Neoplasia I - Nichols Flashcards
Define desmoplasia.
formation of abundant fibrous stroma by some carcinomas
What is carcinoma in situ?
tissue with all the cytologic (individual cel) features of malignancy without visible invasion
What differences would you see between anaplastic and dysplastic cells under a microscope? What about malignant cells?
anaplasia - lack of visible differentiation of cells. Larger in size, larger nuclei and smaller cytoplasms, varying size and shape, angulated shape, hyperchromatism, clumped chromatin, mistoses and nuclei.
Dysplasia - disordered growth and varying size. Will look more varied than anaplasia and have different cell types.
Malignant - invasive, usually extending through basement membranes. Lack of differentiation.
What are the 5 most common causes of cancer in the US in order?
- smoking
- obesity
- alcohol
- diet
- HPV
- UV light
- asbestos and other carcinogens
What are the 4 most common causes of cancer death in the US in order?
- Lung
2-3. Breast (women) and Prostate (men) - Colon
What are the 9 most common types of cancer caused by smoking?
- over 90% in lungs
- mouth
- pharynx
- larynx
- esophagus
- stomach
- pancreas
- kidneys
- bladder
What are the 6 hallmarks of cancer?
- self-sufficiency in growth signals
- insensitivity to suppression signals
- evasion of apoptosis
- sustained angiogenesis
- limitless replicative potential
- ability to invade tissue and metastisize
What is the RB tumor suppressor gene?
Involved in retinoblastoma. Normally prevents cell proliferation by binding to E2F transcription factor when it is hypophosphorylated. When Rb is phosphorylated by cyclinD-CDK4 and cyclinE-CDK2 complexes it releases E2F and E2F is activated, stimulating cell proliferation.
What is the APC tumor suppressor gene?
tumor suppressor gene that controls intestinal stem cell proliferation by WNT signaling. Breaks down beta-catenin so it does not bind to transcription factor TCF, which activates many genes that promote cell proliferation. Mutations in APC are present in 100% of familial colon cancers.
What is the p53 tumor suppressor gene?
tumor suppressor gene. prevents propagation of genetically damaged DNA, arresting the cell cycle to enable DNA repair and initiating apoptosis when repair is impossible. Half life of only 20 minutes and is degenerated by ubiquitin. Is destroyed by MDM2.
What is the NF-1 tumor suppressor gene?
suppressor genes in neurofibromatosis. activates a GTPase, creating GDP that binds to cell membrane RAS protein, inactivating the RAS so it does not transduce growth factors for proliferation. Mutations will cause uncontrolled growth factor production.
What is the Von Hippel Lindau tumor suppressor gene?
(VHL). tumor suppresssor. Causes ubiquitination and degradation of HIF-1 (hypoxia inducible transcription factor-1) that would cause increased PDGF and VEGF if left around. Mutations in it cause kidney cancer, pheochromacytoma (adrenal medullary tumor), retinal angioma and other tumors.
What are the features of the HER2 oncogene?
is an EGFR receptor that is commonly overexpressed in breast cancers.
What are the features of the K-RAS oncogene?
oncogene that codes for a GTPase in the cytoplasm on the inner side of the cell membrane bound to the EGFR. It carries out signal transduction from cytoplasm to nucleus when EGFR binds growth factors, causing the cell to proliferate. When EGFR binds, it stimulates K-RAS to make more GTPase to convert the GTP to GDP. High GTP levels cause unrestricted proliferation.
What is a teratoma?
a mixed germ cell tumor. Has componenets of more than one germ cell layer, usually all three (ectoderm, mesoderm and endoderm). Can be benign or malignant
What is a hamartoma?
mass of mature but disorganized tissue indigenous to its site and a is a developmental anomaly.
What is a choristoma?
ectopic rest or mass of normal tissue present outside its normal site. A developmental anomaly.
