Colon Cancer Cell-Derived High Mobility Group 1/Amphoterin Induces Growth Inhibition and Apoptosis in Macrophages

Abstract

High mobility group (HMGB)1/amphoterin is a multifunctional cytokine involved in invasion and metastasis of cancer and in inflammation. To investigate HMGB1/amphoterin effects on macrophages, U937 human monocytic leukemia cells and rat peritoneal and human alveolar macrophages were examined. U937 cells expressed low levels of an HMGB1/amphoterin receptor, receptor for advanced glycation end-products (RAGE), whereas RAGE production was induced in differentiated phorbol 12-myristate 13-acetate (PMA)-U937 cells. Treatment with cultured medium of HMGB1/amphoterin-secreting WiDr human colon cancer cells showed growth inhibition of both U937 and PMA-U937 cells and apoptosis in PMA-U937 cells. The number of PMA-U937 cells was markedly decreased by co-culture with WiDr cells exposed to HMGB1/amphoterin sense S-oligodeoxynucleotide (ODN) in spheroids or monolayers. In contrast, PMA-U937 cells co-cultured with WiDr cells exposed to HMGB1/amphoterin anti-sense S-ODN were preserved in number. PMA-U937 cells exposed to RAGE anti-sense S-ODN were insensitive to WiDr-cultured medium. Recombinant human HMGB1/amphoterin induced growth inhibition in thioglycollate-induced rat peritoneal macrophages, PMA-U937 cells, and human alveolar macrophages, an effect that was abrogated by absorption with anti-HMGB1 antibody. Phosphorylation of JNK and Rac1 was induced in PMA-U937 cells treated with HMGB1/amphoterin. These results suggest that HMGB1/amphoterin induces growth inhibition and apoptosis in macrophages through RAGE intracellular signaling pathway.

Masquerader: High Mobility Group Box-1 and Cancer

“…Coexpression of RAGE and HMGB1 enhanced migration and invasion by colon carcinoma cells Colo320, DLD1, WiDr, and TCO with RAGE and HMGB1 protein and mRNA measured at similar levels (31). Colon cancer tumors expressing HMGB1 have less extensive macrophage infiltration (32), and HMGB1 derived from the WiDr cell line induces growth inhibition and apoptosis in macrophages, suggesting a role for HMGB1 in the inhibition of host immune responses within the tumor microenvironment (31). Phosphorylation levels of Rac and c-Jun-NH 2 -kinase/stress-activated protein kinase SAPK were increased in macrophages similarly treated with HMGB1-containing media derived from colon cancer cells (32).…”

Pro‑metastatic signaling of the trans fatty acid elaidic acid is associated with lipid rafts

“…The cells (1x10 4 per well) were seeded in a 12-well dish. Cell growth was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay or by counting the number of cells with an Autocytometer (Sysmex, Kobe, Japan) after 48 h, as described previously (13 For analyzing the metastasis to the liver, lung, and peritoneum, cancer cells (1x10 6 cells) were inoculated into the spleen, the tail vein, or peritoneal cavity, respectively. EA or OA were administrated through a gavage.…”

Paracrine Receptor Activation by Microenvironment Triggers Bypass Survival Signals and ALK Inhibitor Resistance in EML4-ALK Lung Cancer Cells

“…Macrophage differentiation of U937 cells was induced by incubation in RPMI-1640 medium containing 10 ng/mL phorbol 12-myristate 13-acetate (Sigma Chemical Co.; ref. 25) for 5 days, with floating cells removed by rinsing with PBS, as described (26). Differentiated U937 cells (PMA-U937 cells) attached to the dishes were used for in vitro assays at passages 6 to 8.…”