DECREASED EXPRESSION OF MICRORNA-629 IN GASTRIC CANCER SAMPLES POTENTIATED BY THE VIRULENCE MARKER OF H. PYLORI, CAGA GENE.

BACKGROUND: Helicobacter pylori (H. pylori) is a gram-negative bacterium associated with the etiology of several gastrointestinal tract pathologies, and cagA-positive (cagA+) strains are found in populations with gastric ulcers and precancerous lesions, inducing pro-inflammatory responses. The development of neoplasms is related to microRNA (miRNA) dysregulation, indicating highly expressed miRNA-629. The article aims to correlate the expression level of miRNA-629 with the presence of H. pylori and the pathogenicity marker cagA. METHODS: 203 gastric biopsy samples were evaluated from individuals with normal gastric tissue (n=60), gastritis (n=96), and gastric cancer (n=47) of both genders and over 18 years old. The samples were subdivided according to the presence or absence of H. pylori, detected by polymerase chain reaction (PCR). RNA was extracted using a commercial kit and quantified. Complementary DNA (cDNA) was synthesized using commercial kits, and the relative expression was calculated using the 2-ΔΔCt method. RESULTS: Individuals infected with H. pylori are nine times more likely to develop gastric cancer. Cancer patients appeared to have decreased expression of miRNA-629; however, the presence of the bacterium would not influence this reduction. Individuals in the cancer group showed lower miRNA-629 expression when cagA+; however, in the control group, the expression was higher when cagA+. CONCLUSION: H. pylori is a factor involved in the etiology and progression of gastric diseases. Reduction in miRNA-629 expression in cancer patients occurs independent of the presence of the bacterium, but when the cagA pathogenicity marker is present, it induces changes in the gene expression of the respective miRNA.

Diminuição da expressão do microRNA-629 em amostras de câncer gástrico potencializada pelo marcador de virulências do H. pylori, gene cagA / Decreased expression of microrna-629 in gastric cancer samples potentiated by the virulence marker of h. pylori, caga gene

ABSTRACT Background: Helicobacter pylori (H. pylori) is a gram-negative bacterium associated with the etiology of several gastrointestinal tract pathologies, and cagA-positive (cagA+) strains are found in populations with gastric ulcers and precancerous lesions, inducing pro-inflammatory responses. The development of neoplasms is related to microRNA (miRNA) dysregulation, indicating highly expressed miRNA-629. The article aims to correlate the expression level of miRNA-629 with the presence of H. pylori and the pathogenicity marker cagA. Methods: 203 gastric biopsy samples were evaluated from individuals with normal gastric tissue (n=60), gastritis (n=96), and gastric cancer (n=47) of both genders and over 18 years old. The samples were subdivided according to the presence or absence of H. pylori, detected by polymerase chain reaction (PCR). RNA was extracted using a commercial kit and quantified. Complementary DNA (cDNA) was synthesized using commercial kits, and the relative expression was calculated using the 2-ΔΔCt method. Results: Individuals infected with H. pylori are nine times more likely to develop gastric cancer. Cancer patients appeared to have decreased expression of miRNA-629; however, the presence of the bacterium would not influence this reduction. Individuals in the cancer group showed lower miRNA-629 expression when cagA+; however, in the control group, the expression was higher when cagA+. Conclusion: H. pylori is a factor involved in the etiology and progression of gastric diseases. Reduction in miRNA-629 expression in cancer patients occurs independent of the presence of the bacterium, but when the cagA pathogenicity marker is present, it induces changes in the gene expression of the respective miRNA.

