Cyclin-dependent Kinase Inhibitor 1B Research Articles

Deletion of the Long Non-coding RNA <i>ANRIL</i> In Addition to the Protein-Coding Genes of the INK4-ARF Locus in the A549 Cell Line: An Existing Phenomenon or a Novel Genetic Alteration?

Background: A549, a human lung adenocarcinoma cell line, is a KRAS mutant cell used for over 5 decades as a type II alveolar cell and non-small cell lung adenocarcinoma model. Cyclin-dependent kinase inhibitor 2 A (CDKN2A) and cyclin-dependent kinase inhibitor 2 B (CDKN2B) are protein-coding genes in the INK4-ARF locus and function as tumor suppressors and negative regulators of the cell cycle. These genes have been reported to be deleted in the A549 cell line. The Long non-coding RNAANRIL is located in the antisense direction of CDKN2B and shares a bidirectional promoter with CDKN2A. ANRIL is a negative regulator of the INK4-ARF locus genes and has an oncogenic role in cancers. ANRIL deletion in the A549 cell line has not been reported to date. Objectives: Herein, the presence of ANRIL was investigated in the A549 cell line. Methods: In this study, the A549 cell line from 2 different sources was tested for the presence of the INK4-ARF locus genes by polymerase chain reaction (PCR) using specific primers at both DNA and RNA levels. We compared our findings with Calu-6, MRC-5, and HepG2 cell lines. Results: Our analysis revealed that all protein-coding genes in the INK4-ARF locus, including CDKN2A and CDKN2B, were deleted in the A549 cell lines. Furthermore, we observed that ANRIL was entirely deleted in the A549 cells. The evaluated locus and all of its genes are present and expressed in other investigated cell lines. Conclusions: For the deletion of ANRIL in the A549 cell line, 2 scenarios are possible: First, from a structural point of view, the deletion of the protein-coding genes in the antisense of ANRIL in the INK4-ARF locus implies the possibility of a concurrent loss of ANRIL with the deletion of these genes in the A549 cell line. Second, as cancer cell lines are genetically unstable and are always susceptible to the acquisition of new mutations, ANRIL loss may have occurred later, following a novel genetic alteRNAtion in a population derived from a mutated cell.

Associations of the Expression Levels and Risk Variants of CDKN2B-AS1 Long Noncoding RNA With the Susceptibility and Progression of Prostate Cancer.

Genetic variants of deregulated long noncoding RNAs (lncRNAs) have been implicated in tumorigenesis, cancer progression and cancer recurrence. Single-nucleotide polymorphisms (SNPs) of the lncRNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) have been associated with the risk and progression of various cancers; however, their role in prostate cancer (PCa) remains underexplored. In this case-control study, we investigated the associations of CDKN2B-AS1 expression levels and variants with PCa risk and progression. For this, five SNPs of CDKN2B-AS1-rs564398, rs1333048, rs1537373, rs2151280 and rs8181047-were genotyped using a TaqMan allelic discrimination assay; data were collected from 695 patients with PCa and 695 healthy controls. Our findings revealed that, under a dominant model, patients with PCa carrying at least one minor C allele of rs1333048 exhibited an increased risk of developing tumours with high Gleason grades; this risk was particularly high in patients without biochemical recurrence. Data from the Genotype-Tissue Expression database indicated upregulated CDKN2B-AS1 expression in the prostates of individuals carrying the polymorphic C allele of rs1333048. Genotype screening of rs1333048 in PCa cell lines showed that cells with at least one minor C allele had higher CDKN2B-AS1 levels than those with the AA genotype. Furthermore, data from The Cancer Genome Atlas indicated that higher CDKN2B-AS1 levels in PCa tissues were correlated with larger tumour sizes (T3 + T4), more lymph node metastasis (N1), higher Gleason scores and shorter progression-free survival. In conclusion, the polymorphic variants of CDKN2B-AS1 at rs1333048 may modulate CDKN2B-AS1 expression, thus accelerating PCa progression.

