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Featured researches published by Kojiro Ohba.


Clinical Cancer Research | 2006

Lymphangiogenesis and Angiogenesis in Bladder Cancer: Prognostic Implications and Regulation by Vascular Endothelial Growth Factors-A, -C, and -D

Yasuyoshi Miyata; Shigeru Kanda; Kojiro Ohba; Koichiro Nomata; Yasushi Hayashida; Jiro Eguchi; Tomayoshi Hayashi; Hiroshi Kanetake

Purpose: Lymph vessel density (LVD) and microvessel density (MVD) correlate with the malignant potential of tumors and patient survival. Vascular endothelial growth factors (VEGF)-A, VEGF-C, and VEGF-D could modulate LVD and MVD. We investigated the clinical and prognostic significance of LVD and MVD on lymphangiogenic and angiogenic function of VEGF-A, VEGF-C, and VEGF-D in human bladder cancer. Experimental Design: We reviewed tissue samples from patients with nonmetastatic bladder cancer who had undergone transurethral resections (n = 126). The densities of D2-40-positive vessels (LVD) and CD34-positive vessels (MVD) were measured by a computer-aided image analysis system. Expression of VEGF-A, VEGF-C, and VEGF-D was examined by immunohistochemistry; survival analyses and their independent roles were investigated using multivariate analysis models. Results: LVD was associated with tumor grade but not with pT stage. LVD was associated with metastasis-free survival (log rank P = 0.039), but was not an independent prognostic factor. Although MVD affected survival, the combination of high LVD and high MVD in tumors was an independent predictor of metastasis-free survival. Although VEGF-C expression was positively associated with both LVD and MVD, VEGF-D was associated only with LVD. VEGF-A expression was associated with MVD in univariate analysis, however, it was not an independent factor. Conclusions: Lymphangiogenesis and angiogenesis influence metastasis-free survival, and are regulated by VEGF-C and/or VEGF-D. Our results suggest that LVD and MVD are useful tools for the selection of postoperative management and treatment strategies in patients with bladder cancer.


Clinical Cancer Research | 2006

Expression of Matrix Metalloproteinase-7 on Cancer Cells and Tissue Endothelial Cells in Renal Cell Carcinoma: Prognostic Implications and Clinical Significance for Invasion and Metastasis

Yasuyoshi Miyata; Takahisa Iwata; Kojiro Ohba; Shigeru Kanda; Masaharu Nishikido; Hiroshi Kanetake

Purpose: The expression of matrix metalloproteinase-7 (MMP-7) correlates with the malignant potential of various tumors and patient survival. We investigated the clinical and prognostic significance of MMP-7 expression in cancer cells and endothelial cells in human renal cell carcinoma (RCC). Experimental Design: We reviewed tissue samples of 156 patients with RCC who had undergone radical operation. MMP-7 expression was examined by immunohistochemistry. Sections containing MMP-7-positive vessels were also stained for CD34. The density of MMP-7-positive vessels was determined by a computer-aided image analysis system. Multivariate analysis was done to assess relevant variables for invasion, metastasis, and cause-specific survival. Results: The proportion of MMP-7-expressing tumor cells were significantly higher (P < 0.001) than that of normal cells. MMP-7-positive vessels were considered blood vessels based on staining for CD34, and their density was increased in tumor areas. The proportion of MMP-7-expressing cancer cells and density of MMP-7-positive vessels correlated with grade, pathologic tumor stage, and metastasis. Multivariate analysis showed that MMP-7 expression on cancer cells correlated with pathologic tumor stage only, whereas MMP-7-positive vessel density correlated with metastasis only. The elevated status of MMP-7 in cancer tissues was an independent predictor for cause-specific survival (odds ratio, 8.61; P = 0.040) by multivariate analysis. Conclusions: Our results showed that MMP-7 influences tumor progression by regulating invasion and angiogenesis. Multivariate analysis showed that MMP-7 status of cancer tissues was strong predictor of poor prognosis. Our results suggest that MMP-7 targeting treatment may be a potential target against RCC.


