Background Specificity protein (Sp) transcription factors play pivotal functions in maintaining
Background Specificity protein (Sp) transcription factors play pivotal functions in maintaining the phenotypes of many cancers. colon malignancy cells, which resulted in the upregulation of the Sp-repressor ZBTB10 and this resulted in downregulation of Sp proteins. Findings The results suggest that the malignancy chemotherapeutic effects of sulindac in colon malignancy cells are due, in part, to its metabolite sulindac sulfide which downregulates Sp transcription factors and Sp-regulated pro-oncogenic gene products. value of <0.05 was considered statistically significant. Experiments were carried out in triplicate and all results are expressed as mean??standard deviation (S.D.) for at least three impartial determinations for each group. Rabbit polyclonal to Dcp1a Results Results buy GSK2141795 illustrated in Fig.?1a and ?andbb show that sulindac and sulindac sulfone inhibited growth of SW480 and RKO cells at cytostatic concentrations between 600C900 and 225C300?M, respectively. Western blot analysis of whole cell lysates from these cells indicated that 600 to 1200?M concentrations of sulindac did not affect expression of Sp1, Sp3 and Sp4 proteins in SW480 and RKO cells after treatment for 24 and 48?h (Fig.?1c). Comparable results were observed in these cells after treatment with 225 or 300?M sulindac sulfone for 24 and 48?h (Fig.?1d) suggesting that growth inhibitory effects of these compounds was Sp-independent. Treatment of SW480 and RKO cells with 50 or 75?M sulindac sulfide for 24?h inhibited cell proliferation (Fig.?2a and ?andb)w) and also slightly decreased manifestation of Sp1, Sp3 and Sp4 proteins in SW480 and RKO cells (Fig.?2c and ?andd).deb). Sulindac sulfide induced comparable responses after treatment for 48?h; however, at this time point, there was a pronounced downregulation of Sp1, Sp3 and Sp4 proteins in SW480 (Fig.?2c) and RKO (Fig.?2d) cells. Thus, sulindac sulfide was the most active sulindac derivative as observed in previous studies [33, 34] and the results suggest that the growth inhibitory effects of sulindac sulfide are correlated with downregulation of pro-oncogenic Sp buy GSK2141795 proteins, and previous studies show that knockdown of one or more [35, 36] buy GSK2141795 Sp proteins in colon malignancy cells decreases cell cycle progression buy GSK2141795 and induces apoptosis. Fig. 1 Sulindac and sulindac sulfone prevent colon malignancy cell growth without decreasing manifestation of Sp1, Sp3 and Sp4 proteins. a, w Sulindac and sulindac sulfone prevent SW480 and RKO cell proliferation. Cells were treated with solvent control (DMSO), 600 … Fig. 2 Sulindac sulfide inhibits colon malignancy cell growth and decreases manifestation of Sp1, Sp3 and Sp4 protein. a, c Sulindac sulfide inhibits SW480 and RKO cell proliferation. Cells were treated with DMSO, 25, 50, and 75?M sulindac sulfide … We also investigated the effects of sulindac sulfide on Sp-dependent pro-apoptotic, growth inhibitory and anti-angiogenic responses in colon malignancy cells. Results illustrated in Figs.?3a buy GSK2141795 and ?andbb show that sulindac sulfide decreased EGFR expression in SW480 and RKO cells after treatment for 24 and 48?h and this is usually consistent with a decrease of EGFR mRNA (qPCR data not shown). We also examined the effects of sulindac sulfide on the p65 subunit of NFB which is usually an Sp-dependent gene product in some malignancy cell lines [26, 35, 37] and sulindac sulfide also decreased p65 manifestation in SW480 and RKO cells (Figs.?3a and ?andb).w). In addition, sulindac sulfide also decreased manifestation of NFB subunit p105 and upregulated manifestation of the NFB inhibitor IB in SW480 and RKO cells (qPCR data not shown). Thus,.