Kazushige Adachi

Inhibition of phosphorylation of BAD and Raf-1 by Akt sensitizes human ovarian cancer cells to paclitaxel.

We studied the roles of the phosphatidylinositol 3-kinase (PI-3K)-Akt-BAD cascade, ERK-BAD cascade, and Akt-Raf-1 cascade in the paclitaxel-resistant SW626 human ovarian cancer cell line, which lacks functional p53. Treatment of SW626 cells with paclitaxel activates Akt and ERK with different time frames. Interference with the Akt cascade either by treatment with PI-3K inhibitor (wortmannin or LY294002) or by exogenous expression of a dominant negative Akt in SW626 cells caused decreased cell viability following treatment with paclitaxel. Interference with the ERK cascade by treatment with an MEK inhibitor, PD98059, in SW626 cells also caused decreased cell viability following treatment with paclitaxel. Treatment of cells with paclitaxel also stimulated the phosphorylation of BAD at both the Ser-112 and Ser-136 sites. The phosphorylation of BAD at Ser-136 was blocked by treatment with wortmannin or cotransfection with the dominant negative Akt. On the other hand, the phosphorylation of BAD at Ser-112 was blocked by PD98059. We further examined the role of BAD in the viability following paclitaxel treatment using BAD mutants. Exogenous expression of doubly substituted BAD2SA in SW626 cells caused decreased viability following treatment with paclitaxel. Moreover, because paclitaxel-induced apoptosis is mediated by activated Raf-1 and the region surrounding Ser-259 in Raf-1 conforms to a consensus sequence for phosphorylation by Akt, the regulation of Raf-1 by Akt was examined. We demonstrated an association between Akt and Raf-1 and showed that the phosphorylation of Raf-1 on Ser-259 induced by paclitaxel was blocked by treatment with wortmannin or LY294002. Furthermore, interference with the Akt cascade induced by paclitaxel up-regulated Raf-1 activity, and expression of constitutively active Akt inhibited Raf-1 activity, suggesting that Akt negatively regulates Raf-1. Our findings suggest that paclitaxel induces the phosphorylation of BAD Ser-112 via the ERK cascade, and the phosphorylation of both BAD Ser-136 and Raf-1 Ser-259 via the PI-3K-Akt cascade, and that inhibition of either of these cascades sensitizes ovarian cancer cells to paclitaxel.

Molecular Cloning and Characterization of the Murine Staf cDNA Encoding a Transcription Activating Factor for the Selenocysteine tRNA Gene in Mouse Mammary Gland

We have isolated and characterized a cDNA encoding a transcription activating factor for the mouse selenocysteine tRNA (tRNAsec) gene from mouse mammary gland. The full-length cDNA, designated m-Staf, has a 1878-base pair open reading frame encoding 626 amino acids. The predicted amino acid sequence of m-Staf is highly homologous to that of Staf, another selenocysteine tRNA gene transcription activating factor ofXenopus laevis. Like Staf, m-Staf contains seven tandemly repeated zinc fingers and four repeated motifs. Gel shift assays indicated that the recombinant m-Staf specifically bound to the activator element region in the mouse tRNAsec gene. Transient co-transfection experiments in DrosophilaSchneider cells, which lack endogenous Staf-like binding activity, showed that m-Staf increased the mouse tRNAsec gene transcription about 15-fold, whereas it stimulated Pol II-dependent thymidine kinase promoter only 2-fold. Northern blot analysis detected the presence of a 3.4-kilobase pair m-Staf transcript, which was widely but differentially expressed in various murine tissues. The binding activity of m-Staf in mouse mammary gland was undetectable during virgin and postlactating periods but increased markedly in parallel with the increase of tRNAsectranscript during the periods of pregnancy and lactation, when the gland undergoes growth and development. These results indicate that m-Staf is a transcriptional activator of the mouse tRNAsecgene and that its binding activity in the mammary gland undergoes developmental alterations.

Transforming growth factor‐α promotes tumor markers secretion from human ovarian cancers in vitro

The regulatory mechanism of tumor markers secretion has not been well clarified.

