BMC Cancer Research article Aberrant Expression of ID2 protein and its correlation with EBV-LMP1 and P16(INK4A) in Classical Hodgkin Lymphoma in China Po Zhao†, Yali Lu†, Lin Liu† and Mei Zhong*† BioMed Central Open Access Address: Department of Pathology, Chinese People's Liberation Army (PLA) General Hospital, 28 Fuxing Road, Beijing 100853, PR China Email: Po Zhao - zhaopo@301hospital.com.cn; Yali Lu - lyl301@263.net; Lin Liu - liulin@263.net; Mei Zhong* - zhongmei@sina.com * Corresponding author †Equal contributors Published: 19 December 2008 BMC Cancer 2008, 8:379 doi:10.1186/1471-2407-8-379 This article is available from: http://www.biomedcentral.com/1471-2407/8/379 Received: 22 April 2008 Accepted: 19 December 2008 © 2008 Zhao et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: The relationships between the expression of ID2, EBV-LMP1 and P16(INK4A) in Chinese classical Hodgkin lymphoma are unknown and need exploring. Methods: Samples of classical Hodgkin lymphoma from 60 Chinese patients were analyzed for the expression of ID2, EBV-LMP1 and p16(INK4A) proteins by immunohistochemistry. Results: ID2 protein was expressed in 83.3% of this group of classical Hodgkin lymphoma, staining strongly in both cytoplasm and nucleus of the Hodgkin and Reed-Sternberg (HRS) cells. EBV-LMP1 and P16(INK4A) were overexpressed in 85.0% and 71.7% of Hodgkin lymphoma, respectively. EBV- LMP1 was noted in the cytoplasm, membrane and nucleus of HRS cells; P16(INK4A) was in the nucleus and cytoplasm. Microscopically, ID2, EBV-LMP1 and P16(INK4A) staining distinguished the HRS cells from the complex background of lymphocytes. ID2 was positively correlated with EBV- LMP1(P < 0.01), but P16(INK4A) was inversely related to EBV-LMP1 (P < 0.05). Conclusion: It is suggested that ID2, EBV-LMP1 and P16(INK4A) could play an important role in the evolution of classical Hodgkin lymphoma, and be considered as potential adjunct markers to identify HRS cells in diagnosis. Background Hodgkin lymphoma comprises two distinct entities; namely nodular lymphocyte predominant Hodgkin lym- phoma and classical Hodgkin lymphoma. Classical Hodgkin lymphoma is a lymphoid neoplasm composed of monoclonal Hodgkin cells and multinucleated Reed- Sternberg (HRS) cells residing in an infiltrate containing a variable mixture of non-neoplastic small lymphocytes, eosinophils, neutrophils, histiocytes, plasma cells, fibrob- lasts and collagen fibres. [1] There are four morphological variants of classical Hodgkin lymphoma, namely nodular sclerosis, mixed cellularity, lymphocyte-rich and lym- phocyte-depleted. HRS cells are currently thought to be derived from mature B cells at the germinal stage of differ- entiation, and are pathognomonic in Hodgkin lym- phoma. [1] However, HRS cells may often be scanty and difficult to identify in sections. The pathogenesis of classi- cal Hodgkin lymphoma remains unknown. ID proteins are key regulators in several developmental and cellular processes. In general, aberrant ID expression seems to favor proliferation, to inhibit differentiation, and to facilitate tumor neoangiogenesis.[2] From early B- cell development to mature B cells, E2A is the first one of Page 1 of 5 (page number not for citation purposes)