RICARDO RODRIGUES GIORGI
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
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- Differential expression of genes encoding proteins of the HGF/MET system in insulinomas(2015) MURAT, Cahue de Bernardis; ROSA, Paula Waki Lopes da; FORTES, Maria Angela Henriques Zanella; CORREA, Luciana; MACHADO, Marcel Cerqueira Cesar; NOVAK, Estela Maria; SIQUEIRA, Sheila Aparecida Coelho; PEREIRA, Maria Adelaide Albergaria; CORREA-GIANNELLA, Maria Lucia; GIANNELLA-NETO, Daniel; GIORGI, Ricardo RodriguesBackground: Insulinomas are the most common functional pancreatic neuroendocrine tumors, whereas histopathological features do not predict their biological behaviour. In an attempt to better understand the molecular processes involved in the tumorigenesis of islet beta cells, the present study evaluated the expression of genes belonging to the hepatocyte growth factor and its receptor (HGF/MET) system, namely, MET, HGF; HGFAC and ST14 (encode HGF activator and matriptase, respectively, two serine proteases that catalyze conversion of pro-HGF to active HGF); and SPINT1 and SPINT2 (encode serine peptidase inhibitors Kunitz type 1 and type 2, respectively, two inhibitors of HGF activator and of matriptase). Methods: Quantitative real-time reverse transcriptase polymerase chain reaction was employed to assess RNA expression of the target genes in 24 sporadic insulinomas: 15 grade 1 (G1), six grade 2 (G2) and three hepatic metastases. Somatic mutations of MET gene were searched by direct sequencing of exons 2, 10, 14, 16, 17 and 19. Results: Overexpression of MET was observed in the three hepatic metastases concomitantly with upregulation of the genes encoding HGF and matriptase and downregulation of SPINT1. A positive correlation was observed between MET RNA expression and Ki-67 proliferation index while a negative correlation was detected between SPINT1 expression and the mitotic index. No somatic mutations were found in MET gene. Conclusion: The final effect of the increased expression of HGF, its activator (matriptase) and its specific receptor (MET) together with a decreased expression of one potent inhibitor of matriptase (SPINT1) is probably a contribution to tumoral progression and metastatization in insulinomas.
- Antitumoural activity of Brazilian red propolis fraction enriched with xanthochymol and formononetin: An in vitro and in vivo study(2014) NOVAK, Estela Maria; SILVA, Martha Silveira e Costa; MARCUCCI, Maria Cristina; SAWAYA, Alexandra Christine Helena Frankland; LOPEZ, Begona Gimenez-Cassina; FORTES, Maria Angela Henriques Zanella; GIORGI, Ricardo Rodrigues; MARUMO, Kamila Tamie; RODRIGUES, Rosangela Felipe; MARIA, Durvanei AugustoIn this study, ultra-high performance liquid chromatography-mass spectrometry and tandem mass spectrometry of selected ions were used to characterise the ethanolic extract of a sample of Brazilian red propolis (EEBRP) and an active fraction (BRP-IV) containing xanthochymol and formononetin. The antiproliferative effect of BRP-IV was assayed using melanoma tumour xenografts in mice and HL-60, K562, RPMI8226, B16F10 cell lines. This fraction inhibited growth of tumour cell lines with IC50 values of 20.5 +/- 2.4 to 32.6 +/- 2.6 mu g/mL while EEBRP induced cytotoxic effect with IC50 values of 29.7 +/- 1.5 to 42.1 +/- 8.7 mu g/mL. BRP-IV also inhibited the proliferation of B16F10 cells by blocking cell cycle progression in the G2/M phase and inducing apoptosis. Administration of 10 mg/kg/day BRP-IV suppressed the growth of B16F0 tumour xenografts in C57BL/6 mice with less general toxicity than control groups. Taken together, these results indicate that BRP-IV can be considered a promising anticancer drug for the treatment of human cancers.
