ULTIMATE COMPUTING - Quantum Consciousness Studies

124 Cytoskeleton/Cytocomputer
5.7 The Cytoskeleton and Medicine
Defects related to microtubules are specifically linked to several human
diseases. One example is “immotile cilia syndrome” (Afzelius, 1979) which is
caused by altered dynein and results in an inability to expel secretions from the
lungs, leading to recurrent bacterial infections. Another is developmental
disability in infants which is caused by abnormal MT function induced by
defective MAPs (Purpura, 1982). The cytoskeleton participates in the effects of
various diseases (malignancy, Alzheimer’s disease, viral infections), drugs, toxins
and the body’s response to disease.
The pathway to understanding MT led through the disease gout, a painful
swelling of joints caused by the body’s response to accumulation of urate crystals.
Lymphocytes and macrophages, the body’s immune cells, leave the bloodstream
and migrate by amoeboid locomotion towards the urate crystals which often lodge
in a joint of the big toe. Gout may be precipitated by purine containing foods
which are metabolized to urate. The urate crystals are not particularly harmful
except for the painful inflammatory immune response they trigger. By luck, a
drug called colchicine was found to be helpful in relieving the pain and
tenderness. Later it was discovered that colchicine worked by depolymerizing
microtubules and preventing the locomotion and engulfment behavior of the
lymphocytes and macrophages.
In addition to cell migration, the cytoskeleton is clearly involved in the
establishment of normal cell architecture, function, and control of cell division
and growth. In malignancy, control of cell reproduction is lost and growth
proceeds without regard to the needs of the organism. Cancerous cells exhibit a
tendency to break away from their anchorage and set up growth elsewhere in the
body. Malignant cytoskeleton is disorganized with formation of oscillating
aggregates of contractile material that aids dislodgement of the cell from its
anchorage, instability in chromosome number and loss of growth regulation. All
these effects could be primarily cytoskeletal in origin, and Puck (1977) has
proposed that malignancy is a disease of the cytoskeleton. Clearly, the
cytoskeleton is involved in the expression and processes of malignant cells. In
cancer, cell division goes out of control: multipolar or asymmetric mitotic
spindles are commonly observed. Boveri observed in 1929 that such aberrant
distribution of genetic material could result in any combination or permutation of
genes, most of which would be nonviable. However, some permutations may be
sufficiently viable and have the abhorrent traits of malignancy. Many other
factors leading to genetic alterations can account for the same results, so the
precise etiology cannot be pinpointed. Indeed, cancer is probably caused by a
number of etiologies including viruses which infiltrate and usurp the genetic
apparatus and cytoskeleton.
Much of our current knowledge of the cytoskeleton has been learned from
experimental perturbations by toxins, poisons, or drugs. Claude Bernard said in
1875:
The poison becomes an instrument which dissociates and analyzes
the special properties of different living cells; by establishing their
mechanisms and causing cell death or changes in cell function we
can learn indirectly much about the relation between molecular
structure in the physiological process of life.
Peripheral nerve MT and axoplasmic transport are vulnerable to toxin and
drug effects. Vinca alkaloids (vincristine, vinblastine) are commonly employed in
battling cancer because they disrupt MT mitotic spindles as they polymerize.
Because the cancerous cells are dividing so much more rapidly than normal cells,