Yukio Kageyama

Glucocorticoids Suppress Tumor Angiogenesis and In vivo Growth of Prostate Cancer Cells

Purpose: Glucocorticoids, such as prednisone, hydrocortisone, and dexamethasone, are known to produce some clinical benefit for patients with hormone-refractory prostate cancer (HRPC). However, the underlying mechanisms by which glucocorticoids affect HRPC growth are not well established as yet. Here, we hypothesize that the therapeutic effect of glucocorticoids on HRPC can be attributed to a direct inhibition of angiogenesis through the glucocorticoid receptor by down-regulating two major angiogenic factors, vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8). Experimental Design: The effects of dexamethasone on VEGF and IL-8 expression and cell proliferation were examined using DU145, which expresses glucocorticoid receptor. The effects of dexamethasone on DU145 xenografts were determined by analyzing VEGF and IL-8 gene expression, microvessel density, and tumor volume. Results: Dexamethasone significantly down-regulated VEGF and IL-8 gene expression by 50% (P < 0.001) and 89% (P < 0.001), respectively, and decreased VEGF and IL-8 protein production by 55% (P < 0.001) and 74% (P < 0.001), respectively, under normoxic condition. Similarly, hydrocortisone down-regulated VEGF and IL-8 gene expression. The effects of dexamethasone were completely reversed by the glucocorticoid receptor antagonist RU486. Even under hypoxia-like conditions, dexamethasone inhibited VEGF and IL-8 expression. In DU145 xenografts, dexamethasone significantly decreased tumor volume and microvessel density and down-regulated VEGF and IL-8 gene expression, whereas dexamethasone did not affect the in vitro proliferation of the cells. Conclusion: Glucocorticoids suppressed androgen-independent prostate cancer growth possibly due to the inhibition of tumor-associated angiogenesis by decreasing VEGF and IL-8 production directly through glucocorticoid receptor in vivo.

The impact of preoperative serum C‐reactive protein on the prognosis of patients with upper urinary tract urothelial carcinoma treated surgically

To assess the impact of preoperative C‐reactive protein (CRP) levels on the prognosis in patients with upper urinary tract (UUT) urothelial carcinoma (UC) primarily treated surgically, as it is increasingly recognized that a systemic inflammatory response is associated with the prognosis for patients with various malignancies.

MOLECULAR CHARACTERIZATION OF HUMAN AQUAPORIN-7 GENE AND ITS CHROMOSOMAL MAPPING

The cDNA for the seventh mammalian aquaporin (AQP7) was isolated from rat testis, and its expression demonstrated at the tail of late spermatids (Ishibashi et al., J. Biol. Chem. 272 (1997) 20,782-20,786). Here we report the isolation of the mouse and the human AQP7 cDNA and the human AQP7 gene. The human AQP7 gene is identical with human adipose AQP (AQPap or AQP7L). The deduced amino acid sequences of human and mouse AQP7 were 68% and 79% identical to those of rat AQP7, respectively. The mouse AQP7 is 67% identical to the human AQP7. Such a lower conservation of AQP7 among species is unusual in the aquaporin family. The human AQP7 gene is composed of six exons distributing over 6.5 kb. The exon-intron boundaries are identical to those of the human AQP3 gene. The intron sizes are also similar. Moreover, chromosomal localization of AQP7 was assigned to 9p13 by fluorescent in situ hybridization, where AQP3 is also localized, suggesting that 9p13 may be another site of an aquaporin cluster.

C‐reactive protein level predicts prognosis in patients with muscle‐invasive bladder cancer treated with chemoradiotherapy

To investigate the effect of C‐reactive protein (CRP) level on the prognosis of patients with muscle‐invasive bladder cancer treated with chemoradiotherapy (ChRT), as it is increasingly recognized that the presence of a systemic inflammatory response is associated with poor survival in various malignancies.

