Protein Expression Patterns of Candidate Genes Involved in Apoptosis and Cell Cycle Control in Genetic Subgroups of Chronic Lymphocytic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2796-2796
Author(s):  
Christof Schneider ◽  
Dirk Winkler ◽  
Meike Loddenkemper ◽  
Alexander Krober ◽  
Peter Lichter ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Expression ◽  
Cyclin D1 ◽  
Candidate Genes ◽  
Cell Lines ◽  
Normal Karyotype ◽  
Lymphocytic Leukemia ◽  
Expression Levels ◽  
Protein Levels ◽  
Atm Protein

Abstract Chronic lymphocytic leukemia (CLL) is a heterogeneous disease with a highly variable clinical course. Genomic aberrations (such as 13q−, 11q−, +12q, 17p−) can be found in about 80% of CLL cases and define pathogenic as well as clinical subgroups. Similarly, the mutational status of the variable region of the immunoglobulin heavy-chain gene (VH) identifies subgroups with different maturation stage and clinical outcome. In this study protein expression levels of candidate genes involved in cell cycle and apoptosis control (p53, ATM, Akt1, PI3-K, p21, p27, cdk4, Cyclin-D1, D2, D3, Bax, Bcl-2, Apaf-1, Smac, XIAP, cIAP2, survivin) were examined by Western Blotting. A total of 87 CLL cases derived from the subgroups with 11q- (n=22), 17p-/p53 mutation (n=18), +12q (n=24), 13q- (n=8) or a normal karyotype (n=15) were studied and compared to the cell lines EHEB and JVM-2. VH-mutation status was available for 65 cases (unmutated n=48, mutated n=17). Due to limitations in sample availability not all proteins could be examined in all cases. A highly homogenous expression pattern for all the proteins studied was observed in the CLL subgroup with a normal karyotype. This pattern was independent of the VH-status. CLL samples with normal karyotype, +12q and 13q deletion showed equal levels of ATM as compared to EHEB and JVM-2. As compared to cases with a normal karyotype the ATM level within the 11q- subgroup was reduced in 5 cases and absent in 1 case among 11 evaluable 11q- cases. The 17p- subgroup was comprised of 3 cases with concomitant 17p- and 11q- and 15 cases with 17p- but no 11q-. The latter group showed ATM protein levels comparable to the levels of the normal karyotype group. In the group with 17p- and 11q- there was an ATM expression level similar to the groups with 17p- and normal karyotype in two cases while one case had a reduced ATM protein level comparable to the 11q- subgroup. All cases with 17p- exhibited a stronger expression of p53 as compared to the cell lines and all other cases, except for one case with normal karyotype and one with an 11q-. No p53 mutations could be detected in exons 5–9 by sequencing in these two cases. High levels of survivin protein were found in all cases with 17p- and/or 11q-, 13q-, +12q while the subgroup with a normal karyotype showed lower levels. High levels of cdk4 protein were expressed in cases with 17p-, 11q- and 13q- while cdk4 protein levels were low in the subgroup with +12q and normal karyotype. Regarding p21, p27, Bcl2, Bax, Smac, Apaf-1, Cyclin D1–D3, cIAP2, XIAP, Akt1 and PI3K no variation in the expression levels were observed across the genetic CLL subgroups. Comparing the CLL cases to the cell lines the differences in expression levels were found for the cell cycle regulators Cyclin D1, D2, D3, p21 and p27. While the cell lines showed strong protein levels for Cyclin D1, D2, D3 and p21, they were nearly absent in the CLL cases. Expression of p27 was higher in all CLL cases as compared to JVM-2 and EHEB. In conclusion, the 17q- subgroup was the only group with a high level of p53 protein expression indicating that p53 is the affected gene in this subgroup. In contrast, the ATM protein levels are reduced only in a part of the 11q- cases indicating a possible role of additional candidate genes. Cases with +12q and normal karyotype showed weak expression of cdk4 pointing out a possible function in these subgroups.

