Human Leukemia MOLT-4 Cells Research Articles

Synthesis and cytotoxicity of copper(II) semicarbazone complexes with lipophilic counter-anions

A series of (2,4-dihydroxybenzaldehyde dibenzyl semicarbazone) perfluoroalkyl carboxylato copper(II) complexes, [CF3(CF2)nCO2(LH)Cu] (LH2 = 2,4-dihydroxybenzaldehyde dibenzyl semicarbazone; n = 0, 2, 4, 6; 1–4), and (2,4-dihydroxybenzaldehyde dibenzyl semicarbazone) pyridine copper(II) perfluoroalkyl carboxylates, [(LH)(py)Cu]+[CF3(CF2)nCO2]− (5–8) were synthesized. The lipophilicity of these compounds was determined by reverse-phase thin layer chromatography and correlated with their cytotoxicity towards MOLT-4 human leukaemia cells. Cytotoxicity is more strongly correlated with lipophilicity for the non-ionic compounds (1–4) than for the ionic compounds (5–8). Compounds 5–8 (IC50 2.8–3.8 μM) are generally more cytotoxic than compounds 1–4 (IC50 3.6–8.4 μM). They also exhibit slightly higher cytotoxicity than the parent anticancer compound [(LH)(py)Cu]+[NO3]− (IC50 4.15 μM), suggesting that it is possible to enhance the cytotoxicity of [(LH)(py)Cu]+[NO3]− by replacing nitrate with anions of higher lipophilicity. Attempts to synthesize the non-fluorinated analogue [(LH)(py)Cu]+[CH3CO2]− resulted in the formation of the deprotonated complex [L(py)Cu], whose structure was confirmed by X-ray crystallography. The structural parameters indicate that the deprotonation site is the hydrazonic nitrogen of the semicarbazone ligand.

Modification of Polyethylene Glycol-Hydroxypropyl Methacrylate Polymeric Micelles Loaded with Curcumin for Cellular Internalization and Cytotoxicity to Wilms Tumor 1-Expressing Myeloblastic Leukemia K562 Cells.

Curcumin loaded in micelles of block copolymers of ω-methoxypoly(ethylene glycol) and N-(2-hydroxypropyl) methacrylamide modified with aliphatic dilactate (CD) or aromatic benzoyl group (CN) were previously reported to inhibit human ovarian carcinoma (OVCAR-3), human colorectal adenocarcinoma (Caco-2), and human lymphoblastic leukemia (Molt-4) cells. Myeloblastic leukemia cells (K562) are prone to drug resistance and differ in both cancer genotype and phenotype from the three mentioned cancer cells. In the present study, CD and CN micelles were prepared and their effects on K562 and normal cells were explored. The obtained CD and CN showed a narrow size distribution with diameters of 63 ± 3 and 50 ± 1 nm, respectively. The curcumin entrapment efficiency of CD and CN was similarly high, above 80% (84 ± 8% and 91 ± 3%). Both CD and CN showed suppression on WT1-expressing K562 and high cell-cycle arrest at the G2/M phase. However, CD showed significantly higher cytotoxicity to K562, with faster cellular uptake and internalization than CN. In addition, CD showed better compatibility with normal red blood cells and peripheral blood mononuclear cells than CN. The promising CD will be further investigated in rodents and possibly in clinical studies for leukemia treatment.

Exploration of anti-leukemic effect of soft coral-derived 13-acetoxysarcocrassolide: Induction of apoptosis via oxidative stress as a potent inhibitor of heat shock protein 90 and topoisomerase II.

13-Acetoxysarcocrassolide (13-AC) is a marine cembranoid derived from the aquaculture soft coral of Lobophytum crassum. The cytotoxic effect of 13-AC against leukemia cells was previously reported but its mechanism of action is still unexplored. In the current study, we showed that 13-AC induced apoptosis of human acute lymphoblastic leukemia Molt4 cells, as evidenced by the cleavage of PARP and caspases, phosphatidylserine externalization, as well as the disruption of mitochondrial membrane potential. The use of N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, attenuated the cytotoxic effect induced by 13-AC. Molecular docking and thermal shift assay indicated that the cytotoxic mechanism of action of 13-AC involved the inhibition of heat shock protein 90 (Hsp 90) activity by eliciting the level of Hsp 70 and topoisomerase IIα in Molt4 cells. 13-AC also exhibited potent antitumor activity by reducing the tumor volume (48.3%) and weight (72.5%) in the in vivo Molt4 xenograft mice model. Our findings suggested that the marine cembranoid, 13-AC, acted as a dual inhibitor of Hsp 90 and topoisomerase IIα, exerting more potent apoptotic activity via the enhancement of ROS generation.

