[A Case of Advanced Gastric Cancer Treated with Conversion Surgery followed by Nivolumab Combination Chemotherapy]

The use of nivolumab as first-line therapy for unresectable advanced gastric cancer has now become a standard practice, and its efficacy has been established. This is the first report of a patient with advanced gastric cancer who underwent conversion surgery after first-line nivolumab combination chemotherapy. The patient was a 58-year-old woman. Her medical history included hypertension and dyslipidemia. She had advanced gastric cancer with extensive lymph node metastasis in the left supraclavicular fossa and around the abdominal aorta. After confirming the HER2-negative status and the PD-L1 CPS score to be ≥5, nivolumab was administered in combination with chemotherapy. After the treatment, she underwent a total gastrectomy with D2 dissection, combined splenectomy and pancreatic tail resection for adhesions, and para-aortic lymph node sampling as a conversion surgery. There was no obvious cancerous remnant in the resected specimen, and the pathological response was Grade 3. The patient was alive and recurrence-free at 4 months postoperatively.

Sepsis-associated brain injury: underlying mechanisms and potential therapeutic strategies for acute and long-term cognitive impairments

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Sepsis causes cerebral dysfunction in the short and long term and induces disruption of the blood–brain barrier (BBB), neuroinflammation, hypoperfusion, and accumulation of amyloid β (Aβ) and tau protein in the brain. White matter changes and brain atrophy can be detected using brain imaging, but unfortunately, there is no specific treatment that directly addresses the underlying mechanisms of cognitive impairments in sepsis. Here, we review the underlying mechanisms of sepsis-associated brain injury, with a focus on BBB dysfunction and Aβ and tau protein accumulation in the brain. We also describe the neurological manifestations and imaging findings of sepsis-associated brain injury, and finally, we propose potential therapeutic strategies for acute and long-term cognitive impairments associated with sepsis. In the acute phase of sepsis, we suggest using antibiotics (such as rifampicin), targeting proinflammatory cytokines, and preventing ischemic injuries and hypoperfusion. In the late phase of sepsis, we suggest targeting neuroinflammation, BBB dysfunction, Aβ and tau protein phosphorylation, glycogen synthase kinase-3 beta (GSK3β), and the receptor for advanced glycation end products (RAGE). These proposed strategies are meant to bring new mechanism-based directions for future basic and clinical research aimed at preventing or ameliorating acute and long-term cognitive impairments in patients with sepsis.

HIF-1α stimulates the progression of oesophageal squamous cell carcinoma by activating the Wnt/β-catenin signalling pathway

BACKGROUND

This study aimed to clarify the significance of the crosstalk between hypoxia-inducible factor-1α (HIF-1α) and the Wnt/β-catenin pathway in oesophageal squamous cell carcinoma (ESCC).

METHODS

The oncogenic role of HIF-1α in ESCC was investigated using in vitro and in vivo assays. The clinicopathological significance of HIF-1α, β-catenin and TCF4/TCF7L2 in ESCC were evaluated using quantitative real-time PCR and immunohistochemistry.

RESULTS

The expression level of HIF-1α, β-catenin, and TCF4/TCF7L2 in T.Tn and TE1 cell lines were elevated under hypoxia in vitro. HIF-1α knockdown suppressed proliferation, migration/invasion and epithelial-mesenchymal transition (EMT) progression, induced G0/G1 cell cycle arrest, promoted apoptosis and inhibited 5-fluorouracil chemoresistance in vitro. In vivo assays showed that HIF-1α is essential in maintaining tumour growth, angiogenesis, and 5-fluorouracil chemoresistance. Mechanically, we identified the complex between HIF-1α and β-catenin, HIF-1α can directly bind to the promoter region of TCF4/TCF7L2. The mRNA level of HIF-1α, β-catenin and TCF4/TCF7L2 were increased in ESCC tumour tissues compared to the corresponding non-tumour tissues. High levels of HIF-1α and TCF4/TCF7L2 expression were correlated with aggressive phenotypes and poor prognosis in ESCC patients.

CONCLUSIONS

HIF-1α serves as an oncogenic transcriptional factor in ESCC, probably by directly targeting TCF4/TCF7L2 and activating the Wnt/β-catenin pathway.

SIRT1 Expression Is a Promising Prognostic Biomarker in Esophageal Squamous Cell Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND/AIM

Several articles have assessed the prognostic significance of the expression of sirtuin 1 (SIRT1) in esophageal squamous cell carcinoma (ESCC). However, evidence in this field is insufficient. Thus, we conducted a meta-analysis to investigate the prognostic and clinical impact of SIRT1 expression in ESCC.

MATERIALS AND METHODS

We searched the PubMed, Cochrane Library, and Web of Science databases for articles on the expression of SIRT1 and clinicopathological features in patients with ESCC. A meta-analysis was conducted.

RESULTS

Four studies with 429 patients were included. The meta-analysis revealed a significant relationship between the high expression of SIRT1 and higher T-stage (odds ratio=2.39. 95% confidence interval=1.12-5.13, p=0.02), more advanced TNM stage (odds ratio=2.35. 95% confidence interval=1.20-4.60, p=0.01), and a poor overall survival (hazard ratio=1.90, 95% confidence interval=1.45-2.47, p<0.00001).

CONCLUSION

SIRT1 expression may be a promising prognostic biomarker for patients with ESCC.

Metformin-Induced Heat Shock Protein Family A Member 6 Is a Promising Biomarker of Esophageal Squamous Cell Carcinoma

INTRODUCTION

Anti-diabetic drug metformin exerts various anti-tumor effects on different cancers. Esophageal squamous cell carcinoma (ESCC) is an intractable digestive organ cancer and new treatment strategy is required. In this study, we performed a comprehensive gene expression analysis of esophageal squamous cell carcinoma (ESCC) cell lines treated with metformin, which provided helpful information on the anti-tumor effects of metformin in ESCC. Next, we selected a promising gene among them and examined its effects on ESCC properties.

