Zhuge Yan, Lagman Jo Ann J, Ansenberger Kristine, Mahon Cassandra J, Daikoku Takiko, Dey Sudhansu K, Bahr Janice M, Hales Dale B
Department of Physiology and Biophysics, University of Illinois at Chicago, IL, USA.
Gynecol Oncol. 2009 Jan;112(1):171-8. doi: 10.1016/j.ygyno.2008.09.026. Epub 2008 Oct 29.
Ovarian carcinoma is the most lethal gynecological malignancy. The genetic and molecular mechanisms that cause it still remain largely unknown. CYP1B1 is a cytochrome P450 enzyme that catalyzes the conversion of estrogens to genotoxic catechol estrogens which may cause DNA mutations and initiate ovarian epithelial cancer. Our objectives were to evaluate CYP1B1 expression, distribution and localization in the hen ovary and to determine if there is an increased CYP1B1 expression associated with, and possibly involved in the initiation of ovarian cancer.
Two groups of hens were used: 1. young (50 weeks of age; devoid of cancer) and 2. old (165 weeks of age; divided into two groups: age-matched normal and ovarian cancer). CYP1B1 mRNA and protein expression were analyzed in cancerous ovaries, ovaries of age-matched normal and/or young hens by quantitative real-time PCR (qRT-PCR), in situ hybridization (ISH) and immunohistochemistry (IHC). RNA was extracted from tissue preserved in RNAlater for qRT-PCR. Tissue frozen in liquid nitrogen was used for ISH. Tissue fixed in neutral buffered formalin was subjected to IHC.
Higher expression of CYP1B1 mRNA was observed in cancerous ovaries as compared to ovaries of young and age-matched normal hens by qRT-PCR. ISH and IHC confirmed that the expression of CYP1B1 was much higher in ovarian tumors compared to ovaries of age-matched normal hens. CYP1B1 mRNA and protein were distributed extensively throughout the carcinoma, while primarily localized to the granulosa layer surrounding the follicle in age-matched normal hens. IHC also showed nuclear localization of CYP1B1. Highly expressed CYP1B1 was found in POF-3 from young and age-matched normal hens as compared to POF-1 and POF-2 by qRT-PCR. No significant difference was found in the expression of CYP1B1 between the distal (site of rupture) and the proximal (site of attachment to the ovary) of POF-1 from young and age-matched normal hens.
High expression of CYP1B1 in the hen ovary is associated with ovarian cancer and our data suggest that CYP1B1 may play an important role in the initiation of ovarian cancer and may prove to be a target for intervention. Moreover, the results of this study further confirm that the laying hen is a good model to study human ovarian cancer.
卵巢癌是最致命的妇科恶性肿瘤。其致病的遗传和分子机制仍 largely 未知。CYP1B1 是一种细胞色素 P450 酶，它催化雌激素转化为具有基因毒性的儿茶酚雌激素，这可能导致 DNA 突变并引发卵巢上皮癌。我们的目的是评估 CYP1B1 在母鸡卵巢中的表达、分布和定位，并确定 CYP1B1 表达的增加是否与卵巢癌的发生相关且可能参与其中。
使用两组母鸡：1. 年轻母鸡（50 周龄；无癌症）和 2. 年老母鸡（165 周龄；分为两组：年龄匹配的正常组和卵巢癌组）。通过定量实时 PCR（qRT-PCR）、原位杂交（ISH）和免疫组织化学（IHC）分析 CYP1B1 mRNA 和蛋白在癌性卵巢、年龄匹配的正常母鸡和/或年轻母鸡卵巢中的表达。从保存在 RNAlater 中的组织中提取 RNA 用于 qRT-PCR。液氮冷冻的组织用于 ISH。用中性缓冲福尔马林固定的组织进行 IHC。
通过 qRT-PCR 观察到，与年轻母鸡和年龄匹配的正常母鸡的卵巢相比，癌性卵巢中 CYP1B1 mRNA 的表达更高。ISH 和 IHC 证实，与年龄匹配的正常母鸡的卵巢相比，CYP1B1 在卵巢肿瘤中的表达要高得多。CYP1B1 mRNA 和蛋白广泛分布于整个癌组织中，而在年龄匹配的正常母鸡中主要定位于卵泡周围的颗粒层。IHC 还显示 CYP1B1 的核定位。通过 qRT-PCR 发现，与 POF-1 和 POF-2 相比，年轻母鸡和年龄匹配的正常母鸡的 POF-3 中 CYP1B1 高表达。年轻母鸡和年龄匹配的正常母鸡的 POF-1 的远端（破裂部位）和近端（与卵巢附着部位）之间 CYP1B1 的表达没有显著差异。
母鸡卵巢中 CYP1B1 的高表达与卵巢癌相关，我们的数据表明 CYP1B1 可能在卵巢癌的发生中起重要作用，并且可能被证明是干预的靶点。此外，本研究结果进一步证实产蛋母鸡是研究人类卵巢癌的良好模型。
