Regulation of the miRNA-directed Reprogramming of Normal Omental Fibroblasts

描述（由申请人提供）：手术和积极的化疗在卵巢癌（OvCa）中的成功率为20%，这意味着迫切需要新的治疗方法。卵巢肿瘤由7-83%的基质组成，基质驱动肿瘤进展，增加血管生成并促进转移，但目前的治疗旨在仅靶向癌细胞1，2。虽然肿瘤基质由许多细胞类型组成，但癌症相关成纤维细胞（CAF）是主要成分。Lengyel和Peter实验室最近报道，在卵巢CAF中，与正常或肿瘤相邻的成纤维细胞相比，micro-RNAs（miRNA）miR-31和miR-214下调，而miR-155上调3。此外，显示OvCa细胞足以通过在共培养期间下调miR-214、miR-31和上调miR-155将正常网膜成纤维细胞（NOF）重编程为CAF。通过抑制miRNA和miRNA抑制剂模拟这种失调诱导正常成纤维细胞功能性转化为CAF，如通过体外和体内增加的成纤维细胞运动性和促进肿瘤进展所定义的。此外，反向实验导致CAFs逆转为正常成纤维细胞3。miRNA重编程的正常成纤维细胞和患者来源的CAF共享大量高度富集趋化因子的上调基因，已知其对CAF功能很重要3。发现最高度上调的趋化因子CCL 5是miR- 214的直接靶标3。这些结果表明，在卵巢癌进展的过程中，NOFs通过调节miRNA表达重编程为CAFs。然而，OvCa通过这些miRNAs调节NOF到CAF重编程的因素和机制尚不清楚。因此，我建议确定在NOF到CAF重编程期间调节miR-155，miR-214和miR-31表达的癌源性因子和成纤维细胞信号传导途径，这将导致卵巢癌用于重编程肿瘤基质的关键因子和机制的鉴定。

DESCRIPTION (provided by applicant): Surgery and aggressive chemotherapy has a 20% success rate in ovarian cancer (OvCa) meaning new therapies are desperately needed. Ovarian tumors are composed of 7-83% stroma, which drives tumor progression, increases angiogenesis, and promotes metastasis, yet current therapies are aimed at targeting the cancer cells alone 1,2. While the tumor stroma consists of a number of cell types, cancer associated fibroblasts (CAFs) are a major constituent. The Lengyel and Peter labs recently reported that in ovarian CAFs, the micro-RNAs (miRNA) miR-31 and miR-214 are downregulated while miR-155 is upregulated when compared to normal or tumor-adjacent fibroblasts 3. Additionally, it was shown that OvCa cells are sufficient to reprogram normal omental fibroblasts (NOFs) into CAFs through downregulation of miR-214, miR-31, and upregulation of miR-155 during coculture. Mimicking this deregulation by transfecting miRNAs and miRNA inhibitors induced a functional conversion of normal fibroblasts into CAFs as defined by increased fibroblast motility and promotion of tumor progression both in vitro and in vivo. Furthermore, the reverse experiment resulted in the reversion of CAFs into normal fibroblasts3. The miRNA-reprogrammed normal fibroblasts and patient-derived CAFs shared a large number of upregulated genes highly enriched in chemokines, which are known to be important for CAF function 3. The most highly upregulated chemokine, CCL5, was found to be a direct target of miR- 214 3. These results indicate that during the process of ovarian cancer progression, NOFs are reprogrammed to become CAFs through the regulation of miRNA expression. However, the factors and the mechanisms in which OvCa regulates NOF to CAF reprogramming through these miRNAs are not understood. Therefore I propose to determine the cancer-derived factors and the fibroblast signaling pathways that regulate the expression of miR-155, miR-214, and miR-31 during NOF to CAF reprogramming, which would result in the identification of key factors and mechanisms used by ovarian cancer to reprogram the tumor stroma.