Role and Regulatory Mechanism of circRNA_14820 in the Proliferation and Differentiation of Goat Skeletal Muscle Satellite Cells.

Skeletal muscle satellite cells (SMSCs), a type of myogenic stem cell, play a pivotal role in postnatal muscle regeneration and repair in animals. Circular RNAs (circRNAs) are a distinct class of non-coding RNA molecules capable of regulating muscle development by modulating gene expression, acting as microRNAs, or serving as protein decoys. In this study, we identified circ_14820, an exonic transcript derived from adenosine triphosphatase family protein 2 (ATAD2), through initial RNA-Seq analysis. Importantly, overexpression of circ_14820 markedly enhanced the proliferation of goat SMSCs while concomitantly suppressing their differentiation. Moreover, circ_14820 exhibited predominant localization in the cytoplasm of SMSCs. Subsequent small RNA and mRNA sequencing of circ_14820-overexpressing SMSCs systematically elucidated the molecular regulatory mechanisms associated with circ_14820. Our preliminary findings suggest that the circ_14820-miR-206-CCND2 regulatory axis may govern the development of goat SMSCs. These discoveries contribute to a deeper understanding of circRNA-mediated mechanisms in regulating skeletal muscle development, thereby advancing our knowledge of muscle biology.

Doxycycline-Mediated Control of Cyclin D2 Overexpression in Human-Induced Pluripotent Stem Cells.

Previous studies have demonstrated that when the cyclin D2 (CCND2), a cell-cycle regulatory protein, is overexpressed in human-induced pluripotent stem cells (hiPSCs), cardiomyocytes (CMs) differentiated from these CCND2-overexpressing hiPSCs can proliferate after transplantation into infarcted hearts, which significantly improves the cells' potency for myocardial regeneration. However, persistent CM proliferation could lead to tumor growth or the development of arrhythmogenic complications; thus, the goal of the current study was to generate a line of hiPSCs in which CCND2 overexpression could be tightly controlled. First, we transfected hiPSCs with vectors coding for a doxycycline-inducible Tet-On transactivator and S. pyogenes dCas9 fused to the VPR activation domain; then, the same hiPSCs were engineered to express guide RNAs targeting the CCND2 promotor. Thus, treatment with doxycycline (dox) activated dCas9-VPR expression, and the guide RNAs directed dCas9-VPR to the CCND2 promoter, which activated CCND2 expression. Subsequent experiments confirmed that CCND2 expression was dox-dependent in this newly engineered line of hiPSCs (doxCCND2-hiPSCs): CCND2 protein was abundantly expressed after 48 h of treatment with dox and declined to near baseline level ~96 h after dox treatment was discontinued.

ErbB3 is required for hyperaminoacidemia-induced pancreatic α cell hyperplasia.

Blood amino acid levels are maintained in a narrow physiological range. The pancreatic α cells have emerged as the primary aminoacidemia regulator through glucagon secretion to promote hepatic amino acid catabolism. Interruption of glucagon signaling disrupts the liver-α cells axis leading to hyperaminoacidemia, which triggers a compensatory rise in glucagon secretion and α cell hyperplasia. The mechanisms of hyperaminoacidemia-induced α cell hyperplasia remain incompletely understood. Using a mouse α cell line and in vivo studies in zebrafish and mice, we found that hyperaminoacidemia-induced α cell hyperplasia requires ErbB3 signaling. In addition to mechanistic target of rapamycin complex 1, another ErbB3 downstream effector signal transducer and activator of transcription 3 also plays a role in α cell hyperplasia. Mechanistically, ErbB3 may partner with ErbB2 to stimulate cyclin D2 and suppress p27 via mechanistic target of rapamycin complex 1 and signal transducer and activator of transcription 3. Our study identifies ErbB3 as a new regulator for hyperaminoacidemia-induced α cell proliferation and a critical component of the liver-α cells axis that regulates aminoacidemia.

