Keisuke Ashihara
Osaka Medical College
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Featured researches published by Keisuke Ashihara.
Journal of Ovarian Research | 2014
Masaaki Takai; Yoshito Terai; Hiroshi Kawaguchi; Keisuke Ashihara; Satoe Fujiwara; Tomohito Tanaka; Satoshi Tsunetoh; Yoshimichi Tanaka; Hiroshi Sasaki; Masanori Kanemura; Akiko Tanabe; Masahide Ohmichi
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.
Journal of Obstetrics and Gynaecology Research | 2014
Tomohito Tanaka; Keisuke Ashihara; Michihiko Nakamura; Takayoshi Kanda; Daisuke Fujita; Yoshiki Yamashita; Yoshito Terai; Hideki Kamegai; Masahide Ohmichi
To examine the associations between the pre‐pregnancy body mass index (BMI) and gestational weight gain (GWG) with pregnancy outcomes in Japanese women.
Oncology Reports | 2017
Kiyoko Nakamura; Yoshito Terai; Akiko Tanabe; Yoshihiro J. Ono; Masami Hayashi; Kazuya Maeda; Satoe Fujiwara; Keisuke Ashihara; Michihiko Nakamura; Yoshimichi Tanaka; Tomohito Tanaka; Satoshi Tsunetoh; Hiroshi Sasaki; Masahide Ohmichi
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.
Journal of Ovarian Research | 2014
Hiroshi Kawaguchi; Yoshito Terai; Akiko Tanabe; Hiroshi Sasaki; Masaaki Takai; Satoe Fujiwara; Keisuke Ashihara; Yoshimichi Tanaka; Tomohito Tanaka; Satoshi Tsunetoh; Masanori Kanemura; Masahide Ohmichi
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.
PLOS ONE | 2017
Tomohito Tanaka; Yoshito Terai; Keisuke Ashihara; Satoe Fujiwara; Yoshimichi Tanaka; Hiroshi Sasaki; Satoshi Tsunetoh; Masahide Ohmichi
Background PD-0332991, the selective cyclin-dependent kinase 4/6 inhibitor palbociclib, causes cell cycle arrest by inhibiting phosphorylation of retinoblastoma (Rb) protein. The aim of this study was to evaluate the therapeutic potential of PD-0332991 in endometrial cancer. Methods and findings Four human endometrial cancer cell lines, ECC, HEC1A, HEC108 and TEN, were treated with PD-0332991 and their function was evaluated. In vivo, the therapeutic efficacy was evaluated in a model of subcutaneous endometrial cancer. An immunohistochemical analysis was performed in 337 endometrial cancer specimens. A proliferation assay revealed that 2 of the 4 cell lines that expressed Rb were sensitive to PD-0332991 with an IC50 of 0.65 μM (HEC1A) and 0.58 μM (HEC108), respectively. Both cell lines had G0/G1 cell cycle arrest after treatment with PD-0332991 according to flow cytometry. In vivo, PD-0332991 had antitumoral efficacy with a reduction in the activity of Ki67 and phosphorylation of Rb. Immunohistochemical analyses revealed that the positive rate of Rb was 67.7%, however, there was no significant relationship between the expression levels of Rb and the tumor grade. Conclusions PD-0332991 had therapeutic potential against endometrial cancer cell lines expressing Rb protein. Our immunohistochemical analysis revealed that approximately 70% of patients with endometrial cancer might have therapeutic indications for PD-0332991. Of note, the tumor grade had no impact on the indications for treatment.
