August 30, 2007, 9:28 PM CT

Anti-cancer Drug Made From Corn Lillies

A drug that shuts down a critical cell-signaling pathway in the most common and aggressive type of adult brain cancer successfully kills cancer stem cells thought to fuel tumor growth and help cancers evade drug and radiation treatment, a Johns Hopkins study shows.

In a series of laboratory and animal experiments, Johns Hopkins researchers blocked the signaling system, known as Hedgehog, with an experimental compound called cyclopamine to explore the blockades effect on cancer stem cells that populate glioblastoma multiforme. Cyclopamine has long been known to inhibit Hedgehog signaling.

They reported their findings in the journal Stem Cells published online on July 19.

Our study lends evidence to the idea that the lack of effective therapies for glioblastoma may be due to the survival of a rare population of cancer stem cells that appear immune to conventional radiation and chemotherapy, says Charles G. Eberhart, M.D., Ph.D., associate professor of pathology, ophthalmology and oncology, who led the work. Hedgehog inhibition kills these cancer stem cells and prevents cancer from growing and may thus develop into the first stem cell-directed treatment for glioblastoma.

Eberhart cautioned that while his study appears to prove the principle of Hedgehog blocking, much work remains before cyclopamine or any similar drug can be tested in patients. Researchers must determine whether the drug can be effectively and safely delivered to the whole body or whether it must go into the brain, and what if any adverse impact on normal stem cells the therapy might cause......... Posted by: Andria      Read more         Source

August 28, 2007, 8:55 PM CT

Novel M.S. Drug Against Leukemias

A new study suggests that an experimental drug being tested for the therapy of multiple sclerosis and to prevent organ rejection might also help people with certain deadly forms of chronic and acute leukemia.

The laboratory and animal study focused on the drug, called fingolimod. Scientists said it might help patients with advanced chronic myelogenous leukemia (CML) or acute lymphocytic leukemia (ALL), and whose cancer cells show a particular genetic change called the Philadelphia chromosome.

The study observed that the drug prevented the development of these cancers in mouse models, as well as killing laboratory-grown human CML and ALL cells.

Eventhough the findings must be verified in humans through a future clinical trial, the new research also suggests that the drug might help patients with these leukemias who are resistant to imatinib (Gleevec) and dasatinib (Sprycel), two important current drugs for treating CML and those cases of ALL with the Philadelphia chromosome.

Presently, fingolimod is in advanced clinical-trials testing for the therapy of relapsing multiple sclerosis, and to prevent organ rejection following kidney transplantation.

The new study, led by scientists with the Ohio State University Comprehensive Cancer Center, is published online Aug. 23 in the Journal of Clinical Investigation......... Posted by: Andria      Read more         Source

August 27, 2007, 9:43 PM CT

Cells united against cancer

Sheets of highly organized epithelial cells line all the cavities and free surfaces of the body, forming barriers that control the movement of liquids and cells in the body organs. The organized structure of normal breast epithelial cells may also serve as a barrier against cancer, as per a research studyby University of Helsinki scientists. The work appears this week in the online edition of the Proceedings of the National Academy of Sciences (PNAS).

Finnish scientists observed that the tightly organized architecture of mammary epithelial cells is a powerful restraint against the cancer gene provoked inappropriate proliferation. Their study also links function of a tumor suppressor gene to the development of cancer gene resistant epithelial organization.

"Rogue cancer genes can force epithelial cells to proliferate and proliferation of cancerous cells will certainly disrupt the organized epithelial structure. However, there has always been this chicken or the egg problem: Does cancer gene initiate cell proliferation, which causes disruption of the epithelial structure or does loss of tissue structure come first, creating suitable environment for cancer genes to enforce the cell cycle progression"" explains the research team leader Juha Klefstrom, Ph.D. The present study supports the idea that loss of tissue structure comes first......... Posted by: Andria      Read more         Source

August 23, 2007, 10:16 PM CT

New cancer weapon: nuclear nanocapsules

Rice University chemists have found a way to package some of nature's most powerful radioactive particles inside DNA-sized tubes of pure carbon -- a method they hope to use to target tiny tumors and even lone leukemia cells.

"There are no FDA-approved cancer therapies that employ alpha-particle radiation," said lead researcher Lon Wilson, professor of chemistry. "Approved therapies that use beta particles are not well-suited for treating cancer at the single-cell level because it takes thousands of beta particles to kill a lone cell. By contrast, cancer cells can be destroyed with just one direct hit from an alpha particle on a cell nucleus".