Truncation in CCND1 mRNA 3′ UTR Is Associated with An Aggressive Phenotype and Chemoresistance

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5287-5287
Author(s):  
Robert W Chen ◽  
Myo Htut ◽  
Britta Hoehn ◽  
Eamon Berge ◽  
William Robinson ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Expression ◽  
Cyclin D1 ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
Serum Starvation ◽  
Cycle Progression ◽  
Serum Free ◽  
Aggressive Phenotype ◽  
Free Media

Abstract Mantle Cell Lymphoma (MCL) represents 5–10% of all non-Hodgkins lymphomas, making it an uncommon but difficult form of lymphoma to treat. It has the worst prognosis among the B cell lymphomas with median survival of three years. The genetic hallmark of MCL is the t(11,14)(q13;32) translocation causing amplification of cyclin D1 (CCND1). It is a well known cell cycle regulator. Multiple reports have shown a truncation in the cyclin D1 mRNA 3′ untranslated region. This truncation increases CCND1 protein expression by not only enhancing the half-life of CCND1 mRNA, but also evades microRNA regulation of mRNA translation. The dramatic overexpression of CCND1 mRNA and protein has been associated to poor clinical outcome in patients. We hypothesize that this truncation leads to a more aggressive phenotype and induces chemoresistance in MCL. We have identified 4 MCL cell lines (Granta-519, JVM-2, Jeko-1, and Z138) with different levels of the truncated CCND1 mRNA. We were able to show that Z138 and Jeko-1 have a much higher ratio of truncated CCND1 mRNA to the full length CCND1 mRNA as compared to Granta-519 and JVM-2. We were also able to show that this truncated mRNA leads to an increase in CCND1 protein expression. By using flow cytometry, we correlated the increase in CCND1 protein expression to faster cell cycle progression. We proposed that cell lines with increased CCND1 expression are phenotypically more aggressive, and would be able to continue cell cycle progression without serum support. We were able to arrest JVM-2 in G1 phase after 48 hours of serum starvation. However, we were not able to arrest cell cycle progression in Jeko-1 even after 96 hours of serum starvation. Western blot analysis shows that CCND1 protein expression is decreased in JVM-2 but remains unchanged in Jeko-1 with serum starvation. The same phenomenon was observed in Granta-519 and Z138. The MCL cell lines (Jeko-1 and Z-138) with more CCND1 protein expression were able to continue cell cycle progression in serum free media. The MCL cell lines (JVM-2 and Granta-519) with less CCND1 protein expression were not able to continue cell cycle progression in serum free media. This shows that CCND1 overexpression is associated with a more aggressive phenotype. We then treated the 4 MCL cell lines with varying concentrations of doxorubicin, a standard anthracycline chemotherapy used in the treatment of MCL patients. We used MTS assay to assess cell proliferation after treatment with doxorubicin. We found the IC 50 (inhibitory concentration 50%) of doxorubicin in these cell lines varied from 6nM to 600nM. The cell lines (Jeko-1 and Z-138) with more CCND1 protein expression have a much higher IC 50 as compared to the cell lines (JVM-2 and Granta-519) with less CCND1 protein expression. This demonstrates that CCND1 overexpression is associated with chemoresistance. We conclude truncation in CCND1 mRNA leads to increased CCND1 protein expression and faster cell cycle progression CCND1 overexpression is associated with an aggressive phenotype CCND1 overexpression is associated with chemoresistance.

Cell Cycle Regulation by Iron: Novel Approaches to Mantle Cell Lymphoma Therapy.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2515-2515 ◽  
Author(s):  
Heather Gilbert ◽  
John Cumming ◽  
Josef T. Prchal
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Iron Chelation ◽  
Lymphoma Cell ◽  
Protein Levels ◽  
Mantle Cell

