Taken together, our results suggest that this Bax expression system might represent a useful gene therapy strategy when applied to the treatment of prostate cancer and its efficacy would be independent of the Bcl-2 status and androgen sensitivity of these cancers.
Bcl-2 overexpression is commonly associated with various cancers including breast cancer, prostate cancer, B-cell lymphomas and colorectal adenocarcinomas etc.
In this study, we show that sHA is a potent inhibitor of prostate cancer. sHA blocked the proliferation, motility, and invasion of LNCaP, LNCaP-AI, DU145, and LAPC-4 prostate cancer cells, and induced caspase-8-dependent apoptosis associated with downregulation of Bcl-2 and phospho-Bad. sHA inhibited Akt signaling including androgen receptor (AR) phosphorylation, AR activity, nuclear factor κB (NFκB) activation, and VEGF expression.
A natural BH3-mimetic, small-molecule inhibitor of Bcl-2, (-)-gossypol, shows promise in ongoing phase II and III clinical trials for human prostate cancer.
BCL2 mRNA expression in the same collective of prostate cancer tissue samples was associated with higher Gleason score and extracapsular extension of the tumour (pT3).
The relation of Bcl-2 overexpression and copy number gains or translocation of the BCL-2 gene in prostate cancer under hormone-naïve conditions is unknown.
The analysis of p53, bcl-2, Ki-67, and angiogenesis revealed that only increasing p53 expression and positive family history of PCa approached significance (P = 0.057).
Two prostate cancer cell lines expressing Bcl-2 at different levels (PC-3-Bcl-2 and PC-3-Neo) were subjected to antisense Bcl-2 ODN, reverse control (CTL), or mock treatment.
Information on molecular markers obtained from immunohistochemical staining of prostate tissue, included B cell lymphoma-2 (bcl-2), p53, and microvessel density (MVD), each having a previously documented association with disease progression and increased risk of prostate cancer death.
The prostate cancer antigen gene 3 (PCA3) is embedded in an intron of a second gene BMCC1 (Bcl2-/adenovirus E1B nineteen kDa-interacting protein 2 (BNIP-2) and Cdc42GAP homology BCH motif-containing molecule at the carboxyl terminal region 1) which is also upregulated in prostate cancer.
We genotyped 6 single nucleotide polymorphisms in 6 genes, including p53 (rs1042522), p21 (rs1801270), MDM2 (rs2279744), PTEN (rs701848), GNAS1 (rs7121) and bcl2 (rs2279115), using polymerase chain reaction-restriction fragment length polymorphism and direct DNA sequencing in 140 patients with prostate cancer and 167 age matched controls.
Bcl-2 and Bax expression predict prostate cancer outcome in men treated with androgen deprivation and radiotherapy on radiation therapy oncology group protocol 92-02.
One androgen-insensitive prostate cancer cell line, DU-145, lacking in bcl-2 expression, was found to be completely refractory to the effects of the virus ribozyme, supporting the concept that the cytotoxic effects of the ribozyme are based solely on its effects on bcl-2 expression.
These findings identify combined antisense Bcl-2 and paclitaxel as a potentially new therapeutic strategy for advanced prostate cancer by enhancing paclitaxel chemosensitivity and delaying progression of hormone-refractory prostate cancer.