Lingxiang Liu

MiRNA-21: A biomarker predictive for platinum-based adjuvant chemotherapy response in patients with non-small cell lung cancer

Purpose: To investigate the possible role of microRNAs in the resistance to platinum based chemotherapy in non-small cell lung cancer (NSCLC), explore their potential role and find potential biomarkers for prediction of the response to platinum. Patients and methods: Microarray was employed to compare the expression of miRNAs between A549 and A549/CDDP cells. The effect of a differently expressed miRNA (miR-21) was examined on the sensitivity of cells to platinum. MiR-21 expression in NSCLC tumor tissues and matched plasma sample was also analyzed by Real-time PCR. Results: 21 miRNAs were deregulated in A549/CDDP. Increased miR-21 expression significantly increased the resistance of A549 cell to platinum, whereas reduced miR-21 decreased the resistance of A549/CDDP cell. This finding was further validated in the tissue samples of 58 patients and it was found that miR-21 expression was significantly increased in platinum based chemotherapy-resistant patients (n = 58, p = 0.000). And increased miR-21 expression was associated with the shorter DFS (p = 0.008). Among these 58 patients, 32 had the corresponding plasma samples and similar tendencies were detected in 68.75% patients. Finally, transfection of A549/CDDP with anti-miR-21 increased the expression of PTEN and decreased Bcl-2. In contrast, pre-miR-21 decreased the expression of PTEN and increased Bcl-2 in A549. Conclusion: Our data suggests that the expression level of miR-21 in tumor tissue and plasma might be used as a biomarker to predict adjuvant platinum based chemotherapy response and disease free survival in patients with NSCLC. Thus, it may serve as a novel therapeutic target to modulate platinum-based chemotherapy.

The role of human epidermal growth factor receptor 2 as a prognostic factor in lung cancer: a meta-analysis of published data.

Introduction: Human epidermal growth factor receptor 2 (HER2) is regarded as a poor prognostic factor in many tumors. Conflicting data in many literatures were reported about the association between HER2 and poor prognosis in lung cancer. Methods: We conducted a meta-analysis of published studies from 1966 to the 12th week of 2010. In absence of significant quality difference between positive and negative studies, combined hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) were calculated in terms of overall survival. Results: Forty studies(6135 patients) were included in the analysis. The pooled data showed that HER2 overexpression was a marker of poor prognosis in lung cancer. HR was 1.48 (95% CI: 1.22–1.80) and 3.11 (95% CI: 2.26–4.28) for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) by immunohistochemistry (IHC) assay, respectively. In the NSCLC subgroup analysis of early stage and ethnicities using IHC and in SCLC subgroup of extensive stage using IHC, it also showed that HER2 overexpression determined by IHC was a marker of poor prognosis in NSCLC and SCLC. In other subgroup of squamous cell carcinoma tested by IHC, the combined HR was 0.87 (95% CI: 0.61–1.25), indicating that HER2 overexpression was not a prognostic factor for squamous cell carcinoma. Finally, in the subgroup analysis of HER2 amplification status of NSCLC using fluorescence in situ hybridization, we also found that HER2 amplification determined by fluorescence in situ hybridization was not significantly related to prognosis. Conclusions: Although bias could be inevitable, this meta-analysis suggests that HER2 overexpression is a poor prognostic factor in lung cancer, especially for SCLC, adenocarcinoma, and early-stage NSCLC.

MicroRNA‐133b inhibits the growth of non‐small‐cell lung cancer by targeting the epidermal growth factor receptor

Both the deregulation of microRNAs and epidermal growth factor receptor (EGFR) are emerging as important factors in non‐small‐cell lung cancer (NSCLC). Here, miR‐133b was found to be associated with tumor stage, the extent of regional lymph node involvement, stage, visceral pleura or vessel invasion and EGFR mRNA expression in Chinese patients with NSCLC. Bioinformatic analysis and luciferase reporter assay revealed that miR‐133b can interact specifically with the 3′‐UTR of EGFR mRNA. Functionally, miR‐133b transfection showed regulatory activity in translationally repressing EGFR mRNA. Moreover, miR‐133b transfection may modulate apoptosis, invasion and sensitivity to EGFR‐TKI through the EGFR signaling pathways, especially in EGFR‐addicted NSCLC cells. Taken together, our findings show that miR‐133b can inhibit cell growth of NSCLC through targeting EGFR and regulating its downstream signaling pathway. This finding has important implications for the development of targeted therapeutics for a number of EGFR‐addicted cancers.