Abstract Abstract 2515 Poster Board II-492 Mantle cell lymphoma is a well defined subtype of B-cell non-Hodgkin lymphoma characterized by a translocation that juxtaposes the BCL1 gene on chromosome 11q13 (which encodes cyclin D1) next to the immunoglobulin heavy chain gene promoter on chromosome 14q32. The result is constitutive overexpression of cyclin D1 (CD1) resulting in deregulation of the cell cycle and activation of cell survival mechanisms. There are no “standard” treatments for MCL. Despite response rates to many chemotherapy regimens of 50% to 70%, the disease typically progresses after treatment, with a median survival time of approximately 3-4 years. Mantle cell lymphoma represents a small portion of malignant lymphomas, but it accounts for a disproportionately large percentage of lymphoma-related mortality. Novel therapeutic approaches are needed. In 2007, Nurtjaha-Tjendraputra described how iron chelation causes post-translational degradation of cyclin D1 via von Hippel Lindau protein-independent ubiquitinization and subsequent proteasomal degradation (1). Nurtjaha-Tjendraputra demonstrated that iron chelation inhibits cell cycle progression and induces apoptosis via proteosomal degradation of cyclin D1 in various cell lines, including breast cancer, renal carcinoma, neuroepithelioma and melanoma. Our preliminary data show similar findings in mantle cell lymphoma. To establish whether iron chelation can selectively inhibit and promote apoptosis in mantle cell derived cell lines, the human MCL cell lines Jeko-1, Mino, Granta and Hb-12; the Diffuse Large B cell lymphoma line SUDHL-6; and the Burkitt's Lymphoma lines BL-41 and DG75 were grown with media only, with two different iron chelators (deferoxamine (DFO) and deferasirox) at various concentrations (10, 20, 40, 100 and 250 μM), and with DMSO as an appropriate vehicle control. Cells were harvested at 24, 48 and 72 hours. For detection of apoptotic cells, cell-surface staining was performed with FITC-labeled anti–Annexin V antibody and PI (BD Pharmingen, San Diego, CA). Cell growth was analyzed using the Promega MTS cytotoxicity assay. CD1 protein levels were assessed using standard Western blot techniques. At 24, 48 and 72 hours of incubation with iron chelators, the mantle cell lymphoma cell lines showed significantly increased rates of apoptosis compared to the non-mantle cell lymphoma cell lines (p<0.0001 for all time points). DFO and deferasirox inhibted cell growth with an IC50 of 18 and 12 μM respectively. All of the mantle cell lines had measurable cyclin D1 levels at baseline. None of the non-mantle cell lines expressed baseline measurable cyclin D1. In the mantle cell lines, cyclin D1 protein levels were no longer apparent on western blot after 24 hours of incubation with chelation. We then added ferrous ammonium sulfate (FAS) to DFO in a 1:1 molarity ratio and to deferasirox in a 2:1 ratio, and then treated the same lymphoma cell lines with the FAS/chelator mixture and with FAS alone for 72 hours. Adding iron to the chelators completely negated all the pro-apoptotic effects that were seen with iron chelation treatment. Treating with FAS alone had no effect on cell growth or apoptosis. Iron chelation therapy with both DFO and deferasirox results in decreased cell growth, increased cellular apoptosis, and decreased cyclin D1 protein levels in vitro in mantle cell lymphoma. The cytotoxic effects are prevented by coincubation with ferrous ammonium citrate, confirming that the effects are due to iron depletion. Proposed future research includes further defining the molecular basis of iron chelation effects; studying these therapies in combination with other cancer treatments both in vitro and in vivo; and studying iron chelation therapy in mantle cell lymphoma patients. 1. Nurtjahja-Tjendraputra, E., D. Fu, et al. (2007). “Iron chelation regulates cyclin D1 expression via the proteasome: a link to iron deficiency-mediated growth suppression.” Blood109(9): 4045–54. Disclosures: No relevant conflicts of interest to declare.