RESUMO Contexto: Helicobacter pylori (H. pylori) é uma bactéria gram-negativa associada à etiologia de várias patologias do trato gastrointestinal, e cepas positivas para cagA (cagA+) são encontradas em populações com úlceras gástricas e lesões pré-cancerígenas, induzindo respostas pró-inflamatórias. O desenvolvimento de neoplasias está relacionado à desregulação do microRNA (miRNA), indicando miRNA-629 altamente expresso. O artigo tem como objetivo correlacionar o nível de expressão do miRNA-629 com a presença de H. pylori e o marcador de patogenicidade cagA. Métodos: Foram avaliadas 203 amostras de biópsia gástrica de indivíduos com tecido gástrico normal (n=60), gastrite (n=96) e câncer gástrico (n=47) de ambos os sexos e com mais de 18 anos. As amostras foram subdivididas de acordo com a presença ou ausência de H. pylori, detectado por reação em cadeia da polimerase (PCR). O RNA foi extraído usando um kit comercial e quantificado. O DNA complementar (cDNA) foi sintetizado usando kits comerciais, e a expressão relativa foi calculada usando o método 2-ΔΔCt. Resultados: Indivíduos infectados com H. pylori têm nove vezes mais chances de desenvolver câncer gástrico. Pacientes com câncer parecem ter diminuição da expressão do miRNA-629; no entanto, a presença da bactéria não influenciaria essa redução. Indivíduos no grupo do câncer apresentaram menor expressão do miRNA-629 quando cagA+; no entanto, no grupo controle, a expressão foi maior quando cagA+. Conclusão: H. pylori é um fator envolvido na etiologia e progressão das doenças gástricas. A redução na expressão do miRNA-629 em pacientes com câncer ocorre independentemente da presença da bactéria, mas quando o marcador de patogenicidade cagA está presente, induz mudanças na expressão gênica do respectivo miRNA.

Metastasis-associated lung adenocarcinoma transcript 1 molecular mechanisms in gastric cancer progression.

Gastric cancer (GC) remains among the most common cancers worldwide with a high mortality-to-incidence ratio. Accumulated evidence suggests that long noncoding RNAs (lncRNAs) are involved in gastric carcinogenesis. These transcripts are longer than 200 nucleotides and modulate gene expression at multiple molecular levels, inducing or inhibiting biological processes and diseases. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is one of the best-studied lncRNAs with comprehensive actions contributing to cancer progression. This lncRNA regulates gene expression at the transcriptional and posttranscriptional levels through interactions with microRNAs and proteins. In the present review, we discussed the molecular mechanism of MALAT1 and summarized the current knowledge of its expression in GC. Moreover, we highlighted the potential use of MALAT1 as a biomarker, including liquid biopsy.

CDK10, CDK11, FOXO1, and FOXO3 Gene Expression in Alzheimer's Disease Encephalic Samples.

Alzheimer's disease (AD) is a progressive neuroinflammatory and neurodegenerative disorder that affects different regions of the brain. Its pathophysiology includes the accumulation of ß-amyloid protein, formation of neurofibrillary tangles, and inflammatory processes. Genetic factors are involved in the onset of AD, but they are not fully elucidated. Identification of gene expression in encephalic tissues of patients with AD may help elucidate its development. Our objectives were to characterize and compare the gene expression of CDK10, CDK11, FOXO1, and FOXO3 in encephalic tissue samples from AD patients and elderly controls, from the auditory cortex and cerebellum. RT-qPCR was used on samples from 82 individuals (45 with AD and 37 controls). We observed a statistically significant increase in CDK10 (p = 0.029*) and CDK11 (p = 0.048*) gene expression in the AD group compared to the control, which was most evident in the cerebellum. Furthermore, the Spearman test demonstrated the presence of a positive correlation of gene expression both in the auditory cortex in the AD group (r = 0.046/p = 0.004) and control group (r = 0.454/p = 0.005); and in the cerebellum in the AD group (r = 0.654 /p < 0.001). There was no statistically significant difference and correlation in the gene expression of FOXO1 and FOXO3 in the AD group and the control. In conclusion, CDK10 and CDK11 have high expression in AD patients compared to control, and they present a positive correlation of gene expression in the analyzed groups and tissues, which suggests that they play an important role in the pathogenesis of AD.

Decrease of miR-125a-5p in Gastritis and Gastric Cancer and Its Possible Association with H. pylori.

PURPOSE: The aim of this study was to evaluate the expression of miR-125a-5p in patients with dyspeptic symptoms and gastric cancer, correlating them with the development of this cancer and H. pylori. METHODS: Patients were divided in groups according to histopathological analysis (control, gastritis, and cancer groups). Polymerase chain reaction was performed to detect H. pylori and real-time quantitative PCR to determine miR-125a-5p expression. RESULTS: H. pylori was detected in 44% of the patients, with prevalence in the gastritis and cancer groups. A statistically significant decrease of miR-125a-5p expression was found in the control positive (p = 0.0183*), gastritis positive (p = 0.0380*), and cancer positive (p = 0.0288*) groups when compared with the control negative group. CONCLUSION: We suggest that decreased expression of the miRNA-125a-5p associated with the presence of the H. pylori is an important mechanism in gastric diseases and could be a possible marker for early diagnosis of gastric cancer.

