Pretreatment with kuanxiong aerosol protects against coronary microvascular dysfunction / El pretratamiento con aerosol de kuanxiong protege contra la disfunción microvascular coronaria

This study investigates the efficacy and mechanisms of Kuanxiong Aerosol (KXA) on coronary microvascular dysfunction (CMD) in rats. Thirty-two Sprague-Dawley rats were divided into control, model, KXA, and nicorandil groups, receiving respective treatments for three weeks. The CMD model was established byinjecting lauric acid into the left ventricle. Compared to the model group, the KXA group showed significant reductions in serum CK-MB, LDH, cTnI, ET-1, TNF-α, IL-6, MDA, and ROS (p<0.01) and increased NO and SOD levels (p<0.01). KXA mitigated apoptosis and ameliorated CMD-associated pathological alterations. Pretreatment with KXA improves endothelial function and microvascular structure by counteracting inflammation, oxidative stress, and apoptosis, thereby improving CMD.

Este estudio investiga la eficacia y los mecanismos del Aerosol de Kuanxiong (KXA) sobre la disfunción microvascular coronaria (CMD) en ratas. Treinta y dos ratas Sprague-Dawley se dividieron en grupos de control, modelo, KXA y nicorandil, recibiendo los respectivos tratamientos durante tres semanas. El modelo de CMD se estableció inyectando ácido láurico en el ventrículo izquierdo. En comparación con el grupo modelo, el grupo KXA mostró reducciones significativas en los niveles séricos de CK-MB, LDH, cTnI, ET-1, TNF-α, IL-6, MDA y ROS (p<0.01) y un aumento en los niveles de NO y SOD (p<0.01). KXA mitigó la apoptosis y mejoró las alteraciones patológicas asociadas con la CMD. El pretratamiento con KXA mejora la función endotelial y la estructura microvascular al contrarrestar la inflamación, el estrés oxidativo y la apoptosis, mejorando así la CMD.

Neuroprotective Effect of Curcumin-Metavanadate in the Hippocampus of Aged Rats.

Brain aging is a multifactorial process that includes a reduction in the biological and metabolic activity of individuals. Oxidative stress and inflammatory processes are characteristic of brain aging. Given the current problems, the need arises to implement new therapeutic approaches. Polyoxidovanadates (POV), as well as curcumin, have stood out for their participation in a variety of biological activities. This work aimed to evaluate the coupling of metavanadate and curcumin (Cuma-MV) on learning, memory, redox balance, neuroinflammation, and cell death in the hippocampal region (CA1 and CA3) and dentate gyrus (DG) of aged rats. Rats 18 months old were administered a daily dose of curcumin (Cuma), sodium metavanadate (MV), or Cuma-MV for two months. The results demonstrated that administration of Cuma-MV for 60 days in aged rats improved short- and long-term recognition memory, decreased reactive oxygen species, and substantially improved lipoperoxidation in the hippocampus. Furthermore, the activity of superoxide dismutase and catalase increased in animals treated with Cuma-MV. It is important to highlight that the treatment with Cuma-MV exhibited a significantly greater effect than the treatments with MV or Cuma in all the parameters evaluated. Finally, we conclude that Cuma-MV represents a potential therapeutic option in the prevention and treatment of cognitive decline associated with aging.

The role of tetrahydroxyquinone solubility on apoptosis induction in human colorectal cells.

Tetrahydroxy-1,4-benzoquinone (THQ) is a highly redox-active substance that generates reactive oxygen species (ROS), which can induce apoptosis in cell culture experiments. The underlying mechanism for ROS production has previously been postulated to be the autoxidation of THQ to rhodizonic acid (RhA). However, our results suggest that the cells detoxify THQ by reducing it to hexahydroxybenzene (HHB), catalyzed by the NADPH-quinone-oxidoreductase (NQO1). Then, HHB undergoes autoxidation back to THQ, closing a redox cycle that continuously generates ROS. Only this continuous mechanism produces enough ROS to trigger apoptosis. The cell's protective measures can effectively eliminate the ROS generated by a single autoxidation of THQ to RhA because RhA is not reduced back to THQ and thus does not close a redox cycle. This also explains why only fresh THQ solutions are cytotoxic, whereas older THQ solutions, which are readily autoxidized to RhA, are not.

