Cyclin-dependent Kinase Research Articles

Roles of CDK12 mutations in PCa development and treatment.

Prostate cancer (PCa) is one of the most common cancers in men, and cyclin-dependent kinase 12 (CDK12) is emerging as a novel star player in the PCa tumorigenesis and progression to castration-resistant prostate cancer (CRPC). In PCa, CDK12 alterations are mostly loss-of-function mutations featuring intronic polyadenylation (IPA), focal tandem duplications (FTDs), and R-loops formation and transcription-replication conflicts (TRCs). The occurrence of IPA can result in homologous recombination deficiency (HRD) and androgen receptor (AR) variation. FTDs induce neoantigens and increase the expression of the AR, MYC, and other hotspot- associated genes. R-loops lead to TRCs and influence various cellular processes, including gene expression and genome stability. Due to the poor prognosis of CDK12-mutant PCa patients and the mediocre response to classic standard therapies, HRD and increased neoantigen levels have provided clinicians with new insights into alternative systematic treatments for this novel PCa phenotype. In this review, we summarize the roles of CDK12 mutations in PCa and discuss their clinical value, suggesting that CDK12 potentially represents a target for further research and the development of clinical strategies for PCa.

Design, Synthesis and Biological Evaluation of Novel 9H Purine Derivatives as Potent CDK9 Inhibitors.

Cyclin-dependent kinase 9 (CDK9) is considered as an important target in the research of antitumor drugs. Taking the CDK2/9 inhibitor CYC065 as the positive control and an in-house library compound (64) as the lead compound, four classes of 22 target compounds with 9H purine as the core structure were designed to establish structure-activity relationships (SAR). In general, SAR of 9H purine CDK9 inhibitors is systematically described in this paper, resulting in the discovery of two compounds (B2 and B5) with further research value. After conducting selectivity testing against CDK2/9 kinase, compound B5 demonstrated approximately five-fold greater selectivity towards CDK9-cyclinT1 over CDK2-cyclinE2. This work also provides a reference basis for the subsequent research on CDK9 inhibitors.

Camptothecin Triggers Apoptosis in Human and Mouse Drug-resistant Glioblastoma Cells via ROS-mediated Activation of the p53-p21-CD1/CDK2-E2F1-Bcl-xL Signaling Axis.

Glioblastoma multiforme (GBM) is the most aggressive brain tumor. Temozolomide (TMZ) is the first-line treatment for GBM. However, most patients with GBM develop drug resistance. Our previous study showed the effects of camptothecin (CPT) and CRLX101, a nanoparticle of CPT, in suppressing GBM growth by targeting drug-sensitive glioblastoma cells. This study evaluated the effects of CPT on drug-resistant glioblastoma cells and explored the underlying molecular mechanisms. Expression of type I topoisomerase (Topo-1) gene in GBM was analyzed using the UALCAN database. Human U87MG-R and mouse GL261-R TMZ-resistant glioblastoma cells were developed. After CPT treatment, apoptotic events were successively determined. The role of the p53-p21-cyclin D1 (CD1)/cyclin-dependent kinase 6 (CDK6)-E2F1-Bcl-xL signaling axis was subsequently investigated. The expression of Topo-1 gene was up-regulated in human GBM compared to normal human brains. Treatment of human U87MG-R cells with CPT decreased cell viability. Sequentially, exposure to CPT led to activation of caspase-3, fragmentation of chromosomal DNA, and cell apoptosis. Furthermore, intracellular reactive oxygen species (iROS) were augmented following CPT treatment. Suppression of iROS production concurrently alleviated CPT-triggered apoptotic insults. CPT enhanced the levels of p53, phosphorylated p53, and p21. In contrast, levels of CDK6, CD1, E2F1, and Bcl-xL were decreased by CPT. Attenuating p53 transactivation activity using pifithrin-α also mitigated the CPT-induced apoptosis. The effects of CPT on killing drug-resistant glioblastoma cells were further confirmed in mouse GL261-R cells. CPT could effectively induce apoptosis in drug-resistant glioblastoma cells via iROS-mediated activation of the p53-p21-CD1/CDK6-E2F1-Bcl-xL axis.