Abnormal expression of H-Ras induces S-phase arrest and mitotic catastrophe in human T-lymphocyte leukemia.

Leukemia is a neoplasm with high incidence and mortality rates. Mitotic death has been observed in tumor cells treated with chemotherapeutic agents. Ras family proteins participate in the transduction of signals involved in different processes, such as proliferation, differentiation, survival, and paradoxically, initiation of cell death. This study investigated the effect of H-Ras expression on human T-cell acute lymphoblastic leukemia MOLT-4 cells. Cells were electroporated with either wild-type (Raswt) or oncogenic mutant in codon 12 exon 1 (Rasmut) versions of H-Ras gene and stained for morphological analysis. Cell viability was assessed using trypan blue staining and cell cycle analysis using flow cytometry. H-Ras gene expression was determined using quantitative real-time reverse transcription polymerase chain reaction. The t, ANOVA, and Scheffe tests were used for statistical analysis. Human T-cell acute lymphoblastic leukemia MOLT-4 cells showed nuclear fragmentation and presence of multiple nuclei and micronuclei after transfection with either wt or mutant H-Ras genes. Cell cycle analysis revealed a statistically significant increase in cells in the S phase when transfected with either wt (83.67%, P<0.0005) or mutated (81.79%, P<0.0001) H-Ras genes. Although similar effects for both versions of H-Ras were found, cells transfected with the mutated version died at 120 h of mitotic catastrophe. Transfection of human T-cell acute lymphoblastic leukemia MOLT-4 cells with either normal or mutated H-Ras genes induced alterations in morphology, arrest in the S phase, and death by mitotic catastrophe.

Development of a Sensitive Anti-Human CCR9 Monoclonal Antibody (C9Mab-11) by N-Terminal Peptide Immunization.

The C-C chemokine receptor 9 (CCR9) belongs to the G-protein-coupled receptor superfamily, and is highly expressed on the T cells and intestinal cells. CCR9 regulates various immune responses by binding to the C-C chemokine ligand, CCL25, and is involved in inflammatory diseases and tumors. Therefore, the development of sensitive monoclonal antibodies (mAbs) for CCR9 is necessary for treatment and diagnosis. In this study, we established a specific anti-human CCR9 (hCCR9) mAb; C9Mab-11 (mouse IgG2a, kappa), using the synthetic peptide immunization method. C9Mab-11 reacted with hCCR9-overexpressed Chinese hamster ovary-K1 (CHO/hCCR9) and hCCR9-endogenously expressed MOLT-4 (human T-lymphoblastic leukemia) cells in flow cytometry. The dissociation constant (KD) of C9Mab-11 for CHO/hCCR9 and MOLT-4 cells were determined to be 1.2 × 10-9 M and 4.9 × 10-10 M, respectively, indicating that C9Mab-11 possesses a high affinity for both exogenously and endogenously hCCR9-expressing cells. Furthermore, C9Mab-11 clearly detected hCCR9 protein in CHO/hCCR9 cells using western blot analysis. In summary, C9Mab-11 can be a useful tool for analyzing hCCR9-related biological responses.

Synthesis, Characterization, and Antimicrobial and Antiproliferative Effects of CuO-TiO2-Chitosan-Escin Nanocomposites on Human Leukemic MOLT4 Cells.