A novel naphthylchalcone ([E]-4-(3-[naphthalen-2-yl]-3-oxoprop-1-en-1-yl) induces intrinsic and extrinsic apoptosis in human acute leukemia cell lines.

BACKGROUND: Chalcones have been described in the literature as promising antineoplastic compounds. OBJECTIVES: Therefore, the objective of this study was to analyze the cytotoxic effect of 23 synthetic chalcones on human acute leukemia (AL) cell lines (Jurkat and K562). METHODS: Cytotoxicity assessment was performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Cell death was evaluated using fluorescence microscopy, the DNA fragmentation technique, and the assessment of proteins involved in apoptosis by flow cytometry. RESULTS: The most cytotoxic chalcone (R32) showed no cytotoxicity towards peripheral blood mononuclear cells (PBMC). It exhibited no hemolytic activity, did not alter platelet aggregation after adenosine diphosphate (ADP) and epinephrine stimulation, and did not affect blood coagulation as measured by prothrombin time (PT) and activated partial thromboplastin time (APTT). R32 demonstrated cytotoxic activity by inducing both intrinsic and extrinsic apoptosis, leading to caspase-3 activation and DNA fragmentation. In Jurkat and K562 cells, intrinsic apoptosis was associated with changes in mitochondrial membrane potential (MMP). There was a decreased expression of Bcl-2, increased expression of Bax, decreased expression of survivin, and increased expression of apoptosis-inducing factor (AIF). Extrinsic apoptosis involvement was also observed in both cell lines, characterized by increased expression of the Fas receptor. Additionally, Jurkat cells exhibited decreased expression of the KI-67 cell proliferation marker. CONCLUSION: These findings suggest R32 as a potential compound for the development of novel drugs for the treatment of AL.

Intestinal pathology in goats challenged with Clostridium perfringens type D strain CN1020 wild-type and its genetically modified derivatives.

Clostridium perfringens type D is the causative agent of enterotoxemia in sheep, goats, and cattle. Although in sheep and cattle, the disease is mainly characterized by neurological clinical signs and lesions, goats with type D enterotoxemia frequently have alterations of the alimentary system. Epsilon toxin (ETX) is the main virulence factor of C. perfringens type D, although the role of ETX in intestinal lesions in goats with type D enterotoxemia has not been fully characterized. We evaluated the contribution of ETX to C. perfringens type D enteric pathogenicity using an intraduodenal challenge model in young goats, with the virulent C. perfringens type D wild-type strain CN1020; its isogenic etx null mutant; an etx-complemented strain; and sterile, non-toxic culture medium. The intestinal tract of each animal was evaluated grossly, microscopically, and immunohistochemically for activated caspase-3. Both ETX-producing strains induced extensive enterocolitis characterized by severe mucosal necrosis, apoptosis, and diffuse suppurative infiltrates. No significant gross or microscopic lesions were observed in goats inoculated with the non-ETX-containing inocula. These results confirm that ETX is essential for the production of intestinal lesions in goats with type D disease. Also, our results suggest that the intestinal pathology of type D enterotoxemia in goats is, at least in part, associated with apoptosis.

Essential Oil Extracted from Lippia sidoides Cham. (Verbenaceae) Induces Cell Cycle Arrest, Apoptosis, and Antimigratory Effects in Melanoma Cells.

