AVALIAÇÃO DA CITOTOXICIDADE DE EXTRATOS DA ESPONJA DULCÍCOLA Drulia cristata (PORIFERA: METANIIDAE) DO RIO TAPAJÓS

Extracts from marine sponges and associated microorganisms have already been shown to be important for the development of new drugs. The knowledge about bioactive metabolites of freshwater sponges, however, is still discrete. In this study, the research was carried out using the sponge Drulia cristata and its associated bacteria. The collections were made in Maracanã Beach, Tapajós River, in Santarém. Crude extracts of sponges were obtained and the culture of their bacteria was carried out. After the fermentation of isolated strains, their crude extracts were obtained. The MTT assay was used to evaluate the cytotoxicity of these extracts against HCT-116 line (colorectal carcinoma). The extracts of the sponges had no cytotoxic activity. Extracts from the two strains of bacteria (DTR1 and DTR2) isolated showed moderate cytotoxic activity. From the DTR2 strain, the activity reached 65% inhibition of cancer cells, a promising result for future bioprospecting studies with freshwater sponges.Keywords: Drulia; bioprospecting; MTT assay; cancer.Extratos de esponjas marinhas e microrganismos associados têm demonstrado importância para o desenvolvimento de novas drogas terapêuticas. Entretanto, o conhecimento sobre metabólitos bioativos de esponjas de água doce é ainda bastante discreto. Neste estudo, a pesquisa foi realizada utilizando a esponja Drulia cristata e suas bactérias associadas. As coletas foram feitas na Praia Maracanã, Rio Tapajós, no Município de Santarém. Os extratos brutos da esponja foram obtidos e a cultura de suas bactérias foi realizada. Após a fermentação de cepas isoladas, seus extratos brutos também foram obtidos. O ensaio do MTT foi usado para avaliar a citotoxicidade desses extratos contra a linhagem HCT-116 (carcinoma colorretal). Os extratos da esponja não apresentaram citotoxicidade. Já os extratos das duas cepas de bactérias (DRT1 e DRT2) isoladas apresentaram atividade citotóxica moderada. O extrato da cepa DRT2 atingiu 65% de atividade inibitória sobre as células cancerosas, um resultado promissor para futuros estudos de bioprospecção com esponjas de água doce.Palavras-chave: Drulia, bioprospecção, ensaio do MTT, câncer

Kinase Inhibitor Screening Displayed ALK as a Possible Therapeutic Biomarker for Gastric Cancer

Despite advances in cancer chemotherapy, gastric cancer (GC) continues to have high recurrence rates and poor prognosis with limited treatment options. Understanding the etiology of GC and developing more effective, less harmful therapeutic approaches are vital and urgent. Therefore, this work describes a novel kinase target in malignant gastric cells as a potential therapeutic strategy. Our results demonstrate that among 147 kinase inhibitors (KI), only three molecules were significantly cytotoxic for the AGP-01 cell line. Hence, these three molecules were further characterized in their cellular mode of action. There was significant cell cycle impairment due to the expression modulation of genes such as TP53, CDKN1A, CDC25A, MYC, and CDK2 with subsequent induction of apoptosis. In fact, the Gene Ontology analysis revealed a significant enrichment of pathways related to cell cycle regulation (GO:1902749 and GO:1903047). Moreover, the three selected KIs significantly reduced cell migration and Vimentin mRNA expression after treatment. Surprisingly, the three KIs share the same target, ALK and INSR, but only the ALK gene was found to have a high expression level in the gastric cancer cell line. Additionally, lower survival rates were observed for patients with high ALK expression in TCGA-STAD analysis. In summary, we hypothesize that ALK gene overexpression can be a promising biomarker for prognosis and therapeutic management of gastric adenocarcinoma

Studies of micronuclei and other nuclear abnormalities in red blood cells of Colossoma macropomum exposed to methylmercury

The frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in the peripheral blood of tambaqui (Colossoma macropomum), treated with 2 mg.L−1 methylmercury (MeHg), were analyzed. Two groups (nine specimens in each) were exposed to MeHg for different periods (group A - 24 h; group B - 120 h). A third group served as negative control (group C, untreated; n = 9). Although, when compared to the control group there were no significant differences in MN frequency in the treated groups, for NA, the differences between the frequencies of group B (treated for 120 h) and the control group were extremely significant (p < 0.02), thus demonstrating the potentially adverse effects of MeHg on C. macropomum erythrocytes after prolonged exposure

Efficacy and safety of Zolbetuximab plus chemotherapy for advanced CLDN18.2-positive gastric or gastro-oesophageal adenocarcinoma: a meta-analysis of randomized clinical trials

Abstract Background The benefit of adding Zolbetuximab to the treatment in patients with Claudin-18 isoform 2 (CLDN18.2)-positive, human epidermal growth factor receptor 2-negative, locally advanced unresectable or metastatic gastric or gastro-oesophageal junction adenocarcinoma (GC/GEJ) is not yet fully elucidated. Methods We searched PubMed, Embase and Cochrane databases for randomized controlled trials (RCTs) that investigated Zolbetuximab plus chemotherapy versus chemotherapy alone for GC or GEJ adenocarcinoma. We computed hazard-ratios (HRs) or odds-ratios (ORs) for binary endpoints, with 95% confidence intervals (CIs). Results Three studies and 1,233 patients were included. Comparing with Zolbetuximab plus chemotherapy versus chemotherapy alone, progression-free survival (PFS) rate (HR 0.64; 95% CI 0.49–0.84; p < 0.01) and overall survival (OS) rate (HR 0.72; 95% CI 0.62–0.83; p < 0.01) were significant in favor of the Zolbetuximab group. Regarding effectiveness, the Objective Response Rate (ORR) was (OR 1.15; 95% CI 0.87–1.53; p = 0.34). Conclusions In this comprehensive systematic review and meta-analysis of RCTs, the incorporation of Zolbetuximab alongside chemotherapy offers a promising prospect for reshaping the established treatment paradigms for patients diagnosed with advanced CLDN18.2-positive GC/GEJ cancer

Pisosterol induces G2/M cell cycle arrest and apoptosis via the ATM/ATR signaling pathway in human glioma cells

Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Cultura de Tecidos e Citogenética Ananindeua, PA, Brasil.Universidade Federal do Pará. Instituto de Ciências Biológicas. Laboratório de Citogenética Humana. Belém, PA, Brazil.Universidade Federal do Ceará. Departamento de Fisiologia e Farmacologia. Fortaleza, CE, Brazil.Universidade Federal do Pará. Instituto de Ciências Biológicas. Laboratório de Biologia Molecular Francisco Mauro Salzano. Belém, PA, Brazil.Universidade Federal do Pará. Instituto de Ciências Biológicas. Laboratório de Biologia Molecular Francisco Mauro Salzano. Belém, PA, Brazil.Universidade Federal do Pará. Faculdade de Ciências Naturais. Instituto de Ciências Exatas e Naturais. Belém, PA, Brazil.Background: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. Objective: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. Methods: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). Results: Here, we reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. Conclusions: We, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggest that this compound might be a promising anticancer candidate for further investigation

Detection of Sepsis in Platelets Using MicroRNAs and Membrane Antigens

The present study proposes to legitimize in sepsis a characteristic found in platelets that suffer storage lesions in blood banks, which is the increased expression of miRNA miR-320a in relation to miR-127. Under physiologically normal conditions, an inverse relationship is observed. The aim of this study was to verify whether the analysis of miR-320a and miR-127 expression in platelets could detect a decrease in their viability and function due to the presence of pathogens in the blood of patients hospitalized in the Intensive Care Unit. We also investigated the expression of membrane antigens sensitive to platelet activation. Of the 200 patients analyzed, only those who developed sepsis (140) were found to have a higher relative quantity of miR-320a than that of miR-127. This characteristic and the increased expression of membrane antigens P2Y12, CD62P, CD41, and CD61 showed a significant association (p &lt; 0.01) with all types of sepsis evaluated in this study. Additionally, 40% of patients hospitalized for sepsis had negative results for the first cultures. We conclude that analysis of miR-127 and miR-320a expression combined with membrane antigens evaluation, in association with the available clinical and diagnostic parameters, are important tools to detect the onset of sepsis

