Cancer I Flashcards
Carcinoma = ______ tissue. Examples?
Sarcoma = _________ tissue. Examples?
Carcinoma = epithelial tissue. Breast, colon, and lung
Sarcoma = mesenchymal tissue. Bone, cartilage, muscle, fat, vascular, and hematopoietic
- Estimated cancer deaths per year?
- Estimated new cancer cases per year?
- Highest types of new cancer cases for men?
- Highest types of new cancer cases for women?
- Lowest 5 year survival rates?
- Deaths = 600,000
- New = 1.7 million
- Men = prostate and lung/bronchus
- Women = breast and lung/bronchus
- Lowest = pancreas, followed by lung/bronchus
Tumor progression:
- Cancer arises through a series of ____ changes.
- 2 types of changes?
- Induced by carcinogens, ___ ___, or integration of ____ DNA
Tumor progression:
- Cancer arises through genetic changes
- Heritable (change in DNA sequence) or epigenetic (change in pattern of expression w/o change in DNA)
- Induced by carcinogens, ionizing radiation, or integration of viral DNA
Two hit model of tumor progression:
- Wild type at birth –>?
- Heterozygous at birth –> ?
- Which of these is sporadic and which has inherited suceptibility?
Two hit model of tumor progression:
- Wild type –> mutation –> heterozygous –> LOH (loss of heterozygosity) –> homozygous = malignant
- Heterozygous –> LOH –> homozygous = malignant
- Sporadic = wild type; inherited suceptibility = heterozy.
Properties of normal cells:
- Lifespan?
- Exhibit _____ inhibition. What is this?
- Normal cells depend on ___ ___ for growth and division.
- Normal cells are ____-dependent.
Properties of normal cells:
- Limited lifespan; finite - telomeres
- contact inhibition: only one layer, once there is no more room in the layer they stop replicating
- Normal cells depend on growth factors
- Normal cells are anchorage-dependent
Properties of cancerous cells:
- Abnormally persistant ______ and overcome programmed limits to _____
- They avoid ____. From this they can become invasive and _____.
- Cancer cells can undergo endless divisions = _____ due to preserved ____
Properties of cancerous cells:
- Persistant proliferation and overcome limits to proliferation
- Avoid apoptosis and can metastasize
- immortal__ity due to preserved telomeres
Cell cycle problems:
- What causes a sustained proliferative signal?
- What causes evasion of growth suppression?
- What causes avoidance of immune destruction?
Cell cycle problems:
- Sustained proliferative signal = EGFR inhibitors
- Evasion of growth suppression = CDK inhibitors
- Avoidance of immune system = immune activating anti-CTLA4 mAb
Cell cycle problems:
- What causes immortality?
- What causes tumor-promoting inflammation?
- What activates invasion and metastasis?
Cell cycle problems:
- Immortality = telomerase inhibitors
- Inflammation = selective anti-inflammatory drugs***
- Invasion = inhibitors of HGF/c-Met
Cell cycle problems:
- What induces angiogenesis?
- What causes genome instability and mutation?
- What causes resistance of cell death?
- What causes deregulation of cellular energetics?
Cell cycle problems:
- Angiogenesis = inhibitors of VEGF signaling
- Genome instability = PARP inhibitors
- Resistance of cell death = Proapoptotic BH3 mimetics
- Deregulation of energetics = aerobic glycolysis inhibitors
Drug actions:
- What is the role of 6-mercaptopurine and 6-thioguanine?
- Functions of methotrexate?
- What is the function of PALA?
- Function of hydroxyurea?
Drug actions:
- 6 = inhibit purine ring synthesis and neucleotide interconversion
- Methotrexate = inhibits DHF reduction, blocks TMP (tumor membrane protein) and purine synthesis
- PALA = inhibits pyrimidine biosynthesis
- Hydroxyurea = inhibits ribonucleotide reductase
Drug actions:
- What is the role of camptothecins, etoposide, teniposide, daunorubicin, and doxorubicin?
- What is the function of protein tyrosine kinase inhibitors, bortezomib, and antibodies?
- Function of L-asparaginase?
Drug actions:
- Block topoisomerase function
- Block activity in general
- L-asparaginase - deaminates asparagine and inhibits protein synthesis
Drug actions:
- Function of 5 flourouracil?
- Function of gemecitabine, cytarabine, fludarabine, and chlorodeoxyadenosine?
Drug actions:
- 5-fluorouracil = inhibits TMP synthesis
- Inhibits DNA synthesis
Drug actions:
- Function of platinum analogs, alkylating agents, mitomycin, cisplatin, temozolomide?
- Function of paclitaxel, vinca alkaloids, colchicine, and estramustine?
Drug actions:
- forms adducts with DNA
- Inhibits function of microtubules
Drug actions:
- What drugs inhibit purine ring biosynthesis and nucleotide interconversion?
