In Cancer Cell this week, a team of US researchers report on targeting non-classic oncogenes for the treatment of T-cell acute lymphoblastic leukemia. PI3K/Akt activation is common in T-ALL, the team says. In this study, they report that the absence of PTEN phosphatase tumor suppressor function can lead to the PI3K-gamma or PI3K-delta isoforms supporting leukemogenesis alone, even though suppression of both isoforms was required to suppress tumor formation. "The reliance of PTEN null T-ALL on the combined activities of PI3K-gamma/delta was further demonstrated by the ability of a dual inhibitor to reduce disease burden and prolong survival in mice as well as prevent proliferation and promote activation of proapoptotic pathways in human tumors," the authors write. "These results support combined inhibition of PI3K-gamma/delta as therapy for T-ALL."
Also in Cancer Cell this week, an international team of researchers describe how tumor-stroma interactions during chemotherapy reveal the function of the microenvironment in drug resistance. The team used intravital microscopy to observe chemotherapy-treated mouse mammary carcinomas, and found associations between vascular leakage and response to doxorubicin. "These data show that the microenvironment contributes critically to drug response via regulation of vascular permeability and innate immune cell infiltration," the authors write. "Thus, live imaging can be used to gain insights into drug responses in situ."