Chemo Drugs Biochemistry Tidbits

What is the leaving group of cyclophosphamide?

Chlorine

What remnant of the cyclophosphamide chemical structure is actually tacked onto DNA?

Aziridine cation

What is the leaving group of cisplatin?

Chlorine

What remnant of the cisplatin chemical structure is actually tacked onto DNA?

Platinum cation

What is the leaving group of carboplatin?

Oxygen

What remnant of the carboplatin chemical structure is actually tacked onto DNA?

Platinum cation

What is the leaving group of carboplatin?

Oxygen

What remnant of the oxiplatin chemical structure is actually tacked onto DNA?

Platinum

What step in dTTP biosynthesis does 5-FU block?

dUMP conversion to dTMP by TS enzyme

What step in dTTP biosynthesis does capecitapine block?

dUMP conversion to dTMP by TS enzyme

What step in dTTP biosynthesis does methotrexate block?

dUMP conversion to dTMP by TS enzyme (DHFR usually “helps” TS enzyme)

What step in dTTP biosynthesis does pemetrexed block?

dUMP conversion to dTMP by TS enzyme (DHFR usually “helps” TS enzyme)

What structural feature of doxorubicin enables its MOA?

It is flat/planar

What functional group gives doxorubicin its cardiotoxicity?

Quinone group — forms reactive oxygen species in cardiac tissues

Common melanoma mutation

V600E in BRAF allele

Which mutation that causes non small-cell lung cancer is gefitinib most reliably effective against?

EGFR L858R

Why can afatinib and osimertinib bypass the weaknesses of gefitinib?

Afatinib and osimertinib irreversibly bind to EGFR so it’s much harder for them to lose affinity for their target

Which mutation that causes colorectal cancers is sotarasib used against?

G12C KRAS mutation

Which drug class has an interaction with tamoxifene?

SSRIs (fluoxetine and paroxetine) inhibit tamoxifen conversion to its active form endoxifen