Regulation Of Cyclin D1 Expression Research Articles

Increased expression of long non-coding RNA FIRRE promotes hepatocellular carcinoma by HuR-CyclinD1 axis signaling

There is a critical need to understand the disease processes and identify improved therapeutic strategies for hepatocellular carcinoma (HCC). The long noncoding RNAs (lncRNAs) display diverse effects on biological regulations. The aim of this study was to identify a lncRNA as a potential biomarker of HCC and investigate the mechanisms by which the lncRNA promotes HCC progression using human cell lines and in vivo. Using RNA-Seq analysis, we found that lncRNA FIRRE was significantly upregulated in hepatitis C virus (HCV) associated liver tissue and identified that lncRNA FIRRE is significantly upregulated in HCV associated HCC compared to adjacent non-tumor liver tissue. Further, we observed that FIRRE is significantly upregulated in HCC specimens with other etiologies, suggesting this lncRNA has a potential to serve as an additional biomarker for HCC. Overexpression of FIRRE in hepatocytes induced cell proliferation, colony formation, and xenograft tumor formation as compared to vector transfected control cells. Using RNA pull-down proteomics, we identified HuR as an interacting partner of FIRRE. We further showed that the FIRRE-HuR axis regulates cyclin D1 expression. Our mechanistic investigation uncovered that FIRRE is associated with an RNA binding protein HuR for enhancing hepatocyte growth. Together, these findings provide molecular insights into the role of FIRRE in HCC progression.

Epigenetic Downregulation of Hsa-miR-193b-3p Increases Cyclin D1 Expression Level and Cell Proliferation in Human Meningiomas.

Meningiomas are common intracranial tumors in adults. Abnormal microRNA (miRNA) expression plays a role in their pathogenesis. Change in miRNA expression level can be caused by impaired epigenetic regulation of miRNA-encoding genes. We found the genomic region covering the MIR193B gene to be DNA hypermethylated in meningiomas based on analysis of genome-wide methylation (HumanMethylation450K Illumina arrays). Hypermethylation of MIR193B was also confirmed via bisulfite pyrosequencing. Both hsa-miR-193b-3p and hsa-miR-193b-5p are downregulated in meningiomas. Lower expression of hsa-miR-193b-3p and higher MIR193B methylation was observed in World Health Organization (WHO) grade (G) II/III tumors as compared to GI meningiomas. CCND1 mRNA was identified as a target of hsa-miR-193b-3p as further validated using luciferase reporter assay in IOMM-Lee meningioma cells. IOMM-Lee cells transfected with hsa-miR-193b-3p mimic showed a decreased cyclin D1 level and lower cell viability and proliferation, confirming the suppressive nature of this miRNA. Cyclin D1 protein expression (immunoreactivity) was higher in atypical than in benign meningiomas, accordingly to observations of lower hsa-miR-193b-3p levels in GII tumors. The commonly observed hypermethylation of MIR193B in meningiomas apparently contributes to the downregulation of hsa-miR-193b-3p. Since hsa-miR-193b-3p regulates proliferation of meningioma cells through negative regulation of cyclin D1 expression, it seems to be an important tumor suppressor in meningiomas.

Protein-RNA interactions of FMRP and CCND1: Implications of regulation in neurogenesis.

While originally discovered in the 1960s, adult neurogenesis, the production of mature neurons from neuronal stem cells in adults, has become largely accepted by the field only in the 1990s. Thus, the detailed mechanisms of its regulation remain elusive, requiring further characterization of the protein players involved in this process. Cyclin-D1, a regulatory subunit of cyclin-dependent kinases involved in monitoring entry into the cell cycle, has been identified as a key factor in adult neurogenesis and is encoded by the CCND1 gene. Another identified component of this process is the Fragile X messenger ribonucleoprotein (FMRP), an RNA-binding protein associated with translational regulation. Interestingly, FMRP has been shown to regulate cyclin-D1 expression, emphasizing a potential interplay between FMRP function and cyclin-D1 expression in neurons. FMRP has shown high affinity binding for guanine quadruplex (GQ) forming RNAs. We identified that CCND1 mRNA has a G-rich region in its 3’-untranslated region that has the potential to form GQ structures, and thus possibly interacting with FMRP through the recognition of these structures. To elucidate the presence of a GQ in the CCND1 mRNA, we used biophysical methods, such as 1H NMR, UV thermal denaturation, CD spectroscopy, and native polyacrylamide gel electrophoresis (PAGE). This study effectively characterizes a GQ in the 3’UTR of the CCND1 mRNA and its interactions with FMRP, providing insight on additional regulatory mechanisms of adult neurogenesis and guiding development of novel therapeutic methods.

