Tumor epithelial cells within a tumor coexist with a complex microenvironment in which a variety of interactions between its various components determine the behavior of the primary tumors. Cancer- associated fibroblasts (CAF) and M2 macrophages, characterized by high expression of different markers, including a-SMA, FSP1 and FAP, or CD163 and DCSIGN, respectively, are involved in the malignancy of different tumors. In the present study, expression of the above markers in CAF and M2 macrophages was analyzed using RT-PCR and immunohistochemistry in the normal mucosa and tumor tissue from a cohort of 289 colorectal cancer patients. Expression of CAF and M2 markers is associated with the clinical outcome of colorectal cancer patients. Moreover, the combination of CAF and M2 markers identifies three groups of patients with clear differences in the progression of the disease. This combined variable could be a decisive factor in the survival of advanced-stage patients. Taken together, these analyses demonstrate the prognostic involvement of interrelationships between DCSIGN, CD163, a-SMA, FSP1 and FAP markers in the survival of colon cancer patients.This work has been supported by Fundación Científica AECC, SAF2010-20750, S2010 ⁄BMD-2344, RTICC-RD06 ⁄ 0020 ⁄ 0020, PI12 ⁄ 02037 and Fundación Banco Santander. A.G.H. laboratory was supported by RD06 ⁄ 0020 ⁄ 0040. C.P. is the recipient of a Miguel Servet Contract from the Instituto de Salud Carlos III (CP09 ⁄ 00294) and V.G. is the recipient of a Fundación Científica AECC fellowshi

A significant proportion of extracellular nucleic acids in plasma circulate highly protected in tumor-specific exosomes, but it is unclear how the release of exosomes is modulated in carcinogenesis. We quantified by cytometry exosomes in plasma of 91 colorectal cancer patients to evaluate their potential as a tumor indicator and their repercussions on diagnosis and prognosis. We examined the involvement of TSAP6, a TP53-regulated gene involved in the regulation of vesicular secretion, in levels of circulating exosomes in plasma of colorectal patients and in HCT116 TP53-(wild-type and null) human colorectal cancer cell lines. The fraction of exosomes in cancer patients was statistically higher than in healthy controls (mean rank ¼ 53.93 vs. 24.35). High levels of exosomes in plasma of patients correlated with high levels of carcino-embryonic antigen (P ¼ 0.029) and with poorly differentiated tumors (P ¼ 0.039) and tended to have shorter overall survival than patients with low levels (P ¼ 0.056). Release of exosomes did not correlate with TSAP6 expression; and regulation of TSAP6 by TP53 was not shown either in tumor samples or in HCT116 cell lines. Although it was not suggested that the TP53/TSAP6 pathway regulates the release of exosomes into the plasma of colorectal cancer patients, the level of circulating exosomes may be used as a tumor indicator, because it correlates with poor prognosis parameters and shorter survival.

The identification of tumour biomarkers that detect the presence of disease using noninvasive diagnostic procedures is a key part of cancer research. We determined in plasma the vesicle-related microRNA (miRNA) expression profile of nonsmall cell lung cancer (NSCLC) and evaluate whether plasma miRNAs can be both discriminating (between patients and healthy controls) and prognostic markers.365 human miRNAs were analysed by Taqman1 low-density arrays (Applied Biosystems, Foster City, CA, USA) in the plasma from 28 NSCLC patients and 20 controls. Five selected miRNAs (let7f, miR-20b, miR-30e-3p, miR-223 and miR-301) were validated independently by real-time PCR in plasma from 78 NSCLC and 48 controls and correlated with pathologic parameters and survival.Levels of let-7f, miR-20b and miR-30e-3p were decreased in plasma vesicles of NSCLC patients. Moreover, levels of let-7f and miR-30e-3p distinguished between two groups of patients for stage of disease and therefore possibility of surgery. Plasma levels of miR-30e-3p and let-7f were associated with short disease-free survival and overall survival, respectively. NSCLC patients and healthy controls differ in vesicle-related miRNAs in plasma. Levels of let-7f and miR-30e-3p in NSCLC patients are associated with poor outcome. Thus, plasma vesiclerelated miRNAs obtained by noninvasive methods could serve as circulating tumour biomarkers of discriminating and prognostic value.

About 25-50% of women with Cowden disease, a syndrome associated with germ-line mutations of the PTEN gene (at 10q23), develop breast cancer (BC), but PTEN mutations have been found in only 5% of sporadic BCs. However, 29-48% of BCs display loss of heterozygosity in 10q23, and about 40% of BCs show a decrease or absence of PTEN protein levels at the time of diagnosis. Promoter hypermethylation has been identified as an alternative mechanism of tumor-suppressor gene inactivation, but its importance in PTEN silencing in sporadic BC is unknown. We investigated PTEN promoter hypermethylation in 90 sporadic BCs and its correlations with 11 molecular and pathologic parameters, including mRNA levels of PTEN. The study, a methylation-specific PCR assay, was carried out with methylated specific primers designed in a region with scarce homology with the psiPTEN pseudogene. Expression was analyzed by real-time PCR. We found that the PTEN promoter was hypermethylated in 43 BCs (48%). PTEN hypermethylation was associated with ERBB2 overexpression, larger size, and higher histologic grade (P=0.012, 0.03, and 0.009, respectively). We concluded that PTEN promoter hypermethylation is a common event in sporadic BC, correlating with other well-established prognostic factors of this malignancy. Additionally, PTEN mRNA expression was lower in tumors with aberrant methylation.

Overexpression of TP73 variants in tumor tissues indicates that they may be involved in colon and breast carcinogenesis. The association between upregulation of DeltaTAp73 isoforms and poor prognosis features, specifically advanced tumor stage, suggests that they may be of practical clinical prognostic value. Interestingly, the in vivo associations identified here may indicate a functional network involving p73 variants, p53, and E2F-1.