Biomedical subjects

Tadashi Hayasaka

Publications and source records attributed to Tadashi Hayasaka.

9 recordsLinked to original sources

PubMed2006

Inhibition of phosphatidylinositol 3-kinase increases efficacy of cisplatin in in vivo ovarian cancer models.

The phosphatidylinositol 3-kinase (PI3K)/Akt cascade has an important role in the resistance of ovarian cancer cells to cisplatin in vitro; however, there have been no reports about whether blocking the PI3K/Akt cascade enhances the sensitivity to cisplatin in vivo. We investigated whether inhibition of PI3K increased the efficacy of cisplatin in an in vivo ovarian cancer model. Blocking the PI3K/Akt cascade with a PI3K inhibitor (wortmannin) increased the efficacy of cisplatin-induced inhibition of intraabdominal dissemination and production of ascites in athymic nude mice inoculated ip with the Caov-3 human ovarian cancer cell line. In addition, wortmannin increased the efficacy of cisplatin-induced apoptosis in tumors cells. There were no detectable side effects in mice treated with wortmannin. Moreover, the antitumor effect of cisplatin detected in mice inoculated with Caov-3 cells stably transfected with empty vector was significantly attenuated, compared with mice inoculated with Caov-3 cells stably transfected with a dominant-negative Akt, K179M-Akt. We confirmed that wortmannin blocked Akt phosphorylation and the downstream targets of the PI3K/Akt cascade, such as BAD (Bcl-2-associated death protein) and nuclear factor-kappaB in vivo by immunohistochemical staining and Western blotting. In accordance with the previously reported in vitro results, these in vivo results support the idea that combination therapy with cisplatin and a PI3K inhibitor would increase the therapeutic efficacy of cisplatin.

Androstadienes↗

PubMed2005

Characteristic features of ovarian borderline tumors with invasive implant.

OBJECTIVE: Since ovarian borderline tumor with invasive implant behaves as carcinoma, it should be managed like carcinoma. Since its characteristic features have not been reported, its preoperative diagnosis was thought to be impossible. We evaluated the features of MRI and macroscopic appearance in two cases of ovarian borderline tumor with invasive implant. METHODS: Borderline tumor with invasive implant was evaluated in two patients by MRI and macroscopic examination. RESULTS: In these patients, MRI revealed profuse papillary projections. Although the lesion showed high signal intensity on contrast-enhanced T1-weighted images compared with that on T1-weighted ones, most of the signal intensity on T2-weighted images was high, suggesting that the lesion is an assembly of vesicles and an obvious solid part is absent. The macroscopic appearance of the tumor showed profuse papillary projections consisting of many vesicles perforating and extending far beyond the ovarian capsule, without a solid part. The histological findings indicated serous borderline tumors with invasive implant. CONCLUSION: In these two cases, we found the characteristic features of serous borderline tumor with invasive implant by MRI and macroscopic examination. Our findings may be of clinical value since the preoperative information about the possibility of invasive implant may be quite important for the management of borderline tumor with invasive implant, especially for young patients wishing to bear children.

Adult↗

PubMed2005

Primary mucinous adenocarcinoma of the vagina: possibility of differentiating from metastatic adenocarcinomas.

Primary vaginal adenocarcinomas are rare neoplasms. Herein is reported a case of primary vaginal mucinous adenocarcinoma with an interesting mucin profile, presumably arising from a lesion of adenosis in a patient without in utero exposure to diethylstilbesterol (DES). The patient, a 44-year-old woman, had undergone vaginal total hysterectomy 10 years previously for myoma uteri corporis. The histological features of the vaginal intramural tumor found in this patient resembled those of mucinous adenocarcinoma of the endocervical type. Therefore, it was necessary to determine whether or not the tumor was metastatic from an occult cervical adenocarcinoma. However, the adenocarcinoma cells of the present case did not contain sulfomucin at all, being different from most mucinous adenocarcinoma cells of the endocervical type. Moreover, there were foci of adenosis adjacent to the adenocarcinoma foci, which also did not contain sulfomucin. These findings indicate that the mucinous adenocarcinoma arose from vaginal adenosis. Further studies are necessary to investigate whether lack of sulfomucin expression is a characteristic feature of vaginal adenosis.

