K562 Cell Line Research Articles

MS4A3 regulates hematopoietic myeloid differentiation through ROS/TGF-β/p38MAPK pathway

The hematopoietic homeostasis relies on the intricate regulation of hematopoietic stem cells during their proliferation and differentiation. Myeloid differentiation disorders can lead to chronic myeloid leukemia and acute myeloid leukemia. Previous studies have shown increased expression of MS4A3 in myeloid cells, suggesting that MS4A3 may play a critical role in hematopoietic myeloid differentiation. However, the underlying mechanism and its role in hematopoietic myeloid differentiation require further elucidation. In this study, using K562 cell lines with MS4A3 over-expression (oeMS4A3) and MS4A3 knockdown (shMS4A3), we demonstrated that the overexpression of MS4A3 resulted in an augmented skewing towards myeloid differentiation and cell cycle arrest at G0/G1. In addition, inhibition of ROS, TGF-β, and p38MAPK in oeMS4A3 K562 cells attenuated the skewing of myeloid differentiation. Furthermore, in vivo experiments revealed a slight myeloid differentiation suppression tendency in MS4A3 knockout mice. Taken together, we show that MS4A3 overexpression promote myeloid differentiation skewing through the activation of the ROS/p38MAPK/TGFβ pathway. This study underscored the role of MS4A3 in the hematopoietic myeloid differentiation.

Heterocycles and a Sorbicillinoid from the Coral-Derived Fungus Penicillium chrysogenum

A detailed chemical study of the culture of a coral-derived fungus Penicillium chrysogenum resulted in the isolation and identification of four new aromatic heterocycles chrysoquinazolinones A–B (1–2) and chrysobenzothiazoles A–B (3–4), along with a new sorbicillinoid 4-carboxylsorbicillin (5). Chrysoquinazolinones A–B (1–2) combine a quinazolinone fragment with a bicyclo[2.2.2]octane or a pyrrolidone moiety, respectively, demonstrating the unexpected structures of marine natural products. Chrysobenzothiazoles A–B (3–4) possess a benzothiazole system and are the second isolation of this class of skeleton compounds from marine organisms. The existence of the pair of enantiomers (±3) was deduced by chiral HPLC analysis. Their structures and absolute configurations were elucidated by detailed spectroscopic analysis, comparison with the literature data, single-crystal X-ray crystallographic analysis and TDDFT-ECD calculations. Compound 5 exhibited moderate cytotoxicity against K562 and NCI-H446 cell lines, with IC50 values of 15.00 μM and 16.87 μM, respectively.

5'-Noraristeromycin Repurposing: Well-known S-Adenosyl-L-homocysteine Hydrolase Inhibitor As a Potential Drug Against Leukemia

5ˊ-Noraristeromycin as a racemic mixture of enantiomers was found to exhibit a pronounced cytotoxic effect on leukemia cells; IC50 for the Jurkat, K562, and THP-1 cell lines was 7.3, 1.3, and 3.7 μM, respectively. The general toxicity of 5'-noraristeromycin was studied in experiments on white mice upon single-dose intragastric administration; toxicometric parameters were determined, and the clinical and pathomorphological presentation of acute intoxication was studied. LD50 of the substance was shown to be 63.2 (52.7÷75.8) mg/kg; LD16, 44.7 mg/kg, and LD84, 89.4 mg/kg. Administration of the substance at a dose within the studied dose range is accompanied by systemic damage to the internal organs and tissues of the experimental animals.

Discovery and Development of HDAC Inhibitors: Approaches for the Treatment of Cancer a Mini-review.

Histone deacetylase (HDAC) inhibitors have emerged as promising cancer therapeutics due to their ability to induce differentiation, cell cycle arrest, and apoptosis in cancer cells. In the present review, we have described the systemic discovery and development of HDAC inhibitors. Researchers across the globe have identified various small molecules like benzo[d][1,3]dioxol derivatives, belinostat analogs, pyrazine derivatives, quinazolin-4-one-based derivatives, 2,4-imidazolinedione derivatives, acridine hydroxamic acid derivatives, coumarin derivatives, tetrahydroisoquinoline derivatives, thiazole-5-carboxamide, salicylamide derivatives, β-peptoid-capped HDAC inhibitors, quinazoline derivatives, benzimidazole and benzothiazole derivatives, and β- elemene scaffold containing HDAC inhibitors. Most of the scaffolds have shown attractive IC50 (μM) in various cell lines like HDAC1, HDAC2, HDAC6, PI3K, HeLa, MDA-MB-231, MCF-10A, MCF-7, U937, K562 and Bcr-Abl cell lines.