Cell Cycle Dysregulation Represents an Early Effect of the Proteasome Inhibitor Bortezomib in Mantle Cell Lymphoma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2287-2287 ◽  
Author(s):  
Grit Hutter ◽  
Yvonne Zimmermann ◽  
Malte Rieken ◽  
Marc Weinkauf ◽  
Oliver Weigert ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Expression ◽  
Cyclin D1 ◽  
Mantle Cell Lymphoma ◽  
Cell Lines ◽  
Proteasome Inhibitor ◽  
Cell Lymphoma ◽  
Genetic Alterations ◽  
Cell Cycle Regulators ◽  
Mantle Cell

Abstract Mantle cell lymphoma (MCL) is a distinct subtype of malignant lymphoma with an especially poor clinical outcome, a median survival time of 3 years and virtually no long-term survivors. On the molecular level, MCL is characterized by the chromosomal translocation t(11;14)(q13;q32) resulting in the constitutive overexpression of cyclin D1. However, additional genetic alterations of cell cycle regulators, e.g. deletions of the INK4A gene cluster, are detectable in the majority of cases. In various phase II studies the proteasome inhibitor bortezomib (Velcade) has demonstrated a high clinical efficacy with up to 60% remission rates in relapsed MCL. Additionally, in a previous in vitro study, the inhibitor induced a downregulation of cyclin D1 expression and a concomitant G(1) cell cycle arrest. However, little is known which molecules represent the critical targets of proteosome inhibition and how different regulators of cell cycle and apoptosis (inhibitors of CDK/INK4: p15INK4A, p16INK4B -and p14ARF and other kinase inhibitor proteins/KIP: 21CIP1, p27KIP1 and p57KIP2) are affected. 4 MCL cell lines (HBL2, GRANTA 519, Jeko-1, NCEB-1) and 2 hematological control cell lines (Jurkat, Karpas 422) were exposed to bortezomib at the minimal cytotoxic concentration (25 nmol) which corresponds to clinically achieved drug levels and results in a significant cytolysis after 48 – 72 hours. Real-time RT-PCR and protein expression levels of various CDK inhibitors (INK4s, KIPs) and cyclin D1 were determined a 0, 4, 8 and 12 hours after treatment with bortezomib. In addition, RNA- and protein expression data were compared to functional cell cycle phase (FACS) and cell apoptosis. Prelimenary data indicate that downregulation of cyclin D1 RNA expression after 12 and 24h of treatment represents a rather late event whereas alterations of other cell cycle regulators (like p21CIP1) were detected siginificantly earlier in all four MCL cell lines. Thus, expression of cell cycle regulators may indicate early events of proteasome inhibition. A comparative analysis of the cell cycle regulation network is currently being performed and will be presented at the conference.

scholarly journals Inhibition of Siah2 Ubiquitin Ligase By Vitamin K3 Attenuates Hypoxia and Blocks K562-R Cells Resistance

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5214-5214
Author(s):  
Na Xu ◽  
Yajuan Xiao ◽  
Xuan Zhou ◽  
Lin Li ◽  
Fen Huang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Protein Expression ◽  
Western Blot ◽  
Cell Lines ◽  
Oxygen Concentration ◽  
Ubiquitin Ligase ◽  
Vitamin K3 ◽  
Imatinib Resistance ◽  
Hematopoietic Stem ◽  
Expression Levels

