Michihiko Kogure

Expression of tight-junction-associated proteins in human gastric cancer: downregulation of claudin-4 correlates with tumor aggressiveness and survival

BackgroundClaudin, occludin, and zonula occludens (ZO)-1 are known as tight-junction-associated proteins. The aim of this study was to examine the expression of these proteins in gastric carcinoma.MethodsGastric cancer tissues (n = 124) were obtained from 124 patients who underwent gastrectomy at our hospital between January 2000 and December 2004. The expression of the above tight-junction-associated proteins in carcinoma, normal mucosa, and metaplastic epithelium was examined using immunohistochemistry. In addition, the expression of claudin-4 mRNA was examined in fresh frozen tissue obtained from 34 patients.ResultsSignificant correlations were seen between the expression of claudin-4, occludin, and ZO-1. In regard to claudin-4, significant correlations were seen between the expression of claudin-4 evaluated by immunohistochemistry and the expression of claudin-4 mRNA. Claudin-4 expression was significantly decreased in tumors with undifferentiated-type adenocarcinoma, advanced T stage, lymph node metastasis, and peritoneal metastasis. Occludin and ZO-1 expression was significantly decreased in tumors with undifferentiated-type adenocarcinoma. Overall survival was significantly shorter in patients with low claudin-4 expression. Cox multivariate analysis revealed that low claudin-4 expression was independently associated with significantly decreased overall survival.ConclusionTight-junction-associated proteins, particularly claudin-4, may play important roles in determining invasiveness, metastatic potential, and survival in gastric cancer.

Gene expression profiles in human gastric cancer: expression of maspin correlates with lymph node metastasis

To seek for a candidate gene that would regulate tumour progression and metastasis in gastric cancer, we investigated gene expression profiles by using DNA microarray. Tumour tissue and adjacent normal tissue were obtained from 21 patients with gastric cancer and then examined for their gene expression profiles by the Gene Chip® Human U95Av2 array, which includes 12 000 human genes and EST sequences. A total of 25 genes were upregulated and two genes were downregulated by at least four-fold in the tumour tissue. In a further analysis according to lymph node metastasis, the expressed levels of maspin, as well as carcinoembryonic antigen and nonspecific crossreacting antigen were significantly higher in tumours with lymph node metastasis than in those without it. Maspin expression in 85 gastric cancer patients was further investigated by using immunohistochemistry. Maspin expression was not observed in normal gastric epithelia without intestinal metaplasia. In contrast, maspin was expressed in 74 of 85 tumour tissues. There was a significant correlation between the incidence of maspin-positive tumour staining and lymph node metastasis. These results suggest that maspin has a potential role for tumour metastasis in gastric cancer.

Overexpression of Fatty Acid Synthase in Oesophageal Squamous Cell Dysplasia and Carcinoma

Objective: The expression of fatty acid synthase (FAS), an enzyme necessary for de novo fatty acid synthesis, has been examined in several types of tumours so far, but not in oesophageal cancer and dysplasia. Methods: We examined the immunohistochemical reactivity of FAS in 4 normal adult oesophagi, 14 dysplastic oesophageal lesions, and 80 squamous cell carcinomas and 6 cases with 4 special types of malignancies of the oesophagus. We also analysed the correlation between FAS expression and various clinicopathological features and long-term survival in patients with oesophageal cancer. Results: In the normal oesophagus, only faint cytoplasmic FAS expression was observed in cells of the basal layer. In contrast, FAS-positive cells were found in 92.9% of cases of dysplasia and 96.5% of cases of carcinoma including 6 cases with a specific histological subtype. However, high expression of FAS did not correlate with either clinicopathological features or prognosis of patients with oesophageal cancer. Conclusion: Our results demonstrate that FAS is expressed in almost all oesophageal carcinomas of both usual and special types and dysplastic lesions, suggesting that FAS may be upregulated continuously from the early stage of oesophageal squamous cell carcinogenesis to established carcinoma.