Essential Oils from the Leaves and Stem Barks of Pluchea Indica (L.) Less.: Chemical Analysis, Cytotoxicity, Anti-inflammation, Antimicrobial Activity, Molecular Docking, and ADMET Profiling.

Pluchea indica (L.) Less. is a medicinal plant native to Asia. Traditionally, it is known for numerous traditional uses, such as treatments for fever, cough, and digestive issues. The present investigation aims to determine the chemical compositions of essential oils from its fresh leaves and stem barks. By using hydro-distillation and the GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis, the studied samples were dominated by sesquiterpene hydrocarbons (76.8-82.2 %) and their oxygenated derivatives (8.4-19.0 %). β-Selinene (42.0-43.5 %) and silphinene (21.1-22.9 %) were the main compounds. Significantly, the stem bark essential oil strongly monitored the growth of four cancer cell lines K562, HeLa, HepG2, and MCF-7 with IC50 values of 2.89-7.34 μg/mL. Both studied samples showed strong anti-inflammatory activity against NO (nitric oxide) production with IC50 values of 21.81-23.18 μg/mL. The studied sample also exhibited antimicrobial activity at different levels. The molecular docking study revealed that β-selinene exhibited the strongest binding affinity for all four cancer-related protein targets: epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), Abelson tyrosine-protein kinase 1 (ABL1), and phosphatidylinositol 3-kinase (PI3 K-α). The ADMET profiles of the major compounds were also predicted to provide insights for further research considerations.

Chlorine containing tetrahydropyrimidines: Synthesis, characterization, anticancer activity and mechanism of action

The aim of the presented research was to explore anticancer potential of eleven newly synthesized tetrahydropyrimidine derivatives. The compounds were synthesized via Biginelli multicomponent one-pot reaction using different derivatives of vanillin, ethyl 4-chloroacetoacetate and (N-methyl)urea. The cytotoxic effects of the compounds were examined on three human malignant cell lines (HeLa, K562, and MCF7), and normal lung fibroblasts MRC-5. The mechanisms of anticancer activity were examined for two compounds 4a and 4b which showed the strongest and selective cytotoxicity against chronic myelogenous leukaemia K562 cells (IC50 = 1.76 ± 0.09, and 1.66 ± 0.05, respectively). The changes of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and vascular endothelial growth factor A (VEGFA) were investigated in the K562 cell line, as well as oncomiRNA miR-10b, miR-23a described to have both features, depending on a specific type of malignancy, and miR-34a with mostly described as a tumour suppressor.

Study of TRAIL and SAHA Co-Treatment on Leukemia K562 Cell Line.

TRAIL (Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand) is an attractive agent being considered a potential cancer treatment. It attaches to its death receptors, leading many cancer cells to apoptosis. However, some malignancies indicate substantial resistance to TRAIL, challenging anticancer scientists. Herein, combination therapy with TRAIL plus SAHA (Suberoyl Anilide Hydroxamic Acid) was conducted to evaluate the capability of SAHA to overcome TRAIL resistance in the leukemia K562 cell line. First, the IC50 for SAHA was calculated (2 µM) at 12, 24, 48, and 72 h of treatment using MTT assay. Second, the K562 cells were treated with concentrations of 50 and 100 nM of TRAIL and 2 μM of SAHA separately and together for 24, 48, and 72 h and the survival of these cells was evaluated by Flowcytometry following the annexin-V and PI staining. To demonstrate the non-toxicity of the combined treatment for normal cells, the HEK-293 cell line was treated with the TRAIL 100 nM and SAHA 2 μM combined and separated at the same periods. In the end, by performing real-time PCR, the amount of candidate genes' expression implicated in TRAIL resistance, and the levels of BCR-ABL expression was measured. The drug dosages were not toxic to normal cells. SAHA plus TRAIL strongly triggered apoptosis in K562 cells after 24, 48, and 72 h of exposure. Furthermore, it was shown that DR4, DR5, and CHOP expressions were enhanced, and PI3K, Akt, ERK, STAT3, c-FLIPL, NF-κB, and BCR-ABL expressions were decreased by SAHA in K562 cells. Our study indicated that SAHA combined with TRAIL can increase the sensitivity of K562 leukemic cells to TRAIL by suppressing intracellular anti-apoptotic molecules and augmenting the expressions of DR4/DR5 and CHOP.

