Chronic Myelogenous Leukemia K562 Research Articles

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.

Synthesis of Para-Acetylated Functionalized Ni(II)-POCOP Pincer Complexes and Their Cytotoxicity Evaluation Against Human Cancer Cell Lines.

A series of three Ni(II)-POCOP complexes para-functionalized with an acetoxyl fragment were synthesized. All complexes (2 a-c) were fully characterized through standard analytical techniques. The molecular structure of complex 2 b was unambiguously determined by single-crystal X-ray diffraction, revealing that the metal center is situated in a slightly distorted square-planar environment. Additionally, the acetoxy fragment at the para-position of the phenyl ring was found to be present. The in vitro cytotoxic activity of all complexes was assessed on six human cancer cell lines. Notably, complex 2 b exhibited selective activity against K-562 (chronic myelogenous leukemia) and MCF-7 (mammary adenocarcinoma) with IC50 values of 7.32±0.60 μM and 14.36±0.02 μM, respectively. Furthermore, this compound showed negligible activity on the healthy cell line COS-7, highlighting the potential therapeutic application of 2 b. The cytotoxic evaluations were further complemented with molecular docking calculations to explore the potential biological targets of complex 2 b, revealing interactions with cluster differentiation protein 1a (CD1 A, PDB: 1xz0) for K-562 and with the progesterone receptor for MCF-7.

Polyimidazole ligands: Copper(II) complexes and antiproliferative activity in cancer cells

The design of novel chelators for therapeutic applications has been the subject of extensive research to address various diseases. Many chelators can manipulate the levels of metal ions within cells and effectively modulate the metal excess. In some cases, chelators show significant toxicity to cells.We investigated polyimidazole ligands by potentiometry and UV–Vis spectroscopy for their ability to form copper(II) complexes. We also compared the antiproliferative activity of the polyimidazole ligands and their copper(II) complexes with polypyridine ligands in CaCo-2 (colorectal adenocarcinoma), SH-SY5Y (neuroblastoma) and K562 (chronic myelogenous leukemia) cells and normal HaCaT (keratinocyte) cells.Polyimidazole ligands are less cytotoxic than their analogous polypyridine ligands. All polyimidazole ligands, except the tetraimidazole ligand for K562 cells, did not show any significant effect on the viability of cancer and normal cells. In contrast, the cytotoxic activity of polypiridine ligands was also observed in normal cells with IC50 values similar to those of cancer cells.Tetraimidazole ligand, the only ligand active on the leukemic K562 cell line, induced caspase-dependent apoptosis and increased intracellular reactive oxygen species production with mitochondrial damage.The low cytotoxicity of the polyimidazole ligands, even if it limits their use as anticancer agents, could make them useful in other medical applications, such as in the treatment of metal overload, microbial infections, inflammation or neurodegenerative disorders.

P-373 Melatonin and chemotherapy: does the proposed fertoprotective agent impair the anti-tumor effects of cancer therapy?

