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Cancer evolution is explained by accumulation of driver mutations and subsequent positive selection by acquired growth advantages like Darwin evolution. However, it has not yet been fully investigated whether negative selection of cells that have lost malignant properties contributes to cancer progression. Using intestinal metastatic tumor-derived organoids carrying Apc, Kras, Tgfbr2, and Trp53 quadruple mutations, we show here that approximately 30% of subclones of the organoids show loss of metastatic ability to the liver, while keeping the driver mutations and oncogenic pathways. Notably, highly metastatic subclones also showed gradual loss of metastatic ability during further passages. Such non-metastatic subclones showed significantly decreased survival and proliferation ability in Matrigel and collagen gel culture conditions, which may cause elimination from the tumor tissues in vivo. RNA sequencing indicated that stemness-related genes including Lgr5 and Myb were significantly downregulated in non-metastatic subclones as well as subclones that lost metastatic ability during additional passages. Furthermore, a CGH analysis showed that non-metastatic subclones were derived from minor population of parental organoid cells. These results indicate that metastatic ability is continuously lost with decreased stem cell property in certain subpopulations of malignant tumors, and such subpopulations are eliminated by negative selection. Therefore, it is possible that cancer evolution is regulated not only by positive selection but by negative selection. The mechanism underlying the loss of metastatic ability will be an important for future development of therapeutic strategies against metastasis.

Histological diagnosis of the primary tumors

Increased number of small adenomas by Kras mutation

Colorectal cancer is driven by the accumulation of driver mutations, but the contributions of specific mutations to different steps in malignant progression are not fully understood. In this study, we generated mouse models harboring different combinations of key colorectal cancer driver mutations (Apc, Kras, Tgfbr2, Trp53, Fbxw7) in intestinal epithelial cells to comprehensively investigate their roles in the development of primary tumors and metastases. ApcΔ716 mutation caused intestinal adenomas and combination with Trp53R270H mutation or Tgfbr2 deletion induced submucosal invasion. The addition of KrasG12D mutation yielded epithelial–mesenchymal transition (EMT)-like morphology and lymph vessel intravasation of the invasive tumors. In contrast, combinations of ApcΔ716 with KrasG12D and Fbxw7 mutation were insufficient for submucosal invasion, but still induced EMT-like histology. Studies using tumor-derived organoids showed that KrasG12D was critical for liver metastasis following splenic transplantation, when this mutation was combined with either ApcΔ716 plus Trp53R270H or Tgfbr2 deletion, with the highest incidence of metastasis displayed by tumors with a ApcΔ716 KrasG12D Tgfbr2−/− genotype. RNA sequencing analysis of tumor organoids defined distinct gene expression profiles characteristic for the respective combinations of driver mutations, with upregulated genes in ApcΔ716 KrasG12D Tgfbr2−/− tumors found to be similarly upregulated in specimens of human metastatic colorectal cancer. Our results show how activation of Wnt and Kras with suppression of TGFβ signaling in intestinal epithelial cells is sufficient for colorectal cancer metastasis, with possible implications for the development of metastasis prevention strategies.Significance: These findings illuminate how key driver mutations in colon cancer cooperate to drive the development of metastatic disease, with potential implications for the development of suitable prevention strategies. Cancer Res; 78(5); 1334–46. ©2017 AACR.

Supplementary Figure S5. Representative photographs of the whole intestine of X-ray irradiated wild-type and Tgfbr2ÃŽ?IEC mice.

Legends for Supplementary Figures S1-S6.

Missense-type mutant p53 plays a tumor-promoting role through gain-of-function (GOF) mechanism. In addition, the loss of wild-type TP53 through loss of heterozygosity (LOH) is widely found in cancer cells. However, malignant progression induced by cooperation of TP53 GOF mutation and LOH remains poorly understood. Here, we show that mouse intestinal tumors carrying Trp53 GOF mutation with LOH (AKTPM/LOH) are enriched in metastatic lesions when heterozygous Trp53 mutant cells (AKTP+/M) are transplanted. We show that Trp53 LOH is required for dormant cell survival and clonal expansion of cancer cells. Moreover, AKTPM/LOH cells show an increased in vivo tumor-initiating ability compared with AKTPNull and AKTP+/M cells. RNAseq analyses reveal that inflammatory and growth factor/MAPK pathways are specifically activated in AKTPM/LOH cells, while the stem cell signature is upregulated in both AKTPM/LOH and AKTPNull cells. These results indicate that TP53/Trp53 LOH promotes TP53/Trp53 GOF mutation-driven metastasis through the activation of distinct pathway combination., Both gain-of-function of mutant p53 (GOF) and loss of wild-type p53 (LOH) are independently associated with cancer. Here, the authors show that LOH promotes GOF tumourigenesis by increasing tumor-initiating ability and metastasis.

