Glycosidically bound sialic acid levels as a predictive marker of postoperative adjuvant therapy in gastric cancer

A novel strategy for quantification of α2,3- and α2,6-linked sialic acids in sialylated glycoproteins

Sialic acid, a monosaccharide containing nine carbon atoms, is widely distributed in eukaryotic cells. The bound sialic acids are mainly present at the glycan ends of glycoconjugates via α2-3 or α2-6 glycosidic bonds, and alterations in their expression levels and linkage types are associated with the progress of many diseases and tumors. The present study provides a new strategy for quantification of α2,3- and α2,6-linked sialic acids in sialylated glycoproteins. In fact, quantification of α2,3-linked sialic acids were based on the difference of the bound sialic acids in the sample before and after treatment with α2-3 neuraminidase, whereas the α2,6-linked sialic acids were equal to the bound sialic acids in the α2-3 neuraminidase-treated sample. Subsequently, α2,3/6-linked sialic acids in salivary glycoproteins from healthy volunteers and diabetic patients were quantified in accordance with this method. This work provides an accurate method for the quantification of α2,3- and α2,6-linked sialic acids in the sialoglycoproteins, which is more instructive for understanding the biological roles of α2,3/6-linked sialic acid in sialoglycoproteins.

Adjuvant immunochemotherapy with protein-bound polysaccharide K for colon cancer in relation to oncogenic beta-catenin activation

PURPOSE

Protein-bound polysaccharide K is an immunotherapeutic agent that promotes apoptosis by inhibiting nuclear factor-kappaB activation in cancer cells. We previously showed that oncogenic beta-catenin activates nuclear factor-kappaB and inhibits apoptosis by up-regulating beta-transducin repeat-containing protein. We investigated whether the activation state of beta-catenin in the primary tumor is associated with differences in survival rates of patients with colon cancer undergoing immunochemotherapy with 5-fluorouracil plus polysaccharide K vs. chemotherapy with 5-fluorouracil alone.

METHODS

We assessed the activation states of beta-catenin and nuclear factor-kappaB in the primary tumors of 202 colon cancer patients, and analyzed the data in terms of the clinicopathologic characteristics and survival of patients undergoing the two forms of adjuvant therapy.

RESULTS

We found two distinct patterns of nuclear accumulation of activated beta-catenin in the tumor cells: diffuse nuclear accumulation in 89 cases (44 percent) and selective nuclear accumulation at the tumor invasion front in 18 cases (9 percent). Nuclear factor-kappaB activation was found in 64 cases (32 percent). In patients with diffuse nuclear accumulation-type beta-catenin activation, immunochemotherapy significantly improved recurrence-free survival, cancer death survival, and overall survival rates compared with patients receiving chemotherapy alone. No survival benefit was found in cases with nuclear accumulation at the tumor invasion front-type beta-catenin activation or no activation. Similarly, immunochemotherapy favored the survival of patients with nuclear factor-kappaB activation. Multivariate analysis established the TNM stage and administration of polysaccharide K as independent prognostic factors in the patients with diffuse nuclear accumulation-type beta-catenin activation.

CONCLUSIONS

The presence of diffuse nuclear accumulation-type beta-catenin activation identifies patients with colon cancer who respond better to immunotherapy with polysaccharide K.

Possible predictive markers of immunotherapy in esophageal cancer: retrospective analysis of a randomized study. The Cooperative Study Group for Esophageal Cancer in Japan

The aim of this report is to evaluate retrospectively the data from a prospective randomized study of 158 esophageal cancer patients who actually completed therapy with protein-bound polysaccharide P (PSK) and the 5-year survivals with and without raised alpha 1-antichymotrypsin and sialic acid levels to determine the value of these parameters in predicting effectiveness of immunotherapy. There was a significant difference in survival between the patients with and without PSK therapy. The survival of the radiochemotherapy plus PSK group treated for > 3 months was significantly better than that of the radiochemotherapy group. Among the patients with abnormal levels of alpha 1-antichymotrypsin and sialic acid, those who received PSK may have a significantly better survival than those without PSK. These results indicate that the preoperative serum levels of alpha 1-antichymotrypsin and sialic acid may possibly predict the effectiveness of immunotherapy using PSK.