4-Fluorobenzaldehyde limonene-based thiosemicarbazone induces apoptosis in PC-3 human prostate cancer cells.

AIMS: This study evaluated parameters of toxicity and antiproliferative effects of (+)-N(1)-4-fluorobenzaldehyde-N(4)-{1-methyl-1-[(1R)-4-methylcyclohexene-3-il]-ethyl}-thiossemicarbazone (4-FTSC) in PC-3 adenocarcinoma prostate cells.

MAIN METHODS: Cytotoxicity of 4-FTSC in PC-3 cells was evaluated using MTT assay. Morphology examination of PC-3 cells treated with 4-FTSC was also performed as well as the cell death mechanisms induced were investigated using flow cytometry. Parameters of toxicity of 4-FTSC was conducted by the investigation of its potential myelotoxicity and lymphotoxicity, hemolytic activity and acute oral toxicity profile.

KEY FINDINGS: 4-FTSC showed promising cytotoxic effects against PC-3 cells (IC50  = 18.46 μM). It also triggered apoptotic morphological changes, phosphatidylserine externalization and a significant increase of DNA fragmentation in PC-3 cells. Moreover, 4-FTSC did not show changes in the PC-3 cell cycle with levels of p21, p27, NFĸB and cyclin D1 similar to those found in both control and treated cells. 4-FTSC also promoted an increase of p53 levels associated with mitochondrial impairment through loss of ∆Ψm and ROS overproduction. 4-FTSC-induced cell death mechanism in PC-3 cells involved activation of caspase-3/-7 through apoptosis intrinsic pathway via caspase-9. Regarding toxicological profile, 4-FTSC showed in vitro lymphotoxicity, although with low cytotoxicity for bone marrow progenitors and no hemolytic potential. Moreover, it was classified as GHS category 5 (LD50  > 2000-5000 mg/Kg), suggesting it has low acute oral systemic toxicity.

SIGNIFICANCE: 4-FTSC seems to be a promising candidate to be used as a clinical tool in prostate cancer treatment. Further studies are required to better clarify its toxicopharmacological effects found in this compound.