Development and Characterization of A Novel SpyTagged Modular Nanobody as A Detection Platform for CD22-Positive Cells.

CD22, as a surface protein of B cells, is used in the diagnosis and target-specific immunotherapy of B-cell malignancies. SpyTag and SpyCatcher, on the other hand, are two covalently coupled proteins capable of developing a bi- or multi-specific modular protein. The aim of this study was to develop FITC-conjugated SpyCatcher-SpyTagged anti-CD22 Nanobody (FITC-SpyC-SpyT-CD22Nb) to recognize CD22 on the surface of malignant B cells. In this experimental study, the SpyTag-CD22Nb construct was subcloned into a pET22 vector and expressed in E. coli BL21 (DE3). After purification using His-tag affinity chromatography, the size of the eluted protein was confirmed on a Western blot. In addition, the SpyCatcher protein, subcloned into pET28, was expressed in E. coli BL21 (DE3), purified by His-tag affinity chromatography and subjected to FITC labeling. FITC-SpyCatcher and SpyTag-CD22Nb were coupled in a 1:1 molar ratio. The specific binding of the produced FITC-SpyC-SpyT-CD22Nb was tested using CD22+ Raji and CD22- K562 cell lines and was evaluated by flow cytometry. SpyTag-CD22Nb and SpyCatcher were successfully expressed in E. coli BL21 (DE3). The 1:1 molar ratio of SpyTag-CD22Nb and FITC-SpyCatcher successfully formed FITC-SpyC-SpyT-CD22Nb at room temperature. The flow cytometry results showed that FITC-SpyC-SpyT-CD22Nb specifically binds to the CD22+ Raji cells, while there is no binding to the CD22- K562 control cells. The novel FITC-SpyC-SpyT-CD22Nb produced in the present study is capable of detecting the surficial expression of CD22. According to our findings, FITC-SpyC-SpyT-CD22Nb is applicable for specific targeting of CD22 in a therapeutic manner, i.e., chimeric antigen receptor (CAR)-T cell therapy and antibody drug conjugates (ADCs).

Compound K Promotes Megakaryocytic Differentiation by NLRP3 Inflammasome Activation.

Platelets are essential blood components that maintain hemostasis, prevent excessive bleeding, and facilitate wound healing. Reduced platelet counts are implicated in various diseases, including leukemia, hepatitis, cancer, and Alzheimer's disease. Enhancing megakaryocytic differentiation is a promising strategy to increase platelet production. Compound K (CK), a major bioactive metabolite of ginsenosides from Panax ginseng, has demonstrated anti-cancer and neuroprotective properties. In this study, we investigated the effects of CK on megakaryocytic differentiation and apoptosis in chronic myeloid leukemia (CML) cell lines K562 and Meg-01. CK treatment significantly upregulated the mRNA expression of key megakaryocytic differentiation markers, including CD61, CD41, and CD42a, and promoted the formation of large, multinucleated cells in K562 cells. Additionally, flow cytometry analysis revealed that CK at 5 µM induced apoptosis, a critical process in thrombocytopoiesis, in both K562 and Meg-01 cells. RT2 Profiler PCR array analysis further identified a marked increase in the expression of genes associated with the activation of the NLRP3 inflammasome in CK-treated K562 and Meg-01 cells. This study is the first to demonstrate that CK promotes megakaryocytic differentiation and apoptosis through the activation of the ERK/EGR1 and NLRP3 inflammasome pathways. These findings suggest that CK may enhance platelet production, indicating its potential as a therapeutic candidate for platelet-related disorders and other associated diseases.

Elastin-derived peptides (EDPs) as a potential pro-malignancy factor in human leukemia cell lines.

