Takahiro Koyanagi

Vasohibin-2 Expressed in Human Serous Ovarian Adenocarcinoma Accelerates Tumor Growth by Promoting Angiogenesis

Vasohibin-1 (VASH1) is a VEGF-inducible endothelium-derived angiogenesis inhibitor and VASH2 is its homolog. Our previous analysis revealed that VASH1 is expressed in endothelial cells to terminate angiogenesis, whereas VASH2 is expressed in infiltrating mononuclear cells mobilized from bone marrow to promote angiogenesis in a mouse model of hypoxia-induced subcutaneous angiogenesis. To test the possible involvement of VASH2 in the tumor, we examined human ovarian cancer cells for the presence of VASH2. Immunohistochemical analysis revealed that VASH2 protein was preferentially detected in cancer cells of serous ovarian adenocarcinoma. We then used SKOV-3 and DISS, two representative human serous adenocarcinoma cell lines, and examined the role of VASH2 in the tumor. The knockdown of VASH2 showed little effect on the proliferation of cancer cells in vitro but notably inhibited tumor growth, peritoneal dissemination, and tumor angiogenesis in a murine xenograft model. Next, we stably transfected the human VASH2 gene into two types of murine tumor cells, EL-4 and MLTC-1, in which endogenous VASH2 was absent. When either EL-4 or MLTC-1 cells were inoculated into VASH2 (−/−) mice, the VASH2 transfectants formed bigger tumors when compared with the controls, and the tumor microvessel density was significantly increased. VASH2 stimulated the migration of endothelial cells, and its increased expression in cancer cells is related to the decrease of mir-200b. These results indicate that VASH2 expressed in serous ovarian carcinoma cells promoted tumor growth and peritoneal dissemination by promoting angiogenesis. Mol Cancer Res; 10(9); 1135–46. ©2012 AACR.

In vivo delivery of siRNA targeting vasohibin-2 decreases tumor angiogenesis and suppresses tumor growth in ovarian cancer

Vasohibin‐2 (VASH2) is a homolog of vasohibin‐1 and exhibits pro‐angiogenic activity. We recently reported that VASH2 is expressed in certain ovarian cancers and promotes tumor growth through angiogenesis. To further demonstrate the effectiveness of molecular targeting of VASH2 for anticancer treatment, we applied in vivo delivery of siRNA targeting VASH2 (siVASH2) using atelocollagen to a xenograft model of ovarian cancer. We inoculated mice s.c. with DISS and SKOV‐3, two representative human ovarian serous adenocarcinoma cell lines. When tumors were measurable, we initiated treatment with control or siVASH2 mixed with atelocollagen, which enveloped the whole tumor. Treatment with siVASH2 significantly inhibited s.c. tumor growth by abrogating tumor angiogenesis. We confirmed that expression of VASH2 mRNA in the tumor was downregulated by siVASH2 treatment. In addition, the siVASH2‐treated tumor contained more blood vessels covered with pericytes, indicating that knockdown of VASH2 contributes to the normalization of tumor blood vessels. Based on these results, VASH2 may be a promising molecular target for ovarian cancer treatment.

Autopsy case of disseminated Trichosporon inkin infection identified with molecular biological and biochemical methods

Trichosporon species are usually opportunistic pathogens. Disseminated trichosporonosis is uncommon but is increasingly reported with a high mortality rate, especially in immunocompromised patients. Although Trichosporon asahii and T. mucoides are known as the most common pathogens of disseminated trichosporonosis, cases of systemic infection due to T. inkin have been reported recently. However, no autopsy case of disseminated T. inkin infection has been reported. Herein is presented an autopsy case of disseminated trichosporonosis caused by T. inkin in a 30‐year‐old man with allogenic peripheral blood stem cell transplantation for acute myelocytic leukemia. In the present case, identification of T. inkin was performed with morphological, molecular biological and biochemical methods. It is difficult to make a diagnosis of Trichosporon infection on only histological examination; therefore, molecular biological and biochemical methods are needed in a diagnosis of disseminated trichosporonosis.

