The ETS Transcription Factor ETV7 Exhausts Hematopoietic Stem Cells By Enhancing The Cell Cycle Entry and Cell Proliferation

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 733-733 ◽  
Author(s):  
Masashi Numata ◽  
Ramon Klein Geltink ◽  
Gerard Grosveld
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Brdu Incorporation ◽  
Post Transplantation ◽  
Hematopoietic Stem ◽  
Cell Cycle Entry ◽  
Fcm Analysis

Abstract Although ETS-transcription factors play a role in normal and malignant hematopoiesis, their function in hematopoietic stem cells (HSCs) and leukemia initiating cells (LICs) is largely unknown. We originally identified the novel ETS transcription factor ETV7, which is highly homologous to ETV6/TEL, a frequent target of chromosomal translocation in human leukemia. Previously we have shown that ETV7 is a hematopoietic oncoprotein that requires cooperating mutations to induce leukemic transformation. Microarray analysis revealed that ETV7 expression is upregulated in 70% of pediatric ALL and AML samples. This indicates a possible oncogenic function of ETV7 in a variety of leukemias, although the molecular mechanism of ETV7-mediated leukemogenesis remains to be elucidated. ETV7 is widely but not abundantly expressed in various human tissues. Recently we found that overexpression of ETV7 in human cord blood-derived CD34+ cells depletes the number of CD34+CD38- HSCs. In addition, ETV7-transduced cells slightly accerelated cell proliferation. These results suggest that overexpression of ETV7 activates cell proliferation in primary human CD34+cells and depletes the number of HSCs. Here, by using a mouse model, we show that ectopic expression of ETV7 in quiescent HSCs accelerates their cell cycle entry and proliferation, leading to the exhaust of HSCs in mice. The ETV7 gene locus is deleted in part of the rodents including the mouse despite its high level of conservation among vertebrates. To circumvent this limitation, we have generated an ETV7 BAC transgenic mouse that carries a single copy of a human BAC DNA containing the ETV7 gene locus. In flow cytometry (FCM) analysis of wild type (WT) and ETV7 bone marrow (BM)-derived Lin-Sca1+cKit+(LSK) cells, the size and frequency of LT(long term)-HSCs (CD48-CD150+LSK) in ETV7 LSK was 2-fold lower than that in WT LSK, while the frequency of LSK and hematopoietic common progenitor cells in WT and ETV7 BM are similar. As compared with WT-LSK, ETV7-LSK showed a significantly decreased number of myeloid progenitor colonies in both the initial plating (MC1) and replating of MC1 colonies (MC2) in methylcellulose colony formation assay in vitro. To assess the ETV7 HSC function contributing to blood cell generation in vivo, we performed competitive repopulation assays. In agreement with the in vitro results, the repopulation ability of HSC is significantly compromised in ETV7 mice as measured 7 weeks post transplantation. This defect was even more pronounced 16 weeks post transplantation. Since enhanced cell cycle entry is known to cause loss of hematopoietic stem/progenitor cells (HSPCs) through the activation of a tumor suppressor response, we quantified p19ARF, p16INK4a, and p21CDKN1A gene expression in LSK cells by qRT-PCR. At day 6 and day 9 of in vitro culture, ETV7 LSK cells activated the p19ARF, p16INK4a, and p21CDKN1A genes about 2-fold greater than WT LSK cells. To measure the de novo DNA replication of HSPCs in vivo, BrdU-pulse labeled BM cells were harvested and BrdU incorporation was quantified by FCM analysis. ETV7 LSK cells showed elevated BrdU incorporation compared with that of WT. In addition, Hoechst33342/Pyronin Y staining revealed that ETV7 LSK enhanced transition from G0 to the G1 phase of the cell cycle, suggesting that ETV7 forced cell cycle entry of quiescent HSCs. Finally to clarify the involvement of the CDKN2A tumor suppressor in ETV7-associated HSC exhaustion, we examined the frequency of HSPCs in CDKN2A-/- and ETV7+/-CDKN2A-/- LSK cells in vivo by FCM analysis. Loss of CDKN2A but not ARF restored the depletion of ETV7 LT-HSCs. Moreover, loss of CDKN2A rescued the defect of repopulation ability in vivo and self-renewal activity in vitro of ETV7 HSPCs. These results indicate that exhaustion of HSC in ETV7 BM occurred through ETV7-induced activation of cell proliferation and the CDKN2A tumor suppressor pathway in mice. Disclosures: No relevant conflicts of interest to declare.