The Journal of Urology | 2006

Tumor Lymphangiogenesis in Transitional Cell Carcinoma of the Upper Urinary Tract: Association With Clinicopathological Features and Prognosis

Yasuyoshi Miyata; Shigeru Kanda; Kojiro Ohba; Koichiro Nomata; Jiro Eguchi; Yasushi Hayashida; Hiroshi Kanetake

PURPOSE Lymph node metastasis is an important prognostic factor in many types of cancer. Recently several specific markers for lymphatic endothelium were developed that facilitate the quantification of lymphangiogenesis in human cancer tissues. We investigated the clinical and prognostic significance of lymphangiogenesis in patients with transitional cell carcinoma of the upper urinary tract. MATERIALS AND METHODS We measured lymph vessel density and relative lymphatic vascular area in 125 specimens by quantitative immunohistochemical staining for D2-40 antibody (DakoCytomation, Glostrup, Denmark). These parameters were examined in the intratumor and peritumor areas, and measured using image analysis software. RESULTS Peritumor lymph vessel density and peritumor lymphatic vascular area correlated with lymph node metastasis and tumor grade. In the intratumor area lymphatic vessels were detected in only 16.0% of specimens. However, the presence of intratumor lymphatic vessels was associated with lymph node metastasis (p = 0.002). Multivariate analysis identified high peritumor lymphatic vascular area and the presence of intratumor lymphatic vessels as significant and independent factors of metastasis-free survival after surgery (OR = 5.11, p = 0.020 and OR = 2.92, p = 0.025, respectively). Multivariate analysis also identified the presence of intratumor lymphatic vessels as the only independent predictive factor of cause specific survival (OR = 3.89, p = 0.049). CONCLUSIONS Lymphangiogenesis may have important roles in tumor metastasis and survival in patients with transitional cell carcinoma of the upper urinary tract. Quantification of lymphatic vessels, especially peritumor lymphatic vascular area and intratumor lymphatic vessels, was useful for predicting metastasis-free survival. In addition, the presence of intratumor lymphatic vessels was an independent predictor of cause specific survival.


PLOS ONE | 2013

High expression of HuR in cytoplasm, but not nuclei, is associated with malignant aggressiveness and prognosis in bladder cancer.

Yasuyoshi Miyata; Shin-ichi Watanabe; Yuji Sagara; Kensuke Mitsunari; Tomohiro Matsuo; Kojiro Ohba; Hideki Sakai

Introduction Human antigen R (HuR) regulates the stability of mRNA and is associated with cell proliferation, angiogenesis, and lymphangiogenesis. However, the clinical significance and pathological role of HuR in bladder cancer remains unclear. The main objective of this investigation was to clarify the relationships between HuR expression and clinical significance and cancer cell proliferation, angiogenesis, lymphangiogenesis, and expressions of cyclooxygenase (COX)-2 and vascular endothelial growth factor (VEGF)-A, -C, and -D. Methods All expressions were examined by immunohistochemical techniques in 122 formalin-fixed specimens of bladder cancer patients. HuR expression was evaluated separately with cytoplasmic and nuclear staining. Cell proliferation, angiogenesis and lymphangiogenesis were measured as the percentage of Ki-67-positive cell (proliferation index, PI), CD34-stained vessels (microvessel density, MVD), and D2-40-stained vessels (lymph vessel density, LVD). Relationships between each HuR expression and clinicopathological features, prognosis, and expressions of COX-2 and VEGFs were analyzed by multi-variate analyses. HuR expression was also investigated in 10 mice of N-Butyl-N-[4-hydroxybutil] nitrosamine (BBN) induced bladder cancer model. Results In human tissues, high cytoplasmic expression was seen in 5% and 25.4% of normal and cancer cells, respectively. Nuclear HuR expression bore no significant relationship to any pathological features. However, cytoplasmic HuR expression appeared positively associated with pT stage and grade (P<0.001). In mouse tissues, similar trends were confirmed. Cytoplasmic expression correlated with PI, MVD, and LVD, as well as expression of VEGF-A and -C, but not VEGF-D. High cytoplasmic expression of HuR was a significant predictor of metastasis and cause-specific survival, and was identified as a prognostic correlative factor for metastasis (hazard ratio, 4.75; P = 0.028) in a multivariate analysis model that included pathological features. Conclusions Cytoplasmic HuR appears to play important roles in cell proliferation, progression, and survival of bladder cancer patients. Its expression was associated with angiogenesis, lymphangiogenesis, and expressions of VEGF-A and –C.


Virchows Archiv | 2013

CD105 is a more appropriate marker for evaluating angiogenesis in urothelial cancer of the upper urinary tract than CD31 or CD34

Yasuyoshi Miyata; Yuji Sagara; Shin-ichi Watanabe; Akihiro Asai; Tomohiro Matsuo; Kojiro Ohba; Tomayoshi Hayashi; Hideki Sakai

