STUDY OF LIPID BIOMARKERS OF PATIENTS WITH POLYPS AND COLORECTAL CÂNCER.

BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of cancer worldwide. Early diagnostic methods using serum biomarkers are required. The study of omics, most recently lipidomics, has the purpose of analyzing lipids for a better understanding of human lipidoma. The evolution of mass spectrometry methods, such as MALDI-MS technology, has enabled the detection and identification of a wide variety of lipids with great potential to open new avenues for predictive and preventive medicine. OBJECTIVE: To determine the lipid profile of patients with colorectal cancer and polyps. METHODS: Patients with stage I-III CRC, adenomatous polyps and individuals with normal colonoscopy were selected. All patients underwent peripheral blood collection for lipid extraction. The samples were analyzed by MALDI-MS technique for lipid identification. STATISTICAL ANALYSIS: Univariate and multivariate (principal component analysis [PCA] and discriminant analysis by partial least squares [PLS-DA]) analyses workflows were applied to the dataset, using MetaboAnalyst 3.0 software. The ions were identified according to the class of lipids using the online database Lipid Maps (http://www.lipidmaps.org). RESULTS: We included 88 individuals, 40 with CRC, 12 with polyps and 32 controls. Boxplot analysis showed eight VIP ions in the three groups. Differences were observed between the cancer and control groups, as well as between cancer and polyp, but not between polyps and control. The polyketide (810.1) was the lipid represented in cancer and overrepresented in polyp and control. Among the patients with CRC we observed differences between lipids with lymph node invasion (N1-2) compared to those without lymph node invasion (N). CONCLUSION: Possible lipid biomarkers were identified among cancer patients compared to control and polyp groups. The polyketide lipid (810.1) was the best biomarker to differentiate the cancer group from control and polyp. We found no difference between the biomarkers in the polyp group in relation to the control.

Estudo de biomarcadores lipídicos em pacientes portadores com pólipos e câncer colorretal / Study of lipid biomarkers of patients with polyps and colorectal câncer

ABSTRACT BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of cancer worldwide. Early diagnostic methods using serum biomarkers are required. The study of omics, most recently lipidomics, has the purpose of analyzing lipids for a better understanding of human lipidoma. The evolution of mass spectrometry methods, such as MALDI-MS technology, has enabled the detection and identification of a wide variety of lipids with great potential to open new avenues for predictive and preventive medicine. OBJECTIVE: To determine the lipid profile of patients with colorectal cancer and polyps. METHODS: Patients with stage I-III CRC, adenomatous polyps and individuals with normal colonoscopy were selected. All patients underwent peripheral blood collection for lipid extraction. The samples were analyzed by MALDI-MS technique for lipid identification. STATISTICAL ANALYSIS: Univariate and multivariate (principal component analysis [PCA] and discriminant analysis by partial least squares [PLS-DA]) analyses workflows were applied to the dataset, using MetaboAnalyst 3.0 software. The ions were identified according to the class of lipids using the online database Lipid Maps (http://www.lipidmaps.org). RESULTS: We included 88 individuals, 40 with CRC, 12 with polyps and 32 controls. Boxplot analysis showed eight VIP ions in the three groups. Differences were observed between the cancer and control groups, as well as between cancer and polyp, but not between polyps and control. The polyketide (810.1) was the lipid represented in cancer and overrepresented in polyp and control. Among the patients with CRC we observed differences between lipids with lymph node invasion (N1-2) compared to those without lymph node invasion (N). CONCLUSION: Possible lipid biomarkers were identified among cancer patients compared to control and polyp groups. The polyketide lipid (810.1) was the best biomarker to differentiate the cancer group from control and polyp. We found no difference between the biomarkers in the polyp group in relation to the control.

RESUMO CONTEXTO: O câncer colorretal (CCR) é, mundialmente, uma das principais causas de câncer. Métodos de diagnóstico precoce através de biomarcadores séricos são necessários. O estudo das ômicas, mais recentemente a lipidômica, tem a finalidade de analisar os lipídeos para melhor compreensão do lipidoma humano. A evolução dos métodos de espectrometria de massa, como a tecnologia por MALDI-MS, possibilitou a detecção e a identificação de uma ampla variedade de lipídeos com grande potencial para abrir novos caminhos para a medicina preditiva e preventiva. OBJETIVO: Determinar o perfil lipidômico de pacientes com câncer colorretal e pólipos. MÉTODOS: Foram selecionados pacientes com CCR estádio I-III, com pólipos adenomatosos e indivíduos com colonoscopia normal. Todos os pacientes foram submetidos a coleta do sangue periférico para extração do lipídeo. As amostras foram analisadas por técnica de MALDI-MS para a identificação dos lipídeos. ANÁLISE ESTATÍSTICA: Para análise univariada e multivariada foram utilizados a análise de componentes principais (PCA) e a análise discriminante pelos quadrados mínimos (PLS-DA). Os íons foram identificados de acordo com a classe de lipídeos usando-se o Lipid Maps (http://www.lipidmaps.org). RESULTADOS: Foram incluídos 88 indivíduos, 40 com CCR, 12 com pólipos e 32 controles. A análise de boxbolt evidenciou oito íons VIP nos três grupos. Observou-se diferenças entre os grupos câncer e controle, assim como entre câncer e pólipo, mas não entre pólipos e controle. O policetídeo (810,1) foi o lipídeo hipo-representado no câncer e hiperrepresentado no pólipo e controle. Entre os pacientes com CCR observamos diferenças entre os lipídeos com invasão linfonodal (N1-2) comparados aos sem invasão linfonodal (N0). CONCLUSÃO: Foram identificados possíveis biomarcadores lipídicos entre os pacientes com câncer comparados aos grupos controle e pólipo. O lipídeo policetídeo (810,1) foi o melhor biomarcador para diferenciar o grupo câncer do controle e pólipo. Não encontramos diferença entre os biomarcadores no grupo pólipo em relação ao controle.