A systematic-analysis of predicted miR-21 targets identifies a signature for lung cancer

INTRODUCTION The well-known oncomiR-miR-21 was previously reported oncogenic activity in lung cancer. We sought to determine the expression of all predicted target genes of miR-21 and their potential function, pathways and networks, which are involved in the biological behavior of lung cancer. METHODS After a systematic review of English language studies of lung cancer-related molecules were pooled; genes were classified in three functional groups by gene ontology (GO) analysis. The key molecules were indentified by establishing lung cancer related networks and pathways. MiR-21 targets were predicted by computational method, followed by screening for matched gene symbols in NCBI human sequences and GO, pathway and network analysis. MiR-21 targets and their network, which are involved in the malignant mechanisms of lung cancer, were obtained by the final integrative analysis. RESULT We indentified the potential functions, pathways and networks of lung cancer relating molecules and miR-21 targets respectively in the initial analysis. In the final integrative analysis of lung cancer related miR-21-targets analysis, 24 hub genes were identified by overlap calculation, suggesting that miR-21 may play an important role in the development and progression of lung cancer through JAK/STAT signal pathway, MAPK signaling pathway, Wnt signaling pathway, cell cycle, PPAR signaling pathway, apoptosis pathway and other pathways. CONCLUSION Our data may help researchers to predict the molecular mechanisms of miR-21 in the development and progression of lung cancer comprehensively. Moreover, the present data indicate that miR-21-targets may be a series of promising candidates as biomarkers for lung cancer.

Systematic Review and Meta-Analysis on the Association between IL-1B Polymorphisms and Cancer Risk

Background Interleukin-1 beta (IL-1β), a pro-inflammatory cytokine, is emerging as a key mediator of carcinogenesis that characterizes host-environment interactions. Epidemiological studies investigating the association between two polymorphisms of IL-1B (−511C/T and +3954C/T) and cancer susceptibility have shown conflicting results. The aim of this study is to derive a more precise estimation of the relationship. Methods Related studies were identified through a systematic literature search of PubMed and Web of Science from their inception to September 15, 2012. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for the IL-1B −511C/T and +3954C/T polymorphisms and cancer risk were calculated. Heterogeneity among studies and publication bias were also tested. Results The meta-analysis included 91 case-control studies in 85 publications, 81 studies for the −511C/T (19547 cases and 23935 controls) and 26 studies for the +3954C/T polymorphisms (8083 cases and 9183). The pooled results indicated that IL-1B +3954C/T (dominant model: OR = 1.15, 95% CI: 1.01–1.30) was significantly associated with increased overall cancer risk, especially among hospital-based case-control studies (dominant model: OR = 1.30, 95% CI: 1.02–1.66). As for −511C/T, we observed an inverse relationship in cervical cancer (dominant model: OR = 1.74, 95% CI: 1.35–2.23) and hepatocellular carcinoma (dominant model: OR = 0.68, 95% CI: 0.47–0.99). Moreover, −511C/T was associated with risk of specific subtypes of gastric carcinoma. Conclusion This meta-analysis suggested that both the IL-1B –511C/T and +3954C/T polymorphisms might modulate cancer susceptibility. Further well-designed studies based on larger sample sizes should be performed to confirm the findings.

Plumbagin from Plumbago Zeylanica L Induces Apoptosis in Human Non-small Cell Lung Cancer Cell Lines through NF-κB Inactivation

