Control of proteinase expression by phorbol-ester- and Fos-dependent pathways in human non-small-cell lung-cancer cells

Network Pharmacology-Based Analysis of the Effects of Corydalis decumbens (Thunb.) Pers. in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is one of the most malignant tumors worldwide. The main treatment for NSCLC is based on Western medicine; however, the overall effect is unsatisfactory. This study aimed to investigate the potential therapeutic targets and pharmacological mechanisms of action of the traditional Chinese medicine Corydalis decumbens (Thunb.) Pers. in NSCLC based on network pharmacology and bioinformatics. The overlapping genes between Corydalis decumbens (Thunb.) Pers. and NSCLCs were screened using Venn analysis. Cytoscape 3.7.1 software was used to analyze the overlapping target protein-protein interaction (PPI) network. Gene ontology and pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomics database were performed to exploring biological functions of the overlapping genes. The gene expression profiling interactive analysis dataset was used to analyze the correlation between hub gene expression and disease. This study revealed 38 nodes with 191 edges, which may be therapeutic targets for NSCLC. PPI network analysis showed that the most likely association was between the genes AR and NCOA2, NCOA2, and RXRA and ESR1 and NCOA2. These overlapping genes were mainly enriched in the estrogen signaling pathway, calcium signaling pathway, cholinergic synapse, and PI3K-Akt signaling pathway. ESR2 mRNA levels were significantly downregulated in patients with lung adenocarcinoma (LUAD) getting worse, and KDR levels were lower in lung squamous cell carcinoma (LUSC) than those in normal tissue. PTGS2 expression was correlated with the median survival time of LUAD, and ESR1 expression was correlated with the median survival time of LUSC. The application of network pharmacology revealed the potential mechanism underlying the effects of Corydalis decumbens (Thunb.) Pers. in NSCLC treatment and provided a theoretical basis for further in-depth research in this field.

Human tissue-type plasminogen activator

Tissue-type plasminogen activator (t-PA ) plays an important role in the removal of intravascular fibrin deposits and has several physiological roles and pathological activities in the brain. Its production by many other cell types suggests that t-PA has additional functions outside the vascular and central nervous system. Activity of t-PA is regulated at the level of its gene transcription, its mRNA stability and translation, its storage and regulated release, its interaction with cofactors that enhance its activity, its inhibition by inhibitors such as plasminogen activator inhibitor type 1 or neuroserpin, and its removal by clearance receptors. Gene transcription of t-PA is modulated by a large number of hormones, growth factors, cytokines or drugs and t-PA gene responses may be tissue-specific. The aim of this review is to summarise current knowledge on t-PA function and regulation of its pericellular activity, with an emphasis on regulation of its gene expression.

Proteolytic processing of cut homeobox 1 by neutrophil elastase in the MV4;11 myeloid leukemia cell line

Proteolytic processing by cathepsin L generates p110 Cut homeobox 1 (CUX1) at the end of the G(1) phase, whereas an alternative transcript encodes p75 CUX1. These short CUX1 isoforms were reported to be overexpressed in cancer cells, and transgenic mice overexpressing the p75 isoform were found to develop myeloproliferative disease-like myeloid leukemias. In the present study, we report that the neutrophil elastase can also generate a short CUX1 isoform in the MV4;11 acute myeloid leukemia cell line. Proteolytic processing was so efficient that the full-length CUX1 protein was detected only when cells were maintained in the presence of the specific elastase inhibitor III. In agreement with these findings, higher levels of the processed cyclin E isoforms were also detected in MV4;11 cells. Reappearance of full-length cyclin E and CUX1 could be induced upon the treatment of MV4;11 cells with the differentiation inducer phorbol 12-myristate 13-acetate or, unexpectedly, following overexpression of a short recombinant CUX1 protein. In both cases, the mechanism involved transcriptional repression of the neutrophil elastase gene. This result revealed a negative feedback loop whereby CUX1 shuts down the expression of the protease that cleaves it. Overall, the findings in MV4;11 and other cancer cells suggest that various mechanisms are used in cancer to favor the expression of short CUX1 isoforms.

Matrigel invasion by the prostate cancer cell lines, PC3 and DU145, and cathepsin L+B activity

Cathepsins L and B are lysosomal cysteine proteinases whose activities and cellular location are altered in many types of cancers and cancer cell lines. Cathepsins L and B play an unspecified role in cancer invasion and metastasis. The purpose of our study was to determine whether cathepsins L and B are important for the ability of two prostate cancer cell lines, PC3 and DU 145, to invade the basement membrane-like preparation, Matrigel. Exposure of PC3 and DU145 to the irreversible cysteine proteinase inhibitor, E64, decreases the invasive ability of DU145, but not PC3. PC3 and DU145 were treated with the phorbol ester analogue, phorbol 12-myristate 13-acetate (PMA), a known tumor promoter that activates protein kinase C and contributes to the metastatic phenotype. PMA increased secreted cathepsin L+B activity and the invasive ability of PC3 and DU145; co-exposure to E64 and PMA decreased both cathepsin L+B activity and invasion. We conclude that DU145 requires cathepsin L+B activity more than PC3 for the invasion of the Matrigel. When the amount of secreted cathepsin L+B activity is increased by PMA treatment, however, PC3 becomes dependent on cathepsin L+B for invasion. Our study demonstrates that modulation of the amount of secreted cathepsin L+B activity influences the invasive phenotype of PC3 and DU145.