Abstract 38: The clinical significance of GLUT1 expression in gastrointestinal stromal tumor

Background: Gastrointestinal stromal tumor (GIST) is, though it is as rare as its incidence is about 7 to 20 cases per million population per year, one of the most common non-epithelial malignant tumors of the gastrointestinal tract. Recently it was reported that Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) is useful in diagnosis and evaluation of malignant grade of GIST. At the same time, expression of glucose transporter 1 (GLUT1), which is a membranous protein facilitates the transport of glucose across the plasma membranes into cells, was reported to be correlated with maximum standardized uptake value (SUVmax) in PET/CT and malignant grade of various kinds of cancers. In this study, the correlation of GLUT1 expression with malignant grade in GIST was investigated.

Methods: We evaluated the protein expression of GLUT1 in immunohistochemistry in the surgically resected specimens in 67 GIST cases, and analyzed the correlation of the other clinicopathological factors.

Results: The number of cases in which the expression of GLUT1 judged to be confirmed in immunohistochemistry was 45 (73.7%). GLUT1 expression group had significantly higher preoperative SUVmax in PET/CT than GLUT1 non-expression group (p = 0.03), had larger tumors in diameter (p = 0.015), and was more malignant by Fletcher classification (p<0.01). Additionally, tumor rupture rate tended to be higher in GLUT1 expression group, though there is no tendency of the correlation with tumor necrosis. Eventually, relapse free survival, as not significantly, tend to be shorter in GLUT1 expression group.

Conclusion: In our study, expression of GLUT1 is correlated with malignant grade in GIST. GLUT1 expression might be a phase of higher metabolic and malignant activity of GIST cells. GLUT1 might be a useful prognostic marker in GIST cases.

Citation Format: Daisuke Kuroda, Junji Kurashige, Masaaki Iwatsuki, Tsugio Eto, Yuka Tamaoki, Mayuko Ohuchi, Kenichi Nakamura, Ryuma Tokunaga, Hironobu Shigaki, Hiromitsu Hayashi, Takatsugu Ishimoto, Yoshifumi Baba, Yasuo Sakamoto, Naoya Yoshida, Hideo Baba. The clinical significance of GLUT1 expression in gastrointestinal stromal tumor. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 38.

Abstract 5074: The impact of RHOA mutation related with invasion in diffuse-type gastric cancer

Background: Gastric cancer (GC) is one of the most general causes of cancer related death, especially in East Asia and is divided into intestinal type and diffuse type by Lauren classification. Five-year survival rate of diffuse-type gastric cancer (DGC) is poor compared with the Intestinal-type gastric cancer (IGC). To improve the prognosis of advanced GC patients, molecularly targeted drugs against gastric cancer have been developed including trastuzumab, a recombinant monoclonal antibody against HER2. But, HER2 gene amplification rate is about 10% in DGC, though 30% in IGC. DGC-specific molecular carcinogenic mechanisms have still remained unclear. Recently, some studies revealed RHOA mutations occur specifically in DGCs. They also demonstrated that proliferation and organoid formation are related with RHOA mutations in DGC. However, there is no report in terms of the functional difference among RHOA mutational hotspots in DGCs.

Aim: To investigate the functional difference among RHOA mutations and the impact on prognosis in DGCs.

Method: We prepared RHOA wild type vector and three RHOA mutation vectors (G17E, Y42C, and L57V). We introduced these RHOA vectors into DGC cell lines and examined invasion assay. In invasion assay of RHOA introduced DGC cell lines, we conducted experiments with or without TGFβ1 (RHOA activator).

Result: RHOA overexpression in DGC cells did not exhibit significant upregulation of invasiveness compared with empty vector introduced DGC cells. However, all RHOA mutation introduced DGC cells acquired more significant elevation of invasiveness as well as wild type after treatment with TGF-β1. (wild:p = 0.0001, G17E:p = 0.0001, Y42C:p = 0.0001, L57V: p<0.0001). Among these RHOA mutations, G17E and Y42C RHOA mutation introduced DGC cells exhibited remarkable upregulation of invasiveness compared with wild type RHOA introduced DGCs (G17E:p<0.0001 Y42C:p = 0.009).These results indicate particular RHOA mutations cause higher response to TGF-β1 compared with wild type.

Conclusion: We evaluated the functional difference among RHOA mutations in DGC. These results suggest particular RHOA mutation might have possibility to cause invasion in DGCs. A large cohort study across RHOA mutations in DGCs will be required to identify the clinical significance between hotspot RHOA mutations.

Citation Format: Tsugio Eto, Takatsugu Ishimoto, Daisuke Izumi, Yuka Tamaoki, Daisuke Kuroda, Kota Arima, Takayoshi kaida, Mayuko Ohuchi, Kenichi Nakamura, Ryuma Tokunaga, Hironobu Shigaki, Junji Kurashige, Masaaki Iwatsuki, Yoshifumi Baba, Yasuo Sakamoto, Naoya Yoshida, Hideo Baba. The impact of RHOA mutation related with invasion in diffuse-type gastric cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5074.

Prognostic and clinical impact of PIK3CA mutation in gastric cancer: pyrosequencing technology and literature review

BACKGROUND

Phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations that activate the PI3K/AKT signaling pathway have been observed in several types of carcinoma and have been associated with patient prognosis. However, the significance of PIK3CA mutations in gastric cancer remains unclear. This retrospective study investigated the relationship between PIK3CA mutations and clinical outcomes in patients with gastric cancer. Additionally, we reviewed the rate of PIK3CA mutations in gastric cancer and the association between PIK3CA mutations and prognosis in human cancers.

METHODS

The study included 208 patients with gastric cancer who underwent surgical resection at Kumamoto University Hospital, Japan, between January 2001 and August 2010. Mutations in PIK3CA exons 9 and 20 were quantified by pyrosequencing assays.

RESULTS

PIK3CA mutations were detected in 25 (12 %) of the 208 patients. Ten patients had c.1634A > G (p.E545G), 10 had c.1624G > A (p.E542K), 13 had c.1633G > A (p.E545K), nine had c.3139C > T (p.H1047R), and 1 had c.3140A > G (p.H1047Y) mutations. PIK3CA mutations were not significantly associated with any clinical, epidemiologic, or pathologic characteristic. Kaplan-Meier analysis showed no significant differences in disease-free survival (log rank P = 0.84) and overall survival (log rank P = 0.74) between patients with and without PIK3CA mutations.

CONCLUSIONS

Mutations in PIK3CA did not correlate with prognosis in patients with gastric cancer, providing additional evidence for the lack of relationship between the two.

Orbital Apex Syndrome Caused by Invasive Aspergillosis as an Adverse Effect of Systemic Chemotherapy for Metastatic Colorectal Cancer: a Case Report

Continuous therapy with cytotoxic drugs suppresses humoral immune function and may result in local infection. We present a case of orbital apex syndrome caused by Aspergillus infection during chemotherapy for metastatic colorectal cancer. A 74-year-old man with colorectal liver metastases under long-term continuous systemic chemotherapy presented with painful, progressive orbital apex syndrome. Magnetic resonance imaging disclosed a small enhancing lesion around the right ethmoid sinus. We initially diagnosed colorectal cancer metastasis and he underwent biopsy via the endoscopic endonasal transethmoid approach. However, pathological examination of the cultured specimen revealed Aspergillus fumigatus. The patient was treated with voriconazole and the orbital apex syndrome resolved after 1 month. Orbital aspergillosis is a life-threatening disease and should be listed as a differential diagnosis of uncommon local infections during continuous chemotherapy.

