Cysteine protease activities and tumor development in human colorectal carcinoma

Many studies of malignant cells or tissues in culture have implicated cysteine proteases in the progression of malignancy. We have extended these observations by measuring quantitative and qualitative changes in the expression of cathepsin B-like and L-like cysteine proteases during the growth and development of human colorectal carcinomas. Data derived from matched pairs of normal colorectal mucosa and carcinoma tissue from 27 patients demonstrated that both cathepsin B-like and cathepsin L-like specific activities were significantly elevated (P less than 0.005) in the carcinoma tissue, while levels of endogenous cysteine protease inhibitor remained constant. Correlation of cathepsin enzyme activities with different stages of colorectal cancer demonstrated significantly higher cysteine protease activities in individuals with Dukes' A tumors (tumors confined to the bowel wall) than in patients with more advanced tumors (Dukes' B, C, or D tumors) (P less than 0.01-0.05). The relative proportion of activities contained in tumor epithelial and stromal elements remains to be elucidated. These results suggest an important role for cysteine proteases in the early progression of human colorectal carcinoma.     

Cysteine endopeptidase activity levels in normal human tissues, colorectal adenomas and carcinomas

We have assayed cysteine endopeptidase activities in 17 types of normal human tissue and in matched sets of colorectal mucosa, adenoma and carcinoma samples. Our data indicate that cathepsin B enzyme levels vary 70-fold and cathepsin L enzyme levels vary 20-fold from one normal tissue to another. Cathepsin B specific activity in normal tissues fell into 3 categories. High activity, with a mean of 156.7 +/- 41.5 nmoles min-1 mg-1 protein, was measured in liver, thyroid, kidney and spleen; intermediate activity, with a mean of 60.2 +/- 8.3 nmoles min-1 mg-1 protein, was measured in heart, colon, adrenal and lung; and low activity, with a mean of 18.4 +/- 9.7 nmoles min-1 mg-1 protein, was measured in prostate, testis, nerve, stomach, pancreas, brain, skeletal muscle, skin and breast. Cathepsin L specific activity fell into 2 categories. High activity, with a mean of 51.1 +/- 4.9 nmoles min-1 mg-1 protein, was measured in thyroid, liver and kidney; and low activity, with a mean of 11.4 +/- 5.5 nmoles min-1 mg-1 protein, was measured in spleen, colon, heart, adrenal, lung, testis, brain, nerve, skin, stomach, pancreas, skeletal muscle, prostate and breast. Our characterization of these enzyme levels provides a reference standard for normal cathepsin B and L activities in human tissues that should enhance the detection of their deregulation in disease states. For example, in studies of colorectal carcinoma and normal mucosa, we observed a significant tumor-specific increase in cathepsin B and L activities with particularly high activity levels in earlier (Dukes' A and B) compared to later (Dukes' C and D) stages of colorectal cancer. In contrast, adenomas from colorectal cancer patients expressed normal levels of cathepsin B activity, providing evidence that the increase in expression of cathepsin B may be a sensitive marker for progression from the pre-malignant to the malignant state in the development of colorectal cancer.     

Alterations in cathepsin H activity and protein patterns in human colorectal carcinomas

