COVID-19 receptor and malignant cancers: Association of CTSL expression with susceptibility to SARS-CoV-2

• Published in: International journal of biological sciences 2022-01, Vol.18 (6), p.2362-2371
• Main Authors: Zhang, Lianmei, Wei, Chunli, Li, Dabing, He, Jiayue, Liu, Shuguang, Deng, Haoyue, Cheng, Jingliang, Du, Jiaman, Liu, Xiaoyan, Chen, Hanchun, Sun, Suan, Yu, Hong, Fu, Junjiang
• Format: Article
• Language: English
• Subjects: ACE2; Angiotensin-Converting Enzyme 2; Antibodies; Brain tumors; Breast cancer; Cathepsin L; Cordycepin; Coronaviruses; COVID-19; COVID-19 - drug therapy; COVID-19 - genetics; Cysteine proteinase; Datasets; Furin; Furin - genetics; Furin - metabolism; Gene expression; Genomes; Glioma; Humans; Immunohistochemistry; Infections; Lung cancer; Lung Neoplasms; Lungs; Medical prognosis; Mutation; Mutation rates; Pathogenesis; Patients; Peptidase; Peptidases; Prostate cancer; Protein expression; Proteinase; Proteins; Research Paper; Respiratory diseases; RNA, Messenger; SARS-CoV-2; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Survival; Survival analysis; Tissues; Tumor cell lines
• ISSN: 1449-2288; 1449-2288
• DOI: 10.7150/ijbs.70172

CTSL is expressed by cancerous tissues and encodes a lysosomal cysteine proteinase that regulates cancer progression and SARS-CoV-2 entry. Therefore, it is critical to predict the susceptibility of cancer patients for SARS-CoV-2 and evaluate the correlation between disease outcomes and the expression of CTSL in malignant cancer tissues. In the current study, we analyzed CTSL expression, mutation rate, survival and COVID-19 disease outcomes in cancer and normal tissues, using online databases. We also performed immunohistochemistry (IHC) to test CTSL expression and western blot to monitor its regulation by cordycepin (CD), and N6, N6-dimethyladenosine (m A), respectively. We found that is conserved across different species, and highly expressed in both normal and cancer tissues from human, as compared to ACE2 or other proteinases/proteases. Additionally, the expression of CTSL protein was the highest in the lung tissue. We show that the mRNA expression of is 66.4-fold higher in normal lungs and 54.8-fold higher in cancer tissues, as compared to mRNA expression in the respective tissues. Compared to other proteases/proteinases/convertases such as TMPRSS2 and FURIN, the expression of CTSL was higher in both normal lungs and lung cancer samples. All these data indicate that might play an important role in COVID-19 pathogenesis in normal and cancer tissues of the lungs. Additionally, the CTSL-002 isoform containing both the inhibitor_I29 and Peptidase_C1 domains was highly prevalent in all cancers, suggesting its potential role in tumor progression and SARS-CoV-2 entry in multiple types of cancers. Further analysis of the expression of CTSL mutant showed a correlation with FURIN and TMPRSS2, suggesting a potential role of CTSL mutations in modulating SARS-CoV-2 entry in cancers. Moreover, high expression of significantly correlated with a short overall survival (OS) in lung cancer and glioma. Thus, CTSL might play a major role in the susceptibility of lung cancer and glioma patients to SARS-CoV-2 uptake and COVID-19 severity. Furthermore, CD or m A inhibited CTSL expression in the cancer cell lines A549, MDA-MB-231, and/or PC3 in a dose dependent manner. In conclusion, we show that CTSL is highly expressed in normal tissues and increased in most cancers, and CD or m A could inhibit its expression, suggesting the therapeutic potential of targeting CTSL for cancer and COVID-19 treatment.