Friday, May 28, 2010

Potential miRNA drug target identified for mesothelioma

Although mesothelioma is generally regarded to be a rare cancer, it appears to be getting more common. More than 2,300 people are diagnosed with the disease every year in the UK alone, with approximately five-times as many cases in men as in women. According to Cancer Research UK, the number of cases of mesothelioma in the UK each year is expected to rise dramatically over the next 20 years because of the heavy use of asbestos in industry from the end of the second world war up until the mid-1970s. Mesothelioma in the chest (pleural mesothelioma; PM) is much more common than in the abdomen (peritoneal mesothelioma).

Recent work by Rosetta Genomics and New York University demonstrated the potential of miR-31, an miRNA that has recently been characterised as a suppressor of breast cancer metastases, to be used for the development of new therapies against mesothelioma and other cancers. In the study, published in the 12th May online edition of the Journal of Biological Chemistry (10.1074/jbc.M110.100354), cell lines derived from mesothelioma patients were found not to express miR-31. Functional assessment of miR-31 activity revealed its ability to inhibit proliferation, migration, invasion and clonogenicity of mesothelioma cells. The reintroduction of miR-31 suppressed cell cycle and inhibited expression of multiple factors involved in co-operative maintenance of DNA replication and cell cycle progression.

miRNAs, described as the body's master switches, hold significant potential for therapeutic applications, and have been shown to be highly-sensitive and specific biomarkers in recent work. Kenneth A Berlin, President and CEO of Rosetta, commented: "This latest publication is another demonstration of miRNAs' potential role in cancer therapeutics and details the significant impact a single miRNA can have on disease course." Using its diagnostic tests for cancer, and robust and diverse miRNA-based product pipeline, Rosetta plans to continue its research in this field by harnessing the power of miRNAs.

A further development in mesothelioma also occurred in May, as MolMed received clearance from the FDA for the IND application filed to initiate a Phase III trial of its investigational antitumour drug, NGR-hTNF, for the treatment of malignant PM (MPM). The study, NGR015, is a pivotal randomised, double-blind, placebo-controlled, international, multi-centre, Phase III trial, expecting to enrol adult patients affected by MPM with disease progressing after chemotherapy. The main endpoint of the trial is overall survival; secondary endpoints include progression-free survival, disease control rate, safety and patient quality of life. Based on the positive results of a multi-centre, Phase II study, this Phase III trial is optimally designed to investigate the full therapeutic potential of NGR-hTNF in the treatment of MPM. If positive data are yielded from this study, NGR-hTNF may represent a novel treatment option for malignant mesothelioma.

Alice Rossiter
Editor, Cancer Drug News

Friday, May 14, 2010

New findings could advance fight against BC

Recent findings by scientists could help advance the fight against breast cancer (BC). A team at the University of Kentucky (UoK) Markey Cancer Center has identified a key molecular mechanism in BC that enables tumour cells to metastasise, while a separate study has uncovered five new regions of the genome that increase a woman's risk of developing the disease by between 6 and 16 per cent.

The work conducted by the UoK could lead to new lines of research aimed at developing treatments for metastatic BC (MBC). The research, published in the 13th April online issue of The EMBO Journal (10.1038/emboj.2010.63), focused on the process by which tumour cells stop clinging to other cells and become motile. The increased motility of tumour cells at the initial step of metastasis is similar to epithelial-mesenchymal transition (EMT). In all EMT processes, cells lose the expression of E-cadherin, which functions as a "molecular glue" that attaches cells to one another. The team explained that when E-cadherin is broken down, tumour cells start to migrate and spread throughout the body.

A protein called Snail acts as a master switch in the cell's nucleus to suppress E-cadherin expression and induce EMT in the cell. Agents that can disrupt the interaction of Snail are thought to have great therapeutic potential for treating MBC. Leading on from these findings, the scientists at the UoK are keen to develop drugs that can treat metastatic cancer.

Separately, a study funded by Cancer Research UK (CRUK) and the Wellcome Trust has found five new regions of the genome that increase a woman's risk of developing BC by between 6 and 16 per cent. As more of these low-risk sites are found, scientists believe that it may be possible to create tests for a combination of them that together significantly increase risk, which could ultimately help doctors to make decisions about prevention, diagnosis and treatment for women who are more likely to get BC.

The scientists scanned the entire genetic code of over 4,000 women with BC and a family history of the disease for genetic variations that appeared more often compared to healthy women. They then tested the most promising regions in over 12,000 women with BC and 12,000 women without the disease in an international collaboration. Although the results now take the total number of gene regions linked to the risk of BC to 18, scientists are still unsure which genes are causing this increased risk. Lead author, Professor Doug Easton, director of CRUK's Genetic Epidemiology Unit at the University of Cambridge, commented: "While each of these sites have a small impact on breast cancer risk, by finding more of these genes, we may be able to develop a test that can predict more reliably a woman's risk of developing breast cancer."

Alice Rossiter - Editor, Cancer Drug News