Novel nano-sized N-Thiazolylpyridylamines targeting CDK2: Design, divergent synthesis, conformational studies, and multifaceted In silico analysis.

This study involves the design, divergent synthesis, conformational and structural analysis, target prediction, and molecular docking simulations of novel nano N-thiazolylpyridylamines 2-7 and 10 as potential cyclin-dependent kinase 2 (CDK2) inhibitors. Using a divergent synthesis approach, the compounds were designed with structural variation and optimization in mind. The conformational and structural properties were explored through various spectroscopic techniques, confirming the structure, stability, and preferred conformations. Additionally, nanocrystalline characterization, including X-ray diffraction analysis, revealed the nanoscale structural features of the synthesized molecules. Most compounds exhibited a crystalline nature with crystallite sizes ranging from 10.75 to 57.77nm, which is crucial for improving cellular uptake and anticancer efficacy. Biological testing was performed to evaluate the cytotoxicity of compounds 2-7 and 10 against cancer cell lines, including HepG2, MCF-7, and HCT-116. Compound 5 exhibited significant cytotoxicity with IC50 values of 10.9±0.5μM, 6.98±0.3μM, and 6.3±0.2μM against MCF-7, HePG2, and HCT116, respectively. Other compounds demonstrated varied activities, with compounds 4, 6, and 10 showing moderate activity against the MCF-7cell line. Computational techniques suggested a strong probability of these compounds targeting CDK2, with molecular docking and dynamics used to predict their binding mechanisms. These findings suggest that N-thiazolylpyridylamines may serve as new anticancer agents for further lead optimization.

Interactions between lncRNAs and cyclins/CDKs complexes; key players in determining cancer cell response to CDKs inhibitors.

Transcription takes place over a significant portion of the human genome. However, only a small portion of the transcriptome, roughly 1.2%, consists of RNAs translated into proteins; the majority of transcripts, on the other hand, comprise a variety of RNA families with varying sizes and functions. A substantial portion of this diverse RNA universe consists of sequences longer than 200 bases, called the long non-coding RNA (lncRNA). The control of gene transcription, changes to DNA topology, nucleosome organization and structure, paraspeckle creation, and assistance for developing cellular organelles are only a few of the numerous tasks performed by lncRNA. The main focus of this study is on the function of lncRNA in controlling the levels and actions of cyclin-dependent kinase inhibitors (CDKIs). The enzymes required for the mitotic cycle's regulated progression are called cyclin-dependent kinases (CDKs). They have many degrees of regulation over their activities and interact with CDKIs as their crucial mechanisms. Interestingly, culminating evidence has clarified that lncRNAs are associated with several illnesses and use CDKI regulation to control cellular function. Nonetheless, despite the abundance of solid evidence in the literature, it still seems unlikely that lncRNA will have much of an impact on controlling cell proliferation or modulating CDKIs.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i): Mechanisms of resistance and where to find them

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i): Mechanisms of resistance and where to find them

Involvement of CRMP2 Phosphorylation in Amyloid Beta-induced Tau Phosphorylation of Hippocampal Neurons in Alzheimer's Disease Mouse Model.

Alzheimer's disease (AD) is the most common form of dementia, characterized by amyloid-β (Aβ) deposition and the formation of neurofibrillary tangles composed of hyperphosphorylated tau. Collapsin response mediator protein 2 (CRMP2), a microtubule (MT)-binding protein, regulates MT dynamics and is phosphorylated at Ser522 by cyclin-dependent kinase 5. Previous studies have shown increased CRMP2 phosphorylation at Ser522 (CRMP2-pSer522) in early AD stages and AD mouse models, where it colocalizes with phosphorylated tau. However, the role of CRMP-pSer522 in AD pathology remains unclear. In this study, we generated double transgenic mice by crossing tau Tg (PS19) mice and CRMP2 S522A knock-in (CRMP2KI) mice, in which S522 of CRMP2 was replaced with alanine to create a phospho-defective model. No significant change in tau phosphorylation was observed in the hippocampus of tau Tg; CRMP2KI mice compared to tau Tg littermates. However, when Aβ25-35 oligomers were injected into the hippocampus, tau phosphorylation was significantly reduced in Aβ-injected tau Tg; CRMP2KI mice compared to Aβ-injected tau Tg controls. These findings suggest that CRMP2 phosphorylation at Ser522 promotes Aβ-induced tau phosphorylation in this mouse model of AD.

