The ‘Other’ subfamily of HECT E3 ubiquitin ligases evaluate the tumour immune microenvironment and prognosis in patients with hepatocellular carcinoma

Primary liver cancer is the sixth most common cancer and the third leading cause of cancer-related death worldwide. The role of the ‘Other’ subfamily of HECT E3 ligases (E3s) in hepatocellular carcinoma (HCC) remains unknown. The expression of the ‘Other’ HECT E3s was performed using The Cancer Genome Atlas (TCGA) data, and the authors found that the ‘Other’ HECT E3s were differentially expressed in HCC. Prognostic values were assessed using the Kaplan–Meier method and indicated that the high expressions of HECTD2, HECTD3, and HACE1 were associated with a worse clinical prognosis of HCC patients. The expression of HECTD2 was significantly correlated with the infiltration of CD4⁺T cells and neutrophils. The levels of HECTD3 and HACE1 were notably related to the dendritic cells and memory B cells infiltrated in HCC. In addition, the three previously mentioned genes have shown to be associated with immune checkpoint genes, such as FOXP3, CCR8, STAT5B, TGFB1 and TIM-3. Moreover, HECTD2 could promote the proliferative activity, cell migration and invasive ability of HCC cells. Collectively, the authors’ study demonstrated that HECTD2 was a novel immune-related prognostic biomarker for HCC, providing new insight into the treatment and prognosis of HCC.