Experimental renal and hepatic artery embolization with a new embolic agent, atelocollagen, in a porcine model

PURPOSEWe aimed to investigate the potentiality of atelocollagen, a new embolic agent which is collagen type I in a porcine experimental model. MATERIALS AND METHODSThree pigs underwent transcatheter embolization of lower interlobular arteries of the renal artery (n=6) and one branch of the hepatic artery (n=3) with collagen type I. Angiography was performed prearterial, during, and postarterial embolization. After the procedure, samples from the embolized organs were evaluated by histological analysis. RESULTSSix lower interlobular renal arteries and three hepatic arteries were successfully embolized by administration of 0.8±0.3 mL and 2.9±1.2 mL, respectively, of the collagen type I. Histological findings of the embolized kidney specimens showed that the collagenous materials filled the arterial lumen, whose size ranged from 2.02 to 839.82 μm and reached the level of afferent arteries of glomerular tufts. Although the area of occluded arteries of the liver was smaller than the kidney, histological findings of the liver specimens showed that the collagenous materials filled small arterial lumens from 2.81 to 187.86 μm in diameter. CONCLUSIONAtelocollagen, a collagen type I, has the potential to be used to embolize the distal vessels of both renal and hepatic arteries

Expression of MUC17 is regulated by HIF1α-mediated hypoxic responses and requires a methylation-free hypoxia responsible element in pancreatic cancer.

MUC17 is a type 1 membrane-bound glycoprotein that is mainly expressed in the digestive tract. Recent studies have demonstrated that the aberrant overexpression of MUC17 is correlated with the malignant potential of pancreatic ductal adenocarcinomas (PDACs); however, the exact regulatory mechanism of MUC17 expression has yet to be identified. Here, we provide the first report of the MUC17 regulatory mechanism under hypoxia, an essential feature of the tumor microenvironment and a driving force of cancer progression. Our data revealed that MUC17 was significantly induced by hypoxic stimulation through a hypoxia-inducible factor 1α (HIF1α)-dependent pathway in some pancreatic cancer cells (e.g., AsPC1), whereas other pancreatic cancer cells (e.g., BxPC3) exhibited little response to hypoxia. Interestingly, these low-responsive cells have highly methylated CpG motifs within the hypoxia responsive element (HRE, 5\u27-RCGTG-3\u27), a binding site for HIF1α. Thus, we investigated the demethylation effects of CpG at HRE on the hypoxic induction of MUC17. Treatment of low-responsive cells with 5-aza-2\u27-deoxycytidine followed by additional hypoxic incubation resulted in the restoration of hypoxic MUC17 induction. Furthermore, DNA methylation of HRE in pancreatic tissues from patients with PDACs showed higher hypomethylation status as compared to those from non-cancerous tissues, and hypomethylation was also correlated with MUC17 mRNA expression. Taken together, these findings suggested that the HIF1α-mediated hypoxic signal pathway contributes to MUC17 expression, and DNA methylation of HRE could be a determinant of the hypoxic inducibility of MUC17 in pancreatic cancer cells

MUC4 and MUC1 expression in adenocarcinoma of the stomach correlates with vessel invasion and lymph node metastasis: an immunohistochemical study of early gastric cancer.

We have previously reported that MUC4 expression is a poor prognostic factor in various carcinomas. Our previous study also showed that MUC1 expression in gastric cancers, including the early and advanced stages is a poor prognostic factor. In the present study, the expression profiles of MUC4 and MUC1 were examined by immunohistochemistry (IHC) using two anti-MUC4 monoclonal antibodies (MAbs), 8G7 and 1G8, and anti-MUC1 MAb DF3 in 104 gastrectomy specimens of early gastric adenocarcinoma with submucosal invasion (pT1b2), including 197 histological subtype lesions. Before the IHC study of the human specimens, we evaluated the specificity of the two MAbs by Western blotting and IHC of two MUC4 mRNA expressing gastric cancer cell lines. MAb 8G7 reacted clearly, whereas MAb 1G8 did not show any reactivity, in either Western blotting or IHC. In the IHC of the gastric cancers, the expression rates of MUC4/8G7 detected by MAb 8G7, MUC4/1G8 detected by MAb 1G8 and MUC1/DF3 detected by MAb DF3 in well differentiated types (70%, 38/54; 67%, 36/54; 52%, 28/54) were significantly higher than those in poorly differentiated types (18%, 10/55; 36%, 20/55; 13%, 7/55) (

Pathobiological implications of mucin (MUC) expression in the outcome of small bowel cancer.

