Novel levamisole derivative induces extrinsic pathway of apoptosis in cancer cells and inhibits tumor progression in mice

In vitro evaluation of p-coumaric acid and naringin combination in human epidermoid carcinoma cell line (A431)

Cancer is considered most detrimental due to high mortality worldwide. Among them, skin cancers play a major part by affecting one in three cancer patients globally. About 2-3 million cancer cases were reported to be non-melanoma and melanoma skin cancers, respectively. Although chemotherapeutic drugs act on cancer cells but results in long-lasting morbidities which affects one's quality of life and also works only in the initial stage of the cancer. Hence, an idea of traditional medicine to cure the disease efficiently with less side effects was pursued by the researchers. We have assessed the combination effect of p-coumaric acid and naringin in exerting anticancer activity using A431 (epidermoid carcinoma) cells. The MTT analysis of the combination on A431 cells showed the least IC50 concentration of 41 µg/ml which is effective than the standard drug imiquimod with IC50 concentration of 52 µg/ml. Further, flow cytometric analysis was carried out to identify the molecular mechanism behind the anticancer effects of the combination. The results revealed that the combination arrested the A431 cell cycle at S phase, induced apoptosis as indicated by more early and late apoptotic cells when compared with the control, and further altered reactive oxygen species (ROS) and mitochondrial membrane potential in A431 cells. Hence, the results suggest the potential anticancer effects of p-coumaric acid and naringin combination against the skin cancer (A431) cell line. The observed effects may be additive or synergistic effects in inducing ROS generation and apoptosis, and reducing the viability of A431 cells.

Identification of antiparasitic drug targets using a multi-omics workflow in the acanthocephalan model

Background

With the expansion of animal production, parasitic helminths are gaining increasing economic importance. However, application of several established deworming agents can harm treated hosts and environment due to their low specificity. Furthermore, the number of parasite strains showing resistance is growing, while hardly any new anthelminthics are being developed. Here, we present a bioinformatics workflow designed to reduce the time and cost in the development of new strategies against parasites. The workflow includes quantitative transcriptomics and proteomics, 3D structure modeling, binding site prediction, and virtual ligand screening. Its use is demonstrated for Acanthocephala (thorny-headed worms) which are an emerging pest in fish aquaculture. We included three acanthocephalans (Pomphorhynchus laevis, Neoechinorhynchus agilis, Neoechinorhynchus buttnerae) from four fish species (common barbel, European eel, thinlip mullet, tambaqui).

Results

The workflow led to eleven highly specific candidate targets in acanthocephalans. The candidate targets showed constant and elevated transcript abundances across definitive and accidental hosts, suggestive of constitutive expression and functional importance. Hence, the impairment of the corresponding proteins should enable specific and effective killing of acanthocephalans. Candidate targets were also highly abundant in the acanthocephalan body wall, through which these gutless parasites take up nutrients. Thus, the candidate targets are likely to be accessible to compounds that are orally administered to fish. Virtual ligand screening led to ten compounds, of which five appeared to be especially promising according to ADMET, GHS, and RO5 criteria: tadalafil, pranazepide, piketoprofen, heliomycin, and the nematicide derquantel.

Conclusions

The combination of genomics, transcriptomics, and proteomics led to a broadly applicable procedure for the cost- and time-saving identification of candidate target proteins in parasites. The ligands predicted to bind can now be further evaluated for their suitability in the control of acanthocephalans. The workflow has been deposited at the Galaxy workflow server under the URL tinyurl.com/yx72rda7.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08882-1.

Novel AR/AR-V7 and Mnk1/2 Degrader, VNPP433-3β: Molecular Mechanisms of Action and Efficacy in AR-Overexpressing Castration Resistant Prostate Cancer In Vitro and In Vivo Models

Prostate cancer (PCa) relies in part on AR-signaling for disease development and progression. Earlier, we developed drug candidate galeterone, which advanced through phase 2-clinical trials in treating castration-resistant PCa (CRPC). Subsequently, we designed, synthesized, and evaluated next-generation galeterone-analogs including VNPP433-3β which is potently efficacious against pre-clinical models of PCa. This study describes the mechanism of action of VNPP433-3β that promotes degradation of full-length AR (fAR) and its splice variant AR-V7 besides depleting MNK1/2 in in vitro and in vivo CRPC models that stably overexpresses fAR. VNPP433-3β directly engages AR within the cell and promotes proteasomal degradation of fAR and its splice variant AR-V7 by enhancing the interaction of AR with E3 ligases MDM2/CHIP but disrupting AR-HSP90 binding. Next, VNPP433-3β decreases phosphorylation of 4EBP1 and abates binding of eIF4E and eIF4G to 5' cap of mRNA by depleting MNK1/2 with consequent depletion of phosphorylated eIF4E. Finally, RNA-seq demonstrates modulation of multiple pathways that synergistically contribute to PCa inhibition. Therefore, VNPP433-3β exerts its antitumor effect by imposing 1) transcriptional regulation of AR and AR-responsive oncogenes 2) translational regulation by disrupting mRNA-5'cap-dependent translation initiation, 3) reducing AR half-life through enhanced proteasomal degradation in vitro and AR-overexpressing tumor xenografts in vivo.

