PAI-1 secreted from metastatic ovarian cancer cells triggers the tumor-promoting role of the mesothelium in a feedback loop to accelerate peritoneal dissemination.

The mesothelium, covered by a continuous monolayer of mesothelial cells, is the first protective barrier against metastatic ovarian cancer. However, mesothelial cells release tumor-promoting factors that accelerate the process of peritoneal metastasis. We identified cancer-associated mesothelial cells (CAMs) that had tumor-promoting potential. Here, we found that plasminogen activator inhibitor-1 (PAI-1) induced the formation of CAMs, after which CAMs increasingly secreted the oncogenic factors interleukin-8 (IL-8) and C-X-C motif chemokine ligand 5 (CXCL5), further promoting the metastasis of ovarian cancer cells in a feedback loop. After the formation of CAMs, PAI-1 activated the nuclear factor kappa B (NFκB) pathway in the CAMs, thus transcriptionally upregulating the expression of the downstream NFκB targets IL-8 and CXCL5. Moreover, PAI-1 correlated with peritoneal metastasis in ovarian cancer patients and indicated a poor prognosis. In both ex vivo and in vivo models, after PAI-1 expression was knocked down, the metastasis of ovarian cancer cells decreased significantly. Therefore, targeting PAI-1 may provide a potential target for future therapeutics to prevent the formation of CAMs and alleviate peritoneal metastasis in ovarian cancer patients.

A novel mechanism of neovascularization in peritoneal dissemination via cancer-associated mesothelial cells affected by TGF-ß derived from ovarian cancer.

Epithelial ovarian cancer (EOC) is believed to cause peritoneum dissemination through microenvironmental cell­to-cell communication between the tumor and mesothelium, leading to the further acquisition of progressive and metastatic potentials. In the present study, we aimed to determine the role of cancer-associated mesothelial cells (CAMCs) in the promotion of tumor neovascularization and vascular permeability via enhanced vascular endothelial growth factor (VEGF) production. We examined whether a characteristic morphological change in human peritoneal mesothelial cells (HPMCs) was observed in the presence of malignant ascites and tumor-derived TGF-ß. We focused on the enhanced production of VEGF in CAMCs and its crucial role in endothelial migration and tube formation. Normal HPMCs showed an epithelial morphology with a cobblestone appearance. When HPMCs were co-cultured with malignant ascites from patients with advanced EOC, a dramatic morphologic change was noted from an epithelioid pattern to an α-SMA-positive fibroblastic, mesenchymal pattern. Additionally, we found that EOC-derived TGF-ß induced typical EMT-like morphological alteration in HPMCs, which was associated with CAMCs. We further discovered that CAMCs play a crucial role in the enhanced migration and tube formation of endothelial cells by the promotion of VEGF production. In conclusion, our findings indicate the possible involvement of CAMCs in the neovascularization of EOC and enhancement of vascular permeability, resulting in the formation of malignant ascites. The novel mechanism of CAMCs as a facilitator of EOC progression is displayed by microenvironmental cell-to-cell communication between EOC and the mesothelium.

Erratum: High-dose chemotherapy with autologous peripheral blood stem cell transplantation for choriocarcinoma: A case report and literature review.

[This corrects the article DOI: 10.3892/mco.2016.1011.].

High-dose chemotherapy with autologous peripheral blood stem cell transplantation for choriocarcinoma: A case report and literature review.

Choriocarcinoma is a malignant gestational trophoblastic neoplasia (GTN) and one of the curable types of gynecological cancer. However, 10% of choriocarcinoma patients have a poor prognosis, particularly when they have metastasis, apart from pulmonary metastasis, or do not go into remission by the second chemotherapeutic regimen. We herein present the case of a 36-year-old patient who had choriocarcinoma with metastases to the lungs, liver and kidneys. The 5th and 6th regimens with cisplatin for choriocarcinoma failed and the patient developed brain metastases. She was then treated with four cycles of high-dose ifosfamide, carboplatin and etoposide (ICE) with blood progenitor cell support after confirming the effectiveness of ICE at normal doses. The serum human chorionic gonadotropin (hCG) level was 140,009 mIU/ml at the start of high-dose ICE and the patient tolerated this regimen well. However, the beneficial effect was decreasing with each successive course of treatment, with the lowest level of hCG at 103 mIU/ml after the fourth course. The patient did not achieve complete remission and succumbed to the disease 4 months after the last chemotherapy. The findings of the present case and a review of the related literature suggest that high-dose ICE with stem cell rescue may be considered as a viable treatment option for a multi-drug resistant choriocarcinoma or GTN.