Nanocomposites comprised of CuO-TiO2-chitosan-escin, which has adjustable physicochemical properties, provide a solution for therapeutic selectivity in cancer treatment. By controlling the intrinsic signaling primarily through the mitochondrial signaling pathway, we desired nanocomposites with enhanced anticancer activity by containing CuO-TiO2-chitosan-escin. The metal oxides CuO and TiO2, the natural polymer chitosan, and a phytochemical compound escin were combined to form CuO-TiO2-chitosan-escin nanocomposites. The synthesized nanocomposites were confirmed and characterized using FTIR spectroscopy, TEM, and UV-Vis absorption spectroscopy. A human leukemia cell line (MOLT-4) was used to assess the efficacy and selectivity of nanocomposites. Based on a cytotoxicity study, CuO-TiO2-chitosan-escin nanocomposites had inhibition concentrations (IC50) of 13.68, 8.9, and 7.14 µg/mL against human T lymphoblast cells after 24, 48, and 72 h of incubation, respectively. Compared with untreated MOLT-4 cells, CuO-TiO2-chitosan-escin nanocomposite-treated cells significantly increased (p &lt; 0.05) caspase-3, -8, and -9 and decreased the levels of antioxidant enzymes GR, SOD, and GSH. Furthermore, MDA for lipid peroxidase and ROS levels significantly increased (p &lt; 0.05) in the treated cells than in the untreated cells. Remarkably, CuO-TiO2-chitosan-escin nanocomposite-mediated control of cell cycles were mainly achieved through the activation of caspase-3, -8, and -9.

Genistein impairs proliferation and induces apoptosis in human leukemia MOLT-4 cells by down-regulation of anti-apoptotic proteins

Genistein impairs proliferation and induces apoptosis in human leukemia MOLT-4 cells by down-regulation of anti-apoptotic proteins

Synthesis, Characterization, and Antiproliferative Effect of CuO-TiO2-Chitosan-Amygdalin Nanocomposites in Human Leukemic MOLT4 Cells.

The main aim of this study was to synthesize copper oxide- (CuO-) titanium oxide- (TiO2-) chitosan-amygdalin nanocomposites (CTCANc) and to characterize them physically and biologically (antimicrobial and anticancer activity using MOLT4 blood cancer cell line) to endorse their useful applications as potential drug candidates in anticancer avenues. CuO-TiO2-chitosan-amygdalin nanocomposites were synthesized according to standard, reported methods. Physical characterization of the nanocomposites was performed using methods like X-ray diffractometer (XRD), and morphological and ultrastructural analysis of nanocomposites were done using electron microscope scanning and transmission. FTIR was recorded using a Perkin-Elmer spectrometer, and photoluminescence (PL) spectra were done using the spectrometer. Further, antibacterial activities were assessed using standard bacterial cultures. To demonstrate the nanocomposite's anticancer effects, MTT assay, morphological analysis, apoptosis studies using acridine orange/ethidium bromide (AO/EtBr) dual staining, reactive oxygen species (ROS) analysis, and levels of antioxidant enzymes were analyzed using the MOLT4 blood cancer cell line. Synthesized nanocomposites were characterized using XRD and showed various peaks, respectively, for CuO-TiO2, amygdalin, and chitosan. MTT assay indicated an IC50 value of 38.41 μg/ml concentration of CTCANc. Hence, 30 and 40 μg/ml were used for the subsequent experiments. Morphological analysis, staining for apoptosis using AO/EtBr, mitochondrial membrane potential (MMP or ΔΨm) analysis, ROS analysis, and determination of the SOD, CAT, MDA, and GSH levels were performed. Observations like a significant loss of morphology, induction of apoptosis, elevated ROS, and decreased MMP were significant in 30 and 40 μg/ml nanocomposite-treated cells when compared to control cells. The bimetallic nanocomposites exhibited typical nanocomposites characteristics and significant antibacterial and anticancer effects. The study results endorse the antibacterial, anticancer activity of CuO-TiO2-chitosan-amygdalin nanocomposites and strongly suggest that further in-depth research using CuO-TiO2-chitosan-amygdalin nanocomposites could reveal their efficacy in the clinical scenario.

Structural, Optical, Antibacterial, and Anticancer Properties of Cerium Oxide Nanoparticles Prepared by Green Synthesis Using Morinda citrifolia Leaves Extract.

