OnobotulinumtoxinA has no effects on growth of LNCaP and PC3 human prostate cancer cells

Objectives: Intraprostatic injection of botulinum toxin (BTX) has been reported to have therapeutic effects on lower urinary tract symptoms related to benign prostate hyperplasia (BPH). Patients with BPH are at risk of having prostate cancer. The present study was conducted to assess the effect of onobotulinumtoxinA on prostate cancer in vitro and in vivo. Methods: Human prostate cancer cell lines, LNCaP and PC3 were exposed to different doses of onobotulinumtoxinA (0-10 U; Allergan, Irvine, CA, USA). Cell viability, DNA fragmentation and apoptosis assay were subsequently measured. For the in vivo study, LNCaP and PC3 xenografts were introduced into nude mice and treated with intra-tumoral onobotulinumtoxinA or saline injection. Tumor volume, histopathology and apoptosis were assessed. Presence of SNAP-25 protein, the molecular target of onobotulinumtoxinA, was studied in both cell lines by Western blot analysis. Results: OnobotulinumtoxinA did not significantly affect cell proliferation or apoptosis in LNCaP and PC3 cells. There was no significant difference in tumor size and histopathological findings between the experimental and control groups. There was no detectable SNAP-25 protein in both cell lines. Conclusion: OnobotulinumtoxinA does not affect the growth of LNCaP or PC3 cells in vitro and in vivo or produce significant anti-tumor effects. Intraprostatic BTX injection for BPH might not affect the growth of prostate cancer.