[Bioinformatic analysis of CCND2 expression in papillary thyroid carcinoma and its impact on immune infiltration].

OBJECTIVE: To investigate cyclin D2 (CCND2) expression in papillary thyroid carcinoma (PTC) and its association with the clinicopathological features. METHODS: The public databases TCGA, TIMER 2.0 and UALCAN were used to explore CCND2 expression level in PTC and adjacent tissues, and its diagnostic value for PTC was analyzed using ROC curves. GO enrichment analysis of CCND2-related differentially expressed genes (DEGs) in PTC was performed, and tumor immune infiltration of CCND2 in thyroid cancer was analyzed using TIMER database and CIBERSORT data source. RT-qPCR and Western blot were used to detect CCND2 expression in normal human thyroid cell line Nthy-ori-3-1 and human PTC cell lines TPC-1 and BCPAP. CCND2 expression was also detected in clinical specimens of PTC and adjacent tissues by immunohistochemistry, and its correlation with clinicopathological features of the patients were analyzed. RESULTS: Informatic analysis revealed significantly higher CCND2 mRNA expression in thyroid cancer than in the adjacent tissues (P < 0.001) in close correlation with tumor stage, gender, age, pathological subtype, and lymph node involvement (P < 0.05). ROC curve analysis showed that at the cutoff value of 4.983, the diagnostic sensitivity, specificity, and accuracy of CCND2 expression for PTC was 83.6%, 94.9%, and 78.5%, respectively. CCND2 expression was positively correlated with B cells, CD4+ T cells, and macrophages (P < 0.001) and negatively with CD8+ T cells (P < 0.01), and also correlated with memory B-cell infiltration, CD4+ T-cell memory activation, M2 macrophages, resting mast cells, and mast cell activation (P < 0.05). RT-qPCR, Western blot and immunohistochemistry showed significantly higher CCND2 expression in the PTC cells than in Nthy-ori-3-1 cells (P < 0.01) and also in clinical PTC tissues than in the adjacent tissues (P < 0.05) in correlation with tumor size, lymph node metastasis and TNM stage (P < 0.05). CONCLUSION: CCND2 overexpression is closely correlated with tumor progression and immune cell infiltration in PTC patients..

Trans-Activation of the Coactivator-Associated Arginine Methyltransferase 1 (Carm1) Gene by the Oncogene Product Tax of Human T-Cell Leukemia Virus Type 1.

Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma. The oncogene product Tax of HTLV-I is thought to play crucial roles in leukemogenesis by promoting proliferation of the virus-infected cells through activation of growth-promoting genes. These genes code for growth factors and their receptors, cytokines, cell adhesion molecules, growth signal transducers, transcription factors and cell cycle regulators. We show here that Tax activates the gene coding for coactivator-associated arginine methyltransferase 1 (CARM1), which epigenetically enhances gene expression through methylation of histones. Tax activated the Carm1 gene and increased protein expression, not only in human T-cell lines but also in normal peripheral blood lymphocytes (PHA-PBLs). Tax increased R17-methylated histone H3 on the target gene IL-2Rα, concomitant with increased expression of CARM1. Short hairpin RNA (shRNA)-mediated knockdown of CARM1 decreased Tax-mediated induction of IL-2Rα and Cyclin D2 gene expression, reduced E2F activation and inhibited cell cycle progression. Tax acted via response elements in intron 1 of the Carm1 gene, through the NF-κB pathway. These results suggest that Tax-mediated activation of the Carm1 gene contributes to leukemogenic target-gene expression and cell cycle progression, identifying the first epigenetic target gene for Tax-mediated trans-activation in cell growth promotion.

A de novo Mutation (p.Gln277X) of Cyclin D2 is Responsible for a Child with Megalencephaly-Polymicrogyria-Polydactyly-Hydrocephalus Syndrome.

Megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH), a type of overgrowth syndrome, is characterized by progressive megalencephaly, cortical brain malformations, and distal limb anomalies. Previous studies have revealed that the overactivity of the phosphatidylinositol 3-kinase-Protein kinase B pathway and the increased cyclin D2 (CCND2) expression were the main factors contributing to this disease. Here, we present the case of a patient who exhibited megalencephaly, polymicrogyria, abnormal neuronal migration, and developmental delay. Serum tandem mass spectrometry and chromosome examination did not detect any metabolic abnormalities or copy number variants. However, whole-exome sequencing and Sanger sequencing revealed a de novo nonsense mutation (NM_001759.3: c.829C>T; p.Gln277X) in the CCND2 gene of the patient. Bioinformatics analysis predicted that this mutation may disrupt the structure and surface charge of the CCND2 protein. This disruption could potentially prevent polyubiquitination of CCND2, leading to its resistance against degradation. Consequently, this could drive cell division and growth by altering the activity of key cell cycle regulatory nodes, ultimately contributing to the development of MPPH. This study not only presents a new case of MPPH and expands the mutation spectrum of CCND2 but also enhances our understanding of the mechanisms connecting CCND2 with overgrowth syndromes.

Circ_0002331 Interacts with ELAVL1 to Improve ox-LDL-Induced Vascular Endothelial Cell Dysfunction via Regulating CCND2 mRNA Stability.

Circular RNAs (circRNAs) have been discovered to serve as vital regulators in atherosclerosis (AS). However, the role and mechanism of circ_0002331 in AS process are still unclear. Human umbilical vein endothelial cells (HUVECs) were treated with ox-LDL to establish an in vitro model for AS. The expression levels of circ_0002331, Cyclin D2 (CCND2) and ELAVL1 were analyzed by quantitative real-time PCR. Cell proliferation, apoptosis, migration, invasion and angiogenesis were assessed by EdU assay, flow cytometry, transwell assay and tube formation assay. The protein levels of CCND2, ELAVL1, and autophagy-related markers were detected using western blot analysis. IL-8 level was analyzed by ELISA. The relationship between ELAVL1 and circ_0002331 or CCND2 was analyzed by RIP assay and RNA pull-down assay. Moreover, FISH assay was used to analyze the co-localization of ELAVL1 and CCND2 in HUVECs. Our data showed that circ_0002331 was obviously downregulated in AS patients and ox-LDL-induced HUVECs. Overexpression of circ_0002331 could promote proliferation, migration, invasion and angiogenesis, while inhibit apoptosis, autophagy and inflammation in ox-LDL-induced HUVECs. Furthermore, CCND2 was positively regulated by circ_0002331, and circ_0002331 could bind with ELAVL1 to promote CCND2 mRNA stability. Besides, CCND2 overexpression suppressed ox-LDL-induced HUVECs dysfunction, and its knockdown also reversed the regulation of circ_0002331 on ox-LDL-induced HUVECs dysfunction. In conclusion, circ_0002331 might be a potential target for AS treatment, which could improve ox-LDL-induced dysfunction of HUVECs via regulating CCND2 by binding with ELAVL1.

Up-regulation of lncRNA WT1-AS ameliorates Aß-stimulated neuronal injury through modulation of miR-186-5p/CCND2 axis in Alzheimer's disease.

