Schlagwort: DNA
MCM-Moleküle begrenzen die Bildung von DNA-Schleifen
19. Mai 2022
Das genomische Material einer Zelle muss so in einen winzigen Zellkern verpackt werden, dass es einerseits geordnet ist und andererseits nach Bedarf abgelesen, verdoppelt oder repariert werden kann. Für eine platzsparende Verpackung sind Proteine verantwortlich, die die DNA aufrollen oder auch in Schleifen legen können. Die Wissenschaftler Kikuë Tachibana und Karl Duderstadt des Max-Planck-Instituts für Biochemie in Martinsried erforschen die Aufgabe und Funktionsweise dieser molekularen Maschinen. Wie sie herausfinden konnten, spielt der MCM-Komplex eine wichtige Rolle bei der Begrenzung der Schleifenbildung und somit auch bei der dreidimensionalen Struktur des Genoms und der Genregulation.
MCM molecules impede the formation of DNA loops
19. Mai 2022
The entire genomic material of a cell must be packed into a tiny cell nucleus in such a way, that on the one hand, it can be stored in an organized manner and, on the other hand, it can be transcribed, duplicated or repaired as needed. Different proteins are responsible for space-saving packaging, which can roll up or loop the DNA. Scientists Kikuë Tachibana and Karl Duderstadt from the Max Planck Institute of Biochemistry in Martinsried are investigating the exact task and function of these molecular machines. They discovered that the MCM complex plays an important role in restricting DNA loop formation and thus in the three-dimensional structure of the genome and in gene regulation.
Gene deletion behind anomaly in blood cancer cells
6. April 2022
Although clinical labs have known for almost a century that a oddly shaped nucleus resembling pince-nez glasses in blood cells could indicate leukemia, the cause of this anomaly remained unknown. Scientists have now discovered that loss of nuclear Lamin B1 induces defects in the nuclear morphology and in human hematopoietic [blood-forming] stem cells associated with malignancy. The scientists went on to detail that lamin B1 deficiency alters genome organization. This in turn causes expansion of blood-forming stem cells, a bias towards their becoming myeloids, genome instability due to defective DNA damage repair and other problems that set the stage for cancer.
Gene deletion behind anomaly in blood cancer cells
6. April 2022
Although clinical labs have known for almost a century that a oddly shaped nucleus resembling pince-nez glasses in blood cells could indicate leukemia, the cause of this anomaly remained unknown. Scientists have now discovered that loss of nuclear Lamin B1 induces defects in the nuclear morphology and in human hematopoietic [blood-forming] stem cells associated with malignancy. The scientists went on to detail that lamin B1 deficiency alters genome organization. This in turn causes expansion of blood-forming stem cells, a bias towards their becoming myeloids, genome instability due to defective DNA damage repair and other problems that set the stage for cancer.
DNA discovery reveals a critical ‚accordion effect‘ for switching off genes
6. April 2022
Researchers have revealed how an ‚accordion effect‘ is critical to switching off genes, in a study that transforms the fundamentals of what we know about gene silencing. The finding expands our understanding of how we switch genes on and off to make the different cell types in our bodies, as we develop in the womb.
DNA discovery reveals a critical ‚accordion effect‘ for switching off genes
6. April 2022
Researchers have revealed how an ‚accordion effect‘ is critical to switching off genes, in a study that transforms the fundamentals of what we know about gene silencing. The finding expands our understanding of how we switch genes on and off to make the different cell types in our bodies, as we develop in the womb.
New pathway for DNA transfer discovered in tumor microenvironment
27. März 2022
Researchers have discovered another way tumor cells transfer genetic material to other cells in their microenvironment, causing cancer to spread.
Chronologically young, biologically old: DNA linked to cancer survivors premature aging
23. März 2022
Scientists have identified variants in two genes that are associated with accelerated aging in childhood cancer survivors.
Research advances understanding of DNA repair
9. März 2022
A researcher has made a discovery that alters our understanding of how the body’s DNA repair process works and may lead to new chemotherapy treatments for cancer and other disorders. Researchers discovered that base excision repair has a built-in mechanism to increase its effectiveness — it just needs to be captured at a very precise point in the cell life cycle.
Visualizing the invisible: New fluorescent DNA label reveals nanoscopic cancer features
5. März 2022
Researchers have developed a new fluorescent label that gives a clearer picture of how DNA architecture is disrupted in cancer cells. The findings could improve cancer diagnoses for patients and classification of future cancer risk.
RNA molecules control repair of human DNA in cancer cells
24. Februar 2022
A new study shows how certain RNA molecules control the repair of damaged DNA in cancer cells, a discovery that could eventually give rise to better cancer treatments.
RNA ‘heroes’ can disarm bad-actor proteins in leukemia
6. Februar 2022
Scientists believe it may be possible to prevent DNA changes driven by two proteins highly active in leukemia and other cancers. They recently reported a new mechanistic target for drug development.
Researchers identify key regulator of blood stem cell development
29. Januar 2022
A protein that masterminds the way DNA is wrapped within chromosomes has a major role in the healthy functioning of blood stem cells, which produce all blood cells in the body, according to a new study.
Ground-breaking study reveals dynamics of DNA replication ‘licensing’
27. Januar 2022
A new study has illuminated an important process that occurs during cell division and is a likely source of DNA damage under some circumstances, including cancer.