Transcriptome profiling reveals that VNPP433-3β, the lead next-generation galeterone analog inhibits prostate cancer stem cells by downregulating epithelial-mesenchymal transition and stem cell markers

Cancer stem cells (CSCs) virtually present in all tumors albeit in small numbers are primarily responsible for driving cancer progression, metastasis, drug resistance, and recurrence. Prostate cancer (PCa) is the second most frequent cancer in men worldwide, and castration resistant prostate cancer (CRPC) remains a major challenge despite the tremendous advancements in medicine. Currently, none of the available treatment options are effective in treating CRPC. We earlier reported that VNPP433-3β, the lead next-generation galeterone analog is effective in treating preclinical in vivo models of CRPC. In this study using RNA-seq, cytological, and biochemical methods, we report that VNPP433-3β inhibits prostate CSCs by targeting key pathways critical to stemness and epithelial-mesenchymal transition. VNPP433-3β inhibits CSCs in PCa, presumably by degrading the androgen receptor (AR) thereby decreasing the AR-mediated transcription of several stem cell markers including BMI1 and KLF4. Transcriptome analyses by RNA-seq, Ingenuity Pathway Analysis, and Gene Set Enrichment Analysis demonstrate that VNPP433-3β inhibits transcription of several genes and functional pathways critical to the prostate CSCs thereby inhibiting CSCs in PCa besides targeting the bulk of the tumor.

Curcumin derivative 1, 2-bis [(3E, 5E)-3, 5-bis [(2-chlorophenyl) methylene]-4-oxo-1-piperidyl] ethane-1, 2-dione (ST03) induces mitochondria mediated apoptosis in ovarian cancer cells and inhibits tumor progression in EAC mouse model

Curcumin is known for its anticancer properties, but its clinical application is limited due to its poor bioavailability and chemical stability. In this study we report the curcumin derivative, ST03 (1,2-bis[(3E,5E)-3,5-bis[(2-chlorophenyl)methylene]-4-oxo-1-piperidyl]ethane-1,2-dione) exhibits ∼ 14 fold better bioavailability compared to curcumin and is detectable in plasma up to 12 h. ST03 induces ROS, activates the intrinsic apoptotic pathway as evident by disruption of mitochondrial membrane potential, and induction of proapoptotic proteins in ovarian cancer lines PA1 and A2780. ST03 also blocked the migration of ovarian cancer cells. ST03 exerted its antitumor effect in-vivo in the EAC mouse model by activating the intrinsic apoptotic pathway. Our findings demonstrate ST03, a curcumin derivative, with better bioavailability and stability with no discernable toxicity in vivo to be a promising drug candidate for anticancer therapies.

Synthesis, Molecular Docking and Preliminary Antileukemic Activity of 4-Methoxybenzyl Derivatives Bearing Imidazo[2,1-b][1,3,4]thiadiazole

In this study, we synthesized 22 compounds in a series with various substitution on imidazo[2,1-b][1,3,4]thiadiazole. The potential cytotoxic activity of these compounds investigated in leukemia cell lines by Differential Nuclear Staining (DNS). Our results identified two compounds, 2-(4-methoxybenzyl)-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl thiocyanate and 6-(4-chlorophenyl)-2-(4-methoxybenzyl)imidazo[2,1-b][1,3,4]thiadiazole-5-carbaldehyde, exhibited the most cytotoxic effect against murine leukemia cells (L1210), human T-lymphocyte cells (CEM) and human cervix carcinoma cells (HeLa) with IC50 values ranging between 0.79 and 1.6 μM. The results indicate that 2-(4-methoxybenzyl)-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl thiocyanate is inducing phosphatidylserine externalization and caspase-3 activation which are both a hallmark of apoptosis. Docking studies showed that 2-(4-methoxybenzyl)-6-(2-oxo-2H-chromen-3-yl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl thiocyanate binds within the active sites of transforming growth factor beta (TGF-β) type I receptor kinase domain by strong hydrogen binding and hydrophobic interactions.

Deciphering the molecular pathways of apoptosis using purified fractions from leaf extract of Basella alba through studying the regulation of apoptosis related genes

