RESUMO
BACKGROUND: The BRCA proteins play a key role in the homologous recombination (HR) pathway. Beyond BRCA1/2, other genes are involved in the HR repair (HRR). Due to the prominent role in the cellular repair process, pathogenic or likely pathogenic variants (PV/LPVs) in HRR genes may cause inadequate DNA damage repair in cardiomyocytes. PATIENTS AND METHODS: This was a multicenter, hospital-based, retrospective cohort study to investigate the heart toxicity from anthracycline-containing regimens (ACRs) in the adjuvant setting of breast cancer (BC) patients carrying germline BRCA PV/LPVs and no-BRCA HRR pathway genes. The left ventricular ejection fraction (LVEF) was assessed using cardiac ultrasound before starting ACR therapy and at subsequent time points according to clinical indications. RESULTS: Five hundred and three BC patients were included in the study. We predefined three groups: (i) BRCA cohort; (ii) no-BRCA cohort; (iii) variant of uncertain significance (VUS)/wild-type (WT) cohort. When baseline (T0) and post-ACR (T1) LVEFs between the three cohorts were compared, pre-treatment LVEF values were not different (BRCA1/2 versus HRR-no-BRCA versus VUS/WT cohort). Notably, during monitoring (T1, median 3.4 months), patients carrying BRCA or HRR no-BRCA germline pathogenic or likely pathogenic variants showed a statistically significant reduction of LVEF compared to baseline (T0). To assess the relevance of HRR on the results, we included the analysis of the subgroup of 20 BC patients carrying PV/LPVs in other genes not involved in HRR, such as mismatch repair genes (MUTYH, PMS2, MSH6). Unlike HRR genes, no significant differences in T0-T1 were found in this subgroup of patients. CONCLUSION: Our data suggest that deleterious variants in HRR genes, leading to impaired HR, could increase the sensitivity of cardiomyocytes to ACR in early BC patients. In this subgroup of patients, other measurements, such as the global longitudinal strain, and a more in-depth assessment of risk factors may be proposed in the future to optimize cardiovascular risk management and improve long-term survival.
Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteína BRCA1/genética , Cardiotoxicidade/genética , Antraciclinas/efeitos adversos , Estudos Retrospectivos , Volume Sistólico , Proteína BRCA2/genética , Função Ventricular Esquerda , Recombinação HomólogaRESUMO
BACKGROUND: The incidence of cutaneous melanoma is increasing in Italy, in parallel with the implementation of gene panels. Therefore, a revision of national genetic assessment criteria for hereditary melanoma may be needed. The aim of this study was to identify predictors of susceptibility variants in the largest prospective cohort of Italian high-risk melanoma cases studied to date. MATERIALS AND METHODS: From 25 Italian centers, we recruited 1044 family members and germline sequenced 940 cutaneous melanoma index cases through a shared gene panel, which included the following genes: CDKN2A, CDK4, BAP1, POT1, ACD, TERF2IP, MITF and ATM. We assessed detection rate according to familial status, region of origin, number of melanomas and presence and type of non-melanoma tumors. RESULTS: The overall detection rate was 9.47% (5.53% analyzing CDKN2A alone), ranging from 5.14% in sporadic multiple melanoma cases (spoMPM) with two cutaneous melanomas to 13.9% in familial cases with at least three affected members. Three or more cutaneous melanomas in spoMPM cases, pancreatic cancer and region of origin predicted germline status [odds ratio (OR) = 3.23, 3.15, 2.43, P < 0.05]. Conversely, age > 60 years was a negative independent predictor (OR = 0.13, P = 0.008), and was the age category with the lowest detection rate, especially for CDKN2A. Detection rate was 19% when cutaneous melanoma and pancreatic cancer clustered together. CONCLUSIONS: Gene panel doubled the detection rate given by CDKN2A alone. National genetic testing criteria may need a revision, especially regarding age cut-off (60) in the absence of strong family history, pancreatic cancer and/or a high number of cutaneous melanomas.
