Cytometric assessment of DNA damage in relation to cell cycle phase and apoptosis

Small Molecule Targeting PPM1A Activates Autophagy for Mycobacterium tuberculosis Host-Directed Therapy

Mycobacterium tuberculosis (Mtb), the infectious agent of tuberculosis (TB), causes over 1.5 million deaths globally every year. Host-directed therapies (HDT) for TB are desirable for their potential to shorten treatment and reduce the development of antibiotic resistance. Previously, we described a modular biomimetic strategy to identify SMIP-30, targeting PPM1A (IC50 = 1.19 μM), a metal-dependent phosphatase exploited by Mtb to survive intracellularly. SMIP-30 restricted the survival of Mtb in macrophages and lungs of infected mice. Herein, we redesigned SMIP-30 to create SMIP-031, which is a more potent inhibitor for PPM1A (IC50 = 180 nM). SMIP-031 efficiently increased the level of phosphorylation of S403-p62 and the expression of LC3B-II to activate autophagy, resulting in the dose-dependent clearance of Mtb in infected macrophages. SMIP-031 possesses a good pharmacokinetic profile and oral bioavailability (F = 74%). In vivo, SMIP-031 is well tolerated up to 50 mg/kg and significantly reduces the bacteria burden in the spleens of infected mice.

Melatonin improves mouse oocyte quality from 2-ethylhexyl diphenyl phosphate-induced toxicity by enhancing mitochondrial function

2-Ethylhexyl diphenyl phosphate (EHDPP) is a representative organophosphorus flame retardant (OPFR) that has garnered attention due to its widespread use and potential adverse effects. EHDPP exhibits cytotoxicity, genotoxicity, developmental toxicity, and endocrine disruption. However, the toxicity of EHDPP in mammalian oocytes and the underlying mechanisms remain poorly understood. Melatonin is a natural free radical scavenger that has demonstrated cytoprotective properties. In this study, we investigated the effect of EHDPP on mouse oocytes in vitro culture system and evaluated the rescue effect of melatonin on oocytes exposed to EHDPP. Our results indicated that EHDPP disrupted oocyte maturation, resulting in the majority of oocytes arrested at the metaphase I (MI) stage, accompanied by cytoskeletal damage and elevated levels of reactive oxygen species (ROS). Nevertheless, melatonin supplementation partially rescued EHDPP-induced mouse oocyte maturation impairment. Results of single-cell RNA sequencing (scRNA-seq) analysis elucidated potential mechanisms underlying these protective effects. According to the results of scRNA-seq, we conducted further tests and found that EHDPP primarily disrupts mitochondrial distribution and function, kinetochore-microtubule (K-MT) attachment, DNA damage, apoptosis, and histone modification, which were rescued upon the supplementation of melatonin. This study reveals the mechanisms of EHDPP on female reproduction and indicates the efficacy of melatonin as a therapeutic intervention for EHDPP-induced defects in mouse oocytes.

Pd(II)/diphosphine/curcumin complexes as potential anticancer agents

Palladium(II) complexes have stimulated research interest mainly due to their in vitro cytotoxicity against various cancer cell lines and their low cytotoxicity in healthy cells. Thus, in this work, we combined Pd(II)/phosphine systems with the natural product curcumin as a ligand, obtaining a series of complexes, [Pd(cur)(PPh3)2]PF6 (A1), [Pd(cur)(dppe)]PF6 (A2), [Pd(cur)(dppp)]PF6 (A3), [Pd(cur)(dppb)]PF6 (A4) and [Pd(cur)(dppf)]PF6 (A5), where dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, and dppf = 1,1'-bis(diphenylphosphino)ferrocene (P-P), which were characterized by elemental analysis, molar conductivity analysis, and mass, NMR (1H, 13C, 31P{1H}), UV-vis, and IR spectroscopies, and four of them (A1, A2, A4, and A5) by X-ray crystallography. The in vitro cell viability of the complexes A1-A5, cisplatin, and the free ligand curcumin against MDA-MB-231 (human triple-negative breast tumor cells), SK-BR-3 (human breast tumor cells), A549 (human lung tumor cells), MRC-5 (non-tumor human lung cells), A2780 (human ovarian carcinoma cells), and A2780cis (cisplatin-resistant human ovarian carcinoma cells), was evaluated by the MTT colorimetric assay. For the tumor cell lines tested, the complexes showed good anticancer activities. The results showed that in general the complexes had lower IC50 values than free curcumin and the precursors [PdCl2(P-P)]. IC50 results obtained for the A1-A5 complexes, in the MCF-7 cell line, are similar to those that had already been observed for some Pd/bipy/curcumin complexes. In the MDA-MB-231 cell line, complexes A1 and A5 stood out, with their lowest IC50 values, around 5 μmol L-1, and the complexes appeared to be more active (lower IC50 values) against the ovarian cell lines. Complex A1 was 23 and 22-fold more cytotoxic than cisplatin, against the A2780 and A2780cis cells, respectively. The complex A1 was studied on A2780cis cells and it was found that this complex inhibits colony formation and induces cell cycle arrest in the sub-G1 phase in a concentration-dependent manner and leads to cell death by apoptosis. The DCFDA assay revealed a potent ROS induction for complex A1.

H2AX: A key player in DNA damage response and a promising target for cancer therapy

Cancer is caused by a complex interaction of factors that interrupt the normal growth and division of cells. At the center of this process is the intricate relationship between DNA damage and the cellular mechanisms responsible for maintaining genomic stability. When DNA damage is not repaired, it can cause genetic mutations that contribute to the initiation and progression of cancer. On the other hand, the DNA damage response system, which involves the phosphorylation of the histone variant H2AX (γH2AX), is crucial in preserving genomic integrity by signaling and facilitating the repair of DNA double-strand breaks. This review provides an explanation of the molecular dynamics of H2AX in the context of DNA damage response. It emphasizes the crucial role of H2AX in recruiting and localizing repair machinery at sites of chromatin damage. The review explains how H2AX phosphorylation, facilitated by the master kinases ATM and ATR, acts as a signal for DNA damage, triggering downstream pathways that govern cell cycle checkpoints, apoptosis, and the cellular fate decision between repair and cell death. The phosphorylation of H2AX is a critical regulatory point, ensuring cell survival by promoting repair or steering cells towards apoptosis in cases of catastrophic genomic damage. Moreover, we explore the therapeutic potential of targeting H2AX in cancer treatment, leveraging its dual function as a biomarker of DNA integrity and a therapeutic target. By delineating the pathways that lead to H2AX phosphorylation and its roles in apoptosis and cell cycle control, we highlight the significance of H2AX as both a prognostic tool and a focal point for therapeutic intervention, offering insights into its utility in enhancing the efficacy of cancer treatments.

High-throughput assays to assess variant effects on disease

Interpreting the wealth of rare genetic variants discovered in population-scale sequencing efforts and deciphering their associations with human health and disease present a critical challenge due to the lack of sufficient clinical case reports. One promising avenue to overcome this problem is deep mutational scanning (DMS), a method of introducing and evaluating large-scale genetic variants in model cell lines. DMS allows unbiased investigation of variants, including those that are not found in clinical reports, thus improving rare disease diagnostics. Currently, the main obstacle limiting the full potential of DMS is the availability of functional assays that are specific to disease mechanisms. Thus, we explore high-throughput functional methodologies suitable to examine broad disease mechanisms. We specifically focus on methods that do not require robotics or automation but instead use well-designed molecular tools to transform biological mechanisms into easily detectable signals, such as cell survival rate, fluorescence or drug resistance. Here, we aim to bridge the gap between disease-relevant assays and their integration into the DMS framework.