- What drugs block topoisomerase function?
- What drug inhibits TMP synthesis?
Drug actions:
- Purine/nucleotide = 6mercaptopurine and 6tioguanine
- Topoisomerase = camptothecins, etoposide, teniposide, daunorubicin, and doxorubicin
- TMP synthesis = 5-fluorouracil
Drug actions:
- What drug inhibit pyrimidine synthesis?
- What drugs inhibit DNA synthesis?
- What drug deaminates asparagine and inhibits protein synthesis?
Drug actions:
- Pyrimidine = PALA
- DNA = gemcitabine, cytaabine, fudarabine, chlorodeoxyadenosine
- L-asparaginase
Drug actions:
- What drugs form adducts with DNA?
- What drugs inhibit function of microtubules?
Drug actions:
- Adducts = platinum analogs, alkylating agents, mitomycin, cisplatin, temozolomide
- Microtubules = vinca alkaloids, paclitaxel, colchicine, estramustine
Drug actions:
- What drug inhibits ribonucleotide reductase?
- What blocks activity in general?
Drug actions:
- Ribonucleotide = hydroxyurea
- Activity = protein tyrosine kinase inhibitors and bortezomib antibodies
Cell cycle:
- What phase is the principal determinant of cell cycle length?
- What makes up interphase?
- What is the growth fraction?**
Cell cycle:
- Principle determinant of length = G1
- Interphase = G1, S, and G2
- Growth fraction = ratio of proliferating cells to G0 cells**
Drugs:
- Cytotoxic drugs act by disrupting what 2 things?
- Drugs have a tendency to affect normal tissues with high growth fractions: what are these tissues?
- Growth fraction of solid tumors vs disseminated cancers response to cytotoxic drugs?
- What are common cancers treated with cytotoxic drugs?
Drugs:
- Cytotoxic drugs disrupt DNA synthesis or Mitosis
- High growth fraction tissues: GI epithelium, bone marrow, hair follicles, and sperm forming cells
- Solid - less responsive; disseminated - more responsive
- Common cancers treated with cytotoxic drugs: leukemia and lymphoma
Drugs:
- 4 cell cycle specific agent classes?
- Cell cycle nonspecific agents?
- Most frequently mutated gene in human cancer? Activated by?
Drugs:
- Specific = Antimetabolites, bleomycin, podophyllin alkaloids, and vinca alkaloids
- Nonspecific = Antibiotics
- P53 is the most frequently mutated gene activated by DNA damage
Apoptosis:
- Tissue cell# = ?
- Apoptosis is ______ regulated. Fragmented where?
- How is apoptosis different from necrosis?
Apoptosis:
- Tissue cell # = cell proliferation (oncogenes - tumor suppressor genes) - cell death (apoptosis - anti-apoptosis genes)
- Genetically regulated; fragmented in between nucleosomes in the chromatin
- Necrosis = cell membrane destroyed first and inflammation (no inflammation with apoptosis and nuclear membrane first)
Intrinsic apoptosis:
This is also known as the ___ pathway. Stimuli trigger the release of ______ ____ from the mitochondria as well as ___ and apoptosis _____ factor. Once released ____ ___ together with dATP, binds to ____ and this complex, along with ____ nucleotides, promotes procaspase __ autoactivation which in turn activates caspases __, __, __, __, and __
Intrinsic apoptosis:
This is also known as the mitochondrial pathway. Stimuli trigger the release of cytochrome C from the mitochondria as well as caspases, and apoptosis inducing factor. Once released cyto c together with dATP, binds to APAF-1, along with adenine nucleotides, promotes procaspase 9 autoactivation which in turn activates caspases 2, 3, 6, 8, and 10
Extrinsic apoptosis pathway:
This is also referred to as the ___ ___ - mediated apoptosis pathway. __/___ ligand, __/___ receptor ligation, or TRAIL with __ or ___ transduce death signals to activate caspase ___, which activates the downstream caspases. This caspase also cleaves a ___-apoptotic Bcl-2 family member, ___, and this induces mitochondrial ___ __ release. Both caspase __ and __ activate caspase 3.
Extrinsic apoptosis pathway:
This is also referred to as the death receptor - mediated apoptosis pathway. Fas/Fas ligand, TNF/TNF receptor ligation, or TRAIL with DR4 or DR5 transduce death signals to activate caspase 8, which activates the downstream caspases. This caspase also cleaves a proapoptotic Bcl-2 family member, BID, and this induces mitochondrial cyochrome c release. Both caspase 8 and 9 activate caspase 3
Bcl-2 family:
- Which are pro-apoptotic?
- Which are anti-apoptotic?
- In tumor cells, Bcl-2 has been found to confer resistance in response to what drugs?