Assuntos
Melanoma , Neoplasias Pancreáticas , Neoplasias Cutâneas , Inibidor p16 de Quinase Dependente de Ciclina , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Melanoma Maligno Cutâneo , Neoplasias PancreáticasRESUMO
BACKGROUND: Hereditary breast cancer (BC), ovarian cancer (OC), and pancreatic cancer (PC) are the major BRCA-associated tumours. However, some BRCA1/2-wild-type (wt) patients with a strong personal and/or family history of cancer need a further genetic testing through a multi-gene panel containing other high- and moderate-risk susceptibility genes. PATIENTS AND METHODS: Our study was aimed to assess if some BC, OC, or PC patients should be offered multi-gene panel testing, based on well-defined criteria concerning their personal and/or family history of cancer, such as earliness of cancer onset, occurrence of multiple tumours, or presence of at least two or more affected first-degree relatives. For this purpose, 205 out of 915 BC, OC, or PC patients, resulted negative for BRCA1/2 and with significant personal and/or family history of cancer, were genetically tested for germline pathogenic or likely pathogenic variants (PVs/LPVs) in genes different from BRCA1/2. RESULTS: Our investigation revealed that 31 (15.1%) out of 205 patients harboured germline PVs/LPVs in no-BRCA genes, including PALB2, CHEK2, ATM, MUTYH, MSH2, and RAD51C. Interestingly, in the absence of an analysis conducted through multi-gene panel, a considerable percentage (15.1%) of PVs/LPVs would have been lost. CONCLUSIONS: Providing a multi-gene panel testing to BRCA1/2-wt BC/OC/PC patients with a strong personal and/or family history of cancer could significantly increase the detection rates of germline PVs/LPVs in other cancer predisposition genes beyond BRCA1/2. The use of a multi-gene panel testing could improve the inherited cancer risk estimation and clinical management of patients and unaffected family members.
Assuntos
Neoplasias da Mama , Neoplasias Ovarianas , Neoplasias Pancreáticas , Proteína BRCA1/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Feminino , Predisposição Genética para Doença , Testes Genéticos , Humanos , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/genética , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genéticaRESUMO
BACKGROUND: The role of tumor mutational burden (TMB) is still debated for selecting advanced non-oncogene addicted non-small-cell lung cancer (NSCLC) patients who might benefit from immune checkpoint inhibitors (ICIs). Of note, TMB failed to predict a benefit in overall survival (OS) among such patients. MATERIALS AND METHODS: The purpose of this meta-analysis was to compare efficacy outcomes among first-line immune-oncology (IO) agents versus standard platinum-based chemotherapy (CT) within two subgroups (TMB-low and TMB-high on either tissue or blood). We collected hazard ratios (HRs) to evaluate the association for progression-free survival (PFS) and OS, with the relative 95% confidence intervals (CIs). Risk ratios (RRs) were used as an association measure for objective response rate (ORR). RESULTS: Eight different cohorts of five randomized controlled phase III studies (3848 patients) were analyzed. In TMB-high patients, IO agents were associated with improved ORR (RRs 1.37, 95% CI 1.13-1.66), PFS (HR 0.69, 95% CI 0.61-0.79) and OS (HR 0.67, 95% CI 0.59-0.77) when compared with CT, thus suggesting a possible predictive role of high TMB for IO regimens. In TMB-low patients, the IO strategy did not lead to any significant benefit in survival and activity, whereas the pooled results of both ORR and PFS were intriguingly associated with a statistical significance in favor of CT. CONCLUSIONS: This meta-analysis resulted in a proven benefit in OS in favor of IO agents in the TMB-high population. Although more prospective data are warranted, we postulated the hypothesis that monitoring TMB, in addition to the existing programmed death-ligand 1 (PD-L1) expression level, could represent the preferable option for future clinical research in the first-line management of advanced non-oncogene addicted NSCLC patients.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Ensaios Clínicos Fase III como Assunto , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Prognóstico , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
The inhibition of the mechanisms of tumor neo-angiogenesis represents a milestone that in the last 10 years has seen the advent of numerous molecules to target action against the vascular endothelial growth factor (VEGF). More recently, new molecules have been developed that inhibit tumor spread by the blockade of specific VEGF receptors (VEGFRs), thereby preventing the binding of a ligand to its receptor and the cascade of proliferative events downstream. Ramucirumab is a fully humanized IgG1 monoclonal antibody that performs its action by blocking the isoform 2 of the VEGF receptor (VEGFR-2). Numerous preclinical and clinical studies have demonstrated its activity in several solid tumors, demonstrating a remarkable efficacy in terms of progression-free survival and overall survival in addition to a favorable toxicity profile. This review analyzes in detail the role of ramucirumab in the treatment of advanced gastric and gastroesophageal junction cancers.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados , Antineoplásicos/efeitos adversos , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Ensaios Clínicos como Assunto , Humanos , RamucirumabRESUMO
