Project description:Tumor recurrence years after seemingly successful treatment of primary tumors is one of the major causes of mortality in cancer patients. Reactivation of dormant tumor cells is largely responsible for this phenomenon. Using models of lung and ovarian cancer, we found a specific mechanism that may govern this process mediated by stress and neutrophils. Stress hormones cause rapid release of S100A8/A9 proteins by neutrophils. S100A8/A9 induce activation of myeloperoxidase resulting in accumulation of oxidized lipids. These lipids up-regulate fibroblast growth factor pathway in tumor cells causing tumor cell exit from the dormancy and formation of tumor lesions. Higher serum levels of S100A8/A9 were associated with shorter time to recurrence in patients with lung cancer after complete tumor resection. Targeting of S100A8/A9 or β2 adrenergic receptors abrogated stress induced reactivation of dormant tumor cells. These observations demonstrate a mechanism linking stress, and specific neutrophils activation with early recurrence in cancer.
Project description:Recombinant-murine S100A8 and the corresponding Cys42 to Ala42 mutant were used at 10 mg/50 ml HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, 12 or 20 h post-inhalation of S100A8 or 12 and 20 h post-inhalation of Ala42S100A8. For comparison with Dex inhalation (used at 10 mg/50 ml HBSS), lungs were harvested 6 and 12 h post administration. Because S100A8 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyse 63 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors.
Project description:Recombinant-murine S100A8 and the corresponding Cys42 to Ala42 mutant were used at 10 mg/50 ml HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, 12 or 20 h post-inhalation of S100A8 or 12 and 20 h post-inhalation of Ala42S100A8. For comparison with Dex inhalation (used at 10 mg/50 ml HBSS), lungs were harvested 6 and 12 h post administration. Because S100A8 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyse 63 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors.
Project description:Recombinant-murine S100A8 and the corresponding Cys42 to Ala42 mutant were used at 10 mg/50 ml HBSS administered onto the nares of BALB/C mice. To assess direct effects, mice were sacrificed 1, 4, 6, 12 or 20 h post-inhalation of S100A8 or 12 and 20 h post-inhalation of Ala42S100A8. For comparison with Dex inhalation (used at 10 mg/50 ml HBSS), lungs were harvested 6 and 12 h post administration. Because S100A8 is reported to initiate proinflammatory responses by ligating TLR4 and/or RAGE, a quantitative PCR array was developed to analyse 63 genes, selected to reflect potential acute inflammatory changes induced by ligation of these receptors. Expression of inflammatory genes was evaluated with the RT-qPCR array. Relative quantities of mRNA in duplicate samples were obtained using the LightCyclerM-BM-. 480 Software 1.5 and the Efficiency-Method.