Lewis blood group antigens (a and b) in human breast tissues. Loss of Lewis-b in breast cancer cells and correlation with tumor grade.

The Lewis blood group antigens (Lewis-a [Lea] and Lewis-b [Leb]) and their precursors are present on various normal human epithelial cell surfaces. The authors examined 35 benign and malignant human breast lesions using mouse monoclonal antibodies to synthetic Lea and Leb carbohydrate antigens. Normal breast lobular and ductal epithelium and benign breast lesions showed Leb staining but only occasional Lea staining. In invasive ductal carcinomas of breast, of all grades, a loss of Leb antigen staining was found in 80% of the breast cancer cases. This reduced Leb antigen expression increased with the grade of malignancy. Therefore, the loss of Leb blood group antigens on breast cancer cell surfaces may suggest altered fucosylation patterns in malignant cells and reflect the degree of malignancy and/or invasiveness.     

Detection of ABO(H) blood group antigens: a study in tissue culture

The association between malignant transformation and the loss of ABO(H) blood group antigens was documented by several authors. Most of the work was done on paraffin sections, though a small portion was performed on fresh frozen tissues. We suggest that the specific red cell adherance (SRCA) test can be applied to tissues cultivated in tissue culture for determination of malignant transformation. This study supports this assumption.     

Natural IgM and IgG antibodies to Thomsen-Friedenreich (T) antigen in serum of patients with gastric cancer and blood donors--relation to Lewis (a,b) histo-blood group phenotype

A possible association of serum anti-T IgM and IgG antibody levels with Lewis blood-group phenotype was investigated in 168 blood donors and 132 gastric cancer patients using ELISA with synthetic T-disaccharide-polyacrylamide conjugate as antigen. The donors of Le(a-b+) phenotype showed the highest anti-T IgM level irrespective of ABO(H) blood group. A significant decrease in anti-T IgM in serum was observed among cancer patients of Le(a-b+) phenotype: 95% of weak responders versus 17.5% for related groups of donors (p < 10(-6)). In contrast, no significant difference between patients and donors was found for Le(b-) individuals. Thus, a level of natural anti-T antibodies in serum of blood donors and its decrease in patients with gastric cancer are related to Le(a,b) phenotype. This should be taken into account where anti-T antibody level in the serum is used as a tumour marker or for monitoring patients during cancer immunotherapy with mucin-type vaccines.     

Synchronous double tumor of breast cancer and gastrointestinal stromal tumor in a patient with neurofibromatosis type 1: report of a case

We report a rare case of synchronous double tumor formation of breast cancer and gastrointestinal stromal tumor (GIST) in a patient with neurofibromatosis type 1(NF-1). A 76-year-old woman with a history of NF-1 who had undergone left modified mastectomy for breast cancer seven years previously was admitted to our hospital because of a right breast tumor and abdominal discomfort. Computed tomography revealed an enhanced irregular tumor in the right breast and peripheral enhanced tumors in the abdomen. The patient underwent right modified mastectomy and laparoscopic tumor resection combined with small intestine surgery. Histopathological examination revealed the presence of invasive lobular carcinoma in the right breast and GIST in the abdomen. The synchronous development of breast cancer and GIST in a patient with NF-1 is extremely rare, with this being the second case ever reported.     

Specificity and immunobiological properties of monoclonal antibody IMH2, established after immunization with Le(b)/Le(a) glycosphingolipid, a novel extended type 1 chain antigen.