scholarly journals HB9 Represses Hematopoietic Stem Cell Proliferation and Induces Senescence

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1539-1539
Author(s):  
Deborah Ingenhag ◽  
Franziska Auer ◽  
Arndt Borkhardt ◽  
Julia Hauer
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Line ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Oncogenic Potential ◽  
Stem Cell Proliferation ◽  
Senescent Phenotype

Abstract Introduction: HB9 is a transcription factor encoded by homeobox gene B9 (HLXB9). It is physiologically expressed during early embryonic development as well as in pancreatic beta- and motor neuronal cell development. Ectopic HB9 expression is found in infant acute myeloid leukemia with translocation t(7;12), accounting for up to one third of infant AML cases with a poor 3-year EFS of 0% irrespective of the treatment approach. We previously showed that HB9 regulates cell-cell interaction/adhesion (Wildenhain et al. Leukemia, 2010) in hematopoietic cells and influences the prostaglandin signalling pathway (Wildenhain & Ingenhag et al. JBC, 2012). In this study we focussed on the oncogenic potential of HB9 in hematopoiesis. Methods: To investigate the oncogenic influence of HB9 expression on hematopoiesis, we developed an in vivo murine transplantation model. HB9-transduced lineage negative (Lin-) murine HSCs were transplanted into lethally irradiated wild-type mice and we monitored hematopoietic reconstitution and leukemia emergence by serial retroorbital bleedings for up to one year. Final analysis included comprehensive flow cytometric analysis of all hematopoietic compartments, with respect to dissemination of blast cells and cellular distribution. In vitro studies included proliferation as well as cell cycle analysis. Senescent phenotype was characterized by senescence-associated beta-galactosidase staining and cellular morphology. Knockdown of p53 was obtained via transfection of siRNA. Results: Transplantation of HB9- or mock-transduced murine Lin- cells into lethally irradiated wild-type recipient mice (n=10) showed >80% donor chimerism and HB9-transduced Lin- cells gave rise to all hematopoietic lineages (B-lineage: CD19+, T-lineage: CD3+, NK-lineage: Nk1.1+, granulocytic lineage: Gr-1+, Monocytic lineage: CD11b+) in the peripheral blood, indicating no lineage-related preference of HB9-expressing HSCs. Reconstitution of peripheral blood cell compartments in HB9 transplanted mice, however, was significantly decreased in all three lineages (CD3+: 9.5-fold, CD19+: 34.7-fold , Gr+: 1.8-fold) compared to the control group with respect to copy number, mRNA and protein expression. We did not observe an accumulation of hematopoietic stem (LT-HSC, ST-HSC, MPP) and precursor cells subsets (CLP, MEP, CMP, GMP) in the bone marrow of mice transplanted with HB9-positive Lin- cells. Finally, mice transplanted with HB9-transduced Lin- cells did not develop leukemia after 12 months follow-up. The decreased reconstitution capacity of HB9 expressing HSCs led us to the assumption that HB9 represses cellular proliferation in vivo. Thus we performed proliferation studies in vitro. Ectopic expression of HB9 in the murine NIH3T3 cell line revealed a complete inhibition of cell proliferation compared to mock control (n=3). The same effect was observed in human HT1080 cell line. Cell cycle analysis revealed a significant decrease of the S-phase (2-fold, p<0.05), stalling the cells in G1 and G2 phase of the cell cycle. In both cell line models HB9-transduced cells developed a senescent phenotype being multinuclear, flattened and enlarged. Staining for senescence-associated β-galactosidase activity was positive in HB9-transduced cells in contrast to complete absence in mock-transduced cells. Immunoblot analysis revealed that the HB9 dependent cell cycle arrest was mediated via p53-induced upregulation of p21. Knockdown experiments using p53-targeting siRNAs confirmed that the p53-signalling is responsible for the growth arrest because p53-knockdown was able to reverse the effect. Conclusion:In our study HB9 represses hematopoietic stem cell proliferation in vivo and induces a senescent phenotype in vitro. Senescence is an evasion mechanism in response to aberrant oncogene expression and induction of senescence is the first evidence for an oncogenic potential of HB9. Future studies elucidating the signal pattern of HB9-induced senescence will shed new light on the pathomechanism and potential therapeutic targets in the treatment of translocation t(7;12) positive AML. Disclosures No relevant conflicts of interest to declare.

