Notaro Sara, Reimer Daniel, Duggan-Peer Michaela, Fiegl Heidi, Wiedermair Annamarie, Rössler Julia, Altevogt Peter, Marth Christian, Zeimet Alain Gustave
Department of Gynecology and Obstetrics, Medical University of Innsbruck, Innsbruck, Austria.
Department of Gynecology and Obstetrics, University of Brescia, Brescia, Italy.
Oncotarget. 2016 Jun 28;7(26):40221-40232. doi: 10.18632/oncotarget.9574.
Management of endometrial carcinoma (EC) still needs improvement of risk assessment. Recently, L1CAM immunohistochemical (IHC) evaluation showed a unique value to predict the outcome of early EC. However IHC results are often conflicting for lack of inter-laboratory standardisation.
Here, as a proof of concept and to increase reproducibility we assayed eighty-two EC and 26 normal endometrium samples for L1CAM expression (L1CAMEXP) via qRT-PCR. The IHC evaluation was performed in 50 cancer samples. Moreover, we aimed to substantiate the in-vitro findings of L1CAM regulation through its promoter methylation (L1CAMMET), miR-34a expression and miR-34a promoter methylation. DNA methylation was assessed with MethyLight PCR technique.
High overall concordant results between IHC and RT-PCR evaluations were found. L1CAMEXP was detected in 11% of cancer specimens. These positive cancers exhibited a worse DFS (p=0.032) and OS (p=0.016) in a multivariate COX-regression model. L1CAMEXP predicted distant failure (p=0.007) and L1CAMMET predicted risk-reduction of lymph-node involvement (p=0.005). Inverse correlations between L1CAMEXP and L1CAMMET (p=0.004) and between L1CAMEXP and miR-34a expression (p=0.002) were found.
In conclusion qRT-PCR analysis is a reliable approach to evaluate L1CAM status in EC and L1CAMEXP was highly predictive for distant failure and poor outcome, confirming the large IHC-based studies. Interestingly, L1CAMMET was able to assess the risk of pelvic lymph-node involvement. Especially the latter finding has to be confirmed in larger prospective series.
子宫内膜癌(EC)的管理仍需改进风险评估。最近,L1细胞粘附分子(L1CAM)免疫组化(IHC)评估显示出预测早期EC预后的独特价值。然而,由于缺乏实验室间标准化,免疫组化结果常常相互矛盾。
在此,作为概念验证并提高可重复性,我们通过定量逆转录聚合酶链反应(qRT-PCR)检测了82例EC样本和26例正常子宫内膜样本中的L1CAM表达(L1CAMEXP)。对50例癌症样本进行了免疫组化评估。此外,我们旨在通过其启动子甲基化(L1CAMMET)、miR-34a表达和miR-34a启动子甲基化来证实L1CAM调控的体外研究结果。用甲基化荧光定量聚合酶链反应(MethyLight PCR)技术评估DNA甲基化。
免疫组化和逆转录聚合酶链反应评估之间发现了高度一致的总体结果。在11%的癌症标本中检测到L1CAMEXP。在多变量COX回归模型中,这些阳性癌症表现出更差的无病生存期(DFS,p = 0.032)和总生存期(OS,p = 0.016)。L1CAMEXP预测远处转移(p = 0.007),L1CAMMET预测淋巴结受累风险降低(p = 0.005)。发现L1CAMEXP与L1CAMMET之间呈负相关(p = 0.004),L1CAMEXP与miR-34a表达之间呈负相关(p = 0.002)。
总之,定量逆转录聚合酶链反应分析是评估EC中L1CAM状态的可靠方法,L1CAMEXP对远处转移和不良预后具有高度预测性,证实了基于免疫组化的大型研究。有趣的是,L1CAMMET能够评估盆腔淋巴结受累的风险。特别是后一发现必须在更大规模的前瞻性研究中得到证实。