As a common neurodegenerative disorder, Alzheimer's disease (AD) seriously threatens human life. Long non-coding RNAs (lncRNAs) exhibit essential functions in AD development. Nevertheless, the detailed effects and possible mechanisms of lncRNA Wilms tumor 1 Antisense RNA (WT1-AS) in AD are largely unknown. In our studies, a total of 30 serum samples from AD patients were collected, and WT1-AS expressions were detected through qRT-PCR analysis. Additionally, an in vitro AD model was constructed by treating Aß1-42 in human neuroblastoma cells. Functional assays were implemented to assess the impacts of WT1-AS on Aß1-42-stimulated human neuroblastoma cell proliferation together with apoptosis. Moreover, relationship of WT1-AS, microRNA (miR)-186-5p as well as cyclin D2 (CCND2) could be predicted through bioinformatics tools as well as proved via dual-luciferase reporter experiments. Our results showed that WT1-AS together with CCND2 were low-expressed, while miR-186-5p presented high expression in AD serum samples together with Aß1-42-stimulated human neuroblastoma cells. WT1-AS over-expression or miR-186-5p depletion notably promoted the proliferation, reduced the apoptosis, and decreased the p-Tau protein expressions of human neuroblastoma cells induced with Aß1-42. Moreover, miR-186-5p combined with WT1-AS, and CCND2 was modulated by miR-186-5p. Furthermore, CCND2 elevation partially offsets the impacts of miR-186-5p elevation on Aß1-42-stimulated cell proliferation as well as apoptosis mediated with WT1-AS up-regulation. Our results indicated that up-regulation of lncRNA WT1-AS ameliorated Aß-stimulated neuronal damage through modulating miR-186-5p/CCND2 axis, offering a novel direction for AD therapy.

Generation of adult hippocampal neural stem cells occurs in the early postnatal dentate gyrus and depends on cyclin D2.

Lifelong hippocampal neurogenesis is maintained by a pool of multipotent adult neural stem cells (aNSCs) residing in the subgranular zone of the dentate gyrus (DG). The mechanisms guiding transition of NSCs from the developmental to the adult state remain unclear. We show here, by using nestin-based reporter mice deficient for cyclin D2, that the aNSC pool is established through cyclin D2-dependent proliferation during the first two weeks of life. The absence of cyclin D2 does not affect normal development of the dentate gyrus until birth but prevents postnatal formation of radial glia-like aNSCs. Furthermore, retroviral fate mapping reveals that aNSCs are born on-site from precursors located in the dentate gyrus shortly after birth. Taken together, our data identify the critical time window and the spatial location of the precursor divisions that generate the persistent population of aNSCs and demonstrate the central role of cyclin D2 in this process.

Enhanced expression of miR-204 attenuates LPS stimulated inflammatory injury through inhibiting the Wnt/ß-catenin pathway via targeting CCND2.

One of the most common bacterial diseases of the reproductive system in dairy cows is endometritis, which will cause huge economic loss. Here, we investigate the mechanisms of miR-204 on LPS-stimulated endometritis in vitro and in vivo. Experiments displayed that the expression of miR-204 was lower in bovine uterine tissue samples or bovine endometrial epithelial cell line (BEND) that stimulated by LPS. Compared with the negative group, miR-204 treatment significantly suppressed the production of proinflammatory factors and the Wnt/ß-catenin pathway activation. Additionally, the result of the dual luciferase assay showed that miR-204 targeted cyclin D2. More importantly, up-regulation of miR-204 alleviated LPS induced uterine injury was confirmed in vivo studies. Molecular experiments indicated that the expression level of tight junctional proteins Claudin3 and cadherin1 were both enchanced by miR-204 treatment. Accordingly, miR-204 may serve as a new measure to prevent and treat endometritis caused by LPS.

Quantification of cyclin D1 and D2 proteins in multiple myeloma identifies different expression patterns from those revealed by gene expression profiling.

Upregulation of a cyclin D gene determined by expression microarrays is an almost universal event in multiple myeloma (MM), but this finding has not been properly confirmed at the protein level. For this reason, we carried out a quantitative analysis of cyclin D proteins using a capillary electrophoresis nanoimmunoassay in newly diagnosed MM patients. Exclusive expression of cyclin D1 and D2 proteins was detected in 54 of 165 (33%) and 30 of 165 (18%) of the MM patients, respectively. Of note, cyclin D1 or D2 proteins were undetectable in 41% of the samples. High levels of cyclin D1 protein were strongly associated with the presence of t(11;14) or 11q gains. Cyclin D2 protein was detected in all the cases bearing t(14;16), but in only 24% of patients with t(4;14). The presence of cyclin D2 was associated with shorter overall survival (hazard ratio =2.14; P=0.017), although patients expressing cyclin D2 protein, but without 1q gains, had a favorable prognosis. In conclusion, although one of the cyclins D is overexpressed at the mRNA level in almost all MM patients, in approximately half of the patients this does not translate into detectable protein. This suggests that cyclins D could not play an oncogenic role in a proportion of patients with MM (clinicaltrials gov. identifier: NCT01916252).

