Genome-wide Discovery And Expression Analysis Of MiRNAs Involved In The Small Cell Lung Cancer Via Deep Sequencing

Objective:The aim of this study was to identify the main miRNAs involved in human small cell lung cancer at the genome-wide level and the role in the process of progress.Methods:Solexa sequencing was employed to sequence two small RNA(sRNA)libraries from the small cell lung cancer tissues and the corresponding normal tissues.Deep sequencing of the two sRNA libraries identified many conserved miRNAs and differential expression analysis of these miRNAs Their expression trends determined by sequencing were validated by qRT-PCR analysis in the small cell lung cancer.Use of gene transfection and build animal models in research of micrornas on the biological properties of lung cancerResults:Deep sequencing of the two sRNA libraries identified many conserved miRNAs,and differential expression analysis of these miRNAs discovered 81 miRNAs in response to small cell lung cancer and more than half of them were down-regulated.The results of qRT-PCR showed that miR-30a-3p was low Expression in SCLC tissue,NCI-H449,SBC-5 and NCI-H46 cell.miR-30a-3p was transfected with recombinant plasmid in NCI-H449 and make the NCI-H449Slow-growing.Flow cytometry results show that the cells after transfection have high ratio of apoptosis and most of that was stucked in G0 / G1 phase.NCI-H449 transfected with miR-30a-3p was set up the model of transplanted tumor.The expression of VEGF-C,Blood vessel,Lymphtic vessel was low in transfected group.The growth of transplanted tumor also was low in transfected group.Conclusions:A total of 81 differential expression miRNAs were identified.miRNA-30a-3p was low expressed in small cell lung cancer tissues and cells.High expression of miRNA-30a-3p Can restrain small cell lung cancer cell proliferation,promote apoptosis,cell cycle arrest and indirectly reduce the expression of VEGF-C and the small cell lung cancer transplanted tumor tissue of vascular and lymphatic vessels density.