Effect of DPP4/CD26 expression on SARS­CoV­2 susceptibility, immune response, adenosine (derivatives m62A and CD) regulations on patients with cancer and healthy individuals.

The worldwide COVID­19 pandemic was brought on by a new coronavirus (SARS Cov­2). A marker/receptor called Dipeptidyl peptidase 4/CD26(DPP4/CD26) may be crucial in determining susceptibility to tumors and coronaviruses. However, the regulation of DPP4 in COVID­invaded cancer patients and its role on small molecule compounds remain unclear. The present study used the Human Protein Atlas, Monaco, and Schmiedel databases to analyze the expression of DPP4 in human tissues and immune cells. The association between DPP4 expression and survival in various tumor tissues was compared using GEPIA 2. The DNMIVD database was used to analyze the correlation between DPP4 expression and promoter methylation in various tumors. On the cBioPortal network, the frequency of DPP4 DNA mutations in various cancers was analyzed. The correlation between DPP4 expression and immunomodulators was analyzed by TISIDB database. The inhibitory effects of cordycepin (CD), N6, N6­dimethyladenosine (m62A) and adenosine (AD) on DPP4 in cancer cells were evaluated. DPP4 was mainly expressed in endocrine tissue, followed by gastrointestinal tract, female tissue (mainly in placenta), male tissue (mainly in prostate and seminal vesicle), proximal digestive tract, kidney, bladder, liver, gallbladder and respiratory system. In immune cells, DPP4 mRNA was mainly expressed in T cells, and its expression was upregulated in esophageal carcinoma, kidney renal papillary cell carcinoma (KIRP), liver hepatocellular carcinoma (LIHC), lung adenocarcinoma, pancreatic adenocarcinoma, prostate adenocarcinoma, stomach adenocarcinoma, thyroid carcinoma and thymoma. However, it was downregulated in breast invasive carcinoma, kidney chromophobe, lung squamous cell carcinoma and skin cutaneous melanoma. Thus, DPP4 is involved in viral invasion in most types of cancer. The expression of DPP4 could be inhibited by CD, m62A and AD in different tumor cells. Moreover, CD significantly inhibited the formation of GFP­positive syncytial cells. In vivo experiments with AD injection further showed that AD significantly inhibited lymphocyte activating factor 3 expression. These drugs may have potential to treat COVID­19 by targeting DPP4. Thus, DPP4 may be medically significant for SARS­CoV­2­infected cancer patients, providing prospective novel targets and concepts for the creation of drugs against COVID­19.

Impact of TMPRSS2 Expression, Mutation Prognostics, and Small Molecule (CD, AD, TQ, and TQFL12) Inhibition on Pan-Cancer Tumors and Susceptibility to SARS-CoV-2.

As a cellular protease, transmembrane serine protease 2 (TMPRSS2) plays roles in various physiological and pathological processes, including cancer and viral entry, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein, we conducted expression, mutation, and prognostic analyses for the TMPRSS2 gene in pan-cancers as well as in COVID-19-infected lung tissues. The results indicate that TMPRSS2 expression was highest in prostate cancer. A high expression of TMPRSS2 was significantly associated with a short overall survival in breast invasive carcinoma (BRCA), sarcoma (SARC), and uveal melanoma (UVM), while a low expression of TMPRSS2 was significantly associated with a short overall survival in lung adenocarcinoma (LUAD), demonstrating TMPRSS2 roles in cancer patient susceptibility and severity. Additionally, TMPRSS2 expression in COVID-19-infected lung tissues was significantly reduced compared to healthy lung tissues, indicating that a low TMPRSS2 expression may result in COVID-19 severity and death. Importantly, TMPRSS2 mutation frequency was significantly higher in prostate adenocarcinoma (PRAD), and the mutant TMPRSS2 pan-cancer group was significantly associated with long overall, progression-free, disease-specific, and disease-free survival rates compared to the wild-type (WT) TMPRSS2 pan-cancer group, demonstrating loss of functional roles due to mutation. Cancer cell lines were treated with small molecules, including cordycepin (CD), adenosine (AD), thymoquinone (TQ), and TQFL12, to mediate TMPRSS2 expression. Notably, CD, AD, TQ, and TQFL12 inhibited TMPRSS2 expression in cancer cell lines, including the PC3 prostate cancer cell line, implying a therapeutic role for preventing COVID-19 in cancer patients. Together, these findings are the first to demonstrate that small molecules, such as CD, AD, TQ, and TQFL12, inhibit TMPRSS2 expression, providing novel therapeutic strategies for preventing COVID-19 and cancers.

The regulation of ISG20 expression on SARS-CoV-2 infection in cancer patients and healthy individuals.

ISG20 inhibits viruses such as SARS-CoV-2 invasion; however, details of its expression and regulation with viral susceptibility remain to be elucidated. The present study analyzed ISG20 expression, isoform information, survival rate, methylation patterns, immune cell infiltration, and COVID-19 outcomes in healthy and cancerous individuals. Cordycepin (CD) and N6, N6-dimethyladenosine (m6 2A) were used to treat cancer cells for ISG20 expression. We revealed that ISG20 mRNA expression was primarily located in the bone marrow and lymphoid tissues. Interestingly, its expression was significantly increased in 11 different types of cancer, indicating that cancer patients may be less vulnerable to SARS-CoV-2 infection. Among them, higher expression of ISG20 was associated with a long OS in CESC and SKCM, suggesting that ISG20 may be a good marker for both viral prevention and cancer progress. ISG20 promoter methylation was significantly lower in BLCA, READ, and THCA tumor tissues than in the matched normal tissues, while higher in BRCA, LUSC, KIRC, and PAAD. Hypermethylation of ISG20 in KIRC and PAAD tumor tissues was correlated with higher expression of ISG20, suggesting that methylation of ISG20 may not underlie its overexpression. Furthermore, ISG20 expression was significantly correlated with immune infiltration levels, including immune lymphocytes, chemokine, receptors, immunoinhibitors, immunostimulators, and MHC molecules in pan-cancer. STAD exhibited the highest degree of ISG20 mutations; the median progression-free survival time in months for the unaltered group was 61.84, while it was 81.01 in the mutant group. Isoforms ISG20-001 and ISG20-009 showed the same RNase_T domain structure, demonstrating the functional roles in tumorigenesis and SARS-CoV-2 invasion inhibition in cancer patients. Moreover, CD and m6 2A increase ISG20 expression in various cancer cell lines, implying the antiviral/anti-SARS-CoV-2 therapeutic potential. Altogether, this study highlighted the value of combating cancer by targeting ISG20 during the COVID-19 pandemic, and small molecules extracted from traditional Chinese medicines, such as CD, may have potential as anti-SARS-CoV-2 and anticancer agents by promoting ISG20 expression.

The regulation of ISG20 expression on SARS-CoV-2 infection in cancer patients and healthy individuals

ISG20 inhibits viruses such as SARS-CoV-2 invasion;however, details of its expression and regulation with viral susceptibility remain to be elucidated. The present study analyzed ISG20 expression, isoform information, survival rate, methylation patterns, immune cell infiltration, and COVID-19 outcomes in healthy and cancerous individuals. Cordycepin (CD) and N6, N6-dimethyladenosine (m62A) were used to treat cancer cells for ISG20 expression. We revealed that ISG20 mRNA expression was primarily located in the bone marrow and lymphoid tissues. Interestingly, its expression was significantly increased in 11 different types of cancer, indicating that cancer patients may be less vulnerable to SARS-CoV-2 infection. Among them, higher expression of ISG20 was associated with a long OS in CESC and SKCM, suggesting that ISG20 may be a good marker for both viral prevention and cancer progress. ISG20 promoter methylation was significantly lower in BLCA, READ, and THCA tumor tissues than in the matched normal tissues, while higher in BRCA, LUSC, KIRC, and PAAD. Hypermethylation of ISG20 in KIRC and PAAD tumor tissues was correlated with higher expression of ISG20, suggesting that methylation of ISG20 may not underlie its overexpression. Furthermore, ISG20 expression was significantly correlated with immune infiltration levels, including immune lymphocytes, chemokine, receptors, immunoinhibitors, immunostimulators, and MHC molecules in pan-cancer. STAD exhibited the highest degree of ISG20 mutations;the median progression-free survival time in months for the unaltered group was 61.84, while it was 81.01 in the mutant group. Isoforms ISG20-001 and ISG20−009 showed the same RNase_T domain structure, demonstrating the functional roles in tumorigenesis and SARS-CoV-2 invasion inhibition in cancer patients. Moreover, CD and m62A increase ISG20 expression in various cancer cell lines, implying the antiviral/anti-SARS-CoV-2 therapeutic potential. Altogether, this study highlighted the value of combating cancer by targeting ISG20 during the COVID-19 pandemic, and small molecules extracted from traditional Chinese medicines, such as CD, may have potential as anti-SARS-CoV-2 and anticancer agents by promoting ISG20 expression.

The Correlation Between Immune Invasion and SARS-COV-2 Entry Protein ADAM17 in Cancer Patients by Bioinformatic Analysis.

SARS-Cov-2 caused the COVID-19 pandemic worldwide. ADAM17 functions as a disintegrin and transmembrane metalloproteinase domain protein involved in the regulation of SARS-CoV-2 receptor ACE2. However, its impact on cancer patients infected with COVID-19 and its correlation with immune cell infiltration is unclear. This study compared ADAM17 expression between normal and tumor tissues based on GEPIA. The correlations between ADAM17 expression and immune cell infiltration and immunomodulators were investigated. Besides, treated drugs for targeting ADAM17 were searched in the TISDB database. We found that ADAM17 was highly conserved in many species and was mainly expressed in lung, brain, female tissues, bone marrow and lymphoid tissues. It was also highly expressed in respiratory epithelial cells of rhinitis and bronchus. ADAM17 expression in tumors was higher than that in several paired normal tissues and was negatively correlated with the prognosis of patients with malignant tumors. Interestingly, ADAM17 expression significantly correlated with immunomodulators and immune cell infiltration in normal and tumor tissues. Moreover, eight small molecules targeting ADAM17 only demonstrate therapeutic significance. These findings imply important implications for ADAM17 in cancer patients infected with COVID-19 and provide new clues for development strategy of anti-COVID-19.