Abstract Study question Does the proposed fertoprotective agent melatonin interfere with the anti-cancer activity of imatinib chemotherapy in a chronic myelogenous leukemia (CML) cell line? Summary answer At low concentrations, melatonin demonstrates mild inhibition of imatinib activity, however this is overcome at therapeutic concentrations. Melatonin also shows anti-tumor activity against CML. What is known already A harmful consequence of cancer therapy is a resultant loss of fertility. Pharmacologic interventions that reduce radiation or chemotherapy-induced gonadotoxicity are a major unmet medical need. Several ‘fertoprotective’ agents have shown promise in protecting the gonads from injury during treatment, including melatonin. However, melatonin is not currently applied in humans for this purpose. Key safety and efficacy data are needed to move potential fertoprotective agents into clinical trials. Study design, size, duration We evaluated the interaction of varying combined concentrations of melatonin and imatinib, a tyrosine kinase inhibitor, within an in-vitro matrix experiment. The interaction was be evaluated within K562, a cell line derived from human chronic myelogenous leukemia (CML). This chemotherapy and cell line were selected due to CML’s dependence on BCR-ABL for survival, which is inhibited by imatinib, permitting direct evaluation of melatonin-imatinib cross-interaction. Participants/materials, setting, methods K562 were seeded in 384-well plates into which increasing concentrations of imantinib and melatonin were progressively dispensed. The cells were cultured for 48 hours. Viable cell concentrations were then determined using a cell luminescent assay. Drug interaction was then determined using drug synergy analysis software.The expected drug combination responses were calculated based on ZIP reference model using SynergyFinder 3.0. Deviations between observed and expected responses with positive and negative values denote synergy and antagonism respectively. Main results and the role of chance Melatonin demonstrated toxicity to K562 CML cell lines independent of imatinib, with a mean inhibition of cell growth of 74.7% at 1uM, CI [69.6%, 79.7%]. This anti-tumor activity was progressively seen at concentrations >0.1 uM. At low imatinib concentrations (<0.2 uM), melatonin decreased the anti-cancer potency of imatinib. This effect was overcome at higher concentrations of imatinib. The overall mean synergy score was -5.87, CI [-7.145, -4.588]. Limitations, reasons for caution These experiments were carried out in an in-vitro setting in a tightly controlled environment. In a clinical setting, the complexity of potential interactions between melatonin and chemotherapy will increase (i.e. metabolism, distribution), thus animal models will be a necessary next step of evaluation before clinical safety trials may proceed. Wider implications of the findings Melatonin may serve as an inexpensive, well-tolerated adjuvant to help protect the gonad from chemotherapy, while additionally exhibiting its own anti-cancer effects in certain settings. Our preliminary data suggests that the risk of melatonin to impair active imatinib treatment may be low, however continued investigation is necessary. Trial registration number Not applicable

Abstract 1320: Engineered expression of HLA-E and HLA-G protects iPSC-derived cells from killing by primary NK cells

Abstract Background: A major challenge to off-the-shelf allogeneic cell therapies is the HLA-targeted elimination of genetically dissimilar cells. To combat this, HLA Class I can be deleted through transgene insertion at the beta-2 microglobulin (B2M) locus, while HLA Class II can be deleted by disruption of the gene encoding MHC Class II Transactivator (CIITA). Lack of HLA Class I expression, however, marks cells for elimination by natural killer (NK) cells, which normally receive inhibitory signals from this protein family. HLA-E and HLA-G are non-classical HLA Class I molecules that are far less polymorphic than HLA-A/B/C. They can inhibit natural killer cell-mediated activation by engaging NKG2A, KIR2DL4, ILT2, and ILT4. The objective of this study was to assess allo-evasion from NK cells by iPSC-derived cells engineered to overexpress HLA-E and -G. Methods: Allo-evasion by HLA-E, -G or both was first assessed in the chronic myelogenous leukemia K562 cell line, which expresses very low HLA Class I and is highly susceptible to NK-mediated killing. K562 cells were engineered using CRISPR/CAS9 to express chimeric molecules encoding either HLA-E or HLA-G heavy chains tethered to a defined nominal self-peptide and B2M, or HLA-E/peptide/B2M-P2A-HLA-G/peptide/B2M. Along with parental K562, these were used as targets in co-cultures with allogeneic PBMCs (n=22 donors) at different E:T ratios. Target killing was observed using flow cytometry and normalized to parental K562. Phenotyping of effector PBMCs for NK frequency and expression of HLA-E and -G receptors (NKG2A, KIR2DL4, ILT2, and ILT4) was performed to study correlations with killing efficiency and allo-evasion. IPSCs with endogenous B2M knocked out were also engineered to overexpress HLA-E and -G with the constructs described above. These were then differentiated into NK cells and gamma delta T cells using proprietary processes. Allo-evasion of these cells from killing by the same PBMC cohort was evaluated by flow cytometry. Results: While NK cells across donors expressed heterogeneous combinations of HLA-E and -G receptors, the strongest correlation with PBMC allo-responsiveness was NK frequency. K562 and iPSC-derived cells lacking HLA were susceptible to killing by PBMCs. Overexpression of HLA-E and -G offered protection to K562 and iPSC-derived cells against all tested donors. HLA-E offered more protection than HLA-G, and the combination of both HLA-E and -G was most potent. Conclusion: When genetically dissimilar HLA Class I protein family must be deleted to prevent graft rejection, expression of the more-conserved HLA-E and -G can effectively protect allogeneic drug products from elimination. These Allo-evasionTM edits may increase the in vivo persistence and enable multi-dosing of our iPSC-derived allogeneic cell therapies. Citation Format: Andriana Lebid, Dae Hwan Kim, Gabrielle Greco, Heidi Jessup, Alyssa Suarez, Shelby Brown, Nicholas Alexander, Mitan Desai, Buddha Gurung, Barry Morse, Daniel J. Perry, Michael F. Naso, Hyam Levitsky. Engineered expression of HLA-E and HLA-G protects iPSC-derived cells from killing by primary NK cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1320.