Exploring the antiproliferative effect of PI3K/Akt/mTOR pathway and CDK4/6 inhibitors in human papillomavirus‑positive and ‑negative head and neck squamous cell carcinoma cell lines.

Human papillomavirus (HPV)‑positive and -negative head and neck squamous cell carcinoma (HNSCC) are often associated with activation of the phosphatidylinositol 3‑kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway due to mutations or amplifications in PI3KCA, loss of PTEN or activation of receptor tyrosine kinases. In HPV‑negative tumors, CDKN2A (encoding p16 protein) inactivation or CCND1 (encoding Cyclin D1 protein) amplification frequently results in sustained cyclin‑dependent kinase (CDK) 4/6 activation. The present study aimed to investigate the efficacy of the CDK4/6 inhibitors (CDKi) palbociclib and ribociclib, and the PI3K/Akt/mTOR pathway inhibitors (PI3Ki) gedatolisib, buparlisib and alpelisib, in suppressing cell viability of HPV‑positive and ‑negative HNSCC cell lines. Inhibitor efficacy was assessed in vitro using MTT assay and western blotting analysis. Cell cycle analysis was performed using flow cytometry and apoptosis was assessed using annexin V staining. Metabolic changes in terms of glycolysis and oxidative metabolism were measured by Seahorse XF96 extracellular Flux analysis. The results of the present study showed that both HPV‑positive and ‑negative HNSCC cell lines were sensitive to PI3Ki. In general, PI3Ki decreased PI3K/Akt/mTOR pathway activity, resulting in apoptosis, and decreased oxidative and glycolytic metabolism. The CDKi were particularly effective in blocking HPV‑negative cell line viability, showing decreased retinoblastoma expression and G1‑phase cell cycle arrest, whereas apoptosis was not induced. Thus, PI3Ki and CDKi efficiently inhibited their respective pathways and HNSCC cell viability in vitro, with the latter occurring only in HPV‑negative cell lines. Whereas PI3Ki induced apoptosis and attenuated cellular metabolism, CDKi led to cell cycle arrest. Further research should be performed to elucidate whether (a combination of) these inhibitors may be effective therapeutic agents for patients with HNSCC.

3,6-Anhydro-L-galactose suppresses mouse lymphocyte proliferation by attenuating JAK-STAT growth factor signal transduction and G1-S cell cycle progression.

Recombinant GH16B β-agarase-catalyzed liquefaction of 5-7%(w/v) melted agarose at 50°C completely hydrolyzed agarose into neoagarohexaose (NA6) and neoagarotetraose (NA4). Subsequent saccharification by recombinant GH50A β-agarase or recombinant GH50A β-agarase/recombinant GH117A α-neoagarobiose hydrolase at 35°C converted NA6/NA4 into neoagarobiose (NA2) or 3,6-anhydro-L-galactose (L-AHG)/D-galactose, respectively. Purification of NA6/NA4 and NA2 was achieved by Sephadex G-15 column chromatography, while L-AHG was purified by Sephadex G-10, achieving≥98% purity. L-AHG (25-200μg/mL), but not NA2, NA4, or NA6, inhibited the proliferation of immobilized anti-CD3/anti-CD28-activated T cells and immobilized anti-CD40+soluble anti-IgM+interleukin (IL)-4-activated B cells. This inhibition impacted the G1-S traverse in the cell cycle without influencing CD69 expression and p27Kip1 down-regulation, markers of the exit from G0 into G1 phase in activated lymphocytes. L-AHG impeded cyclin-dependent kinases (CDKs)-driven retinoblastoma phosphorylation, necessary for the G1-S traverse, by reducing the activating phosphorylation of CDKs (CDK4, CDK2, and CDK1) and lowering cyclin D3, cyclin A2 and cyclin B1 levels. Furthermore, L-AHG diminished the production of growth factors, including IL-2 in activated T cells and IL-6 in activated B cells. The antiproliferative effect of L-AHG on T cells was partially restored by exogenous IL-2 but was unaffected by exogenous IL-6 on B cells. L-AHG inhibited the activating phosphorylation of Janus kinase 1 (JAK1), affecting signal transducer and activator of transcription 1 (STAT1) and STAT3 signaling. These results demonstrate that L-AHG may serve as a novel immunosuppressant by impairing JAK-STAT growth factor signaling and G1-S cell cycle progression in T and B lymphocytes.