Platinum-induced upregulation of ITGA6 promotes chemoresistance and spreading in ovarian cancer

Platinum (PT)-resistant Epithelial Ovarian Cancer (EOC) grows as a metastatic disease, disseminating in the abdomen and pelvis. Very few options are available for PT-resistant EOC patients, and little is known about how the acquisition of PT-resistance mediates the increased spreading capabilities of EOC. Here, using isogenic PT-resistant cells, genetic and pharmacological approaches, and patient-derived models, we report that Integrin α6 (ITGA6) is overexpressed by PT-resistant cells and is necessary to sustain EOC metastatic ability and adhesion-dependent PT-resistance. Using in vitro approaches, we showed that PT induces a positive loop that, by stimulating ITGA6 transcription and secretion, contributes to the formation of a pre-metastatic niche enabling EOC cells to disseminate. At molecular level, ITGA6 engagement regulates the production and availability of insulin-like growth factors (IGFs), over-stimulating the IGF1R pathway and upregulating Snail expression. In vitro data were recapitulated using in vivo models in which the targeting of ITGA6 prevents PT-resistant EOC dissemination and improves PT-activity, supporting ITGA6 as a promising druggable target for EOC patients.

Elevated MSH2 MSH3 expression interferes with DNA metabolism in vivo

The Msh2-Msh3 mismatch repair (MMR) complex in Saccharomyces cerevisiae recognizes and directs repair of insertion/deletion loops (IDLs) up to ∼17 nucleotides. Msh2-Msh3 also recognizes and binds distinct looped and branched DNA structures with varying affinities, thereby contributing to genome stability outside post-replicative MMR through homologous recombination, double-strand break repair (DSBR) and the DNA damage response. In contrast, Msh2-Msh3 promotes genome instability through trinucleotide repeat (TNR) expansions, presumably by binding structures that form from single-stranded (ss) TNR sequences. We previously demonstrated that Msh2-Msh3 binding to 5' ssDNA flap structures interfered with Rad27 (Fen1 in humans)-mediated Okazaki fragment maturation (OFM) in vitro. Here we demonstrate that elevated Msh2-Msh3 levels interfere with DNA replication and base excision repair in vivo. Elevated Msh2-Msh3 also induced a cell cycle arrest that was dependent on RAD9 and ELG1 and led to PCNA modification. These phenotypes also required Msh2-Msh3 ATPase activity and downstream MMR proteins, indicating an active mechanism that is not simply a result of Msh2-Msh3 DNA-binding activity. This study provides new mechanistic details regarding how excess Msh2-Msh3 can disrupt DNA replication and repair and highlights the role of Msh2-Msh3 protein abundance in Msh2-Msh3-mediated genomic instability.

Identification of hub genes associated with prognosis of lung cancer via integrated bioinformatics and in vitro approach

Lung cancer is a severe health problem that affects more men than women around the world. The goal of this study was to identify the biomarker hub genes for lung cancer in order to ascertain the biological pathway and protein- protein interaction networks. The microarray datasets GSE80796, GSE68571, GSE118370 and GSE43458 were retrieved from the GEO database and were analysed using GEO2R. STRING, Cytoscape, and cytoHubba were used to construct the PPI network and hub genes. GEPIA was used to obtain the overall survival and expression level in LUAD/LUSC and normal tissue. The MTT assay was used to examine antiproliferative activity. PI staining was used to determine the cell cycle arrest. qPCR was used to analyse gene expressions. The datasets revealed a total of 401 common DEGs, with 258 up-regulated genes and 143 down-regulated genes. Further, in-vitro study of gallic acid cytotoxic effect in human lung cancer cell line A549 indicated that gallic acid dramatically suppressed cell growth in A549 cells. Gallic acid also, significantly promoted programmed cell death by halting cells in the G0/G1 phase of the cell cycle. Taken together, our study indicated that gallic acid is a promising natural STAT1 inhibitor as it hindered lung cancer progression by inducing cell cycle arrest and apoptosis which can be employed to increase the therapeutic efficacy of existing lung cancer treatments and to improve overall patient survival.Communicated by Ramaswamy H. Sarma.

ZEB1 promotes DNA homologous recombination repair and contributes to the 5-Fluorouracil resistance in colorectal cancer

Chemotherapy resistance represents a significant obstacle in clinical practice of colorectal cancer (CRC). In this study we aim to clarify the underlying mechanism of chemotherapy resistance mediated by ZEB1 in CRC. shRNA-mediated repression of ZEB1 induced DNA damage in SW480 and RKO cells. Ectopic expression of ZEB1 suppressed the DNA damage caused by ZEB1 knocking down in SW480 and RKO cells. In addition, ZEB1 directly targeted several DNA damage response (DDR) factors including NBS1, RNF8 and RNF168, and thereby the homologous recombination (HR) repair is mediated by ZEB1 via NBS1, RNF8 and RNF168 in CRC cells. Furthermore, ZEB1 maintained chromosome stability in CRC cells. By inducing NBS1, RNF8 and RNF168, ZEB1 is capable of promoting the 5-Fluorouracil (5-FU) resistance in CRC cells via enhancing the DDR signaling and DNA repair. The high expression of ZEB1, NBS1, RNF8 and RNF168 is associated with chemotherapy resistance in primary CRC patients. In conclusion, ZEB1 directly induces the expression of NBS1, RNF8 and RNF168, and thereby enhances DNA HR repair in CRC. The ZEB1-mediated DNA repair contributes to the 5-FU resistance in CRC.

"Half-Sandwich" Ruthenium Complexes with Alizarin as Anticancer Agents: In Vitro and In Vivo Studies

Upon exploration of the chemistry of the combination of ruthenium/arene with anthraquinone alizarin (L), three new complexes with the general formulas [Ru(L)Cl(η⁶-p-cymene)] (C1), [Ru(L)(η⁶-p-cymene)(PPh₃)]PF₆ (C2), and [Ru(L)(η⁶-p-cymene)(PEt₃)]PF₆ (C3) were synthesized and characterized using spectroscopic techniques (mass, IR, and 1D and 2D NMR), molar conductivity, elemental analysis, and X-ray diffraction. Complex C1 exhibited fluorescence, such as free alizarin, while in C2 and C3, the emission was probably quenched by monophosphines and the crystallographic data showed that hydrophobic interactions are predominant in intermolecular contacts. The cytotoxicity of the complexes was evaluated in the MDA-MB-231 (triple-negative breast cancer), MCF-7 (breast cancer), and A549 (lung) tumor cell lines and MCF-10A (breast) and MRC-5 (lung) nontumor cell lines. Complexes C1 and C2 were more selective to the breast tumor cell lines, and C2 was the most cytotoxic (IC₅₀ = 6.5 μM for MDA-MB-231). In addition, compound C1 performs a covalent interaction with DNA, while C2 and C3 present only weak interactions; however, internalization studies by flow cytometry and confocal microscopy showed that complex C1 does not accumulate in viable MDA-MB-231 cells and is detected in the cytoplasm only after cell permeabilization. Investigations of the mechanism of action of the complexes indicate that C2 promotes cell cycle arrest in the Sub-G₁ phase in MDA-MB-231, inhibits its colony formation, and has a possible antimetastatic action, impeding cell migration in the wound-healing experiment (13% of wound healing in 24 h). The in vivo toxicological experiments with zebrafish indicate that C1 and C3 exhibit the most zebrafish embryo developmental toxicity (inhibition of spontaneous movements and heartbeats), while C2, the most promising anticancer drug in the in vitro preclinical tests, revealed the lowest toxicity in in vivo preclinical screening.