Melanoma, the most aggressive form of skin cancer, poses a substantial global health threat with increasing incidence rates. Although novel targeted therapies have improved melanoma treatment, challenges persist due to poor response rates and drug resistance. Plant-derived compounds have been crucial in anticancer drug discovery, with many natural products demonstrating the ability to target molecular pathways involved in tumor development. In this study, the anti-melanoma potential of essential oil extracted from the aerial parts of Lippia sidoides Cham. (EO-LS), composed mainly by the monoterpene thymol (96 %), was demonstrated. Obtained results demonstrated that EO-LS disrupted critical cancer hallmarks in A2058 melanoma cells harboring the BRAFV600E mutation. Specifically, EO-LS induced G1-phase cell cycle arrest and apoptosis, as assessed by annexin-V, caspase-3 activity, and TUNEL assays. EO-LS also inhibited cell migration and disrupted the AKT signaling pathway, which is a critical regulator of melanoma progression. Furthermore, a dose-dependent increase in reactive oxygen species (ROS) generation was observed, indicating pro-oxidant properties. These findings highlighted the significant in vitro anticancer properties of EO-LS suggesting its potential as a promising molecular scaffold for developing of novel anti-melanoma candidates.

Exposure to Pyriproxyfen Impacts Heart Development Causing Tissue and Cellular Impairments, Heart Arrhythmia and Reduced Embryonic Growth.

In recent years, concerns have been raised regarding the safety of exposure to pyriproxyfen (PPF), a larvicide commonly used in drinking water reservoirs to control populations of disease-vector mosquitoes for human safety. These concerns are focused mainly on exposure by pregnant women, since studies have shown deleterious effects of PPF on embryonic development, mainly addressing the central nervous system. However, since previous studies showed reduced growth in embryos exposed to PPF, we hypothesize that PPF exposure impairs the cardiovascular system, responsible for ensuring appropriate blood supply, which leads to stunted growth. This study aimed to investigate the impact of PPF exposure on heart ventricular morphology, its influence on cell proliferation and apoptosis, as well as assess the impact on the functionality of the heart and on embryonic growth. Chicken embryos were used as a model and two sublethal concentrations were tested: 0.01 mg/L and 10 mg/L PPF. Thinning of cardiac tissue was evident in heart structures at 10 mg/L PPF. Furthermore, DNA double-strand breaks and reduced cell proliferation were observed, combined with decreased apoptosis suggesting cell cycle arrest, especially in the left ventricle for both concentrations. In addition, these PPF concentrations induced heart arrhythmia, although no changes in heart rate were observed. Embryos exposed to 0.01 mg/L showed reduced body and heart mass, crown-rump length, and thoracic perimeter, while head circumference was reduced in both exposed groups. Together, combining morphological, molecular, and physiological parameters, this study showed the cardiotoxic effects of PPF exposure and elucidated its impacts on embryonic growth.

The role of long non-coding RNA NORAD in digestive system tumors.

In recent years, it has been discovered that the expression of long non-coding RNAs is highly deregulated in several types of cancer and contributes to its progression and development. Recently, it has been described that in tumors of the digestive system, such as colorectal cancer, pancreatic cancer, and gastric cancer, DNA damage-activated lncRNA (NORAD) was frequently up-regulated. The purpose of this review is to elucidate the functions of NORAD in tumors of the digestive system, emphasizing its involvement in important cellular processes such as invasion, metastasis, proliferation, and apoptosis. NORAD acts as a ceRNA (competitive endogenous RNA) that sponges microRNAs and regulates the expression of target genes involved in tumorigenesis. Thus, the mechanisms underlying the effects of NORAD are complex and involve multiple signaling pathways. This review consolidates current knowledge on the role of NORAD in digestive cancers and highlights the need for further research to explore its potential as a therapeutic target. Understanding the intricate functions of NORAD could elucidate the way for innovative approaches to cancer treatment.

In silico, in vitro, and ex vivo analysis reveals miR-27a-3p and miR-155-5p as key microRNAs for glioblastoma progression: Insights into Th1 differentiation and apoptosis induction.