Contribution of Cyclin Dependent Kinase Inhibitor 1A Genotypes to Childhood Acute Lymphocytic Leukemia Risk in Taiwan.

The disruption of cell-cycle control can lead to an imbalance in cell proliferation, often accompanied by genomic instability, which in turn can facilitate carcinogenesis. This study aimed to examine the impact of CDKN1A rs1801270 and rs1059234 polymorphisms on the risk of childhood acute lymphocytic leukemia (ALL) in Taiwan. The genotypes of CDKN1A rs1801270 and rs1059234 in 266 childhood ALL cases and 266 controls were determined using PCR-RFLP techniques. The genotypic and allelic frequencies for CDKN1A rs1801270 and rs1059234 did not significantly differ between childhood ALL cases and controls (all p>0.05). However, stratified analysis revealed that the CDKN1A rs1801270 AA variant was associated with a reduced risk of childhood ALL in males (OR=0.40, 95%CI=0.20-0.82, p=0.0178). Additionally, the AC and AA genotypes of rs1801270 were linked to a lower risk classification for childhood ALL and longer survival times (OR=0.57 and 0.31, 95%CI=0.33-0.97 and 0.18-0.56, p=0.0538 and 0.0001, respectively). No significant associations were found for rs1059234 in the stratified analyses (p>0.05 for all). Although CDKN rs1801270 and rs1059234 genotypes were not associated with an overall risk of childhood ALL, CDKN1A rs1801270 polymorphism may serve as a protective predictor in males and as a potential marker for better prognosis of childhood ALL. Validation in larger and more diverse populations is necessary to confirm the feasibility of this predictor.

Cyclin E Expression and p16 Loss Are Strong Prognostic Biomarkers in Primary Invasive Cutaneous Melanoma.

The traditional melanoma staging system is not ideal for predicting patients' individual risk of disease recurrence and death. Subsequently, suboptimal adjuvant treatment may be offered. Hence, identification of biomarkers to optimize risk stratification is warranted. Cyclins and cyclin-dependent kinase inhibitors, key players in the cell cycle regulation, are candidate prognostic biomarkers. Herein, their expression and prognostic value in melanoma are studied. The expression of Cyclin D1, Cyclin E, p16, p21, and p27 were assessed using immunohistochemistry in samples from 59 patients with melanoma and correlated with clinicopathological parameters, as well as relapse-free survival (RFS) and overall survival (OS). Cyclin E expression in the nucleus, observed in 19% of patients, was correlated with Breslow thickness (p=0.017), whereas p16 loss in the cytoplasm and nucleus, detected in 68% and 61% of patients respectively, was correlated with Breslow thickness (p=0.001) and ulceration (p=0.035). The high expression of Cyclin E in the nucleus (p<0.001) and the loss of p16 in the cytoplasm (p=0.012) and nucleus (p=0.002) were associated with shorter OS. Cyclin E in the nucleus was a prognostic factor for RFS and OS at least as strong as Breslow thickness. Expression of Cyclin E and loss of p16 appeared to be significant prognostic biomarkers, with Cyclin E being prognostically at least as strong as Breslow thickness regarding RFS and OS. Both biomarkers may potentially be used to improve stratification of individual patient's risk of recurrent disease and survival, and subsequently optimize adjuvant treatment.

Self-assembled natural triterpenoids for the delivery of cyclin-dependent kinase 4/6 inhibitors to enhance cancer chemoimmunotherapy.