Esophageal adenocarcinoma originates from columnar metaplastic epithelium of the distal esophagus. Various steps for this carcinogenetic process are known. Before the onset of high-grade dysplasia and adenocarcinoma, endoscopic surveillance is possible. However, because of the high cost of long-term surveillance, predictive factors for cancer are being evaluated to identify subjects with metaplasia who have a higher risk of developing malignancy. Molecular changes seem suitable for this purpose, but could require a high resource expenditure. While trying to identify the best predictive factors for cancer risk, molecular changes and differences in miRNA expression profile between the various steps leading to cancer could help to clarify Barrett's carcinogenesis. In this attempt to find a molecular explanation for the onset of esophageal adenocarcinoma, it is still difficult to understand whether the molecular changes are causes or effects of the neoplastic phenotypic modifications.
Assuntos
Adenocarcinoma/genética , Esôfago de Barrett/genética , Esôfago de Barrett/patologia , Carcinogênese/genética , Neoplasias Esofágicas/genética , Adenocarcinoma/epidemiologia , Adenocarcinoma/metabolismo , Esôfago de Barrett/epidemiologia , Biomarcadores , Carcinogênese/metabolismo , Progressão da Doença , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/metabolismo , Humanos , MicroRNAs/genética , MicroRNAs/metabolismoRESUMO
Recently, the hypothesis that colorectal tumors originate from a subpopulation of cells called 'cancer stem cells' (CSCs) or tumor-initiating cells, which exhibit stem-like features, has been confirmed experimentally in various human cancers. Several studies have confirmed the existence of colorectal CSCs (CRCSCs) and have demonstrated that this rare cell population can be isolated by the expression of specific cell surface biomarkers. MicroRNAs (miRNAs) are a class of small non-coding RNAs, which are crucial for post-transcriptional regulation of gene expression and participate in a wide variety of biological functions, including development, cell proliferation, differentiation, metabolism and signal transduction. Moreover, new evidences suggest that miRNAs could contribute to preserve stemness of embryonic stem cells and could be involved in maintaining stemness of CSCs. Recent studies have begun to outline the role of miRNAs in regulation of CRCSCs. This review aims to summarize the recent advancement about the roles of miRNAs in CRCSCs that may represent a step forward in understanding the molecular mechanisms and the possible approaches for colorectal cancer therapy.
RESUMO
Breast cancer (BC) is a heterogeneous disease that exhibits familial aggregation. Family linkage studies have identified high-penetrance genes, BRCA1, BRCA2, PTEN and TP53, that are responsible for inherited BC syndromes. Moreover, a combination of family-based and population-based approaches indicated that genes involved in DNA repair, such as CHEK2, ATM, BRIP and PALB2, are associated with moderate risk. Therefore, all of these known genes account for only 25% of the familial aggregation cases. Recently, genome wide association studies (GWAS) in BC revealed single nucleotide polymorphisms (SNPs) in five novel genes associated to susceptibility: TNRC9, FGFR2, MAP3K1, H19 and lymphocyte-specific protein 1 (LSP1). The most strongly associated SNP was in intron 2 of the FGFR2 gene that is amplified and overexpressed in 5-10% of BC. rs3803662 of TNRC9 gene has been shown to be the SNP with the strongest association with BC, in particular, this polymorphism seems to be correlated with bone metastases and estrogen receptor positivity. Relevant data indicate that SNP rs889312 in MAP3K1 is correlated with BC susceptibility only in BRCA2 mutation carriers, but is not associated with an increased risk in BRCA1 carriers. Finally, different SNPs in LSP1 and H19 and in minor genes probably were associated with BC risk. New susceptibility allelic variants associated with BC risk were recently discovered including potential causative genes involved in regulation of cell cycle, apoptosis, metabolism and mitochondrial functions. In conclusion, the identification of disease susceptibility loci may lead to a better understanding of the biological mechanism for BC to improve prevention, early detection and treatment.