The extracellular matrix (ECM) is currently considered to be an important factor influencing the migration and progression of cancer cells. Therefore, the aim of our study was to investigate the mechanism of action of elastin-derived peptides in cancerous cells derived from the immunological system, i.e., HL-60, K562, and MEG-A2 cell lines. Moreover, an attempt to clarify the involvement of c-SRC kinase in EDP mechanism of action was also undertaken. Our data show that the VGVAPG and VVGPGA peptides are not toxic in the studied cell lines. Moreover, due to the involvement of KI67 and PCNA proteins in the cell cycle and proliferation, we can assume that neither peptide stimulates cell proliferation. Our data suggest that both peptides could initiate the differentiation process in all the studied cell lines. However, due to the different origins (HL-60 and K562-leukemic cell line vs. MEG-A2-megakaryoblastic origin) of the cell lines, the mechanism may differ. The increase in the ELANE mRNA expression noted in our experiments may also suggest enhancement of the migration of the tested cells. However, more research is needed to fully explain the mechanism of action of the VGVAPG and VVGPGA peptides in the HL-60, K562, and MEG-A2 cell lines. HIGHLIGHTS: • VGVAPG and VVGPGA peptides do not affect the metabolic activity of HL-60, K562, and MEG-A2 cells. • mTOR and PPARγ proteins are involved in the mechanism of action of VGVAPG and VVGPGA peptides. • Both peptides may initiate differentiation in HL-60, K562, and MEG-A2 cell lines.

In Vitro Amplification of NK Cells from Feeder Layer Cells Expressing IL-21

To investigate the effect of feeder layer cells expressing interleukin (IL)-21 on the amplification of NK cells In Vitro . The K562 cell line with IL-21 expression on its membrane was constructed by electroporation, and co-cultured with NK cells after inactivation. The proliferation of NK cells was observed. The killing function of the amplified NK cells In Vitro was evaluated by the lactate dehydrogenase (LDH) and interferon-γ (IFN-γ) release assay. A colorectal cancer xenograft model in NOD/SCID mice was established, and a blank control group, a NK cell group and an amplified NK cell group were set up to detect the tumor killing effect of amplified NK cells in vivo. K562 cells expressing IL-21 on the membrane were successfully constructed by electroporation. After co-culturing with K562 cells expressing IL-21 on the membrane for 17 days, the NK cells increased to 700 times, which showed an enhanced amplification ability compared with control group (P < 0.001). In the tumor cell killing experiment In Vitro , there was no significant difference in the killing activity on tumor cells between NK cells and amplified NK cells, and there was also no significant difference in mice in vivo. K562 cells expressing IL-21 on the membrane can significantly increase the amplification ability of NK cells In Vitro , but do not affect the killing function of NK cells In Vitro and in vivo. It can be used for the subsequent large-scale production of NK cells In Vitro .

Bcr-Abl Inhibitory Activities of Imatinib Derivatives

Background: Imatinib, a frontline targeted-therapeutic agent for patients with chronic myelogenous leukemia (CML), was a synthetic tyrosine kinase inhibitor approved by the US Food and Drug Administration. Objective: To expand the structural diversity of Bcr-Abl inhibitors, we synthesized nine novel imatinib analogues (1a-1i) and evaluated their cytostatic effects against human cancer cell lines in vitro. Method: Imatinib and its analogues were successfully synthesized by an improved method in six main steps. Inhibitory activities of all compounds were evaluated on K562, HL-60, MCF-7, A549 and PBMC in vitro. Then, the effect of the most active compound was studied using flow cytometer, real-time qPCR and western blot experiments to determine its mechanism action. Finally, the molecular docking of the most active compound were determined. Results: The IC50 of one imatinib analogue (compound 1h) for K562 and HL-60 was lower than imatinib itself. Further studies indicate that the pro-apoptotic effect of compound 1h on K562 cells was stronger than imatinib over a range of concentrations. Importantly, the real-time qPCR and western blot experiments showed that compound 1h was superior to imatinib in inhibiting Bcr-Abl expression. The structure-activity relationship was analyzed by determining the inhibitory rate of each imatinib analogue. Introducing benzene (A ring) and piperidine (E ring) rings instead of pyridine (A ring) and piperazine (E ring) in imatinib significantly enhanced the potency of imatinib against K562 and HL-60 cell lines, which is consistent with the docking results. Conclusion: Imatinib analogue 1h showed a better inhibitory effect on leukemia cell lines than other cell lines, which was consistent with the imatinib-like structure, moreover, had little effect on PBMC. Overall, we conclude that compound 1h has the potential to treat chronic myeloid leukemia.

