Abstract：
Arachidonate 5-lipoxygenase (ALOX5) is a cardinal enzyme in the synthesis of leukotrienes, which are powerful immune-regulating lipid mediators. We previously reported that ALOX5 is preferentially expressed in B lymphocytes in the mantle zone of human lymphoid tissue. In the context of physiological relevance, the loss of the Alox5 gene in mice significantly impairs the development of follicular B helper T cells and antibody production. However, ALOX5 expression in B-cell lymphomas has not been investigated in detail. In this study, we examined ALOX5 expression in representative B-cell lymphomas and non-neoplastic lymphoid tissues by immunohistochemistry with a commercially available anti-ALOX5 antibody that can be used on formalin-fixed paraffin-embedded specimens. Interestingly, 22/22 cases of mantle cell lymphoma, 7/7 cases of chronic lymphocytic leukemia/small cell lymphoma, and 20/20 cases of follicular lymphoma expressed ALOX5. A small proportion of extranodal marginal zone lymphoma/mucosa-associated lymphoid tissue lymphoma or nodal marginal zone lymphoma cases were positive for ALOX5 (2/13 or 1/3, respectively). In contrast, no cases with diffuse large B-cell lymphoma, regardless of germinal center B cell (GCB) or non-GCB type, expressed ALOX5 (0/25 cases). These findings suggest that ALOX5 may be a novel marker for identifying the cell of origin of B-cell lymphoma. Further investigation is required to clarify the biological significance of ALOX5 expression in lymphoma cells.
摘要：
花生四烯酸酯5-脂氧合酶（ALOX5）是白三烯合成中的主要酶，它们是强大的免疫调节脂质介质。我们先前报道了ALOX5在人淋巴组织的地幔区的B淋巴细胞中优先表达。在生理相关性的背景下，小鼠中Alox5基因的丢失显着损害了滤泡B辅助性T细胞的发育和抗体的产生。然而,尚未详细研究B细胞淋巴瘤中ALOX5的表达。在这项研究中,我们使用市售的抗ALOX5抗体通过免疫组织化学检测了代表性B细胞淋巴瘤和非肿瘤性淋巴组织中的ALOX5表达,该抗体可用于福尔马林固定的石蜡包埋标本.有趣的是,22/22例套细胞淋巴瘤，7/7例慢性淋巴细胞白血病/小细胞淋巴瘤，20/20例滤泡性淋巴瘤表达ALOX5。结外边缘区淋巴瘤/粘膜相关淋巴组织淋巴瘤或淋巴结边缘区淋巴瘤病例中有一小部分ALOX5阳性（分别为2/13或1/3）。相比之下,无弥漫性大B细胞淋巴瘤,无论生发中心B细胞（GCB）或非GCB类型，表达ALOX5(0/25例)。这些发现表明ALOX5可能是鉴定B细胞淋巴瘤起源细胞的新标记。需要进一步研究以阐明ALOX5在淋巴瘤细胞中表达的生物学意义。
