Hirokazu Usui

High Aromatase Expression in Uterine Leiomyoma Tissues of African-American Women

CONTEXT Symptomatic uterine leiomyoma is associated with irregular uterine bleeding, anemia, and recurrent pregnancy loss. African-American women develop uterine leiomyomas at an earlier age and with higher frequency compared with Caucasian-American women or other races; however, the underlying mechanism for this discrepancy is unknown. OBJECTIVE Our objective was to determine whether gene targets of emerging leiomyoma therapeutics such as aromatase inhibitors and antiprogestins, which reduce tumor size and symptoms, are differentially expressed in tissues of African-American (n = 31), Caucasian-American (n = 34), and Japanese women (n = 36). RESULTS We found strikingly higher aromatase mRNA levels in leiomyoma compared with adjacent myometrium in African-American (83 fold), Caucasian-American (38 fold), and Japanese women (33 fold). Among the four major promoters that regulate aromatase expression in leiomyoma, the proximal promoter II accounted for higher aromatase mRNA levels in tissues from African-American women. Estrogen receptor subtype alpha mRNA levels were significantly, and 1.8- to 2.6-fold, higher in leiomyoma compared with adjacent myometrium in all groups, whereas leiomyoma estrogen receptor subtype beta mRNA levels were significantly elevated only in Japanese women. Leiomyoma progesterone receptor mRNA levels were significantly higher in Japanese women compared with African-American or Caucasian-American women. CONCLUSIONS Leiomyoma tissues from African-American women contained the highest level of aromatase expression, which may result in elevated tissue concentrations of estrogen, and account for the higher prevalence and earlier incidence. Analysis of leiomyoma tissue for biomarkers may predict the response to hormonal treatments such as aromatase inhibitors.

Characterization of RGS5 in regulation of G protein-coupled receptor signaling.

RGS proteins (regulators of G protein signaling) serve as GTPase-activating proteins (GAPs) for G alpha subunits and negatively regulate G protein-coupled receptor signaling. In this study, we characterized biochemical properties of RGS5 and its N terminal (1-33)-deleted mutant (deltaN-RGS5). RGS5 bound to G alpha(i1), G alpha(i2), G alpha(i3), G alpha(o) and G alpha(q) but not to G alpha(s) and G alpha13 in the presence of GDP/AIF4-, and accelerated the catalytic rate of GTP hydrolysis of G alpha(i3) subunit. When expressed in 293T cells stably expressing angiotensin (Ang) AT1a receptors (AT1a-293T cells), RGS5 suppressed Ang II- and endothelin (ET)-1-induced intracellular Ca2+ transients. The effect of RGS5 was concentration-dependent, and the slope of the concentration-response relationship showed that a 10-fold increase in amounts of RGS5 induced about 20-25% reduction of the Ca2+ signaling. Furthermore, a comparison study of three sets of 293T cells with different expression levels of AT1a receptors showed that RGS5 inhibited Ang II-induced responses more effectively in 293T cells with the lower density of AT1a receptors, suggesting that the degree of inhibition by RGS proteins reflects the ratio of amounts of RGS proteins to those of activated G alpha subunits after receptor stimulation by agonists. When expressed in AT1a-293T cells, deltaN-RGS5 was localized almost exclusively in the cytosolic fraction, and exerted the inhibitory effects as potently as RGS5 which was present in both membrane and cytosolic fractions. Studies on relationship between subcellular localization and inhibitory effects of RGS5 and deltaN-RGS5 revealed that the N terminal (1-33) of RGS5 plays a role in targeting this protein to membranes, and that the N terminal region of RGS5 is not essential for exerting activities.

