Cancer Cure or Conservation?

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Cancer Cure or Conservation?
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Pacific Yew

• Taxus brevifolia
• Coniferous tree
• Shade tolerant
• In undisturbed stands is usually found as an
  understory tree
• Slow growing
• Pacific yew rarely exceeds 24 in d.b.h., and 49
  ft in height. The largest on record is 56 in
  d.b.h., and 60 ft in height.

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Pacific Yew

• Shade Tolerant
• Understory

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• "Conifer" -"to bear cones
• Cones are sort of like a flower.
• Leaves - needles or scale-like.
• Drop their leaves (deciduous) in autumn.
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• Shade tolerance is an ecological concept that
  refers to plants' abilities to tolerate low light
  levels.
• Able to thrive in the shade, and in the presence
  of natural competition by other plants.

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Pacific Yew
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Pacific Yew

Age (years) Diameter - 6 ab gr (inches)
25 1
50 2
75 4.5
100 6
125 9
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Pacific Yew

• Significant numbers of Pacific yew trees are
  found in old-growth forests on federal lands in
  the Pacific northwest
• Before the importance of taxol was discovered,
  the Pacific yew was considered a trash tree and
  was often burned in slash piles after timber
  operations

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Pacific Yew
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Taxol

• Generic name Paclitaxel
• anti-cancer chemotherapy drug
• Taxol was isolated from the bark of the pacific
  yew in 1971
• Taxol is used for the treatment of breast,
  ovarian, lung, bladder, prostate, melanoma,
  esophageal, as well as other types of solid tumor
  cancers. It has also been used in Kaposi's
  sarcoma.

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Taxol How Does It Work?

• Cancerous tumors are characterized by cell
  division, which is no longer controlled as it is
  in normal tissue.
• "Normal" cells stop dividing when they come into
  contact with like cells, a mechanism known as
  contact inhibition.  Cancerous cells lose this
  ability. 
• Cancer cells no longer have the normal checks and
  balances in place that control and limit cell
  division. 

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Taxol How Does It Work?

• The ability of chemotherapy to kill cancer cells
  depends on its ability to halt cell division. 
• Usually, the drugs work by damaging the RNA or
  DNA that tells the cell how to copy itself in
  division. 
• If the cells are unable to divide, they die. 

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Taxol How Does It Work?

• Taxol is an antimicrotubule agent
• Antimicrotubule agents inhibit the microtubule
  structures within the cell. 
• Microtubules are part of the cell's apparatus for
  dividing and replicating itself. 
• Inhibition of these structures ultimately results
  in cell death.

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Taxol Whats it Worth?

• To date, Taxol is the best-selling cancer drug
  ever manufactured. Annual sales of the drug
  peaked in 2000, reaching 1.6 billion
• Bristol-Myers Squibb was given exclusive rights
  to provide Taxol from T. brevifolia under a
  cooperative research and development agreement
  with the U.S. government in 1991.

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What Does Taxol Cure?

• Ovarian Cancer
• Cancer that forms in tissues of the ovary. Most
  ovarian cancers are either ovarian epithelial
  carcinomas (cancer that begins in the cells on
  the surface of the ovary) or malignant germ cell
  tumors (cancer that begins in egg cells).
• In 2007
• New Cases 22,430
• Deaths 15,280

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What Does Taxol Cure?

• Breast Cancer
• Cancer that forms in tissues of the breast,
  usually the ducts (tubes that carry milk to the
  nipple) and lobules (glands that make milk). It
  occurs in both men and women, although male
  breast cancer is rare.
• In 2007
• New Cases 178,480 (females), 2,030 (males)
• Deaths 40,460 (females), 450 (males)

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What Does Taxol Cure?

• Breast Cancer
• 12.7 percent of women born in the United States
  today will develop breast cancer at some time in
  their lives
• 1 in 8

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What Does Taxol Cure?

• Lung Cancer
• Cancer that forms in tissues of the lung, usually
  in the cells lining air passages.
• In 2007
• New Cases 213,380
• Deaths 160,390

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Melanoma

• Skin cancer
• It is due to uncontrolled growth of pigment
  cells, called melanocytes.

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Kaposi's sarcoma

• Kaposi's sarcoma (KS) is a tumor caused by Human
  herpesvirus 8 (HHV8), also known as Kaposi's
  sarcoma-associated herpesvirus (KSHV).
• It became more widely known as one of the AIDS
  defining illnesses in the 1980s.
• Although KS is now well-established to be caused
  by a virus infection, there is widespread lack of
  awareness of this even among persons at risk for
  KSHV/HHV-8 infection

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Native American Uses of the Pacific Yew

• Used for the manufacture of bows, arrows,
  harpoons, spear handles, paddles, war clubs,
  digging sticks, wedges, boxes, drums, spoons,
  dishes, cups, and bowls.
• The fragrant foliage was used as a deodorant and
  cleaning agent

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Native American Uses of the Pacific Yew

• Some American Indian peoples traditionally
  associated Pacific yew with death and
  bereavement.
• Tonics made from Pacific yew were used
  medicinally by many peoples of the Pacific
  Northwest.
• Some Native American tribes in Washington used
  the yew boughs and needles for symbolic building
  of body strength.
• Quinault tribe used the Pacific Yew as medicine
  for a broad range of ailments
• Several tribes also have dried the needles for
  smoking, either in combination with other
  products or later with tobacco (caused
  dizziness).

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Native American Uses of the Pacific Yew

• Saanich Tribal women used Pacific yew to remove
  underarm hair
• Okanagans made a red paint from ground yew wood
  mixed with fish oil
• Haidas believed that women who ate yew berries
  would not conceive.

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Pacific Yew Act

• The public outcry against the proposed harvesting
  of T. brevifolia trees and shrubs in federal
  lands in California, Idaho, Montana, Oregon, and
  Washington led to the Pacific Yew Act and
  increased awareness and regulation of
  bio-prospecting worldwide.

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Pacific Yew Act

• The purpose of this Act is to ensure maintenance
  of the supply of Pacific yew for medicinal uses.
• The Secretaries of Agriculture and the Interior
  are given broad powers to ensure the minimization
  of the illegal harvest and sale of the Pacific
  yew, and to negotiate the sale of Pacific yew
  growing under their jurisdiction.

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Pacific Yew Act

• The Act requires the Secretaries concerned to
  pursue a conservation and management policy with
  respect to lands and interests in lands under the
  jurisdiction of the Forest Service or the Bureau
  of Land Management which contain the Pacific yew.
  
• The policy must provide for the sustainable
  harvest and long-term conservation of the Pacific
  yew, with consultation as necessary under the
  Endangered Species Act to determine the effect of
  harvesting on endangered and threatened species
  and critical habitat

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Assignment

• If you were in Jim Redwoods position, how would
  you vote and why? This case study is a question
  of ethics so there is no correct answer, but
  you must justify your position.
• Please limit your response to one paragraph (no
  more than a ½ page long typed).
• This assignment is due next week at the beginning
  of lab.