Our analyses of cathepsin H activity levels and protein forms in human colorectal cancers compared to matched control mucosa support the concept that altered proteinase expression patterns may reflect both cancer stage and site. Cathepsin H-specific activity was significantly increased in colorectal cancers compared to control mucosa (P = 0.003; n = 77). Highest specific activities and cancer/normal ratios (C/N) for activity were measured in Dukes' B and C stage carcinomas, cancers involved in local spread and invasion to lymph nodes. In contrast, cathepsin B and L activities analysed in the same paired extracts had been shown to be most frequently elevated in earlier stage carcinomas (Dukes' A and B), confirming that cathepsin H demonstrates a distinct pattern of expression during colorectal cancer progression. Although cathepsin H activities were most commonly elevated in Dukes' C cancers at all colon sites, both specific activity and C/N ratios were significantly higher for cancers of the left colon compared to other colon locations. A subset of 43 paired extracts analysed on Western blots also revealed consistent changes in cathepsin H protein forms in cancers. Normal mucosa typically showed a strong protein doublet at 31 and 29 kDa while cancers demonstrated decreased expression or total loss of the 31 kDa protein (90% of cases), equal or increased expression of the 29-kDa protein (67% of cases) and the new appearance or up-regulation of a cathepsin H band at 22 kDa (78% of cases). C/N ratios for cathepsin H enzyme activity correlated significantly with C/N ratios for the 29 kDa mature single-chain protein form (P < 0.001), with increased activity most commonly associated with elevated expression of 29-kDa cathepsin H but also with up-regulation of the 22-kDa band, suggesting a shift to more fully processed, mature active cathepsin H protein forms in cancers. Changes in cathepsin H expression were also detected by immunohistochemistry as elevated cathepsin H staining in tumour epithelial cells.     

Cathepsin D protein levels in colorectal tumors: divergent expression patterns suggest complex regulation and function

Cathepsin D protein patterns were analyzed in 59 colorectal tumors by Western blotting, glycosylation and immunohistochemical assays. Measurement of protein content by laser densitometry of tumor/normal pairs on Western blots revealed loss of cathepsin D protein in more than 50% of colorectal tumors. Independent loading controls and statistical estimates of reproducibility on duplicate assays confirmed frequent decreases in cathepsin D. For cases having a tumor/normal ratio (T/N) <1, the average T/N was 0.50+/-0.19, equivalent to the loss of one cathepsin D allele. However, 2-fold increases in cathepsin D protein levels were also observed in approximately 1/3 of tumors, supporting the concept that colorectal cancers develop via divergent molecular pathways and that cathepsin D may function differently in different cancers. Although normal cathepsin D expression was detected in some earlier stage tumors, protein levels became increasingly bimodal with progression such that cathepsin D levels were increased in 1/3 but decreased in 2/3 of stage III and IV cancers. Other laboratories have reported both significant loss and gain of chromosome 11 (site of the cathepsin D gene) in different colorectal tumors, providing a possible mechanism for our observations on cathepsin D. However, differential regulation of cathepsin D expression by mutant versus wild-type p53 may also contribute to variable cathepsin D levels in colorectal cancers. Immunohistochemical studies demonstrated a shift from a predominantly punctate distribution of cathepsin D protein in normal mucosa to a more diffuse cytoplasmic distribution in tumor tissues. Mutant forms of cathepsin D were not detected in tumors either as changes in electrophoretic mobility or altered glycosylation but minor changes in protein sequence could not be ruled out. Loss of cathepsin D protein may provide an advantage to colorectal tumors related to a loss of cathepsin D function in proapototic or antiangiogenic pathways while increased cathepsin D may promote cancer cell proliferation or invasion.     

Cyclooxygenase-2 expression correlates with tumor neovascularization and prognosis in human colorectal carcinoma patients.

The role of cyclooxygenase-2 (COX-2) in tumor neovascularization of human colorectal carcinoma is yet to be delineated. One hundred colorectal carcinoma specimens were evaluated for COX-2 expression and CD34-stained microvessel density (MVD) by immunohistochemical methods. The relationships between COX-2 expression and clinicopathological feature of the patients, MVD, and survival time were analyzed. Increased COX-2 expression was significantly correlated with pathologically unfavorable findings such as tumor size (> 3.0 cm), tumor differentiation (poor, moderate > well differentiated), number of metastatic lymph nodes (24), and Dukes' stage (Dukes' B, C, and D). Larger number of microvessels congregated around the COX-2-expressing area, and the Spearman rank correlation test showed a strong correlation between COX-2 expression and tumor MVD (P < 0.0001). Patients with COX-2-positive tumors had a significantly (P = 0.037, by log-rank test) shorter survival time than those with negative tumors did. In the multivariate analysis, however, only Dukes' stage and number of metastatic lymph nodes remained as independent prognostic factors. Augmented tumor neovascularization may be one of the several effects of COX-2 responsible for poor prognosis in human colorectal carcinoma patients.     

