Identificação e estudo de biomarcadores personalizados para avaliação e seguimento de pacientes com câncer de reto tratados com quimioradioterapia neoadjuvante / Identification and study of personalized biomarkers for assessment and follow-up of patients with rectal cancer treated with neoadjuvant chemoradiotherapy

O tratamento padrão para pacientes com câncer de reto localmente avançado consiste no uso de quimioradioterapia neoadjuvante (QRTn), seguida por cirurgia. Uma fração significativa dos pacientes responde completamente ao tratamento e no momento da reavaliação não apresenta evidência clínica nem radiológica de doença. Uma abordagem alternativa, Watch and Wait, propõe não operar imediatamente esses pacientes e submetê-los a um protocolo de observação frequente, a fim de evitar as morbidades associadas à cirurgia. No entanto, a avaliação da resposta ao tratamento ainda é um desafio, devido à subjetividade da avaliação clínica e a ausência de exames radiológicos suficientemente sensíveis e específicos para garantir a ausência de células tumorais residuais ou capazes de detectar a recorrência precoce da doença. DNA circulante contendo alterações genéticas específicas do tumor (ctDNA) pode ser encontrado na fração livre de células do sangue e tem sido utilizado para monitorar a dinâmica tumoral em tumores sólidos. Avanços recentes das tecnologias de sequenciamento permitem a identificação eficiente e rápida e a um custo relativamente baixo de alterações genéticas em tumores individuais, superando o problema imposto pela ausência de alterações genéticas recorrentes nesses tumores. Essas alterações podem ser utilizadas como biomarcadores personalizados para monitorar a resposta ao tratamento, detectar doença residual e a recidiva precoce do tumor. O objetivo deste trabalho foi identificar e estudar biomarcadores personalizados em pacientes com câncer de reto localmente avançado tratados com QRTn e avaliar a capacidade desses biomarcadores para monitorar a dinâmica tumoral, e auxiliar na definição da conduta cirúrgica e na detecção da recidiva precoce da doença. Biópsias de seis pacientes com adenocarcinoma de reto distal (cT2- 3N0-1M0), foram coletadas prospectivamente pré-tratamento. O DNA genômico extraído a partir das biópsias foi usado para construir bibliotecas tipo mate-pair para o sequenciamento do genoma completo, utilizando a plataforma SOLiD. Rearranjos inter e intracromossômicos foram identificados utilizando programas computacionais desenvolvidos pelo nosso grupo de pesquisa e em seguida foram validados utilizando PCR e sequenciamento Sanger. Foram validadas, pelo menos, três variações estruturais para cada paciente. Amostras de plasma foram coletadas no momento do diagnóstico, depois da QRTn e durante o seguimento. DNA circulante total foi extraído a partir das amostras de plasma e ensaios personalizados foram desenvolvidos para monitorar a presença de variações estruturais através de PCR Digital. ctDNA foi detectado em todas amostras de plasma pré-tratamento de pacientes com tumores T3. A detecção desses biomarcadores apresentou boa correlação com a resposta ao tratamento, no entanto, esta abordagem não foi sensível o suficiente para detectar doença residual. Para dois pacientes que desenvolveram doença metastática foi verificado um aumento nos níveis de ctDNA com pelo menos 36 semanas antes do diagnóstico clínico de doença metastática, sendo possível correlacionar os níveis de ctDNA detectados em coletas subsequentes com a resposta ao tratamento sistêmico de segunda linha. Este estudo, embora de caráter exploratório, gerou dados relevantes e suficientes para justificar a realização de estudos adicionais para avaliar a aplicação dos biomarcadores personalizados na definição da conduta cirúrgica e no acompanhamento de pacientes com câncer de reto tratados com QRTn