Abstract Background and objective: Hypoxia has been shown to favor the self-renewal of murine and human hematopoietic stem cells. Hypoxia as a key feature of the “stem cell niches” in vivo, and studies found that hypoxia modified proliferation and differentiation of chronic myeloid leukemia (CML) stem cells.The E3 ubiquitin ligase Siah2 is an important regulator of the hypoxic response,which has been implicated in the regulation of the hypoxia response, as well as in the control of Ras, JNK/p38/NF-κB, MAPK signaling pathways. In the present study, we identified that SIAH2 induced k562 cells resistance to imatinib by hypoxia-inducible factor (HIF)-1a activated vascular epithelial growth factor (VEGF) pathway in hypoxia micro environment. In this study we show that SIAH2/Hif-1α induced K562 cell remain in G0 stage and resistance to imatinib, and we verified that vitamin K3 (SIAH2 inhibitor) reversed K562-R drug resistance in hypoxia microenvironment. Methods: We detected Siah2 expression levels in K562-wild type (K562-W) and K562-imatinib-resistance type (K562-R) cell lines by western blot analysis. Those two cell lines were further cultured for 24 h and 48 h under the condition of normal and hypoxia concentration of oxygen (1%, 5%), and treated K562-R with 0A5A15A30mM vitamin K3 for 72 hours in hypoxia concentration, explored cell cycle and apoptosis by flow cytometry (FCM) dyed by Annexin-V; analyzed the expression levels of Siah2, HIF-1α respectively by real-time PCR and western blot. Results: The protein of Siah2 and HIF-1α was significantly higher in K562-R compared with K562-w cells (P<0.01). Cell cycle analysis showed a 3% increase in K562-W G0/G1 cells in 1% O2 compared with normal O2, and 7% in K562-R. Under hypoxia condition, the cellular apoptotic ratio of K562-R was 5.46%, much less than 11.08% in K562-W cells. G0 cell proportion increased significantly with the long time Hypoxia (P<0.01); After being cultured in 1% oxygen concentration for 24 hours, we confirmed Siah2,HIF-1α were all up regulated in both cell lines, moreover, it was more obvious in K562-R cells. Siah2 protein expression increased along treated with vitamin K3 concentration (0, 5, 15, 30 mM) (P<0.05), on the contrary ,HIF-1α protein expression decreased with vitamin K3 concentration (P<0.05). the proportion of G0 cell was decreased in K562-R cells treated with Vitamin K3 (15mM)for 48h Under the condition of 1% oxygen concentration compared with control group (P=0.02). Conclusions: Hypoxia up-regulated of Siah2 and Hif-1α expression in K562-R, promoted cell apoptosis and arrested cells in G0 stage, and reduced cell sensitivity to Imatinib. Vitamin K3 could inhibit Siah2 and lowered Hif-1α in K562-R. These findings reveal an effective treatment for the identification of Siah2 inhibitors and would reverse TKI resistance for CML patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals Exosome Component 4 Promotes Epithelial Ovarian Cancer Cell Proliferation, Migration, and Invasion via the Wnt Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Chang Xiong ◽  
Zhongfeng Sun ◽  
Jinjin Yu ◽  
Yaying Lin
Keyword(s):  
Ovarian Cancer ◽  
Protein Expression ◽  
Epithelial Ovarian Cancer ◽  
Cyclin D1 ◽  
Cell Lines ◽  
Wnt Pathway ◽  
Migration And Invasion ◽  
Mrna Levels ◽  
Expression Levels ◽  
E Cadherin

BackgroundOf gynecologic malignancies, ovarian cancer is the leading cause of death, mainly due to the lack of sensitive tumor markers, which means it almost always presents at an advanced stage. Exosome Component 4 (EXOSC4) is involved in RNA degradation, but its role in epithelial ovarian cancer (EOC) is unclear.MethodsThe expression levels of EXOSC4 in EOC and normal ovarian tissue specimens were determined by immunohistochemical staining. The overall survival (OS) and progression-free survival (PFS) of patients with EOC were evaluated after patients were classified into high and low EXOSC4 expression groups, and the Cox regression model was established to identify independent predictors of patient prognosis. The effects of EXOSC4 on proliferation, colony formation, migration, and invasion were examined in the SKOV-3 and HO8910 cell lines by lentivirus-mediated shRNA knockdown. Flow cytometry was used to detect cell cycle changes. The mRNA levels of cyclin D1, CDK4, and c-myc were detected by RT-PCR. The protein expression levels of β-catenin, cyclin D1, CDK4, c-myc, vimentin, N-cadherin, and E-cadherin were assessed by western blot. Wnt/β-catenin activation was measured by TCF/LEF reporter assay.ResultsEXOSC4 was significantly elevated in EOC tissues and cell lines. High EXOSC4 expression was correlated with the International Federation of Gynecology and Obstetrics (FIGO) stage and pathological grade, and identified as an independent predictor of shorter OS and PFS. EXOSC4 knockdown suppressed proliferation, migration, and invasion in EOC cell lines. Cells were arrested at G0/G1 phase after EXOSC4 knockdown. The mRNA levels of cyclin D1, CDK4, and c-myc were decreased. β-catenin, cyclin D1, CDK4, c-myc, vimentin, and N-cadherin protein expression levels were reduced, while those of E-cadherin was increased. Wnt/β-catenin activity was suppressed after the EXOSC4 knockdown.ConclusionsEXOSC4 is involved in EOC. Knockdown of EXOSC4 can inhibit the proliferation, migration, and invasion ability of EOC by suppressing the Wnt pathway. EXOSC4 is expected to be a novel biomarker and molecular target in EOC.

