GFAP expression was upregulated in differentiated NPCs treated with IL-1β for 4 days, but expression of DCX and microtubule associated protein-2 (MAP2) was decreased.
The protein level of FSTL1 was decreased in primary NPC tumors and was associated with downregulated interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α).
Analysis using reverse transcriptase-PCR revealed the expression of a panel of cytokines in the NPC biopsies: interleukin (IL)-1alpha, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma, tumor necrosis factor-alpha, transforming growth factor-beta, and IL-1 receptor types I and II.
Furthermore, the inflammatory cytokines whose genes are classically induced by IL-1 and TNF were found expressed only in C17 and C19 suggesting another level of heterogeneity among NPCs.