Evaluation the Anti-leukemia effect of Methanol extracts of Camellia cuongiana on the K562 cell line

This study aims to examine the anti-proliferation effects of Camellia cuongiana methanolic extracts on the K562 chronic myelogenous leukaemia cell line. The crude extract was obtained by soaking the sample with methanol, following concentration using a rotary evaporator. Trypan blue exclusion test was performed in five concentrations of extract to detect the anti-cancer characteristic of Camellia cuongiana. Morphological changes in the treatment cell were observed using a phase-contrast microscope. After 72 hours of treatment, the extracts inhibited cell proliferation, with IC50 values of 72.26±5.75µg/mL. Increasing the extract concentration decreased the number of living cells. The most frequently observed abnormal morphology was cell shrinkage. Evidently, Camellia cuongiana could inhibit cancer cell proliferation and induce programmed cell death.

A label free chemoproteomic-based platform to disclose cannabidiol molecular mechanism of action on chronic myelogenous leukemia cancer cells

The discovery of the interactome of cannabidiol (CBD), a non-psychoactive cannabinoid from Cannabis sativa L., has been here performed on chronic myelogenous leukemia cancer cells, using an optimized chemo-proteomic stage, which links Drug Affinity Responsive Target Stability with Limited Proteolysis Multiple Reaction Monitoring approaches. The obtained results showed the ability of CBD to target simultaneously some potential protein partners, corroborating its well-known poly-pharmacology activity. In human chronic myelogenous leukemia K562 cancer cells, the most fascinating protein partner was identified as the 116 kDa U5 small nuclear ribonucleoprotein element called EFTUD2, which fits with the spliceosome complex. The binding mode of this oncogenic protein with CBD was clarified using mass spectrometry-based and in silico analysis.

A Scalable, Off-the-Shelf, and Cost-Effective NK Cell Manufacturing Platform for Developing NK Cell-Based Immunotherapy

