Cyclin-dependent Kinase Research Articles

Methylation of KSHV vCyclin by PRMT5 contributes to cell cycle progression and cell proliferation.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a double-stranded DNA virus that encodes numerous cellular homologs, including cyclin D, G protein-coupled protein, interleukin-6, and macrophage inflammatory proteins 1 and 2. KSHV vCyclin encoded by ORF72, is the homolog of cellular cyclinD2. KSHV vCyclin can regulate virus replication and cell proliferation by constitutively activating cellular cyclin-dependent kinase 6 (CDK6). However, the regulatory mechanism of KSHV vCyclin has not been fully elucidated. In the present study, we identified a host protein named protein arginine methyltransferase 5 (PRMT5) that interacts with KSHV vCyclin. We further demonstrated that PRMT5 is upregulated by latency-associated nuclear antigen (LANA) through transcriptional activation. Remarkably, knockdown or pharmaceutical inhibition (using EPZ015666) of PRMT5 inhibited the cell cycle progression and cell proliferation of KSHV latently infected tumor cells. Mechanistically, PRMT5 methylates vCyclin symmetrically at arginine 128 and stabilizes vCyclin in a methyltransferase activity-dependent manner. We also show that the methylation of vCyclin by PRMT5 positively regulates the phosphorylate retinoblastoma protein (pRB) pathway. Taken together, our findings reveal an important regulatory effect of PRMT5 on vCyclin that facilitates cell cycle progression and proliferation, which provides a potential therapeutic target for KSHV-associated malignancies.

MOF-mediated acetylation of CDK9 promotes global transcription by modulating P-TEFb complex formation.

Cyclin-dependent kinase 9 (CDK9), a catalytic subunit of the positive transcription elongation factor b (P-TEFb) complex, is a global transcriptional elongation factor associated with cell proliferation. CDK9 activity is regulated by certain histone acetyltransferases, such as p300, GCN5 and P/CAF. However, the impact of males absent on the first (MOF) (also known as KAT8 or MYST1) on CDK9 activity has not been reported. Therefore, the present study aimed to elucidate the regulatory role of MOF on CDK9. We present evidence from systematic biochemical assays and molecular biology approaches arguing that MOF interacts with and acetylates CDK9 at the lysine 35 (i.e. K35) site, and that this acetyl-group can be removed by histone deacetylase HDAC1. Notably, MOF-mediated acetylation of CDK9 at K35 promotes the formation of the P-TEFb complex through stabilizing CDK9 protein and enhancing its association with cyclin T1, which further increases RNA polymerase II serine 2 residues levels and global transcription. Our study reveals for the first time that MOF promotes global transcription by acetylating CDK9, providing a new strategy for exploring the comprehensive mechanism of the MOF-CDK9 axis in cellular processes.

New treatment strategy for early hormone receptor-positive HER2-negative breast cancer: updated results of adjuvant abemaciclib trial in operable and locally advanced breast cancer

Abemaciclib is an oral inhibitor 4 and 6 (CDK4/6). Abemaciclib differs from other drugs in this group in suppression spectrum of cyclin-dependent kinases and is proven to improve survival rates in different treatment lines of metastatic breast cancer. In randomized clinical trials 3rd phase in patients with early hormone-dependent HR+ HER2 negative breast cancer high risk of progression abemaciclib in conjunction with hormone therapy significantly improves invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS). Long- term outcome studies monarchE with 5 – year follow – up of patients showed that abemaciclib adding to ET increases 5-year IDFS from 76 to 83.6% (HR0.680; 95% CI 0.599 to 0.772; p <0.001) and 5-year DRFS from 79.2% to 86.0% (HR0.675; 95% CI 0.588 to 0.774; p <0.001). Adverse events of 3rd degree and higher are registrated in 45.5% of patients in abemaciclib group and in 12,7% in control group and mainly presented by neutropenia (18.6 and 0.7%) and diarrhea (7,6 and 0.1%). Toxicity profile was expected and controlled. The reasonable dose reduction of abemaciclib did not lead to deterioration of long-term treatment result.