Journal of Gynecologic Oncology | 2017
Tomohito Tanaka; Yoshito Terai; Keisuke Ashihara; Satoshi Tsunetoh; Hiroyuki Akagi; Takashi Yamada; Masahide Ohmichi
Objective Our objective was to determine the feasibility and detection rates and clarify the most effective combination of injected tracer types for sentinel lymph node (SLN) mapping in uterine cervical cancer in patients who have undergone laparoscopic surgery or neoadjuvant chemotherapy (NAC). Methods A total of 119 patients with cervical cancer underwent SLN biopsy at radical hysterectomy using three types of tracers. The various factors related to side-specific detection rate, sensitivity, and false negative (FN) rate were analyzed. Results The SLN detection rates using 99m-technetium (99mTc)-tin colloid, indigo carmine, and indocyanine green (ICG) were 85.8%, 20.2%, and 61.6%, respectively. The patients with ≥2-cm-diameter tumors and those who received NAC had lower detection rates than those with <2-cm-diameter tumors (75.7% vs. 91.5%, p<0.01) and those who did not receive NAC (67.9% vs. 86.3%, p<0.01), respectively. Laparoscopic procedures had a higher detection rate than laparotomy (100.0% vs. 77.1%, p<0.01). No factors significantly affected the sensitivity; however, the patients with ≥2-cm-diameter tumors (86.0% vs. 1.4%, p<0.01), NAC (19.4% vs. 2.2%, p<0.01), and those who underwent laparotomy (7.4% vs. 0%, p<0.01) had an unfavorable FN rate. Conclusion Among the examined tracers, 99mTc had the highest detection of SLN mapping in patients with uterine cervical cancer. Patients with local advanced cervical cancer with/without NAC treatment might be unsuited for SLN mapping. SLN mapping is feasible and results in an excellent detection rate in patients with <2-cm-diameter cervical cancer. Laparoscopic surgery is the best procedure for SLN detection in patients with early-stage disease.
Oncology Reports | 2015
Tomohito Tanaka; Yoshito Terai; Yuhei Kogata; Keisuke Ashihara; Kazuya Maeda; Satoe Fujiwara; Saha Yoo; Yoshimichi Tanaka; Satoshi Tsunetoh; Hiroshi Sasaki; Masanori Kanemura; Akiko Tanabe; Masahide Ohmichi
CD24, a small heavily glycosylated mucin-like glycosylphosphatidylinositol-anchored cell surface protein, plays an important role in the carcinogenesis of various human malignancies. However, its function in cervical cancer remains unclear. The aim of the present study was to evaluate the expression of CD24 clinicopathologically and to analyze its functional behavior biologically in cervical cancer. A total of 117 uterine cervical cancer tumors were immunohistochemically analyzed using a CD24 monoclonal antibody on paraffin blocks. We also examined whether CD24 enhanced the invasive activity or the Akt, ERK, NF-κB and MMP activity in a uterine cervical cancer cell line (CaSki) by a western blot analysis. The patients with enhanced CD24 expression had a higher rate of advanced clinical stage (50 vs. 16.5%, p<0.01), lymph node metastasis (34.6 vs. 14.3%) and lymphovascular involvement (65.4 vs. 20.4%, p=0.01), and a poor overall and disease-free survival (5-year survival rate: 62 vs. 86%, p=0.03). CD24 overexpression in CaSki cells resulted in activation of Cell Signaling proteins, including Akt, ERK, NF-κB and MMP-9. An invasion assay showed that CD24 overexpression in CaSki cells led to increased invasion ability. The CD24 overexpression also increased mRNA expression of Slug but not Snail. Moreover, the CD24 overexpression also decreased expression of E-cadherin and increased N-cadherin protein levels. Increased expression of CD24 may be associated with tumor progression and prognosis in patients with uterine cervical cancer. CD24 expression may therefore be used not only as a prognostic marker in uterine cervical cancer, but also as a target for the development of new therapeutic approaches.
