What is Which is not a tumor suppressor gene? and explain in detail?
D i.e. RASGenes that promote autonomous cell growth in cancer cells are called oncogenes and their normal cellular counterpasQ are called proto-oncogenesQ. RAS is an oncogeneQ.Growth factorGrowth factor receptorsProteins involved in signaltransductionNuclear regulatory proteinsProtooncogeneEncodeProtooncogeneEncodeProtooncogeneRelated toProtooncogeneRelated toHST-1, 1NT-2Fibroblast growthfactorERB-B2 &ERB-B1(ECRF)EGF-receptorfamilyRAS-K/ H/NGTP bindingMYC-C/N/LTranscriptionalactivatorQTGF aTransforminggrowth factor- aFMSColonystimulating factor(CSF)-1ABLNonreceptortyrosine kinaseCell cycle regulatorsHGFHapatocytegrowth factorRETReceptor forneurotrophicfactorsBRAFRAS signaltransductionCyclin D/ECyclinsSISPlatelett growthtactor 13-chainKITReceptor for stemcell (steel)factor[3-cateninVVNT-signaltransductionCDK-4CyclindependentkinaseMYC - protooncogene is expressed in almost all eukaryotic cell. MYC - protein is translocated to nucleus (sometimes as hetrodimer with MAX protein) and is a potent transcription activator. MYC activation causes cell proliferation, induces histone acetylation, protein synthesis and cell motality & decreases cell adhesion & proteinase activity. Cells in culture undergo apoptosis if MYC activation occurs in absence of growth factorsQ, but it is not clear whether MYC induced apoptosis occurs in vivo.Retinoblastoma susceptibility protein (RB), in hypophosphorylated state, prevents cell from replicating by forming complex with transcription factor E2F (E2F/D P1/RB - complex). Phosphorylation of RB dissociates the complex, release E2F, eliminates main barrier to cell cycle progression & promotes cell replication. Cyclin D, which is the first cyclin to increase in cell cycle, (appears in GI phase but becomes detectable in S phase) activates CDK4 and form cyclin D- CDK4 complex that phosphorylates RB. During M phase RB is again hypophosphorylated.Normal growth requires - protooncogenes not oncogenes , tumor suppressor genes, genes involved in apoptosis and DNA reapirQ