Expression of TSC genes in oral tumor samples and cell lines. a) Semi-quantitative RT-PCR analysis of TSC genes in 16 matched normal and tumor samples. Note, downregulation of both genes in tumor samples. Each square or triangle corresponds to data from one sample. Horizontal lines represent mean values of mRNA expression across normal or tumor samples. b) Western blot analysis of TSC1 and TSC2 in eight matched normal and tumor tissues. TSC1 and TSC2 show no expression or downregulation in tumor samples. c) Western blot analysis of TSC1 and TSC2 in three oral cancer (KB, SCC 104 and SCC 131), lung carcinoma (A549), embryonic kidney (HEK-293T), cervical carcinoma (HeLa) and hepatic carcinoma (HepG2) cell lines. Note, the expression of TSC2 is not detectable in the oral cancer cell line SCC 131.