1st Pdf Flashcards
Cancer is fundamentally a
Genetic disease
Etiology of cancer
Mutations and progression
Many cancer are complex
Mutations and environments factors
Cancer is a disease characterized by
Uncontrolled cellular proliferation leading to a mass or tumor
Malignant tumors progress by
Invading neighboring tissues
Malignant spreading to more
distant sites
Properties of cancer cells
They display abnormalities in the mechanism that regulate cell proliferation
Survival
Differentiation
The development of cancer “ oncogenesis”
Result from mutations in genes that
• regulate cell growth and • programmed cell death
Most cancers are But there are
Sporadic
Hereditary
Cancer cells relation to density dependent
They are not sensitive
Normal cells stops proliferation when
They reach finite cell density
Tumor cells stops proliferation
They don’t they continue to proliferate
GF is real ateş to which phonomenon
Density dependent inhibition of normal cells
In cancer cell what requirements are reduced
Extracellular GF
In some cancer cells they produce their own
GF that stimulate their own proliferation:
Autocrine GF production
Infra cellular signaling pathways
GF receptor
RAS protein
Normal cells stop cell proliferation
When the form a single layered cultures and when they contact each other
Are tumor cells inhibited by cell contact
No they are not inhibited by cell contact and they migrate over one another
Cancer cells anchorage dependence
Normal cells display dependency
Cancer cells loss dependency
Loss of e cadherin results in
Development of carcinomas
Reduced expression of adhesion molecules in cancer leads to
Breakdown of cell to cell attachment| cell to matrix attachments
Reduced adhesiveness also results into
Morophological and cytoskeletal alterations
Cancer cells shape
Spherical shape
How do cancer cells escape from home tissue
Secrete proteases that digest extracellular matrix components
Başak lamina ( IV collagen )
Allows the cell to invade
After they enter blood circulation and migrate they produce 2nd tumors
Metastasis
Cancer cells divide 50 times then
Enter resting state and die
Cancer cells fail to undergo
Apoptosis
Normal growth regulatory genes
Cell cycle control genes
Growth promoting gene
Protooncogenes - dominant affect ( activating mutations)
Growth inhibiting genes
Tumor suppressor genes ( inactivating genes ) - recessive effect
Programmed cell death or apoptosis regulation genes
Regulation of apoptosis- توازن بين الحياة و الموت
Are cancer cells resistant to apoptosis?
Yes which allows them to increase number and survive
Cell division and proliferation are regulated by the products of
Proto oncogenes
Tumor suppressor genes
Cell death is regulated by
Antipoptic genes
Apoptic genes
Mechanisms of oncogenesis
1 (+) proto oncogene
2 (-) loss tumor suppressor
3 antiapoptotic genes
Or
4 loss of apoptotic gene
Some tumor suppressor genes
1 directly regulate function ( gatekeepers )
2 more indirectly genome integrity ieisisnwj ( caretakers)
BCL 2
Activated in a B cell lymphoma by chromosomal translocation
P53 mutations
Allow cancer cell to survive and proliferate
Convert a proto-oncogenesis into an oncogene
1 changes : Point mutations
Translocation
Deletion
2 activation by amplification:
موجود في السناب شات
Philadelphia chromosome cause BCR/ABI fusion
Leukemia
