Single-cell transcriptome landscape in hepatocellular carcinoma of BALB/C mice after azvudine treatment

Hepatocellular carcinoma is the sixth most common malignant tumor in the world, but there is a lack of effective drugs for the treatment of HCC, so it is urgent to find new treatment strategies. Azvudine is the world's first dual-target innovative anti-AIDS drug, which can selectively enter CD4+T lymphocytes to exert immunomodulatory effects. In the early stage, we found through a retrospective cohort study that azivudine can significantly reduce all-cause mortality and the incidence of composite disease progression in COVID-19 patients with tumors compared with COVID-19 patients without tumors. Therefore, we performed single-cell RNA sequencing on tumor tissues of BALB/C mice treated with azivudine or treated with vehicle to reveal the changes in the tumor microenvironment of azivudine against liver cancer. Four- to six-week-old male BALB/c mice weighing 20.0 ± 2 g were purchased from BEJING HFK BIOSCIENCE Co., Ltd. (Beijing, China). Mice were housed in a specific pathogen-free environment. Each mouse was subcutaneously injected with 5×10^5 H22 cells into the right flank. When the tumors reached approximately 100 mm^3, the mice were randomly divided into three groups to receive oral treatment: the azvudine group (1 mg/kg, QD), and the control group (solvent). The solvent was prepared by sequentially adding the following reagents: 5% DMSO, 40% PEG300, 5% Tween-80, and 50% saline. Tumor volumes were measured daily using a caliper and calculated with the following formula: volume = (length × width2)/2. The mice were euthanized when the tumor volume exceeded 1500 mm^3 or if the maximum tumor diameter exceeded 15 mm. Tumor tissues were subsequently used to performe single-cell RNA sequencing.