Radiofrequency ablation for pulmonary metastases from esophageal squamous cell carcinoma

138

Background: Radiofrequency ablation (RFA) is increasingly being used for the treatment of intrathoracic malignancies. Although RFA has been found to be promising in the treatment of lung metastases from some types of neoplasms, little is known concerning its clinical significance in the treatment of pulmonary metastasis from esophageal squamous cell carcinoma (ESCC). This retrospective study evaluated the feasibility, safety, and effectiveness of computed tomography-guided RFA for pulmonary metastasis from ESCC. Methods: Of 322 patients with ESCC underwent esophagectomy at Kumamoto University Hospital between January 2007 and May 2015, 23 cases had pulmonary recurrence. Selection criteria for CT-guided RFA for pulmonary metastasis were as follows: (i) there were no distant metastases except for pulmonary lesions, when there were extrapulmonary recurrences that had to be controlled by additional therapies; (ii) there were up to three pulmonary tumors; (iii) the number of pulmonary tumors did not increase over a certain period while receiving pre-RFA chemotherapy; (iv) the metastatic lesions were not adjacent to major pulmonary vessels, major bronchi, or the heart. 17 patients who underwent CT-guided RFA for metachronous pulmonary metastasis from ESCC were included in this study. Results: Correct placement of the ablation device into the target tumor proved to be feasible in all tumors (100%). The mean visual analog scale score, with values that ranged from 0 (no pain) to 10 (worst pain possible), was 1. This suggested that this procedure was well tolerated. No procedure-related deaths occurred. A pneumothorax needing drainage was a major complication in two patients. 6 patients died of recurrent disease. The predicted 1- and 2-year overall survival rates after lung RFA were 78.8% and 46.7%, respectively. Conclusions: Percutaneous computed tomography-guided RFA yielded relatively high levels of local control in patients with pulmonary metastases from ESCC and was associated with an acceptable level of complications. It was concluded that a prospective study will be necessary to evaluate the effectiveness of a combination of systemic therapy and RFA for ESCC lung metastases.

The Prognostic Significance of Histone Lysine Demethylase JMJD3/KDM6B in Colorectal Cancer

BACKGROUND

Jumonji-domain containing 3 (JMJD3) affects transcriptional regulation by demethylating lysine 27 residue of histone 3. We investigated its function and prognostic significance in colorectal cancer (CRC).

METHODS

The influence of JMJD3 on cell proliferation was assessed using quantitative RT-PCR and western blot on the downstream target gene of JMJD3, in knock-down (KD) experiments and clinical samples from 151 CRC patients.

RESULTS

Cells with KD JMJD3 significantly increased proliferation through cell cycle progression and apoptosis suppression. Expression of P15INK4B was remarkably decreased in KD JMJD3 cells; and JMJD3 expression strongly correlated with p15INK4B expression in clinical CRC samples (P < 0.001, r = 0.566). Low JMJD3 also was an independent predictor of poor prognosis (P = 0.042) in surgically resected CRC patients.

CONCLUSIONS

JMJD3 has prognostic significance in CRC and mediates p15INK4B expression. These results imply that elucidation of the JMJD3 role may lead to a new therapeutic approach for CRC patients.

Cryptogenic repetitive severe colitis after ileostomy closure

We describe a case of cryptogenic repetitive severe colitis after ileostomy closure. A 50-year-old man was referred to our hospital for treatment of advanced rectal cancer. The patient underwent laparoscopic intersphincteric resection combined with synchronous partial liver resection for colorectal liver metastasis detected intraoperatively and construction of a diverting ileostomy. Ileostomy closure was performed 3 months later. Five days following ileostomy closure, the patient complained of lower abdominal pain and developed multiple daily fever episodes. Colonoscopy revealed multiple ulcers in the sigmoid colon and rectum. Because symptoms did not improve despite fasting and antibiotic therapy, ileostomy reconstruction was performed. Re-closure was performed 6 months after the previous ileostomy closure; however, severe colitis recurred with similar symptoms, and construction of a colostomy at the transverse colon was then performed. Despite varied examinations, the cause of the colitis was not identified. To our knowledge, there are no previous reports of repetitive severe colitis after ileostomy closure.

Suppressor microRNA-145 Is Epigenetically Regulated by Promoter Hypermethylation in Esophageal Squamous Cell Carcinoma

BACKGROUND/AIM

DNA methylation is a common epigenetic change in cancer. However, microRNA (miRNA) regulation by epigenetic alteration, especially CpG island hypermethylation, remains poorly understood in esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

miRNAs which were up-regulated after de-methylation with 5-aza-2'-deoxycytidine (5-AZA) were analyzed using the Human miFinder 384HC miScript miRNA PCR Array. The DNA methylation level was evaluated by bisulfite-pyrosequencing assay.

RESULTS

In two of the cell lines, 20 miRNAs, including miR-145-5p, were found to be up-regulated by more than three-fold after 5-AZA treatment. The miRNA-145 promoter was significantly more hypermethylated in the cancer tissues than in matched normal adjacent esophageal epithelial mucosa (p=0.0042; paired t-test). Moreover, the miRNA-145-5p expression levels were significantly lower in cancerous tissues (p=0.0024).

CONCLUSION

miRNA-145 expression in ESCC seems to be regulated by hypermethylation of the miRNA-145 promoter region.

Carbohydrate antigen 19-9 is a useful prognostic marker in esophagogastric junction adenocarcinoma

The incidence rate of esophagogastric junction (EGJ) adenocarcinoma has been rapidly increasing worldwide. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are major serum tumor markers in gastrointestinal cancers. However, the role of these markers in EGJ adenocarcinoma has not been thoroughly investigated. A total of 211 patients with EGJ adenocarcinoma who underwent surgery or endoscopic submucosal dissection at two academic institutions, Kumamoto University Hospital or Kyushu University Hospital between January 1996 and March 2014, were eligible for this study. Serum CEA and CA19-9 were examined within 1 month before resection. The cut-off values for CEA and CA19-9 were set at 5.0 ng/mL and 37 U/mL, respectively. The clinicopathological features and prognostic roles of the markers were examined using univariate and multivariate analyses. The positive ratios for preoperative CEA (>5.0 ng/mL) and CA19-9 (>37 U/mL) were 20.3% and 12.9%, respectively. The positive ratio of CEA and CA19-9 was significantly higher in patients with tumors invading muscular or deeper layers (P = 0.002 and <0.001, respectively). Cox proportional hazards model revealed that CA19-9 positivity, but not CEA positivity, was an independent prognostic factor in patients with EGJ adenocarcinoma for cancer-specific survival (multivariate hazard ratio [HR] = 3.89, 95% confidence interval [CI] 1.41-10.33; P = 0.010) and overall survival (multivariate HR = 2.43, 95% CI 1.03-5.35; P = 0.043). Preoperative serum CA19-9 is a useful prognostic marker in patients with EGJ adenocarcinoma.

Prognostic Impact of Visceral Fat Amount and Branched-Chain Amino Acids (BCAA) in Hepatocellular Carcinoma

BACKGROUND

Dysregulation of lipid and amino acid metabolism in patients with liver diseases results in obesity-related carcinogenesis and decreased levels of branched-chain amino acids (BCAA), respectively. This study assessed the clinical and prognostic impact of visceral fat amount (VFA) and its association with amino acid metabolism in patients with hepatocellular carcinoma (HCC).

METHODS

In this study, 215 patients who underwent hepatic resection for HCC were divided into two groups based on VFA criteria for metabolic abnormalities in Japan. Computed tomography was used to measure VFA at the third lumbar vertebra in the inferior direction.

