Kazutaka Obama

Genome-wide analysis of gene expression in human intrahepatic cholangiocarcinoma†

Intrahepatic cholangiocarcinoma is a neoplasm arising in the liver, and its incidence is increasing in Japan as well as in Western countries. Prognosis of patients with this type of tumor remains unsatisfactory because no effective chemotherapeutic drugs are available, we have no sensitive tumor markers to detect this tumor in its early stage, and it is difficult to identify a high‐risk group for the disease. To clarify the molecular mechanism of tumorigenesis and identify molecular targets for diagnosis and treatment, we analyzed global gene‐expression profiles of 25 intrahepatic cholangiocarcinomas using tumor cell populations purified by laser microbeam microdissection and a cDNA microarray containing 27,648 genes. We identified 52 genes that were commonly upregulated and 421 that were downregulated in intrahepatic cholangiocarcinomas compared with noncancerous biliary epithelial cells. From the 52 upregulated genes, we selected P‐cadherin and survivin for further investigation and corroborated enhanced expression of their products in cancer tissues by immunohistochemical staining. Furthermore, comparison between tumors with lymph node metastasis and those without metastasis identified 30 genes that were associated with lymph node involvement. In conclusion, these data should be helpful for a better understanding of the tumorigenesis of intrahepatic cholangiocarcinoma and should contribute to the development of diagnostic and therapeutic strategies for this type of tumor. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270‐9139/suppmat/index.html). (HEPATOLOGY 2005.)

Survival in Nonocclusive Mesenteric Ischemia: Early Diagnosis by Multidetector Row Computed Tomography and Early Treatment With Continuous Intravenous High-dose Prostaglandin E1

Objectives:The aim of the study was to establish a procedure for early diagnosis and treatment of nonocclusive mesenteric ischemia (NOMI). Background:NOMI has a high mortality rate, and early diagnosis and treatment are important for improving survival in patients with this condition. Methods:The subjects were 22 patients treated at our hospital over 13 years. Diagnostic criteria for NOMI were established based on the first 13 cases. In the 9 more recent cases, we performed abdominal contrast multidetector row computed tomography (MDCT) upon suspicion of NOMI based on these criteria. Imaging allowed definite diagnosis of NOMI, and continuous intravenous high-dose PGE1 administration was initiated immediately after diagnosis (dose, 0.01–0.03 μg/kg per min; mean administration period, 4.8 days). Results:Nine of the first 13 patients died of multiple organ failure associated with multiple intestinal necrosis. These cases suggested that NOMI may develop when 3 of the following 4 criteria are met after cardiovascular surgery or maintenance dialysis in elderly patients: symptoms of the ileus develop slowly from abdominal symptoms, such as an unpleasant abdominal feeling or pain; a requirement for catecholamine treatment; an episode of hypotension; and slow elevation of the serum transaminase level. In the 9 recent cases, definite diagnosis was made from spasm of the principal arteries in arterial volume rendering and curved planar reformation MDCT images. Early treatment with PGE1 prevented acute-stage NOMI in 8 of the 9 cases. Conclusions:Early diagnosis of NOMI is possible using the above criteria and MDCT, and initiation of PGE1 treatment may increase survival in patients with NOMI.

Comparison of gene expression profiles between Opisthorchis viverrini and non-Opisthorchis viverrini associated human intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary cancer in the liver, and its incidence is highest in the northeastern part of Thailand. ICCs in this region are known to be associated with infection with liver flukes, particularly Opisthorchis viverrini (OV), as well as nitrosamines from food. To clarify molecular mechanisms of ICC associated with or without liver flukes, we analyzed gene expression profiles of OV‐associated ICCs from 20 Thai patients and compared their profiles with those of 20 Japanese ICCs that were not associated with OV, by means of laser microbeam microdissection and a cDNA microarray containing 27,648 genes. We identified 77 commonly upregulated genes and 325 commonly downregulated genes in the two ICC groups. Unsupervised hierarchical cluster analysis separated the 40 ICCs into two major branches almost completely according to the fluke status. The putative signature of OV‐associated ICC exhibited elevated expression of genes involved in xenobiotic metabolism (UGT2B11, UGT1A10, CHST4, SULT1C1), whereas that of non–OV‐associated ICC represented enhanced expression of genes related to growth factor signaling (TGFBI, PGF, IGFBP1, IGFBP3). Additional random permutation tests identified a total of 49 genes whose expression levels were significantly different between the two groups. We also identified genes associated with macroscopic type of ICCs. In conclusion, these data may not only contribute to clarification of common and OV‐specific mechanisms underlying ICC, but also may serve as a starting point for the identification of novel diagnostic markers or therapeutic targets for the disease. (HEPATOLOGY 2006;44:1025–1038.)