The standard treatment for patients with locally advanced rectal cancer comprises in neoadjuvant chemo radiotherapy (nCRT), followed by surgery. A significant fraction of these patients show complete response to the treatment and at the time of reassessment, there are no clinical and nor radiological evidence of residual tumor. An alternative approach, Watch and Wait, proposes not to immediately operate these patients, but to submit them to a protocol of frequent observation in order to avoid the morbidities associated with radical surgery. However, assessment of treatment response remains a significant challenge due to the subjectivity of the clinical examination and to the lack of sufficiently sensitive tools to ensure the absence of tumor cells or to detect early disease recurrence. Circulating DNA carrying tumor-specific genetic alterations (circulating tumor DNA - ctDNA) can be found in the cell-free fraction of the blood and has been successfully used to monitor the tumor dynamics in solid tumors. Recent advances in sequencing technologies have enabled the rapid and cost effective identification of genetic alterations in individual tumors, overcoming the problem imposed by the absence of recurrent genetic alterations in these tumors. These alterations can be used as personalized biomarkers to monitor treatment response, detect residual disease and early tumor recurrence. The purpose of this work was to identify and validate the use of personalized biomarkers for patients with locally advanced rectal cancer treated with nCRT and to evaluate the ability of these biomarkers to monitor the tumor dynamics, to define surgical approach and to detect early recurrence of the disease. Pre-treatment biopsies from 6 patients with cT2-3N0-1M0 distal rectal adenocarcinoma were prospectively collected. Genomic DNA extracted from the biopsies was used to construct mate-pair libraries for whole genome sequencing using SOLiD platform. Inter and intrachromosomal rearrangements were identified using an in-house bioinformatics pipeline and validated using PCR amplification and Sanger sequencing. At least three structural variations were validated for each patient. Plasma samples were collect at diagnosis, after nCRT and follow-up. Circulating DNA was obtained from the plasma samples and personalized assays were designed to monitor the presence of structural variations using Droplet Digital PCR. ctDNA was detected in all pre-treatment plasma samples for patients with T3 tumors. The detection of these biomarkers showed a good correlation with the treatment response, nonetheless, the approach was not sensitive enough to detect residual disease. In two patients who developed metastatic disease, an increase in ctDNA levels was observed at least 36 weeks before clinical detection of metastatic disease, and it was possible to correlate the level of ctDNA in subsequent plasma samples with response to the second-line treatment. This study, although exploratory, generated relevant and sufficient data to support additional studies to evaluate the use of personalized biomarkers in the surgical management and follow-up of rectal cancer patients treated with nCRT

A Case of CD4+T-Cell Large Granular Lymphocytic Leukemia

We report here a case of a 59-yr-old man with CD4+ T-cell large granular lymphocytic leukemia (T-LGL). Peripheral blood examination indicated leukocytosis (45x10(9) cells/L) that consisted of 34% neoplastic lymphoid cells. Other laboratory results indicated no specific abnormalities except for serum antinuclear antibody titer (1:640), glucose (1.39 g/L), and hemoglobin A1c (7.7%) levels. Computed tomography indicated multiple small enlarged lymph nodes (<1 cm in diameter) in both the axillary and inguinal areas, a cutaneous nodule (1.5 cm in diameter) in the left suboccipital area, and mild hepatosplenomegaly. Bone marrow examination revealed hypercellular marrow that consisted of 2.4% neoplastic lymphoid cells. The neoplastic lymphoid cells exhibited a medium size, irregularly shaped nuclei, a moderate amount of cytoplasm, and large granules in the cytoplasm. Immunohistochemical analysis indicated CD3+, CD4+, T-cell receptor betaF1+, granzyme B+, and TIA1+. Flow cytometric analysis of the neoplastic lymphoid cells revealed CD3+, cytoplasmic CD3+, CD4+, and CD7+. Cytogenetic analysis indicated an abnormal karyotype of 46,XY,inv(3)(p21q27),t(12;17)(q24.1;q21),del(13)(q14q22)[2]/46,XY[28]. The patient was diagnosed with CD4+ T-LGL and received chemotherapy (10.0 mg methotrexate). This is the second case of CD4+ T-LGL that has been reported in Korea.

