4 - Neoplasia Flashcards
Metastasis
Dissemination of neoplastic cells to discontinuous secondary sites where they proliferate to form a macroscopic mass
Metastasis has decreased
E - cadherin
Metastasis steps
Cancer cells leaves the site of primary tumor, pass through to tumor basement membrane then through or between endothelial cells, enter the circulation , resist annoikis, evade immune recognition, arrest at distant organs , leave circulation, survive in a hostile microenvirommetn
What is inefficient
Metastasis
What % of cancer cells survive at distant sites
1
Premetastatic niche
Modulation of the secondary micro environment before the cancer cell arrive
The commone feature of cancer is
Uncontrolled cellular proliferation
Tumors arise from
Accumulation of mutations
Neoplasms evade
Normal constrains of proliferation
Mutations can be
Inherited or environmental
Most mutations are silent and
Do not affect cell function
What are examples of preneoplasia
Hypertrophy , hyperplasia, metaplasia and dysplasia
You can go from preneoplastic back to normal cells, but not
Neoplastic back to preneoplasti/normals
Multi - stage carcinogensis results from
Accumulation of mutations in a stepwise fashion overtime
What is the key to carcinogenesisi
Non lethal genetic damage
Tumor is formed by what type of expansion
Clonal expansion
What are the steps of mutations
Initiation, promotion, ad progression
Initiation
Mutation of a single gene, irreversible
ProMotion
Proliferation of the initiated cell in response to stimuli
Promotion can result in
Formation of a benign tumor
Is promotion reversible
Yes
Progression is
Benign to malignant
An accumulation of mutations lead to
Uncontrolled cell growth
What are some intrinsic factors which allow mutations to arise
Inherited, hormonal, reactive oxygen intermediates
Hormonal intrinsic factors causing mutations, what is an example of this
Mammary tumors and perianal tumors
What is an example of intrisinic ROS
Aging and inflammation
Inflammation causing mutations can produce tumors such as
SCC in dogs, feline injection site sarcomas, FPTOS
FPTOS what is the time period between trauma and diagnosis
7 year
What viruses cause lymphoma
Bovine leukosis, avian leukosis, and feline leukemia
Insertional mutagenesis reliever
Oncogenes or disrupt cellular oncogenes
Bovine papillomaviruses can cause e
Equine sarcoidosis
Complete carcinogen
Can push through all three stages on their own
What is an examples of complete carcinogen
Ultraviolet radiation
4 examples of genes that mutations that can be critical for neoplasms to arise
Proto-oncogenes, tumor suppressor genders, DNA repairs genes, genders that regulate apoptosis
Protoconcogenes
Excess of stimulation of the cell cycle
Tumor suppressor genes
Deficiency of cell cycle inhibition
DNA repair genes
Failure to recognize and repair damaged DNA
Genes that regulate apoptosis
Failure to induce apoptosis on injured cells
G1/S cell cycle
Monitors DNA integrity, irreversibility commits cell resources to DNA replication
What happens after G1/S checkpoint
Cell replication occurs independently to Extracellular growth signals
G2/ M checkpoint
Pre-mitosis check point that ensures DNA replication is accurate before the cell divides
Which cell cycle checkpoint checks for DNA synthesis errors
G2/M
Which cell cycle checkpoints make sure DNA is safe to duplicate
G1/S
Protooncogenes are genes taht promote
Autonomous cell growth
What can cause Genoese that promote cell growth to mutate
Growth factors are overproduced, growth factor receptors, cycling are over-produced and allow progression through the cell cycle
When mutated, protoncogenes turn to
Oncogenes
Tumor suppressor genes aer genes that stop
The cell cycle
What are samples of tumor supressor genes
P53
DNA repair genes allow accumulation of
More and more mutations