Immunogenic cell death (ICD) has recently emerged as a promising strategy in reinforcing anti-PD-L1 blockade immunotherapy of triple-negative breast cancer (TNBC). The CDK4/6 inhibitor palbociclib (PAL), as a clinical star medicine targeting the cell cycle machinery, is an ideal candidate for fabricating a highly efficient ICD inducer for TNBC chemoimmunotherapy. However, the frequently observed chemoresistance and clinical adverse effects, as well as significant antagonistic effects when co-administered with certain chemotherapeutics, have seriously restricted the efficiency of PAL and the feasibility of combination strategies. Herein, we screened and identified six self-assembled natural pentacyclic triterpenoid (PT) molecules that can serve as competent co-administration nanoplatforms for the synergistic or combined delivery of PAL. Analysis of two representative PT-PAL nano-assemblies validated that PT-mediated co-assembly enhances the cytotoxicity and synergy of PAL by inhibiting the PI3K/AKT/mTOR signaling pathway, rather than directly targeting CDK4/6 proteins. Importantly, the PAL nanoassemblies exhibited multiple favorable therapeutic features and stronger accumulative ICD induction, ensuring highly efficient synergistic anti-PD-L1 chemoimmunotherapy by simultaneously facilitating T-cell immune response and reversing the immunosuppressive tumor microenvironment. This study offers possibilities for improving the anticancer efficacy of CDK4/6 inhibitors and potential avenues for clinical applications of chemoimmunotherapy in treating TNBC.

Lactobacillus salivarius metabolite succinate enhances chicken intestinal stem cell activities via the SUCNR1-mitochondria axis.

The activity of intestinal stem cells (ISCs) can be modulated by Lactobacillus, which subsequently affects the mucosal absorptive capacity. However, the underlying mechanisms remain unclear. In this study, a total of 189 Hy-Line Brown chickens (Gallus) were randomly assigned to one of seven experimental groups (n = 27 per group). These groups included a control group, a vehicle group (MRS group), a Lactobacillus salivarius group, a L. salivarius supernatant group, and three succinate treatment groups with various dosages. Each group was further subdivided into three replicates, with 9 chickens per replicate. The results indicate that the administration of Lactobacillus salivarius supernatant to laying hens notably increased the mRNA abundance of the amino acid transporters oligopeptide transporter 1 (PepT1) and sodium-dependent neutral amino acid transporter (B0AT). Metabolomic analyses indicated that the supernatant contains a high concentration of organic acids. Among them, succinate could enhance mRNA abundance of PepT1, B0AT and excitatory amino acid transporters 3 (EAAT3) both in vivo and in vitro. Accordingly, succinate could accelerate intestinal epithelial turnover, as indicated by the increased levels of cyclin-dependent kinase 2 (Cdk2) mRNA and proliferating cell nuclear antigen protein (PCNA), as well as ISC differentiation-related protein leucine-rich repeat containing G protein-coupled receptor 5 (LGR5). Furthermore, succinate treatment was shown to elevate the levels of mitochondrial fusion proteins optic atrophy 1 (OPA1) and translocase of outer mitochondrial membrane 20 (TOMM20), resulting in increased local ATP levels. However, pretreatment with NF-56-EJ40, a succinate receptor antagonist, attenuated the effects of succinate on OPA1, TOMM20, and ATP levels, alone with the reducing LGR5 and PCNA levels. Collectively, succinate, a metabolite of L. salivarius, activates the SUCNR1-mitochondria axis in ISCs, facilitating mitochondrial ATP synthesis, promoting ISC activity, and ultimately enhancing mucosal absorptive capacity.

Clinical Impact of Cellular Senescence and RNA Dysregulation in HCC Is Associated With MASLD and HCV-SVR.

