Choudhary Dharamainder, Hegde Poornima, Voznesensky Olga, Choudhary Shilpa, Kopsiaftis Stavros, Claffey Kevin P, Pilbeam Carol C, Taylor John A
Department of Surgery, University of Connecticut Health Center, Farmington, CT.
Department of Pathology, University of Connecticut Health Center, Farmington, CT.
Urol Oncol. 2015 Sep;33(9):387.e17-27. doi: 10.1016/j.urolonc.2014.12.009. Epub 2015 Jan 22.
L-Selectin (CD62L) is a vascular adhesion molecule constitutively expressed on leukocytes with a primary function of directing leukocyte migration and homing of lymphocytes to lymph nodes. In a gene expression microarray study comparing laser-captured microdissected high-grade muscle-invasive bladder cancer (MIBC) without prior treatment and low-grade bladder cancer (LGBC) human samples, we found CD62L to be the highest differentially expressed gene. We sought to examine the differential expression of CD62L in MIBCs and its clinical relevance.
Unfixed fresh and formalin-fixed paraffin-embedded human bladder cancer specimens and serum samples were obtained from the University of Connecticut Health Center tumor bank. Tumor cells were isolated from frozen tumor tissue sections by laser-captured microdissected followed by RNA isolation. Quantitative polymerase chain reaction was used to validate the level of CD62L transcripts. Immunohistochemistry and enzyme-linked immunosorbent assay were performed to evaluate the CD62L protein localization and expression level. Flow cytometry was used to identify the relative number of cells expressing CD62L in fresh tumor tissue. In silico studies were performed using the Oncomine database.
Immunostaining showed a uniformly higher expression of CD62L in MIBC specimens vs. LGBCs specimens. Further, CD62L localization was seen in foci of metastatic tumor cells in lymph node specimens from patients with high-grade MIBC and known nodal involvement. Up-regulated expression of CD62L was also observed by flow cytometric analysis of freshly isolated tumor cells from biopsies of high-grade cancers vs. LGBC specimens. Circulating CD62L levels were also found to be higher in serum samples from patients with high-grade metastatic vs. high-grade nonmetastatic MIBC. In addition, in silico analysis of Oncomine Microarray Database showed a significant correlation between CD62L expression and tumor aggressiveness and clinical outcomes.
These data confirm the expression of CD62L on urothelial carcinoma cells and suggest that CD62L may serve as biomarker to predict the presence of or risk for developing metastatic disease in patients with bladder cancer.
L-选择素（CD62L）是一种在白细胞上组成性表达的血管粘附分子，其主要功能是引导白细胞迁移以及淋巴细胞归巢至淋巴结。在一项基因表达微阵列研究中，我们比较了未经治疗的激光捕获显微切割的高级别肌肉浸润性膀胱癌（MIBC）和低级别膀胱癌（LGBC）的人类样本，发现CD62L是差异表达最高的基因。我们试图研究CD62L在MIBC中的差异表达及其临床相关性。
从不列颠哥伦比亚大学健康中心肿瘤库获取未固定的新鲜和福尔马林固定石蜡包埋的人类膀胱癌标本及血清样本。通过激光捕获显微切割从冷冻肿瘤组织切片中分离肿瘤细胞，随后进行RNA分离。采用定量聚合酶链反应来验证CD62L转录本水平。进行免疫组织化学和酶联免疫吸附测定以评估CD62L蛋白的定位和表达水平。使用流式细胞术鉴定新鲜肿瘤组织中表达CD62L的细胞相对数量。利用Oncomine数据库进行生物信息学研究。
免疫染色显示，与LGBC标本相比，MIBC标本中CD62L的表达普遍更高。此外，在已知有淋巴结转移的高级别MIBC患者的淋巴结标本中，转移肿瘤细胞灶可见CD62L定位。对高级别癌症活检新鲜分离的肿瘤细胞与LGBC标本进行流式细胞术分析，也观察到CD62L表达上调。还发现高级别转移性MIBC患者血清样本中循环CD62L水平高于高级别非转移性MIBC患者。此外，Oncomine微阵列数据库的生物信息学分析显示CD62L表达与肿瘤侵袭性及临床结果之间存在显著相关性。
这些数据证实了CD62L在尿路上皮癌细胞上的表达，并表明CD62L可能作为一种生物标志物，用于预测膀胱癌患者发生转移疾病的存在或风险。