The study's results are available online and slated to appear in an upcoming issue of the journal Small.

In the study, Wilson, Rice graduate student Keith Hartman, University of Washington (UW) radiation oncologist Scott Wilbur and UW research scientist Donald Hamlin, developed and tested a process to load astatine atoms inside short sections of carbon nanotubes. Because astatine is the rarest naturally occurring element on Earth -- with less than a teaspoon estimated to exist in the Earth's crust at any given time -- the research was conducted using astatine created in a UW cyclotron.

Astatine, like radium and uranium, emits alpha particles via radioactive decay. Alpha particles, which contain two protons and two neutrons, are the most massive particles emitted as radiation. They are about 4,000 times more massive than the electrons emitted by beta decay -- the type of radiation most usually used to treat cancer......... Posted by: Andria      Read more         Source

August 16, 2007, 8:58 PM CT

Tumors use enzyme to recruit

One way tumors fly under the radar of the immune system is by using IDO, an enzyme used by fetuses to help avoid rejection, to recruit powerful regulatory T cells that turn down the immune response, scientists say.

It was known tumors assemble a protective barrier of regulatory T cells, or Tregs, but how they are such able recruiters was an unknown, says Dr. David Munn, pediatric hematologist/oncologist at the Medical College of Georgia Cancer Center.

People have been very interested in how the tumor gets so a number of of these cells and how they get activated so they tend to be very aggressive, more suppressive in the tumor than they appear to be elsewhere in the body, Dr. Munn says of Tregs, major players in preventing autoimmune diseases such as arthritis and type 1 diabetes, where the immune system attacks body tissue.

Research published online Aug. 16 in The Journal of Clinical Investigation shows IDO, which seems to play a powerful role in tumor survival despite the relatively few number of cells in the tumors draining lymph nodes, directly activates existing Tregs which become strongly suppressive within a day. The number doesnt change a lot, but their activation state changes hugely, says Dr. Munn, corresponding author.

Studies in a tumor animal model show this rapid conversion occurs only in lymph nodes connected to tumors......... Posted by: Andria      Read more         Source

August 8, 2007, 8:44 PM CT

Light-activated Molecules To Kill Cancer Cells

A key challenge facing doctors as they treat patients suffering from cancer or other diseases resulting from genetic mutations is that the drugs at their disposal often dont discriminate between healthy cells and dangerous ones -- think of the brute-force approach of chemotherapy, for instance. To address this challenge, Florida State University researchers are investigating techniques for using certain molecules that, when exposed to light, will kill only the harmful cells.

Igor V. Alabugin is an associate professor of chemistry and biochemistry at FSU. He specializes in a branch of chemistry known as photochemistry, in which the interactions between atoms, small molecules and light are analyzed.

When one of the two strands of our cellular DNA is broken, intricate cell machinery is mobilized to repair the damage, he said. Only because this process is efficient can humans function in an environment full of ultraviolet irradiation, heavy metals and other factors that constantly damage our cells.

However, a cell that sustains so much damage that both DNA strands are broken at the same time eventually will commit suicide -- a process known as apoptosis.

In our research, were working on ways to induce apoptosis in cancer cells -- or any cells that have harmful genetic mutations -- by damaging both of their DNA strands, Alabugin said. We have found that a group of cancer-killing molecules known as lysine conjugates can identify a damaged spot, or cleavage, in a single strand of DNA and then induce cleavage on the DNA strand opposite the damage site. This double cleavage of the DNA is very difficult for the cell to repair and typically leads to apoptosis......... Posted by: Andria      Read more         Source

August 1, 2007, 9:32 PM CT

Marijuana and virus that causes Kaposi's sarcoma

The major active component of marijuana could enhance the ability of the virus that causes Kaposis sarcoma to infect cells and multiply, according to a team of researchers at Harvard Medical School. According to the researchers, low doses of -9 tetrahydrocannabinol (THC), equivalent to that in the bloodstream of an average marijuana smoker, could be enough to facilitate infection of skin cells and could even coax these cells into malignancy.

While most people are not at risk from Kaposis sarcoma herpes virus (KSHV), researchers say those with lowered immune systems, such as AIDS patients or transplant recipients, are more susceptible to developing the sarcoma as a result of infection. Their findings, reported in the August 1 issue of Cancer Research, a journal of the American Association for Cancer Research, offer cautionary evidence that those with weakened immune systems should speak with their doctors before using marijuana medicinally or recreationally.