Downregulation of vasohibin-2, a novel angiogenesis regulator, suppresses tumor growth by inhibiting angiogenesis in endometrial cancer cells

The vasohibin-2 (VASH2) gene was originally found to be expressed in infiltrating mononuclear cells of a mouse model of hypoxia-induced subcutaneous angiogenesis. These cells are mobilized from bone marrow to promote angiogenesis. Recently, VASH2 has been demonstrated to be expressed in several types of cancer in which it promotes tumor development through angiogenesis. However, its role in endometrial cancer remains unknown. Using quantitative reverse transcription-polymerase chain reaction (RT-PCR), we found that VASH2 was overexpressed in several human endometrial cancer cell lines, including the HEC50B cell line, which we used to further examine the role of VASH2. Although knockdown of VASH2 with stable transfection of shRNA had little effect on the proliferation of HEC50B cells in vitro, knockdown in an in vivo murine xenograft model inhibited tumor growth by decreasing tumor angiogenesis. In addition, the supernatant from HEC50B cells that expressed VASH2 significantly promoted the proliferation of human umbilical vein endothelial cells. By contrast, knockdown of VASH2 significantly attenuated the proliferative effect. These results indicate that VASH2 contributes to the development of endometrial cancer by promoting angiogenesis through a paracrine mode of action. Consequently, VASH2 may be considered to be a novel molecular target for endometrial cancer therapy.

Radiation Therapy for Chemotherapy-Resistant Recurrent Epithelial Ovarian Cancer

Objectives: While radiation therapy is administered as a palliative treatment for recurrent ovarian cancer, it remains unclear whether it improves the prognosis. Methods: The effects and adverse events of radiation therapy for patients with recurrent epithelial ovarian cancer were investigated using medical records. Results: Herein, 46 subjects comprising 33 patients whose recurrent lesions were contained within the irradiation field (therapeutic radiation group; TRG) and 13 patients with some recurrent lesions outside the irradiation field (palliative radiation group; PRG) were included. The TRG achieved a response rate (RR) of 66%, a disease control rate (DCR) of 100%, a progression-free survival (PFS) of 10 months, and an overall survival (OS) of 20 months. The PFS after radiation therapy was significantly longer than that following chemotherapy received just before radiation therapy. The PFS of patients with recurrent intrapelvic lesions was longer than that of patients with some extrapelvic recurrence. There was no significant association between PFS after radiation therapy and the duration from the previous chemotherapy or histological type. The RR, DCR, PFS, and OS of the PRG were 30 and 90% and 2 and 6 months, respectively. Serious adverse events were rare. Conclusions: Radiation therapy is a potential option for chemotherapy-resistant, localized recurrent ovarian cancer.

The angiogenesis regulator vasohibin-1 inhibits ovarian cancer growth and peritoneal dissemination and prolongs host survival

Vasohibin-1 (VASH1) is expressed in vascular endothelial cells stimulated by several angiogenic growth factors and displays autocrine activity to regulate angiogenesis via a negative feedback mechanism. In this study, we investigated the effect of VASH1 on ovarian cancer progression using VASH1-expressing ovarian cancer cells in vitro and in vivo. The growth ability of ovarian cancer cells engineered to express the VASH1 gene remained unchanged in vitro. However, we showed that VASH1 secretion by tumor cells inhibited the growth of human umbilical vein endothelial cells. Further, animal experiments showed that VASH1 expression inhibited tumor angiogenesis and growth. In a murine model of peritoneal dissemination of ovarian cancer cells, VASH1 inhibited peritoneal dissemination and ascites, resulting in significantly prolonged survival in mice. This indicates that VASH1 exerts an antitumor effect on ovarian cancer by inhibiting angiogenesis in the tumor environment. These findings suggest that a novel therapy based on VASH1 could be a useful therapeutic strategy for ovarian cancer.

Vasohibin-1 expression inhibits advancement of ovarian cancer producing various angiogenic factors.

Vasohibin‐1 (VASH1) is a negative feedback regulator of angiogenesis, the first to be discovered, and was identified in vascular endothelial growth factor (VEGF)‐stimulated vascular endothelial cells. Vasohibin‐1 inhibits abnormal vascularization induced by various angiogenic factors including fibroblast growth factor and platelet‐derived growth factor (PDGF), in addition to VEGF. By focusing on this characteristic of VASH1, we investigated the antitumor effects of VASH1 expression on ovarian cancer cells that produce different angiogenic factors. By using a high VEGF‐producing ovarian cancer cell line, SHIN‐3, and a high PDGF‐producing ovarian cancer cell line, KOC‐2S, the cells were transfected with either a VEGF antagonist, soluble VEGF receptor‐1 (sVEGFR‐1, or sFlt‐1), or VASH1 genes to establish their respective cellular expression. The characteristics of these transfectants were compared with controls. We previously reported that the expression of sFlt‐1 inhibited tumor vascularization and growth of high VEGF‐producing ovarian cancer cells, reduced peritoneal dissemination and ascites development, and prolonged the survival time of the host. However, in the current study, the expression of sFlt‐1 had no such effect on the high PDGF‐producing ovarian cancer cells used here, whereas VASH1 expression inhibited tumor vascularization and growth, not only in high VEGF‐producing cells, but also in high PDGF‐producing cells, reduced their peritoneal dissemination and ascites, and prolonged the survival time of the host. These results suggest that VASH1 is an effective treatment for ovarian cancer cells that produce different angiogenic factors.

