| Title |
Hypomethylation of L1 retrotransposons in colorectal cancer and adjacent normal tissue
|
|---|---|
| Published in |
International Journal of Colorectal Disease, October 2003
|
| DOI | 10.1007/s00384-003-0539-3 |
| Pubmed ID | |
| Authors |
Catherine M. Suter, David I. Martin, Robyn L. Ward |
| Abstract |
Malignant cells often exhibit perturbations in the pattern of cytosine methylation. Hypermethylation of CpG islands has been extensively documented, but genome-wide hypomethylation is also a common feature of malignant cells. The bulk of cytosine methylation in the mammalian genome occurs on repetitive elements. This study analysed the methylation status of L1 retrotransposons in colorectal cancer. Methylation-sensitive Southern blotting was used to determine L1 promoter methylation in colon tumours, adjacent normal tissue, and normal colonic mucosa from healthy individuals. Hypomethylation of L1 promoter sequences was detected in all tumours but was also detected in the histologically normal colonic mucosa of 6 of 19 cancer patients, even at a considerable distance from the tumour. L1 hypomethylation was not detected in matched normal peripheral blood, lymph node or smooth muscle tissue from cancer patients or in the colonic mucosa of 14 healthy individuals. We also assayed for the total proportion of methylated CpG in normal bowel specimens from normal and colon cancer patients. Normal mucosa from cancer patients exhibited lower levels of genomic methylation than the mucosa from healthy individuals, and levels were significantly lower in those patients exhibiting L1 promoter hypomethylation. These results suggest that genomic hypomethylation is an early event in tumourigenesis. Progressive demethylation of L1 promoter sequences could lead to disturbance of normal gene expression and facilitate the process of neoplastic progression. |
Mendeley readers
The data shown below were compiled from readership statistics for 70 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United Kingdom | 1 | 1% |
| India | 1 | 1% |
| Unknown | 68 | 97% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Ph. D. Student | 17 | 24% |
| Researcher | 11 | 16% |
| Student > Doctoral Student | 8 | 11% |
| Student > Master | 6 | 9% |
| Student > Postgraduate | 5 | 7% |
| Other | 10 | 14% |
| Unknown | 13 | 19% |
| Readers by discipline | Count | As % |
|---|---|---|
| Biochemistry, Genetics and Molecular Biology | 20 | 29% |
| Agricultural and Biological Sciences | 14 | 20% |
| Medicine and Dentistry | 8 | 11% |
| Unspecified | 2 | 3% |
| Computer Science | 2 | 3% |
| Other | 7 | 10% |
| Unknown | 17 | 24% |
Attention Score in Context
This research output has an Altmetric Attention Score of 3. 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 23 June 2010.
All research outputs
#8,534,976
of 25,374,647 outputs
Outputs from International Journal of Colorectal Disease
#444
of 1,928 outputs
Outputs of similar age
#19,904
of 56,747 outputs
Outputs of similar age from International Journal of Colorectal Disease
#2
of 10 outputs
Altmetric has tracked 25,374,647 research outputs across all sources so far. This one is in the 43rd percentile – i.e., 43% of other outputs scored the same or lower than it.
So far Altmetric has tracked 1,928 research outputs from this source. They receive a mean Attention Score of 3.4. This one has gotten more attention than average, scoring higher than 54% 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 56,747 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 12th percentile – i.e., 12% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 10 others from the same source and published within six weeks on either side of this one. This one has scored higher than 8 of them.