Prediction of sensitivity to fluoropyrimidines by metabolic and target enzyme activities in gastric cancer

BackgroundThis study was designed to investigate the role of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and thymidine phosphorylase (TP) in tumor progression and sensitivity to 5-fluorouracil (5-FU).MethodsA total of 275 tumor samples from 275 patients with gastric cancer were utilized in this study. TS activity was determined in 130 samples by 5-fluorodeoxyuridine monophosphate binding assay. DPD activity was measured in 140 samples by radioenzymatic assay, and TP protein level was determined in 157 samples by an enzyme-linked immunosorbent assay (ELISA) system. These parameters were compared with several clinicopathologic factors and sensitivity to 5-FU determined by in-vitro ATP assay. The antitumor activities of 5-FU, uracil plus tegafur (UFT), and 1 M tegafur — 0.4 M 5-chloro-2,4-dihydroxypyridine — 1 M potassium oxonate (S-1 [TS-1®]) were also compared, using three human gastric cancer xenografts in nude mice.ResultsThere was no correlation between either TS or TP and sensitivity to 5-FU. However, a weak inverse correlation was found between DPD activity and sensitivity to 5-FU. High DPD activity in tumor resulted in poor prognosis, especially in patients who received 5-FU-based adjuvant chemotherapy. Although TP was significantly correlated with depth of tumor invasion and with lymphatic and venous invasions, TP alone had no impact on survival. On the other hand, TS, as well as peritoneal, hepatic, and lymph node metastases, was selected as an independent prognostic factor in gastric cancer. In the animal model, there was no significant difference in antitumor activities among the drugs in a tumor with low DPD activity. However, S-1 showed superior antitumor activity to 5-FU or UFT in tumors with high DPD activity.ConclusionDPD is considered to be a most important predictive factor of 5-FU sensitivity. The use of DPD inhibitory fluoropyrimidines is strongly recommended for tumors with high DPD activity.

Detection of cancer cells disseminated in bone marrow using real-time quantitative RT-PCR of CEA, CK19, and CK20 mRNA in patients with gastric cancer

BackgroundTo determine the significance of bone marrow disseminated tumor cells in gastric cancer, we investigated the mRNA expression levels of carcinoembryonic antigen (CEA), cytokeratin 19 (CK19), and cytokeratin 20 (CK20) using the real-time quantitative reverse-transcription polymerase chain reaction (RQ-PCR).MethodsBone marrow samples were aspirated from the sternum at the time of surgery in 65 patients with resectable gastric cancer. Total RNA was extracted from bone marrow; and the expression levels of CEA, CK19, and CK20 mRNA were determined by RQ-PCR using an ABI PRISM 7000 and quantified against the GAPDH mRNA level.ResultsThe detection limits of these genes were determined in the gastric cancer cell line MKN-45 and the colon cancer cell line C-1, which had been serially diluted in peripheral blood mononuclear cells (PBMCs). A rate of 1 cancer cell/million PBMCs was obtained by detecting CEA and CK19 mRNA in MKN-45 and by detecting CK20 mRNA in C-1. In the clinical samples, only 1 of the 65 gastric cancer patients (1.5%) who had stage IV disease was positive for CEA, CK19, and CK20 mRNA; none of CEA, CK19, or CK20 mRNA was positive in the remaining 64 patients. No significant correlation was observed between disseminated cancer cells in bone marrow and clinicopathological features, including simultaneous or metachronous hepatic metastasis and patient survival.ConclusionThe incidence of disseminated cancer cells in bone marrow in our study appears low, unlike that in previous reports. The significance of disseminated cancer cells in bone marrow may also be quite low in gastric cancer.

Management Strategy of Isolated Spontaneous Dissection of the Superior Mesenteric Artery

OBJECTIVE Isolated spontaneous dissection of the superior mesenteric artery (SMA) is very rare among of the visceral artery dissection and its treatment is not established. In this paper we present our experiences and consider the treatment of isolated SMA dissection. METHODS A retrospective review of our cases from 2005 was performed. Clinical symptoms, radiologic findings and results were evaluated. There were 14 cases of visceral artery dissection, in which all cases were with SMA dissection. There were 12 males and 2 females with a mean age of 57 years (range 41-78 years). RESULTS We categorized SMA dissection into the six types according to the Sakamotos and Zerbibs classification. One patient with type VI underwent emergent endovascular surgery with stent. One patient with type VI received thrombectomy and intimectomy with open surgery. One patient with type II underwent aneurysmectomy due to enlarged dissected SMA 3 months later from onset. The other eleven patients were managed conservatively. At follow-up, the diameter of SMA did not enlarged and the length of the dissection significantly decreased to 20.7 ± 15.7 mm from 38.0 ± 15.1 mm at onset (p <0.01). After treatment, imaging indicated the following changes in classification: type I, one patient; type II, 4 patients; type IV, 4 patients; complete remodeling, one patient, all without any event during the follow-up period of 5-82 months. CONCLUSION Most patients with isolated visceral artery dissection occurred in superior mesenteric artery and can be treated conservatively; however, endovascular or surgical procedures including laparotomy are indicated when there is suspicion of severe mesenteric ischemia. Because the dissection configuration will change, long term follow-up is necessary. (English translation of Jpn J Vasc Surg 2013; 22: 695-701).

