Navigation Links
Escape cancer, but age sooner? The dark side of the tumor suppressing process
Date:12/1/2008

Cells shut down and stop dividing when their DNA is damaged, in a process known as cellular senescence, so as to prevent damaged DNA from leading to unregulated cell division and therefore cancer. However, a new study, published in this week's issue of PLoS Biology, has found that when these cells shut down they also spew proteins into their surrounding environment. This causes inflammation and sets up conditions that support the development of age-related diseases including, ironically, cancer. The new research includes the first comprehensive molecular description of a paradoxical process that prevents cancer in younger people, but promotes age-related cancers and other maladies later in life.

"We provide for the first time a broad molecular description of how this well known mechanism for cancer prevention drives aging and age-related disease by changing the local tissue environment," said Judith Campisi, PhD, lead author of the study, who is a Faculty Member of the Buck Institute for Age Research and also Senior Scientist at Lawrence Berkeley National Laboratory.

The study shows that the senescent cells secrete inflammatory, growth-stimulating, immunomodulatory, and other proteins that dramatically change the tissue microenvironment, both in cells grown in the lab and in people undergoing chemotherapy, which can cause DNA damage.

The study also showed that normal cells that acquire a highly active, mutant version of a cancer-promoting protein known as Ras secrete higher levels of the tissue-altering molecules, as do cells that lose functions of the tumor suppressor protein p53. The study therefore explains why the presence of senescent cells can promote the growth and aggressiveness of nearby precancerous or cancer cells, and further defines a new mechanism by which precancerous or cancer cells that have lost the p53 tumor suppressor, or gained an oncogene such as Ras, promote cancer so efficiently.

"This study defines a new paradigm for how oncogenes promote, and how tumor suppressor genes suppress the development of cancer," said Campisi. "The established role for these genes is to control the cell itself. Our findings show that both types of genes also strongly change the tissue microenvironment, and therefore control cancer by mechanisms that depend not only on the response of the affected cells themselves, but also on the response of neighboring cells, or the local tissue environment." Campisi said the findings also help explain why cancer patients feel so sick when they get chemotherapy. "Chemotherapy is brutal -- both normal and cancerous cells are forced into senescence, with resulting secretion of inflammatory factors that can produce flu-like symptoms during treatment," Campisi said.

While Campisi emphasizes that chemotherapy can cure cancer, she says the study provides a cautionary note for younger patients who receive treatments that could promote the development of further cancers later in life. Campisi said the study points out the need for new biologically targeted therapies for cancer that exploit more specific differences between normal and cancer cells. Current DNA damaging chemotherapy focuses on cells that divide rapidly - impacting cancer cells, as well as all dividing cells including cells in the alimentary canal and hair follicles.

The next phase of the ongoing research involves efforts to encourage the body to eliminate senescent cells more rapidly than it normally does. "That's got to be the goal," said Campisi. "Although senescent cells exist for the good purpose of preventing cancer, we don't want them to hang around we want the body to be able to get rid of them."


'/>"/>

Contact: Sally Hubbard
press@plos.org
Public Library of Science
Source:Eurekalert

Related medicine news :

1. Yo Mujer: Woman Escapes from Abusive Marriage in New Spanish-Language Novel
2. Defending Champions Andy Potts and Leanda Cave Win 28th Annual Accenture Escape From Alcatraz(TM) Triathlon Sunday, June 8
3. Escape the Cold and Flu Season With a Free Vacation to the Sunshine State
4. Virtual game helps children escape realities of burn unit
5. Report Shows Progress in Fight Against Cancer, but Congress, States Must Step Up Efforts to Reduce Smoking, Lung Cancer
6. AMA Immediate Past President Ron Davis Loses Battle With Cancer, Leaves Enduring AMA and Public Health Legacy
7. First Major Medical Meeting Convening for MRI-guided Focused Ultrasound to Treat Cancer, Stroke, Fibroids, Other Conditions
8. Surgery Helps With Prostate Cancer, Sometimes
9. Dogster.com Teams With Morris Animal Foundation to Cure Canine Cancer, While Helping Dogs Suffering From Cancer Today - Makes $2 Donation for Each Subscription
10. American Lung Association Report Finds Lung Disease Death Rates Increasing While Cancer, Heart Disease and Stroke Death Rates Are Decreasing
11. June 2008 Mayo Clinic Health Letter Highlights New MRI Scanning Technology, Obesity-Related Cancer, and Do-It-Yourself Massage
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/30/2016)... ... April 30, 2016 , ... Orlando-based Maximized Living has selected Dr. ... gold in Rio. Under the care of Maximized Living doctors at the London ... unprecedented showing, Maximized Living is sending the largest contingent of elite chiropractors to Rio ...
(Date:4/29/2016)... ... April 29, 2016 , ... Memorial Healthcare System Graduate ... Education (ACGME) that it has received accreditation for its residency program on Physical ... programs that Memorial is currently pursuing, including Pediatrics and Internal Medicine. This accreditation ...
(Date:4/29/2016)... ... April 29, 2016 , ... ... and author of best seller "LOVE, MEDICINE and MIRACLES") addresses touchy topics related ... 2016 and podcasted thereafter . Dr. Bernie Siegel, author of a plethora ...
(Date:4/29/2016)... ... April 29, 2016 , ... Spine Team Texas, a comprehensive spine physician ... one of their physicians has been invited to be a featured speaker at the ... Review conference on April 30, 2016. , Dr. R. Scott McPherson, a physical ...
(Date:4/29/2016)... ... 29, 2016 , ... Melanoma is the deadliest type of skin cancer. Although only about 1 ... skin cancer deaths. More than 10,000 people are expected to die of melanoma this year. ... is the one of the most commonly diagnosed cancers in young women. A recent breakthrough ...
Breaking Medicine News(10 mins):
(Date:4/27/2016)... 2016 Tie-up with Government hospitals ... to save newborns   Fortis La Femme, ... in collaboration with Breast Milk Foundation (BMF), a non-profit organization ... Milk Bank, ,Amaara, in Delhi-NCR today. This non-profit centre recognizes ... infants and should be available to babies deprived of mother,s ...
(Date:4/27/2016)... 2016 Oasmia Pharmaceutical AB ... a new generation of drugs within human and ... for Paclical/Apealea in the Phase III study that ... ovarian cancer. These preliminary results showed non-inferiority between ... carboplatin versus Taxol in combination with carboplatin. In ...
(Date:4/26/2016)... FLINT, Mich. , April 26, 2016 ... the promotion of Jennifer Hagerman , Pharm D., ... In her growing role at Diplomat, Hagerman will continue ... of the company that delivers custom education and training ... to the specialty pharmacy industry. Diplomat University also houses ...
Breaking Medicine Technology: