Activation of p53 mediated glycolytic inhibition-oxidative stress-apoptosis pathway in Dalton's lymphoma by a ruthenium (II)-complex containing 4-carboxy N-ethylbenzamide

A Murine Database of Structural Variants Enables the Genetic Architecture of a Spontaneous Murine Lymphoma to be Characterized

A more complete map of the pattern of genetic variation among inbred mouse strains is essential for characterizing the genetic architecture of the many available mouse genetic models of important biomedical traits. Although structural variants (SVs) are a major component of genetic variation, they have not been adequately characterized among inbred strains due to methodological limitations. To address this, we generated high-quality long-read sequencing data for 40 inbred strains; and designed a pipeline to optimally identify and validate different types of SVs. This generated a database for 40 inbred strains with 573,191SVs, which included 10,815 duplications and 2,115 inversions, that also has 70 million SNPs and 7.5 million insertions/deletions. Analysis of this SV database led to the discovery of a novel bi-genic model for susceptibility to a B cell lymphoma that spontaneously develops in SJL mice, which was initially described 55 years ago. The first genetic factor is a previously identified endogenous retrovirus encoded protein that stimulates CD4 T cells to produce the cytokines required for lymphoma growth. The second genetic factor is a newly found deletion SV, which ablates a protein whose promotes B lymphoma development in SJL mice. Characterizing the genetic architecture of SJL lymphoma susceptibility could provide new insight into the pathogenesis of a human lymphoma that has similarities with this murine lymphoma.

Design and fabrication of functionalized curdlan-curcumin delivery system to facilitate the therapeutic effects of curcumin on breast cancer

We developed a facile method for the fabrication of a biodegradable delivery system composed of two blocks: curdlan and curcumin. This was achieved by chemical functionalization of curdlan through tosylation, amination followed by complexation with curcumin. A comprehensive evaluation of structural characterization and component stability showed that cur-cum complex exhibited better anticancer properties with enhanced thermal properties. The cur-cum complex shows pH sensitive sustained release behaviour with higher release at acidic pH and kinetic data of drug release follows the Korsmeyer-Peppas model. The cur-cum complex has ability to block the proliferation of the MCF-7 cell line as revealed by MTT assay which showed increased toxicity of cur-cum complex against these cell lines. The results obtained from western blot analysis demonstrated that the co-administration of cur and cum effectively induced apoptosis in MCF-7 cells. This effect was observed by a considerable upregulation of the Bcl-2/Bax ratio, a decline in mRNA expression of LDHA, level of lactate and LDH activity. The results clearly depict the role of functionalized curdlan as efficient carrier for curcumin delivery with prolonged, sustained release and enhanced bioavailability, thereby improving the overall anticancer activity.

Glutor, a Glucose Transporter Inhibitor, Exerts Antineoplastic Action on Tumor Cells of Thymic Origin: Implication of Modulated Metabolism, Survival, Oxidative Stress, Mitochondrial Membrane Potential, pH Homeostasis, and Chemosensitivity

Neoplastic cells overexpress glucose transporters (GLUT), particularly GLUT1 and GLUT3, to support altered metabolism. Hence, novel strategies are being explored to effectively inhibit GLUTs for a daunting interference of glucose uptake. Glutor, a piperazine-2-one derivative, is a newly reported pan-GLUT inhibitor with a promising antineoplastic potential. However, several aspects of the underlying mechanisms remain obscure. To understand this better, tumor cells of thymic origin designated as Dalton's lymphoma (DL) were treated with glutor and analyzed for survival and metabolism regulatory molecular events. Treatment of tumor cells with glutor caused a decrease in cell survival with augmented induction of apoptosis. It also caused a decrease in glucose uptake associated with altered expression of GLUT1 and GLUT3. HIF-1α, HK-2, LDH-A, and MCT1 also decreased with diminished lactate production and deregulated pH homeostasis. Moreover, glutor treatment modulated the expression of cell survival regulatory molecules p53, Hsp70, IL-2 receptor CD25, and C-myc along with mitochondrial membrane depolarization, increased intracellular ROS expression, and altered Bcl-2/BAX ratio. Glutor also enhanced the chemosensitivity of tumor cells to cisplatin, accompanied by decreased MDR1 expression. Adding fructose to the culture medium containing glutor reversed the latter's inhibitory action on tumor cell survival. These results demonstrate that in addition to inhibited glucose uptake, modulated tumor growth regulatory molecular pathways are also implicated in the manifestation of the antineoplastic action of glutor. Thus, the novel findings of this study will have a long-lasting clinical significance in evaluating and optimizing the use of glutor in anticancer therapeutic strategies.

