Most cancers result from _______ cell mutations
somatic
Cancer cell shared properties:
- __________ cell proliferation
- __________ spread
uncontrolled
metastatic
All cancer cells in primary and secondary tumors are ______, meaning that they originated from a common ancestral cell that accumulated numerous specific mutations.
clonal
____-related cancer is an indication that cancer develops from the accumulation of several mutagenic events.
age
The multistep nature of cancer development is supported by the observation that cancers often develop in _______ steps
progressive
________ cancer is a good example that cancers develop in progressive steps
cervical
Cancer cells contain genetic defects affecting genomic _______ and DNA ______
stability; reapir
The high level of genomic instability in cancer cells is known as the ________ phenotype
mutator
translocations, aneuploidy, chromosome loss, DNA amplification, and chromosomal deletion are examples of the genomic _______ caused by cancer
instability
Cancer cells contain genetic defects affecting ____ ______ regulation
cell cycle
Cell cycle
G0-G1-S-G2-M
cell cycles do not enter which cell cycle phase, why?
G0, that’s where cell stop proliferating
Cancer cells often have defects in _______ ________ pathways, which is why they do not enter which cell cycle phase. . .
signal transduction; G0
Regulation of cell cycle progress is mediated by ______ and _____-________ ______ (____s).
cycilin and cylcin-dependent kinases
Cells halt progress through the cell cycle if DNA replication, repair, or chromosome assembly is _________
aberrant
A series of proteases called _______ are responsible for initiating apoptosis and for digesting intracellular components.
capases
cyclin-dependent kinases do what?
regulate cell cycle
Most inherited cancer-susceptibility genes ARE / ARE NOT sufficient in themselves to trigger cancer development
are not
Mutations in other genes are also usually _______ to fully express the cancer phenotype.
necessary
Most animal viruses that cause cancer are _________
retroviruses
A retrovirus can cause cancer by integrating near or integrating a copy of of this into its genome . . .
a proto-oncogene
The _____ oncogene may be mutated or expressed at abnormal levels.
viral
. . . are genes whose products promote cell growth and division
proto-oncogenes
. . . is a proto-oncogene that is mutated or aberrantly expressed and contributes to the development of cancer
oncogene
proto-oncogene vs oncogene
proto-oncogene - promote cell growth and division
oncogene - mutated to overexpress
The products of . . . genes normally regulate cell cycle checkpoints
and initiate the process of apoptosis
tumor suppressor
cyclin ___ and __ are proto-oncogenes that act at what cell cycle junction
D1 and E; G1-S
___ genes encode signal transduction molecules that regulate cell growth and division
ras
how do mutations that convert ras proto-oncogenes to oncogenes work?
freeze in active conformation, causing constant division
Cells lacking ____ are unable to arrest at cell cycle checkpoints or enter apoptosis in response to DNA damage
p53
retinoblastoma protein (pRB) is a . . . protein
tumor suppressor
retinoblastoma protein (pRB) controls the __/__ cycle checkpoint
G1-S
oncogenes vs tumor supressor genes
- regulation of cell growth
oncogenes: POSITIVE regulation
TS: NEGATIVE regulator
oncogenes vs tumor supressor genes
- regulation of cell growth
oncogenes: POSITIVE regulation
TS: NEGATIVE regulator
oncogenes vs tumor supressor genes
- ACTIVE VS INACTIVE forms promotion of malignancy
oncogenes: ACTIVE promote
TS: INACTIVE promote
oncogenes vs tumor supressor genes
- mutated form dominant vs recessive
oncogenes: mutant is DOMINANT
TS: mutant is RECESSIVE
____ is mutated in 40% of human
tumors.
Ras
___ genes encode signal transduction molecules that regulate cell growth and division.
ras
In cancer cells, what changes in Ras
unregulated
The _________ protein (pRB) is a tumor suppressor protein
retinoblastoma
Loss or mutation of the
____ tumor suppressor gene contributes to unregulated progression through the cell cycle.
RB1 (retinoblastoma protein 1)
Mutations in other genes are also usually necessary to fully express the cancer phenotype. An example is the development of . . .
familial adenomatous polyposis (FAP)
Mutations in other genes are also usually necessary to fully express the cancer phenotype. An example is the development of . . .
familial adenomatous polyposis (FAP)
______ contribute to Cancer in Both Humans and Animals
viruses
Most animal viruses that cause cancer are _______
retroviruses
A retrovirus can cause cancer by integrating ____ a proto-oncogene or by integrating a copy of a host proto-oncogene _______(where?)
near; its genome
retrovirus infects a cell and inserts a ________ near a strong viral promoter
provirus
a provirus (inserted by a retrovirus) causes a promoter to stimulate over-expression of a . . .
proto-oncogene
v-onc stands for
oncovirus (viral oncogene)
differences between c-onc and v-onc:
- introns?
c-onc - introns
v-onc - no introns
c-onc stands for
cellular oncogene
differences between c-onc and v-onc:
- active state
c-onc - encode proteins in active or inactive state
v-onc - encode proteins in active or inactive state
_______-________ transition: means by which transformed epithelial cells invade
epithelial-mesenchymal
Any substance or event that damages DNA has the potential to be _______ if it causes mutations to occur in proto- oncogenes or tumor suppressor genes
carcinogenic
carcinogenic means…
causes cancer
________ include chemicals, radiation, some viruses, and chronic infections.
carcinogens