Oxidative stress-induced DNA damage and cell cycle regulation in B65 dopaminergic cell line

AbstractBackgroundPatients with brain tumors treated with radiotherapy (RT) and chemotherapy (CT) often experience cognitive dysfunction. We reported that single nucleotide polymorphisms (SNPs) in the APOE, COMT, and BDNF genes may influence cognition in brain tumor patients. In this study, we assessed whether genes associated with late-onset Alzheimer’s disease (LOAD), inflammation, cholesterol transport, dopamine and myelin regulation, and DNA repair may influence cognitive outcome in this population.MethodsOne hundred and fifty brain tumor patients treated with RT ± CT or CT alone completed a neurocognitive assessment and provided a blood sample for genotyping. We genotyped genes/SNPs in these pathways: (i) LOAD risk/inflammation/cholesterol transport, (ii) dopamine regulation, (iii) myelin regulation, (iv) DNA repair, (v) blood–brain barrier disruption, (vi) cell cycle regulation, and (vii) response to oxidative stress. White matter (WM) abnormalities were rated on brain MRIs.ResultsMultivariable linear regression analysis with Bayesian shrinkage estimation of SNP effects, adjusting for relevant demographic, disease, and treatment variables, indicated strong associations (posterior association summary [PAS] ≥ 0.95) among tests of attention, executive functions, and memory and 33 SNPs in genes involved in: LOAD/inflammation/cholesterol transport (eg, PDE7A, IL-6), dopamine regulation (eg, DRD1, COMT), myelin repair (eg, TCF4), DNA repair (eg, RAD51), cell cycle regulation (eg, SESN1), and response to oxidative stress (eg, GSTP1). The SNPs were not significantly associated with WM abnormalities.ConclusionThis novel study suggests that polymorphisms in genes involved in aging and inflammation, dopamine, myelin and cell cycle regulation, and DNA repair and response to oxidative stress may be associated with cognitive outcome in patients with brain tumors.

Download Full-text

Babam2 Regulates Cell Cycle Progression and Pluripotency in Mouse Embryonic Stem Cells as Revealed by Induced DNA Damage

Biomedicines ◽

10.3390/biomedicines8100397 ◽

2020 ◽

Vol 8 (10) ◽

pp. 397

Author(s):

Cheuk Yiu Tenny Chung ◽

Paulisally Hau Yi Lo ◽

Kenneth Ka Ho Lee

Keyword(s):

Cell Cycle ◽

Stem Cells ◽

Dna Damage ◽

Gamma Irradiation ◽

Cellular Senescence ◽

Cell Cycle Regulation ◽

Cell Cycle Progression ◽

Embryonic Stem ◽

Cycle Progression ◽

Cycle Regulation

BRISC and BRCA1-A complex member 2 (Babam2) plays an essential role in promoting cell cycle progression and preventing cellular senescence. Babam2-deficient fibroblasts show proliferation defect and premature senescence compared with their wild-type (WT) counterpart. Pluripotent mouse embryonic stem cells (mESCs) are known to have unlimited cell proliferation and self-renewal capability without entering cellular senescence. Therefore, studying the role of Babam2 in ESCs would enable us to understand the mechanism of Babam2 in cellular aging, cell cycle regulation, and pluripotency in ESCs. For this study, we generated Babam2 knockout (Babam2−/−) mESCs to investigate the function of Babam2 in mESCs. We demonstrated that the loss of Babam2 in mESCs leads to abnormal G1 phase retention in response to DNA damage induced by gamma irradiation or doxorubicin treatments. Key cell cycle regulators, CDC25A and CDK2, were found to be degraded in Babam2−/− mESCs following gamma irradiation. In addition, Babam2−/− mESCs expressed p53 strongly and significantly longer than in control mESCs, where p53 inhibited Nanog expression and G1/S cell cycle progression. The combined effects significantly reduced developmental pluripotency in Babam2−/− mESCs. In summary, Babam2 maintains cell cycle regulation and pluripotency in mESCs in response to induced DNA damage.

Download Full-text

PCNA-Mediated Degradation of p21 Coordinates the DNA Damage Response and Cell Cycle Regulation in Individual Cells

Cell Reports ◽

10.1016/j.celrep.2019.03.031 ◽

2019 ◽

Vol 27 (1) ◽

pp. 48-58.e7 ◽

Cited By ~ 10

Author(s):

Caibin Sheng ◽

Isabella-Hilda Mendler ◽

Sara Rieke ◽

Petra Snyder ◽

Marcel Jentsch ◽

...

