mRNA in NM, MA and CRC. *P,0,05 vs NM. Band intensity of ThPOK protein and ThPOK mRNA level for NM were arbitrarily set to 1. doi:10.1371/journal.pone.0054488.g(P,0.05 vs NM). In CRC there was a lower level of colocalization with CD4 (P,0.05 vs both NM and MA), the increased levels of double staining of ThPOK and CD8 was similar to MA, and the amount of ThPOK+/CD56+ cells was almost undetectable (Figure 4, panel D).difference was not significant in CRC samples, where the level of RUNX3-ThPOK-coexpressing CD8+ T cells and of RUNX3positive CD8+ T cells became equal (Figure 5, panel D and Figure 6).Discussion ThPOK and Treg LymphocytesWe performed cellular colocalization studies by triple immunofluorescence analysis coupled with confocal microscopy in order to look for a coexpression of ThPOK and Foxp3 in colorectal carcinogenesis. ThPOK did not 
colocalize with Foxp3 in all the specimens, but either shown a comparable expression profile. The IFIS levels of Foxp3 increased from NM (IFIS 23.563.2) to MA (IFIS 40.766.7) and CRC (IFIS 49.463.4) (Figure 5, panel A). Our study focused on colorect.Ls were present in most samples of CRC 1516647 (Table 1, P,0.05 between all pairs of groups, and Figure 3, panels G-I). The samples of NM were weakly stained for ThPOK, whereas both in MA and in CRC ThPOK staining was significantly higher (Table 1, P,0.05 vs NM, and Figure 3 panels A-I).Colocalization AnalysesIn order to identify the type of stromal cells positive for CD4, CD8 and CD56 which mostly expressed ThPOK, we performed cellular colocalization studies by double immunofluorescence analysis coupled with confocal microscopy. Figure 4 shows thelocalization of anti-CD4, anti-CD8 and anti-CD56 antibodies coupled with ThPOK staining in samples of NM, MA, and CRC. The colocalization image was used to calculate the overlap coefficient according to Manders [32]. We observed interesting changes in the colocalization levels during neoplastic progression (Figure 4). The degree of ThPOK/CD4 colocalization in NM and MA was similar, it was significantly lower in colorectal carcinomas (Figure 4, panel A). The Manders coefficient for ThPOK and CD8 showed a peak in MA samples. Although the increased alignment of ThPOK and CD8 was more prominent in MA compared to colorectal carcinomas, in both groups it was statistically higher than in NM (P,0.05 between all pair of groups, Figure 4, panel B). The colocalization degree of ThPOK with CD56 increased in samples of colorectal carcinomas compared to normal mucosa and microadenomas (P,0.05 Figure 4, panel C), although the level of CD56 in carcinomas was very low. By normalizing the co-expression data to the fluorescence levels, we observed that, in NM, most of ThPOK+ cells was CD4+, and a lower level of colocalization was observed between ThPOK 11967625 and the others markers. In MA the level of colocalization of ThPOK with CD4 remained similar to NM, whereas the highest colocalization was with CD8, statistically higher when compared to NM (P,0.05 vs NM), and smaller colocalization with CDThPOK in Colorectal CarcinogenesisFigure 2. ThPOK protein and mRNA during colorectal neoplastic progression. Measurement of ThPOK protein and mRNA in normal colorectal mucosa (NM), microadenomas (MA), and colorectal cancer (CRC). Panel A: NM, MA and CRC were subjected to SDS AGE/western blot using the anti-ThPOK antibody; densitometric analysis and bands at 60 kD for ThPOK and at 42 kD for a-actin.* P,0.05 vs NM. Panel B: Real-time PCR analysis of ThPOK mRNA in NM, MA and CRC. *P,0,05 vs NM. Band intensity of ThPOK protein and ThPOK mRNA level for NM were arbitrarily set to 1. doi:10.1371/journal.pone.0054488.g(P,0.05 vs NM). In CRC there was a lower level of colocalization with CD4 (P,0.05 vs both NM and MA), the increased levels of double staining of ThPOK and CD8 was similar to MA, and the amount of ThPOK+/CD56+ cells was almost undetectable (Figure 4, panel D).difference was not significant in CRC samples, where the level of RUNX3-ThPOK-coexpressing CD8+ T cells and of RUNX3positive CD8+ T cells became equal (Figure 5, panel D and Figure 6).Discussion ThPOK and Treg LymphocytesWe performed cellular colocalization studies by triple immunofluorescence analysis coupled with confocal microscopy in order to look for a coexpression of ThPOK and Foxp3 in colorectal carcinogenesis. ThPOK did not colocalize with Foxp3 in all the specimens, but either shown a comparable expression profile. The IFIS levels of Foxp3 increased from NM (IFIS 23.563.2) to MA (IFIS 40.766.7) and CRC (IFIS 49.463.4) (Figure 5, panel A). Our study focused on colorect.