Protective and therapeutic effects of sildenafil and tadalafil on aflatoxin B1-induced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has been classified as one of the most common forms of liver cancer occurring worldwide, and risk factors include hepatitis B & C virus, alcoholism, and dietary carcinogens like aflatoxin B1 (AFB1), which is produced by fungus Aspergillus flavus and Aspergillus parasiticus. Metabolism of AFB1 resulted into the formation of AFB1-exo-8, 9-epoxide which is largely responsible for HCC development. So far conventional cytotoxic chemotherapy has not provided much benefit in HCC, necessitating the need for newer treatment modalities. Recent reports suggest that phosphodiesterase-5 inhibitors (PDE5i) may have anticancer activity, but till date, the anticancer property of PDE5i (tadalafil & sildenafil) has not been evaluated in HCC. The present study was aimed to define the anticancer property of tadalafil and sildenafil against AFB1-induced HCC rats. Rats were randomly divided into five groups with five rats in each group. Except normal control group, rats of all other groups were fed with 5% alcohol via drinking water for 3 weeks. After 3 weeks, two successive dose of AFB1 (1 mg/kg bw, ip) was administered on subsequent days followed by the administration of PDE5i (tadalafil & sildenafil, 10 mg/kg bw) along with drinking water after 6 weeks of treatment with AFB1 for 2 weeks. An in-depth investigation into its mechanistic aspect revealed that development of HCC induced by aflatoxin B1, decreased the mRNA expression and activity of antioxidant enzyme SOD, GPx, catalase, GR and GST, and GSH content with a concomitant increase in the level of lipid peroxidation. Post-treatment with PDE5 inhibitor (tadalafil & sildenafil) restored the above parameters towards normal, and this result was more effective in case of sildenafil. Thus, results from the above studies suggest that PDE5 inhibitors may act as anticancer agents by preventing the development and progression of HCC by modulating the key parameters of antioxidant pathway.

Modulation of antioxidant enzymes, SIRT1 and NF-κB by resveratrol and nicotinamide in alcohol-aflatoxin B1-induced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most commonly diagnosed cancer worldwide and is associated with poor prognosis. The current study aimed to assess the therapeutic efficacy of resveratrol when administered alone and in combination with nicotinamide against alcohol-aflatoxin B1-induced HCC. Results reveal that during the development and progression of cancer, there was a decline in the level of antioxidant enzymes catalase, glutathione peroxidase, glutathione reductase (GR), antioxidant glutathione, and glutathione S-transferase, which is an enzyme of detoxification pathways. Treatment of resveratrol restored the level of catalase and glutathione peroxidase toward normal in alcohol-aflatoxin B1-induced HCC; however, nicotinamide worked in concert with resveratrol only in upregulating the activity of glutathione reductase, glutathione level, and glutathione S-transferase. SIRT1 agonist resveratrol was observed to modulate the activity of antioxidant enzymes by negatively regulating the expression of nuclear factor-κB (NF-κB) in alcohol-aflatoxin B1-induced HCC, thereby suggesting a cross-talk between antioxidant enzymes SIRT1 and NF-κB during the development and progression of HCC and its therapeutics by resveratrol and nicotinamide.

SIRT1-mediated amelioration of oxidative stress in kidney of alcohol-aflatoxin-B1-induced hepatocellular carcinoma by resveratrol is catalase dependent and GPx independent

Hepatocellular carcinoma (HCC) is a type of primary liver cancer and dietary exposure to aflatoxins is a major risk factor of HCC. The current study aimed to assess the role of resveratrol and nicotinamide in renal toxicity during alcohol-aflatoxin-B1-induced HCC. The results revealed that resveratrol treatment normalized the level of urea, lipid peroxidation, lactate and lactate dehydrogenase, which were increased in HCC. It also downregulated the increased expression of sirtuin 1 in HCC kidney. Furthermore, amelioration of oxidative stress in kidney of HCC rats by resveratrol was observed to be catalase dependent and glutathione peroxidase independent.

