Arly (UICC I/II) and late stage (UICC III/IV) of the disease. (A) Increased CD4+, CD25+, Foxp3+, IL-10+, and TGF-b+ expression at stage UICC I/II as compared with those at UICC III/IV. The result of the staining was expressed in percentages ( ) positivity. All values were expressed as mean 6 SD. All pairwise tests result in p,0.001 with three exceptions: Foxp3+, control vs. UICC III/IV, p = 0.091; IL-10+, UICC I/II vs. UICC III/IV, p = 0.021; TGF-?, UICC I/II vs. UICC III/IV, p = 0.020. (B) Representative example of an Title Loaded From File immunofluorescence double staining of Foxp3+ and CD4+ in Treg. Foxp3 expression was mainly observed on CD4+ Treg (arrow) (6400 magnification). FITC, green Fluoresceinisothiocyanate, Cy3, indocarbocyanin red, and DAPI 49,6-Diamidino-2- phenylindoldihydrochlorid blue ?nuclear counterstaining. doi:10.1371/journal.pone.0053630.gFigure 3. Immunofluorescence double staining of Foxp3 and EPCAM in cancer cells from patients with CRC. Representative example of an immunofluorescence double staining, showing Foxp3 expression and EPCAM costaining in cancer cells of patients with CRC (6100 magnification above; 6400 magnification below). FITC, green Fluoresceinisothiocyanate, Cy3, indocarbocyanin red and DAPI 49,6-Diamidino-2- phenylindoldihydrochlorid blue ?nuclear counterstaining. doi:10.1371/journal.pone.0053630.gFoxp3 Expression and CRC Disease ProgressionFigure 4. Protein expression of Foxp3 in colon cancer cell lines by flow cytometry and immunofluorecence double staining analysis. (A) Flow cytometry assay of Foxp3 expression in SW480, SW620, and HCT-116 colon cancer cell lines compared to isotype control. 3.8 to 6.1 of colon cancer cells express Foxp3; PE: phycoerythrin; FS: forward scatter Title Loaded From File linear. (B) Representative examples of immunofluorescence double staining of Foxp3+ expression in SW480, SW620, and HCT-116 cancer cells. Cy3, indocarbocyanin red and DAPI 49,6-Diamidino-2phenylindoldihydrochlorid blue ?nuclear counterstaining (6400 magnification). doi:10.1371/journal.pone.0053630.ga continuous variable, regression analysis showed that Foxp3+ cancer cell expression had a weak but significant inverse correlation with the Foxp3+ Treg expression (R2 = 0.17, p = 0.01, n = 65; r = 20.41) (Figure 6A). Immunohistochemistry showed increased Foxp3+ Treg expression in Foxp3 negative cancer stromal tissue (arrow) (Figure 6B). In contrast, there was no or negligible Foxp3+ Treg expression found in Foxp3 positive cancer tissue (arrow) (Figure 6C).Overall survivalMultivariate Cox regression analysis was performed stepwise including age, gender, primary tumor (colon or rectum), UICC (I/ II or III/IV), depth of tumor invasion (T category 1/2 or 3/4), differentiation (1/2 or 3/4), lymph node metastasis (N category), Foxp3 ( ), Treg ( ), TGF-?( ), and IL-10 ( ). The stepwise procedure kept in the model the N category and Foxp3 expression in colon cancer cells as prognostic parameters (Chi-quadrat statistics, p,0.01, Table 2).Univariate results using Kaplan-MeierTable 1. Quantitative Real Time PCR analysis of Foxp3 expression in colon cancer cell lines. The identified prognostic factors from Cox regression model are presented in Figures 7A and C. The mean value of Foxp3+ cancer cell expression by immunohistochemical analysis for all studied tissue samples of the 65 tumors was determined at 16 . Among patients with CRC, those with high Foxp3+ cancer cell expression (.16 ) had a poorer prognosis than those with low Foxp3+ expression levels (,16.Arly (UICC I/II) and late stage (UICC III/IV) of the disease. (A) Increased CD4+, CD25+, Foxp3+, IL-10+, and TGF-b+ expression at stage UICC I/II as compared with those at UICC III/IV. The result of the staining was expressed in percentages ( ) positivity. All values were expressed as mean 6 SD. All pairwise tests result in p,0.001 with three exceptions: Foxp3+, control vs. UICC III/IV, p = 0.091; IL-10+, UICC I/II vs. UICC III/IV, p = 0.021; TGF-?, UICC I/II vs. UICC III/IV, p = 0.020. (B) Representative example of an immunofluorescence double staining of Foxp3+ and CD4+ in Treg. Foxp3 expression was mainly observed on CD4+ Treg (arrow) (6400 magnification). FITC, green Fluoresceinisothiocyanate, Cy3, indocarbocyanin red, and DAPI 49,6-Diamidino-2- phenylindoldihydrochlorid blue ?nuclear counterstaining. doi:10.1371/journal.pone.0053630.gFigure 3. Immunofluorescence double staining of Foxp3 and EPCAM in cancer cells from patients with CRC. Representative example of an immunofluorescence double staining, showing Foxp3 expression and EPCAM costaining in cancer cells of patients with CRC (6100 magnification above; 6400 magnification below). FITC, green Fluoresceinisothiocyanate, Cy3, indocarbocyanin red and DAPI 49,6-Diamidino-2- phenylindoldihydrochlorid blue ?nuclear counterstaining. doi:10.1371/journal.pone.0053630.gFoxp3 Expression and CRC Disease ProgressionFigure 4. Protein expression of Foxp3 in colon cancer cell lines by flow cytometry and immunofluorecence double staining analysis. (A) Flow cytometry assay of Foxp3 expression in SW480, SW620, and HCT-116 colon cancer cell lines compared to isotype control. 3.8 to 6.1 of colon cancer cells express Foxp3; PE: phycoerythrin; FS: forward scatter linear. (B) Representative examples of immunofluorescence double staining of Foxp3+ expression in SW480, SW620, and HCT-116 cancer cells. Cy3, indocarbocyanin red and DAPI 49,6-Diamidino-2phenylindoldihydrochlorid blue ?nuclear counterstaining (6400 magnification). doi:10.1371/journal.pone.0053630.ga continuous variable, regression analysis showed that Foxp3+ cancer cell expression had a weak but significant inverse correlation with the Foxp3+ Treg expression (R2 = 0.17, p = 0.01, n = 65; r = 20.41) (Figure 6A). Immunohistochemistry showed increased Foxp3+ Treg expression in Foxp3 negative cancer stromal tissue (arrow) (Figure 6B). In contrast, there was no or negligible Foxp3+ Treg expression found in Foxp3 positive cancer tissue (arrow) (Figure 6C).Overall survivalMultivariate Cox regression analysis was performed stepwise including age, gender, primary tumor (colon or rectum), UICC (I/ II or III/IV), depth of tumor invasion (T category 1/2 or 3/4), differentiation (1/2 or 3/4), lymph node metastasis (N category), Foxp3 ( ), Treg ( ), TGF-?( ), and IL-10 ( ). The stepwise procedure kept in the model the N category and Foxp3 expression in colon cancer cells as prognostic parameters (Chi-quadrat statistics, p,0.01, Table 2).Univariate results using Kaplan-MeierTable 1. Quantitative Real Time PCR analysis of Foxp3 expression in colon cancer cell lines. The identified prognostic factors from Cox regression model are presented in Figures 7A and C. The mean value of Foxp3+ cancer cell expression by immunohistochemical analysis for all studied tissue samples of the 65 tumors was determined at 16 . Among patients with CRC, those with high Foxp3+ cancer cell expression (.16 ) had a poorer prognosis than those with low Foxp3+ expression levels (,16.
