Mutant p53 and pro-inflammatory gene expression in colorectal cancer cells

Abstract

p53 gene is the most commonly mutated gene in cancer, and in many malignancies a loss of p53 promotes cancer progression. However recent evidence has shown that missense mutations in p53, particularly those that lead to the protein acquiring abilities not seen in the wild-type form, may actually aid oncogenesis. These so-called ‘gain of function’ mutations are thought to upregulate many pro-inflammatory cytokines, which can enhance tumour growth, and inhibit other proteins, such as TP63 – which has been shown to have anti-oncogenic properties.

The central question of this project is to establish whether gain-of-function mutations in p53 influence the expression of pro-inflammatory genes in colorectal cancer (CRC) cells. To address this question, shRNA constructs against MDM2 were generated to stablise mutant p53, which were then transfected into various CRC cell lines that either harboured a gain-of-function mutation, had wildtype p53, or were void of all p53. In addition, a puromycin-resistance gene was included allowing for the selection of positively transfected cells using puromycin. qPCR primer sets were also developed for measuring the expression of several selected chemokines once the CRC lines had been transfected. To assess the ability of mutant p53 to functionally interact with p63, I attempted to generate a puromycin-selectable p63 expression construct.

Resulting data suggest that gain-of-function p53 mutations may indeed heighten expression of various chemokines.