Búsqueda de mutaciones en el gen hGH-N en pacientes con deficiencia de hormona del crecimiento humano

Tesis (Maestría en Ciencias con Especialidad en Biología Moleculare Ingeniería Genética) UANLUANLhttp://www.uanl.mx

Detección de microRNAs extracelulares y su potencial como biomarcadores moleculares

RESUMEN Los microRNAs (miRNAs) son moléculas de RNA de 18 a 24 nucleótidos de longitud involucrados en la regulación de la expresión génica a nivel postranscripcional en la célula. En este trabajo analizamos la expresión de miRNAs en muestras de tejido y suero de pacientes con cáncer mamario, y este perfil permite distinguir pacientes con cáncer de mama y mujeres sanas con alta sensibilidad, especificidad y eficiencia. La combinación de dos miRNAs para tejido y tres para suero, usados en conjunto como un solo grupo, eleva significativamente la eficiencia de la prueba, y demuestra que los miRNAs tienen gran potencial como nuevos biomarcadores no invasivos en cáncer de mama. Adicionalmente, se realizó la búsqueda de miRNAs en el protozoario Entamoeba histolytica, por secuenciación profunda, lo que permitió realizar la primera descripción de miRNAs en este parásito. Se identificaron 199 miRNAs exclusivos para este parásito, que servirán de base para el estudio de la regulación génica en E. histolytica y el establecimiento de nuevos biomarcadores para la amibiasis. ABSTRACT MicroRNAs (miRNAs) are 18 to 24 nucleotide-long RNA molecules responsible for the regulation of gene expression at the post-transcriptional level in the cell. In this work, we analyzed the expression of miRNAs in tissue samples and serum of patients with breast cancer and we found that miRNA expression patterns distinguish patients with breast cancer from healthy women with high sensitivity, specificity, and efficiency. The combination of 2 and 3 miRNAs used as a group in tissue and serum respectively, significantly increases the efficiency of the test and shows that miRNAs have potential as novel noninvasive biomarkers in breast cancer detection. Additionally, miRNAs were detected by deep sequence in the protozoan parasite Entamoeba histolytica, which allowed the first description of miRNAs in this parasite. We identified 199 new miRNAs in E. histolytica, which are the base for the study of gene regulation and the establishment of new biomarkers for amoebiasis

Serum circulating microRNA profiling for identification of potential breast cancer biomarkers

Abstract. MicroRNAs (miRNAs) are a class of small, non-coding RNA molecules that can regulate gene expression, thereby affecting crucial processes in cancer development. miRNAs offer great potential as biomarkers for cancer detection because of their remarkable stability in blood and their characteristic expression in different diseases. We investigated whether quantitative RT-PCR miRNA profiling on serum could discriminate between breast cancer patients and healthy controls. We performed miRNA profiling on serum from breast cancer patients, followed by construction of ROC (Receiver Operating Characteristic) curves to determine the sensitivity and specificity of the assay. We found that seven miRNAs (miR-10b, miR-21, miR-125b, miR-145, miR-155 miR-191 and miR-382) had different expression patterns in serum of breast cancer patients compared to healthy controls. ROC curve analyses revealed that three serum miRNAs could be valuable biomarkers for distinguishing BC from normal controls. Additionally, a combination of ROC curve analyses of miR-145, miR-155 and miR-382 showed better sensitivity and specificity of our assay. miRNA profiling in serum has potential as a novel method for breast cancer detection in the Mexican population