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Dna Damage Response ◽

Cell Cycle Regulation ◽

Damage Response ◽

Cycle Regulation

Download Full-text

Glutathione: A key player in metal chelation, nutrient homeostasis, cell cycle regulation and the DNA damage response in cadmium-exposed Arabidopsis thaliana

Plant Physiology and Biochemistry ◽

10.1016/j.plaphy.2020.06.006 ◽

2020 ◽

Vol 154 ◽

pp. 498-507 ◽

Cited By ~ 5

Author(s):

Sophie Hendrix ◽

Marijke Jozefczak ◽

Małgorzata Wójcik ◽

Jana Deckers ◽

Jaco Vangronsveld ◽

...

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Arabidopsis Thaliana ◽

Dna Damage Response ◽

Cell Cycle Regulation ◽

Metal Chelation ◽

Damage Response ◽

Cycle Regulation ◽

Nutrient Homeostasis

Download Full-text

Cell cycle regulation by the Wee1 Inhibitor PD0166285, Pyrido [2,3-d] pyimidine, in the B16 mouse melanoma cell line

BMC Cancer ◽

10.1186/1471-2407-6-292 ◽

2006 ◽

Vol 6 (1) ◽

Cited By ~ 40

Author(s):

Osamu Hashimoto ◽

Masako Shinkawa ◽

Takuji Torimura ◽

Toru Nakamura ◽

Karuppaiyah Selvendiran ◽

...

Keyword(s):

Cell Cycle ◽

Cell Line ◽

Melanoma Cell ◽

Cell Cycle Regulation ◽

Melanoma Cell Line ◽

Mouse Melanoma ◽

Mouse Melanoma Cell ◽

B16 Mouse Melanoma ◽

Cycle Regulation ◽

Mouse Melanoma Cell Line

Download Full-text

Dose Escalated RAD001 (Everolimus) Enhances Chemosensitivity in Precursor-B Acute Lymphoblastic Leukemia, through a JNK Dependent Suppression of Cell Cycle Checkpoint Regulation.

Blood ◽

10.1182/blood.v112.11.1604.1604 ◽

2008 ◽

Vol 112 (11) ◽

pp. 1604-1604

Author(s):

Philip O. Saunders ◽

Kenneth F. Bradstock ◽

Linda J. Bendall

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Regulation ◽

Cell Cycle Checkpoint ◽

G2 Arrest ◽

Jnk Pathway ◽

Microtubule Disruption ◽

Cell Kill ◽

Cycle Checkpoint ◽

Cycle Regulation

Abstract Five year survival for patients with relapsed pre-B ALL remains less than 10%, requiring new approaches to therapy. We sought to evaluate the potential of mTOR inhibitor RAD001 to enhance pre-B ALL cell killing by agents that induce DNA damage or microtubule disruption and identify interactions that may indicate novel approaches to therapy. Combining 16μM RAD001 with agents that cause DNA damage or microtubule disruption in vitro, enhanced caspase-dependent killing (p<0.05) of pre-B ALL cells. We observed 16μM RAD001 suppressed p53 and markedly attenuated p21 responses to DNA damage or vincristine. Lentiviral siRNA knock down of p53 in Nalm6 cells led to significantly increased (p<0.05) cell kill by vincristine relative to luciferase knockdown cells with an intact p53 response. This data indicates enhanced killing by combining RAD001 with DNA damage or vincristine does not require p53. Intracellular flow cytometry revealed that combining 16μM RAD001 with DNA damage or vincristine activates the JNK pathway. c-Jun has been reported to promote proliferation, apoptosis, suppress p53 and p21 promoters and prolong the half-life of p53 analogue, p73. Concordantly, we observed up regulation of p73, puma, bax, bim and cleaved caspase 3, associated with enhanced cell death. This data indicates that p73 provides an alternate pathway to apoptosis. We hypothesized that 16μM RAD001 enhances chemosensitivity through a JNK dependent suppression of cell cycle checkpoint regulation. We observed 1.5μM RAD001 inhibited pRb, Ki67 and PCNA expression, increasing G0/1 cell cycle arrest in response to DNA damage or vincristine, however 16μM RAD001 increased pRb, cyclin D1, Ki67, active CDC2 and PCNA expression. Increased DNA content, BrdU uptake and PCNA expression indicate cell cycle progression occurs in the presence of DNA damage or vincristine, when combined with 16μM RAD001. To validate the role of the JNK pathway in enhancing chemosensitivity we evaluated the impact of JNK inhibition on cell cycle regulation and cell survival. We observed enhanced cell cycle checkpoint regulation, indicated by reduced expression of c-jun, pRb, PCNA and Ki67 in Nalm6 cells. Furthermore, JNK inhibition enhanced G0/1 or G2 arrest in response to DNA damage in Nalm6 and REH cell lines respectively and enhanced G2 arrest in response to vincristine. JNK inhibition led to reduced cell kill by DNA damage or microtubule disruption in Nalm6 and REH cell lines. This data strongly suggests that impaired cell cycle regulation by 16μM RAD001 is mediated through a JNK dependent mechanism. We conclude that dose escalated RAD001 enhances chemosensitivity independently of p53, through a JNK dependent impairment of cell cycle regulation, in response to DNA damage or microtubule disruption. Our data indicates that dose escalated RAD001 has the potential to enhance chemosensitivity in patients with pre-B ALL and provides a rationale for combining agents which induce JNK activation with DNA damage or microtubule disruption, as a therapeutic strategy in pre-B ALL.

