2013 Antineoplastics

CELL CYCLE SPECIFICITY
Cell cycle was presented by Dr. Holy in Principles and is reviewed in Molecular Biology of the Cell.

Cancer drugs can be divided into two general classes:  CELL CYCLE SPECIFIC DRUGS (CCS; esp. plant alkaloids and antimetabolites), and CELL CYCLE NON-SPECIFIC DRUGS (CCNS; esp. alkylating agents and some natural products).  Antineoplastic agents can also be organized according to their chemical class, mechanism of action, therapeutic use or their toxicities. Critical Fact Icon
  • Cell Cycle Diagramall cells (normal and neoplastic) progress through the cell cycle

  • cells spend a different percentage of time in each portion of the cell cycle
    • the percentages indicated in the figure are typical for a neoplastic cell
    • in particular, the duration of both G0 and G1 can vary dramatically

  • Example Questiondrugs that act only during a specific portion of the cell cycle (CCS drugs) will be least effective at treating cancers who have low growth fractions (i.e., most of the cells are in G0)

  • it is common to follow treatment with a CCNS drug with a CCS drug, so that cancer cells are recruited into the cell cycle, where CCS drugs can be more effective
CELL CYCLE SPECIFIC DRUGS (CCS)
CELL CYCLE NON-SPECIFIC DRUGS (CCNS)
  • only proliferating cells killed (high growth factor tumors preferentially eliminated)
  • both proliferating and non-proliferating cells killed (attack both high and low growth factor tumours)
  • schedule dependent
    (duration and timing rather than dose)
  • dose dependent
    (total dose rather than schedule)

 

 

 

 

Email: Dr. Janet Fitzakerley | ©2013 University of Minnesota Medical School Duluth | Last modified: 2-apr-13 2:57 PM