Extended lacto-series type 1 chain antigens lacking type 2 chain core have recently been shown to comprise a new type of tumor-associated carbohydrate antigen. Examples are Le(a)/Le(a) (IV3Gal beta 1----3[Fuc alpha 1----4]Glc-NAcLc4Cer) and Le(b)/Le(a) (IV3Fuc alpha 1----2Gal beta 1----3[Fuc alpha 1----4]Glc-NAcLc4Cer) (M. R. Stroud, et al., J. Biol. Chem., 266: 8439-8446, 1991; Eur. J. Biochem., 203: 577-586, 1992). We have now established an IgG3 mouse monoclonal antibody (IMH2) after immunization of mice with Le(b)/Le(a) antigen; however, monoclonal antibody (MAb) IMH2 reacted not only with the immunogen used but also with Le(y)/Le(x) and to a lesser degree with short-chain Le(y) or Le(b) with hexasaccharide ceramide (i.e., IV2FucIII3FucnLc4Cer or IV2FucIII4FucLc4Cer). It showed a high incidence of staining and strong reactivity with carcinomas of colon, rectum, liver, pancreas, and endometrium, but no reactivity with normal colonic mucosa at various loci, and minimal reactivity with normal liver, pancreas, or uterine endometrium. On the other hand, it reacted with normal gastric mucosa, cecal mucosa, urothelium, adrenal glands, and thymus. Its expression in colorectal tumors and normal cecal tissue was independent of secretor status, whereas that in normal urothelium was dependent on secretor status. MAb IMH2 displayed strong lymphocyte-activated or complement-dependent killing of human colonic cancer Colo205 cells in vitro, and inhibition of Colo205 growth in vivo; this inhibition was comparable to that by MAb NCC-ST-421, which is directed to Le(a)/Le(a) epitope (M. Watanabe, et al., Cancer Res., 51:2199, 1991). These results indicate that a new extended type 1 chain structure, Le(b)/Le(a), is a useful tumor marker associated with carcinomas of colon, rectum, pancreas, liver, and endometrium and that MAb IMH2 has potential diagnostic or therapeutic applicability for these carcinomas.     

Lymphokine-activated killer-cell function of lymphocytes from peripheral blood, regional lymph nodes and tumor tissues of patients with oral cancer

Lymphokine-activated killer (LAK) cells, generated from peripheral blood lymphocytes (PBL) from patients with oral cancer or oral leukoplakia and from healthy donors showed comparable lysis of 6 target tumor cell lines, including 3 derived from head and neck and oral cancers. The tumor burden of the host did not appear to influence the systemic LAK activity. LAK activity of lymphocytes infiltrating the tumor tissues (TIL) was also comparable to that of the PBL. Both TIL and PBL showed a parallel increase in proportion of HNK-I+ and CD-25+ cells upon activation with IL-2. The lymph-node lymphocytes (LNL) from metastatic (met) and non-metastatic (non-met) draining lymph nodes, however, showed reduced LAK activity and an increase in CD8+ cells, in addition to CD25+ and HNK-I+ cells, when cultured with IL-2. When IL-2-activated LNL were co-cultured with autologous PBL during IL-2 activation of the latter, a strong suppressive effect was exerted by LNL. In contrast, IL-2-activated PBL did not suppress autologous LAK generation in spite of an increase in CD8+ cells seen after activation with IL-2. Frequency distribution of LAK precursors was significantly lower in LNL than in PBL from oral cancer patients. LAK precursor frequency in TIL was comparable to that of PBL. The results show that, in oral cancer, regional lymph nodes may not have adequate IL-2-inducible cytotoxic potential, due to a reduced number of LAK progenitors and possible activation of suppressor cells. Alternatively, TIL can be a potential source for LAK cell function.     

Heterogeneity of ovarian cancer: relationships among histological group, stage of disease, tumor markers, patient characteristics, and survival

Epidemiological studies have established associations between various reproductive factors and risk of ovarian cancer; it has also been observed that some of these risk factors are only associated with specific histological subgroups. To investigate the correlation of genetic alterations with these risk factors, we examined a consecutive series of 158 ovarian cancer cases treated at the University of Kentucky (1990-96). Common molecular genetic alterations (LOH on chromosome 17, P53 alterations, K-RAS mutations), histological and clinical characteristics of the disease, demographic patient information and survival were evaluated. These latter data were from the Kentucky Cancer Registry. Univariate analysis showed higher frequencies of chromosome 17 loss and P53 mutations in tumors of advanced stage and grade, and in older and post-menopausal women. Non-mucinous tumors were more likely to be classified as late stage, high-grade cancers, and to have chromosome 17 loss and P53 mutations. Survival analysis indicated that stage was the only independent significant variable. When stage was the outcome variable in multiple logistic regression analysis, histology and chromosome 17 loss were significantly associated with poor survival. This case-case study provides evidence that ovarian cancers of mucinous and non-mucinous histology are significantly different with respect to clinical characteristics, survival and molecular alterations. It also lends support to the hypothesis that ovarian cancer is a heterogeneous disease with distinct etiological factors and clinical outcomes, which may require different approaches to treatment.     