Cathepsin L is highly expressed in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract that are diagnosed by c-kit staining in most cases. A lysosomal cysteine proteinase termed cathepsin L has been commonly associated with malignancy in several cancer types, but this finding has not been reported for GISTs. We analyzed the cathepsin L mRNA and protein expression in GISTs. Real-time reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that cathepsin L levels were higher in GISTs than those in gastric or colorectal tumors; this finding was supported by results of the Western blot analysis. Immunohistochemistry revealed that cathepsin L was localized to the cytoplasm of GIST cells as an intense granular signal, which was not observed in the cells of leiomyoma, a mesenchymal tumor that was analyzed as a control specimen. Double immunofluorescence microscopy revealed that a portion of the granular signal colocalized with lysosome-associated membrane protein-1 (LAMP-1), which is a lysosomal marker. Moreover, immunohistochemical analysis of 43 tumor specimens revealed that 86.0% (n=37) were cathepsin-L positive, and this positivity was significantly correlated with c-kit positivity but not with other clinicopathological factors, including gender, age, region, size, mitosis and risk of recurrence. From these results, we conclude that cathepsin L is highly expressed in GISTs compared to its expression in other cancerous lesions; this identifies cathepsin-L as a new diagnostic marker for GISTs.

Activation of the sonic hedgehog pathway and its prognostic impact in patients with gastric cancer.

Background: The sonic hedgehog (SHH) signaling pathway is critical in fetal organogenesis. Activation of the SHH pathway has been associated with several types of human cancer; however, the clinical impact of SHH activation in patients with gastric cancer is still unknown. Methods: The present study included 41 patients with gastric cancer who underwent gastrectomy between 2000 and 2004. SHH, Patched-1 (PTCH1), Smoothened (SMO) and Glioma-associated oncogene-1 (GLI1) were examined immunohistochemically, and these of mRNAs from the cancer lesions were evaluated using real-time quantitative RT-PCR. Results: Immunohistological expressions of SHH-related molecules were relatively intense in cancer tissue, but no significant correlation was found with any clinicopathological factors of tumor. PTCH1 was only the molecule associated with poor prognosis of patients with differentiated type of tumor. For mRNA analysis, a significant correlation was demonstrated between certain clinicopathological factors and PTCH1, SMO or/and GLI1 mRNA levels. High levels of SHH and PTCH1 mRNA were associated with poor prognosis. Multivariate analysis demonstrated the PTCH1 mRNA level and liver metastasis as significant independent prognostic factors. Conclusions:PTCH1 expression in the SHH pathway was possibly involved in gastric cancer tumor progression, and could be a useful indicator for the prognosis of gastric cancer.

A Case Report of Aneuysmectomy after Thrombo-Intimectomy for Spontaneous Isolated Superior Mesenteric Artery Dissection

A 53 year-old man was admitted with acute onset of severe abdominal pain, and we performed emergent thrombectomy and intimectomy for acute, complete occlusion of superior mesenteric artery (SMA) due to its spontaneous dissection. However, 4 months later the operated part of the SMA enlarged due to aneurysm and the patient was treated by aneuysmectomy and iliac-mesenteric bypass using a saphenous vein. Aggressive treatment such as surgical or endovascular procedure is necessary for severe ischemia due to SMA dissection.

Prognostic role of immunosuppressive acidic protein in patients with esophageal cancer

Immunosuppressive acidic protein (IAP) suppresses several immune responses in vivo and in vitro , and high preoperative IAP levels could predict the impairment of the hosts immunity. In this study prognostic significance of preoperative IAP levels was investigated in 68 esophageal cancer patients with curative resection and eight with non-curative resection. The curative group had significantly lower levels than the non-curative group (432 +/- 183 mg/mL vs. 739 +/- 235 mg/mL, P < 0.0001). The IAP levels were associated with T-status (P < 0.0001), lymphatic invasion (P < 0.05), and p-stages (P < 0.0001). When 5-year survival rate of patients with curative resection was compared by setting various cutoff values of IAP between high and low IAP groups, several cutoff points (400-580 mg/mL) were revealed to be significantly associated with survival. Setting cutoff value of IAP to 560 mg/mL resulted in a most significant difference of 5-year survival rate of patients between the high and low IAP groups (13.9% and 61.5%, P < 0.0001). These data indicate that pre-operative IAP level is a useful parameter to predict the prognosis of esophageal cancer patients after curative resection.