NEOPLASIA II Flashcards
tumor mass results from clonal expansion of a single progenitor cell that has incurred genetic damage
monoclonal theory of cancer
the cause of carcinogenesis; nonlethal because dead cells cant replicate
non lethal genetic damage
growth promoting genes, generally responsible for cancer
proto oncogenes
growth inhibiting genes
tumor suppressor genes
RAS is the #1 gene under this category
point mutation
fusion of gene w/ new sequences, places genes next to strong promoters/enhancers
translocation
translocation from 9 to 22
philadelphia chromosome
amplification of n-MYC gene in human neuroblastomas is an example of?
gene amplification
loss of tumor suppressor gene or apoptosis of regular gene; second most prevalent abnormality
deletions
non coding single stranded RNA’s, 22 nucleotides long
microRNAs
reversible heritable changes in gene expression, occurring without mutation
post translational mods of histones and DNA methylation
epigenetic modification
number of chromosomes is not a multiple of the haploid state (23); common in malignancies
aneuploidy
multi step process at both phenotypic and genetic levels, resulting from the accumulation of multiple mutations
carcinogenesis
a malignant genotype mutated or overexpressed versions of normal genes that induce a transformed phenotype when expressed in cells
oncogenes
normal cellular genes that control growth growth and differentiation
proto oncogenes
normal cellular genes that prevent uncontrolled growth
tumor suppressor genes
classic tumor suppressors like RB gene involved in the TGF-B pathway
governors/promotors
these sense genomic damage like the p53 gene
guardians/caretakers
normal cellular genes that prevent mutations in other genes to be passed onto daughter cells
DNA repair genes
best to consider these genes in the context of 6 fundamental changes in cell physiology which dictate the malignant phenotype
cancer related genes
these bind to cell membrane and inhibit growth
growth inhibitory factors
down regulation of growth promoting signals
signal transduction
carcinogenesis is a multistep process
non random chromosomal abnormalities
no single oncogene can fully transform cells
every cancer has multiple genetic alterations
molecular basis
