KISS1 Protein Required for Metastasis Suppression
A new study led in part by Cancer Center Senior Scientist Danny Welch, Ph.D., and Medical Scientist Training Program student Kevin Nash, Ph.D., has found that the secretion of a protein known as KISS1 blocks the growth of tumor cells that have already spread from the primary tumor. This discovery suggests a new target for antimetastatic therapy: blocking the outgrowth of disseminated cells.

Using a human melanoma cell line that could not express KISS1, the researchers inserted an unaltered KISS1 gene that produced and secreted a KISS1 protein or a KISS1 gene whose protein could not be secreted. The cells were later placed in mice that were monitored for changes in survival rates and metastatic activity of the injected cells.

The researchers concluded that KISS1 secretion was required for metastasis suppression of the melanoma cells. Only the cells with the intact form of KISS1 showed less metastatic activity when injected into the mice than those with the altered version. Mice injected with the gene for the intact KISS1 protein lived much longer, on average, than the mice with the nonsecretable version.

“The finding that KISS1 can inhibit metastatic growth in multiple organs is a particularly important feature for an antimetastatic molecular agent,” Dr. Welch says. “Even if tumor cells have already begun to migrate before diagnosis, we are finding they may still be susceptible to therapeutic intervention.”


New Data from HPV Vaccine Trials Available
Results from three years of follow-up to the FUTURE I and FUTURE II clinical trials of Gardasil®, a vaccine that protects against the two types of human papillomavirus (HPV) responsible for 70 percent of cervical cancer cases, were recently published in the New England Journal of Medicine.

The FUTURE I study found that for women ages 16-24 who had not been previously exposed to HPV 16 or 18, Gardasil® was 100 percent effective in preventing vaginal lesions. Among those who had been exposed to HPV 16 or 18, the vaccine efficacy was 55 percent against cervical lesions related to those HPV types. The FUTURE II study found the vaccine was 98 percent effective among women ages 15-26 not previously exposed to HPV and 44 percent effective in those already exposed.

For more information about HPV vaccines and cervical cancer, visit www.cancer.gov/cancertopics/hpv-vaccines.


Mammography Rates Drop
Mammography rates in the United States have dropped in recent years, causing concern over a future rise in breast-cancer deaths, according to a study published in the journal Cancer.

Scientists from the National Cancer Institute found mammography screenings declined to 60 percent in 2005, down from 66 percent in 2000. Rates were lower for nearly all groups of women examined, with the largest declines among women aged 50-64, those with higher incomes and women aged 40-64 with private insurance coverage.

Researchers fear the drop will lead to an increase in late diagnoses of the disease, and they urge women to undergo yearly mammograms beginning at age 40.


Cancer Burden Expected to Soar
As the American population continues to live longer, the number of cancer patients and survivors is expected to swell by 55 percent by 2020, according to a study in the Journal of Oncology Practice.

Approximately one in 26 Americans have had cancer. By 2020, the study predicts that one in 19 will have been diagnosed with the disease. This is a cause for concern among some in the medical community, who fear that there will not be enough oncology physicians and nurses to care for the increase in patients.

However, declining smoking rates could signal a reduction in lung-cancer deaths, and screenings such as colonoscopies and mammograms can reduce the incidence of colorectal and breast cancer, respectively. Experts stress the importance of these and other preventive measures in maintaining a healthy population.


Poliovirus Used to Destroy Tumors
The childhood disease poliovirus could possibly be used to treat another childhood disease, neuroblastoma. In a study published in the March 15 issue of Cancer Research, researchers reported that a nonvirulent form of poliovirus was effective in destroying neuroblastoma tumors in mice.

By its nature, poliovirus destroys the cells it infects in an attempt to duplicate itself. Once the cell is killed, the new particles then attack surrounding cells. Researchers took advantage of this property to target the tumors; any viral particles that made it into the bloodstream were then destroyed by antibodies created by a poliovirus vaccine.

Neuroblastoma is the most common form of solid tumor in children, with the average age at diagnosis being around 17 months.


Breast Cancer Drug Could Help Prostate Patients
Toremifene (Fareston®), a drug already approved to treat advanced breast cancer, may help protect men from heart disease and bone fractures, which are common side effects of prostate cancer treatment.

About one-third of the two million American men with prostate cancer are treated with hormone-deprivation therapy, which can cause them to gain weight and fat and lose muscle. A study presented at the 2006 Prostate Cancer Symposium reported that men with advanced prostate cancer who took Fareston® for two years gained bone density, while those who took a placebo lost bone. The early results also make doctors hopeful that Fareston® may be used to prevent prostate cancer in men with precancerous growths.