Papers by Hiroyasu Kashima

Applied immunohistochemistry & molecular morphology : AIMM / official publication of the Society for Applied Immunohistochemistry, Jan 9, 2016
Sirtuin 1 (SIRT1), originally identified as a longevity gene, regulates DNA repair and metabolism... more Sirtuin 1 (SIRT1), originally identified as a longevity gene, regulates DNA repair and metabolism by deacetylating target proteins such as p53. SIRT1 plays a key role in the pathophysiology of metabolic diseases and neurodegenerative disorders, and is considered to protect against age-related diseases including cancer. In contrast, SIRT1 may be oncogenic because its overexpression has been detected in many cancers. The aim of the present study was to clarify the expression and the role of SIRT1 in ovarian carcinoma (OvCa). The expression of SIRT1 was evaluated immunohistochemically in 16 cases of normal ovaries, 35 cases of endometriosis with/without carcinoma, and 68 cases of OvCa (endometrioid, 16; clear cell, 20; mucinous, 16; serous, 16). Staining results were evaluated semiquantitatively by the Immunoreactive Scoring System, and the relationships with clinicopathologic features and outcomes of patients were analyzed. The expression of SIRT1 was higher in endometrioid, mucinous,...

Free Radical Research, 2016
Ovarian clear cell carcinoma (CCC) arises from ovarian endometriosis. Intra-cystic fluid contains... more Ovarian clear cell carcinoma (CCC) arises from ovarian endometriosis. Intra-cystic fluid contains abundant amounts of free iron, which causes persistent oxidative stress, a factor that has been suggested to induce malignant transformation. However, the mechanisms linking oxidative stress and carcinogenesis in CCC currently remain unclear. Lipocalin 2 (LCN2), a multifunctional secretory protein, functions as an iron transporter as well as an antioxidant. Therefore, we herein examined the roles of LCN2 in the regulation of intracellular iron concentrations, oxidative stress, DNA damage, and antioxidative functions using LCN2-overexpressing (ES2), and LCN2-silenced (RMG-1) CCC cell lines. The results of calcein staining indicated that the up-regulated expression of LCN2 correlated with increases in intracellular iron concentrations. However, a DCFH-DA assay and 8OHdG staining revealed that LCN2 reduced intracellular levels of reactive oxygen species and DNA damage. Furthermore, the expression of LCN2 suppressed hydrogen peroxide-induced apoptosis and prolonged cell survival, suggesting an antioxidative role for LCN2. The expression of mRNAs and proteins for various oxidative stress-catalyzing enzymes, such as heme oxygenase (HO), superoxide dismutase (SOD), and glutathione peroxidase, was not affected by LCN2, whereas the intracellular concentration of the potent antioxidant, glutathione (GSH), was increased by LCN2. Furthermore, the expression of xCT, a cystine transporter protein, and CD44 variant 8-10 (CD44v), a stem cell marker, was up-regulated by LCN2. Although LCN2 increased intracellular iron concentrations, LCN2-induced GSH may catalyze and override oxidative stress via CD44v and xCT, and subsequently enhance the survival of CCC cells in oxidative stress-rich endometriosis.

Gynecol Endocrinol, 2010
Cyclin-dependent-kinase (cdk) inhibitor, p27 Kip1 (p27), has been shown to participate in progest... more Cyclin-dependent-kinase (cdk) inhibitor, p27 Kip1 (p27), has been shown to participate in progestin-induced growth suppression of normal endometrial glands. To analyze the molecular mechanisms regulating p27 protein, we examined immunohistochemical expression of the SCF Skp2 complex factors, i.e., Skp1, Cul1 and Skp2, and compared them with that of p27, steroid receptors and Ki-67. In normal endometrial glands, the expression of Skp2 was observed in the proliferative phase, whereas that of p27 was observed in the secretory phase. Cultured normal endometrial glandular cells showed that progesterone induced the down-regulation of Skp2 along with up-regulation of p27. In endometrial carcinomas, the inverse topological correlation between Skp2 and p27 was evident in 39/66 (59%) cases, and the expression of Skp2 showed a strong correlation with Ki-67. These findings suggest that the expression of SCF Skp2 complex changes during the menstrual cycle in normal endometrium and the SCF Skp2 ubiquitin-proteasome pathway may also work in endometrial carcinomas. Miyamoto T et al. Page 3
Anticancer research
Background: β-catenin has recently been reported to act as a cell growth promoter through cyclin ... more Background: β-catenin has recently been reported to act as a cell growth promoter through cyclin Dl transcription. However, the correlation between β-catenin and cyclin Dl expressions is not fully understood in endometrial tissues. Materials and Methods: ...

