Rhomboid domain containing 2 (RHBDD2): A novel cancer-related gene over-expressed in breast cancer

AbstractIn the course of breast cancer global gene expression studies, we identified an uncharacterized gene known as RHBDD2 (Rhomboid domain containing 2) to be markedly over-expressed in primary tumors from patients with recurrent disease. In this study, we identified RHBDD2 mRNA and protein expression significantly elevated in breast carcinomas compared with normal breast samples as analyzed by SAGE (n=46) and immunohistochemistry (n=213). Interestingly, specimens displaying RHBDD2 over-expression were predominantly advanced stage III breast carcinomas (p=0.001). Western-blot, RT-PCR and cDNA sequencing analyses allowed us to identify two RHBDD2 alternatively spliced mRNA isoforms expressed in breast cancer cell lines. We further investigated the occurrence and frequency of gene amplification and over-expression affecting RHBDD2 in 131 breast samples. RHBDD2 gene amplification was detected in 21% of 98 invasive breast carcinomas analyzed. However, no RHBDD2 amplification was detected in normal breast tissues (n=17) or breast benign lesions (n=16) (p=0.014). Interestingly, siRNA-mediated silencing of RHBDD2 expression results in a decrease of MCF7 breast cancer cells proliferation compared with the corresponding controls (p=0.001). In addition, analysis of publicly available gene expression data showed a strong association between high RHBDD2 expression and decreased overall survival (p=0.0023), relapse-free survival (p=0.0013), and metastasis-free interval (p=0.006) in patients with primary ER-negative breast carcinomas. In conclusion, our findings suggest that RHBDD2 over-expression behaves as an indicator of poor prognosis and may play a role facilitating breast cancer progression

Clinical importance of circulating immune complexes in human acute lymphoblastic leukemia

A total of 122 sera from acute lymphoblastic leukemia (ALL) patients were analyzed for circulating immune complexes (CIC) by two methods: the 125I-C1q binding assay and the polyethylene glycol precipitation test (PEG). The results were correlated with induction, remission and relapse stages of the disease. Using the first method the levels of CIC in induction were 15.18±9.15, with 19/29 positive cases (65.50%), P<0.001 compared with controls. In the remission phase the levels were 9.02±5.62, 11/45 (24.49%) nonsignificant P value, and in relapse they were 16.14±11.17 28/48 (58.33%) P<0.001. The PEG precipitation test results were: 0.33±0.10, 8/22 (36.36%); 0.24±0.11, 10/48 (20.83%) and 0.28±0.10, 6/28 (21.42%), respectively. Thus the values of CIC as measured by PEG in the three clinical of phases ALL did not differ significantly from controls. This contrasts with results obtained by the radioiodinated C1q binding assay, where the incidence of positive values was significantly higher in induction and in relapse and lower in the remission phase. These observations were extended in sequential vertical studies performed in a group of patients. These results suggest that raised CIC detected by the 125I-C1q method may reflect a progressive state in ALL and that quantitation of these immune complexes may provide an adequate biochemical marker for prognosis.Facultad de Ciencias Médica

Metástasis cutáneas de cáncer de mama

El objetivo de este estudio es identificar perfiles correspondientes a la metástasis cutánea en el cáncer de mama mediante el análisis de marcadores tumorales tales como MUC1 y antígenos carbohidratos asociados

MUC1 expression and anti-MUC1 serum immune response in head and neck squamous cell carcinoma (HNSCC): a multivariate analysis

BACKGROUND: HNSCC progression to adjacent tissue and nodes may be mediated by altered glycoproteins and glycolipids such as MUC1 mucin. This report constitutes a detailed statistical study about MUC1 expression and anti-MUC1 immune responses in relation to different clinical and pathological parameters which may be useful to develop new anti HNSCC therapeutic strategies. PATIENTS AND METHODS: Fifty three pre treatment HNSCC patients were included: 26 (49.1%) bearing oral cavity tumors, 17 (32.1%) localized in the larynx and 10 (18.8%) in the pharynx. Three patients (5.7%) were at stage I, 5 (9.4%) stage II, 15 (28.3%) stage III and 30 (56.6%) at stage IV. MUC1 tumor expression was studied by immunohistochemistry employing two anti-MUC1 antibodies: CT33, anti cytoplasmic tail MUC1 polyclonal antibody (Ab) and C595 anti-peptidic core MUC1 monoclonal antibody. Serum levels of MUC1 and free anti-MUC1 antibodies were detected by ELISA and circulating immune complexes (CIC) by precipitation in polyethylene glycol (PEG) 3.5%; MUC1 isolation from circulating immune complexes was performed by protein A-sepharose CL-4B affinity chromatography followed by SDS-PAGE and Western blot. Statistical analysis consisted in Multivariate Principal Component Analysis (PCA); ANOVA test (Tukey's test) was employed to find differences among groups; nonparametrical correlations (Kendall's Tau) were applied when necessary. Statistical significance was set to p < 0.05 in all cases. RESULTS: MUC1 cytoplasmic tail was detected in 40/50 (80%) and MUC1 protein core in 9/50 (18%) samples while serum MUC1 levels were elevated in 8/53 (15%) patients. A significant statistical correlation was found between MUC1 serum levels and anti-MUC1 IgG free antibodies, while a negative correlation between MUC1 serum levels and anti-MUC1 IgM free antibodies was found. Circulating immune complexes were elevated in 16/53 (30%) samples and were also statistically associated with advanced tumor stage. MUC1 was identified as an antigenic component of IgG circulating immune complexes. Moreover, poorly differentiated tumors were inversely correlated with tumor and serum MUC1 detection and positively correlated with node involvement and tumor mass. CONCLUSION: Possibly, tumor cells produce MUC1 mucin which is liberated to the circulation and captured by IgG antibodies forming MUC1-IgG-CIC. Another interesting conclusion is that poorly differentiated tumors are inversely correlated with tumor and serum MUC1 detection

