Tumor-associated fibrosis: a unique mechanism promoting ovarian cancer metastasis and peritoneal dissemination.

Epithelial ovarian cancer (EOC) is often diagnosed in advanced stage with peritoneal dissemination. Recent studies indicate that aberrant accumulation of collagen fibers in tumor stroma has a variety of effects on tumor progression. We refer to remodeled fibrous stroma with altered expression of collagen molecules, increased stiffness, and highly oriented collagen fibers as tumor-associated fibrosis (TAF). TAF contributes to EOC cell invasion and metastasis in the intraperitoneal cavity. However, an understanding of molecular events involved is only just beginning to emerge. Further development in this field will lead to new strategies to treat EOC. In this review, we focus on the recent findings on how the TAF contributes to EOC malignancy. Furthermore, we will review the recent initiatives and future therapeutic strategies for targeting TAF in EOC.

Chondroitin Sulfate Proteoglycan 4 Provides New Treatment Approach to Preventing Peritoneal Dissemination in Ovarian Cancer.

Most epithelial ovarian cancer (EOC) patients are diagnosed with peritoneal dissemination. Cellular interactions are an important aspect of EOC cells when they detach from the primary site of the ovary. However, the mechanism remains underexplored. Our study aimed to reveal the role of chondroitin sulfate proteoglycan 4 (CSPG4) in EOC with a major focus on cell-cell interactions. We examined the expression of CSPG4 in clinical samples and cell lines of EOC. The proliferation, migration, and invasion abilities of the CSPG4 knockdown cells were assessed. We also assessed the role of CSPG4 in spheroid formation and peritoneal metastasis in an in vivo model using sh-CSPG4 EOC cell lines. Of the clinical samples, 23 (44.2%) samples expressed CSPG4. CSPG4 was associated with a worse prognosis in patients with advanced EOC. Among the EOC cell lines, aggressive cell lines, including ES2, expressed CSPG4. When CSPG4 was knocked down using siRNA or shRNA, the cell proliferation, migration, and invasion abilities were significantly decreased compared to the control cells. Proteomic analyses showed changes in the expression of proteins related to the cell movement pathways. Spheroid formation was significantly inhibited when CSPG4 was inhibited. The number of nodules and the tumor burden of the omentum were significantly decreased in the sh-CSPG4 mouse models. In the peritoneal wash fluid from mice injected with sh-CSPG4 EOC cells, significantly fewer spheroids were present. Reduced CSPG4 expression was observed in lymphoid enhancer-binding factor 1-inhibited cells. CSPG4 is associated with aggressive features of EOC and poor prognosis. CSPG4 could be a new treatment target for blocking peritoneal metastasis by inhibiting spheroid formation.

Indoxyl Sulfate Promotes Metastatic Characteristics of Ovarian Cancer Cells via Aryl Hydrocarbon Receptor-Mediated Downregulation of the Mas Receptor.

Although platinum-combination chemotherapy shows a high response rate at the primary site, epithelial ovarian cancer (EOC) treatment remains challenging because of tumor recurrence and metastasis. Recent studies have revealed that chemotherapy paradoxically promotes cancer cell survival, proliferation, and metastasis, although the reason for this remains unclear. The underlying molecular mechanisms that contribute to chemotherapy-induced metastasis need to be elucidated to establish effective therapeutic strategies. Acute kidney injury is a known side effect of cisplatin treatment, and kidney dysfunction results in the accumulation of uremic toxins in the serum. The present study aimed to investigate whether indoxyl sulfate (IS), a representative uremic toxin, affects the pathophysiology of EOC. In this study, IS reduced the expression of Mas receptor (MasR) in cultured human EOC cells. Both knockdown of the aryl hydrocarbon receptor (AhR), which is an intracellular IS receptor, and inhibition of AhR function suppressed IS-mediated downregulation of MasR in SK-OV-3 cells. IS induced the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in an AhR-dependent manner. Inhibition of the STAT3 pathway or reactive oxygen species production suppressed the IS-mediated reduction of MasR. IS stimulated cell migration and invasion of SK-OV-3 cells in an AhR-dependent manner. Cisplatin-nephropathy model mice exhibited elevated levels of serum IS accompanied by elevated levels of blood urea nitrogen and serum creatinine. Furthermore, intraperitoneal administration of IS in mice promoted tumor growth and metastasis. Finally, we found that the MasR agonist Ang-(1-7) suppressed the IS-mediated effects on cell proliferation, migration, and invasion of SK-OV-3 cells. However, the knockdown of MasR expression by specific small interfering RNA in the absence of IS resulted in only minimal promotion of cell migration and invasion. These findings demonstrate that IS promotes malignancy in ovarian cancer via AhR-mediated downregulation of MasR function, whereas Ang-(1-7) attenuates this effect, thereby suggesting that Ang-(1-7) could provide a future treatment strategy for this cancer type.

