Unit 6: Cancer

cancer

class/family of diseases caused by uncontrolled cell growth

• more common in older ppl bc of: accumulation of mutations over time (genetic, environmental, consumption/exposure)

severity of cancer has to do w/ stage of tissue affected

stage 1 → stage 4 (metastatic)

Angiogenesis

formation of new blood vessels that feed tumor

metastasis

cancer has spread to other tissues in the body (stage 4)

• occurs through lymphatic, blood/circulatory systems

how are cancer cells defined

by the cell from which they orignicate

• carcinomas

• sarcomas

• leukemias & lymphomas

carcinomas

form in epithelial tissue cells that line organs (protect the body from air & internal fluids)

sarcomas

form in supportive/connective tissues such as bones, muscles, fat, blood vessels, and lymphatic vessels

Leukemias & lymphomas

form in cells in the blood and the immune system

apoptosis

G0 → programmed cell death

• cancer cells are good at evading apoptosis

Cancer arises from DNA mutation caused by:

Enviromental factors: sunlight (UV radiation), X-rays, cigarette smoke, alcohol, some viruses or bacteria

• carcinogen: is a chemical that is capable of causing cancer in living tissue

• mutagen: is a chemical that is known to induce DNA mutations

Genetic Susceptibility

• mutations in genes that cause cancer by disrupting protein functionality (inherited)

Mutations in these genes can cause cancer

tumor suppressor genes: make proteins that regulate/stop cell growth (often protein checkpoints)

• functioning properly slow down division/trigger apoptosis

Oncogenes: promote cell growth/division

• w/o it = uncontrolled growth

• some mutation cause this cell to become a cancer cell

detection & treatment take advantage of fact that cancer cells are dividing rapidly

PET scan: Uses radioactive tracers to identify diseased areas in the body (cells light up)

Biopsy (tissue and blood):

• Pathology (examining the cells for structural abnormalities)

• Genomics (sequencing the DNA for known genetic differences in cancer patients like tumor suppressor genes or oncogenes)
  

treatment of cancer

• chemotherapy: drugs that impact (kill) ALL cells

• immunotherapy: use bodies own immune response to control/limit growth (i.e. CART cells)

• radiation: beams of intense radiation impacting 1 area of cells

• surgery: remove cancerous tissue (i.e. tumor)

Big Picture Points:

• Cancer is a family of similar diseases, not just one disease with one cure.

• Cancer is caused by mutations.

• Drugs are being developed to target specific proteins involved in cell signaling.  Biomarkers can be used to target certain drugs for individual patients.