Does vitamin A inhibit PI3K/Akt?

[heblaj01]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15608670&dopt=Abstract

Cellular retinol-binding protein-I inhibits PI3K/Akt signaling through a retinoic acid receptor-dependent mechanism that regulates p85-p110 heterodimerization

I do not understand the possible implications of this research paper.
Does it mean that vitamin A (once converted into retinol in tissues) could inhibit PI3K/Akt & thus, among other things, reverse resistance to Herceptin?

Can someone shed some light?

I also noticed an article on high levels of retinol associated with lower risk of liver cancer.

[Tom]

Hi Heblaj,

I have not read the specific research you site, but I do know that retinol and retinoic acid analogues have been found to be useful in fighting many cancers. The problem with them has always been getting enough biologically available retinol into the tumor cells.


This might sound funny, but a friend of mine had a Golden Retriever with cutaneous T-cell lymphoma, which is deadly in dogs. The treatment that produced a response was dosing of Accutane, which is derived from retinoic acid. Oddly enough, it is also used to treat severe acne in teenagers.

Mom also takes vitamin A in the form of Beta Carotene. That is perhaps the safest way to obtain vitamin A without much risk of overdose.


I have been giving Mom IP-6 (inositol hexaphosphate) for some time now, as it has been shown to promote NK (natural killer cell) activity within the immune system. It is also an inibitor of PI3K.


Tom

[Becky]

I take vitamin A in my multi which is 10,000 IU (half as beta carotene and half as acetate) plus 1250IU in Cod Liver Oil and an extra 8000 IU (as fish liver oil) at night. This is mainly due to some research about P13K as well as the fact that Vitamin A can (not that it does or will) cover the ER receptor. I am ER+ but I think it could be beneficial to the ER neg women (because they could change from neg to pos).


Maybe I take too much but everyone needs to make their own choices.

Remember that one week from today the topic chats start up again with Nutrition and Supplements so...

Take care

Becky

[Lani]

I believe it is produced by Ligand Pharmaceuticals and is called targretin. It was explained to me that its effect was to cause the cancer cells to differentiate ie, stop multiplying and instead utillize the same energy for performing the normal appropriate functions for the cell--something all cancers could use!

It produced excellent results with someone I helped (by researching) with NKTcell lymphoma.

I read a paper out of MD Anderson(from several years ago) where they were looking into whether it might prevent breast cancer, but they did not seem to get good results and gave up on it it seems. if you want to research it look up breast cancer and targretin.

[angelwings]

Got one friend who usually orders some accutane from either http://bbonlinepharmacy.com/product/175/accutane-isotretionin-roaccutane or as isotrex on http://drugdelivery.ca/s3582-s-isotrex.aspx for its content in vitaminA which seems to be ok. Hoever i am not really sure of its safety cause i have a lot of side-effects concerned with accutane so was a bit concerned about my friend.
but then is really VitaminA in the form of beta carotene the safest way??

[RobinP]

I take Vita too for the same reasons Becky cited. Tom what is PI-6 stand for and where do you get it?

[Lani]

http://www.ansci.cornell.edu/courses/as625/625vita.html

[Lani]

to be confusing! ie, is it a long-term result of the chemo, a side effect of the antihormonal or a side effect of the herceptin (or just from age and menopause?)



There are two types of vitamin A toxicity, one caused by taking too much vitamin A over a short period of time (acute form) and one that occurs when the excess of the vitamin is present over a longer period (chronic hypervitaminosis A).

In an infant, the suddenly intake of too much vitamin A may cause a bulging fontanelle ("soft spot" on the head) and symptoms resembling those of a brain tumor. This group of symptoms is called "pseudotumor cerebri" and it includes a bulging fontanelle, papilledema (swelling of the optic disc), and double vision. Vomiting and drowsiness are common.

The symptoms in adults are less specific. Headache, visual changes, and impaired consciousness suggestive of pseudotumor cerebri may occur. Other symptoms can include nausea, vomiting, dizziness, and blurry vision.

Chronic vitamin A toxicity develops after taking excessive doses of the substance for extended periods. Bone pain and swelling of the bones is common, often associated with high levels of calcium in the blood. Other symptoms include hair loss, high cholesterol, liver damage, and vision problems. Symptoms are often subtle and may include fatigue, malaise, and nausea.

In children, hypervitaminosis A can cause craniotabes (abnormal softening of the skull bones). Irritability, decreased appetite, itchy skin, and poor weight gain are common. There may be skin changes with seborrhea (extremely oily skin and hair) and cracking at the corners of the mouth.

Increased intracranial pressure is seen in both acute and chronic forms.

[Lolly]

I have friends who for a time were subsisting on quite alot of dried salmon as they were living off the land....long story short they began to develop vision changes ie fuzzy/double vision and finally realized it was due to the high intake of fish/Vit.A. They cut back on the fish and the vision problems resolved. True story.