Retinoic acid and evernyl-based menadione-triazole hybrid cooperate to induce differentiation of neuroblastoma cells.

Neuroblastoma arises when immature neural precursor cells do not mature into specialized cells. Although retinoic acid (RA), a pro-differentiation agent, improves the survival of low-grade neuroblastoma, resistance to retinoic acid is found in high-grade neuroblastoma patients. Histone deacetylases (HDAC) inhibitors induce differentiation and arrest the growth of cancer cells; however, HDAC inhibitors are FDA-approved mostly for liquid tumors. Therefore, combining histone deacetylase (HDAC) inhibitors and retinoic acid can be explored as a strategy to trigger the differentiation of neuroblastoma cells and to overcome resistance to retinoic acid. Based on this rationale, in this study, we linked evernyl group and menadione-triazole motifs to synthesize evernyl-based menadione-triazole hybrids and asked if the hybrids cooperate with retinoic acid to trigger the differentiation of neuroblastoma cells. To answer this question, we treated neuroblastoma cells using evernyl-based menadione-triazole hybrids (6a-6i) or RA or both and examined the differentiation of neuroblastoma cells. Among the hybrids, we found that compound 6b inhibits class-I HDAC activity, induces differentiation, and RA co-treatments increase 6b-induced differentiation of neuroblastoma cells. In addition, 6b reduces cell proliferation, induces expression of differentiation-specific microRNAs leading to N-Myc downregulation, and RA co-treatments enhance the 6b-induced effects. We observed that 6b and RA trigger a switch from glycolysis to oxidative phosphorylation, maintain mitochondrial polarization, and increase oxygen consumption rate. We conclude that in evernyl-based menadione-triazole hybrid, 6b cooperates with RA to induce differentiation of neuroblastoma cells. Based on our results, we suggest that combining RA and 6b can be pursued as therapy for neuroblastoma. Schematic representation of RA and 6b in inducing differentiation of neuroblastoma cells.

Anticancer effect and apoptosis induction by azaflavanone derivative in human prostate cancer cells.

Polyphenols are naturally occurring organic compounds with varying structures represented by four major groups: flavonoids, phenolic acids, lignans and stilbenes. Several studies suggested that these secondary metabolites have health benefits due to its anti-tumorigenic effect. Therefore, substantial effort has been put forward to isolate and characterize these natural compounds and synthesize analogues that may serve as potential anti-cancer therapeutics. This present study is aimed at designing and synthesis of azaflavanone derivative and in understanding its mechanism of action in vitro and in vivo. Molecular docking studies predicted that the compound can potentially bind strongly to the Cyclin E1-Cdk2 complex which is a key mediator of the cell cycle progression indicating a biological interference in aggressive prostate cancer. Further downstream studies to understand its cytotoxicity and mechanism of action showed this azaflavanone derivative markedly inhibits viability of prostate cancer cells (DU145) showing an IC50 value of 0.4 µM compared to other cancer cells. The pharmacological ROS insult using the azaflavanone derivative increases the oxidative damage leading to high expression of apoptotic markers with increasing concentration. On compound treatment, the cells lose the metabolic flexibility accompanied by mitochondrial dysfunction leading to cell cycle arrest and apoptosis. Further, no compound mediated toxicity was observed in xenograft mouse model of prostate cancer at a concentration as high as 5 mg/kg. The tumor burden was reduced to 60% rendering the azaflavanone derivative a potential candidate in cancer therapeutics. Collectively, the compound triggers cell cycle arrest and ROS mediated oxidative stress sensitizing the cancerous cells towards apoptosis.

Downregulation of BORIS/CTCFL leads to ROS-dependent cellular senescence and drug sensitivity in MYCN-amplified neuroblastoma.