Apoptosis plays a pivotal role in the exclusion of abnormal cells without any ruin of surrounding healthy cells. Generally, it occurs through an orderly and autonomously process which is controlled by proper function of various genes. Therefore, the current experiments detect the expression level/pattern of those genes to confirm the involvement of extrinsic and intrinsic pathway using Basella alba leaf (BAL). Several fractions after gel filtration chromatography of BAL extract have been pooled to evaluates its apoptosis induction potentiality on Ehrlich's Ascites Carcinoma (EAC) cells through conducting a number of bio-assays such as cell growth inhibition assay, fluorescence and optical microscopy, DNA fragmentation assay and gene expression analysis etc. The pooled fractions of BAL showed 12-56% inhibitory effect on EAC cell line at the concentration range of 25-400 μg/ml that was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. They also exhibited excellent cell growth inhibition at in vivo and in vitro condition when treated with 10, 20 and 40 mg/kg day. After administration of six consequent days, significant morphological features of apoptosis were observed in EAC cells under both fluorescence and optical microscope which was further supported by DNA fragmentation assay. The polymerase chain reaction amplification of bax, bcl-2 (B-cell lymphoma 2), p53, tumor necrosis factor-α, Fas, NF-kβ (Nuclear factor-Kappa-B), PARP-1 (Poly (ADP-ribose) polymerase), Cyt-c cas-8, cas-9 and cas-3 revealed that the experimental sample able to induce apoptosis in both extrinsic and intrinsic pathways through altering the gene expression. The current findings suggest that sample from BAL occupy wonderful competence to induce cell apoptosis and become an ideal resource for cancer treatment.

Musa acuminata lectin exerts anti-cancer effects on HeLa and EAC cells via activation of caspase and inhibitions of Akt, Erk, and Jnk pathway expression and suppresses the neoangiogenesis in in-vivo models

In the present study aimed to purify the lectin from the sap of Musa acuminata pseudostem and elucidate the apoptotic and angiogenic molecular mechanism in both in-vitro and in-vivo model. Mannose specific lectin was purified by using mannose affinity column chromatography and analyzed by RP-HPLC, SDS-PAGE, and PAS staining method. Furthermore, the protein was identified by MALDI-MS/MS. MAL effectively agglutinates trypsinized RBCs and showed effective cytotoxicity against various human cancer cell lines. MAL mitigates the cell proliferation, colony formation, cell migration, arrest the cell cycle in the G2/M phase, and induce apoptosis by altering the expression of apoptotic proteins/mRNA level (Bax and Bcl-2) via caspase 8/9, 3 dependent pathway in both in-vitro and in-vivo. Supporting this, in-vivo EAC tumor mice models prove the efficacy of MAL by inducing cell death and inhibiting the neovessel formation by targeting the MVD, inhibition of VEGF secretion, suppressing the expression of MMPs, HIF-1α, Flt-1, Akt, Jnk, and Erk1/2. More importantly, the MAL treatment leads to effective inhibition of tumor growth and an increase in the survivability of EAC mice. Our study summarizes that the MAL having a significant anticancer potential expressively degenerates the tumor development by inducing apoptosis and suppressing neoangiogenesis.

Novel 3-(3, 5-difluoro-4-hydroxyphenyl)-1-(naphthalen-2-yl) prop-2-en-1-one as a potent inhibitor of MAP-kinase in HeLa cell lines and anti-angiogenic activity is mediated by HIF-1α in EAC animal model

In the present investigation, we synthesized chalcone bearing naphthalene compound d1, and on the basis of ¹H-NMR, ¹³C NMR, and LC-MS data we had specified the structure of the synthesized compound. The resultant compound d1 was assessed for their antiproliferative action against human cancer cell lines (HeLa, HCT116, HT29, MDA-MB-231, MCF-7, and SKBR3). The IC₅₀ range was estimated at 5.58 to 11.13 μM shows that compound d1 had remarkable anticancer activity on HeLa cell lines. Besides, it was discovered that d1 incited the mitochondrial apoptotic pathway by controlling Bax and Bcl-2 transcripts by expanding the Caspase 3 activation. We depicted the in-vivo effects of tumor advancement and the antiangiogenic activity of d1 in the EAC animal model. Tumor growth had inhibited and without symptoms the longevity of EAC containing mice expanded by the treatment of d1. Inhibition of nuclear transcriptional factor HIF-1α in EAC cells and finally it also inhibited phosphorylation of downstream signaling proteins such as ERK_1/2, p38, and JNK in HeLa cells. The present investigation uncovered that d1 indicated noteworthy tumor-repressing abilities much less concentration in in-vitro and in-vivo recommended that compound d1 as the potent anticancer medication.

Levamisole enhances DR4-independent apoptosis induced by TRAIL through inhibiting the activation of JNK in lung cancer

THE HEADINGS AIMS

Levamisole has anti-parasite and antitumor activities, but the anti-lung cancer mechanism has not been studied. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is regarded as a promising drug because of the ability to selectively target cancer cells. However, the tolerance of cancer cells to TRAIL limits its antitumor activity. Other drugs combined with TRAIL need to be explored to enhance its antitumor activity. Based on the adjuvant anticancer effect of levamisole on anticancer drugs activity, the antitumor activity of levamisole combined with TRAIL will be investigated.

MATERIALS AND METHODS

In vitro and in vivo experiments were employed to investigate the anti-tumor activity. Flow-cytometry analysis, western blotting and siRNA transfection were used to explore the molecular mechanism.

KEY FINDINGS

Levamisole decreased the proliferation of lung cancer cells in vitro and in vivo and induced cell cycle arrest in G0/G1 phase. Besides, levamisole also enhanced TRAIL-induced DR4-independent apoptosis by inhibiting the phosphorylation of cJUN. A new cellular protective pathway LC3B-DR4/Erk was also disclosed, in which levamisole only increased the expression of LC3B and then activated the phosphorylation of Erk and increased the expression of DR4, while p-Erk and DR4 inter-regulated.