本研究は、長崎県健康・栄養調査の食生活習慣状況調査における食生活の自己評価と食習慣、身体状況、栄養摂取状況との関連を明らかにすることを目的とした。対象者は、平成28年度長崎県健康・栄養調査の対象者のうち590名を解析対象とし、食生活の自己評価により2群に分け、食習慣やBMI、栄養摂取状況を比較した。その結果、食生活の自己評価が高い者の特徴としては、年代が高いこと、食生活に関する意識が高いことが示唆されたが、対象者の自己評価と栄養摂取のコントロールには関連があまりみられなかった。その点から、自ら食をコントロールし、自己評価につなげられるように望ましい食生活について量などの具体的な知識の普及に関する健康教育を行い、食意識のレベルアップを図る必要がある。

Comprehensive genome analyses have identified frequently mutated genes in human colorectal cancers (CRC). These include

Loss-of-function mutations in RNF43 induce activation of Wnt ligand-dependent Wnt/β-catenin signaling through stabilization of the Frizzled receptor, which is often found in microsatellite instability (MSI)-type colorectal cancer (CRC) that develops from sessile serrated adenomas. However, the mechanism underlying how RNF43 mutations promote tumorigenesis remains poorly understood. In this study, we established nine human CRC-derived organoids and found that three organoid lines carried RNF43 frameshift mutations associated with MSI-high and BRAF

Cellular senescence caused by oncogenic stimuli is associated with the development of various age-related pathologies through the senescence-associated secretory phenotype (SASP). SASP is mediated by the activation of cytoplasmic nucleic acid sensors. However, the molecular mechanism underlying the accumulation of nucleotide ligands in senescent cells is unclear. In this study, we revealed that the expression of RNaseH2A, which removes ribonucleoside monophosphates (rNMPs) from the genome, is regulated by E2F transcription factors, and it decreases during cellular senescence. Residual rNMPs cause genomic DNA fragmentation and aberrant activation of cytoplasmic nucleic acid sensors, thereby provoking subsequent SASP factor gene expression in senescent cells. In addition, RNaseH2A expression was significantly decreased in aged mouse tissues and cells from individuals with Werner syndrome. Furthermore, RNaseH2A degradation using the auxin-inducible degron system induced the accumulation of nucleotide ligands and induction of certain tumourigenic SASP-like factors, promoting the metastatic properties of colorectal cancer cells. Our results indicate that RNaseH2A downregulation provokes SASP through nucleotide ligand accumulation, which likely contributes to the pathological features of senescent, progeroid, and cancer cells.

Significance During the aging process, senescent cells secrete inflammatory factors, causing various age-related pathologies. Thus, controlling the senescence-associated secretory phenotype (SASP) can tremendously benefit human health. Although SASP seems to be induced by the alteration of chromosomal organization, its underlying mechanism remains unclear. Here, it has been revealed that noncoding RNA (ncRNA) transcribed from pericentromeric repetitive elements impairs the DNA binding of CCCTC-binding factor, resulting in the alteration of chromosomal accessibility and the activation of SASP-like inflammatory genes. Notably, the ncRNA was transferred into surrounding cells via small extracellular vesicles, acting as a tumorigenic SASP factor. Our study highlights a novel mechanism regulating chromatin interaction and inflammatory gene expression in senescence and cancer., Cellular senescence causes a dramatic alteration of chromatin organization and changes the gene expression profile of proinflammatory factors, thereby contributing to various age-related pathologies through the senescence-associated secretory phenotype (SASP). Chromatin organization and global gene expression are maintained by the CCCTC-binding factor (CTCF); however, the molecular mechanism underlying CTCF regulation and its association with SASP gene expression remains unclear. We discovered that noncoding RNA (ncRNA) derived from normally silenced pericentromeric repetitive sequences directly impairs the DNA binding of CTCF. This CTCF disturbance increases the accessibility of chromatin and activates the transcription of SASP-like inflammatory genes, promoting malignant transformation. Notably, pericentromeric ncRNA was transferred into surrounding cells via small extracellular vesicles acting as a tumorigenic SASP factor. Because CTCF blocks the expression of pericentromeric ncRNA in young cells, the down-regulation of CTCF during cellular senescence triggers the up-regulation of this ncRNA and SASP-related inflammatory gene expression. In this study, we show that pericentromeric ncRNA provokes chromosomal alteration by inhibiting CTCF, leading to a SASP-like inflammatory response in a cell-autonomous and non–cell-autonomous manner and thus may contribute to the risk of tumorigenesis during aging.

Recent genetic studies have indicated relationships between gene mutations and colon cancer phenotypes. However, how physical properties of tumor cells are changed by genetic alterations has not been elucidated. We examined genotype-defined mouse intestinal tumor-derived cells using a high-speed scanning ion conductance microscope (HS-SICM) that can obtain high-resolution live images of nano-scale topography and stiffness. The tumor cells used in this study carried mutations in Apc (A), Kras (K), Tgfbr2 (T), Trp53 (P), and Fbxw7 (F) in various combinations. Notably, high-metastatic cancer-derived cells carrying AKT mutations (AKT, AKTP, and AKTPF) showed specific ridge-like morphology with active membrane volume change, which was not found in low-metastatic and adenoma-derived cells. Furthermore, the membrane was significantly softer in the metastatic AKT-type cancer cells than other genotype cells. Importantly, a principal component analysis using RNAseq data showed similar distributions of expression profiles and physical properties, indicating a link between genetic alterations and physical properties. Finally, the malignant cell-specific physical properties were confirmed by an HS-SICM using human colon cancer-derived cells. These results indicate that the HS-SICM analysis is useful as a novel diagnostic strategy for predicting the metastatic ability of cancer cells.

A concept of polyclonal metastasis has recently been proposed, wherein tumor cell clusters break off from the primary site and are disseminated. However, the involvement of driver mutations in such polyclonal mechanism is not fully understood. Here, we show that non-metastatic AP cells metastasize to the liver with metastatic AKTP cells after co-transplantation to the spleen. Furthermore, AKTP cell depletion after the development of metastases results in the continuous proliferation of the remaining AP cells, indicating a role of AKTP cells in the early step of polyclonal metastasis. Importantly, AKTP cells, but not AP cells, induce fibrotic niche generation when arrested in the sinusoid, and such fibrotic microenvironment promotes the colonization of AP cells. These results indicate that non-metastatic cells can metastasize via the polyclonal metastasis mechanism using the fibrotic niche induced by malignant cells. Thus, targeting the fibrotic niche is an effective strategy for halting polyclonal metastasis., Cancer cell clusters metastasize to distant organ by polyclonal manner. Here, the authors show that malignant subclone induces fibrotic niche generation in the liver by hepatic stellate cell activation, supporting survival and colonization of non-metastatic cells to develop polyclonal metastasis.

