Hidetaka Katabuchi

CD44 variant 6 is correlated with peritoneal dissemination and poor prognosis in patients with advanced epithelial ovarian cancer

Cancer stem cells (CSCs) drive tumor initiation and metastasis in several types of human cancer. However, the contribution of ovarian CSCs to peritoneal metastasis remains unresolved. The cell adhesion molecule CD44 has been identified as a major marker for CSCs in solid tumors, including epithelial ovarian cancer. CD44 exists as a standard form (CD44s) and also as numerous variant isoforms (CD44v) generated by alternative mRNA splicing. Here we show that disseminated ovarian tumors in the pelvic peritoneum contain highly enriched CD44v6‐positive cancer cells, which drive tumor metastasis and are responsible for tumor resistance to chemotherapy. Clinically, an increased number of CD44v6‐positive cancer cells in primary tumors was associated with a shortened overall survival in stage III–IV ovarian cancer patients. Furthermore, a subpopulation of CD44v6‐positive cancer cells manifested the ability to initiate tumor metastasis in the pelvic peritoneum in an in vivo mouse model, suggesting that CD44v6‐positive cells show the potential to serve as metastasis‐initiating cells. Thus, the peritoneal disseminated metastasis of epithelial ovarian cancer is initiated by the CD44v6‐positive subpopulation, and CD44v6 expression is a biomarker for the clinical outcome of advanced ovarian cancer patients. Given that a distinct subpopulation of CD44v6‐positive cancer cells plays a critical role in peritoneal metastasis, definitive treatment should target this subpopulation of CD44v6‐positive cells in epithelial ovarian cancer.

Possible involvement of signal transducer and activator of transcription-3 in cell-cell interactions of peritoneal macrophages and endometrial stromal cells in human endometriosis

OBJECTIVEnTo investigate interactions between peritoneal macrophages and endometrial stromal cells (ESCs) involved in the development of endometriosis.nnnDESIGNnClinicopathologic and in vitro studies.nnnSETTINGnDepartment of Obstetrics and Gynecology and Department of Pathology, Kumamoto University Hospital.nnnPATIENT(S)nWomen undergoing laparoscopy or laparotomy to treat endometriosis or other benign gynecologic conditions.nnnINTERVENTION(S)nWe collected samples of peritoneal fluid (ascites), endometrium, and endometriotic tissues. We cocultured ESCs in vitro with or without human macrophages.nnnMAIN OUTCOME MEASURE(S)nMacrophage phenotypes in peritoneal fluid were determined via immunostaining. Proliferation of ESCs and activation of signal transducer and activator of transcription-3 (Stat3) in cocultures were evaluated.nnnRESULT(S)nThe endometriosis group had a significantly higher total number of macrophages in ascites compared with the control group, but the ratios of CD163+ alternatively activated macrophages (M2) in the two groups did not differ significantly. Coculture with M2 macrophages significantly up-regulated ESC proliferation and Stat3 activation in ESCs in vitro. Proliferation of ESCs was suppressed after Stat3 was down-regulated by small interfering RNA. Stat3 was activated in epithelial cells and ESCs in human endometriotic lesions.nnnCONCLUSION(S)nInteractions between M2 macrophages and ESCs via Stat3 activation may play an important role in the development of endometriosis.

Corosolic acid enhances the antitumor effects of chemotherapy on epithelial ovarian cancer by inhibiting signal transducer and activator of transcription 3 signaling

Resistance to chemotherapy poses a serious problem for the treatment of advanced epithelial ovarian cancer patients. The mechanisms of chemoresistance are complex and studies have implicated signal transducer and activator of transcription 3 (STAT3) signaling in the chemoresistance of cancer cells. The present study investigated whether corosolic acid (CA), which has been previously reported to be a STAT3 inhibitor, was able to increase the sensitivity to chemotherapeutic drugs in epithelial ovarian cancer cells. CA also markedly enhanced the anticancer effect of paclitaxel, cisplatin and doxorubicin. In addition, CA abrogated the cell-cell interactions between macrophages and epithelial ovarian cancer cells and inhibited the macrophage-induced activation of epithelial ovarian cancer cells. These data indicated that CA was able to reverse the chemoresistance of epithelial ovarian cancer cells and suppress the cell-cell interaction with tumorigenic macrophages. Thus, CA may be useful as an adjuvant treatment to patients with advanced ovarian and other types of cancer due to the multiple anticancer effects.

