Cancer Cure or Conservation?

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.

Pacific Yew

• Shade Tolerant

• Understory

• "Conifer" -"to bear cones“

• Cones are sort of like a flower.

• Leaves - needles or scale-like.

• Drop their leaves (deciduous) in autumn.• http://images.google.com/images?hl=en&q=pacific+yew&um=1&ie=UTF-

8&sa=X&oi=image_result_group&resnum=4&ct=title

• 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.

Pacific Yew

Pacific Yew

Age

(years)

Diameter - 6” ab gr

(inches)

25 1

50 2

75 4.5

100 6

125 9

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

Pacific Yew

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.

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. 

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. 

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.

Taxol – What’s 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.

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

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)

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”

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

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

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

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

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).

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.

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.

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.

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

Assignment• If you were in Jim Redwood’s 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.