Stem cells, metastasis and cancer - molecular test 2

Differentiation =

specialization

Cancers usually become more what

stem-cell like

Cancers are _______ and more differentiated cells can be found in ______ cancers

heterogenous, some

Embryonic Rest Hypothesis: Cancer cells look like ________ cells or immature organs that are in an unspecialized (undifferentiated) state of development

embryonic

Embryonic Rest Hypothesis: through that cancer might emerge from ______ embryonic cells that have never really developed.

"extra"

What is the cancer stem cell hypothesis states?

all cancers arise from stem or progenitor cells

Cancer stem cell hypothesis -

All cancers arise from stem or

progenitor cells; some of the

subsequent cells can differentiate

making the tumor a heterogenous

arrangement of differentiated and

undifferentiated cells

VS.

• Cancers can come from non-growing

differentiated cells that can be

induced to dedifferentiate; over time,

more and more dedifferentiation is

seen

Stem cells

divide giving rise to one stem cell and one progenitor cell

What do progenitor cells do?

replicate a few more times

what cells do not replicate?

differentiated cells

Hallmarks of cancer cells that stem cells have?

- immortality

- ability to replicate quickly

- lower contact inhibition

- survival

Cancer cells arise from the stem cell niche in .....

skin, hematopoietic, and colon cells

basal cell carcinoma

Most common and least severe type of skin cancer; often characterized by light or pearly nodules.

What else can some cancers arise from

More mature cells that have dedifferentiated

less mature cells in cancer are what?

cancer stem cells

What cells can from new cancers?

stem cells

What cells die off?

progenitor cells and mature cells

What cells tend to take over cancer in later stages?

stem cells

What can stem cells do?

drive cancer cell proliferation

Stem cells can _________ further mutations that make cancer less _____________

sustain, heterogenous

If stem cells take over cancer, inducing cancer stem cells to differentiate may decrease the ___________ of late stage cancer

steminess

Sonic hedgehog pathway

helps maintain the stem cell niche in some tissues, particularly neurons and skin

What can the sonic hedgehog pathway be seen in?

development of the brain, digits, and facial patterning

Overexpression of the sonic hedgehog pathway in adults can lead to

glioblastomas and basal cell carcinomas

Without sonic hedgehodge pathway?

• Ptch inhibits Smo

• Fused and Sufu bind Gli

• Gli in cytoplasm

With the sonic hedgehog pathway?

• Shh inhibits Ptch

• Smo activated

• Fused inhibits Sufu

• Gli released to nucleus

Loss of Shh leads to what in mice

decrease in brain cells in Shh-/-

loss of one allele of Shh can lead to what

holoproscencephaly

Increase in shh expression can lead to what

polydactyly

What is the oncogene in the Wnt pathway?

beta catenin

What are the tumor suppressor genes in the Wnt pathway?

APC and axin

neuroblastoma

highly malignant tumor of the sympathetic nervous system

- is often found in infants and small children

What does neuroblastoma arise from?

immature neuroblast cells

Neuroblastoma, some causes will spontaneously ______ if in the presence other cells that secrete differntiation factors.

differentiate

Inhibition of Shh pathway

cyclopamine - inhibitor of smoothened

- found in corn lilies

- has been used in brain and breast cancer

- causes cells to differntiatie and stop growing