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Rock and rho: Proteins that help cancer cells groove

"High levels of RhoA and ROCK1 were known to worsen outcomes for breast cancer patients by endowing cancer cells with the ability to move, but the trigger for their production was a mystery," says Gregg Semenza, M.D., Ph.D., the C. Michael Armstrong Professor of Medicine at the Johns Hopkins University School of Medicine and senior author of the article. "We now know that the production of these proteins increases dramatically when breast cancer cells are exposed to low oxygen conditions." To move, cancer cells must make many changes to their internal structures, Semenza says. Thin, parallel filaments form throughout the cells, allowing them to contract and cellular "hands" arise, allowing cells to "grab" external surfaces to pull themselves along. …

Malignant cells adopt different pathway for genome duplication

For one of our cells to give birth to two daughter cells, it must first replicate its DNA which consists of around 6.4 billion pairs of nucleotides. The double-stranded DNA opens up like a zipper, producing a ‘replication fork’ upon which a group of enzymes move about. Present in different regions in the DNA, the forks move with the progression of the replication. Cell proliferation is controlled in particular by specific genes known as proto-oncogenes…

Mutations in cancer often affect the X chromosome

By studying when and where mutations occur the researchers hope to gain insights into the early mechanisms that send cells along a pathway to cancer. The new international study coordinated by Roland Eils has now for the first time analyzed the exact distribution of somatic mutations in the genomes of tumor cells of various types of cancer. Mutations do not affect all regions of the genome to the same extent. It is known, for example, that the number of somatic mutations depends on the sequence of bases making up a gene and the frequency at which it is transcribed into RNA molecules. …

Recommended treatment for bone metastases not widely used

“Palliative radiotherapy, comprising l or more fractions (i.e., treatments) of daily radiation, is the mainstay of treatment for painful bone metastases. In 2005, a U.S.-based randomized trial demonstrated no difference in pain relief between single- and multiple-fraction radiotherapy for uncomplicated bone metastases, confirming results from international trials,” according to background information in the article appearing in the October 9 issue of JAMA…

Chemotherapy drug improves survival following surgery for pancreatic cancer

"Pancreatic cancer is a disease with a poor prognosis, mainly because of the inability to detect the tumor at an early stage, its high potential for early dissemination, and its relatively poor sensitivity to chemotherapy or radiation therapy," according to background information in the article. Even after complete removal of the tumor, the vast majority of patients relapse within 2 years, leading to a 5-year survival rate of less than 25 percent. No consensus has been reached on a standard treatment approach for additional therapy…