title: miR-107 functions as a tumor suppressor in human esophageal squamous cell carcinoma and targets Cdc42.
abstract: Previously, we reported significantly decreased expression of tissue and circulating miR-107 in esophageal cancer (EC). However, its role in esophageal tumorigenesis still remains elusive. Therefore, the aim of the present study was to analyze the role of miR-107 in esophageal squamous cell carcinoma (ESCC). The role of miR-107 in ESCC was evaluated using MTT assay, cell cycle analysis by flow cytometry, annexin assay, colony formation assay and scratch assay. Overexpression of miR-107 in KYSE-410 cells suppressed cell proliferation at 72 h post-transfection (p=0.0001). Moreover, a significant increase in the G0/G1 population (p<0.001) and a significant decrease in the G2/M (p=0.032) population was also observed in the miR-107-treated cells as compared to the negative control (NC). Notably, miR-107 overexpression attenuated the colony formation potential of ESCC cells by 41.83% as compared to the NC (p=0.007). miR-107 mimic inhibited ESCC cell migration in a time-dependent manner, reducing the wound closure to only 50.41±7.23% at 72 h post-transfection (p=0.041). Further analysis by Matrigel invasion assay revealed a significant decrease in the migratory and invasive abilities of the KYSE-410 cells at 72 h post miR-107 transfection. qRT-PCR analysis showed decreased expression of one of the newly identified targets of miR-107, Cdc42, at the mRNA level. Further validation by western blotting confirmed a significant reduction in the identified target at the protein level. In addition, the relative luciferase activity of the reporter containing Cdc42 3'UTR was significantly decreased upon miR-107 co-transfection, indicating it to be a direct target of miR-107. Our results herein document that miR-107 functions as a tumor suppressor and inhibits the proliferation, migration and invasion of ESCC cells. Moreover, this is the first report showing Cdc42 as a downstream target of miR-107.
authors.affiliation: University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi 110078, India.
authors.forename: Priyanka
authors.initials: P
authors.lastname: Sharma
authors.affiliation: Functional Genomics Unit, CSIR Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India.
authors.forename: Neeru
authors.initials: N
authors.lastname: Saini
authors.affiliation: University School of Biotechnology, Guru Gobind Singh Indraprastha University, New Delhi 110078, India.
authors.forename: Rinu
authors.initials: R
authors.lastname: Sharma
mesh_terms: D020413:3' Untranslated Regions; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015536:Down-Regulation; D004938:Esophageal Neoplasms / Q000235:genetics*; D000077277:Esophageal Squamous Cell Carcinoma; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009361:Neoplasm Invasiveness; D011401:Promoter Regions, Genetic; D020764:cdc42 GTP-Binding Protein / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; C549045:MIRN107 microRNA, human; D035683:MicroRNAs; D020764:cdc42 GTP-Binding Protein