Expression of Cathepsin B and L antigen and activity is associated with early colorectal cancer progression

Cathepsin B and Cathepsin L are cysteine proteases important in the process of invasion and metastasis. The aim of our study was to assay antigen and activity levels of these enzymes and to correlate these with established clinical and pathological prognostic parameters including patient survival. 99 patients undergoing operations for colorectal cancer were included in this study. We quantitated cathepsin B and L levels in matched normal mucosa and cancer samples using an enzyme-linked immunosorbent assay (ELISA) and specific activity assays and expressed the results as tumour/normal ratios. Significant correlations were found between tumour/normal cathepsin B and L antigen and activity ratios. Cathepsin B and L tumour/normal activity ratios were greater than 1 in early stage disease and there were gradual reductions in cathepsin B (P = 0.02) and L (P = 0.03) activity ratios with advancing tumour stage. Survival of patients with potentially curative disease was inversely related to both cathepsin B (P = 0.007) and L (P = 0.001) activity ratio, in addition to cathepsin L antigen ratio (P = 0.008). Our findings suggest that cysteine proteases play an important role in colorectal cancer progression.     

Decreased expression of repulsive guidance molecule member A by DNA methylation in colorectal cancer is related to tumor progression

Previous studies have shown decreased expression of repulsive guidance molecule member A (RGMa) in colorectal cancer. However, the relationship between the expression levels and promoter DNA methylation status of RGMa and the clinical characteristics of colorectal cancer has not been previously reported. Here, we investigated the expression of RGMa by immunohistochemistry, real-time PCR and western blotting and analyzed the methylation status of the RGMa promoter using Sequenom's MassARRAY platform in colorectal cancer tissues and adjacent normal colorectal tissues. The results showed that RGMa expression was decreased in cancer tissues compared with adjacent normal tissues (p<0.01). Furthermore, a tendency for decreased expression in tumor tissues was observed from Dukes' stage A to stage D (p<0.01). In addition, significantly higher levels of hypermethylation in promoter regions of RGMa were observed in colorectal cancer tissues, compared with those in adjacent normal colorectal tissues (p<0.01). Moreover, the methylation levels of RGMa in tumor tissues were significantly increased in Dukes' stage C and D compared with Dukes' stage A and B (p<0.01). Our results indicate that RGMa expression and promoter methylation status are closely related to colorectal cancer genesis and progression. Determination of the expression level and methylation frequency of RGMa in colorectal cancer tissues may have benefit for early diagnosis and for evaluating patient prognosis.     

Securin induces genetic instability in colorectal cancer by inhibiting double-stranded DNA repair activity

Genetic instability (GI) is a hallmark feature of tumor development. Securin, also known as pituitary tumor transforming gene (PTTG), is a mitotic checkpoint protein which is highly expressed in numerous cancers, is associated with tumor invasiveness, and induces GI in thyroid cells. We used fluorescence inter-simple sequence repeat PCR to assess GI caused primarily by DNA breakage events in 19 colorectal tumors. GI values ranged significantly, with Dukes' stage C&D colorectal tumors exhibiting greater GI and higher securin expression than Dukes' stage A&B tumors. Consistent with these findings, we observed a dose-dependent increase in GI in HCT116 cells in response to securin overexpression, as well as in non-transformed human fibroblasts. As securin has been implicated in a novel DNA repair pathway in fission yeast, we investigated its potential role in chemotoxic DNA damage response pathways in mammalian cells, using host cell reactivation assays. Securin overexpression in HCT116 cells inhibited etoposide-induced double-stranded DNA damage repair activity, and repressed Ku heterodimer function. Additionally, we observed that securin and Ku70 showed a reciprocal cytosol-nuclear translocation in response to etoposide-induced dsDNA damage. Our data suggest that, by repressing Ku70 activity and inhibiting the non-homologous end-joining dsDNA repair pathway, securin may be a critical gene in the development of GI in colorectal cancer.     