SIGNIFICANCE

Levamisole may be used as an adjuvant of TRAIL in treating lung cancer. The discovery of LC3B-DR4/Erk as a new protective pathway provides a new direction for sensitizing lung cancer cells to TRAIL.

Gene signatures and potential therapeutic targets of amino acid metabolism in estrogen receptor-positive breast cancer

Increased activity of amino acid transporters has been observed in a wide variety of cancers. However, whether amino acid metabolism is related to estrogen receptor-positive (ER⁺) breast cancer has been less well studied. We identified the rate-limiting enzyme involved in amino acid metabolism associated with ER⁺ breast cancer by integrating numerous bioinformatics tools and laboratory studies. The bioinformatics analysis revealed that highly expressed genes in ER⁺ breast cancer patients were correlated with breast cancer-related pathways, including ESR1 and PI3K signaling. The metabolic signaling and the amino acid metabolism were significantly regulated in breast neoplasms. We used the ER⁺ breast cancer cell line MCF-7 and breast cancer tissue from National Cheng Kung University Hospital to validate our findings in bioinformatics. In estradiol-treated MCF-7 cells, genes associated with anabolic metabolism of serine and methionine and genes associated with catabolic metabolism of tyrosine, phenylalanine and arginine were upregulated. Furthermore, the expression levels of ARG2, PSAT1, PSPH, TH, PAH, and MAT1A mRNA were increased in breast cancer patients relative to controls. The aforementioned genes were also found to be highly correlated with distant metastasis-free survival in breast cancer patients. High expression levels of ARG2, CBS, PHGDH, AHCY, HAL, TDO2, SHMT2, MAT1A, MAT2A, GLDC, GLS2, BCAT2, GLUD1, PAH and MTR contributed to poor prognoses, whereas high mRNA expression levels of HECA, CTH, PRODH, TAT, and MAT2B were correlated with good prognoses. FDA-approved drugs, including piperlongumine, ellipticine, etidronic acid, harmine, and meclozine, may have novel therapeutic effects in ER⁺ patients based on connectivity map (CMap) analyses. Collectively, our present study demonstrated that amino acid metabolism genes play crucial roles in tumor development and may serve as prospective drug targets or biomarkers for ER⁺ breast cancer.

Subcutaneous Ehrlich Ascites Carcinoma mice model for studying cancer-induced cardiomyopathy

Cardiomyopathy is one of the characteristic features of cancer. In this study, we establish a suitable model to study breast cancer-induced cardiomyopathy in mice. We used Ehrlich Ascites Carcinoma cells to induce subcutaneous tumor in 129/SvJ mice and studied its effect on heart function. In Ehrlich Ascites Carcinoma bearing mice, we found significant reduction in left ventricle wall thickness, ejection fraction, and fractional shortening increase in left ventricle internal diameter. We found higher muscle atrophy, degeneration, fibrosis, expression of cell-adhesion molecules and cell death in tumor-bearing mice hearts. As observed in cancer patients, we found that mTOR, a key signalling molecule responsible for maintaining cell growth and autophagy was suppressed in this model. Tumor bearing mice hearts show increased expression and nuclear localization of TFEB and FoxO3a transcription factors, which are involved in the upregulation of muscle atrophy genes, lysosomal biogenesis genes and autophagy genes. We propose that Ehrlich Ascites Carcinoma induced tumor can be used as a model to identify potential therapeutic targets for the treatment of heart failure in patients suffering from cancer-induced cardiomyopathy. This model can also be used to test the adverse consequences of cancer chemotherapy in heart.

A Benzothiazole Derivative (5g) Induces DNA Damage And Potent G2/M Arrest In Cancer Cells

Chemically synthesized small molecules play important role in anticancer therapy. Several chemical compounds have been reported to damage the DNA, either directly or indirectly slowing down the cancer cell progression by causing a cell cycle arrest. Direct or indirect reactive oxygen species formation causes DNA damage leading to cell cycle arrest and subsequent cell death. Therefore, identification of chemically synthesized compounds with anticancer potential is important. Here we investigate the effect of benzothiazole derivative (5g) for its ability to inhibit cell proliferation in different cancer models. Interestingly, 5g interfered with cell proliferation in both, cell lines and tumor cells leading to significant G2/M arrest. 5g treatment resulted in elevated levels of ROS and subsequently, DNA double-strand breaks (DSBs) explaining observed G2/M arrest. Consistently, we observed deregulation of many cell cycle associated proteins such as CDK1, BCL2 and their phosphorylated form, CyclinB1, CDC25c etc. Besides, 5g treatment led to decreased levels of mitochondrial membrane potential and activation of apoptosis. Interestingly, 5g administration inhibited tumor growth in mice without significant side effects. Thus, our study identifies 5g as a potent biochemical inhibitor to induce G2/M phase arrest of the cell cycle, and demonstrates its anticancer properties both ex vivo and in vivo.