First voltammetric studies, spectrophotometric and molecular docking investigations of the interaction of an anticancer drug ribociclib-DNA and analytical applications of disposable pencil graphite sensor

Ribociclib (RIB) is a cyclin-dependent kinase inhibitor used in the treatment of breast cancer. In this study, for the first time, the electrochemical behavior, quantification and interaction of RIB with DNA were carried out using voltammetric, spectrophotometric and molecular docking techniques. An environmentally-friendly disposable pencil graphite electrode (PGE) sensor was used as the working electrode. Utilizing the cyclic voltammetry technique, RIB produced an irreversible anodic wave around +0.837 V and reversible signals around +0.278 V/+0.209 V on the PGE surface. Using the PGE sensor, the RIB compound gave a very distinct anodic signal at a potential of +0.77 V in PBS (pH 3.0). For this analytical signal, the limit of detection and limit of quantitation values of RIB in the concentration range of 0.0139 3 M–0.0973 3 M in PBS (pH 3.0) were determined as 2.84 nM and 9.46 nM, respectively. The interaction of RIB with DNA was studied by voltammetric, spectrophotometric and molecular docking techniques. In the evaluation of the results obtained with all three techniques, the interaction of the RIB molecule with DNA was determined to occur through minor groove binding.

Impact of CDKN2A gene expression on colon adenocarcinoma via biosignature analysis.

Colorectal adenocarcinoma (COAD) has a poor prognosis. Cyclin-dependent kinase inhibitor 2A (CDKN2A) significantly affects the development and progression of various human tumors. However, the significance and pathological mechanisms of CDKN2A in COAD remain to be elucidated. We assessed expression levels, clinical significance, biological function, co-expressed genes, and enrichment of related pathways of CDKN2A in COAD using various databases, including The University of Alabama at Birmingham Cancer Data Analysis Portal, Gene Expression Profiling Interactive Analysis, Tumor Immune Estimation Resource, Human Protein Atlas, STRING, GeneMANIA, cBioPortal, and Linked Omics. Our investigation showed that CDKN2A was highly expressed in colon adenocarcinomas (P < .001). It is weakly expressed or not expressed in normal tissues. The survival time of patients with colon adenocarcinoma with high CDKN2A expression is significantly shorter than that of patients with low expression levels (P = .011). There was a significant positive correlation between the expression level of CDKN2A in colon adenocarcinoma tissues and the infiltration of CD4+ T cells, macrophages, and neutrophils. Moreover, there was a significant negative association between the expression level of CDKN2A in colon adenocarcinoma tissues and B cell infiltration. The ten hub genes included tumor protein 53, V-myc Avian Myelocytomatosis Viral Oncogene Homolog, AKT serine/threonine kinase 1, cyclin-dependent kinase 2, phosphatase and tensin homolog deleted on chromosome ten, cyclin D1, cyclin dependent kinase 4, cyclin dependent kinase inhibitor 1A, catenin beta 1, and B-Raf proto-oncogene, serine/threonine kinase. Mutations in the CDKN2A genome in colon adenocarcinoma reduce survival. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that the differentially expressed genes were enriched in apoptotic signaling pathways and multiple pathways related to metabolic progression. Our results indicate that CDKN2A can be used as a marker of poor prognosis in patients with colon adenocarcinoma. CDKN2A may regulate the occurrence and development of colon adenocarcinomas by influencing immune cell infiltration and metabolic pathways.

Protein Kinase C-Delta Mediates Cell Cycle Reentry and Apoptosis Induced by Amyloid-Beta Peptide in Post-Mitotic Cortical Neurons.

Amyloid-beta peptide (Aβ) is a neurotoxic constituent of senile plaques in the brains of Alzheimer's disease (AD) patients. The detailed mechanisms by which protein kinase C-delta (PKCδ) contributes to Aβ toxicity is not yet entirely understood. Using fully differentiated primary rat cortical neurons, we found that inhibition of Aβ25-35-induced PKCδ increased cell viability with restoration of neuronal morphology. Using cyclin D1, proliferating cell nuclear antigen (PCNA), and histone H3 phosphorylated at Ser-10 (p-Histone H3) as the respective markers for the G1-, S-, and G2/M-phases, PKCδ inhibition mitigated cell cycle reentry (CCR) and subsequent caspase-3 cleavage induced by both Aβ25-35 and Aβ1-42 in the post-mitotic cortical neurons. Upstream of PKCδ, signal transducers and activators of transcription (STAT)-3 mediated PKCδ induction, CCR, and caspase-3 cleavage upon Aβ exposure. Downstream of PKCδ, aberrant neuronal CCR was triggered by overactivating cyclin-dependent kinase-5 (CDK5) via calpain2-dependent p35 cleavage into p25. Finally, PKCδ and CDK5 also contributed to Aβ25-35 induction of p53-upregulated modulator of apoptosis (PUMA) in cortical neurons. Together, we demonstrated that, in the post-mitotic neurons exposed to Aβs, STAT3-dependent PKCδ expression triggers calpain2-mediated p35 cleavage into p25 to overactivate CDK5, thus leading to aberrant CCR, PUMA induction, caspase-3 cleavage, and ultimately apoptosis.