METHODS

We examined metformin-induced mRNA expression changes in two human esophageal squamous cell carcinoma (ESCC) cell lines by performing next-generation sequencing (NGS) and pathway analysis. Heat shock protein family A (Hsp70) member 6 (HSPA6) expression in surgical specimens obtained from 83 ESCC patients who underwent curative operations was evaluated immunohistochemically and analyzed.

RESULTS

Metformin upregulated mRNA expression of the many genes, including HSPA6, a cancer immune related gene, and inhibited mRNA expression of the other many genes. Pathway analysis indicated major canonical pathways and upstream regulators related to metformin. The result indicated HSPA6 as a promising biomarker. HSPA6 expression correlated with disease-free survival (DFS) of the patients with all stage ESCC (p = 0.021), especially with stage I/II ESCC (p <0.001). With stage III, low HSPA6 expression was not associated with poor DFS (p = 0.918). Multivariate analysis indicated that independent low HSPA6 expression was an independent poor prognostic factor of stage I/II ESCC (p <0.001). However, HSPA6 expression did not correlate with the clinicopathological characteristics, including age, sex, tumor depth, lymph node metastasis, tumor stage, and tumor markers of the patients with stage I/II ESCC.

CONCLUSIONS

This NGS analysis detected prospective candidate genes, including HSPA6. Our results indicate that HSPA6 is a promising biomarker of the recurrence risk of stage I/II ESCC. Further studies on HSPA6 would lead to better treatment.

Targeting Pin1 renders pancreatic cancer eradicable by synergizing with immunochemotherapy

Pancreatic ductal adenocarcinoma (PDAC) is characterized by notorious resistance to current therapies attributed to inherent tumor heterogeneity and highly desmoplastic and immunosuppressive tumor microenvironment (TME). Unique proline isomerase Pin1 regulates multiple cancer pathways, but its role in the TME and cancer immunotherapy is unknown. Here, we find that Pin1 is overexpressed both in cancer cells and cancer-associated fibroblasts (CAFs) and correlates with poor survival in PDAC patients. Targeting Pin1 using clinically available drugs induces complete elimination or sustained remissions of aggressive PDAC by synergizing with anti-PD-1 and gemcitabine in diverse model systems. Mechanistically, Pin1 drives the desmoplastic and immunosuppressive TME by acting on CAFs and induces lysosomal degradation of the PD-1 ligand PD-L1 and the gemcitabine transporter ENT1 in cancer cells, besides activating multiple cancer pathways. Thus, Pin1 inhibition simultaneously blocks multiple cancer pathways, disrupts the desmoplastic and immunosuppressive TME, and upregulates PD-L1 and ENT1, rendering PDAC eradicable by immunochemotherapy.

Tumor-derived exosomes influence the cell cycle and cell migration of human esophageal cancer cell lines

Our laboratory previously reported the usefulness as biomarkers of exosomes in the plasma of esophageal squamous cell carcinoma (ESCC) patients. However, the influence of tumor‐derived exosomes on the tumor itself and underlying mechanisms remain unclear. We here report changes in the phenotype and gene expression when cancer cells exist in an environment with tumor‐derived exosomes. The exosomes were isolated from the culture medium of human ESCC cells (TE2, T.Tn) by ultracentrifugation; cell proliferation assay, wound‐healing assay, and fluorescence imaging of the cell cycle were performed to clarify the phenotypic changes in the high concentration of tumor‐derived exosomes. Gene expression changes were also assessed by mRNA microarray, and the data were analyzed by gene set enrichment analysis (GSEA). The data revealed that the proliferation of both TE2 and T.Tn was inhibited, and cell migration ability was upregulated in the exosome exposure group (P < .05). Fluorescence imaging using a fluorescent ubiquitination‐based cell cycle indicator expressing ESCC cells revealed that the ratio of G1‐phase cells was significantly increased in the exosome exposure group (P < .05). Findings of the GSEA clarified that high‐density exposure of cancer‐derived exosomes to their parent cancer cells downregulated the expression of genes related to cell proliferation and cell cycle, and upregulated the expression of genes related to actin filament length and extracellular structure organization. In conclusion, an environment of high‐density tumor‐derived exosomes induces changes in the gene expression and phenotype of tumor cells and may lead to tumor progression or malignant transformation.

Caspase recruitment domain family member 9 expression is a promising biomarker in esophageal squamous cell carcinoma

AIM

Esophageal squamous cell carcinoma (ESCC) is a refractory digestive organ cancer that requires better treatment strategies. We have recently reported that the antidiabetic drug metformin exerts antitumor effects on ESCC by inhibition of nuclear factor kappa B (NF-κB) nuclear translocation. In the present study, we focused on caspase recruitment domain family member 9 (CARD9), an essential signal adapter in NF-κB activation to examine whether it can be used as a prognostic factor in ESCC.

METHODS

We investigated CARD9 expression immunohistochemically in clinical samples obtained from 93 patients with ESCC who underwent curative esophagectomy. CARD9 expression was analyzed for correlation with clinicopathological characteristics and ESCC prognosis. The molecular effects were investigated by knocking down ESCC cells. Comprehensive RNA expression changes in these ESCC cells were detected by next-generation sequencing (NGS).

RESULTS

High CARD9 expression is significantly correlated with advanced tumor depth (P < .001), positive lymph node metastasis (P = .005) and advanced stage (P = .001). Kaplan-Meier method and the log-rank test showed that overall survival (OS) and disease-free survival (DFS) were significantly poor in the high CARD9 expression group (OS: P = .027, DFS: P = .005). Univariate and multivariate analysis showed that high CARD9 expression is a significant poor prognostic factor for DFS. Cell proliferation and migration were suppressed by CARD9 knockdown. NGS detected altered the expression of some RNAs including maternally expressed 3 (MEG3).

CONCLUSION

High CARD9 expression is significantly associated with poor prognosis. Therefore, CARD9 expression may be a prospective prognostic biomarker in ESCC.