Human Mesenchymal Stem Cells Derived from the Placenta and Chorion Suppress the Proliferation while Enhancing the Migration of Human Breast Cancer Cells.

Breast cancer is the most frequently diagnosed malignancy among women, resulting from abnormal proliferation of mammary epithelial cells. The highly vascularized nature of breast tissue leads to a high incidence of breast cancer metastases, resulting in a poor survival rate. Previous studies suggest that human mesenchymal stem cells (hMSCs) play essential roles in the growth, metastasis, and drug responses of many cancers, including breast cancer. However, hMSCs from different sources may release different combinations of cytokines that affect breast cancer differently. In this study, we have isolated hMSCs from the placenta (PL-hMSCs) and the chorion (CH-hMSCs) and determined how these hMSCs affect the proliferation, migration, invasion, and gene expression of two human breast cancer cells, MCF-7 and MDA-MB-231, as well as the possible mechanisms underlying those effects. The results showed that the soluble factors derived from PL-hMSCs and CH-hMSCs inhibited the proliferation of MCF-7 and MDA-MB-231 cells but increased the migration of MDA-MB-231 cells. The study of gene expression showed that PL-hMSCs and CH-hMSCs downregulated the expression levels of the protooncogene CyclinD1 while upregulating the expression levels of tumor suppressor genes, P16 and P21 in MCF-7 and MDA-MB-231 cells. Furthermore, hMSCs from both sources also increased the expression levels of MYC, SNAI1, and TWIST, which promote the epithelial-mesenchymal transition and migration of breast cancer cells in both cell lines. The functional study suggests that the suppressive effect of CH-hMSCs and PL-hMSCs on MCF-7 and MDA-MB231 cell proliferation was mediated, at least in part, through IFN-γ. Our study suggests that CH-hMSCs and PL-hMSCs inhibited breast cancer cell proliferation by negatively regulating CYCLIND1 expression and upregulating the expression of the P16 and P21 genes. In contrast, hMSCs from both sources enhanced breast cancer cell migration, possibly by increasing the expression of MYC, SNAI1, and TWIST genes in those cells.

CAMTA1 gene affects the ischemia-reperfusion injury by regulating CCND1.

Epigenetic modulations lead to changes in gene expression, including DNA methylation, histone modifications, and noncoding RNAs. In recent years, epigenetic modifications have been related to the pathogenesis of different types of cancer, cardiovascular disease, and other diseases. Emerging evidence indicates that DNA methylation could be associated with ischemic stroke (IS) and plays a role in pathological progression, but the underlying mechanism has not yet been fully understood. In this study, we used human methylation 850K BeadChip to analyze the differences in gene methylation status in the peripheral blood samples from two groups (3 IS patients vs. 3 healthy controls). According to their bioinformatics profiling, we found 278 genes with significantly different methylation levels. Seven genes with the most significant methylation modifications were validated in two expanded groups (100 IS patients vs. 100 healthy controls). The CAMTA1 gene had significantly different methylation changes in patients compared to the controls. To understand the CAMTA1 function in stroke, we generated CAMTA1 knockout in SH-SY5Y cells. RNA seq results in CAMTA1 knockout cells revealed the pathways and gene set enrichments involved in cellular proliferation and cell cycle. Furthermore, a series of experiments demonstrated that in the oxygen-glucose deprivation/re-oxygenation (OGD/R) model system, the expression of cyclin D1, an essential regulator of cell cycle progression, was increased in SH-SY5Y CAMTA1 KO cells. Increasing evidence demonstrated that ischemic stress could inappropriately raise cyclin D1 levels in mature neurons. However, the molecular signals leading to an increased cyclin D1 level are unclear. Our findings demonstrate for the first time that the CAMTA1 gene could regulate cyclin D1 expression and implicate their role in strokes.