- HOXB7 mRNA is overexpressed in pancreatic ductal adenocarcinomas and its knockdown induces cell cycle arrest and apoptosis(2013) CHILE, Thais; FORTES, Maria Angela Henriques Zanella; CORREA-GIANNELLA, Maria Lucia Cardillo; BRENTANI, Helena Paula; MARIA, Durvanei Augusto; PUGA, Renato David; PAULA, Vanessa de Jesus R. de; KUBRUSLY, Marcia Saldanha; NOVAK, Estela Maria; BACCHELLA, Telesforo; GIORGI, Ricardo RodriguesBackground: Human homeobox genes encode nuclear proteins that act as transcription factors involved in the control of differentiation and proliferation. Currently, the role of these genes in development and tumor progression has been extensively studied. Recently, increased expression of HOXB7 homeobox gene (HOXB7) in pancreatic ductal adenocarcinomas (PDAC) was shown to correlate with an invasive phenotype, lymph node metastasis and worse survival outcomes, but no influence on cell proliferation or viability was detected. In the present study, the effects arising from the knockdown of HOXB7 in PDAC cell lines was investigated. Methods: Real time quantitative PCR (qRT-PCR) (Taqman) was employed to assess HOXB7 mRNA expression in 29 PDAC, 6 metastatic tissues, 24 peritumoral tissues and two PDAC cell lines. siRNA was used to knockdown HOXB7 mRNA in the cell lines and its consequences on apoptosis rate and cell proliferation were measured by flow cytometry and MTT assay respectively. Results: Overexpression of HOXB7 mRNA was observed in the tumoral tissues and in the cell lines MIA PaCa-2 and Capan-1. HOXB7 knockdown elicited (1) an increase in the expression of the pro-apoptotic proteins BAX and BAD in both cell lines; (2) a decrease in the expression of the anti-apoptotic protein BCL-2 and in cyclin D1 and an increase in the number of apoptotic cells in the MIA PaCa-2 cell line; (3) accumulation of cell in sub-G1 phase in both cell lines; (4) the modulation of several biological processes, especially in MIA PaCa-2, such as proteasomal ubiquit-independent catabolic process and cell cycle. Conclusion: The present study confirms the overexpression of HOXB7 mRNA expression in PDAC and demonstrates that decreasing its protein level by siRNA could significantly increase apoptosis and modulate several biological processes. HOXB7 might be a promising target for future therapies.
- BLM germline and somatic PKMYT1 and AHCY mutations: Genetic variations beyond MYCN and prognosis in neuroblastoma(2016) NOVAK, E. M.; HALLEY, N. S.; GIMENEZ, T. M.; RANGEL-SANTOS, A.; AZAMBUJA, A. M. P.; BRUMATTI, M.; PEREIRA, P. L.; VINCE, C. S. C.; GIORGI, R. R.; BENDITE, I.; CRISTOFANI, L. M.; ODONE-FILHO, V.Neuroblastoma (NB) is the most common extra cranial solid tumor of childhood and often lethal in childhood. Clinical and biologic characteristics that are independently prognostic of outcome in NB are currently used for risk stratification to optimally the therapy. It includes age at diagnosis, International Neuroblastoma Staging System tumor histopathology and MYCN amplification. However, even in patients with theoretically good prognosis, such as localized tumor and non amplified MYCN, either disease progress or recurrence may occur. Potential genetic determinants of this unfavorable behavior are not yet fully clarified. The presence of elevated expression of AHCY, PKMYT1, and BLM has accompanied poor prognosis MYCN-amplified neuroblastoma patients. Considering the potential implication of these genes on the clinical management of NB, we hypothesize that the identification-of genetic variations may have significant impact during development of the recurrent or progressive disease. Using targeted DNA sequencing, we analyzed the mutation profiles of the genes PKMYT1, AHCY, and BLM in tumor samples of five patients with MYCN amplified and 15 MYCN non-amplified NB. In our study, BLM germline variants were detected in two patients with MYCN-non-amplified neuroblastoma. Our data allow us to hypothesize that, regardless of MYCN status, these mutations partially abolish BLM protein activity by impairing its ATPase and helicase activities. BLM mutations are also clinically relevant because BLM plays an important role in DNA damage repair and the maintenance of genomic integrity. We also found a novel variant in our cohort, PKMYT1 mutation localized in the C-terminal domain with effect unknown on NB. We hypothesize that this variant may affect the catalytic activity of PKMYT1 in NB, specifically when CDK1 is complexed to cyclins. The prognostic value of this mutation must be further investigated. Another mutation identified was a nonsynonymous variant in AHCY. This variant may be related to the slow progression of the disease, even in more aggressive cases. It affects the maintenance of the catalytic capacity of AHCY, leading to the consequent functional effects observed in the NB patients studied. In conclusion, our hypothesis may provide that mutations in BLM, AHCY and PKMYT1 genes found in children with MYCN-amplified or MYCN-non amplified neuroblastomas, may be associated with the prognosis of the disease.