All of the following are the subphases of interphase except?
A restriction point is when
a cell is irreversibly committed to cell cycle progression or apoptosis
a cell is reversibly committed to cell cycle progression or apoptosis
None of the above
Cell cycle is regulated by Cyclin-dependent kinases true or false
All of the following about Cdks are true except
Cdk levels are usually constant
Cdks are inactive in the absence of Cyclin
Cdks are activated by binding to Cyclins
Cdks phosphorylate cell regulatory proteins
Cdk levels vary with cell cycle
All of the following are true about Cyclin D except?
It is made at the start of G1 by growth factor mediated gene transcription
Cyclin D binds and activates CDK4,6
Cyclin D is degraded at the end of G1
Cdk 4/6 is active in the absence of cyclin D
all of the following are true except?
Cyclin D-CDK 4/6 will phosphorylate Rb
Activated Rb will release E2F
E2F will cause Cyclin E synthesis
Cyclin E binds and activates CDK-2
Dephosphylated Rb is active
DNA damage-induced pathways target degradation of Cyclin D first and then Cyclin E which stops cell cycle progression true or false
hypophosphorylated Rb prevents E2F activity thereby preventing cell cycle progression true or false
All of the following about negative regulators of cell cycle are correct except?
INK4 (inhibitors of kinase4) family bind and inhibit only cyclin D-Cdk4/6 complexes at restriction point p15,p16
CIP (Cdk inhibitory protein) family bind and inhibit all cyclin-Cdk complexes at the restriction point p21
p16 normally inhibits Cdk4
in the absence of p16 Cdk 4 is active and phosphorylate Rb wichin in turn activates E2F
p16 normally activates Cdk4
Normally p53 levels are kept low by MDM2 true or false
All of the following about p53 are correct except?
p53 expressed at very high levels normally
DNA damage leads to phosphorylation of p53 stabilizing it and increasing its concentration
p53 acts as transcriptional activator increasing synthesis of Cdk inhibitor p21
p21 inhibits Cdk/ cyclin G1 and S complexes --> cell cycle arrest in G1
Abnormally high level of Myc causes systhesis of ARF which binds and inhibits MDm2 causing increase p53 which causes cell cycle arrest true or false
Cell cycle progression at check point 2 (G2-M) is regulated by phosphorylation of Cdk1-Cyclin B complex true or false
All of the following are inducers of apoptosis except?
Virus infected cells
Growth factor withdrawal
tumor necrosis factor
Following is the sequence of Extrinsic apoptotic pathway except?
Extrinsic apoptotic pathway is initiated by binding of death-inducing ligand to a death receptor (Cys-rich repeat in the extracellular domain)
Death receptor are FasR and TNF receptor which are integral membrane proteins with their receptor domains exposed at the surface of te cell
binding of the death activator (FasL and TNF-alpha) leads to activation of caspase -9
which in turn initiates a cascade of caspase activation leading to cell death
All of the following are pro-apoptotic genes except
Bid links he 2 apoptotic pathways (extrinsic and intrinsic) true or false
Both pathways converge on the activation of Caspase-3,6,7 true or false
All of the following stimulate angiogenesis except
TIP Statin anywhere stops (from static)
Hypoxia --> HIF which induces VEGF which binds to RTK and dramatically decreases metastatic potential - true or false
VEGF is secreted by all of the following except?
Healthy tissues needing more blood
Highly oxygenated tissues
All the following statements are true except?
Bevacizumab blocks VEGF
Sunitinib, Sorafenib block VEGFR
Angiostatin inhibits plasminogen fragment
Endostatin inhibits endothelial cell BM collagen XVIII fragment
Tumstatin inhibits collagen IV fragment
Thrombospondin inhibits Fas-R expression
Cefuximab inhibits EGFR
Herceptin (Trastuzumab) inhibits HER2
All of the following are true except?
Serine proteases (uPA, tPA, plasminogen) activate MMPs
MMPs digest ECM by digesting type IV collagenase
Plasminogen promotes clotthing
Tumor motility factors AMF,HGF, EGF all promote motility via Rho GTPases - true or false
Tumor arrest in a specific tissue is by chance only true or false
Breast cancer cell express CXCR4, which bind to ligand CXCL12 in the lung,liver and bone - true or false
Major limiting step of the metastasis is the hospitability of the host microenvironment true or false
The following are matched properly except
Topisomerase II inhibitors: Doxorubicin and Daunorubicin
Vinca alkaloids (Vinblastine and Vincristine) enhances polymerization of microtubles
Taxol(Paclitaxel) binds and stabilizes microtubles
Borezomib (Velcade) blocks proteasome activity which prevents IkB degradation build up of Bax and Bak which leads to apoptosis
Tarceva and Iressa inhibit EGFR TKi
Imatinib?Gleevec inhibit TKi in CML