IFNs Upregulate Sca-1 and Block Proliferation in Murine Hematopoietic Stem and Progenitor Cells,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3394-3394
Author(s):  
Kaitlyn Shank ◽  
Yusup Shin ◽  
Carson Wills ◽  
Nicole Cunningham ◽  
Alevtina Domashenko ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Progenitor Cells ◽  
Caspase 3 ◽  
Inflammatory Responses ◽  
Conflicts Of Interest ◽  
Brdu Incorporation ◽  
Apparent Paradox ◽  
Hematopoietic Stem

Abstract Abstract 3394 Hematopoietic stem cells (HSC) replenish the cellular components of the blood throughout life by a homeostatic process in which the majority of HSCs remain quiescent while a small percentage enter the cell cycle to either self-review or differentiate. During inflammatory responses to infections, Interferons (IFNa, IFNg) perturb HSC homeostasis, presumably in response to the demand for increased numbers of inflammatory cells. Previous studies have highlighted an apparent paradox, i.e. IFNs suppress the proliferation of normally cycling murine hematopoietic progenitor cells (HPCs), yet increase the fraction of normally quiescent Sca+ HSCs that proliferate. To investigate the mechanisms underlying this paradox, we dissected the dynamics of cell surface phenotypes, cell cycle kinetics, pro- and anti-apoptotic pathways within the HSC and HPC compartments in response to pIpC and IFNs both in vivo and in vitro. Forty-eight hours after pIpC injection, bone marrow (BM) cellularity declined by 60%, the proportion of Sca- kit+ HPCs fell from 0.45% to 0.05%, while the proportion of BM cells with the Sca+ kit+ HSC phenotype increased from 0.17 to 0.26%. To determine whether the increase in Sca+kit+ cells was due to proliferation of HSCs or upregulation of Sca-1 on HPCs, we cultured purified CD150+ Sca-Kit+ HPCs and CD150+Sca+kit+ HSCs in vitro with IFNa, IFNg, or PBS. Sca expression was induced on previously Sca- HPCs, and the level of Sca expression on HSCs was also increased. This induction was detectable as early as 6 hours after treatment and accompanied by an increase in Sca mRNA. BrdU incorporation into both HPC and HSC populations decreased from pre-treatment baselines, further indicating that the increase in cells with the HSC phenotype was not due to HSC proliferation, but rather the appearance of cycling HPCs within the HSC staining gate following IFN-induced upregulation of Sca. Staining with FITC-DEVD-FMK identified active cleaved capase-3 in pIpC- or IFN-treated cells, suggesting that the reduced cellularity following IFN reflected a cellular stress that killed Lin+ precursors cells and some HPCs, but spared HSCs. In contrast to lin+kit- precursors, all kit + HPCs and HSCs expressed bcl-2, suggesting that expression of anti-apoptotic proteins may prevent IFN-induced stress from resulting in HSC/HPC apoptosis despite the initial triggering of caspase-3 cleavage. In summary, acute treatment with IFNs has anti-proliferative effects on all hematopoietic cells, including precursors, HPCs and HSCs, with the apparent increase in HSC proliferation the result of HPCs masquerading as Sca+HSCs after exposure to IFN. Unlike precursors, HSCs and some HPCs survive treatment to IFNs despite activation of cleaved caspase-3, possibly due to their expression of bcl-2, and likely related anti-apoptotic regulators. The previously observed increase in HSC proliferation days and weeks following IFN treatment is most likely due to the homeostatic response of HSCs to the depopulation of the precursor and HPCs caused by acute IFN exposure. Disclosures: No relevant conflicts of interest to declare.