[Successful Treatment of Gastric Cancer with Conversion Surgery after Nivolumab Treatment-A Case Report]

Immunocheckpoint inhibitors including anti-PD-1 antibody have shown certain therapeutic effects on various cancer types. They have also attracted great attention as novel cancer treatment options in addition to surgical resection, chemotherapy, and radiation therapy. Herein, we report a case of gastric cancer that was successfully treated with conversion surgery after nivolumab treatment. The patient was 68 years old and male. Upper gastrointestinal endoscopy revealed a type 3 tumor in the antrum, and he was referred to our department for further examination. The gastric cancer was diagnosed as cT4aN2M0, cStage ⅢA, and he was administered SOX as the first-line and nab-PTX/RAM as the second-line treatment, which was also a PD. As the third-line treatment, nivolumab showed remarkable reduction of the tumor after initiation, and after 14 courses, conversion surgery was performed. The patient remains alive without recurrence.

[Development of TP53-Targeted Treatment in Esophageal Squamous Cell Carcinoma Using Cancer Genomic Profiling Test]

Recently, the interest in cancer genomic medicine has increased, owing to the powerful and cost-effective technology of next-generation sequencing(NGS), which allows rapid identification of a large number of gene mutations. TP53 mutations are frequently found in solid cancers, especially in esophageal squamous cell carcinoma(ESCC), wherein the frequency of TP53 mutation is considered to be 90% or more. However, there is no clinical targeted therapy as yet utilizing TP53. Here, we aimed to characterize TP53 mutations associated with ESCC, in order to assess its feasibility as a therapeutic target. We extracted DNA and RNA from specimens of ESCC patients and analyzed them using NGS, which revealed different TP53 mutations. Based on previous reports, it is considered that different TP53 mutations lead to different functions of the protein, and subsequently account for varied prognosis in squamous cell carcinoma of the head and neck. We also performed cell viability assay using ESCC cell lines with different TP53 mutations and 2 kinds of p53-targeted drug and found differences in the growth inhibition of the cell lines. Although individual treatment can be determined depending on the type of TP53 mutation, it would be necessary to further examine the interaction of TP53 with other genes to determine its therapeutic efficacy as a target.

Genome-wide ChIP-seq data with a transcriptome analysis reveals the groups of genes regulated by histone demethylase LSD1 inhibition in esophageal squamous cell carcinoma cells

Expression of genes is controlled by histone modification, histone acetylation and methylation, but abnormalities of these modifications have been observed in carcinogenesis and cancer development. The effect of the lysine-specific histone demethylase 1 (LSD1) inhibitor, a demethylating enzyme of histones, is thought to be caused by controlling the expression of genes. The aim of the present study is to elucidate the efficacies of the LSD1 inhibitor on the gene expression of esophageal cancer cell lines using chromatin immunoprecipitation (ChIP)-Seq. A comprehensive analysis of gene expression changes in esophageal squamous cell carcinoma (ESCC) cell lines induced by the LSD1 inhibitor NCL1 was clarified via analysis using microarray. In addition, ChIP-seq analysis was conducted using a SimpleChIP plus Enzymatic Chromatin IP kit. NCL1 strongly suppressed the proliferation of T.Tn and TE2 cells, which are ESCC cell lines, and further induced apoptosis. According to the combinatory analysis of ChIP-seq and microarray, 17 genes were upregulated, and 16 genes were downregulated in both cell lines. The comprehensive gene expression study performed in the present study is considered to be useful for analyzing the mechanism of the antitumor effect of the LSD1 inhibitor in patients with ESCC.

[Dawn of Cancer Clinical Sequencing in Chiba University Hospital]

Genome medicine has been attractingmuch of attention in Japan. The combination of molecular targetingdrug s and somatic mutations has been developed for cancer treatment, which was introduced clinically with evidence by cancer type. Several cancer somatic mutations can be identified in a single test inexpensively using next-generation sequencing(NGS). Drug approval not based on organs but on cancer genome analysis has been practiced mainly in the United States, and is also being implemented in Japan. However, cancer treatment strategies using molecular targeting drugs and the associated diagnosis are limited in each type of cancer. Furthermore, the benefit of NGS, which is an improved and inexpensive technique, is still insignificant in Japan. However, the clinical biobank system was initiated in 2011 to prepare the era of cancer genome medicine in our department. The quality of biological samples was strictly controlled by the standardized sampling procedures, which can be used by the researchers accordingto their convenience. Furthermore, the cooperative research involvingcommercial corporations has been started.

The concentration of programmed cell death-ligand 1 in the peripheral blood is a useful biomarker for esophageal squamous cell carcinoma

BACKGROUND

We determined the serum concentrations of Programmed cell death-1 (PD-1) and its ligands (PD-L1 and PD-L2) in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Blood samples were collected from 85 patients with histologically proved ESCC. Serum levels of PD-1, PD-L1, and PD-L2 were measured using enzyme linked immunosorbent assays. Correlations between serum PD-1, PD-L1, and PD-L2 concentration and tumor depth, number of lymph node metastases, organ metastasis status, or disease stage were assessed and five-year survival rates according to clinicopathological characteristics were calculated.

RESULTS

The concentration of PD-1 was not differed according to tumor progression. On the other hand, the average concentration of PD-L1 in patients with T3/T4 disease was 15.6 (12.2-18.3) pg/mL (25-75%), and this was significantly higher than that in patients with Tis/T1/T2 disease (p = 0.020). Similarly, PD-L1 levels were significantly higher in patients with positive lymph nodes than in cases with negative lymph node involvement (p = 0.006) and were higher in patients with organ metastasis (p = 0.123) and in more advanced stage (p = 0.006). Similar tendency was observed regarding PD-L2 concentrations. PD-L2 concentration was higher in T3, T4 cases (p = 0.008), in LN positive cases (p = 0.032), and in more advanced stage (p = 0.024).

CONCLUSION

Our data showed that a concentration of PD-L1 in peripheral blood was high in advanced cancer and high concentration of PD-L1 predicted disease progression and also poor survival in patients with ESCC.

