• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.387-392
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• 2013

Objective: The aim of the present study was to explore mechanisms by which let-7c suppresses NSCLC cell proliferation. Methods: The expression level of let-7c was quantified by qRT-PCR. A549 and H1299 cells were transfected with let-7c mimics to restore the expression of let-7c. The effects of let-7c were then assessed by cell proliferation, colony formation and cell cycle assay. Mouse experiments were used to confirm the effect of let-7c on tumorigenicity in vivo. Luciferase reporter assays and Western blotting were performed to identify target genes for let-7c. Results: HOXA1 was identified as a novel target of let-7c. MTS, colony formation and flow cytometry assays demonstrated that forced expression of let-7c inhibited NSCLC cell proliferation by inducing G1 arrest in vitro, consistent with inhibitory effects induced by knockdown of HOXA1. Mouse experiments demonstrated that let-7c expression suppressed tumorigenesis. Furthermore, we found that let-7c could regulate the expression of HOXA1 downstream effectors CCND1, CDC25A and CDK2. Conclusions: Collectively, these results demonstrate let-7c inhibits NSCLC cell proliferation and tumorigenesis by partial direct targeting of the HOXA1 pathway, which suggests that restoration of let-7c expression may thus offer a potential therapeutic intervention strategy for NSCLC.

• Journal of Life Science
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• v.29 no.6
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• pp.645-652
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• 2019

Non-small cell lung cancer (NSCLC) has the infamous distinction of being the leading cause of global cancer-related death over the past decade, and novel molecular targets are urgently required to change this status. We previously conducted a microarray analysis to investigate the association of transcription factor activating enhancer-binding protein 2C (TFAP2C) with NSCLC and revealed its oncogenic roles in NSCLC development. In this study, to identify new biomarkers for NSCLC, we focused on several oncogenes from the microarray analysis that are transcriptionally regulated by TFAP2C. Here, the cell division cycle 20 (CDC20) and tribbles pseudokinase 3 (TRIB3) were subsequently found as potential potent oncogenes as they are positively regulated by TFAP2C. The results showed that the mRNA and protein levels of CDC20 and TRIB3 were down-regulated in two NSCLC cell lines (NCI-H292 and NCI-H838), which were treated with TFAP2C siRNA, and that the overexpression of either CDC20 or TRIB3 was responsible for promoting cell viability in both NSCLC cell lines. In addition, apoptotic levels of NCI-H292 and NCI-H838 cells treated with TFAP2C siRNA were found to be suppressed by the overexpression of either CDC20 or TRIB3. Together, these results suggest that CDC20 and TRIB3 are positively related to NSCLC tumorigenesis and that they should be considered as potential prognostic markers for developing an NSCLC therapy.

• Molecules and Cells
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• v.42 no.2
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• pp.161-165
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• 2019

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide and has high rates of metastasis. Transforming growth factor beta-inducible protein (TGFBI) is an extracellular matrix component involved in tumour growth and metastasis. However, the exact role of TGFBI in NSCLC remains controversial. Gene silencing via DNA methylation of the promoter region is common in lung tumorigenesis and could thus be used for the development of molecular biomarkers. We analysed the methylation status of the TGFBI promoter in 138 NSCLC specimens via methylation-specific PCR and evaluated the correlation between TGFBI methylation and patient survival. TGFBI promoter methylation was detected in 25 (18.1%) of the tumours and was demonstrated to be associated with gene silencing. We observed no statistical correlation between TGFBI methylation and clinicopathological characteristics. Univariate and multivariate analyses showed that TGFBI methylation is significantly associated with poor survival outcomes in adenocarcinoma cases (adjusted hazard ratio = 2.88, 95% confidence interval = 1.19-6.99, P = 0.019), but not in squamous cell cases. Our findings suggest that methylation in the TGFBI promoter may be associated with pathogenesis of NSCLC and can be used as a predictive marker for lung adenocarcinoma prognosis. Further large-scale studies are needed to confirm these findings.