Transvaginal Methotrexate Injection for the Treatment of Cesarean Scar Pregnancy: Efficacy and Subsequent Fecundity

STUDY OBJECTIVEnTo investigate the efficacy of local methotrexate (MTX) injections under transvaginal ultrasound guidance for treatment of cesarean scar pregnancy (CSP) and to assess fecundity after treatment.nnnDESIGNnRetrospective review (Canadian Task Force classification II-3).nnnSETTINGnUniversity hospital.nnnPATIENTSnEight women with CSP.nnnINTERVENTIONnTransvaginal MTX injection.nnnMEASUREMENTS AND MAIN RESULTSnWe retrospectively reviewed 8 CSP cases treated with local MTX injection under transvaginal ultrasonographic guidance. In all cases, the serum human chorionic gonadotropin concentration was monitored and the gestational sac was evaluated using ultrasonography after treatment. Magnetic resonance imaging was performed as necessary. Patient clinical characteristics, clinical course after treatment, treatment efficacy, and fecundity after treatment in patients desiring subsequent pregnancies were evaluated. All 8 women were successfully treated without the need for blood transfusions or surgical procedures, although 2 required additional MTX therapy via local injection or systemic administration. The mean (SD) time to human chorionic gonadotropin normalization was 78.5 (37.7) days (range, 42-166 days). Four of 5 patients desiring subsequent pregnancies after the treatment had uneventful parturition, and recurrent CSP was diagnosed in 1 patient.nnnCONCLUSIONSnTransvaginal MTX injection was effective and safe as sole treatment of CSP. Although the treatment course tended to be long, this method can be considered the first choice of treatment in patients desiring future pregnancies. However, careful attention should be paid to the possibility of CSP recurrence.

Onionin A inhibits ovarian cancer progression by suppressing cancer cell proliferation and the protumour function of macrophages

It is well known that tumour-associated macrophages (TAMs) play an important role in tumour development by modulating the tumour microenvironment, and targeting of protumour activation or the M2 polarization of TAMs is expected to be an effective therapy for cancer patients. We previously demonstrated that onionin A (ONA), a natural low molecular weight compound isolated from onions, has an inhibitory effect on M2 macrophage polarization. In the present study, we investigated whether ONA had a therapeutic anti-ovarian cancer effect using in vitro and in vivo studies. We found that ONA reduced the extent of ovarian cancer cell proliferation induced by co-culture with human macrophages. In addition, we also found that ONA directly suppressed cancer cell proliferation. A combinatorial effect with ONA and anti-cancer drugs was also observed. The activation of signal transducer and activator of transcription 3 (STAT3), which is involved in cell proliferation and chemo-resistance, was significantly abrogated by ONA in ovarian cancer cells. Furthermore, the administration of ONA suppressed cancer progression and prolonged the survival time in a murine ovarian cancer model under single and combined treatment conditions. Thus, ONA is considered useful for the additional treatment of patients with ovarian cancer owing to its suppression of the protumour activation of TAMs and direct cytotoxicity against cancer cells.

CD44 Variant 6 as a Predictive Biomarker for Distant Metastasis in Patients With Epithelial Ovarian Cancer.

OBJECTIVE: To investigate the role of cancer stem cell marker CD44 variant 6 in the development of distant metastasis in patients with epithelial ovarian cancer. METHODS: A retrospective cohort study was performed in 186 patients who underwent surgery for ovarian cancer from 2005 to 2013 at the Kumamoto University Hospital. The association between the expression of CD44 variant 6 and distant metastasis was evaluated based on a large-scale immunohistochemical analysis. Primary ovarian tumors that contained at least 10% CD44 variant 6–positive cancer cells were categorized as CD44v6-high (n=53), and the tumors that contained less than 10% CD44 variant 6–positive cells were categorized as CD44v6-low (n=133). Distant metastasis–free survival was compared between the CD44v6-high and -low groups. Multivariate analysis was performed to estimate the influence of various clinicopathologic factors on the development of distant metastasis. RESULTS: At the time of ovarian cancer diagnosis, distant metastasis occurred in 13 of 53 patients (24.5%) in the CD44v6-high group and 17 of 133 patients (12.8%) in the CD44v6-low group (P=.049). The median metastasis-free survival after stage I–III ovarian cancer diagnosis was 19.5 months (range 11–55 months) in the CD44v6-high group (n=40) and 39.5 months (range 22–57 months) in the CD44v6-low group (n=116) (P=.071). Multivariate analysis demonstrated that CD44 variant 6 expression was an independent risk factor for distant metastatic recurrence (hazard ratio 4.09, 95% confidence interval 1.29–12.98; P=.017). CONCLUSION: CD44 variant 6 represents an important predictor of distant metastasis and CD44 variant 6–positive ovarian cancer cells play a crucial role in the formation of distant metastases in patients with ovarian cancer.

Development of a mouse model for testing therapeutic agents: the anticancer effect of dienogest on endometrial neoplasms.