scholarly journals Dihydropyrimidine Dehydrogenase Levels in Colorectal Cancer Cells Treated with a Combination of Heat Shock Protein 90 Inhibitor and Oxaliplatin or Capecitabine

2019 ◽  
Vol 9 (3) ◽  
pp. 439-444 ◽  
Author(s):  
Mahshid Mohammadian ◽  
Shima Zeynali-Moghaddam ◽  
Mohammad Hassan Khadem Ansari ◽  
Yousef Rasmi ◽  
Anahita Fathi Azarbayjani ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Protein Expression ◽  
Cell Lines ◽  
Dihydropyrimidine Dehydrogenase ◽  
Heat Shock Protein 90 ◽  
Water Soluble ◽  
Chemotherapy Response ◽  
Expression Levels ◽  
Protein Levels ◽  
Gene And Protein Expression

Purpose: Dihydropyrimidine dehydrogenase (DPD) is the principal enzyme in the catabolism of fluoropyrimidine drugs including capecitabine. A recent report has suggested that oxaliplatin chemotherapy is associated with elevated DPD levels and chemoresistance pattern. As a newly developed chemotherapeutic agent, 17-allyloamino-17-demethoxy-geldanamycin (17-AAG) can be effective in combination therapy with oxaliplatin and capecitabine in colorectal cancer (CRC). DPD expression level can be a predictive factor in oxaliplatin and capecitabine-based chemotherapy. We evaluated DPD in mRNA and protein levels with new treatments: 17-AAG in combination with oxaliplatin and capecitabine in HT-29 and HCT-116 cell lines. Methods: Drug sensitivity was determined by the water-soluble tetrazolium-1 assay in a previous survey. Then, we evaluated the expression levels of DPD and its relationship with the chemotherapy response in capecitabine, oxaliplatin, and 17-AAG treated cases in single and combination cases in two panels of CRC cell lines. DPD gene and protein expression levels were determined by real-time polymerase chain reaction and western blotting assay, respectively. Results: DPD gene expression levels insignificantly increased in single-treated cases versus untreated controls in both cell lines versus controls. Then, the capecitabine and oxaliplatin were added in double combinations, where DPD gene and protein expression increased in combination cases compared to pre-chemotherapy and single drug treatments. Conclusion: The elevated levels of cytotoxicity in more effective combinations could be related to a different mechanism apart from DPD mediating effects or high DPD level in the remaining resistance cells (drug-insensitive cells), which should be investigated in subsequent studies.

RB1 Haploinsufficiency Confers a Proliferation Advantage in Myeloma Cell Lines.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2489-2489
Author(s):  
Travis J. Henry ◽  
Wee Joo Chng ◽  
John Carpten ◽  
P. Leif Bergsagel ◽  
Rafael Fonseca
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Protein Expression ◽  
Cell Lines ◽  
Single Copy ◽  
S Phase ◽  
Interferon Response ◽  
Proliferation Index ◽  
Rb Protein ◽  
Protein Levels

