Session: FP29-Adrenal Tumors & Pheochromocytoma
Room 134 (Moscone Center)
Poster Board MON-4
Objective: Investigate if siRNA could downregulate IGF-1R expression in a human adrenocortical cell line and evaluate its effects on cell proliferation and apoptosis.
Methods: The human adrenocortical tumor NCI H295R line was cultured in RPMI 1640 medium. All experiments were carried out in four groups: 1) untreated NCI H295R cells, 2) NCI H295R cells transfected with a siRNA negative control, 3) NCI H295R cells transfected with specific IGF1R siRNA # 1 (exon 18) and 4) NCI H295R cells transfected with specific IGF1R siRNA # 2 (exon 2). IGF-1R gene and protein expression were determined by real-time PCR and Western blot, respectively. The effects of IGF-1R silencing on cancer cell growth was assessed by a colorimetric assay. Apoptosis analysis was based on the caspase-3/7 activity after treatment with siRNA.
Results: The relative values of IGF1R mRNA decreased approximately 50% and Western blot analysis revealed a 30% of reduction in IGF-1R protein. The two specific siRNA for IGF1R had similar efficiency and were able to reduce significantly IGF-1R expression both at the messenger RNA (p < 0.01 for both siRNAs) and protein levels (p = 0.027 for siRNA # 1 and p = 0.009 for siRNA # 2). The untreated cells and the negative control group exhibited equivalent mRNA and protein expressions (p = ns). Downregulation of this gene was accompanied by a reduction in 40% of cell growth in vitro and an increase in 45% in cell apoptosis.
Conclusion: These findings demonstrated that decreasing IGF-1R mRNA and protein expressions with siRNA in NCI H295R cells could inhibit tumoral cell growth in vitro.
Nothing to Disclose: TCR, AALJ, LRM, MQA, BFS, MYN, BBM, ACL
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