(A) GS modulates cell cycle regulatory and anti-apoptotic proteins. SCC4 cells were incubated for different time points (0 h - 36 h) with of GS (50 μM) and whole-cell extracts were prepared. Panel shows western blot analysis of (i) cyclin D1, (ii) p27, (iii) p21, (iv) Bax, (v) Bcl2, (vi) Bak, (vii) tBid, (viii) xIAP, (ix) Mcl1, (x) c-myc and (xi) survivin (xii) α-tubulin served as a loading control, (xiii) histograms showing fold change (mean ± S.D.) of protein expression, (xiv) histograms showing increased Bax/Bcl2 ratio (mean ± S.D.) in SCC4 cells (*,**p < 0.005) (B) Panel shows increased expression of cytochrome c in cytosolic fractions of GS-treated SCC4 cells in a time dependent manner (0 h - 36 h). Absence of succinate dehydrogenase (mitochondrial protein) expression in cytosolic fractions (C) confirmed the purity of cytosolic (C) and mitochondrial (M) sub-cellular fractions (* p < 0.05).