Anticancer research
Background: The E-cadherin/‚-catenin complex plays a crucial role in epithelial cell-cell adhesio... more Background: The E-cadherin/‚-catenin complex plays a crucial role in epithelial cell-cell adhesion and in the maintenance of tissue architecture. We previously reported aberrant expression of ‚-catenin in endometrial carcinomas. However, the expression and correlation of E-cadherin and ‚catenin in normal and malignant endometrial tissues are not fully understood. Materials and Methods: Immunohistochemical expression of E-cadherin and ‚-catenin was detected in 30 cases of normal endometrium and 73 cases of endometrial carcinoma. Results: In the normal endometrium, the expression of E-cadherin and cytoplasmic ‚-catenin in glandular cells was predominantly observed in the proliferative phase, and decreased in the secretory phase. In endometrial carcinomas, the expression of E-cadherin and cytoplasmic ‚-catenin decreased compared to that in the normal proliferative endometrial glands. The expression of E-cadherin and cytoplasmic ‚-catenin tended to be reduced in histologically high-grade tumors compared to low-grade tumors. Nuclear expression of ‚-catenin was observed in the glandular cells in the late proliferative and early secretory phases, as well as in high-grade endometrial carcinomas. Interestingly, nuclear ‚-catenin expression was associated with the loss of E-cadherin expression in normal and carcinoma cells, indicating an inverse correlation. Conclusion: The cyclic expression of E-cadherin and ‚-catenin in the normal endometrium suggests that the adhesion complex may act to maintain the endometrial architectures. In addition, nuclear ‚catenin expression associated with loss of E-cadherin expression may be involved in the acquisition of aggressive biological behavior, especially in high-grade tumors.

Gynecologic Oncology, 2015
Molecular markers associated with tumor progression in uterine carcinoma are poorly defined. In t... more Molecular markers associated with tumor progression in uterine carcinoma are poorly defined. In this study, we determine whether upregulation of LAMC1, a gene encoding extracellular matrix protein laminin γ1, is associated with various uterine carcinoma subtypes and stages of tumor progression. An analysis of the immunostaining patterns of laminin γ1 in normal endometrium, atypical hyperplasia, and a total of 150 uterine carcinomas, including low-grade and high-grade endometrioid carcinomas, uterine serous and clear cell carcinoma, was performed. Clinicopathological correlation was performed to determine biological significance. The Cancer Genome Atlas (TCGA) dataset was used to validate our results. As compared to normal proliferative and secretory endometrium, for which laminin γ1 immunoreactivity was almost undetectable, increasing laminin C1 staining intensity was observed in epithelial cells from atypical hyperplasia to low-grade endometrioid to high-grade endometrioid carcinoma, respectively. Laminin γ1 expression was significantly associated with FIGO stage, myometrial invasion, cervical/adnexal involvement, angiolymphatic invasion and lymph node metastasis. Similarly, analysis of the endometrial carcinoma data set from TCGA revealed that LAMC1 transcript levels were higher in high-grade than in low-grade endometrioid carcinoma. Silencing LAMC1 expression by siRNAs in a high-grade endometrioid carcinoma cell line did not affect its proliferative activity but significantly suppressed cell motility and invasion in vitro. These data suggest that tumoral laminin γ1 may contribute to the development and progression of uterine carcinoma, likely through enhancing tumor cell motility and invasion. Laminin γ1 warrants further investigation regarding its role as a biomarker and therapeutic target in uterine carcinoma.