Lack of Association between IL-6 Polymorphisms and Haplotypes with Gastric Cancer.

The process of combating neoplasms and mononuclear cells, and during H. pylori infection, several pro-inflammatory and anti-inflammatory cytokines are synthesized. In view of the involvement of the IL-6 law and the presence of H. pylori in the development of gastric diseases, the present study aimed to characterize the promoter-region polymorphism -597 (G/A) (rs1800797), -572 (C/G) (rs1800796), and -174 (G/C) (rs1800795) by PCR-RFLP in 375 gastric biopsy specimens from patients with peptic symptoms. A total of 375 samples were analyzed: 87 patients (without lesion without gastric tissue); 236 patients with gastritis and 52 patients with gastric cancer analyzed the PCR-RFLP techniques. All the results were normalized in relation to the presence of H. pylori. The frequencies of the three polymorphisms were compared in the Control vs Gastritis groups and a statistically significant test observed: -174 (G/C) (OR: 1.27; 95% CI: 0.84-1.93; P = 0.26), 572 (C/G) (OR: 1.42; 95% CI: 0.78-2.59; P = 0.25), and 597 (G/A) (OR: 0.98; 95% CI, 0.64-1.52; P = 0.94). Similar results were obtained when the gastric cancer group was compared to the control group: -174 (G/C) (OR: 1.27; 95% CI: 0.66-2.47; P = 0.47), -572 (C/G) (OR: 1.07; 95% CI: 0.43-2.68; P = 0.88), and -597 (G/A) (OR: 1.01; 95% CI, 0.5-0.9; P = 0.99). The haplotypes were and were not observed statistically significant differences. In conclusion, we found no correlations between any of the three polymorphisms in the IL-6 gene analyzed in this study and a higher risk of gastritis or gastric cancer.

Expression of miRNA-146a, miRNA-155, IL-2, and TNF-α in inflammatory response to Helicobacter pylori infection associated with cancer progression.

miRNAs appear to play an important role in controlling the expression of several genes, and they are a potential biomarker and prognostic tool in gastric diseases. We analyzed 53 controls, 86 patients with gastritis, and 19 patients with gastric cancer. Real-time-PCR was used to determine the expression levels of miRNA-146a, miRNA-155, IL-2, and TNF-α. The subsequent analysis of the target genes was performed using the bioinformatics approach. There was no difference in IL-2 expression between the groups. However, there was a significant increase in TNF-α expression in the gastritis group relative to the control and a significant decrease in the gastric cancer group relative to the control. There was also a statistically significant increase in miRNA-146a and miRNA-155 expression in the gastritis group relative to the control, but not in the gastric cancer group. Similar results were found when the presence of H. pylori was considered. The data revealed an increase in miRNA-146a and miRNA-155 expression but not enough to control the expression of TNF-α. The presence of H. pylori was found to affect increases in TNF-α and microRNA expression, and miRNA-146a and miRNA-155 alone were not able to eliminate bacteria or restore tissue homeostasis.

Anti-wrinkle and anti-whitening effects of jucá (Libidibia ferrea Mart.) extracts.

Skin aging is a natural process of the human body that may be accelerated due to extrinsic causes. Libidibia ferrea, popularly known as jucá, is a small tree, which possesses an abundant phenolic composition with potential antioxidant and enzymatic inhibition activities. Thus, this work aimed to investigate the anti-wrinkle and anti-whitening potentials of jucá trunk bark (LFB) and pod (LFP) extracts. A comprehensive analysis of LFB and LFP phenolic composition was accomplished by means of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Effects on skin degradation were assessed by inhibitory enzymatic activity against elastase, hyaluronidase and collagenase through colorimetric assays. Cellular viability in B16F10 and primary fibroblasts were determined by Trypan Blue exclusion assay. Anti-melanogenic effects on B16F10 cells were evaluated using cellular tyrosinase, melanin content, western blot, and RT-qPCR analyses. Inhibition of matrix metalloproteinase-2 and metalloproteinase-9 (MMP-2 and MMP-9) was determined by gelatin zymography and western blot methodologies. LC-MS/MS analyses of LFB and LFP extracts allowed the characterization of 18 compounds, among them, flavonoids, phenolic acids, and secoridoids. Additionally the pod and trunk bark compositions were compared. Hyaluronidase inhibitory activity for both extracts, LFB (IC50 = 8.5 ± 0.8 µg/mL) and LFP (IC50 = 16 ± 0.5 µg/mL), was stronger than standard rutin (IC50 = 27.6 ± 0.06). Pro-MMP-2 was significantly inhibited by both extracts. LFB and LFP decreased the melanin content in B16F10 due to tyrosinase inhibitory activity. L. ferrea extracts has high potential as a cosmetic ingredient due to its anti-wrinkle and depigmentant effects.