OBJECTIVE To detect effects of plumbagin on proliferation and apoptosis in non-small cell lung cancer cell lines, and investigate the underlying mechanisms. MATERIALS AND METHODS Human non-small cell lung cancer cell lines A549, H292 and H460 were treated with various concentrations of plumbagin. Cell proliferation rates was determined using both cell counting kit-8 (CCK-8) and clonogenic assays. Apoptosis was detected by annexin V/propidium iodide double-labeled flow cytometry and TUNEL assay. The levels of reactive oxygen species (ROS) were detected by flow cytometry. Activity of NF-κB was examined by electrophoretic mobility shift assay (EMSA) and luciferase reporter assay. Western blotting was used to assess the expression of both NF-κB regulated apoptotic-related gene and activation of p65 and IκBκ. RESULTS Plumbagin dose-dependently inhibited proliferation of the lung cancer cells. The IC50 values of plumbagin in A549, H292, and H460 cells were 10.3 μmol/L, 7.3 μmol/L, and 6.1 μmol/L for 12 hours, respectively. The compound concentration-dependently induced apoptosis of the three cell lines. Treatment with plumbagin increased the intracellular level of ROS, and inhibited the activation of NK-κB. In addition to inhibition of NF-κB/p65 nuclear translocation, the compound also suppressed the degradation of IκBκ. ROS scavenger NAC highly reversed the effect of plumbagin on apoptosis and inactivation of NK-κB in H460 cell line. Treatment with plumbagin also increased the activity of caspase-9 and caspase-3, downregulated the expression of Bcl-2, upregulated the expression of Bax, Bak, and CytC. CONCLUSIONS Plumbagin inhibits cell growth and induces apoptosis in human lung cancer cells through an NF-κB-regulated mitochondrial-mediated pathway, involving activation of ROS.

Meta-Analysis on the Association Between Nonsteroidal Anti-Inflammatory Drug Use and Lung Cancer Risk

BACKGROUND Nonsteroidal anti-inflammatory drugs (NSAIDs), especially aspirin, have emerged as the most potential chemopreventive agents. However, epidemiologic studies reported a controversial association between NSAID use and lung cancer risk. We conducted a meta-analysis to summarize the evidence for such relationship. METHODS Eligible studies were identified by searching the electronic literature PubMed, Medline, Embase, and ScienceDirect databases for relevant reports and bibliographies. Studies were included if they designed as cohort study, case-control study, or clinical trial on the NSAID exposure and lung cancer with sufficient raw data to analyzes. Relative risk (RR) or odds ratio (OR) was used to evaluate the association between NSAIDs and lung cancer. Stratified analysis was also performed. RESULTS A total of 19 studies including 20,266 lung cancer cases met the inclusion criteria. To the effect of aspirin on lung cancer, the combined RR for cohort studies was 0.96 (95%confidence interval [CI]: 0.78-1.19) and OR for case-control studies was 0.87 (95%CI: 0.69-1.09). When restricted in exposure of aspirin use to 7 tablets per week, the OR was 0.80 (95%CI: 0.67-0.95). The summary risk estimates showed no significant association between non-aspirin NSAID or overall NSAID use and lung cancer risk. CONCLUSIONS Aspirin use with a dose of 7 tablets per week can significantly reduce lung cancer risk, whereas non-aspirin NSAIDs showed no chemopreventive value. Greater attention should be paid to identifying appropriate individuals for this new indication of aspirin and the optimal dose and duration as a chemopreventive agent.

Association of ERCC1-C118T and -C8092A polymorphisms with lung cancer risk and survival of advanced-stage non-small cell lung cancer patients receiving platinum-based chemotherapy: A pooled analysis based on 39 reports

The published data on the predictive role of ERCC1 polymorphisms in lung cancer risk and survival of patients with advanced non-small cell lung cancer (NSCLC) receiving platinum-based chemotherapy remains inconsistent. The aim of this meta-analysis was to determine the role of ERCC1 gene polymorphisms (C118T and C8092A) in this clinical situation. Eligible studies were included and assessed for quality using multiple search strategies. Thirty-nine published papers involving 9615 cases (4606 with Stage III/IV disease) and 5542 controls were included in the analysis. Pooled odds ratios (OR) or hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate risk. ERCC1-C118T was associated with lung cancer risk. The OR was 0.90 (95% CI: 0.81-0.99, p=0.043) in an additive genetic model (C allele vs. T allele) and 0.77 (95% CI: 0.63-0.95, p=0.013) in a recessive genetic model (CC/CT vs. TT). The corresponding risk was 0.74 (95% CI: 0.58-0.94, p=0.013) based on a homozygous comparison (CC vs. TT). No significant correlation was found for ERCC1 C8092A and there was no obvious relationship between ERCC1 C118T/C8092A polymorphisms and objective response to platinum-based chemotherapy. Overall survival (OS) of patients with non-small cell lung cancer (NSCLC) receiving platinum-based chemotherapy was significantly related to ERCC1 C118T (HR: 1.29, 95% CI: 1.07-1.56, p=0.007, CT/TT vs. CC). There was no relationship between ERCC1 C8092A and survival (HR: 1.32, 95% CI: 0.84-2.10, p=0.23, CA/AA vs. CC). These findings suggest that ERCC1 C118T polymorphisms may serve as a biomarker for lung cancer risk and have prognostic value in patients with advanced non-small cell lung cancer (NSCLC) undergoing platinum-based treatment. Further studies with larger numbers of subjects from a worldwide arena are needed to validate the associations.

