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Hironobu Sasano

Publications and source records attributed to Hironobu Sasano.

At least 19 recordsLinked to original sources
PubMed2007

5Alpha-reductase type 1 and aromatase in breast carcinoma as regulators of in situ androgen production.

Previous in vitro studies demonstrated that bioactive androgen 5alpha-dihydrotestosterone (DHT) exerted antiproliferative effects through an interaction with androgen receptor (AR) in breast carcinoma cells. However, AR status has not been examined in association with DHT concentration in breast carcinoma tissues, and significance of androgenic actions remains unclear in breast carcinomas. Therefore, in our study, we first examined intratumoral DHT concentrations in 38 breast carcinoma tissues using liquid chromatography/electrospray tandem mass spectrometry. Intratumoral DHT concentration was positively associated with 5alpha-reductase type 1 (5alphaRed1), and negatively correlated with aromatase. We then examined clinical significance of AR and 5alphaRed1 status in 115 breast carcinoma tissues by immunohistochemistry. Breast carcinomas positive for both AR and 5alphaRed1 were inversely associated with tumor size or Ki-67. These patients showed significant associations with a decreased risk of recurrence and improved prognosis for overall survival, and the AR / 5alphaRed1 status was demonstrated an independent prognostic factor. Moreover, we examined possible regulation of DHT production by aromatase in in vitro studies. DHT synthesis from androstenedione in MCF-7 cells was significantly inhibited by coculture with aromatase-positive stromal cells, which was significantly reversed by addition of aromatase inhibitor exemestane. These results suggest that intratumoral DHT concentration is mainly determined by 5alphaRed1 and aromatase in breast carcinoma tissues, and antiproliferative effect of DHT may primarily occur in the cases positive for both AR and 5alphaRed1. Aromatase inhibitors may be more effective in these patients, possibly due to increasing local DHT concentration with estrogen deprivation.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2006

Regulatory role of neuron-restrictive silencing factor in expression of TRPC1.

Neuron-restrictive silencer factor (NRSF) binds its consensus element to repress the transcription of various genes. The dominant-negative form (dnNRSF) has a hypertrophic effect on cardiogenesis through an unidentified mechanism. We examined the involvement of transient receptor potential (TRP) channel proteins, using transgenic mice overexpressing dnNRSF (dnNRSF mice). Electrophoretic mobility-shift assays revealed an interaction between NRSF and a neuron-restrictive silencer element-like sequence in intron 4 of TRPC1 genomic DNA. According to RT-PCR and Western analyses, TRPC1 was up-regulated in dnNRSF mouse heart. Transient overexpression of TRPC1 in HEK 293T cells increased the activity of the nuclear factor in activated T cells (NFAT) promoter and stimulated store-operated Ca(2+) channel (SOCC)-mediated Ca(2+) entry. Transfection of TRPC1 into primary cardiomyocytes increased NFAT activity, indicating a major role for TRPC1 in NFAT activation. Our findings strongly suggest that NRSF regulates TRP1 gene expression and causes changes in the levels of calcium entry through SOCCs.

Animals↗
PubMed2006

Endogenous secretory receptor for advanced glycation end products in non-small cell lung carcinoma.

RATIONALE: The receptor for advanced glycation end products is a multiligand receptor that plays an important role in regulating the invasiveness and metastatic potential of cancer cells. A recently discovered novel splice variant, the endogenous secretory receptor for advanced glycation end products, mediates the receptor for advanced glycation end-product-associated cell responses by functioning as a decoy receptor. OBJECTIVES: To evaluate the expression pattern of endogenous secretory receptor for advanced glycation end products in non-small cell lung carcinoma, and analyze its impact on prognosis. METHODS: We performed immunohistochemical evaluation in 182 non-small cell lung carcinoma surgical specimens. The effect of an overexpressed receptor in cancer cell proliferation was also evaluated. MEASUREMENTS AND MAIN RESULTS: The endogenous secretory receptor for advanced glycation end-product expression in cytoplasm was reduced or absent in 137 of the 182 (75%) carcinomas in contrast to normal lung tissues. mRNA expression was also suppressed in cancer cells. Overexpression of the secretory receptor in lung cancer cell lines had an inhibitory effect on cell proliferation, suggesting the reduced receptor expression accelerated tumor growth. Among patients with low expression of the cytoplasmic secretory receptor, the overall survival rate was significantly lower than that of patients with normal expression (p = 0.0003). This association was most prominent in TNM stage I patients (p = 0.0001). In a multivariate analysis, endogenous secretory receptor immunoreactivity was an independent prognostic factor with a relative risk of 3.1. CONCLUSIONS: The cytoplasmic endogenous secretory receptor for advanced glycation end-product expression has the potential to be a prognostic factor for predicting the outcome of curative surgery in patients with non-small cell lung carcinoma.