Blood group and blood-group-related antigens in normal pancreas and pancreas cancer: Enhanced expression of precursor type 1, Tn and Sialyl-Tn in pancreas cancer

Expression of blood-group antigens A, B, Le^a, sialyl-Le^a (sLe^a), Le^b, Le^x, Le^y, precursor type 1, Tn and sialyl-Tn (sTn) was examined in non-neoplastic pancreas (n = 37) and pancreas cancer (n = 21) using mouse monoclonal antibodies (MAbs). Immunohistochemical assays were performed on sections of paraffin-embedded tissues using the avidin-biotin complex method. In normal pancreas, antibodies detecting Le^a, sLe^a and Tn reacted with ductal epithelium, and antibodies detecting A and B reacted with acini and ducts, independently of secretor status. Le^x was weakly expressed in ducts and acini, and sTn could not be detected in normal pancreas. Expression of Le^b, Le^y and precursor type 1 was regulated by secretor status: Le^b and Le^y were expressed in ducts of secretor and Le^a-b? individuals, but not in ducts of non-secretors; precursor type I was weakly expressed in acini and ducts of non-secretors and Le^a-b? individuals, and was absent in acini and ducts of secretors. The following alterations in the expression of blood-group antigens were observed in pancreas cancer: (1) enhanced expression of Le^x, Tn and sTn; (2) enhanced expression of precursor type I independently of secretor status; (3) loss of regulation of Le^b by the secretor gene; (4) decreased expression of Le^y. The weak expression of precursor type 1, Tn and sTn in non-neoplastic pancreas, and their stronger expression in pancreas cancer, suggests that up-regulation of their expression is associated with malignant transformation of pancreatic duct cells.     

Prognostic value of serum sialyl Lewis(a), sialyl Lewis(x) and sialyl Tn antigens in blood from the tumor drainage vein of colorectal cancer patients.

The serum levels of sialyl Lewis(a) (CA19-9), sialyl Lewis(x) (SLX), sialyl Tn (STN) and carcinoembryonic antigen (CEA) in peripheral venous blood and tumor drainage venous blood of colorectal cancer patients were examined to determine their value as prognostic factors after surgery. Blood samples were obtained from the peripheral vein and from the tumor drainage vein from 124 colorectal cancer patients during surgical excision of the tumor. The patients were divided into high-antigen and low-antigen groups for each antigen in each location. Serum levels of SLX, STN and CEA in tumor drainage venous blood (d-SLX, d-STN and d-CEA, respectively) were significantly higher than in peripheral venous blood (p-SLX, p-STN and p-CEA, respectively). The survival time after surgery for patients with high d-SLX or d-CEA levels and low levels of the same antigen in peripheral venous blood was significantly shorter than the survival time for those patients with low levels of antigen at both sites (p = 0.0003 or p = 0.0406, respectively). Cox's regression analysis revealed that a high d-SLX or high d-CEA level was an independent prognostic variable for patient survival. In conclusion, determining d-SLX or d-CEA is more useful than p-SLX or p-CEA in predicting the outcome for colorectal cancer patients.     

A critical evaluation of loss of heterozygosity detected in tumor tissues,blood serum and bone marrow plasma from patients with breast cancer

Introduction  

The aim of the study was to perform a comparative analysis of LOH (loss of heterozygosity) in primary tumors as well as peripheral blood and bone marrow (BM) of patients with breast cancer (BCa).     