Angiogenesis plays an important role in cancer progression in many types of cancer. Evaluation of angiogenesis is often performed, but the optimal methodology for human cancer has not been agreed upon. As adequate evaluation of angiogenesis in cancer tissues might be important for prediction of prognosis and treatment decisions, we evaluated angiogenesis semiquantitatively by assessing microvessel density (MVD) in urothelial cancer of the upper urinary tract (UC-UUT). We compared the performance of three endothelial cell markers (CD31, CD34, and CD105) on formalin-fixed tissues from 122 patients diagnosed with UC-UUT without metastasis. Vascular endothelial growth factor (VEGF)-A expression was also evaluated immunohistochemically. Correlations between MVD with each marker and pT stage, grade, survival, and VEGF-A expression were investigated. Mean (standard deviation) MVD as estimated by immunohistochemical staining with anti-CD31, anti-CD34, and anti-CD105 were 47.1 (17.9)/high-power field (HPF), 70.9 (19.5)/HPF, and 31.2 (16.7)/HPF, respectively. Although all MVDs were significantly associated with pT stage and grade, CD105-MVD showed the strongest association. Similarly, CD105-MVD showed the strongest correlation with VEGF-A expression (r = 0.530, p < 0.001). Although all MVDs were associated with metastasis-free survival and cause-specific survival on univariate analysis, only CD105-MVD was retained as an independent predictor in multivariate analysis including pT stage and grade. CD105-MVD may be the preferred marker for semiquantitative assessment of angiogenesis in patients with UC-UUT.


Clinical Transplantation | 2004

Clinicopathological study of vesicoureteral reflux (VUR)-associated pyelonephritis in renal transplantation.

Kojiro Ohba; M Matsuo; Mitsuru Noguchi; Masaharu Nishikido; Shigehiko Koga; Hiroshi Kanetake; Arifa Nazneen; Diange Liu; Mohammed S. Razzaque; Takashi Taguchi

Abstract:  We retrospectively studied the occurrence of vesicoureteral reflux (VUR)‐associated pyelonephritis using renal biopsies obtained from the transplanted kidneys, and correlated the histological changes with clinical parameters. Out of a total of 131 renal biopsies performed between 1990 and 2001 on renal transplant patients at the department of Urology of Nagasaki University Graduate School of Biomedical Sciences, 12 patients showed pyuria more than twice in a single year. Seven of these 12 patients were available for determining VUR by voiding cystourethrography (VCUG). Cystoureterography demonstrated VUR in three of seven studied patients with pyuria. A histopathological examination revealed dilatation of both proximal and distal tubules in renal biopsies of transplant patients with VUR, compared to renal biopsies of transplant patients without VUR, or non‐transplanted patients with thin membrane disease. One of the patients with VUR showed advanced features of chronic pyelonephritis in four consecutive biopsies at different time points, suggesting a late stage of reflux nephropathy in the transplanted kidney. We conclude from our study that the occurrence of VUR‐related pyelonephritis may be one of the important long‐term complications in the survival of renal allografts.


Cancers | 2014

Met in Urological Cancers

Yasuyoshi Miyata; Akihiro Asai; Kensuke Mitsunari; Tomohiro Matsuo; Kojiro Ohba; Yasushi Mochizuki; Hideki Sakai

Met is a tyrosine kinase receptor that is considered to be a proto-oncogene. The hepatocyte growth factor (HGF)-Met signaling system plays an important role in tumor growth, invasion, and metastasis in many types of malignancies. Furthermore, Met expression has been reported to be a useful predictive biomarker for disease progression and patient survival in these malignancies. Many studies have focused on the clinical significance and prognostic role of Met in urological cancers, including prostate cancer (PCa), renal cell carcinoma (RCC), and urothelial cancer. Several preclinical studies and clinical trials are in progress. In this review, the current understanding of the pathological role of Met in cancer cell lines, its clinical significance in cancer tissues, and its predictive value in patients with urological cancers are summarized. In particular, Met-related malignant behavior in castration-resistant PCa and the different pathological roles Met plays in papillary RCC and other histological types of RCC are the subjects of focus. In addition, the pathological significance of phosphorylated Met in these cancers is shown. In recent years, Met has been recognized as a potential therapeutic target in various types of cancer; therapeutic strategies used by Met-targeted agents in urological cancers are summarized in this review.


Urology | 2011

Pathologic Significance and Prognostic Value of Phosphorylated Cortactin Expression in Patients With Sarcomatoid Renal Cell Carcinoma

Tomohiro Matsuo; Yasuyoshi Miyata; Shin-ichi Watanabe; Kojiro Ohba; Tomayoshi Hayashi; Shigeru Kanda; Hideki Sakai

