Strictly regulated agonist-dependent activation of AMPA-R is the key characteristic of TAK-653 for robust synaptic responses and cognitive improvement

Agonistic profiles of AMPA receptor (AMPA-R) potentiators may be associated with seizure risk and bell-shaped dose-response effects. Here, we report the pharmacological characteristics of a novel AMPA-R potentiator, TAK-653, which exhibits minimal agonistic properties. TAK-653 bound to the ligand binding domain of recombinant AMPA-R in a glutamate-dependent manner. TAK-653 strictly potentiated a glutamate-induced Ca2+ influx in hGluA1i-expressing CHO cells through structural interference at Ser743 in GluA1. In primary neurons, TAK-653 augmented AMPA-induced Ca2+ influx and AMPA-elicited currents via physiological AMPA-R with little agonistic effects. Interestingly, TAK-653 enhanced electrically evoked AMPA-R-mediated EPSPs more potently than AMPA (agonist) or LY451646 (AMPA-R potentiator with a prominent agonistic effect) in brain slices. Moreover, TAK-653 improved cognition for both working memory and recognition memory, while LY451646 did so only for recognition memory, and AMPA did not improve either. These data suggest that the facilitation of phasic AMPA-R activation by physiologically-released glutamate is the key to enhancing synaptic and cognitive functions, and nonselective activation of resting AMPA-Rs may negatively affect this process. Importantly, TAK-653 had a wide safety margin against convulsion; TAK-653 showed a 419-fold (plasma Cmax) and 1017-fold (AUC plasma) margin in rats. These findings provide insight into a therapeutically important aspect of AMPA-R potentiation.

Correlation of progression-free and post-progression survival with overall survival in phase III trials of first-line chemotherapy for advanced epithelial ovarian cancer

PURPOSE OF INVESTIGATION

The authors examined the relation between post-progression survival (PPS) and overall survival (OS) in phase III trials of first-line chemotherapy for advanced epithelial ovarian cancer.

MATERIALS AND METHODS

The authors partitioned OS into progression-free survival (PFS) and PPS and evaluated the relation between OS and either PFS or PPS. They also examined whether any association might be affected by the year of completion of trial enrollment.

RESULTS

The average PPS was longer in recent trials than in older trials (26.9 vs. 20.2 months,p = 0.0002). For all trials, PPS was strongly associated with OS (r = 0.94), whereas PFS was more moderately but still strongly correlated with OS (r = 0.83). The average proportion of median OS accounted for by median PPS significantly increased from 54.1% in older trials to 60.3% in recent trials (p = 0.0001).

CONCLUSION

The present findings indicate that, especially for recent trials, PPS is more highly associated than PFS with OS in first-line chemotherapy for advanced epithelial ovarian cancer.

Effect of an investigational CYP17A1 inhibitor, orteronel (TAK-700), on estrogen- and corticoid-synthesis pathways in hypophysectomized female rats and on the serum estradiol levels in female cynomolgus monkeys

Orteronel (TAK-700) is an investigational, non-steroidal inhibitor of CYP17A1 with preferential inhibition of 17,20-lyase in NCI-H295 cells. Estrogen is synthesized from androgen by aromatase activity, and the effect of orteronel on estrogen synthesis was therefore evaluated. First, it was confirmed that orteronel does not directly inhibit aromatase activity. Second, the specific decline of serum estradiol and androgen levels in hypophysectomized female rats by orteronel in comparison with aromatase inhibitor anastrozole was evaluated; orteronel at doses ≥3mg/kg significantly suppressed serum estradiol, testosterone, androstenedione and 17-hydroxyprogesterone levels, and increased progesterone levels in the estrogen-synthesis pathway. Orteronel, at a dose of 300mg/kg, suppressed serum estradiol concentrations to a similar degree as 0.1mg/kg anastrozole. In contrast, in the corticoid-synthesis pathway, serum aldosterone, corticosterone, and progesterone levels did not change significantly following administration of 300mg/kg of orteronel. Third, the effect of multiple oral administration of orteronel on serum estradiol levels in regularly cycling female cynomolgus monkeys was evaluated. Orteronel at 15mg/kg/day (7.5mg/kg/treatment, twice daily [bid]) continued to suppress the estradiol surge prior to the start of luteal phase for 1.5-times the average duration of three consecutive, pre-treatment menstrual cycles, while serum progesterone was maintained at levels almost equal to those in the luteal phase although a certain portion of this increased level of progesterone could be of adrenal-origin. This suppressive effect on estradiol surge was thought to be reversible since serum estradiol levels started to rise immediately after the discontinuation of orteronel. Estradiol surge was not abrogated by treatment with anastrozole 0.2mg/kg/day (0.1mg/kg/treatment, bid). In summary, orteronel can suppress serum estradiol concentrations in hypophysectomized female rats and monkeys through selective inhibition of CYP17A1 activity, suggesting that orteronel might be effective for hormone-dependent breast cancers and estrogen-dependent diseases.

Effect of a novel 17,20-lyase inhibitor, orteronel (TAK-700), on androgen synthesis in male rats

Endogenous androgens play a role in the development and progression of prostate cancer (PC), thus androgen suppression may offer an effective therapeutic strategy for this disease. Orteronel (TAK-700), 6-[(7S)-7-hydroxy-6,7-dihydro-5H-pyrrolo[1,2-c]imidazol-7-yl]-N-methyl-2-naphthamide, is a novel, non-steroidal, selective inhibitor of the 17,20-lyase activity of CYP17A--a key enzyme in the production of steroidal hormones--and is being developed as a therapy for PC. The purpose of this study was to elucidate the inhibitory activity of orteronel, in particular its specificity for androgen synthesis enzymes, in male rats--an androgen-synthesis model that largely reflects this pathway in humans. Orteronel inhibited 17,20-lyase activity in rats with an IC(50) of 1200 nM but did not inhibit 17α-hydroxylase or 11β-hydroxylase (CYP11B1) activity in rats at concentrations up to 10 μM. In cellular steroidogenesis assays using rat testicular cells, orteronel suppressed testosterone and androstenedione production with an IC(50) of 640 nM and 210 nM, respectively, but did not suppress either corticosterone or aldosterone production in rat adrenal cells at concentrations up to 30 μM. In addition, serum testosterone and androstenedione levels in human chorionic gonadotropin-injected hypophysectomized rats were significantly reduced by single oral administration of orteronel at a dose of 30 mg/kg (both p ≤ 0.01); serum corticosterone and aldosterone levels in ACTH-injected hypophysectomized rats did not result in significant differences compared with controls, following orteronel administration at doses up to 300 mg/kg. Serum testosterone levels in intact male rats were significantly reduced by orteronel 4h after dosing at 100mg/kg (p ≤ 0.01); testosterone levels showed a tendency to recover afterward. In intact male rats, the weight of the prostate glands and seminal vesicles was decreased in a dose-dependent manner following multiple doses of orteronel at 37.5, 150, and 600 mg/kg, TID for 4 days. The reversibility of orteronel was further confirmed using a human adrenocortical tumor cell line. In summary, orteronel is a selective and reversible 17,20-lyase inhibitor, and decreases the weight of androgen-dependent organs in male rats. Our data suggests that orteronel would therefore be effective for androgen-dependent disorders such as PC.

