A Study of Gene Expression of Survivin, its Antiapoptotic Variants, and Targeting Survivin In Vitro for Therapy in Retinoblastoma.
Apoptosis is a natural process regulated by apoptotic and antiapoptotic molecules. We investigated mRNA expression of survivin and its splice variants, along with B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax), in a cohort of 20 retinoblastoma (RB) tumors by real-time polymerase chain reaction. We hypothesized a correlation between the Bcl-2/Bax and survivin splice variants and also that expression of these would be associated with clinicopathologic features of tumors. The Bcl-2 expression was significantly higher (P<0.001) in RB, and Bcl-2/Bax ratio was remarkably higher in poorly differentiated tumors. A statistically significant higher expression of Survivin-WT (wild type) compared with its variant Survivin-2β (P<0.05) was observed. Bcl-2 did not exhibit positive correlation with any of the survivin variants except Survivin-2β, whereas Bax exhibited significant (P<0.05) correlation with the variants. Thus, it could be suggested that a superior player out of a likely interaction between the variants and Bcl-2/Bax uses its activity for the progression of RB. Silencing of Survivin-WT in the Y79 cell line was studied by siRNA technology and cell-permeable dominant negative survivin (SurR9-C84A). siRNA showed higher proapoptotic effects and increased caspase 3/7 activity in Y79 cells. Effective internalization of SurR9-C84A in Y79 cells induced cytotoxic effects. Thus, the current study confirms survivin as a promising target for therapy.
*Department of Nanobiotechnology §L&T Ocular Pathology Department, Kamalnayan Bajaj Research Institute, Vision Research Foundation ‡Department of Vitreoretinal Services, Medical Research Foundation, Sankara Nethralaya, Chennai, India †Nanomedicine-Laboratory of Immunology and Molecular Biomedical Research (N-LIMBR), Centre for Molecular and Medical Research, School of Medicine, Faculty of Health, Deakin University, Waurn Ponds, Vic. 3216 Australia.
Jaisy
J
Samuel
Rupinder K
RK
Kanwar
Jagat R
JR
Kanwar
Vikas
V
Khetan
Subramanian
S
Krishnakumar
D017209:Apoptosis; D045744:Cell Line, Tumor; D002470:Cell Survival; D005260:Female; D006801:Humans; D007223:Infant; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors / Q000235:genetics*; D008297:Male; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D034741:RNA, Small Interfering / Q000235:genetics; D019572:Retinal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D012175:Retinoblastoma / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D000077022:Survivin; D051028:bcl-2-Associated X Protein / Q000235:genetics*
C494826:BAX protein, human; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D000077022:Survivin; D051028:bcl-2-Associated X Protein