Downregulated Expression of E-cadherin and TP53 in Patients with Gastric Diseases: the Involvement of H. pylori Infection and Its Virulence Markers.

PURPOSE: Gastritis caused by infection with Helicobacter pylori is characterized by chronic inflammation and damage in gastric tissue, which is a main risk factor for gastric cancer. Associated with H. pylori, the TP53 gene tumor suppressor and the cell adhesion glycoprotein epithelial cadherin develop a relevant role in the integrity and carcinogenesis of the epithelium. We aimed to detection of H. pylori and its main virulence markers and measured the messenger RNA (mRNA) expression levels of E-cadherin and TP53 genes. METHODS: The detection of H. pylori and its virulence markers, as well as the mRNA expression levels of E-cadherin and TP53 genes, were obtained for 161 samples of gastric biopsies including 37 with normal gastric tissue, 70 with gastritis, 24 from neoplastic tissue, and 27 from adjacent non-neoplastic by means of a quantitative real-time polymerase chain reaction. RESULTS: The mRNA expression levels of E-cadherin and TP53 were found to be decreased in patients with gastritis, independently of H. pylori infection. In samples from gastric patients, the neoplastic tissue showed an accentuated decrease of expression; on the other hand, the expression of E-cadherin was normal in adjacent non-neoplastic. CONCLUSIONS: No evidence was found of the involvement of the cagA and vacA genes in the decreased expression of E-cadherin and TP53. The process of carcinogenesis is complex, and the decrease of the E-cadherin gene expression and TP53 gene expression appears to contribute significantly.

Lack of association among TNF-alfa gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Background Tumor necrosis factor plays a critical role in the pathogenesis of gastric diseases such as gastric cancer, and an abnormal inflammatory response has frequently been observed in dyspeptic patients. Helicobacter pylori infection can induce a gastric mucosal inflammatory response that may be influenced by -308 (G > A) polymorphisms and gene expression of theTNF- gene. Methods One hundred and thirty-four gastric biopsy samples were collected from patients of both genders (61 and 73, mean age 40.3 ± 24.2 years) with gastric symptoms. The -308 (G > A) polymorphism of TNF- was characterized using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The expression level was measured using real-time PCR, and relative quantification (RQ) was calculated using the comparative CT method (2-CT). Results The analysis revealed an increase in TNF- gene expression in patients with gastritis; on the other hand, no statistical differences were observed in patients with gastric cancer. In addition, no association was found among -308 polymorphism genotypes, virulence markers, or TNF- gene expression. Conclusions Helicobacter pylori induces a large increase in TNF- expression in patients with gastritis, regardless of tissue inflammation, but after the tissue becomes neoplastic, the presence of bacteria did not influence expression. These results suggest that the TNF- pathway may play an important role in the progression from gastritis to gastric cancer.

Lack of association among TNF-α gene expression, -308 polymorphism (G > A) and virulence markers of Helicobacter pylori

Background Tumor necrosis factor plays a critical role in the pathogenesis of gastric diseases such as gastric cancer, and an abnormal inflammatory response has frequently been observed in dyspeptic patients. Helicobacter pylori infection can induce a gastric mucosal inflammatory response that may be influenced by -308 (G > A) polymorphisms and gene expression of theTNF-α gene. Methods One hundred and thirty-four gastric biopsy samples were collected from patients of both genders (61♂ and 73♀, mean age 40.3 ± 24.2 years) with gastric symptoms. The -308 (G > A) polymorphism of TNF-α; was characterized using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The expression level was measured using real-time PCR, and relative quantification (RQ) was calculated using the comparative CT method (2-ΔΔCT). Results The analysis revealed an increase in TNF-α gene expression in patients with gastritis; on the other hand, no statistical differences were observed in patients with gastric cancer. In addition, no association was found among -308 polymorphism genotypes, virulence markers, or TNF-α gene expression. Conclusions Helicobacter pylori induces a large increase in TNF-α expression in patients with gastritis, regardless of tissue inflammation, but after the tissue becomes neoplastic, the presence of bacteria did not influence expression. These results suggest that the TNF-α; pathway may play an important role in the progression from gastritis to gastric cancer(AU)

Assessment of sleep satisfaction in patients with dementia due to Alzheimer's disease.