The expression of lysosomal proteinases and their inhibitors in breast cancer: Possible relationship to prognosis of the disease

Proteolytic enzymes have been proposed as new biological prognostic indicators to facilitate decisions about treatment of breast cancer patients following surgery. We reported earlier that the activities of cysteine proteinases (CP), cathepsin (Cat) B and cathepsin (Cat) L and the expression of stefin A might be associated with breast tumor progression and prognosis. Here, the protein concentrations of Cats D, B and L and stefin A have been measured in a series of 60 matched pairs of breast tumours and control adjacent tissues, using ELIS As developed in our laboratory. Median tumor concentrations of Cat D (47 pm/mg), Cat B (222 ng/mg) and Cat L (88 ng/mg) were significantly (p<0.0005) increased by 7 fold, 27 fold and 6 fold, respectively. Much greater increases in the activities of Cat B (63 fold) and of Cat L (274 fold) were found, indicating enhanced activation of cysteine proteinases in tumors, due either to proteolytic activation of proCat B and proCat L and/or to a decrease in specific endogenous cystatins. However, the 1.6-fold decreased (p<0.0001) levels of inhibition by cystatins could not be entirely responsible for more than 100-fold increased ratio of CP:cystatins activity. Moreover, stefin A was either increased or decreased in tumor samples, resulting in a 1.4-fold median increase in tumors. Comparing the biological parameters with the established histo-pathological prognosticators, we found that the increased protein concentration of Cat B was associated with lymph node involvement (p<0.009) and higher stage (p<0.003), and both Cat B and Cat L activities were more increased in high grade tumours (p<0.05). Survival analysis revealed that stefin A was the most significant prognostic factor for disease-free (p<0.008) and overall survival (p<0.02), followed by increased Cat B activity and protein concentration. Cat L was of borderline significance while Cat D was not significant for prognosis. We conclude that enhanced activation of CP, due partially to an imbalance between cysteine proteinases and inhibitors is linked to the progression of breast cancer. Larger sample size is needed to confirm the prognostic significance of stefin A, Cat B and Cat L.     

Expression of cathepsin D in bladder carcinoma: correlation with pathological features and serum cystatin C levels

AIMS AND BACKGROUND: The aim of this study is to evaluate the expression of cathepsin D in primary bladder cancer and to determine its relationship with conventional pathological features and serum cystatin C levels. METHODS: The immunohistochemical cathepsin D expression and staining patterns of epithelial and stromal cells were investigated in 21 patients with primary bladder carcinoma. Serum cystatin C levels were determined by immunoturbidimetry and compared with matched controls. RESULTS: There were 7 papillary neoplasms of low malignant potential, 7 low-grade and 7 high-grade carcinomas. Six tumors were invasive. Statistical analysis showed a significant inverse relationship between cathepsin D expression of the tumor cells and tumor grade and stage (P = 0.018 and P = 0.046, respectively). Serum cystatin C levels of the controls and patients varied between 0.39 mg/L and 1.99 mg/L (P > 0.05). There was no significant relation between cathepsin D expression in tumor tissue and serum cystatin C levels. CONCLUSIONS: Loss of cathepsin D expression in bladder carcinomas may be associated with high-grade and invasive tumors. Thus, increased cathepsin D expression by tumor cells may be related to local tumor invasion at an early stage, but it seems that extracellular cystatin C is not affected by cathepsin D expression of tumor or stromal cells, and cystatin C concentrations are not directly correlated with the progression of primary bladder carcinomas.     