Cellular uptake of CPX-351 by scavenger receptor class B type 1-mediated nonendocytic pathway

The proper uptake of drugs in liposome formulations into target cells markedly impacts therapeutic efficacy. The protein corona (PC), formed by the adsorption of serum proteins onto the liposome surface, binds to specific surface receptors of target cells, influencing the uptake pathway. We investigated the uptake pathway into leukemia cells based on PC analysis of CPX-351, a liposome containing cytarabine and daunorubicin in a fixed 5:1 synergistic molar ratio. The PC of CPX-351 mixed with fetal bovine serum was analyzed by nanoflow liquid chromatography-tandem mass spectrometry. CPX-351 uptake in HL-60, K562, and THP-1 leukemia cell lines, was measured by flow cytometry using daunorubicin fluorescence. The major components of CPX-351 PC were apolipoproteins A-I and A-II, which bind to scavenger receptor class B type 1 (SR-BI), a nonendocytic pathway that takes up only liposome contents. SR-BI was expressed in each cell, and its expression correlated with CPX-351 uptake. The uptake was significantly decreased by the inhibition of clathrin-mediated endocytosis and macropinocytosis. Additionally, blocks lipid transport-1 (BLT-1), a selective inhibitor of SR-BI, decreased the uptake; however, high-dose BLT-1 addition significantly increased the uptake, which was more strongly inhibited by macropinocytosis suppression compared with clathrin-mediated endocytosis. BLT-1 enhances the binding of SR-BI to liposomes in a dose-dependent manner. These findings indicate that the enhancement of binding between SR-BI and CPX-351 activates different pathways, such as macropinocytosis, distinct from CPX-351 alone. SR-BI may be a biomarker for CPX-351 therapy, and the combination of CPX-351 with high-dose BLT-1 may augment therapeutic efficacy.

Differentiating leukemia subtypes based on metabolic signatures using hyperpolarized 13C NMR.

Leukemia is a group of blood cancers that are classified in four major classes. Within these four classes, many different subtypes exists with similar origin, genetic mutations, and level of maturity, which can make them difficult to distinguish. Despite their similarities, they might respond differently to treatment, and therefore distinguishing between them is of crucial importance. A deranged metabolic phenotype (Warburg effect) is often seen in cancer cells, leukemia cells included, and is increasingly a target for improved diagnosis and treatment. In this study, hyperpolarized 13C NMR spectroscopy was used to characterize the metabolic signatures of the six leukemia cell lines ML-1, CCRF-CEM, THP-1, MOLT-4, HL-60, and K562. This was done using [1-13C]pyruvate and [1-13C]alanine as bioprobes for downstream metabolite quantification and kinetic analysis on cultured cells with and without 2-deoxy-D-glucose treatment. The metabolic signatures of similar leukemia subtypes could be readily distinguished. This includes ML-1 and THP-1, which are of the similar M4 and M5 AML subtypes, CCRF-CEM and MOLT-4, which are of the similar T-ALL lineage at different maturation states, and HL-60 and K562, which are of the closely related M1 and M2 AML subtypes. The data presented here demonstrate the potential of hyperpolarized 13C NMR spectroscopy as a method to differentiate between leukemia subtypes of similar origin. Combining this method with bioreactor setups could potentially allow for better leukemia disease management as metabolic signatures could be acquired from a single biopsy through repeated experimentation and intervention.

Synthesis, antimicrobial, anticancer activity, 3D QSAR, ADMET properties, and in silico target fishing of novel N,N-disubstituted chloroacetamides