Tumor selective Ru(III) Schiff bases complexes with strong in vitro activity toward cisplatin-resistant MDA-MB-231 breast cancer cells

Novel ruthenium(III) complexes of general formula Na[RuCl2(L1-3-N,O)2] where L(1-3) denote deprotonated Schiff bases (HL1-HL3) derived from 5-substituted salicyladehyde and alkylamine (propyl- or butylamine) were prepared and characterized based on elemental analysis, mass spectra, infrared, electron spin/paramagnetic resonance (ESR/EPR) spectroscopy, and cyclovoltammetric study. Optimization of five isomers of complex C1 was done by DFT calculation. The interaction of C1-C3 complexes with DNA (Deoxyribonucleic acid) and BSA (Bovine serum albumin) was investigated by electron spectroscopy and fluorescence quenching. The cytotoxic activity of C1-C3 was investigated in a panel of four human cancer cell lines (K562, A549, EA.hy926, MDA-MB-231) and one human non-tumor cell line (MRC-5). Complexes displayed an apparent cytoselective profile, with IC50 values in the low micromolar range from 1.6 ± 0.3 to 23.0 ± 0.1 µM. Cisplatin-resistant triple-negative breast cancer cells MDA-MB-231 displayed the highest sensitivity to complexes, with Ru(III) compound containing two chlorides and two deprotonated N-propyl-5-chloro-salicylidenimine (hereinafter C1) as the most potent (IC50 = 1.6 µM), and approximately ten times more active than cisplatin (IC50 = 21.9 µM). MDA-MB-231 cells treated for 24 h with C1 presented with apoptotic morphology, as seen by acridine orange/ethidium bromide staining, while 48 h of treatment induced DNA fragmentation, and necrotic changes in cells, as seen by flow cytometry analysis. Drug-accumulation study by inductively coupled plasma mass spectrometry (ICP-MS) demonstrated markedly higher intracellular accumulation of C1 compared with cisplatin.

Differential Apoptotic Effects of Bee Product Mixtures on Normal and Cancer Hepatic Cells

Most effective anticancer drugs normally generate considerable cytotoxicity in normal cells; therefore, the preferential activation of apoptosis in cancer cells and the reduction of toxicity in normal cells is a great challenge in cancer research. Natural products with selective anticancer properties used as complementary medicine can help to achieve this goal. The aim of the present study was to analyze the effect of the addition of bee products [propolis (PR) or royal jelly (RJ) or propolis and royal jelly (PR+RJ), 2-10%] to thyme (TH) and chestnut honeys (CH) on the differential anticancer properties, mainly the cytotoxic and pro-apoptotic effects, in normal and cancer hepatic cells. The cytotoxic effects of samples were analyzed using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay (0-250 mg/mL) and the effects on apoptosis were analyzed using cell cycle analysis, TdT-dUTP terminal nick-end labeling (TUNEL) assay, DR5 (Death Receptor 5) and BAX (BCL-2-Associated X) activation, and caspases 8, 9, and 3 activities. Both honey samples alone and honey mixtures had no or very little apoptotic effect on normal cells. Antioxidant honey mixtures enhanced the apoptotic capacity of the corresponding honey alone via both extrinsic and intrinsic pathways. Of all the samples, chestnut honey enriched with 10% royal jelly and 10% propolis (sample 14, CH+10RJ+10PR) showed the highest apoptotic effect on tumor liver cells. The enrichment of monofloral honey with bee products could be used together with conventional anticancer treatments as a dietary supplement without side effects. On the other hand, it could be included in the diet as a natural sweetener with high added value.

Factors to Consider for the Correct Use of γH2AX in the Evaluation of DNA Double-Strand Breaks Damage Caused by Ionizing Radiation

People exposed to ionizing radiation (IR) both for diagnostic and therapeutic purposes is constantly increasing. Since the use of IR involves a risk of harmful effects, such as the DNA DSB induction, an accurate determination of this induced DNA damage and a correct evaluation of the risk-benefit ratio in the clinical field are of key relevance. γH2AX (the phosphorylated form of the histone variant H2AX) is a very early marker of DSBs that can be induced both in physiological conditions, such as in the absence of specific external agents, and by external factors such as smoking, heat, background environmental radiation, and drugs. All these internal and external conditions result in a basal level of γH2AX which must be considered for the correct assessment of the DSBs after IR exposure. In this review we analyze the most common conditions that induce H2AX phosphorylation, including specific exogenous stimuli, cellular states, basic environmental factors, and lifestyles. Moreover, we discuss the most widely used methods for γH2AX determination and describe the principal applications of γH2AX scoring, paying particular attention to clinical studies. This knowledge will help us optimize the use of available methods in order to discern the specific γH2AX following IR-induced DSBs from the basal level of γH2AX in the cells.

Efficacy of Clinically Used PARP Inhibitors in a Murine Model of Acute Lung Injury

Poly(ADP-ribose) polymerase 1 (PARP1), as a potential target for the experimental therapy of acute lung injury (ALI), was identified over 20 years ago. However, clinical translation of this concept was not possible due to the lack of clinically useful PARP inhibitors. With the clinical introduction of several novel, ultrapotent PARP inhibitors, the concept of PARP inhibitor repurposing has re-emerged. Here, we evaluated the effect of 5 clinical-stage PARP inhibitors in oxidatively stressed cultured human epithelial cells and monocytes in vitro and demonstrated that all inhibitors (1-30 µM) provide a comparable degree of cytoprotection. Subsequent in vivo studies using a murine model of ALI compared the efficacy of olaparib and rucaparib. Both inhibitors (1-10 mg/kg) provided beneficial effects against lung extravasation and pro-inflammatory mediator production-both in pre- and post-treatment paradigms. The underlying mechanisms include protection against cell dysfunction/necrosis, inhibition of NF-kB and caspase 3 activation, suppression of the NLRP3 inflammasome, and the modulation of pro-inflammatory mediators. Importantly, the efficacy of PARP inhibitors was demonstrated without any potentiation of DNA damage, at least as assessed by the TUNEL method. These results support the concept that clinically approved PARP inhibitors may be repurposable for the experimental therapy of ALI.

Schedule-Dependent Treatment Increases Chemotherapy Efficacy in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a rare but aggressive thoracic malignancy with limited treatment options. One of the standard treatments for MPM is chemotherapy, which consists of concurrent treatment with pemetrexed and cisplatin. Pemetrexed limits tumor growth by inhibiting critical metabolic enzymes involved in nucleotide synthesis. Cisplatin causes direct DNA damage, such as intra-strand and inter-strand cross-links, which are repaired by the nucleotide excision repair pathway, which depends on relatively high nucleotide levels. We hypothesized that prolonged pretreatment with pemetrexed might deplete nucleotide pools, thereby sensitizing cancer cells to subsequent cisplatin treatment. The MPM cell lines ACC-MESO-1 and NCI-H28 were treated for 72 h with pemetrexed. Three treatment schedules were evaluated by initiating 24 h of cisplatin treatment at 0 h (concomitant), 24 h, and 48 h relative to pemetrexed treatment, resulting in either concomitant administration or pemetrexed pretreatment for 24 h or 48 h, respectively. Multicolor flow cytometry was performed to detect γH2AX (phosphorylation of histone H2AX), a surrogate marker for the activation of the DNA damage response pathway. DAPI staining of DNA was used to analyze cell cycle distribution. Forward and side scatter intensity was used to distinguish subpopulations based on cellular size and granularity, respectively. Our study revealed that prolonged pemetrexed pretreatment for 48 h prior to cisplatin significantly reduced long-term cell growth. Specifically, pretreatment for 48 h with pemetrexed induced a cell cycle arrest, mainly in the G2/M phase, accumulation of persistent DNA damage, and induction of a senescence phenotype. The present study demonstrates that optimizing the treatment schedule by pretreatment with pemetrexed increases the efficacy of the pemetrexed-cisplatin combination therapy in MPM. We show that the observed benefits are associated with the persistence of treatment-induced DNA damage. Our study suggests that an adjustment of the treatment schedule could improve the efficacy of the standard chemotherapy regimen for MPM and might improve patient outcomes.

