Detección de mutaciones en el dominio tirosina quinasa de BCR-ABL1 en pacientes colombianos con leucemia mieloide crónica LMC, resistentes al imatinib / Detection of BCR-ABL1 tyrosine kinase domain mutations in chronic myeloid leukaemia patients with Imatinib resistance in Colombia

Resumen Introducción: Las mutaciones en el dominio BCR-ABL1, tirosina quinasa (TK) son mecanismos importantes de resistencia de los inhibidores de la tirosina quinasa (ITK) en pacientes con leucemia mieloide crónica (LMC). Objetivo: Determinar el tipo y la frecuencia de las mutaciones en el dominio tirosina quinasa del gen BCR-ABL1, asociadas con falla en la respuesta al tratamiento con imatinib en pacientes con LMC y correlacionar el perfil de mutaciones con los hallazgos clínicos, demográficos, respuesta citogenética y respuesta molecular. Materiales y métodos: Se realizó un estudio descriptivo de tipo prospectivo en pacientes con LMC en tratamiento con IMATINIB a quienes se les realizó cariotipo y análisis de mutaciones del dominio BCR-ABL1 mediante la técnica de PCR anidada. Resultados: De los 23 pacientes estudiados en cuatro se encontraron mutaciones: dos presentaron la mutación E255K, uno presentó la mutación H396P y otro presentó doble mutación L387L y T389P. Las mutaciones E255K que se ubican en la región P-loop y H396P en A-loop se asocian con mal pronóstico. La mutación T389P localizada en la región A-loop no está informada en algunas bases de datos. Conclusiones: En este estudio encontramos cuatro mutaciones en el dominio tirosina quinasa (E255K, H396P, L387L y T389P) que podrían aportar información valiosa y guiar las decisiones de tratamiento. Es importante destacar que esta investigación de análisis mutacional del dominio BCR-ABL es la primera que se realiza en el país con la particularidad adicional de cubrir una población triétnica.

Abstract Mutations in the BCR-ABL1 tyrosine kinase domain mutations, are one of the principal mechanisms associated with tyrosine kinase inhibitors (TKI) resistance in patients with chronic myeloid leukaemia (CML). Objectives: To determine the type and frequency of mutations in the tyrosine kinase domain of the BCR-ABL1 gene associated with failure to respond to treatment with Imatinib and Imatinib in patients with CMK, and to correlate the mutation profile with the clinical and demographic variables, as well as the cytogenetic and molecular response. Materials and methods: A descriptive prospective study was carried out on patients with CML treated with Imatinib. Karyotyping and analysis of the BCR-ABL1 domain mutations were performed on the patients using nested PCR. Results: Four types of mutations were found in the 23 patients studied, of which two of them were the E225 mutation, one with the H396P mutation, another with a double mutation L387L and T389P. Both the E255K mutation located in the P-loop region, and H396P mutation in the A-loop region, are associated with a poor prognosis. The T389P mutation located within A-loop region has not been reported in any of the databases. Conclusions: Four mutations were found in the tyrosine kinase domain (E255K, H396P, L387L and T389P) were found in this study. These findings provide valuable information and as a guideline to help make treatment decisions. It is important to point out that this analytical study on mutations of the BCR-ABL domain is the first one carried out in the country and, specifically, in a tri-ethnic population.

[Mutagenicity, genotoxicity and gene expression of Rad51C, Xiap, P53 and Nrf2 induced by antimalarial extracts of plants collected from the middle Vaupés region, Colombia].

