Department of Integrative Biosciences, Oregon National Primate Center, Oregon Health and Science University, Portland, USA.
Islets. 2010 Mar-Apr;2(2):82-8. doi: 10.4161/isl.2.2.10807.
Involvement of caspase (C)-3 has been implicated in β-cells from diabetic subjects. This study is aimed to immunocytochemically identify cleaved caspase-3 (CC-3) positive cells in pancreatic endocrine tumors (PETs) compared with control islets.
Control islets revealed some CC-3 positive cells, ranging from 3.6 to 7.3% of total islet cells. Small islets in the pseudocapsule of PETs showed higher immunopositive cells at about 9% for CC -3, suggesting an accelerated apoptosis in these compressed, elongated islets before proceeding to imminent cell death. Majority of primary PETs except 9 cases were negative for CC -3 immunostaining: five insulinomas, one somatostatinoma, one gastrinoma and one pancreatic peptidoma (PPoma) were positive for CC -3.
Using commercially available rabbit anti-CC-3, immunocytochemical staining was performed in 42 cases of PETs compared with control islets.
CONCLUSIONS/INTERPRETATION: Majority of primary PETs (28/37, 76%) were negative for CC-3, suggesting that majority of PETs are not on apoptotic program of the normal islets. Since 21 of 24 (88%) of potentially malignant primary non-β-cell PETs were negative, whereas 5 of 12 (42%) benign insulinomas were positive for CC-3 immunostaining, CC-3 negative immunostaining may serve as a possible malignant marker for all PETs.
已有研究表明半胱氨酸天冬氨酸蛋白酶（Caspase）-3 的激活参与了糖尿病患者胰岛β细胞的凋亡。本研究旨在通过免疫细胞化学方法比较胰岛内分泌肿瘤（Pancreatic Endocrine Tumors，PETs）与正常胰岛中 cleaved caspase-3（CC-3）阳性细胞的分布。
正常胰岛中存在少量的 CC-3 阳性细胞，占胰岛细胞总数的 3.6%至 7.3%。PETs 假包膜中小胰岛中 CC-3 阳性细胞比例较高，约为 9%，提示这些受压、拉长的胰岛在发生即将发生的细胞死亡之前经历了加速凋亡。除 9 例外，大多数原发性 PETs 均未出现 CC-3 免疫染色阳性：5 例胰岛素瘤、1 例生长抑素瘤、1 例胃泌素瘤和 1 例胰多肽瘤（PPoma）CC-3 阳性。
使用商业上可获得的兔抗 CC-3 抗体，对 42 例 PETs 与正常胰岛进行免疫细胞化学染色。
结论/解释：大多数原发性 PETs（28/37，76%）CC-3 染色阴性，提示大多数 PETs 未进入正常胰岛的凋亡程序。由于 24 例潜在恶性非β细胞原发性 PETs 中 21 例（88%）CC-3 染色阴性，而 12 例良性胰岛素瘤中 5 例（42%）CC-3 染色阳性，因此 CC-3 染色阴性可能是所有 PETs 的潜在恶性标志物。
