IDO is highly expressed in breast cancer and breast cancer-derived circulating microvesicles and associated to aggressive types of tumors by in silico analysis.

Indoleamine-2,3-dioxygenase (IDO) has been established as a normal mechanism of peripheral tolerance and immunosuppression. Besides, malignant tumors release microvesicles (MV) related with tumor dissemination. The aims of this study were to determine the expression of IDO in breast cancer and circulating microvesicles from breast cancer patients and to perform an in silico analysis to find genes co-expressed to IDO. One hundred and twenty-two tissue and serum breast samples (91 malignant, 21 benign, and 10 normal), and MCF7, MDA-MB-231, and T47D breast cancer cell lines were included. Standard immunohistochemistry (IHC), immunocytochemistry (ICC), Western blot (WB), and RT-PCR were employed. Microvesicle isolation from plasma samples was obtained by serial centrifugation and ultracentrifugation. By IHC, 60 % breast cancer, 43 % benign, and 20 % normal samples were positive. Significant differences were found among normal, benign, and malignant samples. Breast cancer stages I, II, and III expressed IDO in 42, 66, and 71 % of samples, respectively, while breast cancer cell lines also reacted; by WB, 9/25 microvesicles fractions showed bands at 42 kD. In silico analysis of IDO 1 gene expression in breast cancer showed its association with several genes related to immune response and apoptosis. Moreover, IDO and co-expressed genes were found predominately in basal and erbB2 subtypes. The cumulative data indicate a high expression of IDO in breast cancer which increased with higher stages. Furthermore, IDO was found in association with circulating breast cancer MV, while experimental and in silico gene expression revealed that IDO was mainly expressed in a triple-negative subgroup.

Detection of circulating mammary mucin (Muc1) and MUC1 immune complexes (Muc1-CIC) in healthy women.

There is convincing epidemiological evidence that multiparity provides protection against the development of breast cancer. In the present study we evaluated the levels of MUC1 and MUC1 circulating immune complexes (MUC1-CIC) in 135 serum samples obtained from healthy women. The study population included 13 women who had never been pregnant, 31 primiparous pregnant women, 36 multiparous pregnant women who had lactated, 5 multiparous pregnant women who had never lactated, 24 multiparous non-pregnant women who were lactating at the time of the study, 24 multiparous non-pregnant women who had lactated, and 2 multiparous non-pregnant women who had never lactated. The purpose of this work was to detect MUC1 variations during pregnancy and lactation as well as to study the possible induction of a humoral immune response against MUC1 in these conditions. We employed ELISA techniques to measure MUC1 (CASA test) and MUC1-CIC (IgM and IgG) using two anti-MUC1 monoclonal antibodies (MAbs): C595 and SM3. Statistical analysis was performed using the ANOVA test. The pooled results pertaining to pregnant versus non-pregnant women were compared and significant differences were observed in MUC1 and MUC1-CIC-lgM levels detected with both MAbs; the MUC1-CIC-lgG levels detected with C595 were increased in the pregnant group while the MUC1-CIC-lgG levels detected with SM3 did not show any significant differences. When the results were compared between lactating and non-lactating women, no significant differences were found. In conclusion, MUC1 and MUC1-CIC-lgM, detected with both MAbs, and MUC1-CIC-4gG levels detected with the MAb C595 are apparently induced by pregnancy.

Humoral immune response induced by the protein core of MUC1 mucin in pregnant and healthy women.

UNLABELLED: Serum levels of MUC1 and antibodies (Abs) against MUC1 (IgG and IgM-MUC1) were evaluated in healthy women related to pregnancy and lactation status. A total of 149 serum samples were obtained from: nulliparous, primiparous pregnant, multiparous pregnant that have lactated, multiparous pregnant without lactation, multiparous non-pregnant actual lactating, multiparous non-pregnant that have lactated and finally, multiparous non-pregnant women without lactation. In all assays, we included pre- and post-serum samples belonging to a breast cancer patient vaccinated with a MUC1 derived peptide. CASA test was employed to measure MUC1 while IgG- and IgM-MUC1 serum Abs were evaluated with an ELISA using a 100 mer peptide as catcher. In all groups, mean IgM levels were higher than IgG mean values; when samples were grouped in pregnants versus non-pregnants, a significant difference was detected with both Abs, being raised in non-pregnants. When samples were grouped in lactating versus non-lactating a significant difference was detected with IgG-MUC1, being raised in lactating women while no significant difference was found with IgM-MUC1. The evaluation of serum MUC1 levels confirmed previous results since a significant difference between pregnant versus non-pregnant groups was found while lactating versus non-lactating samples did not. CONCLUSIONS: (i) Increased MUC1 serum levels are apparently associated with pregnancy but not with lactation; (ii) MUC1 Abs are mainly associated with lactation and with non-pregnant status. These results may be considered a contribution on studies about protection against breast cancer induced by pregnancy and lactation.