Abstract A23: Alternative cyclin D1 transcripts in Mantle Cell Lymphoma

Abstract Mantle Cell Lymphoma (MCL) is a rare aggressive subtype of Non-Hodgkin’s Lymphoma. Upon diagnosis, treatments are varied and there is no universal standard of care. MCL is considered clinically incurable upon relapse. Better understanding of the development of MCL at the molecular level is needed. The initiating event is a hallmark (11; 14) translocation event that juxtaposes cyclin D1 (CCND1) downstream of the IgH enhancer element thus activating protein expression. This IgH recombination precedes the MCL diagnosis by several years. By itself, expression of cyclin D1 is insufficient for tumorigenesis. However, increased cyclin D1 expression combined with alterations in one of several DNA repair genes facilitates lymphomagenesis characterized by high genomic instability. Interestingly at the mRNA level, CCND1 transcripts containing the full length 3`untranslated regions (3`UTRs) have a half-life of ~30 minutes. CCND1 transcripts containing truncated 3`UTRs have a longer half-life up to ~8 hours resulting in increased translation. A subset of MCL patients with highly proliferative disease express CCND1 mRNAs with truncated 3`UTRs. Wiestner et al showed that truncated CCND1 3`UTR expression was associated with a reduction in patient survival by almost two years. While CCND1 3`UTR shortening in 20% of patient samples was due to mutations, the mechanisms driving this event in the rest of patients remain unknown. Our goal is to identify the different truncated CCND1 transcripts in MCL and determine how they are expressed. Using 3′Rapid Amplification of cDNA ends (3′RACE) we previously identified a novel fusion transcript where a short CCND1 3′UTR sequence was linked to intronic sequences of the MRCKB/CDC42BPB gene. In order to measure levels of expression of differently sized CCND1 3`UTR transcripts we used specifically designed primers for qRT-PCR. To determine the type of truncated CCND1 3`UTR expressed in other MCL cell lines we used 3′RACE. Iso Sequencing was used to verify the occurrence of the novel CCND1/MRCK fusion transcript. Cell viability assays were used to determine the impact of targeting the CCND1/MRCK fusion or cyclin D1 activated cyclin dependent kinase 4/6 inhibitor. Our qRT-PCR results showed that most of the MCL cell lines predominantly expressed CCND1 transcripts with truncated 3′UTRs with the exception of Mino-1 where the longer 3′UTR was more dominant. The 3′RACE results indicate that different mechanisms may result in the expression of the truncated CCND1 3`UTR transcript in each cell line. Iso Sequencing data identified 1,032 total reads supporting the CCND1/MRCK fusion transcript verifying our 3’RACE results. Our results suggest that there are different molecular mechanisms being used to regulate cyclin D1 expression in MCL. Cell viability assays showed decreased cell proliferation. In conclusion, identifying and understanding the mechanisms of expression of different CCND1 transcripts has potential in understanding MCL pathogenesis and the development of MCL therapeutics. Funding: 1R01-GM135361-01 to C. P. Masamha. Citation Format: Naazneen Khan, Chioniso P Masamha. Alternative cyclin D1 transcripts in Mantle Cell Lymphoma [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A23.

Type IIB PKA is highly expressed in β cells and controls cell proliferation via regulating Cyclin D1 expression

β cell number is maintained mainly by cell proliferation and cell apoptosis. Protein kinase A (PKA) pathway is an important intracellular signalling-mediating β cell proliferation. However, the precise roles of PKA isoforms are not well-defined. We found that the RIIB subunit of PKA is expressed specifically by β cells of mouse and human islets. Sixty percent pancreatectomy caused increased β cell proliferation. Deletion of type IIB PKA by disruption of RIIB expression further promoted β cell proliferation, leading to enhanced β cell mass expansion. RIIB KO mice also showed increased insulin levels and improved glucose tolerance. Mechanistically, activation of type IIB PKA decreased Cyclin D1 levels and inhibition of RIIB expression increased Cyclin D1 levels. Consistently, activation of type IIB PKA inhibited cell cycle entry. These results suggest that type IIB PKA plays a pivotal role in β cell proliferation via regulating Cyclin D1 expression.

LncRNA DLGAP1-AS2 regulates miR-503/cyclin D1 to promote cell proliferation in non-small cell lung cancer

BackgroundLncRNA DLGAP1-AS2 plays an oncogenic role in glioma, while its role in other cancers is unknown. This study aimed to study the role of DLGAP1-AS2 in non-small cell lung cancer (NSCLC).MethodsExpression of DLGAP1-AS2 in NSCLC and paired non-tumor tissues from 64 NSCLC patients and the prognostic value of DLGAP1-AS2 for NSCLC were analyzed by performing a 5-year follow-up study. The interaction between DLGAP1-AS2 and miR-503 was confirmed by dual luciferase reporter assay, and their relationship was explored in NSCLC cells transfected with DLGAP1-AS2 expression vector or miR-503 mimic. The roles of DLGAP1-AS2 and miR-503 in regulating cyclin D1 expression were analyzed by RT-qPCR and Western blot. Cell proliferation was analyzed by CCK-8 assay.ResultsDLGAP1-AS2 was upregulated in NSCLC and predicted poor survival. Interaction between DLGAP1-AS2 and miR-503 was confirmed by dual luciferase activity assay. Overexpression experiments showed that DLGAP1-AS2 and miR-503 overexpression failed to significantly affect the expression of each other. Interestingly, DLGAP1-AS2 overexpression upregulated cyclin D1, a target of miR-503, increased cell proliferation and reduced the effects of miR-503 overexpression on cyclin D1 expression and cell proliferation.ConclusionsDLGAP1-AS2 may regulate miR-503/cyclin D1 to promote cell proliferation in NSCLC.

