RUNX1 predicts poor prognosis and correlates with tumor progression in clear cell renal carcinoma

Background: Runt-related transcription factor 1 (RUNX1), also called acute myeloid leukaemia 1, is a member of RUNX family of transcription factors. This family is composed of evolutionarily conserved transcription factors that function as critical lineage determinants in various tissues, however its function in cancer development and clinical significance in RCC are still unknown. Methods: We used paraffin-embedded tumor tissues from 100 patients and fresh-harvested and paired adjacent normal renal tissues from 15 RCC patients who underwent primary surgical resection in Xijing Hospital between 2018 and 2022. The expression level of RUNX1 was evaluated by immunohistochemistry and Western Blot. RUNX1 promoted tumor cells proliferation, migration and invasion were verified by CCK-8, wound-healing and transwell assays. Finally, we constructed a xenografts model of the 786-O cell lines to observe the effect of RUNX1 on tumorigenesis in vivo. Results: TCGA database showed higher RUNX1 expression levels in KIRC (kidney renal clear cell carcinoma). In overall survival analysis, RCC patients with higher RUNX1 expression level would have a shorter survival period than those with lower expression. Similarly, immunohistochemical results of our cohort also showed that RUNX1 was over-expression in cancer tissues than in corresponding non-cancer tissues. We also proved this result at protein level by western-blot. Meanwhile, prognostic and OS analyses of our cohort showed that the RUNX1 expression level was an individual prognostic factor in RCC patients. CCK-8, wound-healing and transwell assays proved that the overexpression of RUNX1 in Caki-1 cells promoted the proliferation, migration and invasion of the cells. Knocking down RUNX1 in 786-O cells inhibited the proliferation, migration and invasion of cells. The experimental results of xenografts model in nude mice showed that the knockdown of RUNX1 in 786-O cells slowed down the growth of tumor. Conclusion: RUNX1 is a poor prognostic factor of clear cell renal carcinoma, which may provide a novel therapeutic target for ccRCC.