ERβ-mediated estradiol enhances epithelial mesenchymal transition of lung adenocarcinoma through increasing transcription of midkine.
Epithelial-mesenchymal transition (EMT) plays a specific role in the migration of tumor cells. Both estrogen and midkine (MK) have been thought to be important factors in promoting the progression of non-small-cell lung cancer (NSCLC) and can enhance EMT. Some evidence indicated the correlation between estradiol (E2) and MK, but the precise mechanism on their interreaction is unknown. Here, we try to clarify whether and how E2 regulates MK expression to promote EMT. We found that E2 increased MK mRNA expression in lung adenocarcinoma cells LTEP-a2 and A549 in a time-dependent manner. E2-induced MK expression was inhibited by the estrogen receptor (ER) antagonist ICI 182,780 and tamoxifen but not by phosphoinositide-3 kinase and MAPK inhibitors, suggesting a genomic mechanism of E2 on the regulation of MK transcription. Moreover, luciferase reporter and chromatin immunoprecipitation assays exhibited that E2 induced ERβ recruitment to the estrogen response element in the MK promoter. Small interfering RNA to ERα and ERβ revealed that ERβ mainly mediated E2-induced MK transcription. Interestingly, E2 enhanced MK expression in accordance with increase of EMT, whereas knockdown of MK could block EMT under E2 stimulation. Importantly, through analyzing lung adenocarcinoma tissues, there was indeed a correlation among levels of E2, MK, and EMT-related protein expression. Taken together, we reported a previously unrecognized mechanism on E2 in the regulation of MK expression and proved that MK plays a pivotal role in progression of E2-regulated EMT.
Immunology and Reproductive Biology Laboratory, Medical School & State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, PR China.
Guangfeng
G
Zhao
Yunzhong
Y
Nie
Mingming
M
Lv
Lingfang
L
He
Tingting
T
Wang
Yayi
Y
Hou
D000230:Adenocarcinoma / Q000097:blood / Q000378:metabolism / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D004958:Estradiol / Q000097:blood / Q000502:physiology*; D047628:Estrogen Receptor alpha / Q000819:agonists; D047629:Estrogen Receptor beta / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D000078792:Midkine; D009414:Nerve Growth Factors / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D010636:Phenols; D011422:Propionates / Q000494:pharmacology; D011485:Protein Binding; D011720:Pyrazoles / Q000494:pharmacology; D034622:RNA Interference; D020218:Response Elements; D015398:Signal Transduction; D018709:Statistics, Nonparametric; D014158:Transcription, Genetic
C486182:2,3-bis(4-hydroxyphenyl)-propionitrile; D014408:Biomarkers, Tumor; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; C066254:MDK protein, human; D009414:Nerve Growth Factors; D009570:Nitriles; D010636:Phenols; D011422:Propionates; D011720:Pyrazoles; C486184:4,4',4''-(4-propyl-((1)H)-pyrazole-1,3,5-triyl) tris-phenol; D000078792:Midkine; D004958:Estradiol