Orteronel (TAK-700), a novel non-steroidal 17,20-lyase inhibitor: effects on steroid synthesis in human and monkey adrenal cells and serum steroid levels in cynomolgus monkeys

Surgical or pharmacologic methods to control gonadal androgen biosynthesis are effective approaches in the treatment of a variety of non-neoplastic and neoplastic diseases. For example, androgen ablation and its consequent reduction in circulating levels of testosterone is an effective therapy for advanced prostate cancers. Unfortunately, the therapeutic effectiveness of this approach is often temporary because of disease progression to the 'castration resistant' (CRPC) state, a situation for which there are limited treatment options. One mechanism thought to be responsible for the development of CRPC is extra-gonadal androgen synthesis and the resulting impact of these residual extra-gonadal androgens on prostate tumor cell proliferation. An important enzyme responsible for the synthesis of extra-gonadal androgens is CYP17A1 which possesses both 17,20-lyase and 17-hydroxylase catalytic activities with the 17,20-lyase activity being key in the androgen biosynthetic process. Orteronel (TAK-700), a novel, selective, and potent inhibitor of 17,20-lyase is under development as a drug to inhibit androgen synthesis. In this study, we quantified the inhibitory activity and specificity of orteronel for testicular and adrenal androgen production by evaluating its effects on CYP17A1 enzymatic activity, steroid production in monkey adrenal cells and human adrenal tumor cells, and serum levels of dehydroepiandrosterone (DHEA), cortisol, and testosterone after oral dosing in castrated and intact male cynomolgus monkeys. We report that orteronel potently suppresses androgen production in monkey adrenal cells but only weakly suppresses corticosterone and aldosterone production; the IC(50) value of orteronel for cortisol was ~3-fold higher than that for DHEA. After single oral dosing, serum levels of DHEA, cortisol, and testosterone were rapidly suppressed in intact cynomolgus monkeys. In castrated monkeys treated twice daily with orteronel, suppression of DHEA and testosterone persisted throughout the treatment period. In both in vivo models and in agreement with our in vitro data, suppression of serum cortisol levels following oral dosing was less than that seen for DHEA. In terms of human CYP17A1 and human adrenal tumor cells, orteronel inhibited 17,20-lyase activity 5.4 times more potently than 17-hydroxylase activity in cell-free enzyme assays and DHEA production 27 times more potently than cortisol production in human adrenal tumor cells, suggesting greater specificity of inhibition between 17,20-lyase and 17-hydroxylase activities in humans vs monkeys. In summary, orteronel potently inhibited the 17,20-lyase activity of monkey and human CYP17A1 and reduced serum androgen levels in vivo in monkeys. These findings suggest that orteronel may be an effective therapeutic option for diseases where androgen suppression is critical, such as androgen sensitive and CRPC.

Discovery of orteronel (TAK-700), a naphthylmethylimidazole derivative, as a highly selective 17,20-lyase inhibitor with potential utility in the treatment of prostate cancer

A novel naphthylmethylimidazole derivative 1 and its related compounds were identified as 17,20-lyase inhibitors. Based on the structure-activity relationship around the naphthalene scaffold and the results of a docking study of 1a in the homology model of 17,20-lyase, the 6,7-dihydro-5H-pyrrolo[1,2-c]imidazole derivative (+)-3c was synthesized and identified as a potent and highly selective 17,20-lyase inhibitor. Biological evaluation of (+)-3c at a dose of 1mg/kg in a male monkey model revealed marked reductions in both serum testosterone and dehydroepiandrosterone concentrations. Therefore, (+)-3c (termed orteronel [TAK-700]) was selected as a candidate for clinical evaluation and is currently in phase III clinical trials for the treatment of castration-resistant prostate cancer.

Abstract DD01-03: TAK-700, an inhibitor of 17,20-lyase

Background: Recent studies suggest that residual adrenal androgen after castration could be responsible for the progression of castration-resistant prostate cancer (CRPC). To develop an effective therapy for CRPC that inhibits the production of adrenal and testicular androgens, we searched for a novel, non-steroidal, selective, and potent inhibitor of 17,20-lyase, a key enzyme in androgen synthesis, and identified TAK-700 as a clinical candidate.

Methods: Enzyme assay was conducted using radiolabeled substrates. The enzyme reaction products were separated by thin layer chromatography and the radioactivity was measured by a bio-image analyzer. We assessed the activity and specificity of TAK-700 on androgen production in vitro in monkey adrenal cells and human adrenocortical tumor cell line, using a radioimmunoassay. Using a single dose of [14C]TAK-700 1 mg/kg, we investigated the pharmacokinetics and bioavailability of TAK-700 in cynomolgus monkeys, and assessed the effects of TAK-700 7.5 and 15 mg/kg twice daily (BID) for 7 days on serum androgen levels in castrated and intact cynomolgus monkeys.