Retinoic acid inhibition of cell proliferation via activation of CDKN1B signaling in the forebrain and spinal cord during mouse embryonic development

BackgroundThe active metabolite of vitamin A (retinol) is retinoic acid (RA). RA is essential for developing several organs as a signaling molecule that is tightly regulated during embryogenesis. We explored the teratogenic effects of RA on forebrain and spinal cord development modified by cyclin-dependent kinase inhibitor 1B (CDKN1B), as the mechanism underlying RA's teratogenic impacts requires further investigation. The study involved four groups of pregnant mice: the negative control group, the positive control group treated with dimethyl sulfoxide (DMSO) diluted in sunflower oil, the RA-treated group receiving a low dosage (5 mg/kg), and the RA-treated group receiving a high dosage (10 mg/kg). The treatment groups received daily intraperitoneal RA dissolved in DMSO and diluted with sunflower oil on gestational days 10.5, 11.5, and 12.5. On day 13.5 of pregnancy, the pregnant mice were euthanized by cervical dislocation, and immunohistochemical analyses of brain and spinal cord tissues were performed.ResultsMorphologically, we observed a decrease in the number of implantation sites and the presence of hematomas in several uterus areas in the high-dose RA (10 mg/kg) group. Additionally, RA was shown to cause adverse changes in uterine weight and length. RA treatment indicated elevated levels of CDKN1B expression in spinal cord development, the diencephalon, and the telencephalon.ConclusionOur findings demonstrated that by activating CDKN1B as an RA target gene for cell cycle arrest, an excess of RA during brain development in mouse embryos can induce cell undifferentiation during development.

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.

The miR-15b-5p/miR-379-3p-FOXO axis regulates cell cycle and apoptosis in scleral remodeling during experimental myopia

BackgroundMyopia is one of the most common eye diseases in children and adolescents worldwide, and scleral remodeling plays a role in myopia progression. However, the identity of the initiating factors and signaling pathways that induce myopia-associated scleral remodeling is still unclear. This study aimed to identify biomarkers of scleral remodeling to elucidate the pathogenesis of myopia.MethodsThe gene expression omnibus (GEO) and comparative toxicogenomics database (CTD) mining were used to identify the miRNA-mRNA regulatory network related to scleral remodeling in myopia. Real-time quantitative PCR (RT-qPCR), Western blot, immunofluorescence, H&E staining, Masson staining, and flow cytometry were used to detect the changes in the FOXO signaling pathway, fibrosis, apoptosis, cell cycle, and other related factors in scleral remodeling.ResultsmiR-15b-5p/miR-379-3p can regulate the FOXO signaling pathway. Confirmatory studies confirmed that the axial length of the eye was significantly increased, the scleral thickness was thinner, the levels of miR-15b-5p, miR-379-3p, PTEN, p-PTEN, FOXO3a, cyclin-dependent kinase (CDK) inhibitor 1B (CDKN1B) were increased, and the levels of IGF1R were decreased in Len-induced myopia (LIM) group. CDK2, cyclin D1 (CCND1), and cell cycle block assessed by flow cytometry indicated G1/S cell cycle arrest in myopic sclera. The increase in BAX level and the decrease in BCL-2 level indicated enhanced apoptosis of the myopic sclera. In addition, we found that the levels of transforming growth factor-β1 (TGF-β1), collagen type 1 (COL-1), and α-smooth muscle actin (α-SMA) were decreased, suggesting scleral remodeling occurred in myopia.ConclusionsmiR-15b-5p/miR-379-3p can regulate the scleral cell cycle and apoptosis through the IGF1R/PTEN/FOXO signaling pathway, thereby promoting scleral remodeling in myopia progression.Graphical

Genetic association of diabetic retinopathy with long noncoding RNA CDKN2B-AS1 gene polymorphism.

