Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America.
PLoS One. 2013 Sep 9;8(9):e72637. doi: 10.1371/journal.pone.0072637. eCollection 2013.
Distinctive genotypic and phenotypic features of ovarian cancer via epithelial-mesenchymal transition (EMT) have been correlated with drug resistance and disease recurrence. We investigated whether therapeutic reversal of EMT could re-sensitize ovarian cancer cells (OCCs) to existing chemotherapy. We report that epimorphin, a morphogenic protein, has pivotal control over mesenchymal versus epithelial cell lineage decision of the putative OCCs. Exposure to epimorphin induced morphological changes reminiscent of mesenchymal-to-epithelial transition (MET), but in a dose dependent manner, i.e., at 10 µg/mL of epimorphin cells obtain a more mesenchymal-like morphology while at 20 µg/mL of epimorphin cells display an epithelial morphology. The latter changes were accompanied by suppression of mesenchymal markers, such as vimentin (∼8-fold↓, p<0.02), Twist1 (∼7-fold↓, p<0.03), dystroglycan (∼4-fold↓, p<0.01) and palladin (∼3-fold↓, p<0.01). Conversely, significant elevations of KLF4 (∼28-fold↑, p<0.002), β-catenin (∼6-fold↑, p<0.004), EpCAM (∼6-fold↑, p<0.0002) and occludin (∼15-fold↑, p<0.004) mRNAs as part of the commitment to the epithelial cell lineage were detected in response to 20 µg/mL of exogenous epimorphin. Changes in occludin mRNA levels were accompanied by a parallel, albeit weaker expression at the protein level (∼5-fold↑, p<0.001). Likewise, acquisition of epithelial-like properties, including mucin1, CK19, and β-catenin gene expression, was also obtained following epimorphin treatment. Further, MMP3 production was found to be reduced whereas laminin secretion was strongly amplified upon epimorphin-induced MET. These results suggest there is a dosage window for actions of epimorphin on cellular differentiation, wherein it can either suppress or enhance epithelial differentiation of OCCs. Importantly, induction of epithelial-like phenotypes by epimorphin led to an enhanced sensitivity to carboplatin. Overall, we demonstrate that epimorphin can revert OCCs away from their mesenchymal phenotype and toward an epithelial phenotype, thereby enhancing their sensitivity to a front-line chemotherapeutic agent.
通过上皮-间充质转化（EMT），卵巢癌细胞（OCC）表现出独特的基因型和表型特征，与耐药性和疾病复发相关。我们研究了 EMT 的治疗逆转是否可以使卵巢癌细胞重新对现有化疗敏感。我们报告称，形态发生蛋白 epimorphin 对 OCC 中间充质与上皮细胞谱系的决定具有关键控制作用。暴露于 epimorphin 诱导出类似于间充质向上皮转化（MET）的形态变化，但呈剂量依赖性，即 10μg/mL 的 epimorphin 使细胞获得更类似间充质的形态，而 20μg/mL 的 epimorphin 使细胞呈现上皮形态。后者的变化伴随着间充质标志物的抑制，例如波形蛋白（8 倍↓，p<0.02）、Twist1（7 倍↓，p<0.03）、dystroglycan（4 倍↓，p<0.01）和 palladin（3 倍↓，p<0.01）。相反，在响应 20μg/mL 的外源性 epimorphin 时，检测到 KLF4（28 倍↑，p<0.002）、β-catenin（6 倍↑，p<0.004）、EpCAM（6 倍↑，p<0.0002）和 occludin（15 倍↑，p<0.004）mRNA 的显著升高，作为向上皮细胞谱系分化的一部分。occludin mRNA 水平的变化伴随着蛋白水平的平行但较弱的表达（~5 倍↑，p<0.001）。同样，在 epimorphin 处理后，也获得了上皮样特性，包括 mucin1、CK19 和β-catenin 基因表达。此外，MMP3 的产生减少，而层粘连蛋白的分泌在 epimorphin 诱导的 MET 后强烈放大。这些结果表明，epimorphin 对细胞分化的作用存在剂量窗口，它可以抑制或增强 OCC 的上皮分化。重要的是，epimorphin 诱导的上皮样表型导致对卡铂的敏感性增强。总的来说，我们证明 epimorphin 可以使 OCC 从间充质表型逆转到上皮表型，从而增强其对一线化疗药物的敏感性。
