We assume that at least a portion of the proliferating population consists of LgR5+ Barrett cells and these results are compatible with the view that a minority population of Barrett cells is able to proliferate and contribute to the numbers of a larger Barrett cell population with a modified capacity for proliferation. Such a situation would be analogous to that found in normal hemopoietic differentiation, where a minority population of stem cells proliferates and gives rise to a AZD3965 molecular weight large population of progeny, most of which have lost stem cell properties. Finally,

adenocarcinoma in BE may contain a cellular subcomponent that retains key stem cell properties [13, 33, 35, 36]. Chronic activation of LgR5 expressed by BE in these putative pluripotent cancer-initiating cells may sustain inflammation responses, mediate resistance to apoptosis and promote further progression of the metaplasia – intraepithelial neoplasia – carcinoma sequence. Therefore targeting of LgR5 signalling might be a potential mechanism to abrogate this inflammation-mediated effect in tumor progression. This may be the reason for the higher expression of LgR5

in precancerous cells of BE, in comparison to cells of invasive AC. LgR5 signalling may therefore play a biological role in potentially cancer-initiating BE cells. Although Barrett’s esophagus (BE) is regarded as precancerous lesion of esophageal adenocarcinomas (EAC), some doubts have been raised regarding this association selleck chemicals [7]. A substantial proportion of adenocarcinomas in the distal esophagus were not associated with Barrett mucosa. There are different potential explanations regarding pathogenesis and

origin of these EAC without Barrett. – First, AC without BE may have originated within a Barrett mucosa, which may have been previously destroyed (‘overgrown’) by the tumor [37, 38]. It has been suggested, that neoadjuvant therapy may result in ‘unmasking’ of the previously ‘overgrown’ Phosphoprotein phosphatase Barrett mucosa. – Moreover, AC without BE may have originated in very small spots of (ulta short segment) Barrett mucosa or cases in which intestinal metaplasia was not stained with Cdx-2 [19]. – Finally AC without BE may have originated from another cell type, which might be the putative cancer stem cell. A prognostic effect of LgR5 expression on protein level (IHC) was shown on univariate survival Selleckchem Bafilomycin A1 analysis. Patients with a high percentage of LgR5+ cells (>33%) exhibited a worse prognosis, in comparison to patients with lower LgR5+ staining. This was shown for the whole population of all patients with EAC under investigation, a result which is in line with previously published results [33]. We have furthermore shown, that a similar prognostic effect could be seen, when LgR5 expression was examined in a similar fashinon in adjacent Barrett’s mucosa in EACs with BE. This result has not been decribed before and may be regarded due to the effect of ‘field cancerization [39].