Natural killer (NK) cells are innate lymphocytes that play a key role in the control of infection and malignancy. NK cells are potent killers of target cells and act in an MHC-independent manner, enabling their application as allogenic therapy for cancer. Human iPSCs are pluripotent with the ability to self-renew, thus providing an inexhaustible source for deriving NK cells. With a two-tiered cell bank system, we can manufacture NK cells with more homogeneity between batches. In principle, one single iPSC clone-derived master cell bank and working cell banks can support the life cycle of an affordable, off-the-shelf NK cell product. We developed a robust stepwise protocol for large-scale generation of high-purity NK cells from human iPSCs without the cell isolation procedure. First, human iPSCs formed embryoid bodies and then were differentiated into highly purified (>98.0%) CD34 + CD43 + hematopoietic stem and progenitor cells (HSPCs) using a combination of cytokines and small molecles such as BMP-4, VEGF, BFGF, SCF, FLT-3 and ascorbic acid. During this period, we observed up to an 180-fold cell increase in the number of HSPCs compared with human iPSCs. Second, these HSPCs were differentiated into NK cells with FLT3, SCF, IL-3, IL-7, and IL-15 etc., with cell number increased approximately 9000-fold compared with iPSCs. In the final step, iPSC-derived NK cells were further expanded up to 8000-fold which enable us to produce 1E12 NK cells from less than 1 million iPSCs. After expansion, iNK cells became more homogenous and exhibited a more mature phenotype. More than 99.0% of cells expressed both CD45 and CD56, and more than 70% expressed CD16. The expression of activating and co-stimulatory receptors (NKG2D, NKp46,NKp44, NKp30, CD244 and CD226) of NK cells was also high in these iNK cells. Intrestingly, the cells exhibited robust anti-tumor efficacy against K562 (chronic myelogenous leukemia), RPMI 8226 (multiple myeloma). Furthermore, the cryopreserved iNK cells demonstrated dramatic cytotoxicity to U-87 MG cells (malignant gliomas) in 2D culture and the tumor organoid, indicating that iNK cells derived from our protocol can be used as off-the-shelf therapy for both hematological and solid tumors. We also observed that these iNK cells had variable cytotoxicity in other tumors. For example, our iNK were not obviously cytotoxic to the NCI-H929 cell line, derived from a plasmacytoma myeloma patient and expressing BCMA at a high level. To improve the specific cytotoxicity of NK cells to NCI-H929 cells, we transduced a anti-BCMA CAR to the donor iPSC. Following differentiation, the CAR-transduced iNK cells showed approximately 6-fold cytotoxicity compared with WT iNK. (Figure 1) Collectively, our serum-free and strom cell-free NK cell generation produre from human iPSCs provides a scalable, consistent, off-the-shelf and cost-effective NK/CAR-NK cell manufacturing platform for clinical application and NK cell-based immunotherapies.

Metal Complexes of Schiff Bases Prepared from Quinoline-3-Carbohydrazide with 2-Nitrobenzaldehyde, 2-Chlorobenzaldehyde and 2,4-Dihydroxybenzaldehyde: Structure and Biological Activity

Three Schiff base ligands, NQ, CQ and HQ, were prepared from the reaction of quinoline-3-carbohydrazide with 2-nitrobenzaldehyde, 2-chlorobenzaldehyde and 2,4-dihydroxybenzaldehyde, respectively, and were investigated for their coordination to Cu (II), Ni(II), Co(II), Cd(II), Cr(III) and Fe(III) chlorides. The NQ preparation and the X-ray structure of NQ and CQ, as well as the transition metal complexes of NQ, CQ and HQ, were reported for the first time. FTIR, 1H-NMR, magnetic susceptibility and elemental analysis were used to study the coordination of ligands to the metal ions. Based on the magnetic susceptibility and elemental analysis results, octahedral structures of the complexes such as [CuL2Cl(OH)], [FeL2Cl2(OH)] and [CoL2Cl(OH)] were proposed for L = NQ, CQ and HQ. The relatively large Cd(II) exhibited [CdL3(OH)2]. The FTIR study revealed that NQ and CQ are coordinated to the metal ions via azomethine nitrogen and carbonyl oxygen while HQ through azomethine nitrogen and phenolic oxygen. Despite the high solvation power of DMSO solvent in 1H-NMR experiments, the azomethine HC=N peak at 9.3 ppm is the most affected by complexation with metal ions. On the other hand, quinoline nitrogen seems to be a weaker coordinating site than the azomethine nitrogen. The HQ ligand, containing phenolic groups, and its complexes with Cu and Ni were found to have inhibitory effects on human breast adenocarcinoma MCF-7 and human chronic myelogenous leukemia K562. Nevertheless, metal ions did not exhibit a significant synergistic effect on the antiproliferative activity of the ligands investigated.