Cathepsin B promotes colorectal tumorigenesis,cell invasion,and metastasis

Cathepsin B is a cysteine proteinase that primarily functions as an endopeptidase within endolysosomal compartments in normal cells. However, during tumoral expansion, the regulation of cathepsin B can be altered at multiple levels, thereby resulting in its overexpression and export outside of the cell. This may suggest a possible role of cathepsin B in alterations leading to cancer progression. The aim of this study was to determine the contribution of intracellular and extracellular cathepsin B in growth, tumorigenesis, and invasion of colorectal cancer (CRC) cells. Results show that mRNA and activated levels of cathepsin B were both increased in human adenomas and in CRCs of all stages. Treatment of CRC cells with the highly selective and non‐permeant cathepsin B inhibitor Ca074 revealed that extracellular cathepsin B actively contributed to the invasiveness of human CRC cells while not essential for their growth in soft agar. Cathepsin B silencing by RNAi in human CRC cells inhibited their growth in soft agar, as well as their invasion capacity, tumoral expansion, and metastatic spread in immunodeficient mice. Higher levels of the cell cycle inhibitor p27^Kip1 were observed in cathepsin B‐deficient tumors as well as an increase in cyclin B1. Finally, cathepsin B colocalized with p27^Kip1 within the lysosomes and efficiently degraded the inhibitor. In conclusion, the present data demonstrate that cathepsin B is a significant factor in colorectal tumor development, invasion, and metastatic spreading and may, therefore, represent a potential pharmacological target for colorectal tumor therapy. © 2015 The Authors. Molecular Carcinogenesis, published by Wiley Periodicals, Inc.     

Immunohistochemical and biochemical study of a cathepsin B-like proteinase in human colonic cancers

An immunohistological study was carried out on 51 human colorectal adenocarcinomas and eight samples of histologically normal colonic mucosa removed far from tumors, using anti-rabbit cathepsin B and anti-human cathepsin B immunoglobulins. Positive reactions were obtained on tumor cells and macrophage-like cells. However, as these immunoglobulins could not discriminate between cathepsin B and cathepsin B-like proteinases, and as they cross-reacted with cathepsins H and L, a partial characterization of the proteinase activities was performed in order to identify the type of enzyme present in the positive cells. The levels of cathepsins H and L were very low in extracts of colorectal tumors and normal colonic mucosa. A peculiar cathepsin B-like proteinase activity with pH optimum at 6.8 was found in tumor extracts together with the lysosomal cathepsin B, whereas normal colonic mucosa showed only cathepsin B activity (pH optimum, 6.0). These results indicate that lysosomal cathepsin B is responsible for staining of macrophage-like cells found in the lamina propria of colonic mucosa and in the peritumoral stroma. Immunohistochemical staining of colonic tumor cells observed in 29/51 cases seems on the other hand to be primarily due to a cathepsin B-like proteinase. Three colonic tumor cell lines, Colo-205, HT-29, and SW-1116, were also studied using the same methods. These cells produced a latent cathepsin B-like proteinase which, after activation, was similar to that found in tumor extracts. This latent proteinase was detected mainly in the culture media. The cultured colonic tumor cells, after staining by anti-cathepsin B antibodies, showed strongly positive granules. In conclusion, this work demonstrates that malignant colonic cells are the source of a cathepsin B-like proteinase, with optimal activity near neutrality. Its secretion into the extracellular space indicates furthermore, that it may be an important component of the "proteinase cascade" associated with tumor invasion and metastasis.     