Currently, new advancements in the area of nanotechnology opened up new prospects in the field of medicine that could provide us with a solution for numerous medical complications. Although a several varieties of nanoparticles is being explored to be used as nanomedicines, cerium oxide nanoparticles (CeO2 NPs) are the most attractive due to their biocompatibility and their switchable oxidation state (+3 and +4) or in other words the ability to act as prooxidant and antioxidant depending on the pH condition. Green synthesis of nanoparticles is preferred to make it more economical, eco-friendly, and less toxic. The aim of our study here is to formulate the CeO2 NPs (CeO2 NPs) using Morinda citrifolia (Noni) leaf extract and study its optical, structural, antibacterial, and anticancer abilities. Their optical and structural characterization was accomplished by employing X-ray diffractography (XRD), TEM, EDAX, FTIR, UV-vis, and photoluminescence assays. Our CeO2 NPs expressed strong antibacterial effects against Gram-positive S. aureus and S. pneumonia in addition to Gram-negative E. coli and K. pneumonia when compared with amoxicillin. The anticancer properties of the green synthesized CeO2 NPs against human acute lymphoblastic leukemia (ALL) MOLT-4 cells were further explored by the meticulous study of their ability to diminish cancer cell viability (cytotoxicity), accelerate apoptosis, escalate intracellular reactive oxygen species (ROS) accumulation, decline the mitochondria membrane potential (MMP) level, modify the cell adhesion, and shoot up the activation of proapoptotic markers, caspase−3, −8, and −9, in the tumor cells. Altogether, the outcomes demonstrated that our green synthesized CeO2 NPs are an excellent candidate for alternative cancer therapy.

A Novel RNA Synthesis Inhibitor, STK160830, Has Negligible DNA-Intercalating Activity for Triggering A p53 Response, and Can Inhibit p53-Dependent Apoptosis.

RNA synthesis inhibitors and protein synthesis inhibitors are useful for investigating whether biological events with unknown mechanisms require transcription or translation; however, the dependence of RNA synthesis has been difficult to verify because many RNA synthesis inhibitors cause adverse events that trigger a p53 response. In this study, we screened a library containing 9600 core compounds and obtained STK160830 that shows anti-apoptotic effects in irradiated wild-type-p53-bearing human T-cell leukemia MOLT-4 cells and murine thymocytes. In many of the p53-impaired cells and p53-knockdown cells tested, STK160830 did not show a remarkable anti-apoptotic effect, suggesting that the anti-apoptotic activity is p53-dependent. In the expression analysis of p53, p53-target gene products, and reference proteins by immunoblotting, STK160830 down-regulated the expression of many of the proteins examined, and the downregulation correlated strongly with its inhibitory effect on cell death. mRNA expression analyses by qPCR and nascent RNA capture kit revealed that STK160830 showed a decreased mRNA expression, which was similar to that induced by the RNA synthesis inhibitor actinomycin D but differed to some extent. Furthermore, unlike other RNA synthesis inhibitors such as actinomycin D, p53 accumulation by STK160830 alone was negligible, and a DNA melting-curve analysis showed very weak DNA-intercalating activity, indicating that STK160830 is a useful inhibitor for RNA synthesis without triggering p53-mediated damage responses.

Trikoveramides A-C, cyclic depsipeptides from the marine cyanobacterium Symploca hydnoides

Trikoveramides A – C, members of the kulolide superfamily of cyclic depsipeptides, were isolated from the marine cyanobacterium, Symploca hydnoides, collected from Bintan Island, Indonesia. Their planar structures were elucidated by a combination of NMR spectroscopy and HRMS spectral data. The absolute configurations of the amino acid and phenyllactic acid units were confirmed by Marfey's and chiral HPLC analyses, respectively, while the relative stereochemistry of the 3-hydroxy-2-methyl-7-octynoic acid (Hmoya) unit in trikoveramide A was elucidated by the application of the J-based configuration analysis and NOE correlations. The cytotoxic activity of the trikoveramides were evaluated against MOLT-4 human leukemia cells and gave IC50 values of 9.3 μM, 35.6 μM and 48.8 μM for trikoveramide B, trikoveramide C and trikoveramide A, respectively. In addition, trikoveramides A – C showed weak to moderate inhibition in the quorum sensing inhibitory assay based on the Pseudomonas aeruginosa lasB-gfp and rhlA-gfp bioreporter strains.

D-carvone induced ROS mediated apoptotic cell death in human leukemic cell lines (Molt-4).

