The CRISPR gene editing system holds tremendous promise. It has already revolutionized biomedical research by making gene editing a straightforward process. It involves using a guide RNA molecule that has a unique sequence, which matches with a target location in genomic DNA. This guide RNA brings an enzyme called Cas9 to that genetic location, where Cas9 makes a cut in the DNA. Scientists have been modifying and improving on the CRISPR technique since it was created. Many of those improvements are related to the Cas9 enzyme, and ensuring that it makes the proper cut in the correct place.
Category: genetics – Page 106
Restoring order to dividing cancer cells may halt triple negative breast cancer spread
Triple negative breast cancer (TNBC) is one of the most aggressive and hardest forms of breast cancer to treat, but a new study led by Weill Cornell Medicine suggests a surprising way to stop it from spreading. Researchers have discovered that an enzyme called EZH2 drives TNBC cells to divide abnormally, which enables them to relocate to distant organs. The preclinical study also found drugs that block EZH2 could restore order to dividing cells and thwart the spread of TNBC cells.
“Metastasis is the main reason patients with triple negative breast cancer face poor survival odds,” said senior author Dr. Vivek Mittal, Ford-Isom Research Professor of Cardiothoracic Surgery and member of the Sandra and Edward Meyer Cancer Center at Weill Cornell Medicine. “Our study suggests a new therapeutic approach to block metastasis before it starts and help patients overcome this deadly cancer.”
The findings, published Oct. 2 in Cancer Discovery, challenge the popular notion that cancer treatments should boost cell division errors already occurring in tumor cells beyond the breaking point to induce cell death. When normal cells divide, the chromosomes—DNA “packages” carrying genes—are duplicated and split evenly into two daughter cells. This process goes haywire in many cancer cells, leading to chromosomal instability: too many, too few, or jumbled chromosomes in multiple daughter cells.
Ancient viral DNA is essential for human embryo development, study shows
Our ancient past isn’t always buried history. When it comes to our DNA, nearly 9% of the human genome is made up of leftover genetic material from ancient viruses (called endogenous retroviruses or ERVs) that infected our ancestors millions of years ago and became permanently integrated into our genetic code. In a new study published in the journal Nature, scientists have demonstrated that one piece of this viral junk is essential for the earliest stages of human life.
Genetic and behavioral links found between musical rhythm perception and developmental language disorders
In a paper published in Nature Communications, researchers at Vanderbilt University Medical Center’s Department of Otolaryngology–Head and Neck Surgery leveraged two main studies—one focused on behavior and one focused on genetics—to highlight the correlation between participants’ musical rhythm abilities and developmental speech-language disorders.
These disorders include developmental language disorder, dyslexia and stuttering, among others.
Evidence showed that deficiency in musical rhythm perception is a “modest but consistent risk factor for developmental speech, language and reading disorders,” according to the study’s lead author, Srishti Nayak, Ph.D., assistant professor of Otolaryngology-Head and Neck Surgery.
Experiment explores contribution of neural, epigenetic and behavioral factors to autism spectrum disorder
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that is estimated to be experienced by roughly 1 in 127 people worldwide. It is characterized by atypical patterns in brain development, which manifest in differences in communication, social interactions, behavior and responses to sensory information.
Past neuroscientific and genetic studies suggest that a variety of factors contribute to the development of ASD. These can include genetic factors, chemical alterations that influence the expressions of genes (i.e., epigenetic factors), differences in the structure of specific brain regions or neural circuits, and environmental factors, such as early life events or infections or immune responses during pregnancy.
Researchers at the Korea Brain Research Institute and University of Fukui in Japan recently carried out a study aimed at further exploring these different dimensions of ASD, focusing on brain structure, the communication between brain regions, epigenetic changes and behavioral patterns. Their findings, published in Translational Psychiatry, paint a clearer picture of the intricate underpinnings of the disorder and could inform the development of more precise tools for diagnosing it.
Autism should not be seen as single condition with one cause, say scientists
Autism should not be viewed as a single condition with a unified underlying cause, according to scientists who found that those diagnosed early in childhood typically have a distinct genetic profile to those diagnosed later.
The international study, based on genetic data from more than 45,000 autistic people in Europe and the US, showed that those diagnosed in early childhood, typically before six years old, were more likely to show behavioural difficulties from early childhood, including problems with social interaction, but remain stable.
Those diagnosed with autism later, typically after the age of 10, were more likely to experience increasing social and behavioural difficulties during adolescence and also had an increased likelihood of mental health conditions such as depression.
Study reveals genetic and developmental differences in people with earlier versus later autism diagnosis
Researchers find different genetic profiles related to two trajectories that autistic children tend to follow. One is linked to early diagnosis and communication difficulties in infancy. The other is linked to later diagnosis, increased social and behavioral difficulties in adolescence, and higher rates of conditions like ADHD, depression, and PTSD.
An international study led by researchers at the University of Cambridge has discovered that autism diagnosed in early childhood has a different genetic and developmental profile than that of autism diagnosed from late childhood onwards.
The scientists say that the findings challenge the long-held assumption that autism is a single condition with a unified underlying cause.
Enlarged cancer cell nuclei may limit spread rather than signal severity
In tissue biopsies, cancer cells are frequently observed to have nuclei (the cell’s genetic information storage) that are larger than normal. Until now, this was considered a sign that the cancer was worsening, but the exact cause and effect had not been elucidated.
In a new study, a KAIST research team has found that cancer cell nuclear hypertrophy is not a cause of malignancy but a temporary response to replication stress, and that it can, in fact, suppress metastasis. This discovery is expected to lead to the development of new diagnostic and therapeutic strategies for cancer and metastasis inhibition.
The research team, led by Professor Joon Kim of the Graduate School of Medical Science and Engineering, in collaboration with the research teams of Professor Ji Hun Kim and Professor You-Me Kim, confirmed that DNA replication stress (the burden and error signal that occurs when a cell copies its DNA), which is common in cancer cells, causes the “actin” protein inside the nucleus to aggregate (polymerize), which is the direct cause of the nuclear enlargement.