Identification of transcription factor SP-1 upregulating the expression of L-plastin in hormone-independent prostate cancer / 中国病理生理杂志

ABSTRACT

AIM: To identify the non-steroid transcription factors upregulating the expression of L-plastin in hormone-independent prostate cancer, and partly elucidate the mechanism of hormone-refractory prostate cancer. METHODS: TF SEARCH software was used to analysis the possible binding sites of transcription factors in the 3’ end of L-plastin promoter that had been identified as important part of regulation response elements. Gel shift assay and supershift assay were used to confirm the transcription factors binding the speculated response elements. PCR site-mutagenesis technique was performed to delete the binding site of transcription factor and luciferase activity assay was carried out after deletion of the binding site. RESULTS: SP-1 respond element GGTGGGGCGGGGA located at -54- -41 of L-plastin promoter was identified with the TF SEARCH software. Gel shift assay and supershift assay confirmed that SP-1 was the transcription factor binding to GGTGGGGCGGGGA. Mutant deleted the SP-1 binding-site had low-luciferase activity than that of the naive. CONCLUSION: SP-1 plays an important role in the up-regulation of L-plastin expression in hormone-independent prostate cancer.