Abstract
More than 200 million people have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and 4 million deaths have been reported worldwide to date. Cathepsin B/cathepsin L (CTSB/L) are SARS-CoV-2 entry–associated proteases and facilitate SARS-CoV-2 to infect host cells. However, the expressions of CTSB/L in healthy individuals and cancer patients remain not fully elucidated yet. Here, we comprehensively profiled the expressions and distributions of CTSB/L in human normal tissues, cancer tissues, and cell lines. Moreover, we compared CTSB/L expressions between various cancers and matched normal tissues, and investigated their genetic alteration and prognostic values in pan-cancer. Finally, we also explored the correlation between CTSB/L expressions and immune infiltration. We found that CTSB was highly expressed in most tissues, and CTSL was highly expressed predominantly in the digestive, urinary, and respiratory systems, such as the lungs, liver and gallbladder, and kidney tissues in the translational level. Moreover, cancer patients may be more susceptible to SARS-CoV-2 infection. Our data suggested that CTSB/L are overexpressed in aerodigestive and genitourinary cancers when compared with that in matched normal tissues, and their expressions were closely related to the prognosis of some cancer types. Interestingly, CTSB/L expressions were significantly correlated with immune cell infiltration in manifold cancer tissues and their corresponding normal tissues. In conclusion, our study shows a comprehensive bioinformatic analysis of two important SARS-CoV-2 entry–related proteases, which could provide a potential indication on prevention of SARS-CoV-2 infection.
Highlights
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered as a new human-infecting betacoronavirus, which has resulted in an outbreak of coronavirus diseases 2019 (COVID-19) worldwide (Lu et al, 2020; Zhu et al, 2020)
It was found that the expression of cathepsin B (CTSB) mRNA was primarily located in the endocrine, adipose and soft, and bone marrow and lymphoid tissues, whereas the expressional distribution of the CTSB protein was significantly different from its mRNA expression
Evidence has shown that CTSB/L play a critical role in the process of coronavirus infecting host cells
Summary
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered as a new human-infecting betacoronavirus, which has resulted in an outbreak of coronavirus diseases 2019 (COVID-19) worldwide (Lu et al, 2020; Zhu et al, 2020). It is well known that the spike glycoprotein of SARS-CoV-2 can bind the angiotensin-converting enzyme 2 to facilitate its entrance into the host cells (Hoffmann et al, 2020; Lan et al, 2020). Some host cell proteases such as cathepsin B (CTSB) and cathepsin L (CTSL) can cleave and activate the spike protein, leading to the virus infection (Smieszek et al, 2020; Bollavaram et al, 2021). The expressions and distributions of CTSL/B may explain the differences in susceptibility to SARSCoV-2 infection
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call