We attempted to test the influences of cyclin dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) gene polymorphisms on the susceptibility to Diabetic retinopathy (DR). Five single-nucleotide polymorphisms (SNPs) of the CDKN2B-AS1 gene, rs564398, rs1333048, rs1537373, rs2151280, and rs8181047 were examined in 280 DR cases and 455 DR-free diabetic controls. Among these loci tested, we demonstrated that diabetic carriers of at least one polymorphic allele (G) of rs2151280 (AG and GG; AOR, 1.613; 95% CI, 1.040-2.501; p = 0.033) are more susceptible to proliferative DR but not non-proliferative DR. This genetic association with the risk of developing proliferative DR was further strengthened in homozygotes for the polymorphic allele (G) of rs2151280 (GG; AOR, 2.194; 95% CI, 1.117-4.308; p = 0.023). We detected a significant association of the polymorphic allele (G) of rs2151280 with proliferative DR patients (OR, 1.503; 95% CI, 1.112-2.033; p = 0.008) but not with the entire DR or non-proliferative DR group. Moreover, as compared to those who do not possess the polymorphic allele of rs2151280 (AA), DR patients carrying at least one polymorphic allele of rs2151280 (AG + GG) exhibited a lower glomerular filtration rate and HDL cholesterol level, revealing a promotive role of rs2151280 in renal and cardiovascular complications of diabetes. Taken together, our findings implicate an impact of CDKN2B-AS1 gene polymorphisms on the progression of DR.

Syndromic MEN1 Parathyroid Adenomas Consist of Both Subclonal Nodules and Clonally Independent Tumors

Abstract Background Primary hyperparathyroidism with parathyroid tumors is a characteristic presentation in Multiple Endocrine Neoplasia Type 1 (MEN1), historically referred to as "primary hyperplasia." The question of whether these tumors signify a multi-glandular clonal disorder or hyperplasia remains inconclusive. Loss of Menin protein expression serves as a reliable surrogate marker for biallelic inactivation and indicates a mutation in the MEN1 gene. The cyclin-dependent kinase inhibitor 1B (CDKN1B) gene, associated with MEN4, encodes the p27 protein, whose expression is inadequately explored in the context of syndromic MEN1. Aims The aim was to explore the molecular basis of syndromic MEN1 parathyroid adenomas, identifying hyperplasia, multiple independent clones, and the extent of Menin loss. Additionally, p27 expression was assessed to evaluate its potential in indicating a germline mutation, especially in distinguishing MEN4 as a clinical alternative to MEN1. Methods In this investigation, we examined histomorphology and protein expression of Menin and p27 in parathyroid adenomas from 25 patients in two independent, well-characterized MEN1 cohorts. Loss of heterozygosity (LOH) patterns were evaluated using fluorescence in situ hybridization (FISH) in one MEN1-associated parathyroid adenoma. Furthermore, next-generation sequencing (NGS) was conducted on eleven nodules from four MEN1 patients. Results Morphologically, the majority of MEN1 adenomas displayed multiple distinct nodules, characterized by predominantly lost Menin expression and reduced p27 protein expression. FISH analysis indicated that most nodules exhibited MEN1 loss, with or without centromere 11 loss. NGS demonstrated both subclonal evolution and the existence of clonally unrelated tumors. Conclusion Syndromic MEN1 parathyroid adenomas, therefore, consist of multiple clones with subclones, aligning with the current framework of the novel WHO classification of parathyroid tumors (2022). The observed loss of p27 expression in a significant fraction of MEN1 parathyroids emphasizes the need for caution when inferring MEN4 solely based on p27 expression.

Genetic study of the CDKN2A and CDKN2B genes in renal cell carcinoma patients

ObjectivesWhile recent studies have demonstrated several genetic alterations are associated with pathogenesis of RCC, the significance of cyclin-dependent kinase inhibitor 2A (CDKN2A) and cyclin-dependent kinase inhibitor 2B (CDKN2B) in tumorigenesis of RCC is less clear. We investigate the distribution of CDKN2A and CDKN2B mutations in patients with RCC and analyze the impact of CDKN2A and CDKN2B mutations on RCC. MethodsA pathological examination was conducted using thirty fresh renal tissue samples with renal masses that had undergone partial or radical nephrectomy. Multiplex ligation-dependent probe amplification (MLPA) was used to detect genetic aberrations of CDKN2A and CDKN2B in genomic DNA isolated from samples. Subsequently, CDKN2A and CDKN2B mutations were confirmed using chromosomal microarray technique. ResultsTwenty-one patients were diagnosed with RCC, eight with benign diseases, including angiomyolipoma (AML) and oncocytoma, and one with mucinous adenocarcinoma of renal pelvis. Two of twenty-one patients (9.5 %) with clear-cell RCC were positive for CDKN2A and CDKN2B gene deletions. Interestingly, patients with CDKN2A and CDKN2B mutations were associated with sarcomatoid patterns of RCC (2 out of 4, 50 %). In contrast, no CDKN2A or CDKN2B deletions were detected in samples from benign renal tumors, papillary RCC, or other kidney cancers. ConclusionsThis study demonstrated the potential use of CDKN2A and CDKN2B as biomarkers for the prognostic and molecular classification of renal cancer. CDKN2A and CDKN2B mutations may be associated with RCC development and sarcomatoid changes. Further research is needed to understand the underlying molecular mechanisms of CDKN2A and CDKN2B in the pathogenesis of RCC.