The impact of chemokine receptor CXCR4 on breast cancer prognosis: A meta-analysis

BACKGROUND C-X-C chemokine receptor type 4 (CXCR4) has been implicated in the invasiveness and metastasis of diverse cancers. However, the published data remain controversial on the correlation between CXCR4 expression level, as well as its subcellular distribution in tumor cells, and the clinical outcome of patients with breast cancer. METHODS To identify the precise role of CXCR4 in the clinical outcome of breast cancer, we performed a meta-analysis including 15 published studies. Original data included the hazard ratios (HRs) of overall survival (OS) and disease-free survival (DFS) in breast cancer with high CXCR4 expression versus low expression. We pooled hazard ratios (HRs) with 95% confidence intervals (CIs) to estimate the hazard. RESULTS A total of 15 published studies (including 3104 patients) were eligible. Overall survival (OS) and disease-free survival (DFS) of breast cancer were found to be significantly related to CXCR4 expression level, with the HR being 1.65 (95%CI: 1.34-2.03; P<0.00001) and 1.94 (95%CI: 1.42-2.65; P<0.00001) respectively. Stratified analysis according to subcellular distribution of CXCR4 showed that high expression in whole cells, cytoplasm and nucleus could predict unfavorable OS, with the HR of 2.02 (95%CI: 1.43-2.85; P<0.0001), 1.57 (95%CI: 1.13-2.18; P=0.007), and 1.47 (95%CI: 1.19-1.81; P=0.0004) respectively. As for DFS, elevated expression level of CXCR4 both in whole cells and cytoplasm predicted a poor outcome, with the HR being 2.23 (95%CI: 1.48-3.37; P=0.0001) and 1.76 (95%CI: 1.11-2.80; P=0.02), while high expression in the nucleus had no statistical significance, with HR 1.15 (95%CI: 0.52-2.55; P=0.73). CONCLUSIONS Increased CXCR4 expression, especially in whole cells and cytoplasm, may serve as a poor prognostic indicator in patients with breast cancer. Future studies are warranted to investigate the relationship between CXCR4 expression and survival of patients with breast carcinoma, which could help predict the clinical outcome and guide clinical decision-making for therapy.

Genetic Variation in a MicroRNA-502 Minding Site in SET8 Gene Confers Clinical Outcome of Non-Small Cell Lung Cancer in a Chinese Population

Background Genetic variants may influence microRNA-target interaction through modulate their binding affinity, creating or destroying miRNA-binding sites. SET8, a member of the SET domain-containing methyltransferase, has been implicated in a variety array of biological processes. Methods Using Taqman assay, we genotyped a polymorphism rs16917496 T>C within the miR-502 binding site in the 3′-untranslated region of the SET8 gene in 576 non-small cell lung cancer (NSCLC) patients. Functions of rs16917496 were investigated using luciferase activity assay and validated by immunostaining. Results Log-rank test and cox regression indicated that the CC genotype was associated with a longer survival and a reduced risk of death for NSCLC [58.0 vs. 41.0 months, P = 0.031; hazard ratio = 0.44, 95% confidential interval: 0.26–0.74]. Further stepwise regression analysis suggested rs16917496 was an independently favorable factor for prognosis and the protective effect more prominent in never smokers, patients without diabetes and patients who received chemotherapy. A significant interaction was observed between rs16917496 and smoking status in relation to NSCLC survival (P<0.001). Luciferase activity assay showed a lower expression level for C allele as compared with T allele, and the miR-502 had an effect on modulation of SET8 gene in vitro. The CC genotype was associated with reduced SET8 protein expression based on immunostaining of 192 NSCLC tissue sample (P = 0.007). Lower levels of SET8 were associated with a non-significantly longer survival (55.0 vs. 43.1 months). Conclusion Our data suggested that the rs16917496 T>C located at miR-502 binding site contributes to NSCLC survival by altering SET8 expression through modulating miRNA-target interaction.