Cytotoxic and antiparasitic activities of diphosphine-metal complexes of group 10 containing acylthiourea as ligands

In this work, group 10 transition metal complexes bearing dppe [1,2-bis(diphenylphosphino)ethane] and acylthiourea ligands were evaluated for their cytotoxic and antiparasitic activities. Six new complexes with a general formula [M(L_n)(dppe)]BF₄ [where M = Ni^II, Pd^II or Pt^II; L_n = N, N'-dimethyl-N-benzoyl thiourea (L₁) or N, N'-dimethyl-N-tiofenyl thiourea (L₂) were synthesized and characterized by infrared, NMR (³¹P{¹H}, ¹H and ¹³C{¹H}) spectroscopies, elemental analysis and molar conductivity. The structures of the complexes were confirmed by X-ray diffraction technique. The biological activity of the complexes was evaluated on breast cancer cells (MDA-MB-231 and MCF-7) and causative agents of chagas disease and leishmaniasis. The complexes presented higher cytotoxicity for breast cancer cell lines compared to non-tumor cells. Nickel complexes stood out when evaluated against the triple-negative breast cancer line (MDA-MB-231), presenting considerably lower IC₅₀ values (about 10 to 22×), when compared to palladium and platinum complexes, and the cisplatin drug. When evaluated on the triple-negative line (MDA-MB-231), the complexes [Ni(L₂)(dppe)]BF₄(2), [Pd(L₂)(dppe)]BF₄(4) and [Pt(L₂)(dppe)]BF₄(6) were able to induce cell morphological changes, influence on the cell colony formation and the size of the cells. The complexes inhibit cell migration and cause changes to the cell cytoskeleton and nuclear arrangement. In the same cell line, the compounds caused cell arrest in the Sub-G1 phase of the cell cycle. The compounds were also tested against the Trypanosom Cruzi (T. cruzi) and Leishmania sp. parasites, which cause Chagas and leishmaniasis disease, respectively. The compounds showed good anti-parasitic activity, mainly for T. cruzi, with lower IC₅₀ values, when compared to the commercial drug, benznidazole. The compounds interact with CT-DNA, indicating that interaction occurs by the minor groove of the biomolecule.

Ruthenium(II)-diphosphine complexes containing acylthiourea ligands are effective against lung and breast cancers

We have synthesized and characterized three new ruthenium(II) diphosphine complexes containing an acylthiourea ligand, with the general formula [Ru(DPEPhos)(O,S)(bipy)]PF₆, where DPEPhos = bis(2-(diphenylphosphino)phenyl)ether, bipy = 2,2'-bipyridine, and O,S = N,N-dimethyl-N'-(benzoyl)thiourea (1), N,N-dimethyl-N'-(furoyl)thiourea (2), and N,N-dimethyl-N'-(thiophenyl)thiourea (3), by several physicochemical techniques. We evaluated the ruthenium complexes for their cytotoxicity against two human cancer cell lines, A549 (lung) and MDA-MB-231 (breast), and two corresponding lines of non-cancer cells, MRC-5 (lung) and MCF-10A (breast). All the complexes are cytotoxic against the cancer cell lines; the IC₅₀ values lie in the micromolar range (0.07-0.70 μM). Ruthenium complex 1 is more selective (7 times more active) toward lung cancer cells (A549) than toward non-cancer cells (MRC-5) and is 160 times more cytotoxic than cisplatin against A549 cells. Investigations of the mechanism of action of complex 1 in A549 cells demonstrated that it inhibits colony formation and promotes cell cycle arrest in the G1 phase and apoptotic cell death. DNA binding studies revealed that complexes 1-3 interact with the biomolecule via minor grooves. These complexes also interact with human serum albumin (HSA) and have affinity for site I by hydrophobic forces. Therefore, this new class of ruthenium complexes can act as cytotoxic agents, mainly for lung cancer treatment.

Ketoprofen Combined with UVA Irradiation Exerts Higher Selectivity in the Mode of Action against Melanotic Melanoma Cells than against Normal Human Melanocytes

Malignant melanoma is responsible for the majority of skin cancer-related deaths. The methods of cancer treatment include surgical removal, chemotherapy, immunotherapy, and targeted therapy. However, neither of these methods gives satisfactory results. Therefore, the development of new anticancer therapeutic strategies is very important and may extend the life span of people suffering from melanoma. The aim of this study was to examine the effect of ketoprofen (KTP) and UVA radiation (UVAR) therapy on cell proliferation, apoptosis, and cell cycle distribution in both melanotic melanoma cells (COLO829) and human melanocytes (HEMn-DP) in relation to its supportive effect in the treatment of melanoma. The therapy combining the use of pre-incubation with KTP and UVAR causes a significant increase in the anti-proliferative properties of ketoprofen towards melanoma cells and the co-exposure of melanotic melanoma cells induced apoptosis shown as the mitochondrial membrane breakdown, cell-cycle deregulation, and DNA fragmentation. Moreover, co-treatment led to GSH depletion showing its pro-apoptotic effect dependent on ROS overproduction. The treatment did not show a significant effect on normal cells—melanocytes—which indicates its high selectivity. The results suggest a possible benefit from the use of the ketoprofen and ultraviolet A irradiation as a new concept of melanotic melanoma therapy.

Recent progress in cytometric technologies and their applications in ecotoxicology and environmental risk assessment

Environmental toxicology focuses on identifying and predicting impact of potentially toxic anthropogenic chemicals on biosphere at various levels of biological organization. Presently there is a significant drive to gain deeper understanding of cellular and sub-cellular mechanisms of ecotoxicity. Most notable is increased focus on elucidation of cellular-response networks, interactomes, and greater implementation of cell-based biotests using high-throughput procedures, while at the same time decreasing the reliance on standard animal models used in ecotoxicity testing. This is aimed at discovery and interpretation of molecular pathways of ecotoxicity at large scale. In this regard, the applications of cytometry are perhaps one of the most fundamental prospective analytical tools for the next generation and high-throughput ecotoxicology research. The diversity of this modern technology spans flow, laser-scanning, imaging, and more recently, Raman as well as mass cytometry. The cornerstone advantages of cytometry include the possibility of multi-parameter measurements, gating and rapid analysis. Cytometry overcomes, thus, limitations of traditional bulk techniques such as spectrophotometry or gel-based techniques that average the results from pooled cell populations or small model organisms. Novel technologies such as cell imaging in flow, laser scanning cytometry, as well as mass cytometry provide innovative and tremendously powerful capabilities to analyze cells, tissues as well as to perform in situ analysis of small model organisms. In this review, we outline cytometry as a tremendously diverse field that is still vastly underutilized and often largely unknown in environmental sciences. The main motivation of this work is to highlight the potential and wide-reaching applications of cytometry in ecotoxicology, guide environmental scientists in the technological aspects as well as popularize its broader adoption in environmental risk assessment.