Nucleotide Receptor P2Y14 Modulates Hematopoietic Stem Cell Response to Tissue Injury Altering Stem Cell Preservation and Tissue Recovery.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 679-679 ◽  
Author(s):  
Yoriko Saito ◽  
Eyal Attar ◽  
Samyukta Jana ◽  
David Dombkowski ◽  
Viktor Janzen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stem Cell ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Chemical Injury ◽  
Cell Cycle Entry ◽  
Induced Apoptosis ◽  
Lethal Irradiation

Abstract P2 receptors are functionally diverse cell surface receptors that bind nucleotides adenine (ADP, ATP) and uridine (UDP, UTP). P2Y receptors are metabotropic G protein-coupled receptors that mediate vascular and immune responses to injury. We previously reported the differential expression cloning of the UTP-glycoconjugate receptor, P2Y14 from quiescent primary human bone marrow (BM) hematopoietic stem cells (HSCs). Using P2Y14−/− mice, we now report that the presence of P2Y14 protects HSCs from apoptosis in the face of cytotoxic chemical injury. P2Y14 null mice develop normally and showed no significant differences in peripheral blood cell counts, BM cellularity or the absolute number/proportion of lin−cKit+Sca1+ (LKS+) and CD34−/lowLKS+ (34-LKS+) cells compared to their wildtype littermates. Similarly, cell cycle status, in vitro colony-forming cell (CFC) capacity, in vivo homing and in vivo colony-forming unit-spleen (CFU-S) function were unaffected. Since the role of nucleotide receptors in injury response have been reported, we examined BM HSC content following IP injection of 200mg/kg cyclophosphamide (CTX) and found that the relative protection of LKS+ and 34-LKS+ cells from CTX-induced apoptosis was lost in P2Y14 null animals (WT LKS+: 12.7% AnnexinV+7AAD-, KO LKS+ 36.8% AnnexinV+7AAD−, n=5 each, p=0.004; WT 34-LKS+: 13.2% AnnexinV+7AAD−, KO LKS+ 38.7% AnnexinV+7AAD−, n=5 each, p=0.007). In addition, the kinetics of long-term myeloid recovery after a single injection of 5-Fluorouracil (5FU) IP 150mg/kg was significantly more accentuated in P2Y14 null animals, with significantly greater peripheral blood Gr-1+ cell count at days 21–56 post-injection (n=10 each, p=0.009). When sorted BM LKS+ cells were exposed in vitro to UDP-glucose, a putative P2Y14 ligand known to be released from cytoplasm during cellular injury, BrDU incorporation was significantly reduced (n=3 each, p&lt;0.05), suggesting that P2Y14 activation with UDP-glucose reduces HSC cell cycle entry in response to injury. While these in vivo models examine HSC response to injury to both BM microenvironment and the HSCs themselves, when uninjured HSCs were reintroduced into injured microenvironment in the setting of hematopoietic reconstitution following lethal irradiation, P2Y14 null BM HSCs performed better in serial transplantation (n=10 each, p&lt;0.01 for primary, secondary and tertiary transplantation), showing greater reconstitution and self-renewal capacity compared with WT littermates. From these findings, we propose that P2Y14 protects HSCs from chemical injury by acting as a sensor for metabolic “danger signal” in the form of released intracellular UDP-glucose during acute chemical injury in the BM and maintaining relative resistance of HSCs to toxin-induced apoptosis by restricting cell cycle entry. In the setting of injury exclusive to BM microenvironment (HSC transplantation), P2Y14 null HSCs, unable to detect UDP-glucose, respond to highly proliferative environment following lethal irradiation, resulting in greater reconstitution and self-renewal.

scholarly journals BRD4 PROTAC degrader ARV-825 inhibits T-cell acute lymphoblastic leukemia by targeting 'Undruggable' Myc-pathway genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Acute Lymphoblastic Leukemia ◽  
Caspase 3 ◽  
Lymphoblastic Leukemia ◽  
Rna Seq ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Bet Protein

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.

scholarly journals Tanshinone IIA Inhibits Osteosarcoma Growth through a Src Kinase-Dependent Mechanism

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Chao Hu ◽  
Xiaobin Zhu ◽  
Taogen Zhang ◽  
Zhouming Deng ◽  
Yuanlong Xie ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathways ◽  
Cell Lines ◽  
Src Kinase ◽  
Akt Signaling ◽  
Cellular Level ◽  
Tanshinone Iia

