Akria Ishikawa

Dr. Akria Ishikawa

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Research Focus & Metrics

Academic Career Length

35Years (1992-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2020 in Clinical and Translational Gastroenterology
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Journal Article
Open access
MYMasami Yamauchi
Masami Yamauchi
AOAtsushi Ono
Atsushi Ono
AIAkria Ishikawa
Akria Ishikawa
KKKenichiro Kodama
Kenichiro Kodama
SUShinsuke Uchikawa
Shinsuke Uchikawa
KCKazuaki Chayama
Kazuaki Chayama
OBJECTIVES: Biomarkers for optimizing the outcome of treatment with lenvatinib in patients with advanced hepatocellular carcinoma remain to be established despite intensive and comprehensive genomic research. Lenvatinib is characterized by its prominent inhibitory potency for fibroblast growth factor receptor (FGFR) 4 compared with earlier tyrosine kinase inhibitors. Thus, in this study, we focused on simplified quantification of FGFR4 in tumors as a potential predictive indicator. METHODS: According to The Cancer Genome Atlas data set curation, FGFR4 messenger RNA is broadly overexpressed in hepatocellular carcinoma in the absence of gene alteration. Gene set enrichment analysis revealed that the aggressiveness of the tumor was closely related to the FGFR4 level. To confirm the relationship between the benefits of lenvatinib and tumor addiction to the FGFR4 pathway, we analyzed protein levels in tumors and peripheral blood obtained from 57 prospectively registered patients treated with lenvatinib. RESULTS: Positive immunohistochemistry (>10% of tumor cells) for FGFR4 in biopsy samples before treatment was associated with a longer progression-free survival (2.5 vs 5.5 months, P = 0.01) and a favorable objective response rate (31% vs 81%, P = 0.006). By contrast, the concentration of soluble FGFR4 in peripheral blood as measured by an enzyme-linked immunosorbent assay was not associated with survival outcomes, because its fluctuations reflect hepatic fibrosis. Additional RNA sequencing analysis using archival surgical specimens (n = 90) suggested that alternative RNA splicing of FGFR4 in cancer may also explain this discrepancy. DISCUSSION: The tumor FGFR4 level was an independent predictor of response to lenvatinib.

4 September 2012 in Proceedings of the National Academy of Sciences
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Journal Article
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YKYuichiro Kashiyama
Yuichiro Kashiyama
AYAkiko Yokoyama
Akiko Yokoyama
YKYusuke Kinoshita
Yusuke Kinoshita
SSSunao Shoji
Sunao Shoji
HMHideaki Miyashiya
Hideaki Miyashiya
HTHitoshi Tamiaki
Hitoshi Tamiaki
Chlorophylls are essential components of the photosynthetic apparati that sustain all of the life forms that ultimately depend on solar energy. However, a drawback of the extraordinary photosensitizing efficiency of certain chlorophyll species is their ability to generate harmful singlet oxygen. Recent studies have clarified the catabolic processes involved in the detoxification of chlorophylls in land plants, but little is understood about these strategies in aquatic ecosystem. Here, we report that a variety of heterotrophic protists accumulate the chlorophyll a catabolite 13 2 ,17 3 -cyclopheophorbide a enol (cPPB- a E) after their ingestion of algae. This chlorophyll derivative is nonfluorescent in solution, and its inability to generate singlet oxygen in vitro qualifies it as a detoxified catabolite of chlorophyll a . Using a modified analytical method, we show that cPPB- a E is ubiquitous in aquatic environments, and it is often the major chlorophyll a derivative. Our findings suggest that cPPB- a E metabolism is one of the most important, widely distributed processes in aquatic ecosystems. Therefore, the herbivorous protists that convert chlorophyll a to cPPB- a E are suggested to play more significant roles in the modern oceanic carbon flux than was previously recognized, critically linking microscopic primary producers to the macroscopic food web and carbon sequestration in the ocean.

