Expression signature, prognosis value and immune characteristics of cathepsin F in non-small cell lung cancer identified by bioinformatics assessment.

BACKGROUND: In recent years, immunotherapies and targeted therapies contribute to population-level improvement in NSCLC cancer-specific survival, however, the two novel therapeutic options have mainly benefit patients containing mutated driven genes. Thus, to explore other potential genes related with immunity or targeted therapies may provide novel options to improve survival of lung cancer patients without mutated driven genes. CTSF is unique in human cysteine proteinases. Presently, CTSF has been detected in several cell lines of lung cancer, but its role in progression and prognosis of lung cancer remains unclear. METHODS: CTSF expression and clinical datasets of lung cancer patients were obtained from GTEx, TIMER, CCLE, THPA, and TCGA, respectively. Association of CTSF expression with clinicopathological parameters and prognosis of lung cancer patients was analyzed using UALCAN and Kaplan-Meier Plotter, respectively. LinkedOmics were used to analyze correlation between CTSF and CTSF co-expressed genes. Protein-protein interaction and gene-gene interaction were analyzed using STRING and GeneMANIA, respectively. Association of CTSF with molecular markers of immune cells and immunomodulators was analyzed with Immunedeconv and TISIDB, respectively. RESULTS: CTSF expression was currently only available for patients with NSCLC. Compared to normal tissues, CTSF was downregulated in NSCLC samples and high expressed CTSF was correlated with favorable prognosis of NSCLC. Additionally, CTSF expression was correlated with that of immune cell molecular markers and immunomodulators both in LUAD and LUSC. Noticeably, high expression of CTSF-related CTLA-4 was found to be associated with better OS of LUAD patients. Increased expression of CTSF-related LAG-3 was related with poor prognosis of LUAD patients while there was no association between CTSF-related PD-1/PD-L1 and prognosis of LUAD patients. Moreover, increased expression of CTSF-related CD27 was related with poor prognosis of LUAD patients while favorable prognosis of LUSC patients. CONCLUSIONS: CTSF might play an anti-tumor effect via regulating immune response of NSCLC.

Bldesin, the first functionally characterized pathogenic fungus defensin with Kv1.3 channel and chymotrypsin inhibitory activities.

Fungus defensin is a kind of important natural peptide resource, such as plectasin from the soil fungus Pseudoplectania nigrella with potential application in the antimicrobial peptide lead drug discovery. Here, a fungus defensin named Bldesin with Kv1.3 channel and serine protease inhibitory activities was first explored. By GST-Bldesin fusion expression and enterokinase cleaving strategy, recombinant Bldesin was obtained successfully. Antimicrobial assays showed that Bldesin had potent activity against Gram-positive Staphylococcus aureus, but had no effect on Gram-negative Escherichia coli. Electrophysiological experiments showed that Bldesin had Kv1.3 channel inhibitory activity. Serine protease inhibitory associated experiments showed that Bldesin had unique chymotrypsin protease inhibitory, elastase protease inhibitory, and serine protease-associated coagulation inhibitory activities. To the best of our knowledge, Bldesin is the first functionally characterized pathogenic fungus defensin with Kv1.3 channel and chymotrypsin inhibitory activities and highlighted novel pharmacological effects of fungus-derived defensin peptides.