7 Neoplasia Flashcards
anaplastic
cells in MALIGNANT TUMORS that have lost their mature or specialized features.
suffixes
BENIGN = “-oma”
MALIGNANT = “-carcinoma” “-sarcoma”
exceptions to benign=”-oma” rule
lymphoma
hepatoma
melanoma
*all three are malignant
carcinoma
epithelial origin
-malignant
sarcoma
mesenchymal (nerve, bone, muscle)
-malignant
genetic mechanisms of cancer
1 carcinogen
2 oncogene
3 tumor suppressor gene
carcinogen
potential cancer-causing agent
types oncogene
1 proto-oncogene in its mutant overactive form
2 proto-oncogene enhance the growth-producing pathways
tumor suppressor gene
- inhibits cell proliferation
- cancers may arise when tumor suppressor gene function is lost or abnormally inhibited
oncogene
normal cellular genes that can be transformed into oncogenes by activating “gain of function” mutations
what does gain-of function mutations code for?
1 growth factors
2 receptors
3 cytoplasmic signaling molecules
4 nuclear transcription factors
proto-oncogene
become activated oncogenes when mutations alter their activity so that proliferation-promoting signals are generated inappropriately
4 retroviruses
1 HIV
2 EPSTEIN-BARR VIRUS
3 HUMAN T-LYMPH VIRUS TYPE 1
4 HEPATITIS C
HIV cancer
kaposi’s sarcoma
EPSTAIN-BARR VIRUS
burkitt lymphoma
HUMAN T-LYMPH VIRUS TYPE 1
adult T-cell leukemia/lymphoma
tumor-supperssor genes
contribute to cancer only when NOT present
- loss of function
- stops cell cycle for repairment
- one can inherit a defective tumor-suppressor gene which incr the risk of cancer
autosomal recessive
both copies of tumor suppressor genes are inactivated when cancer develops
Rb Gene
- normally “master brake” for cell cycle
- normally blocks/stops cell division
- -binds to transcription factors to inhibit fr transcribing
p53 gene
- most common tumor-suppressor gene defect ID’d in cancer cells
- normally inhibits cell cycling
- more than half of all types of tumors lack functional p53
BRCA1 + BRCA2 Genes
associated w breast cancer
metastasis
- process by which cancer cells escape their tissue of origin and initiate new colonies of cancer in distant sites
- cancer cells generally
how do cancer cells generally spread in metastasis?
via circulatory or lymphatic systems
survival signal
suppresses apoptosis
hypercalcermia
high calcium in blood
effect of paraneoplastic syndrome/cancer
radiation therapy
- radiolysis (damages cell DNA)
- may not directly kill cells, initiates apoptosis
- targets all rapidly dividing cells (even normal ones)
drug therapy
- most are cytotoxic
- targets all rapidly dividing cells (even normal ones)
