[结外B细胞淋巴瘤中API2-MALT1融合基因的检测及其意义]

[Detection of API2-MALT1 fusion gene in extranodal B-cell lymphoma and its significance].

作者信息

Yang Wen-xiu, Li Gan-di, Zhou Qiao, Liu Wei-ping, Li Lei, Chen Ni

机构信息

Department of Pathology, West China Hospital, Sichuan University, Chengdu 610041, China.

出版信息

Zhonghua Bing Li Xue Za Zhi. 2006 Feb;35(2):92-6.

PMID:16630483

Abstract

OBJECTIVE

To study the expression of API2-MALT1 mRNA in mucosa-associated lymphoid tissue (MALT) lymphoma, extranodal diffuse large B-cell lymphoma (DLBCL) and Hashimoto's thyroiditis, to investigate the expression pattern of API2-MALT1 variants, and to correlate the findings with the clinicopathologic features and prognosis.

METHODS

Sixty-two cases of MALT lymphoma (10 from lung, 31 from stomach, 9 from intestine and 12 from thyroid), 32 cases of extranodal DLBCL (16 from stomach, 13 from intestine and 3 from thyroid), 8 cases of Hashimoto's thyroiditis and 5 cases of reactive lymph nodes hyperplasia as negative controls were collected. The expression of API2-MALT1 mRNA was studied in all cases by reverse transcriptase (RT)-polymerase chain reaction (PCR) and nested PCR. The 94 cases of lymphoma were subdivided into API2-MALT1-positive and API2-MALT1-negative groups. Among the patients, 78 were followed up for 6 to 120 months. The differences in clinicopathologic features and prognosis between the two groups were analyzed.

RESULTS

API2-MALT1 transcripts were detected in 39 of the 94 lymphoma cases (with 28 cases being MALT lymphoma and 11 cases being extranodal DLBCL). mRNA expression was not detected in all cases of Hashimoto's thyroiditis and the negative controls. Two fusion gene variants, A1446-M1123 and A1446-M814 were found, and A1446-M1123 expression was more common. As for MALT lymphoma cases, the frequency of the fusion gene expression was lower in thyroid, when compared with that in lung, stomach and intestine. API2-MALT1-positive cases had tumors in an earlier stage with milder infiltration of cancer cells, lower relapse rate, and higher five-year survival rate.

CONCLUSIONS

The expression of API2-MALT1 mRNA can be detected in both MALT lymphoma and extranodal DLBCL, but not in Hashimoto's thyroiditis. These cases tend to show a more indolent clinical course and better survival. The frequency of t (11; 18) (q21; q21) correlates with the primary sites of MALT lymphoma. The higher incidence of breakpoint at 1123 bp of MALT1 gene in Chinese people may be due to geographical variation.

摘要

目的

研究API2 - MALT1 mRNA在黏膜相关淋巴组织（MALT）淋巴瘤、结外弥漫性大B细胞淋巴瘤（DLBCL）及桥本甲状腺炎中的表达，探讨API2 - MALT1变异体的表达模式，并将研究结果与临床病理特征及预后相关联。

方法

收集62例MALT淋巴瘤（10例来自肺，31例来自胃，9例来自肠，12例来自甲状腺）、32例结外DLBCL（16例来自胃，13例来自肠，3例来自甲状腺）、8例桥本甲状腺炎及5例反应性淋巴结增生作为阴性对照。采用逆转录（RT）-聚合酶链反应（PCR）及巢式PCR研究所有病例中API2 - MALT1 mRNA的表达。94例淋巴瘤病例被分为API2 - MALT1阳性组和API2 - MALT1阴性组。其中78例患者进行了6至120个月的随访。分析两组间临床病理特征及预后的差异。

结果

94例淋巴瘤病例中有39例检测到API2 - MALT1转录本（28例为MALT淋巴瘤，11例为结外DLBCL）。所有桥本甲状腺炎病例及阴性对照均未检测到mRNA表达。发现两种融合基因变异体，A1446 - M1123和A1446 - M814，且A1446 - M1123表达更为常见。对于MALT淋巴瘤病例，与肺、胃和肠相比，甲状腺中融合基因表达频率较低。API2 - MALT1阳性病例肿瘤分期较早，癌细胞浸润较轻，复发率较低，五年生存率较高。

结论

在MALT淋巴瘤和结外DLBCL中均可检测到API2 - MALT1 mRNA的表达，但在桥本甲状腺炎中未检测到。这些病例往往临床病程较为惰性，生存率较高。t（11；18）（q21；q21）的频率与MALT淋巴瘤的原发部位相关。中国人中MALT1基因1123 bp处断点发生率较高可能与地域差异有关。