PARP14 regulates cyclin D1 expression to promote cell-cycle progression.

Cyclin D1 is an essential regulator of the G1-S cell-cycle transition and is overexpressed in many cancers. Expression of cyclin D1 is under tight cellular regulation that is controlled by many signaling pathways. Here we report that PARP14, a member of the poly(ADP-ribose) polymerase (PARP) family, is a regulator of cyclin D1 expression. Depletion of PARP14 leads to decreased cyclin D1 protein levels. In cells with a functional retinoblastoma (RB) protein pathway, this results in G1 cell-cycle arrest and reduced proliferation. Mechanistically, we found that PARP14 controls cyclin D1 mRNA levels. Using luciferase assays, we show that PARP14 specifically regulates cyclin D1 3'UTR mRNA stability. Finally, we also provide evidence that G1 arrest in PARP14-depleted cells is dependent on an intact p53-p21 pathway. Our work uncovers a new role for PARP14 in promoting cell-cycle progression through both cyclin D1 and the p53 pathway.

Cyclin D1: A Golden Gene in Cancer, Cardiotoxicity, and Cardioprotection

Objective: Cyclin D1 is an essential protein that acts as a mitogenic sensor. In this manuscript, we discuss the importance of cyclin D1 in oncology and cardio-oncology, and we challenge the prognostic and therapeutic response values of cyclin D1 to figure out if it can be a beneficial marker. We also discuss the agents and microRNAs that can be used as a potential therapeutic approach via regulating cyclin D1 expression in oncology and cardio-oncology. Discussion: Clinical significance of cyclin D1 is defined not only in several cancers such as breast cancer, melanoma, and glioblastoma but also in cardiomyocyte regeneration and cardiac hypertrophic growth. Several studies have indicated that the injection of cardiotoxic agents such as doxorubicin (DOX) induces damage to the cardiac system and increases cyclin D expression at single injection, which might be related to DXO-mediated damage in the adult heart. However, cyclin D1 overexpression leads to hypertrophic growth of cardiomyocytes, and cyclin-dependent kinase (CDK)) inhibitors such as p16 do not inhibit the hypertrophic growth of cardiomyocytes. Thus, the reaction is CDK-independent. Conclusions: Cyclin D1 overexpression is positively correlated with tumor progression, treatment response, cardiotoxicity, and poor prognosis. Cyclin D1 expression has an important role in cardiac hypertrophy, and it can be a promising marker in monitoring cardiomyocyte treatment responses, cardioprotection, and cardiotoxicity. Finally, cyclin D1 plays an important role in hypertrophic growth of cardiomyocytes via a novel mechanism. Given all these pieces of evidence, cyclin D1 can be introduced as a favorable biomarker in future cardiology and cardio-oncology.

Let-7c-5p Regulates CyclinD1 in Fluoride-Mediated Osteoblast Proliferation and Activation.

Endemic fluorosis is caused by the intake of high environmental fluoride, which causes dental and skeletal fluorosis. Osteoblast proliferation and activation is closely related to skeletal fluorosis and is tightly regulated by the cell cycle. Several biological processes, including bone metabolism and osteoblast proliferation and activation, are regulated by a type of noncoding RNA called microRNAs (miRNAs). However, the understanding of miRNA functions in skeletal fluorosis is limited. Based on our previous miRNA sequencing results and bioinformatics analysis, we investigated the function of the miRNA let-7c-5p to regulate CyclinD1 in fluoride-induced osteoblast proliferation and activation. We designed population experiments as well as in vitro studies using 5-Ethynyl-2'-deoxyuridine (EdU), flow cytometry, immunofluorescence, dual-luciferase reporters, and chromatin immunoprecipitation. The population-based analysis showed a decrease in let-7c-5p expression as fluoride exposure increased. In addition, let-7c-5p levels were negatively correlated with CyclinD1 and Wnt9a (another let-7c-5p target). We verified in vitro that let-7c-5p participates in the fluoride-induced proliferation and activation of human osteoblasts by directly targeting CyclinD1. Furthermore, we demonstrated that let-7c-5p regulates CyclinD1 expression via the Wnt/β-catenin signaling pathway. This study demonstrated the participation of let-7c-5p in fluoride-induced proliferation and activation of human osteoblasts by regulation of CyclinD1 expression at the post-transcriptional and transcriptional levels.

