Glucose uptake is essential for cancer glycolysis and is involved in non-shivering thermogenesis of adipose tissues^1–6. Most cancers use glycolysis to harness energy for their infinite growth, invasion and metastasis^2,7,8. Activation of thermogenic metabolism in brown adipose tissue (BAT) by cold and drugs instigates blood glucose uptake in adipocytes^4,5,9. However, the functional effects of the global metabolic changes associated with BAT activation on tumour growth are unclear. Here we show that exposure of tumour-bearing mice to cold conditions markedly inhibits the growth of various types of solid tumours, including clinically untreatable cancers such as pancreatic cancers. Mechanistically, cold-induced BAT activation substantially decreases blood glucose and impedes the glycolysis-based metabolism in cancer cells. The removal of BAT and feeding on a high-glucose diet under cold exposure restore tumour growth, and genetic deletion of Ucp1—the key mediator for BAT-thermogenesis—ablates the cold-triggered anticancer effect. In a pilot human study, mild cold exposure activates a substantial amount of BAT in both healthy humans and a patient with cancer with mitigated glucose uptake in the tumour tissue. These findings provide a previously undescribed concept and paradigm for cancer therapy that uses a simple and effective approach. We anticipate that cold exposure and activation of BAT through any other approach, such as drugs and devices either alone or in combination with other anticancer therapeutics, will provide a general approach for the effective treatment of various cancers.

Molecular mechanisms underlying the cancer stroma in metastasis need further exploration. Here, we discovered that cancer-associated fibroblasts (CAFs) produced high levels of IL-33 that acted on tumor-associated macrophages (TAMs), causing them to undergo the M1 to M2 transition. Genomic profiling of metastasis-related genes in the IL-33–stimulated TAMs showed a >200-fold increase of MMP9. Signaling analysis demonstrated the IL-33-ST2-NF-κB-MMP9-laminin pathway that governed tumor stroma–mediated metastasis. In mouse and human fibroblast-rich pancreatic cancers, genetic deletion of IL-33, ST2, or MMP9 markedly blocked metastasis. Pharmacological inhibition of NF-κB and MMP9 also blocked cancer metastasis. Deletion of IL-33, ST2, or MMP9 restored laminin, a key basement membrane component associated with tumor microvessels. Together, our data provide mechanistic insights on the IL-33-NF-κB-MMP9-laminin axis that mediates the CAF-TAM–committed cancer metastasis. Thus, targeting the CAF-TAM-vessel axis provides an outstanding therapeutic opportunity for cancer treatment.

Molecular signaling in the tumor microenvironment (TME) is complex, and crosstalk among various cell compartments in supporting metastasis remains poorly understood. In particular, the role of vascular pericytes, a critical cellular component in the TME, in cancer invasion and metastasis warrants further investigation. Here, we report that an elevation of FGF-2 signaling in samples from patients with nasopharyngeal carcinoma (NPC) and xenograft mouse models promoted NPC metastasis. Mechanistically, tumor cell–derived FGF-2 strongly promoted pericyte proliferation and pericyte-specific expression of an orphan chemokine (C-X-C motif) ligand 14 (CXCL14) via FGFR1/AHR signaling. Gain- and loss-of-function experiments validated that pericyte-derived CXCL14 promoted macrophage recruitment and polarization toward an M2-like phenotype. Genetic knockdown of FGF2 or genetic depletion of tumoral pericytes blocked CXCL14 expression and tumor-associated macrophage (TAM) infiltration. Pharmacological inhibition of TAMs by clodronate liposome treatment resulted in a reduction of FGF-2–induced pulmonary metastasis. Together, these findings shed light on the inflammatory role of tumoral pericytes in promoting TAM-mediated metastasis. We provide mechanistic insight into an FGF-2/FGFR1/pericyte/CXCL14/TAM stromal communication axis in NPC and propose an effective antimetastasis therapy concept by targeting a pericyte-derived inflammation for NPC or FGF-2 ^hi tumors.

Significance: The clinical efficacy of immunotherapy in cancer patients is limited. We have developed a zebrafish model that allows us to visualize the metastatic cancer cell-killing effect by tumor-infiltrating lymphocytes and chimeric antigen receptor T cells in vivo at the single-cell level. This in vivo model accurately predicts clinical efficacy of T cell-mediated cancer therapy. Our data provide an in vivo platform for validating antimetastatic effects by human T cell-mediated immunotherapy. Based on our findings, it is highly recommended that anticancer effects of T cells isolated from cancer patients or genetically propagated T cells should be evaluated in this in vivo animal model before clinical application. If so, millions of cancer patients might benefit from our work.

Defining reliable surrogate markers and overcoming drug resistance are the most challenging issues for improving therapeutic outcomes of antiangiogenic drugs (AADs) in cancer patients. At the time of this writing, no biomarkers are clinically available to predict AAD therapeutic benefits and drug resistance. Here, we uncovered a unique mechanism of AAD resistance in epithelial carcinomas with KRAS mutations that targeted angiopoietin 2 (ANG2) to circumvent antivascular endothelial growth factor (anti-VEGF) responses. Mechanistically, KRAS mutations up-regulated the FOXC2 transcription factor that directly elevated ANG2 expression at the transcriptional level. ANG2 bestowed anti-VEGF resistance as an alternative pathway to augment VEGF-independent tumor angiogenesis. Most colorectal and pancreatic cancers with KRAS mutations were intrinsically resistant to monotherapies of anti-VEGF or anti-ANG2 drugs. However, combination therapy with anti-VEGF and anti-ANG2 drugs produced synergistic and potent anticancer effects in KRAS-mutated cancers. Together, these data demonstrate that KRAS mutations in tumors serve as a predictive marker for anti-VEGF resistance and are susceptible to combination therapy with anti-VEGF and anti-ANG2 drugs.

Brown adipose tissue (BAT) is a highly specialized adipose tissue in its immobile location and size during the entire adulthood. In response to cold exposure and other β3-adrenoreceptor stimuli, BAT commits energy consumption by nonshivering thermogenesis (NST). However, the molecular machinery in controlling the BAT mass in adults is unknown. Here, we show our surprising findings that the BAT mass and functions can be manipulated in adult animals by controlling BAT adipocyte differentiation in vivo. Platelet-derived growth factor receptor α (PDGFα) expressed in BAT progenitor cells served a signaling function to avert adipose progenitor differentiation. Genetic and pharmacological loss-of-function of PDGFRα eliminated the differentiation barrier and permitted progenitor cell differentiation to mature and functional BAT adipocytes. Consequently, an enlarged BAT mass (megaBAT) was created by PDGFRα inhibition owing to increases of brown adipocyte numbers. Under cold exposure, a microRNA-485 (miR-485) was identified as a master suppressor of the PDGFRα signaling, and delivery of miR-485 also produced megaBAT in adult animals. Noticeably, megaBAT markedly improved global metabolism, insulin sensitivity, high-fat-diet (HFD)-induced obesity, and diabetes by enhancing NST. Together, our findings demonstrate that the adult BAT mass can be increased by blocking the previously unprecedented inhibitory signaling for BAT progenitor cell differentiation. Thus, blocking the PDGFRα for the generation of megaBAT provides an attractive strategy for treating obesity and type 2 diabetes mellitus (T2DM).