INTRODUCTION: Due to Plasmodium resistance to antimalarial drugs, it is important to find new therapeutic alternatives for malaria treatment and control. Based on the knowledge of Colombian indigenous communities, we collected extracts of plants with potential antimalarial effects from the middle Vaupés region. OBJECTIVE: To evaluate the mutagenic and genotoxic effects, as well as the gene expression of Rad51C, Xiap, P53 and Nrf2 induced by four ethanolic extracts with antimalarial activity (R001, T002, T015 and T028). MATERIALS AND METHODS: We evaluated four ethanolic extracts with antimalarial activity using the Ames test to assess mutagenicity, and the comet assay on HepG2 cells to determine the genotoxicicity. We also evaluated the expression of Rad51C, Xiap, P53 and Nrf2 from HepG2 cells stimulated with the four extracts. RESULTS: None of the four extracts was mutagenic in Salmonella typhimurium TA98 strain in the presence and absence of S9 metabolic activity. Extracts R001, T015 and T028 were weakly mutagenic on the TA100 strain in the presence of S9, with mutagenic indexes (MI) of 1.58, 1.53 and 1.61, respectively. The T015 strain showed the same behavior without S9 with an MI of 1.36. The results of the comet assay showed that the four extracts produced category 1 or 2 damage, with comets between 36.7 and 51.48 µm in length. However, the genetic damage index suggested that most of the cells were affected by the treatments. Regarding gene expression, extracts R001 and T028 induced an overexpression of genes Xiap and P53 with an 1.84 to 3.99 fold-change compared with untreated cells. CONCLUSIONS: These results revealed that the T002 extract was the safest as it had antimalarial activity and was not cytotoxic on HepG2 cells. Moreover, it was not mutagenic and it only produced category 1 damage on the DNA. Also, the extract did not induce a change in the expression of the tested genes.

Efecto mutagénico y genotóxico, y expresión de los genes Rad51C , Xiap , P53 y Nrf2 inducidos por extractos antipalúdicos de plantas recolectadas en el Vaupés medio, Colombia / Mutagenicity, genotoxicity and gene expression of Rad51C, Xiap, P53 and Nrf2 induced by antimalarial extracts of plants collected from the middle Vaupés region, Colombia

Resumen Introducción. Dada la resistencia de Plasmodium a los medicamentos antipalúdicos, es necesario encontrar nuevas alternativas terapéuticas para su tratamiento y control. Con base en el saber indígena colombiano, se recopilaron extractos de plantas del Vaupés medio con potencial efecto antipalúdico. Objetivo. Evaluar el efecto mutagénico y genotóxico, y la expresión de los genes Rad51C, Xiap, P53 yNrf2, inducidos por cuatro extractos etanólicos con actividad anti-Plasmodium(R001, T002, T015 y T028). Materiales y métodos. Se evaluó el potencial mutagénico de cuatro extractos etanólicos con efecto antiplasmódico utilizando el test de Ames y el efecto genotóxico, con un ensayo del cometa; asimismo, se analizó la expresión de los genes Rad51C, Xiap, P53 y Nrf2 en células HepG2. Resultados. Los extractos no fueron mutágenos en la cepa TA98 de Salmonella typhimurium en presencia y ausencia de actividad metabólica de la fracción S9. En la cepa TA100, los extractos R001, T015 y T028 se comportaron como mutágenos débiles en presencia de S9, con índices mutagénicos de 1,58; 1,38; 1,53 y 1,61, respectivamente; T015 tuvo el mismo comportamiento en ausencia de S9, con un índice mutagénico de 1,36. En el ensayo del cometa, todos los extractos provocaron daño de categorías 1 o 2, con colas de cometas entre 36,7 y 51,48 µm de longitud; sin embargo, el índice dedaño genético sugirió que los tratamientos afectaron la mayoría de las células. En los genes en estudio, los extractos R001 y T028 indujeron una sobreexpresiónde 1,84 a 3,99 frente a las células sin tratar de los genes Xiap y P53. Conclusiones. Los resultados evidenciaron que el extracto T002 fue el más seguro, ya que presentó actividad anti-Plasmodium, no fue citotóxico en las células HepG2, no fue mutágeno, causó daño de categoría 1 en el ADN y no modificó la expresión de los genes evaluados.

