Wuhan, China

Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China (Tong QS, Tang ST, Li SW, Jiang GS, Cai JB, Liu Y, Ruan QL); Department of Pathology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China (Zheng LD)

Corresponding Author: Qiang-Song Tong, PhD, MD, Department of Pediatric Surgery, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China (Tel: 86-27-85991567; Email: qstong@mails.tjmu.edu.cn)

Background: Recent evidences indicated that tumor cells could induce apoptosis of T cells by combining Fas on active T cells' surface with self-expressed FasL to escape immune surveillance. This study was undertaken to detect the expression of the Fas/FasL system in neuroblastoma (NB) tissues and its clinical significance in clinical practice.

Methods: Immunohistochemical staining was performed to detect the expression of Fas and FasL in 40 cases of NB. The relations among Fas and FasL expression, clinical stages, pathological types, and postoperative survival time of patients were analyzed.

Results: The positive expression rates of Fas in I-II, III-IV and IV-S stages were 64.3%, 22.2% and 50.0% respectively (P<0.05). The positive expression rate of FasL in III-IV stage was 33.3%, which was significantly higher than that in I-II (21.4%) and IV-S stages (12.5%). FasL expression rates in patients with NB (28.1%) and unfavorable histology (UFH) (33.3%) were higher than those of patients with ganglioneuroblastoma (GNB) (12.5%) and favorable histology (FH) (15.8%). However, Fas expression rates in patients with GNB (50%) and FH (63.2%) were higher than those of patients with NB (40.6%) and UFH (23.8%). A positive correlation was observed between Fas expression and postoperative survival time (n=25, r=0.354), but no obvious correlation between FasL expression and postoperative survival time.

Conclusions: Abnormalities of the Fas/FasL system are related to the development of NB. Detection of the expression of Fas/FasL system may be useful to evaluate the clinical prognosis of NB.

Key words: neuroblastoma; Fas; FasL; gene expression; immune escape

World J Pediatr 2007;3(3):209-213