Clinical cancer research : an official journal of the American Association for Cancer Research, Jan 24, 2015
Statins are among the most frequently prescribed drugs because of their efficacy and low toxicity... more Statins are among the most frequently prescribed drugs because of their efficacy and low toxicity in treating hypercholesterolemia. Recently, statins have been reported to inhibit the proliferative activity of cancer cells, especially those with TP53 mutations. Since TP53 mutations occur in almost all of the ovarian high-grade serous carcinoma, we determined if statins suppressed tumor growth in animal models of ovarian cancer. Two ovarian cancer mouse models were employed. The first one was a genetically engineered model, mogp-TAg, in which the promoter of oviduct glycoprotein-1 was used to drive the expression of SV40 T-antigen in gynecologic tissues. These mice spontaneously develop serous tubal intraepithelial carcinomas (STICs), which are known as ovarian cancer precursor lesions. The second model was a xenograft tumor model in which human ovarian cancer cells were inoculated into immunocompromised mice. Mice in both models were treated with lovastatin, and effects on tumor gro...

Human pathology, 2011
Endometrial carcinoma often arises from normal endometrial glandular cells via a precursor, atypi... more Endometrial carcinoma often arises from normal endometrial glandular cells via a precursor, atypical endometrial hyperplasia. However, the genetic changes involved in this carcinogenetic process are not fully understood. Differentially expressed genes were selected from glandular cells of normal proliferative-phase endometria, atypical endometrial hyperplasia, and endometrial carcinoma using laser-captured microdissection and microarray. The microarray analysis revealed a total of 51 genes to be up-regulated and 23 genes to be down-regulated in neoplastic endometrial epithelia. We focused on lipocalin2 (LCN2), which showed the largest magnitude of up-regulation. Immunostaining for lipocalin2 confirmed a stepwise increase in its expression in endometrial hyperplasia and carcinoma. In addition, elevated expression of lipocalin2 was correlated with the poor outcome of endometrial carcinoma patients. The subcellular distribution of lipocalin2 was both cytoplasmic and nuclear, despite re...

Human pathology, 2010
Overexpression of histone deacetylases has been reported in various human malignancies; however, ... more Overexpression of histone deacetylases has been reported in various human malignancies; however, the expression of histone deacetylases in endometrial tissue is not fully understood. In the present study, the expression of histone deacetylase 1, histone deacetylase 2, and Ki-67 was examined immunohistochemically in 30 normal and 66 malignant endometrial tissue samples. The results were expressed as a positivity index and compared with the positivity index for Ki-67 and rates of patient survival. The effect of 2 histone deacetylase inhibitors, trichostatin A and apicidine, on cell proliferation and the expression of cell cycle regulators such as cyclins (D1, E, and A), p21, p27, and p16 were investigated using 6 endometrial carcinoma cell lines. The positivity index for histone deacetylase 1 (79.8 +/- 33.0, mean +/- SD) and histone deacetylase 2 (106.3 +/- 41.9) was higher in endometrial carcinoma than the normal endometrium, with a significant difference for histone deacetylase 2. T...

Anticancer research, 2009
Although progestins have been used for the treatment of endometrial neoplasias, the mechanisms of... more Although progestins have been used for the treatment of endometrial neoplasias, the mechanisms of progestin-induced growth suppression remain undetermined. Immunostaining for steroid receptor coactivators (SRC-1, p300/CBP), corepressors (NCoR, SMRT) and Ki-67 in 15 neoplastic endometria before and after the treatment with medroxyprogesterone acetate (MPA) was performed. The effect of progestin on cell proliferation and cofactors expression were examined using T47D cells. Of the 15 cases, 10 showed good histological responses to MPA (Responder) and 5 poor responses (Non-responder). In Responders, MPA treatment resulted in reduced expression of Ki-67 by 78% (p=0.0076) along with increased NCoR expression by 158 % (p=0.0077). Progestin treatment for T47D cells resulted in up-regulation of NCoR mRNA and protein with the suppression of cell proliferation. Immunoprecipitation revealed that NCoR was bound to estrogen receptor alpha, but not to progesterone receptor in T47D cells. The up-re...