The metabolite 5-methyl-1,3-benzenediol and its derivative methyl-2,4-dihydroxy-6-methylbenzoate from the lichen Parmotrema tinctorum with potent apoptotic and anti-angiogenesis effects

Nature has been a rich resource of novel anticancer agents, one such source being lichens, which represent the symbiosis between algae and fungi with diverse range of secondary metabolites having therapeutic significance. With respect to this, the present study evaluates the in vitro apoptogenic profile of secondary metabolites from the lichen Parmotrema tinctorum towards cancer cell lines. Treatment with TLC-purified fraction 1 from P. tinctorum resulted in significant reduction in the cell viabilities of cancer cells with IC50 values ranging between 1.2 and 12.8 μg/ml. The potential anticancer effect of the bioactive fraction was further supported by Trypan blue cell viability, LDH and DNA fragmentation assays. At the cellular level, induction of apoptosis was confirmed through the activation of the caspase cascade and apoptotic cells accumulating in the Sub-G1 phase of cell cycle. Angiogenesis being one of the major characteristics needed for cancer growth, the ability of the lichen fraction to inhibit angiogenesis was checked through in ovo Yolk Sac Membrane (YSM) assay and was found to be significant. The study also verified the non-toxic nature of the bioactive fraction towards normal human peripheral lymphocytes. HPLC analysis and GC-MS characterisation of the bioactive fraction indicated the presence of 5-methyl-1,3-benzenediol and its derivative methyl-2,4-dihydroxy-6-methylbenzoate.

Assessment of the cytotoxic, genotoxic, and apoptotic potential of flurbiprofen in HeLa and HepG2 cell lines

In the literature, the anticancer potential of flurbiprofen isn't fully understood. In this study, the cytotoxic, genotoxic, and apoptotic effects of flurbiprofen were evaluated in human cervical and liver cancer cells. Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and it was observed that cytotoxicity increased in a concentration- and time-dependent manner. Genotoxicity was determined using alkaline Comet assay. DNA damage increased in a concentration-dependent manner. Early apoptosis was evaluated using real-time polymerase chain reaction, and it was found that apoptotic gene levels increased while antiapoptotic gene levels decreased. Late apoptosis and cell cycle analyzes were determined using flow cytometry. No evidence of late apoptosis was observed, and no significant arrest was found in the cell cycle. In conclusion, it seems that flurbiprofen has a cytotoxic, genotoxic, and apoptotic effects in both human cancer cell lines. Moreover, the findings indicate that flurbiprofen is effective at the gene level and induces apoptosis with an intracellular pathway.

The role of UVA radiation in ketoprofen-mediated BRAF-mutant amelanotic melanoma cells death - A study at the cellular and molecular level

Malignant melanoma is the cause of 80% of deaths in skin cancer patients. Treatment of melanoma in the 4th stage of clinical advancement, in which inoperable metastasis occur, does not provide sufficient effects. Ketoprofen has phototoxic properties and it can be used as a new treatment option for skin cancers as a part of photochemotherapy. The present study was designed to investigate whether ketoprofen in combination with UVA induces cytotoxic, anti-proliferative and pro-apoptotic effects on melanoma cells. It was stated that co-treatment with 1.0 mM ketoprofen and UVA irradiation disturbed homeostasis of C32 melanoma cells by lowering its vitality (decrease of GSH level). Contrary to C32 cells, melanocytes showed low sensitivity to ketoprofen and UVA radiation, pointing selectivity in the mode of action towards melanoma cells. Co-treatment with ketoprofen and UVA irradiation has cytotoxic and anti-proliferative and pro-apoptotic effect on C32. The co-treatment triggered the DNA fragmentation and changed the cell cycle in C32 cells. In conclusion, it could be stated that local application of ketoprofen in combination with UVA irradiation may be used to support the treatment of melanoma and creates the possibility of reducing the risk of cancer recurrence and metastasis.

Looking for genetic effects of polluted anthropized environments on Caiman crocodilus crocodilus (Reptilia, Crocodylia): A comparative genotoxic and chromosomal analysis

The Amazon aquatic ecosystems have been modified by the human population growth, going through changes in their water bodies and aquatic biota. The spectacled alligator (Caiman crocodilus crocodilus) has a wide distribution and adaptability to several environments, even those polluted ones. This study aimed to investigate if a Caiman species living in urban streams of Manaus city (Amazonas State, Brazil) is affected by environmental pollution. For that, it was used classical and molecular cytogenetic procedures, in addition to micronucleus and comet assays. Although the karyotype macrostructure remains unaltered (2 n = 42 chromosomes; 24 t + 18 m/sm; NF = 60), the genotoxic analysis and the cytogenetic mapping of repetitive DNA sequences demonstrated that polluted environments alter the genome of the specimens, affecting both the chromosomal organization and the genetic material.

Mechanical Regulation of Apoptosis in the Cardiovascular System

Apoptosis is a highly conserved physiological process of programmed cell death which is critical for proper organism development, tissue maintenance, and overall organism homeostasis. Proper regulation of cell removal is crucial, as both excessive and reduced apoptotic rates can lead to the onset of a variety of diseases. Apoptosis can be induced in cells in response to biochemical, electrical, and mechanical stimuli. Here, we review literature on specific mechanical stimuli that regulate apoptosis and the current understanding of how mechanotransduction plays a role in apoptotic signaling. We focus on how insufficient or excessive mechanical forces may induce apoptosis in the cardiovascular system and thus contribute to cardiovascular disease. Although studies have demonstrated that a broad range of mechanical stimuli initiate and/or potentiate apoptosis, they are predominantly correlative, and no mechanisms have been established. In this review, we attempt to establish a unifying mechanism for how various mechanical stimuli initiate a single cellular response, i.e. apoptosis. We hypothesize that the cytoskeleton plays a central role in this process as it does in determining myriad cell behaviors in response to mechanical inputs. We also describe potential approaches of using mechanomedicines to treat various diseases by altering apoptotic rates in specific cells. The goal of this review is to summarize the current state of the mechanobiology field and suggest potential avenues where future research can explore.

Silver(I) complexes of 3-methoxy-4-hydroxybenzaldehyde thiosemicarbazones and triphenylphosphine: structural, cytotoxicity, and apoptotic studies

Novel silver(i) complexes of the type [AgCl(PPh3)2(L)] {PPh3 = triphenylphosphine; L = VTSC = 3-methoxy-4-hydroxybenzaldehyde thiosemicarbazone (1); VMTSC = 3-methoxy-4-[2-(morpholine-1-yl)ethoxy]benzaldehyde thiosemicarbazone (2); VPTSC = 3-methoxy-4-[2-(piperidine-1-yl)ethoxy]benzaldehyde thiosemicarbazone (3)} were synthesized and fully characterized by spectroscopic techniques. The molecular structures of complexes 2 and 3 were determined by single crystal X-ray diffraction. Compounds 1-3 exhibited appreciable cytotoxic activity against human tumor cells (lung A549, breast MDA-MB-231 and MCF-7) with IC50 values in 48 h of incubation ranging from 5.6 to 18 μM. Cellular uptake studies showed that complexes 1-3 were efficiently internalized after 3 hours of treatment in MDA-MB-231 cells. The effects of complex 1 on the cell morphology, cell cycle, induction of apoptosis, mitochondrial membrane potential (Δψm), and reactive oxygen species (ROS) production have been evaluated in triple negative breast cancer (TNBC) cells MDA-MB-231. Our results showed that complex 1 induced typical morphological alterations of cell death, an increase in cells at the sub-G1 phase, apoptosis, and mitochondrial membrane depolarization. Furthermore, DNA binding studies evidenced that 1 can bind to ct-DNA and does so without modifying the B-structure of the DNA, but that the binding is weak compared to that of Hoechst 33258.

