Edmead Lec 4 - Stem Cells Flashcards
Want to maintain a balance between a_____, p_____ and d______. Aberrations in any of these pathways can alter the balance resulting in accumulation of non functional cells.
Apoptosis
Proliferation
Differentiation
Many cancer cells look immature (____ ____), their morphology has changed and this leads to ____ of function. As cells differentiate and become more _____, generally proliferation _____ SO there is a theory that cancerous growth can be reduced by making cells more differentiated. However, the issue is that cancer is a disease of ______ cells.
Blast like Loss Specialised Reduces Proliferating
If a cell is not dividing it is ___ likely to acquire mutations as it is not passing genetic information onto ______ cells.
Less
Daughter
Tumours are often a ________ mass in terms of cellular differentiation (not all cells look the same). Cells on the outside of a tumour are exposed to ________ fluid and have a different _______ to those in the centre of the tumour. This differing ______ of cells is the reason why tumour masses response differently to drugs - some of the mass is more susceptible to the drugs and those that are resistant are left, often in the ____ of the tumour. These resistant cells can then regrow.
Heterogenous Extracellular Morphology Morphology Core
Cancers are ____ (arise from single cells) but not all of theses cells look the same.
Clonal
Most cells have a _____ lifetime and do not live long enough to acquire 3 or more mutations. Every mutation that occurs should be picked up by ____ _____ enzymes and killed off by _____. So these cells need to evade ____ and live long enough to maintain mutations to pass on to daughter cells. Hence why cancer is a disease of the _____ - need time to accumulate mutations.
Finite DNA repair enzymes Apoptosis Apoptosis Elderly
Embryonic stem cells are _____ and can differentiate into many different cell types. Mature cells that are differentiated are no longer ______ and cannot __-differentiate.
Pluripotent
Pluripotent
De-differentiate
As _____ embryonic cells change into differentiated cells they go through various stages - _____ phases make them become more _____.
Pluripotent
Progenitor
Specialised
Generally differentiation is ____ and these cells cannot acquire properties of ____ _____ and __-______.
Terminal
Self Renewal
De-differentiation
Stem cell division is _____. When they divide they produce one identical copy and one more _____ copy.
4 stages - what are they?
Asymmetric
1) Totipotent stem cell
2) Multipotent stem cell - restricted potential stem cell
3) Unipotent stem cell - progenitor cell
4) Terminally differentiated cell
A small number of residual stem cells have been identified in adult tissues - 1st seen in ____ ____. Stem cells are required here as ___ and ___ have a high turnover so _____ stem cells divide to produce these cells.
Bone marrow
RBC and WBC
Progenitor
In other tissues with reduced turnover, stem cell function is used in healing. So if tissues are damaged then stem cells proliferate to produce new cells e.g. in ____ or ____ cells.
Liver
Muscle
Adult stem cells are present in ___ numbers. Proliferation is normally _____ as it is only required when repair is needed. If repair is needed, ______ is released and _____ occurs and when enough cells are produced they are _____ again.
Small Suppressed Suppression Proliferation Suppressed
If you take _____ stem cells or early stage _____ cells and implant them into tissues (in animal models) they grow into ____. (With variety of tissues as they _____ into different tissues)
Embryonic
Progenitor
Tumours
Differentiate
____ may occur in tissue stem cells e.g. proto-oncogene to oncogene or loss of ____ ____ genes or changes to chromosomal structure. As stem cells reside for a long time, when they are reactivated they grow quickly and can pass ____ onto ______ cells which then acquire more ______.
Mutations Tumour suppressor Mutations Daughter Mutations
