(A) Conversion of oncogenes to proto-oncogenes
(B) Conversion of protooncogenes to oncogenes
(C) Activation of tumor suppressor genes
(D) Inactivation of anti-apoptic factors
Cancer is an uncontrolled proliferation caused by mutation of the genes which control cell division and apoptosis. Two main genes involved are oncogenes and tumor suppressor genes. Mutations involve the conversion of precursor protooncogenes to oncogenes which lead to enhanced proliferation and inactivation of tumor suppressor genes leads to uncontrolled proliferation.
(A) In the liver, cyclophosphamide splits in to phosphoramide mustard and acrolein
(B) Phosphoramide mustard causes haemorrhagic cystitis
(C) It is treated by N-Acetylcysteine
(D) Cisplatin is a polar co-ordination complex
Cyclophosphamide is a prodrug that breaks into phosphoramide mustard and acrolein in vivo. The former produces cytotoxic effect on cancer cells by alkylation of DNA. Acrolein is also cytotoxic mainly interacts with the thiol groups on proteins in the bladder resulting in depletion of thiol groups and consequent bladder toxicity and hemorrhagic cystitis. In order to treat this condition thiol donating groups are used which prevent interaction of acrolein with thiol groups in bladder. 2-Mercapto Ethane Sulfonate sodium can be used to prevent bladder toxicity.
Capecitabine is prodrug of 5-fluorouracil.
(A) Breast cancer
(B) Prostate cancer
(C) B-cell lymphomas
(D) Renal tumor
Rituximab is a monoclonal antibody that binds to CD-20 which is more expressed on B cell lymphocytes. Hence it can be used for B-cell lymphoma.