Circulating microRNA expression profile in B-cell acute lymphoblastic leukemia

BACKGROUND: Acute lymphoblastic leukemia (ALL) is a highly diverse disease characterized by cytogenetic and molecularabnormalities, including altered microRNA (miRNA) expression signatures. AIM: We perform and validate a plasma miRNA expression profiling to identify potential miRNA involved in leukemogenesis METHODS: MiRNA expression profiling assay was realized in 39 B-ALL and 7 normal control plasma samples using TaqMan Low Density Array (TLDA) plates on Applied Biosystems 7900 HT Fast Real-Time PCR System. MiRNA validation was done for six miRNA differentially expressed by quantitative real-time PCR. RESULTS: Seventy-seven circulating miRNA differentially expressed: hsa-miR-511, -222, and -34a were overexpressed, whereas hsa-miR-199a-3p, -223, -221, and -26a were underexpressed (p values < 0.005 for both sets). According to operating characteristic curve analysis, hsa-miR-511 was the most valuable biomarker for distinguishing B-ALL from normal controls,with an area under curve value of 1 and 100% for sensitivity, and specificity respectively. CONCLUSIONS: Measuring circulating levels of specific miRNA implicated in regulation of cell differentiation and/or cell proliferation such as hsa-miRNA-511, offers high sensitivity and specificity in B-ALL detection and may be potentially useful for detection of disease progression, as indicator of therapeutic response, and in the assessment of biological and/or therapeutic targets for patients with B-ALL

Evidence of transfer of miRNAs from the diet to the blood still inconclusive

MicroRNAs (miRNAs) are short, non-coding, single-strand RNA molecules that act as regulators of gene expression in plants and animals. In 2012, the first evidence was found that plant miRNAs could enter the bloodstream through the digestive tract. Since then, there has been an ongoing discussion about whether miRNAs from the diet are transferred to blood, accumulate in tissues, and regulate gene expression. Different research groups have tried to replicate these findings, using both plant and animal sources. Here, we review the evidence for and against the transfer of diet-derived miRNAs from plants, meat, milk and exosome and their assimilation and putative molecular regulation role in the consuming organism. Some groups using both miRNAs from plant and animal sources have claimed success, whereas others have not shown transfer. In spite of the biological barriers that may limit miRNA transference, several diet-derived miRNAs can transfer into the circulating system and targets genes for transcription regulation, which adds arguments that miRNAs can be absorbed from the diet and target specific genes by regulating their expression. However, many other studies show that cross-kingdom transfer of exogenous miRNAs appears to be insignificant and not biologically relevant. The main source of controversy in plant studies is the lack of reproducibility of the findings. For meat-derived miRNAs, studies concluded that the miRNAs can survive the cooking process; nevertheless, our evidence shows that the bovine miRNAs are not transferred to human bloodstream. The most important contributions and promising evidence in this controversial field is the transference of milk miRNAs in exosomes and the finding that plant miRNAs in beebread regulate honeybee caste development, and cause similar changes when fed to Drosophila. MiRNAs encapsulated in exosomes ensure their stability and resistance in the harsh conditions presented in milk, bloodstream, and gastrointestinaltract to reinforce the idea of transference. Regardless of the model organism, the idea of source of miRNAs, or the approach—bioinformatics or in vivo—the issue of transfer of miRNAs from the diet remains in doubt. Our understanding of the cross-kingdom talk of miRNAs needs more research to study the transfer of “xenomiRs” from different food sources to complement and expand what we know so far regarding the interspecies transfer of miRNAs

Serum Circulating microRNA Profiling for Identification of Potential Breast Cancer Biomarkers

MicroRNAs (miRNAs) are a class of small, non-coding RNA molecules that can regulate gene expression, thereby affecting crucial processes in cancer development. miRNAs offer great potential as biomarkers for cancer detection because of their remarkable stability in blood and their characteristic expression in different diseases. We investigated whether quantitative RT-PCR miRNA profiling on serum could discriminate between breast cancer patients and healthy controls. We performed miRNA profiling on serum from breast cancer patients, followed by construction of ROC (Receiver Operating Characteristic) curves to determine the sensitivity and specificity of the assay. We found that seven miRNAs (miR-10b, miR-21, miR-125b, miR-145, miR-155 miR-191 and miR-382) had different expression patterns in serum of breast cancer patients compared to healthy controls. ROC curve analyses revealed that three serum miRNAs could be valuable biomarkers for distinguishing BC from normal controls. Additionally, a combination of ROC curve analyses of miR-145, miR-155 and miR-382 showed better sensitivity and specificity of our assay. miRNA profiling in serum has potential as a novel method for breast cancer detection in the Mexican population