Assuntos
Neoplasias da Mama/genética , Estudo de Associação Genômica Ampla , Herança Multifatorial , Proteínas Reguladoras de Apoptose , Feminino , Predisposição Genética para Doença , Proteínas de Grupo de Alta Mobilidade , Humanos , MAP Quinase Quinase Quinase 1/genética , Proteínas dos Microfilamentos/genética , Polimorfismo de Nucleotídeo Único , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Receptores de Progesterona/genética , TransativadoresRESUMO
Sorghum fibers were pretreated with ammonium hydroxide and the effectiveness of the pretreatment evaluated by enzyme hydrolysis and ethanol production. The treatment was carried out by mixing sorghum fibers, ammonia, and water at a ratio of 1:0.14:8 at 160 degrees C for 1 h under 140-160 psi pressure. Approximately 44% lignin and 35% hemicellulose were removed during the process. Untreated and dilute-ammonia-treated fibers at 10% dry solids were hydrolyzed using combinations of commercially available enzymes, Spezyme CP and Novozyme 188. Enzyme combinations were tested at full strength (60 FPU Spezyme CP and 64 CBU Novozyme 188/g glucan) and at half strength (30 FPU Spezyme CP and 32 CBU Novozyme 188/g glucan). Biomass enzyme hydrolysis was conducted for 24 h. Saccharomyces cerevisiae D(5)A was added post hydrolysis for conversion of glucose to ethanol. Theoretical cellulose yields for treated biomass were 84% and 73%, and hemicellulose yields were 73% and 55% for full strength and half strength, respectively. Average cellulose yield was 38% and hemicellulose yield was 14.5% for untreated biomass. Ethanol yields were 25 g/100 g dry biomass and 21 g/100 g dry biomass for full strength and half strength enzyme concentrations, respectively. Controls averaged 10 g ethanol/100 g dry biomass.
Assuntos
Etanol/metabolismo , Sorghum/metabolismo , Amônia/farmacologia , Biocombustíveis , Biomassa , Biotecnologia , Fermentação , Glucose/metabolismo , Hidrólise , Microbiologia Industrial , Cinética , Microscopia Eletrônica de Varredura , Saccharomyces cerevisiae/metabolismo , Sorghum/efeitos dos fármacos , Sorghum/crescimento & desenvolvimento , Sorghum/ultraestrutura , beta-Glucosidase/metabolismoRESUMO
BACKGROUND: The development of oesophageal adenocarcinoma is generally closely associated with the presence of a specialised intestinal-type epithelium such as that found in Barrett's oesophagus (BO). A particular histological condition is when the distal oesophagus showing cardiac and/or fundic mucosa without intestinal metaplasia cannot be defined as 'Barrett's mucosa' [condition that we call 'columnar-lined oesophagus' (CLO)] and up till now, there has been no agreement in literature about the management of this condition. Aurora-A overexpression leads to centrosome amplification, chromosomal instability and aneuploidy in mammalian cells. PATIENTS AND METHODS: A prospective study was carried out on 28 consecutive patients who presented columnar mucosa above the gastro-oesophageal junction (GOJ) at endoscopy. As controls, two more biopsies were obtained, one on the normal-appearing squamous oesophagus above the GOJ, as far as possible from the columnar mucosa (controls A), and one taken 1 cm below the GOJ (controls B). The Aurora-A and p53 expression levels were analysed respectively by Quantitative Real Time PCR and immunohistochemistry. RESULTS: Twelve patients were affected by BO (43%) while the other 16 patients (57%) had a CLO. Nine of 28 (32%) cases were focally positive for p53 immunostaining. All the BO/CLO samples were positive for the Aurora-A transcript with regard to controls. Furthermore, 13 of 28 (46%) cases showed overexpression (above the median for the whole group). CONCLUSION: Due to the low number of cases, we are not at present able to state that statistically significant quantitative differences in Aurora-A messenger RNA expression exist between CLO and BO cases with and without dysplasia and p53-positive immunostaining. Further studies on a larger number of cases with a follow-up period are necessary in order to establish the risk of progression and the correct management of these subjects.
