Bone is not the inorganic, inanimate scaffolding it may so often unfairly be considered, but makes up an important and complex living organic network. It supports, interacts, responds and develops with the rest of the body over time according to both intrinsic (including hormonal) and environmental factors. Like all other organs, the skeleton is vulnerable to disorders and diseases, e.g. osteoporosis and cancers. Transient receptor potential (TRP) ion channels are currently receiving much interest, and may be linked to store-operated calcium entry (SOCE). TRP channels are not particularly selective, and are generally quite widely expressed with increased expression in some malignancies¹, and TRPV1 and TRPM8 ligands may have potential uses as anti-cancer agents². We aim to improve on current knowledge and further characterise TRP channels in bone and hormone-sensitive tissues, and the role they play in calcium storage and release, and subsequently in bone disorders. RT-PCR was carried out using primer pairs for TRPM7, TRPM8, TRPV1, TRPV5 and TRPV6 subunits in MG63 osteoblast-like cells, and LNCaP and DU145 prostate cancer cells. Cell growth assays were performed to test the effects of TRPV1 and TRPM8 agonists, modulators and blockers on cell number, using trypan blue exclusion testing and MTS-conversion absorbance measurement. TRPV1 was shown to be expressed in MG63, DU145 and LNCaP cell lines by RT-PCR. TRPM8 was also shown to be clearly present in LNCaP cells, but present only in low numbers in DU145s and MG63s. RT-PCR also shows that TRPM7, TRPV5 and TRPV6 are also expressed in MG63 cells. In the presence of ≥ 10 μM capsaicin or capsazepine, MG63 cell number was significantly reduced (P < 0.05). Resiniferatoxin (TRPV1 agonist), SB366791 (TRPV1 blocker) and anandamide (cannabinoid and TRPV1 modulator) all decreased MG63 cell numbers. Single channel electrophysiology has shown channel openings characteristic of TRPM8 and TRPV1, but menthol (100 μM) and capsaicin (1 – 10 μM) did not increase activity. As these TRP channel subunits are clearly expressed in MG63, DU145 and LNCaP cell lines, further work is required to locate and also investigate their role in bone and hormone-sensitive cancers.