Inhibition of the RPS6KA1/FoxO1 signaling axis by hydroxycitric acid attenuates HFD-induced obesity through MCE suppression

BackgroundBecause obesity is associated with a hyperplasia-mediated increase in adipose tissue, inhibiting cell proliferation during mitotic clonal expansion (MCE) is a leading strategy for preventing obesity. Although (–)-hydroxycitric acid (HCA) is used to control obesity, the molecular mechanisms underlying its effects on MCE are poorly understood. PurposeThis study aimed to investigate the potential effects of HCA on MCE and underlying molecular mechanisms affecting adipogenesis and obesity improvements. MethodsPreadipocyte cell line, 3T3-L1, were treated with HCA; oil red O, cell proliferation, cell cycle, and related alterations in signaling pathways were examined. High-fat diet (HFD)-fed mice were administered HCA for 12 weeks; body and adipose tissues weights were evaluated, and the regulation of signaling pathways in epidydimal white adipose tissue were examined in vivo. ResultsHere, we report that during MCE, HCA attenuates the proliferation of the preadipocyte cell line, 3T3-L1, by arresting the cell cycle at the G0/G1 phase. In addition, HCA markedly inhibits Forkhead Box O1 (FoxO1) phosphorylation, thereby inducing the expression of cyclin-dependent kinase inhibitor 1B and suppressing the levels of cyclin-dependent kinase 2, cyclin E1, proliferating cell nuclear antigen, and phosphorylated retinoblastoma. Importantly, we found that ribosomal protein S6 kinase A1 (RPS6KA1) influences HCA-mediated inactivation of FoxO1 and its nuclear exclusion. An animal model of obesity revealed that HCA reduced high-fat diet-induced obesity by suppressing adipocyte numbers as well as epididymal and mesenteric white adipose tissue mass, which is attributed to the regulation of RPS6KA1, FoxO1, CDKN1B and PCNA that had been consistently identified in vitro. ConclusionsThese findings provide novel insights into the mechanism by which HCA regulates adipogenesis and highlight the RPS6KA1/FoxO1 signaling axis as a therapeutic target for obesity.

Downregulation of lncRNA CDKN2B-AS1 attenuates inflammatory response in mice with allergic rhinitis by regulating miR-98-5p/SOCS1 axis

Long non-coding RNA cyclin-dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) in various diseases has been verified. However, the underlying mechanism of CDKN2B-AS1 contributes to the development of allergic rhinitis (AR) remains unknown. To evaluate the impact of CDKN2B-AS1 on AR, BALB/c mice were sensitized by intraperitoneal injection of normal saline containing ovalbumin (OVA) and calmogastrin to establish an AR model. Nasal rubbing and sneezing were documented after the final OVA treatment. The concentrations of IgE, IgG1, and inflammatory elements were quantified using ELISA. Hematoxylin and eosin (H&E) staining and immunofluorescence were used to assess histopathological variations and tryptase expression, respectively. StarBase, TargetScan and luciferase reporter assays were applied to predict and confirm the interactions among CDKN2B-AS1, miR-98-5p, and SOCS1. CDKN2B-AS1, miR-98-5p, and SOCS1 levels were assessed by quantitative real-time PCR (qRT-PCR) or western blotting. Our results revealed that CDKN2B-AS1 was obviously over-expressed in the nasal mucosa of AR patients and AR mice. Down-regulation of CDKN2B-AS1 significantly decreased nasal rubbing and sneezing frequencies, IgE and IgG1 concentrations, and cytokine levels. Furthermore, down-regulation of CDKN2B-AS1 also relieved the pathological changes in the nasal mucosa, and the infiltration of eosinophils and mast cells. Importantly, these results were reversed by the miR-98-5p inhibitor, whereas miR-98-5p directly targeted CDKN2B-AS1, and miR-98-5p negatively regulated SOCS1 level. Our findings demonstrate that down-regulation of CDKN2B-AS1 improves allergic inflammation and symptoms in a murine model of AR through the miR-98-5p/SOCS1 axis, which provides new insights into the latent functions of CDKN2B-AS1 in AR treatment.

