Effects of indomethacin on expression of PTEN tumour suppressor in human cancers

BACKGROUND: Previous studies reported that Non-steroidal Anti-inflammatory Drugs (NSAIDs), chemicals, and food supplements can be used to up-regulate the PTEN mRNA and protein expression, suggesting that these substances may be used in prevention and/or treatment of various human cancers like spinal, brain, colon, breast, prostate, bladder and endometrial cancers. AIM: This was to study expression and sub-cellular localisation of PTEN protein, and review the effect(s) of indomethacin on PTEN's expression in cultured Human Endometrial Cancer (HEC 1B) cell line, which is known to express significant amounts of the wild-type PTEN. MATERIALS AND METHODS: This involves culture and incubation of artificial HEC 1B cells. All procedures were undertaken in the cell culture hood under the recommended sterile conditions. The cells were then incubated with different concentrations of indomethacin solution, for variable durations and finally fixed (with paraformaldehyde) and stained with fluorescein-labelled diluted secondary antibody (FITC). Immunocytochemistry (IHC) and fluorescent microscopy were then employed for the detection and localisation of the specific antigen (PTEN), using antibodies. RESULTS: The HEC 1B cells, which were cultured and incubated with different concentrations of indomethacin solution, expressed the PTEN protein, most of which was localised to the nucleus with minimal cytoplasmic expression. Increased PTEN expression was observed following treatment of the cells with various concentrations of the solution for variable durations, although there was cell death at higher concentrations and longer duration. This procedure was repeated several times, in order to have consistency and to validate the results. CONCLUSION: This study agrees with previous studies in similar human cell lines and supports the idea that NSAIDs and other drugs may be used in the future for prevention of human cancers. However, more studies need to be carried out to substantiate these observations.