ABSTRACT
To study the influence of glycosylation on breast cancer progression by analyses on glycan, mRNA, and protein level. For detection of glycan structures, we performed lectin histochemistry with five lectins of different specificity (UEA-1, HPA, GNA, PNA, and PHA-L) on a tissue microarray with >400 breast cancer samples. For comparison, mRNA expression of glycosylation enzymes involved in the synthesis of HPA and PNA binding glycostructures (GALNT family members and C1GALT1) was analyzed in microarray data of 194 carcinomas. Additionally, C1GALT1 protein expression was analyzed by Western blot analysis in 106 tumors. Correlations with clinical and histological parameters including recurrence-free (RFS) and overall survival (OAS) were calculated. Positive binding of four lectins (HPA, GNA, PNA, and PHA-L) correlated significantly with parameters involved in tumor metastasis, namely lymphangiosis, vascular invasion, lymph node involvement, and presence of disseminated tumor cells in bone marrow. HPA and PNA binding also showed a negative prognostic impact in our cohort. Correspondingly, high expression of C1GALT1, GALNT1, GALNT8, or GALNT14 mRNA and C1GALT1 protein correlated significantly with shorter OAS. Notably, combined overexpression of C1GALT1/GALNT1 or C1GALT1/GALNT8 mRNA was associated with a significantly reduced OAS (HR 3.15 and 2.73) and RFS (HR 2.01 and 1.94), pointing to an additive influence of these enzymes. This prognostic impact retained significance in multivariate analysis including classical prognostic markers. Our data indicate that glycan structures containing ßGal-ßGalNAc residues and the enzymes involved in their synthesis play a role in breast cancer progression, at least partly by their promoting influence on haematogenic and lymphatic spread.
Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Galactosyltransferases/metabolism , N-Acetylgalactosaminyltransferases/metabolism , Polysaccharides/metabolism , Adult , Aged , Biomarkers, Tumor , Breast Neoplasms/genetics , Breast Neoplasms/mortality , Breast Neoplasms/therapy , Female , Galactosyltransferases/genetics , Gene Expression , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Lectins/genetics , Middle Aged , N-Acetylgalactosaminyltransferases/genetics , Neoplasm Grading , Neoplasm Invasiveness , Neoplasm Metastasis , Neoplasm Staging , Protein Binding , Treatment Outcome , Polypeptide N-acetylgalactosaminyltransferaseABSTRACT
BACKGROUND: Protein levels of urokinase plasminogen activator (uPA) and its inhibitor (PAI-1) determined by enzyme-linked immunosorbent assay from fresh-frozen tumor tissue have been evaluated as prognostic factors in prospectively randomized trials in breast cancer. However, the role of uPA and PAI-1 in the context of breast cancer subtypes and for mRNA expression of these factors is less clear. METHODS: We evaluated uPA and PAI-1 mRNA expression using the Affymetrix HG-U 133A array within molecular subgroups of breast cancer in cohorts of patients with systemic treatment (cohort A, n=362) and without systemic treatment (cohort B, n=200). We validated mRNA expression in a cohort of HER2-positive breast cancer patients (cohort C, n=290). Luminal, triple-negative, and HER2-positive subcohorts were defined by ESR1 and ERBB2 mRNA expression using predefined cutoffs. RESULTS: In the entire cohort A, elevated PAI-1 but not uPA mRNA expression was associated with shorter disease-free survival (P=0.007 for PAI and 0.069 for uPA). Regarding different molecular subgroups, 67% (n=244) of tumors were luminal, 14% (n=49) were HER2-positive, and 19% (n=69) were triple-negative. Elevated PAI-1 mRNA expression was associated with shorter disease-free survival only in the HER2-positive subgroup (P=0.031). The same disease-free survival results were found for uPA in HER2-positive patients (P=0.011). In contrast, no association between either marker and survival was observed in the luminal or triple-negative subgroups. In the HER2-positive validation cohort C, elevated uPA and PAI-1 mRNA expression also showed strong associations with shorter disease-free survival (P=0.014 for PAI-1, P<0.001 for uPA). CONCLUSION: In this study, the prognostic impact of uPA and PAI-1 expression was mainly observed in patients with HER2-positive tumors.
