Papers - SUZUKI Hiromu

大腸腫瘍の表面構造が反映する腫瘍内不均一性(Microsurface structures are associated with mutational intratumoral heterogeneity in colorectal tumors)

山本 英一郎, 山野 泰穂, 青木 敬則, 須藤 豪太, 新沼 猛, 甲斐 正広, 佐々木 泰史, 時野 隆至, 菅井 有, 仲瀬 裕志, 鈴木 拓

日本癌学会総会記事 ( (一社)日本癌学会 )  77回   2405 - 2405  2018.09

慢性胃炎および胃がんに関連する長鎖non-coding RNAの同定と機能解析(Identification and characterization of a long non-coding RNA associated with chronic gastritis and gastric caner)

北嶋 洋志, 丸山 玲緒, 山本 英一郎, 新沼 猛, 甲斐 正広, 佐々木 泰史, 時野 隆至, 仲瀬 裕志, 鈴木 拓

日本癌学会総会記事 ( (一社)日本癌学会 )  77回   512 - 512  2018.09

トリプルネガティブ乳癌におけるSALL3の高頻度なエピジェネティックな不活化機構(Downregulation of SALL3 by recurrent genetic and epigenetic alterations is involved in triple negative breast cancers)

松下 洋輔, 小松 正人, 清谷 一馬, 吉丸 哲郎, 新沼 猛, 鈴木 拓, 本田 純子, 井本 逸勢, 丹黒 章, 三好 康雄, 笹 三徳, 片桐 豊雅

日本癌学会総会記事 ( 日本癌学会 )  77回   1410 - 1410  2018.09  [Refereed]

Screening for long noncoding RNAs associated with oral squamous cell carcinoma reveals the potentially oncogenic actions of DLEU1.

Koyo Nishiyama, Reo Maruyama, Takeshi Niinuma, Masahiro Kai, Hiroshi Kitajima, Mutsumi Toyota, Yui Hatanaka, Tomohiro Igarashi, Jun-Ichi Kobayashi, Kazuhiro Ogi, Hironari Dehari, Akihiro Miyazaki, Akira Yorozu, Eiichiro Yamamoto, Masashi Idogawa, Yasushi Sasaki, Tamotsu Sugai, Takashi Tokino, Hiroyoshi Hiratsuka, Hiromu Suzuki

Cell death & disease   9 ( 8 ) 826 - 826  2018.08  [Refereed]  [International journal]

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Recent studies have shown that long noncoding RNAs (lncRNAs) have pivotal roles in human malignancies, although their significance in oral squamous cell carcinoma (OSCC) is not fully understood. In the present study, we identified lncRNAs functionally associated with OSCC. By analyzing RNA-seq datasets obtained from primary head and neck squamous cell carcinoma (HNSCC), we identified 15 lncRNAs aberrantly expressed in cancer tissues. We then validated their expression in 18 OSCC cell lines using qRT-PCR and identified 6 lncRNAs frequently overexpressed in OSCC. Among those, we found that knocking down DLEU1 (deleted in lymphocytic leukemia 1) strongly suppressed OSCC cell proliferation. DLEU1 knockdown also suppressed migration, invasion, and xenograft formation by OSCC cells, which is suggestive of its oncogenic functionality. Microarray analysis revealed that DLEU1 knockdown significantly affects expression of a number of cancer-related genes in OSCC cells, including HAS3, CD44, and TP63, suggesting that DLEU1 regulates HA-CD44 signaling. Expression of DLEU1 was elevated in 71% of primary OSCC tissues, and high DLEU1 expression was associated with shorter overall survival of HNSCC patients. These data suggest that elevated DLEU1 expression contributes to OSCC development, and that DLEU1 may be a useful therapeutic target in OSCC.

DOI PubMed

Subtypes of the Type II Pit Pattern Reflect Distinct Molecular Subclasses in the Serrated Neoplastic Pathway.