Adult↗
PubMed2006

Progesterone receptor isoforms as a prognostic marker in human endometrial carcinoma.

The possible role of specific progesterone receptor (PR) isoforms (PRA and PRB) as predictive factors in endometrial carcinoma is unclear. The present study was undertaken to evaluate the clinical significance of intratumoral PR isoform status in patients with endometrioid endometrial carcinoma. We studied 103 cases of endometrioid endometrial carcinoma using immunohistochemistry. We correlated the findings with various clinicopathological parameters of the patients. PRA and PRB immunoreactivity was detected in 51/103 (48.5%) and 79/103 (76.7%) of carcinoma cases, respectively. A significant positive correlation was detected between the status of PRB immunoreactivity and the amount of PRB mRNA by real-time reverse transcription-polymerase chain reaction (P = 0.012). PR isoform expression was significantly lower in the cases with higher histological grade (P = 0.0001 and P = 0.002, for PRA and PRB, respectively). Cases that were negative for either one or both PR isoforms were significantly associated with shorter disease-free and overall survival of the patients. The absence of either one or both of these two PR isoforms was detected in all nine patients who died (100.0%), whereas the absence of these immunoreactivities was detected only in 43 of 94 (45.7%) patients who had lived during the same period. In addition, multivariate analysis demonstrated that an absence of PRA immunoreactivity was an independent risk factor in disease-free survival of the patients (P = 0.0258). The results of our study demonstrated that loss or absence of PR isoform expression determined by immunohistochemistry could become an important prognostic indicator in patients with endometrioid endometrial carcinoma.

Adenocarcinoma↗
PubMed2006

A case of preclinical Cushing's syndrome associated with diurnal rhythms of ACTH and cortisol in blood: correlation with histological findings.

We describe a case of adrenocortical adenoma with preclinical Cushing's syndrome demonstrating diurnal rhythms of ACTH and cortisol in blood. A 50-year-old man was admitted to the hospital for the evaluation of incidental right adrenal mass with hyperglycemia and hypertension. On admission, there were no signs of clinical manifestation of hypercortisolism. The basal levels of cortisol (9.3 microg/dl) and ACTH (9.4 pg/ml) at 0800 h were not elevated and these diurnal rhythms were maintained. One or 8 mg of dexamethasone given orally overnight suppressed the plasma ACTH but not serum cortisol. Ultrasonogram, CT and scintiscan of (131)I adosterol all demonstrated an enlarged adrenal mass in the right adrenal gland. The right adrenal gland was subsequently resected by laparoscopic surgery. Histopathological findings of resected adrenal tumor were consistent with adrenocortical adenoma. Adjacent non-neoplastic adrenal tissue demonstrated adrenocortical atrophy but DHEA-sulfotransferase immunoreactivity in the zona reticularis was detected.

Adrenal Cortex Neoplasms↗
PubMed2006

Peroxisome proliferator-activated receptor gamma and growth inhibition by its ligands in uterine endometrial carcinoma.

