Marlana
06-30-2004, 07:07 AM
I am not sure if I am allowed to do this but if I am not, then I apologize. Here is some info I found on the urolgoical conference they recently had. It may be repetitive of what is in the Optimist but here we go. THis is for those grasping at straws like me.
Researchers Now Know What APF Is
Susan Keay, MD, PhD, of the University of Maryland, Baltimore, and her colleagues have found out exactly what antiproliferative factor (APF) is—the substance made in the bladder lining cells and secreted into the urine in IC patients but not in healthy people. APF could actually be a cause of IC because it puts the brakes on the growth of the bladder lining.
APF is a sialoglycopeptide, which means it’s a small protein, that has three sugars attached. The protein part of APF turns out to be identical to a portion of a much larger human protein, called "frizzled 8." It’s one of a group of recently discovered proteins, called "frizzled" proteins, that seem to be very important in the development of cells of the nervous system and of epithelium—skin and the linings of organs, such as the bladder. Interestingly, these proteins are usually made during development of the embryo and not very much during adulthood.
APF is also the first known of the peptides from secreted frizzled proteins that contains the part of the protein that’s able to go through the cells’ membranes (lining) and it is also the first one known that appears to control the growth of the cells it comes from. "So this may help us to understand yet another way that segments of these frizzled-related proteins play a role in the development of both neurologic and epithelial cells," said Dr. Keay.
It could be that frizzled 8 is important in bladder cell development, and it doesn’t get switched off in IC patients. Another possibility is that it is usually never made in normal bladder cells and there’s something, either outside or inside the cells, that kicks frizzled 8 and APF into production.
Now that Dr. Keay and her team know exactly what APF is and can produce it in the lab, they are going to take the next steps to try to make a practical test for IC. The way she and her colleagues detect APF now is difficult and labor-intensive, but detection could be easier once the researchers can make antibodies that react to APF. "We are in the process of making those antibodies and determining the feasibility and how sensitive that assay will be. But we also are in the process of looking for an industrial partner who can help us with development of that type of assay."
There is a growth factor that counteracts the effects of APF, at least in the lab, called heparin-binding growth factor-like growth factor (HB-EGF) that could become a basis for a drug. Also, if she and her colleagues get clues as to what regulates APF production in cells, they may be able to find a way to stop it, such as through gene therapy.
APF, as a strong inhibitor of bladder lining cell growth, also stops the growth of at least one type of bladder cancer cell in the lab, and APF itself, a bad actor in IC patients, might hold a key to treatment of bladder cancer, where the cells grow out of control. Whether this means that IC patients aren’t likely to get bladder cancer, we don’t know.
Researchers Now Know What APF Is
Susan Keay, MD, PhD, of the University of Maryland, Baltimore, and her colleagues have found out exactly what antiproliferative factor (APF) is—the substance made in the bladder lining cells and secreted into the urine in IC patients but not in healthy people. APF could actually be a cause of IC because it puts the brakes on the growth of the bladder lining.
APF is a sialoglycopeptide, which means it’s a small protein, that has three sugars attached. The protein part of APF turns out to be identical to a portion of a much larger human protein, called "frizzled 8." It’s one of a group of recently discovered proteins, called "frizzled" proteins, that seem to be very important in the development of cells of the nervous system and of epithelium—skin and the linings of organs, such as the bladder. Interestingly, these proteins are usually made during development of the embryo and not very much during adulthood.
APF is also the first known of the peptides from secreted frizzled proteins that contains the part of the protein that’s able to go through the cells’ membranes (lining) and it is also the first one known that appears to control the growth of the cells it comes from. "So this may help us to understand yet another way that segments of these frizzled-related proteins play a role in the development of both neurologic and epithelial cells," said Dr. Keay.
It could be that frizzled 8 is important in bladder cell development, and it doesn’t get switched off in IC patients. Another possibility is that it is usually never made in normal bladder cells and there’s something, either outside or inside the cells, that kicks frizzled 8 and APF into production.
Now that Dr. Keay and her team know exactly what APF is and can produce it in the lab, they are going to take the next steps to try to make a practical test for IC. The way she and her colleagues detect APF now is difficult and labor-intensive, but detection could be easier once the researchers can make antibodies that react to APF. "We are in the process of making those antibodies and determining the feasibility and how sensitive that assay will be. But we also are in the process of looking for an industrial partner who can help us with development of that type of assay."
There is a growth factor that counteracts the effects of APF, at least in the lab, called heparin-binding growth factor-like growth factor (HB-EGF) that could become a basis for a drug. Also, if she and her colleagues get clues as to what regulates APF production in cells, they may be able to find a way to stop it, such as through gene therapy.
APF, as a strong inhibitor of bladder lining cell growth, also stops the growth of at least one type of bladder cancer cell in the lab, and APF itself, a bad actor in IC patients, might hold a key to treatment of bladder cancer, where the cells grow out of control. Whether this means that IC patients aren’t likely to get bladder cancer, we don’t know.