ABSTRACT
Glycosylation of cellular proteins has important impact on their stability and functional properties, and glycan structures strongly influence cell adhesion. Many enzymes are involved in glycoconjugate synthesis and degradation, but there is only limited information about their role in breast cancer progression. Therefore, we retrieved RNA expression data of 202 glycosylation genes generated by microarray analysis (Affymetrix HG-U133A) in a cohort of 194 mammary carcinomas with long-term follow-up information. After univariate and multivariate Cox regression analysis, genes with independent prognostic value were identified. These were further analysed by Kaplan-Meier analysis and log-rank tests, and their prognostic value was validated in a second cohort of 200 tumour samples from patients without systemic therapy. In our first cohort, we identified 24 genes with independent prognostic value, coding for sixteen anabolic and eight catabolic enzymes. Functionally, these genes are involved in all important glycosylation pathways, namely O-glycosylation, N-glycosylation, O-fucosylation, synthesis of glycosaminoglycans and glycolipids. Eighteen genes also showed prognostic significance in chemotherapy-treated patients. In the second cohort, six of the 24 relevant genes were of prognostic significance (FUT1, FUCA1, POFUT1, MAN1A1, RPN1 and DPM1), whereas a trend was observed for three additional probesets (GCNT4, ST3GAL6 and UGCG). In a stratified analysis of molecular subtypes combining both cohorts, great differences appeared suggesting a predominant role of N-glycosylation in luminal cancers and O-glycosylation in triple-negative ones. Correlations of gene expression with metastases of various localizations point to a role of glycan structures in organ-specific metastatic spread. Our results indicate that various glycosylation reactions influence progression and metastasis of breast cancer and might thus represent potential therapeutic targets.
Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Cohort Studies , Enzymes/genetics , Enzymes/metabolism , Female , Fucosyltransferases/genetics , Glycosylation , Humans , Kaplan-Meier Estimate , Lymph Nodes/pathology , Mannosidases/genetics , Mannosyltransferases/genetics , Prognosis , Proportional Hazards Models , Sialyltransferases/genetics , alpha-L-Fucosidase/genetics , beta-Galactoside alpha-2,3-Sialyltransferase , Galactoside 2-alpha-L-fucosyltransferaseABSTRACT
PURPOSE: The androgen receptor (AR) is intensively discussed as a prognostic and/or predictive marker in breast cancer patients. METHODS: We evaluated the value of AR mRNA expression with the Affymetrix HG-U 133A array in 3 different cohorts: a cohort of breast cancer patients who received adjuvant treatment (cohort A; n = 165), a cohort of untreated breast cancer patients (cohort B; n = 200) and a cohort of chemotherapy-treated breast cancer patients with estrogen receptor (ER)-positive tumors (cohort C; n = 223). RESULTS: AR mRNA expression was associated with lower grading (Grades 1 and 2) as well as ER and progesterone receptor (PgR) positivity in all cohorts. In the treated cohort (cohort A), low androgen receptor expression was associated with shorter event-free survival (OR 2,34, 95 % CI 1.01-5.43, p = 0.047) which was not seen in the untreated cohort B. Subgroup analysis revealed that shorter survival of patients with low AR mRNA expression was observed mainly in the ER-positive subgroup of patients treated with adjuvant chemotherapy. In the validation cohort C we could confirm a benefit of chemotherapy for the group of tumors with high AR mRNA expression (5-year event-free survival (EFS) 74 % versus 57 %, p = 0.013). In this cohort, low AR mRNA expression was associated with shorter event-free survival also in multivariate analysis (OR 2.86, 95 % CI 1.29-6.35, p = 0.010) adjusted for HER2, ki-67, tumor size, age and tumor grade. CONCLUSIONS: We provide evidence that AR expression is associated with chemotherapy responsiveness in ER-positive patients.
Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/genetics , Receptors, Androgen/genetics , Adult , Aged , Aged, 80 and over , Antineoplastic Agents, Hormonal/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Cohort Studies , Female , Follow-Up Studies , Gene Expression Regulation, Neoplastic , Humans , Middle Aged , Neoplasm Grading , Neoplasm Staging , Prognosis , Receptor, ErbB-2/genetics , Receptors, Estrogen/genetics , Receptors, Progesterone/geneticsABSTRACT
BACKGROUND: Carbonic anhydrase IX (CAIX) is involved in pH homeostasis, growth and survival of tumor cells. Besides the membranous form of CAIX, a soluble form is detectable in serum (s-CAIX). Overexpression of CAIX in tumors offers the opportunity for therapeutic strategies such as CAIX targeting antibodies. The aim of this study was to examine the relationships of CAIX mRNA expression and s-CAIX levels with clinicopathological parameters and survival of patients with primary breast cancer. METHODS: Tumor tissue of 169 primary breast cancer patients was analyzed for RNA expression by microarray analysis (Affymetrix HG-U133A). Concentration of s-CAIX was determined by ELISA in blood samples of 140 patients. RESULTS: In tumor tissue, CAIX mRNA signal intensities (MAS5 values) ranged from 34 to 2,513. Higher CAIX expression was associated with younger age (