Assuntos
Esôfago de Barrett/genética , Refluxo Gastroesofágico/genética , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/genética , Adenocarcinoma/enzimologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adulto , Aurora Quinases , Esôfago de Barrett/enzimologia , Esôfago de Barrett/patologia , Biomarcadores/metabolismo , Neoplasias Esofágicas/enzimologia , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Feminino , Refluxo Gastroesofágico/enzimologia , Refluxo Gastroesofágico/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa/enzimologia , Mucosa/patologia , Estudos ProspectivosRESUMO
Recently, new chemotherapy agents which target the non-structural components of mitosis have been developed. An important protein involved in several mitotic phases is the Aurora-A protein. By means of the phosphorylation of different substrates, Aurora-A regulates the correct development of the various phases of mitosis. The kinase activity of this protein makes Aurora-A an excellent candidate as an oncogene. The first data of Aurora-A involvement in cancer regarded the identification of Aurora-A overexpression in primary breast and colon tumour samples. With regard to the predictive role of Aurora-A, it has been shown that its overexpression disrupts the spindle checkpoint activated by paclitaxel (Taxol) or nocodazole treatment, thus inducing the cells to become resistant to these drugs. The development therefore of small molecules with an Aurora-A inhibition function may make it possible to reduce or block the oncogenic activity of Aurora-A and in addition may improve the survival of oncological patients showing resistance to paclitaxel or nocodazole treatment. Three novel Aurora kinase inhibitors have recently been described--Hesperadin, ZM447439 and VX-680. All these three drugs have been designed to target the ATP-binding site of Aurora kinase, so they inhibit all three Aurora kinase family members showing a similar phenotype when tested in cell-based assays. Among these three different molecules, VX-680 has shown promising results in in vitro and in vivo studies. In conclusion, it is clear that we are entering a new era in anti-mitotic therapy with the identification and now clinical translation of new targets in mitosis beyond tubulin but many questions remain with regard to Aurora function.
Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/enzimologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Antineoplásicos/farmacologia , Aurora Quinases , Humanos , Neoplasias/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/genéticaRESUMO
Mutation screening of the BRCA1 and BRCA2 genes in probands with familial breast/ovarian cancer has been greatly improved by the multiplex ligation-dependent probe amplification (MLPA) assay able to evidence gene rearrangements not detectable by standard screening methods. However, no criteria for selection of cases to be submitted to the MLPA test have been reported yet. We used the BRCAPro software for the selection of familial breast/ovarian cancer probands investigated with the MLPA approach after negative BRCA1/2 conventional mutation screening. One hundred and seventy-seven probands were investigated for germline BRCA1/2 mutations after assessment of genetic risk using BRCAPro. Probands were classified as BRCAPro positive (n = 67) when the carrier probability (CP) was >10% and as BRCAPro negative (n = 110), when the CP was <10%. Conventional mutational analyses of the BRCA1/2 genes and, in one case, of p53 identified 22 pathogenetic germline mutations, 12 in BRCA1, 9 in BRCA2 and 1 in p53, in 22/177 (12.4%) probands. All the mutations except one were detected in BRCAPro-positive patients. In the 46 BRCAPro-positive cases that resulted negative by BRCA1/2 mutation, screening analysis of rearrangements within BRCA1/2 by MLPA was carried out. Three patients with a very high CP showed BRCA1 deletions, consisting of deletions of exons 1-2 in two probands and of exon 24 in the third proband. In one case, the exons 1-2 deletion was shown to cosegregate with disease in the family. No BRCA2 rearrangements were detected, but one patient showed the 1100delC of the CHEK2 gene, whose probe is present in the BRCA2 kit. In our series, the highest carrier detection rate of mutation screening plus MLPA analysis (52.3%) was in patients with a BRCAPro CP >50%.