Serum YKL-40 as a marker for cervical adenocarcinoma

BACKGROUND The current study examined the clinical usefulness of YKL-40 in detection and prognosis of uterine cervical cancer. PATIENTS AND METHODS Serum levels of YKL-40, cancer antigen 125 (CA 125), carbohydrate antigen 19-9 (CA19-9), and squamous cell carcinoma (SCC) antigen were determined by enzyme-linked immunosorbent assay in women with benign gynecologic disease (n=24), cervical malignancy (SCC, n=104; adenocarcinoma, n=37), and age-matched healthy controls (n=45). Immunohistochemical analysis for local YKL-40 expression was carried out on 28 adenocarcinomas. RESULTS Receiver operating characteristic curve analysis showed that YKL-40 [area under the curve (AUC)=0.882] was significantly better at discriminating adenocarcinoma from healthy control than SCC antigen, CA 125, and CA19-9. For SCC, YKL-40 (AUC=0.898) carried out similarly to SCC antigen and was better than CA 125 and CA19-9. Using a cut-off YKL-40 value of 92.2 ng/ml, sensitivity of YKL-40 in stage I adenocarcinoma (68%) was higher than that of the other three markers (11%-21%). Tumor-associated macrophages showed immunoreactivity for YKL-40 in 2 of 28 adenocarcinoma tissue samples, but adenocarcinoma cells themselves were nonimmunoreactive in all samples. Multivariate Cox regression analysis revealed that elevated pretreatment YKL-40 levels predicted unfavorable prognosis, independent of International Federation of Gynecology and Obstetrics stage and age at diagnosis. CONCLUSIONS Pretreatment serum YKL-40 level is a possible prognosticator of cervical adenocarcinoma.

The risk of post-molar gestational trophoblastic neoplasia is higher in heterozygous than in homozygous complete hydatidiform moles

BACKGROUND Complete hydatidiform mole (CHM) is a high-risk pregnancy for gestational trophoblastic neoplasia (GTN). Patients with CHM have a 10-30% chance of trophoblastic sequelae. CHM includes androgenic homozygous (monospermic) and androgenic heterozygous (dispermic) moles. It is controversial whether the risk of GTN is higher with heterozygous than with homozygous CHM. A prospective cohort study was conducted to assess risk of GTN in homozygous and heterozygous CHM using short tandem repeat (STR) polymorphisms, and a meta-analysis of previous reports. METHODS Twenty-eight consecutive molar pregnancies were evacuated and followed by regular hCG measurements to detect GTN. Persistent GTN was diagnosed according to the International Federation of Gynecology and Obstetrics 2000 system. Cytogenesis of the mole was determined by STR polymorphisms of molar tissue and parental blood. A meta-analysis of the GTN rate from previous reports was conducted using Mantel-Haenszel methods. RESULTS Of 28 molar pregnancies, 24 were homozygous and three were heterozygous CHM. The remaining mole was diandric triploidy (a partial hydatidiform mole). Of the 24 homozygous CHMs, six (25%) cases developed GTN and received chemotherapy. Meanwhile, all three cases (100%) of heterozygous mole developed GTN and needed chemotherapy. The GTN risk was higher in heterozygous (P = 0.029, Fishers exact test) than homozygous moles. A systematic review revealed only five previous reports (with more than 15 cytogenetically diagnosed cases), and the pooled relative risk of persistent GTN for heterozygous mole was not significant (odds ratio, 2.0; 95% confidence interval, 0.98-4.07). CONCLUSIONS Heterozygous CHM had a higher risk for GTN than homozygous CHM.

Discordance between serum level and tissue immunohistochemical staining of CA125 in endometrioid adenocarcinoma of the uterine corpus.

This study was designed to correlate tissue expression of CA125 with the corresponding serum value in endometrial cancer. The records of 52 endometrioid adenocarcinomas diagnosed were reviewed. Serum CA125 levels were examined before definitive surgery, and 20 U/ml was used as the cutoff value. Immunohistochemical staining for CA125 was assessed according to the ImmunoReactive Score. Statistical analyzes were performed to identify independent factor for high serum CA125 levels, including CA125 staining and the conventional pathologic features. Elevated serum CA125 levels were found in 15 of 52 patients (29%) (range, 0.1-172.1; mean 22.6 U/ml). The frequency of positive CA125 tissue staining (35/52, 67%) tended to be higher than that of elevated serum levels (p = 0.046). Fifteen patients with elevated serum CA125 levels statistically differed from the remaining 37 patients with normal serum CA125 level with respect to International Federation of Gynecology and Obstetrics (FIGO) stage (p = 0.027) and lymph node metastasis (p = 0.024), and tended to have positive washing cytology (p = 0.052). In multivariate analysis, elevated serum CA125 significantly correlated only with FIGO stage III, but not with tumor size or CA125 tissue staining. Intrauterine tumor may not be the main source of serum CA125 in endometrial cancer, and elevated serum level is closely related to the presence of disseminated cancer cells in the peritoneal cavity.

