Temozolomide (TMZ) is an alkylating chemotherapy agent used in the clinical treatment of glioblastoma multiforme (GBM) patients. Piperine (PIP) is a naturally occurring pungent nitrogenous substance present in the fruits of peppers. We investigated the anti-cancer efficacies of PIP alone and in combination with TMZ in GBM cellsusingparameters such as cell proliferation, cellular apoptosis, caspase-8/-9/-3 activities, cell cycle kinetics, wound-healing ability, and loss of mitochondrial membrane potential (MMP). Treatment with PIP and alow concentration of PIP-TMZ, inhibited cell growth, similar to TMZ.PIP-TMZ promoted apoptosis by activation of caspase-8/-9/-3, MMP loss, and inhibition of in vitro wound-healing motility. Reverse transcription polymerase chain reaction analysis showed significant inhibition of Cyclin-dependent kinases (CDK)4/6−cyclin D and CDK2−cyclin-E expression upon treatment with a low concentration PIP-TMZ, suggesting an S to G1 arrest. Our findings provide insight into the apoptotic potential of the combination of a low concentration of PIP-TMZ, though further in vivo study will be needed for its validation.

The extract of Phyllodium (P.) elegans was investigated for its anti-cancer properties on brain astroglioma cells (U251-MG), colorectal carcinoma cells (HCT116), and malignant melanoma cells (A375). P. elegans methanolic extract (PeME) showed cytotoxicity on all three cancer cell lines tested. The cell viability assay revealed that PeME significantly reduced the viability of these cells. Clear apoptotic features such as cellular morphology, cell shrinkage, and augmentation of dead cells were observed. Flow cytometry and fluorescence staining techniques confirmed the apoptotic property of PeME. In vitro scratch invasion assay showed that cell migration rate was significantly reduced. Fluorescence microscopic studies using 4′,6-diamidino-2-phenylindole staining showed early and late signs of apoptosis after PeME treatment. Upon PeME stimulation, activation of caspase-3/-9 and Mu-2-related death-inducing gene (MUDENG, MuD) was observed by western blot analysis. JC-1 staining analysis by flow cytometry showed that PeME depolarized the mitochondria membrane potential (MMP). Collectively, these findings, for the first time, point to the fact that PeME has anti-cancer properties against brain, colon, and skin cancer cell lines by depolarizing the MMP and activating apoptotic signaling through the activation of caspase-3/-9 as well as MuD. This is the first report reporting the anticancer activity of this specific plant extract.

Graviola (Annona muricate) is a coveted tropical plant that has been found to be effective against many human cancers.

Mu-2-related death-inducing gene (MUDENG, MuD) has been reported to be involved in the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-associated apoptotic pathway of glioblastoma multiforme (GBM) cells; however, its expression level, interactors, and role in tumors are yet to be discovered. To investigate whether MuD expression correlates with cancer progression, we analyzed The Cancer Genome Atlas (TCGA) database using UALCAN and Gene Expression Profiling Interactive Analysis (GEPIA). Differential expression of MuD was detected in 6 and 10 cancer types, respectively. Validation performed using data from the Gene Expression Omnibus database showed that MuD expression is downregulated in KIRC tumor and correlate with higher chance of survival. Upregulation of MuD expression in GBM tumors was detected through GEPIA and high MuD expression correlated with higher survival in proneural GBM, whereas the opposite was observed in classical GBM subtype. GBM biospecimens analysis shows that MuD protein level was upregulated in three of six specimens, whereas mRNA level remained relatively unaltered. Therefore, MuD may exert differential effects according to subtypes, and/or be subjected to post-translational regulation in GBM. Correlation analysis between GBM cohort database and experiments using GBM cell lines revealed its positive effect on regulation of protein phosphatase 2 regulatory subunit B’Epsilon (PPP2R5E) and son of sevenless homolog 2 (SOS2). STRING database analysis indicated that the components of adaptor protein complexes putatively interacted with MuD but showed no correlation in terms of survival of patients with different GBM subtypes. In summary, we analyzed the expression of MuD in publicly available cancer patient data sets, GBM cell lines, and biospecimens to demonstrate its potential role as a biomarker for cancer prognosis and identified its candidate interacting molecules.