Lecture 3 - Cancer Flashcards
By what is the cell cycle controlled?
Cyclins.
Growth factors increase cyclins through CDKs (cyclin-dependent kinases)
What is differentiation?
process where cell gains specific characteristics.
usually loses its ability to replicate
What is transformation
when a normal cell becomes malignant
What is cancer progression?
invasion and destruction of normal tissue by cancer cells
What is neoplasm?
tumor that spreads through metastasis from primary to distal site
Differences between benign and malignant tumors…
Benign:
- looks like tissue of origin
- slow growth
- encapsulated
- no metastasis
- no necrosis or ulcer
- not fatal
- slight vascularity
Malignant:
- looks different than tissue
- rapid growth
- spreads to other tissue
- metastasis
- necrosis
- recurrence
- fatal
- high vascularity
Of what origins?…
- Carcinoma
- Sarcoma
- Lymphoma
- Leukemia
- Glioma
- epithelial (in situ, invasive)
- connective
- lymphatic
- bone marrow
- glial cells of CNS
Cancer grades…
Grade I: well differentiated
II: increased mitosis
III: much variation in size and shape and greatly increased mitosis
IV: no resemblance to tissue of origin
What do cancer cells lack?
density-dependent inhibition of growth
Manifestations of malignant cells…
local inc in cell # inc mitosis inc nuclear size/density abnormal mitosis and chromes loss of normal arrangement variation in cell shape, size, structure, etc anchorage independent for cell growth
What do tumor cells often produce?
Hormones not usually associated with the tissue.
Called tumor markers
Also growth factors, or are independent of GFs for growth
Proto-oncogene
a gene that may become an oncogene due to inc expression or mutation
oncogene
a gene that has the potential to cause cancer
The master tumor suppressor gene
p53
Environmental factors that cause altered DNA
tobacco diet alcohol pollution UV ionizing radiation
some oncogenic viruses
Human papilloma virus
Epstein-Barr virus
Hepadenoviruses
Human T leukemia virus
Stages of cancer
Initiation: mutation of proto-oncogene or tumor suppressor
Promotion: constant exposure to growth factors or mimics
Progression: now grows in absence of GFs
Immortalization: telomerase activity increases and cancer cells can divide indefinitely
Can our immune system recognize cancer cells as foreign?
Yes. Thus our immune system can help and kill malignant cells
How can cancer cells escape immune system?
alter TAAs - rid of them, alter, cover
inhibit immune system with produced chemicals
Cancer cells are carried to other parts of the body by…
fluid in body cavity
spaces b/w tissues
lymph vessels
blood vessels
manifestations of cancer
Pain Fatigue Cachexia Decreased synth of blood cells leads to anemia, leukopenia, thrombocytopenia
treatments of cancer
chemotherapy radiation surgery immunotherapy hormone therapy decrease angiogenesis
causes of cancer death
infection hemorrhage blood clots anemia weakness due to weight loss loss of function of organs