Adenocarcinoma↗

PubMed2004

Inhibition of inhibitor of nuclear factor-kappaB phosphorylation increases the efficacy of paclitaxel in in vitro and in vivo ovarian cancer models.

We investigated whether inhibition of nuclear factor-kappaB (NFkappaB) increases the efficacy of paclitaxel in in vitro and in vivo ovarian cancer models. Treatment of paclitaxel-sensitive Caov-3 cells with paclitaxel transiently activated the phosphorylation of Akt, the phosphorylation of IkappaB kinase (IKK), and the phosphorylation of inhibitor of NFkappaB (IkappaBalpha). Paclitaxel also caused a transient increase in NFkappaB activity, followed by a decrease in NFkappaB activity. We show an association between Akt and IKK and show that the phosphorylation of IKK induced by paclitaxel is blocked by treatment with a phosphatidylinositol 3-kinase inhibitor (wortmannin or LY294002). Furthermore, interference of the Akt signaling cascade inhibits the transient induction of IkappaBalpha phosphorylation and NFkappaB activity by paclitaxel. Inhibition of NFkappaB activity by treatment with an IkappaBalpha phosphorylation inhibitor (BAY 11-7085) attenuated both basal and transient induction of IkappaBalpha phosphorylation by paclitaxel. Treatment with BAY 11-7085 also enhanced the inhibition of NFkappaB activity by paclitaxel for up to 24 hours. In addition, treatment with BAY 11-7085 decreased the viability of cells treated with paclitaxel. Moreover, treatment with BAY 11-7085 increased the efficacy of paclitaxel-induced inhibition of intraabdominal dissemination and production of ascites in athymic nude mice inoculated intraperitoneally with Caov-3 cells. These results suggest that paclitaxel transiently induces NFkappaB activity via the phosphatidylinositol 3-kinase/Akt cascade and that combination therapy with paclitaxel and an NFkappaB inhibitor would increase the therapeutic efficacy of paclitaxel.

Androstadienes↗

PubMed2004

Intravenous leiomyomatosis with cardiac extension.

Intravenous leiomyomatosis with cardiac extension is an extremely rare uterine tumor. We report here a case of a patient with a uterine leiomyoma which extended into the right atrium through the left ovarian vein, progressing into the left renal vein along the inferior vena cava. Complete one-stage removal of the tumor was performed using cardiopulmonary bypass, and the patient has shown a favorable outcome. Successful therapy for intravenous leiomyomatosis is dependent on total surgical excision of the tumor, cessation of ovarian function and avoidance of postoperative estrogen replacement therapy.

Cardiopulmonary Bypass↗

PubMed2004

Inhibition of NFkappaB increases the efficacy of cisplatin in in vitro and in vivo ovarian cancer models.

Whether or not inhibition of NFkappaB increases the efficacy of cisplatin in in vitro and in vivo ovarian cancer models was investigated. We compared the basal levels of phosphorylation of IkappaBalpha and activity of NFkappaB between cisplatin-sensitive A2780 cells and cisplatin-resistant Caov-3 cells. The basal levels of phosphorylation of IkappaBalpha and activity of NFkappaB in Caov-3 cells were significantly higher than those in A2780 cells. Cisplatin caused a more marked decrease in the phosphorylation of IkappaBalpha and activity of NFkappaB in A2780 cells than in Caov-3 cells. Thus, high basal levels of phosphorylation of IkappaBalpha and activation of NFkappaB and less marked inhibition of the phosphorylation of IkappaBalpha and activation of NFkappaB by cisplatin seem to reduce the sensitivity of cells to cisplatin. Inhibition of NFkappaB activity either by treatment with the IkappaBalpha phosphorylation inhibitor (BAY 11-7085) or a specific NFkappaB nuclear translocation inhibitor (SN-50) or by transfection of p50DeltaNLS (which lacks the nuclear localization signal domain) increased the efficacy of both the cisplatin-induced attenuation of IkappaBalpha phosphorylation and NFkappaB activity and the cisplatin-induced apoptosis. In addition, treatment with BAY 11-7085 increased the efficacy of the cisplatin-induced attenuation of both the expression of X-linked inhibitor of apoptosis protein (XIAP) and cell invasion through Matrigel. Moreover, treatment with BAY 11-7085 increased the efficacy of the cisplatin-induced inhibition of the intra-abdominal dissemination and production of ascites using athymic nude mice inoculated intraperitoneally with Caov-3 cells. These results suggest that combination therapy of cisplatin with the NFkappaB inhibitor should increase the therapeutic efficacy of cisplatin.