We explored key microRNAs (miRNAs) related to tumorigenesis and immune modulation in glioblastoma (GBM), employing in silico, in vitro, and ex vivo analysis along with an assessment of the cellular impacts resulting from miRNA inhibition. GBM and T cells miRNA expression profiles from public datasets were used to evaluate differentially expressed miRNAs (DEmiRNAs). Some DEmiRNAs were chosen for validation in GBM cell lines, primary cell cultures, and brain tumor patient samples, using RT-qPCR. Target genes and pathways were identified with bioinformatic analyses. In silico functional enrichment analysis revealed that miR-27a-3p and miR-155-5p modulate immune, metabolic, and GBM-related pathways. A172 cells were transfected with miRNA inhibitors and the effects on cellular processes and immunomodulation were analyzed by co-culture assays and flow cytometry. Upon validation, miR-27a-3p and miR-155-5p miRNAs expressions were consistently increased. Inhibiting these two miRNAs reduced cell viability, but only the inhibition of miR-27a-3p led to apoptosis. Co-culture assays showed an increase in Th1 cells along with elevated Th1/Treg and Th17/Treg ratios, and an increase in Th17 cells exclusively with miR-155-5p inhibition. Immune cells' gene expression modulation induced an antitumor profile, concomitant with an increase in the expression of apoptotic genes in cancer cells after co-culture. This study unveils potential targets for immune and tumor regulation, highlighting overexpressed miRNAs modulation as a novel therapeutic approach for GBM.

Gyosaponin ameliorates sevoflurane anesthesia-induced cognitive dysfunction and neuronal apoptosis in rats through modulation of the PI3K/AKT/mTOR pathway.

BACKGROUND: Sevoflurane (Sev) is an inhalational anesthetic for surgical procedures where it can trigger cognitive dysfunction and neuronal apoptosis. Gyosaponin (GpS) was studied for its effects on brain morphology and cognitive behaviors in Sev-anesthetized rats. METHODS: Male Sprague-Dawley rats were induced by 3 % Sev anesthesia, and 25 mg/kg and 100 mg/kg GpS were injected into the rats by tail vein. The in vitro model of Sev anesthesia was constructed by treating primary rat hippocampal neurons with 4.1 % Sev in the presence of GpS (5, 10, and 20 µM). The neuroprotective effects of GpS against Sev-induced cognitive deficits in rats were evaluated using the open field and Morris water maze tests. The apoptosis of hippocampal neurons was observed using HE staining and TUNEL assay. Apoptosis-related proteins and proteins related to the PI3K/Akt/mTOR pathway were determined via Western blot. Also, pro-inflammatory factors were measured via ELISA. RESULTS: GpS diminished the Sev-triggered apoptosis in neurons and Cleaved caspase-3, BAX, TNF-α, IL-6, lessened oxidative stress damage, and stimulated the PI3K/Akt/mTOR pathway. GpS therapy markedly enhanced learning and memory abilities in rats suffering from Sev-related cognitive impairments. CONCLUSION: GpS ameliorates Sev-induced neurotoxicity and cognitive dysfunction by modulating the PI3K/Akt/mTOR pathway and alleviating neuronal apoptosis and oxidative stress.

Parkinson's disease models and death signaling: what do we know until now?