Anticancer research
The E-cadherin/beta-catenin complex plays a crucial role in epithelial cell-cell adhesion and in ... more The E-cadherin/beta-catenin complex plays a crucial role in epithelial cell-cell adhesion and in the maintenance of tissue architecture. We previously reported aberrant expression of beta-catenin in endometrial carcinomas. However, the expression and correlation of E-cadherin and beta-catenin in normal and malignant endometrial tissues are not fully understood. Immunohistochemical expression of E-cadherin and beta-catenin was detected in 30 cases of normal endometrium and 73 cases of endometrial carcinoma. In the normal endometrium, the expression of E-cadherin and cytoplasmic beta-catenin in glandular cells was predominantly observed in the proliferative phase, and decreased in the secretory phase. In endometrial carcinomas, the expression of E-cadherin and cytoplasmic beta-catenin decreased compared to that in the normal proliferative endometrial glands. The expression of E-cadherin and cytoplasmic beta-catenin tended to be reduced in histologically high-grade tumors compared to l...

Anticancer research
beta-catenin has recently been reported to act as a cell growth promoter through cyclin D1 transc... more beta-catenin has recently been reported to act as a cell growth promoter through cyclin D1 transcription. However, the correlation between beta-catenin and cyclin D1 expressions is not fully understood in endometrial tissues. Immunohistochemical expression of beta-catenin was examined in normal endometria (32 cases) and endometrial carcinomas (82 cases), and its expression was compared with that of cyclins (D1, E, A, B1). Sporadic nuclear staining of beta-catenin and cyclins was observed from proliferative phase of early secretory phase endometria, however, spacial correlations between beta-catenin and cyclins were not evident. In endometrial carcinomas, positivity for nuclear beta-catenin and cyclins increased compared to the normal endometria. Topologically, the cyclin D1-positive cells were frequently found in nuclear beta-catenin-positive cells. In addition, Spearman's rank correlation analysis revealed that the nuclear expression of beta-catenin correlated positively with t...

Human Pathology, 2005
Aurora kinases such as Aurora A and Aurora B are key regulators of mitosis and have been reported... more Aurora kinases such as Aurora A and Aurora B are key regulators of mitosis and have been reported to be overexpressed in various malignancies. However, the expression and localization of Aurora kinases in normal and neoplastic endometrial tissues remain undetermined. In the present study, immunohistochemical expression of Aurora A and B was examined in 40 normal, 30 hyperplastic, and 73 malignant endometria. The data were compared with the expression of Ki-67 and patient survivals. The expression of Aurora A and B at protein and messenger RNA levels was also examined using Western blotting and the reverse transcriptase polymerase chain reaction. The expression of Aurora A in normal endometrium was observed mainly in the proliferative phase and was decreased in the secretory phase. The Aurora A expression was significantly increased in carcinomas compared with normal proliferative endometrium; however, there was no correlation of Aurora A expression with Ki-67 expression or patient survival. The expression of Aurora B in normal endometrium was significantly higher in the proliferative phase than in the secretory phase. In endometrial carcinomas, the expression of Aurora B was correlated with Ki-67 expression and was significantly increased in high-grade tumors. In addition, patients with Aurora B-positive carcinoma showed poor prognosis compared with those with Aurora B-negative carcinoma ( P = .0135). Accordingly, the present study indicates the aberrant expression of Aurora A and Aurora B in endometrial carcinomas and the clinical importance of Aurora B expression in relationship to patient prognosis. D