金沢大学ナノ生命科学研究所, Signal transducer and activator of transcription 3 (Stat3) has been shown to play a role in intestinal regeneration and colitis-associated colon carcinogenesis. However, the role of Stat3 in the Wnt-driven sporadic intestinal tumorigenesis remains poorly understood. We examined the roles of Stat3 in intestinal regeneration and tumorigenesis by organoid culture experiments using Stat3∆IEC mouse-derived intestinal epithelial cells in which Stat3 was disrupted. The regeneration of intestinal mucosa and organoid formation were significantly suppressed by Stat3 disruption, which was compensated by Wnt activation. Furthermore, once organoids were recovered, Stat3 was no longer required for organoid growth. These results indicate that Stat3 and Wnt signaling cooperatively protect epithelial cells at the early phase of intestinal regeneration. In contrast, intestinal tumorigenesis was not suppressed by Stat3 disruption in adenomatous polyposis coli ( Apc) Δ716 and Apc∆716 Tgfbr2∆IEC mice, thus indicating that Stat3 is not required for Wnt activation-driven intestinal tumorigenesis. Mechanistically, Itga5 and Itga6 were down-regulated by Stat3 disruption, and focal adhesion kinase (FAK) activation was also suppressed. Notably, FAK inhibitor suppressed the organoid formation of wild-type epithelial cells. These results indicate that Stat3 is indispensable for the survival of epithelial cells through the activation of integrin signaling and the downstream FAK pathway; however, it is not required for the Wnt signaling-activated normal or tumor epithelial cells.-Oshima, H., Kok, S.-Y., Nakayama, M., Murakami, K., Voon, D. C.-C., Kimura, T., Oshima, M. Stat3 is indispensable for damage-induced crypt regeneration but not for Wnt-driven intestinal tumorigenesis.

金沢大学新学術創成研究機構ナノ生命科学研究所, Accumulating evidence has indicated that the inflammatory response is important for tumor promotion. However, the mechanisms underlying the induction of the inflammatory response in cancer tissues and how it promotes tumorigenesis remain poorly understood. We constructed several mouse models that develop inflammation-associated gastric and intestinal tumors and examined the in vivo mechanisms of tumorigenesis. Of note, the activation of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) pathway and Toll-like receptor (TLR)/MyD88 signaling cooperatively induced the generation of an inflammatory microenvironment, which is required for early-stage tumorigenesis. The inflammatory response in the stroma induces TNF-α signaling in tumor cells, and the NOX1/ROS signaling pathway is activated downstream. In addition, the inflammatory pathway induces the expression of TLR2 in tumor epithelial cells. Both the NOX1/ROS and TLR2 pathways in tumor cells contribute to the acquisition and maintenance of stemness, which is an important tumor-promoting mechanism stimulated by inflammation. We also found that inflammation promotes malignant processes, like submucosal invasion, of TGF-β signaling-suppressed tumor cells through the activation of MMP2 protease. Moreover, we showed that mutant p53 induces innate immune and inflammatory signaling in the tumor stroma by a gain-of-function mechanism of mutant p53, which may explain the “cancer-induced inflammation” mechanism. These results indicate that the regulation of the inflammatory microenvironment via the inhibition of the COX-2/PGE2 and TLR/MyD88 pathways in combination will be an effective preventive or therapeutic strategy against gastrointestinal cancer development and malignant progression, especially those carrying p53 gain-of-function mutations. © 2018 Elsevier Ltd., Embargo Period 12 months

SUMMARYInterleukin (IL)-11 is a member of the IL-6 family of cytokines and involved in multiple cellular responses, including tumor development. However, the origin and functions of IL-11-producing (IL-11+) cells are not fully understood. To characterize IL-11+ cells in vivo, we generated Il11 reporter mice. IL-11+ cells appeared in the colon of three murine tumor models, and a murine acute colitis model. Il11ra1 or Il11 deletion attenuated the development of colitis-associated colorectal cancer. IL-11+ cells expressed fibroblast markers, and genes associated with cell proliferation and tissue repair. IL-11 induced STAT3 phosphorylation in colonic fibroblasts, suggesting the activation of IL-11+ fibroblasts. Analysis using the human cancer database revealed that genes enriched in IL-11+ fibroblasts were elevated in human colorectal cancer, and correlated with reduced disease-free survival. Together, our results suggested that tumor cells induced IL-11+ fibroblasts, and that a feed-forward loop between IL-11 and IL-11+ fibroblasts might contribute to tumor development.

Cellular senescence caused by oncogenic stimuli is related to the development of various age-related diseases via senescence-associated secretory phenotype (SASP). Recent studies have revealed that the SASP is induced via the cGAS-STING (cyclic GMP-AMP synthase linked to stimulator of interferon genes) pathway. However, the molecular mechanism of nucleotide ligand production for these cytoplasmic sensors remains unclear. Here, we discover that the expression of RNaseH2A is regulated by E2F transcription factor and decreases during cellular senescence, thus abnormally incorporated ribonucleoside monophosphates (rNMPs) cause genomic DNA fragmentation, while excess R-loop structures lead to RNA-DNA hybrid accumulation in the nucleoli and cytoplasm of senescent cells. Consequently, both chromosomal DNA fragments and RNA-DNA hybrids induce aberrant activation of the cGAS-STING pathway and SASP-factor gene expression. Furthermore, RNaseH2A reduction was associated with pathological features and poor prognoses in individuals with Werner syndrome and cervical, ovarian and colorectal cancers. Our findings provide new insights into how nucleotide ligand production relates to SASP induction.

