UBE2Q1 as a novel cancer biomarker for lung adenocarcinoma: Short Title: Oncogenic function of UBE2Q1 in lung adenocarcinoma.

Purpose: Ubiquitin-conjugating enzymes (E2s) participate in various tumor-promoting processes. UBE2Q1 is a member of the E2 family. This research aimed to detect the expression level of UBE2Q1 in human lung adenocarcinoma and to study its malignant biological function.

Methods: Western blot, qRT-PCR and immunohistochemistry was used to measure the expression of UBE2Q1 in human lung adenocarcinoma tissues. The association between UBE2Q1 expression and clinic-pathological variables in 99 lung adenocarcinoma samples was analyzed by immunohistochemistry. In vitro experiment, establishing UBE2Q1 knockdown pattern, the markers of apoptosis, cell cycle and epithelial-mesenchymal transition (EMT) were analyzed by Western blot. CCK8, colony formation, Transwell and invasion assay analyzed the effect of UBE2Q1 knockdown on the proliferation, metastasis and invasion of lung cancer cells.

Results: UBE2Q1 was overexpressed in lung adenocarcinoma, and the expression level of UBE2Q1 was related with TNM stage, tumor size, and lymph node metastasis. The high level of UBE2Q1 expression was also associated with poor survival and was an independent risk factor. In vitro, It was also confirmed that steady downregulation of UBE2Q1 could promote apoptosis, induce G2/M cell cycle arrest and regulate EMT. UBE2Q1 silencing dramatically reduce lung tumor cells proliferation, migration and invasion capacities.

Conclusions: UBE2Q1 may serve as a prognostic biomarker and a new therapeutic target of lung adenocarcinoma.