Increased Cell-surface Urokinase in Advanced Ovarian Cancer

Urokinase-type plasminogen activator (uPA), uPA receptors, and cathepsin B were quantitatcd by using an immunological method, enzyme-linked immunosorbent assay, and amidolytic activity assays in 15 malignant and 10 benign epithelial ovarian tumors. The levels of uPA and uPA receptors, as well as cathepsin B, were found to be higher in membrane preparations obtained from malignant tumors than in those obtained from benign tumors. Acid-treated membranes acquired the ability to bind uPA, indicating that uPA is bound to a specific surface receptor that is not completely saturated. Levels of single-chain uPA (pro-uPA) and high-molecular-weight uPA in membrane preparations were measured by immunoadsorbent-amidolytic assay. The finding of a significant increase in amidolytic activity following activation of uPAs by plasmin suggested that less than half (30–40%) of all membrane immunoreactive uPAs is present in the enzymatically inactive pro-uPA form. In the membranes of malignant tumors, levels of uPA receptor and cathepsin B did not vary with stage of disease. On the other hand, we found that the level of receptor-bound uPA antigen/activity was significantly increased in advanced malignant tumors. Receptor-bound uPA may play an important role in determining invasive potential of tumor cells. Since ovarian cancer cells produce both pro-uPA and cathepsin B, the possibility of activation of tumor cell-derived pro-uPA by cellular protease cathepsin B must be considered.     

Immunostained cathepsins B and L correlate with depth of invasion and different metastatic pathways in early stage gastric carcinoma

BACKGROUND: With the recent development of minimal treatment for early stage gastric carcinoma, identifying specific indicators of the metastatic potential of primary tumors has become more important. Cathepsin B and cathepsin L, both lysosomal cysteine proteases, degrade the extracellular matrix during tumor progression. Although many studies have shown their relation to human cancer progression, little is known about their roles in the early stage. The clinicopathologic significance of cathepsins was therefore studied in early stage gastric carcinoma. METHODS: Expression of both cathepsins was studied immunohistochemically in 51 tissue specimens from gastric carcinomas that invaded the submucosal layer or muscularis propria. The relation between their expression and clinicopathologic factors was analyzed. RESULTS: Both cathepsins were expressed at higher levels in tumors that invaded the muscularis propria than in those within the submucosa (P < 0.05). In addition, tumors with lymphatic invasion showed higher cathepsin B expression than those without it (P < 0.05), whereas tumors with venous invasion showed higher cathepsin L expression than those without it (P < 0.05). No other clinicopathologic factors correlated with expression of either cathepsin. CONCLUSIONS: Tumors with overexpression of cathepsins have powerful potential for invasiveness in the early stage of gastric carcinoma. Moreover, the authors hypothesize that cathepsins may be one of the determinants of the metastatic route. To the authors' knowledge, this is the first report on specific proteases concerning the mode of metastasis, and the results of this study suggest that therapeutic strategies for early stage gastric carcinoma might need to be changed according to the status of cathepsins.     

Prognostic significance of PDCD4 expression and association with microRNA-21 in each Dukes' stage of colorectal cancer patients

Down-regulation of the novel tumor suppressor gene programmed cell death 4 (PDCD4) was demonstrated in several types of cancer and regulation by micro-RNA is gaining attention. However, the clinical significance of the PDCD4 gene in colorectal cancer (CRC) patients still remains unclear. In particular, the significance of PDCD4 mRNA expression in each tumor stage has not been reported. In this study, we evaluated the prognostic value of PDCD4 expression in each Dukes' stage of CRC patients. Furthermore, relationships between the PDCD4 mRNA and microRNA-21 (miR-21) were evaluated. Tumor tissues and normal adjacent tumor tissues from 326 patients with CRC (Dukes' stage A, 44 cases; Dukes' B, 118 cases; Dukes' C, 100 cases; Dukes' D, 64 cases) were examined. The PDCD4 mRNA was investigated by the quantitative real-time RT-PCR method and miR-21 was examined by TaqMan microRNA assays. The overall survival rates (OS) and disease-free survival rates (DFS) of low PDCD4 patients were significantly worse than those of patients with high expression. In analysis of each tumor stage, OS and DFS of patients with low PDCD4 levels were significantly worse than those with high PDCD4 levels in Dukes' stage B and C. In Dukes' stage D, patients with low PDCD4 expression showed a significant worse OS compared to those of patients with high PDCD4 expression. In contrast, no significant differences were seen between these groups in patients with Dukes' stage A. PDCD4 expression in CRC tissues was an independent prognostic factor in Dukes' stage B, C and D. Significant inverse correlations were demonstrated between PDCD4 and miR-21. The reduced PDCD4 mRNA expression is associated with poor prognosis in CRC patients with Dukes' stage B, C and D. Furthermore, PDCD4 mRNA levels were negatively regulated by miR-21in each tumor stage of CRC.     