Metastatic Voyage of Ovarian Cancer Cells in Ascites with the Assistance of Various Cellular Components.

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and has a unique metastatic route using ascites, known as the transcoelomic root. However, studies on ascites and contained cellular components have not yet been sufficiently clarified. In this review, we focus on the significance of accumulating ascites, contained EOC cells in the form of spheroids, and interaction with non-malignant host cells. To become resistant against anoikis, EOC cells form spheroids in ascites, where epithelial-to-mesenchymal transition stimulated by transforming growth factor-ß can be a key pathway. As spheroids form, EOC cells are also gaining the ability to attach and invade the peritoneum to induce intraperitoneal metastasis, as well as resistance to conventional chemotherapy. Recently, accumulating evidence suggests that EOC spheroids in ascites are composed of not only cancer cells, but also non-malignant cells existing with higher abundance than EOC cells in ascites, including macrophages, mesothelial cells, and lymphocytes. Moreover, hetero-cellular spheroids are demonstrated to form more aggregated spheroids and have higher adhesion ability for the mesothelial layer. To improve the poor prognosis, we need to elucidate the mechanisms of spheroid formation and interactions with non-malignant cells in ascites that are a unique tumor microenvironment for EOC.

Pro-tumoral behavior of omental adipocyte-derived fibroblasts in tumor microenvironment at the metastatic site of ovarian cancer.

Adipocyte-rich omentum offers "good soil" for disseminating ovarian cancer (OvCa), contributing to therapeutic difficulty. However, little is understood about the association between adipocytes and tumor growth at peritoneal dissemination site. Herein, we report the induction of adipocyte dedifferentiation by OvCa cells and pro-tumorigenic effects of resulted adipocyte-derived fibroblasts. We confirmed that malignant ascites promoted the dedifferentiation of the primary human adipocytes obtained from surgical omental specimen into omental adipocyte-derived fibroblast (O-ADF) that possess both mesenchymal stem cell and myofibroblast-like features. This promotion of dedifferentiation by malignant ascites was blocked by addition of Wnt signaling inhibitor. The effects of dedifferentiated adipocytes in proliferation and migration of OvCa cells were analyzed with in vitro coculturing experimental models and in vivo mice model, and we demonstrated that OvCa cell lines showed enhanced proliferative characteristics, as well as increased migratory abilities upon coculturing with O-ADF. Additionally, exogenous transforming growth factor-ß1 augmented desmoplastic morphological change of O-ADF, leading to higher proliferative ability. Our results suggest that OvCa cells promote dedifferentiation of peritoneal adipocytes by activating Wnt/ß-catenin signaling, and generated O-ADFs exhibit pro-tumoral hallmarks.

Filopodia play an important role in the trans-mesothelial migration of ovarian cancer cells.

Ovarian cancer cells shed from primary tumors can spread easily to the peritoneum via the peritoneal fluid. To allow further metastasis, the cancer cells must interact with the mesothelial cell layer, which covers the entire surface of the peritoneal organs. Although the clinical importance of this interaction between cancer and mesothelial cells has been increasingly recognized, the molecular mechanisms utilized by cancer cells to adhere to and migrate through the mesothelial cell layer are poorly understood. To investigate the molecular mechanisms of cancer cell trans-mesothelial migration, we set up an in vitro trans-mesothelial migration assay using primary peritoneal mesothelial cells. Using this method, we found that downregulation of filopodial protein fascin-1 or myosin X expression in ES-2 cells significantly inhibited the rate of trans-mesothelial migration of cancer cells, whereas upregulation of fascin-1 in SK-OV-3 cells enhanced this rate. Furthermore, downregulation of N-cadherin or integrin ß1 inhibited the rate of cancer cell trans-mesothelial migration. Conversely, downregulation of cortactin or TKS5 or treatment with the MMP inhibitor GM6001 or the N-WASP inhibitor wiskostatin did not have any effect on cancer cell trans-mesothelial migration. These results suggest that filopodia, but not lamellipodia or invadopodia, play an important role in the trans-mesothelial migration of ovarian cancer cells.

