CD44在小细胞肺癌中的异质性表达及意义

Heterogeneity and significance of CD44 expression in small cell lung cancer

目的:探讨细胞粘附分子CD44在小细胞肺癌中的表达是否存在异质性及其临床意义。方法:应用免疫荧光细胞化学和免疫组织化学法检测3种小细胞肺癌细胞系和50例小细胞肺癌组织中CD44的表达。流式细胞仪分选出CD44+和CD44-细胞亚群,体外Transwell实验研究细胞系中CD44不同表达强度细胞侵袭能力的差异。结果:H69、H209和H1688细胞系均呈CD44阳性表达,阳性百分率分别为82%±9.4%、79%±8.4%和88%±7.5%;不同细胞系之间及同一细胞系内表达强度均有差异。50例小细胞肺癌组织中23例可见CD44阳性表达,阳性率46%。CD44阳性癌细胞在癌巢中呈散在分布,癌巢周边部分的癌细胞及血管周围浸润的癌细胞呈聚集阳性表达。淋巴结转移组的阳性率为53.6%(22/41),无淋巴结转移组的阳性率为11.1%(1/9),两组间阳性率差异有统计学意义(P<0.05),CD44阳性表达与临床参数(患者性别、年龄、肿瘤大小)无相关性。体外侵袭实验发现H209和H1688细胞系中CD44+细胞亚群侵袭能力强于CD44-细胞亚群。结论:CD44在小细胞肺癌细胞系及组织中有表达,且其表达存在异质性,CD44可能与癌浸润转移有关。

Objective： To study the heterogeneity of CD44 expression in small cell lung cancer （SCLC）and its correlation with clinical parameters. Methods： Immunofluorescence cytochemistry and immunohistochemistry methods were used to investigate the expression of CD44 in 3 SCLC cell lines and 50 cases of SCLC tissue specimens, CD44-positive and CD44-negative cancer cells were isolated by FACS, Transwell chambers were used to investigate the role of CD44 in invasion of SCLC cell lines in vitro. Results： Positive expression of CD44 was observed in all three cell lines H69, H209 and H1688, but there were varying intensity expression in different cell lines even in the same cell line. CD44 was expressed in 23 of 50 cases （46%）of SCLC tissue specimens. CD44 positive cancer cells were diffuse distributed within the cancer nests and mesenchymal tissue, preferentially distributed in the peripheral part of the nests and the interstitial part near the blood vessels. CD44 expression was 53.6%（22/41 ） in lymph node-positive group, while in lymph node-negative group was 11.1%（1/9） （P〈0.05）.There was no relationship between the expression of CD44 and clinical parameters. Invasion potential of CD44 positive cancer cells was significantly higher than that of CD44 negative cancer cells in SCLC cell lines H209 and H1688 tested by in vitro Transwell assay. Conclusion： The heterogeneity of CD44 expression exist in SCLC cell lines and tissue specimens, which may be correlated with the behavior of tumor invasion and metastasis.