Abstract 1037: Targeting the RBM38-EIF4E complex to increase wild-type p53 as a novel cancer therapeutic strategy

Abstract

Abstract To date, dysregulation of more than 450 RNA-binding proteins (RBPs) across a multitude of cancers has been implicated in tumorigenesis and chemoresistance. In fact, emerging evidence suggests RBPs are principal modulators of every hallmark of cancer progression. Functionally, RBPs are believed to modulate the stability, localization, and translation of transcripts encoding for virtually all known oncogenes and tumor suppressor genes. Consequently, aberrant expression of RBPs may contribute to the malignant transformation of cancer cells through enhancing the expression of oncogenes or decreasing the expression of tumors suppressor genes, such as TP53. As a potent transcription factor, TP53 is a leading regulator of numerous signaling pathways involved in tumor suppression. While mutation or deletion of TP53 contributes to tumorigenesis in more than half of all human cancers, suppression of wild-type TP53 expression also drives tumorigenesis. Thus far, multiple RBPs have been implicated in the repression of wild-type TP53, such as RNA-binding motif protein 38 (RBM38). Specifically, RBM38 interacts with eukaryotic translation initiation factor 4E (EIF4E) on the TP53 transcript, preventing EIF4E from binding to TP53 m7G cap, thus inhibiting TP53 translation. We previously demonstrated that Pep8, an 8 amino acid peptide derived from RBM38, disrupts the RBM38-EIF4E complex enhancing TP53 expression. Moreover, Pep8 alone or in combination with doxorubicin, significantly decreased tumor xenograft growth. As activation of wild-type TP53 by targeting non-genetic mechanisms that inhibit TP53 expression is a promising therapeutic tactic for malignancies that carry wild-type TP53, we are developing more efficacious Pep8 derivatives as a novel therapeutic approach for cancers that express wild-type TP53. Citation Format: Chris August Lucchesi, Jin Zhang, Xinbin Chen. Targeting the RBM38-EIF4E complex to increase wild-type p53 as a novel cancer therapeutic strategy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1037.