Results: TAK-700 potently inhibited the activities of human and monkey 17, 20-lyase (CYP17A1) with IC50 values of 140 and 27nmol/L, respectively. The inhibitory activity of TAK-700 on 17-hydroxylase was lower than that on 17, 20-lyase in all the enzyme preparations. IC50 values of ketoconazole and abiraterone for human 17, 20-lyase were 110 and 27nmol/L, respectively. TAK-700 did not inhibit monkey 11-hydroxylase up to 10μmol/L. In addition, IC50 values of TAK-700 for all CYP-specific activities (drug-metabolizing enzymes) examined were higher than 10 μmol/L. TAK-700 suppressed the production of DHEA, androstenedione, cortisol, corticosterone and aldosterone by monkey adrenal cells with IC50 values of 110, 130, 310, >100,000 and 4,400nmol/L, respectively. The IC50 value for cortisol production was only 3-fold higher than that for DHEA production in monkeys, reflecting low specificity of inhibition between monkey 17, 20-lyase and 17-hydroxylase activity (IC50 values: 27 vs 38nmol/L). Ketoconazole suppressed the production of DHEA, androstenedione, cortisol, corticosterone and aldosterone by monkey adrenal cells with IC50 values of 340, 580, 340, 1,500 and 350nmol/L, respectively. TAK-700 inhibited the production of dehydroepiandrosterone (DHEA) and cortisol in human adrenocortical tumor line NCI-H295R cells with IC50 values of 37 and 990nmol/L, respectively, showing about 27-fold selectivity for DHEA production. Ketoconazole inhibited the production of DHEA and cortisol with IC50 values of 330 and 480nmol/L (selectivity 1.5-fold), respectively, and abiraterone inhibited the production of DHEA and cortisol with IC50 values of 2.7 and 23nmol/L (selectivity: 8.5-fold), respectively. TAK-700 showed the highest specificity of inhibition for DHEA production among these 3 compounds. After oral administration of [14C]TAK-700 1 mg/kg, maximum plasma concentration (Cmax) was 0.147 μg/mL, time to Cmax (Tmax) was 1.7 hours, elimination half-life (t1/2) was 3.8 hours, and exposure (area under the plasma concentration-time curve in 24 hours, AUC0-24h) was 0.727 μg·h/mL. Oral bioavailability of TAK-700 in monkeys was 70.5%. Oral dosing of TAK-700 7.5 and 15 mg/kg BID rapidly (within 1 day) suppressed serum levels of the androgens dehydroepiandrosterone (DHEA) and testosterone and of cortisol in both castrated and gonadally intact monkeys. While suppression of DHEA and cortisol levels persisted during the 7-day treatment period in castrated monkeys, suppression of testosterone was attenuated from the second day of treatment, possibly due to activation of the hypothalamus-pituitary-gonad axis. TAK-700 had a milder suppressive effect on cortisol levels than on DHEA levels. During the treatment period, mean DHEA levels decreased to 9.0% and 6.9% of baseline levels in castrated monkeys treated with TAK-700 7.5 and 15 mg/kg, respectively. The mean cortisol levels decreased to 26.0% and 17.3% of baseline levels with TAK-700 7.5 and 15 mg/kg, respectively. In vitro results have shown that the specificity of TAK-700 suppression of DHEA production over cortisol production is 10-fold greater in human adrenal-origin cells than in monkey adrenal cells. Therefore, the impact of TAK-700 on human serum cortisol levels may be smaller than that in monkeys.

Conclusion: As TAK-700 potently and selectively inhibited 17, 20-lyase activity and DHEA production by H295R cells and suppressed serum androgen levels in castrated monkeys, TAK-700 may be effective for at least some types of CRPC, and clinical evaluation of TAK-700 is now underway in patients with CRPC.

Citation Format: Masuo Yamaoka, Takahito Hara, Hiroshi Miki, Takenori Hitaka, Tomohiro Kaku, Naohiro Kawaguchi, Hitomi Yamasaki, Toshiyuki Takeuchi, Akihiro Tasaka, Masami Kusaka. TAK-700, an inhibitor of 17,20-lyase [abstract]. In: Proceedings of the AACR 101st Annual Meeting 2010; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr DD01-03

Bepridil up-regulates cardiac Na+ channels as a long-term effect by blunting proteasome signals through inhibition of calmodulin activity

BACKGROUND AND PURPOSE

Bepridil is an anti-arrhythmic agent with anti-electrical remodelling effects that target many cardiac ion channels, including the voltage-gated Na+ channel. However, long-term effects of bepridil on the Na+ channel remain unclear. We explored the long-term effect of bepridil on the Na+ channel in isolated neonatal rat cardiomyocytes and in a heterologous expression system of human Na(v)1.5 channel.

EXPERIMENTAL APPROACH

Na+ currents were recorded by whole-cell voltage-clamp technique. Na+ channel message and protein were evaluated by real-time RT-PCR and Western blot analysis.

KEY RESULTS

Treatment of cardiomyocytes with 10 micromol.L(-1) bepridil for 24 h augmented Na+ channel current (I(Na)) in a dose- and time-dependent manner. This long-term effect of bepridil was mimicked or masked by application of W-7, a calmodulin inhibitor, but not KN93 [2-[N-(2-hydroxyethyl)-N-(4-methoxy benzenesulphonyl)]-amino-N-(4-chlorocinnamyl)-N-methylbenzylamine], a Ca2+/calmodulin-dependent kinase inhibitor. During inhibition of protein synthesis by cycloheximide, the I(Na) increase due to bepridil was larger than the increase without cycloheximide. Bepridil and W-7 significantly slowed the time course of Na(v)1.5 protein degradation in neonatal cardiomyocytes, although the mRNA levels of Na(v)1.5 were not modified. Bepridil and W-7 did not increase I(Na) any further in the presence of the proteasome inhibitor MG132 [N-[(phenylmethoxy)carbonyl]-L-leucyl-N-[(1S)-1-formyl-3-methylbutyl]-L-leucinamide]. Bepridil, W-7 and MG132 but not KN93 significantly decreased 20S proteasome activity in a concentration-dependent manner.

CONCLUSIONS AND IMPLICATIONS

We conclude that long-term exposure of cardiomyocytes to bepridil at therapeutic concentrations inhibits calmodulin action, which decreased degradation of the Na(v)1.5 alpha-subunit, which in turn increased Na+ current.

Oral health status of vulnerable groups in a village of the Central Highlands, southern Vietnam

OBJECTIVES

Oral health status of vulnerable people in developing countries tends to be given lower priority than other health issues. Consequently, few studies have examined the oral health status of the poor and minorities in developing countries. We aim to examine the dental caries and periodontal status, and explore the risk indicators of dental caries between two ethnic groups in rural villages in southern Vietnam.

METHODS

We examined the caries status and its risk indicators of 150 participants (Co-Ho minority and Kinh majority) living in a hamlet of Dangphuong village in Vietnam. We also assessed periodontal status of the participants aged 14 and over by Community Periodontal Index.