Abstracts Introduction: Due to Plasmodium resistance to antimalarial drugs, it is important to find new therapeutic alternatives for malaria treatment and control. Based on the knowledge of Colombian indigenous communities, we collected extracts of plants with potential antimalarial effects from the middle Vaupés region. Objective: To evaluate the mutagenic and genotoxic effects, as well as the gene expression of Rad51C, Xiap, P53 and Nrf2 induced by four ethanolic extracts with antimalarial activity (R001, T002, T015 and T028). Materials and methods: We evaluated four ethanolic extracts with antimalarial activity using the Ames test to assess mutagenicity, and the comet assay on HepG2 cells to determine the genotoxicicity. We also evaluated the expression of Rad51C, Xiap, P53 and Nrf2 from HepG2 cells stimulated with the four extracts. Results: None of the four extracts was mutagenic in Salmonella typhimurium TA98 strain in the presence and absence of S9 metabolic activity. Extracts R001, T015 and T028 were weakly mutagenic on the TA100 strain in the presence of S9, with mutagenic indexes (MI) of 1.58, 1.53 and 1.61, respectively. The T015 strain showed the same behavior without S9 with an MI of 1.36. The results of the comet assay showed that the four extracts produced category 1 or 2 damage, with comets between 36.7 and 51.48 µm in length. However, the genetic damage index suggested that most of the cells were affected by the treatments. Regarding gene expression, extracts R001 and T028 induced an overexpression of genes Xiap and P53 with an 1.84 to 3.99 fold-change compared with untreated cells. Conclusions: These results revealed that the T002 extract was the safest as it had antimalarial activity and was not cytotoxic on HepG2 cells. Moreover, it was not mutagenic and it only produced category 1 damage on the DNA. Also, the extract did not induce a change in the expression of the tested genes.

Frecuencia de los transcriptos p190BCR-ABL y p210BCR-ABL en una población colombiana con leucemia mieloide crónica (LMC) usando RT-PCR cualitativa / Detection of p190BCR-ABL AND p210BCR-ABL fusion transcripts in patients with chronic myeloid leukemia (CML) using qualitative RT-PCR / Frequência dos transcritos p190BCR-ABL e p210BCR- ABL numa população colombiana com leucemia mielóide crônica (LMC) usando RT-PCR qualitativa

Introducción: la leucemia mieloide crónica (LMC) se caracteriza por la presencia del cromosoma Filadelfia (Ph) que resulta de la translocación recíproca balanceada t(9;22)(q34;q11); este marcador cromosómico se encuentra con menor frecuencia en pacientes con leucemia linfoide aguda (LLA). Objetivo: determinar la frecuencia de las fusiones génicas BCR-ABL, que codifican para los transcriptos p210BCR-ABL y p190 BCR-ABL en pacientes colombianos con diagnóstico de LMC, en diferentes fases de la enfermedad o de su tratamiento. Materiales y métodos: estudio descriptivo de corte transversal de 31 pacientes con LMC (15-78 años). El análisis se hizo a partir de muestras de sangre periférica con la técnica PCR anidada cualitativa para las isoformas P210 BCR-ABL (b3a2 e b2a2) y P190 BCR-ABL (e1a2). Resultados: se detectó el transcripto p210BCR-ABL en 29 de los 31 casos (93,6%). En ellos se identificaron las fusiones génicas b2a2 (16/29; 55,2%), b3a2 (10/29; 34,5%) y la coexpresión b3a2 y b2a2 (3/29; 10,3%). Conclusión: la fusión génica b2a2 fue la más frecuente en esta población con LMC.

Introduction: Chronic myelogenous leukemia (CML) is characterized by the presence of the Philadelphia chromosome (Ph), resulting from the balanced reciprocal translocation t(9;22)(q34;q11). This marker chromosome is found less frequently in patients suffering from acute lymphoblastic leukemia. Objective: To determine the frequency of BCR-ABL gene fusions encoding the p210BCR-ABL y p190 BCR-ABL transcripts in Colombian patients diagnosed with CML in different stages of the disease and/or its treatment. Materials and methods: Cross sectional, descriptive study of thirty one CML patients (aged 15-78). Analysis was carried out through qualitative nested PCR for the isoforms P210 BCR-ABL (b3a2 e b2a2) and P190 BCR-ABL (e1a2), and based on peripheral blood samples. Results: In 29 of the 31 patients (93.6%) transcript p210BCR-ABL was detected; b2a2 and b3a2 gene fusions and the coexpression b3a2 y b2a2 were identified in 55.2% (16/29), 34.5% (10/29) and 10.3% (3/29) of the cases, respectively. Conclusion: b2a2 gene fusion was the most frequent in this CML population.