Cytotoxic and apoptotic effects of ternary silver(i) complexes bearing 2-formylpyridine thiosemicarbazones and 1,10-phenanthroline

New silver(i) compounds containing 2-formylpyridine-N(4)-R-thiosemicarbazones and 1,10-phenanthroline (phen) were synthesized and characterized by spectroscopic techniques (IR and NMR), elemental analysis, ESI-MS and molar conductance measurements. In these complexes, both phen and thiosemicarbazone ligands are coordinated in a chelating bidentate fashion. Compounds 1-3 not only showed good in vitro antiproliferative activity against human lung (A549) and breast tumor cells (MDA-MB-231 and MCF-7), with IC50 values ranging from 1.49 to 20.90 μM, but were also demonstrated to be less toxic towards human breast non-tumor cells (MCF-10A). Cellular uptake studies indicated that compounds 1-3 were taken up by the MDA-MB-231 cells in 6 hours. Cell death assays in the MDA-MB-231 cells were conducted with compound 1 aiming to evaluate its effects on cell morphology, induction of apoptosis, the cell cycle, reactive oxygen species (ROS) formation and mitochondrial membrane potential (Δψm). Compound 1 caused morphological changes, such as cell shrinkage and rounding, increased the sub-G1 phase population, and induced apoptotic cell death, ROS formation and loss of mitochondrial membrane potential (Δψm). DNA binding results revealed that 1 interacted with the ct-DNA minor groove. Complexes 1-3 also exhibited good in vitro activity against M. tuberculosis H37Rv, with MIC values ranging from 3.37 to 4.65 μM.

Lapachol in the Design of a New Ruthenium(II)-Diphosphine Complex as a Promising Anticancer Metallodrug

The preparation of two new Ru(II)/diphosphine complexes containing Lapachol (Lap) and Lawsone (Law): (1) [Ru(Lap)(dppm)₂]PF₆ and (2) [Ru(Law)(dppm)₂]PF₆, where dppm = bis(diphenylphosphino)methane, is reported here. The complexes were synthetized and fully characterized by elemental analyses, molar conductivity, UV-Vis, IR, ³¹P{¹H}, ¹H and ¹³C NMR, and the crystal structure of the complex (1) was determined by X-ray diffraction. Complexes (1) and (2) showed high in vitro cytotoxicity against four cancer cells (MDA-MB-231, MCF-7, A549 and DU-145), with IC₅₀ values in the micromolar range (0.03 to 2.70 μM). Importantly, complexes (1) and (2) were more active than the cisplatin, the drug used as a reference in the cytotoxic assays. Moreover, complex (1) showed high selectivity to triple-negative breast cancer cells (MDA-MB-231). Studies of the mechanism of action in MDA-MB-231 cancer cells showed that complex (1) inhibits cell migration, colony formation, and induces cell cycle arrest and apoptosis by activation of the mitochondrial pathway through the loss of mitochondrial membrane potential (ΔΨm). Furthermore, complex (1) induces ROS (Reactive Oxygen Species) generation in MDA-MB-231 cells, which can cause DNA damage. Finally, complexes (1) and (2) interact with DNA by minor grooves and show a moderate interaction with BSA (Bovine Serum Albumin), with the involvement of hydrophobic interactions. Essentially, Ru(II)/diphosphine-naphthoquinone complexes have remarkable cytotoxic effects with high selectivity to triple-negative breast cancer (MDA-MB-231) and could be promising anticancer candidates for cancer treatment. SYNOPSIS: The naphthoquinones Lapachol and Lawsone can form new ruthenium compounds with promising anticancer properties.

Sustained Activation of AMPK Enhances Differentiation of Human iPSC-Derived Cardiomyocytes via Sirtuin Activation

Recent studies suggest that metabolic regulation may improve differentiation of cardiomyocytes derived from induced pluripotent stem cells (iPSCs). AMP-activated protein kinase (AMPK) is a master regulator of metabolic activities. We investigated whether AMPK participates in iPSC-derived cardiomyocyte differentiation. We observed that AMPK phosphorylation at Thr172 increased at day 9 but then decreased after day 11 of differentiation to cardiomyocytes. Inhibition of AMPK with compound C significantly reduced mRNA and protein expression of cardiac troponins TNNT2 and TNNI3. Moreover, sustained AMPK activation using AICAR from days 9 to 14 of differentiation increased mRNA and protein expression of both TNNT2 and TNNI3. AICAR decreased acetylation of histone 3 at Lys9 and 56 and histone 4 at Lys16 (known target sites for nuclear-localized sirtuins [SIRT1, SIRT6]), suggesting that AMPK activation enhances sirtuin activity. Sustained AMPK activation during days 9–14 of differentiation induces sirtuin-mediated histone deacetylation and may enhance cardiomyocyte differentiation from iPSCs.

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iPSC-derived cardiomyocytes transiently increased AMPK phosphorylation at Thr172

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Chemical inhibition of AMPK with compound C decreased TNNI3 and TNNT2 expression

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Sustained activation of AMPK using AICAR increased expression of TNNT2 and TNNI3

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AICAR decreased acetylation of histones H3 (at Lys9 and Lys56) and H4 (at Lys16).

HDAC3 Activity is Essential for Human Leukemic Cell Growth and the Expression of β-catenin, MYC, and WT1

Therapy of acute myeloid leukemia (AML) is unsatisfactory. Histone deacetylase inhibitors (HDACi) are active against leukemic cells in vitro and in vivo. Clinical data suggest further testing of such epigenetic drugs and to identify mechanisms and markers for their efficacy. Primary and permanent AML cells were screened for viability, replication stress/DNA damage, and regrowth capacities after single exposures to the clinically used pan-HDACi panobinostat (LBH589), the class I HDACi entinostat/romidepsin (MS-275/FK228), the HDAC3 inhibitor RGFP966, the HDAC6 inhibitor marbostat-100, the non-steroidal anti-inflammatory drug (NSAID) indomethacin, and the replication stress inducer hydroxyurea (HU). Immunoblotting was used to test if HDACi modulate the leukemia-associated transcription factors β-catenin, Wilms tumor (WT1), and myelocytomatosis oncogene (MYC). RNAi was used to delineate how these factors interact. We show that LBH589, MS-275, FK228, RGFP966, and HU induce apoptosis, replication stress/DNA damage, and apoptotic fragmentation of β-catenin. Indomethacin destabilizes β-catenin and potentiates anti-proliferative effects of HDACi. HDACi attenuate WT1 and MYC caspase-dependently and -independently. Genetic experiments reveal a cross-regulation between MYC and WT1 and a regulation of β-catenin by WT1. In conclusion, reduced levels of β-catenin, MYC, and WT1 are molecular markers for the efficacy of HDACi. HDAC3 inhibition induces apoptosis and disrupts tumor-associated protein expression.

Identification of intracellular cavin target proteins reveals cavin-PP1alpha interactions regulate apoptosis

Caveolae are specialized domains of the plasma membrane. Formation of these invaginations is dependent on the expression of Caveolin-1 or -3 and proteins of the cavin family. In response to stress, caveolae disassemble and cavins are released from caveolae, allowing cavins to potentially interact with intracellular targets. Here, we describe the intracellular (non-plasma membrane) cavin interactome using biotin affinity proteomics and mass spectrometry. We validate 47 potential cavin-interactor proteins using a cell-free expression system and protein-protein binding assays. These data, together with pathway analyses, reveal unknown roles for cavin proteins in metabolism and stress signaling. We validated the interaction between one candidate interactor protein, protein phosphatase 1 alpha (PP1α), and Cavin-1 and -3 and show that UV treatment causes release of Cavin3 from caveolae allowing interaction with, and inhibition of, PP1α. This interaction increases H2AX phosphorylation to stimulate apoptosis, identifying a pro-apoptotic signaling pathway from surface caveolae to the nucleus.