PURPOSE: In this study, we evaluated the correlation between endometrial carcinoma and peroxisome proliferator-activated receptor gamma (PPARgamma) expression and assessed whether PPARgamma ligands influence carcinoma growth. EXPERIMENTAL DESIGN: We examined the presence and cellular distribution of PPARgamma protein in 42 normal endometria, 32 endometria with hyperplasia, and 103 endometria with endometrial carcinoma by immunohistochemistry. We then compared PPARgamma mRNA expression in endometrial carcinoma with that in normal endometria using real-time reverse transcription-PCR. We subsequently confirmed expression of PPARgamma mRNA by real-time reverse transcription-PCR and PPARgamma protein by immunoblotting in endometrial carcinoma cell lines (Ishikawa, Sawano, and RL95-2 cells). We further examined the effects of PPARgamma agonist 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), a naturally occurring PPARgamma ligand, to these endometrial carcinoma cell lines. We also examined the status of apoptosis and p21 mRNA expression of these endometrial carcinoma cell lines following addition of 15d-PGJ2. RESULTS: PPARgamma immunoreactivity was detected in 11 of 23 (48%) of proliferative-phase endometrium, 14 of 19 (74%) of secretory-phase endometrium, 27 of 32 (84%) of endometrial hyperplasia, and 67 of 103 (65%) of carcinoma cases. PPARgamma immunoreactivity was significantly lower in endometrial carcinoma than in secretory-phase endometrium (P = 0.012) and endometrial hyperplasia (P = 0.006). There was a significant positive association between the status of PPARgamma and p21 expression in endometrial carcinoma (P < 0.0001). There was a significant negative association between the body mass index and PPARgamma labeling index of carcinoma tissue in the patients with endometrial carcinoma (P < 0.0001). PPARgamma mRNA was expressed abundantly in normal endometria but not in endometrial carcinoma. We showed that PPARgamma agonist 15d-PGJ2 inhibited cell proliferation and induced p21 mRNA of endometrial carcinoma cell lines. CONCLUSION: We showed the expression of PPARgamma in human endometrial carcinoma and the effects of PPARgamma ligand in endometrial carcinoma cells. These findings suggest that a PPARgamma ligand, 15d-PGJ2, has antiproliferative activity against endometrial carcinoma.

Aged↗
PubMed2006

SP1 and SP3 mediate progesterone-dependent induction of the 17beta hydroxysteroid dehydrogenase type 2 gene in human endometrium.

The opposing actions of estrogen and progesterone during the menstrual cycle regulate the cyclical and predictable endometrial proliferation and differentiation that is required for implantation. Progesterone indirectly stimulates the expression of 17beta hydroxysteroid dehydrogenase type 2 (HSD17B2), which catalyzes the conversion of biologically potent estradiol to weakly estrogenic estrone in the endometrial epithelium. We previously demonstrated upregulation of the HSD17B2 gene in human endometrial epithelial cells by factors secreted from endometrial stromal cells in response to progesterone. We investigated the underlying mechanism by which these stroma-derived, progesterone-induced paracrine factors stimulate HSD17B2 expression. Here, we show that transcription factors SP1 and SP3 interact with specific motifs in HSD17B2 promoter to upregulate enzyme expression in human endometrial epithelial cell lines. Conditioned medium (CM) from progestin-treated stromal cells increased levels of SP1 and SP3 in endometrial epithelial cells and induced HSD17B2 mRNA expression. Mithramycin A, an inhibitor of SP1-DNA interaction, reduced epithelial HSD17B2 promoter activity in a dose-dependent manner. Serial deletion and site-directed mutants of the HSD17B2 promoter demonstrated that two overlapping SP1 motifs (nt -82/-65) are essential for induction of promoter activity by CM or overexpression of SP1/SP3. CM markedly enhanced, whereas anti-SP1/SP3 antibodies inhibited, binding of nuclear proteins to this region of the HSD17B2 promoter. In vivo, we demonstrated a significant spatiotemporal association between epithelial SP1/SP3 and HSD17B2 levels in human endometrial biopsies. Taken together, these data suggest that HSD17B2 expression in endometrial epithelial cells, and, therefore, estrogen inactivation, is regulated by SP1 and SP3, which are downstream targets of progesterone-dependent paracrine signals originating from endometrial stromal cells.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Neuronal pathway from the liver modulates energy expenditure and systemic insulin sensitivity.

Coordinated control of energy metabolism and glucose homeostasis requires communication between organs and tissues. We identified a neuronal pathway that participates in the cross talk between the liver and adipose tissue. By studying a mouse model, we showed that adenovirus-mediated expression of peroxisome proliferator-activated receptor (PPAR)-g2 in the liver induces acute hepatic steatosis while markedly decreasing peripheral adiposity. These changes were accompanied by increased energy expenditure and improved systemic insulin sensitivity. Hepatic vagotomy and selective afferent blockage of the hepatic vagus revealed that the effects on peripheral tissues involve the afferent vagal nerve. Furthermore, an antidiabetic thiazolidinedione, a PPARg agonist, enhanced this pathway. This neuronal pathway from the liver may function to protect against metabolic perturbation induced by excessive energy storage.

Adipose Tissue↗
PubMed2006

Steroid sulfatase and estrogen sulfotransferase in human prostate cancer.