Ovarian cancer-associated mesothelial cells induce acquired platinum-resistance in peritoneal metastasis via the FN1/Akt signaling pathway.

Peritoneal dissemination of ovarian cancer (OvCa) arises from the surface of the peritoneum, covered by monolayer of mesothelial cells (MCs). Given that both OvCa cells and MCs are present in the same peritoneal metastatic microenvironment, they may establish cell-to-cell crosstalk or phenotypic alterations including the acquisition of platinum-resistance in OvCa cells. Herein, we report how OvCa-associated mesothelial cells (OCAMs) induce platinum-resistance in OvCa cells through direct cell-to-cell crosstalk. We evaluated mutual associations between OvCa cells and human primary MCs with in vitro coculturing experimental models and in silico omics data analysis. The role of OCAMs was also investigated using clinical samples and in vivo mice models. Results of in vitro experiments show that mesenchymal transition is induced in OCAMs primarily by TGF-ß1 stimulation. Furthermore, OCAMs influence the behavior of OvCa cells as a component of the tumor microenvironment of peritoneal metastasis. Mechanistically, OCAMs can induce decreased platinum-sensitivity in OvCa cells via induction of the FN1/Akt signaling pathway via cell-to-cell interactions. Histological analysis of OvCa peritoneal metastasis also illustrated FN1 expression in stromal cells that are supposed to originate from MCs. Further, we also confirmed the activation of Akt signaling in OvCa cells in contact with TGF-ß1 stimulated peritoneum, using an in vivo mice model. Our results suggest that the tumor microenvironment, enhanced by direct cell-to-cell crosstalk between OvCa cells and OCAMs, induces acquisition of platinum-resistance in OvCa cells, which may serve as a novel therapeutic target for prevention of OvCa peritoneal dissemination.

Folate-appended cyclodextrin carrier targets ovarian cancer cells expressing the proton-coupled folate transporter.

Folate receptor alpha (FRα) is overexpressed in >80% of epithelial ovarian cancer (EOC). Accordingly, folate is attracting attention as a targeting ligand for EOC. For EOC patients, paclitaxel (PTX) is generally used as a first-line chemotherapeutic agent in combination with platinum-based drugs. Cyclodextrin (CyD) is a potential new formulation vehicle for PTX that could replace Cremophor-EL, a traditional formulation vehicle that causes significant side effects, including neutropenia. Several years ago, folate-appended ß-CyD (Fol-c1 -ß-CyD) was developed as an FRα-targeting drug carrier, but its efficacy as a treatment for EOC remains to be determined. In this study, we assessed the antitumor activity of PTX in Fol-c1 -ß-CyD (PTX/Fol-c1 -ß-CyD) in EOC-derived cell lines. We found that PTX/Fol-c1 -ß-CyD killed not only FRα-expressing cells but also FRα-negative cells. In the FRα-negative A2780 cells, knockdown of proton-coupled folate transporter (PCFT) significantly decreased the cytotoxicity of PTX/Fol-c1 -ß-CyD, whereas knockdown of FRα did not. By contrast, knockdown of either FRα or proton-coupled folate transporter (PCFT) decreased the cytotoxicity of PTX/Fol-c1 -ß-CyD in FRα-expressing SK-OV-3 cells. Furthermore, the cytotoxicity of PTX/Fol-c1 -ß-CyD in A2780 cells was increased at acidic pH, and this increase was suppressed by PCFT inhibitor. In mice intraperitoneally inoculated with FRα-expressing or PCFT-expressing EOC cells, intraperitoneal administration of PTX/Fol-c1 -ß-CyD significantly suppressed the growth of both types of EOC cells relative to PTX alone, without inducing a significant change in the neutrophil/white blood cell ratio. Our data suggest that Fol-c1 -ß-CyD targets not only FRα but also PCFT, and can efficiently deliver anticancer drugs to EOC cells in the peritoneal cavity.