The recent FDA approval of afatanib, ibrutinib, and osimertinib, which covalently bind to specific cysteine residues in target kinases, has renewed interest in covalent drug discovery. Besides α,β-unsaturated carbonyls, chloroacetamides have emerged as popular warheads for designing targeted covalent inhibitors. In this study, we synthesized thirteen N,N-disubstituted chloroacetamides (1–13) by acylating secondary amines with chloroacetyl chloride, selecting substituents to provide a wide range of lipophilicity. We evaluated their anticancer and antimicrobial activity, finding five compounds with significant cytotoxicity against HeLa, K562, and A549 cell lines (IC50 <10 μM). Notably, compound 10 activated caspases 3, 8, and 9, promoting both intrinsic and extrinsic apoptotic pathways, while compounds 9–12 were strong apoptosis inducers. A 3D QSAR model showed that aromatic substituents on nitrogen atoms reduced HeLa potency, whereas the overall molecular shape had a positive effect. ChemBL and pharmacophoric similarity searches suggested potential anticancer targets, including alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), glycogen synthase kinase-3β, and calmodulin. Docking studies indicated that chloroacetamides bind to ADH and ALDH via hydrogen bonds and hydrophobic interactions. Pharmacokinetics predictions suggest that chloroacetamides are druglike molecules with promising ADMET properties.

Growth hormone is involved in GATA1 gene expression via STAT5B in human erythroleukemia and monocytic cell lines

GATAs are a family of transcription factors consisting of six members. Particularly, GATA1 and GATA2 have been reported to promote the development of erythrocytes, megakaryocytes, eosinophils, and mast cells. However, little information is available on the extracellular ligands that promote GATA1 expression. We evaluated whether growth hormone (GH) is an extracellular stimulator that participates in the signal transduction of GATAs, focusing on GATA1 expression in hematopoietic cell lineages. We used a reporter assay, RT-PCR, real-time quantitative PCR, and western blotting to evaluate GH-induced expression of GATA1 and GATA2 in the human erythroleukemic cell line K562 and the non-erythroid cell line U937. GATA1 expression in these hematopoietic cell lines increased at the transcriptional and protein levels in the presence of GH, and was inhibited by a STAT5 specific inhibitor. Cells transfected with activated STAT5B showed increased expression of GATA1. We identified functional STAT5B consensus sequences as binding site-158 bp from the transcription starting site in the GATA1 promoter region. These results suggest that GH directly induces GATA1 expression via GHR/JAK/STAT5 and is related to hematopoietic cell proliferation.

Anti-cancer activity of brucine loaded Cu(OH)2/ZnO nanoparticles against chronic myeloid leukemia cell line (K562) via apoptotic signaling pathway

Background and objectiveChronic myeloid leukemia (CML) is marked by abnormal blood cell production and traditional treatments often cause severe side effects and resistance. This study improves cancer therapy by using copper (II) hydroxide (Cu(OH)₂) and zinc oxide (ZnO) nanoparticles combined with brucine (Bru) to enhance targeted drug delivery and efficacy. Materials and methodsBru-Cu(OH)₂-ZnO NPs were synthesized and characterized using various analytical techniques. Their cytotoxicity was evaluated on K562 myeloid leukemia cells through cell viability assays, dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining, and measurement of oxidative stress indicators such as nitric oxide and lipid peroxidation levels. Antioxidant activity was assessed by glutathione (GSH) levels, while apoptosis was investigated via Caspase 3 and 9 activity and gene expression analysis (Bax, p53, and Bcl-2) using real-time polymerase chain reaction (RT-PCR). ResultsThe novel Bru-Cu(OH)₂-ZnO NPs demonstrated significant anti-cancer activity by markedly reducing K562 cell viability and enhancing cytotoxicity in a dose-dependent manner. These nanoparticles effectively scavenged free radicals, increased lipid peroxidation and nitric oxide levels, and improved caspase activity. Notably, gene expression analysis revealed that Bru-Cu(OH)₂-ZnO NPs led to overexpression of pro-apoptotic genes (Bax and p53) and downregulation of the anti-apoptotic gene (Bcl-2), highlighting their potential as effective cancer therapeutics. ConclusionThe synthesized Bru-Cu(OH)2-ZnO NPs shown excellent anti-cancer efficacy against the K562 cell line. This study underscores the potential of combining bioactive compounds with metal oxide nanoparticles to enhance targeted drug delivery and therapeutic effectiveness, offering a promising approach for advancing cancer treatment.

