Tinal metaplastic glands exhibit contrastive staining of CTSE. Typically, intestinal MedChemExpress Solvent Yellow 14 metaplasia is classified into two categories: mixed gastric-and-intestinal type (incomplete type) and solely intestinal type (complete type) [29,38]. It is well established that the former one expresses both MUC5AC (301353-96-8 gastric marker mucin) and MUC2 (intestinal marker mucin), whereas the latter one expresses not MUC5AC but MUC2 [29]. In both types of intestinal metaplasia in stomach, we confirmed that expression of CTSE is similar to MUC5AC and opposite to MUC2 (Figure 3B and 3C).To assess the association of CTSE expression with MUC5AC and MUC2 expression, their immunostaining was statistically evaluated using endoscopically resected 84 gastric tumor tissues (Table S2). The correlation analyses showed that CTSE expression is positively associated with gastric marker MUC5AC (p,0.0001) and negatively associated with intestinal marker MUC2 (p = 0.0019). Synthetically, we concluded that CTSE, like MUC5AC, is one of the gastric differentiation markers.More Undifferentiated Tubular Adenocarcinoma Tends to Arise from the Background Mucosa with Decreased Both “gastric” and “intestinal” FeaturesTo investigate the initiation step of gastric tumorigenesis, the background mucosa of early cancer and adenoma was furtherFigure 3. Expression of CTSE in non-malignant but precancerous gastric mucosa analyzed with immunohistochemistry. (A) CTSE immunostaining (left panel) and HE staining (right panel) of the stomach showing the mixture of normal fundic glands and intestinal metaplastic glands. (B, C) Immunostaining for CTSE (left), MUC5AC (middle), and MUC2 (right) in gastric intestinal metaplasia. Typical images of intestinal metaplasia with mixed gastric- and intestinal- feature (incomplete type, B) and solely intestinal feature (complete type, C) were shown. doi:10.1371/journal.pone.0056766.gCTSE: A Marker of Signet-Ring Cell Gastric Cancerevaluated, using 84 endoscopically resected specimens. CTSE expression of non-cancerous gastric mucosa adjacent to tumor lesion was evaluated, together with MUC5AC and MUC2 (Table 4). For sig-type GC, both the tumor lesion and background mucosa mostly showed strong expression of CTSE and MUC5AC, whereas expression of MUC2 was very weak in both of them (Table 4). Similar expression patterns of the three markers in the tumor and adjacent mucosa suggest that initiation of sig-type GC reflects the features of background mucosa, from the view of “gastric” and “intestinal” differentiation. That is to say, sig-type GC with non-intestinal gastric properties initially occurs from the background mucosa with non-intestinal and 1317923 gastric features. For gastric adenoma and tubular adenocarcinoma (tub1/tub2type GC), contrastively, expression profiles of the three markers are very interesting (Table 4). More undifferentiated gastric tumors tend to increase expression of CTSE and MUC5AC in tumor lesions (tub2. tub1. adenoma) but decrease expression of these gastric markers in the background mucosa (tub2, tub1, adenoma). These suggest that more undifferentiated (hence more malignant) gastric tumors apt to show the stronger gastric property, whereas they tend to arise from the background mucosa with decreased gastric features. On the other hand, more differentiated gastric tumors tend to express MUC2 in both tumor lesions and background mucosa (adenoma.tub1. tub2). This suggests that intestinal differentiation of background gastric mucosa leads to t.Tinal metaplastic glands exhibit contrastive staining of CTSE. Typically, intestinal metaplasia is classified into two categories: mixed gastric-and-intestinal type (incomplete type) and solely intestinal type (complete type) [29,38]. It is well established that the former one expresses both MUC5AC (gastric marker mucin) and MUC2 (intestinal marker mucin), whereas the latter one expresses not MUC5AC but MUC2 [29]. In both types of intestinal metaplasia in stomach, we confirmed that expression of CTSE is similar to MUC5AC and opposite to MUC2 (Figure 3B and 3C).To assess the association of CTSE expression with MUC5AC and MUC2 expression, their immunostaining was statistically evaluated using endoscopically resected 84 gastric tumor tissues (Table S2). The correlation analyses showed that CTSE expression is positively associated with gastric marker MUC5AC (p,0.0001) and negatively associated with intestinal marker MUC2 (p = 0.0019). Synthetically, we concluded that CTSE, like MUC5AC, is one of the gastric differentiation markers.More Undifferentiated Tubular Adenocarcinoma Tends to Arise from the Background Mucosa with Decreased Both “gastric” and “intestinal” FeaturesTo investigate the initiation step of gastric tumorigenesis, the background mucosa of early cancer and adenoma was furtherFigure 3. Expression of CTSE in non-malignant but precancerous gastric mucosa analyzed with immunohistochemistry. (A) CTSE immunostaining (left panel) and HE staining (right panel) of the stomach showing the mixture of normal fundic glands and intestinal metaplastic glands. (B, C) Immunostaining for CTSE (left), MUC5AC (middle), and MUC2 (right) in gastric intestinal metaplasia. Typical images of intestinal metaplasia with mixed gastric- and intestinal- feature (incomplete type, B) and solely intestinal feature (complete type, C) were shown. doi:10.1371/journal.pone.0056766.gCTSE: A Marker of Signet-Ring Cell Gastric Cancerevaluated, using 84 endoscopically resected specimens. CTSE expression of non-cancerous gastric mucosa adjacent to tumor lesion was evaluated, together with MUC5AC and MUC2 (Table 4). For sig-type GC, both the tumor lesion and background mucosa mostly showed strong expression of CTSE and MUC5AC, whereas expression of MUC2 was very weak in both of them (Table 4). Similar expression patterns of the three markers in the tumor and adjacent mucosa suggest that initiation of sig-type GC reflects the features of background mucosa, from the view of “gastric” and “intestinal” differentiation. That is to say, sig-type GC with non-intestinal gastric properties initially occurs from the background mucosa with non-intestinal and 1317923 gastric features. For gastric adenoma and tubular adenocarcinoma (tub1/tub2type GC), contrastively, expression profiles of the three markers are very interesting (Table 4). More undifferentiated gastric tumors tend to increase expression of CTSE and MUC5AC in tumor lesions (tub2. tub1. adenoma) but decrease expression of these gastric markers in the background mucosa (tub2, tub1, adenoma). These suggest that more undifferentiated (hence more malignant) gastric tumors apt to show the stronger gastric property, whereas they tend to arise from the background mucosa with decreased gastric features. On the other hand, more differentiated gastric tumors tend to express MUC2 in both tumor lesions and background mucosa (adenoma.tub1. tub2). This suggests that intestinal differentiation of background gastric mucosa leads to t.
