Abstract
Tumor budding (TB) has become a crucial factor for predicting the malignancy grade and prognostic outcome for multiple types of solid cancer. Studies have investigated the prognostic value of TB in hepatocellular carcinoma (HCC). However, its molecular mechanism in HCC remains unclear. To the best of our knowledge, the present study was the first to compare the expression of differentially expressed genes (DEGs) between TB-positive (TB-pos) and TB-negative HCC tissues. In the present study, total RNA was extracted from 40 HCC tissue specimens and then sequenced. According to Gene Ontology (GO) functional annotation, upregulated DEGs were markedly associated with embryonic kidney development-related GO terms, which suggested that the TB process may at least partly mimic the process of embryonic kidney development. Subsequently, two genes, a disintegrin and metalloproteinase domain with thrombospondin motifs 16 (ADAMTS16) and bone morphogenetic protein 2 (BMP2), were screened and verified through immunohistochemical analysis of HCC tissue microarrays. According to the immunohistochemical results, ADAMTS16 and BMP2 were upregulated in TB-pos HCC samples, and BMP2 expression was increased in budding cells compared with the tumor center. Additionally, through cell culture experiments, it was demonstrated that ADAMTS16 and BMP2 may promote TB of liver cancer, thus promoting the malignant progression of liver cancer. Further analysis revealed that ADAMTS16 expression was associated with necrosis and cholestasis, and BMP2 expression was associated with the Barcelona Clinic Liver Cancer stage and the vessels encapsulating tumor clusters. Overall, the findings of the present study provided insights into the possible mechanisms of TB in HCC and revealed potential anti-HCC therapeutic targets.