Gang Li1, Fang Wu2, Han Yang3, Xia Deng3, Yawei Yuan4. 1. Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, PR China; Department of Chemoradiation Oncology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China. 2. Department of Gastroenterology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China. 3. Department of Chemoradiation Oncology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China. 4. Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, PR China; Department of Radiation Oncology, Cancer Center of Guangzhou Medical University, Guangzhou, Guangdong, PR China. Electronic address: fengdeyingzi@126.com.
Abstract
BACKGROUND: Increasing evidence indicates that the dysregulation of microRNAs (miRNAs) play critical roles tumor progression and metastasis, but very few papers had reported the function of miR-9-5p in lung cancer, especially in NSCLCs. METHODS: In this study, we investigated the role of miR-9-5p in non-small cell lung cancers (NSCLCs). MiR-9-5p level were analyzed in 62 clinical NSCLC lung tissue samples and adjacent normal lung tissues by RT-PCR. The target of miR-9-5p was predicted by TargetScan and luciferase reporter assay was used to verify the binding site of miR-9-5p on TGFBR2 mRNA. MTT assay, wound healing assay and invasion assay were performed in both miR-5p inhibitor transfected A549 and miR-5p mimic transfected SK-MES-1 cells. To further investigate whether TGFBR2 is the major target of miR-9-5p, we used TGFBR2 siRNA to transfect A549 and SK-MES-1 cells with miR-9-5p inhibitor or miR-9-5p mimic transfection. Western blot were then used to analyze TGFBR2, p-smad2 and p-smad3 protein expressions after transfection. RESULTS: Results indicated that NSCLC patients' tissues had a significantly higher expression of miR-9-5p compared to adjacent normal lung tissues. MiR-9-5p mimic transfection promoted proliferation, metastasis and invasion abilities in both A549 and SK-MES-1 cells. Conversely, miR-9-5p inhibitor transfection showed the decreased abilities of these cells. Luciferase reporter assay indicated that TGFBR2 is a direct target of miR-9-5p and the up-regulation of TGFBR2 suppressed cell proliferation, metastasis and invasion. The knock down of TGFBR2 abrogated the effect of miR-9-5p in down-regulating p-smad2 and p-smad3 expressions, which indicated that TGFBR2 is the major target of miR-9-5p in NSCLC cells. CONCLUSIONS: Our finding indicated that miR-9-5p promotes the proliferation, metastasis and invasion of NSCLC cells by down-regulating TGFBR2 expression.
BACKGROUND: Increasing evidence indicates that the dysregulation of microRNAs (miRNAs) play critical roles tumor progression and metastasis, but very few papers had reported the function of miR-9-5p in lung cancer, especially in NSCLCs. METHODS: In this study, we investigated the role of miR-9-5p in non-small cell lung cancers (NSCLCs). MiR-9-5p level were analyzed in 62 clinical NSCLC lung tissue samples and adjacent normal lung tissues by RT-PCR. The target of miR-9-5p was predicted by TargetScan and luciferase reporter assay was used to verify the binding site of miR-9-5p on TGFBR2 mRNA. MTT assay, wound healing assay and invasion assay were performed in both miR-5p inhibitor transfected A549 and miR-5p mimic transfected SK-MES-1 cells. To further investigate whether TGFBR2 is the major target of miR-9-5p, we used TGFBR2 siRNA to transfect A549 and SK-MES-1 cells with miR-9-5p inhibitor or miR-9-5p mimic transfection. Western blot were then used to analyze TGFBR2, p-smad2 and p-smad3 protein expressions after transfection. RESULTS: Results indicated that NSCLCpatients' tissues had a significantly higher expression of miR-9-5p compared to adjacent normal lung tissues. MiR-9-5p mimic transfection promoted proliferation, metastasis and invasion abilities in both A549 and SK-MES-1 cells. Conversely, miR-9-5p inhibitor transfection showed the decreased abilities of these cells. Luciferase reporter assay indicated that TGFBR2 is a direct target of miR-9-5p and the up-regulation of TGFBR2 suppressed cell proliferation, metastasis and invasion. The knock down of TGFBR2 abrogated the effect of miR-9-5p in down-regulating p-smad2 and p-smad3 expressions, which indicated that TGFBR2 is the major target of miR-9-5p in NSCLC cells. CONCLUSIONS: Our finding indicated that miR-9-5p promotes the proliferation, metastasis and invasion of NSCLC cells by down-regulating TGFBR2 expression.