RESULTS

Of the 215 patients, 132 had high and 83 had low VFA. High VFA was significantly associated with older age and higher body mass index (BMI), subcutaneous fat amount, and BCAA, but not with liver function, nutrient status, or tumoral factors. VFA was positively correlated with BMI (P < 0.0001; r = 0.63) and BCAA levels (P < 0.0001; r = 0.29). Overall survival was significantly greater in the high than in the low VFA group (P = 0.002). Multivariate analyses showed that high VFA [hazard ratio (HR) 7.06; P = 0.024] and neutrophil/lymphocyte ratio (HR 3.47; P = 0.049) were significantly prognostic of overall survival, whereas subcutaneous fat amount, BMI, BCAA, serum albumin, and prognostic nutritional index were not.

CONCLUSIONS

High VFA was associated with a high BCAA level, with high VFA prognostic of improved overall survival in Japanese patients with HCC.

Abstract 2277: Prognostic impact of enhancer of zeste homologue 2 (EZH2) in patients underwent hepatectomy for colorectal liver metastases who received preoperative oxaliplatin-based chemotherapy

Purpose: Colorectal cancer (CRC) is the second most commonly diagnosed cancer and the third leading cause of cancer mortality in Japan. Almost 15% and 10% of patients with CRC are diagnosed with synchronous and metachronous liver metastasis, respectively. In the last decade, the therapeutic strategies including chemotherapy and molecular targeted therapy have improved. However, the prognosis of patients with CRC remains poor because of their acquirement of chemoresistance.

Previous studies have shown that enhancer of zeste homologue 2 (EZH2) is associated with proliferation of various cancers. EZH2 is the catalytic subunit of Polycomb repressive complex2 (PRC2) which catalyzes the methylation of lysine 27 on histone H3 (H3K27), leading to repress the transcription of tumor-suppressor genes. In addition, high EZH2 expression is associated with the resistance to cisplatin in non-small cell lung carcinoma. However, the association between the resistance to oxaliplatin and the expression of EZH2 is unrevealed.

The aim of this study is to investigate the correlation between the expression of EZH2 and response to oxaliplatin-based chemotherapy as well as survival of patients with colorectal liver metastasis (CRLM).

Experimental Design: Sixty-one patients who underwent first-line oxaliplatin-based chemotherapy before resection of CRLM were enrolled in this study. Immunohistochemistry of EZH2 was performed, and then the correlation between response to chemotherapy and survival was evaluated.

Results: Immunohistochemistry revealed 38 patients (62.3%) with high EZH2 expression, and 23 patients (37.7%) with low EZH2 expression. Of the 38 patients with EZH2 high expression, 15 patients (39.5%) responded to oxaliplatin-based chemotherapy with either complete response or partial response. Of the 23 patients with low EZH2 expression, 14 patients (60.9%) exhibited a response to chemotherapy. There was significant difference in response to oxaliplatin-based chemotherapy between high and low EZH2 expression patients (p = 0.04). Univariate survival analysis indicated that patients with high EZH2 expression had a lower overall survival than those with low EZH2 expression. Moreover, multivariate Cox regression analysis revealed that high EZH2 expression was an independent prognostic factor for overall survival. Kaplan-Meier survival curves also confirmed that high EZH2 expression correlates with poor prognosis in patients who underwent hepatectomy for CRLM.

Conclusions: Our results indicated that prognosis of patients with high EZH2 expression who received preoperative oxaliplatin-based chemotherapy and underwent hepatectomy for CRLM was worse than those with low EZH2 expression. EZH2 may be a predictive factor for oxaliplatin-based chemotherapy response and overall survival in patients with CRLM.

Citation Format: Mayuko Ohuchi, Yasuo Sakamoto, Ryuma Tokunaga, Kenichi Nakamura, Yuki Kiyozumi, Daisuke Izumi, Keisuke Kosumi, Kazuto Harada, Junji Kurashige, Yukiharu Hiyoshi, Shiro Iwagami, Yoshifumi Baba, Yuji Miyamoto, Naoya Yoshida, Hideo Baba. Prognostic impact of enhancer of zeste homologue 2 (EZH2) in patients underwent hepatectomy for colorectal liver metastases who received preoperative oxaliplatin-based chemotherapy. [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 2277. doi:10.1158/1538-7445.AM2015-2277

Abstract 3132: Suppressor microRNA-145 is epigenetically regulated by promoter hypermethylation in esophageal squamous cell carcinoma

Objectives: DNA methylation change is common epigenetic change in cancer. The promoter CpG island hypermethylation is one of the most common mechanisms by which tumor suppressor miRNAs are inactivated during tumorigenesis. However, microRNA (miRNA) regulations by epigenetic alteration, especially CpG island hypermethylation, have been not yet substantially understood in esophageal squamous cell carcinoma (ESCC). Therefore, we performed the screening of miRNAs which should be up-regulated after 5-aza-20-deoxycytidine (5-Aza) treatment in ESCC cell lines, then from up-regulated miRNAs, we focused on a suppressor miR-145-5p. Since miRNA-145-5p attracts an increasing attention as a tumor suppressor miRNA in ESCC, we evaluated miRNA-145 promoter methylation level and miRNA-145-5p expression level in ESCC

Methods: The screening of miRNAs was analyzed using the Human miFinder 384HC miScript miRNA PCR Array. DNA methylation level was evaluated by using bisulfite-pyrosequencing assay. miRNA expression level was evaluated by using TaqMan quantitative real-time reverse transcription-polymerase chain reaction. miRNA-145-5p expression and its promoter methylation levels were quantified in 15 ESCC and matched 15 normal adjacent esophageal mucosa frozen tissues and in 105 formalin-fixed paraffin-embedded ESCC tissues between September 2009 and June 2012 at Kumamoto University Hospital (Kumamoto, Japan).

Results Twenty miRNAs including miR-145-5p were up-regulated more than 3 fold in both TE-1 and KYSE30 after 5-Aza treatment by using miRNA PCR array analysis. After 5-Aza treatment, miRNA-145 promoter methylation level decreased and the expression level of miRNA-145-5p was significantly enhanced in 8 of 10 ESCC cell lines. The miRNA-145-5p expression levels in the cancer tissues (mean ± SD; 6.37 ± 1.47) was significantly lower than in matched normal adjacent esophageal epithelial mucosa (235.6 ± 61.9) (p = 0.0024). Moreover, the miRNA-145 promoter in the cancer tissues (41.4 ± 3.05) was significantly hyper methylated than in matched normal adjacent epithelial mucosa (mean; 57.1 ± 3.36) (p = 0.0042 by the paired t test). In 105 ESCC samples, the “high miRNA-145-5p expression level group” and “low miRNA-145-5p expression level group” experienced similar overall survival (Kaplan-Meier analysis; log rank p = 0.58) and disease-free survival (Kaplan-Meier analysis; log rank p = 0.80)

Conclusions: Our results suggest that hypermethylation of the miRNA-145 promoter region might regulate miRNA-145 expression in ESCC. This is the first report on the epigenetic regulation of miRNA-145 in ESCC. However, further work is needed to assess our results and to make them more definite.

Citation Format: kazuto harada, Yoshifumi Baba, Keisuke Kosumi, Ryuma Tokunaga, Daisuke Izumi, Mayuko Ouchi, Kennichi Nakamura, Yuki Kiyozumi, Junji Kurashige, Yukiharu Hiyoshi, Shiro Iwagami, Yuji Miyamoato, Yasuo Sakamoto, Naoya Yoshida, Masayuki Watanabe, Hideo Baba. Suppressor microRNA-145 is epigenetically regulated by promoter hypermethylation in 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 3132. doi:10.1158/1538-7445.AM2015-3132

Abstract 4829: The clinical significance of APOBEC3B in esophageal squamous cell carcinoma

Backgrounds:

APOBEC3B is one of the cytidine deaminase apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC3) family, and APOBEC3B can induce transitions into target DNA through cytidine deamination. To date, APOBEC attracts attention due to its functioning as part of the innate immune system by protecting against retrovirus and retrotransposon propagation. And, recent studies revealed that APOBEC3B might contribute to several mutations in various types of cancers, including cervical, breast, head and neck, lung, bladder cancers, and APOBEC3B may have a crucial role in carcinogenesis and cancer development. Esophageal squamous cell carcinoma (ESCC) reportedly has several molecular features, and we recently reported that long interspersed nucleotide element 1 (LINE-1) hypomethylation might contribute to poor prognosis and PIK3CA mutation to good prognosis in ESCC. However, there is no report which investigates the relationship between APOBEC3B expression, clinical and pathological features in ESCC.

