Tomohito Tanaka

GPR30 regulates the EGFR-Akt cascade and predicts lower survival in patients with ovarian cancer

ObjectivesG protein-coupled receptor 30 (GPR30) is a 7-transmembrane estrogen receptor that functions alongside traditional estrogen receptors to regulate the cellular responses to estrogen. Recent studies suggest that GPR30 expression is associated with a poor prognosis, and that this is due to the GPR30-mediated transactivation of the EGFR in breast cancer. However, the biological contribution of GPR30 in ovarian cancer remains unclear. The purpose of this study was to elucidate the relationships between GPR30 expression and the clinicopathological findings, and to determine how the signaling cascade influences the prognosis of ovarian cancer.MethodsThe expression levels of GPR30, EGFR, ERα, and ERβ were analyzed using an immunohistochemical analysis, and their correlations with the clinicopathological features were examined in 10 patients with borderline malignant tumors and 152 patients with epithelial ovarian cancer. We also examined whether GPR30 signaling activates the EGFR-Akt pathway in an ovarian cancer cell line (Caov-3) by a Western blotting analysis.ResultsThe GPR30 expression in ovarian carcinomas was significantly higher than that in borderline malignancies (p=0.0016), and was not associated with the expression of the EGFR, ERα, or ERβ. The expression of GPR30 in clear cell carcinomas was significantly lower than that in other subtypes of cancer (P <; 0.001). The expression of both GPR30 and EGFR was significantly associated with a poor prognosis in terms of the progression-free survival rate. The phosphorylation of the EGFR and Akt could be significantly enhanced by G1 (p <; 0.05) and inhibited by a Src family kinase inhibitor.ConclusionThe expression of both GPR30 and EGFR is associated with a poor outcome in ovarian cancer, and GPR30 increases the phosphorylation of Akt via the EGFR in ovarian cancer cells. The regulation of GPR30 might be a potentially useful new therapeutic target in ovarian cancer.

The EMT (epithelial-mesenchymal-transition)- related protein expression indicates the metastatic status and prognosis in patients with ovarian cancer

ObjectivesThe epithelial-mesenchymal-transition (EMT) is an important step in the invasion and metastasis of cancer. A critical molecular feature of this process is the downregulation of the E-cadherin expression, which is primarily controlled by Snail-related zinc-finger transcription factors. The aim of this study was to evaluate the prognostic impact of the expression of EMT-related proteins (E-cadherin and Snail) in patients with ovarian cancer.MethodsAn immunohistochemical analysis was conducted using tissue microarray samples of 174 primary tumors and 34 metastases of ovarian carcinoma, and the relationships between the protein expression, clinicopathological features and outcomes were investigated.ResultsA reduced E-cadherin expression was observed in 36.8% of the primary tumors and 30.4%, 35.7%, 37.7% and 52.7% of the stage I, II, III and IV tumors, respectively. The nuclear expression of Snail was positive in 33.9% of the primary tumors. The rate of an EMT-positive status, as represented by both a reduced E-cadherin expression and a nuclear expression of Snail, was significantly higher in the patients with peritoneal dissemination than in those without (p < 0.05). The EMT status was significantly associated with both the progression-free survival and overall survival (p <0.01). A multivariate analysis showed an EMT-positive status to be a significant predictor of both the progression-free survival (p < 0.05) and overall survival (P < 0.01).ConclusionsThese data indicate that the EMT status is significantly associated with peritoneal metastasis and both the progression-free survival and overall survival in patients with ovarian cancer. Therefore, clarifying and controlling EMT signaling is a promising approach to molecular targeted therapy for ovarian cancer.

Comparison of the perinatal outcomes after laparoscopic myomectomy versus abdominal myomectomy.

Background/Aims: To compare the perinatal outcomes after laparoscopic myomectomy (LM) versus abdominal myomectomy (AM). Methods: The medical records of 105 Japanese females who delivered after myomectomy from 2004 to 2012 at Osaka Medical College were reviewed retrospectively. Results: Of the 105 females who delivered after myomectomy, 48 had undergone LM and 57 had undergone AM. There were no significant differences in the perinatal outcomes including the rates of emergency cesarean sections, preterm deliveries, placental abnormalities, pregnancy-induced hypertension, low Apgar score, non-reassuring fetal heart rate patterns, and intrauterine fetal death. No significant difference was observed in the incidence of post-partum hemorrhage. There was no uterine rupture in either group. 15 (31%) of the females who had LM were candidates for transvaginal delivery, and 14 delivered vaginally (93% success rate). In contrast, 20 (35%) of the females who had AM were candidates for transvaginal delivery, and 19 delivered vaginally (95% success rate). Conclusion: There were no significant differences in the perinatal outcomes between the females who had LM and AM. Moreover, both groups had a high rate of successful transvaginal delivery after selecting the appropriate candidates.

