Skip to comments.A protein that makes breast cancer spread
Posted on 03/16/2008 12:46:17 PM PDT by neverdem
Researchers pinpoint protein 'boss' that controls gene expression.
Link to Getty photo from a microscope
Will it spread? One protein controls the expression of many genes that dictate whether breast cancer will metastasize. Getty
A protein that determines whether breast cancer will spread and become deadly has been found. Researchers say that the protein, which is found inside the nuclei of cells, would be difficult and potentially dangerous to target with drugs. But monitoring for the protein could help patients to know how dangerous their cancer is before it spreads elsewhere, and help them to decide which treatment to chose.
Because breasts are not critical to survival, cancers that remain within breast tissue do not kill the patient. But if the cancer cells break away from the original tumour, settle and start dividing elsewhere, these secondary tumours can threaten the function of vital organs.
Rather like an invasive plant landing on an island, the circulating breast cancer cell needs to evolve genetic changes to survive in a new environment. It has to find a way to stick to a new type of cell or supporting structure, called a matrix, and form links to surrounding cells, for instance.
Now a protein has been found that changes the levels at which more than a thousand genes are expressed in breast cancer cells, seemingly controlling whether cancer cells will survive elsewhere. The protein is called SATB1. All sorts of molecular pathways that enable the cell to invade and inhabit a new microenvironment are under the control of SATB1, says Terumi Kohwi-Shigematsu of the University of California, Berkeley, who was an author of the study.
The nuclear organizer
Kohwi-Shigematsu and her colleagues had previously shown that SATB1 acts as an architect inside the nuclei of cells, directing loops of DNA to clump together. By changing the spatial arrangement of DNA, SATB1 can alter the proteins surrounding some sections of the genome, and in changing this 'casing' effectively turn some genes on and others off.
When the researchers looked for SATB1 in breast cancer cells from more than 1,300 samples, they found a striking pattern. In almost all cases, the more SATB1 those cells contained, the more aggressive the tumour was.
At present, the test to see whether a cancer can spread to other organs, or metastasize, involves looking for the cancer in the lymph nodes. But this catches a tumour only in the act of spreading, rather than beforehand. Crucially, in this study the link between high levels of SATB1 and aggressive tumours held for breast cancers that had not yet spread to the lymph nodes.
This means that the protein could be a good prognostic test for women with breast cancer. If we discover that this protein is present in the primary tumour, we will have a good idea that the prognosis of this woman will be different and maybe that will lead to a different choice of treatment, says co-author Jose Russo from the Fox Chase Cancer Center in Philadelphia, Pennsylvania. Patients with more aggressive tumours may chose to be more precautionary and have a larger section of their breast removed, for example.
To show that SATB1 was both necessary and sufficient for breast cancer metastasis, the team used a technique called RNA interference to remove it from highly aggressive cancer cells in mice. This inhibited tumour growth. They then added SATB1 to non-aggressive breast cancer cells in mice. This caused those cells to alter the combinations of genes they expressed, and made the cells resemble metastatic cells. The study is published in the journal Nature 1.
Researchers have been describing changes to the DNA casing of large groups of genes in cancer cells, but they have not understood what causes those changes, says Frances Shannon, a researcher at the Australian National University in Canberra. This study goes a step further by identifying what causes those changes," she says. But, she adds, the next question is "what leads SATB1 levels to rise?".
Now we just need to find the corresponding protein for liberalism...
Now we just need to find the corresponding protein for liberalism...
Oh, and seriously: are there anaologues between this protein and ones in embryonic stem cells (in utero) which allow them to be so flexible in taking on all the different identities while building a new person?
Check the second link in comment# 29 on that thread, or check this. You might want to save it. The capitalized letters are the title of the NY State Dept. of Health study of breast cancer on Long Island, except “BREAST CANCER RISK FACTORS,” which is the title of a section. Here’s how I saved it to a working file on my desktop:
CORAM, MT. SINAI, PORT JEFFERSON STATION (CMP)
BREAST CANCER RISK FACTORS with references starts on page 25.
The importance of reproductive factors in affecting breast cancer risk has been known for a long time. Women who have never given birth (or had a full-term pregnancy) are at a higher risk for breast cancer compared to women who have carried a pregnancy to term.(Page 26)
Notice how they weasel around abortion.
FReepmail me if you want on or off my health and science ping list. Anyone can post any unposted link as they see fit.
Thanks very much for
this critically important post!
Well .. what makes the “protein” develop in the first place ..??
Could the “protein” be part of the natural hormones which develop after an egg is fertilized ..??
As in pregnancy? Entering pregnancy and SATB1 at PubMed yields nada. SATB1 gets a fair number of immunology hits.
I was just curious because there has been a lot of talk about there being a connection between abortion and breast cancer. And .. while it has been “quietly” ignored - I’ve always wondered if there was really anything to it.
My thoughts - I sincerely believe a link could be possible because one of the first signs a woman is pregnant is that her breasts begin to prepare for milk production (and milk is full of protein). The breasts become enlarged, or swollen, and painful to the touch.
When an abortion takes place .. the breasts could potentially experience a traumatic effect when the body suddenly signals that the new milk production is no longer needed.
It may seem like a wild guess for any of my statements, but when they said it was a “protein” which made the breast cancer spread .. it only seemed more possible to me to connect abortion and breast cancer.
If people disagree with me - fine!
Did you read comment# 6?
It may seem like a wild guess for any of my statements, but when they said it was a protein which made the breast cancer spread ..
This protein appears involved with the epigenetics of metastasis, i.e. distant spreading, not the initial tumor.
I was 28 when I had breast cancer...never pregnant. It ran in my family for three generations (that I know of).
Please keep your poisonous speculation to yourself! You hurt many people like me!
Excuse me .. did I accuse you of anything ..??
I think you’re over-reacting .. I was discussing my thoughts with someone else. You didn’t even need to say anything .. did you ..??
bump for later
...so, you are the arbiter of who can say things????
This is the depths to which this site has fallen.
Why are you taking this so personal - I wasn’t pointing a finger at you.
And .. as a matter of fact, I know of a person who had 2 cysts removed from her breasts - they thought it was cancer. She had a miscarriage when she was first married.
So .. I do have a vested interest in finding out if there is a relationship between breast cancer and losing a baby.
But for you to say I’m at fault because you replied to my question ..?? Isn’t that backwards. I didn’t stop you from saying ANYTHING and I surely didn’t require you to say anything either. YOU CHOOSE TO SAY SOMETHING!!
You can’t have it both ways. You can’t reply and then blame me for your reply .. sorry .. won’t buy that.
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