Antitumor effects of metformin are a result of inhibiting nuclear factor kappa B nuclear translocation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is an intractable digestive organ cancer that has proven difficult to treat despite multidisciplinary therapy, and a new treatment strategy is demanded. Metformin is used for type 2 diabetes mellitus and its antitumor effects have been reported recently. Metformin exerts antitumor effects in various respects, such as inhibiting inflammation, tumor growth and epithelial‐mesenchymal transition (EMT). However, few reports have described the efficacy of metformin on ESCC, and their findings have been controversial. We analyzed the antitumor effects of metformin and clarified its effects on anti‐inflammation, growth suppression and EMT inhibition. Activation of nuclear factor kappa B (NF‐κB), the major transcription factor induced by inflammation, was investigated by immunostaining. We found that localization of NF‐κB in the nucleus was reduced after metformin treatment. This suggests that metformin inhibited the activation of NF‐κB. Metformin inhibited tumor growth and induced apoptosis in ESCC cell lines. Associated with EMT, we examined cell motility by a wound healing assay and the epithelial marker E‐cadherin expression of various ESCC cell lines by western blotting. Metformin inhibited cell motility and induced E‐cadherin expression. In conclusion, metformin showed multiple antitumor effects such as growth suppression, invasion inhibition, and control of EMT by inhibiting NF‐κB localization on ESCC. Further exploration of the marker of treatment efficacy and combination therapy could result in the possibility for novel treatment to use metformin on ESCC.

ZNF750 Expression Is a Potential Prognostic Biomarker in Esophageal Squamous Cell Carcinoma

OBJECTIVE

ZNF750, a transcriptional regulator of epidermal differentiation, has been identified as a tumor suppressor in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to investigate the clinical and prognostic significance of ZNF750 expression and to evaluate the effect of ZNF750 knockdown on cell proliferation, migration, and invasion in ESCC.

METHODS

A total of 124 patients with ESCC who underwent curative esophagectomy were evaluated in this study. The expression of ZNF750 in surgical specimens was immunohistochemically assessed and used in the analysis of clinicopathological features and overall survival (OS). The molecular role of ZNF750 was investigated by ZNF750 knockdown using small interfering RNA (siRNA) in ESCC cell lines.

RESULTS

Low ZNF750 expression had a significant correlation with positive lymph node metastasis (p = 0.028). Furthermore, there was a significant relationship between low expression of ZNF750 in ESCC and a poor OS, and a multivariate analysis showed that low ZNF750 expression was an independent prognostic factor (p = 0.020). The cell growth, migration, and invasion were significantly increased by downregulation of ZNF750.

CONCLUSIONS

The low expression of ZNF750 was significantly associated with a poor prognosis, and ZNF750 expression may, therefore, be a reliable prognostic biomarker in ESCC.

Abstract B07: Analysis of allele specific expression in esophageal squamous cell carcinoma with combination of exome sequencing and mRNA Sequencing

In recent years, large-scale international studies have provide comprehensive catalogues of genomic alterations in cancers including Esophageal Squamous Cell Cancer(ESCC). They revealed that some gene associated with cell cycle/apoptosis pathway, NOTCH pathway, WNT pathway, such as TP53 and NOTCH1, harbored genetic abnormalities frequently. As the next step clinical sequencing studies are starting to evaluate efficacy of using targeted agents to patients with specific molecular aberrations.

We performed exome sequencing and RNA sequencing for 25 Japanese patients with esophageal squamous cell carcinoma (ESCC) to provide a comprehensive catalogue of genomic abnormalities in ESCC and found TP53 and ZNF750 significantly mutated genes. Additionally, we performed allele specific expression analysis of TP53, integrating mRNA sequencing data into the information of genomic abnormality. This analysis revealed that levels of expression changes depending on mutation types and nearly mono-allelic expression of TP53 was a common signature of ESCC patients with somatic mutations. And pattern of mono-allelic expression was dependent on mutation types. We expanded this analysis to all genes with somatic SNV mutations and revealed that mutant allele specific expression was observed in other genes including ZNF750, and many of them were belonged to cancer pathway in KEGG database.

About TP53, our investigation might provide better understanding of the involvement of somatic mutations. And fluctuations in transcriptional regulation of TP53 could be predicted based on type of somatic mutation. In addition to this, analysis of allele specific expression suggested that not only somatic mutation of DNA, but also mutant allele expression should be considered to understand cancer genetic pathophysiology better and build more effective therapeutic strategies.

Citation Format: Masahiko Takahashi, Hirofumi Nakaoka, Yasunori Akutsu, Naoyuki Hanari, Kentaro Murakami, Masayuki Kano, Yasunori Matsumoto, Ryota Otsuka, Nobufumi Sekino, Masaya Yokoyama, Itsuro Inoue, Hisahiro Matsubara. Analysis of allele specific expression in esophageal squamous cell carcinoma with combination of exome sequencing and mRNA Sequencing [abstract]. In: Proceedings of the AACR Precision Medicine Series: Opportunities and Challenges of Exploiting Synthetic Lethality in Cancer; Jan 4-7, 2017; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2017;16(10 Suppl):Abstract nr B07.

Abstract 4032: Functional analysis of exosomes derived from human esophageal squamous cell carcinoma

Exosomes are small membrane vesicles (30-100 nm) released by many types of cells including cancer cells, and are thought to play an important role in cell-to-cell communications. Exosomes contain lipids, proteins, and nucleic acids such as mRNAs or microRNAs, they are tought to have relationship with tumor growth or metastasis. Our laboratory was previously reported the level of microRNA-1246, expressed mainly in tumor tissues of esophageal squamous cell carcinoma (ESCC), was significantly high in exosomes extracted from the serum of ESCC patients. However, the exosome dynamics and transportation between cancer cells and the other cells are still unclear. In this study, we assessed the cell-to-cell communication via exosomes with fluorescent imaging and analyzed the effect of cancer cell derived exosome to tumor progression.

In order to image and analyze the movement of cancer cell-derived exosomes, green fluorescent protein (GFP)-tagged CD63, which is a general marker of exosomes, was expressed in human esophageal squamous cancer cell line TE2. Exosomes were extracted from supernatant with ultracentrifuge method. Extracted GFP-tagged exosomes were added to the other cells to obtain the images of transportation. The effects of exosomes to tumor progression were also assessed with cell proliferation assay, invasion oassay, and migration assay. Our data indicates that cancer cell derived exosomes affect tumor progression.