Inhibition of protein kinases by anticancer DNA intercalator, 4-butylaminopyrimido[4',5':4,5]thieno(2,3-b)quinoline

Targeting protein kinases (PKs) has been a promising strategy in treating cancer, as PKs are key regulators of cell survival and proliferation. Here in this study, we studied the ability of pyrimido[4′,5′:4,5]thieno(2,3-b)quinolines (PTQ) to inhibit different PKs by performing computational docking and in vitro screening. Docking studies revealed that 4-butylaminopyrimido[4′,5′:4,5]thieno(2,3-b)quinoline (BPTQ) has a higher order of interaction with the kinase receptors than other PTQ derivatives. In vitro screening confirms that BPTQ inhibits VEGFR1 and CHK2, with the IC₅₀ values of 0.54 and 1.70 µmol/L, respectively. Further, cytotoxicity of BPTQ was measured by trypan blue assay. Treatment with BPTQ decreased the proliferation of HL-60 cells with an IC₅₀ value of 12 µmol/L and induces apoptosis, as explicated by the fall in the mitochondrial membrane potential, annexin V labeling and increased expression of caspase-3. Taken together, these data suggest that BPTQ possess ability to inhibit PKs and to induce cell death in human promyelocytic leukemia cells.

Expression of heterologous oxalate decarboxylase in HEK293 cells confers protection against oxalate induced oxidative stress as a therapeutic approach for calcium oxalate stone disease

Oxalates stimulate alterations in renal epithelial cells and thereby induce calcium oxalate (CaOx) stone formation. Bacillus subtilis YvrK gene encodes for oxalate decarboxylase (OxdC) which degrades oxalate to formate and CO₂. The present work is aimed to clone the oxdC gene in a mammalian expression vector pcDNA and transfect into Human Embryonic Kidney 293 (HEK293) cells and evaluate the oxdC expression, cell survival rate and oxalate degrading efficiency. The results indicate cell survival rate of HEK293/pcDNAOXDC cells pre-incubated with oxalate was enhanced by 28%. HEK293/pcDNAOXDC cells expressing OxdC treated with oxalate, significantly restored antioxidant activity, mitochondrial membrane potential and intracellular reactive oxygen species (ROS) generation compared with HEK293/pcDNA. Apoptotic marker caspase 3 downregulation illustrates HEK293/pcDNAOXDC cells were able to survive under oxalate-mediated oxidative stress. The findings suggest HEK293 cells expressing oxdC capable of degrading oxalate protect cells from oxidative damage and thus serve as a therapeutic option for prevention of CaOx stone disease.

A Novel Resveratrol Based Tubulin Inhibitor Induces Mitotic Arrest and Activates Apoptosis in Cancer Cells

Resveratrol is one of the most widely studied bioactive plant polyphenols which possesses anticancer properties. Previously we have reported synthesis, characterization and identification of a novel resveratrol analog, SS28. In the present study, we show that SS28 induced cytotoxicity in several cancer cell lines ex vivo with an IC₅₀ value of 3–5 μM. Mechanistic evaluation of effect of SS28 in non-small cell lung cancer cell line (A549) and T-cell leukemic cell line (CEM) showed that it inhibited Tubulin polymerization during cell division to cause cell cycle arrest at G2/M phase of the cell cycle at 12–18 h time period. Immunofluorescence studies confirmed the mitotic arrest upon treatment with SS28. Besides, we show that SS28 binds to Tubulin with a dissociation constant of 0.414 ± 0.11 μM. Further, SS28 treatment resulted in loss of mitochondrial membrane potential, activation of Caspase 9 and Caspase 3, leading to PARP-1 cleavage and finally cell death via intrinsic pathway of apoptosis. Importantly, treatment with SS28 resulted in regression of tumor in mice. Hence, our study reveals the antiproliferative activity of SS28 by disrupting microtubule dynamics by binding to its cellular target Tubulin and its potential to be developed as an anticancer molecule.

BP-1T, an antiangiogenic benzophenone-thiazole pharmacophore, counteracts HIF-1 signalling through p53/MDM2-mediated HIF-1α proteasomal degradation

Hypoxia is a feature of all solid tumours, contributing to tumour progression. Activation of HIF-1α plays a critical role in promoting tumour angiogenesis and metastasis. Since its expression is positively correlated with poor prognosis for cancer patients, HIF-1α is one of the most convincing anticancer targets. BP-1T is a novel antiproliferative agent with promising antiangiogenic effects. In the present study, the molecular mechanism underlying cytotoxic/antiangiogenic effects of BP-1T on tumour/non-tumour angiogenesis was evaluated. Evidences show that BP-1T exhibits potent cytotoxicity with prolonged activity and effectively regressed neovessel formation both in reliable non-tumour and tumour angiogenic models. The expression of CoCl₂-induced HIF-1α was inhibited by BP-1T in various p53 (WT)-expressing cancer cells, including A549, MCF-7 and DLA, but not in mutant p53-expressing SCC-9 cells. Mechanistically, BP-1T mediates the HIF-1α proteasomal degradation by activating p53/MDM2 pathway and thereby downregulated HIF-1α-dependent angiogenic genes such as VEGF-A, Flt-1, MMP-2 and MMP-9 under hypoxic condition of in vitro and in vivo solid tumour, eventually leading to abolition of migration and invasion. Based on these observations, we conclude that BP-1T acts on HIF-1α degradation through p53/MDM2 proteasome pathway.