Sleep length and architecture are potential markers of progressive cognitive impairment, while neuropsychiatric symptoms and APOE4- haplotypes have been associated with more sleep complaints in patients with dementia due to Alzheimer's disease (AD). In this cross-sectional study, we sought to investigate which factors might be related to sleep satisfaction in patients with AD. A total of 217 consecutive patients with AD were assessed for demographic features, neuropsychiatric symptoms, cognitive decline, functional impairment for activities of daily living, caregiver burden, APOE haplotypes, self-reported sleep satisfaction and length of sleep. Statistical comparisons were conducted with significance at p<0.05. Concerning sleep complaints, 179 patients (82.5%) reported satisfactory sleep, while 38 (17.5%) were unsatisfied, with no relation to age, sex, APOE haplotypes, obesity, education, marital status, alcohol consumption or smoking found. Length of sleep (p=0.011) and behavioural symptoms (p=0.009) had significant associations with sleep satisfaction. Length of sleep was positively correlated with apathy (p=0.014) and scores on the Clock Drawing Test (p=0.015), and inversely correlated with anxiety (p=0.015) and independence for instrumental activities of daily living (p=0.003). Patients who were treated with memantine (p=0.02) or anti-psychotics (p<0.01) had longer duration of sleep. In conclusion, behavioural symptoms had strong associations with sleep satisfaction, which is highly correlated with length of sleep in patients with AD. Functional independence, apathy, anxiety, use of memantine or anti-psychotics, and scores on the Clock Drawing Test were significantly associated with length of sleep in this sample.

Reference genes for quantitative RT-PCR data in gastric tissues and cell lines.

AIM: To evaluate the suitability of reference genes in gastric tissue samples and cell lines. METHODS: The suitability of genes ACTB, B2M, GAPDH, RPL29, and 18S rRNA was assessed in 21 matched pairs of neoplastic and adjacent non-neoplastic gastric tissues from patients with gastric adenocarcinoma, 27 normal gastric tissues from patients without cancer, and 4 cell lines using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). The ranking of the best single and combination of reference genes was determined by NormFinder, geNorm™, BestKeeper, and DataAssist™. In addition, GenEx software was used to determine the optimal number of reference genes. To validate the results, the mRNA expression of a target gene, DNMT1, was quantified using the different reference gene combinations suggested by the various software packages for normalization. RESULTS: ACTB was the best reference gene for all gastric tissues, cell lines and all gastric tissues plus cell lines. GAPDH + B2M or ACTB + B2M was the best combination of reference genes for all the gastric tissues. On the other hand, ACTB + B2M was the best combination for all the cell lines tested and was also the best combination for analyses involving all the gastric tissues plus cell lines. According to the GenEx software, 2 or 3 genes were the optimal number of references genes for all the gastric tissues. The relative quantification of DNMT1 showed similar patterns when normalized by each combination of reference genes. The level of expression of DNMT1 in neoplastic, adjacent non-neoplastic and normal gastric tissues did not differ when these samples were normalized using GAPDH + B2M (P = 0.32), ACTB + B2M (P = 0.61), or GAPDH + B2M + ACTB (P = 0.44). CONCLUSION: GAPDH + B2M or ACTB + B2M is the best combination of reference gene for all the gastric tissues, and ACTB + B2M is the best combination for the cell lines tested.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

DNA and histone methylation in gastric carcinogenesis.

Epigenetic alterations contribute significantly to the development and progression of gastric cancer, one of the leading causes of cancer death worldwide. Epigenetics refers to the number of modifications of the chromatin structure that affect gene expression without altering the primary sequence of DNA, and these changes lead to transcriptional activation or silencing of the gene. Over the years, the study of epigenetic processes has increased, and novel therapeutic approaches that target DNA methylation and histone modifications have emerged. A greater understanding of epigenetics and the therapeutic potential of manipulating these processes is necessary for gastric cancer treatment. Here, we review recent research on the effects of aberrant DNA and histone methylation on the onset and progression of gastric tumors and the development of compounds that target enzymes that regulate the epigenome.