Introduction. Osteosarcoma is a malignant tumor associated with high mortality rates due to the toxic side effects of current therapeutic methods. Tanshinone IIA can inhibit cell proliferation and promote apoptosis in vitro, but the exact mechanism is still unknown. The aims of this study are to explore the antiosteosarcoma effect of tanshinone IIA via Src kinase and demonstrate the mechanism of this effect. Materials and Methods. Osteosarcoma MG-63 and U2-OS cell lines were stable transfections with Src-shRNA. Then, the antiosteosarcoma effect of tanshinone IIA was tested in vitro. The protein expression levels of Src, p-Src, p-ERK1/2, and p-AKt were detected by Western blot and RT-PCR. CCK-8 assay and BrdU immunofluorescence assay were used to detect cell proliferation. Transwell assay, cell scratch assay, and flow cytometry were used to detect cell invasion, migration, and cell cycle. Tumor-bearing nude mice with osteosarcoma were constructed. The effect of tanshinone IIA was detected by tumor HE staining, tumor inhibition rate, incidence of lung metastasis, and X-ray. Results. The oncogene role of Src kinase in osteosarcoma is reflected in promoting cell proliferation, invasion, and migration and in inhibiting apoptosis. However, Src has different effects on cell proliferation, apoptosis, and cell cycle regulation among cell lines. At a cellular level, the antiosteosarcoma effect of tanshinone IIA is mediated by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways. At the animal level, tanshinone IIA played a role in resisting osteosarcoma formation by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways. Conclusion. Tanshinone IIA plays an antiosteosarcoma role in vitro and in vivo and inhibits the progression of osteosarcoma mediated by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways.

scholarly journals Positive feedback between lncRNA FLVCR1-AS1 and KLF10 may inhibit pancreatic cancer progression via the PTEN/AKT pathway

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jiewei Lin ◽  
Shuyu Zhai ◽  
Siyi Zou ◽  
Zhiwei Xu ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Pancreatic Cancer ◽  
Cell Proliferation ◽  
Cancer Progression ◽  
Positive Feedback ◽  
Molecular Mechanisms ◽  
Tumor Tissues ◽  
And Migration

Abstract Background FLVCR1-AS1 is a key regulator of cancer progression. However, the biological functions and underlying molecular mechanisms of pancreatic cancer (PC) remain unknown. Methods FLVCR1-AS1 expression levels in 77 PC tissues and matched non-tumor tissues were analyzed by qRT-PCR. Moreover, the role of FLVCR1-AS1 in PC cell proliferation, cell cycle, and migration was verified via functional in vitro and in vivo experiments. Further, the potential competitive endogenous RNA (ceRNA) network between FLVCR1-AS1 and KLF10, as well as FLVCR1-AS1 transcription levels, were investigated. Results FLVCR1-AS1 expression was low in both PC tissues and PC cell lines, and FLVCR1-AS1 downregulation was associated with a worse prognosis in patients with PC. Functional experiments demonstrated that FLVCR1-AS1 overexpression significantly suppressed PC cell proliferation, cell cycle, and migration both in vitro and in vivo. Mechanistic investigations revealed that FLVCR1-AS1 acts as a ceRNA to sequester miR-513c-5p or miR-514b-5p from the sponging KLF10 mRNA, thereby relieving their suppressive effects on KLF10 expression. Additionally, FLVCR1-AS1 was shown to be a direct transcriptional target of KLF10. Conclusions Our research suggests that FLVCR1-AS1 plays a tumor-suppressive role in PC by inhibiting proliferation, cell cycle, and migration through a positive feedback loop with KLF10, thereby providing a novel therapeutic strategy for PC treatment.

