Researchers from the Weizmann Institute of Science and the Tel Aviv Sourasky Medical Center have found 30 genes that seem to be responsible for the resistance that multiple myeloma shows to treatment, which may help lead to more informed, personalized treatment for patients.
Malignant myeloma is a cancer of the antibody-producing plasma cells in bone marrow. Most patients develop resistance to medications and in some, the cancer is resistant to therapy from the start.
The study, published in Nature Medicine last week, examined newly diagnosed myeloma patients at Sourasky and 14 other hospitals whose cancers had failed to respond to initial therapy or relapsed soon afterwards.
The patients were enrolled in a clinical trial aimed at testing whether a combination of four anti-myeloma drugs could overcome the cancer's resistance.
While the physicians evaluated the success and safety of the treatment, the Weizmann scientists worked to figure out what genetic changes had occurred in the cancers to make them resistant to the drugs. Samples of bone marrow were taken from the patients before, at various stages during and after the therapy and analyzed with singe-cell RNA sequencing.
Single-cell RNA sequencing creates high-resolution genetic profiles of thousands of individual cells simultaneously, allowing researchers to analyze genetic makeup at an extremely high level of detail.
“What’s unique about this technology is that it helps distinguish between different types of cancer cells in the same patient, whereas standard hospital techniques examine all those cells together, including the healthy plasma cells, in bulk,” said Dr. Assaf Weiner, a member of the Weizmann team. “These different cell types may respond differently to treatment, so obtaining a complete cellular and molecular profile of the cancer is crucial to understanding why a certain treatment might not work, or why some tumor cells may develop resistance.”