It’s well known that some types of mesothelioma cells are more aggressive than others, and are likewise more resistant to certain therapies. A team of researchers from the University of Torino in Italy believe that they have found a cellular variant that may be responsible for these differences
There are three different cell types that have been identified in cases of mesothelioma. The most common is epithelioid mesothelioma, which is the cell type most responsive to treatment.
Epithelioid is followed by biphasic mesothelioma, which appears in roughly 20 to 35 percent of cases and which represents a mix of epithelioid and sarcomatoid cells.
Then, there are sarcomatoid mesothelioma cells, which are the most difficult to treat. The researchers, led by Dr. Erika Ortolan of the Laboratory of Immunogenetics and oncologist Dr. Alice Giacomino, focused on a molecule called CD157 which is found in ovarian cancer.
Knowing that ovarian cancer cells and epithelial mesothelioma cells originate in the same place, the study tried to determine whether CD157 was also present in mesothelioma cell lines They found that in testing nine malignant pleural mesothelioma cell groups, four of them had high levels of CD 157.
They also found it present in disproportionate levels in 85.2% of the mesothelioma tissues that they examined and that it was directly linked to clinical aggressiveness. The researchers were able to manipulate the levels of CD157 in mesothelioma cells, and in doing so found that it had a direct impact on the cells growth, its propensity to metastasize, and its conversion into tumors.
These effects were seen most often in biphasic mesothelioma cells. It was also noted that CD157 caused a decline in the effectiveness of platinum-based chemotherapy on the cells. This type of chemotherapy is generally the first line of defense in the treatment of mesothelioma patients.
In reviewing their results, which were published in the journal Oncotarget, the study’s authors wrote, “These findings indicate that CD157 is implicated in multiple aspects of malignant pleural mesothelioma progression and suggest that CD157 expression could be used to stratify patients into different prognostic groups or to select patients that might benefit from a particular chemotherapeutic approach.”