Effect and mechanism of YB-1 knockdown on glioma cell growth, migration, and apoptosis

2020 ◽  
Vol 52 (2) ◽  
pp. 168-179 ◽  
Author(s):  
Huilin Gong ◽  
Shan Gao ◽  
Chenghuan Yu ◽  
Meihe Li ◽  
Ping Liu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Growth ◽  
Glioma Cell ◽  
Cell Transformation ◽  
Malignant Cell ◽  
Protein Levels ◽  
Glioma Progression

Abstract Y-box binding protein 1 (YB-1) is manifested as its involvement in cell proliferation and differentiation and malignant cell transformation. Overexpression of YB-1 is associated with glioma progression and patient survival. The aim of this study is to investigate the influence of YB-1 knockdown on glioma cell progression and reveal the mechanisms of YB-1 knockdown on glioma cell growth, migration, and apoptosis. It was found that the knockdown of YB-1 decreased the mRNA and protein levels of YB-1 in U251 glioma cells. The knockdown of YB-1 significantly inhibited cell proliferation, colony formation, and migration in vitro and tumor growth in vivo. Proteome and phosphoproteome data revealed that YB-1 is involved in glioma progression through regulating the expression and phosphorylation of major proteins involved in cell cycle, adhesion, and apoptosis. The main regulated proteins included CCNB1, CCNDBP1, CDK2, CDK3, ADGRG1, CDH-2, MMP14, AIFM1, HO-1, and BAX. Furthermore, it was also found that YB-1 knockdown is associated with the hypo-phosphorylation of ErbB, mTOR, HIF-1, cGMP-PKG, and insulin signaling pathways, and proteoglycans in cancer. Our findings indicated that YB-1 plays a key role in glioma progression in multiple ways, including regulating the expression and phosphorylation of major proteins associated with cell cycle, adhesion, and apoptosis.

scholarly journals Tumor quiescence: elevating SOX2 in diverse tumor cell types downregulates a broad spectrum of the cell cycle machinery and inhibits tumor growth

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ethan P. Metz ◽  
Erin L. Wuebben ◽  
Phillip J. Wilder ◽  
Jesse L. Cox ◽  
Kaustubh Datta ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Cell Cycle Machinery

Abstract Background Quiescent tumor cells pose a major clinical challenge due to their ability to resist conventional chemotherapies and to drive tumor recurrence. Understanding the molecular mechanisms that promote quiescence of tumor cells could help identify therapies to eliminate these cells. Significantly, recent studies have determined that the function of SOX2 in cancer cells is highly dose dependent. Specifically, SOX2 levels in tumor cells are optimized to promote tumor growth: knocking down or elevating SOX2 inhibits proliferation. Furthermore, recent studies have shown that quiescent tumor cells express higher levels of SOX2 compared to adjacent proliferating cells. Currently, the mechanisms through which elevated levels of SOX2 restrict tumor cell proliferation have not been characterized. Methods To understand how elevated levels of SOX2 restrict the proliferation of tumor cells, we engineered diverse types of tumor cells for inducible overexpression of SOX2. Using these cells, we examined the effects of elevating SOX2 on their proliferation, both in vitro and in vivo. In addition, we examined how elevating SOX2 influences their expression of cyclins, cyclin-dependent kinases (CDKs), and p27Kip1. Results Elevating SOX2 in diverse tumor cell types led to growth inhibition in vitro. Significantly, elevating SOX2 in vivo in pancreatic ductal adenocarcinoma, medulloblastoma, and prostate cancer cells induced a reversible state of tumor growth arrest. In all three tumor types, elevation of SOX2 in vivo quickly halted tumor growth. Remarkably, tumor growth resumed rapidly when SOX2 returned to endogenous levels. We also determined that elevation of SOX2 in six tumor cell lines decreased the levels of cyclins and CDKs that control each phase of the cell cycle, while upregulating p27Kip1. Conclusions Our findings indicate that elevating SOX2 above endogenous levels in a diverse set of tumor cell types leads to growth inhibition both in vitro and in vivo. Moreover, our findings indicate that SOX2 can function as a master regulator by controlling the expression of a broad spectrum of cell cycle machinery. Importantly, our SOX2-inducible tumor studies provide a novel model system for investigating the molecular mechanisms by which elevated levels of SOX2 restrict cell proliferation and tumor growth.

scholarly journals TRB3 is elevated in psoriasis vulgaris lesions and mediates HaCaT cells proliferation in vitro

2017 ◽  
Vol 65 (7) ◽  
pp. 1084-1088 ◽  
Author(s):  
Xiao-Jing Yu ◽  
Tie-Jun Song ◽  
Lu-Wei Zhang ◽  
Ying Su ◽  
Ke-Yu Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Messenger Rna ◽  
Psoriasis Vulgaris ◽  
Metabolic Diseases ◽  
Brdu Incorporation ◽  
Cell Cycle Distribution ◽  
Hacat Cells ◽  
Keratinocyte Proliferation

