Cancer Pharm Flashcards
adenoma
tumors that start in the epithelial tissue of a gland
fibroids
made of connective tissue, often form in the uterus, can lead to bleeding, bladder problems and pelvic pain
lipoma
formed by fat cells, most common benign tumors
meningioma
develop in the brain and spinal cord membranes, commonly benign
nevi
typically known as moles and appear on the skin
oncogene
mutated form of a gene involved in normal cell growth
structurally and functionally heterogeneous group of genes
PDGF-β
platelet-derived growth factor-beta
proto-oncogene: PDGFB
mode of activation: overexpression
associated tumor: astrocytoma
fibroblast growth factors
HST1: overexpression, osteosarcoma
FGF3: amplification, stomach/bladder/breast cancer, melanoma
TGF-α
transforming growth factor alpha
TGFA, overexpression
astrocytomas
HGF
hepatocyte growth factor, aka “scatter factor”
overexpression, hepatocellular carcinomas
growth factor receptors, RAS, PI3K, MYC, and D cyclins
oncoproteins that are activated by mutations in various cancers
GTPase-activating proteins (GAPs)
apply brakes to RAS activation
phosphatase and tensin homologue (PTEN)
applies breaks to PI3K activation
BCR-ABL
target of imatinib
p53
important at G1/S and G2/M checkpoints
restriction point
G1 phase cell cycle checkpoint at which the cell becomes “committed” to the cell cycle
after this extracellular signals are no longer required to stimulate proliferation
phosphorylation of retinoblastoma (Rb) gene protein
occurs in nucleus
unphosphorylated Rb inhibits E2F-mediated transcription
pRb –> E2F mediated transcription of cyclins A & E
overactive CDKs and underactive CKIs lead to
decrease stringency of constriction point
activation of normal p53 by DNA-damaging agents or by hypoxia leads to
cell cycle arrest in G1 and induction of DNA repair by transcriptional upregulation of the cyclin-dependent kinase inhibitor CDKN1A (encoding the cyclin-dependent kinase inhibitor p21) and GADD45 genes
TP53 gene –> p53 protein
guardian of the genome
more energy obtained from glycolysis, less from
O2 consumption if cells or growing and/or cancerous –> Warburg effect
3 IDH isoforms in humans
mutations in the isocitrate dehydrogenase gene IDH1 found in several brain tumors
mutations of IDH2 and IDH1 were found in up to 20% of cytogenetically normal acute myeloid leukemia (AML)
2-hydroxyglutarate
oncometabolite
Wnt
gate keeper of colonic neoplasia
E-cadherin sequesters
β-catenin
curative surgery
removes cancerous tumor or growth
used when tumor is localized
often considered primary treatment but may have radiation before/after
preventative surgery
removes tissue that does not contain cancerous cells, but may develop into a malignant tumor (e.g., colon polyps)
diagnostic surgery
samples tissue for pathologist to determine if cells are cancerous and then type+/-stage if cancerous
staging surgery
works to uncover the extent of cancer by , for example, via laparoscopy and biopsy
debulking surgery
removes a portion of a cancerous tumor when all cannot be removed with hope that radiation or chemotherapy can treat the rest
palliative surgery
used to relieve discomfort the cancer or its treatment efforts may have created
supportive surgery
helps other cancer treatments work more effectively (eg, insertion of catheter)
restorative surgery
used to change or restore a person’s appearance or the function of a body part (e.g., breast reconstruction after breast cancer, mouth reconstruction after oral cancer)
cryosurgery
surgery technique that uses extremely cold temperatures (eg, liquid nitrogen or “cryoprobe”) to kill cancer cells, most often for skin cancer or cervical cancer
laser surgery
uses laser beams to precisely remove very small cancers (w/o damaging surrounding tissue), to shrink or destroy tumors, or to activate drugs to kill cancer cells
can be used to treat body areas that are difficult to reach including the skin, cervix, rectum, and larynx
electrosurgery
uses electrical current to kill cancer cells, sometimes used for skin or oral cancer
microscopically controlled surgery
