Induction of apoptosis and cell cycle arrest in renal carcinoma cells by phenethyl isothiocyanate and the mechanisms involved

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dc.contributor.advisorDeGraffenried, Lindaen
dc.contributor.advisorCiolino, Henry P.en
dc.contributor.committeeMemberSanders, Bob G.en
dc.contributor.committeeMemberNunez, Nomeli P.en
dc.contributor.committeeMemberFischer, Susan M.en
dc.creatorKhan, Marufen
dc.date.accessioned2011-07-06T16:00:07Zen
dc.date.available2011-07-06T16:00:07Zen
dc.date.issued2011-05en
dc.date.submittedMay 2011en
dc.date.updated2011-07-06T16:00:12Zen
dc.descriptiontexten
dc.description.abstractRenal Cell Carcinoma (RCC) has low 5 year survival rate and is resistant to radiation and chemotherapy. Phenethyl Isothiocyanate (PEITC) is a naturally occurring phytochemical that has a variety of anti-cancer properties. Here we explore two anti-cancer properties of PEITC: induction of apoptosis and induction of cell cycle arrest in RCC cells and the underlying mechanisms. We used two human RCC cell lines Caki-1 and Caki-2. Survival and cell proliferation was assayed using Calcein AM. Annexin V staining was used to measure apoptosis. Caspase-3/7 induction was measured using a fluorescent substrate. Cell cycle was studied using Propidium Iodide staining. DNA damage was determined using phospho [gamma]-H2AX antibody. Protein expression and phosphorylation was determined using immunoblotting. PEITC significantly reduced survival of Caki-1 and Caki-2 cells and inhibited their proliferation as determined by Calcein AM. 15 and 20 [mu]M PEITC induced apoptosis in both cell lines and induced caspase-3/7 activity. Western blot analysis revealed caspase-8, caspase-9 and Bid cleavage as well as upregulation of the death receptors Fas and DR5. Lower doses (up to 10 [mu]M) arrested Caki-1 cells in G2/M phase, and this was associated with increased p38 and MK2 (Thr334) phosphorylation. The p38 inhibitor SB203850 inhibited this G2 arrest induced by PEITC. 15 and 20 [mu]M PEITC treatment resulted in increased [gamma]-H2AX phosphorylation suggesting DNA damage, but this was completely blocked by caspase inhibitor. In summary, our study shows that PEITC induces apoptosis in Caki-1 and Caki-2 cells by upregulating Fas and DR5 and activating the downstream apoptosis cascade. PEITC does not cause direct DNA damage to the cells; the observed DNA damage is a result of the apoptotic process and is blocked by caspase inhibitor. PEITC induces G2/M arrest in Caki-1 cells and the mechanism involves p38 phosphorylation which activates MK2. Inducing cell cycle arrest and apoptosis may play an important role in the anti-cancer properties of PEITC. Fully understanding the mechanism by which PEITC induces apoptosis and cell cycle arrest in RCC cells may lead to development of novel chemotherapeutic drugs against RCC.en
dc.description.departmentNutritional Sciencesen
dc.format.mimetypeapplication/pdfen
dc.identifier.slug2152/ETD-UT-2011-05-3411en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-05-3411en
dc.language.isoengen
dc.subjectIsothiocyanatesen
dc.subjectPhenethyl isothiocyanateen
dc.subjectPEITCen
dc.subjectITCen
dc.subjectRenal cell carcinomaen
dc.subjectRCCen
dc.subjectKidney canceren
dc.subjectPhytochemicalsen
dc.subjectDeath receptoren
dc.subjectDR5en
dc.subjectFasen
dc.subjectCaki-1en
dc.subjectCaki-2en
dc.subjectChemotherapyen
dc.titleInduction of apoptosis and cell cycle arrest in renal carcinoma cells by phenethyl isothiocyanate and the mechanisms involveden
dc.type.genrethesisen

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