Methods:

We compared the expression of APOBEC3B mRNA between cancer tissues and noncancerous esophageal mucosae by using GEO profiles and ESCC frozen tissues. In addition, we investigated the relationships between the APOBEC3B immunohistochemical expression levels, clinical and pathological features, and molecular features including p53 expression, global DNA methylation level and PIK3CA mutation. We quantified LINE-1 retrotransposons, of which a substantial portion of the human genome consists, to assess global DNA methylation.

Results:

APOBEC3B expression at mRNA level was significantly higher in cancer tissues than in noncancerous esophageal mucosae (P = 0.050). In the immunohistochemical study, the APOBEC3B expression of ESCC was stronger than that of noncancerous esophageal mucosa. We found no significant correlation of APOBEC3B expression with tumor size, T stage, N stage and pStage (P = 0.74, P = 0.32, P = 0.19, P = 0.23, respectively). There were no correlation between APOBEC3B expression and prognosis. There was no correlation between APOBEC3B expression and p53 expression (P = 0.23), but, interestingly, a high expression of APOBEC3B was significantly associated with LINE-1 hypomethyaltion and PIK3CA mutation (P = 0.029, P = 0.020).

Conclusions:

APOBEC3B high expression had significant relationships with LINE-1 hypomethylation and PIK3CA mutation, supporting that APOBEC3B might contribute to malignant behavior through the molecular features in ESCC.

Citation Format: Keisuke Kosumi, Yoshifumi Baba, Takatsugu Ishimoto, Kenichi Nakamura, Kazuto Harada, Mayuko Ohuchi, Yuki Kiyozumi, Daisuke Izumi, Ryuma Tokunaga, Junji Kurashige, Ryuichi Karashima, Yukiharu Hiyoshi, Shiro Iwagami, Yasuo Sakamoto, Yuji Miyamoto, Naoya Yoshida, Masayuki Watanabe, Hideo Baba. The clinical significance of APOBEC3B in 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 4829. doi:10.1158/1538-7445.AM2015-4829

Abstract 568: Fibroblast growth factor receptors 2 is a novel therapeutic target in esophagogastric junction adenocarcinoma

Background: The prognosis of esophagogastric junction (EGJ) adenocarcinoma remains poor, though it is increasing worldwide. The fibroblast growth factor receptors (FGFRs) play critical roles in various human cancers, especially FGFR2 amplification has been implicated as a key genetic alteration in EGJ adenocarcinoma. In this study, we confirmed that FGFR2 can be a therapeutic target for EGJ adenocarcinoma.

Methods: Utilizing 200 cases with EGJ adenocarcinoma (Siewert types I-III), FGFR2 copy number was assayed by Real-time PCR (using RNaseP as a referent), and FGFR2 expression was detected by immunohistochemistry. We examined whether FGFR2 amplification correlates with FGFR2 expression. The associations between FGFR2 expression and clinicopathological factors, and prognostic impact of FGFR2 expression were examined. We investigated the role of FGFR2 in cell proliferation, invasion, apoptosis and cell cycle, using OACM 5.1C (FGFR2 overexpressing cell line), by siRNA technique targeting FGFR2.

Results: FGFR2 amplification was detected in 33 (22%) cases, and FGFR2 expression was observed in 112 (58%) cases. FGFR2 amplification significantly correlated with FGFR2 expression (p = 0.045). FGFR2 expression was significantly associated with tumor depth of invasion, nodal involvement, distant metastasis, lymphatic invasion, and vascular invasion (all, p &lt; 0.001). In survival analysis, tumors harboring FGFR2 expression experienced significantly unfavorable outcome (p = 0.039). We observed that si-FGFR2 significantly suppressed phosphorylation of Akt and Erk, resulting in suppressing cell proliferation and invasion; and inducing apoptosis and cell-cycle arrest (p&lt;0.001). We also confirmed that FGF 7 promoted the proliferation and AZD4547 inhibited the proliferation through RAS-ERK and PI3K-AKT pathways.

Conclusion: FGFR2 can be a therapeutic target for EGJ adenocarcinoma.

Citation Format: Ryuma Tokunaga, Yu Imamura, Kenichi Nakamura, Takatsugu Ishimoto, Shiro Iwagami, Junji Kurashige, Daisuke Izumi, Keisuke Kosumi,, Takaaki Higashi, Katsunobu Taki, Yukiharu Hiyoshi, Yoshifumi Baba, Yasuo Sakamoto, Yuji Miyamoto, Naoya Yoshida, Saeki Hiroshi, Eiji Oki, Yoshihiko Maehara, Hideo Baba. Fibroblast growth factor receptors 2 is a novel therapeutic target in esophagogastric junction adenocarcinoma. [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 568. doi:10.1158/1538-7445.AM2015-568

Abstract 423: CXCL12/CXCR4 activation by cancer-associated fibroblasts promotes integrin β1 clustering and invasive ability in gastric cancer

Purpose: Gastric cancer (GC) is the fourth most commonly diagnosed cancer and the third leading cause of cancer mortality worldwide. The range of therapeutic strategies available for the treatment of GC has improved in recent decades. However, the prognosis of patients with advanced GC remains poor even after curative resection, mainly because of recurrence, such as peritoneal dissemination and liver metastases. Previous studies have shown that the interaction between cancer cells and their surrounding stroma plays an important role in tumor development. Cancer-associated fibroblasts (CAFs) have been reported to be involved in invasion and metastasis in cancers, including gastric cancer (GC), via their stimulation of CXCL12/CXCR4 signaling. However, the mechanisms underlying the tumor-promoting effects and the potential of developing therapeutic targets using CXCL12/CXCR4 signaling activated by CAFs are not fully understood.

Experimental Design: We first analyzed CXCL12 expression in resected GC tissues of 110 patients by immunohistochemistry (IHC). We next established primary normal fibroblasts (NFs) and CAFs from GC tissues and examined the functional differences between these primary fibroblasts using co-culture assays with GC cell lines. Furthermore, we evaluated the efficacy of a CXCR4 antagonist (AMD3100) and a FAK inhibitor (PF-573,228) on the invasive ability of GC cells.

Results: We determined that high CXCL12 expression was significantly associated with larger tumor size, deeper tumor depth, lymphatic invasion and poor prognosis in GC. We established new primary CAFs and their adjacent NFs from resected stomach tissue in GC patients. We evaluated the change in mobility during the direct co-culture of GC cells and fibroblasts using real-time imaging. The motility of GC cells significantly increased upon direct co-culture with CAFs more than it did in cells with NFs compared with control RPMI during observation for 24 hours. The motility of GC cells with CAFs was effectively suppressed by AMD 3100 compared to GC cells with NFs. CXCL12/CXCR4 activation by CAFs mediated the clustering of integrin β1 on the cell surface and promoted the invasive ability of GC cells. Notably, AMD3100 was more efficient at inhibiting GC cell invasion through the suppression of integrin β1/FAK signaling compared with PF-573,228.