Microphthalmia-Associated Transcription Factor-Dependent Melanoma Cell Adhesion Molecule Activation Promotes Peritoneal Metastasis of Ovarian Cancer.

Ovarian cancer (OvCa) is one of the leading causes of death due to its high metastasis rate to the peritoneum. Recurrent peritoneal tumors also develop despite the use of conventional platinum-based chemotherapies. Therefore, it is still important to explore the factors associated with peritoneal metastasis, as these predict the prognosis of patients with OvCa. In this study, we investigated the function of microphthalmia-associated transcription factor (MITF), which contributes to the development of melanoma, in epithelial ovarian cancer (OvCa). High MITF expression was significantly associated with a poor prognosis in OvCa. Notably, MITF contributed to the motility and invasion of OvCa cells, and specifically with their peri-mesothelial migration. In addition, MITF-positive cells expressed the melanoma cell adhesion molecule (MCAM/CD146), which was initially identified as a marker of melanoma progression and metastasis, and MCAM expression was regulated by MITF. MCAM was also identified as a significant prognostic factor for poor progression-free survival in patients with OvCa. Collectively, our results suggest that MITF is a novel therapeutic target that potentially promotes peritoneal metastasis of OvCa.

Lgr4 controls specialization of female gonads in mice.

Leucine-rich repeat-containing G protein-coupled receptor 4 (Lgr4) is a type of membrane receptor with a seven-transmembrane structure. LGR4 is homologous to gonadotropin receptors, such as follicle-stimulating hormone receptor (Fshr) and luteinizing hormone/choriogonadotropin receptor (Lhcgr). Recently, it has been reported that Lgr4 is a membrane receptor for R-spondin ligands, which mediate Wnt/beta-catenin signaling. Defects of R-spondin homolog (Rspo1) and wingless-type MMTV integration site family, member 4 (Wnt4) cause masculinization of female gonads. We observed that Lgr4(-/-) female mice show abnormal development of the Wolffian ducts and somatic cells similar to that in the male gonads. Lgr4(-/-) female mice exhibited masculinization similar to that observed in Rspo1-deficient mice. In Lgr4(-/-) ovarian somatic cells, the expression levels of lymphoid enhancer-binding factor 1 (Lefl) and Axin2 (Axin2), which are target genes of Wnt/beta-catenin signaling, were lower than they were in wild-type mice. This study suggests that Lgr4 is critical for ovarian somatic cell specialization via the cooperative signaling of Rspo1 and Wnt/beta-catenin.

Nitric oxide and reactive oxygen species in the pathogenesis of preeclampsia.

Preeclampsia (PE) is characterized by disturbed extravillous trophoblast migration toward uterine spiral arteries leading to increased uteroplacental vascular resistance and by vascular dysfunction resulting in reduced systemic vasodilatory properties. Its pathogenesis is mediated by an altered bioavailability of nitric oxide (NO) and tissue damage caused by increased levels of reactive oxygen species (ROS). Furthermore, superoxide (O2-) rapidly inactivates NO and forms peroxynitrite (ONOO-). It is known that ONOO- accumulates in the placental tissues and injures the placental function in PE. In addition, ROS could stimulate platelet adhesion and aggregation leading to intravascular coagulopathy. ROS-induced coagulopathy causes placental infarction and impairs the uteroplacental blood flow in PE. The disorders could lead to the reduction of oxygen and nutrients required for normal fetal development resulting in fetal growth restriction. On the other hand, several antioxidants scavenge ROS and protect tissues against oxidative damage. Placental antioxidants including catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx) protect the vasculature from ROS and maintain the vascular function. However, placental ischemia in PE decreases the antioxidant activity resulting in further elevated oxidative stress, which leads to the appearance of the pathological conditions of PE including hypertension and proteinuria. Oxidative stress is defined as an imbalance between ROS and antioxidant activity. This review provides new insights about roles of oxidative stress in the pathophysiology of PE.