A comparative study of pepsinogen (PG) and lactic acid dehydrogenase (LDH) activities and isoenzyme patterns in tissues from human primary gastric cancer, gastric cancer xenografts in nude mice and gastric cancer cell lines]

Tissue and cell homogenates were prepared for PG and LDH study from 20 samples of histologically proven gastric cancer (GC), 6 samples of gastric cancer xenografts (THPGC-1) of different passages (GCXG) and cultured cells of 3 different gastric cancer cell lines (GCCL). Normal gastric mucosa (NGM) was also obtained from the resected stomach far distant from the primary tumor and histologically tumor free. The results indicated that the expression of PG isoenzymes was low or absent and the PG activities were significantly decreased in GC, GCXG and GCCL as compared to NGM. The activity of LDH was also significantly increased in GC, GCXG and GCCL. In addition, there was a change in isoenzyme pattern in GC and GCXG in which isoenzyme type M was observed whereas isoenzyme type H was preponderent in NGM. The results show that the human gastric cancer xenograft, THPGC-1, has biological properties very similar to those of the primary tumor suggesting that THPGC-1 is a reliable model for the study of the molecular biology of human gastric cancer.     

Characterization of a 54 kDa, alpha 1-antitrypsin-like protein isolated from ascitic fluid of an endometrial cancer patient

A protein factor which stimulated [3H]thymidine uptake into free hepatocytes prepared from normal mouse liver was detected in the ascitic fluid of gynecological cancer patients. The factor was subsequently further purified from the ascitic fluid of an endometrial cancer patient by DEAE-Sephacel, Sephadex G-150 and Phenyl-Sepharose CL-4B column chromatographies, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a single protein band of 54,000 Da, designated tentatively as 54K ascitic protein (54K-AP). 54K-AP was similar to human alpha 1-antitrypsin (alpha 1-AT) in terms of SDS-PAGE and immunological behavior, but was slightly different in terms of amino acid sequence and isoelectric point. Although 54K-AP inhibited the activities of bovine trypsin and alpha-chymotrypsin as did human alpha 1-AT, 54K-AP inhibited the plasminogen activator released from human endometrial cancer Ishikawa cells more efficiently than alpha 1-AT. Because, in contrast to normal serum, the serum from the endometrial cancer patients stimulated [3H]thymidine uptake into hepatocytes, the possibility arises that 54K-AP could be produced by the cancer host as a defence mechanism against the cancer.     

Expression of a hybrid form of alkaline phosphatase isoenzyme in a newly established cell line (HuG-1) from a gastric cancer patient

An unusual alkaline phosphatase (AP), named HuG-AP, was found in a newly established cell line (HuG-1) derived from a patient with stomach cancer. The enzyme was purified about 300-fold by affinity chromatography. On polyacrylamide gradient (4-30%) gel electrophoresis, the one band with the enzyme activity was observed. The enzymic properties of HuG-AP did not conform to those of liver, intestinal, placental, and germ cell AP isoenzymes which were recognized as homodimeric structure. Thermostability of the HuG-AP showed an intermediate value between intestinal and placental APs. Immunologically, the HuG-AP reacted with both anti-intestinal and anti-placental AP monoclonal antibodies. Dot blot analysis showed that both intestinal and placental AP mRNAs were expressed in HuG-1 cells concurrently. Therefore, we concluded that this novel AP had a hybrid form, namely heterodimeric structure, consisting of one subunit each of intestinal and placental APs. However, all of the properties of this hybrid AP did not conform to the intermediate enzymic properties between intestinal and placental APs which would be shown when they both coexist. Because an AP identical to HuG-AP had already been found in the metastatic lesion of the liver of the same patient, the expression of this novel AP seemed to occur in the patient's original cancer cells but did not result from spontaneous transformation of cultured cells.     

Overweight, obesity and gastric cancer risk: Results from a meta-analysis of cohort studies

The relationship between excess body weight and gastric cancer risk has not been well studied to date. We therefore carried out a systematic review and meta-analysis of published cohort studies to evaluate the association between excess body weight and gastric cancer risk. An electronic search of the MEDLINE, PubMed, EMBASE and Academic Search Premier (EBSCO) databases, which contain articles published from 1950 onwards, was conducted in order to select studies for this meta-analysis. Ten studies with a total number of 9492 gastric cancer cases and a studied population of 3,097,794 were identified. Overall, excess body weight [body mass index (BMI)  25] was associated with an increased risk of gastric cancer [odds ratio (OR) = 1.22; 95% confidence intervals (CIs) = 1.06–1.41]. Specifically, a stratified analysis showed that excess body weight was associated with an increased risk of cardia gastric cancer [overweight and obese (BMI  25), OR = 1.55, 95% CIs = 1.31–1.84] and gastric cancer among non-Asians (overweight and obese, OR = 1.24, 95% CIs = 1.14–1.36); however, the stratified analysis also showed that there was no statistically significant link between excess body weight and gastric cancer in the following subgroups: males (overweight and obese, OR = 1.22, 95% CIs = 0.96–1.55), females (overweight and obese, OR = 1.13, 95% CIs = 0.65–1.94), non-cardia gastric cancer (overweight and obese, OR = 1.18, 95% CIs = 0.96–1.45) and Asians (overweight and obese, OR = 1.17, 95% CIs = 0.88–1.56).The combined results of this meta-analysis, however, do indicate that overweight and obesity are associated with an increased risk of gastric cancer. The strength of the association also increases with increasing BMI.     

