Detecting cell-in-cell structures in human tumor samples by E-cadherin/CD68/CD45 triple staining

// Hongyan Huang 1, 2, * , Ang Chen 2, * , Ting Wang 3, * , Manna Wang 2 , Xiangkai Ning 2 , Meifang He 2 , Yazhuo Hu 4 , Long Yuan 2 , Shichong Li 2 , Qiwei Wang 2 , Hong Liu 2 , Zhaolie Chen 2 , Jun Ren 1 , Qiang Sun 2 1 Department of Oncology, Beijing Shijitan Hospital of Capital Medical University, Beijing, P. R. China 2 Laboratory of Cell Engineering, Institute of Biotechnology, Beijing, P. R. China 3 Department of Vascular and Endocrine Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China, Xi'an, Shaanxi Province, P. R. China 4 Beijing Key Laboratory for Aging and Geriatrics, Institute of Geriatrics, General Hospital of Chinese PLA, Beijing, P.R. China * These authors have contributed equally to this work Correspondence to: Qiang Sun, e-mail: sunqiang@bmi.ac.cn Jun Ren, e-mail: renjun9688@yahoo.com Keywords: cell-in-cell structures, cell cannibalism, EML method, epithelium, macrophage Received: March 08, 2015 Accepted: June 08, 2015 Published: June 18, 2015 ABSTRACT Although Cell-in-cell structures (CICs) had been documented in human tumors for decades, it is unclear what types of CICs were formed largely due to low resolution of traditional way such as H&E staining. In this work, we employed immunofluorescent method to stain a panel of human tumor samples simultaneously with antibodies against E-cadherin for Epithelium, CD68 for Macrophage and CD45 for Leukocytes, which we termed as “EML method” based on the cells detected. Detail analysis revealed four types of CICs, with tumor cells or macrophage engulfing tumor cells or leukocytes respectively. Interestingly, tumor cells seem to be dominant over macrophage (93% vs 7%) as the engulfer cells in all CICs detected, whereas the overall amount of internalized tumor cells is comparable to that of internalized CD45 + leukocytes (57% vs 43%). The CICs profiles vary from tumor to tumor, which may indicate different malignant stages and/or inflammatory conditions. Given the potential impacts different types of CICs might have on tumor growth, we therefore recommend EML analysis of tumor samples to clarify the correlation of CICs subtypes with clinical prognosis in future researches.