TJP1 suppresses trophoblast cell invasion by expressing E2F8 in the human placenta.

Adequate extravillous trophoblast (EVT) invasion into the maternal decidua is important for human placental development. We identified that E2F transcription factor 8 (E2F8) suppresses EVT invasion, and that tight junction protein-1 (TJP1) is a potential downstream target gene of E2F8. We investigated the role of TJP1 in the human placenta and regulation of TJP1 expression by E2F8. TJP1 expression decreased in E2F8 knockdown HTR-8/SVneo cells. TJP1 and E2F8 were co-expressed in villi in the first-trimester placenta and in EVTs and villi in the third-trimester placenta. TJP1 was significantly increased in the pre-eclamptic compared with control placenta. TJP1 knockdown increased the invasion of HTR-8/SVneo cells, while TJP1 overexpression inhibited cell invasion. Halo-E2F8 overexpression significantly increased TJP1 expression and TJP1 transcription compared with control placenta. Our findings suggest that E2F8 promotes TJP1 transcription, and that TJP1 expression by E2F8 inhibits EVT invasion. TJP1 and E2F8 may be related to pre-eclampsia pathogenesis.

Leucine zipper protein 1 (LUZP1) regulates the constriction velocity of the contractile ring during cytokinesis.

There has been a great deal of research on cell division and its mechanisms; however, its processes still have many unknowns. To find novel proteins that regulate cell division, we performed the screening using siRNAs and/or the expression plasmid of the target genes and identified leucine zipper protein 1 (LUZP1). Recent studies have shown that LUZP1 interacts with various proteins and stabilizes the actin cytoskeleton; however, the function of LUZP1 in mitosis is not known. In this study, we found that LUZP1 colocalized with the chromosomal passenger complex (CPC) at the centromere in metaphase and at the central spindle in anaphase and that these LUZP1 localizations were regulated by CPC activity and kinesin family member 20A (KIF20A). Mass spectrometry analysis identified that LUZP1 interacted with death-associated protein kinase 3 (DAPK3), one regulator of the cleavage furrow ingression in cytokinesis. In addition, we found that LUZP1 also interacted with myosin light chain 9 (MYL9), a substrate of DAPK3, and comprehensively inhibited MYL9 phosphorylation by DAPK3. In line with a known role for MYL9 in the actin-myosin contraction, LUZP1 suppression accelerated the constriction velocity at the division plane in our time-lapse analysis. Our study indicates that LUZP1 is a novel regulator for cytokinesis that regulates the constriction velocity of the contractile ring.

9-oxo-ODAs suppresses the proliferation of human cervical cancer cells through the inhibition of CDKs and HPV oncoproteins.

Mucosal human papillomavirus (HPV) subtypes 16 and 18 are causative agents of cervical cancer, a leading cause of cancer-related deaths among women worldwide. In Japan, eggplant calyx is a folk remedy used to treat common warts. 9-oxo-(10E,12E)-octadecadienoic acid, isolated from eggplant calyx, may have antitumor effects. This study investigated the antitumor effects of 9-oxo-(10E, 12Z)-octadecadienoic acid and 9-oxo-(10E,12E)-octadecadienoic acid (9-oxo-ODAs) on human cervical cancer cells. 9-oxo-ODAs suppressed the proliferation of human cervical cancer cell lines (HeLa, and SiHa) in a concentration-dependent manner (IC50 = 25-50 µM). FCM analysis revealed that 9-oxo-ODAs induced apoptosis. Transcriptome, proteomics, and enrichment analyses revealed that treatment with 9-oxo-ODAs significantly altered the cell cycle and p53 pathways and decreased cyclin-dependent kinase 1 (CDK1) protein expression. Real-time PCR analysis demonstrated that 9-oxo-ODAs reduced CDK1 mRNA expression in a concentration-dependent manner. In vitro, 9-oxo-ODAs reduced the HPV oncoprotein expression. In ex vivo human cervical cancer tissues, 9-oxo-ODAs decreased CDK1 expression and increased cleaved caspase 3, an apoptosis marker. Further, 9-oxo-ODAs showed the potential to suppressed metastatic formation and growth of cervical cancer in vivo. These findings suggest that 9-oxo-ODAs induce cell cycle arrest and apoptosis in HPV-positive human cervical cancer cells, and this process involves CDK1. Consequently, 9-oxo-ODAs may be potential therapeutic agents for cervical cancer.