Introdução: a leucemia mielóide crônica (LMC) caracteriza- se pela presença do cromossomo Filadélfia (Ph) que resulta da translocação recíproca balanceada t(9;22)(q34;q11); este marcador cromossômico se encontra com menor frequência em pacientes com leucemia linfoide aguda (LLA). Objetivo: determinar a frequência das fusões genéticas BCR-ABL, que codificam para os transcritos p210BCR-ABL e p190 BCR-ABL em pacientes colombianos com diagnóstico de LMC, em diferentes fases da doença ou de seu tratamento. Materiais e métodos: estudo descritivo de corte transversal de 31 pacientes com LMC (15-78 anos). A análise se fez a partir de mostras de sangue periférico com a técnica PCR aninhada qualitativa para as isoformas P210 BCR-ABL (b3a2 e b2a2) e P190 BCR-ABL (e1a2). Resultados: detectou-se o transcrito p210BCR-ABL em 29 dos 31 casos (93,6%). Neles se identificaram as fusões genéticas b2a2 (16/29; 55,2%), b3a2 (10/29; 34,5%) e a co-expressão b3a2 e b2a2 (3/29; 10,3%). Conclusão: a fusão genética b2a2 foi a mais frequente nesta população com LMC.

Expresión diferencial de proteínas en Leishmania (Viannia) panamensis asociadas con mecanismos de resistencia a antimoniato de meglumina / Differential expression of proteins in Leishmania (Viannia) panamensis associated with mechanisms of resistance to meglumine antimoniate.

Introducción. Los mecanismos de resistencia al antimonio pentavalente conocidos hasta el momento, se han descrito ampliamente en cepas del subgénero Leishmania, pero poco se sabe sobre las proteínas involucradas en los mecanismos de resistencia presentes en cepas del subgénero Viannia, como Leishmania panamensis. Objetivo. Identificar proteínas diferencialmente expresadas entre las cepas de L. panamensis (UA140), sensible y resistente al antimonio pentavalente, y analizar el posible papel de estas proteínas en mecanismos de resistencia. Materiales y métodos. Las proteínas de las cepas, sensible y resistente al antimonio pentavalente, se compararon usando electroforesis bidimensional. Las proteínas con aumento de la expresión fueron aisladas e identificadas por espectrometría de masas mediante MALDI-TOF/TOF (Matrix Assisted Laser Desorption Ionization/Time of Flight). La expresión del ARNm de cinco de estas proteínas se cuantificó mediante PCR en tiempo real. Resultados. Los geles bidimensionales de las cepas sensible y resistente detectaron 532±39 y 541±43 manchas proteicas. Se encontraron 10 manchas con aumento de la expresión en la cepa resistente, identificadas como proteínas de choque térmico (Hsp60 mitocondrial, Hsp70 mitocondrial y citosólica), isomerasa de disulfuro, proteasa de cisteína, enolasa, factor de elongación 5-α, la subunidad 5-α del proteasoma y dos proteínas hipotéticas nombradas como Sp(2) y Sp(25). Conclusión. Este es el primer estudio llevado a cabo con una cepa resistente al antimonio pentavalente en L. panamensis, en el cual se han identificado proteínas que están relacionadas con el mecanismo de resistencia del parásito frente al medicamento, abriendo el camino para futuros estudios de estas proteínas como blancos terapéuticos.