Suppression of neuronal CDK9/p53/VDAC signaling provides bioenergetic support and improves post-stroke neuropsychiatric outcomes

Bioenergy decline occurs with reperfusion following acute ischemic stroke. However, the molecular mechanisms that limit energy metabolism and their impact on post-stroke cognitive and emotional complications are still unclear. In the present study, we demonstrate that the p53 transcriptional response is responsible for neuronal adenosine triphosphate (ATP) deficiency and progressively neuropsychiatric disturbances, involving the downregulation of mitochondrial voltage-dependent anion channels (VDACs). Neuronal p53 transactivated the promoter of microRNA-183 (miR-183) cluster, thereby upregulating biogenesis of miR-183-5p (miR-183), miR-96-5p (miR-96), and miR-182-5p. Both miR-183 and miR-96 directly targeted and post-transcriptionally suppressed VDACs. Neuronal ablation of p53 protected against ATP deficiency and neurological deficits, whereas post-stroke rescue of miR-183/VDAC signaling reversed these benefits. Interestingly, cyclin-dependent kinase 9 (CDK9) was found to be enriched in cortical neurons and upregulated the p53-induced transcription of the miR-183 cluster in neurons after ischemia. Post-treatment with the CDK9 inhibitor oroxylin A promoted neuronal ATP production mainly through suppressing the miR-183 cluster/VDAC axis, further improved long-term sensorimotor abilities and spatial memory, and alleviated depressive-like behaviors in mice following stroke. Our findings reveal an intrinsic CDK9/p53/VDAC pathway that drives neuronal bioenergy decline and underlies post-stroke cognitive impairment and depression, thus highlighting the therapeutic potential of oroxylin A for better outcomes.

The choice of optimal therapy for ER+ HER2-metastatic breast cancer (PROMETHEUS): all-Russian analysis of physicians’ preferences – updated survey results

Cyclin-dependent kinase 4/6 inhibitors (iCDK4/6) are the generally accepted standard of care for the treatment of luminal HER2-negative metastatic breast cancer (ER+HER2- mBC). Data from randomized and observational studies have proven the high effectiveness of the combination of iCDK4/6 and endocrine therapy (ET) both in the 1st and in subsequent lines. The use of new drugs in real clinical practice is determined by a number of factors, including the awareness of doctors, their personal experience and subjective preferences, as well as financial support and availability in a particular region. To assess the frequency of prescription of CDK4/6, as well as other types of treatment in the 1st‑2nd line of therapy for ER+ HER2- mBC in real clinical practice in Russia, as well as to determine the factors and preferences of doctors influencing their choice, the National Association of Oncomammologists (NAOM) conducted a survey “Prometheus” of oncology specialists. From February 15 to August 30, 2023, a web survey of healthcare professionals who treat patients with mBC was conducted on the website anketolog.ru. An invitation to survey was sent out through the NAOM database, 112 questionnaires were received and processed. Earlier, in 2020, the “Prometheus” survey was conducted on the territory of the Russian Federation for a similar purpose. In this paper, we present the results of an updated and expanded survey and evaluate changes that have occurred over the past 3 years in actual clinical practice. The results of a 2023 survey conducted in the Russian Federation on the choice of early-line therapy for ER+HER2- mBC showed that, compared with the 2020 survey, the level of “trust” in iCDK4/6 has increased among practicing physicians, and the indications for their use have expanded, including visceral metastases (and even pending visceral crisis), the indications for prescribing chemotherapy in the 1st line have narrowed. When using monoET in the 1st line, the majority of respondents prescribe iCDK4/6 in the 2nd line. Obviously, the wider use of iCDK4/6 is associated not only with the accumulation of clinical knowledge and experience in the use of drugs, but also with improved drug supply. However, the main limitations to the use of iCDK4/6 are still insufficient funding and organizational difficulties. However, it should be noted that 1/5 of the respondents do not face any restrictions and widely prescribe combination therapy.

Knockdown of Fzr inhibited the growth of Nilaparvata lugens by blocking endocycle.