DNA Damage Does Not Cause BrdU Labeling of Mouse or Human β-Cells

Pancreatic β-cell regeneration, the therapeutic expansion of β-cell number to reverse diabetes, is an important goal. Replication of differentiated insulin-producing cells is the major source of new β-cells in adult mice and juvenile humans. Nucleoside analogs such as BrdU, which are incorporated into DNA during S-phase, have been widely used to quantify β-cell proliferation. However, reports of β-cell nuclei labeling with both BrdU and γ-phosphorylated H2A histone family member X (γH2AX), a DNA damage marker, have raised questions about the fidelity of BrdU to label S-phase, especially during conditions when DNA damage is present. We performed experiments to clarify the causes of BrdU-γH2AX double labeling in mouse and human β-cells. BrdU-γH2AX colabeling is neither an age-related phenomenon nor limited to human β-cells. DNA damage suppressed BrdU labeling and BrdU-γH2AX colabeling. In dispersed islet cells, but not in intact islets or in vivo, pro-proliferative conditions promoted both BrdU and γH2AX labeling, which could indicate DNA damage, DNA replication stress, or cell cycle-related intrinsic H2AX phosphorylation. Strategies to increase β-cell number must not only tackle the difficult challenge of enticing a quiescent cell to enter the cell cycle, but also achieve safe completion of the cell division process.

Ag(I) and Au(III) Mercaptobenzothiazole complexes induced apoptotic cell death

2-Mercaptobenzothiazole (MBT) complexes of Ag(I) and Au(III) were synthesized by wet chemical method. The structural, optical, 1HNMR, ICP - MS and electrochemical studies of the complexes were carried out. The TUNEL assay studies of Ag(I)MBT and Au(III)MBT complexes on A549 cell line indicated induced apoptosis in the cells. TUNEL assay showed 60% cell viability for Ag(I)MBT whereas 80% for Au(III)MBT. Thus Ag(I)MBT can induce cell apoptosis in cells at a higher rate than Au(III)MBT. Therefore these complexes studied here can be a viable option as anti - proliferating agent.

Anti-Proliferative and Anti-Migration Activity of Arene–Ruthenium(II) Complexes with Azole Therapeutic Agents

The efficacy of organoruthenium complexes containing ergosterol biosynthesis inhibitors (CTZ: clotrimazole, KTZ: ketoconazole and FCZ: fluconazole) against tumor cells, and their interaction with important macro-biomolecules such as human serum albumin and DNA have been investigated here. Our experimental results indicated that these ruthenium(II) complexes present spontaneous electrostatic interactions with albumin, and act as minor groove binders with the DNA. The ability of these Ru(II)–azole complexes to inhibit the proliferation of selected human tumor and non-tumor cell lines was determined by MTT assay. Complexes [RuCl(CTZ)(η6-p-cymene)(PPh3)]PF6 (3) and [RuCl(KTZ)(η6-p-cymene)(PPh3)]PF6 (4) were shown to be between 3- and 40-fold more cytotoxic than the free ligands and the positive control cisplatin. Complex 3 was selected to continue studies on the triple negative breast tumor cell line MDA-MB-231, inducing morphological changes, loss of adhesion, inhibition of colony formation, and migration through Boyden chambers, cell cycle arrest in the sub-G1 phase, and a mechanism of cell death by apoptosis. All these interesting results show the potential of this class of organometallic Ru(II) complexes as an antiproliferative agent.

Measuring cell cycle-dependent DNA damage responses and p53 regulation on a cell-by-cell basis from image analysis

DNA damage in cells occurs from both endogenous and exogenous sources, and failure to repair such damage is associated with the emergence of different cancers, neurological disorders and aging. DNA damage responses (DDR) in cells are closely associated with the cell cycle. While most of our knowledge of DDR comes from bulk biochemistry, such methods require cells to be arrested at specific stages for cell cycle studies, potentially altering measured responses; nor is cell to cell variability in DDR or direct cell-level correlation of two response metrics measured in such methods. To overcome these limitations we developed a microscopy-based assay for determining cell cycle stages over large cell numbers. This method can be used to study cell-cycle-dependent DDR in cultured cells without the need for cell synchronization. Upon DNA damage γH2A.X induction was correlated to nuclear enrichment of p53 on a cell-by-cell basis and in a cell cycle dependent manner. Imaging-based cell cycle staging was combined with single molecule P53 mRNA detection and immunofluorescence for p53 protein in the very same cells to reveal an intriguing repression of P53 transcript numbers due to reduced transcription across different stages of the cell cycle during DNA damage. Our study hints at an unexplored mechanism for p53 regulation and underscores the importance of measuring single cell level responses to DNA damage.

Erybraedin A is a potential Src inhibitor that blocks the adhesion and viability of non-small-cell lung cancer cells

The adhesion of cancer cells to the extracellular matrix (ECM) is crucial for cell proliferation, survival, and metastasis. Thus, it is necessary to inhibit cell-ECM adhesion by blocking the activation of the associated signaling to control cancer. Here, we identify erybraedin A (EBA) as a potential Src inhibitor that blocks cell adhesion and viability in non-small-cell lung cancer (NSCLC). EBA significantly inhibited the adhesion of NSCLC cells to fibronectin. EBA also markedly inhibited the activation of Src and its downstream targets, including FAK and Akt. The interaction between integrin β1 or integrin β3 and Src was inhibited by EBA treatment. A docking study revealed the bindings of EBA to the ATP-binding pocket and the allosteric regulatory site of the Src kinase. Additionally, EBA markedly inhibited the viability and the colony formation of NSCLC cells and induced apoptotic cell death. These results describe novel biological properties of EBA, which can block the Src-mediated adhesion and survival of NSCLC cells, suggesting the potential of EBA as an anticancer Src inhibitor that warrants further development in advanced preclinical and clinical settings.

Millepachine, a potential topoisomerase II inhibitor induces apoptosis via activation of NF-κB pathway in ovarian cancer

Millepachine (MIL) was a novel chalcone that was separated from Millettia pachycarpa Benth (Leguminosae). We found MIL induced apoptosis through activating NF-κB pathway both in SK-OV-3 and A2780S cells. Western blot showed that MIL increased the levels of IKKα, p-IKKα/β, p-IκBα and NF-κB (p65) proteins, and decreased the expression of IκBα protein. Immunohistochemistry analysis indicated that translocation of NF-κB into the nucleus increased in both ovarian cancer cells. EMSA assay proved MIL enhanced NF-κB DNA-binding activity in the nuclear. That specific NF-κB inhibitors alleviated MIL-induced apoptosis suggested NF-κB activation showed a pro-apoptotic function in SK-OV-3 and A2780S cells. Since NF-κB could be activated by double strand breaks and showed a pro-apoptotic function in the DNA damage response, SCGE assay and western blot revealed that MIL caused DNA strand breaks and significantly increased the level of p-ATM protein and further increased the levels of p-IKKα/β and NF-κB (p65) protein in SK-OV-3 and A2780S cells, while a specific ATM inhibitor could alleviated these effects. Moreover, Topoisomerase II drug screening kit and computer modeling assay were used to prove that MIL induced the production of linear DNA and inhibited the activity of topoisomerase II through binding with Topoisomerase II-Cleaved DNA complex to stabilize the complex. Taken together, our results identified that MIL exhibited anti-tumor activity through inhibiting topoisomerase II activity to induce tumor cells DNA damage, and MIL-activated NF-κB pathway showed a pro-apoptotic function in response to DNA damage.