Profiling the polyadenylated transcriptome of extracellular vesicles with long-read nanopore sequencing

BackgroundWhile numerous studies have described the transcriptomes of extracellular vesicles (EVs) in different cellular contexts, these efforts have typically relied on sequencing methods requiring RNA fragmentation, which limits interpretations on the integrity and isoform diversity of EV-targeted RNA populations. It has been assumed that mRNA signatures in EVs are likely to be fragmentation products of the cellular mRNA material, and the extent to which full-length mRNAs are present within EVs remains to be clarified.ResultsUsing long-read nanopore RNA sequencing, we sought to characterize the full-length polyadenylated (poly-A) transcriptome of EVs released by human chronic myelogenous leukemia K562 cells. We detected 443 and 280 RNAs that were respectively enriched or depleted in EVs. EV-enriched poly-A transcripts consist of a variety of biotypes, including mRNAs, long non-coding RNAs, and pseudogenes. Our analysis revealed that 10.58% of all EV reads, and 18.67% of all cellular (WC) reads, corresponded to known full-length transcripts, with mRNAs representing the largest biotype for each group (EV = 58.13%, WC = 43.93%). We also observed that for many well-represented coding and non-coding genes, diverse full-length transcript isoforms were present in EV specimens, and these isoforms were reflective-of but often in different ratio compared to cellular samples.ConclusionThis work provides novel insights into the compositional diversity of poly-A transcript isoforms enriched within EVs, while also underscoring the potential usefulness of nanopore sequencing to interrogate secreted RNA transcriptomes.

Synthesis and Biological Evaluation of Novel Paracetamol-Triazole Conjugates

Some new triazole containing acetamide derivatives 9-20 using paracetamol as starting material were synthesized and their structure were characterized by FTIR, 1H-NMR, 13C-NMR and MS data. In vitro cytotoxic activities of all synthesized molecules against five cancer cell lines (human lung cancer A549, human chronic myelogenous leukemia K562, human breast cancer MCF-7, human prostate cancer PC-3, human neuroblastoma SH-SY5Y cell lines) were examined and were also tested their cytotoxic effect on mouse embryonic fibroblast cells (NIH/3T3) to define selectivity. MTT assay were used these in vitro activity studies. Additionally, twelve target compounds 9-20 were screened for their mPGES-1 and COX-1/2 inhibitory activities. While none of the synthesized compounds showed a significant inhibition against both cancer cells and mPGES-1 as well as COX-1/2, it was determined that they were not cytotoxic against healthy cells, too. Finally, ADMET data were presented by predicting the drug-like properties of newly synthesized compounds using computational methods.

NDRG3 regulates imatinib resistance by promoting β‑catenin accumulation in the nucleus in chronic myelogenous leukemia.

Imatinib resistance in chronic myelogenous leukemia (CML) is a clinical problem. The present study examined the role of N‑Myc downstream regulatory gene3 (NDRG3) in imatinib resistance in CML. Quantitative PCR demonstrated that NDRG3 was highly expressed in patients with CML. Cell Counting Kit (CCK)‑8 experiments proved that NDRG3 promoted the proliferation of K562 CML cells and enhanced imatinib resistance. Dual‑luciferase assay showed that microRNA (miR)‑204‑5p inhibited expression of NDRG3 and immunofluorescence experiments showed that NDRG3 promoted accumulation of β‑catenin in the nucleus, thereby increasing the expression of downstream drug resistance‑ and cell cycle‑associated factors (c‑Myc and MDR1). At the same time, cell proliferation experiments showed that β‑catenin played a role in cell proliferation and drug resistance. Co‑transfection with small interfering (si)‑β‑catenin partially reversed the effect of NDRG3. This finding indicated that NDRG3 plays an important role in imatinib resistance and miR‑204‑5p and β‑catenin are involved in the biological behavior of NDRG3. The present results provide theoretical support for overcoming drug resistance in CML.

Anti-Cancer Effects of Oxygen-Atom-Modified Derivatives of Wasabi Components on Human Leukemia Cells.

