Ing performed by two independent investigators blinded for the underlying disease. The magnified fields were representative for the whole tumor section. The result of the staining was expressed in percentages ( ) positivity. All values were expressed as 22948146 mean 6 SD.Real-time quantitative reverse transcription-PCR analysisTo analyze gene expression of CD4, CD25, Foxp3, TGF-b, and IL-10 by RT-qPCR, we extracted total cellular RNA using the RNeasy Minikit from Qiagen (Hilden, Germany). Areas of interest (only epithelial regions) for each tissue section were manually microdissected using a scalpel blade. Equal amounts of tissue areas were 
assessed (261.5 cm2 surface area per section, thickness of 10 mm). RNA extraction of patient samples and establishedFoxp3 Expression and CRC Disease Progressionhuman colon cell lines (for Foxp3) was performed according to the manufacturer’s instructions. Primer sets were obtained from Qiagen, 18S RNA primer pairs (forward: TCA AGA ACG AAA GTC GGA GGT TCG, reverse: TTA TTG CTC AAT CTC GGG TGG CTG) were designed by Biomers (Ulm, Germany). Matched human colon cDNA was purchased from Pharmingen (Heidelberg, Germany) as control and was standardized to baseline. The housekeeping genes Glyceraldehyde-3phosphate dehydrogenase (GAPDH), ?actin, and 18S RNA [33] were used for Tunicamycin relative 61177-45-5 quantification and cDNA quality control. All PCR reactions were carried out with a DNA Engine Opticon 2 System (MJ Research, Biozym, Oldendorf, Germany). The relative quantification value, fold difference, was expressed as 22DDCt. For the analysis in colon cancer cell lines expression is indicated in mean value, DCt and relative expression (Foxp3/ Housekeeping genes).set at 12 for Foxp3 in tumor infiltrating Treg and 16 for Foxp3 in cancer cells. Univariate analysis of significance for Foxp3 expression of tumor infiltrating Treg and cancer cell expression differences in survival curves were evaluated by Log-rank test. In the same way survival curves were compared for N and T categories as well as primary tumor. Two independent groups of patients were analyzed using Student’s t test (Satterthwaite). More than two groups were analyzed applying PROC GLM (analysis of variances) with posthoc testing (Tukey). Frequency distributions were compared using kxm tables (Chi-quadrat). Pearson’s correlation coefficient was used to describe and to test bivariate correlations. A p-value of less than 0.05 was considered statistically significant.AcknowledgmentsThe authors thank Mr. Dipl.-Math. Mathias Brosz for statistical advice and Mrs. Sabine Muller-Morath, Mrs. Mariola Dragan, Ms. Nadine Guter?muth, and Mrs. Ingrid Strauss for their technical support.Statistical analysisStatistical analysis was performed using SAS 9.2. Overall survival was defined as the time period between randomisation and death of any cause. Patients, who were lost to follow-up were censored at the date of last contact. The overall survival was evaluated by means of PROC PHREG (Cox Proportional Hazards Model). The parameters of prognostic potential, identified in a stepwise procedure, have been further investigated by Kaplan-Meier method (PROC LIFETEST). For univariate analysis mean cut-off value for either high or low expression wasAuthor ContributionsConceived and designed the experiments: MK TG MG ML AR EM IT RB UH CTG AMWG MG. Performed the experiments: MK TG ML MG EM. Analyzed the data: MK TG ML MG AR EM IT AMWG MG. Contributed reagents/materials/analysis tools: AR RB UH CTG.Ing performed by two independent investigators blinded for the underlying disease. The magnified fields were representative for the whole tumor section. The result of the staining was expressed in percentages ( ) positivity. All values were expressed as 22948146 mean 6 SD.Real-time quantitative reverse transcription-PCR analysisTo analyze gene expression of CD4, CD25, Foxp3, TGF-b, and IL-10 by RT-qPCR, we extracted total cellular RNA using the RNeasy Minikit from Qiagen (Hilden, Germany). Areas of interest (only epithelial regions) for each tissue section were manually microdissected using a scalpel blade. Equal amounts of tissue areas were assessed (261.5 cm2 surface area per section, thickness of 10 mm). RNA extraction of patient samples and establishedFoxp3 Expression and CRC Disease Progressionhuman colon cell lines (for Foxp3) was performed according to the manufacturer’s instructions. Primer sets were obtained from Qiagen, 18S RNA primer pairs (forward: TCA AGA ACG AAA GTC GGA GGT TCG, reverse: TTA TTG CTC AAT CTC GGG TGG CTG) were designed by Biomers (Ulm, Germany). Matched human colon cDNA was purchased from Pharmingen (Heidelberg, Germany) as control and was standardized to baseline. The housekeeping genes Glyceraldehyde-3phosphate dehydrogenase (GAPDH), ?actin, and 18S RNA [33] were used for relative quantification and cDNA quality control. All PCR reactions were carried out with a DNA Engine Opticon 2 System (MJ Research, Biozym, Oldendorf, Germany). The relative quantification value, fold difference, was expressed as 22DDCt. For the analysis in colon cancer cell lines expression is indicated in mean value, DCt and relative expression (Foxp3/ Housekeeping genes).set at 12 for Foxp3 in tumor infiltrating Treg and 16 for Foxp3 in cancer cells. Univariate analysis of significance for Foxp3 expression of tumor infiltrating Treg and cancer cell expression differences in survival curves were evaluated by Log-rank test. In the same way survival curves were compared for N and T categories as well as primary tumor. Two independent groups of patients were analyzed using Student’s t test (Satterthwaite). More than two groups were analyzed applying PROC GLM (analysis of variances) with posthoc testing (Tukey). Frequency distributions were compared using kxm tables (Chi-quadrat). Pearson’s correlation coefficient was used to describe and to test bivariate correlations. A p-value of less than 0.05 was considered statistically significant.AcknowledgmentsThe authors thank Mr. Dipl.-Math. Mathias Brosz for statistical advice and Mrs. Sabine Muller-Morath, Mrs. Mariola Dragan, Ms. Nadine Guter?muth, and Mrs. Ingrid Strauss for their technical support.Statistical analysisStatistical analysis was performed using SAS 9.2. Overall survival was defined as the time period between randomisation and death of any cause. Patients, who were lost to follow-up were censored at the date of last contact. The overall survival was evaluated by means of PROC PHREG (Cox Proportional Hazards Model). The parameters of prognostic potential, identified in a stepwise procedure, have been further investigated by Kaplan-Meier method (PROC LIFETEST). For univariate analysis mean cut-off value for either high or low expression wasAuthor ContributionsConceived and designed the experiments: MK TG MG ML AR EM IT RB UH CTG AMWG MG. Performed the experiments: MK TG ML MG EM. Analyzed the data: MK TG ML MG AR EM IT AMWG MG. Contributed reagents/materials/analysis tools: AR RB UH CTG.
