A researcher named D.M. Eccles wrote an article about developments in genetic testing for Breast, Ovarian and Colorectal Cancer Predisposition in an effort to illustrate how this new testing could aid doctors in finding cancerous cells early in development or prevent them before they even develop.

Eccles started by explaining over years of prior research into where cancer comes from he explained that it had been discovered that in the 1980’s the first high risk cancer susceptibility genes were (FAP) Familial Adenomatous Polyposis which is when numerous polyps form in the epithelium of large intestine which can develop into colon cancer if not treated. Then along in 1993 there arose a condition known Lynch Syndrome which is known as an autosomal dominant (expression of non sex genes) genetic condition that has risk for ovarian, colon, and some skin cancers. Then the following year in 94’ in the BRCA 1 and BRCA 2 genes researchers found the location and sequences of both these caretaker genes are found in the breast and that stabilize genomes and repair DNA. If these are damaged then they aren’t able to fix DNA and can’t be fixed themselves which comes to yield cancerous results such as breast and ovarian. So after finding out these things researchers have started using genetic testing in a clinical aspect to figure what genes are forcing which types of cancers to occur. For example, if there was gene mutation in the BRCA1 and BRCA 2 proteins in someone’s family and all those affected were deceased and researchers tested someone from the family who was unaffected but at risk may reassure that fact that this mutation brought about ovarian cancer. But in actuality after testing the cancer could’ve come from a mutation in the RAD51C and RAD51D genes. These are a set of genes that are responsible at a high risk for ovarian cancer and possibly breast cancer if the genes happened to be mutated. So all the reason for the genetic testing is to distinguish between these and figure out with of these genes can be targeted as the one developing into becoming cancerous.

The specifics of how to figure out which genes to target for cancer prevention where narrowed more as Eccles discussed gene expressivity and penetrance. Not all people who carry the gene that makes predisposed to cancer will ever develop it which is known as incomplete penetrance. So in a family that may contain a mutation can have predictive genetic testing done to identify if the high risk gene. People who have (FAP) with polyps that are benign and may be on the verge of them becoming carcinogenic usually have mutation genetic testing which will identify where the causative mutation is in the gene. If that is discovered then a predictive test can be done on any member of the same family to have target surveillance on all the gene carriers. So even though colonoscopies, self-breast examinations, and oophorectomy are classics in detecting colon, breast, and ovarian cancer researchers are trying to push these new methods in genetic testing to catch these cancers fairly early on.

James

Kaitlyn Culler

BIO 305

30 March 2012

There has been an increase for the need in the number of donors for organ transplant, Because there is such a high demand but a major lack of human donors, many people have died while waiting to receive a transplant. Researchers are trying to find alternatives by performing organ transplants in animals like pigs and monkeys. A study was done by transplanting pig livers into baboons to see if the organ was compatible with that of the baboon and if liver function was possible. The pigs were genetically modified by implanting a gene for a human regulating protein or deleting that produces antigens in which human have natural antibodies for. Six baboons received liver grafts from the genetically modified pigs.

The surgery carried out was typical of that used in human liver transplants. The baboons were then followed up for measurements over the next 4 to 7 days to test for levels of liver enzymes, clotting factors, and protein production. The presence of proteins was tested using the Western blot, which is used to test the presence of specific proteins in a sample of tissue. In four of the baboons clotting factors were measured. Tests were also run to determine how much the pig liver complemented the activity of the baboons’ bodies and biopsies of the liver were taken two hours after surgery and after death of baboons. Out of the six baboons tested, one survived seven days, three survived six days, one survived five days, and one survived four days. Except for the baboon that died within four days, the remaining five showed signs of liver function.

Liver failure can be detrimental to a person’s life, and since there is a shortage of human organs for transplants, finding alternatives is very important. Even though there were detections of liver function in the baboons, sufficient liver function and the production of pro and anti- clotting factors would need to be assured. There have been a few studies that prove that a liver graft would be sufficient for human transplant. One study done in 1993 did a baboon to human liver transplant; the recipient survived 70 days, and normal liver function was reported.

I found this article very interesting because I plan on going into the health field and this is a very important aspect of a health and medicine career. Research like this is very important not only to be used for liver transplants, but for other organs as well. The life expectancy of the older generations is greater than it used to be, so the number of organ donors has decreased, and more people are dying because the demand of the number of transplants available is greater than the supply currently available. If researchers can find a way to use animal organs for human transplants, the new doors opening in the medical world would be endless. Doctors would not have to worry about patients dying while waiting for a much needed transplant, and so many patients would have a chance for a longer and healthier life with this advance in genetics and medicine.