YWHAE-NUTM2 oncoprotein regulates proliferation and cyclin D1 via RAF/MAPK and Hippo pathways

Endometrial stromal sarcoma (ESS) is the second most common subtype of uterine mesenchymal cancer, after leiomyosarcoma, and oncogenic fusion proteins are found in many ESS. Our previous studies demonstrated transforming properties and diagnostic relevance of the fusion oncoprotein YWHAE–NUTM2 in high-grade endometrial stromal sarcoma (HG-ESS) and showed that cyclin D1 is a diagnostic biomarker in these HG-ESS. However, YWHAE–NUTM2 mechanisms of oncogenesis and roles in cyclin D1 expression have not been characterized. In the current studies, we show YWHAE-NUTM2 complexes with both BRAF/RAF1 and YAP/TAZ in HG-ESS. These interactions are functionally relevant because YWHAE-NUTM2 knockdown in HG-ESS and other models inhibits RAF/MEK/MAPK phosphorylation, cyclin D1 expression, and cell proliferation. Further, cyclin D1 knockdown in HG-ESS dephosphorylates RB1 and inhibits proliferation. In keeping with these findings, we show that MEK and CDK4/6 inhibitors have anti-proliferative effects in HG-ESS, and combinations of these inhibitors have synergistic activity. These findings establish that YWHAE-NUTM2 regulates cyclin D1 expression and cell proliferation by dysregulating RAF/MEK/MAPK and Hippo/YAP-TAZ signaling pathways. Recent studies demonstrate Hippo/YAP-TAZ pathway aberrations in many sarcomas, but this is among the first studies to demonstrate a well-defined oncogenic mechanism as the cause of Hippo pathway dysregulation.

Effect of lncRNA-BLACAT1 on drug resistance of non-small cell lung cancer cells in DDP chemotherapy by regulating cyclin D1 expression.

The aim of this study was to investigate the effect of long non-coding ribonucleic acid (lncRNA)-bladder cancer associated transcript 1 (BLACAT1) on the drug resistance of non-small cell lung cancer (NSCLC) cells in cisplatin (DDP) chemotherapy by regulating the expression of Cyclin D1. The analysis of the lncRNA expression profiles in 483 cases of NSCLC tissues and 347 cases of cancer-adjacent tissues in Gene Expression Omnibus (GEO) database revealed that lncRNA-BLACAT1 was differentially expressed in NSCLC and related to prognosis. In order to further study its mechanism of action on DDP-resistant cells, the expression level of lncRNA-BLACAT1 in normal human lung bronchial epithelial cell line BEAS-2B, NSCLC cell line A549, and DDP-resistant cell line A549 (A549/DDP) was detected by quantitative Polymerase Chain Reaction (qPCR). LncRNA-BLACAT1 small interfering RNA (siRNA) (si-BLACAT1) and lncRNA-BLACAT1 negative control (si-NC) were transfected into A549/DPP cells. Then, qPCR was carried out to detect the changes in the expression of lncRNA-BLACAT1 before and after transfection. Thereafter, cell cycle and cell growth rate were detected by flow cytometry and the cell growth curve. Besides, the changes in cell migration, cell apoptosis, and Cyclin D1 were detected via wound healing assay, flow cytometry, and Western blotting (WB). In GEO database, lncRNA-BLACAT1 was significantly overexpressed in NSCLC (p<0.05), and the prognosis of NSCLC in BLACAT1 low-expression group was better than that in the BLACAT1 high-expression group (p<0.0001). Compared with that in BEAS-2B cells, BLACAT messenger RNA (mRNA) was notably highly expressed in A549 cells (p<0.05), and compared with that in A549 cells, BLACAT1 mRNA in A549/DPP was significantly highly expressed in A549/DDP cells (p<0.05). Additionally, in comparison with that in the si-NC group, the content of lncRNA-BLACAT1 in si-BLACAT1 group was remarkably decreased (p<0.01). Moreover, flow cytometry detection of cell cycle revealed that compared with those in si-NC group, G0/G1 phase was markedly prolonged and S phase was shortened in si-BLACAT1 group. MTS assay manifested that the absorbance at 450 nm in si-BLACAT1 group was evidently decreased on the 3rd day compared with that in the si-NC group (p<0.05), and the difference between the two groups was the most significant on the 5th day (p<0.001). According to wound healing assay, compared with those in si-NC group, the distance between cells became larger, the cell migration ability was remarkably weakened (p<0.05), and cell apoptosis was prominently reduced in si-BLACAT1 group (p<0.05). WB results showed that compared with si-NC group, si-BLACAT1 group had significantly reduced Cyclin D1 (p<0.05) CONCLUSIONS: LncRNA-BLACAT1 regulates the expression of Cyclin D1, reduces the malignant phenotype of drug-resistant cells, and increases the sensitivity of lung cancer cells to DDP.