RESULTS

We first found that dental caries were highly prevalent among both the Co-Ho minority and Kinh majority groups. Second, the higher numbers of dental caries among children with primary teeth were associated with a higher frequency of consuming sweets. Third, most people (87%) aged 14 and over had periodontal problems. Finally, the Kinh majority tended to have more dental caries than Co-Ho among people aged less than 30.

CONCLUSION

Oral health promotion should be considered as a part of the development programmes for vulnerable groups in Vietnam and other developing countries.

Anti-monocyte chemoattractant protein 1 gene therapy attenuates experimental chronic pancreatitis induced by dibutyltin dichloride in rats

BACKGROUND

Monocyte chemoattractant protein 1 (MCP-1) is a member of the C-C chemokine family and exerts strong chemoattractant activity in monocytes, macrophages, and lymphocytes. Rat pancreatic fibrosis induced by dibutyltin dichloride (DBTC) is considered to be an appropriate chronic pancreatitis model histologically and enzymatically, as has demonstrated in a previous study.

AIM

We examined the effect of human dominant negative inhibitor of MCP-1 (mutant MCP-1) on progression of chronic pancreatitis induced by DBTC in a rat model.

METHODS

We used the experimental model of chronic pancreatitis induced by DBTC in rats. Mutant MCP-1 or empty plasmid at a dose of 50 microg/body weight was administrated into rat thigh muscles on days 4, 11, and 18 after administration of DBTC. On days 14 and 28, we evaluated the effect of mutant MCP-1 morphologically and biochemically.

RESULTS

The mutant MCP-1 treated group inhibited early pancreatic inflammation and later pancreatic fibrosis histologically, and showed a decrease in serum MCP-1 concentration, intrapancreatic hydroxyproline, alpha-smooth muscle actin, and an increase in intrapancreatic amylase and protein content compared with the empty plasmid treated group. The mutant MCP-1 group also inhibited intrapancreatic mRNA expression of cytokines and chemokines.

CONCLUSIONS

: Our findings suggest that monocyte/macrophage recruitment and the systemic MCP-1 signal pathway contribute to progression of chronic pancreatitis, and that blockade of MCP-1 may suppress the development of pancreatic fibrosis.

Cytological study of early cervical adenocarcinoma: special reference to the depth of invasion

OBJECTIVE

Early cervical adenocarcinoma (ECA) with a tumour depth of <3 mm has a good prognosis. To clarify the cytological features of ECAs with depth <3 mm, these were compared with those of ECA with 3-5 mm and invasive adenocarcinoma (IA) invading the cervical wall with more than 5 mm in depth.

METHODS

The cervical cytological features of ECAs with depth <3 mm (14 cases) were compared with those of ECA with 3-5 mm (four cases) and IA (13 cases). Cytologically, the presence or absence of tumour diathesis, number of atypical cells, crowded cell groups, groups with glandular structures, feathering, groups with palisading borders, rosettes, clusters, cell shape and size, nuclear shape and size, nucleolar shape and size, chromatin distribution, border and character of cytoplasm, and single cell pattern were evaluated.

RESULTS

A tumour diathesis was seen in five of 14 ECA <3 mm in depth (36%), all four ECA with 3-5 mm (100%) and 11 of 13 IA with more than 5 mm (85%). Single cells, macronucleoli and coarsely granular chromatin pattern were less frequent in ECA of <3 mm than that in ECA with 3-5 mm and IA. The number of atypical cells and glandular structures in ECA was significantly less than that in IA. Cell crowding, feathering, palisading and rosettes were common in both ECA and IA.

CONCLUSION

The characteristic cytological features of ECA with depth <3 mm, having a good prognosis, were clean background, fewer single cells and macronucleoli, and less frequent coarsely granular chromatin pattern compared with those in ECA with 3-5 mm and IA. The number of atypical cells and glandular structures in ECA was significantly less than that in IA. Familiarity with the cytological features of ECA and its mimics is essential.

Clinico-cytological study of uterine papillary serous carcinoma

OBJECTIVE

The aim of this study was to determine whether or not we could distinguish uterine papillary serous carcinoma (UPSC) from other types of endometrial cancer by cytology.

METHODS

We examined the cytological findings of the endometrium from five cases with UPSC and compared them with 10 cases with endometrioid adenocarcinoma, grade 1 (G1). A morphometric analysis was performed. Cytological samples from the cervix and ascites of the patients with UPSC were also reviewed.

RESULTS

All five patients had FIGO stage III and IV tumours. Three patients died of the disease and two are still alive with disease. The tumour cells of UPSC tended to be shed in papillary clusters with a tumour diathesis. Psammoma bodies were seen only in UPSC. The frequency of irregular-shaped nuclei, membrane thickness and eccentric nuclei in UPSC was higher than in G1. The chromatin pattern was coarsely granular, and both anisonucleosis and bare nuclei were prominent in UPSC. Cytomorphometrically, the maximum diameter of the nuclei in UPSC was significantly greater than that in G1. The nucleoli were also more often seen in UPSC than in G1. The findings of the nuclei and nucleoli in the cervical and peritoneal fluid cytology closely resembled those in endometrial smears. The features of the cervical smears and peritoneal fluid cytology were different from those of endometrial cytology regarding clear background and small clusters of cells.

CONCLUSION

As the endometrial cytology findings accurately suggested the histological diagnosis of UPSC, the diagnosis of UPSC was confirmed in this study by endometrial cytology. The cytological diagnosis of UPSC should be based on the findings of tumour diathesis, psammoma bodies and papillary clusters composed of tumour cells with enlarged nuclei and numerous nucleoli.

C(17,20)-lyase inhibitors. Part 2: design, synthesis and structure-activity relationships of (2-naphthylmethyl)-1H-imidazoles as novel C(17,20)-lyase inhibitors

A series of 1- and 4-(2-naphthylmethyl)-1H-imidazoles (3 and 4) has been synthesized and evaluated as C(17,20)-lyase inhibitors. Several 6-methoxynaphthyl derivatives showed potent C(17,20)-lyase inhibition, suppression of testosterone biosynthesis in rats and reduction in the weight of prostate and seminal vesicles in rats, whereas most of these compounds increased the liver weight after consecutive administrations. The effect on the liver weight was removed by incorporation of a hydroxy group and an isopropyl group at the methylene bridge, as seen in (S)-28d and (S)-42. Selectivity for C(17,20)-lyase over 11beta-hydroxylase is also discussed, and (S)-42 was found to be a more than 260-fold selective inhibitor. Furthermore, (S)-42 showed a potent suppression of testosterone biosynthesis after a single oral administration in monkeys. These data suggest that (S)-42 may be a promising agent for the treatment of androgen-dependent prostate cancer.

