Kamimura Katsuhito, Hojo Hiroshi, Abe Masafumi
First Department of Pathology, Fukushima Medical University School of Medicine, Hikariga-oka, Fukushima, Japan.
Pathol Int. 2004 Apr;54(4):224-30. doi: 10.1111/j.1440-1827.2004.01612.x.
Protein kinase C (PKC) enzymes play a major role in signal transduction and contribute to the regulation of cellular differentiation and proliferation. However, little is known about subtype-specific intracellular expression of PKC in human malignant lymphoma. To characterize the relationship between expression of PKC and B-cell lymphomas based on the different subspecies, we investigated the expression of four subspecies (alpha, beta II, gamma and delta) in five cases of reactive lymphoid tissues, 77 cases of human B-cell lymphoma and 17 human lymphoma cell lines. In the reactive lymphoid tissues, PKC beta II-positive cells were found in the mantle zones and marginal zones, and centroblasts and centrocytes in the germinal centers showed cytoplasmic staining with strong intensity against PKC delta. The present study is the first report to examine the expression of PKC delta in reactive lymphoid tissues. In interfollicular areas, a small number of T-cells were positive for PKC alpha. Protein kinase C gamma-positive cells were not found in these lymphoid tissues. Eight cases of Burkitt lymphoma (BL) (8/10; 80%) showed the overexpression of PKC alpha (P < 0.01), but other B-cell lymphoma cases except three cases of diffuse large B-cell lymphoma did not express PKC alpha. In addition, six and eight out of nine BL cell lines expressed the protein and mRNA of PKC alpha, respectively. These results indicate that PKC alpha was predominantly expressed on BL in comparison with other types of lymphoma. The expression of PKC gamma was observed in only five cases of BL. The overall survival of PKC gamma-positive BL was significantly better than that of PKC gamma-negative BL (P < 0.05). The expression of PKC gamma seems to be associated with a better prognosis in the limited number of BL cases in the present study.
蛋白激酶C（PKC）酶在信号转导中起主要作用，并参与细胞分化和增殖的调节。然而，关于PKC在人类恶性淋巴瘤中的亚型特异性细胞内表达情况，人们了解甚少。为了基于不同亚类来表征PKC表达与B细胞淋巴瘤之间的关系，我们研究了5例反应性淋巴组织、77例人类B细胞淋巴瘤和17个人类淋巴瘤细胞系中4种亚类（α、βII、γ和δ）的表达情况。在反应性淋巴组织中，PKCβII阳性细胞见于外套区和边缘区，生发中心的中心母细胞和中心细胞显示出针对PKCδ的强强度细胞质染色。本研究是首篇检测反应性淋巴组织中PKCδ表达的报告。在滤泡间区，少数T细胞PKCα呈阳性。在这些淋巴组织中未发现蛋白激酶Cγ阳性细胞。8例伯基特淋巴瘤（BL）（8/10；80%）显示PKCα过表达（P<0.01），但除3例弥漫性大B细胞淋巴瘤外的其他B细胞淋巴瘤病例未表达PKCα。此外，9个BL细胞系中有6个和8个分别表达PKCα的蛋白和mRNA。这些结果表明，与其他类型淋巴瘤相比，PKCα主要在BL上表达。仅在5例BL中观察到PKCγ的表达。PKCγ阳性BL的总生存期显著优于PKCγ阴性BL（P<0.05）。在本研究中，PKCγ的表达似乎与有限数量BL病例的较好预后相关。
