Deregulated expression of Nucleophosmin 1 in gastric cancer and its clinicopathological implications

Background: the process of gastric carcinogenesis still remains to be elucidated. the identification of genes related to this process may help to reduce mortality rates through early diagnosis and the development of new anticancer therapies. Nucleophosmin 1 (NPM1) acts in ribosome biogenesis, centrosome duplication, maintenance of genomic stability, and embryonic development. Recently, NPM1 has been implicated in the tumorigenesis processes. Here, we evaluated NPM1 gene and protein expression in gastric tumors and in corresponding non-neoplastic gastric samples.Methods: NPM1 protein expression was determined by Western blot in 17 pairs of gastric tumors and corresponding non-neoplastic gastric tissue. the protein immunoreactivity was observed in 12 tumor samples. mRNA expression was evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR) in 22 pairs of gastric tumors and in matched non-neoplastic gastric tissue.Results: NPM1 protein expression was significantly reduced in gastric cancer samples compared to matched non-neoplastic gastric samples (P = 0.019). the protein level of NPM1 was reduced at least 1.5-fold in 35% of tumors compared to paired non-neoplastic gastric tissue. However, NPM1 immunoreactivity was detected in neoplastic and non-neoplastic cells, including in intestinal metaplastic, gastritis and inflammatory cells. NPM1 was mainly expressed in nucleus and nucleolus subcellular compartments. the staining intensity and the percentage of immunoreactive cells varied among the studied cases. the NPM1 mRNA level was reduced at least 1.5-fold in 45.5% of samples and increased in 27.3% of samples. An inverse correlation between protein and mRNA expression was detected (r = -0.509, P = 0.037). Intestinal-type gastric cancer presented higher mRNA levels than diffuse-type (P = 0.026). However, reduced NPM1 protein expression was associated with intestinal-type gastric cancer compared to matched non-neoplastic gastric samples (P = 0.018). in addition, tumors from patients with known distant metastasis presented reduced NPM1 protein levels compared to tumors from patients without distant metastasis (P < 0.001).Conclusion: Although the expression of NPM1 is heterogeneous in gastric tumors, our results suggest that NPM1 down-regulation may have a role in gastric carcinogenesis and may help in the selection of anticancer treatment strategies.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Morphol & Genet, Div Genet, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Orthoped & Traumatol, BR-04038031 São Paulo, BrazilUniv São Paulo, Sch Med, Dept Radiol, Expt Oncol Lab, BR-01246903 São Paulo, BrazilSão Paulo State Canc Inst, Ctr Translat Oncol, BR-01246000 São Paulo, BrazilFed Univ Para, Joao de Barros Barreto Univ Hosp, Oncol Res Ctr, BR-60673000 Belem, Para, BrazilFed Univ Para, Inst Biol Sci, Human Cytogenet Lab, BR-66073000 Belem, Para, BrazilUniversidade Federal de São Paulo, Dept Morphol & Genet, Div Genet, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Orthoped & Traumatol, BR-04038031 São Paulo, BrazilWeb of Scienc

Prohibitin Expression Deregulation in Gastric Cancer Is Associated with the 3 ' Untranslated Region 1630 C > T Polymorphism and Copy Number Variation

PHB is a reported oncogene and tumor suppressor in gastric cancer. Here, we evaluated whether the PHB copy number and the rs6917 polymorphism affect its expression in gastric cancer. Down-regulation and up-regulation of PHB were observed in the evaluated tumors. Reduced expression was associated with tumor dedifferentiation and cancer initiation. the T allele of the rs6917 polymorphism was associated with reduced PHB mRNA levels. Moreover, the up-regulation of PHB appeared to be regulated by the gain of additional gene copies. Thus, PHB copy number variation and differential expression of the rs6917 polymorphism may play a role in PHB transcriptional regulation.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Disciplina Genet, Dept Morfol & Genet, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ortopedia & Traumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, Dept Radiol, Lab Oncol Expt, São Paulo, BrazilInst Canc Estado São Paulo, Ctr Invest Translat Oncol, São Paulo, BrazilFed Univ Para, Hosp Univ Joao Barros Barreto, BR-66059 Belem, Para, BrazilFed Univ Para, Inst Ciencias Biol, Lab Citogenet Humana, BR-66059 Belem, Para, BrazilUniversidade Federal de São Paulo, Disciplina Genet, Dept Morfol & Genet, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ortopedia & Traumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, Dept Radiol, Lab Oncol Expt, São Paulo, BrazilWeb of Scienc