Citation Format: Yasunori Matsumoto, Masayuki Kano, Yasunori Akutsu, Takanori Nishimori, Naoyuki Hanari, Isamu Hoshino, Kentaro Murakami, Takeshi Toyozumi, Hiroshi Suito, Masahiko Takahashi, Nobufumi Sekino, Yoshihiro Nabeya, Hisahiro Matsubara. Functional analysis of exosomes derived from human esophageal squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4032. doi:10.1158/1538-7445.AM2015-4032

Histone Demethylase LSD1 Inhibitors Prevent Cell Growth by Regulating Gene Expression in Esophageal Squamous Cell Carcinoma Cells

BACKGROUND

The expression of genes can be influenced by the balance of histone acetylation and/or histone demethylation, with an imbalance of these processes possibly observed in many cancers. The histone demethylase LSD1 inhibitor activity is associated with selective transcriptional regulation and alterations in the gene expression. However, the exact mechanisms underlying the antitumor effects of LSD1 inhibitors are not fully understood.

METHODS

The antitumor effects of NCL1, an LSD1 inhibitor, in esophageal squamous cell cancer (ESCC) cell lines were evaluated. A comprehensive analysis of the changes in the gene expression in ESCC cell lines induced by NCL1 was carried out using a microarray analysis. A loss-of-function assay using a siRNA analysis was performed to examine the oncogenic function of the gene.

RESULTS

NCL1 strongly inhibited the cell growth of T.Tn and TE2 ESCC cells and induced apoptosis. According to the microarray analysis, 81 genes in the T.Tn cells and 149 genes in the TE2 cells were up- or down-regulated 2-fold or more by NCL1 exposure. Among these genes, 27 were contained in both cell lines and exhibited similar expression patterns. PHLDB2, one of the genes down-regulated by NCL1, was overexpressed in the ESCC tumor tissues. Moreover, a high expression level of PHLDB2 was found to be significantly correlated with poor prognosis.

CONCLUSIONS

The present observations of the comprehensive analysis of the gene expression levels provide insight into the mechanisms underlying the antitumor effects of LSD1 inhibitors in ESCC patients.

Mouse Epidermal Keratinocytes in Three-Dimensional Organotypic Coculture with Dermal Fibroblasts Form a Stratified Sheet Resembling Skin

We describe an organotypic model of mouse skin consisting of a stratified sheet of epidermal keratinocytes and dermal fibroblasts within a contracted collagen gel. The model was designed to maintain the polarity of stratified keratinocytes and permit their long-term culture at an air-liquid interface. After air exposure, the thickness of the keratinocyte sheet transiently increased and then decreased to two cell layers at 2 weeks. The two-cell-layer structure is similar to that of the adult mouse epidermis. Cytokeratin 5 was localized in the lowest cell layer in the epithelial sheet, but cytokeratin 1 and loricrin were localized in the outer cell layers, resembling mouse skin. The expressions of interleukin 1alpha and 1beta in the keratinocytes and of keratinocyte growth factor 1 and 2 in the fibroblasts correlated with keratinocyte stratification. The mouse organotypic coculture is useful in studying epithelial cell-mesenchymal cell interactions in vitro.

Usefulness of troglitazone administration to obese hyperglycaemic patients with near-normoglycaemia

AIMS

We assessed the effectiveness of 400 mg/day of troglitazone administered to hyperglycaemic patients with near-normoglycaemia who were obese and who had hyperinsulinaemia.

RESULTS

The area under the plasma glucose curve in oral glucose tolerance tests (OGTT) significantly decreased from 39.8 +/- 19.4-20.5 +/- 10.2 mg/dL. h and the area under the insulin-response curve from 31.8 +/- 22.5-12.2 +/- 5.7 microU/ml x h 4 months after the start of treatment. The level of HbA1c significantly improved from 6.6 +/- 0.2 to 6.3 +/- 0.2% (p < 0.05) by 1 month after administration, and that of serum 1,5-anhydroglucitol (1,5-AG) from 12.6 +/- 1.1-18.3 +/- 2.5 micro/ml (p < 0.05). In some cases, recovery of the first-phase insulin secretion was observed.

CONCLUSIONS

These findings suggest that the administration of this insulin sensitizer is useful in the treatment of obese Japanese subjects with borderline or mild diabetics accompanied by hyperinsulinaemia.

Development of a new haemostatic dissecting forceps utilizing controlled heat as an energy source

We tested a prototype of a new thermal surgical system in animal experiments. This device utilizes controlled heat as an energy source and seals and divides small- to medium-size vessels. The forceps we used in the current study are shaped like dissecting forceps used in conventional open surgery, and their grippers can open bilaterally. Heating elements are built into a gripper. The temperature adjustment is controlled by monitoring the electric resistance. Since the new device utilizes no ultrasonic energy, unfavorable phenomena such as cavitations or mist production are not observed. In a preliminary experiment, 12 segments of animal arteries were sealed and cut by the prototype forceps. Five artery stumps did not burst at the maximum pressure of the manometer system (1471 mmHg). The other seven stumps showed burst pressure ranging from 525 mmHg to 1051 mmHg. It is feasible to utilize controlled heat as a new alternative energy source for haemostatic surgical dissection. The new thermal dissector we are in the process of developing showed safe and quick sealing and cutting of the vessels in the experimental settings.

