Bioinformatics Analysis and Validation Identify CDK1 and MAD2L1 as Prognostic Markers of Rhabdomyosarcoma

The goal of the current study was to identify potential prognostic biomarkers of rhabdomyosarcoma (RMS).

We screened chip sequencing datasets of RMS through the gene expression omnibus (GEO) database. A total of 74 RMS patient tissues and 39 normal muscle cell tissues were analyzed. Limma R software was used to identify the differentially expressed genes (DEGs) between RMS tissues and normal controls. The GO plot R package was used to visualize the results of the GO analysis. We screened for pathaffy package enrichment of DEGs by the Kyoto Encyclopedia of Genes and Genomes (KEGG). The cutoff criterion was a P-value <0.05. Immunohistochemistry (IHC) was applied to validate the expression of CDK1 (cyclin-dependent kinases 1) and MAD2L1 (Mitotic Arrest Deficient 2 Like 1) in RMS.

We obtained a total of 498 up- and 480 down-regulated DEGs. The hub genes are mainly involved in the cell cycle and P53 singling pathway. CDK1 expression was associated with tumor size and COG-STS (Children's Oncology Group-soft tissue sarcoma) staging of RMS. For the low CDK1 expression group and high CDK1 expression group, the 5-year overall survival (OS) rate was 83.0% vs 63.5% (P = 0.004), and the 5-year event-free survival (EFS) rate was 47.5% vs 27.5% (P = 0.049) respectively. When compared low MAD2L1 expression group with high MAD2L1 expression group, the 5-year OS rate was 80.0% vs 43.2% (P = 0.001), and the 5-year EFS rate was 45.1% vs 21.8% (P = 0.038), respectively. If patients were divided into three groups: low CDK1 and low MAD2L1 expression group, high CDK1 or high MAD2L1 expression group, and high CDK1 and high MAD2L1 expression group, the 5-year OS rate was 87.1%, 58.6%, 39.6% (P = 0.001), while the 5-year EFS rate of RMS patients was 54.2%, 23.2%, 21.7% (P = 0.028), respectively.

This study has identified that CDK1 and MAD2L1 were adverse prognostic factors of RMS.