Parkinson's disease (PD) is the second neurodegenerative disorder most prevalent in the world, characterized by the loss of dopaminergic neurons in the Substantia Nigra (SN). It is well known for its motor and non-motor symptoms including bradykinesia, resting tremor, psychiatric, cardiorespiratory, and other dysfunctions. Pathological apoptosis contributes to a wide variety of diseases including PD. Various insults and/or cellular phenotypes have been shown to trigger distinct signaling events leading to cell death in neurons affected by PD. The intrinsic or mitochondrial pathway, inflammatory or oxidative stress-induced extrinsic pathways are the main events associated with apoptosis in PD-related neuronal loss. Although SN is the main brain area studied so far, other brain nuclei are also affected by the disease leading to non-classical motor symptoms as well as non-motor symptoms. Among these, the respiratory symptoms are often overlooked, yet they can cause discomfort and may contribute to patients shortened lifespan after disease diagnosis. While animal and in vitro models are frequently used to investigate the mechanisms involved in the pathogenesis of PD in both the SN and other brain regions, these models provide only a limited understanding of the disease's actual progression. This review offers a comprehensive overview of some of the most studied forms of cell death, including recent research on potential treatment targets for these pathways. It highlights key findings and milestones in the field, shedding light on the potential role of understanding cell death in the prevention and treatment of the PD. Therefore, unraveling the connection between these pathways and the notable pathological mechanisms observed during PD progression could enhance our comprehension of the disease's origin and provide valuable insights into potential molecular targets for the developing therapeutic interventions.

Cytotoxic effects of ivermectin on Giardia lamblia: induction of apoptosis and cell cycle arrest.

Introduction: Giardia lamblia is a flagellated protozoan parasite causing giardiasis, a common intestinal infection characterized by diarrhea, abdominal cramps, and nausea. Treatments employed to combat this parasitic infection have remained unchanged for the past 40 years, leading to the emergence of resistant strains and prompting the search for new therapeutic agents. Methods: This study investigated the cytotoxic effects of ivermectin (IVM) on G. lamblia trophozoites. We conducted dose-response experiments to assess IVM-induced cytotoxicity. We utilized various biochemical and ultrastructural analyses to explore the underlying mechanisms of cell death, including reactive oxygen species (ROS) production, DNA fragmentation, cell cycle arrest, and apoptosis markers. Results: Our findings demonstrate that IVM induces dose-dependent cytotoxicity and triggers cell death pathways. We found that IVM treatment generates elevated levels of reactive oxygen species (ROS), DNA fragmentation, and arrests of trophozoites in the cell cycle's S phase. Additionally, ultrastructural analysis reveals morphological alterations consistent with apoptosis, such as cytoplasmic vacuolization, chromatin condensation, and tubulin distribution. Discussion: The insights gained from this study may contribute to developing new therapeutic strategies against giardiasis, addressing the challenge posed by drug-resistant strains.

Withanolide derivatives: natural compounds with anticancer potential offer low toxicity to fertility and ovarian follicles in mice.

Anticancer therapy often leads to premature ovarian insufficiency (POI) and infertility due to the extreme sensitivity of the ovarian follicle reserve to the effects of chemotherapy. Withanolides are known for their cytotoxic effect on cancer cells and low cytotoxicity on non-malignant or healthy cells. Therefore, this study aimed to investigate the in vivo effects of three withanolides derivatives: 27-dehydroxy-24,25-epoxywithaferin A (WT1), 27-dehydroxywithaferin A (WT2), and withaferin A (WTA) on fertility, and the ovarian preantral follicles of young female mice. To achieve this, mice received 7 intraperitoneal doses of WT1, WT2, or WTA at a concentration of 2 mg/kg (Experiment I) and 5 or 10 mg/kg (Experiment II) over 15 alternate days. In experiment I, two days after administration of the last dose, half of the mice were mated to evaluate the effects of withanolides on fertility. The other half of the mice, as well as all mice from experiment II, were sacrificed for histological, inflammation, senescence, and immunohistochemical analyses of the follicles present in the ovary. Regardless of the administered withanolide, the concentration of 2 mg/kg did not show toxicity on the follicular morphology, ovarian function, or fertility of the mice. However, at concentrations of 5 and 10 mg/kg, the three derivatives (WT1, WT2, and WTA) increased follicular activation, cell proliferation, and ovarian senescence without affecting inflammatory cells. Furthermore, at a concentration of 10 mg/kg, the three withanolides showed intensified toxic effects, leading to DNA damage as evidenced by the labeling of γH2AX, activated Caspase 3, and TUNEL. We conclude that the cytotoxic effect of the tested withanolide derivatives (WT1, WT2, and WTA) in the concentration of 2 mg/kg did not show toxicity on the ovary. However, in higher concentrations, such as 10 mg/kg, toxic effects are potentiated, causing DNA damage.