Characterization of a novel C. elegans RGS protein with a C2 domain: evidence for direct association between C2 domain and Gαq subunit

RGS (regulator of G protein signaling) proteins are GTPase-activating proteins (GAPs) for heterotrimeric G protein alpha subunits and negatively regulate G protein-mediated signal transduction. In this study, we determined the cDNA sequence of a novel Caenorhabditis elegans (C. elegans) RGS protein. The predicted protein, termed C2-RGS, consists of 782 amino acids, and contains a C2 domain and an RGS domain. C2 domains are typically known to be Ca(2+) and phospholipid binding sites, found in many proteins involved in membrane traffic or signal transduction, and most of their biological roles are not identified. To study the function of C2-RGS protein, a series of six truncated versions of C2-RGS were constructed. When the full-length protein of C2-RGS was expressed transiently in AT1a-293T cells, ET-1-induced Ca(2+) responses were strongly suppressed. When each of the mutants with either RGS domain or C2 domain was expressed, the Ca(2+) responses were suppressed moderately. Furthermore, we found that C2 domain of PLC-beta1 also had a similar moderate inhibitory effect. RGS domain of C2-RGS bound to mammalian and C. elegans Galphai/o and Galphaq subunits only in the presence of GDP/AlF(4)(-), and had GAP activity to Galphai3. On the other hand, C2 domains of C2-RGS and PLC-beta1 also bound strongly to Galphaq subunit, in the presence of GDP, GDP/AlF(4)(-), and GTPgammaS, suggesting the stable persistent association between these C2 domains and Galphaq subunit at any stage during GTPase cycle. These results indicate that both the RGS domain and the C2 domain are responsible for the inhibitory effect of the full-length C2-RGS protein on Galphaq-mediated signaling, and suggest that C2 domains of C2-RGS and PLC-beta1 may act as a scaffold module to organize Galphaq and the respective whole protein molecule in a stable signaling complex, both in the absence and presence of stimulus.

The clinical characteristics and early detection of postpartum choriocarcinoma.

Objectives This study aimed to identify the clinical and demographic characteristics and prognosis of patients with conditions diagnosed with postpartum choriocarcinoma based on the International Federation of Gynecology and Obstetrics 2000 prognosis scoring system or based on pathologically confirmed choriocarcinoma and to analyze the patients’ clinical symptoms for early detection of this disease. Methods/Materials Between January 1983 and August 2013, 24 consecutive women with postpartum choriocarcinoma were treated at 2 hospitals. Data on clinical and demographic characteristics, including initial presenting symptoms, type of antecedent pregnancy, fetal complications, and prognosis of these patients, were analyzed. According to the time interval between the previous delivery and the onset of disease, patients were divided into 2 groups: the short and long interval groups. Results The most common symptom among the 24 patients with postpartum choriocarcinoma was irregular vaginal bleeding (14/24); in some cases, bleeding was caused by metastatic foci (7/24). Massive genital bleeding causing emergency hysterectomy and several obstetric complications, such as unknown severe fetal anemia and fetal growth retardation, was only observed in the short interval group. The overall primary remission rate was 91.7%. Conclusions The most common symptom of patients with postpartum choriocarcinoma in the short and long interval groups was genital bleeding, and the overall prognosis may be improved by introduction of an appropriate chemotherapy regimen. Careful pathological examination of the placenta is needed in cases of fetomaternal hemorrhage, unknown fetal anemia, and abnormal obstetric events, including premature delivery, still birth, and infantile growth retardation, for the early detection of intraplacental choriocarcinoma.

Daily low-dose cisplatin-based concurrent chemoradiotherapy in patients with uterine cervical cancer with emphasis on elderly patients: a phase 2 trial.

