, Gefetinib, or PA-MSHA plus Gefetinib at different concentrations and times. The effects of the drugs on proliferation, cell cycle distribution and apoptosis were evaluated. The activation of EGFR and apoptotic signaling-related molecules was evaluated by Western blotting in the presence or absence of EGFR siRNA. Tumor growth and pathway signaling activation was assessed by xenografts in nude mice. A time-dependent and concentration-dependent cytotoxic effect of PA-MSHA was observed in all NSCLC cells tested. The combination of PA-MSHA plus Gefitinib enhanced the growth inhibition, sub-G1 content and apoptosis over that observed with either agent alone. Furthermore, the combination of PA-MSHA plus Gefitinib resulted in caspase-3/caspase-9 cleavage and increased inhibition of EGFR-dependent activation of AKT and ERK phosphorylation. Combination treatment was more effective in reducing tumor size and EGFR activation than either agent alone. These data suggest that PA-MSHA and Gefitinib function additively to suppress the proliferative effects of NSCLC cells of differential EGFR status. The combination of PA-MSHA and Gefitinib provides a potential new strategy to conquer drug resistance for anti-EGFR-targeted therapy of NSCLC.

A novel point mutation in exon 20 of EGFR showed sensitivity to erlotinib

Abstract Mutations of epidermal growth factor receptor (EGFR) gene are good predictors of response to treatment with EGFR tyrosine kinase inhibitors (TKIs) for non-small cell lung cancer (NSCLC). It is well established that classic mutations, such as in-frame deletions in exon 19 and the point mutation L858R in exon 21, are associated with high sensitivity to EGFR TKIs. Though mutations in exon 20 are almost correlated with EGFR–TKIs resistance, the awareness that they might confer sensitivity to TKI treatment should be emphasized. Herein, we describe a novel mutation in exon 20 of EGFR in a Chinese male non-smoker, who was diagnosed with stage IV lung adenocarcinoma and characterized by the codon 769 point mutation GTG>GCG, which translates into alanine instead of valine (p.V769A). In this case, the patient showed a good clinical response to erlotinib after paclitaxel/cisplatin first-line and docetaxel second-line chemotherapies. Therefore, we suggest that this rare mutation (p.V769A) may be a sensitive EGFR mutation in NSCLC. The identification of novel EGFR mutations provides new predictive biomarkers for TKI treatment and is essential to the successful use of targeted therapies.

Typing of killer-cell immunoglobulin-like receptors and their cognate human leukocyte antigen class I ligands predicts survival of Chinese Han patients with metastatic non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) may establish an immunosuppressive tumor microenvironment that is conducive to tumor growth. Natural killer (NK) cells play a pivotal role in immunological surveillance. Activation of NK cells partially depends on the interactions between killer-cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands. We herein investigated the association of KIRs and HLA ligands with survival in metastatic NSCLC (mNSCLC) patients treated with chemotherapy in a Chinese Han population. Polymerase chain reaction with sequence-specific primers was used to type 15 KIRs at the DNA and mRNA level and 6 HLA ligands in 70 mNSCLC patients. Survival curves were estimated using the Kaplan-Meier method and compared with the log-rank test. Cox proportional hazard regression model was applied for multivariate survival analysis, with the stepwise selection, to determine independent predictors of survival. It was observed that patients with KIR2DS4del gene expression at the mRNA level or HLA-Bw4T80 exhibited poor overall survival (OS). The multivariate analysis revealed that HLA-Bw4T80 and KIR2DS4del expression were independent predictors of OS. This observation indicated that the KIR/HLA ligand is a promising predictor of survival in mNSCLC and may also provide a strategy for treatment stratification and patient management.

A phase II study of gemcitabine, vincristine, and cisplatin as second-line treatment for patients with advanced soft tissue sarcoma

AbstractPatients with advanced soft tissue sarcoma (aSTS) typically have a poor prognosis. Patients progressing to doxorubicin-based regimen have limited therapeutic options. Monotherapy with cytotoxic drugs appears to have only modest activity in the second-line setting. The purpose of this phase II study was to prospectively evaluate the safety and efficacy of combination regimen with gemcitabine, vincristine, and cisplatin (GVP) as a salvage treatment for patients with aSTS.Eligible patients were female with 18∼75 years old, and had aSTS that had progressed after 1 prior anthracyclines-based chemotherapy regimen. Patients were treated with 1,000 mg/m2 gemcitabine intravenously (IV) on days 1 and 8, 1.4 mg/m2 (max 2 mg) vincristine IV on day 1 and 25 mg/m2 cisplatin IV on days 1 through 3 every 21 days until disease progression, unacceptable toxicity or up to 6 cycles. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), over response rate (ORR) and safety. This trial was registered with www.clinicaltrials.gov (no. NCT01192633).A total of 26 patients with a median age 47 years (21–72) were recruited. ORR was 23.1% [1 complete response and 5 partial responses]. The median PFS and OS were 4.8 (95% CI, 0.1–9.5) months and 15.0 (95% CI, 6.1–23.9) months, respectively. Grade 3/4 hematologic toxicities included neutropenia (34.6%), leukopenia (23.1%), thrombocytopenia (11.5%) and anemia (3.8%). No febrile neutropenia and grade 3/4 non-hematologic toxicities occurred. The most frequent non-hematologic toxicities were nausea/vomiting (50.0%), fatigue (30.8%), and fever (11.5%).We conclude that GVP regimen is effective with a favorable safety profile as the second-line chemotherapy in aSTS patients, which warrants further investigation in a phase III study.

Detection of ALK rearrangements in lung cancer patients using a homebrew PCR assay

Lung cancer patients with anaplastic lymphoma kinase (ALK) rearrangements are candidates for targeted therapeutics. However, patients must be tested with a companion diagnostic assay to realize their ALK rearrangement status. We analyzed the publicly available E-GEOD-31210 microarray dataset and identified a non-coding RNA, sweyjawbu, which is strongly associated with ALK rearrangements. We validated these results using quantitative real-time PCR in an independent cohort consisting of 4 cell lines and 83 clinical samples. We could differentiate between ALK rearrangement-positive and -negative lung cancer samples by comparing sweyjawbu expression. Additionally, ALK rearrangement status was determined by comparing the expression of the 5′ and 3′ regions of the ALK transcript or by detecting known ALK hybrid subtypes. Thus, using our homebrew PCR assay, we were able to accurately detect ALK rearrangements, which could be used for diagnostic screening of lung cancer patients. The prototype could potentially be transferred to an automatic multiplex PCR platform (FilmArray) to differentiate between ALK rearrangement-positive and -negative patients in point-of-care settings.