HPV positive, wild type TP53, and p16 overexpression correlate with the absence of residual tumors after chemoradiotherapy in anal squamous cell carcinoma

Abstract Background Anal residual tumors are consensually identified within six months of chemoradiotherapy and represent a persistent lesion that may have prognostic value for overall survival. The aim of this study was to evaluate the association of HPV and HIV status, p16 expression level and TP53 mutations with the absence of residual tumors (local response) in Squamous Cell Carcinoma (SCC) of the anal canal after chemoradiotherapy. Methods We performed a study on 78 patients with SCC of the anal canal who submitted to chemoradiotherapy and were followed for a six-month period to identify the absence or presence of residual tumors. HPV DNA was identified by polymerase chain reaction and direct sequencing, HIV RNA was detected by TaqMan amplification, p16 expression was detected by western blotting, and the mutational analysis of TP53 was performed by direct sequencing; additionally, samples carrying mutations underwent fluorescent in sit hybridization. The evaluation of the tumor response to treatment was conducted six months after the conclusion of chemoradiotherapy. The following classifications were used to evaluate the outcomes: a) no response (presence of residual tumor) and b) complete response (absence of residual tumor). Results The significant variables associated with the absence of residual tumors were HPV positive, p16 overexpressed, wild-type TP53, female gender, and stages I and II. Only the presence of HPV was independently correlated with the clinical response; this variable increased the chances of a response within six months by 31-fold. Conclusions The presence of HPV in tumor cells was correlated with the absence of a residual tumor. This correlation is valuable and can direct future therapeutic approaches in the anal canal

Lack of evidence for human infection with Xenotropic murine leukemia virus-related virus in the Brazilian Amazon basin

Introduction: This study confirmed the absence of natural infection with Xenotropic murine leukemia virus-related virus (XMRV) or XMRV-related disease in human populations of the Brazilian Amazon basin. We demonstrated that 803 individuals of both sexes, who were residents of Belem in the Brazilian State of Pará, were not infected with XMRV. Methods: Individuals were divided into 4 subgroups: healthy individuals, individuals infected with human immunodeficiency virus, type 1 (HIV-1), individuals infected with human T-lymphotrophic virus, types 1 or 2 (HTLV-1/2), and individuals with prostate cancer. XMRV infection was investigated by nested PCR to detect the viral gag gene and by quantitative PCR to detect pol. Results: There was no amplification of either gag or pol segments from XRMV in any of the samples examined. Conclusions: This study supports the conclusions of the studies that eventually led to the retraction of the original study reporting the association between XMRV and human diseases

Dideoxy single allele-specific PCR - DSASP new method to discrimination allelic

Gastric cancer (GC) is a multifactorial disease with a high mortality rate in Brazil and worldwide. This work aimed to evaluate single nucleotide polymorphisms (SNP) rs1695, in the Glutathione S-Transferase Pi (GSTP1) gene in GC samples by comparative analysis Specific PCR - ASP and Dideoxy Single Allele-Specific PCR - DSASP methods. The DSASP is the proposed new method for allelic discrimination. This work analyzed 60 GC samples, 26 diffuse and 34 intestinal types. The SNP rs1695 of the GSTP1 gene was significantly associated with GC analyzed by DSASP method (χ 2 = 9.7, P 0.05). These results suggest that the SNP rs1695 of the GSTP1 gene was a risk factor associated with gastric carcinogens is and the DSASP method was a new successfully low-cost strategy to study allelic discrimination