Post-load glucose measurements in oral glucose tolerance tests correlate well with 1,5-anhydroglucitol, an indicator of overall glycaemic state, in subjects with impaired glucose tolerance

Using both cross-sectional and longitudinal methods, we investigated the relationship between post-load serum glucose concentration in a 75 g oral glucose tolerance test (OGTT) and overall glycaemic state in subjects with impaired glucose tolerance (IGT). Glycaemic state was assessed by measuring glycated haemoglobin (HbA1c) and the serum concentration of 1,5-anhydroglucitol (1,5-AG). In the cross-sectional study, the concentration of 1,5-AG, while remaining within a normal range, was reduced to a degree proportional to the post-load glycaemic level. Although the correlation between HbA1c and post-load plasma glucose was relatively weak (r=0.281, P<0.001), a significant inverse correlation (r=-0.824, P<0.0001) was found between 1,5-AG and mean post-load plasma glucose concentration in 211 subjects with IGT. Fasting plasma glucose (r=-0.539, P<0.0001) and 2 h plasma glucose (r=-0.621, P<0.0001) were correlated with 1,5-AG less strongly than was post-load glycaemia. Both 1,5-AG and HbA1c were correlated weakly but significantly with the fasting insulin concentration. In the longitudinal study we measured 1,5-AG and mean post-load plasma glucose with an OGTT once yearly for 10 years in 15 subjects with IGT. Strong inverse correlations were seen between 1,5-AG and mean post-load plasma glucose in each subject (range of r values among subjects of -0.584 to -0.978). These findings suggest a close relationship between post-load plasma glucose concentration measured by OGTT and overall glycaemic state in subjects with IGT.

Functional conformation changes in the TF(1)-ATPase beta subunit probed by 12 tyrosine residues

The effect of nucleotide binding on the structure of the F(1)-ATPase beta subunit from thermophilic bacillus PS-3 (TF(1)beta) was investigated by monitoring the NMR signals of the 12 tyrosine residues. The 3,5-proton resonances of 12 tyrosine residues could be observed for the specifically deuterated beta subunit. The assignment of 3,5-proton resonances of all of the tyrosine residues was accomplished using 14 mutant proteins, in each of which one or two tyrosine residues were replaced by phenylalanine. Binding of Mg. ATP induced an upfield shift of Tyr(341) resonance, suggesting that their aromatic rings are stacked to each other. Besides Tyr(341), the signal shift observed on Mg.ATP binding was restricted to the resonances of Tyr(148), Tyr(199), Tyr(238), and Tyr(307), suggesting that Mg.ATP induces a conformational change in the hinge region. This can be correlated to the change from the open to closed conformations as implicated in the crystal structure. Mg.ADP induced a similar but distinctly different conformational change. Therefore, the intrinsic conformational change in the beta subunit induced by the nucleotide binding is proposed to be one of the essential driving forces for the F(1) rotation. Reconstitution experiments showed that Tyr(277), one of the four conserved tyrosines, is essential to the formation of the alpha(3)beta(3)gamma complex.

Acute glucosuria after continuous glucocorticoid loading in the rat in vivo

We investigated the effects of the continuous infusion of various steroids in rats on renal tubular reabsorption of glucose in vivo to elucidate the pathogenesis of steroid-induced glucosuria. Urinary glucose excretion increased 60 min after administration of dexamethasone (2.38 mM). By 120 min, urinary excretion of glucose was three times higher in the dexamethasone group than in the control group (24.1 +/- 4.6 versus 72.4 +/- 16.7 micromol); the plasma level of glucose did not increase. Dexamethasone had no effect on the resorption of 1,5-anhydro-D-glucitol, which is a glucose-resembling polyol that is actively absorbed by the renal tubules as glucose. Neither estradiol nor progesterone increased urinary excretion of glucose. These findings suggest that continuous administration of a high-dose glucocorticoid selectively influences the glucose reabsorption system in the kidney.

Nonstereospecific actions of ketamine isomers on the force of contraction, spontaneous beating rate, and Ca2+ current in the guinea pig heart

Ketamine possesses stereospecific actions of anesthesia with the S(+)-isomer being three to four times as potent an anesthetic as the R(-)-isomer. We investigated the mechanical and electrophysiologic effects of ketamine isomers in guinea pig cardiac preparations. Both isomers decreased the contractile force of electrically driven papillary muscles and the spontaneously beating rate of the right atria in a concentration-dependent manner. There were no significant differences between the S(+)- and R(-)-isomers for these measured variables. Consistent with the results from mechanical experiments, electrophysiologic experiments using whole cell voltage clamp techniques revealed that both isomers suppressed identically the transsarcolemmal Ca2+ current (ICa), which plays a role in the generation of the force of contraction and the spontaneous firing of sinoatrial node cells. In conclusion, the optical isomers of ketamine have equipotent cardiodepressant effects in the guinea pig. Inasmuch as the S(+)-isomer is the more potent anesthetic, it could offer significant clinical advantage over the R(-)-isomer or the racemate, in terms of impairment of cardiac functions, if the present results could be extrapolated to the clinical setting.

Clinical usefulness of serum 1,5-anhydroglucitol in monitoring glycaemic control

BACKGROUND

To evaluate prospectively the clinical value of measuring serum concentrations of 1,5-anhydroglucitol (1,5AG) in monitoring glycaemia in patients with newly diagnosed non-insulin-dependent diabetes mellitus (NIDDM), we measured serum 1,5AG in 56 such patients.

METHODS

28 patients (group A) were started on, and continuously received, an oral hypoglycaemic agent for at least 6 weeks. The other 28 patients (group B) were given such agents for 4 weeks, and then stopped taking them for at least 2 weeks. All patients were then followed for an additional 10 weeks. Serum 1,5AG, fructosamine, glycated haemoglobin (HbA1c), and self-monitoring of blood glucose were monitored every 14 days for 16 weeks.

FINDINGS

When sudden worsening of glycaemia occurred within 2 weeks, entailing withdrawal of oral treatment, 1,5AG accurately detected the slight change in glycaemia whereas HbA1c and fructosamine both failed to detect it. Although the change was detected by measurement of fasting plasma glucose (FPG) concentrations, FPG was less sensitive than 1,5AG. In patients with "near-normoglycaemia" (HbA1c about 6.5%) in the preceding 8 weeks, those who showed a lower concentration of 1,5AG (<10.0 micrograms/mL) manifested a higher mean daily plasma glucose concentration even though HbA1c measurement suggested good control of glycaemia. Results of 1,5AG were correlated more strongly with the FPG (r=0.790) and mean daily plasma glucose (r=-0.835) estimated on the same day than those estimaoffted in the preceding 2, 4 and 8 weeks, and with a fall in the Spearman correlation coefficient at any preceding time interval.

