Inflammation and Cancer: Role of Annexin A1 and FPR2/ALX in Proliferation and Metastasis in Human Laryngeal Squamous Cell Carcinoma

The anti-inflammatory protein annexin A1 (ANXA1) has been associated with cancer progression and metastasis, suggesting its role in regulating tumor cell proliferation. We investigated the mechanism of ANXA1 interaction with formylated peptide receptor 2 (FPR2/ALX) in control, peritumoral and tumor larynx tissue samples from 20 patients, to quantitate the neutrophils and mast cells, and to evaluate the protein expression and co-localization of ANXA1/FPR2 in these inflammatory cells and laryngeal squamous cells by immunocytochemistry. in addition, we performed in vitro experiments to further investigate the functional role of ANXA1/FPR2 in the proliferation and metastasis of Hep-2 cells, a cell line from larynx epidermoid carcinoma, after treatment with ANXA1(2-26) (annexin A1 N-terminal-derived peptide), Boc2 (antagonist of FPR) and/or dexamethasone. Under these treatments, the level of Hep-2 cell proliferation, pro-inflammatory cytokines, ANXA1/FPR2 co-localization, and the prostaglandin signalling were analyzed using ELISA, immunocytochemistry and real-time PCR. An influx of neutrophils and degranulated mast cells was detected in tumor samples. in these inflammatory cells of peritumoral and tumor samples, ANXA1/FPR2 expression was markedly exacerbated, however, in laryngeal carcinoma cells, this expression was downregulated. ANXA1(2-26) treatment reduced the proliferation of the Hep-2 cells, an effect that was blocked by Boc2, and up-regulated ANXA1/FPR2 expression. ANXA1(2-26) treatment also reduced the levels of pro-inflammatory cytokines and affected the expression of metalloproteinases and EP receptors, which are involved in the prostaglandin signalling. Overall, this study identified potential roles for the molecular mechanism of the ANXA1/FPR2 interaction in laryngeal cancer, including its relationship with the prostaglandin pathway, providing promising starting points for future research. ANXA1 may contribute to the regulation of tumor growth and metastasis through paracrine mechanisms that are mediated by FPR2/ALX. These data may lead to new biological targets for therapeutic intervention in human laryngeal cancer.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fed Univ São Paulo UNIFESP, Paulista Sch Med EPM, São Paulo, BrazilFac Med FAMERP, Dept Mol Biol, Sao Jose Do Rio Preto, SP, BrazilFac Med FAMERP, Dept Otorhinolaringol, Sao Jose Do Rio Preto, SP, BrazilFac Med FAMERP, Dept Pathol, Sao Jose Do Rio Preto, SP, BrazilSão Paulo State Univ UNESP, Dept Biol & Zoot, Ilha Solteira, SP, BrazilUniv São Paulo, Inst Biosci, Dept Genet & Evolutionary Biol, São Paulo, BrazilSão Paulo State Univ UNESP, Dept Biol, Inst Biociencias Letras & Ciencias Exatas IBILCE, Saa Jose Do Rio Preto, SP, BrazilFed Univ São Paulo UNIFESP, Paulista Sch Med EPM, São Paulo, BrazilFAPESP: 2008/08187-4FAPESP: 2008/01655-2CNPq: 302768/2010-6Web of Scienc