Now showing 1 - 3 of 3
  • Publication
    The analysis of serum response factor expression in bone and soft tissue prostate cancer metastases
    Castration-resistant prostate cancer (CRPC) represents a challenge to treat with no effective treatment options available. We recently identified serum response factor (SRF) as a key transcription factor in an in vitro model of castration resistance where we showed that SRF inhibition resulted in reduced cellular proliferation. We also demonstrated an association between SRF protein expression and CRPC in a cohort of castrate-resistant transurethral resections of the prostate (TURPS). The mechanisms regulating the growth of CRPC bone and visceral metastases have not been explored in depth due to the paucity of patient-related material available for analysis. In this study, we aim to evaluate SRF protein expression in prostate cancer (PCa) metastases, which has not previously been reported.
    Scopus© Citations 15  539
  • Publication
    Relationship between serum response factor and androgen receptor in prostate cancer
    Background: Serum response factor (SRF) is an important transcription factor in castrate-resistant prostate cancer (CRPC). Since CRPC is associated with androgen receptor (AR) hypersensitivity, we investigated the relationship between SRF and AR. Materials and Methods: Transcriptional activity was assessed by luciferase assay. Cell proliferation was measured by MTT and flow cytometry. Protein expression in patients was assessed by immunohistochemistry. Results: To investigate AR involvement in SRF response to androgen, AR expression was down-regulated using siRNA. This resulted in the abrogation of SRF induction post-DHT. Moreover, DHT stimulation failed to induce SRF transcriptional activity in AR-negative PC346 DCC cells, which was only restored following AR over-expression. Next, SRF expression was down-regulated by siRNA, resulting in AR increased transcriptional activity in castrate-resistant LNCaP Abl cells but not in the parental LNCaP. This negative feedback loop in the resistant cells was confirmed by immunohistochemistry which showed a negative correlation between AR and SRF expression in CRPC bone metastases and a positive correlation in androgen-naïve prostatectomies. Cell proliferation was next assessed following SRF inhibition, demonstrating that SRF inhibition is more effective than AR inhibition in castrate-resistant cells. Conclusion: Our data support SRF as a promising therapeutic target in combination with current treatments. Prostate 75:1704–1717, 2015. © 2015 Wiley Periodicals, Inc.
    Scopus© Citations 6  504
  • Publication
    Role of serum response factor expression in prostate cancer biochemical recurrence
    Background: Up to a third of prostate cancer patients fail curative treatment strategiessuch as surgery and radiation therapy in the form of biochemical recurrence (BCR) whichcan be predictive of poor outcome. Recent clinical trials have shown that menexperiencing BCR might benefit from earlier intervention post-radical prostatectomy(RP). Therefore, there is an urgent need to identify earlier prognostic biomarkers whichwill guide clinicians in making accurate diagnosis and timely decisions on the nextappropriate treatment. The objective of this study was to evaluate Serum ResponseFactor (SRF) protein expression following RP and to investigate its association with BCR.Materials and Methods: SRF nuclear expression was evaluated by immunohistochemistry(IHC) in TMAs across three international radical prostatectomy cohorts for a totalof 615 patients. Log-rank test and Kaplan-Meier analyses were used for BCRcomparisons. Stepwise backwards elimination proportional hazard regression analysiswas used to explore the significance of SRF in predicting BCR in the context of otherclinical pathological variables. Area under the curve (AUC) values were generated bysimulating repeated random sub-samples.Results: Analysis of the immunohistochemical staining of benign versus cancer coresshowed higher expression of nuclear SRF protein expression in cancer cores comparedwith benign for all the three TMAs analysed (P < 0.001, n = 615). Kaplan-Meier curves ofthe three TMAs combined showed that patients with higher SRF nuclear expression hada shorter time to BCR compared with patients with lower SRF expression (P < 0.001,n = 215). Together with pathological T stage T3, SRF was identified as a predictor of BCRusing stepwise backwards elimination proportional hazard regression analysis(P = 0.0521). Moreover ROC curves and AUC values showed that SRF was betterthan T stage in predicting BCR at year 3 and 5 following radical prostatectomy, thecombination of SRF and T stage had a higher AUC value than the two taken separately.Conclusions: SRF assessment by IHC following RP could be useful in guiding cliniciansto better identify patients for appropriate follow-up and timely treatment.
      432Scopus© Citations 8