Conclusions: These results suggest that CXCL12 derived from CAFs promotes invasive ability by enhancing the clustering of integrin β1 in GC cells and results in GC progression. The current data provide evidence that CXCL12/CXCR4 inhibition by AMD3100 is more efficient in suppressing GC cell invasion by not only inhibiting intracellular signaling but also by attenuating the interaction between cancer cells and the extracellular matrix compared with PF-573,228. Our present study represents the rationale for establishing a therapeutic strategy targeting CXCL12/CXCR4 signaling.

Citation Format: Daisuke Izumi, Takatsugu Ishimoto, Hidetaka Sugihara, Eto Kojiro, Hiroshi Sawayama, Keisuke Miyake, Yuki Kiyozumi, Keisuke Kosumi, Ryuma Tokunaga, Kazuto Harada, Junji Kurashige, Masaaki Iwatsuki, Shiro Iwagami, Yoshifumi Baba, Yasuo Sakamoto, Yuji Miyamoto, Naoya Yoshida, Masayuki Watanabe, Hideo Baba. CXCL12/CXCR4 activation by cancer-associated fibroblasts promotes integrin β1 clustering and invasive ability in gastric cancer. [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 423. doi:10.1158/1538-7445.AM2015-423

Negative Impact of Skeletal Muscle Loss after Systemic Chemotherapy in Patients with Unresectable Colorectal Cancer

Background

Skeletal muscle depletion (sarcopenia) is closely associated with limited physical ability and high mortality. This study evaluated the prognostic significance of skeletal muscle status before and after chemotherapy in patients with unresectable colorectal cancer (CRC).

Methods

We conducted a retrospective analysis of 215 consecutive patients with unresectable CRC who underwent systemic chemotherapy. Skeletal muscle cross-sectional area was measured by computed tomography. We evaluated the prognostic value of skeletal muscle mass before chemotherapy and the rate of skeletal muscle change in cross-sectional area after chemotherapy.

Results

One-hundred-eighty-two patients met our inclusion criteria. There were no significant differences in progression-free survival (PFS) or overall survival (OS) associated with skeletal muscle mass before chemotherapy. However, 22 patients with skeletal muscle loss (>5%) after chemotherapy showed significantly shorter PFS and OS compared with those without skeletal muscle loss (PFS, log-rank p = 0.029; OS, log-rank p = 0.009). Multivariate Cox regression analysis revealed that skeletal muscle loss after chemotherapy (hazard ratio, 2.079; 95% confidence interval, 1.194–3.619; p = 0.010) was independently associated with OS.

Conclusions

Skeletal muscle loss after chemotherapy was an independent, negative prognostic factor in unresectable CRC.

Neutrophil/lymphocyte ratio predicts the prognosis in esophageal squamous cell carcinoma patients

PURPOSE

As cancer advances, changes in the systemic inflammatory response alter the relative levels of circulating white blood cell types and may contribute to the progression and outcomes of cancer. The aim of the current study is to clarify the impact of the preoperative neutrophil/lymphocyte ratio (NLR) on the prognosis and whether clinical and pathological features modify the influence of the NLR on the prognosis of esophageal squamous cell carcinoma (ESCC) patients.

METHODS

We retrospectively analyzed the mortality hazard ratios (HRs), including the preoperative NLR, obtained from data for 283 ESCC patients undergoing resection in the period from 2005 to 2011, adjusting for clinical and pathological features.

RESULTS

A high NLR was associated with a significantly shorter overall survival (p = 0.0018) and cancer-specific survival (p = 0.0097). In the multivariate Cox model, we confirmed that the NLR was an independent prognostic marker for both overall survival (p = 0.0081) and cancer-specific survival (p = 0.028). The outcomes were not significantly modified by other diagnostic factors, including the tumor stage, in the survival analysis.

CONCLUSIONS

The preoperative NLR is significantly associated with a poor prognosis in patients with ESCC, suggesting the utility of NLR as a cost-effective and broadly available independent prognostic marker of ESCC.

Low Visceral Fat Content is Associated with Poor Prognosis in a Database of 507 Upper Gastrointestinal Cancers

BACKGROUND

Excess visceral adipose tissue may promote cancer development and progression via an obesity-related metabolic derangements, including adipocytokine-related inflammation, insulin resistance, and hypoxia. The relationship between visceral fat content and patient prognosis has been reported in some types of cancers, but not in the upper gastrointestinal cancer. The purpose of this retrospective study was to investigate the relationship between visceral fat status and clinical outcome in patients with upper gastrointestinal cancers (esophageal cancer and gastric cancer) treated by surgical resection.

METHODS

This retrospective study was conducted in a single, academic hospital in Kumamoto, Japan, and involved 507 patients with upper gastrointestinal cancers between April 2005 and December 2010. Preoperative visceral fat content was quantified by radiologic measures using standard computed tomography scans.

RESULTS

Higher visceral fat mount was correlated with male sex, presence of preoperative comorbidity, absence of preoperative therapy, low tumor depth, low tumor stage, and gastric cancer. Compared to high visceral fat cases, low visceral fat cases experienced a higher overall mortality rate [log-rank p = 0.0050; univariate hazard ratio (HR) = 1.73, 95 % confidence interval (CI) 1.16-2.54; p = 0.0075; multivariate HR 1.57; 95 % CI 1.02-2.37; p = 0.031]. Interestingly, the influence of low visceral fat on patient outcome was modified by age at surgery (p for interaction = 0.036); low visceral fat was associated with a poor prognosis, especially in elderly patients (log-rank p < 0.0001).

CONCLUSION

Visceral fat content in the upper gastrointestinal cancers was associated with a poor prognosis, thus suggesting that it has potential for use as a prognostic biomarker.

Usefulness of modified PERCIST for defining response of neoadjuvant chemotherapy in esophageal cancer

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Background: It is sometimes difficult to exactly measure maximum diameters of tumor after chemotherapy in esophageal cancer. Richard et al. proposed PET Response Criteria in Solid Tumor (PERCIST) for assessing response of tumor after chemotherapy by PET in 2009. The first purpose is to investigate the utility of PERCIST after neoadjvant chemotherapy in esophageal cancer. The second purpose is to clarify the utility of modified PERCIST of which we use the SUV of normal (non-cancerous) esophagus as a reference of comparison for diagnosing complete response (CR) instead of the right lobe liver SUV. Methods: The clinicopathological data of the 71 esophageal cancer patients who received neoadjuvant chemotherapy (DCF) and underwent curative resection from November 2008 to May 2012 were collected. Among them, we compared pathological grade with PERCIST of the 26 esophageal cancer patients who were examined by PET before and after chemotherapy. Furthermore we investigated which reference of comparison is appropriate for diagnosing complete response between the right lobe of liver (L group) and normal esophagus (E group). Results: We could measure the tumor size of all cases after chemotherapy by PERCIST although 6 cases could not be assessed by RECIST. All of the 6 cases which were diagnosed as stable disease or progressive disease by PERCIST were pathological grade1a. The cases of complete response are 7 cases in L group and 3 cases in esophageal cases. Among the complete response cases in L group, 1 case were pathological grade1 a and 2 cases were grade 2 although all the complete response cases in E group were pathological grade 3. One case of L group relapsed after curative resection although there was no recurrent case in E group. Conclusions: The esophageal cancer patients often have history of massive alcohol intake or liver damage caused by viral hepatitis or fatty liver. Although PERCIST is useful for evaluating the effect of neoadjuvant chemotherapy of esophageal cancer, it is better to use normal esophagus as a comparison standard for diagnosing complete response.

Sarcopenia is a Negative Prognostic Factor After Curative Resection of Colorectal Cancer

BACKGROUND

Skeletal muscle depletion (sarcopenia) is closely associated with limited physical ability and high mortality. This study was performed to evaluate the prognostic significance of skeletal muscle depletion in patients with resectable stage I-III colorectal cancer (CRC).

