Role of MiR-3619-5p in β-Catenin-Mediated Non-Small Cell Lung Cancer Growth and Invasion

Background/Aims: β-catenin is an integral component of the canonical Wnt signaling pathway, and its mutations are an autosomal recessive cause of colorectal cancer (CRC), medulloblastoma (MDB), and ovarian cancer. Nevertheless, little is known about its function in lung cancers. Methods: We first knocked down β-catenin by siRNA to investigate its effects on lung cancer cell proliferation, migration and apoptosis. Then we verified the interaction between β-catenin and CREB binding protein (CBP) by immunofluoresence and co-immunoprecipition assays. Finally, the expression of β-catenin and CBP in human lung adenocarcinoma specimens were analyzed by immunohistochemistry assay. Results: β-catenin knockdown inhibited cell proliferation, promoted apoptosis and suppressed cell migration in A549 and H460 cells accompanied by the decreased expression of Myc, PCNA, VEGF, CD44, MMP-9, MMP-13 and activated bax/caspase-3 pathway. Furthermore, co-immunoprecipition and immunofluoresence analyses revealed that CBP interacted with β-catenin and contributed to β-catenin-mediated lung cancer cell growth. Abolishment of their interaction by the Wnt/β-catenin inhibitor ICG-001 remarkably suppressed cell proliferation. Immunohistochemistry assay of tissue microarrays from patients with lung cancer indicated that both CBP and β-catenin were highly expressed in tumor tissues and predicted poor prognosis in lung adenocarcinoma patients. Conclusions: Our study has provided new evidence for the role of β-catenin in promoting the growth of lung cancer cells through cooperation with CBP, and suggested that dual targeting of β-catenin and CBP could be a potential therapeutic strategy in lung cancer treatment.

Section: Discussionsupporting

confidence: 39%

β-Catenin Cooperates with CREB Binding Protein to Promote the Growth of Tumor Cells

Zheng

et al. 2017

“…A single miRNA can target multiple genes, whereas multiple miRNAs can target a single gene. Recently, miRNA regulatory mechanisms that are dysfunctional in lung cancer have been reported [25-27]. To date, some tumour suppressor miRNAs have been confirmed using cultured cancer cells or animal models of cancer [28, 29].…”

Section: Discussionmentioning

confidence: 99%

MiR-193a-3p is an Important Tumour Suppressor in Lung Cancer and Directly Targets KRAS

Fan

Zhang

et al. 2017

Background/Aims: MicroRNAs (miRNAs) have emerged as major regulators of tumour development and progression in non-small cell lung cancer (NSCLC). However, the role of miR-193a-3p in NSCLC is still unclear. Methods: Quantitative RT-PCR was used to detect miR-193a-3p expression levels in NSCLC tumour tissues. CCK8, EdU and cell migration assays were performed to analyse the biological functions of miR-193a-3p in NSCLC cells. Luciferase reporter assays were used to validate the bioinformatics-predicted target genes of miR-193a-3p. Western blotting and RNA/DNA interference carried out to evaluate the association between miR-193a-3p and KRAS. Results: miR-193a-3p expression was decreased in the NSCLC tumour tissues. We investigated the biological effects of miR-193a-3p both in vivo and in vitro and found that enforced expression of miR-193a-3p inhibited tumour formation and suppressed cell proliferation and cell migration. KRAS was found to be a potential target of miR-193a-3p, and dual luciferase reporter assays showed that miR-193a-3p directly binds to the 3’-untranslated region (3’-UTR) of KRAS mRNA. In addition, we found that changing the expression of KRAS had the opposite results to those induced by miR-193a-3p in the NSCLC cells. Importantly, simultaneous overexpression of miR-193a-3p and KRAS could counteract the effects of both on cellular functions. Conclusion: These findings highlight an important role for miR-193a-3p as a tumour suppressor in NSCLC pathogenesis via the regulation of KRAS expression.

“…MiRNAs play a significant role in the regulation of cell development, differentiation, proliferation, metastasis, invasion and cell apoptosis [7-14]. Thus, the abnormal alteration of miRNAs could be crucial to the development of diseases including cancers [15-18].…”

Section: Introductionmentioning

confidence: 99%

MiR-106b-5p Promotes Proliferation and Inhibits Apoptosis by Regulating BTG3 in Non-Small Cell Lung Cancer

Wei

Pan

Yao

et al. 2017

Background/Aims: MicroRNAs have been validated to play a crucial role in tumorigenesis of non-small cell lung cancer (NSCLC). Although miR-106b-5p has been reported to play a vital role in various malignancies the physiological function of miR-106b-5p in NSCLC still remain unknown. In this study, we investigated the role of miR-106b-5p in NSCLC. Methods: Quantitative real-time polymerase chain reaction was conducted to estimate the expression of miR-106b-5p and BTG3 in both NSCLC tissues and cell lines. The effects of miR-106b-5p on proliferation were determined in vitro using CCK-8 proliferation assays, 5-ethynyl-2’-deoxyuridine (EdU) incorporation, colony formation assays and cell-cycle assays and the in vivo effects were evaluated by a mouse tumorigenicity model. Cell apoptosis and cell cycle was investigated by flow cytometric analysis in vitro. The molecular mechanism underlying the relevance between miR-106b-5p and BTG3 was confirmed by luciferase assay and western blot. Results: In current study, we found a relatively higher miR-106b-5p and lower BTG3 expression in NSCLC specimens and cell lines. BTG3 was verified as a direct target of miR-106b-5p by luciferase assay. In vitro, over-expression of miR-106b-5p promoted proliferation and inhibited apoptosis by down-regulating BTG3 expression. In vivo, miR-106b-5p promoted xenograft tumor formation. Conclusion: Our findings revealed for the first time that miR-106b-5p plays a tumorigenesis role in NSCLC progression by down-regulating BTG3 expression, which may lead to a novel insight to the potential biomarker and novel therapeutic strategies for NSCLC patients.