Hironori Aoki, Eiichiro Yamamoto, Hiro-O Yamano, Tamotsu Sugai, Tomoaki Kimura, Yoshihito Tanaka, Hiro-O Matsushita, Kenjiro Yoshikawa, Ryo Takagi, Eiji Harada, Michiko Nakaoka, Yuko Yoshida, Taku Harada, Gota Sudo, Makoto Eizuka, Akira Yorozu, Hiroshi Kitajima, Takeshi Niinuma, Masahiro Kai, Masanori Nojima, Hiromu Suzuki, Hiroshi Nakase

Digestive diseases and sciences   63 ( 7 ) 1920 - 1928  2018.07  [Refereed]  [International journal]

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BACKGROUND: Colorectal serrated lesions (SLs) are important premalignant lesions whose clinical and biological features are not fully understood. AIMS: We aimed to establish accurate colonoscopic diagnosis and treatment of SLs through evaluation of associations among the morphological, pathological, and molecular characteristics of SLs. METHODS: A total of 388 premalignant and 18 malignant colorectal lesions were studied. Using magnifying colonoscopy, microsurface structures were assessed based on Kudo's pit pattern classification system, and the Type II pit pattern was subcategorized into classical Type II, Type II-Open (Type II-O) and Type II-Long (Type II-L). BRAF/KRAS mutations and DNA methylation of CpG island methylator phenotype (CIMP) markers (MINT1, - 2, - 12, - 31, p16, and MLH1) were analyzed through pyrosequencing. RESULTS: Type II-O was tightly associated with sessile serrated adenoma/polyps (SSA/Ps) with BRAF mutation and CIMP-high. Most lesions with simple Type II or Type II-L were hyperplastic polyps, while mixtures of Type II or Type II-L plus more advanced pit patterns (III/IV) were characteristic of traditional serrated adenomas (TSAs). Type II-positive TSAs frequently exhibited BRAF mutation and CIMP-low, while Type II-L-positive TSAs were tightly associated with KRAS mutation and CIMP-low. Analysis of lesions containing both premalignant and cancerous components suggested Type II-L-positive TSAs may develop into KRAS-mutated/CIMP-low/microsatellite stable cancers, while Type II-O-positive SSA/Ps develop into BRAF-mutated/CIMP-high/microsatellite unstable cancers. CONCLUSIONS: These results suggest that Type II subtypes reflect distinct molecular subclasses in the serrated neoplasia pathway and that they could be useful hallmarks for identifying SLs at high risk of developing into CRC.

DOI PubMed

Translational regulation by miR-301b upregulates AMP deaminase in diabetic hearts

Yuki Tatekoshi, Masaya Tanno, Hidemichi Kouzu, Koki Abe, Takayuki Miki, Atsushi Kuno, Toshiyuki Yano, Satoko Ishikawa, Wataru Ohwada, Tatsuya Sato, Takeshi Niinuma, Hiromu Suzuki, Tetsuji Miura

Journal of Molecular and Cellular Cardiology ( Academic Press )  119   138 - 146  2018.06  [Refereed]

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AMP deaminase (AMPD) plays a crucial role in adenine nucleotide metabolism. Recently we found that upregulated AMPD activity is associated with ATP depletion and contractile dysfunction under the condition of pressure overloading in the heart of a rat model of type 2 diabetes mellitus (T2DM), OLETF. Here we examined the mechanism of AMPD upregulation by T2DM. The protein level of 90-kDa full-length AMPD3 was increased in whole myocardial lysates by 55% in OLETF compared to those in LETO, a non-diabetic control. In contrast, the mRNA levels of AMPD3 in the myocardium were similar in OLETF and LETO. AMPD3 was comparably ubiquitinated in OLETF and LETO, and its degradation ex vivo was more sensitive to MG-132, a proteasome inhibitor, in OLETF than in LETO. MicroRNA array analysis revealed downregulation (> 50%) of 57 microRNAs in OLETF compared to those in LETO, among which miR-301b was predicted to interact with the 3'UTR of AMPD3 mRNA. AMPD3 protein level was significantly increased by a miR-301b inhibitor and was decreased by a miR-301b mimetic in H9c2 cells. A luciferase reporter assay confirmed binding of miR-301b to the 3′UTR of AMPD3 mRNA. Transfection of neonatal rat cardiomyocytes with a miR-301b inhibitor increased 90-kDa AMPD3 and reduced ATP level. The results indicate that translational regulation by miR-301b mediates upregulated expression of cardiac AMPD3 protein in OLETF, which potentially reduces the adenine nucleotide pool at the time of increased work load. The miR-301b-AMPD3 axis may be a novel therapeutic target for intervening enegy metabolism in diabetic hearts.

DOI PubMed

Epigenetic silencing of miR-200b is associated with cisplatin resistance in bladder cancer.

