title: Direct progesterone receptor and indirect androgen receptor interactions with the kallikrein-related peptidase 4 gene promoter in breast and prostate cancer.
abstract: Kallikrein 4 (KLK4) is a member of the human KLK gene family of serine proteases, many of which are implicated in hormone-dependent cancers. Like other KLKs, such as KLK3/PSA and KLK2, KLK4 gene expression is also regulated by steroid hormones in hormone-dependent cancers, although the transcriptional mechanisms are ill defined. Here, we have investigated the mechanisms mediating the hormonal regulation of KLK4 in breast (T47D) and prostate (LNCaP and 22Rv1) cancer cells. We have shown that KLK4 is only expressed in breast and prostate cancers that express the progesterone receptor (PR) and androgen receptor (AR), respectively. Expression analysis in PR- and AR-positive cells showed that the two predominant KLK4 variants that use either TIS1 or TIS2a/b are both up-regulated by progesterone in T47D cells and androgens in LNCaP cells. Two putative hormone response elements, K4.pPRE and K4.pARE at -2419 bp and -1005 bp, respectively, were identified in silico. Electrophoretic mobility shift assays and luciferase reporter experiments suggest that neither K4.pARE nor approximately 2.8 kb of the KLK4 promoter interacts directly with the AR to mediate KLK4 expression in LNCaP and 22Rv1 cells. However, we have shown that K4.pPRE interacts directly with the PR to up-regulate KLK4 gene expression in T47D cells. Further, chromatin immunoprecipitation experiments showed a time-dependent recruitment of the PR to the KLK4 promoter (-2496 to -2283), which harbors K4.pPRE. This is the first study to show that progesterone-regulated KLK4 expression in T47D cells is mediated partly by a hormone response element (K4.pPRE) at -2419 bp.
authors.affiliation: Hormone Dependent Cancer Program, School of Life Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Cnr Blamey Street and Musk Avenue, Kelvin Grove, QLD 4059, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Lai
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Myers
authors.forename: Mitchell G
authors.initials: MG
authors.lastname: Lawrence
authors.forename: Dimitri M
authors.initials: DM
authors.lastname: Odorico
authors.forename: Judith A
authors.initials: JA
authors.lastname: Clements
mesh_terms: D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics*; D002874:Chromosome Mapping; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007610:Kallikreins / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics*; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D011944:Receptors, Androgen / Q000235:genetics*; D011980:Receptors, Progesterone / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D012334:RNA, Neoplasm; D011944:Receptors, Androgen; D011980:Receptors, Progesterone; C425336:KLK14 protein, human; D007610:Kallikreins