Regulation of the microRNA 200b (miRNA-200b) by transcriptional regulators PEA3 and ELK-1 protein affects expression of Pin1 protein to control anoikis.
MicroRNA (miRNA) 200s regulate E-cadherin by directly targeting ZEB1/ZEB2, which are transcriptional repressors of E-cadherin. Decreased expression of E-cadherin results in cancer cells losing interaction with the extracellular matrix and detaching from the primary tumor. Normally, cells will undergo anoikis after losing interaction with the extracellular matrix. Cancer cells must, therefore, possess the ability to resist anoikis during the process of metastasis. Here we show that miRNA-200b regulates anoikis by directly targeting the 3' UTR of Pin1 mRNA and regulating Pin1 expression at the translational level. We found that down-regulation of miRNA-200b promotes cancer cells survival during metastasis, and the homeless state of these cells resulted in decreased expression of miRNA-200b in the MCF-7 cell line. We also found that expression of miRNA-200b is down-regulated in human breast cancer during lymph node metastasis, which has a significant negative correlation with Pin1 expression. Two members of the ETS (E-26) family (PEA3 and ELK-1) regulate the expression of miRNA-200b. PEA3 promotes the expression of miRNA-200b, and ELK-1 is a transcriptional repressor of miRNA-200b. In addition, miRNA-200b regulates the activity of PEA3 and ELK-1 via the Pin1-pERK pathway and forms self-regulated feedback loops. This study characterizes the role of miRNA-200b in the regulation of anoikis and demonstrates the regulation of its own expression in the process of metastasis.
From the State Key Laboratory of Molecular Oncology.
Xusen
X
Zhang
Department of Abdominal Surgery, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
Bailin
B
Zhang
Department of Abdominal Surgery, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
Jidong
J
Gao
Department of Abdominal Surgery, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100021, China.
Xiang
X
Wang
From the State Key Laboratory of Molecular Oncology. Electronic address: liuzh@cicams.ac.cn.
Zhihua
Z
Liu
D020413:3' Untranslated Regions / Q000235:genetics; D023102:Anoikis; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008207:Lymphatic Metastasis; D020935:MAP Kinase Signaling System / Q000235:genetics; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase / Q000096:biosynthesis* / Q000235:genetics; D012334:RNA, Neoplasm / Q000096:biosynthesis* / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D050807:ets-Domain Protein Elk-1 / Q000235:genetics / Q000378:metabolism*
D020413:3' Untranslated Regions; C494112:ELK1 protein, human; C533896:MIRN200 microRNA, human; D035683:MicroRNAs; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D012334:RNA, Neoplasm; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; C065788:transcription factor PEA3; C000606846:PIN1 protein, human; D019696:Peptidylprolyl Isomerase
AKT; Apoptosis; ERK; ETS Family Transcription Factor; MicroRNA