A Case of CD4+T-Cell Large Granular Lymphocytic Leukemia

We report here a case of a 59-yr-old man with CD4+ T-cell large granular lymphocytic leukemia (T-LGL). Peripheral blood examination indicated leukocytosis (45x10(9) cells/L) that consisted of 34% neoplastic lymphoid cells. Other laboratory results indicated no specific abnormalities except for serum antinuclear antibody titer (1:640), glucose (1.39 g/L), and hemoglobin A1c (7.7%) levels. Computed tomography indicated multiple small enlarged lymph nodes (<1 cm in diameter) in both the axillary and inguinal areas, a cutaneous nodule (1.5 cm in diameter) in the left suboccipital area, and mild hepatosplenomegaly. Bone marrow examination revealed hypercellular marrow that consisted of 2.4% neoplastic lymphoid cells. The neoplastic lymphoid cells exhibited a medium size, irregularly shaped nuclei, a moderate amount of cytoplasm, and large granules in the cytoplasm. Immunohistochemical analysis indicated CD3+, CD4+, T-cell receptor betaF1+, granzyme B+, and TIA1+. Flow cytometric analysis of the neoplastic lymphoid cells revealed CD3+, cytoplasmic CD3+, CD4+, and CD7+. Cytogenetic analysis indicated an abnormal karyotype of 46,XY,inv(3)(p21q27),t(12;17)(q24.1;q21),del(13)(q14q22)[2]/46,XY[28]. The patient was diagnosed with CD4+ T-LGL and received chemotherapy (10.0 mg methotrexate). This is the second case of CD4+ T-LGL that has been reported in Korea.

Espresión de enzima metalproteinasa de matriz 2 (MPM-2) en células prostáticas en circulación sanguínea (CPCS) en pacientes con cáncer prostático: estudio utilizando inmunocitoquímica / Expression of matrix metalproteinasa enzyme 2 (MPM-2) in prostate cells in blood circulation (CPCS) in men with prostate cancer: an immunocytochemistry study

La metaloproteinasa de matriz-2 (MPM-2) es una gelatinasa implicada en el proceso de metástasis. Las células que expresan MPM-2pueden cruzar la matriz extracelular y diseminarse a los tejidos distantes. Presentamos un estudio de la detección de células prostáticas en la circulación sanguínea y la expresión de MPM-2 en varones con cáncer prostático antes y después de una prostatectomía radical. Método y pacientes: Estudio prospectivo, multicéntrico, de pacientes atendidos en el Hospital de Carabineros de Chile, INRAD y el Instituto de Bío-Oncología, entre los años 2006 y 2008. Después de un consentimiento informado por escrito, 4 ml de sangre venosa fueron obtenidos. Las células mononucleares fueron aisladas por centrifugación diferencial y la CPCs detectadas con anti-PSA e identificadas mediante inmunocitoquímica con un sistema basado en fosfatasa alcalina con neofuscina como cromógeno. Las muestras positivas tuvieron un segundo proceso con anti-MPM-2, un sistema de detección basado en peroxidasa y Vector VIP como cromogen. Detalles de la etapa, la edad y nivel de APE sérico fueron registrados. Resultados: 105 pacientes participaron, 30 pretratamiento y 75 postratamiento, con una edad promedio de 71,3 +/- 8,4 años. Existió una asociación entre la frecuencia de detección de CPCs, la etapa clínica y el índice de Gleason. Todas las CPCs expresaron MPM-2. Conclusiones: Los resultados confirman que la expresión de MPM-2 tiene un papel importante en la 1a y 2a diseminación de células cancerosas y no hay una asociación de los otros factores pronóstico. La presencia de las CPCs no implica la presencia de micrometástasis ni su origen de diseminación en el 2o caso de CPCs, pero implica un riesgo más elevado de la enfermedad micrometastásica. Su detección podría ser útil durante el seguimiento para la detección precoz de estos pacientes.

