EXPRESSION OF P53 PROTEIN ASSOCIATES WITH ANTI-PD-L1 TREATMENT RESPONSE ON HUMAN-DERIVED XENOGRAFT MODEL OF GATA3/CR5/6-NEGATIVE RECURRENT NONMUSCULAR INVASIVE BLADDER UROTHELIAL CARCINOMA

Abstract

Annotation: The study investigated the prognostic role of p53 expression in patients with GATA3 / CR5 / 6-negative recurrent nonmuscular invasive bladder cancer on the background of anti-PD-L1 treatment using a xenograft model in immunodeficient BALB / c nu / nu mice obtained from a patient. Twenty lines of patient-derived xenografts of relapsed high-PD-L1(+) double-negative NMIBC were developed, of which 10 lines represented high-grade tumors and the other ones—low-grade bladder cancer. Acceptors of each grade-related branch received specific anti-PD-L1 antibodies. Animals’ survival, tumor-doubling time, and remote metastasis were followed during the post-interventional period. PD-L1, GATA3, CR5/6, and p53 protein expressions in engrafted tumors were assessed by immunohistochemistry. The expression of p53 protein is an independent factor affecting the animals’ survival time of anti-PD-L1-treated mice with low-grade high-PD-L1(+) double-negative nonmuscular invasive bladder cancer. P53 expression may be considered as a prognostic factor for the anti-PD-L1 treatment efficacy of low-grade high-PD-L1-positive GATA3(-)/CR5/6(-)-relapsed noninvasive bladder cancer.