Pharmacological Preconditioning with Fenofibrate in Cardiomyocyte Cultures of Neonatal Rats Subjected to Hypoxia/Reoxygenation, High Glucose, and Their Combination.

Pharmacological preconditioning is an alternative to protect the heart against the consequences of damage from ischemia/reperfusion (I/R). It is based on the administration of specific drugs that imitate the effect of ischemic preconditioning (IPC). Peroxisomal proliferator-activated receptors (PPARs) can prevent apoptosis in pathologies such as I/R and heart failure. Therefore, our objective was to determine if the stimulation of PPARα with fenofibrate (feno) decreases the apoptotic process induced by hypoxia/reoxygenation (HR), high glucose (HG), and HR/HG. For that purpose, cardiomyocyte cultures were divided into the following groups: Group 1-control (Ctrl); Group 2-HR; Group 3-HR + 10 µM feno; Group 4-HG, (25 mM glucose); Group 5-HG + feno; Group 6-HR/HG, and Group 7-HR/HG + feno. Our results indicate that cell viability decreases in neonatal cardiomyocytes undergoing HR, HG, and their combination, while feno improved cell viability. Feno treatment decreased apoptosis compared with HG-, HR-, or HG/HR-vehicle-treated. Nuclear- and mitochondrial-apoptosis markers increased in neonatal cardiomyocytes from HR, HG, and HR/HG; while the cytotoxicity decreased in cells treated with feno. In addition, the expression of Bax, Bad, and caspase 9 decreased due to feno, while 14-3-3ɛ and Bcl2 were increased. Inner mitochondrial cytochrome C increased with feno in every condition, as well as mitochondrial activity. Feno treatment prevented injury in the ultrastructure and in the mitochondrial membranes. Thus, our results suggest that feno decreases apoptosis in neonatal cardiomyocytes, improving the ultrastructure of mitochondria in the pathological conditions studied.

New Dichalcogenides Induce Oxidative Stress and Cell Death of Leishmania amazonensis.

Leishmaniasis are caused by protozoa of the genus Leishmania and affect millions of people worldwide. They are considered neglected diseases that primarily impact individuals in tropical and subtropical regions. The drugs currently available for treating this infection have limitations, such as high toxicity, adverse reactions, and a long therapeutic intervention period. Numerous studies, using various experimental models, have sought to develop more effective and less toxic chemotherapeutic agents against these protozoa. In this context, the present study aimed to evaluate the antileishmanial activity of two new dichalcogenides, LQ64 and LQ62, as well as their possible mechanism of action in promastigote forms of Leishmania amazonensis. Both substances, LQ64 and LQ62, exhibited activity against promastigote (IC50 = 2.35 and 12.59 µM, respectively), and amastigote forms (IC50 = 3.50 and 6.58 µM, respectively). Furthermore, the substances revealed selectivity for the parasite when analyzing their cytotoxicity in J774A-1 macrophages. Moreover, electron microscopy analysis and mechanisms of action assays investigated in promastigote forms with both substances showed mitochondrial depolarization. This phenomenon possibly promoted changes in intracellular ATP levels, resulting in increased reactive species and lipid peroxidation, leading the parasites to oxidative stress. Additionally, the treatments induced changes in plasma membrane integrity, lipid body accumulation, alterations in the cell cycle, and phosphatidylserine externalization. Thus, the results indicate that LQ64 and LQ62 may induce characteristic changes in the protozoan suggestive of apoptosis cell death.

Black Mulberry (Morus nigra L.): A Review of Attributes as an Anticancer Agent to Encourage Pharmaceutical Development.

