The effect of endostatin mediated by human mesenchymal stem cells on ovarian cancer cells in vitro

Enhancement of Radiotherapy with Human Mesenchymal Stem Cells Containing Gold Nanoparticles

Radiotherapy is a common approach for the treatment of a wide variety of cancer types. Available data indicate that nanoparticles can enhance the effect of radiotherapy. We report the use of human mesenchymal stem cells to selectively deliver gold nanoparticles (GNPs) to MDA-MB-231 breast tumor xenografts in mice for the purpose of enhancing the effect of radiation therapy. Targeted delivery of GNPs to the tumor site, followed by irradiation of the tumor, enabled control of tumor growth. The results indicate that tumor-selective GNP delivery by human mesenchymal stem cells may represent a viable way to enhance the effectiveness of radiotherapy.

Epigenetic Crosstalk between the Tumor Microenvironment and Ovarian Cancer Cells: A Therapeutic Road Less Traveled

Metastatic dissemination of epithelial ovarian cancer (EOC) predominantly occurs through direct cell shedding from the primary tumor into the intra-abdominal cavity that is filled with malignant ascitic effusions. Facilitated by the fluid flow, cells distribute throughout the cavity, broadly seed and invade through peritoneal lining, and resume secondary tumor growth in abdominal and pelvic organs. At all steps of this unique metastatic process, cancer cells exist within a multidimensional tumor microenvironment consisting of intraperitoneally residing cancer-reprogramed fibroblasts, adipose, immune, mesenchymal stem, mesothelial, and vascular cells that exert miscellaneous bioactive molecules into malignant ascites and contribute to EOC progression and metastasis via distinct molecular mechanisms and epigenetic dysregulation. This review outlines basic epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA regulators, and summarizes current knowledge on reciprocal interactions between each participant of the EOC cellular milieu and tumor cells in the context of aberrant epigenetic crosstalk. Promising research directions and potential therapeutic strategies that may encompass epigenetic tailoring as a component of complex EOC treatment are discussed.

Recent Progress in Gene Therapy for Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy in developed countries. This is due to the lack of specific symptoms that hinder early diagnosis and to the high relapse rate after treatment with radical surgery and chemotherapy. Hence, novel therapeutic modalities to improve clinical outcomes in ovarian malignancy are needed. Progress in gene therapy has allowed the development of several strategies against ovarian cancer. Most are focused on the design of improved vectors to enhance gene delivery on the one hand, and, on the other hand, on the development of new therapeutic tools based on the restoration or destruction of a deregulated gene, the use of suicide genes, genetic immunopotentiation, the inhibition of tumour angiogenesis, the alteration of pharmacological resistance, and oncolytic virotherapy. In the present manuscript, we review the recent advances made in gene therapy for ovarian cancer, highlighting the latest clinical trials experience, the current challenges and future perspectives.

Revisiting ovarian cancer microenvironment: a friend or a foe?

Development of ovarian cancer involves the co-evolution of neoplastic cells together with the adjacent microenvironment. Steps of malignant progression including primary tumor outgrowth, therapeutic resistance, and distant metastasis are not determined solely by genetic alterations in ovarian cancer cells, but considerably shaped by the fitness advantage conferred by benign components in the ovarian stroma. As the dynamic cancer topography varies drastically during disease progression, heterologous cell types within the tumor microenvironment (TME) can actively determine the pathological track of ovarian cancer. Resembling many other solid tumor types, ovarian malignancy is nurtured by a TME whose dark side may have been overlooked, rather than overestimated. Further, harnessing breakthrough and targeting cures in human ovarian cancer requires insightful understanding of the merits and drawbacks of current treatment modalities, which mainly target transformed cells. Thus, designing novel and precise strategies that both eliminate cancer cells and manipulate the TME is increasingly recognized as a rational avenue to improve therapeutic outcome and prevent disease deterioration of ovarian cancer patients.

Human endometrial mesenchymal stem cells exhibit intrinsic anti-tumor properties on human epithelial ovarian cancer cells