Analysis of the Lipid Profile in Patients with Colorectal Cancer in Advanced Stages

Backgrounds: Colorectal (CRC) is one of the main cause of cancer worldwide. The search for noninvasive markers for diagnosis and monitoring as the use of analytical technologies such as mass spectrometry (MS), which allowed the search for lipid metabolites as candidates for probable biomarkers are needed. Objective and Methods: The objective was to establish the lipid profile of patients with locally advanced, unresectable or metastatic CRC. Peripheral blood was collected from patients with CRC and controls with normal colonoscopy. After lipid extraction, the samples were processed and analyzed in the MALDI TOF / TOF equipment. From the data matrix, the statistical analyzes were performed by the principal component analysis methods and the least squares discriminant analysis. The importance of the variable in the projection was used to identify the ions that had the greatest discriminatory effect between the groups. Results: Eight lipids were identified as potential biomarkers and a multiple logistic regression model was proposed to calculate the performance of the test where we observed values of AUC 0.87, sensitivity 88.33% and specificity 83.78% and for a validation test with 1,000 permutations a p <0.001. The classes of lipids found were sphingolipids, glycerophospholipids and policetidis. The strength of the association between the peak intensities of these lipids and the presence of CRC make these metabolites candidates for possible biomarkers. The sphingolipid (m / z = 742.98869) could be a biomarker in monitoring patients with CRC. In the survival analysis, three lipids showed a prognostic value for colorectal cancer, sphingolipid (m / z = 857.11525) and policetidis (m / z = 876.20796) and glycerophospholipid (m / z = 1031.54773).

[Role of the genetic polymorphism of p53 (codon 72) gene in colorectal cancer]. / Estudo do polimorfismo genético no gene p53 (códon 72) em câncer colorretal.

BACKGROUND: Polymorphisms are genetic variations that can occur in sequences of codons, leading to defective proteins. p53 is the most commonly gene affected in human cancer. The polymorphism of this gene occurs by a substitution of a base in codon 72 and may increase the risk of cancer. AIM: To investigate the possible association between p53 arginine/72 proline polymorphism and susceptibility to colorectal cancer. PATIENTS AND METHODS: This polymorphism was studied by polymerization chain reaction using specific primers in 100 patients with colorectal cancer paired by sex and age to 100 patients without cancer. Alcohol and tobacco used by all the patients and clinical aspects as stage, grade of differentiation and recurrence in the case group was compared with the genotype analyzed. RESULTS: The frequency of homozygosis for arginine was 56% in the cancer group and 58% in the control group. No significant difference was observed among both groups. This genotype was more frequent in colorectal cancer patients stage IV than in stage I (80% versus 14%). There was no significant difference between genotypes and alcohol, tobacco, grade of differentiation or recurrence. CONCLUSION: Homozygosity for arginine was the most prevalent genotype in both groups. The frequency of codon 72 proline/arginine p53 gene polymorphism was not correlated with a higher risk of colorectal cancer. Arginine/arginine genotype was more prevalent in advanced cancer patients (stage IV).

Estudo do polimorfismo genético no gene p53 (códon 72) em câncer colorretal / Role of the genetic polymorphism of p53 (codon 72) gene in colorectal cancer

RACIONAL: Polimorfismos genéticos são variações genéticas que podem ocorrer em seqüências codificadoras e não-codificadoras, levando a alterações qualitativas e/ou quantitativas das proteínas em questão. O p53 é o gene mais comumente alterado no câncer humano. O polimorfismo desse gene no códon 72 ocorre por substituição de uma base e tem sido associado a maior risco de câncer. OBJETIVO: Determinar a possível associação entre o polimorfismo no códon 72 (72 arginina/prolina) do gene p53 e câncer colorretal. CASUíSTICA E MÉTODOS: Foram avaliados em 100 pacientes com câncer colorretal e em 100 indivíduos sem câncer, pareados quanto ao sexo idade, o hábito de fumar, o etilismo e no grupo caso o estádio, o grau de diferenciação e a evolução da doença. O genótipo (72 arginina/prolina) foi determinado por PCR, utilizando-se primers (seqüências de nucleotídeos) específicos. RESULTADOS: O genótipo homozigoto arginina/arginina foi prevalente em 56 por cento no grupo controle e em 58 por cento no grupo caso. Não se observou diferença entre os dois grupos. No estádio IV este genótipo foi mais freqüente quando comparado ao estádio I (80 por cento versus 14 por cento). Não se observou diferença entre as variações do genótipo e fumo, álcool, evolução clínica ou grau de diferenciação. CONCLUSAO: A prevalência do genótipo arginina/arginina foi a mais freqüente nos dois grupos. Não foi encontrada correlação entre maior risco de câncer e o polimorfismo no códon 72 prolina/arginina do gene p53. Apesar do pequeno número de doentes com câncer em estádio avançado (IV), estes tiveram maior prevalência do genótipo arginina/arginina.