Researchers in Europe and the U.S. have identified a biomarker (a measurable substance in tissues) for measuring the progression of mesothelioma, a rare asbestos-related form of cancer.

Recently published in the Journal of Cellular Physiology, the findings may point out the way toward better treatments and management of the disease, ultimately resulting in “more effective and personalized medicine.”

About Mesothelioma

A malignancy that attacks the visceral lining between the internal organs and the inner wall of the chest and abdomen, mesothelioma has only two known causes. One is exposure to nuclear radiation (including radiation therapy), and the other is exposure to asbestos.

Between 85 and 90 percent of all patients who are diagnosed with mesothelioma have been exposed to a form of asbestos known as amphiboles, the fibers of which are similar to microscopic needles. When ingested or inhaled, amphibole fibers literally drill their way through organ tissues from the inside out, causing chronic inflammation that leads to the formation of malignant cells.

Mesothelioma has a very lengthy latency period; it can be decades after initial exposure to asbestos fibers before symptoms become apparent. Unlike most tumors, this particular form of cancer grows in a flat, sheet-like manner. For this reason, mesothelioma can be very difficult to identify, and is usually not diagnosed until it has reached an advanced stage, making treatment difficult – but prognosis improves with early detection.

Most people who contract mesothelioma were exposed to asbestos in shipyards or building construction sites in which asbestos insulation was used. Prominent victims of the disease include late film actor Steve McQueen, who may have been exposed to asbestos on naval ships or by wearing fire suits used in auto racing.

A “Novel Targetable Axis”

The recent study is titled “Data Mining Analysis of the PP2A-Cell Cycle Axis in Mesothelioma Patients.” The term “PP2A” refers to the enzyme protein phosphatase 2, which regulates cell cycles. It also suppresses the formation of tumors; as one might expect, PP2A is often deactivated in cancer patients.

Examining previous data on mesothelioma patients and comparing gene expression (the process by which genetic information is transferred) of known PP2A inhibitors, the research team discovered higher levels of proteins that prevent the formation and action of PP2A.

Two specific PP2A inhibitors, identified as ANP32E and CIP2A, were implicated in poorer outcomes in mesothelioma patients. When these levels are high, the stimulate the production of other types of PP2A inhibitors, creating a sort of feedback loop that may lead to progression of the disease.

The researchers believe that treatments designed to target these PP2A inhibitors may slow or even stop the progression of the disease as well as provide a way to assess the seriousness of the patient’s condition.

Hope for Other Types of Cancer?

Lead author Dr. Rafaella Pippa writes, “We hypothesize that we can improve patients’ survival by targeting both cyclin/CDKs and PP2A inhibitors. Our future goal is to define whether the relevance of this association might be extended to other types of solid cancer beyond mesothelioma.”