Exploring the potential of newly synthesized 4-methyl-6-morpholino-pyrimidine derivatives as antiproliferative agents

A series of 4-methyl-6-morpholinopyrimidine derivatives were synthesised and found to prevent cancer cell proliferation by inducing apoptosis.

Ruthenium–arene complexes with NSAIDs: synthesis, characterization and bioactivity

Two non-steroidal antiinflammatory drugs indomethacin and mefenamic acid were coordinated to Ru(ii)–arenes to afford four new complexes.

Overexpression of lamin B1 induces mitotic catastrophe in colon cancer LoVo cells and is associated with worse clinical outcomes

Lamins are the major components of the nuclear lamina and play important roles in many cellular processes. The role of lamins in cancer development and progression is still unclear but it is known that reduced expression of lamin B1 has been observed in colon cancer. Thus, the aim of the present study was to elucidate the influence of LMNB1 upregulation on colon cancer cell line after treatment with 5-FU. The results indicate, that overexpression of LMNB1 induced dose-dependent cell death mainly by mitotic catastrophe pathway. Furthermore, after upregulation of this intermediate protein, lower expression of lamin A/C was observed. Moreover, we observed an increase in fluorescence intensity of nuclear β-catenin and decrease in cell-cell interaction area, that was connected with inhibition of colon cancer cells migration. We present the reorganization of actin filament and β-tubulin, because these cytoskeletal proteins are directly or indirectly linked with lamins, and analyzing publicly available mRNA data we show that patients with overexpression of LMNB1 are characterized by lower survival rates within the first 30 months from diagnosis. Summarizing our results, upregulation of LMNB1 induce mitotic catastrophe and only small percentage of apoptosis. Moreover, we showed inhibition of cell migration and promotion of cell-cell contact as a results of direct and indirect regulation of β-catenin, lamin A/C, actin and tubulin. However, it is possible that mitotic catastrophe cells in patients with colorectal cancer may be a reservoir of the cells responsible for faster disease progression, and further investigations are necessary to confirm this hypothesis.

Phenotypic and genotypic characterization of antioxidant enzyme system in human population exposed to radiation from mobile towers

In the present era, cellular phones have changed the life style of human beings completely and have become an essential part of their lives. The number of cell phones and cell towers are increasing in spite of their disadvantages. These cell towers transmit radiation continuously without any interruption, so people living within 100s of meters from the tower receive 10,000 to 10,000,000 times stronger signal than required for mobile communication. In the present study, we have examined superoxide dismutase (SOD) enzyme activity, catalase (CAT) enzyme activity, lipid peroxidation assay, and effect of functional polymorphism of SOD and CAT antioxidant genes against mobile tower-induced oxidative stress in human population. From our results, we have found a significantly lower mean value of manganese superoxide dismutase (MnSOD) enzyme activity, catalase (CAT) enzyme activity, and a high value of lipid peroxidation assay in exposed as compared to control subjects. Polymorphisms in antioxidant MnSOD and CAT genes significantly contributed to its phenotype. In the current study, a significant association of genetic polymorphism of antioxidant genes with genetic damage has been observed in human population exposed to radiations emitted from mobile towers.

Loss of p27kip1 increases genomic instability and induces radio-resistance in luminal breast cancer cells

Genomic instability represents a typical feature of aggressive cancers. Normal cells have evolved intricate responses to preserve genomic integrity in response to stress, such as DNA damage induced by γ-irradiation. Cyclin-dependent kinases (CDKs) take crucial part to these safeguard mechanisms, but involvement of CDK-inhibitors, such as p27^Kip1, is less clear. We generated immortalized fibroblasts from p27^kip1 knock-out (KO) mouse embryos and re-expressed p27^kip1 WT, or its mutant forms, to identify the function of different domains. We γ-irradiated fibroblasts and observed that loss of p27^Kip1 was associated to accumulation of residual DNA damage, increased number of mitotic aberration and, eventually, to survival advantage. Nuclear localization and cyclin/CDK-binding of p27^Kip1 were critical to mediate proper response to DNA damage. In human luminal breast cancer (LBC) p27^kip1 is frequently down-modulated and CDKN1B, p27^Kip1 gene, sporadically mutated. We recapitulated results obtained in mouse fibroblasts in a LBC cell line genetically manipulated to be KO for CDKN1B gene. Following γ-irradiation, we confirmed that p27^kip1 expression was necessary to preserve genomic integrity and to recognize and clear-out aberrant cells. Our study provides important insights into mechanisms underlying radio-resistance and unveils the possibility for novel treatment options exploiting DNA repair defects in LBC.

Interlaboratory evaluation of a multiplexed high information content in vitro genotoxicity assay

We previously described a multiplexed in vitro genotoxicity assay based on flow cytometric analysis of detergent-liberated nuclei that are simultaneously stained with propidium iodide and labeled with fluorescent antibodies against p53, γH2AX, and phospho-histone H3. Inclusion of a known number of microspheres provides absolute nuclei counts. The work described herein was undertaken to evaluate the interlaboratory transferability of this assay, commercially known as MultiFlow^® DNA Damage Kit-p53, γH2AX, Phospho-Histone H3. For these experiments, seven laboratories studied reference chemicals from a group of 84 representing clastogens, aneugens, and nongenotoxicants. TK6 cells were exposed to chemicals in 96-well plates over a range of concentrations for 24 hr. At 4 and 24 hr, cell aliquots were added to the MultiFlow reagent mix and following a brief incubation period flow cytometric analysis occurred, in most cases directly from a 96-well plate via a robotic walk-away data acquisition system. Multiplexed response data were evaluated using two analysis approaches, one based on global evaluation factors (i.e., cutoff values derived from all interlaboratory data), and a second based on multinomial logistic regression that considers multiple biomarkers simultaneously. Both data analysis strategies were devised to categorize chemicals as predominately exhibiting a clastogenic, aneugenic, or nongenotoxic mode of action (MoA). Based on the aggregate 231 experiments that were performed, assay sensitivity, specificity, and concordance in relation to a priori MoA grouping were ≥ 92%. These results are encouraging as they suggest that two distinct data analysis strategies can rapidly and reliably predict new chemicals' predominant genotoxic MoA based on data from an efficient and transferable multiplexed in vitro assay. Environ. Mol. Mutagen. 58:146-161, 2017. © 2017 Wiley Periodicals, Inc.

gamma-H2AX: Can it be established as a classical cancer prognostic factor?

Double-strand breaks are among the first procedures taking place in cancer formation and progression as a result of endogenic and exogenic factors. The histone variant H2AX undergoes phosphorylation at serine 139 due to double-strand breaks, and the gamma-H2AX is formatted as a result of genomic instability. The detection of gamma-H2AX can potentially serve as a biomarker for transformation of normal tissue to premalignant and consequently to malignant tissues. gamma-H2AX has already been investigated in a variety of cancer types, including breast, lung, colon, cervix, and ovary cancers. The prognostic value of gamma-H2AX is indicated in certain cancer types, such as breast or endometrial cancer, but further investigation is needed to establish gamma-H2AX as a prognostic marker. This review outlines the role of gamma-H2AX in cell cycle, and its formation as a result of DNA damage. We investigate the role of gamma-H2AX formation in several cancer types and its correlation with other prognostic factors, and we try to find out whether it fulfills the requirements for its establishment as a classical cancer prognostic factor.