METHODS

We conducted a retrospective analysis of 220 consecutive patients with stage I-III CRC who underwent curative resection. The skeletal muscle cross-sectional area was measured by preoperative computed tomography. The lowest sex-specific quartile of skeletal muscle mass was classified as sarcopenia. Factors contributing to recurrence-free survival (RFS) were analyzed by univariate and multivariate Cox proportional hazard models.

RESULTS

Of 220 patients who met our inclusion criteria, 55 (25 %) had sarcopenia. The median follow-up duration was 41.4 months. Patients with sarcopenia were younger and had higher carcinoembryonic antigen levels than patients without sarcopenia. RFS and overall survival (OS) were significantly shorter in patients with sarcopenia than those without (5-year RFS, 56 vs. 79 %, log-rank p = 0.006; 5-year OS, 68 vs. 85 %, log-rank p = 0.015). Multivariate Cox regression analysis revealed that sarcopenia was independently associated with shorter RFS (hazard ratio [HR] 2.176; 95 % confidence interval [CI] 1.200-3.943; p = 0.010) and OS (HR 2.270; 95 % CI 1.147-4.494; p = 0.019). The influence of sarcopenia on patient outcome was modified by age at surgery (p value for interaction = 0.026); sarcopenia was associated with a poor prognosis, especially in young patients (log-rank p < 0.001).

CONCLUSIONS

Sarcopenia negatively impacts survival in patients undergoing curative resection for stage I-III CRC.

Abstract 4732: Vasohibine-1 negative and EZH2 positive may predict the prognosis of cholangiocarcinoma

Background: Vasohibin-1 (VASH1) is isolated as an endogenous angiogenesis inhibitor produced by the vascular endothelium, and the status of VASH1 expression has been documented in various cancer prognosis. Some reports shows that VASH1 was negatively regulated by enhancer of zeste homolog 2 (EZH2) epigenetically. The aim of this study was to assess the relationship between EZH2 and VASH1, and the prognostic value of this two molecules in intrahepatic cholangiocarcinoma (ICC) patients.

Method: We examine 47 cases of intrahepatic cholangiocarcinoma to which the R0 liver resection had been performed by our department between 1993 years and 2010. Immunohistochemical staining of VASH1 and EZH2 was performed using paraffin-embedded block, and we examined the relation among the expression of VASH1 and a clinicopathological factor (sex, age, tumor diameter, tumor number, differentiation level, microscopic vascular invasion, and metastasis in lymph node), EZH2 expression, recurrence-free survival (RFS) and overall survival (OS).

Result: VASH1 and EZH2 positivity was observed in 24 (51.1%) and 24 (51.1%) patients respectively, and VASH1 positivity was inversely correlated with EZH2 high expression (R=0.3870, p=0.0018). VASH1 positivity was not significantly correlate with RFS or OS. On the other hands, VASH1 negative and EZH2 positive was observed in 17 (36.2%) patients, and was a significant disadvantage to both RFS (relative risk (RR) 3.39, 95% confidence interval (CI) 1.28-8.67, p=0.0157) and OS (RR 3.69, 95% CI 1.20-11.2, 0.0237) in univariate Cox hazard analysis. In multivariate analysis, VASH1 negative and EZH2 positive group was an independent risk factor for both RFS (RR 4.19, 95% CI 1.33-13.13, p=0.0150), and OS (RR 8.11, 95% CI 2.01-42.1, p=0.0030).

Conclusion: The expression of VASH1 was inversely correlate with EZH2 expression. VASH1 negative and EZH2 positive was an independent risk factor for OS and DFS in ICC patients.

Citation Format: Shigeki Nakagawa, Yasuo Sakamoto, Ryuma Tokunaga, Takaaki Higashi, Keita Sakamoto, Akira Chikamoto, Takatoshi Ishiko, Toru Beppu, Hideo Baba. Vasohibine-1 negative and EZH2 positive may predict the prognosis of cholangiocarcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4732. doi:10.1158/1538-7445.AM2014-4732

Epigenetic therapy with the histone methyltransferase EZH2 inhibitor 3-deazaneplanocin A inhibits the growth of cholangiocarcinoma cells

Enhancer of zeste homolog 2 (EZH2) is involved in malignant transformation and the biological aggressiveness of several human malignancies. Growing evidence indicates that EZH2 may be an appropriate therapeutic target for malignancies, including cholangiocarcinoma. Recently, an S-adenosyl-L-homocysteine hydrolase inhibitor, 3-deazaneplanocin A (DZNep) was shown to deplete and inhibit EZH2. The aim of this study was to determine the effect of DZNep and the combination of gemcitabine and DZNep in cholangiocarcinoma cells. The effects of DZNep and its combination with gemcitabine were assessed in the cholangiocarcinoma cell lines RBE and TFK-1. DZNep depleted the cellular levels of EZH2 and inhibited the associated histone H3 lysine 27 trimethylation. DZNep treatment resulted in the inhibition of proliferation in the cholangiocarcinoma cell lines, and the combination of DZNep and gemcitabine showed synergistic inhibition of cell proliferation. DZNep induced apoptosis and G1 phase cell cycle arrest in cholangiocarcinoma cells, and the combination of DZNep and gemcitabine enhanced the induced apoptosis and G1 arrest when compared with gemcitabine alone. Inhibition of cell proliferation by DZNep was partially associated with upregulation of p16INK4a and p17KIP1. The present study shows that DZNep inhibits cell proliferation by inducing G1 arrest and apoptosis. These results indicate that an epigenetic therapy that pharmacologically targets EZH2 via DZNep may constitute a novel approach for the treatment of cholangiocarcinoma.

Statins inhibit tumor progression via an enhancer of zeste homolog 2-mediated epigenetic alteration in colorectal cancer

While statin intake has been proven to reduce the risk of colorectal cancer (CRC), the mechanism of antitumor effects and clinical significance in survival benefits remain unclear. Statin-induced antiproliferative effects and its underlying mechanism were examined using six CRC cell lines. Statins except pravastatin showed antiproliferative effects (simvastatin ≥ fluvastatin > atorvastatin) even though both of simvastatin and pravastatin could activate mevalonate pathways, suggesting the statin-mediated antiproliferative effects depended on non-mevalonate pathway. Indeed, statin induced p27(KIP1) expression by downregulation of histone methyltransferase enhancer of zeste homolog 2 (EZH2), which acts as an epigenetic gene silencer. Additionally, the use of simvastatin plus classII histone deacetylase (HDAC) inhibitor (MC1568) induced further overexpression of p27(KIP1) by inhibiting HDAC5 induction originated from downregulated EZH2 in CRC cells and synergistically led to considerable antiproliferative effects. In the clinical setting, Statin intake (except pravastatin) displayed the downregulated EZH2 expression and inversely upregulated p27(KIP1) expression in the resected CRC by immunohistochemical staining and resulted in the significantly better prognoses both in overall survival (p = 0.02) and disease free survival (p < 0.01) compared to patients without statin intake. Statins may inhibit tumor progression via an EZH2-mediated epigenetic alteration, which results in survival benefits after resected CRC. Furthermore, statin plus classII HDAC inhibitor could be a novel anticancer therapy by their synergistic effects in CRC.