Identification and characterization of novel ligase I inhibitors

The terminal step of ligation of single and/or double-strand breaks during physiological processes such as DNA replication, repair and recombination requires participation of DNA ligases in all mammals. DNA Ligase I has been well characterised to play vital roles during these processes. Considering the indispensable role of DNA Ligase I, a therapeutic strategy to impede proliferation of cancer cells is by using specific small molecule inhibitors against it. In the present study, we have designed and chemically synthesised putative DNA Ligase I inhibitors. Based on various biochemical and biophysical screening approaches, we identify two prospective DNA Ligase I inhibitors, SCR17 and SCR21. Both the inhibitors blocked ligation of nicks on DNA in a concentration-dependent manner, when catalysed by cell-free extracts or purified Ligase I. Docking studies in conjunction with biolayer interferometry and gel shift assays revealed that both SCR17 and SCR21 can bind to Ligase I, particularly to the DNA Binding Domain of Ligase I with KD values in nanomolar range. The inhibitors did not show significant affinity towards DNA Ligase III and DNA Ligase IV. Further, addition of Ligase I could restore the joining, when the inhibitors were treated with testicular cell-free extracts. Ex vivo studies using multiple assays showed that even though cell death was limited in the presence of inhibitors in cancer cells, their proliferation was compromised. Hence, we identify two promising DNA Ligase I inhibitors, which can be used in biochemical and cellular assays, and could be further modified and optimised to target cancer cells. © 2016 Wiley Periodicals, Inc.

Selective activation of TNFR1 and NF-κB inhibition by a novel biyouyanagin analogue promotes apoptosis in acute leukemia cells

BACKGROUND

Acquired resistance towards apoptosis is a hallmark of cancer. Elimination of cells bearing activated oncogenes or stimulation of tumor suppressor mediators may provide a selection pressure to overcome resistance. KC-53 is a novel biyouyanagin analogue known to elicit strong anti-inflammatory and anti-viral activity. The current study was designed to evaluate the anticancer efficacy and molecular mechanisms of KC-53 against human cancer cells.

METHODS

Using the MTT assay we examined initially how KC-53 affects the proliferation rates of thirteen representative human cancer cell lines in comparison to normal peripheral blood mononuclear cells (PBMCs) and immortalized cell lines. To decipher the key molecular events underlying its mode of action we selected the human promyelocytic leukemia HL-60 and the acute lymphocytic leukemia CCRF/CEM cell lines that were found to be the most sensitive to the antiproliferative effects of KC-53.

RESULTS

KC-53 promoted rapidly and irreversibly apoptosis in both leukemia cell lines at relatively low concentrations. Apoptosis was characterized by an increase in membrane-associated TNFR1, activation of Caspase-8 and proteolytic inactivation of the death domain kinase RIP1 indicating that KC-53 induced mainly the extrinsic/death receptor apoptotic pathway. Regardless, induction of the intrinsic/mitochondrial pathway was also achieved by Caspase-8 processing of Bid, activation of Caspase-9 and increased translocation of AIF to the nucleus. FADD protein knockdown restored HL-60 and CCRF/CEM cell viability and completely blocked KC-53-induced apoptosis. Furthermore, KC-53 administration dramatically inhibited TNFα-induced serine phosphorylation on TRAF2 and on IκBα hindering therefore p65/NF-κΒ translocation to nucleus. Reduced transcriptional expression of pro-inflammatory and pro-survival p65 target genes, confirmed that the agent functionally inhibited the transcriptional activity of p65.

CONCLUSIONS

Our findings demonstrate, for the first time, the selective anticancer properties of KC-53 towards leukemic cell lines and provide a detailed understanding of the molecular events underlying its dual anti-proliferative and pro-apoptotic properties. These results provide new insights into the development of innovative and targeted therapies for the treatment of some forms of leukemia.

Quercetin, a Natural Flavonoid Interacts with DNA, Arrests Cell Cycle and Causes Tumor Regression by Activating Mitochondrial Pathway of Apoptosis

Naturally occurring compounds are considered as attractive candidates for cancer treatment and prevention. Quercetin and ellagic acid are naturally occurring flavonoids abundantly seen in several fruits and vegetables. In the present study, we evaluate and compare antitumor efficacies of quercetin and ellagic acid in animal models and cancer cell lines in a comprehensive manner. We found that quercetin induced cytotoxicity in leukemic cells in a dose-dependent manner, while ellagic acid showed only limited toxicity. Besides leukemic cells, quercetin also induced cytotoxicity in breast cancer cells, however, its effect on normal cells was limited or none. Further, quercetin caused S phase arrest during cell cycle progression in tested cancer cells. Quercetin induced tumor regression in mice at a concentration 3-fold lower than ellagic acid. Importantly, administration of quercetin lead to ~5 fold increase in the life span in tumor bearing mice compared to that of untreated controls. Further, we found that quercetin interacts with DNA directly, and could be one of the mechanisms for inducing apoptosis in both, cancer cell lines and tumor tissues by activating the intrinsic pathway. Thus, our data suggests that quercetin can be further explored for its potential to be used in cancer therapeutics and combination therapy.