Objective We evaluated the usefulness of daily low-dose cisplatin-based concurrent chemoradiotherapy (daily CCRT) in patients with cervical cancer with an emphasis on elderly patients. Methods Between January 2003 and December 2008, a total of 65 patients with untreated stage IIA to IIIB cervical cancer were enrolled and 54 were selected for this nonrandomized prospective study. The daily CCRT comprised pelvic external beam radiotherapy (2 Gy/d × 25) with daily low-dose cisplatin (8.0 mg/m2 per day) and either low- or high-dose rate intracavitary brachytherapy. Results The median age of the patients was 62 years (range, 29–85 years), and 21 patients (39%) were 70 years or older. The median follow-up period was 47 months (range, 4–107 months). Daily CCRT was successfully completed in 91% (49/54) of the patients. The mean total cisplatin dose was 191 mg/m2 (range, 128–224 mg/m2), and a neutropenia grade higher than 3 was observed in 24% of the patients. Of the 21 patients 70 years or older, 17 (81%) completed daily CCRT with acceptable toxicity. The 3-year overall survival (OS) rate for all the patients was 82.9%. No statistically significant differences in the OS rate and toxicity were observed between patients 70 years or older and those younger than 70 years. Conclusions Daily CCRT showed acceptable toxicity and compliance, leading to the use of a high total dosage of cisplatin. The OS rate for daily CCRT was comparable to that for previously reported weekly CCRT. Daily CCRT could be an alternate choice for the CCRT treatment in elderly patients with cervical cancer.

Mature cystic teratomas arise from meiotic oocytes, but not from pre-meiotic oogonia.

Mature cystic teratomas (MCTs) in the ovaries have been thought to originate from germ cells from all developmental stages, i.e., from pre‐meiotic oogonia through meiotic oocytes to mature post‐meiotic ova. This view was based on research on MCTs by classical methods, including those involving centromeric heteromorphisms in karyotypes, enzyme polymorphisms, and DNA polymorphisms. However, insufficient genomic information was obtained in those studies. The current study aimed to confirm the cytogenetic origin of ovarian MCTs by using short tandem repeat (STR) polymorphism analysis to obtain sufficient genomic information, especially in connection with centromeric loci. Tissue samples of MCTs (57 ovaries from 51 patients, 91 MCTs, 156 specimens in total) obtained from cystectomies or oophorectomies were used. We categorized the specimens into two groups: i) solid components of MCTs and ii) cyst walls. The numbers of solid components of MCTs from pre‐meiotic oogonia, primary oocytes, secondary oocytes, and ova were 0, 33, 16, and 15, respectively. There were no pre‐meiotic oogonia in this series of solid‐component specimens. We propose a hypothesis for the tumorigenesis of ovarian MCTs: the precursors of ovarian MCTs are not functional oocytes or ova, but are primary oocytes that have escaped from meiotic arrest. This hypothesis could satisfactorily explain the lack of pre‐meiotic teratomas observed in this study and the nearly equal distribution of teratomas originating from primary oocytes, secondary oocytes, and ova in previous studies. Furthermore, this hypothesis could provide a starting point for determining the mechanism underlying tumorigenesis of ovarian MCTs.

The tumor-suppressive microRNA-1/133a cluster targets PDE7A and inhibits cancer cell migration and invasion in endometrial cancer

In developed countries, endometrial cancer (EC) is the most common malignancy among women. Unopposed estrogen therapy, obesity, nulliparity, diabetes mellitus and arterial hypertension have been linked to an increased risk of EC. However, the molecular mechanisms of EC oncogenesis and metastasis have not yet been fully elucidated. Our recent studies of microRNA (miRNA) expression signatures revealed that the microRNA-1/133a (miR‑1/133a) cluster is frequently downregulated in various types of human cancers. However, the functional role of the miR‑1/133a cluster in EC cells is still unknown. Thus, the aim of this study was to investigate the functional significance of the miR‑1/133a cluster and its regulated molecular targets, with an emphasis on the contributions of miR‑1/133a to EC oncogenesis and metastasis. We found that the expression levels of miR‑1 and miR‑133a were significantly reduced in EC tissues. Moreover, restoration of mature miR‑1 or miR‑133a miRNAs significantly inhibited cancer cell migration and invasion, suggesting that these clustered miRNAs act as tumor suppressors. Prediction of miRNA targets revealed that phosphodiesterase 7A (PDE7A) was a potential target gene regulated by both miR‑1 and miR‑133a. PDE7A was confirmed to be overexpressed in EC clinical specimens and silencing of PDE7A significantly inhibited cancer cell migration and invasion. Our data demonstrated that downregulation of the miR‑1/133a cluster promoted cancer cell migration and invasion via overexpression of PDE7A in EC cells. Elucidation of the molecular networks regulated by tumor-suppressive miRNAs will provide insights into the molecular mechanisms of EC oncogenesis and metastasis.