GABA regulates the proliferation and apoptosis of head and neck squamous cell carcinoma cells by promoting the expression of CCND2 and BCL2L1.

Gamma-aminobutyric acid (GABA) is a multifunctional molecule that is widely present in the nervous system and nonneuronal tissues. It plays pivotal roles in neurotransmission, regulation of secretion, cell differentiation, proliferation, and tumorigenesis. However, the exact mechanisms of GABA in head and neck squamous cell carcinomas (HNSCCs) are unknown. We took advantage of RNA sequencing in this work and uncovered the potential gene expression profiles of the GABA-treated HNSCC cell line HN4-2. We found that the expression of CCND2 and BCL2L1 was significantly upregulated. Furthermore, GABA treatment inhibited the cell apoptosis induced by cisplatin and regulated the cell cycle after treatment with cisplatin in HN4-2 cells. Moreover, we also found that GABA could upregulate the expression of CCND2 and BCL2L1 after treatment with cisplatin. Our results not only reveal the potential pro-tumorigenic effect of GABA on HNSCCs but also provide a novel therapeutic target for HNSCC treatment.

CCND2 Modified mRNA Activates Cell Cycle of Cardiomyocytes in Hearts With Myocardial Infarction in Mice and Pigs.

BACKGROUND: Experiments in mammalian models of cardiac injury suggest that the cardiomyocyte-specific overexpression of CCND2 (cyclin D2, in humans) improves recovery from myocardial infarction (MI). The primary objective of this investigation was to demonstrate that our specific modified mRNA translation system (SMRTs) can induce CCND2 expression in cardiomyocytes and replicate the benefits observed in other studies of cardiomyocyte-specific CCND2 overexpression for myocardial repair. METHODS: The CCND2-cardiomyocyte-specific modified mRNA translation system (cardiomyocyte SMRTs) consists of 2 modRNA constructs: one codes for CCND2 and contains a binding site for L7Ae, and the other codes for L7Ae and contains recognition elements for the cardiomyocyte-specific microRNAs miR-1 and miR-208. Thus, L7Ae suppresses CCND2 translation in noncardiomyocytes but is itself suppressed by endogenous miR-1 and -208 in cardiomyocytes, thereby facilitating cardiomyocyte-specific CCND2 expression. Experiments were conducted in both mouse and pig models of MI, and control assessments were performed in animals treated with an SMRTs coding for the cardiomyocyte-specific expression of luciferase or green fluorescent protein (GFP), in animals treated with L7Ae modRNA alone or with the delivery vehicle, and in Sham-operated animals. RESULTS: CCND2 was abundantly expressed in cultured, postmitotic cardiomyocytes 2 days after transfection with the CCND2-cardiomyocyte SMRTs, and the increase was accompanied by the upregulation of markers for cell-cycle activation and proliferation (eg, Ki67 and Aurora B kinase). When the GFP-cardiomyocyte SMRTs were intramyocardially injected into infarcted mouse hearts, the GFP signal was observed in cardiomyocytes but no other cell type. In both MI models, cardiomyocyte proliferation (on day 7 and day 3 after treatment administration in mice and pigs, respectively) was significantly greater, left-ventricular ejection fractions (days 7 and 28 in mice, days 10 and 28 in pigs) were significantly higher, and infarcts (day 28 in both species) were significantly smaller in animals treated with the CCND2-cardiomyocyte SMRTs than in any other group that underwent MI induction. CONCLUSIONS: Intramyocardial injections of the CCND2-cardiomyocyte SMRTs promoted cardiomyocyte proliferation, reduced infarct size, and improved cardiac performance in small and large mammalian hearts with MI.