Transrectal ultrasound-guided transperineal 14-core systematic biopsy detects apico-anterior cancer foci of T1c prostate cancer

Abstract  Aim:  The optimal biopsy strategy for prostate cancer detection, especially in men with isolated prostate‐specific antigen (PSA) elevation, remains to be defined. We evaluated diagnostic yield and safety of transrectal ultrasound (TRUS)‐guided transperineal systematic 14‐core biopsy and compared the spatial distribution of cancer foci detected with this technique in men with and without abnormality on digital rectal examination (DRE).

Regulation of vascular endothelial growth factor transcription by endothelial PAS domain protein 1 (EPAS1) and possible involvement of EPAS1 in the angiogenesis of renal cell carcinoma

Endothelial PAS domain protein 1 (EPAS1) is a basic helix‐loop‐helix/PAS domain transcription factor that expressed most abundantly in highly vascularized organs. The authors examined the effect of transfection of EPAS1 cDNA on the endogenous expression of vascular endothelial growth factor (VEGF) in the 293 Tet‐Off cell line and the possible involvement of EPAS1 in the angiogenesis of renal cell carcinoma (RCC).

Down-regulation of vascular endothelial growth factor in renal cell carcinoma cells by glucocorticoids.

Metastatic renal cell carcinomas (RCC) remain highly resistant to systemic therapy. RCCs are highly vascular tumors, which overproduce angiogenic peptides such as vascular endothelial growth factor (VEGF) even under normoxic conditions. A potential suggested role of antiangiogenic therapeutic strategies is the treatment of RCC by inhibiting VEGF production. The down-regulation of VEGF expression by glucocorticoids has recently been demonstrated in several cells. In this study, the direct effects of glucocorticoids on VEGF production by RCC cells were evaluated. Four RCC cell lines A498, RCC270, Caki1, and ACHN were treated with dexamethasone (DEX), hydrocortisone (HC), 5-alpha-dihydrotestosterone (DHT), or estradiol (E2). RU486 was used as a glucocorticoid receptor (GR) antagonist. Cell growth was studied with MTS assays. VEGF mRNA and protein were evaluated with quantitative real-time RT-PCR and ELISA, respectively, and GR expression was examined using RT-PCR and immunocytochemistry. All four RCC cell lines expressed GR. DEX at 100 nM down-regulated VEGF secretions by more than 50% in three lines (A498, RCC270, and Caki1) and had a weak inhibitory effect on ACHN cells. The effect of DEX on reducing VEGF mRNA levels in A498 cells was concentration-dependent and maximal at 100 nM (80% inhibition). HC had similar but weaker effects on VEGF production in the RCC cells, but E2 and DHT had no effect. RU486 reversed the effects of DEX. DEX at 1-1000 nM did not affect cell growth in any of the four RCC cell lines. This is the first study showing that glucocorticoids, at concentrations achievable in vivo by oral administration of low doses of DEX, have an inhibitory effect on VEGF mRNA expression and protein secretion of RCC cells possibly through the GR pathway. Furthermore, DEX might have a potential role in antiangiogenic therapeutic strategies by inhibiting VEGF production during metastatic RCC treatment.