Abstract The retinoblastoma 1 (RB1) gene is a frequent target of mutation or inactivation in neoplastic diseases. However, the current model for RB1-mediated malignancy requires inactivation of both alleles for tumor progression. Single–copy loss of RB1 has been shown to correlate with an approximate 50% reduction in RB1 mRNA expression in patients diagnosed with multiple myeloma and survival in this cohort of patients is significantly reduced. Using siRNA to reduce Rb protein levels to 50% and Rb-expressing adenovirus to restore RB1, variations in proliferation and cell cycle were observed. The KMS–11 adherent cell line with normal Rb protein expression was labeled with carboxyfluorescein succinimidyl ester (CFSE) for tracking of cellular division and RB1 siRNA added to silence 50% of protein expression. Transfection efficiency for siRNA was measured at 95% or greater. Flow cytometric analysis was performed at 72 hours to identify changes in proliferation between controls and Rb knock–down. Using CFSE proliferation analysis software, reduction of Rb protein levels by 50% caused an average increase in the proliferation index from 2.05 to 2.50. Additionally, reduction of Rb protein levels caused an increase in the percentage of cells in S–phase, from 24 to 29%. CFSE and cell cycle experiments were performed in triplicate. Conversely, addition of Rb–expressing adenovirus to MM.1R and U266 cell lines, with mono-allelic and bi-allelic loss of RB1 respectively, resulted in a decrease in proliferation assayed by CFSE and an average decrease in the percentage of cells in S-phase from 29 to 23% compared to controls. No changes in proliferation or cell cycle compared to untreated controls were observed following null adenovirus infection. Western blot and quantitative RT–PCR (qPCR) were used to confirm reduction or addition of RB1 to cell lines. Further, qPCR was used to identify potential activation of the interferon response following addition of siRNA and adenovirus. No changes in annexin V expression were observed following reduction or replacement of Rb as compared to controls. These results suggest the addition of proliferation advantages to tumors with single copy loss of RB1. For malignancies such as multiple myeloma characterized by deletion of 13q14 coupled with an extended period of development, the proliferation advantage associated with RB1 haploinsufficiency may contribute to decreased survival in the deletion 13 cohort.

scholarly journals Cannabidiol Induces Cell Cycle Arrest and Cell Apoptosis in Human Gastric Cancer SGC-7901 Cells

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 302 ◽  
Author(s):  
Xin Zhang ◽  
Yao Qin ◽  
Zhaohai Pan ◽  
Minjing Li ◽  
Xiaona Liu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Protein Expression ◽  
Cell Cycle Arrest ◽  
Phase Cell ◽  
G1 Phase ◽  
Therapeutic Effects ◽  
Human Gastric Cancer ◽  
Expression Levels ◽  
Cycle Arrest

The main chemical component of cannabis, cannabidiol (CBD), has been shown to have antitumor properties. The present study examined the in vitro effects of CBD on human gastric cancer SGC-7901 cells. We found that CBD significantly inhibited the proliferation and colony formation of SGC-7901 cells. Further investigation showed that CBD significantly upregulated ataxia telangiectasia-mutated gene (ATM) and p53 protein expression and downregulated p21 protein expression in SGC-7901 cells, which subsequently inhibited the levels of CDK2 and cyclin E, thereby resulting in cell cycle arrest at the G0–G1 phase. In addition, CBD significantly increased Bax expression levels, decreased Bcl-2 expression levels and mitochondrial membrane potential, and then upregulated the levels of cleaved caspase-3 and cleaved caspase-9, thereby inducing apoptosis in SGC-7901 cells. Finally, we found that intracellular reactive oxygen species (ROS) increased after CBD treatment. These results indicated that CBD could induce G0–G1 phase cell cycle arrest and apoptosis by increasing ROS production, leading to the inhibition of SGC-7901 cell proliferation, thereby suggesting that CBD may have therapeutic effects on gastric cancer.

scholarly journals Bioinformatics study on genes related to a high-risk postoperative recurrence of lung adenocarcinoma

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110180
Author(s):  
Xiao Lin ◽  
Meng Zhou ◽  
Zehong Xu ◽  
Yusheng Chen ◽  
Fan Lin
Keyword(s):  
Cell Cycle ◽  
Gene Ontology ◽  
High Risk ◽  
Lung Adenocarcinoma ◽  
Candidate Genes ◽  
Postoperative Recurrence ◽  
High Expression ◽  
Ppi Network ◽  
Hub Genes ◽  
Expression Levels

