Week 4 Flashcards
What are nuclear receptors?
A family of ligand-regulated transcription factors that are activated by steroid hormones, such as estrogen and progesterone, and various other lipid-soluble signals, including retinoic acid, oxysterols, and thyroid hormone
How does endocrine signalling operate?
The signaling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites
What is the hormonal system?
A network of glands and organs in the body that produces hormones
How does the hormonal system work?
When a hormone is released from a gland, it travels in the bloodstream through the body. It passes by most cells, but eventually reaches its target.
What medical conditions relate to the hormonal system?
Some common hormonal problems are:
- Diabetes
- Thyroid problems, such as hypothyroidism and hyperthyroidism
- Cushing’s syndrome
- Some fertility problems
- Congenital adrenal hyperplasia
Examples of polypeptide/protein hormones?
- Growth hormone
- Vasopressin
- Insulin
- Glucagon
- Parathyroid hormone
What’s the difference between peptide hormones and protein hormones?
Peptide hormones consist of short chains of amino acids, whereas protein hormones are longer polypeptides.
What are lipophilic hormones?
Lipid-soluble hormones
What is a hormone receptor?
A receptor molecule that binds to a specific chemical messenger.
What is meant by nuclear receptors?
Nuclear receptors are a family of ligand-regulated transcription factors that are activated by steroid hormones, such as estrogen and progesterone, and various other lipid-soluble signals, including retinoic acid, oxysterols, and thyroid hormone
What do nuclear receptors sense?
Changes in lipid metabolite levels to drive differential gene expression, producing distinct physiologic effects
What does the allosteric binding of nuclear receptors?
Drives the recruitment of diverse transcriptional co‐regulators at chromatin and ultimately transactivation or transrepression of target genes
What does the dysregulation of nuclear receptors lead to?
Various malignances, metabolic disorders, and inflammatory disease
What ligands bind to nuclear receptors?
lipophilic substances such as endogenous hormones, vitamins A and D, and xenobiotic hormones
What is cortisol?
A steroid hormone, in the glucocorticoid class of hormones.
What does the biosynthesis of a hormone require?
The coordinated expression of the enzymes that comprise the pathways via which specific hormones are synthesized
What does the term ‘general mechanism of action’ mean?
A term used to describe how a drug or other substance produces an effect in the body
What are the different type of nuclear receptors?
According to this classification, nuclear receptors are grouped in seven subfamilies: NR1, NR2, NR3, NR4, NR5, NR6, and NR0
What does SRC-3 regulate?
Not only the transcriptional activity of nuclear receptors but also many other transcription factors
What does the nuclear receptor superfamily regulate?
Gene expression in response to endocrine signalling, and recruitment of coregulators affords these receptors considerable functional flexibility.
What does the interplay between the tumour microenvironment and tumour cells represent?
A key contributor to immune evasiveness, physiological hardiness and the local and systemic invasiveness of malignant cells
How many nuclear receptors do humans have?
48 nuclear receptors, which when dysregulated are often linked to diseases
How do estrogen receptors act?
By regulating transcriptional processes
What does it mean to be ER positive in breast cancer?
The cells of this type of breast cancer have receptors that allow them to use the hormone estrogen to grow
What does metabolic reprogramming enable?
Cancer cells to adapt to the changing microenvironment in order to maintain metabolic energy and to provide the necessary biological macromolecules required for cell growth and tumor progression
What are aromatase inhibitors?
A class of drugs used in the treatment of breast cancer in postmenopausal women and in men, and gynecomastia in men
What are SERMs?
A class of drugs that act on the estrogen receptor.
What is the common cause of Cushing Syndrome?
Most cases of Cushing’s syndrome are not genetic. However, some individuals may develop Cushing’s syndrome due to an inherited tendency to develop tumors of one or more endocrine glands.
What is the relationship between androgens and prostate cancer?
Androgens are also necessary for prostate cancers to grow