INTERPRETATION

Because 1,5AG accurately detected a slight change in glycaemia without delay, it is suitable for use in monitoring for strict control of glycaemia, an important clinical goal.

Conformational dynamics monitored by His-179 and His-200 of isolated thermophilic F1-ATPase beta subunit which reside at the entrance of the 'conical tunnel' in holoenzyme

When monitored by 1H NMR at various pH values, most of the C-2 proton signals from 12 His residues of the isolated beta subunit of thermophilic F1-ATPase (TF1) could be separately observed. Two of them were assigned to His-179 and His-200 which reside at the entrance of a 'conical tunnel' to reach catalytic site in the crystal structure of F1-ATPase. His-200 gave doublet, suggesting that this region is not a rigid alpha-helix in the isolated beta subunit. The binding of Mg.AMP-PNP changed the chemical shifts of His-179 and His-200 significantly. Although His-119 located at the opposite side of the conical tunnel was not affected by the nucleotide-binding, it contributed to the stability of beta subunit and the efficiency of the catalysis of the holoenzyme.

Interaction of theta-toxin (perfringolysin O), a cholesterol-binding cytolysin, with liposomal membranes: change in the aromatic side chains upon binding and insertion

To understand the mechanism of membrane lysis by theta-toxin (perfringolysin O) from Clostridium perfringens, a cholesterol-binding, pore-forming cytolysin, we undertook a spectroscopic analysis of the structural changes that occur during the lytic process using lipid vesicles. In particular, the spectra were compared with those obtained using a modified theta-toxin, MC theta, that binds membrane cholesterol without forming oligomeric pores, thus bypassing the oligomerization step. The interaction of theta-toxin with liposomes composed of cholesterol and phosphatidylcholine but not with cholesterol-free liposomes caused a remarkable increase in the intensity of the tryptophan fluorescence emission spectra and ellipticity changes in the near- and far-UV CD peaks. A CD peak shift from 292 to 300 nm was specific for theta-toxin, suggesting oligomerization-specific changes occurring around tryptophan residues. Structural changes in the aromatic side chains were detected in the near-UV CD and fluorescence spectra upon MC theta-liposome interaction, although the far-UV CD spectra indicate that the beta-rich secondary structure of MC theta is well-conserved after membrane binding. Quenching of the intrinsic tryptophan fluorescence of MC theta by brominated lecithin/cholesterol liposomes suggests that theta-toxin inserts at least partly into membranes in the absence of oligomerization. These results indicate that regardless of oligomerization, the binding of theta-toxin to cholesterol induces partial membrane insertion and triggers conformational changes accompanied by aromatic side chain rearrangement with retention of secondary structure.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolonged hyperalimentation as a possible cause of renal tubular dysfunction: evaluation of 1,5-anhydro-D-glucitol resorption and N-acetylglucosaminidase excretion in humans

1. A major polyol found in the sera and other tissues of humans, 1,5-anhydro-D-glucitol, is mainly ingested in the diet and is excreted in urine. We compared the influence of the long-term administration of total parenteral nutrition free of 1,5-anhydro-D-glucitol with that of total enteral nutrition on the serum level of 1,5-anhydro-D-glucitol in 46 patients who could not take food by mouth. 2. The serum concentration of 1,5-anhydro-D-glucitol and its kinetics remained unchanged in the group receiving total enteral nutrition (n = 21) over a period of 12 months. However, after 1 month on total parenteral nutrition (n = 25), the serum level of 1,5-anhydro-D-glucitol decreased, falling to about one-sixth the pretreatment level in the 12th month. Because the serum level of 1,5-anhydro-D-glucitol continued to decline, falling below the limit at which its renal reabsorption is normally activated, this decrease did not seem to be caused directly by a nutritional deficiency of this substance. 3. The urinary excretion of 1,5-anhydro-D-glucitol was closely correlated (r = 0.792) with that of N-acetyl-beta-glucosaminidase; but not with the serum creatinine level or of the urinary excretion of microalbumin or of urinary beta 2-microglobulin. We observed no glucosuria, hyperuricuria or changes in serum electrolytes during total parenteral nutrition. 4. The reduction in the serum level of 1,5-anhydro-D-glucitol and the urinary excretion of N-acetyl-beta-glucosaminidase were correlated with the duration of total parenteral nutrition administration.(ABSTRACT TRUNCATED AT 250 WORDS)

IS1-encoded proteins, InsA and the InsA-B'-InsB transframe protein (transposase): functions deduced from their DNA-binding ability

Insertion sequence IS1 encodes a transframe protein, InsA-B'-InsB, which is produced from two out-of-phase reading frames, insA and B'-insB, by translational frameshifting at a run of adenines. Unless the frameshifting event occurs, the InsA protein is produced from IS1. We found that cells harboring a plasmid carrying an IS1 mutant with a single adenine insertion in the run of adenines contained miniplasmids. Cloning and DNA sequencing analyses of the miniplasmids revealed that they had a deletion extending from an inverted repeat (IR) at the left end of IS1. This indicates that they were generated by IS1-mediated deletion due to efficient production of the InsA-B'-InsB transframe protein that is IS1 transposase. Both the InsA protein and transposase were partially purified as a fusion protein with collagen-LacZ by LacZ-specific affinity column chromatography. The InsA* and the collagenolyzed InsA* were found to bind specifically to a 24-bp region within each of the IRs at the ends of IS1. The transposase Tnp* and the collagenolyzed Tnp* were found to bind to the sequence with or without IR, but preferentially to that with IR. The nonspecific DNA-binding ability of transposase may be involved in recognition of the target DNA, an important process of transposition of IS1. Both InsA and transposase have the IR-specific DNA binding ability and a common polypeptide segment containing the alpha-helix-turn-alpha-helix motif, supporting the previous indication that InsA competes with transposase to bind to IRs and thus becomes a transposition inhibitor. Based on the observations described in this article, we speculate that transposase of IS1 consists of at least two domains, the N-terminal half, which almost entirely overlaps InsA, and the C-terminal half, which almost entirely overlaps B'-InsB. The frameshifting event adds the latter domain to the former to give the transposase activity recognizing IRs and the target sequence to initiate the transposition reaction.

