STK36, a member of the serine/threonine kinase family, has been reported to be highly expressed in cancers. However, there have been fewer reports on the expression and role of STK36 in hepatocellular carcinoma (HCC).

We used the Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases to evaluate the differential expression of STK36 in HCC and normal tissues. Immunohistochemistry (IHC) and quantitative real-time reverse transcription polymerase chain reaction(qRT-PCR) validated the expression of STK36 in HCC. The chi-square test was employed to study the relationship between STK36 and clinical characteristics. The prognostic significance of STK36 expression was analyzed using Kaplan-Meier and Cox regression methods. We also studied the association between STK36 and immunity. We discussed STK36 expression at the single-cell and spatial transcriptome distribution levels. Drug sensitivity analysis was utilized to discuss the link between STK36 expression and small-molecule drugs. Gene Set Enrichment Analysis (GSEA) was used to discuss the function of STK36 in HCC.

STK36 expression was elevated in HCC from the TCGA and ICGC databases. IHC and qRT-PCR confirmed the overexpression of STK36 in HCC. STK36 expression had a positive correlation with T stage (tumor stage). STK36 expression was an independent prognostic factor affecting HCC patients’ outcomes. A relationship existed between STK36 expression and the infiltration of immune cells as well as immune checkpoints. Single-cell and spatial transcriptome analyses demonstrated that STK36 was upregulated in HCC. GSEA showed that STK36 was involved in some pathways, including ECM-receptor interaction, cell cycle, etc.

STK36 acts as a potential prognostic index in HCC, serves as a potential biomarker for predicting response to immunotherapy, and provides a rationale for further functional studies.