METTL3 promotes cellular senescence of colorectal cancer via modulation of CDKN2B transcription and mRNA stability.

Cellular senescence plays a critical role in cancer development, but the underlying mechanisms remain poorly understood. Our recent study uncovered that replicative senescent colorectal cancer (CRC) cells exhibit increased levels of mRNA N6-methyladenosine (m6A) and methyltransferase METTL3. Knockdown of METTL3 can restore the senescence-associated secretory phenotype (SASP) of CRC cells. Our findings, which were confirmed by m6A-sequencing and functional studies, demonstrate that the cyclin-dependent kinase inhibitor 2B (CDKN2B, encoding p15INK4B) is a mediator of METTL3-regulated CRC senescence. Specifically, m6A modification at position A413 in the coding sequence (CDS) of CDKN2B positively regulates its mRNA stability by recruiting IGF2BP3 and preventing binding with the CCR4-NOT complex. Moreover, increased METTL3 methylates and stabilizes the mRNA of E2F1, which binds to the -208 to -198 regions of the CDKN2B promoter to facilitate transcription. Inhibition of METTL3 or specifically targeting CDKN2B methylation can suppress CRC senescence. Finally, the METTL3/CDKN2B axis-induced senescence can facilitate M2 macrophage polarization and is correlated with aging and CRC progression. The involvement of METTL3/CDKN2B in cell senescence provides a new potential therapeutic target for CRC treatment and expands our understanding of mRNA methylation's role in cellular senescence.

Syndromic MEN1 parathyroid adenomas consist of both subclonal nodules and clonally independent tumors

Primary hyperparathyroidism with parathyroid tumors is a typical manifestation of Multiple Endocrine Neoplasia Type 1 (MEN1) and is historically termed “primary hyperplasia”. Whether these tumors represent a multi-glandular clonal disease or hyperplasia has not been robustly proven so far. Loss of Menin protein expression is associated with inactivation of both alleles and a good surrogate for a MEN1 gene mutation. The cyclin-dependent kinase inhibitor 1B (CDKN1B) gene is mutated in MEN4 and encodes for protein p27 whose expression is poorly studied in the syndromic MEN1 setting.Here, we analyzed histomorphology and protein expression of Menin and p27 in parathyroid adenomas of 25 patients of two independent, well-characterized MEN1 cohorts. The pattern of loss of heterozygosity (LOH) was assessed by fluorescence in situ hybridization (FISH) in one MEN1-associated parathyroid adenoma. Further, next-generation sequencing (NGS) was performed on eleven nodules of four MEN1 patients.Morphologically, the majority of MEN1 adenomas consisted of multiple distinct nodules, in which Menin expression was mostly lost and p27 protein expression reduced. FISH analysis revealed that most nodules exhibited MEN1 loss, with or without the loss of centromere 11. NGS demonstrated both subclonal evolution and the existence of clonally unrelated tumors.Syndromic MEN1 parathyroid adenomas therefore consist of multiple clones with subclones, which supports the current concept of the novel WHO classification of parathyroid tumors (2022). p27 expression was lost in a large fraction of MEN1 parathyroids and must therefore be used with caution in suggesting MEN4.

Refinement of prognostication for IDH-mutant astrocytomas using DNA methylation-based classification.

