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Eu incorporated ZnO–graphene nanocomposite in human breast cancer cells (MCF7) under a confocal laser scanning microscope.

For rapid tumor growth, cancer cells often reprogram the cellular metabolic processes to obtain enhanced anabolic precursors and energy. The molecular changes of such metabolic rewiring are far from established. Here we explored the role of mTOR (mechanistic target of rapamycin), which serves as a key regulator of cell growth, proliferation and survival, in the metabolic reprograming of cancer cells. When we inhibited mTOR in human hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC) cells, using pharmacologic inhibitors or by RNA interference, we noticed shuttle of the glycolytic flux to gluconeogenesis pathway along with reduction in cellular proliferation and survival. Augmentation of gluconeogenesis was mechanistically linked to upregulation of the key gluconeogenic enzymes PCK1 and G6PC expressions, enhanced lactate dehydrogenase activity and glucose-derived lipogenesis without causing any attenuation in mitochondrial function. Interestingly, concomitant knocking down of PCK1 and not G6PC along with mTOR pathway could overcome the inhibition of cancer cell proliferation and survival. These observations were validated by identifying distinctive diminution of PCK1 and G6PC expressions in human HCC and RCC transcriptome data. Significant correlation between mTOR-dependent upregulation of PCK1 and cell death in different cancer cell lines further emphasizes the physiological relevance of this pathway. We reveal for the first time that inhibition of mTORC2 and consequent redistribution of glycolytic flux can have a prosurvival role in HCC and RCC cancer cells only in the presence of downregulation of gluconeogenesis pathway genes, thus identifying novel pivots of cancer cell metabolic rewiring and targets for therapy.

Selective targeting of cancer cells employing multiple combinations as co-drug holds promise for new generation therapeutics. Betulinic acid (BA), a plant secondary metabolite kills cancer cells and Dichloroacetate (DCA) is capable of reversing the Warburg phenotype by inhibiting pyruvate dehydrogenase kinase (PDK). Here, we report synthesis, characterization and tumoricidal potential of a co-drug Bet-CA, where a DCA molecule has been appended on C-3 hydroxyl group of BA to generate an ester derivative for increased solubility and subsequent cleavage by internal esterase(s) to release one unit each of BA and DCA. In vitro studies revealed pronounced synergistic cytotoxicity of Bet-CA against a broad spectrum of cancer cells and it selectively killed them when co-cultured with human fibroblasts. Bet-CA treatment increased reactive oxygen species (ROS) production, significantly altered mitochondrial membrane potential gradient (ΔΨm); followed by the release of cytochrome c (Cyt c) which prompted cells to undergo mitochondria mediated apoptosis. In vivo experimentation expectedly exhibited tumor inhibitory potential of Bet-CA and clinically achievable doses did not produce any apparent toxicity. Taken together, results suggestively raise an important corollary hypothesis stating that Bet-CA selectively and synergistically combats cancer without producing toxic manifestations and emerges to be the prospect for the new generation therapeutics.

29Mutations in the p53 tumor suppressor occur very frequently in human cancer. 30Often, such mutations lead to the constitutive overproduction of mutant p53 31 (mtp53) proteins, which can exert a cancer-promoting gain-of-function (GOF). We 32 have identified a novel mechanism by which mtp53 controls both cell-autonomous 33 and non-cell autonomous signaling to promote cancer cell survival and suppress 34 tumor immune surveillance. Mtp53 interferes with the function of the cytoplasmic 35 DNA sensing machinery, cGAS-STING-TBK1-IRF3, that controls the activation of 36 the innate immune response. We find that mtp53, but not wildtype p53, binds to 37 TANK binding protein kinase (TBK1) and inhibits both its basal and agonist-38 induced activity. The association of mtp53 with TBK1 prevents the formation of a 39 trimeric complex between TBK1-STING-IRF3, which is required for activation, 40 nuclear translocation and transcriptional activity of IRF3. Mtp53 knockdown 41 restores TBK1 activity, resulting in the transcriptional induction of IRF3 target 42 genes and IRF3-dependent apoptosis. Furthermore, inactivation of innate immune 43 signaling by mtp53 alters cytokine production resulting in immune evasion. 44 Restored TBK1 signaling was sufficient to bypass mtp53 and reactivate cell-45 autonomous and non-cell autonomous tumor control. Thus, overriding mtp53's 46 inhibition of this cytosolic DNA sensing pathway may ultimately lead to restored 47 an oncogenic mtp53 protein that exhibits gain-of function activities.(5) Recently, it has been 62 reported that 91% of cancers that have a mtp53 allele have lost their second allele through 63 mutation or chromosomal loss.(6) Furthermore, the presence of mtp53 correlates with increased 64 chromosomal instability leading to loss of tumor suppressor genes and amplification of 65 oncogenes.(6, 7) 66 Aneuploidy is considered one of the hallmarks of cancer and is thought to play an 67 important role in driving tumor cell evolution.(8) Aneuploidy has been shown to provoke cell 68 cycle arrest, senescence, increased pro-inflammatory cytokine production and upregulation of 69 Natural Killer (NK) cell ligands in tumor cells, resulting in their subsequent killing by NK 70 cells.(9) In an in vivo setting, the increased production of pro-inflammatory cytokines coupled 71 with increased NK cell ligand expression permits the recruitment of immune cells and clearance 72 of abnormal cells.(10) Thus, in addition to the cell-autonomous mechanisms that suppress 73 genetic instability, cells also utilize non-cell autonomous mechanisms to signal their own 74 destruction.(9) However, chromosomal instability can give rise to micronuclei, which are prone 75 to rupturing and releasing the DNA into the cytoplasm.(11) DNA leaked into the cytoplasm is 76 recognized by the DNA binding protein, cyclic GMP-AMP synthase (cGAS), which in turn triggers 77 innate immune signaling that results in the production of type I interferons.(12) Mechanistically, 78 DNA promotes cGAS homodimerization and production of the secon...

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Herein, we synthesize and elucidate the potential of a novel 'dual hit' molecule, LDCA, to constitutively block lactate dehydrogenase isoform-A (LDH-A) to selectively subvert apoptosis and rigorously attenuate breast tumor progression in a mouse model, comprehensively delineating the therapeutic prospectus of LDCA in the field of cancer metabolics.