Brother of Regulator of Imprinted Sites (BORIS) or CCCTC-binding factor like (CTCFL) is a nucleotide-binding protein, aberrantly expressed in various malignancies. Expression of BORIS has been found to be associated with the expression of oncogenes which regulate the reactive oxygen species (ROS) biogenesis, DNA double-strand break repair, regulation of stemness, and induction of cellular senescence. In the present study, we have analyzed the effects of knockdown of BORIS, a potential oncogene, on the induction of senescence and tumor suppression. Loss of BORIS downregulated the expression of critical oncogenes such as BMI1, Akt, MYCN, and STAT3, whereas overexpression increased their respective expression levels in MYCN-amplified neuroblastoma cells. BORIS knockdown exhibited high levels of ROS biogenesis, indicating an upregulated mitochondrial superoxide production and thereby induction of senescence. Our study also showed that the loss of BORIS facilitated cellular senescence through the disruption of telomere integrity via altering the expression of various proteins required for telomere capping (POT1, TRF2, and TIN1). In addition to affecting ROS production and DNA damage, BORIS knockdown sensitized the cells toward chemotherapeutic drugs and induced apoptosis. Tumor induction studies on in vivo xenograft mouse models showed that cells with loss of BORIS/CTCFL failed to induce tumors. From our study, we conclude that silencing BORIS/CTCFL influences tumor growth and proliferation by regulating key oncogenes. The results also indicated that the BORIS knockdown can cause cellular senescence and upon a combinatorial treatment with chemotherapeutic drugs can induce enhanced drug sensitivity in MYCN-amplified neuroblastoma cells.

Aza-Flavanone Diminishes Parkinsonism in the Drosophila melanogasterParkin Mutant.

Parkinson's disease is a chronic and progressive neurodegenerative disease, induced by slow and progressive death of the dopaminergic (DA) neurons from the midbrain region called substantia nigra (SNc) leading to difficulty in locomotion. At present, very few potential therapeutic drugs are available for treatment, necessitating an urgent need for development. In the current study, the parkin transgenic Drosophila melanogaster model that induces selective loss in dopaminergic neurons and impairment of locomotory functions has been used to see the effect of the aza-flavanone molecule. D. melanogaster serves as an amazing in vivo model making valuable contribution in the development of promising treatment strategies. Our in-silico study showed spontaneous binding of this molecule to the D2 receptor making it a potential dopamine agonist. PARKIN protein is well conserved, and it has been reported that Drosophila PARKIN is 42% identical to human PARKIN. Interestingly, this molecule enhances the motor coordination and survivability rate of the transgenic flies along with an increase in expression of the master regulator of Dopamine synthesis, that is, tyrosine hydroxylase (TH), in the substantia nigra region of the fly brain. Moreover, it plays a significant effect on mitochondrial health and biogenesis via modulation of a conserved mitochondrial protein PHB2. Therefore, this molecule could lead to the development of an effective therapeutic approach for the treatment of PD.

BORIS/CTCFL expression activates the TGFß signaling cascade and induces Drp1 mediated mitochondrial fission in neuroblastoma.

The cancer-testis antigen CTCFL/BORIS (Brother of Regulator of Imprinted Sites) also known, as a paralog of CTCF -the "master weaver of the genome" is a key transcriptional regulator. Both CTCF and BORIS can bind to the same promoter sequence and recruit diverse proteins. BORIS is also known to be associated with actively translating ribosomes suggesting new roles of BORIS in gene expression. Various studies have attempted to elucidate the role of BORIS in different cell types for the development of targeted therapy depending on molecular signatures and genetic aberrations associated with the disease type. The current study is focused on its role in neuroblastoma. Here, we have deciphered the role of BORIS on TGFß1 pathway which is highly affected by embryonic CTCFL expression. BORIS stabilized the SMAD3 and SMAD4 transcripts leading to prolonged TGFß activation. Further, loss of BORIS abrogated both the canonical and non-canonical TGFß signaling suggesting the dependency of TGFß on BORIS. The effect on the metabolic profile of the neuroblastoma cells were analyzed with change in BORIS expression levels. Also, ectopic expression of BORIS leads to Drp1 phosphorylation (Ser616) enhancing mitochondrial fission followed by a switch in cellular metabolism towards glycolysis. This cellular metabolism switch was in turn supported with a reduction in oxygen consumption rate upon BORIS expression. Interestingly methylome analysis revealed patterns of global histone methylation, a mechanism that regulate important signaling pathways in neuroblastoma. This study analyzes the consequence of BORIS expression in neuroblastoma cells and thereby elucidate its downstream targets, which could help in designing effective therapeutic for treating neuroblastoma. Similar results were obtained in both MYCN amplified and non-MYCN neuroblastoma cell lines, indicating a common mechanism of BORIS/CTCFL action in neuroblastoma.

