X-Message-Number: 37 From: Kevin Q. Brown Subject: biotech - cloning, fetal cells, and anti-sense Date: 15 Nov 1988 Cloning ------- Cloning is of particular interest to cryonicists for two reasons: (1) reanimation from today's cryonic suspension techniques will likely require some kind of cloning technology and (2) cloning for spare parts may enable one to postpone (or avoid) having to undergo cryonic suspension. Carol Kahn's article "Double Takes" in the Oct. 1988 OMNI (also reviewed in the Oct. 1988 issue of The Immortalist) outlined the recent history and state of the art of cloning. Cloning technology is improving rapidly and, when the article was written, three mammalian species (cattle, rabbits, and sheep) had been cloned. These clones were not derived from adult somatic cells, but rather by extracting cell nuclei from embryos in the blastocyst stage and inserting the nuclei into enucleated egg cells. In general, the more differentiated a cell becomes, the more difficult it is to clone. (If, however, an adult cell can be turned back to an immature cell, perhaps the technology for cloning adults will soon become available.) The commercial benefits of cloning (prize) farm animals will be enormous and the potential benefits of applying cloning technology to humans promise to become much greater. For example, salamanders can regenerate lost tails and starfish and some frogs can regrow limbs. Perhaps human limbs could be regenerated either from the remaining stumps or in vitro. Paul Segall, of the American Cryonics Society and Trans Time, suggests a simpler and yet more comprehensive approach than cloning individual appendages or organs: create an anencephalic clone by removing from the cloned embryo the cells that would have become the brain and then let the body develop fully (except for the brain). This non-thinking, non-feeling body will provide spare parts with no possibility of rejection and when it is used up, another anencephalic clone can be grown for the next set of spare parts. (The brain cells may also be preserved, in an embryonic state, as transplant material for the brain, as described in the fetal cell research section below.) Paul Segall and Carol Kahn will soon publish a book (last titled "Living Longer, Growing Younger"). Fetal Cell Research ------------------- The cover article of the Nov. 5, 1988 issue of Science News ("Forbidding Fruits of Fetal-Cell Research") focuses on the ethical issues of implanting brain cells from human fetuses to treat Parkinson's disease, diabetes, and possibly other illnesses (such as Alzheimers disease). This is a political hot potato because the fetal brain cells are harvested from induced abortions. Yet no other source of transplant tissue is quite as promising: "Embryonic cells have a number or properties - including their exceptional ability to adapt to a new environment, their capacity to stimulate the growth of new blood vessels and their unique tolerance to long-term storage - that make them ideal as tissue transplants. Perhaps most important, fetal cells are immunologically "naive" - that is, upon being transplanted they generally fail to stimulate a rejection response from the recipient's immune system." Of course, future cell culturing and cloning technologies will reduce or eliminate the need for aborted human fetuses, thereby relieving this political dilemma (and most likely introducing others). (The Nov. 5 issue of Science News also had an article titled "Proteins linked to synaptic 'memory'" concerning recent progress in understanding the proteins involved in long-term potentiation. [See message #27.]) Anti-Sense Medicine ------------------- The "Breakthrough" insert of the Dec. 1, 1988 issue of Privileged Information (Box 10976, Des Moines, IA 50340) reported on a new form of gene therapy called "anti-sense medicine". Traditional gene therapy comes in two flavors: (1) adding new DNA to generate new proteins and (2) replacing "bad" (defective) DNA with "good" DNA. Anti-sense medicine does not operate directly on DNA. Instead, an anti-sense molecule blocks a "bad" gene by binding to its corresponding mRNA, preventing transcription to a protein. This is technically much simpler than the two traditional approaches toward gene therapy. Possible applications include treatment for some cancers (such as leukemia) and also a type of herpes simplex. The article listed several organizations already doing anti-sense medicine research. [ How does anti-sense medicine relate to cloning and fetal cell research? Maybe some biologists could tell me if the following speculation makes sense: If the gene blocked by the anti-sense molecule is one that controls several other genes, the effects of the anti-sense medicine could be much more wide-ranging than just the presence or absence of a single protein. In particular, perhaps anti-sense medicine will someday block the genes responsible for controlling cell differentiation and thereby turn an adult cell into an immature cell suitable for transplantation or cloning? ] - Kevin Q. Brown ...{att|clyde|cuae2}!ho4cad!kqb Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=37