Tetsuya Shindo, Takeshi Niinuma, Naotaka Nishiyama, Nobuo Shinkai, Hiroshi Kitajima, Masahiro Kai, Reo Maruyama, Takashi Tokino, Naoya Masumori, Hiromu Suzuki

Oncotarget   9 ( 36 ) 24457 - 24469  2018.05  [Refereed]  [International journal]

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In this study, we identified microRNAs (miRNAs) involved in cisplatin (CDDP) resistance in bladder cancer (BCa). After establishing CDDP-resistant BCa cell lines (T24RC and EJ138RC), TaqMan arrays revealed that members of the miR-200 family (miR-200b, miR-200a and miR-429) were downregulated in T24RC as compared to parental T24 cells. miR-200b was associated with CDDP sensitivity in BCa cells, and its downregulation was associated with CpG island hypermethylation. Pharmacological demethylation using 5-aza-2'-deoxycytidine restored miR-200b expression, and the combination of 5-aza-2'-deoxycytidine + CDDP strongly inhibited T24RC cell proliferation. Microarray analysis revealed that miR-200b + CDDP induced genes involved in CDDP sensitivity or cytotoxicity, including IGFBP3, ICAM1 and TNFSF10, in the resistant cells. Expression and DNA methylation of miR-200b were inversely associated in primary BCa, and low expression/high methylation was associated with poor overall survival. These results suggest downregulation of miR-200b is associated with CDDP resistance in BCa. Epigenetic silencing of miR-200b may be a marker of CDDP resistance and a useful therapeutic target for overcoming CDDP resistance in BCa.

DOI PubMed

Comprehensive molecular analysis based on somatic copy number alterations in intramucosal colorectal neoplasias and early invasive colorectal cancers

Tamotsu Sugai, Makoto Eizuka, Wataru Habano, Yasuko Fujita, Ayaka Sato, Ryo Sugimoto, Kouki Otsuka, Eiichiro Yamamoto, Takayuki Matsumoto, Hiromu Suzuki

Oncotarget ( Impact Journals LLC )  9 ( 33 ) 22895 - 22906  2018.05  [Refereed]

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It is unclear whether somatic copy number alterations (SCNAs) contribute to the development of colorectal cancer (CRC). Here, we aimed to identify the molecular profiles of early colorectal carcinogenesis based on SCNAs and determine the associations of other molecular abnormalities for the detection of neoplasia in both intramucosal neoplasia (IMN) and invasive CRC with invasion into the muscular layer without metastasis (early invasive CRC). A single nucleotide polymorphism array was used to examine 100 colorectal IMNs (low-grade adenoma [LGA], 40 high-grade adenoma [HGA], 25 intramucosal adenocarcinoma [IMA], 35) and early invasive CRC (20 tumors). In addition, genetic mutations (KRAS, BRAF), TP53 overexpression, microsatellite instability (MSI), and DNA methylation (low, intermediate, high) were examined. Hierarchical clustering analysis based on the SCNA pattern was carried out to identify molecular profiles in IMNs and early invasive CRC. Colorectal tumors were classified into three subgroups based on SCNA patterns. Subgroup 1 was characterized by multiple SCNAs, subgroup 3 was closely associated with infrequent SCNAs, and subgroup 2 was an intermediate subgroup in SCNA pattern between subgroups 1 and 3. Although mutations in KRAS were commonly found in all three subgroups, overexpression of TP53 was observed primarily in subgroup 1 and 2. DNA methylation showed a low/intermediate type. Finally, no MSI was detected. Each subgroup was correlated with histology (subgroup 1, early invasive CRC subgroup 2, LGA subgroups 2 and 3, HGA and IMA). Considerable SCNAs may be required for acquisition of invasive ability in CRC. Our results provide novel insights into early CRC.

DOI PubMed

Frequent downregulation of LRRC26 by epigenetic alterations is involved in the malignant progression of triple-negative breast cancer.