1-Isothiocyanato-6-(methylsulfinyl)-hexanate (6-MITC) is a natural compound found in Wasabia japonica. The synthetic derivatives 1-Isothiocyanato-6-(methylsulfenyl)-hexane (I7447) and 1-Isothiocyanato-6-(methylsulfonyl)-hexane (I7557) were obtained from 6-MITC by deleting and adding an oxygen atom to the sulfone group, respectively. We previously demonstrated that extensive mitotic arrest, spindle multipolarity, and cytoplasmic vacuole accumulation were induced by 6-MITC and inhibited the viability of human chronic myelogenous leukemia K562 cells. In this study, we examined the anti-cancer effects of 6-MITC derivatives on human chronic myelogenous leukemia (CML) cells. Autophagy was identified as the formation of autophagosomes with double-layered membranes using transmission electron microscopy. Cell cycle and differentiation were analyzed using flow cytometry. Apoptosis was detected by annexin V staining. After treatment with I7447 and I7557, the G2/M phase of cell cycle arrest was revealed. Cell death can be induced by a distinct mechanism (the simultaneous occurrence of autophagy and aberrant mitosis). The expression levels of acridine orange were significantly affected by lysosomal inhibitors. The natural wasabi component, 6-MITC, and its synthetic derivatives have similar effects on human chronic myelogenous leukemia cells and may be developed as novel therapeutic agents against leukemia.

Brassinin Induces Apoptosis, Autophagy, and Paraptosis via MAPK Signaling Pathway Activation in Chronic Myelogenous Leukemia Cells.

Brassinin (BSN), a potent phytoalexin found in cruciferous vegetables, has been found to exhibit diverse anti-neoplastic effects on different cancers. However, the impact of BSN on chronic myelogenous leukemia (CML) cells and the possible mode of its actions have not been described earlier. We investigated the anti-cytotoxic effects of BSN on the KBM5, KCL22, K562, and LAMA84 CML cells and its underlying mechanisms of action in inducing programmed cell death. We noted that BSN could induce apoptosis, autophagy, and paraptosis in CML cells. BSN induced PARP cleavage, subG1 peak increase, and early apoptosis. The potential action of BSN on autophagy activation was confirmed by an LC3 expression and acridine orange assay. In addition, BSN induced paraptosis through increasing the reactive oxygen species (ROS) production, mitochondria damage, and endoplasmic reticulum (ER) stress. Moreover, BSN promoted the activation of the MAPK signaling pathway, and pharmacological inhibitors of this signaling pathway could alleviate all three forms of cell death induced by BSN. Our data indicated that BSN could initiate the activation of apoptosis, autophagy, and paraptosis through modulating the MAPK signaling pathway.

Effects of miR-144-3p on Proliferation, Cell Cycle and Apoptosis of K562 Cells

To investigate the effects of miR-144-3p on cell proliferation, cell cycle and apoptosis of blast phase chronic myelogenous leukemia (CML) K562 cells. K562 cells were cultured in vitro and mimics negative control, hsa-miR-144-3p mimics, inhibitor negative control and miR-144-3p inhibitor were respectively transfected into K562 cells with transfection reagents. The cells were divided into five groups including blank control, mimics negative control, miR-144-3p mimics, inhibitor negative control and miR-144-3p inhibitor. After transfection, the cell proliferation activity was detected by CCK-8 assay. The cell cycle distribution and apoptosis were detected by flow cytometry. Compared with the blank control and mimics negative control groups, the proliferation rate of miR-144-3p mimics group was significantly decreased (P<0.05), the proportion of S phase cells was markedly increased (P<0.05), while the proportion of G1 phase cells was obviously decreased (P<0.05), and the apoptosis rate was significantly increased (P<0.05). Compared with the blank control and inhibitor negative control groups, the proliferation rate of miR-144-3p inhibitor group was obviously increased (P<0.05), the proportion of S phase cells was markedly decreased (P<0.05), while the proportion of G1 phase cells was obviously increased (P<0.05), and the apoptosis rate was significantly decreased (P<0.05). miR-144-3p can inhibit the proliferation and promote apoptosis of K562 cells, affect the cell cycle, and block K562 cells in S phase, which indicates that miR-144-3p is involved in the cell cycle activity of CML during blastic phase.

