DNA-Austausch zwischen Zellen: Welche Rolle spielen Exosomen in der Entwicklung von Krebs?

Fast alle Zelltypen sondern Exosomen ab: kleine extrazelluläre Vesikel, die mit Proteinen, RNA und DNA beladen sind. Auf diese Weise können Zellen untereinander kommunizieren und stimmen viele Prozesse ab, wie beispielsweise Zellteilungen. In der Nähe von Tumoren werden solche Exosomen verstärkt abgesondert. „Die darin enthaltenen Biomoleküle verändern die Umgebung von Tumoren und können damit den Verlauf einer Krebserkrankung entscheidend beeinflussen“, so PD Dr. Basant Kumar Thakur von der Kinderklinik III des Universitätsklinikums Essen und Wissenschaftler der Medizinischen Fakultät der Universität Duisburg-Essen.

Quelle: IDW Informationsdienst Wissenschaft

Precise blood diagnostics improve treatment outcome in non-small cell lung cancer patients

Non-small cell lung carcinoma is a particularly aggressive type of lung cancer. Tumor cells and tumor DNA (ctDNA) in the blood of patients with the disease can be analyzed by means of liquid biopsy throughout the course of the disease. This information is important in order to be able to target the constantly changing tumor. A study from the University of Bayreuth is the first to show that liquid biopsy significantly improves treatment outcomes in many cases and can be cost-effective in the German care system. The scientists present their research results in the Journal of Cancer Research and Clinical Oncology.

Quelle: IDW Informationsdienst Wissenschaft

Wie DNA für die Zellteilung verpackt wird

Im Journal „Science“ präsentieren Forschungsgruppen aus Heidelberg und Würzburg das Innenleben der molekularen Maschinerie, die vor der Zellteilung die DNA zu Chromosomen formt.

Quelle: IDW Informationsdienst Wissenschaft

MCM molecules impede the formation of DNA loops

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.

Quelle: IDW Informationsdienst Wissenschaft

MCM-Moleküle begrenzen die Bildung von DNA-Schleifen

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.

Quelle: IDW Informationsdienst Wissenschaft

Gene deletion behind anomaly in blood cancer cells

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.

Quelle: Sciencedaily

Gene deletion behind anomaly in blood cancer cells

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.

Quelle: Sciencedaily

DNA discovery reveals a critical ‚accordion effect‘ for switching off genes

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.

Quelle: Sciencedaily

DNA discovery reveals a critical ‚accordion effect‘ for switching off genes

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.

Quelle: Sciencedaily

New pathway for DNA transfer discovered in tumor microenvironment

Researchers have discovered another way tumor cells transfer genetic material to other cells in their microenvironment, causing cancer to spread.

Quelle: Sciencedaily

Chronologically young, biologically old: DNA linked to cancer survivors premature aging

Scientists have identified variants in two genes that are associated with accelerated aging in childhood cancer survivors.

Quelle: Sciencedaily

Research advances understanding of DNA repair

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.

Quelle: Sciencedaily

Visualizing the invisible: New fluorescent DNA label reveals nanoscopic cancer features

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.

Quelle: Sciencedaily

RNA molecules control repair of human DNA in cancer cells

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.

Quelle: Sciencedaily

Researchers find link between excessive R-loop levels and DNA damage to be a potential cause of disease

New proteomics method identifies proteins binding to R-loops and decodes the role of the DDX41 protein in opposing double-strand breaks in the cells‘ DNA

Quelle: IDW Informationsdienst Wissenschaft

RNA ‘heroes’ can disarm bad-actor proteins in leukemia

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.

Quelle: Sciencedaily

Reading DNA is team work

Dresden researchers explain how liquid-like protein droplets collectively read DNA regions to switch on genes.

Quelle: IDW Informationsdienst Wissenschaft

Das Ablesen von DNA erfordert Teamarbeit

Dresdner Forscher erklären, wie Proteine in flüssigkeitsartigen Tropfen gemeinschaftlich agieren um Bereiche auf der DNA abzulesen und Gene anzuschalten.

Quelle: IDW Informationsdienst Wissenschaft

Researchers identify key regulator of blood stem cell development

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.

Quelle: Sciencedaily

Ground-breaking study reveals dynamics of DNA replication ‘licensing’

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.

Quelle: Sciencedaily

Newly discovered DNA repair mechanisms point to potential therapy targets for cancer and neurodegenerative diseases

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.

Quelle: Sciencedaily

Research team identifies new mechanism for protecting DNA

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.

Quelle: Sciencedaily

Lymphoma: Key signaling pathway involved in tumor formation identified

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.

Quelle: Sciencedaily

Wie DNA in archäologischen Sedimenten über Tausende von Jahren erhalten blieb

Nur wenig war bisher darüber bekannt, wie DNA über lange Zeiträume in Sedimenten überdauert. Ein internationales Team von Forschenden des Max-Planck-Instituts für evolutionäre Anthropologie in Leipzig und anderer Einrichtungen in Deutschland, Australien, Portugal und Russland zeigt, dass alte menschliche und tierische DNA in kleinen „Hot Spots“ konzentriert ist, insbesondere in mikroskopisch kleinen Knochen- und Kotpartikeln. Durch die Entnahme von Mikroproben solcher Partikel können beträchtliche Mengen alter DNA von Menschen, zum Beispiel von Neandertalern und anderen Arten, gewonnen und in mikroskopischem Maßstab mit archäologischen und ökologischen Daten abgeglichen werden.

Quelle: IDW Informationsdienst Wissenschaft

Microorganism sheds new light on cancer resistance

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.

Quelle: Sciencedaily