MCT-1 deactivates p53 but activates p53 inhibitors in tumor development. H1299 tumor biopsies were subjected to qRT-PCR analysis. (A) MCT-1 mRNA levels in the MCT-1 + p53 xenograft tumors were decreased comparative to the MCT-1 xenografts. (B) The p53 mRNA levels in the tumors were significantly declined in the MCT-1 + p53 xenografts relative to the control + p53 xenografts. (C) MDM2 mRNA amounts were moderately increased by ectopic MCT-1 and further promoted by p53 restoration. Low MDM2 mRNA levels were presented that was probably due to ectopic MCT-1 depress the p53 function. (D-E) Pirh2 and Cop1 mRNA levels were constitutively enhanced by oncogenic MCT-1 in a p53-independent manner. Statistical analysis was performed with the Student's t test. ***p < 0.0001.