Clinical significance of MUC1 and MUC2 mucin and p53 protein expression in colorectal carcinoma

BACKGROUND: Up-regulation of MUC1, down-regulation of MUC2 and p53 overexpression are seen in colorectal carcinomas. However, there have been few reports about the associations between MUC1, MUC2 and p53 expression and metastatic potential. The aim of this study was to investigate MUC1, MUC2 and p53 expression in colorectal carcinoma with special reference to regional and distant metastasis. METHODS: Eighty-six colorectal carcinomas were collected from patients undergoing tumor resection. Sections were used for MUC1, MUC2 and p53 immunostaining. Cancers were regarded as MUC1 or MUC2 positive when the positive cells were beyond 30% of cancer cells. Cancers with diffuse or nested patterns were regarded as having p53 overexpression. RESULTS: Of 86 cancers, 37 (43%) were MUC1 positive, 28 (33%) were MUC2 positive and 59 (69%) showed p53 overexpression. A difference was observed only in the frequency of MUC1 positivity with respect to depth of tumor invasion. Neither depth of tumor invasion nor histological differentiation had a positive correlation with MUC1, MUC2 and p53 overexpression. The frequency of MUC1 positive cells in Dukes' C and D tumors was significantly higher than that in Dukes' A and B tumors. The frequency of MUC1 positivity in tumors with hepatic involvement was significantly higher than that in tumors without hepatic involvement (100 vs 39%; p < 0.01). There was no difference in the frequency of MUC2 or p53 positivity in Dukes' stage or hepatic metastasis. MUC1 immunoreactivity of the surface was identical with that of the whole tumor in 81% (70/86) of carcinomas, MUC 2 in 87% and p53 in 100%. CONCLUSIONS: The results suggest that up-regulation of MUC1 is involved in the progression from the non-metastatic to the metastatic stage and that p53 abnormality is not directly involved in it. The data also imply that immunostaining of preoperative biopsy samples is useful for evaluating the immunoreactivity of the whole tumor.     

Levels of soluble intercellular adhesion molecule-1 and total sialic acid in serum of patients with colorectal cancer

BACKGROUND AND OBJECTIVES: Serum soluble intercellular adhesion molecule-1 (sICAM-1) and total sialic acid (TSA) are related to the metastatic potential of cancer cells. The purpose of the present investigation was to determine sICAM-1 and TSA levels in colorectal carcinoma and correlate their levels with the cancer stage. METHODS: The sera from 65 patients with colorectal cancer (18 at Dukes' B, 24 at Dukes' C, 23 at Dukes' D) were extracted before treatment. The concentrations of sICAM-1 and TSA were measured by enzyme-linked immunoassay and the thiobarbituric acid method, respectively, and compared with those from a healthy control group (n = 42). RESULTS: Mean serum sICAM-1 and TSA levels were found to be higher in the total patient group than in the control group (P < 0.0001). The concentrations of sICAM-1 and TSA were significantly higher in patients with Dukes' C and Dukes' D. The correlations between sICAM-1 and TSA became more significant as the stage of the disease increased (r = 0.58, P < 0.05 in Dukes' B, r = 0.88, P < 0.01 in Dukes' C and r = 0.81, P < 0.01 in Dukes' D). CONCLUSIONS: The results of this investigation indicate that sICAM-1 and TSA are the best of the tested markers. These markers should prove useful for monitoring malignant disease stage and for evaluating the effectiveness of various therapeutic approaches for colorectal carcinomas.