Involvement of PLAGL2 in activation of iron deficient- and hypoxia-induced gene expression in mouse cell lines

We searched iron-deficient inducible cDNA, using subtraction cloning and mRNA from desferrioxamine-treated mouse macrophage Raw264.7 cells. We identified a pleomorphic adenoma gene like 2 (PLAGL2), one of PLAG superfamily proteins exhibiting antiproliferative properties on tumor cells. Mouse PLAGL2 consists of 496 amino acids with seven C2H2 zinc-fingers. PLAGL2 mRNA was induced in RAW264.7 cells, mouse erythroleukemia cells and Balb/c 3T3 cells when they were treated with desferrioxamine. Hypoxia also increased PLAGL2 mRNA. Expression of PLAGL2 in COS-7 cells led to nuclear localization. PLAGL2 had potential binding ability to GC-rich oligonucleotide and activated transcription of a gene with the binding sequence in transient reporter assay, a finding consistent with a case seen in a PLAGL2 homolog, ZAC-1. Transient co-transfection of PLAGL2 or ZAC1 cDNA and a reporter containing a lactate dehydrogenase A (LDHA) promoter carrying the hypoxia inducible factor-1 responsive element led to an increase in the basal transcription in Balb/c 3T3 and HepG2 cells. Activation in transcription from the LDHA promoter increased by desferrioxamine treatment or hypoxia was further enhanced when PLAGL2 was expressed. We propose that PLAGL2 is involved in the cell cycle arrest and apoptosis of tumor cells by regulating iron depletion- or hypoxia-inducible gene expression.

Possible involvement of calcium-calmodulin pathways in the positive chronotropic response to angiotensin II on the canine cardiac sympathetic ganglia

We investigated the ganglionic effects of angiotensin II (Ang II) and the signal transduction involved in the cardiac sympathetic ganglia by the direct administration of agents to the ganglia through the right subclavian artery and monitoring the heart rate as an indicator of the ganglionic function in pithed dogs. Ang II given i.a. caused increases in the heart rate, which was inhibited by the treatment with the AT1-receptor antagonist forasartan, but not by the AT2-receptor antagonist PD-123319. The stimulation by Ang II, but not by acetylcholine, was inhibited after treatment with an inhibitor of phospholipase C, U-73122; a cell-permeant modulator of the Ins(1,4,5)P3 receptors, 2-aminoethoxydiphenyl borate; an intracellular calcium and calcium-associated protein kinase inhibitor, HA-1077; calmodulin (CaM) inhibitor, W-7; Ca2+/CaM-dependent protein kinase II inhibitor, KN-93; a selective protein kinase C inhibitor, calphostin C; and Na+H+ exchange inhibitor, dimethylamiloride. These results suggest that Ang II stimulates the ganglionic transmission at postsynaptic sites via the activation of AT1 receptor coupled to either activation of phospholipase C, phosphoinositide hydrolysis and subsequent increase in intracellular Ca2+ and activation of protein kinase C and Ca2+/CaM kinase II, although this ganglionic stimulation seems to involve, at least in part, the protein kinases-dependent increase of amiloride-sensitive Na+ inflow.

Upregulation of immunoreactive angiotensin II release and angiotensinogen mRNA expression by high-frequency preganglionic stimulation at the canine cardiac sympathetic ganglia

The possible involvement of the local angiotensin system in ganglionic functions was investigated in the canine cardiac sympathetic ganglia. Positive chronotropic responses to preganglionic stellate stimulation at high frequencies, after intravenous administration of pentolinium plus atropine, were inhibited by the nonpeptide angiotensin AT(1) receptor antagonist forasartan or the angiotensin I-converting enzyme inhibitor captopril, whereas the rate increases elicited by the postganglionic stellate stimulation and norepinephrine given intravenously failed to be inhibited by these antagonists. The levels of endogenous immunoreactive angiotensin II, as determined by radioimmunoassay in the incubation medium of the stellate and inferior cervical ganglia, were increased after the high-frequency preganglionic stimulation of the isolated ganglia. The increment of the peptide was also antagonized by the pretreatment with captopril but not by a chymase inhibitor, chymostatin. The expression of angiotensinogen mRNA was observed in the stellate ganglion, adrenal, liver, and lung but not in the ovary and spleen. The expression of the mRNA in the stellate and inferior cervical ganglia increased after high-frequency preganglionic stimulation of the in vivo dogs for a period of 1 hour. These results indicate that an intrinsic angiotensin I-converting enzyme-dependent angiotensin system exists in the cardiac sympathetic ganglia, which is activated by high-frequency preganglionic stimulation.

Analysis of the candidate genes responsible for non-syndromic cleft lip and palate in Japanese people

In order to assess the association of alleles for candidate genes with non-syndromic cleft lip and palate, DNA samples from 43 Japanese patients were compared with those from 73 control subjects with respect to the genes encoding transforming growth factor alpha (TGFalpha), TGFbeta and gamma-aminobutyric acid type A receptor beta3 (GABRB3). The restriction fragment length polymorphisms of the 3'-non-coding region of the TGFalpha gene K-primer region were observed after digestion with NcoI and HinfI. Allele 4 was the most common among cases of cleft lip with or without cleft palate, whereas allele 2 was the most common among controls. A significant difference was found in this region between groups with cleft lip (with or without cleft palate) and controls (chi2=10.190; P=0.017). Three alleles of the TGFbeta2 gene were tested, and allele 2 was the most common in both cases and controls. The proportion of allele 2 in the case group was greater than that in the control group, showing a significant difference between cases of cleft lip (with or without cleft palate) and controls (chi(2)=19.208; P<0.0001). No significant differences in variants of TGFbeta3 or GABRB3 between case and control populations were observed. Thus it is concluded that TGF genes play a role in craniofacial development, and that alleles of TGFalpha or/and TGFbeta2 are associated with cleft lip and cleft palate in Japanese populations.

Morphological change, loss of deltapsi(m) and activation of caspases upon apoptosis of colorectal adenocarcinoma induced by 5-FU

Apoptosis is clearly distinguished from necrosis, morphologically and chemically. Morphologically, apoptosis is characterized by a condensed nucleus and the disappearance of microvilli without disruption of the cytoplasm. In this report, we demonstrate that 5-fluorouracil (5-FU)-induced early apoptotic cells are characterized by (i) ultracondensed mitochondria, (ii) no change in the microvilli or nucleus, (iii) a high mitochondrial transmembrane potential (Deltapsi(m)), and (iv) being annexin V(negative). The early apoptotic cells also show the active forms of caspase 8 and caspase 9. They rapidly lose Deltapsi(m) after further incubation. Therefore, we conclude that the ultracondensation of mitochondria precedes the loss of Deltapsi(m) and the exposure of phosphatidylserine to the outer leaflet of the cell membrane.

ELISA for urinary trehalase with monoclonal antibodies: a technique for assessment of renal tubular damage

BACKGROUND

alpha,alpha-Trehalase, located on renal proximal tubules, is a glycoprotein that hydrolyses alpha,alpha-trehalose to two glucose molecules. Urinary trehalase reflects damage to renal proximal tubules, but its activity has not been measured routinely because measurement of catalytic activity is rather complicated and because conventional assays for enzyme activity might not reflect all of the trehalase protein because of enzyme inactivation in urinary samples.

METHODS

We established novel monoclonal antibodies for human trehalase and a sandwich ELISA for quantification of urinary trehalase. We determined the urinary trehalase protein concentration with this ELISA and trehalase catalytic activity, and the results of these two methods were compared.

RESULTS

The ELISA system was more sensitive than the detection of enzyme activity and could detect a subtle difference in the amount of trehalase present in renal diseases. The within- and between-assay CVs in the ELISA were 6.7-7.6% and 6.2-8.2%, respectively. Highly significant increases in both the quantity and activity were seen in patients with nephrotic syndrome (acute phase), Lowe syndrome, and Dent disease. The quantities were 70- to 200-fold greater, whereas enzyme activities were, at most, 10-fold higher than those of control subjects. In the detection of small amounts of trehalase in patients with chronic glomerulonephritis and renal anomalies, quantities were better than enzyme activities.