Development of endometrial cancer following radiation therapy for cervical carcinoma

The clinical and histologic findings in five cases of endometrial cancer, which developed following radiation therapy for squamous cell carcinoma of the cervix, are described. The mean age at endometrial cancer diagnosis was 69 years and average latency period from initial therapy to development of endometrial carcinoma was 13.4 years. For endometrial cancer, one patient had Stage Ib, one patient had Stage IIIa, two patients had Stage IIIc, and one patient did not undergo laparotomy. The histological types were carcinosarcoma in two patients, endometrioid adenocarcinoma, grade 3 in one patient, and clear cell carcinoma in one patient. All patients died of disease within 33 months of diagnosis. Endometrial cancers that develop after radiation treatment have a preponderance of high-risk histological subtypes, and consequently have a poor prognosis. Long-term follow-up should be mandatory for patients surviving radiation therapy for cervical cancer in order to detect and effectively treat second malignancies.

C17,20-lyase inhibitors I. Structure-based de novo design and SAR study of C17,20-lyase inhibitors

Novel nonsteroidal C(17,20)-lyase inhibitors were synthesized using de novo design based on its substrate, 17 alpha-hydroxypregnenolone, and several compounds exhibited potent C(17,20)-lyase inhibition. However, in vivo activities were found to be short-lasting, and in order to improve the duration of action, a series of benzothiophene derivatives were evaluated. As a result, compounds 9h, (S)-9i, and 9k with nanomolar enzyme inhibition (IC(50)=4-9 nM) and 9e (IC(50)=27 nM) were identified to have powerful in vivo efficacy with extended duration of action. The key structural determinants for the in vivo efficacy were demonstrated to be the 5-fluoro group on the benzothiophene ring and the 4-imidazolyl moiety. Superimposition of 9k and 17 alpha-hydroxypregnenolone demonstrated their structural similarity and enabled rationalization of the pharmacological results. In addition, selected compounds were also identified to be potent inhibitors of human enzyme with IC(50) values of 20-30 nM.

Association between RCAS1 expression and clinical outcome in uterine endometrial cancer

RCAS1, which acts as a ligand for a putative receptor on immune cells such as peripheral lymphocytes and natural killer cells, is strongly expressed in human cancers. RCAS1 can induce these cells to undergo apoptotic cell death, which suggests that RCAS1 expression may prohibit the stromal reaction occurring in a tumour. To clarify the clinical significance of RCAS1 expression in uterine endometrial cancer, we analysed the association between RCAS1 expression and clinicopathologic variables by statistical methods. With the use of immunohistochemical techniques, we performed a retrospective study of RCAS1 expression in resected tumour tissue from 147 patients with uterine endometrial cancer. We evaluated the statistical correlation between RCAS1 expression and clinicopathologic variables. RCAS1 was expressed in 106 of 147 patients with uterine endometrial cancer; 30 of these 147 patients showed RCAS1 overexpression. Overexpression of RCAS1 was significantly correlated with age at surgery, stage, extent of myometrial invasion, and positive peritoneal cytologic results. Multivariate analysis revealed that RCAS1 expression and metastasis were clinically significant prognostic factors for the overall survival. These findings indicated that analysis for RCAS1 expression can provide crucial information about the clinical behaviour of uterine endometrial cancer, which may be valuable for the management of patients with this disease.

Inhibition of high K+-evoked gamma-aminobutyric acid release by sodium nitroprusside in rat hippocampus

To clarify whether nitric oxide (NO) modifies high K(+)-evoked gamma-aminobutyric acid (GABA) release, we examined the effects of sodium nitroprusside, an NO donor; diethyldithiocarbamate, an NO trapper; dithiothreitol, a superoxide radical scavenger; and 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one, a specific guanylyl cyclase inhibitor, on high (100 mM) K(+)-evoked GABA release from rat hippocampus in vivo using microdialysis. Perfusion with 0.5 or 5 mM sodium nitroprusside significantly reduced high K(+)-evoked GABA release. Co-perfusion with 0.5 mM sodium nitroprusside and 5 mM diethyldithiocarbamate or 0.5 mM 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one significantly enhanced high K(+)-evoked GABA release. Co-perfusion with 0.5 mM sodium nitroprusside and 1 mM dithiothreitol tended to increase it. These results demonstrate that sodium nitroprusside reduces high K(+)-evoked GABA release both via an NO/cyclic GMP-dependent pathway and via an NO-dependent, but cyclic GMP-independent, pathway in rat hippocampus in vivo.

Different effects of eNOS and nNOS inhibition on transient forebrain ischemia

To clarify the functions of nitric oxide (NO) induced by either neuronal NO synthase (nNOS) or endothelial NO synthase (eNOS) after transient cerebral ischemia, we investigated the effects of L-N(5)-(1-iminoethyl)ornithine (L-NIO), a relatively selective eNOS inhibitor, and 7-nitroindazole (7-NI), a relatively selective nNOS inhibitor, on hippocampal dysfunction caused by cerebral ischemia. We measured mean arterial blood pressure (MABP), hippocampal blood flow, direct current (DC) potential, CA1 population spike (PS) and extracellular concentrations of glutamate from rat hippocampus after transient forebrain ischemia, which was induced by four-vessel occlusion for 10 min. L-NIO (20 mg/kg) and 7-NI (25 mg/kg) were administered intraperitoneally 20 min before ischemia. L-NIO, but not 7-NI, increased MABP before, during and after ischemia, compared with the vehicle group. 7-NI, but not L-NIO, reduced the amplitude of anoxic depolarization induced by ischemia. 7-NI recovered the PS amplitude in part 60 min after ischemia. 7-NI, but not L-NIO, reduced the ischemia-induced levels of glutamate. These results indicate that nNOS inhibition with 7-NI improves, at least in part, hippocampal dysfunction after ischemia, while eNOS inhibition with L-NIO worsens it.