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. Several genome sequencing studies have provided comprehensive CRC genomic datasets. Likewise, in our previous study, we performed genome-wide Sleeping Beauty transposon-based mutagenesis screening in mice and provided comprehensive datasets of candidate CRC driver genes. However, functional validation for most candidate CRC driver genes, which were commonly identified from both human and mice, has not been performed. Here, we describe a platform for functionally validating CRC driver genes that utilizes CRISPR-Cas9 in mouse intestinal tumor organoids and human CRC-derived organoids in xenograft mouse models. We used genetically defined benign tumor-derived organoids carrying 2 frequent gene mutations (Apc and Kras mutations), which act in the early stage of CRC development, so that we could clearly evaluate the tumorigenic ability of the mutation in a single gene. These studies showed that Acvr1b, Acvr2a, and Arid2 could function as tumor suppressor genes (TSGs) in CRC and uncovered a role for Trp53 in tumor metastasis. We also showed that co-occurrent mutations in receptors for activin and transforming growth factor-β (TGF-β) synergistically promote tumorigenesis, and shed light on the role of activin receptors in CRC. This experimental system can also be applied to mouse intestinal organoids carrying other sensitizing mutations as well as organoids derived from other organs, which could further contribute to identification of novel cancer driver genes and new drug targets.

The accumulation of genetic alterations in driver genes is responsible for the development and malignant progression of colorectal cancer. Comprehensive genome analyses have revealed the driver genes, including APC, KRAS, TGFBR2, and TP53, whose mutations are frequently found in human colorectal cancers. Among them, the p53 mutation is found in ~60% of colorectal cancers, and a majority of mutations are missense-type at ‘hot spots’, suggesting an oncogenic role of mutant p53 by ‘gain-of-function’ mechanisms. Mouse model studies have shown that one of these missense-type mutations, p53 R270H (corresponding to human R273H), causes submucosal invasion of intestinal tumors, while the loss of wild-type p53 has a limited effect on the invasion process. Furthermore, the same mutant p53 promotes metastasis when combined with Kras activation and TGF-β suppression. Importantly, either missense-type p53 mutation or loss of wild-type p53 induces NF-κB activation by a variety of mechanisms, such as increasing promoter accessibility by chromatin remodeling, which may contribute to progression to epithelial–mesenchymal transition. These results indicate that missense-type p53 mutations together with loss of wild-type p53 accelerate the late stage of colorectal cancer progression through the activation of both oncogenic and inflammatory pathways. Accordingly, the suppression of the mutant p53 function via the inhibition of nuclear accumulation is expected to be an effective strategy against malignant progression of colorectal cancer.

Genetic alterations in the TGFβ signaling pathway in combination with oncogenic alterations lead to cancer development in the intestines. However, the mechanisms of TGFβ signaling suppression in malignant progression of intestinal tumors have not yet been fully understood. We have examined ApcΔ716 Tgfbr2ΔIEC compound mutant mice that carry mutations in Apc and Tgfbr2 genes in the intestinal epithelial cells. We found inflammatory microenvironment only in the invasive intestinal adenocarcinomas but not in noninvasive benign polyps of the same mice. We thus treated simple Tgfbr2ΔIEC mice with dextran sodium sulfate (DSS) that causes ulcerative colitis. Importantly, these Tgfbr2ΔIEC mice developed invasive colon cancer associated with chronic inflammation. We also found that TGFβ signaling is suppressed in human colitis–associated colon cancer cells. In the mouse invasive tumors, macrophages infiltrated and expressed MT1-MMP, causing MMP2 activation. These results suggest that inflammatory microenvironment contributes to submucosal invasion of TGFβ signaling–repressed epithelial cells through activation of MMP2. We further found that regeneration was impaired in Tgfbr2ΔIEC mice for intestinal mucosa damaged by DSS treatment or X-ray irradiation, resulting in the expansion of undifferentiated epithelial cell population. Moreover, organoids of intestinal epithelial cells cultured from irradiated Tgfbr2ΔIEC mice formed “long crypts” in Matrigel, suggesting acquisition of an invasive phenotype into the extracellular matrix. These results, taken together, indicate that a simple genetic alteration in the TGFβ signaling pathway in the inflamed and regenerating intestinal mucosa can cause invasive intestinal tumors. Such a mechanism may play a role in the colon carcinogenesis associated with inflammatory bowel disease in humans. Cancer Res; 75(4); 766–76. ©2015 AACR.

Colorectal cancer is driven by the accumulation of driver mutations, but the contributions of specific mutations to different steps in malignant progression are not fully understood. In this study, we generated mouse models harboring different combinations of key colorectal cancer driver mutations (