The 2021 World Health Organization (WHO) grading system of isocitrate dehydrogenase (IDH)-mutant astrocytomas relies on histological features and the presence of homozygous deletion of the cyclin-dependent kinase inhibitor 2A and 2B (CDKN2A/B). DNA methylation profiling has become highly relevant in the diagnosis of central nervous system (CNS) tumors including gliomas, and it has been incorporated into routine clinical diagnostics in some countries. In this study, we, therefore, examined the value of DNA methylation-based classification for prognostication of patients with IDH-mutant astrocytomas. We analyzed histopathological diagnoses, genome-wide DNA methylation array data, and chromosomal copy number alteration profiles from a cohort of 385 adult-type IDH-mutant astrocytomas, including a local cohort of 127 cases and 258 cases from public repositories. Prognosis based on WHO 2021 CNS criteria (histological grade and CDKN2A/B homozygous deletion status), other relevant chromosomal/gene alterations in IDH-mutant astrocytomas and DNA methylation-based subclassification according to the molecular neuropathology classifier were assessed. We demonstrate that DNA methylation-based classification of IDH-mutant astrocytomas can be used to predict outcome of the patients equally well as WHO 2021 CNS criteria. In addition, methylation-based subclassification enabled the identification of IDH-mutant astrocytoma patients with poor survival among patients with grade 3 tumors and patients with grade 4 tumors with a more favorable outcome. In conclusion, DNA methylation-based subclassification adds prognostic information for IDH-mutant astrocytomas that can further refine the current WHO 2021 grading scheme for these patients.

P27 Cell Cycle Inhibitor and Survival in Luminal-Type Breast Cancer: Gene Ontology, Machine Learning, and Drug Screening Analysis.

A widely distributed cell cycle inhibitor, p27, regulates cyclin-dependent kinase-cyclin complexes. Although the prognostic value of p27 has been established for various types of carcinomas, its role in luminal breast cancer remains poorly understood. This study aimed to explore the functional enrichment of p27 and identify potential drug targets in patients with luminal-type breast cancer. Clinicopathological data were collected from 868 patients with luminal-type breast cancer. Additionally, publicly available data from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) dataset (1,500 patients) and the Gene Expression Omnibus database (855 patients) were included in the analysis. Immunohistochemical staining for p27, differential gene expression analysis, disease ontology analysis, survival prediction modeling using machine learning (ML), and in vitro drug screening were also performed. Low p27 expression correlated with younger age, advanced tumor stage, estrogen receptor/progesterone receptor negativity, decreased cluster of differentiation 8+ T cell count, and poorer survival outcomes in luminal-type breast cancer. The METABRIC data revealed that reduced cyclin-dependent kinase inhibitor 1B (CDKN1B) expression (encoding p27) was associated with cell proliferation-related pathways and epigenetic polycomb repressive complex 2. Using ML, p27 emerged as the second most significant survival factor after N stage, thereby enhancing survival model performance. Additionally, luminal-type breast cancer cell lines with low CDKN1B expression demonstrated increased sensitivity to specific anticancer drugs such as voxtalisib and serdemetan, implying a potential therapeutic synergy between CDKN1B-targeted approaches and these drugs. The integration of ML and bioinformatic analyses of p27 has the potential to enhance risk stratification and facilitate personalized treatment strategies for patients with breast cancer.

Characterization of senescent mesenchymal stem/stromal cells derived from equine bone marrow and the effects of NANOG on the senescent phenotypes

In equine regenerative medicine using bone marrow-derived mesenchymal stem/stromal cells (BM-MSC), the importance of the quality management of BM-MSC has been widely recognized. However, there is little information concerning the relationship between cellular senescence and the stemness in equine BM-MSC. In this study, we showed that stemness markers (NANOG, OCT4, SOX2 and telomerase reverse transcriptase) and colony forming unit-fibroblast apparently decreased accompanied with incidence of senescence-associated β-galactosidase-positive cells by repeated passage. Additionally, we suggested that down-regulation of cell proliferation in senescent BM-MSC was related to increased expression of cyclin-dependent kinase inhibitor 2B (CDKN2B). On the other hand, forced expression of NANOG into senescent BM-MSC brought upregulation of several stemness markers and downregulation of CKDN2B accompanied with restoration of proliferation potential and osteogenic ability. These results suggested that expression of NANOG was important for the maintenance of the stemness in equine BM-MSC.

