Supplementary Material for: Makorin ring finger protein 1 inhibits cell proliferation in renal angiomyolipoma via the ERK/MAPK signaling pathway

Introduction: Renal angiomyolipomas (AMLs) are clonal tumors formed by the abnormal differentiation of transformed renal progenitor cells. However, the cytogenetic and malignant transformations of renal AMLs require further investigation. Makorin ring finger protein 1 (MKRN1), a transcriptional co-regulator and E3 ubiquitin ligase, may act as a tumor regulator that mediates tumor biological processes. Although it is known as a prognostic marker of renal cell carcinoma, hepatocellular carcinoma, and pancreatic adenocarcinoma, its expression and function in renal AMLs remain unclear. Therefore, we aimed to investigate the expression and function of MKRN1 in AML cells. Methods: MKRN1 expression in AML tissues was evaluated by immunohistochemistry, western blotting and quantitative real-time PCR. To investigate the functional role of MKRN1 in AML, MKRN1 was overexpressed in AML cells, and cell proliferation was assessed using the Cell Counting Kit-8 assay. Proliferative activity was further confirmed by immunofluorescence staining of Ki-67. To elucidate the molecular mechanisms regulated by MKRN1, gene set enrichment analysis (GSEA) was performed on RNA sequencing data, and the identified signaling pathways were further validated by western blotting analysis. Results: MKRN1 expression was significantly lower in renal AML tissues than in para-tumorous tissues (p<0.0001). MKRN1 overexpression notably inhibited the survival and proliferation of SV7 and UMB cells. GSEA and western blotting analyses indicated that MKRN1 downregulates the ERK/MAPK signaling pathway. MKRN1 expression was correlated negatively with phosphorylated ERK (p-ERK) levels in clinical AML samples, which were significantly elevated. MKRN1 overexpression in AML cells reduced p-ERK expression. Conclusion: This study demonstrates that MKRN1 mediates AML cell proliferation by regulating the ERK/MAPK signaling pathway. These findings suggest that MKRN1 plays a crucial role in AML progression and may serve as a potential diagnostic and therapeutic biomarker for AML.