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Satellite RNAs are transcripts of satellite DNA, the long, tandemly repeated sequences mainly found in centromeres and pericentromeric chromosomal regions.
This review discusses the structural features and regulatory roles of satellite RNAs in intracellular architecture and gene regulation:
Satellite RNAs: emerging players in subnuclear architecture and gene regulation
Protein C (encoded by the PROC gene on chromosome 2) is a vitamin K-dependent plasma glycoprotein that is a key component of the anticoagulant system. Protein C is cleaved to its activated form, ‘activated protein C (APC), on endothelial cells by the thrombin-thrombomodulin complex and then acts as a serine protease to degrade the activated forms of coagulation factors V and VIII. Protein S, also a vitamin K-dependent plasma protein, functions as a cofactor to activated protein C.
Heterozygous protein C deficiency is characterized by recurrent venous thrombosis. However, many adults with heterozygous disease may be asymptomatic.
Homozygous or compound heterozygous PROC mutations is a thrombotic condition that can manifest as a severe neonatal disorder or as a milder disorder with late-onset thrombophilia.
The term ‘gene sharing’ means that a polypeptide generated from a specific region of a genome serves at least two distinct molecular functions. This novel concept originated about two decades ago from the work of Piatigorsky and his colleagues, who isolated genes that encode lens structural proteins, the crystallins. Studies of avian and crocodilian lenses first showed that ε-crystallin was similar to the basic metabolic enzyme, lactate dehydrogenase B4; followed by findings that chicken Δ-crystallin was similar to argininosuccinate lyase and that turtle τ-crystallin was similar to α-enolase. When gene identity for the enzyme and crystallin was revealed, both a novel term, ‘gene sharing’, and paradigm emerged.
Cancer is considered a problem of the genome because it arises from changes in the DNA within cells, leading to uncontrolled cell growth. These changes, often referred to as mutations, can alter the way cells grow and multiply, turning healthy cells into cancerous ones.
However, it’s important to note that while cancer is a genetic disease, the genetic component is just one piece of the puzzle. Environmental factors play a significant role in causing these genetic changes. For instance, exposures to certain chemicals, radiation, and lifestyle choices can cause damage to DNA, leading to mutations that can initiate cancer.
According to research, heritable cancers account for just five to ten percent of all cancers. The other 90 to 95 percent are initiated by factors in the exposome, which includes everything your body is exposed to throughout your life. These factors in turn trigger genetic mutations.
In essence, the genome, exposome, and metabolome (all the chemical byproducts of the process of metabolism) operate together in a feedback loop as cancer develops and spreads. This multi-omics perspective, considering the genome, exposome, and metabolome in unison when thinking about cancer, is showing promise for finding treatments and for overcoming the limitations of looking at only one of these factors.
Therefore, while cancer is indeed a problem of the genome, it’s also deeply intertwined with environmental and metabolic factors. Understanding this complex interplay is crucial for developing effective prevention and treatment strategies.
Source: Conversation with Bing, 4/1/2024
an enhancer is a short (50–1500 bp) region of DNA that can be bound by proteins (activators) to increase the likelihood that transcription of a particular gene will occur. These proteins are usually referred to as transcription factors. Enhancers are cis-acting. They can be located up to 1 Mbp (1,000,000 bp) away from the gene, upstream or downstream from the start site. There are hundreds of thousands of enhancers in the human genome. They are found in both prokaryotes and eukaryotes.
Ref: Enhancer (genetics) – Wikipedia
Enhancer RNAs (eRNAs) represent a class of relatively long non-coding RNA molecules (50-2000 nucleotides) transcribed from the DNA sequence of enhancer regions. They are not mRNAs. The expression of a given eRNA correlates with the activity of its corresponding enhancer in target genes. Increasing evidence suggests that eRNAs actively play a role in transcriptional regulation. Their mechanisms of action remain unclear.
I agree with A. Hammouda.
“Empty DNA” is not a scientific term, and it sounds exactly like m-t-DNA (mtDNA).
Liquid biopsy is the analysis of tumor cells or tumor cell products obtained from blood or other body fluids. The tumor is thus accessed by a minimally invasive technique. The blood can be analyzed for circulating tumor cells, circulating tumor-derived DNA, tumor proteome, or tumor metabolome. These constitute tumor markers in the blood.
Is a urine sample considered a liquid biopsy? Yes, if it is obtained to look for markers of a tumor, like tumor cells or tumor DNA.
These are two different terms, though some dictionaries may tell you they are the same. Organelles, in biology, are the microscopic sub-cellular structures seen inside the cells, e.g., mitochondria, chloroplasts, ribosomes, etc. They perform certain functions inside the cell. Organoids, on the other hand, are multicellular 3-D structures made from cultured stem cells on scaffolds. They serve as models for specific organ cells in tissue-like structures. They are used in biological and pharmaceutical studies. Their technology is in continuous and rapid development.
Ten genes in the donor pig were altered before the transplant could take place. Three of these genes cause human bodies to reject pig organs, so these were knocked out. Six genes were inserted to help control immune acceptance of the pig heart, and one additional gene was knocked out to stop excessive growth of the pig heart tissue.