Abstract 5649: PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath tumors

Abstract

Abstract Background: Paired related-homeobox 1 (PRRX1) is a transcription factor in the regulation of developmental morphogenetic processes. There is growing evidence that PRRX1 is highly expressed in certain cancers and is critically involved in human survival prognosis. However, the molecular mechanism of PRRX1 in cancer malignancy remains to be elucidated. Methods: PRRX1 expression in human Malignant peripheral nerve sheath tumors (MPNSTs) samples was detected immunohistochemically to evaluate survival prognosis. MPNST models with PRRX1 gene knockdown or overexpression were constructed in vitro, and the phenotype of MPNST cells was evaluated. Bioinformatics analysis combined with co-immunoprecipitation, mass spectrometry, RNA seq, and structural prediction were used to identify proteins interacting with PRRX1. Results: High expression of PRRX1 was associated with a poor prognosis for MPNST. PRRX1 knockdown suppressed the tumorigenic potential. PRRX1 overexpressed in MPNSTs directly interacts with topoisomerase 2A (TOP2A) to cooperatively promote epithelial-mesenchymal transition and increase expression of tumor malignancy-related gene sets including mTORC1, KRAS, and SRC signaling pathways. Etoposide, a TOP2A inhibitor used in the treatment of MPNST, may exhibit one of its anticancer effects by inhibiting the PRRX1-TOP2A interaction. Conclusion: Targeting the PRRX1-TOP2A interaction in malignant tumors with high PRRX1 expression might provide a novel tumor-selective therapeutic strategy. Significance: MPNST is a malignant tumor with a poor prognosis and still lacks definitive treatment. Our results could hold promise as an alternative therapeutic strategy to inhibit the interaction between PRRX1 and TOP2A, and may improve the prognosis for malignant tumor patients with high expression of PRRX1 and TOP2A such as MPNSTs. Citation Format: Shota Takihira, Eiji Nakata, Daisuke Yamada, Tatsunori Osone, Tomoka Takao, Takeshi Takarada, Akira Hirasawa, Takuto Itano, Tomohiro Fujiwara, Toshiyuki Kunisada, Toshifumi Ozaki. PRRX1-TOP2A interaction is a malignancy-promoting factor in human malignant peripheral nerve sheath tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5649.