Yoshimasa Miyagawa, Yosuke Matsushita, Hiromu Suzuki, Masato Komatsu, Tetsuro Yoshimaru, Ryuichiro Kimura, Ayako Yanai, Junko Honda, Akira Tangoku, Mitsunori Sasa, Yasuo Miyoshi, Toyomasa Katagiri

International journal of oncology   52 ( 5 ) 1539 - 1558  2018.05  [Refereed]  [International journal]

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Triple-negative breast cancer (TNBC), defined as breast cancer lacking estrogen- and progesterone‑receptor expression and human epidermal growth factor receptor 2 (HER2) amplification, is a heterogeneous disease. RNA-sequencing analysis of 15 TNBC specimens and The Cancer Genome Atlas-TNBC dataset analysis identified the frequent downregulation of leucine-rich repeat-containing 26 (LRRC26), which negatively regulates nuclear factor-κB (NF-κB) signaling, in TNBC tissues. Quantitative polymerase chain reaction and bisulfite pyrosequencing analyses revealed that LRRC26 was frequently silenced in TNBC tissues and cell lines as a result of promoter methylation. LRRC26 expression was restored by 5-aza-2'-deoxycytidine (5'-aza-dC) treatment in HCC1937 TNBC cells, which lack LRRC26 expression. Notably, small interfering RNA-mediated knockdown of LRRC26 expression significantly enhanced the anchorage-independent growth, invasion and migration of HCC70 cells, whereas ectopic overexpression of LRRC26 in BT20 cells suppressed their invasion and migration. Conversely, neither knockdown nor overexpression of LRRC26 had an effect on cell viability in the absence of tumor necrosis factor-α (TNF-α) stimulation. Meanwhile, overexpression of LRRC26 caused the reduction of TNF-α-mediated NF-κB luciferase reporter activity, whereas depleting LRRC26 expression resulted in the upregulation of TNF-α-mediated NF-κB downstream genes [interleukin-6 (IL-6), IL-8 and C-X-C motif chemokine ligand-1]. Taken together, these findings demonstrate that LRRC26 is frequently downregulated in TNBC due to DNA methylation and that it suppresses the TNF-α-independent anchorage-independent growth, invasion and migration of TNBC cells. Loss of LRRC26 function may be a critical event in the aggressiveness of TNBC cells through a TNF-α/NF-κB-independent mechanism.

DOI PubMed

Frequent downregulation of LRRC26 by epigenetic alterations is involved in the malignant progression of triple-negative breast cancer.

Yoshimasa Miyagawa, Yosuke Matsushita, Hiromu Suzuki, Masato Komatsu, Tetsuro Yoshimaru, Ryuichiro Kimura, Ayako Yanai, Junko Honda, Akira Tangoku, Mitsunori Sasa, Yasuo Miyoshi, Toyomasa Katagiri

International Journal of Oncology    2018.03  [Refereed]

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Triple-negative breast cancer (TNBC), defined as breast cancer lacking estrogen- and progesterone?receptor expression and human epidermal growth factor receptor 2 (HER2) amplification, is a heterogeneous disease. RNA-sequencing analysis of 15 TNBC specimens and The Cancer Genome Atlas-TNBC dataset analysis identified the frequent downregulation of leucine-rich repeat-containing 26 (LRRC26), which negatively regulates nuclear factor-κB (NF-κB) signaling, in TNBC tissues. Quantitative polymerase chain reaction and bisulfite pyrosequencing analyses revealed that LRRC26 was frequently silenced in TNBC tissues and cell lines as a result of promoter methylation. LRRC26 expression was restored by 5-aza-2'-deoxycytidine (5'-aza-dC) treatment in HCC1937 TNBC cells, which lack LRRC26 expression. Notably, small interfering RNA-mediated knockdown of LRRC26 expression significantly enhanced the anchorage-independent growth, invasion and migration of HCC70 cells, whereas ectopic overexpression of LRRC26 in BT20 cells suppressed their invasion and migration. Conversely, neither knockdown nor overexpression of LRRC26 had an effect on cell viability in the absence of tumor necrosis factor-α (TNF-α) stimulation. Meanwhile, overexpression of LRRC26 caused the reduction of TNF-α-mediated NF-κB luciferase reporter activity, whereas depleting LRRC26 expression resulted in the upregulation of TNF-α-mediated NF-κB downstream genes [interleukin-6 (IL-6), IL-8 and C-X-C motif chemokine ligand-1]. Taken together, these findings demonstrate that LRRC26 is frequently downregulated in TNBC due to DNA methylation and that it suppresses the TNF-α-independent anchorage-independent growth, invasion and migration of TNBC cells. Loss of LRRC26 function may be a critical event in the aggressiveness of TNBC cells through a TNF-α/NF-κB-independent mechanism.

