Dog Cancer Preserves Genes

Genetic analysis of the communicable cancer canine transmissible venereal tumour (CTVT) suggests it appeared in dogs about 11,000 years ago and preserves the identical DNA of the dog from which it originated, allowing a rare comparison of ancient versus modern animals.

Cancer-Resistant Mole Rats

Studies have found both blind mole rats (Spalax spp.) and their cousins naked mole rats (Heterocephalus glaber) have cells that resist tumor growth and make them virtually immune to cancer, the former committing a "concerted cell death" when densities reach a certain level and the latter simply ceasing to grow beyond a certain cell density.

"Immortal" Tasmanian Devil

DNA analysis shows that the bizarre communicable cancer threatening the Tasmanian devil populations can be traced back to a single "immortal" female who lived about 16 years ago and who lives on through the infection, revealing possible leads for a potential vaccine.

Dogs Smell Lung Cancer

Researchers have found that dogs can reliably detect lung cancer from patients' breath alone -- even distinguishing between those with tumors and those with similar-symptom COPD -- although the precise compounds in the breath being detected are still unidentified.

Breast Cancer Marker in Dogs

Researchers studying similarities of breast cancer in women and dogs have found that an important tumor marker, the CEA (carcinoembryonic antigen) receptor, is essentially identical in both species and opens a broad new area for therapeutic research and treatment of the disease.

Enzyme for Cancer Metastasis

Researchers have discovered that a specific enzyme called LOX (lysyl oxidase) is crucial in promoting cancer metastasis, and that drugs to block this enzyme may keep cancer from spreading throughout the body.

Molecular "Decoy" Drives Cancer Cells to Suicide

Researchers at the Curie Institute have developed a molecular "decoy" that mimics DNA damage and drives cancer cells to destroy themselves.

Conventional chemotherapy and radiotherapy strive to cause enough cell damage that the process of apoptosis, or programmed cell death, is triggered in cancerous cells. However, sometimes the damage is not enough and the cancerous cells can repair themselves and live on. Scientists developed tiny DNA fragments called Dbaits that mimic the broken ends of the long molecule. The cancer cells are tricked into believing they are more damaged than they really are, triggering apoptosis.

In laboratory mice, researchers were able to destroy 75% to 100% of tumors injected with Dbaits plus radiotherapy, compared to 30% to 50% using only radiotherapy. Dbaits also have the advantage of requiring lesser doses of radiation, which often damages surrounding healthy tissue as well as cancerous cells.

These results were published in a recent issue of Clinical Cancer Research.

Source: Yahoo!

Targeted Nanospheres Used to Burn Away Melanoma Tumors

Researchers at the Department of Experimental Diagnostic Imaging at the University of Texas M.D. Anderson Cancer Center have developed a method to destroy melanoma using targeted gold nanospheres to burn away the tumor from the inside.

Injecting simple hollow gold nanospheres 40-50 nm in diameter causes them to accumulate in melanoma tumors because their small size allows them to penetrate the abnormally large pores of blood vessels that feed cancerous tumors. However, when filled with a peptide that binds to the melanocortin type 1 receptor abundant in melanoma cells, these nanoparticles are actively drawn into the cells via the cell membrane.

Once these nanoparticles are in place, the tumor is subjected to a process called photothermal ablation. A dose of near-infrared light is applied to the cancer, which penetrates deeper into tissue than visible or ultraviolet light. The energy is absorbed by the nanoparticles, causing them to heat up and destroy the surrounding tissue. At a dose merely 12% of the dose required without the nanoparticles, cancerous tumors are highly targeted and healthy tissue is spared.

The use of elemental gold has a long history of medical applications as it is safe and largely nonreactive to organic tissues. Experiments have been successful in laboratory and mouse models but still await human trials.

These results were published in the February 1st issue of Clinical Cancer Research.

Source: ScienceDaily; Photo: M.D. Anderson

Warburg Theory of Cancer Origin Confirmed

Researchers at Boston College and Washington University School of Medicine have found evidence that supports the theoretical origin of cancerous cells first proposed by Otto H. Warburg in 1924.

The Warburg theory of cancer proposed defects in the mitochondria, the metabolic "power plant" for the cell, as the cause of mutations and cancerous growth. Scientists have now identified a cellular lipid called cardiolipin that is used by the mitochondria in its normal function. Abnormalities in the quantity or composition of cardiolipin have been correlated with all types of cancerous tumors, as well as the energy-producing capacity of the cell.

A noted German biochemist, Warburg first proposed in 1924 that the cause of cancer was mutation or injury to a cell's mitochondria, thereby leading to irreversible damage and significant reductions in cellular metabolism. Warburg's work earned him the 1931 Nobel Prize for Medicine.

These results were published in the December edition of the Journal of Lipid Research.

Source: ScienceDaily; Photo: Wikipedia

Cancer Cells Resist Cell Death

Researchers at the Chinese University of Hong Kong have found that cancer cells can overcome the programmed cell death included with normal cells.

In a process known as apoptosis, normal human cells contain a genetically encoded signal to end their individual lives after a certain point. This process helps keep the body healthy by preventing damaged or defective cells from continuing to multiply. However, cancer cells lack this encoding and continue to multiply without limit, developing into a tumor.

The researchers exposed human cervical, skin, liver and breast cancer cells to a variety of chemicals, each of which triggers apoptosis in normal human cells. Not only did the cancer cells survive, once the chemicals were removed they recovered and again started to multiply.

This research may show why some cancers are resistant to certain chemotherapies, and will assist in the development of more effective treatments.

These results were published in a recent issue of the British Journal of Cancer.

Photo: BBC News