1 January 2017 in Urologic Oncology: Seminars and Original Investigations
Verified
Journal Article
Closed access
YSYohei Sekino
Yohei Sekino
WYWataru Yasui
Wataru Yasui
YSYoshinori Shigematsu
Yoshinori Shigematsu
AIAkria Ishikawa
Akria Ishikawa
NSNaoya Sakamoto
Naoya Sakamoto
WYWataru Yasui
Wataru Yasui

1 November 2017 in Pathobiology
Verified
Journal Article
Open access
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WYWataru Yasui
Wataru Yasui
YYYuji Yamamoto
Yuji Yamamoto
TOTakashi Oshima
Takashi Oshima
RARyuichi Asai
Ryuichi Asai
AIAkria Ishikawa
Akria Ishikawa
WYWataru Yasui
Wataru Yasui
Objective: Spheroid colony formation is a useful method of cancer stem cell (CSC) characterization. We previously showed that the IQ motif containing the GTPase-activating protein 3 gene (IQGAP3) is upregulated in spheroid body-forming gastric cancer (GC) cells compared with parental cells. We investigated IQGAP3 expression in GC. Methods: IQGAP3 protein expression was analyzed by immunohistochemistry in 165 GC cases. RNA interference was used to inhibit IQGAP3 expression in GC cell lines. Results: In non neoplastic gastric mucosa, weak staining of IQGAP3 was observed in the foveolar epithelium, while GC tissue showed stronger, more extensive staining. Of the 165 GC cases, 34 (21%) were positive for IQGAP3 expression. GC cases positive for IQGAP3 were found more frequently in stage II/III/IV cases than in stage I cases. Univariate and multivariate analyses demonstrated that IQGAP3 expression is an independent prognostic classifier of GC patients. Both the number and size of the spheres formed by MKN-74 cells were significantly reduced by knockdown of IQGAP3. The phosphorylation of Akt and Erk1/2 was inhibited by knockdown of IQGAP3. Conclusion: These results suggest that IQGAP3 plays an important role in gastric CSCs. The location of IQGAP3 on the cell membrane makes it a potential therapeutic target for GC.

1 November 2002 in The Journal of Hand Surgery
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Journal Article
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HOHiroshi Orui
Hiroshi Orui
AIAkria Ishikawa
Akria Ishikawa
TTTakashi Tsuchiya
Takashi Tsuchiya
TOToshihiko Ogino
Toshihiko Ogino

22 February 2023 in Cancers
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Journal Article
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RORina Otani
Rina Otani
HTHidehiko Takigawa
Hidehiko Takigawa
RYRyo Yuge
Ryo Yuge
DSDaisuke Shimizu
Daisuke Shimizu
MAMisa Ariyoshi
Misa Ariyoshi
Shinji TanakaShinji Tanaka
Shinji Tanaka
A novel large neutral amino acid transporter 1 (LAT1)-specific inhibitor, JPH203, is expected to cause cancer-specific starvation and possess anti-tumor effects; however, its anti-tumor mechanism for colorectal cancer (CRC) remains unclear. We analyzed LAT family gene expressions in public databases using UCSC Xena and evaluated LAT1 protein expression using immunohistochemistry in 154 cases of surgically resected CRC. We also evaluated mRNA expression using polymerase chain reaction in 10 CRC cell lines. Furthermore, JPH203 treatment experiments were conducted in vitro and in vivo using an allogeneic immune-responsive mouse model with abundant stroma created via the orthotopic transplantation of the mouse-derived CRC cell line CT26 and mesenchymal stem cells. The treatment experiments were followed by comprehensive gene expression analyses with RNA sequencing. Database analyses and immunohistochemistry research on clinical specimens revealed that LAT1 expression was cancer-dominant, and its increase was accompanied by tumor progression. In vitro, JPH203 was effective in an LAT1 expression-dependent manner. In vivo, JPH203 treatment considerably reduced tumor size and metastasis, and RNA sequencing-based pathway analysis showed that not only tumor growth and amino acid metabolism pathways, but also stromal activation-related pathways were suppressed. The results of the RNA sequencing were validated in the clinical specimens, as well as both in vitro and in vivo. LAT1 expression in CRC plays an important role in tumor progression. JPH203 may inhibit the progression of CRC and tumor stromal activity.