Background: MTCH2 and tBID proteins interact to induce apoptosis in the mitochondrial pathway. Results: Molecular and biophysical studies of the tBID-MTCH2 complex led to two peptides, derived from the tBID-MTCH2 binding interface, which induced cell death. Conclusion: tBID and MTCH2 have two major interaction sites. Peptides derived from the interface are anticancer leads. Significance: The tBID-MTCH2 interaction may be a novel anticancer drug target.

Downregulation of the urea cycle enzyme argininosuccinate synthase (ASS1) by either promoter methylation or by HIF1α is associated with increased metastasis and poor prognosis in multiple cancers. We have previously shown that in normoxic conditions, ASS1 downregulation facilitates cancer cell proliferation by increasing aspartate availability for pyrimidine synthesis by the enzyme complex CAD. Here we report that in hypoxia, ASS1 expression in cancerous cells is downregulated further by Hif1α-mediated induction of miR224-5p, making the cells more invasive and dependent on upstream substrates of ASS1 for survival. ASS1 was downregulated under acidic conditions, and ASS1-depleted cancer cells maintained a higher intracellular pH (pHi), depended less on extracellular glutamine, and displayed higher glutathione levels. Depletion of substrates of urea cycle enzymes in ASS1-deficient cancers decreased cancer cell survival. Thus, ASS1 levels in cancer are differentially regulated in various environmental conditions to metabolically benefit cancer progression. Understanding these alterations may help uncover specific context-dependent cancer vulnerabilities that may be targeted for therapeutic purposes.

Structural mitochondrial abnormalities as well as genetic aberrations in mitochondrial proteins have been known in Myelodysplastic syndrome (MDS) , yet there is currently little data regarding the metabolic properties and energy production of MDS cells. In the current study we used state-of-the-art methods to assess OXPHOS in peripheral blood cells obtained from MDS patients and healthy controls We then assessed the effect of food supplements- Coenzyme Q10 and carnitine on mitochondrial function and hematological response .We show here for the first time that in low risk MDS there is a significant impairment of mitochondrial respiration in peripheral blood cells and this can be improved with food supplements. We also show that such myelodysplastic syndrome, mitochondria, oxidative phosphorylation, coenzyme Q10, seahorse XF analyzer. supplements lead to improvement in cytopenia's and quality of life.

<p>Supplementary Figures 1-5 further support our findings regarding the contribution to the maintenance of intracellular pH for ASS1 downregulated cancer cells</p>