MM overview/tutorial Flashcards
Why is an aromatase inhibitor more frequently used in post-menopausal woman?
In a pre-menopausal woman, the hypothalamus secretes GnRH - which leads to the pituitary releasing the FSH and LH which regulate the activity of the ovaries - if you give aromatase inhibitor to a pre-menopausal woman, the body detects lower oestrogen levels therefore it over produces oestrogen to compensate causing other issues - therefore we give this more frequently to post-menopausal women
What is the difference between miRNA and siRNA?
siRNA = originates from double stranded RNA - commonly responds to foreign RNA - it is always 100% complementary to the target mRNA and is specific for that message - we can introduce exogenously (as foreign object) to target specific points
miRNA= is a single stranded RNA folded back on itself like a hair pin - they are not 100% complementary to the target- one miRNA is not specific for one gene- endogenous *They both use the RNA interference pathway with slight modifications*
With an estrogen receptor positive tumor- discuss adjuvant hormonal treatment options with her - explain why adjuvant therapy is given, and describe the role of hormone therapy in cancer treatment giving examples/mechanism of action?
Adjuvant therapy = systemic therapy used in patients with primary tumor removed but who are at high risk of met. disease - such is the case with breast cancer
Hormone based anticancer agents= tumors derived from hormone sensitive tissue can be hormone-dependent- therefore we can target this. tumor growth can be inhibited by hormone agonsits (which bind the receptor and block it’s normal action like Tamoxifen anti-estorgen) or we can use agents that inhibit the synthesis of the relevant hormone like aromatase inhibitors - which target estrogen synthesis
Tamoxifan - most correctly described as a selective estrogen receptor moduclator (SERM) but it mediates it’s anticaner activity by acting as an antagonist of the estorgen recpetor in breast.
It competes with natural estrogens fro binding to ER- It is effective in early and advanced ER breast ancer in pre/post menopausal women .
Mechanism: prodrug converted to active metabolite 4 hydroxytamoxifen - binds to ER. The binding of ER/tamoxifen-complex to estrogen response elements inhibit transcription of estrogen.
