TUESDAY, April 8 (HealthDay News) -- Interrupting communication between cancer cells and cells that promote inflammation blocks an early step in prostate cancer cell's spread, a U.S. study finds.

According to researchers from Northwestern University's Feinberg School of Medicine, Chicago, the findings suggest new ways to control the spread of cancer. They also suggest that existing anti-inflammatory drugs might be useful in controlling inflammation-associated cancers.

Recent studies have suggested an association between chronic inflammation and cancers of the prostate, colon, stomach and liver, according to background information in the study, which was expected to be presented April 8 at the Experimental Biology 2008 meeting in San Diego.

In earlier studies, Dr. Paul Lindholm and his colleagues at Northwestern found that prostate cancer cells have a higher-than-normal density of macrophages and monocytes, cells that play an important role in immune responses and the development of inflammation.

In this new study, Lindholm and his team showed that monocyte-like cells stimulate prostate cancer cells' Nuclear Factor-kappaB -- a gene-regulating transcription factor that's able to stimulate gene activity. When the researchers blocked NF-kappaB activity, there was reduced cancer cell movement and invasion.

In the next phase, the researchers plan to study the effects of macrophages and inflammation and NF-kappaB-inhibiting treatments in mice with a model of invasive prostate cancer. They'll also extend these experiments to include anti-inflammatory drugs.

More information

The U.S. National Cancer Institute has more about metastatic cancer.

MONDAY, April 7 (HealthDay News) -- Injections of testosterone appear to improve bone density and reduce bone loss in older men who have low testosterone levels and may help to prevent osteoporosis, a new study suggests.

Testosterone therapy has been used to improve bone strength and muscle mass in some men. However, the hormone treatment is controversial, because it has been associated with increasing the risk of prostate cancer and high levels of red blood cells. And other potential effects of long-term use of testosterone therapy aren't known.

"These preliminary data show beneficial effects of testosterone therapy on bone turnover markers in older men with low-to-normal testosterone concentrations using both continuous and monthly cycled testosterone replacement," lead researcher E. Lichar Dillon, of the Department of Internal Medicine at the University of Texas Medical Branch in Galveston, said in a prepared statement. "The effects of sex hormones on markers of bone formation are complex, but this is an important step in understanding how the process works."

Preliminary study results were expected to be presented April 7 at the American Physiological Society's annual meeting, during the Experimental Biology 2008 conference, in San Diego.

For the study, Dillon's team studied 13 men, ranging in age from 60 to 85. During the five-month trial, the men were either given weekly injections of testosterone, weekly injections of testosterone every other month, or a placebo.

The researchers found that men receiving testosterone had reduced bone turnover, compared with men on a placebo. While the effects of testosterone therapy over the long term aren't clear, the researchers said they believed the treatment would be beneficial by preserving bone mass and preventing osteoporosis.

One expert said the study was too small to prove or disprove the value of testosterone therapy in preventing bone loss and, perhaps, preventing osteoporosis.

"This small, short-term study indicates that men with low levels of testosterone respond to appropriate replacement as far as turnover markers indicate," said John Eisman, director of the Bone and Mineral Research Program at the Garvan Institute of Medical Research, in Sydney, Australia.

While calling the study "too small and too short to provide any insight into fracture-risk reduction or safety outcomes," Eisman said it does complement research he has done. "Our study showed that men with testosterone in the lowest quartile of the population had much higher risk of osteoporotic fractures," he said.

A large, long-term trial testing whether testosterone can prevent osteoporosis in men is needed to settle the question, Eisman said.

More information

To learn more about men and osteoporosis, visit the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases.

THURSDAY, April 3 (HealthDay News) -- People whose fathers had early-onset obesity are at increased risk for elevated liver enzyme levels and liver disease, says a U.S. study.

Researchers evaluated 1,732 children, average age 42, of participants in the Framingham Heart Study, a long-term study of families in Framingham, Mass. The researchers found that people whose fathers were clinically obese at an early age were more likely to have increased liver enzyme (serum alanine aminotransferase -- ALT) levels, an indicator of liver disease.

When the researchers conducted a secondary analysis that didn't include obese offspring, they still found a strong link between elevated serum ALT levels and paternal early-onset obesity. This demonstrates that the link between obesity in the father and elevated serum ALT levels in children is independent of the offspring's body-mass index (BMI) and persists among non-obese children, the researchers said.

No relationship was found between early-onset obesity in mothers and ALT levels in their children.

"These findings show that familial factors may play a role in elevated serum ALT levels in the general population," study senior author Dr. Caroline S. Fox, medical officer with the Framingham Heart Study, said in a prepared statement.

The study was published in the April issue of Gastroenterology.

Serum ALT levels are a marker of liver disease in the general population, and previous studies have shown that there's a strong link between obesity and elevated serum ALT levels, according to background information in the study.

Up to 7 percent of the adult U.S. population has unexplained elevated ALT serum levels, according to the U.S. National Health and Nutrition Examination Survey. These elevated ALT serum levels may be due to nonalcoholic fatty liver disease (NAFLD), which is believed to be the most common cause of elevated ALT serum levels, which can lead to inflammation of the liver (hepatitis), scarring of the liver (cirrhosis), and liver cancer.

"Serum ALT elevations and NAFLD are more prevalent than ever in the U.S., though we don't know specifically what's causing the increase. Our results point to a genetic connection between early-onset paternal obesity and increased ALT levels," Fox said.

"This study is the first to look at the connection between parental early-onset obesity and elevated serum ALT levels in their children using objective clinical measurements of parental BMI instead of self-reports," study first author Dr. Rohit Loomba, of the Liver Diseases Branch of the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, said in a prepared statement.

"Though we are looking at a very specific, community-based sample in our work, the results suggest an association between elevated serum ALT levels and early-onset paternal obesity. Additional studies are needed to assess whether this connection suggests a genetic predisposition to developing liver disease in larger populations," Loomba said.

More information

The American Liver Foundation explains the progression of liver diseases  .