The PRR11-Hippo axis drives osteosarcoma progression through a DNA damage-cell cycle coupling mechanism

Purpose Osteosarcoma (OS) is a prevalent primary malignant bone tumor that predominantly affects children, adolescents, and young adults. Proline-rich protein 11 (PRR11) is wellknown for its role in regulating cell cycle progression and promoting tumorigenesis. Nevertheless, the precise molecular mechanisms underlying PRR11-driven tumorigenesis in OS have yet to be elucidated. In the present study, we aimed to elucidate the role of PRR11 in OS and its underlying molecular mechanisms. Methods Genotype‒tissueexpression(GTEx) and The Cancer Genome Atlas (TCGA) data were analyzed for PRR11 expression (normal vs OS) and survival differences (low vs high expression). Immunohistochemistry(IHC) and western blotting(WB) were performed to examine the expression distribution of the PRR11 protein in OS tissues and cell lines. Three types of lentiviral vectors were used to establish stable 143B cell lines: (1) miRNA-based shRNA vectors, (2) Lenti-CRISPR-Cas9 vectors, and (3) overexpression vectors. RNA-seq analysis of the miRNA-based shRNAs. WB was used to elucidate the mechanisms by whichPRR11 affects DNA damage, DNA repair, the cell cycle, and the Hippo signaling pathway. Moreover, functional assays included colony formation, wound healing, and transwell assays in vitro and subcutaneous inoculation in vivo . Results This studyidentified PRR11 as a pivotal regulator that promotes OS cell migration, invasion, and proliferation in vitro and promotes OS subcutaneous inoculation. RNA-seq analysis revealed that PRR11 silencing regulates several signaling pathways, including the cell cycle, the DNA damage response, and DNA repair;subsequently, the detection of DNA damage/repair markers and cell cycle-related proteins further confirmed alterations in these signaling pathways. Subsequent flow cytometry experiments revealed that PRR11 could prolong the G0/G1 phase and shorten the G2/M phase. Conclusions PRR11 functions as an oncogene in OS, where the PRR11-Hippo axis drivestumor progression through a DNA damage-cell cycle coupling mechanism.