The recent progresses in understanding of cancer glycolytic phenotype have offered new strategies to manage ovarian cancer and other malignancies. However, therapeutic targeting of glycolysis to treat cancer remains unsuccessful due to complex mechanisms of tumor glycolysis and the lack of selective, potent and safe glycolytic inhibitors. Recently, BAY-876 was identified as a new-generation inhibitor of glucose transporter 1 (GLUT1), a GLUT isoform commonly overexpressed but functionally poorly defined in ovarian cancer. Notably, BAY-876 has not been evaluated in any cell or preclinical animal models since its discovery. We herein took advantage of BAY-876 and molecular approaches to study GLUT1 regulation, targetability, and functional relevance to cancer glycolysis. The anti-tumor activity of BAY-876 was evaluated with ovarian cancer cell line- and patient-derived xenograft (PDX) models. Our results show that inhibition of GLUT1 is sufficient to block basal and stress-regulated glycolysis, and anchorage-dependent and independent growth of ovarian cancer cells. BAY-876 dramatically inhibits tumorigenicity of both cell line-derived xenografts and PDXs. These studies provide direct evidence that GLUT1 is causally linked to the glycolytic phenotype in ovarian cancer. BAY-876 is a potent blocker of GLUT1 activity, glycolytic metabolism and ovarian cancer growth, holding promise as a novel glycolysis-targeted anti-cancer agent.

fatty acid oxidation (fAo) is a key bioenergetic pathway often dysregulated in diseases. the current knowledge on fAo regulators in mammalian cells is limited and sometimes controversial. previous FAO analyses involve nonphysiological culture conditions or lack adequate quantification. We herein described a convenient and quantitative assay to monitor dynamic fAo activities of mammalian cells in physiologically relevant settings. the method enabled us to assess various molecular and pharmacological modulators of the fAo pathway in established cell lines, primary cells and mice. Surprisingly, many previously proposed fAo inhibitors such as ranolazine and trimetazidine lacked FAO-interfering activity. In comparison, etomoxir at low micromolar concentrations was sufficient to saturate its target proteins and to block cellular fAo function. oxfenicine, on the other hand, acted as a partial inhibitor of fAo. As another class of fAo inhibitors that transcriptionally repress fAo genes, antagonists of peroxisome proliferator-activated receptors (ppARs), particularly that of ppARα, significantly decreased cellular FAO activity. Our assay also had sufficient sensitivity to monitor upregulation of fAo in response to environmental glucose depletion and other energy-demanding cues. Altogether this study provided a reliable fAo assay and a clear picture of biological properties of potential fAo modulators in the mammalian system.

Fundamental metabolic pathways are essential for mammalian cells to provide energy, precursors for biosynthesis of macromolecules, and reducing power for redox regulation. While dysregulated metabolism (e.g., aerobic glycolysis also known as the Warburg effect) has long been recognized as a hallmark of cancer, recent discoveries of metabolic reprogramming in immune cells during their activation and differentiation have led to an emerging concept of "immunometabolism." *

Epithelial ovarian carcinoma tissues express high levels of tumor necrosis factor‐alpha (TNF‐α) and other inflammatory cytokines. The underlying mechanism leading to the abnormal TNF‐α expression in ovarian cancer remains poorly understood. In the current study, we demonstrated that lysophosphatidic acid (LPA), a lipid mediator present in ascites of ovarian cancer patients, induced expression of TNF‐α mRNA and release of TNF‐α protein in ovarian cancer cells. LPA also induced expression of interleukin‐1β (IL‐1β) mRNA but no significant increase in IL‐1β protein was detected. LPA enhanced TNF‐α mRNA through NF‐κB‐mediated transcriptional activation. Inactivation of ADAM17, a disintegrin and metalloproteinase, with a specific inhibitor TMI‐1 or by shRNA knockdown prevented ovarian cancer cells from releasing TNF‐α protein in response to LPA, indicating that LPA‐mediated TNF‐α production relies on both transcriptional upregulations of the TNF‐α gene and the activity of ADAM17, the membrane‐associated TNF‐α‐converting enzyme. Like many other biological responses to LPA, induction of TNF‐α by LPA also depended on the transactivation of the epidermal growth factor receptor (EGFR). Interestingly, our results revealed that ADAM17 was also the shedding protease responsible for the transactivation of EGFR by LPA in ovarian cancer cells. To explore the biological outcomes of LPA‐induced TNF‐α, we examined the effects of a TNF‐α neutralizing antibody and recombinant TNF‐α soluble receptor on LPA‐stimulated expression of pro‐tumorigenic cytokines and chemokines overexpressed in ovarian cancer. Blockade of TNF‐α signaling significantly reduced the production of IL‐8, IL‐6, and CXCL1, suggesting a hierarchy of mechanisms contributing to the robust expression of the inflammatory mediators in response to LPA in ovarian cancer cells. In contrast, TNF‐α inhibition did not affect LPA‐dependent cell proliferation. Taken together, our results establish that the bioactive lipid LPA drives the expression of TNF‐α to regulate an inflammatory network in ovarian cancer.

Ovarian cancer (OVC) remains the most lethal gynecological malignancy in the world due to the combined lack of early-stage diagnostics and effective therapeutic strategies. The development and application of advanced proteomics technology and new experimental models has created unique opportunities for translational studies. In this study, we investigated the ovarian cancer proteome of the chicken, an emerging experimental model of OVC that develops ovarian tumors spontaneously. Matched plasma, ovary, and oviduct tissue biospecimens derived from healthy, early-stage OVC, and late-stage OVC birds were quantitatively characterized by label-free proteomics. Over 2600 proteins were identified in this study, 348 of which were differentially expressed by more than twofold (p≤0.05) in early- and late-stage ovarian tumor tissue specimens relative to healthy ovarian tissues. Several of the 348 proteins are known to be differentially regulated in human cancers including B2M, CLDN3, EPCAM, PIGR, S100A6, S100A9, S100A11, and TPD52. Of particular interest was ovostatin 2 (OVOS2), a novel 165-kDa protease inhibitor found to be strongly upregulated in chicken ovarian tumors (p=0.0005) and matched plasma (p=0.003). Indeed, RT-quantitative PCR and Western blot analysis demonstrated that OVOS2 mRNA and protein were also upregulated in multiple human OVC cell lines compared to normal ovarian epithelia (NOE) cells and immunohistochemical staining confirmed overexpression of OVOS2 in primary human ovarian cancers relative to non-cancerous tissues. Collectively, these data provide the first evidence for involvement of OVOS2 in the pathogenesis of both chicken and human ovarian cancer.