Figure 2.

Lung tumor cells expressing p53 mutations show higher Axl levels. (A) RT-qPCR of Axl mRNA levels in lung cancer cell lines H1437 and H1048. Lung cancer cell lines H1048 and H1437 were infected with control shRNA or p53 shRNA lentivirus to generate mutant p53 knockdown cell lines. Western blot analysis was performed on isolated clones to identify p53 knockdown clones. Erk2 was used as a loading control. These clones were further analyzed for Axl mRNA expression by qPCR using primers specific for the Axl gene and normalized by GAPDH. The data indicate that a decrease in mutant p53 levels lowers Axl levels. (B) RT-qPCR of Axl levels in lung tumors. cDNA was prepared from human lung tumor RNA (labeled “VLU” to protect patient identity) and a normal tissue sample (labeled “2N”) using the SuperScript III cDNA synthesis kit (Invitrogen) and qPCR performed using primers specific for Axl. The degree of expression was quantitated using a relative standard curve and normalized to GAPDH corresponding to the cDNA batch. Experiments were performed in technical triplicates as described in the text. Error bars showing standard deviations are indicated.