DOI PubMed

Molecular profiling and genome-wide analysis based on somatic copy number alterations in advanced colorectal cancers

Tamotsu Sugai, Yayoi Takahashi, Makoto Eizuka, Ryo Sugimoto, Yasuko Fujita, Wataru Habano, Kouki Otsuka, Akira Sasaki, Eiichiro Yamamoto, Takayuki Matsumoto, Hiromu Suzuki

Molecular Carcinogenesis ( John Wiley and Sons Inc. )  57 ( 3 ) 451 - 461  2018.03  [Refereed]

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To characterize somatic alterations in colorectal cancer (CRC), we conducted a genome-scale analysis of 106 CRC specimens. We assessed comprehensive somatic copy number alterations (SCNAs) in these CRC specimens. In addition, we examined microsatellite instability (MSI low and high), genetic mutations (KRAS, BRAF, TP53, and PIK3CA), and DNA methylation status (classified into low, intermediate, and high type). We stratified molecular alterations in the CRCs using a hierarchical cluster analysis. The examined CRCs could be categorized into three subgroups using hierarchical cluster analysis. Tumors in subgroup 1 were characterized by a low frequency of SCNAs and a high frequency of MSI-high status, whereas tumors in subgroups 2 and 3 were closely associated with a high frequency of SCNAs. Tumors in subgroup 1 were preferentially present in the right-sided colon and showed frequent MSI-high status. Subgroup 3 was distinguished by specific alterations, including gains at 1q23-44, 1p11-36, 10q11-26, 10p11-13, 12q24-24, and 13q33-33. In contrast, tumors in subgroup 2 were characterized by copy-neutral LOH at 12p12-13, 1q24-25, and 10q22. In addition, KRAS mutations were more frequently found in subgroup 3 than in subgroup 1. TP53 mutations and intermediate levels of DNA methylation were common alterations in the three subgroups. SCNAs contributed to sporadic CRC, and there were three subgroups based on SCNAs that played a different role in driving the development of this disease.

DOI PubMed

Evaluation of Urinary DNA Methylation as a Marker for Recurrent Bladder Cancer: A 2-Center Prospective Study

Tetsuya Shindo, Takashi Shimizu, Masanori Nojima, Takeshi Niinuma, Reo Maruyama, Hiroshi Kitajima, Masahiro Kai, Naoki Itoh, Hiromu Suzuki, Naoya Masumori

Urology ( Elsevier Inc. )  113   71 - 78  2018.03  [Refereed]

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Objective: To clarify the clinical utility of urinary DNA methylation for detection of intravesical recurrence of non–muscle invasive BCa (NMIBC), we performed a 2-center prospective study. Patients and Methods: A series of 207 self-voided urine samples were prospectively collected from 132 patients with NMIBC who had undergone transurethral resection of BCa. Methylation of miRNA genes (miR-9-3, miR-124-2, miR-124-3, and miR-137) was analyzed using bisulfite pyrosequencing. The primary end point was detection of intravesical recurrence the secondary end point was prediction of late recurrence. The number of methylated genes (M-score) or quantitative level of methylation were compared with outcomes. Results: Twenty-six urine specimens were collected on the same day intravesical recurrence was detected, and 14 were collected from patients whose recurrences were found during the subsequent follow-up period (0-632 days, mean, 342.2 days). For detection of current recurrence, M-scores achieved 61.5% sensitivity and 74.0% specificity, and the area under the ROC curve was 0.71. Regarding prediction of late recurrence, patients with a high M-score (≥3) showed worse recurrence-free survival (P < .01). Multivariate analysis revealed that high M-scores were independently associated with current (P =.028) and late recurrence (P =.026). Elevated levels of urinary DNA methylation were also strongly associated with recurrence and radical cystectomy. Conclusion: Our data suggest that urinary methylation of miRNA genes may be a useful marker for detecting and predicting BCa recurrence.

DOI PubMed

Molecular profiling and comprehensive genome-wide analysis of somatic copy number alterations in gastric intramucosal neoplasias based on microsatellite status

Tamotsu Sugai, Makoto Eizuka, Noriyuki Arakawa, Mitsumasa Osakabe, Wataru Habano, Yasuko Fujita, Eiichiro Yamamoto, Hiroo Yamano, Masaki Endoh, Takayuki Matsumoto, Hiromu Suzuki

Gastric Cancer ( Springer Tokyo )  21 ( 5 ) 1 - 11  2018.02  [Refereed]

