PLX260996

GSE76183: Response to ibrutinib treatment in an E-TCL1 mouse model of CLL harboring a p53 alteration

• Organsim mouse
• Type RNASEQ
• Target gene
• Project ARCHS4

Deletion of the short arm of chromosome 17 (17p-) is one of the most critical genetic variants used in B-CLL risk stratification. The tumor suppressor TP53 maps to this region, and its loss or mutation significantly accelerates B-CLL progression, hampers response to chemotherapy, and shortens survival. While florescent in situ hybridization (FISH) analyses for 17p deletions are routinely performed during clinical diagnoses, mutational analyses of the TP53 gene is not widely available and thus its mutational status is often unknown in patients with CLL. Given the limited clinical data that exists for frontline treatment of patients with CLL harboring TP53 mutations, there is a great need to identify novel treatment strategies for this subset of patients. Herein, we use a CLL mouse model (E-TCL1) in the presence or absence of a common TP53 hot-spot mutation (p53R172H, corresponding to p53R175H in humans) to study its impact on disease progression, survival, response to therapy, and dynamic loss of the remaining wild-type Trp53 allele during the course of B-CLL following BTK inhibitor (ibrutinib). We show that ibrutinib was effective in increasing survival and activated gene and cellular programs outside of the p53 pathway in both settings, and thus, did not place selective pressure on the remaining wild type Trp53 allele. These data demonstrate the potent effect of BTK-inhibition in B-CLL and more importantly, provide evidence that ibrutinib acts as an effective treatment for aggressive forms of B-CLL with TP53 mutation and potentially chemo-resistant refractory disease. SOURCE: Yuan Qi (yqi1@mdanderson.org) - University of Texas M.D. Anderson Cancer Center