Psoriasis is a chronic skin disease characterized by abnormal keratinocyte proliferation and differentiation, inflammation, and angiogenesis. Overexpression of tribbles homolog3 (TRB3), which belongs to the tribbles family of pseudokinases, has been found in several human tumors and metabolic diseases, but its role in psoriasis has not been fully clarified. The aim of this study is to investigate the expression of TRB3 in psoriasis and explore its roles in the proliferation of keratinocytes. Twenty-four patients with psoriasis vulgaris were recruited for the study. Diagnosis of psoriasis was based on clinical and histologic examinations. Immunohistochemistry and real-time reverse transcription PCR (RT-PCR) were performed to determine protein and messenger RNA (mRNA) expression of TRB3 in psoriasis lesions. 5-Bromo-2-deoxyUridine (BrdU) incorporation assay were performed for cell proliferation. Cell cycle distribution was assessed by flow cytometry analysis. The levels of TRB3 is elevated in psoriatic lesions compared with psoriatic non-lesions. The HaCat cells expressed the TRB3 gene. We found TRB3 silencing to significantly inhibit HaCat cell proliferation. Furthermore, the specific knockdown of TRB3 slowed down the cell cycle at the gap 0/first gap phase. In conclusion, our data suggest that TRB3 is overexpressed in lesions of patients with psoriasis and may be involved in the abnormal proliferation of keratinocytes. Therefore, TRB3 may be a potential therapeutic target for psoriasis.

191 RISK ASSESSMENT OF BISPHENOL A, AN ENDOCRINE DISRUPTOR, VIA PROLIFERATIVE EFFECT ON THE GROWTH OF ESTROGEN-DEPENDENT OVARIAN CANCER IN CELLULAR AND ANIMAL MODELS

2013 ◽  
Vol 25 (1) ◽  
pp. 244
Author(s):  
K.-A. Hwang ◽  
K.-C. Choi
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Bisphenol A ◽  
Cancer Cells ◽  
The Body ◽  
Brdu Incorporation ◽  
Ovarian Cancer Cells ◽  
Tumour Proliferation

One of estrogens in the body, 17β-oestradiol (E2), is a pleiotropic hormone that regulates the growth and differentiation of many tissues and also acts as a mitogen that promotes the development and proliferation of hormone-responsive cancers such as breast and ovarian carcinomas. Xenoestrogens are chemical compounds that imitate oestrogen in living organisms and are classified as a type of endocrine-disrupting chemical (EDC). Bisphenol A (BPA) is a widely used industrial compound, and also known as an EDC and especially a xenoestrogen. In this study, we examined the effect of E2 or BPA on the cell growth of BG-1 ovarian cancer cells in vivo and in vitro. In the cell proliferation assay in vitro, E2 or BPA increased the growth of the BG-1 ovarian cancer cells expressing oestrogen receptors (ER). Their proliferation activity was reversed by the treatment of ICI 182 780, a well-known antagonist of ER, which demonstrates that the cell proliferation by E2 or BPA is mediated by ER and BPA certainly acts as a xenoestrogen in the BG-1 ovarian cancer cells. Clearly, E2 and BPA increased the expression of cyclin D1, a factor responsible for the G1/S cell cycle transition. These reagents also decreased the expression of p21, a potent cyclin-dependent kinase (CDK) inhibitor that arrests the cell cycle in the G1 phase. As a result, they promoted the proliferation of BG-1 cells via upregulation of the cell cycle progression. In mice xenograft models transplanted with BG-1 ovarian cancer cells, E2 or BPA administration significantly induced the tumour proliferation compared with vehicle (corn oil) treatment for 10 weeks, which was identified by the measurement of tumour volume and histological analysis on tumour tissues such as hematoxylin and eosin (H&E) staining and BrdU incorporation assay. Taken together, as an EDC having a xenoestrogenic activity, BPA was demonstrated to have a risk of tumour proliferation in oestrogen-dependent cancers such as ovarian cancer. This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Ministry of Education, Science and Technology (MEST) of government of Korea (no. 2011-0015385).

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