Targeting human vasohibin-2 by a neutralizing monoclonal antibody for anti-cancer treatment.

There are two members of the vasohibin (VASH) family, VASH1 and VASH2. VASH1 is expressed mainly in endothelial cells to inhibit angiogenesis, whereas VASH2 is expressed mainly in cancer cells to stimulate tumor growth. The aim of the present study was to establish neutralizing monoclonal antibody (mAb) against human VASH2 and apply it as an anti‐cancer treatment. We previously raised mAb against several synthetic peptides of hVASH1, and found that one of them exhibited neutralizing activity against hVASH1. Because of the similarity in the amino acid sequences between VASH1 and VASH2, we hypothesized that they shared the bioactive center. When we mutated four amino acids within the region, the mutant VASH2 lost its pro‐angiogenic activity. Therefore, we raised mAb against a synthetic peptide overlapping the mutated amino acids of hVASH2, and isolated one clone (1760) that almost completely inhibited the stimulatory effect of hVASH2 on the migration of and tube formation by endothelial cells. When we used this clone 1760 antibody for cancer treatment, the peritoneal injection of it inhibited both tumor growth and angiogenesis in a mouse xenograft model of human cancer cells. In terms of anti‐tumor activity, 25 mg/kg of clone 1760 was equivalent to 5 mg/kg of bevacizmab. From these results, we propose the targeting of human VASH2 with neutralizing mAb as a new strategy for cancer treatment.

Complete gallbladder torsion diagnosed with sequential computed tomography scans: a case report

IntroductionTorsion of the gallbladder is an extremely rare cause of acute abdomen, which commonly affects thin elderly women. A prompt surgical approach is necessary to avoid fatal complications associated with gangrene and perforation of the gallbladder. However, it is difficult to make a preoperative diagnosis using ordinary imaging modalities.Case presentationAn 84-year-old Japanese woman was admitted to our hospital due to left lower abdominal pain. Her pain shifted suddenly to the right upper abdomen a half day after admission. Although her enlarged and wall-thickened gallbladder had been already seen at admission, it rotated approximately 180 degrees and deviated to the midline of her abdomen on the second computed tomography scan, which helped us to make a correct diagnosis of gallbladder torsion. The patient underwent an emergency operation (detorsion and cholecystectomy) and recovered without any complications. The gallbladder had necrosis due to torsion.ConclusionSequential diagnostic imaging might be helpful to make a preoperative diagnosis of gallbladder torsion when the gallbladder is enlarged and wall thickened but the patient does not present with typical clinical symptoms.

Effect of providing risk information on undergoing cervical cancer screening: a randomized controlled trial

BackgroundIn Japan, the cervical cancer screening rate is extremely low. Towards improving the cervical cancer screening rate, encouraging eligible people to make an informed choice, which is a decision-making process that relies on beliefs informed by adequate information about the possible benefits and risks of screening, has attracted increased attention in the public health domain. However, there is concern that providing information on possible risks of screening might prevent deter from participating.MethodsIn total, 1,912 women aged 20–39 years who had not participated in screening in the fiscal year were selected from a Japanese urban community setting. Participants were randomly divided into 3 groups. Group A received a printed reminder with information about the possible benefits of screening, group B received a printed reminder with information about possible benefits and risks, and group C received a printed reminder with simple information only (control group).ResultsOut of 1,912 participants, 169 (8.8%) participated in cervical cancer screening. In the intervention groups, 137 (10.9%) participated in cervical cancer screening, compared to only 32 (4.9%) of the control group (p < 0.001). In addition, logistic regression analysis revealed that there was no significant difference in screening rate between group A and group B (p = 0.372).ConclusionsProviding information on the possible risks of screening may not prevent people from taking part in cervical cancer screening among a Japanese non-adherent population.