Menopause | 2014
Risa Maruoka; Akiko Tanabe; Ayako Watanabe; Kiyoko Nakamura; Keisuke Ashihara; Tomohito Tanaka; Yoshito Terai; Masahide Ohmichi
ObjectiveMenopause is defined as the permanent cessation of menses. Although previous studies demonstrated a slight production of androgens and estrogens by postmenopausal ovaries, the impact of hormone production on lipid metabolism is still uncertain. The aim of this study was to evaluate whether the postmenopausal ovary is hormonally active and whether hormone status contributes to lipid metabolism. MethodsThis was a prospective study of 87 women who were treated for gynecological diseases (29% had cervical cancer, 49% had endometrial cancer, 7% had fibroid tumors, and 15% had cervical intraepithelial neoplasia). They were categorized as early postmenopausal (n = 40; mean [SD], 56.8 [3.8] y) or late postmenopausal (n = 47; mean [SD], 66.6 [5.7] y) women. Serum specimens were collected from the peripheral and ovarian veins of participants undergoing bilateral oophorectomy. Sex steroid hormone levels and lipid profiles were determined. ResultsStatistically significant differences in estradiol (E2) and testosterone were seen between the ovarian samples and the peripheral samples in all groups. E2 and estrone obtained from ovarian venous samples gradually decreased with age in postmenopausal women. There was a significant correlation between ovarian E2 and high-density lipoprotein cholesterol levels and the low-density lipoprotein–to–high-density lipoprotein ratio. However, there was no correlation between peripheral E2 levels and any of the lipid parameters examined. ConclusionsAlthough this study investigates women with gynecological diseases, the postmenopausal ovary is hormonally active, and the E2 produced by postmenopausal ovaries may therefore contribute to the maintenance of lipid metabolism.
International Journal of Gynecological Cancer | 2014
Keisuke Ashihara; Tomohito Tanaka; Risa Maruoka; Yoshihiro J. Ono; Akiko Tanabe; Yoshito Terai; Masahide Ohmichi
Objective Type 1 endometrial cancer (EC) is typically sex hormone sensitive; however, most women diagnosed with EC have already gone through menopause. Several studies have reported that the postmenopausal ovary is hormonally active, and estradiol (E2) production from the ovaries persists for as much as 10 years beyond menopause. The aim of this study was to evaluate whether sex steroid production from the ovaries contributes to the pathogenesis of type 1 EC. Materials and Methods This was a prospective study of 53 women treated for EC (28 cases of type 1 disease and 25 cases of type 2 disease). Serum specimens were collected from the peripheral and ovarian veins of participants undergoing bilateral oophorectomy. The sex steroid hormone levels and hormonal milieu on cervical cytology were evaluated as maturation value (MV). In addition, the degree of stromal hyperplasia of the ovary was evaluated histologically. Results Although the E2 levels of the peripheral veins did not show any significant differences [8.2 (5.1–12.4) vs 7.4 (5.1–11.7) pg/mL, respectively; P < 0.05], the patients with type 1 EC had a higher E2 level in the ovarian vein than those with type 2 EC [25 (13.8–42.5) vs 15 (10.0–23.0) pg/mL, respectively; P < 0.05]. There were also no significant differences in the rate of moderate to marked hyperplasia of the ovarian stroma between the groups; however, the thickness of the ovarian cortex demonstrated a correlation with the ovarian E2 level. In addition, the MV displayed a strong correlation with the ovarian E2 level, but not the peripheral E2 level. Conclusions The postmenopausal ovary is hormonally active, especially in patients with type 1 EC. The degree of ovarian stromal hyperplasia may (at least in part) contribute to the progression of type 1 EC, and MV may predict the level of E2 production from the ovaries in postmenopausal women.
Medicine | 2017
Tomohito Tanaka; Yoshito Terai; Kazuya Maeda; Keisuke Ashihara; Yuhei Kogata; Hiroshi Maruoka; Shinichi Terada; Takashi Yamada; Masahide Ohmichi
Abstract The aim of this study was to evaluate the dissemination of cancer cells at laparoscopic hysterectomy according to the intraperitoneal cytology. Patients with endometrial cancer underwent total laparoscopic modified radical hysterectomy. Peritoneal wash cytology was performed on entering the peritoneal cavity before surgical preparation and just after hysterectomy. Seventy-eight patients underwent laparoscopic hysterectomy for endometrial cancer. Among the 15 patients who had positive intraperitoneal cytology on entering the peritoneal cavity, 10 converted to negative intraperitoneal cytology after hysterectomy. In contrast, among the 63 patients who had negative intraperitoneal cytology on entering the peritoneal cavity, 2 converted to positive intraperitoneal cytology after hysterectomy. While surgery can reduce the number of cancer cells in the peritoneal cavity, leakage can occur, as seen in some cases of hysterectomy. Careful washing must be performed after hysterectomy.