Integrative multi-omics characterization of HECTD3 across pan-cancer and its functional validation in thyroid cancer

The E3 ubiquitin ligase HECTD3 has been associated with many cancers; however, its comprehensive pan-cancer attributes and precise function in Thyroid Carcinoma (THCA) have not been thoroughly elucidated. The objective of this investigation is to systematically characterize the multi-omics landscape, diagnostic/prognostic value, and immunological features of HECTD3 across human cancers. Furthermore, we aim to validate its biological functions in THCA through experiments conducted in cell and animal experiment. We analyzed HECTD3 expression, prognosis, and diagnostic value using TCGA, and HPA databases. Cox regression and KM analyses were employed to evaluate survival. UALCAN database was used for methylation analysis. TIMER3.0 were used to assess the tumor immune microenvironment. Drug sensitivity analysis was conducted using GDSC and CTRP databases. Functional validation was performed using CCK-8, colony formation, Transwell, Oris assays, and xenograft mouse models. HECTD3 exhibited significant differential expression across 33 cancer types. It served as an independent protective factor in THCA and KIRC but acted as an oncogene in LAML, LGG, LIHC, MESO, and UCS. Mechanistically, HECTD3 expression was linked to DNA promoter methylation, m6A regulators, and immune infiltration. Elevated expression of HECTD3 was correlated with resistance to various chemotherapeutic agents. In THCA, experiments conducted in vitro and in vivo confirmed that HECTD3 overexpression significantly suppressed tumor cell proliferation, migration, invasion, and xenograft growth, while knockdown promoted malignant phenotypes. This study unveils the tissue-specific duality of HECTD3 in pan-cancer. It identifies HECTD3 as an innovative tumor suppressor and a clinically relevant prognostic marker and a candidate therapeutic target for THCA.