Structural Determinants of p53-Independence in Anticancer Ruthenium-Arene Schiff-Base Complexes

p53 is a key tumor suppressor gene involved in key cellular processes and implicated in cancer therapy. However, it is inactivated in more than 50% of all cancers due to mutation or overexpression of its negative regulators. This leads to drug resistance and poor chemotherapeutic outcome as most clinical drugs act via a p53-dependent mechanism of action. An attractive strategy to circumvent this resistance would be to identify new anticancer drugs that act via p53-independent mode of action. In the present study, we identified 9 Ru (II)-Arene Schiff-base (RAS) complexes able to induce p53-independent cytotoxicity and discuss structural features that are required for their p53-independent activity. Increasing hydrophobicity led to an increase in cellular accumulation in cells with a corresponding increase in efficacy. We further showed that all nine complexes demonstrated p53-independent activity. This was despite significant differences in their physicochemical properties, suggesting that the iminoquinoline ligand, a common structural feature for all the complexes, is required for the p53-independent activity.

Effect of certain entomopathogenic fungi on oxidative stress and mortality of Periplaneta americana

The present paper reports the effects of Metarhizium anisopliae, Isaria fumosoroseus and Hirsutella thompsonaii on Periplaneta americana. I. fumosoroseus and H. thompsonaii were cultured at 28±1°C on potato carrot agar and M. anisopliae was cultured at 28±1°C on potato dextrose agar for 14days. Conidial suspensions of fungi were given to cockroaches through different routes. M. anisopliae shows high virulence against adult cockroaches and mortality ranges from 38.65% to 78.36% after 48h. I. fumosoroseus and H. thompsonii show less virulence compared to M. anisopliae. We also investigated the effect of these three fungi on the activity of lactate dehydrogenase, lipid peroxidation and catalase in different tissues of the insect to gain an understanding of the different target site. The result suggested that the activity of lactate dehydrogenase, catalase and level of malondialdehyde varies in different organs and through different routes of exposure. Based on mortality percentages, all tested fungi had high potentials for biocontrol agents against P. americana. Our study reveals for the first time that I. fumosoroseus and H. thompsonaii fungal infections initiate oxidative stress in the midgut, fat body, whole body and hemolymph of cockroach thereby suggesting them to be the target organs for oxidative damage.

Fisetin Modulates Antioxidant Enzymes and Inflammatory Factors to Inhibit Aflatoxin-B1 Induced Hepatocellular Carcinoma in Rats

Fisetin, a known antioxidant, has been found to be cytotoxic against certain cell lines. However, the mechanism by which it inhibits tumor growth in vivo remains unexplored. Recently, we have demonstrated that Aflatoxin-B1 (AFB1) induced hepatocarcinogenesis is associated with activation of oxidative stress-inflammatory pathway in rat liver. The present paper describes the effect of in vivo treatment with 20 mg/kg b.w. Fisetin on antioxidant enzymes vis-a-vis oxidative stress level and on the profile of certain proinflammatory cytokines in the hepatocellular carcinoma (HCC) induced by two doses of 1 mg/kg b.w. AFB1 i.p. in rats. The reduced levels of most of the antioxidant enzymes, coinciding with the enhanced level of reactive oxygen species in the HCC liver, were observed to regain their normal profiles due to Fisetin treatment. Also, Fisetin treatment could normalize the enhanced expression of TNFα and IL1α, the two proinflammatory cytokines, reported to be involved in HCC pathogenesis. These observations were consistent with the regression of neoplastic lesion and declined GST-pi (placental type glutathione-S-transferase) level, a HCC marker, in the liver of the Fisetin treated HCC rats. The findings suggest that Fisetin attenuates oxidative stress-inflammatory pathway of AFB1 induced hepatocarcinogenesis.

Editorial of Special Issue Ruthenium Complex: The Expanding Chemistry of the Ruthenium Complexes

Recent trends in Ru complex chemistry are surveyed with emphasis on the development of anticancer drugs and applications in catalysis, polymers, materials science and nanotechnology.

Linking the future of anticancer metal-complexes to the therapy of tumour metastases

Cancer chemotherapy is almost always applied to patients with one or more diagnosed metastases and is expected to impact these lesions, thus providing significant benefits to the patient.