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Background: We attempted to identify the molecular profiles of gastric intramucosal neoplasia (IMN low-grade dysplasia, LGD high-grade dysplasia, HGD intramucosal cancer, IMC) by assessing somatic copy number alterations (SCNAs) stratified by microsatellite status (microsatellite stable, MSS microsatellite instable, MSI). Thus, microsatellite status was determined in 84 tumors with MSS status and 16 tumors with MSI status. Methods: One hundred differentiated type IMNs were examined using SCNAs. In addition, genetic mutations (KRAS, BRAF, PIK3CA, and TP53) and DNA methylation status (low, intermediate and high) were also analyzed. Finally, we attempted to identify molecular profiles using a hierarchical clustering analysis. Results: Three patterns could be categorized according to SCNAs in IMNs with the MSS phenotype: subgroups 1 and 2 showing a high frequency of SCNAs, and subgroup 3 displaying a low frequency of SCNAs (subgroup 1 > 2 > 3 for SCNA). Subgroup 1 could be distinguished from subgroup 2 by the numbers of total SCNAs (gains and losses) and SCN gains (subgroup 1 > 2). The SCNA pattern of LGD was different from that of HGD and IMC. Moreover, IMNs with the MSI phenotype could be categorized into two subtypes: high frequency of SCNAs and low frequency of SCNAs. Genetic mutations and DNA methylation status did not differ among subgroups in IMNs. Conclusion: Molecular profiles stratified by SCNAs based on microsatellite status may be useful for elucidation of the mechanisms of early gastric carcinogenesis.

DOI PubMed

Epigenetic silencing of SMOC1 in traditional serrated adenoma and colorectal cancer.

Hironori Aoki, Eiichiro Yamamoto, Akira Takasawa, Takeshi Niinuma, Hiro-O Yamano, Taku Harada, Hiro-O Matsushita, Kenjiro Yoshikawa, Ryo Takagi, Eiji Harada, Yoshihito Tanaka, Yuko Yoshida, Tomoyuki Aoyama, Makoto Eizuka, Akira Yorozu, Hiroshi Kitajima, Masahiro Kai, Norimasa Sawada, Tamotsu Sugai, Hiroshi Nakase, Hiromu Suzuki

Oncotarget   9 ( 4 ) 4707 - 4721  2018.01  [Refereed]  [International journal]

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Colorectal sessile serrated adenoma/polyps (SSA/Ps) are well-known precursors of colorectal cancer (CRC) characterized by BRAF mutation and microsatellite instability. By contrast, the molecular characteristics of traditional serrated adenoma (TSAs) are not fully understood. We analyzed genome-wide DNA methylation in TSAs having both protruding and flat components. We identified 11 genes, including SMOC1, methylation of which progressively increased during the development of TSAs. SMOC1 was prevalently methylated in TSAs, but was rarely methylated in SSA/Ps (p < 0.001). RT-PCR and immunohistochemistry revealed that SMOC1 was expressed in normal colon and SSA/Ps, but its expression was decreased in TSAs. Ectopic expression of SMOC1 suppressed proliferation, colony formation and in vivo tumor formation by CRC cells. Analysis of colorectal lesions (n = 847) revealed that SMOC1 is frequently methylated in TSAs, high-grade adenomas and CRCs. Among these, SMOC1 methylation was strongly associated with KRAS mutation and CpG island methylator phenotype (CIMP)-low. These results demonstrate that epigenetic silencing of SMOC1 is associated with TSA development but is rarely observed in SSA/Ps. SMOC1 expression could thus be a diagnostic marker of serrated lesions, and SMOC1 methylation could play a role in neoplastic pathways in TSAs and conventional adenomas.

DOI PubMed

Molecular characterization and pathogenesis of gastrointestinal stromal tumor

Takeshi Niinuma, Hiromu Suzuki, Tamotsu Sugai

Translational Gastroenterology and Hepatology ( AME Publishing Company )  2018   2  2018.01  [Refereed]

