Cancer Genetics and Cytogenetics 123 (2000) 44–48 0165-4608/00/$ – see front matter © 2000 Elsevier Science Inc. All rights reserved. PII: S0165-4608(00)00298-3 Lack of mutations of BCL6 and BCL10 genes in mucosa-associated lymphoid tissue lymphomas of the orbital adnexa Po-Min Chen a , Jin-Hwang Liu a , I-Ting Yu b , Shu-Ching Kao c , Yu-Chen Lin a , Hung Chiang b , Frank Sheng Fan a , Tzeon-Jye Chiou a , Wei-Shu Wang a , Chueh-Chuan Yen a, * a Section of Medical Oncology, Department of Medicine, Taipei Veterans General Hospital, and National Yang-Ming University, Taipei, Taiwan, ROC b Section of Medical Oncology, Department of Pathology, Taipei Veterans General Hospital, and National Yang-Ming University, Taipei, Taiwan, ROC c Section of Medical Oncology, Department of Ophthalmology, Taipei Veterans General Hospital, and National Yang-Ming University, Taipei, Taiwan, ROC Received 16 March 2000; received in revised form 25 May 2000; accepted 30 May 2000 Abstract Knowledge regarding the molecular pathogenesis and progression of mucosa-associated lymphoid tissue (MALT) lymphomas of ocular adnexa is limited. Eleven cases of ocular MALT lymphoma were analyzed by clonal rearrangement of antigen receptor genes using Southern blot hybridiza- tion. Polymerase chain reaction-single stranded conformational polymorphism analysis and DNA sequencing was utilized to analyze the mutations of BCL6 and BCL10 genes. Clonal rearrange- ment of immunoglobulin heavy genes was found in all 11 patients. No point mutation was found in BCL6 or BCL10 genes in any of the samples analyzed. We suggest that mutations of BCL6 and BCL10 genes are rare in low-grade MALT lymphoma of ocular adnexa and are unlikely to be in- volved in the pathogenesis of the disease. But the role of alterations of both BCL6 and BCL10 genes in the disease progression of low-grade MALT lymphoma require additional study. © 2000 Elsevier Science Inc. All rights reserved. 1. Introduction Lymphomas of mucosa-associated lymphoid tissue (MALT lymphomas) represent a distinct subgroup of B-cell non-Hodgkin lymphomas (NHL) arising from extranodal sites. These neoplasms usually arise from the gastrointesti- nal tract [1,2], but are also found in other parts of the body [3–8]. Low-grade MALT lymphomas tend to remain local- ized to their sites of origin for long periods and respond fa- vorably to surgical excision or radiotherapy. However, these tumors may undergo histologic transformation to high-grade lymphomas and disseminate systemically [1]. Nodal B-cell lymphomas are often associated with dis- tinct genetic lesions such as BCL1, BCL2, or c-MYC, but no cancer-related gene is consistently involved in low-grade MALT lymphomas [9,10]. One possible candidate gene is the BCL6 gene. BCL6 is located on chromosome 3 (3q27) and encodes for a member of the zinc-finger family of pro- teins, which may be involved in the control of B-cell differ- entiation and lymphoid organ development [11]. Rearrange- ment of the BCL6 gene is found in 27% to 45% of the cases of diffuse, large B-cell lymphomas and 6.4% to 14.3% of follicular lymphomas [12–14]. Mutations in the 5' noncod- ing region of BCL6 gene is found in 73% of the cases of dif- fuse, large B-cell lymphomas and 47% of follicular lym- phoma cases [15]. Similar changes are also found in MALT lymphomas, but much less frequently [10,16,17]. Another potential cancer-related gene of MALT lymphomas is BCL10. BCL10 gene is located on chromosome 1p22 and is a novel apoptotic signaling gene. Frequent mutation of BLC10 is found in 45% of B and T cell lineage lymphomas, and in aggressive MALT lymphomas with t(1;14) [18,19]. Lymphomas of ocular adnexa represent approximately 8% of all extranodal lymphomas [6]. Of these, 50 to 70% are MALT lymphomas [5–7]. However, the possible role of BCL6 and BCL10 in the pathogenesis and progression of MALT lymphoma of ocular adnexa has never been re- ported. In this study, we investigated the changes of BCL6 and BCL10 genes in MALT lymphoma of ocular adnexa in Taiwanese patients. 2. Materials and methods 2.1. Patients From 1985 to 1997, we enrolled 11 patients with histo- logically confirmed MALT lymphoma of ocular adnexa in * Corresponding author. Tel.: +886-2-28757529; fax: +886-2-28732184. E-mail address: ccyen@vghtpe.gov.tw (C.-C. Yen).