[ALDH1, CD133, CD34-positive cancer stem cells in lung adenocarcinoma in patients who had a new coronavirus infection and retained the persistence of viral proteins in the lung tissue].

Lung cancer occupies a leading position in the structure of global cancer morbidity and mortality, due to the biological properties of the key pool of tumor cells - cancer stem cells (CSCs). The effects of SARS-CoV2 on tumor CSCs and its niche have not been studied.

Objective: To study CSCs in lung adenocarcinomas after COVID19.

Material and methods: Surgical material from lung adenocarcinoma from 12 patients who had a new coronavirus infection and from 12 patients who did not have COVID19 was examined. Analysis of clinical and anamnestic data, macroscopic and microscopic examination of tumor samples and adjacent intact tissue, immunohistochemical reactions using antibodies to virus proteins and CSC markers ALDH1, CD133 and CD34 were performed.

Results: Adenocarcinoma samples from patients in the main group showed a significant increase in the number of cells expressing the CSCs markers ALDH1, CD133 and CD34 compared to adenocarcinoma samples from control group patients without SARS-CoV2 infection. We found an increase in the number of CSCs in patients with adenocarcinoma metastasis in lymph nodes in both the main and control groups. CSCs of lung adenocarcinomas from SARS-CoV2 survivors contain virus proteins Nucleocapside and Spike protein.

Conclusions: We found an increase in the number of CSCs with expression of ALDH1, CD133 and CD34 in lung adenocarcinoma in patients with new coronavirus infection. Increased number of ALDH1+, CD133+ CD34+ CSCs in tumor tissue enhance the metastatic potential of lung adenocarcinoma. The Nucleocapsid and Spike proteins of SARS-CoV2 virus are detectable in lung tissue from patients with new coronavirus infection, both in adenocarcinoma cells, CSCs, and in type II pneumocytes, macrophages, and endothelial cells, suggesting prolonged persistence of the virus proteins and probably the virus.