Prognostic and Predictive Significance of MYC and KRAS Alterations in Breast Cancer from Women Treated with Neoadjuvant Chemotherapy

Breast cancer is a complex disease, with heterogeneous clinical evolution. Several analyses have been performed to identify the risk factors for breast cancer progression and the patients who respond best to a specific treatment. We aimed to evaluate whether the hormone receptor expression, HER2 and MYC genes and their protein status, and KRAS codon 12 mutations may be prognostic or predictive biomarkers of breast cancer. Protein, gene and mutation status were concomitantly evaluated in 116 breast tumors from women who underwent neoadjuvant chemotherapy with doxorubicin plus cyclophosphamide. We observed that MYC expression was associated with luminal B and HER2 overexpression phenotypes compared to luminal A (p= 2.5 was a protective factor for chemotherapy resistance. On the other hand, age and grade 2 tumors were a risk factor. Additionally, luminal B, HER2 overexpression, and triple-negative tumors presented increased odds of being resistant to chemotherapy relative to luminal A tumors. Thus, breast tumors with KRAS codon 12 mutations seem to present a worse prognosis. Additionally, MYC amplification may help in the identification of tumors that are sensitive to doxorubicin plus cyclophosphamide treatment. If confirmed in a large set of samples, these markers may be useful for clinical stratification and prognosis.Fundacao Amazonia Paraense de Amparo a PesquisaConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Ophir Loyola Hosp, Mastol Unit, Belem, PA, BrazilUniversidade Federal de São Paulo, Dept Orthopaed & Traumatol, São Paulo, BrazilFed Univ Para, Inst Biol Sci, Human Cytogenet Lab, BR-66059 Belem, PA, BrazilHosp Univ La Paz, Res Unit Unidad Invest, Madrid, SpainFed Univ Para, Nucleu Res Oncol, Joao de Barros Barreto Univ Hosp, BR-66059 Belem, PA, BrazilUniv Fed Piaui, Dept Biomed, Parnaiba, PI, BrazilUniversidade Federal de São Paulo, Div Genet, Dept Morphol & Genet, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Orthopaed & Traumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Genet, Dept Morphol & Genet, São Paulo, BrazilFundacao Amazonia Paraense de Amparo a Pesquisa: FAPESPA/PPSUS 247/2009Fundacao Amazonia Paraense de Amparo a Pesquisa: 300240/2009Web of Scienc

Protective Effect of Prolactin against Methylmercury-Induced Mutagenicity and Cytotoxicity on Human Lymphocytes

Mercury exhibits cytotoxic and mutagenic properties as a result of its effect on tubulin. This toxicity mechanism is related to the production of free radicals that can cause DNA damage. Methylmercury (MeHg) is one of the most toxic of the mercury compounds. It accumulates in the aquatic food chain, eventually reaching the human diet. Several studies have demonstrated that prolactin (PRL) may be differently affected by inorganic and organic mercury based on interference with various neurotransmitters involved in the regulation of PRL secretion. This study evaluated the cytoprotective effect of PRL on human lymphocytes exposed to MeHg in vitro, including observation of the kinetics of HL-60 cells (an acute myeloid leukemia lineage) treated with MeHg and PRL at different concentrations, with both treatments with the individual compounds and combined treatments. All treatments with MeHg produced a significant increase in the frequency of chromatid gaps, however, no significant difference was observed in the chromosomal breaks with any treatment. A dose-dependent increase in the mitotic index was observed for treatments with PRL, which also acts as a co-mitogenic factor, regulating proliferation by modulating the expression of genes that are essential for cell cycle progression and cytoskeleton organization. These properties contribute to the protective action of PRL against the cytotoxic and mutagenic effects of MeHg.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)IFPA Itaituba, Fed Inst Educ Sci & Technol Para, BR-68180000 Campinas, Para, BrazilFed Univ Para, Inst Biol Sci, BR-66075110 Belem, Para, BrazilIFPA, Educ Fed Inst Sci & Technol Para, BR-66645240 Belem, Para, BrazilUniv Para, Ctr Biol & Hlth Sci, BR-66050540 Belem, Para, BrazilFed Univ Western Para, UFOPA, BR-68040470 Santarem, Para, BrazilUniversidade Federal de São Paulo, Dept Morphol & Genet, BR-04021001 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morphol & Genet, BR-04021001 São Paulo, BrazilWeb of Scienc