金沢大学ナノ生命科学研究所, Background & Aims: Gastritis is associated with development of stomach cancer, but little is known about changes in microRNA expression patterns during gastric inflammation. Specific changes in gene expression in epithelial cells are difficult to monitor because of the heterogeneity of the tissue. We investigated epithelial cell-specific changes in microRNA expression during gastric inflammation and gastritis-associated carcinogenesis in mice. Methods: We used laser microdissection to enrich epithelial cells from K19-C2mE transgenic mice, which spontaneously develop gastritis-associated hyperplasia, and Gan mice, which express activated prostaglandin E2 and Wnt in the gastric mucosa and develop gastric tumors. We measured expression of epithelial cell-enriched microRNAs and used bioinformatics analyses to integrate data from different systems to identify inflammation-associated microRNAs. We validated our findings in gastric tissues from mice and evaluated protein functions in gastric cell lines (SNU-719, SNU-601, SNU-638, AGS, and GIF-14) and knockout mice. Organoids were cultured from gastric corpus tissues of wild-type and miR-135b–knockout C57BL/6 mice. We measured levels of microRNAs in pairs of gastric tumors and nontumor mucosa from 28 patients in Japan. Results: We found microRNA 135b (miR-135B) to be the most overexpressed microRNA in gastric tissues from K19-C2mE and Gan mice: levels increased during the early stages of gastritis-associated carcinogenesis. Levels of miR-135B were also increased in gastric tumor tissues from gp130 F/F mice and patients compared with nontumor tissues. In gastric organoids and immortalized cell lines, expression of miR-135B was induced by interleukin 1 signaling. K19-C2mE mice with disruption of Mir-135b developed hyperplastic lesions that were 50% smaller than mice without Mir-135b disruption and had significant reductions in cell proliferation. Expression of miR-135B in gastric cancer cell lines increased their colony formation, migration, and sphere formation. We identified FOXN3 and RECK messenger RNAs (mRNAs) as targets of miR-135B; their knockdown reduced migration of gastric cancer cell lines. Levels of FOXN3 and RECK mRNAs correlated inversely with levels of miR-135B in human gastric tumors and in inflamed mucosa from K19-C2mE mice. Conclusions: We found expression of miR-135B to be up-regulated by interleukin L1 signaling in gastric cancer cells and organoids. miR-135B promotes invasiveness and stem-cell features of gastric cancer cells in culture by reducing FOXN3 and RECK messenger RNAs. Levels of these messenger RNA targets, which encode tumor suppressor, are reduced in human gastric tumors. © 2019 AGA Institute, Embargo Period 12 months

SummaryInfluenza A viruses are a major cause of mortality. Given the potential for future lethal pandemics, effective drugs are needed for the treatment of severe influenza such as that caused by H5N1 viruses. Using mediator lipidomics and bioactive lipid screen, we report that the omega-3 polyunsaturated fatty acid (PUFA)-derived lipid mediator protectin D1 (PD1) markedly attenuated influenza virus replication via RNA export machinery. Production of PD1 was suppressed during severe influenza and PD1 levels inversely correlated with the pathogenicity of H5N1 viruses. Suppression of PD1 was genetically mapped to 12/15-lipoxygenase activity. Importantly, PD1 treatment improved the survival and pathology of severe influenza in mice, even under conditions where known antiviral drugs fail to protect from death. These results identify the endogenous lipid mediator PD1 as an innate suppressor of influenza virus replication that protects against lethal influenza virus infection.

Injury to the heart can result in cardiomyocyte hypertrophy, fibrosis, and cell death. Myocarditis sometimes progresses to dilated cardiomyopathy. We previously reported that ONO-1301, a synthetic prostacyclin agonist with thromboxane-synthase inhibitory activity, promotes production of hepatocyte growth factor (HGF) from various cell types and ameliorates ischemia-induced left ventricle dysfunction in the mouse, rat and pig. Here, we investigated the therapeutic efficacy of ONO-1301 in a rat model of myosin-induced experimental autoimmune myocarditis, in which the heart transits from an acute inflammatory phase to a chronic dilated cardiomyopathy phase. Four weeks after myosin injection to Lewis rats, ONO-1301 (6 mg/kg/day) was orally administered for 4 weeks (ONO-1301 group). Hemodynamic parameters and plasma brain natriuretic peptide (BNP) level were significantly improved by ONO-1301. Histological analysis revealed that capillary density in the myocardium was significantly increased by ONO-1301. ONO-1301 increased circulating endothelial progenitor cells (EPC) as determined by FACS analysis. These beneficial effects of ONO-1301 were partially abrogated by a neutralizing anti-HGF antibody (8 mg/kg/dose). These findings indicate beneficial effects of ONO-1301 in a rat experimental autoimmune myocarditis model.

Tumor suppressor TP53 is frequently mutated in colorectal cancer (CRC), and most mutations are missense type. Although gain-of-functions by mutant p53 have been demonstrated experimentally, the precise mechanism for malignant progression in in vivo tumors remains unsolved. We generated ApcΔ716 Trp53LSL•R270H villin-CreER compound mice, in which mutant p53R270H was expressed in the intestinal epithelia upon tamoxifen treatment, and examined the intestinal tumor phenotypes and tumor-derived organoids. Mutant Trp53R270H, but not Trp53-null mutation accelerated submucosal invasion with generation of desmoplastic microenvironment. The nuclear accumulation of p53 was evident in ApcΔ716 Trp53R270H/R270H homozygous tumors like human CRC. Although p53 was distributed to the cytoplasm in ApcΔ716 Trp53+/R270H heterozygous tumors, it accumulated in the nuclei at the invasion front, suggesting a regulation mechanism for p53 localization by the microenvironment. Importantly, mutant p53 induced drastic morphological changes in the tumor organoids to complex glandular structures, which was associated with the acquisition of invasiveness. Consistently, the branching scores of human CRC that carry TP53 mutations at codon 273 significantly increased in comparison with those of TP53 wild-type tumors. Moreover, allografted ApcΔ716 Trp53R270H/R270H organoid tumors showed a malignant histology with an increased number of myofibroblasts in the stroma. These results indicate that nuclear-accumulated mutant p53R270H induces malignant progression of intestinal tumors through complex tumor gland formation and acquisition of invasiveness. Furthermore, RNA sequencing analyses revealed global gene upregulation by mutant p53R270H, which was associated with the activation of inflammatory and innate immune pathways. Accordingly, it is possible that mutant p53R270H induces CRC progression, not only by a cell intrinsic mechanism, but also by the generation or activation of the microenvironment, which may synergistically contribute to the acceleration of submucosal invasion. Therefore, the present study indicates that nuclear-accumulated mutant p53R270H is a potential therapeutic target for the treatment of advanced CRCs.