Mucins have been associated with survival in various cancer patients, but there have been no studies of mucins in small bowel carcinoma (SBC). In this study, we investigated the relationships between mucin expression and clinicopathologic factors in 60 SBC cases, in which expression profiles of MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC6 and MUC16 in cancer and normal tissues were examined by immunohistochemistry. MUC1, MUC5AC and MUC16 expression was increased in SBC lesions compared to the normal epithelium, and expression of these mucins was related to clinicopathologic factors, as follows: MUC1 [tumor location (p = 0.019), depth (p = 0.017) and curability (p = 0.007)], MUC5AC [tumor location (p = 0.063) and lymph node metastasis (p = 0.059)], and MUC16 [venous invasion (p = 0.016) and curability (p = 0.016)]. Analysis of 58 cases with survival data revealed five factors associated with a poor prognosis: poorly-differentiated or neuroendocrine histological type (

The application of methylation specific electrophoresis (MSE) to DNA methylation analysis of the 5' CpG island of mucin in cancer cells

<p>Abstract</p> <p>Background</p> <p>Methylation of CpG sites in genomic DNA plays an important role in gene regulation and especially in gene silencing. We have reported mechanisms of epigenetic regulation for expression of mucins, which are markers of malignancy potential and early detection of human neoplasms. Epigenetic changes in promoter regions appear to be the first step in expression of mucins. Thus, detection of promoter methylation status is important for early diagnosis of cancer, monitoring of tumor behavior, and evaluating the response of tumors to targeted therapy. However, conventional analytical methods for DNA methylation require a large amount of DNA and have low sensitivity.</p> <p>Methods</p> <p>Here, we report a modified version of the bisulfite-DGGE (denaturing gradient gel electrophoresis) using a nested PCR approach. We designated this method as methylation specific electrophoresis (MSE). The MSE method is comprised of the following steps: (a) bisulfite treatment of genomic DNA, (b) amplification of the target DNA by a nested PCR approach and (c) applying to DGGE. To examine whether the MSE method is able to analyze DNA methylation of mucin genes in various samples, we apply it to DNA obtained from state cell lines, ethanol-fixed colonic crypts and human pancreatic juices.</p> <p>Result</p> <p>The MSE method greatly decreases the amount of input DNA. The lower detection limit for distinguishing different methylation status is < 0.1% and the detectable minimum amount of DNA is 20 pg, which can be obtained from only a few cells. We also show that MSE can be used for analysis of challenging samples such as human isolated colonic crypts or human pancreatic juices, from which only a small amount of DNA can be extracted.</p> <p>Conclusions</p> <p>The MSE method can provide a qualitative information of methylated sequence profile. The MSE method allows sensitive and specific analysis of the DNA methylation pattern of almost any block of multiple CpG sites. The MSE method can be applied to analysis of DNA methylation status in many different clinical samples, and this may facilitate identification of new risk markers.</p

Diluted hydrochloric acid generates larger radiofrequency ablation lesions in excised porcine livers

PURPOSEThis study evaluated the influence of continuous infusion of diluted hydrochloric acid during radiofrequency ablation (RFA) on the size of ablated lesions. MATERIALS AND METHODSExperiments were performed in 20 excised porcine livers using three different treatment modalities: (1) normal saline-enhanced RFA (NS-RFA), which was normal saline pumped into ablated tissue during RFA; (2) diluted hydrochloric acid ablation (DHAA), which was 3 mol/L diluted hydrochloric acid (HCl) injected into hepatic tissue without RFA; and (3) HCl-enhanced RFA (HCl-RFA), which was 3 mol/L diluted HCl continuously infused into ablated tissue during RFA. We produced 20 HCl-RFA and NS-RFA lesions, respectively, using a monopolar perfusion electrode connected to a commercially available radiofrequency generator, and 20 DHAA lesions using an 18-gauge Chiba needle. The ablated lesions were evaluated both macroscopically and histologically. Dimensions of lesions were compared among HCl-RFA, NS-RFA, and DHAA. RESULTSThe ablated lesions had an elliptical-like shape and were well-demarcated with normal liver tissue. The mean volume, longitudinal diameter, and transverse diameter of NS-RFA lesions were 11.24±0.29 cm3, 3.49±0.07 cm, and 2.48±0.03 cm, those of HCl-RFA lesions were 58.14±3.05 cm3, 5.51±0.05 cm, and 4.49±0.11 cm, and those of DHAA lesions were 4.41±0.16 cm3, 2.43±0.08 cm, and 1.8±0.03 cm, respectively. The mean dimensions of HCl-RFA lesions were the largest among the three types of ablation (P < 0.001). Under the present experimental conditions, the continuous infusion of diluted HCl during RFA can generate larger ablated lesions than NS-RFA or DHAA in excised porcine livers