Abstract Objective: As the number of younger women with endometrial carcinoma has increased, fertility-sparing treatments have received more attention. Although there have been several reports on conservative treatments with progestins for endometrial carcinoma, only medroxyprogesterone acetate (MPA) is available in Japan. Dienogest has been developed as a fourth-generation progestin for treating endometriosis. Because of its high progesterone activity, its antitumor activity has attracted attention. In this study, we investigated the anticancer effect of dienogest on endometrial neoplasms using mouse model of endometrial carcinoma. Methods/materials: PtenloxP/loxP mice were injected with MPA or dienogest subcutaneously to evaluate the anticancer effect against endometrial neoplasms that developed in the mice. One week after injections, histopathological analyzes were performed. Results: Endometrial neoplasms were found in one of the eight (12.5%) mice from each group treated with either dienogest or MPA. In contrast, they were found in seven of eight (87.5%) mice not treated with progestins. Each progestin treatment showed anticancer activity against endometrial neoplasms that developed in the mice compared to those without treatment. Conclusions: Dienogest and MPA showed potent anticancer activity against endometrial neoplasms in our mouse model. The present study demonstrated that dienogest might be a useful therapeutic agent for human endometrial neoplasms.

Case of concurrent benign metastasizing leiomyoma in the lung and retroperitoneum, with a focus on its etiology

We report a rare, simultaneous occurrence of benign metastasizing leiomyoma in the lung and retroperitoneum in a 49‐year‐old woman who had previously undergone myomectomy at 35u2009years of age and hysterectomy at 45u2009years of age for multiple recurrences of histologically benign uterine leiomyomas. At 49u2009years of age, computed tomography‐guided biopsy indicated benign metastasizing leiomyomas in the lung. In addition, a retroperitoneal leiomyoma was found that was resected along with both the ovaries via laparotomy. No sign or symptom of recurrence was observed 5u2009years later. The coexistence of benign metastasizing leiomyoma in the lung and retroperitoneum following surgery for conventional leiomyomas has rarely been reported. Further, the nature and etiology of benign metastasizing leiomyoma are still not well understood. This case is therefore worth reporting, and exploring its etiology is important.

Clinicopathological heterogeneity in ovarian clear cell adenocarcinoma: a study on individual therapy practice

Ovarian clear cell adenocarcinoma (CCA) has been believed to be a lethal histological subtype of an epithelial ovarian adenocarcinoma (EOA); its precursor has been assumed to be endometriosis. However, it has been reported that CCAs occasionally exhibit different clinical behaviors, suggesting that CCAs might not belong to a single category. We focused on CCAs combined with other histological types of EOAs; we re-evaluated the pathology of 46 CCAs and divided them into two subgroups: 35 CCAs alone (pure-type CCAs); and 11 CCAs with other histological types, endometrioid adenocarcinomas (EAs) or/and serous adenocarcinomas (SAs) (mixed-type CCAs). Immunohistochemical analysis for expression of ARID1A, p53, PTEN, Annexin 4, hepatocyte nuclear factor-1β (HNF-1β), and WT-1 was employed. We identified that patients with endometriosis were younger than those without endometriosis in pure-type CCAs (Pxa0<xa00.005). In mixed-type CCAs, the immunohistochemical-staining patterns revealed internal transition of each histological component. In pure-type CCAs, expressions of ARID1A and p53 were mutually altered, and altered expression of p53 was associated with worse prognosis than that of ARID1A (Pxa0<xa00.001). Our results provide evidence that CCAs would have clinicopathological heterogeneity, determining the patient’s prognosis. Furthermore, immunohistochemical analysis may shed light on the selection of appropriate treatment, including chemotherapy.

Human chorionic gonadotropin induces human macrophages to form intracytoplasmic vacuoles mimicking Hofbauer cells in human chorionic villi.

The most characteristic morphological feature of macrophages in the stroma of placental villi, known as Hofbauer cells, is their highly vacuolated appearance. They also show positive immunostaining for human chorionic gonadotropin (hCG) and express messenger ribonucleic acid of the luteinizing hormone/chorionic gonadotropin receptor with a deletion of exon 9 (LH/CG-R Δ9). Maternal hCG enters fetal plasma through the mesenchyme of the placental villi and promotes male sexual differentiation in early pregnancy; therefore, excess hCG may induce aberrant genital differentiation and hCG must be adjusted at the fetomaternal interface. We hypothesized that hCG is regulated by Hofbauer cells and that their peculiar vacuoles are involved in a cell-specific function. To assess the morphological modification and expression of LH/CG-R Δ9 in human macrophages after hCG exposure, the present study examined phorbol 12-myristate 13-acetate (PMA)-treated THP-1 cells, a human monocyte-macrophage cell line. hCG induced transient vacuole formation in PMA-treated THP-1 cells, morphologically mimicking Hofbauer cells. Immunocytochemistry showed that PMA-treated THP-1 cells incorporated hCG but not luteinizing hormone or follicle-stimulating hormone. Western blotting analyses demonstrated that PMA-treated THP-1 cells expressed an immunoreactive 60-kDa protein, designated as endogenous LH/CG-R Δ9. hCG induced a transient reduction in the LH/CG-R Δ9, which was synchronous with the appearance of cytoplasmic vacuoles. In conclusion, human macrophages regulating hCG via cytoplasmic LH/CG-R Δ9 mimic the morphological characteristics of Hofbauer cells. Their vacuoles may be associated with their cell-specific function to protect the fetus from exposure to excess maternal hCG during pregnancy.