Prostatic Cancer Metastases May Be Programmed by a Single Gene -- EZH2

One of the challenges of clinical oncology has been that some cancer patients are being overtreated. Their tumors may have a biologic nature such that they remain quiescent for long periods of time. However, patients with such lesions are often treated in the same fashion as patients with more aggressive lesions. With current surgical pathology techniques, malignant tumors incapable of metastasizing often cannot be distinguished from those that have this capacity. This knowledge gap may soon be resolved, at least for prostatic cancer (see: Advance Toward Test for Aggressive Prostate Cancer ). Below is an excerpt from this article:

Harvard researchers report what they say is a major advance toward the long-sought goal of a genetic test that can distinguish between aggressive prostate cancers that require urgent treatment and slow-growing tumors that can safely be left alone...."For the first time, we showed in a mouse model that when you take a gene out, you get metastasis and when you put it back in you don't get metastasis," said [the author of a recent article]. "It looks like the entire pathway is driven by this one gene, the cascade that drives metastasis."....The finding could lead to better treatment of prostate cancer, because the molecule whose production is governed by the gene can be a target of drug therapy, [she] said. The molecule, designated EZH2, is an enzyme, and "enzymes are always good potential therapeutic targets," .... "Many companies are working to develop EZH2 inhibitors."....The newly reported study "provides a nice mechanistic link as to why EZH2 leads to metastatic cancer," [another researcher] said. "It is exciting because there is a lot of interest in the biotechnology world in developing inhibitors of EZH2."

The very essence of a malignant lesion is that it can function autonomously, which is to say it operates outside the control of the human organism in which is arises. Malignant cells can invade tissue locally or be transported in the circulatory or lymphatic systems to distant points in the body, at which time the cells multiply to produce metastases. These lesions, in turn, can expand in size. Tumor genes can code for proteins that enable these special capabilities of malignant cells. It appears highly likely that EZH2 is one such protein and will serve as both a diagnostic and therapeutic target. In other words, absence of tumor genes like EZH2 can help select patients not requiring aggressive chemotherapy (see: Genetic Testing to Cull Out the "Un-Right Patient" as a Candidate for a Particular Drug Therapy .