Nitro aspirin (NCX4040) induces apoptosis in PC3 metastatic prostate cancer cells via hydrogen peroxide (H2O2)-mediated oxidative stress

Non-steroidal anti-inflammatory drugs (NSAID) have shown promise as anticancer agents by inducing cell death apart from their antipyretic, anti-inflammatory and anti-thrombogenic effects. In our current study, we investigated the oxidative stress mediated cell death mechanism of a NSAID derivative NCX4040 (a nitric oxide (NO) releasing form of aspirin) in castration-resistant prostate cancer (CRPC) PC3 cell line. Our data revealed that NCX4040 is more potent than its parent compound aspirin or NO releasing compound DETA NONOate. NCX4040 significantly induced hydrogen peroxide formation with ensuing oxidative stress and mitochondrial depolarization resulting in lipid peroxidation, cell cycle arrest, inhibition of colony growth and induction of apoptosis in PC3 cells. Moreover, NCX4040 inhibited migration potential of PC3 cells by depolymerizing F-actin and promoting anoikis. Interestingly, elevated levels of NADPH oxidase 1 (NOX1), superoxide dismutase (SOD) 1 and 2 were observed upon NCX4040 treatment. However, down regulation of anti-apoptotic markers B-cell lymphoma 2 (Bcl2) and anti-oxidant thioredoxin reductase 1 (TXNRD1) expression were observed. In addition, NCX4040 down regulated cyclin D1 expression in PC3 cells further supporting the anticancer effect of NCX4040. Western blot analysis revealed that significant down regulation of key anti-apoptotic markers such as cellular inhibitor of apoptosis protein-1 (cIAP1), X-linked inhibitor of apoptosis (XIAP), survivin, and Cellular-Myc (c-Myc). On the other hand, NCX4040-treated cells showed upregulation of phosho histone H2AX (pH2AX), cleaved caspase3 and cleaved Poly [ADP-ribose] polymerase 1 (PARP1). Taken together, our data demonstrate that NCX4040 treatment enhances free radical formation which in turn induces oxidative stress leading to mitochondrial mediated cell death in metastatic PC3 cells.

Cyclin D1 is a mediator of gastrointestinal stromal tumor KIT-independence.

Oncogenic KIT or PDGFRA tyrosine kinase mutations are compelling therapeutic targets in most gastrointestinal stromal tumors (GISTs), and the KIT inhibitor, imatinib, is therefore standard of care for patients with metastatic GIST. However, some GISTs lose expression of KIT oncoproteins, and therefore become KIT-independent and are consequently resistant to KIT-inhibitor drugs. We identified distinctive biologic features in KIT-independent, imatinib-resistant GISTs as a step towards identifying drug targets in these poorly understood tumors. We developed isogenic GIST lines in which the parental forms were KIT oncoprotein-dependent, whereas sublines had loss of KIT oncoprotein expression, accompanied by markedly downregulated expression of the GIST biomarker, protein kinase C-theta (PRKCQ). Biologic mechanisms unique to KIT-independent GISTs were identified by transcriptome sequencing, qRT-PCR, immunoblotting, protein interaction studies, knockdown and expression assays, and dual-luciferase assays. Transcriptome sequencing showed that cyclin D1 expression was extremely low in two of three parental KIT-dependent GIST lines, whereas cyclin D1 expression was high in each of the KIT-independent GIST sublines. Cyclin D1 inhibition in KIT-independent GISTs had anti-proliferative and pro-apoptotic effects, associated with Rb activation and p27 upregulation. PRKCQ, but not KIT, was a negative regulator of cyclin D1 expression, whereas JUN and Hippo pathway effectors YAP and TAZ were positive regulators of cyclin D1 expression. PRKCQ, JUN, and the Hippo pathway coordinately regulate GIST cyclin D1 expression. These findings highlight the roles of PRKCQ, JUN, Hippo, and cyclin D1 as oncogenic mediators in GISTs that have converted, during TKI-therapy, to a KIT-independent state. Inhibitors of these pathways could be effective therapeutically for these now untreatable tumors.