Assuntos
Proteína BRCA1/genética , Triagem de Portadores Genéticos , Predisposição Genética para Doença , Deleção de Sequência , Software , Adulto , Idoso , Proteína BRCA1/análise , Proteína BRCA1/metabolismo , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama Masculina/epidemiologia , Neoplasias da Mama Masculina/genética , Neoplasias da Mama Masculina/metabolismo , Feminino , Triagem de Portadores Genéticos/métodos , Predisposição Genética para Doença/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Linhagem , Prevalência , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Fatores de RiscoRESUMO
BRCA1 and BRCA2 germline mutations contribute to a significant number of familial and hereditary breast and/or ovarian cancers. The proportion of high-risk families with breast and/or ovarian cancer cases due to mutations in these tumor suppressor genes varies widely among populations. In some population, a wide spectrum of different mutations in both genes are present, whereas in other groups specific mutations in BRCA1 and BRCA2 have been reported with high frequency. Most of these mutations are prevalent in restricted populations as consequence of a founder effect. The comparison of haplotypes between families with the same mutation can distinguish whether high-frequency alleles derive from an older or more recent single mutational event or whether they have arisen independently more than once. Here, we review some of the most well-known and significant examples of founder mutations in BRCA genes found in European and non-European populations. In conclusion, the identification of the ethnic group of families undergoing genetic counseling enables the geneticist and oncologist to make more specific choices, leading to simplify the clinical approach to genetic testing carried out on members of high-risk families. Futhermore, the high frequency of founder mutations, allowing to analyze a large number of cases, might provide accurate information regarding their penetrance.
Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Efeito Fundador , Mutação , Proteínas Reguladoras de Apoptose , Etnicidade/genética , Testes Genéticos , HumanosRESUMO
BACKGROUND: The frequency and the type of BRCA1 mutations vary widely and might have different geographic and ethnic distribution. Most of these alterations are generally found in isolated populations as a consequence of the founder effect. The object of this study was to determine whether 4843delC, a deleterious mutation of the BRCA1 gene, might be due to a founder effect originating in the Sicilian region of Italy. This mutation was described by us for the first time and identified in two unrelated Sicilian families with hereditary breast/ovarian cancer. The two families were from the same geographical area (south-western area of Palermo, Sicily). The homogeneity of the ethnic group of the two families and the Single Nucleotide Polymorphism (SNPs) analysis of probands led us to perform a study of the allelotype of the various members. PATIENTS AND METHODS: The analysis of the haplotype of the probands and of several family members was conducted by means of a study of the highly polymorphic microsatellites within or flanking the BRCA1 gene. RESULTS: This analysis revealed the presence of a common allele associated with the mutation. CONCLUSIONS: We therefore conclude that 4843delC of the BRCA1 gene is a possible founder mutation in the Sicilian population.
Assuntos
Análise Mutacional de DNA , Efeito Fundador , Deleção de Genes , Genes BRCA1 , Neoplasias da Mama/genética , Feminino , Haplótipos , Humanos , Masculino , Repetições de Microssatélites , Neoplasias Ovarianas/genética , Linhagem , SicíliaRESUMO
BACKGROUND: Gastric cancer (GC) development is a multistep process, during which numerous alterations accumulate in nuclear and mitochondrial DNA. A deficiency of repair machinery brings about an accumulation of errors introduced within simple repetitive microsatellite sequences during replication of DNA. Aberrant methylation is related to microsatellite instability (MSI) by the silencing of the hMLH1 gene. The aim of this study is to investigate a possible relationship between the RUNX3 promoter methylation, nuclear microsatellite instability (nMSI) and mitochondrial microsatellite instability (mtMSI), in order to clarify its biological role in GC. PATIENTS AND METHODS: nMSI and mtMSI were evaluated in a consecutive series of 100 GC patients. For the analysis of the nMSI, we followed the National Cancer Institute guidelines. mtMSI was assessed by analyzing a portion of the displacement-loop region. The aberrant methylation of RUNX3 was analyzed in 40 GC patients by methylation-specific PCR. RESULTS: Overall, 55% of GC demonstrated methylation of the RUNX3 promoter; 82% of GC was classified as stable microsatellite instability, 5% as low-level microsatellite instability and 13% as high-level microsatellite instability (MSI-H); mtMSI was detected in 11% of GC. A significant association was found between mtMSI and tumor-node-metastasis staging, furthermore an interesting association between MSI-H status, mtMSI and RUNX3 methylation. CONCLUSION: These data suggest that RUNX3 is an important target of methylation in the evolution of mtMSI and nMSI-H GC.