used for surgery with delicate parts of the body (eg, eye) where layers of tissue are carefully removed until cancerous cells cannot be detected
radiation therapy
one of the most common treatments for cancer
given to >1/2 of people with cancer
not useful if cancer has spread to multiple sites
radiation therapy mechanism
uses high-energy particles or waves, such as x-rays, gamma rays, electron beams or protons –> small breaks in DNA
impairs cell growth and division –> cell death
cure or shrink early-stage cancers as these tend to be very sensitive to radiation
used in effort to prevent cancer from recurring elsewhere
radiation therapy given as
external beam radiation focused on tumor internal radiation (brachytherapy) where a radioactive source is put into/near the tumor systemic radiation … eg, by attaching radionuclide to monoclonal antibody that targets the cancer cells
brachytherapy
internal radiation where a radioactive source is put into or near the tumor
external beam radiation therapy
most often X-rays
ionizing radiation causes breaks in the DNA, including double-stranded breaks
brachytherapy
radioactive sources (ie, “seeds”) placed in intimate contact with the cancerous tumor or gland to cause breaks in the DNA, including double-stranded breaks can be “low-dose” over 1-7 d, “high-dose” over 10-20 min repeated over a few weeks or permanent these patients emit radiation
only cell cycle independent agents mess with DNA structure
alkylating agents, platinum compounds: cross-link DNA
anthracyclines, tiactinomycin: DNA intercalators
bleomycin: DNA strand breakage
selectively toxic in G2and M phases… seems to rely on chelation of iron –> ROS –> DNA breaks
interfere with DNA function
etoposide/teniposide: inhibits topiosomerase II
irinotecan/topotecan: inhibits topiosomerase I
cancer drugs are highly toxic and are routinely administered based on ____
body surface area
classic chemotherapy resistance
mediated by ATP-binding cassette superfamily protein ABCB1 (aka MultiDrugResistance1)
ABCB1
codes for xenobiotic pump phenolic glycoprotein (P-gp)
other cancer cell fortress against drugs
up-reg drug detox mechanisms (CYP450) reduced apoptosis altered proliferation increased DNA damage repair altered drug targets
MDR1 Transporter (ABCB1) roles
helps rid body of waste (liver –> small intestine, kidney)
antitumor antibiotics
bleomycin
dactinomycin
anthracyclines (doxorubicin, daunorubicin)
bleomycin
antitumor antibiotic
mechanism: induces free radical formation, G2/M phase specific
use: testicular cancer, Hodgkin lymphoma
adverse effects: pulmonary fibrosis, skin hyperpigmentation
dactinomycin
antitumor antibiotic
mech: intercalates into DNA, prevent RNA synthesis
use: Wilms tumor, Ewing sarcoma, rhabdomyosarcoma
adverse: myelosuppression
anthracyclines 2
doxorubicin
daunorubicin
anthracyclines
antitumor antibiotic
mech: generate free radicals, inhibits topiosomerase II
use: solid tumors, leukemias, lymphomas
adverse: dilated cardiomyopathy, myelosuppression
antimetabolites
thiopurines (azathioprine, mercaptopurine) cladribine, pentostatin cytarabine (ara-C) 5-fluorouracil hydroxyurea methotrexate
thiopurines: azathioprine, mercaptopurine
antimetabolite
mech: purine (thiol) analogs –> decrease de novo purine synthesis
use: RA, IBD, SLE, ALL, prevention of organ rejection
adverse: myelosuppression, GI/liver toxicity, increase toxicity with allopurinol or febuxostat
cladribine and pentostatin
antimetabolites
mech: purine analogs lead to multiple mech
use: hairy cell leukemia
adverse: myelosuppression
cytarabine (ara-C)
antimetabolite
mech: pyrimidine analog –> DNA termination, inhibit DNA polymerase
use: leukemias (AML), lymphomas
adverse: myelosuppression
5-fluorouracil
antimetabolite
mech: pyrimidine analog bioactivated to 5-dUMP –> thymidylate synthase inhibition –> decrease DNA synthesis
use: colon/pancreatic cancers, actinic keratosis, basal cell carcinoma
adverse: myelosuppression, hand-foot syndrome
hydroxyurea
antimetabolite
mech: inhibits ribonucleotide reductase –> decrease DNA synthesis
use: myeloproliferative disorders (CML, polycythemia vera), sickle cell disease
adverse: severe myelosuppression, megaloblastic anemia