Implantation and growth of epidermal growth factor (EGF) receptor expressing human ovarian cancer xenografts in nude mice is dependent on EGF

Background. The importance of epidermal growth factor (EGF) receptor‐dependent growth has not been clarified for in vivo growth of primary human ovarian cancers.

Intraventricular administration of estradiol modulates rat prolactin secretion and synthesis.

The effect of estradiol (E2) on rat tuberoinfundibular dopaminergic (TIDA) neurons was examined in vivo, employing chronic intraventricular (icv) infusion technique using an osmotic mini-pump. The activity of TIDA neurons was assessed by the release and synthesis of prolactin (PRL) in the rat pituitary gland and by the changes in the 3, 4-dihydroxyphenylacetic acid (DOPAC) and dopamine (DA) levels and in the DOPAC/DA ratio in the rat hypothalamus. We also examined the [3H] E2 binding in the rat hypothalamus. Ovariectomized female Wistar rats with E2 replacement were treated with daily icv infusion of 1μM of E2 or saline vehicle for 1, 3, and 7 days using the Alzet osmotic mini-pump and brain infusion kit. At 1 day of icv infusion of E2, the serum PRL level was significantly decreased compared with that in the vehicle group. Northern blot analysis of the total RNA isolated from the pituitary glands demonstrated a decrease in the PRL gene transcript level in the E2 group. At 3 days of E2 treatment, however, the serum PRL level was significantly increased compared with that of the vehicle-injected group and Northern blot analysis also demonstrated that the PRL gene transcript level was increased in the E2 group. At 7 days of E2 administration, there were no significant differences between the E2 and vehicle groups in either serum PRL or PRL gene transcript levels. There was a significant increase in the DOPAC/DA ratio after 1 day in the E2 group. However, no significant effects of E2 on this ratio were observed at 3 and 7 days of treatment. The DOPAC concentration in the E2 group was significantly increased at day 1 and significantly decreased at day 3, compared with that of the respective time in vehicle group. At day 7 there was no significant change in DOPAC concentration in either groups. The DA concentrations in the hypothalamus was not changed on any day in either group. Specific [3H] E2 binding was observed in the rat hypothalamus. These data suggest that E2 may have a biphasic effect on the accumulation of PRL gene transcripts and on the PRL secretion in the rat pituitary by first stimulating and then inhibiting the TIDA neuronal activity.

Clinical Features Affecting the Results of Estrogen Replacement Therapy on Bone Density in Japanese Postmenopausal Women

Although estrogen replacement therapy (ERT) has been established as an effective treatment for postmenopausal bone loss, the clinical features which predict the effects of ERT have not been well investigated in Japanese postmenopausal women. We analyzed the role of physical factors influencing the effect of ERT on vertebral bone mineral density (BMD) in 94 Japanese postmenopausal women treated for 2 years or longer. The increase in BMD with ERT is 17.6 ± 27.6 mg/cm2/year (mean ± SD) during the first 2 years. Rates of BMD change were negatively correlated with the estimated initial BMD, and positively correlated with age and years since menopause, while no correlation was noted with the body mass index by a simple correlation analysis. The relationships between BMD change and estimated initial BMD or age also held in a multiple regression analysis. The estimated initial BMD and age together accounted for 34.4% of the BMD change during ERT. Furthermore, there were very few (2.4%) nonresponders with a negative linear regression slope of BMD in the osteoporosis and osteopenia group, although 32.7% of the normal initial BMD group were nonresponders. These results suggest that the initial BMD and age are potent predictive factors of the ERT effect on BMD change in Japanese postmenopausal women.