It has been shown that administration of angiogenic factors can augment collateral growth in ischemic tissues. We previously reported that ONO-1301, a synthetic prostacyclin agonist with thromboxane-synthase inhibitory activity, promotes production of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) from various cell types. We evaluated therapeutic efficacy of ONO-1301 in rat cardiac ischemia model. Ligation of left anterior descending coronary arteries was performed to 10-week-old Wistar rats, and the slow releasing form of ONO-1301 was administrated subcutaneously 3 days after the ligation (control group and ONO-1301 group). Hemodynamic parameters and plasma BNP levels were significantly improved by ONO-1301. Histological analysis revealed that ONO-1301 suppressed fibrotic changes in the myocardium (27.7±3.1% vs 23.3±3.6%, p

Hepatic epithelial morphogenesis, including hepatoblast migration and proliferation in the septum transversum, requires the interaction of hepatic epithelium with the embryonic sinusoidal wall. No factors that mediate this interaction have yet been identified. As the beta-catenin pathway is active in hepatoblast proliferation, then Wnt ligands might activate the canonical Wnt pathway during liver development. Here, we investigated the role of Wnts in mediating epithelial vessel interactions in the developing chick liver. We found that Wnt9a was specifically expressed in both endothelial and stellate cells of the embryonic sinusoidal wall. Induced overexpression of Wnt9a resulted in hepatomegaly with hyperplasia of the hepatocellular cords, and in hyperproliferation of hepatocytes. Knockdown of Wnt9a caused a reduction in liver size, with hypoplasia of hepatocellular cord branching, and hypoproliferation of hepatoblasts, and also inhibited glycogen accumulation at later developmental stages. Wnt9a promoted in vivo stabilization of beta-catenin through binding with Frizzled 4, 7, and 9, and activated TOPflash reporter expression in vitro via Frizzled 7 and 9. Our results demonstrate that Wnt9a from the embryonic sinusoidal wall is required for the proper morphogenesis of chick hepatocellular cords, proliferation of hepatoblasts/hepatocytes, and glycogen accumulation in hepatocytes. Wnt9a signaling appears to be mediated by an Fzd7/9-beta-catenin pathway.

It has been established that chronic inflammation plays an important role in cancer development. The expression of cyclooxygenase-2 (COX-2), a rate-limiting enzyme for prostaglandin biosynthesis, is induced in most cancer tissues and plays a key role in tumorigenesis. Helicobacter pylori infection causes atrophic gastritis, which is associated with the induction of COX-2 expression and its downstream product, prostaglandin E2 (PGE2), biosynthesis. Transgenic mice expressing COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1) in the gastric mucosa show the generation of an inflammatory microenvironment via the activation of the COX-2/PGE2 pathway. Notably, simultaneous activation of canonical Wnt signaling and the COX-2/PGE2 pathway causes intestinal-type gastric tumor development, although Wnt activation alone is not sufficient for tumor formation. These results suggest that H. pylori infection-associated chronic inflammation contributes to gastric tumorigenesis through activation of the COX-2/PGE2 pathway. Using a gastric tumor mouse model (Gan mice), we found that the inflammatory microenvironment induces the activation of epidermal growth factor receptor (EGFR) signaling and promotes canonical Wnt signaling. Moreover, infiltrated macrophages express tumor necrosis factor-α (TNF-α) in gastric tumors, which plays an important role in tumor promotion through the induction of NADPH oxidase organizer 1 (NOXO1) expression. NOXO1 contributes to the production of reactive oxygen species (ROS) by the NOX1 complex, which is thought to be important for the maintenance of stem cell properties. These studies indicate that chronic inflammation promotes gastric tumorigenesis through a variety of mechanisms. Accordingly, targeting an inflammatory microenvironment should be an effective therapeutic or preventive strategy for gastric cancer.

The specified hepatic endoderm (hepatoblasts), the bipotential progenitor for hepatocytes and bile duct epithelial cells, proliferates during the primordial stages of liver development. Despite extensive studies, the mechanism that regulates proliferation of bipotential hepatoblasts is not fully understood. Here we show that Id3, a negative regulator of helix-loop-helix transcription factors, is an important regulator of hepatoblast proliferation in the developing chick liver. Id3 was expressed in hepatoblasts at early developmental stages (stages 12-29) but not in hepatocytes at later developmental stages (stage 34 onwards). Depletion of Id3 in hepatoblasts by siRNA results in failure of cell proliferation, but is not associated with either cell death or failure of expression of Hhex and Fibrinogen, the earliest hepatoblast markers. These observations suggest that at early developmental stages, Id3 functions as a positive regulator of hepatoblast proliferation, independent of cell death or maintenance of the non-terminally differentiated state. Interestingly at later developmental stages, the expression pattern of Id3 is complementary to that of Albumin, a marker of mature hepatocytes. Overexpression of Id3 in liver explants delayed the initiation of Albumin expression. Taken together, our observations show that Id3 is not only a positive regulator of hepatoblast proliferation, but also an inhibitor of their differentiation into hepatocytes in the developing chick liver.