CCND2 mutations in atypical chronic myeloid leukemia: a report of two cases.

Atypical chronic myeloid leukemia (aCML) is a rare MDS/MPN disease characterized by the absence of BCR::ABL1 rearrangement and well known typical mutations associated with myeloproliferative disorders. Mutational landscape associated with this disease was recently described with frequent involvement of SETBP1 and ETNK1 mutations. CCND2 mutations have not been frequently detected in MPN or MDS/MPN patients. We describe two cases of aCML with two CCND2 mutations in 280 and 281 codons which rapidly develop progressive characteristics, and we reviewed the literature about this unfavorable association, suggesting a role as a new possible marker of aggressive disease.

MiR-188-5p inhibits cell proliferation and migration in ovarian cancer via competing for CCND2 with ELAVL1.

MicroRNAs (miRNAs) were reportedly demonstrated to participate in ovarian cancer (OC) progression. Here, we inquired into the role of miR-188-5punderneath OC cell proliferation and migration. In this respect, our work examined the miR-188-5p expression and demonstrated its expression level in OC by qRT-PCR analysis. Enforced miR-188-5p expression resulted in a serious downfall of cell growth and mobility, and acceleration apoptosis in OC cells. Furthermore, we identified CCND2 as a target gene of miR-188-5p. RIP assay and luciferase reporter assay verified the interaction of miR-188-5p and CCND2 and exhibited that miR-188-5p greatly hindered the expression of CCND2. Besides, HuR stabilized CCND2 mRNA and counteracted the miR-188-5p suppressive effect on CCND2 mRNA. Functionally, rescue experiments also showed that miR-188-5p-mediated suppression on OC cell proliferation and migration was reverted by CCND2 or HuR overexpression. Our study found miR-188-5p was a tumor suppressor in OC via competing for CCND2 with ELAVL1, contributing to coming up with novel clues for OC therapies.

Loss of individualized behavioral trajectories in adult neurogenesis-deficient cyclin D2 knockout mice.

There is still limited mechanistic insight into how the interaction of individuals with their environment results in the emergence of individuality in behavior and brain structure. Nevertheless, the idea that personal activity shapes the brain is implicit in strategies for healthy cognitive aging as well as in the idea that individuality is reflected in the brain's connectome. We have shown that even isogenic mice kept in a shared enriched environment (ENR) developed divergent and stable social and exploratory trajectories. As these trajectories-measured as roaming entropy (RE)-positively correlated with adult hippocampal neurogenesis, we hypothesized that a feedback between behavioral activity and adult hippocampal neurogenesis might be a causal factor in brain individualization. We used cyclin D2 knockout mice with constitutively extremely low levels of adult hippocampal neurogenesis and their wild-type littermates. We housed them for 3 months in a novel ENR paradigm, consisting of 70 connected cages equipped with radio frequency identification antennae for longitudinal tracking. Cognitive performance was evaluated in the Morris Water Maze task (MWM). With immunohistochemistry we confirmed that adult neurogenesis correlated with RE in both genotypes and that D2 knockout mice had the expected impaired performance in the reversal phase of the MWM. But whereas the wild-type animals developed stable exploratory trajectories with increasing variance, correlating with adult neurogenesis, this individualizing phenotype was absent in D2 knockout mice. Here the behaviors started out more random and revealed less habituation and low variance. Together, these findings suggest that adult neurogenesis contributes to experience-dependent brain individualization.

Ndufa4 Regulates the Proliferation and Apoptosis of Neurons via miR-145a-5p/Homer1/Ccnd2.

