April 30, 2012
Lymphoma Therapy Could Deliver A Double Punch
B cell lymphomas are a group of cancers of that originate in lymphoid tissue from B cells, the specialized immune cell type that produces antibodies. The development of B cell lymphoma is associated with several known genetic changes, including increased expression of MYC, a transcription factor that promotes cell growth and division.
In this issue of the JCI, Andrei Thomas-Tikhonenko and his colleagues at the University of Pennsylvania in Philadelphia report on their studies to better understand the molecular pathways that interact with MYC and contribute to B cell lymphoma development. Using a mouse model of lymphoma, they found that a transcription factor in B cells known as PAX5 controls the level of MYC in cells. They showed that PAX5 stabilizes MYC protein levels through a previously undescribed pathway involving CD19, a surface protein expressed on B cells. When the research team looked in patient samples, they found that high levels of CD19 correlated with high MYC activity, and that both predicted poor patient survival time.Their findings uncover a CD19-dependent pathway that contributes to the cancerous growth of B cell lymphomas. Their work has direct implications for therapies targeting CD19 that are currently in clinical trials, and suggest that these therapies may reduce cancer-promoting signaling in addition to depleting total B cell numbers.
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