Hyaluronic Acid in Normal and Neoplastic Colorectal Tissue: Electrospray Ionization Mass Spectrometric and Fluor Metric Analysis

Abstract

Aim: The aim of the study was to analyze the expression of hyaluronic acid (HA) and its type in human colorectal cancer (CRC) and non-neoplastic mucosa tissues. Methods : The study included 64 adult CRC patients, who met all the inclusion and exclusion criteria. Two tissue samples (neoplastic and non-neoplastic mucosa) from each patient's large intestine were collected and were subjected to electrospray ionization mass spectrometry (ESI-MS) and fluorimetric assays. Results: The analysis of colorectal neoplastic tissue and non-neoplastic mucosa by ESI-MS allowed the identification of HA and its oligosaccharide fragments. Low molecular weight (LMW), nonbiotinylated isoform of HA, and its fragments were identified in both neoplastic and non-neoplastic mucosa. The expression of HA was found to be slightly lower in tumor tissue (0.561 mg HA/g tissue) than in colorectal non-neoplastic mucosa (0.579 mg HA/g tissue), although the difference was not statistically significant ( P = 0.87). This result was probably influenced by the nonbiotinylated LMW-HA. For the specific group of patients that did not present lymph node metastasis, the average HA levels were higher in tumor tissue (0.674 mg HA/g tissue) than in non-neoplastic tissue (0.529 mg HA/g tissue), which managed to reach statistical significance ( P = 0.04). For the group of patients with lymph node involvement, no difference between tumor and nontumor tissue was observed. The HA expression among the tumor tissues within the variables of each clinicopathological parameters assessed failed to elicit any significant difference (location, P = 0.62; size, P = 0.13; lymph node invasion, P = 0.57; degree of cellular differentiation, P = 0.46; venous infiltration, P = 0.73; lymphatic infiltration, P = 0.36; neural infiltration, P = 0.28; tumor node metastasis classification, P = 0.15; and presence of synchronous metastases, P = 0.35; initial versus advanced stage, P = 0.37). Conclusions: The expression of HA was found to be slightly lower in tumor tissue than in colorectal non-neoplastic mucosa, although this difference was not statistically significant. This finding probably influenced the lower expression of HA in tumor tissue than in colorectal non-neoplastic mucosa. Compared to normal tissues, HA levels are significantly increased in the tumor tissues unless they exhibit lymph node metastasis. Otherwise, the expression of HA in tumor tissue did not correlated with the other clinicopathological parameters.