Carcinogenesis Flashcards
abnormal cells with abnormal growth
Carcinogenesis
Abnormal cell differentiation and growth
Carcinogenesis
T/F: In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues
True
Characteristics of Cancer:
_______________ in growth signals
Insensitivity to ____________
Evasion of ____________
Limitless ____________ potential
Tissue ____________ and ____________
Sustained ____________
Self-sufficiency; antigrowth signals; apoptosis; replicative; invasion and metastasis; angiogenesis
stages of carcinogenesis
- Initiation
- Proliferation
- Promotion
In this stage - cancer is already triggered (irreversible)
Initiation stage
proliferation happens in this stage
Promotion
Promotion is __________ (reversible/ireversible)
Reversible
stage where neoplasia happnes
Progression
Abnormal tissue growth in mucosal surface of colon (most common), ear canal, cervix
BENIGN TUMORS/POLY
Can Benign tumors/poly be removed?
Yes, they are not life threatening
Can Benign tumors/poly become malignant?
Yes
Non Cancerous cells
Benign turmors
Benign tumors are found in
mucosal surface of colon (most common), ear canal, cervix
types of malignant tumors
carcinoma
sarcoma
epithelial origin
carcinoma
superficial origin
carcinoma
Most common. Cancer of the skin or organ lining e.g., liver or kidneys
carcinoma
of mesenchymal origin
sarcoma
liquid type
sarcoma
connective tissues
sarcoma
loosely packed and can travel to new positions (e.g. blood vessels)
sarcoma
Cancer of connective tissue e.g., bones, muscles, cartilage, & blood vessels
sarcoma
Blood cancers
Leukemia
Hodgkin or non-hodgkin lymphoma, multiple myeloma
Bone marrow CA
Leukemia
CA of the immune system
Hodgkin or non-hodgkin lymphoma, multiple myeloma
with presence of Reed-Sternberg cells
Hodgkin
These are giant cells found in Hodgkin Lymphoma
Reed-Sternberg cells
Agents that causes change in the gene structure
Mutagens
Mutagens may result from misread DNA through __________ and __________,__________ or broken DNA stands
transitions; transversions; frame-shifting
alter transcription due to insertion/deletion leading to incorrect DNA sequence
Frame shifting
T/F: Frame shfiting may prodce malfunctioning cells
true
DIRECT-ACTING GENOTOXIC CARCINOGENS
Carbonium ions
Nitrenium Ions
Free radicals
Diazonium ions
Epoxides
Aziridinium ions
Episultonium ions
Strained lactones
Sulfonates
Halo ethers
Enals
T/F: The development of cancer following exposure to chemical
carcinogens is a relatively rare event because of a cell’s ability to recognize and repair DNA.
True
DNA Repair mechanism:
The DNA region containing the adduct is removed and a new patch of DNA is synthesized, using the opposite intact strand as a template. The new DNA segment is then spliced into the DNA molecule in place of the defective one. To be effective in restoring a cell to normal, repair of DNA must occur prior to cell division.
Cut-and-Patch by pol 1
According to Cut-and-Patch by pol 1, to be effective in restoring a cell to normal, repair of DNA must occur _____________ (before or after) cell division.
prior/before
In Cut-and-Patch by pol 1, the DNA region containing the adduct is __________ and a new patch of DNA is synthesized, using the ________________ as a template.
removed; opposite intact strand
Fragment translation by pol 1
nick translation by pol 1
Typically repairs chemically modified nucleobases
Base Excision or Mismatch Repair of Single-base Mispairs
Removes altered base in the Base Excision or Mismatch Repair of Single-base Mispairs DNA repair mechansim
DNA glycosylase
In Base Excision or Mismatch Repair of Single-base Mispairs DNA repair mechansim, _________ fills the gap created by DNA glycosylase
pol 1
Cut DNA near apurinic sites
Apurinic endonucleases
The cut by apurinic endonucleases is then extended by ____________, and the resulting gap is repaired by _____________ and ____________
exonucleases; DNA polymerase and ligase
In this repair mechanism, photolyase Binds T-T cyclobutane dimer → Individual pyrimidine bases
Photoreactivation Repair
In photoreactivation repair mechanism, photolyase binds to ____________ (________) resulting to an individual _________ bases
T-T cyclobutane dimer (Thymine-thymine); pyrimidine