Recent considerations of natural sources as potential anticancer agents have arisen due to the origins of numerous drugs commonly used in chemotherapy. Plant-based drugs, in particular, have attracted attention for offering the advantage of low adverse effects. Among these, the black mulberry plant (Morus nigra L.) stands out as a natural source of polyphenols, widely used to treat metabolic dysfunctions and confer benefits on human health. This study explores the potential of this plant as an anticancer agent, examining its effectiveness based on the type of application of the plant extracts or isolated substances, extraction methods, and its potential biological effects on cancer cells. Consequently, this study contributes to a better understanding of the distribution of phytochemicals in M. nigra and their applications in the context of cancer field. Among the compounds found in black mulberry are flavonoids, chlorogenic acid, cryptochlorogenic acid, and protocatechuic acid, along with cyanidin-3-O-glucoside as the main anthocyanin on the fruit. The phytochemicals derived from M. nigra exhibit antinociceptive and antimicrobial activities, while also showing protective effects, such as antioxidant properties that underline their potential as anticancer agents. The black mulberry's roots, stem bark, pulp, and leaves are particularly rich sources of anti-inflammatory compounds. Ethanol and methanol extraction methods appear to be the most effective in cancer management, offering compounds that facilitate the integration of apoptosis induction, cell growth inhibition, and cytotoxicity modulation. These results collectively represent the salient biological attributes that positioned black mulberry as a promising anticancer agent. Therefore, these findings highlight the multifaceted potential of M. nigra as an anticancer agent, making a compelling case for further research to advance prospects in the medical field.

BCL-2 and γ-H2AX immunostaining profile in urothelial bladder cancer prognosis.

Urothelial bladder carcinoma (UBC) is a malignant neoplasm of the urinary tract that is highly prevalent worldwide and has a high rate of tumor recurrence. It is known that the BCL2 apoptosis regulator (BCL-2) gene encodes a mitochondrial protein that regulates programmed death cells by apoptosis. In contrast, the H2A.X histone variant (H2AX) gene encodes a histone responsible for regulating and signaling genomic instability processes. The present study aimed to analyze the immunostaining profiles of BCL-2 and γ-H2AX proteins in tissue samples (n=80) from UBC patients (muscle-invasive MI; and non-muscle invasive NMI) using indirect immunohistochemistry and to correlate the results with prognostic and clinical parameters. BCL-2 protein expression was cytoplasmic and absent in half of the samples, including the MI and NMI groups. Strong nuclear expression was observed for γ-H2AX, predominant in the MI samples. The immunostaining profile of both proteins was not associated with tumor recurrence or invasion, and no significant associations were found in relation to prognosis (tumor grade, pathological staging). No significant correlation was found between protein profiles in malignant tissue. All in all, BCL-2 and γ-H2AX did not prove to be candidate markers for UBC clinical management in the present sample, despite their expression in malignant bladder tissue.

High molecular weight polycyclic aromatic hydrocarbon (HMW-PAH) isomers: unveiling distinct toxic effects from cytotoxicity to oxidative stress-induced DNA damage.

