Background & objective: PC-1 is a novel gene which is overexpressed in bone metastasis and androgen independent prostate cancer cell line C4-2. The objective of this study was to evaluate the expression level of PC-1 gene in multiple human tumor and normal tissues, and clone a series of putative PC-1 gene promoter regions and analyze their promoter activities.
Methods: PC-1 gene specific DNA sequence was used as probe to hybridize with total RNA from 10 pairs of tumor and normal tissues; The C4-2 cell genomic DNA was used as a template in the polymerase chain reaction to amplify PC-1 upstream regions from the translation initiation codon. The PCR product was directly cloned into the luciferase reporter vector pGL3-basic. C4-2 cells were transiently transfected with above recombinant plasmids and the putative promoter activities were analyzed by luciferase assay.
Results: PC-1 gene expression level is remarkable higher in multiple tumor tissues than in their matched normal tissues; there is no promoter activity in the 340 bp fragment from the upstream of initiation codon, while 1099 bp, 1337 bp, 1579 bp, 1831 bp, and 4939 bp fragments had the promoter activities.
Conclusion: The PC-1 gene expression is specifically activated in multiple human tumor tissues, suggesting that PC-1 gene expression might be involved in cancer development. Our primary data shows that the highest promoter activity of PC-1 gene is within the 4939 bp DNA fragment and maybe there exists an enhancer element between the 1831 bp and 4939 bp area.