Cell Cycle Arrest and Induction of Apoptosis in Colon Adenocarcinoma Cells by a DNA Intercalative Quinoline Derivative, 4-Morpholinopyrimido [4',5':4,5] Selenolo (2,3-b) Quinoline

Circular dichroism, topological studies, molecular docking, absorbance, and fluorescence spectral titrations were employed to study the interaction of 4-morpholinopyrimido [4',5':4,5] selenolo (2,3-b) quinoline (MPSQ) with DNA. The association constants of MPSQ-DNA interactions were of the order of 10(4) M(-1). Melting temperature, topological, and docking studies confirmed that the mode of interaction was by intercalation with preference to d(GpC)-d(CpG) site of DNA. Cytotoxicity studies showed the MPSQ-induced dose-dependent inhibitory effect on the proliferation of different cancer cells. Colon adenocarcinoma (COLO 205) cells are more sensitive among the cell lines tested, with an IC50 value of 15 μM. Flow cytometry revealed that MPSQ affects the cell cycle progression by arresting at G2M phase. Further, Annexin V staining, mitochondrial membrane potential assay, and caspase-3 activity assay confirmed that MPSQ leads to mitochondria-mediated apoptotic cell death in COLO 205 cells.

Novel PARP inhibitors sensitize human leukemic cells in an endogenous PARP activity dependent manner

Poly(ADP-ribose) polymerase (PARP) is a critical nuclear enzyme which helps in DNA repair. In this study we report, synthesis and biological studies of novel pyridazine derivatives as PARP inhibitors.

Exposure to Endosulfan can result in male infertility due to testicular atrophy and reduced sperm count

Endosulfan (ES) is a widely used organochlorine pesticide and is speculated to be detrimental to human health. However, very little is known about mechanism of its genotoxicity. Using mouse model system, we show that exposure to ES affected physiology and cellular architecture of organs and tissues. Among all organs, damage to testes was extensive and it resulted in death of different testicular-cell populations. We find that the damage in testes resulted in qualitative and quantitative defects during spermatogenesis in a time-dependent manner, increasing epididymal reactive oxygen species levels, affecting sperm chromatin integrity. This further culminated in reduced number of epididymal sperms and actively motile sperms. Finally, we show that ES exposure affected fertility in male but not in female mice. Therefore, we demonstrate that ES exerts pathophysiological changes in mice, induces testicular atrophy, affects spermatogenesis, reduces quantity and vigour of epididymal sperm and leads to infertility in males.

Simple synthesis of biocompatible biotinylated porous hexagonal ZnO nanodisc for targeted doxorubicin delivery against breast cancer cell: In vitro and in vivo cytotoxic potential

Targeted drug delivery with porous materials features great promise as improved therapeutic potential for treatment of various diseases. In the present study we have attempted a microwave synthesis of porous hexagonal nanodisc of zinc oxide (PZHD) for the first time and its subsequent targeted delivery to breast cancer cells, MCF7. PZHD has been fabricated suitably with 3-aminopropyltriethoxysilane to impart additional stability and surface amines to anchor site directing ligand NHS-biotin. Biotinylated scaffold showed targeted delivery of anticancer drug doxorubicin and pH triggered release to MCF 7 cells with preferential distribution on specified domain. A detailed in vitro cytotoxicity study was associated with it to evaluate the mode of action of Dox loaded PZHD on MCF-7 cells by means of cell cycle analysis, apoptosis assays, Western blot and immuno-fluorescence image analysis. The efficacy of the Dox loaded PZHD was further validated from our in vivo tumor regression studies. Finally, the whole study has been supported by in vitro and in vivo bio-safety studies which also signified its biocompatibility with real time applications. To the best of our knowledge this is the first effort to use biotinylated PZHD for targeted delivery of doxorubicin within MCF 7 cells with a detailed study of its mechanistic application. This study might thus hold future prospects for therapeutic intervention for treatment of cancer.

Synthesis and evaluation of the biological activity of N′-[2-oxo-1,2 dihydro-3H-indol-3-ylidene] benzohydrazides as potential anticancer agents

New N′-[2-oxo-1,2-dihydro-3H-indol-3-ylidene]benzohydrazide derivatives were synthesized and evaluated for their cytotoxic properties against murine leukemia, L1210, human leukemia, REH, K562 and CEM and human cervix carcinoma, HeLa cells.

A novel benzimidazole derivative binds to the DNA minor groove and induces apoptosis in leukemic cells

In the present study, we have synthesized various benzimidazole derivatives, evaluated their potential to act as DNA minor groove binder and tested their chemotherapeutic efficacy.