Tumor necrosis factor (TNF) a can induce both cell death and cell proliferation and exerts its effects by binding to either TNF receptor (TNFR) 1 or 2. When TNFa-bound TNFR2 interacts with TNFR-associated factor 2 (TRAF2), expression of survival/ antiapoptotic genes is up-regulated. In the present study we determined the changes in localization of TNFa and TRAF2 and their mRNAs and the expression of TNFR2 in granulosa cells during follicular atresia in pig ovaries. In healthy follicles, intense signals for TNFa and TRAF2 and their mRNAs were demonstrated in the outer zone of the granulosa layer, where many proliferating cells and no apoptotic cells were observed. In atretic follicles, decreased or trace staining for TRAF2 and its mRNA and decreased expression of TNFR2 were observed in the granulosa layer, where many apoptotic cells were seen. These findings suggested that TNFa acts as a survival factor in granulosa cells during follicular atresia in pig ovaries. apoptosis, follicle, granulosa cell, ovary

To reveal the specific regulatory molecules that control granulosa cell apoptosis during follicular atresia, we immunohistochemically examined the localization of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its receptors in porcine ovaries. A marked reduction in the expression of decoy receptor-1 (DcR1), which has high affinity for TRAIL, was demonstrated in granulosa cells of atretic follicles, but no marked differences were seen in expression of TRAIL or other TRAIL-receptors (death receptor-4 or death receptor-5) in granulosa cells between healthy and atretic follicles. No positive staining for DcR2 was seen. We presum that TRAIL and its receptors are involved in induction of apoptosis in granulosa cells during atresia, and that DcR1 plays an inhibitory role in granulosa cell apoptosis.

Previously, we histochemically demonstrated the expression of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its receptors, death receptor-4 (DR4), death receptor-5 (DR5) and decoy receptor-1 (DcR1) in granulosa cells of porcine follicles. However, TRAIL can induce both cell death and cell proliferation. In the present study, reverse transcription polymerase chain reaction and in situ hybridization analyses revealed increased mRNA expression of TNF receptor-associated death domain protein (TRADD), which transmits the death signal from DR4 and/or DR5 to intracellular apoptosis-signal transduction components, in granulosa cells was demonstrated only in atretic follicles but not in healthy follicles. These findings indicate that TRADD is involved in induction of apoptosis in granulosa cells, and that the TRAIL-receptor system induces apoptosis in granulosa cells during atresia in porcine ovaries.

We prepared IgM and IgG (PFG-5 and PFG-6, respectively) monoclonal antibodies against granulosa cells prepared from healthy antral follicles of porcine ovaries. PFG-5 antibody specifically recognized two cell-membrane proteins (PFG-5 antigen: 55 kD, pl 5.9, and PFG-6 antigen: 42 kD, pl 5.2), and PFG-6 antibody recognized PFG-6 antigen. Immunochemical reactions of these antibodies were only detected in follicular granulosa cells but not any other ovarian tissues for organs. Both antigens were detected in granulose cells of healthy follicles, but PFG-6 antigen disappeard in granulosa cells of atretic follicles. When the isolated granulosa cells prepared from healthy follicles were cultured in medium containing PFG-5 antibody, the cells underwent apoptosis, and co-incubation with PFG-6 antibody inhibited PFG-5 antibody inducible apoptosis. These observations suggested that PFG-5 antigen is a novel cell death receptor, which is different from well-known apoptosis-mediating receptors (Fas or tumor necrosis factor receptor), and that PFG-6 antigen may act as a decoy receptor and inhibit apoptotic signals through PFG-5 antigen.

Determination of the expression level and localization of extracellular matrix (ECM) components is crucial for understanding the mechanism of maintenance and remodeling of the ovarian follicle structure. Previously, we demonstrated species-specific differences in the process of apoptosis in granulosa and theca cells during follicular atresia. In the present study, we histochemically compared the localization of type I, III and IV collagens and the expression of their mRNA. In healthy porcine or bovine follicles, type III and IV collagens were mainly distributed in theca interna layers, and strong to moderate expression of their mRNAs were observed in granulosa and theca interna layers, respectively. During follicular atresia, marked decreases in type I and IV collagens were observed in porcine follicles, while no changes were seen in bovine follicles. These findings indicate that these ECMs have important roles in follicular development and/or degeneration, and that species-specific differences in their production reflect differences in the regulatory mechanism of granulosa cell apoptosis between atretic porcine and bovine follicles.

Species-specific differences in the process of apoptosis in granulosa and theca layers during follicular atresia in porcine and bovine ovaries were investigated by in situ DNA 3’end-labeling (TUNEL) at the level of individual cells. In porcine ovaries, granulosa cells located on the inner surface of the granulosa layer appeared to undergo apoptosis at the first stage, followed by neighboring granulosa cells. In the contrast, granulosa cells located on the middle region appeared to undergo apoptosis at the first stage in bovine ovaries. In both porcine and bovine ovaries, detachment and degeneration of the granulosa cell layer and fragmentation of basement membrane occurred in the follicles at advanced stage of atresia. In the ovaries of both species, theca interna cells were still intact at the stage of early atresia and then apoptotic cells appeared in the late to final stages of atresia, but no apoptotic cells were observed in theca externa layers during follicular atresia. The present findings indicated that apoptosis occurring in granulosa cells is an initial symptom of follicular atresia in the ovaries of both species, and that the apoptosis inducing factor(s) and/or survival factor(s) for the granulosa cells may be different between porcine and bovine ovaries.

