title: miR-135b, upregulated in breast cancer, promotes cell growth and disrupts the cell cycle by regulating LATS2.
abstract: Dysregulation of microRNAs (miRNAs) plays a critical role in cancer progression. They can act as either oncogenes or tumor suppressor genes in human cancer. The purpose of this study was to investigate the crucial role of miR-135b in breast cancer and to validate whether miR-135b could regulate proliferation of breast cancer cells by effecting specific targets in the Hippo pathway. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was carried out to quantify the expression levels of miR-135b in both breast cancer tissues and cell lines. To characterize the function of miR-135b, MTT assays, colony formation assays, cell migration assays, cell invasion assays, and cell cycle assays were used. Luciferase reporter assays were performed to validate the regulation of a putative target of miR-135b, in corroboration with western blot assays. Finally, we verified the changes of cellular function after transfection of LATS2-siRNA. Our experiments indicate that expression of miR-135b was commonly upregulated in breast cancer specimens and breast cancer cells when compared with that in adjacent normal tissues and non-malignant breast epithelial cells. Enforced expression of miR-135b can regulate cellular proliferation, migration and invasion as well as disrupt the cell cycle of breast cancer cells. Luciferase assays revealed that miR-135b directly bound to the 3'-untranslated region (3'-UTR) of LATS2 (large tumor suppressor kinase 2), a critical gene in the Hippo pathway. Western blot analysis verified that miR-135b regulated the expression of LATS2 at protein levels. Further study demonstrated that the downstream gene of LATS2 in the Hippo pathway, such as cyclin-dependent kinase 2 (CDK2) and Phospho-Yes-associated protein (p-YAP), can also be regulated by miR-135b and LATS2 axis. Knockdown of endogenous LATS2 can mimic the result of miR-135b up-regulation in breast cancer. Taken together, our findings reveal that the miR-135b and LATS2 axis may be a potential therapeutic target for breast cancer in the future.
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Kaiyao
authors.initials: K
authors.lastname: Hua
authors.affiliation: Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Jiali
authors.initials: J
authors.lastname: Jin
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Junyong
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Jialu
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Hongming
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Dengfeng
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Niraj
authors.initials: N
authors.lastname: Maskey
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Bingkun
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Chenyang
authors.initials: C
authors.lastname: Wu
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Breast and Thyroid Surgery, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Fang
mesh_terms: D020413:3' Untranslated Regions; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D059447:Cell Cycle Checkpoints; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D000090683:Hippo Signaling Pathway; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; C544965:MIRN135 microRNA, human; D035683:MicroRNAs; D025521:Tumor Suppressor Proteins; C406449:LATS2 protein, human; D017346:Protein Serine-Threonine Kinases