The immature lymphoid cells with chromosomal structural and numerical abnormalities cause the acute lymphoblastic leukemia (ALL). This hematologic disorder constitutes about 25% of cancer prognosis among children and adolescents. D-Carvone, a monocyclic monoterpene obtained from the essential oils extracted from plants is reported to possess the various biological activities. The present study was aimed to investigate the anticancer potential of D-Carvone against the human leukemic Molt-4 cells. The cytotoxicity of DCarvone was analyzed by MTT assay. The level of lipid peroxidation and antioxidants were determined. The intracellular ROS, MMP and apoptosis were demonstrated by fluorescent staining techniques. The MTT assay revealed that the D-Carvone treatment suppressed the viability of Molt-4 cells and the IC50 was determined at 20 µM/ml. The D-Carvone treatment was increased the oxidative stress and reduced the level of antioxidants in the Molt-4 cell lines. The increased intracellular ROS, apoptotic cell death, and diminished MMP was noted in the D-Carvone treatment. In the Molt-4 cells, D-carvone induced the apoptosis in a time and dose dependent manner by the activation of caspases-8, -9 and -3. Thus, data provide insights for the clinical application of D-Carvone in the treatment of blood cancer Molt-4 cells. Our study suggests the therapeutic potential D-Carvone for the treatment of leukemia in future.

Tomentosin inhibits cell proliferation and induces apoptosis in MOLT-4 leukemia cancer cells through the inhibition of mTOR/PI3K/Akt signaling pathway.

Leukemia is amongst the cancers accountable for substantial mortality around the world. Tomentosin is a bioactive compound with a pharmacological significance, and its anticancer property against human leukemiaMOLT-4 cell line has never been reported. Hence, the objective of this study was to explore the anticancer activity of tomentosin in MOLT-4 human leukemia cells. In the current investigation, the cytotoxic effects of tomentosin ensuing potent toxicity (IC50 : 10 µM) in MOLT-4 cells after incubation at 24 h have been presented. Furthermore, tomentosin triggered intracellular reactive oxygen species production and showed the induction of intrinsic/mitochondrial pathways in treated MOLT-4 cells, revealing a significant cytotoxicity activity. Also, fluorescent microscopic studies using acridine orange/ethidium bromide and propidium iodide staining confirmed the occurrence of apoptosis in tomentosin-treated MOLT-4 cells. Quantitative reverse transcription polymerase chain reaction presented a negative regulation of cyclin D1 and BcL-2 expression and a positive regulated BAX and caspase-3 messenger RNA expression in tomentosin-treated MOLT-4 cells. Tomentosin further inhibited the inflammatory transcription factors such as nuclear factor κB (NF-κB), tumor necrosis factor α, interleukin 1β (IL-1β), and IL-6. Additionally, inhibition of the m-TOR/PI3K/AKT protein expression by tomentosin in MOLT-4 cells was confirmed. Overall, these findings lead to a conclusion that tomentosin induces apoptosis in MOLT-4 cells through caspase-facilitated proapoptotic pathway, and inhibition of the NF-κB-stimulated Bcl-2 facilitated the antiapoptotic pathway.

D-Pinitol treatment induced the apoptosis in human leukemia MOLT-4 cells by improved apoptotic signaling pathway

Cancer is still remain as a global burden with the 18.1 million and 9.6 million new cases and mortlities, respectively estimated globally. Leukemia may arise at all ages varied from the infants to elders. In this exploration, we planned to evaluate the antiproliferative effect of D-pinitol on human leukemia MOLT-4 cells. Anticancer potential of D-pinitol was examined using MTT assay. Reactive oxygen species (ROS) generation was studied by fluorescence microscopic method using DCFH-DA staining. Apoptotic morphological alterations were determined by dual staining (acridine orange and ethidium bromide). Western blot and ELISA methods were employed to study apoptotic protein expression. D-pinitol treatment significantly induced cytotoxicity in human leukemia MOLT-4 cells. We observed that D-pinitol induces the generation of ROS in MOLT-4 cells. Further, we noticed that D-pinitol significantly induced apoptosis in a dosage dependent manner. Moreover, western blot and ELISA based analysis revealed that D-pinitol elevated the Bax, Caspase-3, Caspase-9 and attenuated the Bcl-2 expression in leukemic cancer cell. Our findings suggest that D-pinitol treatment induces the apoptosis in human leukemic cells by generating intracellular ROS and modulating apoptotic protein expression.

Knockdown of Enhancer of Zeste Homolog 2 Affects mRNA Expression of Genes Involved in the Induction of Resistance to Apoptosis in MOLT-4 Cells.