The endocycle can generate cells referred to as 'polyploid'. Fizzy-related protein (Fzr) plays an important role in driving the mitosis-to-endocycle transition. The brown planthopper (BPH), Nilaparvata lugens (Stål), a serious insect pest, feeds exclusively on rice. However, polyploidy and its regulatory mechanisms are poorly understood in BPH. Here, we found that the ploidy levels of follicles H (FH) and accessory gland (AG) significantly increased with BPH age when examining the polyploidy of FH and AG of salivary glands. Fzr was identified as an important regulator for polyploidy in BPH salivary gland. Knockdown of Fzr resulted in a decrease in cell size and DNA content in nymph salivary glands. Fzr knockdown transcriptionally upregulated cyclin-dependent kinase 1 (CDK1), CDK2, cyclin A (CycA) and CycB, and downregulated CycD, CycE, Myc and mini-chromosome maintenance protein 2-7 (MCM2-7). Phenotypically, Fzr knockdown significantly suppressed salivary protein production, feeding and survival in BPH nymphs. Our results show that BPH salivary glands exhibit obvious polyploidy, and Fzr positively regulates the endocycle in nymph salivary gland. These findings provide clues for the study of the regulatory mechanisms of insect polyploidy. © 2024 Society of Chemical Industry.

Eslicarbazepine induces apoptosis and cell cycle arrest in C6 glioma cells in vitro and suppresses tumor growth in an intracranial rat model

BackgroundGlioblastoma multiforme (GBM) is the most malignant brain tumor, with a poor prognosis and life expectancy of 14–16 months after diagnosis. The standard treatment for GBM consists of surgery, radiotherapy, and chemotherapy with temozolomide. Most patients become resistant to treatment after some time, and the tumor recurs. Therefore, there is a need for new drugs to manage GBM. Eslicarbazepine (ESL) is a well-known antiepileptic drug belonging to the dibenzazepine group with anticancer potentials. In this study, for the first time, we evaluated the potential effects of ESL on C6 cell growth, both in vitro and in vivo, and examined its molecular effects.MethodsTo determine the effect of ESL on the c6 cell line, cell viability, proliferation, and migration were evaluated by MTT assay, colony formation, and wound healing assay. Also, apoptosis and cell cycle were examined by flow cytometry, qRT-PCR, and western blotting. In addition, an intracranial model in Wistar rats was used to investigate the effect of ESL in vivo, and the tumor size was measured using both Caliper and MRI.ResultsThe obtained results are extremely consistent and highly encouraging. C6 cell viability, proliferation, and migration were significantly suppressed in ESL-treated C6 cells (p < 0.001), as determined by cell-based assays. ESL treatment led to significant enhancement of apoptosis (p < 0.01), as determined by flow cytometry, and upregulation of genes involved in cell apoptosis, such as the Bax/Bcl2 ratio at RNA (p < 0.05) and protein levels (5.37-fold). Flow cytometric analysis of ESL-treated cells revealed G2/M phase cell cycle arrest. ESL-treated cells demonstrated 2.49-fold upregulation of p21 alongside, 0.22-fold downregulation of cyclin B1, and 0.34-fold downregulation of cyclin-dependent kinase-1 at the protein level. Administration of ESL (30 mg/kg) to male rats bearing C6 intracranial tumors also suppressed the tumor volume and weight (p < 0.01).ConclusionsBased on these novel findings, ESL has the potential for further experimental and clinical studies in glioblastoma.Graphical abstract

QTc prolongation across CDK4/6 inhibitors: a systematic review and meta-analysis of randomized controlled trials.

Cyclin-dependent kinases (CDK) 4/6 inhibitors have significantly improved outcomes for patients with ER+/HER2- breast cancer. Nevertheless, they differ from each other in terms of chemical, biological, and pharmacological features, as well as toxicity profiles. We aim to determine whether QTc prolongation is caused by CDK4/6i in general or if it is associated with ribociclib only. We systematically searched PubMed, Embase, and Cochrane Library for randomized controlled trials (RCTs) comparing the prevalence of QTc prolongation as an adverse event in HR+ breast cancer patients treated with CDK4/6i vs those without CDK4/6i. We pooled relative risk (RR) and mean difference (MD) with 95% confidence interval (CI) for the binary endpoint of QT prolongation. We included 14 RCTs comprising 16 196 patients, of whom 8576 underwent therapy with CDK4/6i. An increased risk of QTc prolongation was associated with the use of CDK4/6i (RR = 2.35, 95% CI = 1.67 to 3.29, P < .001; I2 = 44%). Subgroup analyses revealed a significant increase in the QTc interval for the ribociclib and palbociclib cohorts. The ribociclib subgroup showed a relative risk of 3.12 (95% CI = 2.09 to 4.65, P < .001; I2 = 12%), whereas the palbociclib subgroup had a relative risk of 1.51 (95% CI = 1.05 to 2.15, P = .025; I2 = 0%). Palbociclib was associated with QTc prolongation; however, the relative risk for any grade QTc was quantitively twice with ribociclib. Furthermore, grade 3 QTc prolongations were observed exclusively with ribociclib. These results are important for guiding clinical decision-making and provide reassurance regarding the overall safety profile of this drug class.

