The Use of Smoothelin and Other Antibodies in the Diagnosis of Uterine and Soft Tissue Smooth Muscle Tumors.

Smoothelin is a cytoplasmic protein expressed in differentiated smooth muscle cells. Immunohistochemical evaluation of smoothelin has previously been reported in gastrointestinal (GI) smooth muscle tumors, but has yet to be studied in smooth muscle tumors of uterine and other soft tissue origin. DOG1 expression is reported to be specific for GI stromal tumors; however, variable expression has been reported in leiomyosarcomas (LMS) depending on site of origin. Overexpression of p16 is common in LMS of uterine and other sites of origin, but has not been correlated with tumor grade. This study explores the differential expression of these markers, as well as caldesmon, in LMS cases to assess diagnostic utility. Using tissue microarrays and cases from Tulane Medical Center and Medical College of Wisconsin, expression of smoothelin, DOG1, caldesmon, and p16 was evaluated by immunohistochemistry in 87 cases of LMS. The cases were subdivided by location of origin into uterine (N=31) and nonuterine (N=56) with 10 of the nonuterine of GI origin, as well as by grade into low grade (N=27) and intermediate and high grade (N=60). Differential expression among different grades and locations was evaluated. The same markers were evaluated in atypical leiomyoma cases (N=4) and 1 smooth muscle tumor of uncertain malignant potential case (N=1). Smoothelin expression was also assessed in 20 benign uterine leiomyomas. Weak DOG1 expression is rare but possible in extrauterine LMS. Expression of p16 is common in both uterine and extrauterine LMS, and more frequent in higher grades. Expression of smoothelin in this study differed depending on tumor type, grade, and site of origin. All leiomyomas and most atypical leiomyomas showed cytoplasmic positivity for smoothelin, whereas only 5% of LMS had cytoplasmic expression. The study suggests smoothelin may be downregulated in the cytoplasm of malignant smooth muscle tumor cells and may serve as a supportive aid in the distinction of LMS from benign smooth muscle tumors in cases where it is difficult by morphology alone.

The use of bioabsorbable staple line reinforcement for circular stapler (BSG "Seamguard") in colorectal surgery: initial experience.

Of all the complications associated with colorectal surgery, the most devastating and constant, despite all techniques being performed properly is anastomotic leakage, especially in left colon and rectal resections with rates as high as 50% when the rectum is involved. In 2005, our center published the preliminary experience with the use of linear staple line reinforcement for colon surgery. The purpose of this paper is to present a series of cases using a new conformation of bioabsorbable reinforcement for circular staplers in 5 patients, 2 patients with rectal cancer, 2 patients with diverticular disease, and 1 patient with sigmoid cancer. These initial data are very promising and has encouraged us to continue using this device on further patients.

Interleukin-10 induced activating transcription factor 3 transcriptional suppression of matrix metalloproteinase-2 gene expression in human prostate CPTX-1532 Cells.

Aberrant expression of the 72-kDa type IV collagenase [matrix metalloproteinase (MMP)-2] is implicated in the invasion and angiogenesis process of malignant tumors. We investigated the effects of interleukin (IL)-10 on MMP-2 expression in CPTX-1532 human prostate tumor cells. Our results demonstrate that IL-10 significantly inhibited MMP-2 transcription and protein expression induced by a phorbol ester, phorbol 12-myristate 13-acetate. The inhibitory effects of IL-10 on MMP-2 expression correlated with the suppression of MMP-2 promoter activity. To determine the mechanism of IL-10 action, we examined IL-10-dependent promoter activity with luciferase constructs from a 2-kbp promoter region of the human MMP-2 gene. We functionally characterized the promoter fragments by transient transfection experiments with CPTX-1532 cells. The experiments revealed that a cAMP responsive element binding protein (CREB) consensus domain was identified upstream of the 5' transcriptional start site, which was highly responsive to IL-10-dependent down-regulation of promoter luciferase activity. Electrophoretic mobility shift assays combined with antibody "supershift assays" confirmed the data from the luciferase assays. Immunoblot assays of activating transcription factor (ATF) 3 immunoprecipitates with tyrosine specific antibodies revealed that IL-10 stimulated tyrosine phosphorylation of ATF3 to activate binding to the CREB domain and suppress MMP-2 expression. Studies with stable, IL-10 transfected CPTX-1532 subclones further showed that IL-10 failed to suppress MMP-2 expression in ATF3-deficient CPTX-1532 cells, where the ATF3 mRNA was destroyed with a DNAzyme oligonucleotide targeting the 5' region of the mRNA. Finally, reconstitution of ATF3 successfully restored the inhibitory effects of IL-10 on MMP-2 gene expression. Taken together, these data demonstrate the critical role of tyrosine phosphorylated ATF3 and the CREB consensus domain in IL-10 suppression of MMP-2 gene expression in primary human prostate tumor cells.