Newly discovered DNA repair mechanisms point to potential therapy targets for cancer and neurodegenerative diseases
21. Januar 2022
Faulty DNA damage repair can lead to many types of cancer, neurodegenerative diseases, and other serious disorders. Investigators have developed high-throughput microscopy and machine learning systems that can identify and classify DNA repair factors. The investigators have identified nine previously unknown factors involved in the process of cellular DNA repair.
Research team identifies new mechanism for protecting DNA
19. Januar 2022
Researchers have identified a new mechanism by which a protein known for repairing damaged DNA also protects the integrity of DNA by preserving its structural shape. The discovery, involving the protein 53BP1, offers insight into understanding how cells maintain the integrity of DNA in the nucleus, which is critical for preventing diseases like premature aging and cancer.
Lymphoma: Key signaling pathway involved in tumor formation identified
13. Januar 2022
There are myriad reasons why cancers develop. By studying genes which are altered in people with lymphoma, a multidisciplinary team of researchers has identified a key mechanism involved in disease development. This signaling pathway, which the researchers describe in detail, controls the repair of DNA damage.
Microorganism sheds new light on cancer resistance
24. Dezember 2021
Scientists describe T. adhaerens‘ unusual behavior, including its capacity to repair its DNA even after significant radiation damage and to extrude injured cells, which later die. The findings advance scientific investigations of natural cancer-suppression mechanisms across life. Insights gleaned from these evolutionary adaptations may find their way into new and more effective therapies for this leading killer.
New findings on the link between CRISPR gene-editing and mutated cancer cells
19. November 2021
A protein that protects cells from DNA damage, p53, is activated during gene editing using the CRISPR technique. Consequently, cells with mutated p53 have a survival advantage, which can cause cancer. Researchers have found new links between CRISPR, p53 and other cancer genes that could prevent the accumulation of mutated cells without compromising the gene scissors‘ effectiveness.
Cell-free DNA identifies early signs of relapse in pediatric medulloblastoma
27. Oktober 2021
Findings show that cell-free DNA in cerebrospinal fluid can be used to detect measurable residual disease and identify patients at risk of relapse.
Super-enhancers: The villain fueling certain cancers
6. Oktober 2021
Researchers identified a small RNA molecule called miR-766-5p that reduces expression of MYC, a critical cancer-promoting gene. This microRNA reduces levels of proteins CBP and BRD4, which are both involved in super-enhancer (SE) formation. SEs form in areas of DNA that can fuel MYC expression and tumor progression. This study provides strong evidence for developing miR-766-5p as a novel therapeutic to treat MYC-driven cancers.
Looking beyond DNA to see cancer with new clarity
1. Oktober 2021
Researchers have mapped out how hundreds of mutations involved in two types of cancer affect the activity of proteins that are the ultimate actors behind the disease. The work points the way to identifying new precision treatments that may avoid the side effects common with much current chemotherapy.
Insights from our genome and epigenome will help prevent, diagnose and treat cancer
25. September 2021
In 2020, an estimated 10 million people lost their lives to cancer. This devastating disease is underpinned by changes to our DNA — the instruction manual for all our cells.
A global assessment of cancer genomic alterations in epigenetic mechanisms
5. März 2015
Muhammad A Shah, Emily L Denton, Cheryl H Arrowsmith, Mathieu Lupien and Matthieu Schapira
Abstract
Background
The notion that epigenetic mechanisms may be central to cancer initiation and progression is supported by recent next-generation sequencing efforts revealing that genes involved in chromatin-mediated signaling are recurrently mutated in cancer patients.
Results
Here, we analyze mutational and transcriptional profiles from TCGA and the ICGC across a collection 441 chromatin factors and histones. Chromatin factors essential for rapid replication are frequently overexpressed, and those that maintain genome stability frequently mutated. We identify novel mutation hotspots such as K36M in histone H3.1, and uncover a general trend in which transcriptional profiles and somatic mutations in tumor samples favor increased transcriptionally repressive histone methylation, and defective chromatin remodeling.
Conclusions
This unbiased approach confirms previously published data, uncovers novel cancer-associated aberrations targeting epigenetic mechanisms, and justifies continued monitoring of chromatin-related alterations as a class, as more cancer types and distinct cancer stages are represented in cancer genomics data repositories.
Continue reading „A global assessment of cancer genomic alterations in epigenetic mechanisms“ →
A Mitochondrial Paradigm of Metabolic and Degenerative Diseases, Aging, and Cancer: A Dawn for Evolutionary Medicine
23. Februar 2015
Progressive increase in mtDNA 3243A>G heteroplasmy causes abrupt transcriptional reprogramming
Wallace hypothesized mitochondrial dysfunction as a central role in a wide range of age-related disorders and various forms of cancer. Steadily rising increases in mitochondrial DNA mutations cause abrupt shifts in diseases. Discrete changes in nuclear gene expression in response to small increases in DNA mutant level are analogous to the phase shifts that is well known in physics: As heat is added, the ice abruptly turns to water or with more heat abruptly to steam. Therefore, a quantitative change that is an increasing proportion of mitochondrial DNA mutation results in a qualitative change which coordinate changes in nuclear gene expression together with discrete changes in clinical symptoms.