Intracorporeal esophagojejunal anastomosis after laparoscopic total gastrectomy for patients with gastric cancer

BackgroundTo facilitate acceptance of laparoscopic total gastrectomy (LTG) for patients with upper gastric cancer, a simple, secure technique of reconstruction is necessary. The authors developed a new technique for intracorporeal esophagojejunal anastomosis that does not require hand sewing.MethodsFrom September 2006 to January 2008, 16 patients (11 men and 5 women) with gastric cancer underwent LTG at the authors’ institution. Laparoscopic esophagojejunal anastomosis using the following method was attempted for all patients. The esophagus was transected while being rotated by about 45° counterclockwise to make the subsequent anastomosis easier. After the Y-anastomosis was created, an endoscopic linear stapler was applied to create a side-to-side anastomosis between the left dorsal side of the esophagus and the jejunal limb. The entry hole was first closed roughly with hernia staplers. Subsequently, an endoscopic linear stapler was applied so that all hernia staplers could be removed and the closure completed.ResultsLaparoscopic esophagojejunal anastomosis was successfully performed for 15 patients. Intracorporeal anastomosis failed for one patient because a nasogastric tube was caught between the jaws of an endostapler, which resulted in a conversion to open procedure. No postoperative anastomotic complications occurred.ConclusionsUsing the new technique, intracorporeal linear-stapled esophagojejunal anastomosis can be performed easily and securely. This technique could become one of the standard methods for reconstruction after LTG, facilitating the acceptance of LTG as a surgical option for patients with upper gastric cancer.

Advantage of completely laparoscopic gastrectomy with linear stapled reconstruction: a long-term follow-up study.

Background:Completely laparoscopic gastrectomy with intracorporeal anastomosis was introduced to achieve safer anastomosis and smaller scars. Although several reports have shown the feasibility of linear-stapled anastomosis, there are no studies of a large number of patients assessing the long-term complications and functional outcomes. Methods:This retrospective study included 345 patients who had intended to undergo completely laparoscopic distal or total gastrectomy with linear-stapled anastomosis between September 2005 and January 2012. This study evaluated both the short- and long-term complications, as well as the endoscopic findings, changes in body weight and serum albumin. Results:Completely laparoscopic gastrectomy was successfully achieved in 342 patients (99.1%). Short-term complications occurred in 59 patients (17.3%). Reconstruction-related complications were observed in 19 patients (5.6%). Three patients with anastomotic leakage required reoperation. No patient experienced anastomotic stenosis over a mean follow-up period of 29.6 months. Two patients underwent an emergency operation for an internal hernia after total gastrectomy. Adhesive intestinal obstruction was observed in 5 patients (1.5%), but all were resolved without surgical intervention. Body weight loss at 2 years after distal and total gastrectomy was 7.2% and 13.9%, which were similar to previous reports of open surgery. Conclusions:Completely laparoscopic gastrectomy with linear-stapled anastomosis is a feasible choice for gastric cancer patients with some potential long-term advantages such as less anastomotic stenosis and fewer adhesive intestinal obstructions.

Feasibility of laparoscopic gastrectomy with radical lymph node dissection for gastric cancer: from a viewpoint of pancreas-related complications.

BACKGROUND There is little evidence for the technical feasibility of laparoscopic gastrectomy (LG) with peripancreatic lymphadenectomy in terms of postoperative complications. To evaluate the technical feasibility of LG with radical lymphadenectomy, we focused on pancreas-related complications in LG and open gastrectomy (OG), and then investigated whether such complications increased in LG. METHODS We reviewed the surgical outcomes of 138 consecutive patients with gastric cancer who underwent LG with peripancreatic lymphadenectomy in our hospital between July 2005 and February 2009. As a control group, we used 95 consecutive OG cases with peripancreatic lymphadenectomy without splenectomy or para-aortic lymphadenectomy. LG and OG were compared for clinicopathologic characteristics, operative outcomes, postoperative morbidities and mortalities, and amylase concentration of drainage fluid (d-AMY). RESULTS The overall operative morbidity rates were 15% in the LG and 20% in the OG group. Rates of postoperative pancreatic fistula (POPF), Grade B and C in the International Study Group on Pancreatic Fistula definition, were 7% in the LG group and 2% in the OG group, indicating no statistical difference (P = .149). There were no in-hospital deaths. The median value of d-AMY in LG was 934.5 IU/L, while that in OG was 349 IU/L; d-AMY after LG was significantly higher than that after OG (P < .01). CONCLUSION Considering low morbidity and mortality rates, LG with peripancreatic lymphadenectomy is technically feasible. Although POPF after LG was infrequent, d-AMY level was higher than after OG. We should pay attention to the potential risk of pancreatic leakage when carrying out LG with peripancreatic lymphadenectomy.