Associations between the pre-pregnancy body mass index and gestational weight gain with pregnancy outcomes in Japanese women.

To examine the associations between the pre‐pregnancy body mass index (BMI) and gestational weight gain (GWG) with pregnancy outcomes in Japanese women.

Hepatocyte growth factor secreted by ovarian cancer cells stimulates peritoneal implantation via the mesothelial-mesenchymal transition of the peritoneum.

OBJECTIVE A current working model for the metastatic process of ovarian carcinoma suggests that cancer cells are shed from the ovarian tumor into the peritoneal cavity and attach to the layer of mesothelial cells that line the inner surface of the peritoneum, and several studies suggest that hepatocyte growth factor (HGF) plays an important role in the dissemination of ovarian cancer. Our objectives were to evaluate the HGF expression of ovarian cancer using clinical data and assess the effect of HGF secreted from human ovarian cancer cells to human mesothelial cells. METHODS HGF expression was immunohistochemically evaluated in 165 epithelial ovarian cancer patients arranged as tissue microarrays. HGF expression in four ovarian cancer cell lines was evaluated by using semi-quantitative polymerase chain reaction, Western blotting and enzyme-linked immunosorbent assay. The effect of ovarian cancer cell derived HGF to the human mesothelial cells was assessed by using morphologic analysis, Western blotting and cell invasion assay. The effect of HGF on ovarian cancer metastasis was assessed by using in vivo experimental model. RESULTS The clinical data showed a significantly high correlation between the HGF expression and the cancer stage. The in vivo and in vitro experimental models revealed that HGF secreted by ovarian cancer cells induces the mesothelial-to-mesenchymal transition and stimulates the invasion of mesothelial cells. Furthermore, manipulating the HGF activity affected the degree of dissemination and ascite formation. CONCLUSIONS We demonstrated that HGF secreted by ovarian cancer cells plays an important role in cancer peritoneal implantation.

Vaginal stump metastasis from sigmoid colon cancer.

Background: Vaginal metastasis from organs other than the uterus is rare. Generally, patients with vaginal metastasis from colorectal cancer have a dismal prognosis. Although biopsy is the best method to make the diagnosis, massive bleeding may occur. On the other hand, liquid-based cytology (LBC) has the utility to perform immunocytochemistry on additional unstained slides: we can make a diagnosis with several immunocytochemical findings. Case: A 67-year-old postmenopausal female presented to our hospital with vaginal bleeding. The patient had undergone colectomy because of her stage III sigmoid colon cancer 3 years earlier. The patient had also undergone hysterectomy for cervical cancer 30 years earlier. LBC from the vaginal stump revealed adenocarcinoma. Immunocytochemically, cancer cells were negative for cytokeratin 7 and positive for cytokeratin 20, which suggested metastasis from the sigmoid colon cancer; the diagnosis was made without a biopsy. Conclusion: When the patient has a metastatic lesion from colon adenocarcinoma, LBC with immunocytochemistry is useful in making a diagnosis.

Preoperative MRI and intraoperative frozen section diagnosis of myometrial invasion in patients with endometrial cancer.

Objective The rate of lymph node metastasis is extremely low in patients with low-risk endometrial cancer; lymphadenectomy may be unnecessary for these patients under an accurate preoperative diagnosis. The aim of this study was to evaluate the diagnostic accuracy of myometrial invasion (MI) on preoperative magnetic resonance imaging (MRI) and intraoperative frozen sections (FSs). Materials and Methods Endometrial cancer was diagnosed in a total of 378 patients by preoperative endometrial curettage, preoperative magnetic resonance imaging MRI, and intraoperative FSs; the 378 patients underwent hysterectomy. The depth of MI was evaluated between the preoperative MRI, intraoperative FSs, and final paraffin sections (PSs). The histologic grade was also evaluated between preoperative endometrial curettage, intraoperative FSs, and final PSs. Results The sensitivity, specificity, positive predictive value, and negative predictive value for deep MI (≥50%) on MRI were 57.8%, 92.0%, 69.3%, and 87.5%, respectively, with a kappa value of 0.53. These figures on FSs were 66.7%, 97.9%, 90.9%, and 90.4%, with a kappa value of 0.71. When grade 3 endometrioid adenocarcinoma, serous carcinoma, clear cell carcinoma, and carcinosarcoma were considered high-grade tumors, the grade evaluation at the time of FSs was 70.2%, 99.0%, 96.1%, and 89.7%, with a kappa value of 0.75. In the patients with low-grade tumors, including grade 1 or 2 endometrioid adenocarcinoma on preoperative endometrial curettage, the rate of unexpected lymph node metastasis did not differ significantly between the patients who had a diagnosis of MI and lymph node metastasis by MRI and those with diagnosis of MI and histological grade by FSs (4.0% vs 2.6%; P > 0.05). Conclusions Frozen sections had a higher agreement rate for MI than MRI; however, MRI is still considered an acceptable modality to guide preoperative decisions regarding lymphadenectomy especially in grade 1 or 2 endometrioid adenocarcinoma.

