口腔鳞状细胞癌侵犯颌骨与破骨细胞及相关细胞因子的关系

目的:研究在口腔鳞状细胞癌侵犯颌骨的病例中,破骨细胞及与破骨细胞相关的两个重要[细胞因子细胞核因子κB受体活化因子配体(receptor activator of nuclear factor-κB ligand,RANKL)和骨保护素(osteoprotegerin,OPG)]的表达情况.方法:选用12例口腔鳞状细胞癌侵犯颌骨病例的手术标本,将新鲜软组织标本制作成冰冻切片,含骨组织标本经固定脱钙后制成石蜡切片.分别对两种切片进行抗酒石酸酸性磷酸酶(TRAP)染色,以及针对RANKL和OPG两种细胞因子的免疫组织化学染色.结果:TRAP阳性的多核细胞出现在肿瘤与颌骨的交界面附近.其下方的骨组织成锯齿样,TRAP阳性细胞位于骨表面的陷窝内.RANKL免疫组化染色阳性的部位主要有血管内皮和上皮基底膜,在与骨面相近的肿瘤组织中也可见位于血管周围的染色阳性细胞,而在靠近骨面的鳞状细胞癌周围的组织内未见OPG特异性染色阳性.结论:在口腔鳞状细胞癌引起颌骨侵犯的病例中,破骨细胞是受到鳞状细胞癌的影响而分化和活化,并最终引起骨组织的吸收破坏.肿瘤细胞是跟随在破骨细胞后面侵入骨组织,并不直接引起骨的变化.骨侵犯性鳞状细胞癌的细胞及周围的血管可以释放出较多的RANKL类细胞因子,促进破骨细胞的分化和活化,最终导致了破骨活动的发生和发展.

Osteoclastic bone destruction and its regulating factors in oral squamous cell carcinoma

Objective: To investigate the osteoclastic activity in oral squamous cell carcinoma (OSCC) invading the jaws and to observe the expression of RANKL and OPG, the two bone resorption related cytokines, in these cases. Methods: Twelve cases of OSCC invading the mandiblewere studied. After pathological diagnosis, operations were done to remove part of the mandible depending upon the X-ray findings. Fresh soft tissue specimens were frozen-sectioned and other specimens with the bone tissue were fixed and decalcified to make paraffin sections. Tartrate-resistant acid phosphatase(TRAP) staining and immunohistochemical staining were then applied to observe the location of osteoclasts and the expression of RANKL and OPG. Results: TRAP positive multinuclear cells were detected near the interface between the bone and tumor. RANKL positive cells were commonly seen on the endothelium of blood vessel and basement membrane of the epithelium. But OPG reactivities were not seen in these sections. Conclusion: The bone destruction caused by OSCC is mediated by osteoclasts but not by cancer cell itself. It appears that the differentiation and activation of osteclasts were induced by OSCC through cytokines like RANKL.