Inflammatory response in craniopharyngiomas and its clinical significance

Abstract

Objective To investigate the clinical significance of inflammatory reaction in craniopharyngiomas. Methods Antibody microarray was employed for detection of inflammatory cytokines expression in craniopharyngiomas and other common tumors in sellar region (including the pituitary adenoma, meningioma, pilocytic astrocytoma). The methods of qPCR and ELISA were further used for verifying the expression of inflammatory factors in each group. At the same time, the mouse brain neuron cell line (CATH.a) was treated with supernatant of the primary culture medium of craniopharyngiomas, and the apoptotic state of neurons was explored by flow cytometry. Results The craniopharyngioma was more likely to have an inflammatory response than other sellar tumors. The results of antibody microarray showed that the relative expression levels of monocyte chemotactic protein-1 (MCP-1), interleukin 6 (IL-6) and interleukin 1 (IL-1) in adamantinomatous craniopharyngiomas (ACP) (7±1, 6±1, 8±2) were significantly higher than those in papillary craniopharyngiomas (PCP) (2±1, 2±1, 2±1), pilocytic astrocytomas (2±1, 1±0, 2±1), pituitary adenomas (1±0, 2±1, 2±1) and meningiomas (1±0, 1±0, 1±0) (all P<0.05). The qPCR results further verified that the transcriptional levels of 3 inflammatory factors mentioned above in ACP (180±24 pg/ml, 266±19 pg/ml, 243±31 pg/ml) were significantly higher than those in PCP (68 ±14 pg/ml, 98 ±29 pg/ml, 154±21 pg/ml), pilocytic astrocytomas (60±14 pg/ml, 142±29 pg/ml, 149±39 pg/ml), pituitary adenomas (180±24 pg/ml, 266±19 pg/ml, 134±27 pg/ml) and meningiomas (56±14 pg/ml, 89±19 pg/ml, 121±21 pg/ml) (all P<0.05), while Elisa results showed that three kinds of inflammatory factors in the ACP primary cell culture medium supernatant (168±19 pg/ml, 155±34 pg/ml, 228±31 pg/ml) were significantly higher than those in PCP (66±24 pg/ml, 89±19 pg/ml, 112±21 pg/ml) (all P<0.05). After CATH.a cells were stimulated by ACP medium supernatant, their apoptosis increased significantly, while the promotion of apoptosis by supernatant of PCP medium was not obvious. Immunohistochemistry results showed that the inflammatory response in ACP tissue was characterized by infiltration of macrophage inflammatory cells; and activated microglias were observed in the front area between tumor and the third ventricle floor. Conclusions Inflammatory reaction could be found in the craniopharyngioma and the levels of MCP-1, IL-6 and IL-1 were higher in ACP than PCP. The inflammatory reaction of craniopharyngioma seems toxic to CATH.a cells. Key words: Craniopharyngioma; Inflammation reaction; Prognosis; Endocrine