Introduction. The well-known drug resistance mechanisms to pentavalent antimony have been widely described in strains of the Leishmania subgenus, but little is known about the mechanisms of resistance and the proteins associated with it in strains of the Viannia subgenus such as Leishmania panamensis. Objective. Differentially expressed proteins were identified between pentavalent antimonial sensitive and resistant L. panamensis (UA140) strains, and the role of these proteins was analyzed as possible resistance mechanisms. Materials and methods. The protein lysates of pentavalent antimony sensitive and resistant strains were separated by two-dimensional gel electrophoresis,and the protein patterns compared. The proteins identified as overexpressed were separated and analyzed using MALDI-TOF/TOF (Matrix Assisted Laser Desorption Ionization/Time of Flight). The level of mRNA expression of five of these proteins was quantified using real-time PCR. Results. On the 2-dimensional gels, 532 ± 39 protein spots were identified for the sensitive strains, and 541 ± 43 spots for the resistant strains. Ten spots were overexpressed in the resistant strain and identified as heat shock protein (Hsp60 mitochondrial, Hsp70 cytosolic and mitochondrial), disulfide isomerase, cysteine protease, enolase, elongation factor 5-alpha, the proteasome alpha-5 subunit and two hypothetical proteins named as Sp(2) and Sp(25). Conclusion. This is the first proteomic study conducted with a L. panamensis resistant strain where several proteins were identified and related with the parasite resistance mechanism to pentavalent antimony. This opens the way for future studies aimed at modulating the drug resistance or at evaluating these proteins as therapeutic targets.

[Differential expression of proteins in Leishmania (Viannia) panamensis associated with mechanisms of resistance to meglumine antimoniate]. / Expresión diferencial de proteínas en Leishmania (Viannia) panamensis asociadas con mecanismos de resistencia a antimoniato de meglumina.

INTRODUCTION: The well-known drug resistance mechanisms to pentavalent antimony have been widely described in strains of the Leishmania subgenus, but little is known about the mechanisms of resistance and the proteins associated with it in strains of the Viannia subgenus such as Leishmania panamensis. OBJECTIVE: Differentially expressed proteins were identified between pentavalent antimonial sensitive and resistant L. panamensis (UA140) strains, and the role of these proteins was analyzed as possible resistance mechanisms. MATERIALS AND METHODS: The protein lysates of pentavalent antimony sensitive and resistant strains were separated by two-dimensional gel electrophoresis,and the protein patterns compared. The proteins identified as overexpressed were separated and analyzed using MALDI-TOF/TOF (Matrix Assisted Laser Desorption Ionization/Time of Flight). The level of mRNA expression of five of these proteins was quantified using real-time PCR. RESULTS: On the 2-dimensional gels, 532 ± 39 protein spots were identified for the sensitive strains, and 541 ± 43 spots for the resistant strains. Ten spots were overexpressed in the resistant strain and identified as heat shock protein (Hsp60 mitochondrial, Hsp70 cytosolic and mitochondrial), disulfide isomerase, cysteine protease, enolase, elongation factor 5-alpha, the proteasome alpha-5 subunit and two hypothetical proteins named as Sp(2) and Sp(25). CONCLUSION: This is the first proteomic study conducted with a L. panamensis resistant strain where several proteins were identified and related with the parasite resistance mechanism to pentavalent antimony. This opens the way for future studies aimed at modulating the drug resistance or at evaluating these proteins as therapeutic targets.

[Molecular and immunological analyses suggest the absence of hydrophilic surface proteins in Leishmania (Viannia) panamensis]. / El análisis molecular y el inmunogénico sugieren la ausencia de las proteínas hidrofílicas de superficie en Leishmania (Viannia) panamensis.

INTRODUCTION: The genus Leishmania is divided into two subgenera: Leishmania and Viannia. The two subgenera present several important differences such as the pathology they cause in susceptible hosts, their in vitro growth behavior, their genetic characteristics, and the expression pattern of several proteins, including those of the hydrophilic surface protein family. OBJECTIVE: To characterize the hydrophilic surface protein family in Leishmania (Viannia) panamensis. MATERIALS AND METHODS: The hasp genes were amplified in L. (V.) panamensis, using specific primers previously designed to amplify this gene in Leishmania (Leishmania) major. The PCR products were cloned, sequenced, and the sequences analyzed using common bioinformatics tools. Secondly, a serological screening was undertaken with an enzyme-linked immunosorbent assay and Western blot to detect specific antibodies against the hydrophilic surface recombinant protein from L. (L.) major. RESULTS: A copy of a pseudogene was amplified in L. (V.) panamensis which was 60% homologous with the L. (L.) major orthologous gene. Antibodies responded to the hydrophilic surface recombinant proteins only in sera from patients with visceral leishmaniasis [Leishmania (Leishmania) chagasi]. CONCLUSION: These results suggest the lack of a functional hasp gene in L. (V.) panamensis, suggesting probably the loss of the complete gene family in this species of the Viannia subgenus.