The incidence of hepatocellular carcinoma (HCC) associated with metabolic dysfunction-associated steatotic liver disease (MASLD) and hepatitis C virus sustained virologic response (HCV-SVR) are increasing. However, the mechanisms driving HCC development in these patients remain unclear. This study aimed to evaluate the role of cellular senescence and RNA editing in HCC by examining cyclin-dependent kinase inhibitor 2A (p16) and adenosine deaminase acting on RNA (ADAR1) expression. HCC specimens from patients with MASLD or HCV-SVR were analyzed by immunohistochemistry to assess p16 and ADAR1 expression. Statistical analyses were conducted using the Chi-squared test, Fisher's exact test, and Mann-Whitney U-test. Survival analyses were performed using the Kaplan-Meier method, the log-rank test, and Cox regression analysis. Among 122 patients, 59 (48.4%) had MASLD and 63 (51.6%) had HCV-SVR. p16 expression was observed in 69 cases (57.0%) in the noncancerous areas and 53 cases (44.5%) in the cancerous areas. ADAR1 expression was positive in 28 cases (23.5%) in the cancerous areas and significantly associated with p16 expression in the cancerous areas (p=0.039). Patients with p16 expression in the noncancerous areas were older (p=0.045) and had elevated serum ALT levels (p=0.024). p16 expression in the cancerous areas were correlated with a shorter recurrence-free survival (HR=1.65, 95%CI=1.00-2.73, p=0.046). Cellular senescence and RNA editing may play a key role in MASLD- and HCV-SVR-related HCC. p16 expression in the cancerous areas may serve as a prognostic biomarker for surgical outcomes.

Biosynthesis inhibition of miR-142-5p in a N6-methyladenosine-dependent manner induces neuropathic pain through CDK5/TRPV1 signaling

BackgroundNeuropathic pain (NP) represents a debilitating and refractory condition. However, the understanding of NP and the current treatment approaches available for its management are limited. Therefore, there is a significant need to address the dearth of effective therapeutic interventions. This study aims to investigate the regulation of transient receptor potential vanilloid 1 (TRPV1) and cyclin-dependent kinase 5 (CDK5) expression levels by miR-142-5p as a common upstream molecule, and to delve into the mature process of miR-142-5p from the perspective of N6-methyladenosine (m6A) modification.MethodsTo assess the RNA levels of TRPV1, CDK5, miR-142-5p, pre-miR-142, and pri-miR-142, quantitative PCR with reverse transcription (RT–qPCR) was utilized. Western blot analysis was employed to determine changes in protein expression for TRPV1 and CDK5. For assessing the interaction mechanism and binding site between TRPV1 and CDK5, various techniques were applied, including mass spectrometry, coimmunoprecipitation (co-IP), and glutathione-S-transferase (GST)-pulldown assays. The subcellular localization of TRPV1 on the cell membrane was visualized through immunofluorescence, and the translocation was confirmed by western blot analysis after performing membrane-plasma separation in parallel. Moreover, intracellular calcium transport was monitored using calcium imaging as an indicator of cell excitability. The binding of miRNA-142-5p to the 3’UTR of TRPV1 and CDK5 was investigated using the dual-luciferase reporter assay. The overall level of m6A was first determined by RNA m6A methylation assay, and subsequently the methylation level of pri-miR-142 was assessed using the meRIP assay to detect m6A modification. In addition, an in vivo rat chronic constriction injury (CCI) model was established, and miR-142-5p agomir or antagomir was injected intrathecally. An enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of IL-6 and TNF. Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were examined.ResultsThe expression levels of TRPV1 and CDK5 were found to be upregulated not only in the in vivo CCI model but also in the in vitro lipopolysaccharide (LPS) treatment cell model as well. CDK5 was observed to phosphorylate TRPV1 at T406, prompting the translocation of TRPV1 to the cell membrane and consequent augmentation of cellular excitability. Notably, CDK5 was found to directly bind to TRPV1, and the binding region was localized within the 1–390 amino acid sequence of TRPV1. According to database predictions, miR-142-5p, identified as a shared upstream molecule of TRPV1 and CDK5, exhibited downregulation following induction by NP. MiR-142-5p was shown to simultaneously bind to the mRNA of CDK5 and TRPV1, thereby inhibiting their expression. After LPS treatment, it was observed that pri-miR-142 expression increased, while pre-miR-142 and miR-142-5p expression decreased, suggesting inhibition of the maturation process of pri-miR-142. In addition, the overall level of m6A and in particular the pri-miR-142 m6A modification increased upon LPS treatment. Knockdown of METTL14 led to decreased pri-miR-124 expression, increased pre-miR-124 expression, and enhanced mature miR-142-5p expression, indicating the relief of miR-142-5p maturation repression. The in vivo results indicated that miR-142-5p negatively regulated the expression of CDK5 and TRPV1, suppressed the expression of inflammatory factors IL-6 and TNF, and improved the PWMT and PWTL.ConclusionsIn this study, we perform a thorough investigation to examine the effects of CDK5 and TRPV1 on NP, elucidating their binding relationship and the impact of CDK5 on the membrane transport of TRPV1. Notably, our findings reveal that miR-142-5p, acting as a crucial upstream molecule, exhibits inhibitory effects on the expression of both CDK5 and TRPV1. Moreover, we observe that METTL14 facilitates the m6A modification of pri-miR-142, thereby impeding the maturation transition of pri-miR-142 and ultimately leading to the downregulation of mature miR-142-5p.Graphical

