| Title |
The link between the insecticide heptachlor epoxide, estradiol, and breast cancer
|
|---|---|
| Published in |
Breast Cancer Research and Treatment, March 2005
|
| DOI | 10.1007/s10549-004-2755-0 |
| Pubmed ID | |
| Authors |
Richard A. Cassidy, Sridhar Natarajan, George M. Vaughan |
| Abstract |
Given the suspected effects of estrogens on breast cancer, xenoestrogenic insecticides may be a risk factor. Studies of the weak xenoestrogen, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), have failed to demonstrate a causal relationship, though another estrogenic organochlorine insecticide, dieldrin, belonging to the cyclodiene family, has recently been linked to breast cancer. Other cyclodienes such as heptachlor epoxide (HE) and oxychlordane (OC) present in breast tissue have not been evaluated as rigorously, presumably due to their lower concentration and lower recovery using solvent extraction procedures. We used sparging extraction coupled with gas chromatography to determine the levels of HE, OC, and DDE in adipose tissue within breast biopsies in a series of 34 women evaluated for breast abnormality. Of the three insecticides tested, only HE (p=0.007) was positively associated with prevalence of breast cancer in the biopsies. In rapid, non-genomic studies using isolated human leukocytes, flow cytometric methods were used to measure HE-induced oxidants and DNA damage. These studies indicated that HE, at concentrations similar to those in breast biopsies, induced an inverted-U increase in intracellular oxidants and DNA strand breaks [both blocked by specific nitric oxide- (NO-) synthesis blockade withL: -NMMA] in human polymorphonuclear leukocytes (PMNs). HE-treated PMNs also induced damage to surrounding lymphocytes in mixed-leukocyte incubations (also inhibited by NO blockade). The HE-induced changes in NO were inhibited by 17beta-estradiol-(17beta-E2) receptor antagonists and were mimicked by similar concentrations of 17beta-E2. The addition of tumor necrosis factor-alpha (TNF-alpha) increased intracellular oxidants and DNA damage and shifted the responses to lower HE concentrations. This study, along with others, suggests that HE-induced NO production may contribute to initiation, promotion, and progression of cancer. |
X Demographics
The data shown below were collected from the profile of 1 X user who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 1 | 100% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 1 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 30 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| China | 1 | 3% |
| Unknown | 29 | 97% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 7 | 23% |
| Student > Master | 5 | 17% |
| Student > Doctoral Student | 4 | 13% |
| Researcher | 3 | 10% |
| Professor > Associate Professor | 2 | 7% |
| Other | 3 | 10% |
| Unknown | 6 | 20% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 8 | 27% |
| Environmental Science | 5 | 17% |
| Agricultural and Biological Sciences | 3 | 10% |
| Biochemistry, Genetics and Molecular Biology | 2 | 7% |
| Nursing and Health Professions | 1 | 3% |
| Other | 2 | 7% |
| Unknown | 9 | 30% |
Attention Score in Context
This research output has an Altmetric Attention Score of 4. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 26 October 2011.
All research outputs
#6,375,523
of 22,655,397 outputs
Outputs from Breast Cancer Research and Treatment
#1,388
of 4,612 outputs
Outputs of similar age
#18,445
of 59,821 outputs
Outputs of similar age from Breast Cancer Research and Treatment
#6
of 18 outputs
Altmetric has tracked 22,655,397 research outputs across all sources so far. This one has received more attention than most of these and is in the 70th percentile.
So far Altmetric has tracked 4,612 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 7.2. This one has gotten more attention than average, scoring higher than 68% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 59,821 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 67% of its contemporaries.
We're also able to compare this research output to 18 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 50% of its contemporaries.