Epithelial ovarian cancer (EOC) is the most lethal tumor of all gynecologic tumors. There is no curative therapy for EOC thus far. The tumor-homing ability of adult mesenchymal stem cells (MSCs) provide the promising potential to use them as vehicles to transport therapeutic agents to the site of tumor. Meanwhile, studies have showed the intrinsic anti-tumor properties of MSCs against various kinds of cancer, including epithelial ovarian cancer. Human endometrial mesenchymal stem cells (EnSCs) derived from menstrual blood are a novel source for adult MSCs and exert restorative function in some diseases. Whether EnSCs endow innate anti-tumor properties on EOC cells has never been reported. By using tumor-bearing animal model and ex vivo experiments, we found that EnSCs attenuated tumor growth by inducing cell cycle arrest, promoting apoptosis, disturbing mitochondria membrane potential and decreasing pro-angiogenic ability in EOC cells in vitro and/or in vivo. Furthermore, EnSCs decreased AKT phosphorylation and promoted nuclear translocation of Forkhead box O-3a (FoxO3a) in EOC cells. Collectively, our findings elucidated the potential intrinsic anti-tumor properties of EnSCs on EOC cells in vivo and in vitro. This research provides a potential strategy for EnSC-based anti-cancer therapy against epithelial ovarian cancer.

Ovarian cancer microenvironment: implications for cancer dissemination and chemoresistance acquisition

Ovarian adenocarcinoma is characterized by a late detection, dissemination of cancer cells into the whole peritoneum, and the frequent acquisition of chemoresistance. If these particularities can be explained in part by intrinsic properties of ovarian cancer cells, an increased number of studies show the importance of the tumor microenvironment in tumor progression. Ovarian cancer cells can regulate the composition of their stroma in promoting the formation of ascitic fluid, rich in cytokines and bioactive lipids, and in stimulating the differentiation of stromal cells into a pro-tumoral phenotype. In return, cancer-associated fibroblasts, cancer-associated mesenchymal stem cells, tumor-associated macrophages, or other peritoneal cells, such as adipocytes and mesothelial cells can regulate tumor growth, angiogenesis, dissemination, and chemoresistance. This review focuses on the current knowledge about the roles of stromal cells and the associated secreted factors on tumor progression. We also summarize the different studies showing that targeting the microenvironment represents a great potential for improving the prognosis of patients with ovarian adenocarcinoma.

Vascular endothelial growth factor (VEGF) polymorphism and increased risk of epithelial ovarian cancer

INTRODUCTION

Angiogenesis (AG) is essential for epithelial ovarian cancer (EOC) development. Vascular endothelial growth factor (VEGF), encoded by the VEGF gene, and endostatin, the product of the COL18A1 gene, act as a potent promoter and an inhibitor of AG, respectively. In the present study, we tested whether VEGF C936T and COL18A1 D104N polymorphisms alter the risk of EOC.

METHODS

Genomic DNA from 131 EOC patients and 137 controls were analyzed by polymerase chain reaction and restriction fragment length polymorphism methods. The differences between groups were analyzed by χ (2) or Fisher's exact test and logistic regression analysis.

RESULTS

The frequency of the VEGF 936CC genotype was higher in patients than in controls (84.8% vs. 75.3%, P = 0.03). Individuals with respective genotypes had a 1.98 (95% CI 1.04-3.78)-fold increased risk of EOC than those with the remaining genotypes. An excess of VEGF 936CC plus COL18A1 DN genotype was seen in patients when compared to controls (48.6% vs. 30.5%); however, only a tendency toward a statistically significant difference in genotype frequencies was found in the study (P = 0.06), reflecting a trend toward an increased risk of 2.44 for EOC in carriers of the combined genotype.

CONCLUSION

Our data present, for the first time, preliminary evidence that VEGF C936T alone or combined with the COL18A1 D104N polymorphism of AG constitutes an important inherited EOC determinant.

Antiangiogenic and anticancer molecules in cartilage

Cartilage is one of the very few naturally occurring avascular tissues where lack of angiogenesis is the guiding principle for its structure and function. This has attracted investigators who have sought to understand the biochemical basis for its avascular nature, hypothesising that it could be used in designing therapies for treating cancer and related malignancies in humans through antiangiogenic applications. Cartilage encompasses primarily a specialised extracellular matrix synthesised by chondrocytes that is both complex and unique as a result of the myriad molecules of which it is composed. Of these components, a few such as thrombospondin-1, chondromodulin-1, the type XVIII-derived endostatin, SPARC (secreted protein acidic and rich in cysteine) and the type II collagen-derived N-terminal propeptide (PIIBNP) have demonstrated antiangiogenic or antitumour properties in vitro and in vivo preclinical trials that involve several complicated mechanisms that are not completely understood. Thrombospondin-1, endostatin and the shark-cartilage-derived Neovastat preparation have also been investigated in human clinical trials to treat several different kinds of cancers, where, despite the tremendous success seen in preclinical trials, these molecules are yet to show success as anticancer agents. This review summarises the current state-of-the-art antiangiogenic characterisation of these molecules, highlights their most promising aspects and evaluates the future of these molecules in antiangiogenic applications.