CONCLUSIONS

We have established an ELISA system for quantification of urinary trehalase that uses novel monoclonal antibodies. Our ELISA system is simpler and more sensitive than a conventional activity assay and reflects trehalase protein. This ELISA can be a useful as a common tool for clinical assessment of renal proximal tubular damage.

Cloning and expression of the M5 RNA segment encoding outer capsid VP5 of epizootic hemorrhagic disease virus Japan serotype 2, Ibaraki virus

The complete nucleotide sequence of a cDNA clone representing the M5 RNA segment of epizootic hemorrhagic disease virus Japan serotype 2 (EHDV-2), Ibaraki virus, was determined. The M5 segment is 1641 base pairs long with the single open reading frame which predicts a polypeptide of 527 amino acids. The comparison of the amino acid sequence of the VP5 with those of EHDV-1, bluetongue virus serotype 10, and African horse sickness virus serotype 4 revealed that the protein shared 67%, 57% and 42% homologies, respectively. In addition, the VP5 protein was expressed in insect cells by recombinant baculovirus, which could be recognized by the mouse anti-EHDV-2 sera at a position of the expected 59 kDa on immunoblot analysis.

Activated Rac1 selectively up-regulates the expression of integrin alpha6beta4 and induces cell adhesion and membrane ruffles of nonadherent colon cancer Colo201 cells

Functions of small GTPases in integrin expression were investigated when the interaction of nonadherent human colon carcinoma 201 cells with the extracellular matrix (ECM) was examined. By transfection of the constitutively active form of a small GTPase Rac1, Rac V12, adhesion of cells to the ECM increased with concomitant cell spreading and formation of membrane ruffles. Activated Cdc42 and Cdc42 V12, but not wild-type Rac1, Cdc42, or RhoA, also induced the adhesion and spreading of Colo201 cells. This adhesion is integrin beta4 dependent since an antibody for integrin beta4 inhibited the RacV12-dependent cell adhesion and numbers of adhesive cells on laminin-coated plates exceeded those on collagen- and fibronectin-coated plates. By immunofluorescence, in addition to clustering of integrin molecules, expression of integrin alpha6beta4 on the cell surface of Rac V12- and Cdc42 V12-expressing cells was selectively up-regulated without an increase in biosynthesis of alpha6beta4 integrin. Treatment of Rac V12-expressing cells with wortmannin or LY294002, specific inhibitors of phosphoinositide 3-OH kinase, decreased the up-regulated alpha6beta4 and cell adhesion. In light of this evidence, we propose that the regulation of integrin alpha6beta4 expression induced by Rac1 and Cdc42 may play an important role in cell adhesion and tumorigenesis of colon carcinoma cells.

Apoptosis of colorectal adenocarcinoma induced by 5-FU and/or IFN-gamma through caspase 3 and caspase 8

The cytotoxic effect of 5-FU has been shown by the induction of apoptosis in cancer cells, and reported to be enhanced by IFN-gamma. We examined the role of caspases on the apoptosis induction of 5-FU and IFN-gamma using a colorectal adenocarcinoma cell line. The activities of caspase 3 and caspase 8 increased when apoptosis was induced by 5-FU and/or IFN-gamma. Moreover, all apoptotic cells showed high caspase 3 activity in these conditions. Although the inhibitors of caspase 3 and caspase 8 inhibit apoptosis, anti-Fas ligand antibody does not affect the apoptosis induced by 5-FU. Thus, caspase 3 and caspase 8 play crucial roles in apoptosis induced by 5-FU and/or IFN-gamma, regardless of the Fas-Fas ligand system.

A crucial role of caspase 3 and caspase 8 in paclitaxel-induced apoptosis

The anticancer drug paclitaxel is well known as an inhibitor of microtubule depolymerization, resulting in mitosis arrest. We investigated the mechanism underlying antitumor effects of paclitaxel on the lung adenocarcinoma cell line LC-2-AD. Less than 10 microg/ml paclitaxel induced mitosis arrest upon LC-2-AD, followed by apoptosis, but more than 30 microg/ml paclitaxel induced apoptosis without mitosis arrest. LC-2-AD with less than 1 microg/ml paclitaxel showed a loss of mitochondrial transmembrane potential (deltapsim), which correlated with antitumor effects. However, LC-2-AD with more than 10 microg/ml paclitaxel showed slight changes in the loss of deltapsim in spite of its ability to induce apoptosis significantly. The cleavage of caspase 3, caspase 8, and DFF45/ICAD was also observed in paclitaxel-induced apoptosis, and the inhibitor of caspase 3 and caspase 8 inhibited both antitumor effects and apoptosis induced by paclitaxel. These results suggest that activation of caspase 3 and caspase 8 plays a crucial role in paclitaxel-induced apoptosis under any concentrations of paclitaxel.

MAP kinase-independent induction of proto-oncogene c-fos mRNA by hemin in human cells

Treatment of HeLa cells or human skin fibroblast cells with hemin led to a time- and dose-dependent rapid induction of c-fos mRNA. This induction was absent in the cells treated with actinomycin D, indicating that the c-fos induction by hemin occurs at the level of transcription. Metalloporphyrins, including zinc-, cobalt-, and tin-protoporphyrin, ferric ion, and protoporphyrin also induced c-fos mRNA. Transient reporter assay with the reporter constructs of the human c-fos gene promoter up to -404 bp connected to the luciferase gene showed high activity but no induction by hemin, suggesting that cis-acting elements, including the serum response element located about -310 bp upstream of the human c-fos gene promoter, may not contribute to the heme-dependent induction. With in-gel assay of protein kinases, the activity of the mitogen-activated protein (MAP) kinases such as extracellular signal-regulated kinase 12 or p38 MAP kinase in hemin-treated HeLa cells was not stimulated. Stimulation of c-Jun N-terminal kinase by hemin was nil. Furthermore, PD58059 and SB203580, inhibitors for MAP kinases, did not affect the hemin-dependent c-fos induction. Of the inhibitors for protein kinases so far tested, KN-62, a specific inhibitor for calmodulin-dependent protein kinase II (CaMK II), inhibited the induction of c-fos mRNA by hemin. Phosphorylation of CaMK II in hemin-treated cells increased. With gel mobility assay, the DNA AP-1 binding activity transiently increased when treating HeLa cells with hemin. Therefore, induction of c-fos led to an activation of AP-1 in the presence of hemin. We suggest that calmodulin-dependent protein kinase II rather than the MAP kinase family regulates the induction of the human c-fos gene expression by hemin.

Structure and transcriptional regulation of the mouse ferrochelatase gene

Ferrochelatase (EC.4.99.1.1), the final step in the biosynthesis of heme, is widely expressed in various tissues and is induced in erythroid cells. We determined the structure of the mouse ferrochelatase gene after isolation and characterization of lambda phage clones mapping discrete regions of the cDNA. The gene spans about 25 kb and consists of 11 exons. The exon/intron boundary sequences conform to consensus acceptor (GTn)/donor (nAG) sequences, and exons in the gene encode functional protein domains. The promoter region contains multiple Sp1 sites, a CACCC box and GATA-1 binding sites. Function analysis of the promoter by transient transfection assay demonstrated that one Sp1 binding site located at -37/-32 is essential for basic expression of the ferrochelatase gene in both mouse erythroleukemia (MEL) and non-erythroid EL4 cells. In addition, the region (-66/-51) containing a CACCC box and the neighboring GC box partly contributes to the inducible activity of the reporter in MEL cells upon induction with dimethylsulfoxide. It appears that at least two promoter regions of the mouse ferrochelatase gene function in basic and inducible expression.