Novel 1,2,4-triazoles derived from Ibuprofen: synthesis and in vitro evaluation of their mPGES-1 inhibitory and antiproliferative activity.

Some novel triazole-bearing ketone and oxime derivatives were synthesized from Ibuprofen. In vitro cytotoxic activities of all synthesized molecules against five cancer lines (human breast cancer MCF-7, human lung cancer A549, human prostate cancer PC-3, human cervix cancer HeLa, and human chronic myelogenous leukemia K562 cell lines) were evaluated by MTT assay. In addition, mouse embryonic fibroblast cells (NIH/3T3) were also evaluated to determine the selectivity. Compounds 18, 36, and 45 were found to be the most cytotoxic, and their IC50 values were in the range of 17.46-68.76µM, against the tested cancer cells. According to the results, compounds 7 and 13 demonstrated good anti-inflammatory activity against the microsomal enzyme prostaglandin E2 synthase-1 (mPGES-1) enzyme at IC50 values of 13.6 and 4.95µM. The low cytotoxicity and non-mutagenity of these compounds were found interesting. Also, these compounds significantly prevented tube formation in angiogenesis studies. In conclusion, the anti-inflammatory and angiogenesis inhibitory activities of these compounds without toxicity suggested that they may be promising agents in anti-inflammatory treatment and they may be supportive agents for the cancer treatment.

Design, semi-synthesis and examination of new gypsogenin derivatives against leukemia via Abl tyrosine kinase inhibition and apoptosis induction

Chronic myelogenous leukemia (CML) is characterized by Philadelphia translocation arising from Bcr-Abl fusion gene, which encodes abnormal oncoprotein showing tyrosine kinase (TK) function. Certain mutations in kinase domain, off-target effects and resistance problems of current TK inhibitors require the discovery of novel Abl TK inhibitors. For this purpose, herein, we synthesized new gypsogenin derivatives (6a-l) and evaluated their anticancer effects towards CML cells along with healthy cell line and different leukemic cells. Among these compounds, compound 6l was found as the most active anti-leukemic agent against K562 CML cells compared to imatinib exerting less cytotoxicity towards PBMCs (healthy). This compound also revealed significant anti-leukemic effects against Jurkat cell line. Besides, compound 6l enhanced apoptosis in CML cells with 52.4 % when compared with imatinib (61.8 %) and inhibited Abl TK significantly with an IC50 value of 13.04 ± 2.48 μM in a large panel of kinases accentuating Abl TK-mediated apoptosis of compound 6l in CML cells. Molecular docking outcomes showed that compound 6l formed mainly crucial interactions in the ATP-binding cleft of Abl TK similar to that of imatinib. Ultimately, in silico pharmacokinetic evaluation of compound 6l indicated that this compound was endowed with anti-leukemic drug candidate features.

A novel coumarin derivative DBH2 inhibits proliferation and induces apoptosis of chronic myeloid leukemia cells

With the development of tyrosine kinase inhibitor (TKI) resistance, finding the novel effective chemotherapeutic agent is of seminal importance for chronic myelogenous leukemia (CML) treatment. This study aims to find the effective anti-leukemic candidates and investigate the possible underlying mechanism. We synthesized the novel coumarin derivatives and evaluated their anti-leukemic activity. Cell viability assay revealed that compound DBH2 exhibited the potent inhibitory activity on the proliferation of CML K562 cells and TKI resistant K562 cells. Morphological observation and flow cytometry confirmed that DBH2 could selectively induce cell apoptosis and cell cycle arrest at G2/M phase of the K562 cells, which was further confirmed on the bone marrow cells from CML transgenic model mice and CD34+ bone marrow leukemic cells from CML patients. Treatments of DBH2 in combination with imatinib could prolong the survival rate of SCL-tTA-BCR/ABL transgenic model mice significantly. Quantitative RT-PCR revealed that DBH2 inhibited the expression of STAT3 and STAT5 in K562 cells, and caspase-3 knockout alleviated the DBH2 induced apoptosis. Furthermore, DBH2 could induce the expression of PARP1 and ROCK1 in K562 cells, which may play the important role in caspase-dependent apoptosis. Our results concluded that coumarin derivative DBH2 serves as a promising candidate for the CML treatment, especially in the combination with imatinib for the TKI resistant CML, and STAT/caspase-3 pathway was involved in the molecular mechanism of anti-leukemic activity of DBH2.