Download Full-text

MAGE-C1/CT7 Inhibition Increases Myeloma Cell Line Sensitivity to Bortezomib-Induced Apoptosis: New Target for Myeloma Therapy?

Blood ◽

10.1182/blood.v116.21.1908.1908 ◽

2010 ◽

Vol 116 (21) ◽

pp. 1908-1908

Author(s):

Fabricio de Carvalho ◽

Erico T. Costa ◽

Anamaria A. Camargo ◽

Juliana C. Gregorio ◽

Cibele Masotti ◽

...

Keyword(s):

Cell Cycle ◽

Cell Proliferation ◽

Cell Line ◽

Cell Cycle Regulation ◽

Myeloma Cell ◽

Myeloma Cell Line ◽

Empty Vector ◽

M Phase ◽

Induced Apoptosis ◽

Cycle Regulation

Abstract Abstract 1908 Introduction: MAGE-C1/CT7 encodes for a cancer/testis antigen (CTA) frequently expressed in multiple myeloma (MM) that may be a potential target for immunotherapy in this still incurable disease. The expression of this CTA is restricted to malignant plasma cells and a positive correlation between MAGEC1/CT7 expression and advanced stage has been demonstrated for MM. It has been suggested that MAGE-C1/CT7 might play a pathogenic role in MM; however, the exact function of this protein in the pathophysiology of MM is not yet understood. Objectives: (1) To clarify the role of MAGE-C1/CT7 in the control of cellular proliferation and cell cycle regulation in myeloma cell line SKO-007 and (2) to evaluate the impact of silencing MAGE-C1/CT7 on cells treated with bortezomib. Material and Methods: Short hairpin RNA (shRNA) specific for MAGE-C1/CT7 was inserted in the pRETROSUPER(pRS) retroviral vector. The pRS-shRNA-MAGE-C1/CT7 was co-transfected with pCL-amphotropic packing vector in 293T cells to produce virus particles. Sko-007 myeloma cell line was transduced for stable expression of shRNA-MAGE-C1/CT7. Downregulation of MAGE-C1/CT7 was confirmed by real time PCR (RQ-PCR) and western blot. Functional studies included cell proliferation, cell cycle analysis using propidium iodide, and analysis of apoptosis using annexin V staining. Results: SKO-007 MM cell line was transduced for stable expression of shRNA-MAGE-C1/CT7. SKO-007 cells were divided into three derivatives: empty vector (pRS) and ineffective shRNA (antisense strand deleted – GC bases) [both used as controls for all the experiments] and inhibited (shMAGE-C1/CT7). MAGE-C1/CT7 mRNA expression was ∼5 times lower in inhibited cell line than control cells by RQ-PCR. Western blot showed 70–80% decrease in MAGE-C1/CT7 protein expression in inhibited cells when compared with controls. Functional assays did not indicate a difference in cell proliferation and DNA synthesis when inhibited cells were compared with controls. We used empty vector, ineffective shRNA and inhibited cells to determine whether inhibition of MAGE-C1/CT7 was associated with cell cycle dysregulation. We detected differences between inhibited cells and both controls regarding the proportion of myeloma cells in the G2/M phase (p<0.05). When inhibited cells and controls were treated with 10 nM bortezomib for 48h, inhibited cells showed a 48% reduction of cells in the G2/M phase but control cells have 11% (empty vector) and 10% (ineffective shRNA) of reduction (p<0.05). Inhibited cells treated with 15 nM bortezomib showed an increased percentage of apoptotic cells in comparison with bortezomib treated controls (p<0.01) [Figure]. Conclusions: MAGE-C1/CT7 antigen inhibition did not change cell proliferation and DNA synthesis in SKO-007 cells. However, we found that MAGE-C1/CT7 plays in cell cycle regulation, protecting SKO-007 cells against bortezomib-induced apoptosis. Therefore, MAGE-C1/CT7 silencing by shRNA could be a strategy for future therapies in MM, i.e. in combination with proteasome inhibitors. [Supported by CNPq and LICR] Disclosures: No relevant conflicts of interest to declare.

Download Full-text