Resistance mechanisms and therapeutic strategies of CDK4 and CDK6 kinase targeting in cancer.

Cyclin-dependent kinases (CDKs) 4 and 6 (CDK4/6) are important regulators of the cell cycle. Selective CDK4/6 small-molecule inhibitors have shown clinical activity in hormonal receptor-positive (HR+) metastatic breast cancer, but their effectiveness remains limited in other cancer types. CDK4/6 degradation and improved selectivity across CDK paralogs are approaches that could expand the effectiveness of CDK4/6 targeting. Recent studies also suggest the use of CDK4/6-targeting agents in cancer immunotherapy. In this Review, we highlight recent advancements in the mechanistic understanding and development of pharmacological approaches targeting CDK4/6. Collectively, these developments pose new challenges and opportunities for rationally designing more effective treatments.

Investigation into drug resistance to cisplatin in cancer stem cell-enriched population in non-small cell lung cancer

Abstract Objectives understanding drug resistance in cancer is of importance in treatment. Cancer stem cells are main factor for drug resistance. Therefore, the possible gene/gene interactions/proteins were explored in our study using a cancer stem cell-enriched population (H1299/S) derived from a parental non-small cell lung cancer cell line (H1299/P). Methods response to cisplatin, which is the main drug for the treatment of lung cancer, was evaluated with the Adenosine triphosphate (ATP) viability test. As a result of the gene expression analysis, while 14 genes were not evaluated, expression profiles were obtained for 37 genes out of 51 genes. By the drug-protein interaction analyses, Topoisomerase I (TOPI), Topoisomerase 2 alpha (TOP2A), Topoisomerase 2 beta (TOP2B), Cyclin-dependent kinases 4 (CDK4), Cyclin-dependent kinases 6 (CDK6), ATP binding cassette subfamily B member 1 (ABCB1), ATP binding cassette subfamily C member 1 (ABCC1), ATP binding cassette subfamily C member 3 (ABCC3), B-cell leukemia/lymphoma 2 (BCL2), Poly (ADP-ribose) polymerase 1 (PARP1), Breast cancer gene 1 (BRCA1) and Cyclin dependent kinase inhibitor 1A (CDKN1A) genes and protein products were statistically significantly found to be in association with drug resistance. Results and discussion in bioinformatics analyses, it was observed that 13 pathways were affected due to expression changes and 12 genes related to these pathways were determined to activate multidrug resistance mechanisms. Conclusions platinum-based drugs, as well as a broad range of other agents including topoisomerase and PARP1 inhibitors, and anthracyclines, have been shown to potentially possess multiple drug resistance.

Halofuginone prevents inflammation and proliferation of high-altitude pulmonary hypertension by inhibiting the TGF-β1/Smad signaling pathway

The inflammatory response of lung tissue and abnormal proliferation of pulmonary artery smooth muscle cells are involved in the pathogenesis of high-altitude pulmonary hypertension (HAPH). Halofuginone (HF), an active ingredient derivative of Chang Shan (Dichroa febrifuga Lour. [Hydrangeaceae]), has antiproliferative, antihypertrophic, antifibrotic, and other effects, but its protective effects on HAPH remains unclear. In the present study, we evaluated the efficacy of HF on HAPH by establishing a 6000 m HAPH rat model. Male Sprague–Dawley rats were divided into normoxia, normoxia + halofuginone (1 mg/kg), hypoxia, and hypoxia + halofuginone (1 mg/kg) groups. The results showed that HF (1 mg/kg) could prevent hypoxia-induced hemodynamic abnormalities, right ventricular hypertrophy, and pulmonary vascular remodeling in rats. We further detected the expression levels of inflammatory factors interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α) and proliferative/antiproliferative indicators proliferating cell nuclear antigen (PCNA), cyclin-dependent kinase 6 (CDK6), Cyclin D1, p21 in lung tissue, and found that HF could attenuate the lung tissue inflammatory response and proliferative response in HAPH rats. In addition, we also examined the expression levels of transforming growth factor-β1 (TGF-β1), Smad2/3 and p-Smad2/3 in lung tissue, and found that HF exerted therapeutic effects by inhibiting the TGF-β1/Smad signaling pathway.

