PDF file - 428K, Supplemental Figure 1. Administration of rIL-2 inhibits tumor growth in murine hepatic metastasis model in a dose dependent fashion. Supplemental Figure 2. HDIL-2 alone or combined with CQ significantly inhibits Panc02 tumor growth, prolonging survival time in a hepatic metastasis model. Supplemental Figure 3. HDIL-2 combined with CQ inhibits Renca tumor growth in an hepatic metastasis model. Supplemental Figure 4. CQ treatment results in mitochondrial morphologic changes in MC38 cells. Supplemental Figure 5. Murine tumor cells are dependent on glycolysis. Supplemental Figure 6. Ethyl pyruvate alters tumor cell metabolism. Supplemental Figure 7. Proposed mechanisms of autophagy inhibition during HDIL-2 immunotherapy promoting long term tumor regression.
ARTICLE ABSTRACT
Administration of high-dose interleukin-2 (HDIL-2) has durable antitumor effects in 5% to 10% of patients with melanoma and renal cell carcinoma. However, treatment is often limited by side effects, including reversible, multiorgan dysfunction characterized by a cytokine-induced systemic autophagic syndrome. Here, we hypothesized that the autophagy inhibitor chloroquine would enhance IL-2 immunotherapeutic efficacy and limit toxicity. In an advanced murine metastatic liver tumor model, IL-2 inhibited tumor growth in a dose-dependent fashion. These antitumor effects were significantly enhanced upon addition of chloroquine. The combination of IL-2 with chloroquine increased long-term survival, decreased toxicity associated with vascular leakage, and enhanced immune cell proliferation and infiltration in the liver and spleen. HDIL-2 alone increased serum levels of HMGB1, IFN-γ, IL-6, and IL-18 and also induced autophagy within the liver and translocation of HMGB1 from the nucleus to the cytosol in hepatocytes, effects that were inhibited by combined administration with chloroquine. In tumor cells, chloroquine increased autophagic vacuoles and LC3-II levels inhibited oxidative phosphorylation and ATP production and promoted apoptosis, which was associated with increased Annexin-V+/propidium iodide (PI)− cells, cleaved PARP, cleaved caspase-3, and cytochrome c release from mitochondria. Taken together, our findings provide a novel clinical strategy to enhance the efficacy of HDIL-2 immunotherapy for patients with cancer. Cancer Res; 72(11); 2791–801. ©2012 AACR.