Expression of inflammatory cytokines and beta-defensin 1 mRNAs in porcine epithelial rests of Malassez in vitro

In the present study, we investigated the mRNA expression of inflammatory cytokines, including interleukin (IL)-1 alpha, IL-6, IL-8, and granulocyte macrophage colony-stimulating factor (GM-CSF), and beta defensin 1 (BD-1), an antimicrobial peptide, in the epithelial rests of Malassez in vitro. A reverse transcription-polymerase chain reaction (RT-PCR) assay was performed in order to observe the expression of these mRNAs. The effect of lipopolysaccharide (LPS) on the mRNA expression was also studied by quantitative RT-PCR assay, with a LightCycler, using the double-stranded DNA dye SYBR Green I. The mRNAs of the four kinds of inflammatory cytokines and BD-1 were detected in the epithelial cells under normal culture conditions. Immunocytochemical staining showed the expression of CD14, a receptor for LPS, on the epithelial cells. The mRNA expressions of IL-1 alpha, IL-6, IL-8, and GM-CSF were upregulated by stimulation with LPS, in a dose- and time-dependent manner. Epithelial cells incubated with 1000 ng/ml of LPS for 6 h showed the most significant upregulation of the cytokine mRNAs. On the other hand, no obvious alteration of BD-1 expression by LPS stimulation was observed. The results indicated that the epithelial rests of Malassez may actively participate in the inflammatory response to bacterial infection, and that they play an important role in the defense mechanism of the radicular cyst.

Immunohistochemical localization of amelogenin in human odontogenic tumors, using a polyclonal antibody against bovine amelogenin

In the present study, we investigated the localization of amelogenin in odontogenic tumors, using an anti-amelogenin polyclonal antibody. In order to make the antibody, antisera against an amelogenin fraction obtained from the enamel matrix of unerupted bovine tooth was raised in rabbits. By Western blot analysis, a main band of 25 kDa and six minor bands (6.8, 12, 18, 20, 23, and 27 kDa) were detected under nonreducing conditions. Immunoreactivity for the amelogenin was observed in ameloblasts and in the immature enamel matrix of 4-day-old rats. In odontogenic tumors, positive reactions for amelogenin were localized in limited areas in adenomatoid odontogenic tumor, calcifying odontogenic cyst, primary intraosseous carcinoma and odontoma. The strongest immunoreactions were shown in enamel matrices in odontomas. Small mineralized foci in epithelial nests showed positive reactions, and a few reactions were observed in epithelium adjacent to the mineralized foci. In calcifying odontogenic cysts, some ghost cells in the lining epithelium were strongly stained. The results indicate that the present antibody for amelogenin is useful for the determination of odontogenic tumors, especially in those in which small mineralized foci are present in the epithelial nests.

Conservative therapy for adenocarcinoma and atypical endometrial hyperplasia of the endometrium in young women: central pathologic review and treatment outcome

Thirty-nine patients with endometrioid adenocarcinoma (EA) and atypical hyperplasia (AH) of the endometrium who received conservative treatment to preserve fertility were collected from member institutions of the Japan Gynecologic Oncology Study Group. Twenty-nine and ten were originally diagnosed with EA without myometrial invasion and AH, respectively. We performed a central pathological review to make definite diagnoses, and the diagnosis of EA in 29 cases was changed to AH in ten, complex hyperplasia in three and atypical polypoid adenomyoma in three, and AH in ten was changed to EA in one and simple hyperplasia in one. Nine of 12 women (75%) with EA and 15 of 18 women (83%) with AH had an initial response to medroxyprogesterone acetate (MPA) treatment. Two of nine responders with EA later developed relapse, and one of them had metastasis to the left obturator lymph node. Two became pregnant, and one delivered one full-term infant. One of the responders with AH had a relapse in the endometrium. Five became pregnant, and four delivered four normal infants. The young women with endometrial carcinoma localized in the endometrium who wish to preserve fertility may be treated as successfully with MPA as those with AH.

Sodium nitroprusside-induced seizure and taurine release from rat hippocampus

We have recently reported that the nitric oxide (NO) donor, sodium nitroprusside (SNP), induces seizures which are associated with an increase in the basal release of aspartate and glutamate from rat hippocampus (Kaku et al., 1998). In order to determine whether taurine release occurs with SNP-induced seizures, we examined the effects of NO-related compounds, i.e., the NO trapper, diethyldithiocarbamate (DETC), the superoxide radical scavenger, dithiothreitol (DTT), the xanthine oxidase inhibitor, oxypurinol and the guanylyl cyclase inhibitor, 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one (ODQ), on SNP-induced seizures and in vivo taurine release from rat hippocampus using microdialysis. Perfusion with 0.5mM SNP provoked seizures and significantly increased taurine release, with the increase in release occurring primarily during reperfusion with artificial cerebrospinal fluid lacking SNP. Perfusion with 5mM DETC significantly abolished the SNP-induced seizures and reduced taurine release during and after perfusion with the drugs. Perfusion with 1mM DTT significantly reduced both the frequency of the SNP-induced seizures and taurine release during and after perfusion with the drugs. Perfusion with 1 mM oxypurinol or 0.5 mM ODQ did not reduce the frequency of the SNP-induced seizures, but tended to decrease taurine release during and after perfusion with the drugs. These results demonstrate that SNP-induced seizures are triggered by an increase in both NO and peroxynitrite and are related to an increase in taurine release from rat hippocampus.

Immunohistochemical localization of large chondroitin sulphate proteoglycan in porcine gingival epithelia

In this study, we report the immunohistochemical localization of versican in healthy porcine gingival epithelia. The monoclonal antibody (mAb), 5D5, specifically recognizes core proteins of large chondroitin sulphate proteoglycans such as versican, neurocan and brevican, but not the core protein of aggrecan. Because neurocan and brevican appear to be specific to nervous tissue, the large chondroitin sulphate proteoglycans examined in this study is most likely versican. In the keratinized layer of the attached gingival epithelium, the basal and spinous cell surfaces showed intense staining for mAb 5D5. In the parakeratinized layer of the sulcus epithelium, the localization was restricted to the basal and lower spinous layers. In the junctional epithelium, intense staining was observed in one or two cell layers near the enamel surface. Immunoelectron microscopy revealed high-density depositions of 5D5 immunoreactivity on epithelial cell surfaces. At the enamel surface, 5D5 immunoreactivity was localized to the dental cuticle of the junctional epithelium but was not present in the internal basal lamina. These results suggest that versican, a large chondroitin sulphate proteoglycan, is involved in epithelial differentiation and downgrowth.