The Enhancer of Zeste Homolog 2 (EZH2) is a subunit of the polycomb repressive complex 2 that silences the gene transcription via H3K27me3. Previous studies have shown that EZH2 has an important role in the induction of the resistance against the Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL)-Induced Apoptosis (TIA) in some leukemia cells. The aim of this study was to determine the effect of silencing EZH2 gene expression using RNA interference on the expression of death receptors 4 and 5 (DR4/5), Preferentially expressed Antigen in Melanoma (PRAME), and TRAIL human lymphoid leukemia MOLT-4 cells. Quantitative RT-PCR was used to detect the EZH2 expression and other candidate genes following the siRNA knockdown in MOLT-4 cells. The toxicity of the EZH2 siRNA was evaluated using Annexin V/PI assay following the transfection of the cells by 80 pM EZH2 siRNA at 48 hours. Based on the flow-cytometry results, the EZH2 siRNA had no toxic effects on MOLT-4 cells. Also, the EZH2 inhibition increased the expression of DR4/5 but reduced the PRAME gene expression at the mRNA levels. Moreover, the EZH2 silencing could not change the TRAIL mRNA in the transfected cells. Our results revealed that the down-regulation of EZH2 in MOLT-4 cells was able to affect the expression of important genes involved in the induction of resistance against TIA. Hence, we suggest that the silencing of EZH2 using RNA interference can be an effective and safe approach to help defeat the MOLT-4 cell resistance against TIA.

Ruthenium arene complexes with mono-carbonyl analogues of curcumin as pendant or bridging ligands: Synthesis, anti-cancer activity and interaction with quadruplex DNA

Four ruthenium(II) arene complexes containing mono-carbonyl analogues of curcumin (MAC) functioning as pendant or bridging ligands as well as chlorido ancillary ligands have been synthesized and structurally characterized by IR and 1H NMR spectroscopies, ESI mass spectrometry and elemental analysis. Anti-proliferative activity of the complexes determined on MOLT-4 human leukemia cells revealed good to moderate activity. Two of the compounds, 3b and 4b, both of which incorporated cyclohexanone as part of the MAC structural motif, displayed potency comparable to cisplatin. In intercalative binding studies, while the organic MACs did not display any interaction with quadruplex DNA, the ruthenium complexes were found to be able to stabilize quadruplex DNA, with 3b and 4b displaying the greatest selectivity for HTelo over c-myc. Compound 4b, in which the MAC ligand is bridged by two organoruthenium centres, bound to HTelo more tightly than 3b, in which the MAC functions as a pendant ligand towards a single ruthenium arene core. These results suggest that minor changes to the structural motif of the MAC ligand, as well as the presence of the ruthenium arene moiety play an important role in achieving selective quadruplex DNA stabilization.

Development and catalytic characterization of L-asparaginase nano-bioconjugates

The present paper describes efficient immobilization of L-glutaminase free L-asparaginase for developing a new therapeutic system for anticancer therapy. L-asparaginase (L-ASNase) was covalently immobilized on the functionalized aluminum oxide nanoparticles (AONP) and titanium oxide nanoparticles (TONP). The nano-bioconjugates (AONP-ASNase and TONP-ASNase) were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR) and UV–Vis spectral analysis that revealed the successful immobilization. The nano-bioconjugates were optimally active at pH 7.0 and 40 °C. TONP-ASNase activity was enhanced in the presence of NH4+ (160%) and Mn2+ (165%) while AONP-ASNase bioconjugates showed increased relative activity with ethyl acetate (142%) and toluene (160%). The nano-bioconjugates displayed excellent reusability and maintained >90% average activity after nine successive cycles. Maximum cytotoxicity (61%) was noticed with AONP-ASNase (10 μg/ml) against human leukemia MOLT-4 cells. Regarding kinetic values, AONP-ASNase showed better affinity (Km 1.9 μmol) to L-asparagine as compared to free L-ASNase. After 23 days storage at 37 °C, bioconjugates retained 40% residual activity while free L-ASNase was completely deactivated. Thermodynamic characterization revealed higher conversion rate of the E-S complex in case of nano-bioconjugates.

