Carcinogenisis & Neoplasia Flashcards
Neoplasia means
New Growth
Carcinogensis means
Cancer Causing
What is cancer?
Uncontrolled, invasive, abnormal cell division/growth
‘Cancer’ refers only to
Malignant tumours
Collection of genetic mutations is called
Malignant neoplasm
Where do tumours originate? (4)
Epithelial cells (most common)
cells of blood & lymph system
connective tissue cells
neural cells
Cancer cells evade which process
Apoptosis
Oncogene definition
Any mutated gene that contributes to neoplastic transformation
Oncogenes promote:
Cell growth
cell survival
Oncogenes repress:
Cell death
differentiation
Activation of oncogenes: (4)
Point mutations
Deletions
Gene amplification
Chromosomal translocation
Gene amplification:
results in excessive production of oncogene product
Chromosomal translocation:
Where gene is activated inappropriately by another promoter region
Activation of oncogenes: (mode of action)
increased production of growth factor
increased expression of growth factor receptors
Mutant transcription factor production
over-production of factors that prevent cell death
Cancer preventing genes =
Tumour suppressor genes
A Polyp is a
benign tumour
Carcinogenesis (3 stages in order)
Initiation
promotion
progression
Carcinogenesis initiation is
irreversible genetic alteration of a cancer-related gene. (permanent genetic change in cell)
Carcinogenesis promotion is
clonal expansion of initiated cell
Carcinogenesis progression is
stable alteration of an initiated cell, Gaining ability to invade and metastasise.
Carcinogenic agents (3)
Diet (chemical)
Viruses (biological)
Radiation exposure (physical)
Absestos fibres (physical carcinogenesis) once inhaled cause ……. in the …….
neoplasia, lung
