AMANDA IKEGAMI

Projetos de Pesquisa
Unidades Organizacionais
Cargo

Resultados de Busca

Agora exibindo 1 - 4 de 4
  • Resumo IPEN-doc 24634
    Downregulation of NF-ΚB1 enhances the radiosensitivity of renal cell carcinoma
    2017 - IKEGAMI, AMANDA; SILVA, LUIZ F.T. da; BELLINI, MARIA H.
    Introduction: Clear cell renal cell carcinoma (ccRCC) accounts for ∼80% of all renal cell carcinomas (RCC) and has the Von Hippel–Lindau (VHL) tumor suppressor gene mutated. The lack of VHL protein leads to a constitutionally active Hypoxia Inducible Factor (HIF) pathway that confers both chemoresistance and radioresistance for renal tumor. HIF pathway is known to interact with the transcription factor nuclear factor kappa B (NF-kB). Increased NF-κB activity is associated with the development and progression of RCC (IKEGAMI A, TEIXEIRA LF. BRAGA MS et al. The American Society for Cell Biology 2016; 26: 3948-3955). Objective: Evaluate the synergistic effect of NF-kB1 knockdown and ionizing radiation in murine renal adenocarcinoma cell line. Methods: The murine renal adenocarcinoma cell line (Renca cells) (ATCC, USA) was cultured in RPMI 1640 supplemented with 10% FBS and penicillin/streptomycin. Lentiviral shRNA vector was used to knockdown of NF-KB1 gene in Renca cells, as described previously (1). In the clonogenic cell survival assay, the cells were irradiated by 60Co source in the range from 0 to 10 Gy, using the GammaCell 220 – Irradiation Unit of Canadian-Atomic Energy Commision Ltd. (CTR-IPEN). After 10-14 days of culture, cell colonies were fixed and stained with formaldehyde 4% and rhodamine B 2% and counted. To assess cell viability, tetrazolium [3-(4,5-dimethylthiazol-2-yl)-5- (3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-MTS] was performed within 24 hours after irradiation at a dose of 10Gy. The survival variables α e β were fitted according to the linear quadratic equation (SF=exp[-αD-βD2]); SF=survival fraction, D=dose of irradiation and P value was determined by F test. Multiple comparisons were assessed by One-way ANOVA followed by Bonferroni´s tests with GraphPad Prism version 6.0 software. P< 0.05 was considered statistically significant. Data are shown as the mean ± SD. Results: The Renca-shRNA-NF-kB1 cells were found to be significantly more radiosensitive than controls - Renca-WT and Renca-Mock, (P<0.001 vs Renca-Mock). The ratio α/β was increased in Renca-shRNA-NF-kB1: -0.177±0.677 compared with 7.368±1.833 and 11.960±5.240 of the Renca- WT and Renca-Mock, respectively. There was no significant difference in the survival fraction between Renca-WT and Renca-Mock groups. The lethal dose 50% (LD50) of Renca-WT was 3.33 Gy and Renca-Mock was 3.288 Gy whereas for the Renca-shRNA-NF-kB1 group it was 2.08 Gy. Corroborating these data, the Renca-shRNA-NF-kB1 showed reduction of 16.75±0.06% in the viability when compared to the Renca-Mock (P<0.001). Conclusion: The knockdown of NF-kB1 gene mediated by shRNA on Renca cells led to a decrease in the radioresistance. Therefore, this gene can be a therapeutic target for CCR treatment.
  • Artigo IPEN-doc 22807
    Evaluation of the applicability of Doppler velocimetry for monitoring acute kidney injury in rats
    2016 - SILVA, REGIANE M. da; KO, GUI M.; SANTOS, JOSE E.M.; BOIM, MIRIAN A.; IKEGAMI, AMANDA; BELLINI, MARIA H.
    Animal models of renal disease have been used in the study of pathogenesis and therapeutic protocols. In this study, doppler ultrasound was used to evaluate dysfunction in the renal vasculature in acute kidney injury in an animal model. Eight male Wistar rats received gentamicin (80 mg/kg) for 10 days. The blood urea and creatinine levels were measured to assess renal function. All doppler ultrasound measurements were performed on both kidneys and a colour map of the renal circulation was generated. Renal function and Doppler ultrasound measurements were performed 10 days before GM treatment and on the 5th and 10th days of the assay. Gentamicin treatment led to increased serum creatinine and blood urea levels at 5 days and 10 days post initial inoculation. A significant reduction in renal artery blood flow was observed after 5 days. However, these levels remained unchanged until the 10th day, demonstrating a lack of correlation with serum creatinine and blood urea levels. Therefore, the assessment of flow blood velocity of renal arteries by doppler ultrasound is not useful for monitoring acute kidney injury in rats.