Overexpression of peptidyl-prolyl isomerase-like 1 is associated with the growth of colon cancer cells.

Purpose and Experimental Design: To discover novel therapeutic targets for colon cancers, we previously surveyed expression patterns among 23,000 genes in colon cancer tissues using a cDNA microarray. Among the genes that were up-regulated in the tumors, we selected for this study peptidyl-prolyl isomerase-like 1 (PPIL1) encoding PPIL1, a cyclophilin-related protein. Results: Western blot analysis and immunohistochemical staining using PPIL1-specific antibody showed that PPIL1 protein was frequently overexpressed in colon cancer cells compared with noncancerous epithelial cells of the colon mucosa. Colony formation assay showed a growth-promoting effect of wild-type PPIL1 on NIH3T3 and HEK293 cells. Consistently, transfection of short-interfering RNA specific to PPIL1 into SNUC4 and SNUC5 cells effectively reduced expression of the gene and retarded growth of the colon cancer cells. We further identified two PPIL1-interacting proteins, SNW1/SKIP (SKI-binding protein) and stathmin. SNW1/SKIP is involved in the regulation of transcription and mRNA splicing, whereas stathmin is involved in stabilization of microtubules. Therefore, elevated expression of PPIL1 may play an important role in proliferation of cancer cells through the control of SNW1/SKIP and/or stathmin. Conclusion: The findings reported here may offer new insight into colonic carcinogenesis and contribute to the development of new molecular strategies for treatment of human colorectal tumors.

Enhanced Expression of RAD51 Associating Protein-1 Is Involved in the Growth of Intrahepatic Cholangiocarcinoma Cells

Purpose: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary cancer in the liver, and its incidence is increasing in developed countries. Experimental Design: To discover novel molecular targets for the diagnosis and treatment of ICCs, we earlier analyzed expression profiles of 25 ICCs using a cDNA microarray containing 27,648 genes. In this study, we focused on the RAD51 associating protein-1 (RAD51AP1) gene because its expression was frequently elevated in our microarray data. Results: Quantitative PCR confirmed that RAD51AP1 expression was elevated in the great majority of the ICCs examined. Immunohistochemical analysis with anti-RAD51AP1 antibody further corroborated its accumulation in 14 of 23 ICC tissues (61%). Notably, suppression of RAD51AP1 by short interfering RNA resulted in growth suppression of cholangiocarcinoma cells, suggesting its involvement in the development and/or progression of ICC. Because RAD51AP1 interacts with RAD51, a molecule involved in DNA repair, we investigated whether RAD51AP1 is implicated in DNA strand breaks using γ-irradiation. As a result, γ-irradiation augmented RAD51AP1 protein expression and brought a focus formation in the nuclei, where accumulated RAD51AP1 colocalized with phosphorylated histone 2AX (γ-H2AX) and RAD51. These data suggest that RAD51AP1 may play a role in cell proliferation as well as DNA repair. Conclusion: Our findings may contribute to the better understanding of cholangiocarcinogenesis and open a new avenue to the development of novel therapeutic and/or diagnostic approach to this type of tumor.

Current status of robotic gastrectomy for gastric cancer

Although over 3000 da Vinci Surgical System (DVSS) devices have been installed worldwide, robotic surgery for gastric cancer has not yet become widely spread and is only available in several advanced institutions. This is because, at least in part, the advantages of robotic surgery for gastric cancer remain unclear. The safety and feasibility of robotic gastrectomy have been demonstrated in several retrospective studies. However, no sound evidence has been reported to support the superiority of a robotic approach for gastric cancer treatment. In addition, the long-term clinical outcomes following robotic gastrectomy have yet to be clarified. Nevertheless, a robotic approach can potentially overcome the disadvantages of conventional laparoscopic surgery if the advantageous functions of this technique are optimized, such as the use of wristed instruments, tremor filtering and high-resolution 3-D images. The potential advantages of robotic gastrectomy have been discussed in several retrospective studies, including the ability to achieve sufficient lymphadenectomy in the area of the splenic hilum, reductions in local complication rates and a shorter learning curve for the robotic approach compared to conventional laparoscopic gastrectomy. In this review, we present the current status and discuss issues regarding robotic gastrectomy for gastric cancer.

Elevated high-sensitivity C-reactive protein, a marker of advanced stage gastric cancer and postgastrectomy disease recurrence

Gastric cancer recurrence after curative surgery remains high. Although no preoperative marker of gastric cancer progression after radical gastrectomy exists, recent studies suggest that C‐reactive protein (CRP) is associated with cancer progression. Our study evaluated the significance of preoperative high‐sensitivity CRP (hs‐CRP) levels as a marker of disease progression after radical gastrectomy.