Interactive & Instructional Design > Microtubule Destablizers

Microtubule Destablizers

Published by de Souza Institute

This illustrated slide presentation is published in the de Souza Institute’s online course Provincial Standardized Chemotherapy and Biotherapy. This course prepares oncology nurses for administering chemotherapy and biotherapy agents to cancer patients. The illustration is within a module giving an overview of the different classes of chemotherapy drugs, their mechanism of action, administration, and side-effects.

This slide presentation teaches the mechanism of action of microtubule destabilizers, which is a class of chemotherapy drugs used to treat various types of cancer.

Navigate through the slides to read a simplified description of how microtubule disruption inhibits cancer cell growth, but also may cause neurotoxicity.

Microtubules (1) are part of the cell’s cytoskeleton and provide structure within the cell. For example, microtubules form the mitotic spindle during cell mitosis (2). The mitotic spindle aligns chromosomes during mitosis [1, 2].

Microtubules are constructed from tubulin molecules arranged in a cylindrical pattern. Microtubules are not static structures, but are in a constant state of assembly (3) and disassembly (4) [2, 3].

Both mechanisms have the ultimate effect of disrupting mitotic spindle function, which stops cancer cell mitosis, and initiates cancer cell death [1]. Taxanes and vinca alkaloids are effective in both of the G2 and M phases [1].

Microtubules provide the structure needed for the transport of vesicles throughout the cell. In nerve cells, microtubules allow motor proteins to carry vesicles containing neurotransmitters and other cargo from the cell body to the end of the axon (1) [1-3]. Neurotransmitters transported by the microtubules are then available to transmit nerve signals across the synapse (2).

Vinca alkaloids cause neurotoxicity by disrupting the transport of neurotransmitters along the axon (3-4) [1]. This neurotoxicity results in symptoms such as constipation and peripheral neuropathy. The severity of the toxicity is dependent upon both dose and exposure, hence prolonged infusions of any vinca alkaloid would have the greatest severity.

References

  1. Olsen, M.M., LeFebvre, K.B., & Brassil, K.J. (2019). Chemotherapy and Immunotherapy Guidelines. Oncology Nursing Society Pittsburgh, PA
  2. Raven, P. H., et al., (2008) Chapter 4 – Cell Structure. In Raven, P. H., et al., Biology. p 59-85. McGraw-Hill: New York, NY.
  3. Goodsell, David S. (2014) Molecule of the Month – Microtubules. RCSB-Protein Data Bank. July 2014. http://pdb101.rcsb.org/motm/73

 

 

Instructional Design Notes

Audience:

Oncology nurse trainees new to chemotherapy administration.

Learning Objective:

The oncology nurse educator writing this course asked me to design a diagram depicting the mechanism of action taxanes and vinca alkaloids, which are two classes of chemotherapy drugs. The learning objective of this diagram is for nurses to describe how this class of chemotherapy agents kill cancer cells and also how the mechanism of action can lead to adverse effects for the patients taking these therapies.

Instructional Design Challenges:

Adult learning principles have found that adults are interested in learning subjects with immediate relevance to their work. The challenge in this project was that the mechanism of action of chemotherapy agents might seem irrelevant to the nurses taking this course because their work is more concerned with correct administration of the agent and anticipating and managing adverse effects of the agents. For the drug mechanism content to be useful for the learner we would have to tie its relevance directly back to nursing practice. Later in this course, nurses are introduced to some of the side-effects of these agents which includes neurotoxicity manifesting as symptoms such as constipation and peripheral neuropathy. To tie into this, after detailing the mechanism of microtubule destabilizers, the diagrams then describe how the mechanism of action directly contributes to the neurotoxic side-effects of the agents. Tying the mechanism of action to a point of clinical relevance can help the learners remember the mechanism and see its application to nursing practice.