The role of a protein in
enhancing and restoring sensitivity to estrogen-blocking drugs in
estrogen-receptor positive or ER+ cancer, has been determined
- Breast cancer is one of
the most common type of cancer that affects women.
- The most
common type of breast cancer is the estrogen-receptor positive or ER+ breast
cancer where the cancer cells grow in the presence of hormone
- Tamoxifen blocks the estrogen receptors and
prevents estrogen from binding to them, but the main drawback of this treatment
is that the cancer cells develop resistance to the drug, making it less
effective in due course.
- A recent study has determined the
role of a protein GRP78, in enhancing and restoring sensitivity to
. The research has been published in Cancer
develops when the cells in the breast grow out of control.
It often starts as a painless lump in which the cells grow abnormally, invade
the surrounding tissue and spread to distant areas of the body.
‘Drugs targeting protein GRP78, certain dietary measures like polyunsaturated fatty acid supplementation may help in increasing sensitivity of estrogen-receptor positive breast cancer to estrogen-blocking drugs.’
breast cancers originate from the cells that line the ducts that carry milk to
the nipples (ductal cancers). Some originate in the glands that produce milk
(lobular cancers). Other tumors like sarcomas and lymphomas may also be noted
in the breast.
the United States, breast cancer is the most common type of cancer that affects
women after skin cancer
According to the American Cancer Society, breast cancer estimates for 2016 are:
- Around 246, 660 new cases of
invasive breast cancer
- Around 61,000 new cases of
non-invasive breast cancer
- Around 40,450 women are expected
to die due
to breast cancer
India, according to the Indian Council of Medical Research, there will be
around 1.5 lakh new cases of breast cancer in 2016.
know what kind of treatment is most effective, breast cancers are divided into
- Endocrine-receptor positive - The cancer cells have receptors for
either estrogen or progesterone..
- HER2-positive - These cancers have cells with receptors
for the protein HER2.
- Triple positive - The cancer cells
have receptors for estrogen, progesterone and HER2.
negative - The cancers have cells that do not have receptors for estrogen,
progesterone and HER2.
80% of breast cancers detected are estrogen-receptor positive or ER+ cancers.
This type of breast cancer has the most favorable prognosis. The breast cancer
cells receive signals from estrogen that promote their growth or, in simple
words, the cancer cells grow in the presence of estrogen hormone. These cancers
can be treated by lowering the estrogen level or blocking the action of estrogen
that fuels the growth of cancer cells.
are used in the
treatment of ER+ breast cancers. These medications block the estrogen receptors
on the breast cancer cells and prevent estrogen from binding to them. One of
the main drawbacks
of this treatment is that though initially responsive, the cancer cells later
develop resistance making medicines less effective.
Scientists at the Wake
Forest Baptist Medical Center conducted experiments in an animal model and
found that targeting a glucose-regulated protein 78 (GRP78), which is elevated
in breast cancer tumors, could help to enhance and restore sensitivity to
estrogen-blocking drugs in ER+ breast cancers
For their study,
researchers initially used a GRP78 targeting molecule called morpholino. They
found that morpholino successfully inhibited GRP78 and helped in restoring sensitivity
to tamoxifen in resistant tumors
"Morpholinos are candidate drugs already being
used to target other proteins in clinical trials to treat prostate cancer, but
this is the first time inhibiting the gene expression of GRP78 with these
agents may have potential to overcome resistance to chemotherapy," said
Katherine Cook, Ph.D., assistant professor at Wake Forest School of Medicine, a
part of Wake Forest Baptist, Scid and the study's lead author.
The researchers also found that
suppressing GRP78 increased the intracellular concentrations of essential
polyunsaturated fats, including linoleic acid. They therefore fed the tumor-bearing mice with different doses of
linoleic acid, which restored the tamoxifen sensitivity to the tumors
study highlights the importance of fatty acid regulation in cancer, Cook said.
"While drugs against GRP78 protein are further along as a potential cancer
therapy, dietary measures such as polyunsaturated fatty acid supplementation
may also enhance therapeutic sensitivity."
The researchers are currently
looking at the role of diet on breast
cancer in an animal model using different types of fatty acids and diets to see
whether they have an effect on tumor growth or endocrine therapy responsiveness.
Tips to Lower Risk of Breast Cancer
- Eat healthy - Eating
fresh vegetables and fruits and avoiding saturated and
consumption and smoking - Alcohol has shown to increase the risk of breast cancer. Moderation of alcohol
consumption and avoiding tobacco lower the risk of several types of
- Exercise -
Physical activity has shown to lower the risk of several type of cancers. Women
who are physically active for at least 30 minutes in a day have low risk of
developing breast cancer.
- Maintain healthy weight - Being
overweight can increase the risk of many types of cancers especially after
- Breastfeeding for more
than a year has shown to lower the risk of breast cancer.
- Clinical Breast Examination - Getting breasts examined by a professional helps in
detecting early changes and abnormalities that could suggest signs
of breast cancer like change in the
size and shape of breast, puckering or dimpling of the skin, changes in the
nipples or any sort of discharge from them.
- Screening -
Preventive screening with mammography after 40 years of age helps in ruling out
or early detection of breast cancer.
- Preventive Breast Cancer Drugs -
Tamoxifen, which until now has only been used for breast cancer treatment
lowers the risk of the disease by 0% to 40%. It can be used to reduce cancer
risk in high-risk women.
- What Is Breast Cancer? - (http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-key-statistics)
- Hormone Receptor Status - (http://www.breastcancer.org/symptoms/diagnosis/hormone_status)
- Breast Cancer - (http://cancerindia.org.in/cp/index.php/know-about-cancer/breast-cancer#early-detection)