Herman Damir, Leakey Tatiana I, Behrens Alice, Yao-Borengasser Aiwei, Cooney Craig A, Jousheghany Fariba, Phanavanh Bounleut, Siegel Eric R, Safar A Mazin, Korourian Soheila, Kieber-Emmons Thomas, Monzavi-Karbassi Behjatolah
Division of Hematology/Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
Int J Oncol. 2015 Mar;46(3):1243-51. doi: 10.3892/ijo.2015.2828. Epub 2015 Jan 9.
Our previously published data link P-selectin-reactive chondroitin sulfate structures on the surface of breast cancer cells to metastatic behavior of cells. We have shown that a particular sulfation pattern mediated by the expression of carbohydrate (chondroitin 4) sulfotransferase-11 (CHST11) correlates with P-selectin binding and aggressiveness of human breast cancer cell lines. The present study was performed to evaluate the prognostic value of CHST11 expression and determine whether aberrant DNA methylation controls CHST11 expression in breast cancer. Publicly available datasets were used to examine the association of CHST11 expression to aggressiveness and progression of breast cancer. Methylation status was analyzed using bisulfite genomic sequencing. 5-aza-2'-deoxycytidine (5AzadC) was used for DNA demethylation. Reduced representation bisulfite sequencing was performed in the CpG island of CHST11 with a minimum coverage of 10. Quantitative real-time RT-PCR was employed to confirm the expression profile of CHST11 in breast cancer cell lines. Flow cytometry was also used to confirm the expression of the CHST11 product, chondroitin sulfate A (CS-A). The expression of CHST11 was significantly higher in basal-like and Her2-amplified cell lines compared to luminal cell lines. CHST11 was also highly expressed in cancer tissues compared to normal tissues and the expression levels were significantly associated with tumor progression. We observed very low levels of DNA methylation in a CpG island of CHST11 in basal-like cells but very high levels in the same region in luminal cells. Treatment of MCF7 cells, a luminal cell line with very low expression of CHST11, with 5AzadC increased the expression of CHST11 and its immediate product, CS-A, in a dose-dependent manner. These results suggest that CHST11 may play a direct role in progression of breast cancer and that its expression is controlled by DNA methylation. Therefore, in addition to CHST11 mRNA levels, the methylation status of this gene also has potential as a prognostic biomarker.
我们之前发表的数据将乳腺癌细胞表面与P-选择素反应性的硫酸软骨素结构与细胞的转移行为联系起来。我们已经表明，由碳水化合物（硫酸软骨素4）硫酸转移酶-11（CHST11）表达介导的特定硫酸化模式与人乳腺癌细胞系的P-选择素结合及侵袭性相关。本研究旨在评估CHST11表达的预后价值，并确定异常DNA甲基化是否控制乳腺癌中CHST11的表达。利用公开可用的数据集来研究CHST11表达与乳腺癌侵袭性和进展的关联。使用亚硫酸氢盐基因组测序分析甲基化状态。5-氮杂-2'-脱氧胞苷（5AzadC）用于DNA去甲基化。在CHST11的CpG岛进行简化代表性亚硫酸氢盐测序，最低覆盖度为10。采用定量实时RT-PCR来确认CHST11在乳腺癌细胞系中的表达谱。流式细胞术也用于确认CHST11产物硫酸软骨素A（CS-A）的表达。与管腔细胞系相比，基底样和Her2扩增细胞系中CHST11的表达显著更高。与正常组织相比，CHST11在癌组织中也高表达，且表达水平与肿瘤进展显著相关。我们观察到基底样细胞中CHST11的一个CpG岛中的DNA甲基化水平非常低，但管腔细胞中同一区域的甲基化水平非常高。用5AzadC处理CHST11表达非常低的管腔细胞系MCF7细胞，以剂量依赖方式增加了CHST11及其直接产物CS-A的表达。这些结果表明，CHST11可能在乳腺癌进展中起直接作用，且其表达受DNA甲基化控制。因此，除了CHST11 mRNA水平外，该基因的甲基化状态也有作为预后生物标志物的潜力。