• Toxicological Research
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• v.18 no.4
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• pp.411-416
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• 2002

Apoptosis, or programmed cell death, is a genetically regulated pathway that is altered in many cancers. Overexpression of bcl-2 leads to resistance to apoptosis and promotes tumorigenesis. To determine the effect of bcl-2 antisense treatment in human lung cancer cell lines, a 20 mer full phosphorothioate oligonucleotide (ODN) targeted at the coding region of the bcl-2 mRNA was synthesized. Western blot analyses were used to examine bcl-2 protein level in five human non-small cell lung cancer (NSCLC) cell lines (NCI-H226, SK-MES-1 NCI-H358, NCI-H522 and NCI-Hl 299) and four human small cell lung cancer (SCLC) cell lines (NCI-H69, NCI-H4l7, HCC-2108 and SW2). Three out of five NSCLC (NCI-H226, SK-MES-1 and NCI-Hl 299) and all of SCLC cell lines expressed Bcl-2 protein. Treatment of these cell with antisense ODN for 48 hours reduced their viability and Bcl-2 protein level. As a conclusion, bcl-2 antisense treatment appears reduction of the Bcl-2 protein levels and cytotoxic effect including apoptosis in human lung cancer cell lines.

• BMB Reports
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• v.48 no.3
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• pp.159-165
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• 2015

Although the short isoform of ErbB3-binding protein 1 (Ebp1), p42 has been considered to be a potent tumor suppressor in a number of human cancers, whether p42 suppresses tumorigenesis of lung cancer cells has never been clarified. In the current study we investigated the tumor suppressor role of p42 in non-small cell lung cancer cells. Our data suggest that the expression level of p42 is inversely correlated with the cancerous properties of NSCLC cells and that ectopic expression of p42 is sufficient to inhibit cell proliferation, anchorage-independent growth, and invasion as well as tumor growth in vivo. Interestingly, p42 suppresses Akt activation and overexpression of a constitutively active form of Akt restores the tumorigenic activity of A549 cells that is ablated by exogenous p42 expression. Thus, we propose that p42 Ebp1 functions as a potent tumor suppressor of NSCLC through interruption of Akt signaling.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.875-880
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• 2015

Mediator 19 (Med19) is a component of the mediator complex which is a coactivator for DNA-binding factors that activate transcription via RNA polymerase II. Accumulating evidence has shown that Med19 plays important roles in cancer cell proliferation and tumorigenesis. The involvement of Med19 in sensitivity to the chemotherapeutic agent cisplatin was here investigated. We employed RNA interference to reduce Med19 expression in human non-small cell lung cancer (NSCLC) cell lines and analyzed their phenotypic changes. The results showed that after Med19 siRNA transfection, expression of Med19 mRNA and protein was dramatically reduced (p<0.05). Meanwhile, impaired growth potential, arrested cell cycle at G0/G1 phase and enhanced sensitivity to cisplatin were exhibited. Apoptosis and caspase-3 activity were increased when cells were exposed to Med19 siRNA and/or cisplatin. The present findings suggest that Med19 facilitates tumorigenic properties of NSCLC cells and knockdown of Med19 may be a rational therapeutic tool for lung cancer cisplatin sensitization.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.255-260
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• 2012

Patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor (EGFR) mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors ((EGFR-TKIs)-namely gefitinib and erlotinib. However, these patients eventually develop resistance to EGFR-TKIs. Despite the fact that this acquired resistance may be the result of a secondary mutation in the EGFR gene, such as T790M or amplification of the MET proto-oncogene, there are other mechanisms which need to be explored. MicroRNAs (miRs) are a class of small non-coding RNAs that play pivotal roles in tumorigenesis, tumor progression and chemo-resistance. In this study, we firstly successfully established a gefitinib resistant cell line-HCC827/GR, by exposing normal HCC827 cells (an NSCLC cell line with a 746E-750A in-frame deletion of EGFR gene) to increasing concentrations of gefitinib. Then, we found that miR-214 was significantly up-regulated in HCC827/GR. We also showed that miR-214 and PTEN were inversely expressed in HCC827/GR. Knockdown of miR-214 altered the expression of PTEN and p-AKT and re-sensitized HCC827/GR to gefitinib. Taken together, miR-214 may regulate the acquired resistance to gefitinib in HCC827 via PTEN/AKT signaling pathway. Suppression of miR-214 may thus reverse the acquired resistance to EGFR-TKIs therapy.

• Genomics & Informatics
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• v.21 no.3
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• pp.30.1-30.13
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• 2023

