Anticancer agents Flashcards
Cancer statistics
Major cause of death in pets (40-45% of all dogs >10 yrs of age)
23% of all dogs die of cancer
Hallmarks of cancer
Sustaining proliferative signaling
Evading growth suppression
Resisting cell death
Inducing angiogenesis
Enabling replicative immortality
Activating invasion and metastasis
Treating cancer
Surgery
Radiation therapy
Chemmotherapy
Hyperthermia
Photodynamic therapy
Chemotherapy
Mono-therapy for systemic cancers
Adjuvant therapies
Neo-adjuvant therapies (prior to surgery to shrink tumor)
Chemotherapy activation of immune system
Activates macros, T cells and monos → release pro-inflammatory and activation of apaptotic pathways → cell death
Chemotherapy on microtubules
Vincristine inhibition of microtubule aggreggation and Paclitaxel inhibition of microtubule disaggregation → altered function of microtubules → cell arrest
Chemotherapy on the nucleus
Oxaliplatin, cisplatin inhibition of DNA replication and mRNA transcription → DNA/RNA polymerase → cell arrest and death
Chemotherapy on the mitochondria
Oxaliplatin, cisplatin, Vincristine, pacliaxel alter function of resp. chain→ ↑ ROS
OR
→ altered mitochondrial function → activation of apoptosis
Sustained proliferation
Replicative immortality
Cancer cells constantly divide and cycle
What are the subclasses of alkalizing agents?
Nitrogen mustards
Nitrosoureas
Alkyl sulphonates
Atypical
Alkalizing agents MOA
Add alkyl group to the N7 atom of guanine base of the DNA molecule → cross linking of DNA and strand breaks
Alkaline agents in the cell cycle
Binds to DNA in the S-phase
Nitrogen mustards
Cyclophosphamide
Ifosfamide
Melphalan
Chlorambucil
Ifofsamide
Isomer of Cyclophosphamide
Slow IV infusion
Toxicity: Neutropenia, hemorr. cystitis, CNS
MESNA (Mesnex)
Rescue agent for hemorr. cystitis
Well tolerated, could cause N/V
Cyclophosphamide
Most used nitrogen mustard in vet med
Prodrug given IV or oral
Lymphomas K9 and cats
Malignant mammary gland tumors
Cyclophosphamide toxicity
Myelosuppression, alopecia, neutropenia, hemorr cystitis
GI (cats)
Bladder irritation
Amelioration of Ifofsamide and Cyclophosphamide toxicity
Adequate hydration
Diuresis by IV furosemide
Co-admin of MESNA
Melphalan
Orally and IV
Multiple myeloma in K9 and cats, plasma cells tumors, extramedullary plasmacytoma, relapsed lymphoma in K9
The main side effect of melphalan is ____________
Myelosupression
Chlorambucil (Leukran)
One of the most common
Slow acting and least toxic
PO on empty stomach of IV
Replace Cyclophosphamide to avoid hemorr. cystitis
Chlorambucil toxicity
Myelosuppression with neutropenia and thrombocytopenia
Reversible BM suppression
Chlorambucil uses
Slower growing tumors like Chronic lymphocytic leukemia, Small cell lymphoma, GI lymphoma in cats
Anticancer ABX
Doxorubicin
Bleomycin
Mitoxantrone
Doxorubicin MOA
From Streptomyces peucetius
Intercalates to DNA, inhibits topoisomerase 2, interferes with RNA synthesis
Produces free radicals
Act on cells deficient in superoxide dismutase (cardiac and tumor cells)
Doxorubicin uses
Most effective
Lymphoma and leukemia of K9s and cats
Combo with cyclophosphamide to treat lymphosarcoma in K9s and cats
Doxorubicin toxicity
Cardiotoxicity is K9s
Anorexia and nephrotoxicity in cats
Palmer-planta erythrodysesthesia syndrome (treated with B6)
Bleomycin
From S. verticillus
IV, IM, SC
Cell specific: G2 and M phase
Treats squamous cell carcinoma
Bleomycin toxicity
Causes cytoxicity by binding to DNA
Pulmonary toxicity (rales, cough, fatal fibrosis)
Mitoxantrone
Synthetic athracenedione
Treats lymphoproliferative disorders (lymphomas and leukemias)
Transitional cells carcinoma of urinary bladder
Mitoxantrone toxicity
Extravasation necrosis
Mild BM depression
Bluish- green sclera and urine
Antimetabolites
Prevents biosynthesis of cell metabolism
S-phase specific
Metabolized to active form
Used for leukemias
Antimetabolite drugs
Pteridines (methotrexate)
Pyrimidine analogs (fluoroacil)
Purine analogs (6- mercaptopurine)
Methotrexate
Inihibits dihydrofolate reductase
IV, IM, IV, oral
Limited veterinary use
Microtubule inhibitors and the cell cycle
Stope cell separation during division during the G2 phase
Vinca alkaloids taxols and the cell cycle
Stop cell separation during divison during the M phase