6,7-Dimethoxycoumarin Influences the Erythroid Differentiation of Human Chronic Myelogenous Leukemia K562 Cells through Regulating FOXO3/p27 Signal Pathway.

Objective To study the pharmacological activity and the mechanism of action of natural compounds derived from 6,7-dimethoxycoumarin on the differentiation of human chronic myeloid leukemia K562 cells. Methods We use MTT assay (Sigma-Aldrich, USA) to detect cell viability; use flow cytometry to analyze DNA content for cell cycle analysis; use benzidine staining to synthesize hemoglobin to determine K562 cell differentiation; use western blot analysis and qPCR to detect the expression levels of FOX03, P27, CDK4, and their phosphorylation; and use the AOBS laser scanning confocal system (Leica, Wetzlar, Germany) to analyze and quantify the number of positive green spots. The statistical methods used are one-way analysis of variance (ANOVA) and Dunnett's test to analyze within and between groups. Results In order to explore the effect of 6,7-dimethoxycoumarin on the differentiation of K562 cell erythrocytes, it was concluded that 6,7-dimethoxycoumarin promotes the differentiation of K562 cell erythrocytes; the proliferation of K562 cells was detected by MTT method, and the results showed that 6,7-dimethoxycoumarin can inhibit the proliferation of K562 cells; to evaluate the effect of 6,7-dimethoxycoumarin on the proliferation of K562 cells, the results showed that 6,7-dimethoxycoumarin increased the expression of FOXO3, P27, CDK4, and CDK65, and decreased the phosphorylation of CDK4 and CDK6 proteins. To further explore the effect of knocking out FOXO3 on cell differentiation, the results show that 6,7-dimethoxycoumarin can reduce the differentiation and proliferation of K562 cells by increasing the expression of FOXO3. Conclusion This study extended the understanding of the pharmacological activity of 6,7-dimethoxycoumarin and may provide a potential new target for the treatment of chronic myelogenous leukemia. However, we still need to further study the specific molecular capabilities of 6.7 dimethylcoumarin to understand their possible capture mechanism.

Restriction-Assembly: A Solution to Construct Novel Adenovirus Vector.

Gene therapy and vaccine development need more novel adenovirus vectors. Here, we attempt to provide strategies to construct adenovirus vectors based on restriction-assembly for researchers with little experience in this field. Restriction-assembly is a combined method of restriction digestion and Gibson assembly, by which the major part of the obtained plasmid comes from digested DNA fragments instead of PCR products. We demonstrated the capability of restriction-assembly in manipulating the genome of simian adenovirus 1 (SAdV-1) in this study. A PCR product of the plasmid backbone was combined with SAdV-1 genomic DNA to construct an infectious clone, plasmid pKSAV1, by Gibson assembly. Restriction-assembly was performed repeatedly in the steps of intermediate plasmid isolation, modification, and restoration. The generated adenoviral plasmid was linearized by restriction enzyme digestion and transfected into packaging 293 cells to rescue E3-deleted replication-competent SAdV1XE3-CGA virus. Interestingly, SAdV1XE3-CGA could propagate in human chronic myelogenous leukemia K562 cells. The E1 region was similarly modified to generate E1/E3-deleted replication-defective virus SAdV1-EG. SAdV1-EG had a moderate gene transfer ability to adherent mammalian cells, and it could efficiently transduce suspension cells when compared with the human adenovirus 5 control vector. Restriction-assembly is easy to use and can be performed without special experimental materials and instruments. It is highly effective with verifiable outcomes at each step. More importantly, restriction-assembly makes the established vector system modifiable, upgradable and under sustainable development, and it can serve as the instructive method or strategy for the synthetic biology of adenoviruses.