BACKGROUND: Estrogen sulfotransferase (EST) and steroid sulfatase (STS) are known to be involved in in situ estrogen production in estrogen dependent human cancer such as breast cancer, but unknown in prostate cancer. MATERIALS AND METHODS: We first examined whether these enzymes above were expressed and actually involved in estrogen production and metabolism in prostate cancer cell lines (LNCaP, DU-145, and PC-3). We than examined the expression of EST and STS in human prostate cancer tissues obtained from surgery (n = 52) using immunohistochemistry. RESULTS: mRNAs of both enzymes were detected in all prostate cancer cell lines examined, and the synthesis of estrone (E(1)) and estradiol (E(2)) was also confirmed in these cell lines. In addition, STS immunoreactivity was detected in 44 cases (85%) and EST in 39 cases (75%), respectively. CONCLUSIONS: STS and EST are expressed and may be involved in local production and metabolism of estrogens in human prostate cancers.

Cell Line, Tumor↗
PubMed2006

Chemoprevention of breast cancer among Asian women--its perspective and problems.

Chemoprevention of breast cancer employing tamoxifen and others has been demonstrated to be effective in reducing the frequency of developing breast malignancy in Western countries. In Asian countries, the frequency of breast cancer as well as its premalignant lesions has recently increased. Therefore, the possible chemoprevention may benefit those women with potential high risks of developing breast cancer and with premalignant lesions. However, the details of these findings of chemoprevention in Western countries have not been available for women with Asian descendant. In addition, risk factors of developing breast cancer in healthy women have not been established in Asian countries compared to Western countries with relative paucity of familial breast cancer cases. Thus, possible chemoprevention of breast cancer in Asian countries may be targeted toward those with established premalignant breast lesions such as ductal carcinoma in situ and/or atypical ductal hyperplasia. However, due to their recent increment of their incidence, biological and/or clinical features of these premalignant breast lesions have not been extensively characterized in Asian women and further investigations are required for wide spread chemoprevention.

Animals↗
PubMed2006

Systemic distribution and tissue localizations of human 17beta-hydroxysteroid dehydrogenase type 12.

The 17beta-hydroxysteroid dehydrogenases (HSDs) are enzymes that catalyze the reduction of 17-ketosteroids or the oxidation of 17beta-hydroxysteroids. 17beta-HSD type 12, the most recently cloned member of this gene family, was classified into the 17beta-HSD family based on sequence homology, rather than steroid catalyzing activity. Meanwhile, it has been reported that 17beta-HSD type 12 may be involved in fatty acid synthesis. To better understand the role of 17beta-HSD type 12 in lipid metabolism, we determined the detailed systemic distribution and tissue localizations of 17beta-HSD type 12, which, due partly to the lack of antibodies, had not yet been studied. We carried out these investigations by quantitative reverse transcription (RT)-PCR, Northern blot analysis, and immunohistochemistry, using an antibody against 17beta-HSD type 12 that we have generated. 17beta-HSD type 12 is highly expressed in organs related to lipid metabolism such as liver, kidney, heart and skeletal muscle. 17beta-HSD type 12 is also detected in endocrine-related organs such as pancreas, pituitary gland, adrenal gland, testis and placenta, and in the gastrointestinal tract, which point to the possible involvement of 17beta-HSD type 12 in the regulation of lipid biosynthesis and steroid metabolism. These results support previous reports and solidify the possibility that 17beta-HSD type 12 may play critical roles in the physiological processes, such as fatty acid synthesis, in addition to the steroid metabolism.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Expression of cytochrome P-450 4 enzymes in the kidney and liver: regulation by PPAR and species-difference between rat and human.

