BACKGROUNDSerum α1‐acid glycoprotein (AGP), an acute‐phase protein secreted by the liver, carries α(1,3)‐fucosylated structures on its 5 highly branched, N‐linked sugar chains.METHODSSerum AGP levels in patients with various types of malignancies (n = 214 patients) were measured using an enzyme‐linked immunosorbent assay with anti‐AGP antibody. To investigate glycoforms that differed in their degree of branching and extent of fucosylation, serum AGP samples were analyzed by crossed affinoimmunoelectrophoresis (CAIE) with concanavalin A, and Aleuria aurantia lectin (AAL), and anti‐AGP antibody.RESULTSA significant difference (P < 0.001) in serum AGP levels was observed in preoperative patients compared with levels in the healthy control group, but the levels in individual patients did not reflect their clinical status. Conversely, it was found not only that the patterns of AGP glycoforms differed widely in the patient group compared with the healthy control group, but they also changed depending on each patient's clinical status. Furthermore, AGP glycoforms seemed to be appropriate markers of disease progression and prognosis according to follow‐up studies of 45 patients during prolonged preoperative and postoperative periods.CONCLUSIONSPatients with advanced malignancies who had AGP glycoforms that contained highly fucosylated triantennary and tetraantennary sugar chains for long periods after surgery were likely to have a poor prognosis. However, patients who had AGP glycoforms without such changes were expected to have a good prognosis. Cancer 2004. © 2004 American Cancer Society.
Carcinoembryonic antigen (CEA) levels were determined in the peritoneal washings from 120 patients with gastric cancer and 9 patients with benign diseases. Elevated values (> 100 ng/g of protein) were observed in 20 of 25 patients with gastric cancer with visible dissemination and 16 of 25 patients with serosal invasion but no dissemination. The same elevation was found in only 9 of 70 patients with no serosal invasion and none of the patients with benign disease. The &year survival rates after curative operation for the patients with and without elevation of CEA levels were 21% (19 patients) and 100% (66 patients), respectively (P < 0.001). A negative correlation was found between CEA levels and survival times after noncurative operation. These results indicate that the CEA level in peritoneal washings could be a sensitive detector of invisible peritoneal dissemination and a new predictor for the postoperative prognosis of gastric cancer. Cancer 68:44-47,1991. ESPITE PROGRESS in surgical techniques and adju-D vant chemotherapies for gastric cancer, the surgical prognosis of the advanced cancer has not been improved.' Peritoneal metastasis continues to be the most frequent type of recurrence in patients who had no evidence of residual tumor at the time of surgery and it is a significant obstacle in the curative treatment of gastric cancer. Peri-toneal recurrence after curative resection of malignant tumor was considered to be caused by microscopic dissemination of cancer cells from the primary tumor invaded serosal surface.2 The exfoliated cancer cells were reported to be detected by cytologic examination of the peritoneal washings obtained at the time of l a p a r o t ~ m y. ~. ~ However, as many as 50% of the patients who died of peritoneal recurrence after curative resection of malignant tumor were also reported to have negative cytologic find-From the First
Evidence indicates that the presence of aberrant α1→2fucosylation pathways is responsible for the accumulation of large quantities of Leb and Y antigens in human colorectal carcinoma. Significantly higher activities of α1→2 as well as α1→3 and α1→4fucosyltransferases were found in most of the tissues from carcinoma than in the adjacent normal tissues and in healthy subjects. α1→2Fucosyl‐transferases associated with the synthesis of Leb (Fucal→2Galβ1→3[Fucc1→4]GlcNAcβ) and Y (Fucα1→2Ga1β→4[Fucα1→3]GlcNAcβ) structures from Le→ (GaIβ1→3[Fucal→4]GlcNAcβ) and X (Galβ1→4[Fucα 1→3]GlcNAcβ) ones, respectively, were demonstrated in colorectal carcinomas and in colorectal carcinoma cell lines (COLO201, LS174T and SW1116). The activation of α1→2fucosyltransferase with such new substrate specificities in colorectal carcinoma might result in the preferential synthesis of Leb and Y structures from Le→ and X rather than from H type 1 and H type 2 structures.