Assuntos
Núcleo Celular/genética , Subunidade alfa 3 de Fator de Ligação ao Core/genética , Ilhas de CpG/genética , Metilação de DNA , DNA Mitocondrial/genética , Instabilidade de Microssatélites , Neoplasias Gástricas/genética , Idoso , Núcleo Celular/metabolismo , Subunidade alfa 3 de Fator de Ligação ao Core/metabolismo , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias Gástricas/metabolismoRESUMO
Gastric adenomas are rare neoplastic growths characterized by localized polypoid proliferations of dysplastic epithelium that tend to progress to infiltrating adenocarcinoma. Therefore, the identification of molecular markers that could reliably recognize adenomas at risk of progression is advocated in the clinical management. In this study we investigated, in a series of gastric adenoma specimens from an area at high risk of gastric cancer, the relationship between clinicopathological characteristics of adenoma and Helicobacter pylori infection, APC mutational status, and COX-2 and the down-stream enzyme mPGES1 expression. Helicobacter pylori infection, detected in 24%, and 33% by histology and PCR analyses, respectively, did not show any relationship with growth pattern, localization, size, dysplasia grade and presence of synchronous cancer. Pathogenetic mutations of MCR region (codons 1269-1589) of the APC gene were detected only in one case corresponding to a single, small size, low grade, H. pylori-negative adenoma. The expression of COX-2 largely matched that of mPGES(1). Both were overexpressed in 79% of cases showing a relationship with high-grade dysplasia, size >10 mm and presence of a synchronous carcinoma. In conclusion, COX-2 may play a key role in the development and progression of gastric adenoma and could be an attractive target in the management of gastric adenoma at major risk of cancer development.
Assuntos
Adenoma/enzimologia , Adenoma/microbiologia , Ciclo-Oxigenase 2/biossíntese , Genes APC , Infecções por Helicobacter/patologia , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/microbiologia , Adenocarcinoma/enzimologia , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Adenoma/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Mucosa Gástrica/enzimologia , Mucosa Gástrica/patologia , Helicobacter pylori , Humanos , Oxirredutases Intramoleculares/biossíntese , Masculino , Pessoa de Meia-Idade , Mutação , Prostaglandina-E Sintases , Neoplasias Gástricas/patologiaRESUMO
Apoptosis is a form of cell death that permits the removal of damaged, senescent or unwanted cells in multicellular organisms, without damage to the cellular microenvironment. Defective apoptosis represents a major causative factor in the development and progression of cancer. The majority of chemotherapeutic agents, as well as radiation, utilize the apoptotic pathway to induce cancer cell death. Resistance to standard chemotherapeutic strategies also seems to be due to alterations in the apoptotic pathway of cancer cells. Recent knowledge on apoptosis has provided the basis for novel targeted therapies that exploit apoptosis to treat cancer. These new target include those acting in the extrinsic/intrinsic pathway, proteins that control the apoptosis machinery such as the p53 and proteosome pathway. Most of these forms of therapy are still in preclinical development because of their low specifity and susceptibility to drug resistance, but several of them have shown promising results. In particular, this review specifically aims at providing an update of certain molecular players that are already in use in order to target apoptosis (such as bortezomib) or which are still being clinically evaluated (such ONYX-015, survivin and exisulind/aptosyn) or which, following preclinical studies, might have the necessary requirements for becoming part of the anticancer drug programs (such as TRAIL/Apo2L, apoptin/VP3).