Total laparoscopic modified radical hysterectomy with lymphadenectomy for endometrial cancer compared with laparotomy

This is the first report to determine the feasibility and safety of total laparoscopic modified radical hysterectomy (TLMRH) in the treatment of presumed stage I endometrial cancer.

CD24 expression is a marker for predicting clinical outcome and regulates the epithelial-mesenchymal transition in ovarian cancer via both the Akt and ERK pathways

The degree of peritoneal dissemination and chemotherapy-resistant tumors is related to the prognosis in patients with advanced-stage ovarian cancer. The epithelial-mesenchymal-transition (EMT) is a multifaceted pathological program that endows cancer cells with the ability to invade and disseminate. CD24 is frequently overexpressed in various human cancers and is correlated with a poor prognosis. We herein examined the functions of CD24 in human ovarian cancer cell lines and evaluated how it contributes to the molecular mechanism underlying the regeneration of cancer stem-like cells (CSCs) through the EMT mechanism in ovarian carcinoma. We demonstrated that CD24 was expressed in 70.1% of primary ovarian carcinoma tissues, which were obtained from 174 patients, and that the expression of CD24 was an independent predictor of survival in patients with ovarian cancer. The expression of CD24 has been found to be correlated with the FIGO stage, presence of peritoneal and lymph node metastasis. CD24 induces the EMT phenomenon, which is involved in cell invasion, the highly proliferative phenotype, colony formation and which is associated with cisplatin resistance and the properties of CSCs, via the activation of PI3K/Akt, NF-κB and ERK in Caov-3 cisplatin-resistant cell lines. CD24-positive ovarian carcinomas have been shown to have a greater potential for intra-abdominal tumor cell dissemination in in vivo models. Our findings suggest that CD24 induced the EMT phenomenon in ovarian cancer, and that CD24 amplified cell growth-related intracellular signaling via the PI3K/Akt and MAPK pathways by affecting the EMT signal pathways. We believe that CD24 is a key molecule of metastatic progression in the EMT phenomenon and a promising therapeutic target for advanced ovarian cancer.

Gemcitabine as a molecular targeting agent that blocks the Akt cascade in platinum-resistant ovarian cancer

BackgroundGemcitabine (2′, 2′ –difluorodeoxycytidine) is one of many nonplatinum drugs that exhibit activity in recurrent, platinum-resistant ovarian cancer. However, the molecular mechanisms by which Gemcitabine treatment inhibits the proliferation of platinum-resistant ovarian cancer cells still remain unclear. We investigated whether Gemcitabine increases the efficacy of Cisplatin in platinum-resistant ovarian cancer models in vitro and in vivo.MethodsWe used Cisplatin-resistant Caov-3 cells, A2780CP cells and Cisplatin-sensitive A2780 cells to examine the sensitivity of the cell viability of Cisplatin and Gemcitabine using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and the sensitivity of the invasive activity of Cisplatin and Gemcitabine using an invasion assay with Matrigel. We examined the Akt kinase activity and matrix metalloproteinase 9 (MMP9) expression following Cisplatin and Gemcitabine treatment using a Western blot analysis and the mRNA expression of vascular endothelial growth factor (VEGF) using semi-quantitative RT-PCR. Moreover, we evaluated the effects of Cisplatin and Gemcitabine on the intra-abdominal dissemination of ovarian cancer in vivo.ResultsGemcitabine significantly inhibited Cisplatin-induced Akt activation in the Caov-3 and A2780CP cells, but not in the A2780 cells. In the presence of Gemcitabine, Cisplatin-induced growth inhibition and apoptosis were significantly enhanced in the Caov-3 and A2780CP cells. Co-treatment with Cisplatin and Gemcitabine almost completely inhibited invasion of both types of cells through the Matrigel; however, neither Cisplatin nor Gemcitabine alone inhibited the invasion of both types of cells. Gemcitabine inhibited not only the Cisplatin-induced activation of Akt, but also the MMP9 and mRNA expression of VEGF. Moreover, treatment with Gemcitabine increased the efficacy of Cisplatin-induced growth inhibition of the intra-abdominal dissemination and production of ascites in the athymic nude mice inoculated with Caov-3 cells.ConclusionsWe herein demonstrated that Gemcitabine inhibits the Akt kinase activity and angiogenetic activity following treatment with Cisplatin in platinum-resistant ovarian cancer cells. These results provide a rationale for using Gemcitabine in clinical regimens containing molecular targeting agents against platinum-resistant ovarian cancers.