PRAP1 regulates colorectal cancer cell proliferation and ferroptosis through the Nrf2 signaling pathway.

[BACKGROUND] Colorectal cancer (CRC) is a common type of cancer that impacts the digestive tract, and current treatment options have limitations. Studies have confirmed that ferroptosis plays a key role in CRC progression. This research sought to clarify how Proline-rich acidic protein 1 (PRAP1) influences CRC advancement and ferroptosis, and to uncover the underlying mechanisms involved.

[METHODS] Real-time quantitative PCR (RT-qPCR) and western blot were employed to ascertain the levels of PRAP1 in CRC cells (SW480, SW620, and LOVO) and tissues. Immunofluorescence was utilized to locate PRAP1. Biological characterization of CRC cells was determined through CCK-8 assay, EdU staining, Transwell assay, TUNEL staining and Scratch-wound assay. Iron and Fe content was measured using prussian blue staining and iron assay kit. A nude mouse model of xenograft was established, and the impact of PRAP1 on tumor growth was investigated by pathological staining. Expression of ferroptosis-related proteins as well as nuclear factor-erythroid factor 2-related factor 2 (Nrf2) pathway proteins was detected by Western blot.

[RESULTS] PRAP1 levels were elevated in CRC. Overexpression PRAP1 promoted cell proliferation, inhibited apoptosis and ferroptosis. Additionally, overexpression PRAP1 can activate the Nrf2 pathway. However, silencing PRAP1 had the opposite effect. In vivo tumor xenograft experiments showed that silencing PRAP1 resulted in decreased Ki67 positivity and increased TUNEL positivity in tumor tissues, and blocked Nrf2 pathway, thereby inhibited tumor growth.

[CONCLUSION] PRAP1 promotes CRC cell proliferation and inhibits ferroptosis by Nrf2 pathway. This study provides a conceptual framework for the development of novel targeted drugs.