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Dive into the research topics where Jotaro Mikami is active.

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Featured researches published by Jotaro Mikami.


Oncotarget | 2017

Oncological outcomes of neoadjuvant chemotherapy in patients with locally advanced upper tract urothelial carcinoma: a multicenter study

Yuka Kubota; Shingo Hatakeyama; Toshikazu Tanaka; Naoki Fujita; Hiromichi Iwamura; Jotaro Mikami; Hayato Yamamoto; Yuki Tobisawa; Tohru Yoneyama; Takahiro Yoneyama; Yasuhiro Hashimoto; Takuya Koie; Hiroyuki Ito; Kazuaki Yoshikawa; Atsushi Sasaki; Toshiaki Kawaguchi; Chikara Ohyama

Objective The clinical impact of neoadjuvant chemotherapy (NAC) on oncological outcomes in patients with locally advanced upper tract urothelial carcinoma (UTUC) remains unclear. We investigated the oncological outcomes of platinum-based NAC for locally advanced UTUC. Results Of 234 patients, 101 received NAC (NAC group) and 133 did not (Control [Ctrl] group). The regimens in the NAC group included gemcitabine and carboplatin (75%), and gemcitabine and cisplatin (21%). Pathological downstagings of the primary tumor and lymphovascular invasion were significantly improved in the NAC than in the Ctrl groups. NAC for locally advanced UTUC significantly prolonged recurrence-free and cancer-specific survival. Multivariate Cox regression analysis using an inverse probability of treatment weighted (IPTW) method showed that NAC was selected as an independent predictor for prolonged recurrence-free and cancer-specific survival. However, the influence of NAC on overall survival was not statistically significant. Materials and Methods A total of 426 patients who underwent radical nephroureterectomy at five medical centers between January 1995 and April 2017 were examined retrospectively. Of the 426 patients, 234 were treated for a high-risk disease (stages cT3–4 or locally advanced [cN+] disease) with or without NAC. NAC regimens were selected based on eligibility of cisplatin. We retrospectively evaluated post-therapy pathological downstaging, lymphovascular invasion, and prognosis stratified by NAC use. Multivariate Cox regression analysis was performed for independent factors for prognosis. Conclusions Platinum-based NAC for locally advanced UTUC potentially improves oncological outcomes. Further prospective studies are needed to clarify the clinical benefit of NAC for locally advanced UTUC.


PLOS ONE | 2015

Detection of Core2 β-1,6-N-Acetylglucosaminyltransferase in Post-Digital Rectal Examination Urine Is a Reliable Indicator for Extracapsular Extension of Prostate Cancer.

Yuta Kojima; Tohru Yoneyama; Shingo Hatakeyama; Jotaro Mikami; Tendo Sato; Kazuyuki Mori; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama; Minoru Fukuda; Yuki Tobisawa

To identify appropriate candidates for aggressive treatment such as radical prostatectomy or radiation therapy of localized prostate cancer (PCa), novel predictive biomarkers of PCa aggressiveness are essential. Core2 β-1,6-N-acetylglucosaminyltransferase-1 (GCNT1) is a key enzyme that forms core 2-branched O-glycans. Its expression is associated with the progression of several cancers. We established a mouse IgG monoclonal antibody (mAb) against GCNT1 and examined the relationship of GCNT1 expression to the clinicopathological status of PCa. Paraffin-embedded PCa specimens were analyzed by immunohistochemistry for GCNT1 expression using a newly established mouse anti-GCNT1 mAb by ourselves. GCNT1-positive tumor showed significantly higher Gleason score and larger tumor volume. The number of GCNT1-positive cases was significantly lower in cases of organ-confined disease than in cases of extracapsular extension. GCNT1-negative tumors were associated with significantly better prostate-specific antigen (PSA)-free survival compared with GCNT1-positive tumors. Multivariate analysis revealed that detection of GCNT1 expression was an independent risk factor for PSA recurrence. We established new methods for GCNT1 detection from PCa specimens. Immunoblotting was used to examine post-digital rectal examination (DRE) urine from PCa patients. Over 90% of GCNT1-positive PCa patients with high concentrations of PSA showed extracapsular extension. In conclusion, GCNT1 expression closely associates with the aggressive potential of PCa. Further research aims to develop GCNT1 detection in post-DRE urine as a marker for PCa aggressiveness.


The Scientific World Journal | 2014

Preoperative butyrylcholinesterase level as an independent predictor of overall survival in clear cell renal cell carcinoma patients treated with nephrectomy.

Takuya Koie; Chikara Ohyama; Jotaro Mikami; Hiromichi Iwamura; Naoki Fujita; Tendo Sato; Yuta Kojima; Ken Fukushi; Hayato Yamamoto; Atsushi Imai; Shingo Hatakeyama; Takahiro Yoneyama; Yasuhiro Hashimoto; Masato Kitayama; Kazuyoshi Hirota

The prognostic factors for the overall survival (OS) of clear cell renal cell carcinoma (ccRCC) patients treated with nephrectomy are not well defined. In the present study, we investigated the prognostic significance of preoperative butyrylcholinesterase (BChE) levels in 400 ccRCC patients undergoing radical or partial nephrectomy from 1992 to 2013 at our institution. Univariate and multivariate analyses were performed to determine the clinical factors associated with OS. Among the enrolled patients, 302 were diagnosed with organ-confined disease only (T1-2N0M0), 16 with lymph node metastases, and 56 with distant metastases. The median preoperative BChE level was 250 U/L (normal range, 168–470 U/L), and median follow-up period was 36 months. The 3-year OS rate in patients with preoperative BChE levels of ≥100 U/L was significantly higher than in those with levels of <100 U/L (89.3% versus 77.7%, P = 0.004). On univariate analysis, performance status; anemia; hypoalbuminemia; preoperative levels of BChE, corrected calcium, and C-reactive protein; and distant metastasis status were significantly associated with OS. Multivariate analysis revealed that preoperative BChE levels and distant metastasis status were significantly associated with OS. Our findings suggest a possible role of preoperative BChE levels as an independent predictor of OS after nephrectomy in ccRCC patients.


