• A novel treatment for cervical cancer in women infected with cancer-causing human papillomavirus may be designed by suppressing the expression of epidermal growth factor receptor, a protein that is needed to signal cell multiplication. This can be accomplished by genetically modifying the affected cells using antisense strategy.

• A synthetic analogue of vitamin A is found to induce apoptosis in cervical cancer cell line by increasing the production of reactive oxygen species. This effect is not dependent on the well known p53-dependent apoptosis. This action of the compound also bypasses the usual nuclear receptor-dependent mechanism. The new compound appears to be very promising to develop reliable therapy for cervical cancer.

• Early a treatment is administered, the better is the chance of controlling a disease. It is well established that malignant tumors need new blood vessel formation for growth. Now it is observed that preinvasive form of cancer such as cervical intraepithelial neoplasia also require new blood vessels and the severity of the abnormality of the lesions depends on the density of new blood vessels formed. Agents targeted to prevent blood vessel formation at the lesion sites may be developed to contain the spread of this disease.

• Angiogenesis is essential for the growth and "well-being" of solid tumors and their metastases; to stimulate angiogenesis, tumors are capable of upregulating the production of various angiogenic substances, such as the fibroblast growth factor and vascular endothelial growth/vascular permeability factors. Although there is a vast body of knowledge concerning the importance of tumor vascularization, it is only in the last five years that serious efforts have been made to counter these mechanisms which are so essential to malignant proliferation. Recent advances in angiogenesis antagonists are reviewed, since several of them are finally entering clinical trials.

• Hormonal replacement therapy is being routinely employed in many countries for postmenopausal women mainly because it is reported to prevent cardiovascular problems, in addition to possessing beneficial effects such as prevention of osteoporosis. Most of the clinical trials, the results of which are used to make decisions in favor of hormone therapy, are short term and further the number of participants in them are small. When data from several trials are pooled and analyzed together, the results do not appear to support the notion that postmenopausal hormone therapy prevents cardiovascular problems.

• Medical use of marijuana is controversial. Though some clinical trials have been conducted using tetrahydrocannabinol, the potent active agent of marijuana plant, there has been not enough well designed experiments to document potential beneficial effect of marijuana, especially smoked marijuana, in sick patients. More controlled research need to be performed to obtain definitive answers, suggests a group of experts.

• Annexins are a unique family of calcium- and phospholipid-binding proteins, with many known and unknown functions. Indeed, their gene structures, evolutionary genetics, three-dimensional structures and binding characteristics are better understood than their roles, although they have been studied for more than 15 years and they are practically ubiquitous in eukaryocytes. Some annexins have been recently implicated in the pathogenesis of both benign and malignant growth; since they play a functional part in cellular development and differentiation, these findings should not come as a surprise.

• A gene with considerable sequence similarity with the tumor suppressor gene p53 is located in the short arm of human chromosome 1 which is often found to be lost or defective in many cancerous tumors. Despite the structural similarities, p53 and p73 may have distinct roles in cell growth regulation.

• Antigen produced by bladder tumor is shed in the urine and is detected by simple assay. This assay technique is improved. Now this antigen can be detected in a one-step test, using monoclonal antibodies and colloidal gold technology, in a commercially available test device (manufactured by C. R. Bard, Inc.).

• Steroid hormones such as estrogen and progesterone affect cells by interacting with specific cell receptors. Expression of a gene named A1B1 (amplified in breast cancer-1) is found to be associated in the enhancement of estrogen receptor-dependent transcription. A1B1 is definitely involved in the estrogen response pathway which, apart from breast and ovarian cancer, may play an increasingly recognized role in other tumors.

• A member of the cytochrome P450 family, CYP1B1, is a dioxin-inducible enzyme and is found to be expressed in many types of cancer including breast, bladder, colon, kidney and several other cancers. Presence of this enzyme can be used as a tumor marker for diagnosis and can be exploited to engineer novel anticancer drugs that are selectively activated by this enzyme in the tumors.

• Latest findings on the prevention, diagnosis and treatment of lung cancer were discussed in a conference held in Dublin, Ireland, in August 1997. Among them was the effect of docetaxel on non-small cell lung cancer (NSCLC). This agent increases survival of patients who failed a platinum-based therapy. Monotherapy with the topoisomerase I inhibitor topotecan yields similar efficacy to the commonly used regimen when used as second-line therapy for small cell lung cancer (SCLC). To improve cachexia in NSCLC patients macrolide antibiotic clarithromycine was found to be effective. Combination treatment with mitomycin C, vinblastine and cisplatin (MVP) provides good sympton relief in patients with malignant mesothelioma.

Glossary

• A glossary of unfamiliar words and jargons in Cancer Watch, September 1997.