title: The Novel Long Noncoding RNA TUSC7 Inhibits Proliferation by Sponging MiR-211 in Colorectal Cancer.
abstract: OBJECTIVE
  The novel long noncoding RNA (lncRNA) tumor suppressor candidate 7 (TUSC7) has been reported as a potential tumor suppressor, while the functional role of TUSC7 is still unknown in colorectal cancer (CRC). Here, we characterized TUSC7 expression profile in CRC patients and investigated its biological function and potential molecular mechanism.
  
  
  METHODS
  RNA isolation, qRT-PCR, cell counter kit-8 assay, cell cycle assay, EdU assay, and western blot were performed. Statistical analyses were performed using SPSS 18.0 software and p value < 0.05 was considered as statistically significant.
  
  
  RESULTS
  In a cohort of CRC patients, we found TUSC7 was significantly downregulated in CRC tissues compared with adjacent non-tumor tissues (P < 0.01). Patients with high expression of TUSC7 had better survival than those with low expression of TUSC7 (HR = 0.342, 95% CI: 0.120-0.972, P = 0.044). Cell count kit 8 and EdU assays showed that ectopic expression of TUSC7 in HCT116 and SW480 cells significantly inhibited cell proliferation rate. After silence of TUSC7 with small interfering RNA, cell proliferation rate increased. Flow cytometry analyses revealed cycles were arrested at G1 phase after TUSC7 overexpression. We found there were 2 binding sites of miR-211-3p within the sequence of TUSC7 and TUSC7 expression level was negatively correlated with miR-211-3p. TUSC7 overexpression increased the expression level of CDK6, which is a downstream target of miR-211-3p, in both RNA and protein level. Furthermore, luciferase reporter assay indicated that TUSC7 could sponge miR-211-3p.
  
  
  CONCLUSIONS
  To summary, we demonstrated that TUSC7 is a potential tumor suppressor in CRC, and TUSC7 could inhibit CRC cell proliferation by completely sponging miR-211-3p.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000368:Aged; D001665:Binding Sites; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D051361:Cyclin-Dependent Kinase 6 / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D059585:G1 Phase Cell Cycle Checkpoints; D045325:HCT116 Cells; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D034622:RNA Interference; D062085:RNA, Long Noncoding / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism
chemical_list: C549405:MIRN211 microRNA, human; D035683:MicroRNAs; D062085:RNA, Long Noncoding; D034741:RNA, Small Interfering; C000589576:TUSC8 long non-coding RNA, human; D051361:Cyclin-Dependent Kinase 6
keywords: CDK6; CeRNA; Colorectal cancer; Long noncoding RNA; MiR-211-3p; TUSC7