Human plasma α 1-acid glycoprotein (AGP) from cancer patients and healthy volunteers was purified by sequential application of ion-exchange columns, and N-linked glycans enzymatically released from AGP were labeled and applied to a mass spectrometer. Additionally, a novel software system for use in combination with a mass spectrometer to determine N-linked glycans in AGP was developed. A database with 607 glycans including 453 different glycan structures that were theoretically predicted to be present in AGP was prepared for designing the software called AGPAS. This AGPAS was applied to determine relative abundance of each glycan in the AGP molecules based on mass spectra. It was found that the relative abundance of fucosylated glycans in tri- and tetra-antennary structures (FUCAGP) was significantly higher in cancer patients as compared with the healthy group (P < 0.001). Furthermore, extremely elevated levels of FUCAGP were found specifically in patients with a poor prognosis but not in patients with a good prognosis. In conclusion, the present software system allowed rapid determination of the primary structures of AGP glycans. The fucosylated glycans as novel tumor markers have clinical relevance in the diagnosis and assessment of cancer progression as well as patient prognosis.
One standard treatment option for advanced-stage cancer is surgical resection of malignant tumors following by adjuvant chemotherapy and chemoradiotherapy. Additionally, neoadjuvant chemotherapy may be applied if required. During the time course of treatments, patients are generally followed by computed tomography (CT) surveillance, and by tumor marker diagnosis. However, currently, early evidence of recurrence and/or metastasis of tumors with a clinically relevant biomarker remains a major therapeutic challenge. In particular, there has been no validated biomarker for predicting treatment outcomes in therapeutic settings. Recently, we have looked at glycoforms of serum α1-acid glycoprotein (AGP) by using a crossed affinoimmunoelectrophoresis with two lectins and an anti-AGP antibody. The primary glycan structures of AGP were also analyzed by a mass spectrometer and a novel software in a large number of patients with various cancers. Accordingly, the relative abundance of α1,3fucosylated glycans in AGP (FUCAGP) was found to be significantly high in cancer patients as compared with the healthy controls. Further, strikingly elevated levels of FUCAGP were found in patients with poor prognosis but not in patients with good prognosis. In the current study, levels of FUCAGP in serum samples from various cancer patients were analyzed and 17 patients including 13 who had undergone chemotherapy were followed for several years post operation. FUCAGP level determined diligently by using a mass spectrometer was found to change along with disease prognosis as well as with responses to treatments, in particular, to various chemotherapies. Therefore, FUCAGP levels measured during following-up of the patients after operation appeared to be clinically relevant biomarker of treatment intervention.
The expression of type-1 Lewis antigens on erythrocytes and in digestive organs is determined by a Lewis type alpha(1,3/1, 4)-fucosyltransferase (Lewis enzyme) encoded by the Fuc-TIII gene ( FUT3 gene; Lewis gene). We have classified the Lewis alleles in the Japanese population into four types, the wild-type allele ( Le ) and three mutated alleles, i.e., le1, which has missense mutations T59G and G508A, le2, which has T59G and T1067A, and le3, which has only T59G. Here we carried out an extensive study on the biological properties of the three mutant Lewis enzymes, the le1, le2, and le3 enzymes, using native tissues and obtained the following results. (1) In in vivo and in vitro experiments, the le1 and le2 enzymes were found to be susceptible to protease digestion probably because the one missense mutation in the catalytic domains, i.e., Gly170 to Ser in the le1 enzyme and Ile356 to Lys in the le2 enzyme, makes the three-dimensional structures of the enzymesunstable, while the le3 and wild-type Lewis enzymes wereresistant to protease digestion. (2) The le1 and le2 enzymes cannot synthesize type 1 Lewis antigens on either glycolipids or mucins. The le3 enzyme cannot synthesize Lewis-active glycolipids, which result in the Lewis antigen-negative phenotype of erythrocytes, while it can synthesize Lewis antigens on mucins in normal and cancerous colon tissues. The missense mutation, Leu20 to Arg, in the transmembrane domain reduces retention of the le3 enzyme in the Golgi membrane resulting in an apparent reduction of enzyme activity as revealed by the lack of Lewis antigen synthesis. (3) The Lewis gene dosage actually has effects in vivo on the amount of the Lewis enzyme, its activity, and finally the amounts of Lewis carbohydrate antigens. This is the first article that clearly demonstrates the gene dosage effects on the amount of the glycosyltransferase protein, its activity, and the amounts of carbohydrate products in vivo.
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