Title: ADDITIONAL MECHANISMS BY WHICH NON-TARGETED GENES COMPENSATE FOR SPECIFIC GENE THERAPY DIRECTED TOWARDS BCL-2 IN A PROSTATE CANCER MODEL A Summary
Antisense oligonucleotides (oligos) have targeted regulatory proteins in both in vivo and in vitro prostate cancer models featuring both the LNCaP and PC-3 cell lines. In efforts to identify compensatory changes in the expression of non-targeted genes these studies evaluated mono- and bispecific oligos capable of targeting and equally suppressing the expression of bcl-2 (an apoptosis inhibitor). Effects upon non-targeted genes could potentially lead to development of more phenotypically aggressive and metastatic tumors. The summation presented here demonstrate that oligo treated LNCaP cells compensate for diminished bcl-2 by suppressing caspase-3 (an apoptosis promoter) while enhancing the expression of AKT-1 (another apoptosis inhibitor). In addition, we found enhanced expression of the androgen receptor (AR), its p300 and IL-6 coactivators, polymerase transcription mediator MED-12, and growth regulating signal transducer STAT-3. Therefore, therapeutic approaches to restore apoptosis through suppression of bcl-2 lead to altered protein expression of non-targeted genes not only involving apoptosis, but also androgen sensitivity and transcription, and more. In addition, proteins associated with cell division as indicated by increased expression of the KI-67 proliferation antigen and mitosis regulating cyclin D1 are increased as are TMPRSS22 and FLI-1, associated respectively with gene fusion involving the ERG protein, as well as chromosomal instability. The net result is an altered pattern of gene expression often associated with more aggressive and proliferative tumors.