Expression of a murine homolog of apoptosis-inducing human IL-24/MDA-7 in murine tumors fails to induce apoptosis or produce anti-tumor effects

Development of a prognostic model of glioma based on immune-related genes

Glioma is the most common type of primary brain cancer, and the prognosis of most patients with glioma, and particularly that of patients with glioblastoma, is poor. Tumor immunity serves an important role in the development of glioma. However, immunotherapy for glioma has not been completely successful, and thus, comprehensive examination of the immune-related genes (IRGs) of glioma is required. In the present study, differentially expressed genes (DEGs) and differentially expressed IRGs (DEIRGs) were identified using the edgeR package. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was used for functional enrichment analysis of DEIRGs. Survival-associated IRGs were selected via univariate Cox regression analysis. A The Cancer Genome Atlas prognostic model and GSE43378 validation model were established using lasso-penalized Cox regression analysis. Based on the median risk score value, patients were divided into high-risk and low-risk groups for clinical analysis. Receiver operating characteristic curve and nomogram analyses were used to assess the accuracy of the models. Reverse transcription-quantitative PCR was performed to measure the expression levels of relevant genes, such as cyclin-dependent kinase 4 (CDK4), interleukin 24 (IL24), NADPH oxidase 4 (NOX4), bone morphogenetic protein 2 (BMP2) and baculoviral IAP repeat containing 5 (BIRC5). A total of 3,238 DEGs, including 1,950 upregulated and 1,288 downregulated DEGs, and 97 DEIRGs, including 60 upregulated and 37 downregulated DEIRGs, were identified. ‘Neuroactive ligand-receptor interaction’ and ‘Cytokine-cytokine receptor interaction’ were the most significantly enriched pathways according to KEGG pathway analysis. A prognostic model and a validation prognostic model were created for glioma, including 15 survival-associated IRGs (FCER1G, NOX4, TRIM5, SOCS1, APOBEC3C, BIRC5, VIM, TNC, BMP2, CMTM3, IL24, JAG1, CALCRL, HNF4G and CDK4). Furthermore, multivariate Cox regression analysis results suggested that age, high WHO Grade by histopathology, wild type isocitrate dehydrogenase 1 and high risk score were independently associated with poor overall survival. The infiltration of B cells, CD8⁺ T cells, dendritic cells, macrophages and neutrophils was positively associated with the prognostic risk score. In the present study, several clinically significant survival-associated IRGs were identified, and a prognosis evaluation model of glioma was established.

Repurposing L-Menthol for Systems Medicine and Cancer Therapeutics? L-Menthol Induces Apoptosis through Caspase 10 and by Suppressing HSP90

The objective of the present study was to repurpose L-menthol, which is frequently used in oral health and topical formulations, for cancer therapeutics. In this article, we argue that monoterpenes such as L-menthol might offer veritable potentials in systems medicine, for example, as cheaper anti-cancer compounds. Other monoterpenes such as limonene, perillyl alcohol, and geraniol have been shown to induce apoptosis in various cancer cell lines, but their mechanisms of action are yet to be completely elucidated. Earlier, we showed that L-menthol modulates tubulin polymerization and apoptosis to inhibit cancer cell proliferation. In the present report, we used an apoptosis-related gene microarray in conjunction with proteomics analyses, as well as in silico interpretations, to study gene expression modulation in human adenocarcinoma Caco-2 cell line in response to L-menthol treatment. The microarray analysis identified caspase 10 as the important initiator caspase, instead of caspase 8. The proteomics analyses showed downregulation of HSP90 protein (also corroborated by its low transcript abundance), which in turn indicated inhibition of AKT-mediated survival pathway, release of pro-apoptotic factor BAD from BAD and BCLxL complex, besides regulation of other factors related to apoptosis. Based on the combined microarray, proteomics, and in silico data, a signaling pathway for L-menthol-induced apoptosis is being presented for the first time here. These data and literature analysis have significant implications for "repurposing" L-menthol beyond oral medicine, and in understanding the mode of action of plant-derived monoterpenes towards development of cheaper anticancer drugs in future.

Characterization of the canine mda-7 gene, transcripts and expression patterns

Human melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) displays potent growth suppressing and cell killing activity against a wide variety of human and rodent cancer cells. In this study, we identified a canine ortholog of the human mda-7/IL-24 gene located within a cluster of IL-10 family members on chromosome 7. The full-length mRNA sequence of canine mda-7 was determined, which encodes a 186-amino acid protein that has 66% similarity to human MDA-7/IL-24. Canine MDA-7 is constitutively expressed in cultured normal canine epidermal keratinocytes (NCEKs), and its expression levels are increased after lipopolysaccharide stimulation. In cultured NCEKs, the canine mda-7 pre-mRNA is differentially spliced, via exon skipping and alternate 5'-splice donor sites, to yield five splice variants (canine mda-7sv1, canine mda-7sv2, canine mda-7sv3, canine mda-7sv4 and canine mda-7sv5) that encode four protein isoforms of the canine MDA-7 protein. These protein isoforms have a conserved N-terminus (signal peptide sequence) and are dissimilar in amino acid sequences at their C-terminus. Canine MDA-7 is not expressed in primary canine tumor samples, and most tumor derived cancer cell lines tested, like its human counterpart. Unlike human MDA-7/IL-24, canine mda-7 mRNA is not expressed in unstimulated or lipopolysaccharide (LPS), concanavalin A (ConA) or phytohemagglutinin (PHA) stimulated canine peripheral blood mononuclear cells (PBMCs). Furthermore, in-silico analysis revealed that canonical canine MDA-7 has a potential 28 amino acid signal peptide sequence that can target it for active secretion. This data suggests that canine mda-7 is indeed an ortholog of human mda-7/IL-24, its protein product has high amino acid similarity to human MDA-7/IL-24 protein and it may possess similar biological properties to human MDA-7/IL-24, but its expression pattern is more restricted than its human ortholog.