地诺单抗通过STAT3信号通路抑制骨巨细胞瘤的初步研究

Denosumab inhibiting giant cell tumor of bone via STAT3 signaling pathway

目的研究STAT3信号通路及其下游相关分子在地诺单抗治疗骨巨细胞瘤过程中的表达变化及其意义。方法收集我院2013年1月至2018年12月手术治疗的31例骨巨细胞瘤病人,其中28例未经地诺单抗治疗(对照组),3例经地诺单抗治疗(研究组)。通过苏木素-伊红(hematoxylin and eosin, HE)染色检测骨巨细胞瘤组织经地诺单抗治疗前后的病理学变化;通过免疫组化法检测研究组和对照组的骨巨细胞瘤组织中RANKL、STAT3及其下游分子Bcl-2、Cyclin D1分子的表达差异;通过TUNEL法检测上述两组石蜡切片组织中肿瘤细胞的凋亡情况。结果HE染色结果:对照组中骨巨细胞瘤组织主要由肿瘤基质细胞和多核破骨样巨细胞组成;研究组中破骨样巨细胞消失,残留部分细长形肿瘤基质细胞,大量网状纤维组织及编织骨形成并替代肿瘤组织;免疫组化检测结果:RANKL主要表达于肿瘤基质细胞;STAT3主要表达于多核破骨细胞胞浆和肿瘤基质细胞胞膜;Bcl-2主要表达于多核破骨样巨细胞胞浆、散在分布于细胞核;Cyclin D1表达于多核破骨样巨细胞的细胞核中。RANKL、STAT3、Bcl-2和Cyclin D1在对照组肿瘤组织中的阳性表达率分别为70%、53%、77%、73%;研究组肿瘤组织中多核破骨样巨细胞消失,残留的肿瘤基质细胞中RANKL表达量明显减少,未见STAT3、Bcl-2、Cyclin D1分子表达;TUNEL法凋亡结果:对照组中仅有少量的肿瘤细胞凋亡,研究组中可见残留的肿瘤细胞明显凋亡。结论地诺单抗可能通过抑制STAT3信号通路抑制多核破骨样巨细胞的形成及促进肿瘤基质细胞凋亡。

Objective To study the expression and significance of STAT3 signaling pathway and its downstream related molecules in the treatment of giant cell tumor with Denosumab. Methods Thirty-one patients with giant cell tumors of bone treated surgically in our hospital from January 2013 to December 2018 were collected. Among them, 28 patients were not treated with denosumab(control group) and 3 patients were treated with denosumab(experimental group). HE staining was used to detect the pathological changes of giant cell tumor tissues before and after denosumab treatment. The expression levels of RANKL, STAT3, Bcl-2 and Cyclin D1 in giant cell tumor of bone treated with and without Denosumab were detected by immunohistochemistry. The TUNEL method was used to detect apoptosis of tumor cells in paraffin sections with and without Denosumab. Results HE staining results revealed that the giant cell tumor tissue in control group was mainly composed of tumor stromal cells and multinucleated osteoclast-like giant cells;the osteoclast-like giant cells disappeared and the residual part was fine in experimental group, and long-form tumor stromal cells,a large number of reticular fibrous tissue and woven bone formed and replaced tumor tissue.Immunohistochemistry results showed RANKL was mainly expressed in tumor stromal cells, STAT3 was mainly expressed in multinucleated osteoclast cytoplasm and tumor stromal cells in the cell membrane, Bcl-2 was mainly expressed in the cytoplasm of multinucleated osteoclast-like giant cells, scattered in the nucleus, and Cyclin D1 was expressed in the nucleus of multinucleated osteoclast-like giant cells. The positive expression rate of RANKL, STAT3, Bcl-2 and Cyclin D1 in control group was 70%, 53%, 77%, 73%, respectively. In experimental group, the expression of RANKL in tumors was significantly reduced, and the expression of STAT3, Bcl-2 and Cyclin D1 molecules was not detectable. Apoptosis test results indicated only a small number of tumor cells were apoptotic observed in giant cell tumors of bone in control group, and obvious apoptosis of residual tumor stromal cells was observed in experimental group. Conclusion Denosumab may inhibit the formation of multinucleated osteoclast-like giant cells and promote the apoptosis of tumor stromal cells by inhibiting STAT3 signaling pathway.