Nature Medicine

Around 500,000 people suffer from cancer of the head and neck annually, and deaths due to this type of cancer run at 30%. Following successful Phase I trials of a form of gene therapy for this condition, researchers at MD Anderson Cancer Clinic now report promising Phase II results in the August issue of Nature Medicine.

As many as 70% of head and neck tumors carry mutations in the p53 (tumor suppressor) gene. ONYX-015 is an adenovirus engineered to selectively replicate in and destroy p53-deficient cancer cells while sparing normal cells. Fadlo Khuri and colleagues tested a combination of ONYX-015 injected directly into the tumor, and the traditional chemotherapy drugs, cisplatin and 5-fluorouracil, in patients with recurrent squamous cell cancer of the head and neck.

The combination of ONYX-015 and chemotherapy caused tumors to shrink in 25 of 30 patients. Eight had complete and 11 had partial tumor responses. Importantly, only 17% of tumors had pregressed 6 months after treatment. Thus ONYX-015 in combination with chemotherapy is more effective than either treatment alone.

Gene therapy expert, French Anderson, discusses the results in an accompanying News & Views article and explains why he believes that gene therapy will be proven first as a treatment for cancer.

Nature Medicine

A team of scientists from Switzerland is calling for clinical trials of a drug with the potential to enhance the current treatment regimen for HIV.

The ability of the thyroid gland to take up natural iodide and thus to concentrate radioactive iodide has been exploited medically as a diagnostic tool for thyroid diseases and as a treatment for thyroid cancer. Iodide is attracted to the thyroid gland through a molecular gateway known as the sodium iodide symporter (NIS). Now, scientists at Albert Einstein College of Medicine have discovered that a specialized form of the NIS carries iodide into healthy, lactating breast tissue and also into mammary tumors, suggesting that radioactive iodide may serve as a diagnostic tool and a treatment for some forms of breast cancer.

Nancy Carrasco and colleagues demonstrate that mammary adenocarcinomas in transgenic mice actively accumulate iodide via the NIS. Moreover, over 80% of the human breast cancer samples analyzed by immunohistochemistry expressed the breast NIS, compared to none of the normal (non-lactating) samples.

However, Gilbert Daniels and Daniel Haber of Harvard Medical School caution against over optimistic interpretation of the results. They point out that the research team did not test the ability of radioactive iodide to destroy mammary tumors in mice and that the take up of radioactive iodide into breast tissue must be quantified before it can be used clinically.

Nature Medicine

Researchers at the University of Saskatchewan, Canada, have developed an immunization technique that could prove useful in vaccinating babies in the womb against infections such as herpes simplex virus, hepatitis B virus, human cytomegalovirus, group B streptococcus, and hemophilus, which are contracted at, or shortly after, birth. The scientists write that in utero vaccination would avoid the need for cesarean deliveries, infant antibiotic treatment, or maternal treatment with antiviral agents against these viral infections.

Philip Griebel and colleagues gave a single injection of a DNA vaccine for bovine herpesvirus-1 into the oral cavity of lambs in utero. Fetal lambs showed high levels of mucosal antibody production to the bovine virus as well as a strong cell-mediated immune response as measured by lymphocyte proliferation. Because most infectious agents enter newborns through mucosal surfaces, mucosal antibody production is an important protective mechanism. Lambs were normal at birth and developed normally.

Traditional vaccines use either a weakened or killed version of the disease-causing organism to mimic infection and stimulate the immune system to mount an attack against it. DNA vaccination differs from this method because only the DNA coding for a specific component of a disease-causing organism is injected into the body, eliminating any risk of infection associated with live and attenuated virus vaccines.