Previously, we prepared an IgM monoclonal antibody(PFG-1) which specifically recognized a cell-membraneglycoprotein (PFG-1 antigen; 55 kD, pI 5.9),immunohistochemically reacted with granulosa cells ofhealthy follicles but not of atretic follicles, andinduced granulosa cell apoptosis. In the presentstudy, an IgM monoclonal antibody (PFG-3) capable ofinducing granulosa cell apoptosis and an IgGmonoclonal antibody (PFG-4) not capable of inducingapoptosis were produced against granulosa cellsprepared from healthy antral follicles of porcineovaries. Two-dimensional Western blotting analysisrevealed that PFG-3 specifically recognized twocell-membrane proteins (named PFG-3-1 andPFG-3-2/PFG-1 antigens; 42 kD, pI 5.2 and 55 kD, pI5.9, respectively) of healthy granulosa cells, andthat PFG-4 recognized the same two cell-membraneproteins. In atretic granulosa cells, PFG-3-2/PFG-1antigen disappeared. Immunochemical reactions of theseantibodies were only detected in follicular granulosacells but not any other ovarian tissues or organs.PFG-3 and PFG-4 immunohistochemically reacted withgranulosa cells of healthy and atretic follicles. Whenthe isolated granulosa cells prepared from healthyfollicles were cultured in medium containing PFG-3,the cells underwent apoptosis, and co-incubation withPFG-4 inhibited PFG-3-inducible apoptosis. Theseobservations suggested that PFG-3-2/PFG-1 antigen isa novel cell death receptor which is different fromthe apoptosis-mediating receptors (Fas/Apo-1/CD95 orTNF receptor), and that PFG-3-1 antigen may act as adecoy receptor and inhibit apoptotic signal transmission.

Determination of the expression level and localization of cell adhesion molecules is crucial for understanding the mechanism of maintenance and remodeling of the ovarian follicle structure. We immunocytochemically investigated expression of the cell adhesion molecules, "classic" cadherins and β-catenin, in developing and/or atretic follicles of porcine ovaries. Healthy follicles showed strong staining for cadherin-8 and β-catenin in granulosa cells tightly attached to the basement membrane, and moderate/weak staining was seen on the inner surface of the granulosa cell layer. Strong VE-cadherin expression was seen in a single cell layer attached to the basement membrane in the theca interna layer of healthy follicles. The expression of cadherin-8, β-catenin and VE-cadherin decreased during follicular atresia. No positive staining was observed for R-cadherin, E-cadherin, T-cadherin, BR-cadherin or P-cadherin, and a weak positive reaction for N-cadherin was seen only in the granulosa cells of healthy and early atretic follicles. These findings indicate that cadherin-8, N-cadherin and VE-cadherin have important roles in follicular development and/or degeneration, and that decreases in the expression of these cadherins are involved in follicular atresia in porcine follicles.

The process of apoptosis of follicular granulosa cells in porcine ovaries during follicular atresia was investigated by in situ DNA 3'end-labeling at the level of individual cells. Histochemical changes in the follicular basement membrane (BM) were visualized by immunofluorescent staining of BM extracellular matrix (ECM) components, i.e. type IV collagen, laminin and fibronectin. At the first stage, granulosa cells located on the inner surface of the granulosa layer appeared to undergo apoptosis, followed by neighboring granulosa cells. No apoptotic granulosa cells making tight contact with intact BM were observed. Detachment and degeneration of the granulosa cell layer and fragmentation of BM occurred in follicles at the advanced stage of atresia. Finally, intermittent structures of BM and subsequent invasion of macrophages and fibroblasts were observed. Therefore we concluded that granulosa cell apoptosis is an initial symptom of follicular atresia in the porcine ovaries, and the degradation of BM follows granulosa cell apoptosis in the pig. Our results suggest that ECM components of follicular BM act as survival factors on follicular granulosa cells in porcine ovaries.

The present study was designed to investigate the immunohistochemical localization and distribution of basic fibroblast growth factor (bFGF) in the goat pituitary gland. We examined various fixatives for tissue preparation, and confirmed that methyl Carnoy-fixed tissues were associated with a better preservation of bFGF. After fixation, paraffin- embedded tissue sections were prepared, and were stained immunohistochemically with mouse monoclonal antibody against bovine bFGF. Approximately 30% of parenchymal cells in the pars distalis of the goat pituitary gland displayed strong immunoreactivity against the bFGF antibody. Endothelial cells occasionally showed positive immunoreactivity. No immunopositive cells were found in either the pars intermedia of the pituitary gland or posterior lobes. Based on analysis of serial sections stained with antibodies against pituitary hormones (luteinizing hormone and adrenocorticotropic hormone), bFGF-positive cells appear to be a subpopulation of gonadotrophs and or corticotrophs. The present findings indicate that immunohistochemical reactivity for bFGF may be partially attributed to differences in fixatives and that bFGF may play critical roles in the goat pituitary gland.

The adenohypophysial GH cells in Tokara goats were examined by light and electron microscopic immunocytochemistry. The immunoreactive GH cells distributed throughout the Pars distalis except for Zona tuberalis (ZT) and were recognized on a half of all secretory cells in the region in both sexes. The percentage area of GH immunopositive granules were 19.2% in male and 22.7% in female in that region. GH cell had a spherical, oval or irregular shaped nucleus, round or rod-like mitochondria, a lot of secretory granules, jaxtanuclear Golgi apparatus and rough endoplasmic reticulum running among granules. The secretory granules varied in size from cell to cell. Their average diameters w~re 329±15nm in male and 350± 15nm in female. More than 90% of GH cells had the granules of 250 to 400nm in the mean diameter in both sexes. Sex differences in the morphological features of GH cells were not recognized. By the comparison of the granule size with those of the other reports, it was clarified that Tokara goats showed rather small size in domestic ruminants.