Identifying high-grade serous ovarian carcinoma-specific extracellular vesicles by polyketone-coated nanowires.

Cancer cell-derived extracellular vesicles (EVs) have unique protein profiles, making them promising targets as disease biomarkers. High-grade serous ovarian carcinoma (HGSOC) is the deadly subtype of epithelial ovarian cancer, and we aimed to identify HGSOC-specific membrane proteins. Small EVs (sEVs) and medium/large EVs (m/lEVs) from cell lines or patient serum and ascites were analyzed by LC-MS/MS, revealing that both EV subtypes had unique proteomic characteristics. Multivalidation steps identified FRα, Claudin-3, and TACSTD2 as HGSOC-specific sEV proteins, but m/lEV-associated candidates were not identified. In addition, for using a simple-to-use microfluidic device for EV isolation, polyketone-coated nanowires (pNWs) were developed, which efficiently purify sEVs from biofluids. Multiplexed array assays of sEVs isolated by pNW showed specific detectability in cancer patients and predicted clinical status. In summary, the HGSOC-specific marker detection by pNW are a promising platform as clinical biomarkers, and these insights provide detailed proteomic aspects of diverse EVs in HGSOC patients.

Spectrin αII and ßII tetramers contribute to platinum anticancer drug resistance in ovarian serous adenocarcinoma.

To overcome drug resistance in ovarian carcinoma, novel resistance mechanisms must be elucidated for clinical application. We purified 2 proteins in the 300 kDa range from cisplatin-resistant cells (NOS2CR2) by affinity chromatography with cisplatin-exposed Glutathione Sepharose 4B. The purified proteins were identified as spectrin αII and ßII by peptide mass mapping analysis. Western blot analysis detected greater expression of spectrin αII and ßII in NOS2CR2 than in wild-type cells (NOS2). The same result was obtained for spectrin ßII expression by immunohistochemical staining. To determine whether spectrin αII and ßII contribute to resistance, a drug sensitivity test was performed on SKOV3 ovarian cancer cells transfected with small interfering RNA. Sensitivity to platinum drugs was increased in the expression reduced cells. In a clinical study of five ovarian serous adenocarcinoma cases, tumor specimens taken after treatment with carboplatin stained more strongly for spectrin ßII expression than untreated specimens. Fifty-two tumor specimens from 46 patients with ovarian serous adenocarcinoma were immunohistochemically stained for spectrin ßII and scored. Tumors previously treated by chemotherapy scored higher than those not treated. Of 27 cases with detectable residual tumors at the time of surgery, cases scoring 4-6 had shorter progression-free survival periods after platinum-based chemotherapy than cases scoring 0-3 (p = 0.012). The cytoskeleton proteins Spectrin αII and ßII contributed to drug resistance by anchoring the GS-Pt complex to the cell membrane, arresting cisplatin activity. Thus spectrin ßII may be a useful predictor of platinum sensitivity in ovarian serous adenocarcinoma.

Long-term medroxyprogesterone acetate therapy for low-grade endometrial stromal sarcoma.

BACKGROUND: Low-grade endometrial stromal sarcoma (ESS) is a rare tumor. Endocrine treatment is frequently necessary, but treatment details have not been established. PATIENTS AND METHODS: Thirteen consecutive patients with low-grade ESS were examined clinicopathologically. All patients underwent surgery, and six were treated with a uniform regimen of medroxyprogesterone acetate (MPA) against residual or recurrent disease. RESULTS: Of the 13 patients, 9 were in stage I, whereas the others were in advanced stages. The median follow-up period was 117 months (range 43-170 months). Six patients, including three with residual peritoneal dissemination and three with recurrent tumors, were treated with MPA. Six months after the initiation of treatment, 3 patients demonstrated a partial response, and 3 patients demonstrated stable disease. The median dosing period was 64 months (range 28-92 months). Five of the patients, including 2 patients who are alive with no evidence of disease and 3 patients who are alive with disease, continue with MPA therapy. CONCLUSION: The clinicopathological characteristics of the low-grade ESS in this study are consistent with those reported in previous studies. MPA therapy with residual or recurrent disease achieved excellent disease control over a period of 5 years. These results indicate that MPA therapy might be considered as a therapeutic option for residual or recurrent low-grade ESS and perhaps chosen as a first-line therapy.