Three-dimensional microenvironmental priming of human mesenchymal stem cells in hydrogels facilitates efficient and rapid retroviral gene transduction via accelerated cell cycle synchronization

There are numerous approaches to improve the low transduction efficiency of retroviral vectors in two-dimensional (2D) cell culture substrates. However, the effect of a three-dimensional (3D) microenvironment, which better mimics in vivo conditions, is unknown. Cytocompatible hyaluronic acid (HA) hydrogels are a good candidate to study this issue. Here, photocrosslinkable HA hydrogels with an elastic modulus of 1.0–2.7 kPa were successfully prepared by varying the degree of methacrylation in the HA backbone. Culturing human adipose-derived stem cells (hASCs) in a 3D microenvironment significantly reduces the amount of time required for retroviral gene transduction compared with the conventional 2D method and maintains a high transduction efficiency. This acceleration of retroviral gene transduction correlates with the rate of cell-cycle synchronization. hASCs cultured in a 3D microenvironment have a shorter G1 phase and total cell-cycle length than hASCs cultured using the conventional 2D method. This cell-cycle regulation is dependent on expression of cyclin D1. In summary, prior culturing of hASCs in a 3D microenvironment accelerates retroviral gene transduction by regulating cyclin D1 expression and accelerating cell-cycle synchronization. We conclude that priming via culturing in a 3D microenvironment facilitates efficient and rapid retroviral gene transduction of hASCs without inducing apoptosis.

Porphyromonas gingivalis Infection Promoted the Proliferation of Oral Squamous Cell Carcinoma Cells through the miR-21/PDCD4/AP-1 Negative Signaling Pathway.

Recent epidemiological studies have revealed that Porphyromonas gingivalis, a major pathogen in periodontal disease, is associated with the development of oral squamous cell carcinoma (OSCC). However, the underlying mechanisms induced by P.gingivalis have not been well-defined. We aimed to determine the role of P.gingivalis in OSCC proliferation and the relevant molecular mechanisms. A cellular proliferation model of OSCC Tca8113 cells infected by P.gingivalis at a multiplicity of infection (MOI) of 50 was established. Cell proliferation was drastically increased in the infected cells compared with the control cells, while the proportion of cells in S phase was increased and the proportion of cells in G1 phase was decreased in the infected cells compared with the control cells. Additionally, the levels of activator protein 1 (AP-1; c-Jun and c-Fos) and its target gene cyclin D1 were increased in P.gingivalis-infected Tca8113 cells compared with control cells. miR-21 expression was elevated when programmed cell death 4 (PDCD4) expression was downregulated. Cyclin D1 expression was regulated by miR-21, PDCD4, and AP-1. The disruption of the pathway by silencing c-Jun, blocking miR-21 expression, or overexpressing PDCD4 led to decreased cyclin D1 expression and inhibited cell proliferation. P.gingivalis DNA levels were positively correlated with miR-21 and c-Jun expression and negatively correlated with PDCD4 expression in clinical OSCC samples. Our findings indicated that P.gingivalis might promote OSCC proliferation by regulating cyclin D1 expression via the miR-21/PDCD4/AP-1 negative feedback signaling pathway.

Long noncoding RNA H19 promotes vascular remodeling by sponging let-7a to upregulate the expression of cyclin D1

Vascular remodeling is mainly caused by excessive proliferation of vascular smooth muscle cells (VSMCs). Noncoding RNAs (ncRNAs) have emerged as important regulators in diverse pathological processes. Previous work has shown the functions and mechanisms of long noncoding RNA H19 (LncRNA H19) on VSMCs. As long noncoding RNAs (lncRNAs) are complex in their mechanisms of action, the aim of the study is to identify if there are any other molecular mechanisms of LncRNA H19 on VSMCs. In vivo studies demonstrated that cyclin D1 was overexpressed in neointima of balloon-injured artery. In vitro studies identified that the overexpression of LncRNA H19 promoted VSMCs proliferation and cyclin D1 upregulation. On the contrary, cellular proliferation and expression of cyclin D1 were inhibited in VSMCs after infection with let-7a. Furthermore, luciferase reporter assays and RNA pull-down assays were used to explore the regulatory mechanism, we found that LncRNA H19 functioned as a competing endogenous RNA (ceRNA) by sponging let-7a to promote the expression of the target gene cyclin D1. In conclusion, LncRNA H19 positively regulated cyclin D1 expression through directly binding to let-7a in VSMCs. Our findings provide new insight into the mechanism of LncRNA H19 in VSMCs proliferation and vascular remodeling, and further indicate the implications of LncRNA H19 in the diagnosis and treatment of vascular proliferative diseases.

