Bhattacharyya Sumit, Feferman Leo, Tobacman Joanne K
Department of Medicine, The University of Illinois at Chicago and Jesse Brown VAMC, Chicago, Illinois.
Prostate. 2019 May;79(7):689-700. doi: 10.1002/pros.23776. Epub 2019 Feb 22.
In tissue microarrays, immunostaining of the enzyme arylsulfatase B (ARSB; N-acetylgalactosamine-4-sulfatase) was less in recurrent prostate cancers and in cancers with higher Gleason scores. In cultured prostate stem cells, decline in ARSB increased Wnt signaling through effects on Dickkopf Wnt Signaling Pathway Inhibitor (DKK)3. The effects of androgen exposure on ARSB and the impact of decline in ARSB on Wnt signaling in prostate tissue were unknown.
Epithelial and stromal tissues from malignant and normal human prostate were obtained by laser capture microdissection. mRNA expression of ARSB, galactose-6-sulfate-sulfatase (GALNS) and Wnt-signaling targets was determined by QPCR. Non-malignant human epithelial and stromal prostate cells were grown in tissue culture, including two-cell layer cultures. ARSB was silenced by specific siRNA, and epithelial cells were treated with stromal spent media following treatment with IWP-2, an inhibitor of Wnt secretion, and by exogenous recombinant human Wnt3A. Promoter methylation was detected using specific DKK3 and ARSB promoter primers. The effects of DHT and of ARSB overexpression on DKK expression were determined. Cell proliferation was assessed by BrdU incorporation.
Normal stroma showed higher expression of vimentin, ARSB, and Wnt3A than epithelium. Normal epithelium had higher expression of E-cadherin, galactose 6-sulfate-sulfatase (GALNS), and DKK3 than stroma. In malignant epithelium, expression of ARSB and DKK3 declined, and expression of GALNS and Wnt signaling targets increased. In cultured prostate epithelial cells, Wnt-mediated signaling was greatest when ARSB was silenced and cells were exposed to exogenous Wnt3A. Exposure to 5α-dihydrotestosterone (DHT) increased ARSB and DKK3 promoter rmethylation, and effects of DHT on DKK3 expression were reversed when ARSB was overexpressed.
Androgen-induced declines in ARSB and DKK3 may contribute to prostate carcinogenesis by sustained activation of Wnt signaling in prostate epithelium in response to stromal Wnt3A.
在组织芯片中，复发性前列腺癌以及Gleason评分较高的癌症中，芳基硫酸酯酶B（ARSB；N - 乙酰半乳糖胺 - 4 - 硫酸酯酶）的免疫染色较少。在培养的前列腺干细胞中，ARSB的减少通过对Dickkopf Wnt信号通路抑制剂（DKK）3的影响增加了Wnt信号传导。雄激素暴露对ARSB的影响以及ARSB减少对前列腺组织中Wnt信号传导的影响尚不清楚。
通过激光捕获显微切割获得来自恶性和正常人类前列腺的上皮和基质组织。通过QPCR测定ARSB、半乳糖 - 6 - 硫酸酯酶（GALNS）和Wnt信号靶点的mRNA表达。非恶性人类上皮和基质前列腺细胞在组织培养中生长，包括双层培养。通过特异性siRNA使ARSB沉默，在用Wnt分泌抑制剂IWP - 2处理后，以及用外源性重组人Wnt3A处理后，用基质消耗培养基处理上皮细胞。使用特异性DKK3和ARSB启动子引物检测启动子甲基化。确定双氢睾酮（DHT）和ARSB过表达对DKK表达的影响。通过BrdU掺入评估细胞增殖。
正常基质中波形蛋白、ARSB和Wnt3A的表达高于上皮。正常上皮中E - 钙黏蛋白、半乳糖6 - 硫酸酯酶（GALNS）和DKK3的表达高于基质。在恶性上皮中，ARSB和DKK3的表达下降，GALNS和Wnt信号靶点的表达增加。在培养的前列腺上皮细胞中，当ARSB沉默且细胞暴露于外源性Wnt3A时，Wnt介导的信号传导最强。暴露于5α - 二氢睾酮（DHT）增加了ARSB和DKK3启动子的甲基化，当ARSB过表达时，DHT对DKK3表达的影响被逆转。
雄激素诱导的ARSB和DKK3下降可能通过响应基质Wnt3A而持续激活前列腺上皮中的Wnt信号传导，从而促进前列腺癌发生。
