METHODS: Respiratory epithelial cells were isolated and divided into four groups: control (untreated), treated with 0.05% OE (OE group), EMT induced with 5 ng/ml of transforming growth factor beta-1 (TGFβ1 group) and treated with 5 ng/ml TGFβ1 + 0.05% OE (TGFβ1 + OE group). The effects of OE treatment on growth kinetics, morphology and protein expression in RECs were evaluated. Immunocytochemistry analysis was performed to quantitate the total percentage of E-cadherin and vimentin expression from day 1 to day 3.
RESULTS: There were no significant differences between untreated RECs and OE-treated RECs in terms of their morphology, growth kinetics and protein expression. Induction with TGFβ1 caused RECs to have an elongated spindle shape, a slower proliferation rate, a higher expression of vimentin and a lower expression of E-cadherin compared with the control. Cells in the TGFβ1 + OE group had similar epithelial shape to untreated group however it had no significant differences in their proliferation rate when compared to TGFβ1-induced RECs. Cells treated with TGFβ1 + OE showed significantly reduced expression of vimentin and increased expression of E-cadherin compared with the TGFβ1 group (P vimentin) upon treatment with OE and TGFβ1. Therefore, this study could provide insight into the therapeutic potential of OE to inhibit pathological tissue remodelling and persistent inflammation.
MATERIALS AND METHODS: Formalin-fixed paraffinembedded (FFPE) blocks of muscle-invasive bladder cancer patients receiving cisplatin-based chemotherapy between January 2010 to December 2020 were traced. Immunohistochemistry staining was performed on traced blocks using antibodies to e-cadherin, vimentin and actin, and p53.
RESULTS: p53 and e-cadherin were stained positive in most cases (p=0.515 and 0.242 respectively), although e-cadherin showed stronger positive expression in pre-cisplatin receiving MIBC cases. All the cases stained negative for actin and vimentin except for faint staining observed in one pre-cisplatin case.
CONCLUSION: Although this study does not show a significant correlation between EMT markers and p53 with cisplatin-responsiveness in MIBC patients, the results serve as preliminary findings on the heterogeneous outcomes of molecular staining in the Malaysian MIBC patient cohort.
HYPOTHESIS: Intracellular copper levels have been reported to correlate with tumor pathogenesis and affect the sensitivity of cancer cells to cytotoxic chemotherapy. We hypothesized that intracellular copper levels may affect the sensitivity of oral cancer cells to curcumin.
METHODS: We analysed the correlation between intracellular copper levels and response to curcumin treatment in a panel of OSCC cell lines derived from oral cancer patients. Exogenous copper was supplemented in curcumin insensitive cell lines to observe the effect of copper on curcumin-mediated inhibition of cell viability and migration, as well as induction of oxidative stress and apoptosis. Protein markers of cell migration and oxidative stress were also analysed using Western blotting.
RESULTS: Concentrations of curcumin which inhibited 50% OSCC cell viability (IC50) was reduced up to 5 times in the presence of 250 µM copper. Increased copper level in curcumin-treated OSCC cells was accompanied by the induction of intracellular ROS and increased level of Nrf2 which regulates oxidative stress responses in cells. Supplemental copper also inhibited migration of curcumin-treated cells with enhanced level of E-cadherin and decreased vimentin, indications of suppressed epithelial-mesenchymal transition. Early apoptosis was observed in combined treatment but not in treatment with curcumin or copper alone.
CONCLUSION: Supplement of copper significantly enhanced the inhibitory effect of curcumin treatment on migration and viability of oral cancer cells. Together, these findings provide molecular insight into the role of copper in overcoming insensitivity of oral cancer cells to curcumin treatment, suggesting a new strategy for cancer therapy.