Open AccessLnc RNA KCNQ 1 OT 1 enhanced the methotrexate resistance of colorectal cancer cells by regulating miR‐760/ PPP 1R1B via the cAMP signalling pathway
Author(s) -
Xian Di,
Zhao Yu
Publication year - 2019
Publication title -
journal of cellular and molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.44
H-Index - 130
eISSN - 1582-4934
pISSN - 1582-1838
DOI - 10.1111/jcmm.14071
Subject(s) - gene knockdown , competing endogenous rna , rna , microbiology and biotechnology , messenger rna , cell growth , microrna , cancer research , transfection , biology , cell culture , chemistry , long non coding rna , gene , biochemistry , genetics
We aimed to explore the mechanism of the KCNQ 1 OT 1/miR‐760/ PPP 1R1B axis acting to regulate methotrexate ( MTX ) resistance of colorectal cancer ( CRC ). Differentially expressed mRNA s and lnc RNA s in MTX ‐sensitive CRC cell lines and MTX ‐resistant cell lines were determined through microarray analysis. Application of bioinformatics analysis was aimed to uncover the relationships among the lnc RNA s/mi RNA s/ mRNA s, and to demonstrate the effects of cAMP signalling pathway in MTX ‐resistant CRC . The expression level of RNA and proteins was, respectively, detected using qRT ‐ PCR and Western blot assays, whereas the dual‐luciferase reporter gene assay was implemented to verify the targeted relationship. The influence of the lnc RNA /mi RNA / mRNA axis on biological functions of MTX ‐resistant cells and on the growth of tumours determined through both vitro and vivo experiments. Lnc RNA KCNQ 1 OT 1 and PPP 1R1B mRNA were overexpressed in MTX ‐resistant CRC tumour cells. KCNQ 1 OT 1 functioned as a sponge of miR‐760, which targeted PPP 1R1B . Knockdown of KCNQ 1 OT 1 enhanced chemosensitivity towards MTX through the sponging of miR‐760. MiR‐760 expressed at low levels targeted PPP 1R1B in the activated cAMP signalling pathway under MTX treatment. Knockdown of KCNQ 1 OT 1 dampened the proliferation of MTX ‐resistant ( HT 29/ MTX ) cells by regulating the miR‐760/ PPP 1R1B axis, which also induced cell cycle arrest together with apoptosis. KCNQ 1 OT 1 regulated the expression of PPP 1R1B and the downstream genes CREB and CBP in the cAMP signalling pathway. MTX showed a suppressive function on CRC progression. KCNQ 1 OT 1 enhanced the MTX resistance of CRC cells by regulating miR‐760‐mediated PPP 1R1B expression via the cAMP signalling pathway.