Myrtleciclib, a CDK4/6/9 Inhibitor for the Treatment of Aggressive Cancers.

Selective Cyclin-Dependent Kinase 4/6 inhibitors (CDK4/6i) have revolutionized the treatment of breast cancer and have potential in other cancers, being manageable drugs yet with some bone marrow toxicity. Selective CDK9 inhibitors (CDK9i) never advanced into clinical use, partly due to side effects, including gastrointestinal toxicity, and a small window between activity and cytotoxicity, which results in a narrow therapeutic index (TI). To overcome the drawbacks of CDK4/6 and CDK9 inhibitors, we have developed myrtleciclib, a selective CDK4/6/9 inhibitor with few non-critical molecular off-targets. Myrtleciclib appears to bind to an allosteric site, unlike all other CDK4/6i and CDK9i acting by an ATP-competitive mechanism, which supports target specificity. Myrtleciclib's anti-proliferative effects are greater and its Therapeutic Index (TI) is broader than CDK9 and CDK4/6-only inhibitors. This can be explained by a moderate target inhibition, resulting in limited cytotoxicity. Moreover, we documented a synergy between CDK9 and CDK4/6 pathways inhibition, justifying increased drug efficacy, yet such synergy can only be achieved when the inhibition of both CDK9 and CDK4/6 is embedded within the same molecule and balanced within a certain ratio, as it is the case with myrtleciclib. Unlike CDK4/6i, myrtleciclib also induces cell death and apoptosis selectively on cancer cell lines, not on bystander cells. Synergy between myrtleciclib and other drugs with complementary Mechanism of Action (MoA) has also been documented. CDK4/6/9i might represent a new frontier in cancer treatment to overcome the limitations of CDK4/6i and CDK9i for the treatment of cancers, including aggressive cancers with high unmet needs.

Mechanism of KLF2 in young mice with pneumonia induced by Streptococcus pneumoniae

BackgroundStreptococcus pneumoniae (Spn) is a major causative agent of pneumonia, which can disseminate to the bloodstream and brain. Pneumonia remains a leading cause of death among children aged 1–59 months worldwide. This study aims to investigate the role of Kruppel-like factor 2 (KLF2) in lung injury caused by Spn in young mice.MethodsYoung mice were infected with Spn to induce pneumonia, and the bacterial load in the bronchoalveolar lavage fluid was quantified. KLF2 expression in lung tissues was analyzed using real-time quantitative polymerase chain reaction and Western blotting assays. Following KLF2 overexpression, lung tissues were assessed for lung wet-to-dry weight ratio and Myeloperoxidase activity. The effects of KLF2 on lung injury and inflammation were evaluated through hematoxylin and eosin staining and enzyme-linked immunosorbent assay. Chromatin immunoprecipitation and dual-luciferase assay were conducted to examine the binding of KLF2 to the promoter of microRNA (miR)-222-3p and cyclin-dependent kinase inhibitor 1B (CDKN1B), as well as the binding of miR-222-3p to CDKN1B. Levels of miR-222-3p and CDKN1B in lung tissues were also determined.ResultsIn young mice with pneumonia, KLF2 and CDKN1B were downregulated, while miR-222-3p was upregulated in lung tissues. Overexpression of KLF2 reduced lung injury and inflammation, evidenced by decreased bacterial load, reduced lung injury, and lower levels of proinflammatory factors. Co-transfection of miR-222-3p-WT and oe-KLF2 significantly reduced luciferase activity, suggesting that KLF2 binds to the promoter of miR-222-3p and suppresses its expression. Transfection of CDKN1B-WT with miR-222-3p mimics significantly reduced luciferase activity, indicating that miR-222-3p binds to CDKN1B and downregulates its expression. Overexpression of miR-222-3p or downregulation of CDKN1B increased bacterial load in BALF, lung wet/dry weight ratio, MPO activity, and inflammation, thereby reversing the protective effect of KLF2 overexpression on lung injury in young mice with pneumonia.ConclusionsKLF2 alleviates lung injury in young mice with Spn-induced pneumonia by transcriptional regulation of the miR-222-3p/CDKN1B axis.

Enriching Anticancer Drug Pipeline with Potential Inhibitors of Cyclin-Dependent Kinase-8 Identified from Natural Products.

