Clinicopathological Significance Of Expression Of ERK1 And JNK1 In Human Colorectal Cancer

ObjectiveColorectal cancer is one of the most common tumor in our country. There is a trend of increasing morbility of colorectal cancer in recent 20 years. Therefore , it is important to study the molecular mechanisms of colorectal carcinogenesis. MAP Kinase cascades is a very important messenger form, which contains at least three proteins, including c - Jun N - terminal kinase (JNK) , extracellular signal - regulated kinase 1/2 ( ERK1/2) , and p38 kinase. JNK is involved in the regulation of cell proliferation and the respones to immune stimuli. ERK can lead to proliferation or differentiation of cells. p38 is involved in the regulation of the apoptosis and the respones to immune stimuli. Many studies showed that MAP kinase cascades can be activated by many oncogenes or proteins, such as Ras, Raf - 1 or G protein. Recently, many studies show that there is a high level of MAPKs expressions in many tumors including breast cancer, renal cancer and ovarian cancer. It shows that MAPKs is involved in differentiation of tumor. The aim of this study is to verify the expression of MAPK family members : ERK1 and JNK1, and their relationships with the clinicopathological parameters in human colorectal cancer.1. Tissue specimens collection; Fifty — six tumor specimens and sixteen specimens more than 5 cm far from tumor between May 1995 and July 2004 in the Forth Affiliated Hospital of China Medical University were collected and in-dentified as tumors pathologically.2. Main reagents; ERK1 ( C - 16) (rabbit polyclonal antibody to human) and JNK1 (mouse monoclonal IgG1 antibody to human) were purchased from Santa Cruz company in USA. SP reagents kit was purchased from Maixin Biological company.3. Methods; SAB method was used in this study.Results1. The positive rate of ERK1 is 94.6% (53/56) and that of nearly tumor is 62.5% (10/16) (x~2 = 9.00,P = 0.003). The positive rate of JNK1 is 85.7% (48/56)and that of nearly tumor is 43.7% (7/16) (x~2 =9.935,P =0.002).2. The expression of ERK1 was associated with the pathological classification of the tumor which is higher in adenocarcinoma than that in mucous adeno-carcinoma ( U = -2. 147 P =0. 031). The expression of JNK1 was associated with the grade of the tumor which is higher in poor grade than that in moderately or well grade (U = -2.457 P =0.014).Conclusions1. There is a high expression of ERK1 and JNK1 in human colorectal cancer.2. The expression of ERK1 was associated with the pathological classification which is higher in adenocarcinoma than that in mucous adenocarcinoma.3. The expression of JNK1 was associated with the grade of colorectal cancer which is higher in poor grade than that in moderately or well grade.