Low CDKN1B Expression Associated with Reduced CD8+ T Lymphocytes Predicts Poor Outcome in Breast Cancer in a Machine Learning Analysis.

The cyclin-dependent kinase inhibitor 1B (CDKN1B) gene, which encodes the p27Kip1 protein, is important in regulating the cell cycle process and cell proliferation. Its role in breast cancer prognosis is controversial. We evaluated the significance and predictive role of CDKN1B expression in breast cancer prognosis. We investigated the clinicopathologic factors, survival rates, immune cells, gene sets, and prognostic models according to CDKN1B expression in 3794 breast cancer patients. We performed gene set enrichment analysis (GSEA), in silico cytometry, pathway network analyses, gradient boosting machine (GBM) learning, and in vitro drug screening. High CDKN1B expression levels in breast cancer correlated with high lymphocyte infiltration signature scores and increased CD8+ T cells, both of which were associated with improved prognosis in breast cancer. which were associated with a better prognosis. CDKN1B expression was associated with gene sets for the upregulation of T-cell receptor signaling pathways and downregulation of CD8+ T cells. Pathway network analysis revealed a direct link between CDKN1B and the pathway involved in the positive regulation of the protein catabolic process pathway. In addition, an indirect link was identified between CDKN1B and the T-cell receptor signaling pathway. In in vitro drug screening, BMS-345541 demonstrated efficacy as a therapeutic targeting of CDKN1B, effectively impeding the growth of breast cancer cells characterized by low CDKN1B expression. The inclusion of CDKN1B expression in GBM models increased the accuracy of survival predictions. CDKN1B expression plays a significant role in breast cancer progression, implying that targeting CDKN1B might be a promising strategy for treating breast cancer.

CircUBAP2 ameliorates hypoxia-induced acute myocardial injury by competing with miR-148b-3p and mediating CDKN1B expression

BackgroundA recent high-throughput sequencing study revealed an anomalous underexpression of circular RNA UBAP2 (circUBAP2) in acute myocardial infarction (AMI), yet its biological function within this context remains elusive. This study aims to unravel whether circUBAP2 is instrumental in modulating the pathogenesis of AMI and to illuminate the underlying molecular mechanisms at play. ResultscircUBAP2 was abnormally low expressed in AMI. Inducing circUBAP2 ameliorated hypoxia-induced myocardial cell injury by enhancing cellular viability, and decreasing lactate dehydrogenase release, apoptosis, inflammation, and oxidative damage. circUBAP2 targeted miR-148b-3p, miR-148b-3p overexpression offset circUBAP2-induced cardioprotection. Cyclin-dependent kinase inhibitor 1B (CDKN1B) was mediated by miR-148b-3p, and CDKN1B upregulation suppressed the deleterious effect of circUBAP2 silencing on hypoxic AC16 cells. In addition, overexpression of circUBAP2 improved myocardial injury, decreased myocardial cell apoptosis, and alleviated inflammation and oxidative stress in AMI mice. ConclusionscircUBAP2 ameliorates AMI by competitively binding to miR-148b-3p and mediating CDKN1B expression.How to cite: Li F, Xu L, Ou J, et al. circUBAP2 ameliorates hypoxia-induced acute myocardial injury by competing with miR-148b-3p and mediating CDKN1B expression. Electron J Biotechnol 2024;68. https://doi.org/10.1016/j.ejbt.2023.11.003.

