Targeting Mutated p53 for Cancer Therapeutics using Lipid Nanoparticles

p53 is a tumour suppressor protein that plays a key role in cell cycle regulation and cancer prevention. p53 functions primarily as a tetramer transcription factor, activating genes’ expression involved in the response to various cellular stresses. Mutations in the TP53 gene, which encodes p53, are commonly observed in human cancers, leading to the loss of its tumour suppressive activities. Most TP53 mutations identified are dominant negative (DN) mutations, suggesting that mutated p53 (mut-p53) will interfere with wild-type p53 (wt-p53) function when co-expressed in the cell. We hypothesize that delivery of wt-p53 by itself will not be effective as cancer treatment, due to the endogenous expression of the DN mut-p53. We suggest that repression of mut-p53 followed by exogenous expression of wt-p53 can transiently restore the native function of p53 in cancer cells and will lead to apoptosis. For this aim, we will generate lipid nanoparticles (LNPs) encapsulating both CRISPR inhibition (CRISPRi) mRNA targeting p53, and wt-p53 mRNA. While the CRISPRi-LNPs will repress the transcription of endogenous mut-p53, the exogenous wt-p53 will activate various genes that will lead to apoptosis of cancer cells. Our results show that sequential delivery of CRISPRi to repress endogenous mut-p53 and delivery of wt-p53 can lead to significant cell death of ovarian cancer cell line. Next, we screened LNP formulations for efficient delivery to ovarian cancer cells. Our potential to restore the native function of p53 in cancer cells can be utilized as a strategy to target p53-bearing cancers regardless of the p53 mutation type