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Animais , Ácidos Borônicos/farmacologia , Bortezomib , Proteínas do Capsídeo/farmacologia , Humanos , Proteínas Inibidoras de Apoptose , Ligantes , Proteínas Associadas aos Microtúbulos/farmacologia , Proteínas de Neoplasias/farmacologia , Pirazinas/farmacologia , Receptores de Morte Celular/metabolismo , Sulindaco/análogos & derivados , Sulindaco/farmacologia , Survivina , Ligante Indutor de Apoptose Relacionado a TNF/farmacologiaRESUMO
BACKGROUND: Methylation of the p16 promoter is one of the most frequent mechanisms of gene inactivation; its incidence is extremely variable according to the type of tumor involved. Our purpose was to analyze the hypermethylation of the p16 promoter in laryngeal squamous cell carcinomas (LSCC), salivary gland (SG) tumors and in colorectal cancer (CRC), to detect any possible association with the clinicopathological features and to determine the prognostic significance of the p16 gene in the tumors analyzed. PATIENTS AND METHODS: The hypermethylation of the p16 promoter was prospectively analyzed, by MSP, in a consecutive series of 64 locally advanced LSCC patients, in a consecutive series of 33 SG tumor patients and in a consecutive series of 66 sporadic CRC patients. RESULTS: Hypermethylation was observed in 9% of the LSCC cases, in all cases of SG cancer and in 21% of the CRC cases. No significant association was observed between p16 hypermethylation and clinicopathological variables in all the tissue samples analyzed. Moreover at univariate analysis p16 mutations were not independently related at disease relapse and death in LSCC and CRC. CONCLUSIONS: The results of this study suggest that the lack of p16 function could happen in advanced stage of SG tumors.
Assuntos
Neoplasias Colorretais/genética , Metilação de DNA , Genes p16 , Neoplasias de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas/genética , Neoplasias Colorretais/patologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Estadiamento de Neoplasias , Regiões Promotoras GenéticasRESUMO
BACKGROUND: Over 600 different pathogenic mutations have been identified in the BRCA1 gene. Nevertheless, numerous missense mutations of unknown biological function still exist. Understanding of biological significance of these mutations should help in genetic counselling to carriers and their families. PATIENTS AND METHODS: A total of 104 patients with breast and/or ovarian cancer whose genetic counselling answered the criteria of the American Society of Clinical Oncology (ASCO 2003), were prospectively screened for mutations in all coding exons of the BRCA1 gene by automatic direct sequencing. RESULTS: During these mutational screening procedures one case presented three mutations classified in the Breast Cancer Information Core Database as unknown variants. These were 655A/G found in exon 8 of BRCA1, 1575T/C and 1767A/C found in exon 11 of the same gene. The identification of the three unknown variants in the proband (16SIRIO) and in her mother and sister indicates that such alterations exist in cis. CONCLUSIONS: Our results suggest that the charge and stechiometry variations determined by the changes in the amino acids Y179C, F486L and N550H might produce an effect on the conformation of the protein and, consequently, on its function.
Assuntos
Neoplasias da Mama/genética , Genes BRCA1 , Mutação de Sentido Incorreto , Adulto , Proteína BRCA1/química , Proteína BRCA1/genética , DNA de Neoplasias/genética , Éxons , Saúde da Família , Feminino , Aconselhamento Genético , Variação Genética , Mutação em Linhagem Germinativa , Humanos , Neoplasias Ovarianas/genética , Linhagem , Estudos Prospectivos , Conformação Proteica , SicíliaRESUMO
BACKGROUND: Mammaglobin is expressed mainly in mammary tissue, overexpressed in breast cancer (BC) and rarely in other tissue. The aim of this study was to assess the sensitivity and specificity of transcript MGB1 detection and to evaluate the role of MGB1 as potential clinical marker for the detection of disseminated cancer cells in the blood of BC patients. PATIENTS AND METHODS: A consecutive series of 23 BC tissues, 36 peripheral blood BC samples and 35 healthy peripheral blood samples was prospectively recruited to investigate MGB1 expression by means of a quantitative Real Time RT-PCR assay. RESULTS: MGB1 overexpression in tissue samples of BC patients is significantly associated only with high level of Ki67 (P <0.05). None of the samples from peripheral blood of 35 healthy female individuals were positive for MGB1 transcript. In contrast MGB1 mRNA expression was detected in three of 36 (8%) peripheral blood of BC patients. CONCLUSIONS: Our preliminary results demonstrate that the detection of MGB1 transcript in peripheral blood of BC patients was specific but with low sensitivity. MGB1 overexpression by itself or in combination with Ki67 might be considered an index of BC progression.