These findings raise some serious questions about using marijuana, in any form, if you have a weakened immune system, said lead study author Jerome E. Groopman, M.D., professor of medicine at Harvard Medical School. While THC is best known as the main psychotropic part of marijuana, an analog of THC is the active ingredient of marinol, a drug frequently given to AIDS patients, among others, for increasing appetite and limiting chemotherapy-induced nausea and vomiting......... Posted by: Andria      Read more         Source

August 1, 2007, 9:15 PM CT

COX-2 inhibitors delay pancreatic cancer precursors

Nimesulide, a cyclooxygenase-2 (COX-2) inhibitor, delays the progression of premalignant pancreatic lesions in mice, as per scientists at David Geffen School of Medicine at UCLA. While inflammation has been shown to be a factor in a number of forms of cancer, the scientists say this is the first study to demonstrate the effect of an anti-inflammatory COX-2 inhibitor on the development of pancreas cancer.

The study, reported in the August 1 issue of Cancer Research, a journal of the American Association for Cancer Research, suggests a potential role for COX-2 inhibitors in pancreas cancer prevention among high-risk patients. Pancreas cancer is one of the leading causes of cancer death in America over 33,000 Americans will likely die from the disease in 2007, as per projections from the American Cancer Society.

By inhibiting COX-2 in human patients, we may have an option to delay the progression of lesions, said lead author Guido Eibl, M.D., scientific director of the Hirshberg Laboratory of Pancreatic Cancer Research and adjunct assistant professor at UCLA.

Scientists believe pancreas cancer arises from abnormal tissues, or lesions in the pancreas, known as pancreatic intraepithelial neoplasias (PanINs). By stalling the growth of PanINs, scientists hope to slow the development of or prevent pancreas cancer......... Posted by: Andria      Read more         Source

August 1, 2007, 9:07 PM CT

Aggressive Therapy Best For Certain AML Patients

A new study suggests that acute leukemia patients whose cancer cells show a genetic change that commonly predicts a swift return of the disease following remission may remain disease-free longer when given aggressive treatment.

The findings apply to people with acute myeloid leukemia (AML) whose cancer cells have normal-looking chromosomes and a gene mutation called MLL-PTD.

Typically, these AML patients responded poorly following therapy with older standard therapies, often relapsing within a year. Of AML patients with normal chromosomes who lack the mutation, conversely, four in 10 are cured.

The new study suggests that treating patients who have the mutation with an aggressive treatment such as an autologous stem cell transplant while they are in remission might significantly extend their disease-free survival.

An autologous transplant uses stem cells taken from the patient's own blood.

The research was led by researchers at the Ohio State University Comprehensive Cancer Center. It is part of a larger study sponsored by the Cancer and Leukemia Group B (CALGB), a clinical cooperative group composed of oncologists from academic medical centers and community hospitals across the nation.

The findings were published in a recent issue of the journal Blood......... Posted by: Andria      Read more         Source

July 30, 2007, 10:03 PM CT

Treatment target found in Hodgkin lymphoma

Dana-Farber Cancer Institute researchers have identified a protein that prevents the body's immune system from recognizing and attacking Hodgkin lymphoma cells. Based on this finding, the scientists are now investigating targeted therapies to disable this molecular "bodyguard" and boost a patient's ability to fight the blood cancer.

If the strategy proves successful, patients might escape some of the long-term complications -- like heart damage and the threat of a second cancer -- caused by standard therapys that include radiation, said Margaret Shipp, MD, of Dana-Farber, who headed the study. A report will be posted online by the Proceedings of the National Academy of Sciences on July 30 and will appear in an upcoming print issue of the journal.

"We're excited about this therapy lead," said Shipp, a medical oncologist. "We are currently generating antibodies that can neutralize the 'bodyguard' protein, and wed like to fast-track this experimental treatment into clinical trials".

Nearly 8,200 people in the United States -- the great majority of them young adults -- will be diagnosed with Hodgkin lymphoma in 2007, as per the American Cancer Society, with an estimated 1,070 deaths. The cancer begins in the lymph nodes and channels that distribute infection-fighting white blood cells around the body. Its symptoms can include swollen glands in the neck, night sweats and fatigue......... Posted by: Andria      Read more         Source