Polycyclic aromatic hydrocarbons (PAHs) represent one of the most extensive classes of known carcinogenic and genotoxic compounds widely distributed across the globe. Particularly relevant to ecotoxicological studies is the possible presence of PAHs with molecular weight (MW) 302 Da. Since the toxicity of 302 Da PAHs differs significantly from isomer to isomer, understanding their relative toxicity is essential for assessing their potential risks to human health. This study investigates the toxic effects of micromolar concentrations of four HMW-PAHs isomers of MW = 302 Da, namely dibenzo(b,l)fluoranthene (DB(b,l)F), dibenzo(a,j)fluoranthene (DB(a,j)F), dibenzo(a,l)fluoranthene (DB(a,l)F) and naphtho(1-2j)fluoranthene (N(1-2j)F), upon exposure and metabolic activation in HepG2 cells. Appropriate assays were selected to investigate their potential to disrupt cellular viability and to induce cytotoxicity, apoptosis/necrosis, genotoxicity, and oxidative stress with DNA damage. After 48 h of exposure time, DB(a,l)F was the only isomer to reduce cellular viability in a concentration-dependent manner. In all cases, apoptosis was the main mechanism of HepG2 cell death, which could be induced by the significant DNA damage and an increase in 8-hydroxy-2'-deoxyguanosine (8-OHdG) adduct level formation. The highest concentrations of DB(a,l)F tested exhibited the greatest potential to induce HepG2 DNA damage and 8-OHdG formation. Altogether, these facts demonstrate that the distinct arrangements of the atoms in HMW-PAHs isomers can impact on their toxic potential and that DB(a,l)F was the most toxic isomer evaluated in this study. These results shed light on the importance to thoroughly characterize MW302 PAHs to substantiate their human and environmental risk assessments.

Cytotoxic properties of Thuya occidentalis hydroalcoholic extract on androgen unresponsive prostate cancer cells.

Background: Androgen independent phase in prostate cancer (PCa) commonly limits the therapeutic efficacy. Thuya occidentalis through its main active compound, α-thujone, appears to be an option, considering its anti-proliferative, anti-metastatic and pro-apoptotic effects on hepatocellular carcinoma. However, studies on PCa are limited.Objective: To evaluate if T. occidentalis could be useful against androgen responsive and unresponsive PCa cells.Methods: Androgen responsive (LNCaP) and unresponsive (DU145 and PC3) cell lines were exposed to T. occidentalis hydroalcoholic extract (0.05 mL/mL) for different periods. Further, α-thujone was measured in the extract and tested in the cell lines.Results: T. occidentalis and α-thujone showed the highest cytotoxicity on LNCaP cells. In androgen unresponsive cells, T. occidentalis decreased cell viability and density, and promoted apoptosis, necrosis and cell cycle arrest, possibly associated with Cav-1 downregulation. The α-thujone present in the extract significantly LNCaP cells density, but did not affect DU145 and PC3 cells, suggesting that other compounds may also be cytotoxic to androgen unresponsive cells.

The protumorigenic enzyme GPAT2 inhibits arachidonic acid-triggered apoptosis in breast cancer.

BACKGROUND: Cancer is a significant health challenge and the leading cause of mortality globally. Tumor cells use multiple mechanisms to acquire their distinctive capacity for uncontrolled proliferation, one of which is the evasion of apoptosis. It has been shown that in breast, colon, and liver cancer, evasion of apoptosis is associated with the overexpression of enzymes that metabolize arachidonic acid (AA) because free AA is a strong inducer of apoptosis. Glycerol-3-phosphate acyltransferase 2 (GPAT2) is a key enzyme in AA metabolism and is highly expressed in breast and colon cancer, where it promotes the development of essential tumor features. METHODS: In this work, a model of GPAT2 silencing in the human breast cancer-derived cell line MDA-MB-231 was used, and the cells were exposed to exogenous AA. The role of GPAT2 in AA-induced cell death was studied using MTT and TUNEL assays and measurements of caspase activity. The underlying molecular mechanism of cell death was assessed by qRT‒PCR. RESULTS: The results showed that AA reduced cell viability only in GPAT2-silenced cells, and that this cell death was a consequence of an apoptotic process involving BNIP3 overexpression. Additionally, it was demonstrated that GPAT2 silencing triggered a compensatory mechanism by overexpressing other genes involved in AA utilization for eicosanoid biosynthesis. CONCLUSIONS: We concluded that GPAT2 expression is necessary to prevent AA-induced apoptotic cell death in MDA-MB-231 cells and that the overexpression of other AA-metabolizing genes is not sufficient to compensate for the lack of GPAT2 and prevent apoptosis.