Establishment of a human ovarian endometrioid carcinoma cell line by constitutive expression of cyclin-dependent kinase 4, cyclin D1 and telomerase reverse transcriptase

Only a few human ovarian endometrioid carcinoma cell lines are currently available, partly due to the difficulty of establishing cell lines from low-grade cancers. Here, using a cell immortalization strategy consisting of i) inactivation of the p16INK4a-pRb pathway by constitutive expression of mutant cyclin-dependent kinase 4 (R24C) (CDK4R24C) and cyclin D1, and ii) acquisition of telomerase reverse transcriptase (TERT) activity, we established a human ovarian endometrioid carcinoma cell line from a 46-year-old Japanese woman. That line, designated JFE-21, has proliferated continuously for over 6 months with a doubling time of ~ 55 h. JFE-21 cells exhibit polygonal shapes and proliferate without contact inhibition to form a monolayer in a jigsaw puzzle-like arrangement. Ultrastructurally, JFE-21 cells exhibit well-developed rough endoplasmic reticulum, mitochondria and lysosomes in the cytoplasm, with cells contacting each other via desmosomes. G-band karyotype analysis indicated that cells had a near-tetraploid karyotype. Immunofluorescence staining revealed that the expression profile of a series of ovarian carcinoma markers in JFE-21 cells was consistent with ovarian endometrioid carcinoma. Moreover, Sanger sequencing of DNA polymerase ε (POLE) gene and immunohistochemical analysis of mismatch repair (MMR) proteins revealed that JFE-21 cells were classified as the no specific molecular profile (NSMP) subtype. In addition, JFE-21 cells were sensitive to paclitaxel and carboplatin administered to the donor as therapy. These findings indicate that constitutive expression of CDK4R24C, cyclin D1 and TERT genes may be an option to establish cell lines from low-grade cancers, including ovarian endometrioid carcinoma.

Proximal bronchiolar adenoma with malignant transformation to invasive mucinous adenocarcinoma with 4 years follow-up: a case report and literature review

BackgroundBronchiolar adenoma (BA) is a rare benign tumor originating in the bronchial mucosal epithelium and occurring primarily in the periphery of the lung. The most prominent histopathological feature of BA is a double-layer bronchial epithelium containing continuous basal cell layers. However, due to the high mutation frequency of the driver gene, there is still debate as to whether BA has the potential for malignant transformation. In frozen sections, basal cells are difficult to identify under the microscope, which makes it difficult to distinguish from mucinous adenocarcinoma, especially when BA malignancies transform into invasive mucinous adenocarcinoma (IMA), which can only be distinguished by histomorphological criteria, greatly increasing the difficulty of diagnosis.Case summaryIn this paper, we present a case study of a 59-year-old man whose chest computed tomography (CT) revealed a progressively enlarging, high-density nodule over a four-year period in the outer basal segment of the right lower lobe. Consequently, he underwent thoracoscopic wedge resection of the right lower lobe. The postoperative pathological diagnosis revealed BA with mucous gland structure formation combined with partial basal cell loss, raising the possibility of malignant transformation into IMA. Regular postoperative follow-up showed no recurrence or metastasis. Hybridization Capture-based next-generation sequencing (NGS) analysis detected driver gene mutations in Kirsten Rat Sarcoma viral oncogene homolog (KRAS) and Cyclin-Dependent Kinases (CDK) 6 in the case, thereby inferring the malignant transformation of BA into IMA.ConclusionIn this case, the detection of driver gene KRAS mutation and loss of continuity in the basal cell layer within the mucous glandular structures of the nodule suggests the malignant transformation of BA into IMA, inferring the malignant potential of BA.