Bcl-2 family:
- Pro-apoptotic: Bax, Bak, Diva, Bad, Bid, Bim
- Anti: Bcl-2, Bcl-XL, Mcl-1
- Resistance to vincristine, taxol, cisplatin, methotrexate, and cytosine arabinoside
Toxicity of chemotherapeutic drugs:
- Toxicity to normal cells is ___ ____.
- Bone marrow suppression causes?
- GI injury leads to?
Toxicity of chemotherapeutic drugs:
- Toxicity is dose limiting
- BM suppression - infection, bleeding, and anemia
- GI - stomatitis (inflammation, ulderation, infection) and diarrhea
Toxicity of chemotherapeutic drugs:
Hyperuricemia:
- Major complication of ___ ___ ___. Due to?
- Can cause?
- Symptoms?
Toxicity of chemotherapeutic drugs:
Hyperuricemia:
- Major complication of tumor lysis syndrome; due to massive release and breakdown of nucleic acid to uric acid
- Can cause acute renal failure
- Symptoms: N/V, diarrhea, and anorexia
Toxicity of chemotherapeutic drugs:
Other toxic side effects?
Toxicity of chemotherapeutic drugs:
a. N/V
b. Alopecia
c. Reproductive toxicity
d. Local injury
e. Carcinogenesis
Obstacles to successful chemotherapy:
- Cure requires?
- Kinetics? What does this imply?
- Also, affects ___ cells.
Obstacles to successful chemotherapy:
- Cure requires 100% cell kill
- First order kinetics: at any given dose, drug kills a constant percentage of malignant cells
- Also, affects NORMAL cells
Obstacles to successful chemotherapy:
- Role of host immunity?
- Symptoms vs. cancer cells?
- ______ of tumor cell population.
Obstacles to successful chemotherapy:
- Host defenses dont participate because the drugs are immunosuppressive
- Symptoms disappear before all cancer cells are killed
- heterogeneity of tumor cell population
Obstacles to successful chemotherapy:
- Late detection: ___ may have occurred already. ____ tumors are less responsive.
- Limited drug access due to ___ and ___. Example
Obstacles to successful chemotherapy:
- Late detection: metastasis may have already occurred. Large tumors less responsive
- Limited drug access due to location (hard to cross BBB) and vascularization (core of large solid tumor with poor vascularization)
Melanoma:
___ % of melanomas carry a mutation in the ___ gene. ___ blocks this gene and ___% had partial to complete regression. Almost all patients who demonstrated positive response developed ___.
Melanoma
>50% carry a mutation in the BRAF gene. Vemurafenib blocks BRAF and 80% had regression. Most developed resistance
Mechanisms of drug resistance:
- Reduced drug ___.
- Increased drug ___. Example?
- _____ drug activation
- ____ target molecular sensitivity
Mechanisms of drug resistance:
- Reduced drug intake
- Increased drug efflux. P-glycoprotein (pumps drug out of cell; multiple drug resistance)
- Reduced drug activation
- reduced target molecular sensitivity
Mechanisms of drug resistance:
- Drugs do not cause drug resistance mutation but rather?
- ____ number of targeted receptors
- Modify the ___ to make the drug ineffective
Mechanisms of drug resistance:
- Dont cause resistance but rather provide selection pressure favoring resistant mutants
- increase the number of targeted receptors
- Modify the target to make drug ineffective
Strategies to achieve maximal benefits of chemo:
What are the 4 strategies?
Strategies to achieve maximal benefits of chemo:
a. Intermittent chemo
b. combination chemo
c. Optimizing dosing schedule
d. regional drug delivery
Strategies to achieve maximal benefits of chemo:
Intermittent chemo:
- What is the primary technique to have 100% kill with minimal normal tissue damage?
- What is the caveat to intermittent chemo?
Strategies to achieve maximal benefits of chemo:
Intermittent chemo
- Primary technique - intermittent chemotherapy
- Caveat - normal cells must repopulate faster than cancer
Strategies to achieve maximal benefits of chemo:
Combo chemo:
- Causes ____ cell kill. Using different drugs with different ___ and different cell cycle ____
- ___ injury to ____ cells with combos that dont have overlapping ____
- ____ of drug resistance
Strategies to achieve maximal benefits of chemo:
Combo chemo
- Causes increased cell kill using drugs with different MOA and different cell cycle specificity
- Reduced injury to normal cells with combos that dont have overlapping toxicities
- Suppression of resistance
Strategies to achieve maximal benefits of chemo:
- Optimising dosing schedules: what phase specific drugs need longer exposure to tumor cells?
- Regional delivery: what types?
Strategies to achieve maximal benefits of chemo:
- Optimal: S-phase-specific drugs need longer exposure
- Delivery: intra-arterial, intrathecal, portal v, intra-cavity, or carmustine wafer implanted in brain after surgery