Combination of the tumor angiogenesis inhibitor bevacizumab and intratumoral oncolytic herpes virus injections as a treatment strategy for human gastric cancers.

BACKGROUND/AIMS: Advanced gastric cancer is difficult to treat due to the frequency of liver metastases and peritoneal dissemination. A combination of two new strategies, including the anti-angiogenesis inhibitor bevacizumab and an oncolytic herpes virus is a promising treatment for advanced cancer. METHODOLOGY: The effects of bevacizumab on oncolytic herpes virus replication and viral cytotoxicity were examined at varying bevacizumab concentrations and viral titers. In addition, the ability of these two new promising anticancer agents to inhibit tumor growth was studied. Histological examinations of CD31 and LacZ were used to assess angiogenesis and virus distribution within the tumor, respectively. RESULTS: Bevacizumab did not affect viral replication or viral cytotoxicity in vitro. The combination of bevacizumab and the oncolytic herpes virus hrR3 significantly reduced tumor growth in vivo in an experimental gastric cancer model. Bevacizumab inhibited angiogenesis caused by local injection of hrR3 and induced virus spread. Bevacizumab increased the distribution of the intratumorally injected oncolytic herpes virus within the tumor. CONCLUSIONS: Combination therapy consisting of bevacizumab and an oncolytic herpes virus is a promising new treatment strategy for gastric cancer.

Extravasation of pegylated-liposomal doxorubicin: favorable outcome after immediate subcutaneous administration of corticosteroids.

A massive extravasation of pegylated-liposomal doxorubicin (Doxil) accidentally occurred, affecting the right forearm of a 54-year-old woman with metastatic ovarian cancer who was receiving an intravenous infusion of the drug. In accordance with the institutional guidelines for vesicant drugs, a corticosteroid preparation was immediately injected subcutaneously into the surrounding tissues. Clobetasol propionate and an ice pack were then topically applied to the affected region. There were no serious complications at the extravasation site, such as tissue necrosis or severe pain, and only a transient erythema of the skin and desquamation remained after 2 months.

Peritoneal restoration by repurposing vitamin D inhibits ovarian cancer dissemination via blockade of the TGF-ß1/thrombospondin-1 axis.

Ovarian cancer (OvCa), a lethal gynecological malignancy, disseminates to the peritoneum. Mesothelial cells (MCs) act as barriers in the abdominal cavity, preventing the adhesion of cancer cells. However, in patients with OvCa, they are transformed into cancer-associated mesothelial cells (CAMs) via mesenchymal transition and form a favorable microenvironment for tumors to promote metastasis. However, attempts for restoring CAMs to their original state have been limited. Here, we investigated whether inhibition of mesenchymal transition and restoration of MCs by vitamin D suppressed the OvCa dissemination in vitro and in vivo. The effect of vitamin D on the mutual association of MCs and OvCa cells was evaluated using in vitro coculture models and in vivo using a xenograft model. Vitamin D restored the CAMs, and thrombospondin-1 (component of the extracellular matrix that is clinically associated with poor prognosis and is highly expressed in peritoneally metastasized OvCa) was found to promote OvCa cell adhesion and proliferation. Mechanistically, TGF-ß1 secreted from OvCa cells enhanced thrombospondin-1 expression in CAMs via Smad-dependent TGF-ß signaling. Vitamin D inhibited mesenchymal transition in MCs and suppressed thrombospondin-1 expression via vitamin D receptor/Smad3 competition, contributing to the marked reduction in peritoneal dissemination in vivo. Importantly, vitamin D restored CAMs from a stabilized mesenchymal state to the epithelial state and normalized thrombospondin-1 expression in preclinical models that mimic cancerous peritonitis in vivo. MCs are key players in OvCa dissemination and peritoneal restoration and normalization of thrombospondin-1 expression by vitamin D may be a novel strategy for preventing OvCa dissemination.