Genome Analysis of a Mantle Cell Lymphoma Case with t(5;18)(p15;q21) Lacking the Translocation Involving Cyclin D1

Background: Mantle cell lymphoma (MCL) is a moderately aggressive lymphoma and its pathogenesis is not fully understood. The genetic hallmark of MCL is the chromosomal translocation t(11;14)(q13;q32), causing upregulation of cyclin D1. However, approximately 10% of MCL does not harbor this typical alteration. Besides, the chromosome 5p15 region is recurrently targeted by chromosomal translocations in B-cell malignancies including MCL. The pathogenesis of the MCL cases as described above were not clear, and next generation sequencing analysis would be some help for understanding them. We experienced a MCL case which lacks t(11;14) and has a translocation involving 5p15 locus, and performed whole genome sequencing (WGS) analysis of this patient to elucidate its pathological mechanisms.Case: A 62 years old woman with long history of MCL. The karyotype of this patient was 47, XX, +5, t(5;18)(p15;q21), and did not have t(11;14). The pathological findings of resected spleen and bone marrow biopsy showed medium size B cell proliferation with overexpressed cyclin D1 and SOX11, and the diagnosis as MCL was re-confirmed.Methods and Results: We confirmed a chromosome translocation t(5;18) by WGS. Its breakpoint was localized in the intergenic region, so this translocation did not create a fusion gene. This region on chromosome 5 contains the telomerase reverse transcriptase (TERT) and cleft lip and palate transmembrane protein 1-like (CLPTM1L) genes, and WGS analysis also identified SET-binding protein 1 (SETBP1) as the gene located near the breakpoint on chromosome 18. The expression of TERT and SETBP1 of this case was assessed by RT-PCR, and found that both genes were significantly increased compared to EBV-immortalized human B-lymphocyte cell lines. In addition, WGS analysis found the BRAF V600E mutation, which is quite rare among hematologic malignancies excluding hairy cell leukemias. Next, we investigated the role of these aberrations in the overexpression of cyclin D1. In this study, we used some non-hematologic cancer cell lines for transfection assays. The forced expression of TERT did not show any effect on the cyclin D1 expression in several cancer cell lines that we examined. However, BRAF wild type increased the cyclin D1 level in the breast cancer cell lines, MCF-7 and MDA-MB-231. Moreover, the BRAF V600E transfectant showed more upregulated level of cyclin D1 compared to BRAF wild type. These data suggested the possibility of the association of BRAF in the regulation of cyclin D1 expression.Conclusion: Our data suggested that the genes located around the breakpoint would not be related to the regulation of cyclin D1 expression in the MCL case with t(5;18), and that BRAF might contribute to the upregulation of cyclin D1. DisclosuresIida:Chugai Pharmaceutical Co., Ltd.: Research Funding. Nagai:Janssen Pharmaceutical K.K.: Honoraria, Research Funding; Abbvie G. K.: Research Funding; Bayer Yakuhin Ltd.: Research Funding; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Gilead Sciences Inc.: Honoraria, Research Funding; Zenyaku Kogyo Co., Ltd.: Honoraria, Research Funding; Solasia Pharma K.K.: Research Funding; Esai Co., Ltd.: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Mundipharma K.K.: Honoraria, Research Funding; Kyowa Hakko Kirin Co., Ltd.: Honoraria, Research Funding; Ono Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Sanofi K. K.: Honoraria; Roche Ltd.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Research Funding; SymBio Pharmaceuticals Limited: Research Funding; AstraZeneca plc.: Research Funding; HUYA Bioscience International: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding.

FOXA1 is upregulated in glioma and promotes proliferation as well as cell cycle through regulation of cyclin D1 expression.

IntroductionForkhead box A1 (FOXA1) has been found to upregulate in numerous cancers, such as ovarian cancer and glioma. However, the detailed function of FOXA1 in glioma is still not known. The purpose of this study was to explore the underlying mechanism of FOXA1 in glioma cell progression.MethodsThe expressions of FOXA1 in glioma tissues and cells were determined using quantitative reverse transcription-polymerase chain reaction and western blotting assays. Wound healing assay and Transwell invasion assay were employed to detect the effects of FOXA1 on cellular migration and invasion. Cell Counting Kit-8 assay, colony formation assay, and flow cytometry analyses were also performed.ResultsOur study results suggested FOXA1 was upregulated in glioma tissues and cells and revealed that FOXA1 promoted glioma cellular proliferation by facilitating G1/S transition. Previous work has indicated that CCND1 expression is regulated by FOXA1 in ovarian cancer. ChIP and qChIP assay as well as dual luciferase reporter assay validated that CCND1 expression was also regulated by FOXA1 in glioma cells. Moreover, over-expression of CCND1 in siFOXA1-transfected cells partly offsets the effect of FOXA1 inhibition on cellular proliferation.ConclusionFOXA1 promotes glioma cell progression, including cell proliferation and cell cycle, by targeting CCND1, and shows potential for the development of targeted treatment for glioma.