Ephs belong to the largest family of receptor tyrosine kinase and are highly conserved both sequentially and structurally. The structural organization of Eph is similar to other receptor tyrosine kinases; constituting the extracellular ligand binding domain, a fibronectin domain followed by intracellular juxtamembrane kinase, and SAM domain. Eph binds to respective ephrin ligand, through the ligand binding domain and forms a tetrameric complex to activate the kinase domain. Eph-ephrin regulates many downstream pathways that lead to physiological events such as cell migration, proliferation, and growth. Therefore, considering the importance of Eph-ephrin class of protein in tumorigenesis, 7,620 clinically reported missense mutations belonging to the class of variables of unknown significance were retrieved from cBioPortal and evaluated for pathogenicity. Thirty-two mutations predicted to be pathogenic using SIFT, Polyphen-2, PROVEAN, SNPs&GO, PMut, iSTABLE, and PremPS in-silico tools were found located either in critical functional regions or encompassing interactions at the binding interface of Eph-ephrin. However, seven were reported in nonsmall cell lung cancer (NSCLC). Considering the relevance of receptor tyrosine kinases and Eph in NSCLC, these seven mutations were assessed for change in the folding pattern using molecular dynamic simulation. Structural alterations, stability, flexibility, compactness, and solvent-exposed area was observed in EphA3 Trp790Cys, EphA7 Leu749Phe, EphB1 Gly685Cys, EphB4 Val748Ala, and Ephrin A2 Trp112Cys. Hence, it can be concluded that the evaluated mutations have potential to alter the folding pattern and thus can be further validated by in-vitro, structural and in-vivo studies for clinical management.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.24-32
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• 2000

Purpose: Microsatellite instability(MSI) is frequently used as an indicator of microsatellite mutator phenotype(MMP) tumors. MSI has been observed in a percentage of non-small cell lung cancer(NSCLC). However, its role in tumorigenesis of NSCLC remains unknown. The frequency and pattern of MSI in NSCLC were evaluated and clinical parameters of MSI-positive tumors with those of MSS(microsatellite stable) tumors were compared. Materials and Methods: Twenty surgically resected NSCLCs were analyzed for 15 microsatellite markers located at chromosomes 3p and 9p. The peripheral blood lymphocytes of patients were used as the source of the normal DNA. Results: 1) Of 20 cases, 8(40%) demonstrated MSI. 2) Instability was observed more frequently in tri- and tetra-nucleotide repeats than in dinucleotide repeats. In all cases, instability appeared as a shift of individual allelic bands. 3) LDH was observed in 10(50%) of 20 tumors analyzed. 4) Of 20 cases, MSI-H tumor(showing MSI in the majority of markers) was absent. There were 5 MSI-L tumors(showing MSI in a greater than 10% of markers). 5) No significant difference was observed between MSI-L tumors and MSI-negative tumors in terms of clinicopathologic features such as pack-year history of smoking, histologic subtype, and(delete) stage of disease. There was also no significant difference in the incidence of LDH in relation to the status of MSI. Conclusion: These data strongly suggest that MSI plays different roles in lung and colon cancer. MMP pathway appears to be far less important in the tumorigenesis of NSCLC, caused mainly by cigarette smoke, with little familial tendency.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.1881-1895
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• 2015

Background: The vascular endothelial growth factor family has been implicated in tumorigenesis and metastasis. The prognostic value of each vascular endothelial growth factor family member, particular VEGF/VEGFR co-expression, in patients with non-small lung cancer remains controversial. Materials and Methods: Relevant literature was identified by searching PubMed, EMBASE and Web of Science. Studies evaluating expression of VEGFs and/or VEGFRs by immunohistochemistry or ELISA in lung cancer tissue were eligible for inclusion. Hazard ratios (HRs) and 95% confidence intervals (CIs) from individual study were pooled by using a fixed- or random-effect model, heterogeneity and publication bias analyses were also performed. Results: 74 studies covering 7,631 patients were included in the meta-analysis. Regarding pro-angiogenesis factors, the expression of VEGFA (HR=1.633, 95%CI: 1.490-1.791) and VEGFR1 (HR=1.924, 95%CI: 1.220-3.034) was associated separately with poor survival. Especially, VEGFA over-expression was an independent prognostic factor in adenocarcinoma (ADC) (HR=1.775, 95%CI: 1.384-2.275) and SCC (HR=2.919, 95%CI: 2.060-4.137). Co-expression of VEGFA/VEGFR2 (HR=2.011, 95%CI: 1.405-2.876) was also significantly associated with worse survival. For lymphangiogenesis factors, the expression of VEGFC (HR=1.611, 95%CI: 1.407-1.844) predicted a poor prognosis. Co-expression of VEGFC/VEGFR3 (HR=2.436, 95%CI: 1.468-4.043) emerged as a preferable prognostic marker. Conclusions: The expression of VEGFA (particularly in SCC and early stage NSCLC), VEGFC, VEGFR1 indicates separately an unfavorable prognosis in patients with NSCLC. Co-expression VEGFA/VEGFR2 is comparable with VEGFC/VEGFR3, both featuring sufficient discrimination value as preferable as prognostic biologic markers.