Sialylation of tumor cell surface glycoconjugate is thought to contribute to tumor progression and metastasis[7-10]
Sialylation of tumor cell surface glycoconjugate is thought to contribute to tumor progression and metastasis[7-10]. (= 0.020), pancreatic invasion (= 0.016), duodenal invasion (= 0.034), and advanced stage of TNM clinical classification (= 0.010). Survival analysis showed that positive expression of KL-6 was related to a poorer prognosis (= 0.029). CONCLUSION: The aberrant expression of KL-6 mucin is significantly related to unfavorable behaviors of carcinoma of the ampulla of Vater. = 0.020), in cases of pancreatic invasion than those without it (= 0.016), in cases of duodenal invasion than those without it (= 0.034), and in cases classified into III or IV by TNM clinical classification than those classified into I or II (= 0.010). On the other hand, KL-6 expression was not associated with age, sex, histological grade, lymphatic vessel invasion, and venous invasion Golgicide A (Table ?(Table11). Table 1 Relationship between KL-6 expression and clinicopathological parameters in patients with carcinoma of the ampulla of Vater = 26; %)= 26) displayed a significantly poorer prognosis than those showing negative KL-6 expression (= 12): 5-year survival rates were 30.8 and 75.0%, respectively, as determined by the Kaplan-Meier method (= 0.029 by the log rank test). Open in a separate window Figure 4 Kaplan-Meier curves for overall survival rates of patients with carcinoma of the ampulla of Vater. Patients with positive (solid line, = 26) and negative (dotted line, = 12) KL-6 expression were followed-up for over 70 mo. DISCUSSION Mucins are large extracellular glycoproteins with high carbohydrate content and marked diversity both in the apoprotein and Golgicide A in the oligosaccharide moieties. It has been noted that ampullary carcinoma have a heterogeneous mucin expression pattern[16,17] and that overexpression of MUC1 was associated with invasive and metastatic potency of several adenocarcinoma[18-20]. However, the studies on MUC1 expression were mostly done with different antibodies, which recognize Golgicide A different carbohydrate epitopes or the core peptide. This study addresses clinicopathological significance of histochemical expression of KL-6, MUC1 mucin-bearing sialylated carbohydrate epitope recognized by KL-6 antibody, in carcinoma of the ampulla of Vater. Sialylation of tumor cell surface glycoconjugate is thought to contribute to tumor progression and metastasis[7-10]. Furthermore, since sialylated oligosaccharide moieties are exposed on the mucin molecules, KL-6 antibody could effectively recognize the mucin without epitope masking as Cao and Karsten indicated with several antibodies against peptide epitopes of MUC1. Therefore, immunohistochemical detection of KL-6 MPL mucin seems to be Golgicide A a reasonable strategy. The present data shows that aberrant expression of KL-6 mucin is related to unfavorable behaviors of the carcinoma, such as lymph node metastasis, pancreatic invasion, duodenal invasion, and the advanced stage of TNM clinical classification (Table ?(Table1),1), and poorer prognosis (= 0.029, Figure ?Figure4).4). Furthermore, remarkable expression of KL-6 was found in invasive carcinoma cells in pancreatic and duodenal tissues and in metastatic carcinoma cells in lymph nodes (Figures ?(Figures22 and ?and3).3). These results suggest that KL-6 mucin might play an important role in unfavorable tumor behaviors, such as invasions and metastasis of carcinoma of the ampulla of Vater. Several tumor-associated carbohydrate antigens have been identified on mucins[22,23]. Aberrant forms of mucins expressed in cancer cells have been considered to arise as a consequence of the deregulation of expression of enzymes that modify them. The epitope recognized Golgicide A by KL-6 antibody is sialylated carbohydrates included in MUC1 molecule, although the detailed structure of the epitope remains to be determined. Among the many types of carbohydrates, sialic acid is vital for cancer growth, since enhanced sialylation is thought to play a role in tumor progression and metastasis[5,24]. Carbohydrate moieties of glycoconjugates are constructed by complex interactions involving a series of glycosyltransferases[25,26]. In our previous study, the aberrant sialylation of glycoconjugates in carcinoma of the ampulla of Vater has been found in histochemical analyses using sialic acid-binding lectins such as leukoagglutinin and agglutinin. Therefore, it is postulated that the aberrant expression of KL-6 stems from the aberrant expression of the glycosyltransferase(s) such as sialyltransferase, which participates in the construction of the epitope for KL-6 antibody. Relationship of KL-6 expression to invasions and metastasis has also been suggested in colorectal carcinoma[28,29]. Surgery is still the only option that provides a cure for patients with carcinoma of the ampulla of Vater. Patient outcome after surgery for carcinoma of the ampulla of Vater is better than that for pancreatic cancer or bile duct cancer. However, patients with lymph node metastasis or invasion of carcinoma to adjacent organs including the pancreas or duodenum display a poorer prognosis[30,31]. The present study revealed that positive KL-6 expression was significantly related to.