Occurrence of Helicobacter pylori and Epstein-Barr virus infection in endoscopic and gastric cancer patients from Northern Brazil

Background: Helicobacter pylori (HP) and Epstein-Barr virus (EBV) have been associated with cancer development. We evaluated the prevalence of HP, HP CagA(+) and EBV infection in gastric cancer (GC) samples from adults and in gastric tissues from patients who underwent upper endoscopy (UE).Methods: Samples from UE and GC were collected to investigate the presence of HP infection and the HP virulence factor CagA by a urease test and PCR. the presence of EBV was detected by Eber-1 in situ hybridization.Results: in UE, 85.5% of juvenile patients showed some degree of gastritis (45.3% of patients with mild gastritis and 54.7% with moderate/severe gastritis) and patients with mild gastritis were younger than patients with moderate/severe gastritis. Among adults, 48.7% presented mild gastritis and 51.3% moderate/severe gastritis. HP infection was detected in 0% of normal mucosa, 58.5% of juvenile gastritis patients, 69.2% of adult gastritis patients and 88% of GC patients. in these same groups, HP CagA(+) was detected in 0%, 37.7%, 61.5% and 67.2% of tissue samples, respectively. in juvenile patients, HP infection was more common in those with gastritis than in normal samples (p = 0.004). the patients with either HP or HP CagA(+) were older than patients without these pathogens (p < 0.05). in juvenile patients, HP infection was more frequent in cases of moderate/severe gastritis than in cases of mild gastritis (p = 0.026). Moreover, in patients with GC, HP infection was more frequent in males than in females (p = 0.023). GC patients with HP CagA(+) were older than patients with HP CagA-(p = 0.027). HP CagA(+) was more common in intestinal-type than diffuse-type GC (p = 0.012). HP CagA(+) was also associated with lymph-node (p = 0.024) and distal (p = 0.005) metastasis. No association between EBV infection and HP infection or any clinicopathological variable was detected.Conclusions: Our results suggest that HP is involved in the pathophysiology of severe gastric lesions and in the development of GC, particularly when CagA(+) is present. EBV was not the primary pathogenic factor in our samples.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fed Univ Para, Inst Ciencias Biol, Lab Citogenet Humana, BR-66075110 Belem, PA, BrazilFed Univ Para, Inst Ciencias Saude, BR-66075110 Belem, PA, BrazilCtr Univ Para, Belem, PA, BrazilUniversidade Federal de São Paulo, Dept Ortopedia & Traumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol & Genet, Disciplina Genet, São Paulo, BrazilFed Univ Para, BR-66075110 Belem, PA, BrazilUniv Fed Ceara, Fac Odontol, Dept Oral Pathol, Fortaleza, CE, BrazilUniversidade Federal de São Paulo, Dept Ortopedia & Traumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Morfol & Genet, Disciplina Genet, São Paulo, BrazilWeb of Scienc

Differential Proteomic Analysis of Noncardia Gastric Cancer from Individuals of Northern Brazil

Gastric cancer is the second leading cause of cancer-related death worldwide. The identification of new cancer biomarkers is necessary to reduce the mortality rates through the development of new screening assays and early diagnosis, as well as new target therapies. In this study, we performed a proteomic analysis of noncardia gastric neoplasias of individuals from Northern Brazil. The proteins were analyzed by two-dimensional electrophoresis and mass spectrometry. For the identification of differentially expressed proteins, we used statistical tests with bootstrapping resampling to control the type I error in the multiple comparison analyses. We identified 111 proteins involved in gastric carcinogenesis. The computational analysis revealed several proteins involved in the energy production processes and reinforced the Warburg effect in gastric cancer. ENO1 and HSPB1 expression were further evaluated. ENO1 was selected due to its role in aerobic glycolysis that may contribute to the Warburg effect. Although we observed two up-regulated spots of ENO1 in the proteomic analysis, the mean expression of ENO1 was reduced in gastric tumors by western blot. However, mean ENO1 expression seems to increase in more invasive tumors. This lack of correlation between proteomic and western blot analyses may be due to the presence of other ENO1 spots that present a slightly reduced expression, but with a high impact in the mean protein expression. In neoplasias, HSPB1 is induced by cellular stress to protect cells against apoptosis. In the present study, HSPB1 presented an elevated protein and mRNA expression in a subset of gastric cancer samples. However, no association was observed between HSPB1 expression and clinicopathological characteristics. Here, we identified several possible biomarkers of gastric cancer in individuals from Northern Brazil. These biomarkers may be useful for the assessment of prognosis and stratification for therapy if validated in larger clinical study sets.Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP

MYC, FBXW7 and TP53 copy number variation and expression in gastric cancer

BACKGROUND: \ud MYC deregulation is a common event in gastric carcinogenesis, usually as a consequence of gene amplification, chromosomal translocations, or posttranslational mechanisms. FBXW7 is a p53-controlled tumor-suppressor that plays a role in the regulation of cell cycle exit and reentry via MYC degradation.\ud METHODS: \ud We evaluated MYC, FBXW7, and TP53 copy number, mRNA levels, and protein expression in gastric cancer and paired non-neoplastic specimens from 33 patients and also in gastric adenocarcinoma cell lines. We also determined the invasion potential of the gastric cancer cell lines.\ud RESULTS: \ud MYC amplification was observed in 51.5% of gastric tumor samples. Deletion of one copy of FBXW7 and TP53 was observed in 45.5% and 21.2% of gastric tumors, respectively. MYC mRNA expression was significantly higher in tumors than in non-neoplastic samples. FBXW7 and TP53 mRNA expression was markedly lower in tumors than in paired non-neoplastic specimens. Moreover, deregulated MYC and FBXW7 mRNA expression was associated with the presence of lymph node metastasis and tumor stage III-IV. Additionally, MYC immunostaining was more frequently observed in intestinal-type than diffuse-type gastric cancers and was associated with MYC mRNA expression. In vitro studies showed that increased MYC and reduced FBXW7 expression is associated with a more invasive phenotype in gastric cancer cell lines. This result encouraged us to investigate the activity of the gelatinases MMP-2 and MMP-9 in both cell lines. Both gelatinases are synthesized predominantly by stromal cells rather than cancer cells, and it has been proposed that both contribute to cancer progression. We observed a significant increase in MMP-9 activity in ACP02 compared with ACP03 cells. These results confirmed that ACP02 cells have greater invasion capability than ACP03 cells.\ud CONCLUSION: \ud In conclusion, FBXW7 and MYC mRNA may play a role in aggressive biologic behavior of gastric cancer cells and may be a useful indicator of poor prognosis. Furthermore, MYC is a candidate target for new therapies against gastric cancer.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Experimental Gastric Carcinogenesis in Cebus apella Nonhuman Primates

The evolution of gastric carcinogenesis remains largely unknown. We established two gastric carcinogenesis models in New-World nonhuman primates. In the first model, ACP03 gastric cancer cell line was inoculated in 18 animals. In the second model, we treated 6 animals with N-methyl-nitrosourea (MNU). Animals with gastric cancer were also treated with Canova immunomodulator. Clinical, hematologic, and biochemical, including C-reactive protein, folic acid, and homocysteine, analyses were performed in this study. MYC expression and copy number was also evaluated. We observed that all animals inoculated with ACP03 developed gastric cancer on the 9th day though on the 14th day presented total tumor remission. In the second model, all animals developed pre-neoplastic lesions and five died of drug intoxication before the development of cancer. The last surviving MNU-treated animal developed intestinal-type gastric adenocarcinoma observed by endoscopy on the 940th day. The level of C-reactive protein level and homocysteine concentration increased while the level of folic acid decreased with the presence of tumors in ACP03-inoculated animals and MNU treatment. ACP03 inoculation also led to anemia and leukocytosis. The hematologic and biochemical results corroborate those observed in patients with gastric cancer, supporting that our in vivo models are potentially useful to study this neoplasia. In cell line inoculated animals, we detected MYC immunoreactivity, mRNA overexpression, and amplification, as previously observed in vitro. In MNU-treated animals, mRNA expression and MYC copy number increased during the sequential steps of intestinal-type gastric carcinogenesis and immunoreactivity was only observed in intestinal metaplasia and gastric cancer. Thus, MYC deregulation supports the gastric carcinogenesis process. Canova immunomodulator restored several hematologic measurements and therefore, can be applied during/after chemotherapy to increase the tolerability and duration of anticancer treatments