PAXIP1, also known as PAX-interacting protein 1, is a chromatin-binding protein with a BRCT domain. It is involved in multiple biological processes. PAXIP1 is part of a heterodimeric complex with PAGR1, and together they play a role in regulating the chromatin association of the cohesin complex, which is crucial for maintaining sister chromatid cohesion and folding chromatin by DNA loop extrusion [4]. PAXIP1 is also related to the regulation of gene expression, immune cell maturation, and DNA repair [4].

In cancer research, PAXIP1-AS1, an antisense RNA of PAXIP1, has been studied. In gastric cancer, PAXIP1-AS1 is transcriptionally repressed by HOXD9 and its down-regulation is correlated with tumor progression. Overexpression of PAXIP1-AS1 inhibits cell growth and metastasis by destabilizing PABPC1, which enhances the stability of PAK1 mRNA and promotes EMT and metastasis [1]. In ovarian cancer, low expression of PAXIP1-AS1 is associated with poor survival and immune infiltration, suggesting it could be a prognosis biomarker and relevant for immunotherapy [3]. In breast cancer, PAXIP1 mutations co-occur with BRCA1/2 reversions in PARP inhibitor-resistant advanced breast cancer [2]. In hepatocellular carcinoma, lower PAXIP1 levels are associated with improved survival rates, and its expression is related to immune cell infiltration and immune markers [5].

In conclusion, PAXIP1 and its associated lncRNA PAXIP1-AS1 play important roles in cancer progression and prognosis. The study of PAXIP1 through various in vivo models helps in understanding its function in disease conditions, especially in cancer, and may provide potential therapeutic targets.