Clotam enhances anti-proliferative effect of vincristine in Ewing sarcoma cells

This study evaluated the effect of Clotam (tolfenamic acid or TA), a small molecule and inhibitor of Specificity protein1 (Sp1) and survivin for sensitizing ES cell lines to chemother apeutic agent, vincristine (VCR). ES cells (CHLA-9 and TC-32) were treated with TA or VCR or TA + VCR (combination), and cell viability was assessed after 24/48/72 h. Effect of TA or VCR or TA + VCR treatment on cell cycle arrest and apoptosis were evaluated using propidium iodide, cell cy cle assay and Annexin V flow cytometry respectively. The apoptosis markers, caspase 3/7 (activity levels) and cleaved-PARP (protein expression) were measured. Cardiomyocytes, H9C2 were used as non-malignant cells. While, all treatments caused time- and dose-dependent inhibition of cell viability, in terestingly, combination treatment caused significantly higher response (~ 80% inhibition,p <  0.05). Cell viability inhibition was accompanied by inhibition of Sp1 and Survivin. TA + VCR treatment significantly (p <  0.05) increased caspase 3/7 activity which strongly correlated with upregulated c-PARP level and Annexin V staining. Cell cycle arrest was observed at G0/G1 (TA) or G2/M (VCR and TA + VCR). All treatments did not cause cytotoxicity in H9C2 cells. These results suggest that TA could enhance th e anti-cancer activity of VCR in ES cells. Therefore, TA + VCR combination could be further tested to develop as safe/effective therapeutic strategy for treating ES.
Source: Apoptosis - Category: Molecular Biology Source Type: research