Ovarian tumor treated by laparoendoscopic single-site surgery through the preexisting paraumbilical hernia: an initial case report

For benign gynecological diseases, laparoscopic surgery has become a standard method. Its advantages include fast recovery, shorter hospital stay, decreased analgesic requirements, and lower perioperative complications. In recent years, laparoendoscopic single-site (LESS) surgery has become a new branch of surgery that increases cosmetic benefits over traditional endoscopic surgery [1]. Recent reports suggest that LESS surgery has an advantage over conventional laparoscopic surgery in the aspect of postoperative pain and the use of analgesia [2–6]. Here, we present the first case of ovarian tumor treated by LESS surgery, which has been successfully applied in a patient complicated with paraumbilical hernia, using its hernia ring as a placement site for the single port.

Effects of bezafibrate and simvastatin on plasma lipoproteins in hypercholesterolemia resistant to hormone replacement therapy

OBJECTIVES Estrogen replacement therapy has favorable effects on serum lipoprotein levels in postmenopausal women with hypercholesterolemia. However, there are some patients who fail to respond to hormone replacement therapy (HRT) to lower the serum cholesterol level. In these cases, a conventional lipid-lowering therapy will be applied in addition to HRT, while the effects of these drugs are not well understood. In this study, we studied the effects of simvastatin and bezafibrate administered in addition to HRT. METHODS Patients who were hypercholesterolemic even after HRT were randomly assigned to three treatment groups: HRT only (control group, n=10), HRT+simvastatin (10 mg/day, n=10), or HRT+bezafibrate (400 mg/day, n=10). Serum lipids and lipoprotein levels were measured throughout 12 weeks. RESULTS The serum triglyceride levels were decreased by 24+/-28 and 38+/-13% in the HRT+simvastatin and HRT+bezafibrate groups, respectively. HRT+simvastatin decreased the total cholesterol (21+/-10%) and low-density lipoprotein cholesterol (28+/-12%) levels without affecting the high-density lipoprotein cholesterol (HDL-C) level, while HRT+bezafibrate increased the HDL-C level (12+/-11%). CONCLUSIONS Treatment with simvastatin or bezafibrate in addition to HRT should be considered in cases of postmenopausal hypercholesterolemia in which HRT alone fails to lower the serum lipoprotein levels.

Broad ligament hernia successfully repaired by single‐incision laparoscopy: A case report

A 52‐year‐old woman with a history of two parturitions presented with lower abdominal pain. Multi‐detector CT of the abdomen showed discontinuity of the sigmoid colon near the broad ligament on the left side. We assigned a provisional diagnosis of an internal hernia progressing through a defect in the broad ligament. SILS revealed a total broad ligament defect on the left side but no signs of ischemic, necrotic bowel. We successfully repaired the broad ligament defect with suturing. At the 2‐month follow‐up, the patient remained well with no signs of recurrence. This case appears to be the first report of a broad ligament hernia successfully diagnosed and repaired by SILS.

Transumbilical extraction of 151–300-g myomas without morcellator versus conventional laparoscopic myomectomy with power morcellator

Study objective: The aim of this study was to compare the surgical outcomes, particularly the specimen retrieval time, between two methods of laparoscopic myomectomy: transumbilical retrieval of the myoma without a morcellator and conventional retrieval of the myoma using a power morcellator via the left lower quadrant. Design: Retrospective study. Setting: Public hospital. Patients: Seventy-four women undergoing laparoscopic myomectomy. Interventions: Laparoscopic myomectomy followed by myoma retrieval via transumbilical extraction or electric motorized morcellator extraction. Measurements and main results: Seventy-four patients undergoing laparoscopic myomectomy followed by myoma retrieval via transumbilical extraction or electric motorized morcellator extraction were studied. Significant differences were observed in the average weight of the retrieved myomas between the transumbilical and morcellator groups (141.0 vs. 262.8 g, respectively; p < 0.001). Therefore, we chose 27 patients whose total specimen weight was 151–300 g; 13 patients were in the transumbilical extraction group and 14 were in the electric motorized morcellator group. No significant differences were observed in patient characteristics between the two groups. The operative time, blood loss volume, and myoma retrieval time were similar between the two groups. Conclusion: Laparoscopic myomectomy with transumbilical extraction for myoma retrieval is a feasible method for specimens weighing up to 300 g.