Lecture 1- Basics and Definitions Flashcards
Define cancer (according to WHO)
a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body
Two main characteristics of cancer.
- uncontrolled growth
- can spread to other organs
Define hyperplasia
an increase in the number of cells in an organ or tissue; these cells appear normal under a microscope
Define metaplasia
a change of cells to a form that does not normally occur in the tissue in which it is found
Define dysplasia
a term used to describe the presence of abnormal cells within a tissue or organ; not cancer, but sometimes may become cancer
Define neoplasia
tumor; an abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they should; may be benign or malignant;
Define benign neoplasms
may grow large but do not spread into (invade) nearby tissues or other parts of the body
Define malignant neoplasms
can spread into, invade, nearby tissues; can also spread to other parts of the body through blood and lymph systems
All ______ are _______, but not all _________ are _________.
cancers; neoplasm/tumor; neoplasm/tumor; cancer
Match the word to the image: cancer, hyperplasia, normal, dysplasia
normal, hyperplasia, dysplasia, cancer
Benign vs. Malignant Tumors
Benign: no, slow, differentiated, no, yes, +
Malignant: yes, fast, undifferentiated, yes, no, +++
Define carcinoma
cancers derived from epithelial cells
Ex: breast, prostate, lung, pancreas, colon, etc
Define sarcoma
cancers arising from connective tissue
Ex: bone, cartilage, fat, nerve
Define lymphoma/leukemia
these two classes arise from immature cells that originate in the bone marrow, and are intended to fully differentiate and mature into normal components of the immune system (lymphoma) and blood (leukemia)
Define germ cell tumor
Cancer derived from pluripotent cells, most often presenting in testicle/ovary
Define blastoma
cancers derived from immature (precursor) cells/embryonic tissue; generally, but not always, more common in children than older adults
Define oncogene
gene that is a mutated form of a gene involved in normal cell growth; may cause the growth of cancer cells; mutations in genes that become oncogenes can be inherited or caused by being exposed to substances in the environment that cause cancer
What are the categories of oncogenes?
growth factors (mitogens), receptor tyrosine kinases, cytoplasmic tyrosine kinases, cytoplasmic serine/threonine kinases (and regulatory subunits), regulatory GTPases
What are the gene function of growth factors?
aka mitogens; induces cell proliferation
Ex: melanoma
What are the gene functions of receptor tyrosine kinases?
transduce signals for cell growth and differentiation
Ex: breast cancer
What are the gene functions of cytoplasmic tyrosine kinases?
mediate the responses to, and the activation receptors of cell proliferation, migration, differentiation, and survival
Ex: colorectal cancer
What are the gene functions of cytoplasmic serine/threonine kinases and their regulatory subunits?
involved in organism development, cell cycle regulation, cell proliferation, differentiation, cells survival, and apoptosis
Ex: malignant melanoma
What are the gene functions of regulatory GTPases?
involved in signaling a major pathway leading to cell proliferation
Ex: thyroid tumors
Define tumor suppressors
a type of gene that makes a protein called a tumor suppressor protein that helps control cell growth; mutations in these tumor suppressor genes can lead to cancer; aka anti oncogene
What happens when a copy of a tumor suppressor gene (TSG) is inactivated? How can it be inactivated?
can be followed by other mechanisms that facilitate loss of the other gene copy; usually depend on loss of heterozygosity (LOH); inactivation can include mutation or methylation
What is the function of the gene Rb
DNA replication, cell division, death
What is the function of the gene p53?
apoptosis
What is the function of the gene VHL?
cell division, death, and differentiation
What is the function of the gene APC?
DNA damage, cell division, migration, adhesion, death
What is the function of the gene BRCA2?
cell division and death, repair of double-stranded DNA breaks
What is the function of the gene NF1?
cell differentiation, division, development, RAS signal transduction
What is the function of the gene PTCH?
hedgehog signaling
Define apoptosis
programmed cell death; a type of cell death in which a series of molecular steps in a cell lead to its death; this is one method the body uses to get rid of unneeded or abnormal cells; may be blocked in cancer cells
Define necrosis and list the steps
a form of traumatic cell death as a result of acute cellular injury
- always pathological
- cell enlargement
- loss of membrane integrity
- leakage of content
- inflammation
- nuclear degeneration
Apoptosis vs. necrosis
Apoptosis: both internal and external; condensed; remain intact; no/physiological; ladder-like; active; required; individual cells only; engulfed by surrounding cells
Necrosis: external; increase or swollen; disrupted; yes/pathological; random/smeared; passive; depleted; surrounding cells; no
What are the steps of the metastasis cascade?
- local invasion
- intravasation
- transportation
- arrest in microvessels
- extravasation
- micrometastasis formation
- colonization and macrometastasis
Criteria:
T- tumor size
N- node involvement (lymph)
M- metastasis
What criteria is involved in each stage of cancer?
Stage 1: T< 2cm
Stage 2: T< 5cm; N
Stage 3: T> 5cm; N
Stage 4: T> 5cm; N; M
What is the TNM system of cancer description
When a cancer is described by the TNM system, it includes number after each letter indicating the severity of each event
Ex: T1N0MX
(x means cannot be measured)
What are some cancer treatment options?
- hormone therapy
- surgery
- bone marrow transplant
- chemotherapy
- targeted therapy
- radiation therapy
- immunotherapy
Describe each stage of a clinical trial
Phase I: tests if a new treatment is safe and looks for the best way to give the treatment
Phase II: tests if one type of cancer responds to the new treatment
Phase III: tests if a new treatment is better than a standard treatment
Phase IV: trials find more information about long-term benefits and side effects