Cyclin-dependent kinase 8 (CDK8) is highly expressed in various cancers and common complex human diseases, and an important therapeutic target for drug discovery and development. The CDK8 inhibitors are actively sought after, especially among natural products. We performed a virtual screening using the ZINC library comprising approximately 90,000 natural compounds. We applied Lipinski's rule of five, absorption, distribution, metabolism, excretion, and toxicity properties, and pan-assay interference compounds filter to eliminate promiscuous binders. Subsequently, the filtered compounds underwent molecular docking to predict their binding affinity and interactions with the CDK8 protein. Interaction analysis were carried out to elucidate the interaction mechanism of the screened hits with binding pockets of the CDK8. The ZINC02152165, ZINC04236005, and ZINC02134595 were selected with appreciable specificity and affinity with CDK8. An all-atom molecular dynamic (MD) simulation followed by essential dynamics was performed for 200 ns. Taken together, the results suggest that ZINC02152165, ZINC04236005, and ZINC02134595 can be harnessed as potential leads in therapeutic development. Moreover, the binding of the molecules brings change in protein conformation in a way that blocks the ATP-binding site of the protein, obstructing its kinase activity. These new findings from natural products offer insights into the molecular mechanisms underlying CDK8 inhibition. CDK8 was previously associated with behavioral and neurological diseases such as autism spectrum disorder, and cancers, for example, colorectal, prostate, breast, and acute myeloid leukemia. Hence, we call for further research and experimental validation, and with an eye to inform future clinical drug discovery and development in these therapeutic fields.

Design, synthesis, molecular docking, and evaluation of sulfonyl quinazoline analogues as promising liver cancer drugs

Inhibiting cyclin-dependent kinases (CDK) offers an important arsenal for cancer treatments by interfering with apoptotic proteins related to cancer. Novel selective cyclin-dependent kinases inhibitors using the Quinazoline as the cap with multiple electronic donating (EDG) and/or electron withdrawing group (EWG) substituted Aniline chain at the C-2 position were designed, synthesized, and evaluated for activity against liver cancer. Among the tested compounds, compounds B34 and B35 emerged as potent candidates in the series, with IC50 values of 0.102 ± 0.04 µM and 0.058 ± 0.003 µM, respectively. They also suppressed the enzymatic activity of CDK2/cyclinA2 selectively. Further biological studies revealed that compounds B34 and B35 arrested the cell cycle, and induced apoptosis in HepG-2 cancer cells through a Caspase-mediated mechanism, facilitating the release of Cyt-c through modulation of Caspase-3 expression. More importantly, compounds B34 and B35 suppressed the xenografted tumor growth in mice in a dose-dependent manner. Finally, through a molecular docking study, it was confirmed that compoundsB34 andB35 retained crucial hydrogen bonding and hydrophobic interactions with CDK receptor, rationalizing their higher efficacy compared to other compounds in the series. Taken together, the Quinazoline derivatives B34 and B35 may serve as novel chemotherapeutic agents through inhibition of CDK.

NOSTRIN is involved in benign prostatic hyperplasia via inhibition of proliferation, oxidative stress, and inflammation in prostate epithelial cells.

Benign prostatic hyperplasia (BPH) is a common disease among older men characterized by non-malignant proliferation of epithelial cells and inflammation. Nitric oxide synthase traffic inducer (NOSTRIN) is a pleiotropic regulator of endothelial cell function and signaling and exerts anti-inflammatory, anti-proliferation, and modulating nuclear factor-kappa B (NF-κB) signaling effects. Its expression and function in BPH tissues and prostate epithelial cells are unknown. The study aims to investigate the expression and functions of NOSTRIN in BPH, and its possible molecular mechanism. The BPH model was constructed in male Institute of Cancer Research (ICR) mice using 5 mg/kg/day testosterone propionate (TP) for 30 days, and the model was evaluated by detecting prostate index, prostate epithelial thickness, and prostate-specific antigen (PSA) expression. Dihydrotestosterone (DHT, 10 nM)-induced in vitro model of human prostate epithelial cells (RWPE-1) was established. We generated lentivirus-harboring human NOSTRIN. The mRNA expression was detected by real-time quantitative polymerase chain reaction (PCR) assay; the protein expression or localization was detected by western blot assay, immunohistochemistry, or immunofluorescence staining. Cell proliferation was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 5-ethynyl-2'-deoxyuridine (EdU) staining. Reactive oxygen species (ROS) production was observed by dihydroethidium staining. Nitric oxide (NO) and malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were detected using commercial kits. Enzyme-linked immunosorbent assay (ELISA) was used to determine levels of interleukin 1 beta (IL1B), interleukin 6 (IL6), interferon gamma (IFNG), and tumor necrosis factor (TNF). NOSTRIN expression was significantly inhibited in the TP-induced ICR mouse BPH model and DHT-induced model of RWPE-1 proliferation. Protein expression of the BPH-related and proliferation markers PSA and proliferating cell nuclear antigen (PCNA) was suppressed in NOSTRIN-overexpressing RWPE-1 cells exposed to DHT. NOSTRIN overexpression notably inhibited the RWPE-1 cell proliferation in vitro, as evidenced by MTT and EdU staining. NOSTRIN overexpression significantly decreased the expression of cell cycle-related proteins cyclin dependent kinase 4 (CDK4) and cyclin D1 (CCND1) in vitro. The production of ROS, NO, and lipid peroxidation products MDA was inhibited by NOSTRIN overexpression in vitro, while the SOD activity was increased. NOSTRIN overexpression reduced the mRNA expression of inflammatory mediator nitric oxide synthase 2 (NOS2) and inhibited the mRNA expression and secretion of pro-inflammatory cytokines IL1B, IL6, IFNG, and TNF in vitro. The mechanistic studies revealed an increased phosphorylation of NF-κB p65 in vivo and in vitro. Remarkably, NOSTRIN overexpression notably inhibited the protein expression of phospho-NF-κB p65 in vitro. NOSTRIN is involved in BPH by inhibiting proliferation, oxidative stress, and inflammation in prostate epithelial cells. These functions may act through the inhibition of NF-κB signaling.