Differential expression of human beta-defensin 2 in keratinized and non-keratinized oral epithelial lesions; immunohistochemistry and in situ hybridization

Human beta-defensin(hBD)-2, an antimicrobial peptide, is produced by various epithelial cells. Because hBD-2 expression in the oral epithelium has not been assessed, we investigated its localization in normal oral epithelium and epithelial lesions. hBD-2 expression was studied using immunohistochemistry and in situ hybridization on formalin-fixed, paraffin-embedded tissue sections from 30 cases of squamous cell carcinoma and 6 cases of leukoplakia. Immunostaining for hBD-2 was more intense in hyperkeratinized than in ortho- or non-keratinized epithelium. In contrast, signals for hBD-2 mRNA were frequently stronger in non-keratinized epithelium than in hyper- or ortho-keratinized epithelium. The results suggest that keratinization in oral epithelium plays an important role in the biological function of hBD-2 both at the mRNA level and in the retention of the peptide in the epithelium.

Sodium nitroprusside-induced seizures and adenosine release in rat hippocampus

In the present study, we examined the effects of nitric oxide (NO)-related compounds, i.e. sodium nitroprusside (NO donor), diethyldithiocarbamate (NO trapper) and dithiothreitol (superoxide radical scavenger) on release of aspartate and adenosine from rat hippocampus using electrophysiological and microdialysis methods. Perfusion with 0.05 or 0.5 mM sodium nitroprusside significantly reduced high K(+)-evoked release of aspartate during high K(+) perfusion. Perfusion with 0.5 mM sodium nitroprusside always induced seizures and significantly increased release of aspartate and adenosine during washout of sodium nitroprusside. Diethyldithiocarbamate (5 mM) reversed the effects of sodium nitroprusside. Dithiothreitol (1 mM) significantly reduced the increase in adenosine release by sodium nitroprusside. These findings indicate that adenosine release is closely related to development of seizures, which are triggered by an increase in both NO itself and in part peroxynitrite, which results in reaction with superoxide radicals.

Effect of extracellular calcium on the gene expression of bone morphogenetic protein-2 and -4 of normal human bone cells

A high extracellular calcium level inhibits the formation of osteoclast-like cells and stimulates osteoblastic proliferation, indicating that extracellular calcium plays an important role in the process of bone remodeling. The present study examined the effects of a high extracellular calcium level on mRNA levels of bone morphogenetic protein (BMP)-2 and -4, which are well-documented osteoinductive proteins, and the differentiation of normal human mandible-derived bone cells in vitro. High extracellular calcium significantly increased cell proliferation at an optimal dose of 0.4mM CaCl2 added to control medium containing 1.8 mM CaCl2. The addition of 0.1-0.4mM CaCl2 markedly increased the mRNA levels of BMP-2 and -4 following incubation for 0.5 and 24 h as evaluated by reverse transcription-polymerase chain reaction. While an increased extracellular calcium level (addition of 0.1-1.2mM CaCl2) failed to increase alkaline phosphatase activity and osteocalcin secretion, it did significantly increase type I collagen synthesis, monitored by the production of procollagen type I carboxy-terminal peptide. These results indicate that the extracellular calcium level regulates BMPs and type I collagen synthesis in osteoblastic cells.

The clinical significance of tumor-associated antigen RCAS1 expression in the normal, hyperplastic, and malignant uterine endometrium

OBJECTIVE

A tumor-associated antigen, RCAS1, is recognized by 22-1-1 monoclonal antibody. It was found in carcinomas derived from the uterus and ovary and was especially strongly expressed in invasive cancers. A previous investigation showed the RCAS1 expression to be correlated with a poor prognosis in uterine cervical adenocarcinoma. In this study, we examined whether the expression of RCAS1 is associated with the progression of the uterine endometrial neoplasms.

METHODS

The expression of RCAS1 was evaluated by an immunohistochemical analysis. The tissue specimens used in this study included 46 cases of normal uterine endometrium, 40 cases of hyperplasia, and 121 cases of adenocarcinoma. The relationship between RCAS1 expression and several clinicopathological variables (clinical stage, histology, grade, myometrial invasion, lymph-vascular space invasion, and lymph node metastasis) was also assessed in endometrial adenocarcinoma.

RESULTS

RCAS1 was positive in 26% of the normal uterine endometrium specimens (12 of 46 total cases), in 32% of the hyperplasia specimens (13 of 40 total cases), and in 68% of the adenocarcinoma specimens (83 of 121 total cases). As a result, the expression of RCAS1 was statistically higher in adenocarcinoma than in the normal and hyperplastic endometrium (P < 0.0001). RCAS1 was statistically detected more frequently in grade 3 than in grade 1 or 2 (P < 0.05); however, there was no correlation between the antigen expression and the clinical stage, myometrial invasion, lymph-vascular space invasion, or lymph node metastasis.

CONCLUSION

RCAS1 expression might thus be associated with the malignant transformation and poor differentiation observed in uterine endometrial adenocarcinoma.

Prognostic factors in ovarian carcinosarcoma: a clinicopathological and immunohistochemical analysis of 23 cases

Carcinosarcoma of the ovary is a rare, highly aggressive neoplasm comprising histologically of both epithelial and mesenchymal components. The aim of this study was to evaluate the clinicopathological prognostic factors in ovarian carcinosarcoma, including the immunohistochemical expression of p53 protein and Ki67.

METHODS AND RESULTS

Twenty-three cases of carcinosarcoma of the ovary were studied retrospectively. The clinicopathological and immunohistochemical parameters including p53 and Ki67 staining were statistically analysed to investigate the prognostic significance of this tumour. The overall 5-year survival rate was 27.1%; 100% for stage I, 31.3% for stage II, 10.9% for stage III and 0% for stage IV. The low-stage group (stages I and II) was found to be a significant prognostic factor for patient survival (P = 0.0113). None of the other factors (tumour size, histological type of carcinomatous and sarcomatous components, mitotic count, vascular space invasion and immunoreactivity for p53 protein and Ki6 7) was found to be a statistically significant prognostic indicator.

CONCLUSIONS

Ovarian carcinosarcoma is a rare malignancy with poor prognosis. In this study, advanced stage appears to be poor prognostic indicator of survival in patients with ovarian carcinosarcoma.