Animals↗

PubMed2004

Small cell neuroendocrine carcinomas of the uterine cervix: a histological, immunohistochemical, and molecular genetic study.

Small cell carcinomas of the uterine cervix are rare tumors with an aggressive behavior. Although these tumors can exhibit neuroendocrine differentiation, the criteria for neuroendocrine differentiation are subjective and not well defined. In this study, the authors tentatively defined small cell neuroendocrine carcinoma (SCNEC) as a tumor composed of small cells with at least two of the following: argyrophilic cytoplasm, chromogranin A immunoreactivity, and synaptophysin immunoreactivity. We found 10 cases fulfilling these requirements. Five of the 10 tumors were composed mainly of small ("oat") cells and 5 of mainly larger "intermediate" cells. The majority of both subtypes showed an insular pattern. Three of the 10 SCNECs were pure, whereas the other seven were mixed with adenocarcinoma and/or squamous cell carcinoma or cervical intraepithelial neoplasia. In addition to the definitional markers noted earlier, the tumors were immunoreactive for serotonin (6 cases), somatostatin, gastrin, glucagon, and pancreatic polypeptide. No tumors were immunoreactive for cytokeratin 20. Human papillomavirus (HPV)-18 was detected in all of the pure tumors and both the SCNEC and adenocarcinomatous components in four of the mixed tumors. No other types of HPV were detected. The tumors showed a relatively low frequency of loss of heterozygosity for representative tumor suppressor gene sites; p53 mutations were found in only one case.

Adult↗

PubMed2003

Ovarian carcinoid exhibiting double function.

A case of a 58-year-old woman with ovarian carcinoid exhibiting double function is reported. She had suffered from constipation and hirsutism before surgery. Pathological examination revealed that many carcinoid tumor cells were immunohistochemically positive for peptide YY, which inhibits intestinal motility and many peripheral steroid cells. After surgery the patient recovered from constipation immediately. Although the serum level of testosterone also immediately decreased, hirsutism remained for about 2 years. These clinical manifestations are considered to be due to peptide hormone-producing tumor parenchymal cells and testosterone-producing functioning stromal cells. This is the first report of clinically manifested double-functioning ovarian carcinoid; one function is due to tumor cells themselves and another function is due to stromal cells.

Biomarkers, Tumor↗

PubMed2003

Mucin expression in nonneoplastic and neoplastic glandular epithelia of the uterine cervix.

Although it is well known that the uterine cervix contains mucin-producing glandular epithelium, only a few studies have described the changes in mucin that accompany malignant transformation. In this study the authors evaluated the characteristics of mucin expression in the normal endocervical epithelium and mucinous and endometrioid adenocarcinomas of the uterine cervix. The normal endocervical epithelium was characterized by predominant sulfomucin and MUC1 expression in all sites and MUC5AC expression in the surface epithelium, while MUC2 was not detected at all and pyloric gland type mucin (using antibody HIK1083) was detected in less than 1% of cases. Cervical adenocarcinomas, especially mucinous adenocarcinomas, showed marked variability in mucin expression that included mucins of pyloric gland and intestinal type.

Adenocarcinoma, Mucinous↗