Molecular and Cellular Endocrinology, 2015
Catechol estrogens, such as 4-hydroxyestradiol (4-OHE2), are estrogen metabolites that form DNA a... more Catechol estrogens, such as 4-hydroxyestradiol (4-OHE2), are estrogen metabolites that form DNA adducts and may induce mutations and subsequent cell transformation in mammary cells; however, little is known about their roles in endometrial carcinogenesis. Furthermore, it remains unclear whether 4-OHE2 is able to induce DNA damage on specific genes involved in carcinogenesis or a 'pro'-mutation status such as microsatellite instability (MSI). Therefore, we modified terminal transferase-dependent PCR by the application of a capillary sequencer to detect DNA damage at the single base level. Using this method, we demonstrated that 4-OHE2 directly induced DNA damage on codon 130/131 in exon 5 of PTEN, which is a mutation hot spot for PTEN in endometrial carcinoma. Whereas, both estradiol and 4-OHE2 treatment did not affect MSI status in immortalized endometrial glandular cells. 4-OHE2 might contribute to endometrial carcinogenesis by inducing PTEN mutation on codon 130/131.

Virchows Archiv, 2010
To study the steroid hormone-induced growth mechanisms of endometriosis, the immunohistochemical ... more To study the steroid hormone-induced growth mechanisms of endometriosis, the immunohistochemical expression of steroid hormone receptor cofactors was investigated in 37 cases of endometriotic epithelia and was compared with that of eutopic endometria of identical patients. The expression of steroid receptor coactivators (p300/CBP and SRC-1) and corepressors (NCoR and SMRT) was examined in relation to the estrogen receptor (ER), the progesterone receptor (PR), and Ki-67. Results of immunostaining were indicated as a "positivity index" (PI, full score; 100). The expression of ER and PR in endometriotic epithelia largely resembled that in eutopic endometria, however, the expression of Ki-67 in the proliferative phase (PI 13.8 +/- 2.4, mean +/- SD) was significantly lower than that in eutopic endometria (32.6 +/- 10.6). The expression of SRC-1 in eutopic endometria was increased in the proliferative phase (56.5 +/- 16.8) and decreased in the secretory phase (14.8 +/- 6.9). In endometriosis, however, the PI for SRC-1 did not show apparent cyclic changes during the menstrual cycle. Moreover, the expression of SRC-1 in endometriotic epithelia in the proliferative phase was significantly lower than that in eutopic endometria. These findings suggested the reduced proliferative activity in endometriotic epithelia to be related to the reduced expression of SRC-1.

Virchows Archiv, 2005
To further elucidate the significance of p53 mutation in endometrial carcinoma, we investigated i... more To further elucidate the significance of p53 mutation in endometrial carcinoma, we investigated it in endometrioid-type endometrial carcinomas showing intratumoral heterogeneous p53 expression. In addition, we also examined the correlation of p53 mutation and cyclin A expression, because we previously reported a topological correlation between the expression of p53 and cyclin A. The p53 mutation in exons 5-8 in 54 cases of endometrial carcinoma showing immunohistochemical expression of p53 was examined using microdissected tissue DNAs. Of the 54 p53-positive endometrial carcinomas, 23 (43%) had p53 mutation with a tendency in histologically higher grade tumors. Ten of the 54 showed a heterogeneous p53 expression, and in 9 of the 10 cases, p53 mutation was present only in p53-positive sites, which were often found in histologically less differentiated areas with elevated Ki-67 in the same tumor. Cyclin A expression was topologically observed in p53-positive areas; however, it was noted in both tumors with (12/23, 52%) and without (18/31, 58%) p53 mutation. These results suggest that p53 mutation is a late event and plays an important role in the acquisition of malignant potentials in endometrioid-type endometrial adenocarcinomas. Unexpectedly, accumulation of the p53 protein itself may be important in cyclin A overexpression.

