Department of Urology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois.
School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin.
Prostate. 2019 Oct;79(14):1692-1704. doi: 10.1002/pros.23894. Epub 2019 Aug 21.
WNT signaling is implicated in embryonic development, and in adult tissue homeostasis, while its deregulation is evident in disease. This study investigates the unique roles of canonical WNT10B in both normal prostate development and prostate cancer (PCa) progression.
Organ culture and rat ventral prostates (VPs) were used to study Wnt10b ontogeny and growth effect of WNT10B protein. PB-SV40 LTag rat VPs were utilized for Wnt expression polymerase chain reaction (PCR) array and immunohistochemistry. Human localized PCa tissue microarrays (TMAs) were investigated for differential WNT10B expression. Human RNA-seq data sets were queried for differential expression of WNT10B in metastatic and localized PCa. Knockdown of WNT10B in PC3 cells was utilized to study its effects on proliferation, stemness, epithelial to mesenchymal transition (EMT), and xenograft propagation.
Wnt10b expression was highest at birth and rapidly declined in the postnatal rat VP. Exogenous WNT10B addition to culture developing VPs decreased growth suggesting an antiproliferative role. VPs from PB-SV40 LTag rats with localized PCa showed a 25-fold reduction in Wnt10b messenger RNA (mRNA) expession, confirmed at the protein level. Human PCa TMAs revealed elevated WNT10B protein in prostate intraepithelial neoplasia compared with normal prostates but reduced levels in localized PCa specimens. In contrast, RNA-seq data set of annotated human PCa metastasis found a significant increase in WNT10B mRNA expression compared with localized tumors suggesting stage-specific functions of WNT10B. Similarly, WNT10B mRNA levels were increased in metastatic cell lines PC3, PC3M, as well as in HuSLC, a PCa stem-like cell line, as compared with disease-free primary prostate epithelial cells. WNT10B knockdown in PC3 cells reduced expression of EMT genes, MMP9 and stemness genes NANOG and SOX2 and markedly reduced the stem cell-like side population. Furthermore, loss of WNT10B abrogated the ability of PC3 cells to propagate tumors via serial transplantation.
Taken together, these results suggest a dual role for WNT10B in normal development and in PCa progression with opposing functions depending on disease stage. We propose that decreased WNT10B levels in localized cancer allow for a hyperproliferative state, whereas increased levels in advanced disease confer a stemness and malignant propensity which is mitigated by knocking down WNT10B levels. This raises the potential for WNT10B as a novel target for therapeutic intervention in metastatic PCa.
WNT 信号通路参与胚胎发育和成人组织稳态，而其失调在疾病中显而易见。本研究旨在探究经典型 WNT10B 在正常前列腺发育和前列腺癌（PCa）进展中的独特作用。
采用器官培养和大鼠腹侧前列腺（VP）组织研究 Wnt10b 的个体发生，以及 WNT10B 蛋白的生长效应。利用 PB-SV40 LTag 大鼠 VP 进行 Wnt 表达聚合酶链反应（PCR）数组和免疫组织化学分析。对人局限性 PCa 组织微阵列（TMA）进行 WNT10B 差异表达分析。利用人 RNA-seq 数据集查询转移性和局限性 PCa 中 WNT10B 的差异表达。利用 PC3 细胞敲低 WNT10B 研究其对增殖、干性、上皮间质转化（EMT）和异种移植物增殖的影响。
Wnt10b 表达在出生时最高，随后在新生大鼠 VP 中迅速下降。向发育中的 VP 添加外源性 WNT10B 会降低生长速度，提示其具有抗增殖作用。来自 PB-SV40 LTag 大鼠局限性 PCa 的 VP 组织中 Wnt10b 信使 RNA（mRNA）表达降低了 25 倍，这一结果在蛋白水平上得到了证实。人 PCa TMA 显示前列腺上皮内瘤变中 WNT10B 蛋白水平升高，与正常前列腺相比，但局限性 PCa 标本中水平降低。相比之下，注释人 PCa 转移的 RNA-seq 数据集发现，与局限性肿瘤相比，WNT10B mRNA 表达显著增加，这表明 WNT10B 具有阶段特异性功能。同样，与无疾病原发性前列腺上皮细胞相比，转移性细胞系 PC3、PC3M 以及 PCa 干性样细胞系 HuSLC 中 WNT10B mRNA 水平升高。与对照组相比，PC3 细胞中 WNT10B 敲低降低了 EMT 基因 MMP9 和干性基因 NANOG 和 SOX2 的表达，并显著降低了干细胞样侧群。此外，WNT10B 缺失削弱了 PC3 细胞通过连续移植传播肿瘤的能力。
综上所述，这些结果表明 WNT10B 在正常发育和 PCa 进展中具有双重作用，其功能取决于疾病阶段。我们提出，局限性癌症中 WNT10B 水平降低可导致过度增殖状态，而晚期疾病中 WNT10B 水平升高可赋予干性和恶性倾向，WNT10B 水平降低可减轻这种倾向。这提示 WNT10B 作为转移性 PCa 治疗干预的新靶点具有潜力。
