Displaying 1 - 3 of 2476 entries.

Piggy-backing cells hold clue to skin cancer growth

  • Posted on July 27, 2014 at 2:00 pm

Cancer Research UK scientists at The University of Manchester found that some melanoma cells are particularly fast growing, but not very good at invading the surrounding tissue, while other melanoma cells are the opposite — highly invasive but slow-growing.

In a tumor, the faster growing cells ‘piggy-back’ along with the more invasive cells, so together they can be more effective in establishing a new tumor once they have reached different parts of the body.

The scientists conducted the research using see-through zebra fish so that they could see how the cancer cells moved and expanded from the original tumor.

Dr Claudia Wellbrock, study author and Cancer Research UK scientist at The University of Manchester and a member of the Manchester Cancer Research Centre, said: “We used to think that cancer cells spread by first specialising in invading other parts of the body and then change in order to grow rapidly. But this research shows that melanoma can spread by ‘co-operative invasion’.

“Different types of cancer cells with different strengths and weaknesses are both present in the tumor at the same time and can work together to spread faster and more efficiently. This has profound implications for how we find cures for this terrible disease.”

Melanoma is the most dangerous form of skin cancer with around 13,300 people diagnosed in the UK each year.

Worryingly, the incidence rates of malignant melanoma have increased more than fivefold since the mid 1970s.

Professor Richard Marais, director of the Cancer Research UK Manchester Institute, said: “Malignant melanoma is the most deadly form of skin cancer precisely because it spreads quickly and aggressively. This kind of research is vital for establishing how this horrible disease spreads around the body and how we might be able to stop it.

“As well as finding more effective treatments for advanced melanoma, we also need to stress the importance of early diagnosis, detecting tumors before they have a chance to spread.”

source : http://www.sciencedaily.com/releases/2014/07/140724124507.htm

Clearing cells to prevent cervical cancer

  • Posted on July 27, 2014 at 2:00 pm

The findings come from a study that looked at squamocolumnar junction cells, or SCJ cells. These cells reside in the cervical canal and have been implicated as the origins of cervical cancer. A research team co-led by Christopher Crum, MD, director, Brigham and Women’s Hospital (BWH) Women’s and Perinatal Pathology, demonstrated that removal of SCJ cells resulted in a markedly lower risk of cervical intraepithelial neoplasia — a non-cancerous, abnormal growth of cells on the surface of the cervix that may progress to cervical cancer.

One hundred and thirty-one women with cervical intraepithelial neoplasia were treated with a loop electrosurgical excision procedure to remove the SCJ cells. During the follow-up period (of up to four years), 16 recurrences were identified. Four were identified at the first follow-up visit, and determined to be residual disease, meaning they were not removed in the initial procedure. Twelve manifested after the first postoperative visit and all were in the ectocervix or in mature metaplastic epithelium. All of the 12 delayed recurrences were cervical intraepithelial neoplasias and did not have SCJ cells.

“We have always suspected that most recurrences following apparently successful therapy do not develop in the same location as the original precancer, which was at the squamocolumnar junction,” said Crum. “Moreover, studies in the literature have shown that the risk of a significant precancer following successful removal is quite low. Our study is in sync with these observations and suggests that removing SCJ cells might have a significant impact in reducing the risk of cervical cancer.”

Crum emphasizes that eliminating SCJ cells does not prevent cervical intraepithelial neoplasias nor does it prevent human papilloma virus (HPV) infection — which can lead to cervical cancer. But what is significant about the findings, according to the researchers, is that removal of SCJ cells seems to alter recurrence patterns, presumably by removing the population that is most vulnerable to development of the more dangerous precancers.

“This is a concept that is in great need of a controlled clinical trial aimed at prevention rather than treatment,” said Crum. “It would give us important insights into whether preemptive removal of the SCJ region would have the desired effect.”

An accompanying editorial, by Silvia Franceschi, MD, International Agency for Research on Cancer, suggests continuation of the work by “careful evaluation of the impact of prophylactic ablation in the framework of large screening programmes.”

source : http://www.sciencedaily.com/releases/2014/07/140725131558.htm

Epigenetic changes can drive cancer, study shows

  • Posted on July 27, 2014 at 2:00 pm

Researchers at the USDA/ARS Children’s Nutrition Research Center at Baylor College of Medicine and Texas Children’s Hospital have now created a mouse model providing the first in vivo evidence that epigenetic alterations alone can cause cancer. Their report appears in the Journal of Clinical Investigation.

“We knew that epigenetic changes are associated with cancer, but didn’t know whether these were a cause or consequence of cancer. Developing this new approach for ‘epigenetic engineering’ allowed us to test whether DNA methylation changes alone can drive cancer,” said Dr. Lanlan Shen, associate professor of pediatrics at Baylor and senior author of the study.

Shen and colleagues focused on p16, a gene that normally functions to prevent cancer but is commonly methylated in a broad spectrum of human cancers. They devised an approach to engineer DNA methylation specifically to the mouse p16 regulatory region (promoter). As intended, the engineered p16 promoter acted as a ‘methylation magnet’. As the mice reached adulthood, gradually increasing p16 methylation led to a higher incidence of spontaneous cancers, and reduced survival.

“This is not only the first in vivo evidence that epigenetic alteration alone can cause cancer,” said Shen. “This also has profound implications for future studies, because epigenetic changes are potentially reversible. Our findings therefore both provide hope for new epigenetic therapies and validate a novel approach for testing them.”

Shen, who is also with the NCI-designated Dan L. Duncan Cancer Center at Baylor, predicts that this new approach will be widely useful because in addition to p16, there are many other genes and diseases other than cancer that are connected to epigenetics (such as neurodevelopmental diseases, obesity and diabetes). Just as genetic engineering has become a standard approach for studying how genetic mutations cause disease, epigenetic engineering will now enable functional studies of epigenetics.

“This opens up the door for a whole new paradigm of how to understand tumorigenesis. If we can identify epigenetic changes that predispose people to cancer, these may actually be treatable or preventable, so this opens up a lot of optimism in new ways to deal with cancer,” said Dr. Robert Waterland, associate professor of pediatrics at Baylor, who was also involved in the study.

source : http://www.sciencedaily.com/releases/2014/07/140726082322.htm