Prevention of diabetes by thymic hormone in alloxan-treated rats

We investigated the effects of facteur thymique sérique (FTS), a thymic peptide hormone, on alloxan- and streptozotocin-induced diabetes in rats. Pretreatment with intravenous injection of FTS significantly suppressed both alloxan- and streptozotocin-induced hyperglycemia. The effects of FTS were time dependent. FTS suppressed hyperglycemia in a dose range of 1-6600 micrograms/kg. Alloxan-induced hyperglycemia was completely prevented when FTS was injected in doses of 40-50 micrograms/kg 1 min before injection of alloxan. Histological examination of islet areas showed that alloxan-induced destruction of beta-cells was inhibited by FTS. FTS had no significant effects on lymphocyte subsets and immunity-related cells or on plasma superoxide dismutase activity and total glutathione level. The blood half-life time of exogenously injected FTS was short (2-3 min), indicating acute internalization of FTS into pancreatic beta-cells. Our results suggested that FTS acutely and directly blocks some initial effect of alloxan, preventing the destruction of beta-cells.

Transport and accumulation of 1,5-anhydro-D-glucitol in the human erythroleukemia cell line K-562

The transport and intracellular accumulation of 1,5-anhydro-D-glucitol (AG) was studied in the human erythroleukemia cell line K-562 by gas chromatography-mass spectrometry in conjunction with liquid scintillation spectrometry. K-562 cells contained 106 +/- 6 nM/10(6) cells of free AG, primarily in the cytosol. Addition of physiologic amounts of AG to the extracellular medium resulted in rapid intracellular incorporation of AG, with a half-saturation time of 5 s. Intracellular accumulation was linear for 2 h and subsequently reached saturation. AG uptake was temperature and concentration dependent with an apparent Km of 127 mM. AG uptake and accumulation was not inhibited by fructose, fucose, galactose, mannose, glucose, or 3-O-methyl-D-glucose and was less affected by cytochalasin B or phloretin than that of 2-deoxyglucose. Phloridzin did not affect AG uptake but did inhibit 2-deoxyglucose uptake. Efflux of AG from K-562 cells depended on external AG concentration alone and was not affected by extracellular glucose concentration. Intracellular AG concentration decreased rapidly and reached zero within 10 min following removal of AG from the external medium. We therefore propose that both transport and countertransport of AG in K-562 cells are mediated by a specific carrier system.

[Two cases of Campylobacter fetus subsp. fetus sepsis]

We encountered two relatively rare cases of sepsis due to Campylobacter fetus subsp. fetus (C. fetus). Case 1. A 54-year-old female with abdominal polysurgery developed a slight fever and vomiting in August 1984. Despite the administration of some digestive drugs by her family doctor, these symptoms continued. In mid-October, she was hospitalized with high fever with chill and rigor on the skin. On the third hospital day, C. fetus was detected in the blood culture. After combination chemotherapy of intravenous drip infusion of latamoxef (LMOX) (2 g/day) and oral administration of erythromycin (EM) (800 mg/day), her symptoms improved. Case 2. A 57-year-old male with diabetic retinopathy and nephropathy was hospitalized because of slight fever, general edema and pleural effusion. On the 6th hospital day, C. fetus was detected in the blood culture and he was diagnosed with sepsis. Under treatment with the intravenous drip of LMOX (2 g/day) and oral administration of EM (1200 mg/day), his condition improved. Both cases had common underlying diseases such as hypoproteinemia with edema and problems in the lower intestinal tract; the former had polysurgery and malabsorption syndrome, the latter had diffuse ulceration of the colon. Such underlying conditions may have permitted the invasion of C. fetus into the blood.

Nematocidal activity of long alkyl chain amides, amines, and their derivatives on dog roundworm larvae

The nematocidal activity of amides and amines having a long alkyl chain against the second-stage larva of dog roundworm, Toxocara canis, was examined. Long chain acyl amides with smaller substituents on the nitrogen showed stronger activity and the activity of cyclic amine amides was stronger than that of acyclic ones. In a series of homologous amides, the activity was dependent on the alkyl chain length: it reached a maximum at an optimal chain length and decreased in both shorter and longer homologues. The relationship between the activity and hydrophobicity of the homologues was analysed by the use of the bilinear model. The hydrophobicity of a compound, which gives a maximal activity, was similar for all neutral amides, but amides which have an additional amine group in the molecule had different values. Tertiary amines and their salts having a long alkyl chain also showed nematocidal activities comparable to those of the corresponding amides. The salts killed the larva at concentrations lower than their critical micell concentration, suggesting that they behave as a single molecule for the nematocidal action.

[Effect of induction methods of pediatric anesthesia on serum myoglobin]

Two hundred and twenty nine children from infancy to middle teens divided into six groups were studied to determine the effect of induction methods of pediatric general anesthesia on serum myoglobin. After the slow induction with nitrous oxide-oxygen-halothane (GOF), the serum myoglobin increased significantly to 1774.7 +/- 4285.8 ng.ml-1 (mean +/- SD) by iv administration of succinylcholine 1 mg.kg-1. This significant increase of serum myoglobin was reduced by pretreatment with d-tubocurarine (dTc) 0.05 mg.kg-1 before administration of succinylcholine. However, it was not reduced by pretreatment with thiopental 3 mg.kg-1. After the rapid induction with thiopental 5 mg.kg-1 and succinylcholine 1 mg.kg-1, the serum myoglobin increased slightly to 387.6 +/- 596.5 ng.ml-1. But this increase in serum myoglobin was stopped by pretreatment with dTc 0.05 mg.kg-1 before the rapid induction. Serum myoglobin was not changed without succinylcholine after the slow induction with GOF. In each group, there was no relation with serum myoglobin and ages or fasciculation. Serum myoglobin was more influenced by the induction methods of pediatric general anesthesia than by ages.