Cancer Science | 2016

I‐branching N‐acetylglucosaminyltransferase regulates prostate cancer invasiveness by enhancing α5β1 integrin signaling

Jotaro Mikami; Yuki Tobisawa; Tohru Yoneyama; Shingo Hatakeyama; Kazuyuki Mori; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama; Minoru Fukuda

Cell surface carbohydrates are important for cell migration and invasion of prostate cancer (PCa). Accordingly, the I‐branching N‐acetylglucosaminyltransferase (GCNT2) converts linear i‐antigen to I‐branching glycan, and its expression is associated with breast cancer progression. In the present study, we identified relationships between GCNT2 expression and clinicopathological parameters in patients with PCa. Paraffin‐embedded PCa specimens were immunohistochemically tested for GCNT2 expression, and the roles of GCNT2 in PCa progression were investigated using cell lines with high GCNT2 expression and low GCNT2 expression. GCNT2‐positive cells were significantly lesser in organ‐confined disease than in that with extra‐capsular extensions, and GCNT2‐negative tumors were associated with significantly better prostate‐specific antigen‐free survival compared with GCNT2‐positive tumors. Subsequent functional studies revealed that knockdown of GCNT2 expression in PCa cell lines significantly inhibited cell migration and invasion. GCNT2 regulated the expression of cell surface I‐antigen on the O‐glycan and glycolipid. Moreover, I‐antigen‐bearing glycolipids were subject to α5β1 integrin–fibronectin mediated protein kinase B phosphorylation. In conclusion, GCNT2 expression is closely associated with invasive potential of PCa.


Journal of Clinical Oncology | 2016

Long-term effects of Bacilles Calmette-Guerin perfusion therapy for elderly patients with upper urinary tract urothelial carcinoma in situ.

Takahiro Yoneyama; Jotaro Mikami; Naoki Fujita; Tendo Sato; Yuta Kojima; Hiromichi Iwamura; Yuki Tobisawa; Tohru Yoneyama; Kazuyuki Mori; Atsushi Imai; Shingo Hatakeyama; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama

404 Background: According to several guidelines, the standard therapy for carcinoma in situ (CIS) of the upper urinary tract is total nephroureterectomy. However, it is difficult to determine a treatment strategy for elderly patients. Bacillus Calmette-Guerin (BCG) therapy has already been established as a treatment for non-muscle invasive bladder cancer. However, although there are several reports indicating the effectiveness of BCG perfusion therapy for the upper urinary tract CIS, it has not been established yet. We conducted a retrospective study to assess the long-term effects of BCG perfusion therapy for the upper urinary tract CIS for elderly patients. Methods: We treated 34 patients with upper urinary tract CIS at our clinic between August 2004 and March 2015. 29 patients (22 men and 7 women) with the age of 65 years or older were enrolled. 11 subjects had the entire urinary tract CIS, 8 had bilateral, 10 had unilateral CIS of the upper urinary tract. The average period of observation was 45.5 mon...


Biochemical and Biophysical Research Communications | 2016

Core 2 β-1, 6-N-acetylglucosaminyltransferase-1 expression in prostate biopsy specimen is an indicator of prostate cancer aggressiveness.

Tendo Sato; Tohru Yoneyama; Yuki Tobisawa; Shingo Hatakeyama; Hayato Yamamoto; Yuta Kojima; Jotaro Mikami; Kazuyuki Mori; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama


Hinyokika kiyo. Acta urologica Japonica | 2013

[Ureteral endometriosis treated by hormonal therapy : a case report].

Jotaro Mikami; Hayato Yamamoto; Akiko Okamoto; Hirofumi Ishimura; Atsushi Imai; S. Hatakeyama; Takahiro Yoneyama; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama


Journal of Clinical Oncology | 2016

Sequential chemotherapy with gemcitabine+carboplatin followed by gemcitabine+carboplatin+docetaxel for advanced upper-tract urothelial cancer.

Takahiro Yoneyama; Tendo Sato; Jotaro Mikami; Yuta Kojima; Naoki Fujita; Hiromichi Iwamura; Yuki Tobisawa; Tohru Yoneyama; Kazuyuki Mori; Atsushi Imai; Shingo Hatakeyama; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama


Journal of Clinical Oncology | 2016

Carboplatin-based sequential chemotherapy for advanced bladder cancer patient with impaired renal function.

Takahiro Yoneyama; Jotaro Mikami; Naoki Fujita; Tendo Sato; Yuta Kojima; Hiromichi Iwamura; Atsushi Imai; Shingo Hatakeyama; Yasuhiro Hashimoto; Takuya Koie; Chikara Ohyama


The Journal of Urology | 2015

MP69-07 IMPACT OF TARGETED AGENTS ON RENAL FUNCTION IN PATIENTS WITH METASTATIC RCC

Yuta Kojima; Jotaro Mikami; Shingo Hatakeyama; Hayato Yamamoto; Atsushi Imai; Takahiro Yoneyama; Yashuhiro Hashimoto; Takuya Koie; Chikara Ohyama

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