In this study, we aimed to screen out genes associated with a high risk of postoperative recurrence of lung adenocarcinoma and investigate the possible mechanisms of the involvement of these genes in the recurrence of lung adenocarcinoma. We identify Hub genes and verify the expression levels and prognostic roles of these genes. Datasets of GSE40791, GSE31210, and GSE30219 were obtained from the Gene Expression Omnibus database. Enrichment analysis of gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed for the screened candidate genes using the DAVID database. Then, we performed protein–protein interaction (PPI) network analysis through the database STRING. Hub genes were screened out using Cytoscape software, and their expression levels were determined by the GEPIA database. Finally, we assessed the relationships of Hub genes expression levels and the time of survival. Forty-five candidate genes related to a high-risk of lung adenocarcinoma recurrence were screened out. Gene ontology analysis showed that these genes were enriched in the mitotic spindle assembly checkpoint, mitotic sister chromosome segregation, G2/M-phase transition of the mitotic cell cycle, and ATP binding, etc. KEGG analysis showed that these genes were involved predominantly in the cell cycle, p53 signaling pathway, and oocyte meiosis. We screened out the top ten Hub genes related to high expression of lung adenocarcinoma from the PPI network. The high expression levels of eight genes (TOP2A, HMMR, MELK, MAD2L1, BUB1B, BUB1, RRM2, and CCNA2) were related to short recurrence-free survival and they can be used as biomarkers for high risk of lung adenocarcinoma recurrence. This study screened out eight genes associated with a high risk of lung adenocarcinoma recurrence, which might provide novel insights into researching the recurrence mechanisms of lung adenocarcinoma as well as into the selection of targets in the treatment of the disease.

mTOR function in skeletal muscle hypertrophy: increased ribosomal RNA via cell cycle regulators

2005 ◽  
Vol 289 (6) ◽  
pp. C1457-C1465 ◽  
Author(s):  
Gustavo A. Nader ◽  
Thomas J. McLoughlin ◽  
Karyn A. Esser
Keyword(s):  
Cell Cycle ◽  
Protein Expression ◽  
Cyclin D1 ◽  
Ribosomal Rna ◽  
Molecular Mechanisms ◽  
D1 Protein ◽  
Rna Content ◽  
Cyclin D1 Protein ◽  
Rb Phosphorylation ◽  
Myotube Hypertrophy

The purpose of this study was to identify the potential downstream functions associated with mammalian target of rapamycin (mTOR) signaling during myotube hypertrophy. Terminally differentiated myotubes were serum stimulated for 3, 6, 12, 24, and 48 h. This treatment resulted in significant myotube hypertrophy (protein/DNA) and increased RNA content (RNA/DNA) with no changes in DNA content or indices of cell proliferation. During myotube hypertrophy, the increase in RNA content was accompanied by an increase in tumor suppressor protein retinoblastoma (Rb) phosphorylation and a corresponding increase in the availability of the ribosomal DNA transcription factor upstream binding factor (UBF). Serum stimulation also induced an increase in cyclin D1 protein expression in the differentiated myotubes with a concomitant increase in cyclin D1-dependent cyclin-dependent kinase (CDK)-4 activity toward Rb. The increases in myotube hypertrophy and RNA content were blocked by rapamycin treatment, which also prevented the increase in cyclin D1 protein expression, CDK-4 activity, Rb phosphorylation, and the increase in UBF availability. Our findings demonstrate that activation of mTOR is necessary for myotube hypertrophy and suggest that the role of mTOR is in part to modulate cyclin D1-dependent CDK-4 activity in the regulation of Rb and ribosomal RNA synthesis. On the basis of these results, we propose that common molecular mechanisms contribute to the regulation of myotube hypertrophy and growth during the G1 phase of the cell cycle.

Sign in / Sign up

Export Citation Format

Share Document