Virchows Archiv, 2005
We previously reported the overexpression of cyclins in uterine cervical carcinoma; however, thei... more We previously reported the overexpression of cyclins in uterine cervical carcinoma; however, their clinicopathological significance remained undetermined. In the present study, we examined the immunohistochemical expression of cyclins (D1, E, A, B1), p53 and Ki-67 in squamous cell carcinoma (stage Ib+II; 80 cases, stage III+IV; 23 cases). Correlations between the expression of cyclins and clinicopathological parameters and patient survival were statistically evaluated. The results indicated that in the normal squamous epithelium, the expression of cyclins and Ki-67 was sporadically observed in the parabasal layer. Of the 103 cervical carcinomas, overexpression of cyclins D1, E, A, B1 and p53 was observed in 13 (13%), 23 (22%), 25 (24%), 18 (18%) and 23 (22%) cases, respectively, with a slight predominance in advanced stage tumors. The expression of cyclin D1, E, A and p53 significantly correlated with that of Ki-67 (Spearman's rank correlation). Univariate and multivariate analyses revealed that lymph node metastasis and cyclin A overexpression were independent prognostic factors for unfavorable outcomes in stage Ib+II patients. These findings suggest that the overexpression of various cyclins is involved in the acquisition of the vigorous growth potential of cervical carcinoma cells, and that cyclin A is an independent prognosticator of cervical carcinoma in early stages.

Virchows Archiv, 2013
Lobular endocervical glandular hyperplasia (LEGH) is a benign proliferative disease of cervical g... more Lobular endocervical glandular hyperplasia (LEGH) is a benign proliferative disease of cervical glands. Although histological resemblance of minimal deviation adenocarcinoma (MDA) to LEGH and frequent association of LEGH with MDA have been reported, it still remains unclear whether LEGH is a precancerous lesion of MDA. The present study was undertaken to examine the pathogenetic relationship between LEGH and MDA using a clonality analysis and mutational analyses of the STK11 gene, of which mutations have been reported in MDA. Of nine cases of LEGH only, four were polyclonal and five were monoclonal in composition. Of six LEGH lesions associated with MDA or adenocarcinoma, two were polyclonal and four were monoclonal. In cases of MDA or adenocarcinoma coexisting with LEGH, the patterns of X chromosome inactivation in malignant lesions were identical to those in coexisting LEGH lesions. A mutation of STK11 was only identified in one MDA, but not in LEGH. These results indicate that a subset of LEGH may be a precursor to malignant tumors including MDA and that a mutation of STK11 may be involved in progression of LEGH to MDA.
Ultrasound in Obstetrics and Gynecology, 2005

Oncogene, 2004
To explore the mechanism of estrogen-induced growth of normal endometrium, the transactivation sy... more To explore the mechanism of estrogen-induced growth of normal endometrium, the transactivation system of the cyclin D1 gene was analysed using cultured normal endometrial glandular cells. Estradiol (E2) treatment of cultured normal endometrial glandular cells induced upregulation of c-Jun, and then cyclin D1 proteins, followed by serial expressions of cyclins E, A and B1 proteins. Increase in the mRNA expression of cyclin D1 preceded the protein expression of cyclin D1 under E2 treatment. A luciferase assay using deletion constructs of the cyclin D1 promoter indicated that E2-induced increase in transcriptional activity was observed in reporters containing AP-1-binding site sequence, and that in the absence of E2, cotransfection of c-Jun also showed increase of transcriptional activity in the same reporters with AP-1 sequence. A gel shift assay using nuclear extract from E2-treated endometrial glandular cells and AP-1 sequences of the cyclin D1 promoter indicated specific binding between c-Jun protein and the promoter. Transfection of c-jun antisense oligonucleotides to the glandular cells resulted in the suppression of the E2induced upregulation of cyclin D1 mRNA and protein.
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Papers by Hiroyasu Kashima