The Tumor Suppressive Role of MiRNA-509-5p by Targeting FOXM1 in Non-Small Cell Lung Cancer

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.

Section: Discussionmentioning

confidence: 99%

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

Fan

Zhang

et al. 2017

“…A previous study reported that beneficial effects of crizotinib on ALK-positive NSCLC are elicited in combination with radiotherapy [28]. miRNAs play a critical role in the development of NSCLC and are considered as potential biomarkers for NSCLC diagnosis and therapy [29, 30]. Overexpression of miR-124, miR-148a, miR-3619-5p and miR-452 suppresses the growth, proliferation, metastasis and invasion of NSCLC cells [31-33].…”

Section: Discussionmentioning

confidence: 99%

Inhibition of MicroRNA-21-5p Promotes the Radiation Sensitivity of Non-Small Cell Lung Cancer Through HMSH2

Zuo

Qian

et al. 2017

Background: This study aimed to explore the effects of microRNA-21-5p (miR-21-5p) on the radiation sensitivity of non-small cell lung cancer (NSCLC) and the involvement of human MutS homolog 2 (hMSH2) One hundred fourteen NSCLC patients at stage II or III who received surgery and postoperative radiotherapy were enrolled in this study. Methods: The patients were assigned into radiation-sensitive and -insensitive groups. NSCLC A549 cells were transfected to generate control, Negative control (NC), miR-21-5p inhibitor, miR-21-5p mimic, small interfering hMSH2 (sihMSH2), miR-21-5p inhibitor + sihMSH2 and hMSH2 overexpression groups. Immunohistochemistry was performed to detect the hMSH2 expression in transfected and irradiated cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were performed to evaluate A549 miR-21-5p and hMSH2 expression in transfected and irradiated cells. A colony formation assay was adopted for cell survival analysis. The relationship between miR-21-5p and hMSH2 was verified by a luciferase reporter assay. Cell viability was measured by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and apoptosis was assessed by flow cytometry. NSCLC nude mouse models were established, and tumor volumes and tumor weights were recorded. Results: The radiation-sensitive group of patients exhibited lower miR-21-5p but higher hMSH2 expression than the insensitive group. For irradiated A549 cells, lower cell survival, higher apoptosis, increased miR-21-5p expression and decreased hMSH2 expression were observed at 6 and 8 Gy than at 0, 2 and 4 Gy; compared to 6 Gy, cell survival and hMSH2 expression were decreased and apoptosis and miR-21-5p expression were increased at 8 Gy. Additionally, miR-21-5p was found to target hMSH2. Compared with the control group, the cell survival rate was lower and the apoptosis rate higher in the miR-21-5p inhibitor group, whereas the opposite was observed for the miR-21-5p mimic and sihMSH2 groups. For the mouse model, decreased tumor volume and tumor weight and higher hMSH2 expression were found in the miR-21-5p inhibitor, radiation, hMSH2 overexpression, miR-21-5p inhibitor + radiation and hMSH2 overexpression + radiation groups compared with the control group. In addition, tumor volume and tumor weight were decreased and hMSH2 expression increased in the miR-21-5p inhibitor + radiation and hMSH2 overexpression + radiation groups compared with the radiation alone group. Conclusion: These findings indicate that inhibition of miR-21 can promote the radiation sensitivity of NSCLC by targeting hMSH2.

“…To date, deregulated miRNAs and their roles in NSCLC development have attracted much attention. Some of them, including miR-21, miR-34a, miR-124, miR-148, miR-204, miR-221,miR-452, miR-497 and miR-509, et al, have been reported to participate in the initiation and progression of NSCLC and modulate the biological properties of cancer cells [12-25]. However, the role of miR-142-5p in NSCLC tumor development and metastasis has only recently been investigated and remains largely unknown.…”

Section: Introductionmentioning

confidence: 99%

MiR-142-5p Suppresses Tumorigenesis by Targeting PIK3CA in Non-Small Cell Lung Cancer

Wang

Liu

Fang

et al. 2017

Background/Aims: Numerous studies have demonstrated that aberrant microRNA (miRNA) expression is involved in human disease including cancer. To date, the potential miRNAs regulating lung cancer growth and progression are not fully identified yet. Methods: In this study, the expression of miR-142-5p was measured in non-small cell lung cancer tissue and cell lines by qRT-PCR. The functional assays including the cell viability, colony formation, cell migration and invasion were performed in miR-142-5p mimic or inhibitor transfected cell lines (in vitro) and the cell tumorigenesis in nude mice (in vivo). The fluorescence ratios of cell viability were recorded using a multi-plate reader (Synergy 2, BioTek, Winooski, VT, USA) and the colonies were counted using an ELIspot Bioreader 5000 (BIO-SYS, Karben, GE). Results: MiR-142-5p was significantly downregulated in non-small cell lung cancer tissue and cell lines compared to normal human lung tissues. Overexpression of miR-142-5p resulted in decreased expression of PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha) at both mRNA and protein levels. We found that miR-142-5p overexpression markedly suppressed cell proliferation in vitro and in vivo. Conversely, inhibition of miR-142-5p promoted lung cancer growth. Mechanistic studies showed that PIK3CA was a potential target of miR-142-5p and it mediated reduction of PIK3CA resulting in suppression of PI3K/Akt pathway. Conclusions: Our results demonstrate that miR-142-5p functions as a growth suppressive miRNA and plays an important role in inhibiting the tumorigenesis through targeting PIK3CA in non-small cell lung cancer.