The protective effect of Canova homeopathic medicine in cyclophosphamide-treated non-human primates.

BACKGROUND: Canova activates macrophages and indirectly induces lymphocyte proliferation. Here we evaluated the effects of Canova in cyclophosphamide-treated non-human primates. METHODS: Twelve Cebus apella were evaluated. Four animals were treated with Canova only. Eight animals were treated with two doses of cyclophosphamide (50 mg/kg) and four of these animals received Canova. Body weight, biochemistry and hematologic analyses were performed for 40 days. Micronucleus and comet assays were performed for the evaluation of DNA damage. RESULTS: We observed that cyclophosphamide induced abnormal WBC count in all animals. However, the group treated with cyclophosphamide plus Canova presented a higher leukocyte count than that which received only cyclophosphamide. Cyclophosphamide induced micronucleus and DNA damage in all animals. The frequency of these alterations was significantly lower in the Canova group than in the group without this medicine. CONCLUSIONS: Our results demonstrated that Canova treatment minimizes cyclophosphamide myelotoxicity in C. apella.

Clinical implication of 14-3-3 epsilon expression in gastric cancer.

AIM: To evaluate for the first time the protein and mRNA expression of 14-3-3ε in gastric carcinogenesis. METHODS: 14-3-3ε protein expression was determined by western blotting, and mRNA expression was examined by real-time quantitative RT-PCR in gastric tumors and their matched non-neoplastic gastric tissue samples. RESULTS: Authors observed a significant reduction of 14-3-3ε protein expression in gastric cancer (GC) samples compared to their matched non-neoplastic tissue. Reduced levels of 14-3-3ε were also associated with diffuse-type GC and early-onset of this pathology. Our data suggest that reduced 14-3-3ε may have a role in gastric carcinogenesis process. CONCLUSION: Our results reveal that the reduced 14-3-3ε expression in GC and investigation of 14-3-3ε interaction partners may help to elucidate the carcinogenesis process.

Cytogenetic effect of 5-azacytidine in patients with hematological malignancies

BACKGROUND: Recently, the importance of cytogenetics has grown in the diagnosis, prognosis and treatment of leukemias and myelodysplastic syndromes. 5-azacytidine is a drug that has well-known cytogenetical effects and is approved in the treatment of myelodysplastic syndromes. To date, no studies have been performed to evaluate the impact of 5-azacytidine on the chromosomes of patients with hematological neoplasias. This study aimed to investigate the effects of 5-azacytidine on chromosomes of patients with different hematological malignancies using G-band analyses to identify possible cytogenetical alterations. METHODS: The peripheral blood of 18 patients with hematological malignancies and 18 controls was collected in heparinized tubes. 5-azacytidine was added, at a final concentration of 10-5M, to cultures 7 hours prior to harvest. RESULTS: Uncoiled centromeric/pericentromeric heterochromatin of chromosomes-1, 9 and 16 occurred more frequently in the patients than in controls. This higher frequency of uncoiled heterochromatin was statistically significant (p-value = 0.004) for chromosome-9. Conversely, we observed that the fragile site at 19q13 was more frequent in controls (p-value = 0.0468). CONCLUSIONS: The results of this study suggest that satellite sequences, located in the heterochromatin of chromosome-9, are hypomethylated in hematological malignancies. This hypomethylation may contribute to the disease, activating transposable elements and/or promoting genomic instability, enabling the loss of heterozygosity of important tumor suppressor genes. An investigation of the 19q13 region may help to understand whether or not the predominant occurrence of the fragile site at 19q13 in controls is due to hypermethylation of this region.

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 9(th) day though on the 14(th) 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 940(th) 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.

SMARCA5 methylation and expression in gastric cancer.

Here, we first evaluated SMARCA5 expression and promoter DNA methylation in gastric carcinogenesis. Immunohistochemistry and methylation-specific PCR were analyzed in 19 and 48 normal mucosa and in 52 and 92 gastric cancer samples, respectively. We observed higher immunoreactivity of SMARCA5 in gastric cancer samples than in normal mucosa. Moreover, SMARCA5 promoter methylation was associated with the absence of protein expression. Our findings suggest that SMARCA5 has a potential role in proliferation and malignancy in gastric carcinogenesis.