Identified senescence endotypes in aged cartilage are reflected in the blood metabolome

Heterogeneous accumulation of senescent cells expressing the senescence-associated secretory phenotype (SASP) affects tissue homeostasis which leads to diseases, such as osteoarthritis (OA). In this study, we set out to characterize heterogeneity of cellular senescence within aged articular cartilage and explored the presence of corresponding metabolic profiles in blood that could function as representative biomarkers. Hereto, we set out to perform cluster analyses, using a gene-set of 131 senescence genes (N = 57) in a previously established RNA sequencing dataset of aged articular cartilage and a generated metabolic dataset in overlapping blood samples. Using unsupervised hierarchical clustering and pathway analysis, we identified two robust cellular senescent endotypes. Endotype-1 was enriched for cell proliferating pathways, expressing forkhead box protein O4 (FOXO4), RB transcriptional corepressor like 2 (RBL2), and cyclin-dependent kinase inhibitor 1B (CDKN1B); the FOXO mediated cell cycle was identified as possible target for endotype-1 patients. Endotype-2 showed enriched inflammation-associated pathways, expressed by interleukin 6 (IL6), matrix metallopeptidase (MMP)1/3, and vascular endothelial growth factor (VEGF)C and SASP pathways were identified as possible targets for endotype-2 patients. Notably, plasma-based metabolic profiles in overlapping blood samples (N = 21) showed two corresponding metabolic clusters in blood. These non-invasive metabolic profiles could function as biomarkers for patient-tailored targeting of senescence in OA.

Interactive effects of CDKN2B-AS1 gene polymorphism and habitual risk factors on oral cancer.

Oral squamous cell carcinoma (OSCC) is a common malignant disease associated with a high mortality rate and heterogeneous disease aetiology. Cyclin dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1), is a long noncoding RNA that has been shown to act as a scaffold, sponge, or signal hub to promote carcinogenesis. Here, we attempted to assess the effect of CDKN2B-AS1 single-nucleotide polymorphisms (SNPs) on the susceptibility to OSCC. Five CDKN2B-AS1 SNPs, including rs564398, rs1333048, rs1537373, rs2151280 and rs8181047, were analysed in 1060 OSCC cases and 1183 cancer-free controls. No significant association of these five SNPs with the risk of developing OSCC was detected between the case and control group. However, while examining the clinical characteristics, patients bearing at least one minor allele of rs1333048 (CA and CC) were more inclined to develop late-stage (stage III/IV, adjusted OR, 1.480; 95% CI, 1.129-1.940; p = 0.005) and large-size (greater than 2 cm in the greatest dimension, adjusted OR, 1.347; 95% CI, 1.028-1.765; p = 0.031) tumours, as compared with those homologous for the major allele (AA). Further stratification analyses demonstrated that this genetic correlation with the advanced stage of disease was observed only in habitual betel quid chewers (adjusted OR, 1.480; 95% CI, 1.076-2.035; p = 0.016) or cigarette smokers (adjusted OR, 1.531; 95% CI, 1.136-2.063; p = 0.005) but not in patients who were not exposed to these major habitual risks. These data reveal an interactive effect of CDKN2B-AS1 rs1333048 with habitual exposure to behavioural risks on the progression of oral cancer.

Expression analysis of cytoskeleton regulator RNA and Cyclin Dependent Kinase Inhibitor 2B genes in breast cancer.

Breast cancer has been found to be associated with deregulation of several non-coding genes and mRNA coding genes. To assess expressions of CYTOR and CDKN2B in breast cancer and adjacent samples and find their relevance with clinical data. We enumerated expression level of CDKN2B and CYTOR in 43 newly diagnosed breast cancer samples and their adjacent specimens using real-time PCR method Expression data was judged using Wilcoxon matched-pairs signed rank test. CYTOR level was higher in tumors compared with adjacent tissues. Nevertheless, there was no difference in expression of CDKN2B between these two sets of tissues. ROC curve analysis showed that CYTOR levels can differentiate between tumoral and adjacent tissues with AUC, specificity and sensitivity values of 0.65, 37% and 92% (P= 0.017). There was a positive correlation between expression levels of CYTOR and CDKN2B genes in breast cancer tissues (r= 0.5 and P= 0.0008) as well as adjacent tissues (r= 0.79 and P< 0.0001). Relative expression level of CDKN2B in normal tissues was associated with clinical stage (P= 0.014). Moreover, relative expression level of CDKN2B in tumor tissues was associated with the body weight. There was no other association between expressions of CYTOR and CDKN2B and clinical or pathological variables. Cumulatively, this study offers evidence for involvement of these genes in the pathoetiology of breast cancer.