The Dandy-Walker malformation (DWM) is characterized by neuron dysregulation in embryonic development; however, the regulatory mechanisms associated with it are unclear. This study aimed to investigate the role of NADH dehydrogenase 1 alpha subcomplex 4 (NDUFA4) in regulating downstream signaling cascades and neuronal proliferation and apoptosis. Ndufa4 overexpression promoted the proliferation of neurons and inhibited their apoptosis in vitro, which underwent reverse regulation by the Ndufa4 short hairpin RNAs. Ndufa4-knockout (KO) mice showed abnormal histological alterations in the brain tissue, in addition to impaired spatial learning capacity and exploratory activity. Ndufa4 depletion altered the microRNA expressional profiles of the cerebellum: Ndufa4 inhibited miR-145a-5p expression both in the cerebellum and neurons. miR-145a-5p inhibited the proliferation of neurons and promoted their apoptosis. Ndufa4 promoted and miR-145a-5p inhibited the expression of human homer protein homolog 1 and cyclin D2 in neurons. Thus, Ndufa4 promotes the proliferation of neurons and inhibits their apoptosis by inhibiting miR-145a-5p, which directly targets and inhibits the untranslated regions of Homer1 and Ccnd2 expression.

Paternal sleep deprivation induces metabolic perturbations in male offspring via altered LRP5 DNA methylation of pancreatic islets.

Diabetes and metabolic perturbation are global health challenges. Sleep insufficiency may trigger metabolic dysregulation leading to diabetes. However, the intergenerational transmission of this environmental information is not clearly understood. The research objective was to determine the possible effect of paternal sleep deprivation on the metabolic phenotype of the offspring and to investigate the underlying mechanism of epigenetic inheritance. Male offspring of sleep-deprived fathers exhibit glucose intolerance, insulin resistance, and impaired insulin secretion. In these SD-F1 offspring, a reduction in beta cell mass and proliferation of beta cells were observed. Mechanistically, in pancreatic islets of SD-F1 offspring, we identified alterations in DNA methylation at the promoter region of the LRP5 (LDL receptor related protein 5) gene, a coreceptor of Wnt signaling, resulting in downregulation of downstream effectors cyclin D1, cyclin D2, and Ctnnb1. Restoration of Lrp5 in the pancreas of SD-F1 male mice could improve impaired glucose tolerance and expression of cyclin D1, cyclin D2, and Ctnnb1. This study might significantly contribute to our understanding of the effects of sleeplessness on health and metabolic disease risk from the perspective of the heritable epigenome.

Cigarette smoke condensate induces centrosome clustering in normal lung epithelial cells.

BACKGROUND: Unlike normal cells, cancer cells frequently have multiple centrosomes that can cluster to form bipolar mitotic spindles and allow for successful cell division. Inhibiting centrosome clustering, therefore, holds therapeutic promise to promote cancer cell-specific cell death. METHODS: We used confocal microscopy, real-time PCR, siRNA knockdown, and western blot to analyze centrosome clustering and declustering using normal lung bronchial epithelial and nonsmall-cell lung cancer (NSCLC) cell lines. Also, we used Ingenuity Pathway Analysis software to identify novel pathways associated with centrosome clustering. RESULTS: In this study, we found that exposure to cigarette smoke condensate induces centrosome amplification and clustering in human lung epithelial cells. We observed a similar increase in centrosome amplification and clustering in unexposed NSCLC cell lines which may suggest a common underlying mechanism for lung carcinogenesis. We identified a cyclin D2-mediated centrosome clustering pathway that involves a sonic hedgehog-forkhead box protein M1 axis which is critical for mitosis. We also observed that cyclin D2 knockdown induced multipolar mitotic spindles that could eventually lead to cell death. CONCLUSIONS: Here we report a novel role of cyclin D2 in the regulation of centrosome clustering, which could allow the identification of tumors sensitive to cyclin D2 inhibitors. Our data reveal a pathway that can be targeted to inhibit centrosome clustering by interfering with the expression of cyclin D2-associated genes.