Synthesis of some novel methyl ß-orsellinate based 3, 5-disubstituted isoxazoles and their anti-proliferative activity: Identification of potent leads active against MCF-7 breast cancer cell.

A series of sixteen novel methyl ß-orsellinate based 3, 5-disubstituted isoxazole hybrids (3-18) were synthesized in excellent yields by employing 1,3-dipolar cycloaddition reaction of terminal alkyne and corresponding nitriloxides as the key step. The structures of all the synthesized compounds were elucidated by spectroscopic data such as 1H &13C NMR and HRMS. The anti-proliferative activity of newly synthesized compounds were assessed in vitro against a panel of four human cancer cell lines, namely IMR-32 (neuroblastoma), DU-145 (prostate), MIAPACA (pancreatic), MCF-7 (breast) along with a normal cell line HEK-293T (embryonic kidney) by employing Sulforhodamine B (SRB) assay. The biological results revealed that majority of synthesized compounds exhibited anti-proliferative activity. In particular, compound 12 was found to be the most potent one as it exhibited five fold higher activity (IC50: 7.9 ± 0.07 µM) than parent compound 1 (IC50: 40.63 ± 0.11 µM) against MCF-7 breast cancer cell line. Flow cytometric analysis of compound 12 revealed that it induced apoptosis and arrested cell cycle in G2/M phase. Mechanistic studies have shown the compound as a potent activator of pro-apoptotic proteins, Bax and Cytochrome-c via the upregulation of tumour suppressor proteins, p53 and PTEN. From the docking studies, it can be inferred that Compound 12 acts as a novel and attractive anti-cancer therapeutic inhibiting the CDK1-Cyclin B complex.

Imine stilbene analog ameliorate isoproterenol-induced cardiac hypertrophy and hydrogen peroxide-induced apoptosis.

Cardiac hypertrophy is an adaptive response to stress, in order to maintain proper cardiac function. However, sustained stress leads to pathological hypertrophy accompanied by maladaptive responses and ultimately heart failure. At the cellular level, cardiomyocyte hypertrophy is characterized by an increase in myocyte size, reactivation of the fetal gene markers, disassembly of the sarcomere and transcriptional remodelling which are regulated by heart-specific transcription factors like MEF2, GATA4 and immediate early genes like c-jun and c-fos.2. It has been explored and established that the hypertrophic process is associated by oxidative stress and mediated by pathways involving several terminal stress kinases like P38, JNK and ERK1/2. Stilbenoids are bioactive polyphenols and earlier studies have shown that imine stilbene exert cardioprotective and anti aging effects by acting as modulators of Sirt1. The present study was aimed at designing and synthesizing a series of imine stilbene analogs and investigate its anti hypertrophic effects and regulatory mechanism in cardiac hypertrophy and apoptosis. Interestingly one of the analog, compound 3e (10 µM) alleviated isoproterenol (ISO, 25 µM) induced hypertrophy in rat cardiomyocyte (H9c2) cells by showing a marked decrease in the myocyte size. Further, compound 3e also restored the cardiac function by activating the metabolic stress sensor, AMPK. Moreover, molecular docking studies showed stable binding between compound 3e and GSK3ß suggesting that compound 3e may directly regulate GSK3ß activity and ameliorate ISO-induced cardiac hypertrophy. In agreement with this, compound 3e also modulated the crosstalk of all the hypertrophy inducing terminal Kinases by bringing down the expression to near control conditions. The compound also relieved H2O2 (100 µM) mediated ROS and normalized abnormal mitochondrial oxygen demand in hypertrophic conditions indicating the possibility of the compound to show promise in playing a role in cardiac hypertrophy.