No abstract

Proteolytic enzymes, such as type IV collagenases (MMP-2 gelatinase A, 72-kD type IV collagenase and MMP-9 gelatinase B, 92-kD type IV collagenase) play an important role in tumor invasion and metastasis. In the present study the levels of MMP-2 antigenic concentration and immunohistochemical staining were compared in paired colorectal tumor (n = 64) and background colon tissue of the same patients with clinical and pathological staging. The antigenic concentrations were found to be statistically significantly higher in cancer tissue (mean 11.29 ng/mg protein) than in corresponding normal mucosa (10.23 ng/mg protein) (p = 0.008). There was also a positive correlation between MMP-2 antigenic concentration and clinicopathologic parameters such as grade (p < 0.001) and Dukes’ stage (p = 0.001), but not with lymph node involvement. Immunohistological localization of MMP-2 was observed in tumor as well as in stromal cells. Staining intensity increased from adenoma to adenocarcinoma. The degree of staining was associated with grade (p < 0.001), Dukes’ stage (p < 0.001) and lymph node involvement (p < 0.001).

Despite the advances in the medical care of colorectal carcinoma patients, the prognosis has improved only marginally over recent decades. Thus, additional prognostic indicators would be of great clinical value to select patients for adjuvant therapy. In the present study, the antigen levels of urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1, and their immunohistochemical staining were compared in paired colorectal tumor (n = 64) and background colon tissue of the same patients with clinical and pathological staging. The antigen levels, measured with an ELISA method, were found to be significantly higher in cancer tissue (mean 1.92 ng/mg protein for uPA and 7.08 for PAI-1) than in corresponding normal mucosa (0.29 ng/mg protein for uPA and 1.11 ng/mg protein for PAI-1). There was a positive correlation between uPA and PAI-1 antigen levels and clinicopathological parameters such as grade (p < 0.001 and p = 0.01, respectively), while for Dukes’ stage, only PAI-1 correlated positively (p = 0.018). Nodal status correlated positively with uPA but not with PAI-1 antigen levels. Immunohistochemical localization of both antigens was observed mainly in cancer cells and much less in stromal cells. Staining intensity increased from adenoma to adenocarcinoma. The degree of staining was associated with grade, Dukes’ stage and nodal status for uPA (p < 0.001, p = 0.002, p < 0.001, respectively) and only with grade for PAI-1 (p = 0.007).

Apoptosis is an active process regulated by a variety of genes. Recently, the molecular cloning, physical mapping and expression analysis of a novel gene of the Bcl-2 family, BCL2L12, was reported. Expression analysis of the BCL2L12 gene in breast cancer confirmed an association of BCL2L12 with favorable prognosis of patients. In the present study, the expression of the BCL2L12 gene was analyzed in colon cancer by RT-PCR. Two transcripts, BCL2L12 and BCL2L12-A, were overexpressed in the cancer tissues as compared to their paired normal mucosa. An association was found between BCL2L12-A transcript expression and nodal status, as well as Dukes' stage. The BCL2L12-A transcript appears to be of importance for colon cancer since its expression is associated with disease progression.

Mucinous infiltrating invasive ductal adenocarcinoma consists of 2-4% invasive breast cancer, but is a very interesting type due to its macroscopic similarity to non-special-type (NST) ductal carcinoma. The macroscopic similarity of mucinous and infiltrating ductal carcinoma NST adenocarcinomas consists of a loose and edematous stroma, which is often seen in portions of NST carcinoma and may mimic the mucin pools of mucinous carcinoma. In this study the authors examined the ultrastructural differences between mucinous carcinoma and infiltrating ductal carcinoma NST. They also examined the protein expression of the tissues by 2D electrophoresis due to their belief that from the results of these two levels it is possible to understand the changes that take place both in the ultrastructural and biochemical levels in these two types of breast cancer. The ultrastructural results from mucinous carcinoma have shown many changes in cytoplasmic organelles in comparison to normal samples, depending on the grade and the number of metastatic lymph nodes. At the 2D elecrophoresis level the authors studied two interesting polypeptides, calreticulin and thioredoxin. Both of these proteins were found in patterns of fibroadenoma, mucinous carcinoma, and NST carcinoma, but with different quantitative expression among them. In the future the quantitative differences of these two proteins may provide specific tumor markers for these two types of carcinoma.