a1-acid glycoprotein (AGP): a possible carrier of sialyl lewis X (slewis X) antigen in colorectal carcinoma

Objectives: 1- to detect a1-acid glycoprotein (AGP) and sialyl Lewis x (sLex) in colorectal malignant, benign and normal samples; 2- to isolate AGP from colorectal cancer and 3- to study its immunoreactivity with an anti-sLex monoclonal antibody (MAb). Materials and methods: tissue and serum samples from 88 patients with colorectal cancer, 22 adenomas and 23 normal were included. Expression of AGP and sLex was studied by immunohistochemistry (IHC); isolation approach: AGP was precipitated with ammonium sulphate and immunoprecipitated with anti-AGP MAb. The immune complex formed was isolated by protein ASepharose CL-4B affinity chromatography and further eluted; fractions were analysed by SDS-PAGE and Western-blot. Statistical analysis was performed by means of Principal Component Analysis. Results: by Western blot employing anti-AGP MAb and sLex MAbs, isolated fractions from malignant samples showed a band at about 45kD. IHC revealed that AGP was expressed in 70% of colorectal carcinoma samples, 50% of benign and 35% of normals. SLex was detected in 31% of malignant samples, 41% of benign and in one normal sample. In malignant samples, AGP reaction comprised the whole specimen with a strong and homogeneous staining while normal and benign samples showed a restricted reaction. In cancer, sLex expression consisted in an intense reactivity in membrane, cellular debris and some cytoplasmic foci while normal and benign samples were occasionally stained. A statistically significant positive correlation was found between AGP and sLex expression. Serum AGP levels were measured by radial immunodiffusion and statistical comparative analysis with tissue expression did not show a correlation between both parameters. Conclusion: AGP may constitute a carrier of sLex in colorectal cancer

MUC1 positive cutaneous metastasis with transepidermal elimination from a breast carcinoma

Amalia Luna, Maria Emilia Merino, Cecilio G Alberdi, Martin C Abba, Amada Segal-Eiras, Maria Virginia Croce Center of Basic and Applied Immunological Research, Faculty of Medical Sciences, National University of La Plata, Argentina Abstract: Breast cancer is the most common cause of cutaneous metastases from internal malignancies. Generally, the neoplastic cells are located in the dermis or hypodermis, while a finding of transepidermal elimination on cutaneous metastases is exceptional. In this report we present a patient with perforating cutaneous metastases from breast cancer with mucin 1 expression. Cutaneous, bone, lung, and hepatic lesions were detected two years after the diagnosis of the primary tumor. Keywords: breast cancer, cutaneous metastasis, transepidermal elimination, MUC

Invasive breast cancer in Argentine women: association between risk and prognostic factors with antigens of a peptidic and carbohydrate nature

Sandra O Demichelis, Marina T Isla-Larrain, Luciano Cermignani, Cecilio G Alberdi, Amada Segal-Eiras, Mar&amp;iacute;a Virginia CroceCentre of Basic and Applied Immunological Research, Faculty of Medical Sciences, National University of La Plata, La Plata, ArgentinaObjective: In breast cancer, several tumor markers have been identified. The marker most extensively associated with breast cancer is MUC1. The objective of the study was to analyze prognostic and risk factors in relation to tumor markers in order to clarify breast cancer biology. A total of 349 primary tumor samples and lymph nodes from breast cancer patients were studied. Risk and prognostic factors were considered. An immunohistochemical approach was applied and an extensive statistical analysis was performed, including frequency analysis and analysis of variance. Correlation among variables was performed with principal component analysis.Results: All the antigens showed an increased expression according to tumor size increment; moreover, sialyl Lewis x expression showed a significant increase in relation to disease stage, whereas Tn and TF presented a positive tendency. Vascular invasion was related to sialyl Lewis x expression and number of metastatic lymph nodes. Taking into account risk factors, when a patient had at least one child, Lewis antigens diminished their expression. In relation to breastfeeding, sialyl Lewis x expression diminished, although its apical expression increased.Conclusion: Associations between MUC1 and carbohydrate antigens and risk and prognostic factors show the complexity of the cellular biological behavior that these antigens modulate in breast cancer.Keywords: breast cancer, Argentine women, risk factors, prognostic factors, antigenic expressio