Yoshikuni Yonenaga

Absence of Smooth Muscle Actin-Positive Pericyte Coverage of Tumor Vessels Correlates with Hematogenous Metastasis and Prognosis of Colorectal Cancer Patients

Objectives: Immature microvessels, which are not covered by pericytes, are irregular and leaky. We hypothesized that tumor cells can penetrate immature microvessels more easily than mature microvessels. In this study, we investigated the maturation of angiogenesis by the immunohistochemical staining of colorectal cancer specimens and determined the correlation between the microvessel count or the maturity of microvessels and clinicopathological variables. Methods: Ninety-two surgical specimens from our department were used. Double immunostaining of endothelial cells with anti-CD34 antibody and pericytes with anti-α-smooth muscle actin antibody was performed. The microvessel density (MVD) and microvessel pericyte coverage index (MPI) as an index of microvessel maturation were evaluated. Results: The MVD showed a significant positive correlation with tumor size, depth of invasion and Dukes’ stage. The MPI showed a significant positive correlation with the histological differentiation of the tumor tissues and distant metastasis at the time of operation. The high MVD group (≧26.0, n = 50) tended to have a poorer prognosis than the low MVD group (<26.0, n = 42) (p = 0.097). Next, the 50 patients in the high MVD group were classified into two subgroups of high MPI (≧78.1%, n = 25) and low MPI (<78.1%, n = 25). MPI showed a significant negative correlation with hematogenous metastasis, and the low MPI group demonstrated a significantly poorer survival than the high MPI group (p = 0.040). Conclusions: These findings demonstrate that immature neovascularization was observed in poorly differentiated tumors and was correlated with metastasis, resulting in a poorer prognosis. Taken together, not only microvessel density but also vascular maturation were crucial factors for colorectal cancer patients.

Hexokinase II and VEGF expression in liver tumors: correlation with hypoxia-inducible factor-1α and its significance

BACKGROUND/AIMS We analyzed the expressions of hexokinase II (HK II), a key enzyme in glycolysis, and VEGF in hepatocellular carcinoma (HCC) and metastatic liver cancer in relation to tumor vascularity, and the participation of hypoxia-inducible factor-1 (HIF-1) was studied. METHODS A real-time quantitative reverse transcription-polymerase chain reaction was performed to examine the HK II and VEGF mRNA expression. Expression of HIF-1 alpha and HK II protein, and microvessel density (MVD) were examined immunohistochemically. RESULTS MVD was significantly higher in HCCs than in metastatic liver cancers, and VEGF mRNA expression was positively correlated only with MVD of HCCs. HK II mRNA expression was significantly higher in metastatic liver cancers, however, some cases of HCC pretreated with transcatheter arterial embolization (TAE) showed marked HK II mRNA expression. Both HIF-1 alpha and HK II protein expressions were co-localized in the cancer cells near necrosis, and the intensity of HIF-1 alpha protein expression was significantly correlated with HK II mRNA expression in both tumors. CONCLUSIONS These results suggest that, in metastatic liver cancers, glycolysis induced by HIF-1 is the predominant energy source under the hypoxic environment and, at least in some TAE-pretreated HCC cases, cancer cells obtain energy for growth by switching the metabolic profile to glycolysis through HIF-1.

Reappraisal of Surgical Treatment for Radiation Enteritis

Although radiation enteritis is a well-recognized sequel of therapeutic irradiation, the standard surgical method is not universally agreed upon. Not only the short-term effect but also the long-term effect after a surgical intervention has been fairly well reported. To reassess the surgical therapy for radiation enteritis, we retrospectively analyzed 48 patients (5 males and 43 females, mean age 58.6 years) who had been operated on in our department. These patients were divided into two types according to the time of surgery or the clinical manifestation, and operative methods were analyzed. Patient’s status such as bowel movement, body weight, and serum albumin value after surgery were analyzed, together with the patients survival. Our surgical methods were small intestinal resection for the intestinal obstruction, and pull-through reconstruction for proctitis. Two patients died of multiple organ failure caused by perforated peritonitis irrespective of emergent operation. Although the overall morbidity was 21.7%, there was no leakage when bowels were anastomosed. Overall survival after radiation-related complication in patients without previous neoplastic disease recurrence was 89%, 79%, and 69%, at 1, 3, and 5 years after surgery, respectively. Bowel motility, serum albumin level, and body weight recovered gradually soon after the operation and reached satisfactory levels within 6 months. Our analysis showed that small bowel injury should be treated by generous resection of the affected bowel followed by careful anastomosis of the disease-free ends, while rectal resection is best dealt with by restorative proctectomy. This may provide a good quality of life and minimize major postoperative complications such as leakage.