Immunohistochemical analysis of PAI-2 (plasminogen activator inhibitor type 2) and p53 protein in early gastric cancer patients with recurrence: a preliminary report.

BACKGROUND: High levels of urokinase-type plasminogen activator (u-PA) were demonstrated in gastric carcinomas along with inhibitors of plasminogen activators (PAI-1 and PAI-2). They may influence the ability to invade and metastasize and therefore be of importance to the risk of recurrence of stomach neoplasms after curative operation. This also appears to be the case for p53 mutations and p53 protein overexpression. METHODS: Six patients, all differentiated cancer cases who developed recurrent disease 5-10 years after curative operations for early gastric cancers (recurrence group), were studied in comparison with 49 patients who had no recurrence more than 10 years after similar surgery (control group). The expression of u-PA, PAI-1, PAI-2 and p53 was compared immunohistochemically in the recurrence and control groups. RESULTS: The expression of PAI-2 was significantly more frequent in the recurrence group, being found in five (83.3%) patients vs eight (16.3%) in the control group. p53 was expressed in five (83.3%) patients in the recurrence group and in 15 (30.6%) in the control group; the rate was again significantly higher in the former. CONCLUSION: The results suggest that PAI-2 and p53 expressed in differentiated early gastric cancers are possible indices of the risk of recurrence.     

Epigenetic inactivation of paired box gene 5, a novel tumor suppressor gene, through direct upregulation of p53 is associated with prognosis in gastric cancer patients

Using genome-wide methylation screening, we identified that paired box gene 5 (PAX5) is involved in human cancer development. However, the function of PAX5 in gastric cancer (GC) development is largely unclear. We analyzed its epigenetic inactivation, biological functions and clinical application in GC. PAX5 was silenced in seven out of eight GC cell lines. A significant downregulation was also detected in paired gastric tumors compared with adjacent non-cancerous tissues. The downregulation of PAX5 was closely linked to the promoter hypermethylation status and could be restored with demethylation treatment. Ectopic expression of PAX5 in silenced GC cell lines (AGS and BGC823) inhibited colony formation and cell viability, arrested cell cycle, induced apoptosis, suppressed cell migration and invasion and repressed tumorigenicity in nude mice. Consistent with the induction of apoptosis by PAX5 in vitro, terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) staining showed significantly enhanced apoptotic cells in PAX5-expressed tumors compared with the vector control tumors. On the other hand, knockdown of PAX5 by PAX5-short hairpin RNA increased the cell viability and proliferation. The anti-tumorigenic function of PAX5 was revealed to be mediated by upregulating downstream targets of tumor protein 53 (p53), p21, BCL2-associated X protein, metastasis suppressor 1 and tissue inhibitors of metalloproteinase 1, and downregulating BCL2, cyclin D1, mesenchymal-epithelial transition factor (MET) and matrix metalloproteinase 1. Immunoprecipitation assay demonstrated that PAX5 directly bound to the promoters of p53 and MET. Moreover, PAX5 hypermethylation was detected in 77% (144 of 187) of primary GCs compared with 10.5% (2/19) of normal gastric tissues (P<0.0001). GC patients with PAX5 methylation had a significant poor survival compared with the unmethylated cases as demonstrated by Cox regression model and log-rank test. In conclusion, PAX5 is a novel functional tumor suppressor in gastric carcinogenesis. Detection of methylated PAX5 can be utilized as an independent prognostic factor in GC.