Objective: Matrix metalloproteinase-2 is a gelatinase implicated in the metastatic process. Cells expressing MMP-2 can cross the extracellular matrix and disseminate to other tissues. We present a study of MMP-2 express of circulating prostate cells in men with prostate cancer. Methods and Patients: A prospective, multicenter study of men with prostate cancer attending the Hospital de Carabineros de Chile, INRAD and the Instituto de BioOncología between 2006 and 2008. After written informed consent a 4 ml blood sample was taken, mononuclear cells were obtained using differential centrifugation and CPCs identified using immunocytochemistry. Positive samples with PSA staining cells underwent a second process with anti-MPM-2. Age, clinical stage, serum PSA were noted for each patient. Results: 105 patients entered the study, 30 pre-treatment and 75 post treatment, with an average age of 71.3 +/- 8.4 years. There was an association with CPC detection frequency with clinical stage and Gleason score. All CPCs expressed MMP-2. Conclusions: The results indicate that MMP-2 expression is important in the dissemination of primary and secondary prostate cancer cells, that there is no association between prognostic factors and MMP-2 expression in CPCs. The presence of CPCs does not imply the presence of micrometastasis nor origin of dissemination in the case of 2nd CPCs but the presence implies a higher risk of micrometastasis. The detection of these cells could be a useful tool in the follow up of patients with prostate cancer.

Identification of Enhancer of Zeste Homolog 2 Expression in Peripheral Circulating Tumor Cells in Metastatic Prostate Cancer Patients: A Preliminary Study

PURPOSE: Enhancer of zeste homolog 2 (EZH2), a kind of transcriptional repressor, is reportedly over-expressed in metastatic prostate cancer. In this study, we analyzed EZH2 mRNA in circulating tumor cells (CTCs) in peripheral blood as a biomarker in patients with metastatic prostate cancer. PATIENTS AND METHODS: Ber-EP4 coated immunomagnetic beads were used to harvest CTCs, and mRNA was isolated by oligo- dT conjugated immunomagnetic beads. Reverse transcriptase- polymerase chain reaction for EZH2 mRNA was performed and the expression density was measured. The sensitivity of this test for detection of EZH2 mRNA was determined by serial dilutions of a human prostate cancer cell line. Blood samples were collected from 20 patients each with metastatic or localized prostate cancer and 10 healthy volunteers. RESULTS: Sensitivity experiments showed that the test was highly sensitive as it could detect 10 tumor cells per 5mL. EZH2 mRNA expression was obtained from peripheral blood samples of patients and control subjects. EZH2 mRNA expression density in the metastatic prostate cancer group was significantly higher than in the control (p=0.023) and localized prostate cancer groups (p=0.019). There was no difference between the control and localized prostate cancer groups (p > 0.05). CONCLUSION: EZH2 mRNA expression in circulating epithelial cells represents a promising marker for detecting early metastasis in prostate cancer. However, more specific and sensitive techniques for detection of CTCs are needed to avoid mononuclear cell contamination.

Avaliaçäo da atividade citotóxica, antiviral e antimicrobiana de Apocynaceae amazônicas / Evaluation of the activity cytotoxic, antiviral and antimicrobial of Apocynaceae Amazonian

A necessidade de se introduzir novos fármacos quimioterápicos é patente. Para tanto, a modelagem molecular, a terapia gênica e os produtos naturais têm sido os caminhos escolhidos para a obtenção de novas moléculas. As florestas brasileiras estão entre os principais celeiros de biodiversidade, grande parte não estudada do ponto de vista fitoquímico e farmacológico. Isso implica em grandes possibilidades de identificação de novos fármacos, uma vez que a riqueza da biodiversidade biológica pode ser refletida na riqueza da biodiversidade química. Trinta e oito extratos provenientes de espécies de Apocynaceae foram submetidos a um estudo de triagem farmacológica antiviral, antimicrobiana e citotoxicidade, in vitro...