All-trans-Retinoic Acid Attenuates Radiation-Induced Intestinal Fibrosis in Mice

BACKGROUND Intestinal fibrosis leading to severe bowel dysmobility or obstruction is a troublesome adverse effect of abdominal or pelvic radiation therapy. We have recently reported that all-trans-retinoic acid (ATRA) prevents radiation- or bleomycin-induced lung fibrosis. Here, we examined the impact of ATRA on the mouse model of radiation-induced intestinal fibrosis. MATERIALS AND METHODS We evaluated the histology of late radiation fibrosis in surgical samples. We then performed histological examinations and quantitative measurements of mRNA of interleukin-6 and transforming growth factor-beta(1) in intestinal tissues of irradiated mice with or without intraperitoneal administration of ATRA and investigated the effect of ATRA on the transdifferentiation and the production of collagen of irradiated human intestinal fibroblasts. RESULTS Human samples of late radiation enteritis showed thickened submucosa and serosa, consistent with mouse model. Administration of ATRA attenuated irradiation-induced intestinal fibrosis and reduced mRNA of interleukin-6 and transforming growth factor-beta(1). In vitro studies disclosed that ATRA suppressed the transdifferentiation of irradiated intestinal fibroblasts and diminished the production of collagen from the cells. CONCLUSIONS Our findings indicate that ATRA ameliorates irradiation-induced intestinal fibrosis. ATRA could be a novel approach in the treatment of fibrosis associated with chronic radiation enteritis.

Vascular endothelial growth factor reduces mural cell coverage of endothelial cells and induces sprouting rather than luminal division in an HT1080 tumour angiogenesis model.

Vascular endothelial growth factor (VEGF) plays a central role in tumour angiogenesis. In a mouse intramuscular tumour model using VEGF‐transfected HT1080 human fibrosarcoma, we investigated the morphological features and patterns of remodelling in size‐matched tumours. Compared with the control tumours (C group), the VEGF‐transfected tumours (V group) showed vigorous neovascularization with larger vessels. Fenestrations and disruptions of endothelia were specific to the V group. Three types of vascular remodelling, i.e. sprouting, luminal division and intussusceptive microvascular growth, were present in both groups. Morphometric analyses revealed that mural cell coverage of the endothelial cells was significantly smaller in the V group compared with that in the C group (V group, 28.2 ± 18.6%; C group, 41.6 ± 21.1%; P < 0.0001). To determine the prevalence of remodelling patterns, the occurrences of abluminal and luminal processes on endothelial cell surfaces were quantified. Abluminal processes are defined as cytoplasmic protrusions of the abluminal membrane of endothelial cells, which can vary from tiny spurs to solid sprouts of the cell. On the other hand, luminal processes are defined as intraluminal protrusions of the endothelial cell membrane, including various membranous changes from filiform processes to rather thick cytoplasmic bulges. An abluminal process is thought to represent an initial morphological change in sprouting type angiogenesis, and a luminal process to be a sign of implementation of luminal division. The frequency of abluminal processes was significantly higher in the V group than in the C group (V group, 0.243 ± 0.138/µm; C group, 0.114 ± 0.101/µm; P < 0.0001). In contrast, the number of luminal processes on the endothelial cells per micrometre was statistically comparable between the groups (V group, 0.285 ± 0.252/µm; C group, 0.309 ± 0.236/µm, P = 0.381). These results indicate that sprouting is the main mode of VEGF‐induced tumour angiogenesis.

The administration of naked plasmid DNA into the liver induces antitumor innate immunity in a murine liver metastasis model.

Gene therapy is a promising strategy against advanced cancer; however, the safety of viral vectors and the effectiveness of non‐viral vectors have not yet been established. Recently, a hydrodynamics‐based procedure was reported to be an effective and safe method to deliver and transduce DNA into the liver. Herein, we propose a strategy for liver metastasis by a hydrodynamics‐based procedure to deliver naked non‐coding plasmid DNA (pDNA) into the liver as an immunocompetent organ.

Successful Left Hemihepatectomy and Perioperative Management of a Patient with Biliary Cystadenocarcinoma, Complicated with MELAS Syndrome : Report of a Case

Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like syndrome (MELAS) is a rare, fetal disease caused by a mutation in mitochondrial DNA that leads to impaired oxidative metabolism in skeletal muscle, the central nervous system, and liver function. This report presents the case of a 50-year-old woman with biliary cystadenocarcinoma complicated by MELAS who underwent a successful left hemihepatectomy. In this case, the diagnostic key for the malignant tumor was an 18F-fluorodeoxyglucose positron emission tomography study, which was useful even in a patient with MELAS, which causes abnormal glucose metabolism. The perioperative management of such patients includes special precautions to prevent lactic acidosis and deterioration of the reserved liver function after a hepatectomy, since the mitochondrial function in MELAS patients is abnormal. The patient in this report has remained free of liver dysfunctions and cancer recurrence for 2 years following the hepatectomy. This is the first report of a successful major hepatectomy for a patient with MELAS.

Xanthogranulomatous cholecystitis complicated with primary sclerosing cholangitis: report of a case.

Patients with primary sclerosing cholangitis (PSC) are at an increased risk for biliary tract carcinoma. The preoperative diagnosis of a biliary tract tumor as a malignancy is difficult, even using new modalities such as multidetector computed tomography (MD-CT), magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiography (ERC), and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). Surgery is considered to be first line of treatment when these examinations suggest the presence of malignancy in the biliary tract, depending on both the curability of the cancer and the impaired liver function due to PSC. The management of gallbladder masses in patients with PSC remains problematic due to difficulties with the precise diagnosis and adequate surgery. Xanthogranulomatous cholecystitis (XGC) is a type of chronic cholecystitis, and sometimes coexists with gallbladder cancer. It is very difficult to make a preoperative diagnosis differentiating these two diseases. This report presents the case of a patient with XGC, who had been suspected of having gallbladder cancer before surgery, because the tumorous lesion emerged within a year and showed a focally increased uptake by FDG-PET during the follow up for PSC for years. This is the first case of XGC discovered during treatment for PSC.