The first catalyst and solvent-free synthesis of 2-arylimidazo[2,1-b][1,3,4]thiadiazoles: a comparative assessment of greenness

A one-pot, three-component, catalyst and solvent free synthesis of imidazo[2,1-b][1,3,4]thiadiazoles utilizing 5-aryl-1,3,4-thiadiazol-2-amines, aldehydes and isonitriles has been developed. The “greenness” was successfully evaluated within the ambits of green metrics.

Sapodilla plum (Achras sapota) induces apoptosis in cancer cell lines and inhibits tumor progression in mice

Intake of fruits rich in antioxidants in daily diet is suggested to be cancer preventive. Sapota is a tropical fruit grown and consumed extensively in several countries including India and Mexico. Here we show that methanolic extracts of Sapota fruit (MESF) induces cytotoxicity in a dose-dependent manner in cancer cell lines. Cell cycle analysis suggested activation of apoptosis, without arresting cell cycle progression. Annexin V-propidium iodide double-staining demonstrated that Sapota fruit extracts potentiate apoptosis rather than necrosis in cancer cells. Loss of mitochondrial membrane potential, upregulation of proapoptotic proteins, activation of MCL-1, PARP-1, and Caspase 9 suggest that MESF treatment leads to activation of mitochondrial pathway of apoptosis. More importantly, we show that MESF treatment leads to significant inhibition of tumor growth and a 3-fold increase in the life span of tumor bearing animals compared to untreated tumor mice.

The effect of levamisole on mortality rate among patients with severe burn injuries

BACKGROUND

Burn injuries are one of the main causes of mortality and morbidity throughout the world and burn patients have higher chances for infection due to their decreased immune resistance. Levamisole, as an immunomodulation agent, stimulates the immune response against infection.

MATERIALS AND METHODS

This randomized clinical trial was conducted in Motahari Burn Center, Tehran, Iran. Patients who had second- or third-degree burn with involvement of more than 50% of total body surface area (TBSA) were studied. The levamisole group received levamisole tablet, 100 mg per day. Meantime, both the levamisole and control groups received the standard therapy of the Burn Center, based on a standard protocol. Then, the outcome of the patients was evaluated.

RESULTS

237 patients entered the study. After excluding 42 patients with inhalation injury, electrical and chemical burns, and the patients who died in the first 72 h, 195 patients remained in the study, including 110 patients in the control group and 85 in the treatment group. The mean age of all patients (between 13 to 64 years) was 33.29 ± 11.39 years (Mean ± SD), and it was 33.86 ± 11.45 years in the control group and 32.57 ± 11.32 years in the treatment group. The mean percentage of TBSA burn was 64.50 ± 14.34 and 68.58 ± 14.55 for the levamisole and control groups, respectively, with the range of 50-100% and 50-95% TBSA. The mortality rate was 68 (61.8%) patients in the control group and 50 (58.8%) patients in the treatment group (P = 0.8).

CONCLUSION

According to this study, there was no significant relationship between improvement of mortality and levamisole consumption.

Influence of levamisole and other angiogenesis inhibitors on angiogenesis and endothelial cell morphology in vitro

Angiogenesis, the formation of new blood vessels from existing vessels is required for many physiological processes and for growth of solid tumors. Initiated by hypoxia, angiogenesis involves binding of angiogenic factors to endothelial cell (EC) receptors and activation of cellular signaling, differentiation, migration, proliferation, interconnection and canalization of ECs, remodeling of the extracellular matrix and stabilization of newly formed vessels. Experimentally, these processes can be studied by several in vitro and in vivo assays focusing on different steps in the process. In vitro, ECs form networks of capillary-like tubes when propagated for three days in coculture with fibroblasts. The tube formation is dependent on vascular endothelial growth factor (VEGF) and omission of VEGF from the culture medium results in the formation of clusters of undifferentiated ECs. Addition of angiogenesis inhibitors to the coculture system disrupts endothelial network formation and influences EC morphology in two distinct ways. Treatment with antibodies to VEGF, soluble VEGF receptor, the VEGF receptor tyrosine kinase inhibitor SU5614, protein tyrosine phosphatase inhibitor (PTPI) IV or levamisole results in the formation of EC clusters of variable size. This cluster morphology is a result of inhibited EC differentiation and levamisole can be inferred to influence and block VEGF signaling. Treatment with platelet factor 4, thrombospondin, rapamycin, suramin, TNP-470, salubrinal, PTPI I, PTPI II, clodronate, NSC87877 or non-steriodal anti-inflammatory drugs (NSAIDs) results in the formation of short cords of ECs, which suggests that these inhibitors have an influence on later steps in the angiogenic process, such as EC proliferation and migration. A humanized antibody to VEGF is one of a few angiogenesis inhibitors used clinically for treatment of cancer. Levamisole is approved for clinical treatment of cancer and is interesting with respect to anti-angiogenic activity in vivo since it inhibits ECs in vitro with a morphology resembling that obtained with antibodies to VEGF.