Do You Read All Of Our Cancer Blogs?

Do you read all of the blogs published by medicineworld.org? Many of our bloggers are busy keeping you updated on the various health related topics. We publish the following blogs at this time.

Cancer blog: I manage the cancer blog with lots of help and support form other bloggers. Through this cancer blog my friends and I try to bring stories of hope for patients with cancer. The cancer blog often republishes important blog posts from other cancer related blogs at Medicineworld.org. If you are searching for a blog that covers wide variety of cancer topics, this may be the one for you.

Breast cancer blog: Breast cancer blog is run by Emily and other bloggers and they bring you the latest stories, news and events that are related to breast cancer. Increasing awareness about breast cancer among women and in the general population is the main goal of this breast cancer blog.

Lung cancer blog: Lung cancer blog is managed by Scott with the help of other bloggers. Through this blog Scott and his friends constantly remind the readers about the dangers of smoking. It's a never-ending struggle against this miserable disease with which a social stigma of smoking is associated.

Colon cancer blog: Colon cancer blog is run by Sue and other bloggers. Sue brings a personal touch to the colon cancer blog since her mother died of colon cancer few years ago. She writes about stories, research news and advances in treatment related to colon cancer.

Prostate cancer blog: Prostate cancer is the most common cancer among American men. American Cancer Society estimates that over 230,000 new cases of prostate cancer occur in the United state every year. This important blog about prostate cancer is run by Mark and other bloggers. This blog brings news, stories, and other personal observations related to prostate cancer.

Medicineworld.org publishes a diabetes watch blog and this blog is run by JoAnn other bloggers. This diabetes watch blog brings you the latest in the field of diabetes. This includes personal stories, advances in diagnosis and treatment, and other observations about diabetes. Improving awareness about diabetes is an important mission of this group.

Janet      

Strategy To Knock Out Cancer

To remain healthy, all cells must quickly mend any breaks that arise in their DNA strands. But cancer cells are especially dependent on a process called homologous recombination to repair DNA and stay alive.

Now scientists at Washington University School of Medicine in St. Louis have found that a protein known as MDC1 has a role in homologous recombination. This discovery could be exploited in a two-pronged therapy strategy to eliminate cancer cells' ability to repair DNA.

"Frequently cancer cells are more efficient at DNA repair than normal cells," says Simon Powell, M.D., Ph.D., head of the Department of Radiation Oncology and a researcher with the Siteman Cancer Center at Washington University School of Medicine and Barnes-Jewish Hospital. "That's what makes them resistant to drugs or radiation therapys that physicians use in an effort to damage cancer cells' DNA and destroy them."

But in light of their findings, Powell and colleagues believe MDC1 - along with other proteins involved this repair pathway - may be good targets for dual-drug chemotherapeutic approaches that can completely knock out tumor cells' ability to cope with DNA damage. Their study appears in the recent issue of Nature Structural and Molecular Biology.

The research group discovered that MDC1, a protein previously recognized only for its function in sensing DNA damage and signaling its presence, also transports DNA-repair proteins to the site of DNA strand breaks. Without MDC1 to pave the way, repair happens slowly because the fix-it proteins have a hard time reaching damaged areas, which are buried in the tightly packed chromosomal material of the cell's nucleus.

"MDC1 can bind to chromatin, the complex mixture of DNA and proteins that holds the genetic material," Powell says. "Because of chromatin's properties, getting into it to reach the DNA strand requires the right 'passwords.' MDC1 provides the DNA-repair proteins with this privileged access, and efficiently transports them to the site of damage so they can do their jobs."

Chemotherapeutic strategies that reduce the activity of MDC1 could inhibit the ability of cancer cells to restore broken DNA. An accumulation of DNA damage would signal cells to initiate suicide pathways and die.

Eventhough cells can find other ways to repair DNA, Powell says a dual strategy that used a second drug to knock out the survival mechanism in cells would deliver a one-two punch to tumors. It would force tumor cells to rely more heavily on homologous recombination repair and then block that route as well.

The research group already has begun studies that investigate the potential of targeting homologous recombination as a tumor-specific strategy. In this case, they are focusing on tumors with BRCA1 and BRCA2 deficiencies.

BRCA1 and BRCA2 are tumor suppressor proteins, and mutations in the genes for these proteins are widely known for being associated with a high risk of breast cancer in 5 to 10 percent of women. Tumors with BRCA1 and BRCA2 deficiencies have ineffective homologous recombination repair mechanisms, and Powell's group has begun using this handicap to attack the tumors.

"BRCA1- and 2-deficient tumor cells represent a special case in which the homologous recombination repair pathway is already messed up," Powell says. "So, we are trying to further sensitize BRCA1- and 2-deficient cancer cells to see if that approach can destroy them."

Having uncovered a role for MDC1 in homologous recombination repair, the group now will be able to build on their BRCA1/BRCA2 research as they develop chemotherapeutic strategies that take advantage of MDC1's cellular function.

Zhang J, Ma Z, Treszezamsk A, Powell SN. MDC1 interacts with Rad51 and facilitates homologous recombination. Nature Structural and Molecular Biology 2005 Oct;12(10):902-9.

By Gwen Ericson


Source: Washington University in St.Louis - School of Medicine

Did you know?
To remain healthy, all cells must quickly mend any breaks that arise in their DNA strands. But cancer cells are especially dependent on a process called homologous recombination to repair DNA and stay alive. Now scientists at Washington University School of Medicine in St. Louis have found that a protein known as MDC1 has a role in homologous recombination. This discovery could be exploited in a two-pronged therapy strategy to eliminate cancer cells' ability to repair DNA.