Exosomal Protease Cargo as Prognostic Biomarker in Colorectal Cancer.

OBJECTIVE: The aim of the study was to develop a model for predicting cancer risk in colorectal polyps' patients (CPPs), as well as to reveal additional prognosis factors for Stage III colorectal cancer based on differences in subpopulations of tetraspanins, tetraspanin-associated and tetraspanin-non-associated proteases in blood plasma exosomes of CPPs and colorectal cancer patients (CRCPs). METHODS: The subpopulations of CD151- and Tspan8-positive exosomes, the subpopulations of metalloproteinase at the surface of СD9-positive exosomes and the level of 20S proteasomes in plasma exosomes in 15 CPPs (tubulovillous adenomas) and 60 CRCPs were evaluated using flow cytometry and Western blotting. Logistic regression analysis was performed to predict cancer risk of CPPs. RESULTS: The levels of 20S proteasomes in exosomes, MMP9+, MMP9+/MMP2+/EMMPRIN+ in CD9-positive blood plasma exosomes are associated with the risk of malignant transformation of colorectal tubulovillous adenomas.  In patients with Stage III CRC, the levels of 20S proteasomes (less than 2 units) and MMP9+ subpopulations (more than 61%) in plasma exosomes are unfavorable prognostic factors for overall survival. The levels of 20S proteasomes and ADAM10+/ADAM17- subpopulations in CD9-positive blood plasma exosomes are the most significant values for predicting relapse-free survival. CONCLUSION: Protease cargo in CD9-positive blood plasma exosomes is prognostic biomarker for colorectal polyps and colorectal cancer.

Extra-lysosomal localization of arylsulfatase B in human colonic epithelium.

The enzyme arylsulfatase B (N-acetylgalactosamine-4-sulfatase; ARSB; ASB) removes 4-sulfate groups from the sulfated glycosaminoglycans (sGAG) chondroitin-4-sulfate (C4S) and dermatan sulfate (DS). Inborn deficiency of ARSB leads to the lysosomal storage disease mucopolysaccharidosis VI, characterized by accumulation of sGAG in vital organs, disruption of normal physiological processes, severe morbidity, and premature death. Recent published work demonstrated extra-lysosomal localization with nuclear and cell membrane ARSB observed in bronchial and colonic epithelial cells, cerebrovascular cells, and hepatic cells. In this report, the authors present ARSB immunostaining in a colonic microarray and show differences in distribution, intensity, and pattern of ARSB staining among normal colon, adenomas, and adenocarcinomas. Distinctive, intense luminal membrane staining was present in the normal epithelial cells but reduced in the malignancies and less in the grade 3 than in the grade 1 adenocarcinomas. In the normal cores, a distinctive pattern of intense cytoplasmic positivity at the luminal surface was followed by reduced staining deeper in the crypts. ARSB enzymatic activity was significantly greater in normal than in malignant tissue. These study findings affirm extra-lysosomal localization of ARSB and suggest that altered ARSB immunostaining and reduced activity may be useful indicators of malignant transformation in human colonic tissue.

Role of matrix metalloproteinase-7 in colorectal adenomas.

Matrix metalloproteinases (MMPs) degregade and remodel the extracellular matrix. They are known to be overexpressed as normal mucosa progresses to adenomas and carcinomas. In our prospective study we measured the overexpression of MMP-7 immunohistochemically in various types of colonic adenomas. Although MMP-7 has already been shown to be overexpressed in various types of colonic adenomas, tubular versus villous adenomas had not been further seperated to date. Seventy-six patients had either normal mucosa (n=15) or tubular (n=32), tubulovillous (n=16), or villous (n=13) colonic adenoma. MMP-7 expression was classified into three categories, as negative, weakly stained, or strongly stained, depending on the percentage of cells stained. Each adenoma was graded according to the percentage of strongly stained areas in the adenoma as G0, G1, G2, or G3. Sixty-nine percent of villous adenomas showed grade 3 staining of MMP-7, versus none of the tubular adenomas. G0 and G1 staining was not detected in the villous adenomas. The results of the study show that the degrees of overexpression of the three subtypes of colonic adenomas were statistically significantly different. In conclusion, MMP-7 overexpression is thought to be an early event in the adenoma-carcinoma pathway.

Analysis of cyclooxygenase expression in human colorectal adenomas.

INTRODUCTION: Evidence from rodent intestinal tumorigenesis models suggests that both cyclooxygenase-1 and cyclooxygenase-2 may play important roles in the development and progression of human sporadic colorectal adenomas. However, previous studies of cyclooxygenase isoform expression in human colorectal adenomas have produced conflicting data. Cyclooxygenase-1 expression has been poorly studied, and cyclooxygenase-2 positivity of adenomas has been variable depending on the detection technique used. It also remains unclear whether villous adenomas express cyclooxygenase-2. METHODS: Cyclooxygenase isoform expression in human sporadic colorectal adenomas was analyzed by reverse transcription-polymerase chain reaction, Western blot analysis, and immunohistochemistry. RESULTS: Variable cyclooxygenase-1 expression was detected in all adenomas (n = 9) by both reverse transcription-polymerase chain reaction and Western blot analysis. Cyclooxygenase-2 expression was detected in eight (89 percent) of nine adenomas by reverse transcription-polymerase chain reaction and immunohistochemistry. Cyclooxygenase-2 protein was not detected by Western blot analysis in any adenoma. Cyclooxygenase-2 was expressed by all histopathologic types of adenoma and localized predominantly to superficial interstitial cells, in which it was associated with increased adenoma size. CONCLUSION: Cyclooxygenase-1 is expressed at variable levels by all adenomas. Cyclooxygenase-2 is expressed by the majority of adenomas, including those of the villous type, at levels below the sensitivity of Western blot analysis.

Expression of group II phospholipase A2 in Paneth cells of an adenoma of the rectum. A case report.

A case of tubulovillous adenoma in the rectum of a 51-year-old man is presented. The tumour contained numerous Paneth cells which formed well-developed glands in the basal areas. Group II phospholipase A2 and lysozyme were found in the tumour cells by immunohistochemistry. mRNA of group II phospholipase A2 was localized in the tumour cells by in situ hybridization. It was concluded that a considerable part of this rare type of tumour consisted of Paneth cells which were capable of synthesizing group II phospholipase A2.

A study of the lactic dehydrogenase isoenzyme patterns in the adenoma--carcinoma sequence of the colon.

In order to determine whether the LDH isoenzyme pattern, measuring the percentages of LDH4-5 (M monomer), might be a marker in the adenoma-carcinoma sequence, 103 adenomas, 8 adenomas with proven malignant degeneration and 27 adenocarcinomas of the large intestine, as well as 12 biopsy samples of colonic mucosa from normal controls, were studied histologically and histochemically. The proportion of M polypeptide was significantly increased in adenomas of larger size (diameter > 2 cm), in adenomas with a larger villous component, and in those with severe dysplasia. The largest proportion of M polypeptide was found in villous adenomas and colloid adenocarcinomas, and might reflect a common origin. These results suggest that the histochemical study of the LDH isoenzymogram might be a useful marker for detecting early malignant degeneration in adenomas of the colon.