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

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 (m62A), respectively. We found that CTSL 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 CTSL is 66.4-fold higher in normal lungs and 54.8-fold higher in cancer tissues, as compared to ACE2 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 CTSL 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 CTSL 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 m62A 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 m62A could inhibit its expression, suggesting the therapeutic potential of targeting CTSL for cancer and COVID-19 treatment.

COVID-19 disease and malignant cancers: The impact for the furin gene expression in susceptibility to SARS-CoV-2.

Furin is a proprotein convertase that activates different kinds of regulatory proteins, including SARS-CoV-2 spike protein which contains an additional furin-specific cleavage site. It is essential in predicting cancer patients' susceptibility to SARS-CoV-2 and the disease outcomes due to varying furin expressions in tumor tissues. In this study, we analyzed furin's expression, methylation, mutation rate, functional enrichment, survival rate and COVID-19 outcomes in normal and cancer tissues using online databases, and our IHC. As a result, furin presented with biased expression profiles in normal tissues, showing 12.25-fold higher than ACE2 in the lungs. The furin expression in tumors were significantly increased in ESCA and TGCT, and decreased in DLBC and THYM, indicating furin may play critical mechanistic functions in COVID-19 viral entry into cells in these cancer patients. Line with furin over/downexpression, furin promoter hypo-/hyper-methylation may be the regulatory cause of disease and lead to pathogenesis of ESCA and THYM. Furthermore, presence of FURIN-201 isoform with functional domains (P_proprotein, Peptidase_S8 and S8_pro-domain) is highest in all cancer types in comparison to other isoforms, demonstrating its use in tumorigenesis and SARS-Cov-2 entry into tumor tissues. Furin mutation frequency was highest in UCES, and its mutation might elevate ACE2 expression in LUAD and UCEC, reduce ACE2 expression in COAD, elevate HSPA5 expression in PAAD, and elevate TMPRSS2 expression in BRCA. These results showed that furin mutations mostly increased expression of ACE2, HSPA5, and TMPRSS2 in certain cancers, indicating furin mutations might facilitate COVID-19 cell entry in cancer patients. In addition, high expression of furin was significantly inversely correlated with long overall survival (OS) in LGG and correlated with long OS in COAD and KIRC, indicating that it could be used as a favorable prognostic marker for cancer patients' survival. GO and KEGG demonstrated that furin was mostly enriched in genes for metabolic and biosynthetic processes, retinal dehydrogenase activity, tRNA methyltransferase activity, and genes involving COVID-19, further supporting its role in COVID-19 and cancer metabolism. Moreover, Cordycepin (CD) inhibited furin expression in a dosage dependent manner. Altogether, furin's high expression might not only implies increased susceptibility to SARS-CoV-2 and higher severity of COVID-19 symptoms in cancer patients, but also it highlights the need for cancer treatment and therapy during the COVID-19 pandemic. CD might have a potential to develop an anti-SARS-CoV-2 drug through inhibiting furin expression.

Evaluation and characterization of HSPA5 (GRP78) expression profiles in normal individuals and cancer patients with COVID-19.

HSPA5 (BiP, GRP78) has been reported as a potential host-cell receptor for SARS-Cov-2, but its expression profiles on different tissues including tumors, its susceptibility to SARS-Cov-2 virus and severity of its adverse effects on malignant patients are unclear. In the current study, HSPA5 has been found to be expressed ubiquitously in normal tissues and significantly increased in 14 of 31 types of cancer tissues. In lung cancer, mRNA levels of HSPA5 were 253-fold increase than that of ACE2. Meanwhile, in both malignant tumors and matched normal samples across almost all cancer types, mRNA levels of HSPA5 were much higher than those of ACE2. Higher expression of HSPA5 significantly decreased patient overall survival (OS) in 7 types of cancers. Moreover, systematic analyses found that 7.15% of 5,068 COVID-19 cases have malignant cancer coincidental situations, and the rate of severe events of COVID-19 patients with cancers present a higher trend than that for all COVID-19 patients, showing a significant difference (33.33% vs 16.09%, p<0.01). Collectively, these data imply that the tissues with high HSPA5 expression, not low ACE2 expression, are susceptible to be invaded by SARS-CoV-2. Taken together, this study not only indicates the clinical significance of HSPA5 in COVID-19 disease and cancers, but also provides potential clues for further medical treatments and managements of COVID-19 patients.