El análisis molecular y el inmunogénico sugieren la ausencia de las proteínas hidrofílicas de superficie en Leishmania (Viannia) panamensis / Molecular and immunological analyses suggest the absence of hydrophilic surface proteins in Leishmania (Viannia) panamensis

Introducción. Los dos subgéneros en los cuales se divide el género Leishmania: Viannia y Leishmania, presentan diferencias significativas en las manifestaciones clínicas que causan, en su comportamiento de crecimiento en cultivos in vitro, en sus características genéticas y en la expresión de varias proteínas, entre ellas las de la familia hidrofílica de superficie superficie. Objetivo. Caracterizar las proteínas hidrofílicas de superficie en Leishmania (Viannia) panamensis. Materiales y métodos. Se amplificaron los genes hasp en L. (V.) panamensis usando cebadores específicos para la especie Leishmania (Leishmania) major. Los productos de la amplificación fueron clonados, secuenciados y analizados con herramientas bioinformáticas. Posteriormente, se realizó un análisis serológico por medio de ensayo inmunoabsorbente ligado a enzimas y Western blot para detectar la presencia de anticuerpos específicos contra las proteínas hidrofílicas recombinantes de superficie de L. (L.) major en sueros de pacientes con leishmaniasis de zonas endémicas de Colombia. Resultados. Se encontró una copia de un pseudogen en L. (V.) panamensis, el cual presentó una identidad del 60 por ciento con el gen haspa de L. (L.) major. Sólo se encontraron anticuerpos contra las proteínas recombinantes de superficie hidrofílicas en sueros de pacientes con leishmaniasis visceral. Conclusión. Estos resultados sugieren que no existe ninguna copia de un gen funcional hasp en L. (V.) panamensis, lo que indica una pérdida de la familia de genes en esta especie de Leishmania perteneciente al subgénero Viannia.

Diversidad genética de Plasmodium falciparum y sus implicaciones en la epidemiología de la malaria / Genetic diversity of Plasmodium falciparum and its implications in the epidemiology of

La diversidad genética le confiere a Plasmodium falciparum la capacidad de evadir la respuestainmune del hospedero y producir variantes resistentes a medicamentos y a vacunas, aspectos que juegan un papel importante en el establecimiento de medidas de control contra la malaria. Diferentes autores han documentado la existencia de diversas cepas o clones de P. falciparum, cuya diversidad genética se ha confirmado a través de distintos ensayos de PCR (reacción en cadena de la polimerasa). Numerosas investigaciones realizadas en poblaciones con diferente grado de transmisión de malaria han mostrado la relación existente entre la estructura de la población de P. falciparum y la epidemiología de la enfermedad. En este artículo se describen las fases del ciclo de vida en las que los eventos de recombinación originan la diversidad genética de P. falciparum, se revisan los estudios realizados sobre este aspecto en regiones con diferentes grados de endemicidad, así como sobre sus implicaciones en la adquisición de inmunidad y en el desarrollo de medidas de control

[Genetic diversity of Plasmodium falciparum and its implications in the epidemiology of malaria]. / Diversidad genética de Plasmodium falciparum y sus implicaciones en la epidemiología de la malaria.

Genetic diversity provides Plasmodium falciparum with the potential capacity of avoiding the immune response, and possibly supporting the selection of drug or vaccine resistant parasites. These genetic characters play key roles in the selection of appropriate malaria control measures. Diverse clones of Plasmodium falciparum, often denoted as strains, has been documented, and the degree of genetic diversity supported by several kinds of PCR (polymerase chain reaction) assays. Many studies in different endemic regions with differences in their level of disease transmission have clarified the interactions between the parasite populations and malaria epidemiology. This paper describes recombination events of the malaria parasite life cycle that originate such genetic diversity in P. falciparum, reviewing different studies on this aspect and its implications in the immunity and development of control measures in regions with different degrees of endemicity.