Video Experimental Relacionado
Updated: Jun 30, 2026
08:38
Targeted DNA Methylation Analysis by Next-generation Sequencing
Published on: February 24, 2015
La metilación de CpG se mantiene en las células cancerosas humanas que carecen de DNMT1
1The Johns Hopkins Oncology Center, and Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
Nature
|May 9, 2000
Resumen
La ADN metiltransferasa 1 (DNMT1) no es la única responsable de la metilación genómica en las células cancerosas humanas. Otras enzimas mantienen la metilación, lo que indica que DNMT1 tiene especificidad regional.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Investigación del cáncer Investigación del cáncer.
- La epigenética es la epigenética.
Sus antecedentes:
- La metilación aberrante del ADN, particularmente la hipermetilación, es un sello distintivo del cáncer, que a menudo conduce al silenciamiento de los genes supresores de tumores.
- Los mecanismos precisos que impulsan esta metilación anormal no se comprenden completamente, siendo la ADN metiltransferasa 1 (DNMT1) la presunta enzima primaria responsable de la metilación genómica.
Objetivo del estudio:
- Investigar el papel de DNMT1 en el mantenimiento de la metilación genómica global y la metilación de genes específicos en las células de carcinoma colorrectal humano.
- Para determinar si DNMT1 es la única enzima responsable de la metilación aberrante en el cáncer.
Principales métodos:
- Disrupción del gen DNMT1 en las células de carcinoma colorrectal humano utilizando recombinación homóloga.
- Medición de la actividad de la metiltransferasa en el ADN celular.
- Análisis de los niveles generales de metilación genómica.
- Evaluación del estado de metilación en loci específicos, incluidos los satélites juxtacentroméricos y el gen supresor de tumores p16INK4a.
Principales resultados:
- Las células que carecían de DNMT1 mostraron una reducción significativa de la actividad de la metiltransferasa del ADN celular.
- La metilación genómica general disminuyó solo en un 20% en las células deficientes en DNMT1.
- Las regiones satélite juxtacentroméricas estaban significativamente desmetiladas, pero la mayoría de los loci analizados, incluido p16INK4a, permanecieron completamente metilados y silenciados.
- Estos hallazgos sugieren la presencia de actividades alternativas de metilación en las células humanas.
Conclusiones:
- DNMT1 exhibe una inesperada especificidad regional en su actividad de metilación dentro de las células humanas.
- Las enzimas distintas de DNMT1 juegan un papel crucial en el mantenimiento del estado de metilación de la mayoría del genoma humano, incluso en el contexto del cáncer.
Videos de Conceptos Relacionados
01:46Epigenetic Regulation
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
02:30Genomic Imprinting and Inheritance
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
02:23Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
01:37Epigenetic Regulation
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
X-chromosome...
01:06Induced Pluripotent Stem Cells
Stem cells are undifferentiated cells that divide and produce different cell types. Ordinarily, cells that have differentiated into a specific cell type are terminally differentiated; however, scientists have found a way to reprogram these mature cells so that they dedifferentiate and return to an unspecialized, proliferative state. These cells are pluripotent like embryonic stem cells—able to produce all cell types—and are called induced pluripotent stem cells (iPSCs).
Somatic cells are...
Somatic cells are...
01:17Phase II Reactions: Methylation Reactions
Methylation is a phase II biotransformation process involving the attachment of a methyl group to a substrate. Enzymes known as methyltransferases orchestrate this reaction.
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...