Members of the cytochrome P-450 4 (CYP4) family catalyze the omega-hydroxylation of fatty acids, and some of them have the PPAR response element in the promoter area of the genes. The localization of CYP4A and PPAR isoforms and the effect of PPAR agonists on CYP4A protein level and activity were determined in rat kidney and liver. Immunoblot analysis showed that CYP4A was expressed in the liver and proximal tubule, with lower expression in the preglomerular microvessel, glomerulus and thick ascending limb (TAL), but the expression was not detected in the collecting duct. PPARalpha was expressed in the liver, proximal tubule and TAL. PPARgamma was expressed in the collecting duct, with lower expression in the TAL, but no expression in the proximal tubule and liver. The PPARalpha agonist clofibrate induced CYP4A protein levels and activity in the renal cortex and liver. The PPARgamma agonist pioglitazone did not modulate them in these tissues. The localization of CYP4A and CYP4F were further determined in human kidney and liver by immunohistochemical technique. Immunostainings for CYP4A and CYP4F were observed in the hepatocytes of the liver lobule and the proximal tubules, with lower stainings in the TALs and collecting ducts, but no staining in the glomeruli or renal vasculatures. These results indicate that the inducibility of CYP4A by PPAR agonists in the rat tissues correlates with the expression of the respective PPAR isoforms, and that the localization of CYP4 in the kidney has a species-difference between rat and human.

Animals↗
PubMed2006

Immunolocalization of liver receptor homologue-1 (LRH-1) in human breast carcinoma: possible regulator of insitu steroidogenesis.

Liver receptor homologue-1 (LRH-1) belongs to a class of nuclear orphan receptor. We examined immunolocalization of LRH-1 in 106 breast carcinomas. LRH-1 immunoreactivity was detected in 43% of the invasive ductal carcinoma. It was negatively correlated with clinical stage, histological grade and HER2 status, and positively associated with sex-steroid receptors, steroidogenic acute regulatory protein, P450 side-chain cleavage, and 3beta-hydroxysteroid dehydrogenase. LRH-1 immunoreactivity was also detected in 28% of the ductal carcinoma in situ. These results suggest that LRH-1 is frequently detected in breast carcinoma tissues, and plays important roles including the regulation of in situ steroidogenesis.

Breast Neoplasms↗
PubMed2006

17Beta-hydroxysteroid dehydrogenases in human endometrium and its disorders.

In situ estrogen metabolism and synthesis have been considered to play a very important role in the development and progression of human endometrial carcinoma. 17Beta-hydroxysteroid dehydrogenases (17-HSDs) are enzymes involved in the formation of active sex steroids, including testosterone, estrone (E1) and estradiol (E2). Estrogens are interchanged by two enzymes, 17-HSD types 1 and 2, type 1 converts E1 to E2, and type 2 does reverse actions. 17-HSD type 5 catalyzes the reduction of androstenedione to testosterone. 17-HSD type 2 expression was decreased through normal endometrium, hyperplasia and carcinoma accordingly. There was a significant inverse correlation between intratumoral E2 concentration and the level of 17-HSD type 2 mRNA in endometrial carcinoma. 17-HSD type 5 expression was significantly increased through normal endometrium, hyperplasia and carcinoma accordingly. These results indicated that 17-HSD types 2 and 5 play an important role in the regulation of in situ estrogen production in endometrial carcinoma.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Expression of the steroid and xenobiotic receptor and its possible target gene, organic anion transporting polypeptide-A, in human breast carcinoma.

Steroid and xenobiotic receptor (SXR) or human pregnane X receptor (hPXR) has been shown to play an important role in the regulation of genes related to xenobiotic detoxification, such as cytochrome P450 3A4 and multidrug resistance gene 1. Cytochrome P450 enzymes, conjugation enzymes, and transporters are all considered to be involved in the resistance of breast carcinoma to chemotherapeutic or endocrine agents. However, the expression of SXR/hPXR proteins and that of its target genes and their biological or clinical significance have not been examined in human breast carcinomas. Therefore, we first examined SXR/hPXR expression in 60 breast carcinomas using immunohistochemistry and quantitative reverse transcription-PCR. We then searched for possible SXR/hPXR target genes using microarray analysis of carcinoma cells captured by laser microscissors. SXR/hPXR was detected in carcinoma tissues but not in nonneoplastic and stromal cells of breast tumors. A significant positive correlation was detected between the SXR/hPXR labeling index and both the histologic grade and the lymph node status of the carcinoma cases. Furthermore, in estrogen receptor-positive cases, SXR/hPXR expression was also positively correlated with expression of the cell proliferation marker, Ki-67. Microarray analysis showed that organic anion transporting polypeptide-A (OATP-A) was most closely correlated with SXR/hPXR gene expression, and both OATP-A mRNA and protein were significantly associated with SXR/hPXR in both breast carcinoma tissues and its cell lines. These results suggest that SXR/hPXR and its target gene, such as OATP-A, may play important roles in the biology of human breast cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