Hoogland A Marije, Böttcher René, Verhoef Esther, Jenster Guido, van Leenders Geert J L H
Departments of Pathology, Erasmus Medical Center, Rotterdam, The Netherlands.
Departments of Urology, Erasmus Medical Center, Rotterdam, The Netherlands.
Oncotarget. 2016 Jun 21;7(25):37846-37856. doi: 10.18632/oncotarget.9344.
The Gleason score (GS) of prostate cancer on diagnostic biopsies is an important parameter for therapeutic decision-making. Biopsy GS under-estimates the actual GS at radical prostatectomy in a significant number of patients due to samplingartifact. The aim of this study was to identify markers that are differentially expressed in Gleason grade 3 (GG3) tumor glands embedded in GS 4 + 3 = 7 and GS 3 + 3 = 6 prostate cancer using laser capture microdissection and RNA sequencing.GG3 tumor glands embedded in nine GS 3 + 3 = 6 and nine GS 4 + 3 = 7 prostate cancers were isolated by laser capture microdissection of frozen radical prostatectomy specimens. After RNA amplification and RNA sequencing, differentially expressed genes in both GG3 components were identified by a 2log fold change > 1.0 and p-value < 0.05. We applied immunohistochemistry on a tissue micro-array representing 481 radical prostatectomy samples for further validation on protein level.A total of 501 genes were up-regulated and 421 down-regulated in GG3 glands embedded in GS 4 + 3 = 7 as compared to GS 3 + 3 = 6 prostate cancer. We selected HELLS, ZIC2 and ZIC5 genes for further validation. ZIC5 mRNA was up-regulated 17 fold (p = 8.4E-07), ZIC2 8 fold (p = 1.3E-05) and HELLS 2 fold (p = 0.006) in GG3 glands derived from GS 4 + 3 = 7. HELLS expression of ≥ 1% occurred in 10% GS < 7, 17% GS 7 and 43% GS >7 prostate cancer (p < 0.001). Using a cut-off of ≥ 1%, protein expression of ZIC5 was present in 28% GS < 7, 43% GS 7 and 57% GS > 7 cancer (p < 0.001). ZIC2 was neither associated with GS nor outcome in our validation set. HELLS was independently predictive for biochemical-recurrence after radical prostatectomy (HR 2.3; CI 1.5-3.6; p < 0.01).In conclusion, HELLS and ZIC5 might be promising candidate markers for selection of biopsy GS 6 prostate cancer being at risk for up-grading at prostatectomy.
前列腺癌诊断性活检的Gleason评分（GS）是治疗决策的重要参数。由于取样误差，在大量患者中，活检GS会低估根治性前列腺切除术中的实际GS。本研究的目的是使用激光捕获显微切割和RNA测序，鉴定在GS 4 + 3 = 7和GS 3 + 3 = 6前列腺癌中嵌入的Gleason 3级（GG3）肿瘤腺体中差异表达的标志物。通过对冷冻根治性前列腺切除标本进行激光捕获显微切割，分离出嵌入9例GS 3 + 3 = 6和9例GS 4 + 3 = 7前列腺癌中的GG3肿瘤腺体。经过RNA扩增和RNA测序，通过2倍变化> 1.0和p值< 0.05鉴定出两个GG3组分中差异表达的基因。我们在代表481例根治性前列腺切除样本的组织微阵列上进行免疫组织化学，以在蛋白质水平上进行进一步验证。与GS 3 + 3 = 6前列腺癌相比，在GS 4 + 3 = 7中嵌入的GG3腺体中共有501个基因上调，421个基因下调。我们选择HELLS、ZIC2和ZIC5基因进行进一步验证。在源自GS 4 + 3 = 7的GG3腺体中，ZIC5 mRNA上调17倍（p = 8.4E-07），ZIC2上调8倍（p = 1.3E-05），HELLS上调2倍（p = 0.006）。HELLS表达≥1%出现在10%的GS < 7、17%的GS 7和43%的GS >7前列腺癌中（p < 0.001）。使用≥1%的临界值，ZIC5的蛋白表达出现在28%的GS < 7、43%的GS 7和57%的GS > 7癌症中（p < 0.001）。在我们的验证集中，ZIC2与GS或结局均无关联。HELLS是根治性前列腺切除术后生化复发的独立预测因子（HR 2.3；CI 1.5 - 3.6；p < 0.01）。总之，HELLS和ZIC5可能是用于选择活检GS为6且在前列腺切除术中存在升级风险的前列腺癌的有前景的候选标志物。