OBJECTIVES To clarify the clinical and prognostic significance of cortactin and phosphorylated cortactin in patients with sarcomatoid renal cell carcinoma (SRCC). METHODS We retrospectively reviewed the data from 31 patients with SRCC and 33 with conventional renal cell carcinoma matched for clinicopathologic features. The immunoreactive score for cortactin, pY421 cortactin, and pY466 cortactin were measured using immunohistochemistry. The relationships between each immunoreactive score and the clinicopathologic features and survival were investigated. RESULTS The immunoreactive score of p421 cortactin, but not that of cortactin and pY466 cortactin, was significantly greater in SRCC than in conventional renal cell carcinoma (P < .001). The expression of pY421 cortactin in SRCC correlated with the pT stage and metastasis (P < .001). The expression of pY466 cortactin showed a similar trend with pT stage (P = .043) but not with metastasis. Although both of pY421 cortactin and pY466 cortactin were identified as useful predictors for survival in univariate analyses, only pY421 cortactin expression was considered an independent predictor in patients with SRCC (odds ratio 4.53, 95% confidence interval 1.07-19.12, P = .040) in the multivariate analysis model, including pT stage and metastasis. CONCLUSIONS Our results have demonstrated that phosphorylation of cortactin is a key process in malignant aggressiveness, and its expression is a useful predictor of cause-specific survival and could be a useful potential therapeutic target in patients with SRCC.


Virchows Archiv | 2006

Pathological function of prostaglandin E2 receptors in transitional cell carcinoma of the upper urinary tract

Yasuyoshi Miyata; Kojiro Ohba; Shigeru Kanda; Koichiro Nomata; Jiro Eguchi; Tomayoshi Hayashi; Hiroshi Kanetake

The prostaglandin E2 receptor, EP4 receptor (EP4R), plays an important role in the development of transitional cell carcinoma of the upper urinary tract (TCC-UUT). However, the clinical significance of other EP receptors (EP1R–3R) is not clear. Furthermore, the pathological function of EP receptors in such patients is not understood. In the present study, we examined the expression of EP1R–3R in 101 TCC-UUT tissues by immunohistochemistry. Furthermore, we defined the relationship between cyclooxygenase (COX)-2 and EP receptor expression, proliferation index (PI), microvessel density (MVD), and expression of metalloproteinase-2 (MMP-2), urokinase-type plasminogen activator (uPA), and exon v6 containing CD44 isoform (CD44 v6) by multivariate analysis. The expression of EP1R, EP2R, and EP3R was positive in 20 (19.8%), 26 (25.7%), and 14 (13.9%) tumor samples, respectively. Expression of these receptors was not associated with pathological findings or survival. COX-2 and EP4R were independently associated with MVD and MMP-2, and uPA or PI and MMP-2, respectively. Other EP receptors were not influenced by any factors. Our results suggest that EP1R–3R play a minimal role in cancer progression in patients with TCC-UUT. On the other hand, EP4R regulates tumor progression via cancer cell proliferation and MMP-2, distinct from COX-2.


Oncology Letters | 2017

Pathological significance and prognostic implications of heme oxygenase 1 expression in non‑muscle‑invasive bladder cancer: Correlation with cell proliferation, angiogenesis, lymphangiogenesis and expression of VEGFs and COX‑2

Tomohiro Matsuo; Yasuyoshi Miyata; Kensuke Mitsunari; Takuji Yasuda; Kojiro Ohba; Hideki Sakai

Heme oxygenase 1 (HO-1) is a stress-response protein and its expression is associated with malignant potential and poor prognosis in several types of cancer. The present study investigated the association between HO-1 expression levels and the pathological features, clinical outcomes and other associated factors in patients with non-muscle-invasive bladder cancer (NMIBC). HO-1 expression was evaluated using immunohistochemistry in 147 formalin-fixed tissue specimens. The proliferation index, microvessel density, lymph vessel density and expression of cyclooxygenase (COX)-2 and vascular endothelial growth factor (VEGF)-A, -C, and -D were also investigated. Correlations among variables were analyzed by multivariate analysis. Survival was assessed using Kaplan-Meier survival curves and multivariate statistics. HO-1 expression levels in high-grade and pT1 tumors were significantly higher compared with low-grade and pTa tumors, and were correlated with the proliferation index (P<0.001), lymph vessel density (P=0.021) and COX-2 expression levels (P=0.003). The proliferation index and COX-2 expression levels were also identified as independent contributing factors in multivariate models. Kaplan-Meier survival curves associated HO-1 expression with a poor prognosis in metastasis-free (P=0.047) and cause-specific survival (P=0.017), but not with urinary tract recurrence (P=0.231). Furthermore, HO-1 expression was identified by multivariate analysis to be a significant predictor for cause-specific survival (hazard ratio, 4.08; 95% confidence interval, 1.06-15.66; P=0.004). HO-1 has an important role in the malignant aggressiveness of NMIBC and its expression is associated with cause-specific survival. HO-1-associated activities are regulated by cancer cell proliferation, lymphangiogenesis and COX-2. The results suggest that HO-1 may be a potential therapeutic target and a useful predictive prognostic factor in patients with NMIBC.

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