PPARγ ligands suppress proliferation of human urothelial basal cells in vitro

Expression of peroxisome proliferator‐activated receptor (PPAR) γ in the human urinary tract through embryonic development suggests its possible roles in the development, proliferation, and differentiation of uroepithelium. Little is known, however, about physiological roles of PPARγ in the urinary tract. We investigated effects of PPARγ ligands on the proliferation of normal human urothelial cells and stromal cells cultivated from surgical specimens. Active proliferation in vitro as well as high molecular weight cytokeratin expression indicated that cultured urothelial cells possess basal cell phenotype. PPARγ protein, expressed predominantly in the epithelial layer of the normal human urinary tract in vivo, was abundantly expressed in urothelial cells but barely detectable in stromal cells in vitro. Natural ligand for PPARγ, 15‐deoxy‐Δ12,14 prostaglandin J2 (15d‐PGJ2), as well as synthetic ones, troglitazone and pioglitazone, suppressed proliferation of the urothelial cells dose‐dependently. These effects were PPARγ specific because clofibrate or PGF2α did not affect proliferation of urothelial cells. Neither 9‐cis retinoic acid or all‐trans retinoic acid (ATRA) at 1 μM showed any synergism on the antiproliferative effects of PPARγ ligands. Urothelial cells treated with PPARγ ligands showed drastic morphologic changes and cell cycle arrest at G0/G1 phase accompanied with increased mRNA level of a cyclin‐dependent kinase inhibitor p21(WAF1/CIP1). Since 15d‐PGJ2 is present in vivo during the resolution phase of inflammation, these results indicated that PPARγ might be involved in the terminal phase of urothelial re‐epithelialization processes.

Glucocorticoids Suppress Tumor Lymphangiogenesis of Prostate Cancer Cells

Purpose: Glucocorticoids such as prednisone, hydrocortisone, and dexamethasone are known to provide some clinical benefit for patients with hormone-refractory prostate cancer. However, the underlying mechanisms by which glucocorticoids affect hormone-refractory prostate cancer progression are not well established as yet. Our previous study has shown that glucocorticoids inhibit tumor angiogenesis possibly by down-regulation of vascular endothelial growth factor (VEGF) and interleukin 8. Here, we hypothesized that the therapeutic effect of dexamethasone on hormone-refractory prostate cancer can be partly attributed to a direct inhibition of lymphangiogenesis through the glucocorticoid receptor by down-regulating a major lymphangiogenic factor, VEGF-C. Experimental Design: The effects of dexamethasone on the expression of VEGF-C and its receptor, VEGF receptor-3 (VEGFR-3), were examined using an androgen-independent human prostate cancer cell line, DU145, which expresses glucocorticoid receptor. The effects of dexamethasone on tumor-associated lymphangiogenesis in DU145 xenografts were determined by analyzing VEGF-C gene expression, lymphatic vessel density, and relative lymphatic vessel area. Results: Dexamethasone significantly down-regulated VEGF-C gene expression and protein production by 48% (P = 0.003) and 44% (P = 0.002), respectively, under normoxic condition. Similarly, hydrocortisone down-regulated VEGF-C gene expression. The effects of dexamethasone were completely reversed by the glucocorticoid receptor antagonist RU486. Even under hypoxia-like conditions, dexamethasone inhibited VEGF-C gene expression. In DU145 xenografts, dexamethasone significantly down-regulated VEGF-C gene expression and decreased lymphangiogenesis. Dexamethasone did not affect VEGFR-3 gene expression in vitro and in vivo. Conclusion: Glucocorticoids suppressed tumor-associated lymphangiogenesis by down-regulating VEGF-C through glucocorticoid receptor in androgen-independent prostate cancer cells in vivo.

Expression of aquaporins 7 and 8 in the developing rat testis.

Summary. Aquaporin (AQP) is a molecule that facilitates water permeability through cell membranes and is widely distributed in the mammalian body. Among members of the AQP family, AQP7 and AQP8 are predominantly expressed in the testis. This paper examined the expression of these two AQPs in the developing rat testis, using northern blot and immunohistochemistry to visualize their roles during the progression of spermatogenesis in the developing testis. In adult rats, expression of AQP7 was localized to spermatids, whereas AQP8 protein was observed in spermatocytes. In the developing testis, transcripts of AQP7 became detectable between 23 and 25 days post‐partum, when round spermatids have been reported to appear. On the other hand, AQP8 mRNA was first detected between 13 and 16 days post‐partum, consistent with the reported first appearance of spermatocytes (13–14 days). AQP7 and AQP8 proteins were detectable at 28 days post‐partum. The results suggest that AQP7 and AQP8 appear in the testis in accordance with the maturation of germ cells, and are involved in spermatogenesis.