Evidence for the involvement of bone morphogenetic protein-2 in phenytoin-stimulated osteocalcin secretion in human bone cells

Recent work has shown that the actions of phenytoin on bone cell proliferation and differentiation are, in part, mediated through the upregulation of transforming growth factor-beta1 (TGF-beta(1)). The present study was undertaken to examine the effect of phenytoin on bone morphogenetic proteins (BMP)-2 and -4, which are well-recognized osteoinductive proteins of the TGF-beta superfamily, in osteoblastic cells. Treatment with 5-50 microM of phenytoin increased the amount of mRNA for BMP-2 after a 0.5-24 h incubation in normal human mandible-derived bone cells (HOB-M cells), but failed to affect the mRNA for BMP-4. Phenytoin treatment for 48 h significantly increased the secretion of BMP-2 by approx. four-fold, at an optimal concentration of 10 microM. While TGF-beta(1) inhibited osteocalcin secretion from HOB-M cells, both phenytoin and BMP-2 significantly stimulated it. Importantly, the stimulatory effects of phenytoin on osteocalcin release were completely blocked by the neutralizing antihuman BMP-2 monoclonal antibody. These results indicate that the stimulatory action of phenytoin on osteocalcin secretion in normal human bone cells is mediated, at least partly, through the upregulation of BMP-2, rather than that of TGF-beta(1).

Pulsed electromagnetic fields promote bone formation around dental implants inserted into the femur of rabbits

The present study examined the effect of applying a pulsed electromagnetic field (PEMF) on bone formation around a rough-surfaced dental implant. A dental implant was inserted into the femur of Japanese white rabbits bilaterally. A PEMF with a pulse width of 25 microseconds and a pulse frequency of 100 Hz was applied. PEMF stimulation was applied for 4 h or 8 h per day, at a magnetic intensity of 0.2 mT, 0.3 mT or 0.8 mT. The animals were sacrificed 1, 2 or 4 weeks after implantation. After staining the resin sections with 2% basic fuchsin and 0.1% methylene blue, newly formed bone around the implant on tissue sections was evaluated by computer image analysis. The bone contact ratios of the PEMF-treated femurs were significantly larger than those of the control groups. Both the bone contact ratio and bone area ratio of the 0.2 mT- and 0.3 mT-treated femurs were significantly larger than the respective value of the 0.8 mT-treated femurs (P < 0.001). No significant difference in bone contact ratio or bone area ratio was observed whether PEMF was applied for 4 h/day or 8 h/day. Although a significantly greater amount of bone had formed around the implant of the 2-week treated femurs than the 1-week treated femurs, no significant difference was observed between the 2-week and 4-week treated femurs. These results suggest that PEMF stimulation may be useful for promoting bone formation around rough-surfaced dental implants. It is important to select the proper magnetic intensity, duration per day, and length of treatment.

Ovarian endometriosis associated with ovarian carcinoma: a clinicopathological and immunohistochemical study

OBJECTIVE

The purpose of this study was to demonstrate the incidence, the histopathological characteristics, and the proliferation activity of endometriosis and atypical endometriosis associated with ovarian carcinoma.

METHODS

Microscopic slides of primary lesions from 127 patients with primary ovarian carcinoma were reviewed. The presence or absence of endometriosis and the transitions from typical endometriosis to atypical endometriosis and from atypical endometriosis to carcinoma were also histologically evaluated. Ki-67 immunoreactivity of typical and atypical endometriosis and carcinoma was examined. In addition, endometrial metaplasias were also evaluated.

RESULTS

Of the 127 patients, 37 had endometriosis: 70% (30/43) had clear cell adenocarcinoma, 43% (3/7) had endometrioid adenocarcinoma, 7% (4/60) had serous adenocarcinoma, and none (0/17) had mucinous adenocarcinoma. Thirty-three cases showed typical endometriosis and 29 cases had atypical endometriosis (25 cases had both). Tufting and the stratification of the lining epithelium were observed in 25 and 23 cases, respectively. The transition from typical endometriosis to atypical endometriosis was observed in 22 cases, and the transition from atypical endometriosis to carcinoma, in 23 cases. Only one case showed a direct transition from typical endometriosis to carcinoma. The mean Ki-67 indices were as follows: ovarian carcinoma, 23.1; atypical endometriosis, 9.9; typical endometriosis, 2.7. In 18 cases with metaplasia in endometriosis, eosinophilic metaplasia and ciliated metaplasia were the most common types. Five cases had two types of metaplasia.

CONCLUSIONS

Ovarian carcinomas, especially clear cell and endometrioid adenocarcinomas, are highly associated with endometriosis. Atypical endometriosis shows proliferation activity intermediate to those of typical endometriosis and ovarian carcinoma, suggesting it is a precancerous status.

Selective block of late currents in the DeltaKPQ Na(+) channel mutant by pilsicainide and lidocaine with distinct mechanisms

The congenital long QT syndrome is an inherited disorder characterized by a delay in cardiac repolarization, leading to lethal cardiac arrhythmias such as torsade de pointes. One form of this disease involves mutations in the voltage-dependent cardiac Na(+) channel, which includes an in-frame deletion of three amino acids (Lys-1505, Pro-1506, and Gln-1507; DeltaKPQ). The potential for selective suppression of the mutant was examined by heterologous expression of DeltaKPQ-Na(+) channels in Chinese hamster fibroblast cells via single-channel recording. In a single-channel cell-attached patch study, DeltaKPQ-Na(+) channels yielded currents that peaked at approximately 1 ms after voltage steps to 0 mV with aberrant late currents, which were composed of burst and isolated openings. The affinity of certain anesthetics (pilsicainide and lidocaine) to the late currents of the mutant channels was examined. It was revealed that 1) pilsicainide (1 microM), an open channel blocker of voltage-dependent Na(+) channels, remarkably decreased the late currents primarily by the shortening of burst duration without suppressing the initial peak current; and 2) lidocaine (1 microM), an inactivated channel blocker, decreased the late currents primarily by the suppression of isolated channel openings. Because the late currents in DeltaKPQ mutants are mainly composed of the burst openings, we conclude that pilsicainide is capable of selectively blocking the late currents in the mutant Na(+) channels that show dominant abnormal burst openings such as in DeltaKPQ mutants.