Immunohistochemical TRF1 expression in human primary intracranial tumors

Background: The telomeric-repeat binding factor (TRFI) participates in a ph ysiological homeostatic mechanism controlling telomere shortening by inhibi ting telomerase activity: down-regulation of TRFI expression results in tel omere elongation and may be involved in cell immortalization. Patients and Methods: To determine the TRF1 expression by immunohistochemistty (IHC) in human brain tumors, a cohort of 20 consecutive flash-frozen surgical specim ens (14 meningiomas and 6 anaplastic astrocytomas (AA)) were collected. Res ults: Variable levels of TRFI expression in 12 out of the 14 (87.5%) mening ioma samples were observed By contrast, no expression of TRFI in tissue sam ples from AA (p = 0.008) was detected Positive TRF1 cells were usually more differentiated (less atypical features) and Ki67 negative (inverse statist ical association, chi (2) = p < 0.001). Conclusion: We demonstrated, for th e first time, that routine IHC techniques are capable of identifying TRF1 e xpression in intracranial tumors, which is heterogeneously expressed in men ingiomas, but absent in AA. Although these preliminary observations need co nfirmation from larger studies, the TRFI status in intracranial tumors migh t become of prognostic value.