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Most gastrointestinal stromal tumors (GISTs) harbor activating mutations in the receptor tyrosine kinase gene KIT or platelet-derived growth factor receptor alpha (PDGFRA), and the resultant activation of downstream signals plays a pivotal role in the development of GISTs. The sites of the tyrosine kinase gene mutations are associated with the biological behavior of GISTs, including risk category, clinical outcome and drug response. Mutations in RAS signaling pathway genes, including KRAS and BRAF, have also been reported in KIT/PDGFRA wild-type GISTs, though they are rare. Neurofibromin 1 (NF1) is a tumor suppressor gene mutated in neurofibromatosis type 1. Patients with NF1 mutations are at high risk of developing GISTs. Recent findings suggest that altered expression or mutation of members of succinate dehydrogenase (SDH) heterotetramer are causally associated with GIST development through induction of aberrant DNA methylation. At present, GISTs with no alterations in KIT, PDGFRA, RAS signaling genes or SDH family genes are referred to as true wild-type GISTs. KIT and PDGFRA mutations are thought as the earliest events in GIST development, and subsequent accumulation of chromosomal aberrations and other molecular alterations are required for malignant progression. In addition, recent studies have shown that epigenetic alterations and noncoding RNAs also play key roles in the pathogenesis of GISTs.

DOI PubMed

Analysis of the expression of cancer-associated fibroblast- and EMT-related proteins in submucosal invasive colorectal cancer.

Tamotsu Sugai, Noriyuki Uesugi, Yuriko Kitada, Noriyuki Yamada, Mitsumasa Osakabe, Makoto Eizuka, Ryo Sugimoto, Yasuko Fujita, Keisuke Kawasaki, Eiichiro Yamamoto, Hiroo Yamano, Hiromu Suzuki, Takayuki Matsumoto

Journal of Cancer   9 ( 15 ) 2702 - 2712  2018  [Refereed]  [International journal]

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Objective: Recent studies have shown that cancer-associated fibroblasts (CAFs) and the epithelial-mesenchymal transition (EMT) play important roles in the progression and metastasis of CRC. Although prediction of lymph node metastasis in submucosal invasive colorectal cancer (SiCRC) is important, the relationships of CAF and EMT with lymph node metastasis of SiCRC have not yet been examined. Here, we aimed to analyze the expression patterns of CAF- and EMT-related proteins in SiCRC. Materials and Methods: The expression of CAF-related markers, including α-smooth muscle actin, CD10, podoplanin, fibroblast specific protein 1, and adipocyte enhancer-binding protein 1, and EMT-related proteins [zinc finger protein SNAI2 (ZEB1) and twist-related protein 1 (TWIST1) in SiCRC with (n = 29) or without (n = 80) lymph node metastasis was examined by immunohistochemistry. We examined the expression patterns of biomarkers using hierarchical cluster analysis. Consequently, four subgroups were established based on the expression patterns of CAF- and EMT-related markers, and the associations of these subgroups with clinicopathological variables. Results: In multivariate analysis, subgroup 2, which was characterized by high expression of all markers, was correlated with lymph node metastasis (p < 0.01). Next, we examined the associations of individual biomarkers with lymph node metastasis. Multivariate analysis showed that moderately differentiated adenocarcinoma was significantly associated with lymph node metastasis (p < 0.05). Conclusions: Our findings showed that expression patterns of CAF markers and EMT-related proteins may allow for stratification of patients into risk categories for lymph node metastasis in SiCRC.

DOI PubMed

Endoscopic and molecular characterization of colorectal sessile serrated adenoma/polyps with cytologic dysplasia

Yoshihito Tanaka, Hiro-o Yamano, Eiichiro Yamamoto, Hiro-o Matushita, Hironori Aoki, Kenjiro Yoshikawa, Ryo Takagi, Eiji Harada, Michiko Nakaoka, Yuko Yoshida, Makoto Eizuka, Tamotsu Sugai, Hiromu Suzuki, Hiroshi Nakase

GASTROINTESTINAL ENDOSCOPY ( MOSBY-ELSEVIER )  86 ( 6 ) 1131 - +  2017.12  [Refereed]

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Background and Aims: Sessile serrated adenoma/polyps (SSA/Ps), which are precursor lesions of colorectal cancer (CRC) with BRAF mutation and the CpG island methylator phenotype (CIMP), develop cytologic dysplasia (CD) during the progression of colorectal tumorigenesis. In the present study we aimed to clarify the endoscopic and molecular signatures of SSA/Ps, with and without CD. Methods: A series of 208 serrated lesions, including 41 hyperplastic polyps, 90 SSA/Ps, 33 SSA/Ps with CD, and 44 traditional serrated adenomas, were observed and resected using magnifying endoscopy. BRAF and KRAS mutations and methylation of CIMP markers (MINT1, MINT2, MINT12, MINT31, and p16) were analyzed through pyrosequencing. Molecular alterations were then compared with endoscopic and pathologic characteristics. Results: Among SSA/Ps without CD, the Type II-Open pit pattern (Type II-O), BRAF mutation, and CIMP were tightly associated with a proximal colon location. SSA/Ps in the distal colon infrequently exhibited Type II-O and CIMP. By contrast, most SSA/Ps with CD showed Type II-O plus adenomatous pit patterns (Type III or IV), BRAF mutation, and CIMP, irrespective of their locations. Conclusions: Our results suggest that the Type II-O plus III/IV pit pattern is a common feature of SSA/Ps with CD in both the proximal and distal colon and that this pit pattern is a hallmark of serrated lesions at high risk of developing into CRCs.

