[Identification of response element gene sequence for non-steroid hormone transcription factors for the activation and up-regulation of L-plastin expression in prostate cancer].
OBJECTIVE
To search and identify the non-steroid receptor binding cis-acting elements in the L-plastin promoter in prostate cancer, and the correlative regulation pathway and transcription factors.


METHODS
On the basis of construction of the L-plastin promoter luciferase vectors which were removed the steroid hormone receptor AR and ER binding elements, the promoter on the vector was nest-deleted by Exonuclease III and the relative luciferase plasmids were constructed. Transfected these twelve plasmids into prostate cancer cell line LNCaP under dihydrotestosterone-stimulated situation or not and test the intensity of luciferase, then we got the regulation message of every 200 bp part of the promoter in prostate cancer. After the analysis of relative programme, we got the possible regu- lation pathway of non-steroid hormone transcription factors. After removing the possible transcription factors binding site sequence by site-specific mutagenesis, the changes luciferase of activities proved our reasoning.


RESULTS
We succeed in segmental deletion of the L-plastin promoter, and constructing the relative plasmids containing part L-plastin promoter on luciferase vector pGL3-basic. After testing the luciferase activities of constructed plasmids, we found the sequence from 206 to 1 of L-plastin promoter had significant luciferase activity. The software TRANSFECT showed that there were binding elements for transcription factors AP-4 at seq-198 to 192 and SP-1 at seq-54 to 41 on the short part promoter (206 to 1). The recombinant plasmids deleted the AP-4 and SP-1 binding elements had lower luciferase activity than the wild-type.


CONCLUSIONS
There are some other non-steroid hormone pathway to regulate the expression of L-plastin except the steroid hormone pathway in prostate cancer. The main binding sites of the non-steroid hormone regulator lies in the sequence from 206 to 1. Transcription factors AP4 and SP-1 may up-regulated the expression of L-plastin by binding these sites.
Lin
Tian-xin
TX
Department of Urology, the Second Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120, China.
Huang
Jian
J
Huang
Hai
H
Cai
Qing-qing
QQ
Xu
Ke-wei
KW
Yin
Xin-bao
XB
Jiang
Chun
C
D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic; D008156:Luciferases / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins; D051379:Mice; D008840:Microfilament Proteins; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011471:Prostatic Neoplasms / Q000378:metabolism*; D020218:Response Elements; D014157:Transcription Factors / Q000502:physiology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
D004268:DNA-Binding Proteins; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D014157:Transcription Factors; C055473:enhancer-binding protein AP-4; C026742:plastin; D008156:Luciferases