Eco-friendly Synthesis of Indole Conjugated Chromeno[d]Pyrimidines as Anti-cancer Agents and their Molecular Modelling Studies

Introduction: Many medicinally active new chemical entities depend on indole conjugated chromeno[d]pyrimidine derivatives as a building block. The synthesis of 4-(1H-indol-3-yl)-3,4- dihydro-1H-chromeno[4,3-d]pyrimidine-2,5-dione 4 were achieved in the current study by treating 4- hydroxy-2H-chromen-2-one 1, indole aldehydes 2, and urea/thiourea 3 in the presence of L-proline. Methods: By adopting the above protocol, we were able to synthesize eight compounds, i.e. 4-(1Hindol- 3-yl)-3,4-dihydro-1H-chromeno[4,3-d]pyrimidine-2,5-diones (4a-4h), in the presence of Lproline as a catalyst in ethanol as solvent for 2-3 hours at 70-75°C with decent yields of 80-85%, and their structures were ascertained by various spectral techniques. They were further screened for their potentiality to inhibit cancer growth in HepG2 and MDA-MD-231 cells. Results: The scope of the synthesis of biological relevant Indole conjugated Chromeno[ d]Pyrimidines by three-component reaction (MCRs) process was investigated. The most optimised conditions obtained were 0.3 eq of L-proline for 2 hours at 70-75°C which gave the best yield (85%). The few advantages of this newly developed method are excellent yields, no metal catalyst, less toxic solvents, simple workup no chromatographic column purifications. On further screening for their anticancer activities, out of all, the compound 4b displayed noteworthy cytotoxicity with IC50 values of 8.1 and 9.2 μM against HepG2 and MDA-MD-231, respectively. Additionally, in silico studies also supported that compound 4b had favourable binding energy (-7.8 kcal/mol) when compared to the co-crystal ligand (LS5) in inhibiting the human cyclin-dependent kinase 2 (CDK2) protein. Conclusion: In conclusion, we have developed a simple, convenient, and efficient method for the synthesis of structurally diverse indole conjugated chromeno[d]pyrimidine analogues in the presence of L-proline as catalyst in ethanol as solvent with good yields. Further, the in vitro cytotoxic studies against HepG2 and MDA-MD-231 cells demonstrated that the synthesized compounds had good to reasonable activity, except for compound 4d.

Resolving and functional analysis of RNA editing sites in sheep ovaries and associations with litter size

Sheep litter size is a critical trait in mutton production. While litter size regulation in relation to DNA transcription have been rigorously investigated, the function of RNA editing remains less explored. To elucidate the mechanisms controlling sheep fecundity at the RNA editing level and identify pivotal RNA editing sites, this study scrutinised RNA editing sites (RESs) in follicular and luteal phases of ovaries from sheep with high and low fecundity, and the functions of population-specific RESs were subsequently analysed. A total of 2 182 475 RESs, 74.61% of which were A-to-I and C-to-U sites, were identified. These RESs were fairly evenly dispersed over the chromosomes, with 46.8% showing close clustering (inter-site distance < 300 bp). Notably, 93% were primarily situated in intronic and intergenic regions. In the follicular phase, pivotal RESs were found in the introns of genes including LPS responsive beige-like anchor, MCC regulator of Wnt signalling, and RWD domain containing 3, among others, and in the exon region of EvC ciliary complex subunit 2. In the luteal phase, RESs were observed in the introns of genes such as H/ACA ribonucleoprotein assembly factor and SDA1 domain-containing 1, and the exon and 3′UTR regions of polypeptide N-acetylgalactosaminyltransferase 15 and ilvB acetolactate synthase-like, respectively. High-fecundity sheep showed RESs in the follicular phase in genes such as fibrillin 1, cyclin−dependent kinase 6, and roundabout 1, and in genes such as autophagy−related 2B and versican in the luteal phase. Thirteen RESs specific to the follicular phase and eight specific to the luteal phase were identified in high-fecundity sheep ovaries. These RESs offer promising molecular targets and enhance understanding of multiple births in sheep from the perspective of posttranscriptional alterations.