DOI PubMed

Identification and characterization of a metastatic suppressor BRMS1L as a target gene of p53.

Ryota Koyama, Miyuki Tamura, Takafumi Nakagaki, Tomoko Ohashi, Masashi Idogawa, Hiromu Suzuki, Takashi Tokino, Yasushi Sasaki

Cancer science   108 ( 12 ) 2413 - 2421  2017.12  [Refereed]  [International journal]

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The tumor suppressor p53 and its family members, p63 and p73, play a pivotal role in the cell fate determination in response to diverse upstream signals. As transcription factors, p53 family proteins regulate a number of genes that are involved in cell cycle arrest, apoptosis, senescence, and maintenance of genomic stability. Recent studies revealed that p53 family proteins are important for the regulation of cell invasion and migration. Microarray analysis showed that breast cancer metastasis suppressor 1-like (BRMS1L) is upregulated by p53 family proteins, specifically p53, TAp63γ, and TAp73β. We identified two responsive elements of p53 family proteins in the first intron and upstream of BRMS1L. These response elements are well conserved among mammals. Functional analysis showed that ectopic expression of BRMS1L inhibited cancer cell invasion and migration; knockdown of BRMS1L by siRNA induced the opposite effect. Importantly, clinical databases revealed that reduced BRMS1L expression correlated with poor prognosis in patients with breast and brain cancer. Together, these results strongly indicate that BRMS1L is one of the mediators downstream of the p53 pathway, and that it inhibits cancer cell invasion and migration, which are essential steps in cancer metastasis. Collectively, our results indicate that BRMS1L is involved in cancer cell invasion and migration, and could be a therapeutic target for cancer.

DOI PubMed

Identification and characterization of a metastatic suppressor BRMS1L as a target gene of p53

Ryota Koyama, Miyuki Tamura, Takafumi Nakagaki, Tomoko Ohashi, Masashi Idogawa, Hiromu Suzuki, Takashi Tokino, Yasushi Sasaki

CANCER SCIENCE ( WILEY )  108 ( 12 ) 2413 - 2421  2017.12  [Refereed]

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The tumor suppressor p53 and its family members, p63 and p73, play a pivotal role in the cell fate determination in response to diverse upstream signals. As transcription factors, p53 family proteins regulate a number of genes that are involved in cell cycle arrest, apoptosis, senescence, and maintenance of genomic stability. Recent studies revealed that p53 family proteins are important for the regulation of cell invasion and migration. Microarray analysis showed that breast cancer metastasis suppressor 1-like (BRMS1L) is upregulated by p53 family proteins, specifically p53, TAp63, and TAp73. We identified two responsive elements of p53 family proteins in the first intron and upstream of BRMS1L. These response elements are well conserved among mammals. Functional analysis showed that ectopic expression of BRMS1L inhibited cancer cell invasion and migration; knockdown of BRMS1L by siRNA induced the opposite effect. Importantly, clinical databases revealed that reduced BRMS1L expression correlated with poor prognosis in patients with breast and brain cancer. Together, these results strongly indicate that BRMS1L is one of the mediators downstream of the p53 pathway, and that it inhibits cancer cell invasion and migration, which are essential steps in cancer metastasis. Collectively, our results indicate that BRMS1L is involved in cancer cell invasion and migration, and could be a therapeutic target for cancer.

DOI PubMed

p53標的遺伝子BRMS1Lの同定と機能解析

佐々木 泰史, 小山 良太, 田村 みゆき, 中垣 貴文, 大箸 智子, 井戸川 雅史, 鈴木 拓, 時野 隆至

生命科学系学会合同年次大会 ( 生命科学系学会合同年次大会運営事務局 )  2017年度   [1LBA - 057]  2017.12