Induction of autophagy, apoptosis and aquisition of resistance in response to piceatannol toxicity in MOLT-4 human leukemia cells

Piceatannol, a polyphenolic compound present in grapes and wine, has been reported to exhibit anticancer properties. Recently, it has been demonstrated to exert antiproliferative and proapoptotic effects in various human cancer types. The aim of our study was to investigate whether piceatannol induces autophagy and apoptosis in MOLT-4 human leukemia cells. Our results revealed that piceatannol activated autophagy in MOLT-4 cells, as evidenced by the detection of an increased level of LC3-II protein and a concomitant decrease in p62/SQSTM1 protein level. Moreover, piceatannol induced apoptosis in MOLT-4 cells which was accompanied by phosphatidylserine externalization, caspase-3 activation, disruption of mitochondrial membrane potential, internucleosomal DNA fragmentation, PARP1 cleavage, chromatin condensation, and fragmentation of cell nuclei. However, the toxic effects exerted by piceatannol in MOLT4 cells diminished after longer periods of exposure to the compound. Our findings imply that MOLT-4 cells may acquire resistance to piceatannol toxicity, which may result from the induction of efflux transporters such as P-glycoprotein. The present study provides new data showing that the use of piceatannol as a potential chemotherapeutic agent in the treatment of leukemia may be associated with the risk of multidrug resistance.

Roles of intracellular and extracellular ROS formation in apoptosis induced by cold atmospheric helium plasma and X-irradiation in the presence of sulfasalazine

Sulfasalazine (SSZ) is a well-known anti-inflammatory drug and also an inhibitor of the cystine-glutamate antiporter that is known to reduce intracellular glutathione (GSH) level and increase cellular oxidative stress, indicating its anti-tumor potential. However, the combination of SSZ with other physical modalities remains unexplored. Here, the effects of SSZ on cold atmospheric helium plasma (He-CAP), which produces approximately 24 x higher concentration of hydroxyl radicals (. OH) compared to X-irradiation (IR) in aqueous solution, and on IR-induced apoptosis in human leukemia Molt-4 cells were studied to elucidate the mechanism of apoptosis enhancement. Both the Annexin V-FITC/PI and DNA fragmentation assay revealed that pre-treatment of cells with SSZ significantly enhanced He-CAP and IR-induced apoptosis. Similar enhancement was observed during the loss of mitochondrial membrane potential, intracellular Ca2+ ions, and mitochondria- and endoplasmic reticulum-related proteins. The concentration of intracellular reactive oxygen species (ROS) was much higher in He-CAP treated cells than in X-irradiated cells. On the other hand, strong enhancement of Fas expression and caspase-8 and -3 activities were only observed in X-irradiated cells. It might be possible that the higher concentration of intracellular and extracellular ROS suppressed caspase activities and Fas expression in He-CAP-treated cells. Notably, pretreating the cells with an antioxidant N-acetyl-L-cysteine (NAC) dramatically decreased apoptosis in cells treated by He-CAP, but not by IR. These results suggest that IR-induced apoptosis is due to specific and effective ROS distribution since intracellular ROS formation is marginal and the high production of ROS inside and outside of cells plays unique roles in He-CAP induced apoptosis. We conclude that our data provides efficacy and mechanistic insights for SSZ, which might be helpful for establishing SSZ as a future sensitizer in He-CAP or IR therapy for cancer.

Chemical evaluation and cytotoxic mechanism investigation of Clinacanthus nutans extract in lymphoma SUP-T1 cells.

Clinacanthus nutans has been used as herbal medicine with antidiabetic, blood pressure lowering, and diuretic properties in Singapore, Thailand, and Malaysia. The in vitro cellular study showed the chloroform extract possessed significant cytotoxicity against leukemia K562 and lymphoma Raji cells. The clinical study reported that administration of plant could treat or prevent relapse in 12 cancer patients. However, detailed mechanism of the anticancer effects and chemical profiles are not thoroughly studied. The chemical study did show that the acetone extract (MHA) exerted the highest antiproliferative effect on human leukemia MOLT-4 cells and lymphoma SUP-T1 cells in dose-dependent cytotoxicity. We found that the use of MHA increased apoptosis by 4.28%-43.65% and caused disruption of mitochondrial membrane potential (MMP) by 11.79%-26.93%, increased reactive oxygen species (ROS) by 19.54% and increased calcium ion by 233.83%, as demonstrated by annexin-V/PI, JC-1, H2 DCFDA, and Flou-3 staining assays, respectively. MHA-induced ER stress was confirmed by increase expression of CHOP and IRE-1α with western blotting assay. In conclusion, we identified good bioactivity in Clinacanthus nutans and recognize its potential effect on cancer therapy, but further research is needed to determine the use of the plant.