Neoplasia and carcinogenesis Flashcards
What is a neoplasm
Cause of neoplasm and its properties
-formation of new abnormal mass of tissue whose growth and exceeds and is unco-ordinated with that of normal tissue
/genetic alternations ( autonomous, clonal -originates from single cell which proliferates )
Benign mesenchymal nomenclature and exceptions
- add oma to tissue and
sarc , lymph , melan , carci / if -oma present in these names then malignant
Mesenchymal malignant name
Epithelium benign and malignant names
-sarcoma
- adenoma ( tumor forming glands )
- papilloma ( tumor with finger like projections )
-carcinoma
What does a proto-oncogene do
-is a gene sequence which codes for proteins that regulate how often a cell divides and degree of specialization ( controls cells growth and differentiation)
4 classes of regulatory genes
1 tumor suppressor genes
2 Proto-oncogenes
3 apoptosis genes
4 DNA repair genes
Describe how a normal cell can become a mestatic tumor
- normal cell damaged DNA by environmental insults or mutation in DNA repair genes or genes affecting growth and apoptosis
- genome mutates in cells
- activation of proto-oncogenes and abnormal of tumor suppressor genes, apoptosis genes and DNA gene
- uncontrolled cell growth ( angiogenesis)and proliferation ( clonal expansion )
- tumor evades immunity and apoptosis and now malignant
What is carcinogenesis
What is a carcinogen
-process by which normal cells are transformed into neoplastic cells through DNA damage
/agent which causes alterations in DNA leading to tumor formation
Can one oncogene and tumor suppressor gene mutation cause cancer
What is gatekeeper and caretaker
What is heterogeneity
-No
- Proto-oncogene and tumor suppressor genes
- DNA repair gene
-originating form a single cell
What are promoters and initiators
Can either one on its own cause cancer
- promoters cause proliferation ( are hyperplasia inducing agents )
- initiators are carcinogens ( cause mutations )
- needed together to cause neoplasm formation
Why are carcinogens do elusive
/they cause mutations in a hit and run fashion
Ways to identify carcinogens
1 epidemiology Study
2 occupational risk factors
3 testing mutagenicity laboratory animals
4 testing mutagenicity in bacteria
What are oncogenes and their effects
What is gene mutation
/these are mutated Proto-oncogene which are mutated thus permanently turned on and cause uncontrollable proliferation of cells
-alteration of base pairs making a diff gene sequence and thus diff protein made
2 types of gene mutation
1 germ line - hereditary
2 aquired - spontaneous
List the 5 classes of oncogene proteins and describe
1 growth factors - cause uncontrollable cell growth by overproduction of PDGF
2 growth factor receptors - mutations can make receptor permanently on stimulating growth
3 transcription factors - excess can make proteins which stimulate growth
4 signal transducers - intermediate between receptor and nucleus
5 programmed cell death receptors - when in excess prevent apoptosis
Function of tumor suppressor genes
1 normal genes that slow down division
2 repair DNA
3 initiate apoptosis
Diff between oncogene and TSG in causing neoplasm formation
- oncogene is turned on and TSG deactivated
- oncogene mostly through spontaneous and TSM acquired and spontaneous
What happens if DNA repair gene mutated
-no protein to repair errors or breaks and this leads to any damage left unrectified and causes neoplasm formation ( activate oncogene or deactivate TSM )
What happens if apoptosis genes in excess and if abnormal
-cell cannot undergo suicide / programmed cell death
/no signal to stimulate cell death
Describe the diff in
- rate of growth
- differentiation
- local invasion
- metastasis
Of benign and malignant tumors
- slow but progressive , mitosis normal
- frequent and mitosis abnormal
- well differentiated
- anaplasia
- cohesive growth, capsule not breached
- no cohesive , infiltrative
- absent
- present
What is dysplasia
- abnormal growth with some ( but not all ) features of malignant tumors
- may or may not become malignant
List stages of malignant neoplasm based on staged
1 in-situ carcinoma - in epi without going through basement membrane
2 micro invasion - beyond point of origin and past basement membrane
3 local invasion - within organ of origin
4 local mestases - at nearest lymph nodes of organ
2 indicators of malignant neoplasm
1 metastasis - best
2 invasion - next best
List gradings of malignant neoplasm based on differentiation
1 well differentiated
2 moderately
3 poorly
4 anaplasia
( higher grade ie the more the anaplasia , worse prognosis )
Cystolic features of malignant neoplasm
1 increased cellular size
2 lack of differentiation
3 increased nuclear content ( hyperchromatism )
4 prominent nuclei