S-nitrosoglutathione (GSNO) induces necroptotic cell death in K562 cells: Involvement of p73, TSC2 and SIRT1

BackgroundNitric oxide and Reactive Nitrogen Species are known to effect tumorigenicity. GSNO is one of the main NO carrying signalling moiety in cell. In the current study, we tried to delve into the effect of GSNO induced nitrosative stress in three different myelogenous leukemic K562, U937 and THP-1 cell lines. MethodWST-8 assay was performed to investigate cell viability. RT-PCR and western-blot analysis were done to investigate mRNA and protein expression. Spectrophotometric and fluorimetric assays were done to investigate enzyme activities. ResultWe found that GSNO exposure led to reduced cell viability and the mode of cell death in K562 was non apoptotic in nature. GSNO promoted impaired autophagic flux and necroptosis. GSNO treatment heightened phosphorylation of AMPK and TSC2 and inhibited mTOR pathway. We observed increase in NAD+/ NADH ratio following GSNO treatment. Increase in both SIRT1 m-RNA and protein expression was observed. While total SIRT activity remained unaltered. GSNO increased tumor suppressor TAp73/ oncogenic ∆Np73 ratio in K562 cells which was correlated with cell mortality. Surprisingly, GSNO did not alter cellular redox status or redox associated protein expression. However, steep increase in total SNO and PSNO content was observed. Furthermore, inhibition of autophagy, AMPK phosphorylation or SIRT1 exacerbated the effect of GSNO. Altogether our work gives insights into GSNO mediated necroptotic event in K562 cells which can be excavated to develop NO based anticancer therapeutics. ConclusionOur data suggests that GSNO could induce necroptotic cell death in K562 through mitochondrial dysfunctionality and PTM of different cellular proteins.

A comparative analysis of ENCODE and Cistrome in the context of TF binding signal

BackgroundWith the rise of publicly available genomic data repositories, it is now common for scientists to rely on computational models and preprocessed data, either as control or to discover new knowledge. However, different repositories adhere to the different principles and guidelines, and data processing plays a significant role in the quality of the resulting datasets. Two popular repositories for transcription factor binding sites data - ENCODE and Cistrome - process the same biological samples in alternative ways, and their results are not always consistent. Moreover, the output format of the processing (BED narrowPeak) exposes a feature, the signalValue, which is seldom used in consistency checks, but can offer valuable insight on the quality of the data.ResultsWe provide evidence that data points with high signalValue(s) (top 25% of values) are more likely to be consistent between ENCODE and Cistrome in human cell lines K562, GM12878, and HepG2. In addition, we show that filtering according to said high values improves the quality of predictions for a machine learning algorithm that detects transcription factor interactions based only on positional information. Finally, we provide a set of practices and guidelines, based on the signalValue feature, for scientists who wish to compare and merge narrowPeaks from ENCODE and Cistrome.ConclusionsThe signalValue feature is an informative feature that can be effectively used to highlight consistent areas of overlap between different sources of TF binding sites that expose it. Its applicability extends to downstream to positional machine learning algorithms, making it a powerful tool for performance tweaking and data aggregation.

Proteomic Dynamics of Multidrug Resistance Mechanisms in Lucena 1 Cell Line.

The Lucena 1 cell line, derived from the human chronic myeloid leukemia cell line K562 under selective pressure of vincristine supplementation, exhibits multidrug resistance (MDR). This study aims to explore and elucidate the underlying mechanisms driving MDR in the Lucena 1 cell line. A proteomic analysis comparing K562 and Lucena 1 revealed qualitative differences, with a focus on the ATP-dependent efflux pump, Translocase ABCB1, a key contributor to drug resistance. Tubulin analysis identified two unique isoforms, Tubulin beta 8B and alpha chain-like 3, exclusive to Lucena 1, potentially influencing resistance mechanisms. Additionally, the association of Rap1A and Krit1 in cytoskeletal regulation and the presence of STAT1, linked to the urea cycle and tumor development, offered insights into Lucena 1's distinctive biology. The increased expression of carbonic anhydrase I suggested a role in pH regulation. The discovery of COP9, a tumor suppressor targeting p53, further highlighted the Lucena 1 complex molecular landscape. This study offers new insights into the MDR phenotype and its multifactorial consequences in cellular pathways. Thus, unraveling the mechanisms of MDR holds promise for innovating cancer models and antitumor targeted strategies, since inhibiting the P-glycoprotein (P-gp)/ABCB1 protein is not always an effective approach given the associated treatment toxicity.