Experience With Palbociclib in Metastatic Breast Cancer Patients Managed Under a Government Health Scheme at a Cancer Care Center in Southern India.

Introduction According to Globocan 2022, breast cancer ranks number one among the cancers worldwide. South Asian women have a higher incidence comparedto Westerners. Estrogen receptor (ER) and progesterone receptor (PR) positive tumors, termed hormonal receptor-positive tumors, account for most breast cancer presentations. In India, advanced-stage presentations are more common. In metastatic hormone receptor-positive breast cancer, hormonal therapy combined with cyclin-dependent kinase (CDK) 4/6 inhibitors is the standard treatment. Aim This study aimed to analyze the experience with generic palbociclib provided under the Government Health Scheme for metastatic hormone receptor-positive breast cancer at our institution. Methods This retrospective study was conducted on breast cancer patients admitted to a tertiary carecenter in South India. The data of ER and PR receptor-positive metastatic breast cancer patients who received palbociclib were identified and reviewed using medical records from 2023 to 2024. Results A total of 238 patients were analyzed, of which41 received palbociclib for hormone receptor-positive metastatic breast cancer. The median age was 49 (33-75), with 53.5% (22) of women above 50. Denovo stage IV presentation was observed in 21patients (51.2%), while progression to stage IV disease was noted in 11 patients (26.8%), and stages II and IIIwere noted in nine patients (22%). Invasive ductal carcinoma was the most common histology. All patients were ER-positive, and 38 (92.7%) were PR-positive. About 17 patients (41.5%) had visceral metastasis, and 12 (29.3%) had bone-only metastasis. Local recurrence was seen in six patients (14.6%), and bone with visceral metastasis was seen in another six patients (14.6%). Progression within one year of hormonal therapy initiation was observed in 50% (10) of patients. Among 21 patients with upfront metastasis, nine were treated with prior chemotherapy. All patients were given 125 mg of oral palbociclib. Fatigue was the most common side effect in 34.1% (14), followed by myalgia in 21.9% (9), low hemoglobin levels of less than 8 g/dl in 14.6% (6), and nausea and vomiting in only 9.8% (4) of patients. Conclusion Hormone therapy combined with CDK4/6 inhibitors is the backbone of treatment for metastatic hormone-positive breast cancer. However, in developing countries like India, where most patients come from rural areas, using innovator palbociclib may not be feasible for many. With the availability of generic palbociclib under the Government Health Scheme, patients of metastatic hormone receptor-positive breast cancer will receive the protocol-based treatment.

G-Protein-Coupled Receptor Kinase 2 Inhibition Induces Meiotic Arrest by Disturbing Ca2+ Release in Porcine Oocytes.

G-protein-coupled receptor kinase 2 (GRK2) interacts with Gβγ and Gαq, subunits of G-protein alpha, to regulate cell signalling. The second messenger inositol trisphosphate, produced by activated Gαq, promotes calcium release from the endoplasmic reticulum (ER) and regulates maturation-promoting factor (MPF) activity. This study aimed to investigate the role of GRK2 in MPF activity during the meiotic maturation of porcine oocytes. A specific inhibitor of GRK2 (βi) was used in this study. The present study showed that GRK2 inhibition increased the percentage of oocyte arrest at the metaphase I (MI) stage (control: 13.84 ± 0.95%; βi: 31.30 ± 4.18%), which resulted in the reduction of the maturation rate (control: 80.36 ± 1.94%; βi: 65.40 ± 1.14%). The level of phospho-GRK2 decreased in the treated group, suggesting that GRK2 activity was reduced upon GRK2 inhibition. Furthermore, the addition of βi decreased Ca2+ release from the ER. The protein levels of cyclin B and cyclin-dependent kinase 1 were higher in the treatment group than those in the control group, indicating that GRK2 inhibition prevented a decrease in MPF activity. Collectively, GRK2 inhibition induced meiotic arrest at the MI stage in porcine oocytes by preventing a decrease in MPF activity, suggesting that GRK2 is essential for oocyte meiotic maturation in pigs.