One-way analysis of variance (ANOVA) with Dunnett multiple comparison test and t test were performed using GraphPad Prism

version 5.00 for Windows (GraphPad Software, San Diego, CA, USA). The summary P value is represented as a number of an asterisk. The test for linear trend MLN2238 chemical structure between means and column numbers was used to investigate the linear trend of data set. Values were considered statistically significant if P <.05. In addition, Bonferroni multiple comparison was also performed. In this test, the value was considered statistically significant if P <.1. Results Preferential Increases of Prx I and Trx1 mRNA Expression as GANT61 the Predominant Isoforms in Human Breast Cancer Tissue Transcript levels of Prx I in breast tissue were very low (0.65 × 10-4 pg), comparable to those in muscle (0.58 × 10-4 pg), in which the Prx I level was lowest among 48 major human tissues (Figure 1A). Thioredoxin 1, as cytoplasmic electron donor to Prx I, was also expressed at the lowest level (0.24 × 10-4 pg) among 48 major human tissues (Figure 1B). To address whether this low expression was specific to Prx I, we investigated mRNA levels of all members of the Prx family (Prx I-VI) using the same 96-well HMRT

array. Expression profiles of each gene, shown in Figure 2, revealed that all levels of Prx were lowest in breast tissue when compared to the level of Prx in other tissues. The expression profiles of the Prx and Trx families in eight solid cancers (breast, colon, kidney, liver, lung, ovary, P-type ATPase prostate, and thyroid) were studied using the CSRT 96-I array in which 12 samples (n = 3 for normal, n = 9 for corresponding cancer) from different individuals AZD5153 order were included for each type of cancer for a total of 96 samples. As indicated in Figure 3A, the level of Prx1 mRNA was elevated in breast cancer by the highest fold (9.12 ± 1.86) among the eight types of solid tissue cancers, and the induction levels of Prx II-VI in breast cancer ranging from ~2- to ~4-fold) were not significantly different from those in other types of cancers (ranging from

~1- to ~3-fold). Figure 3B showed that Trx1 was also expressed at the highest level in breast cancer (6.47 ± 1.22), whereas Trx2 was not preferentially expressed in breast cancer (2.72 ± 0.28) (P = 0.0067). Figure 1 Expression Profiles of Peroxiredoxin I and Thioredoxin1 in 48 Major Human Tissues. The Human Major Tissue qRT-PCR array was used to determine transcript levels of Prx I (Figure 1A) and Trx1 (Figure 1B). For the human tissue array, tissues were selected from 48 individuals of different ethnicity. The y-axis represents the value of pg × 104 of DNA determined. Data were abtained using the comparative CT method with the values normalized to GAPDH levels and a standard curve. Details are in the “”Materials and Method”" section. Abbreviations: GAPDH, glyceraldehyde 3-phosphate dehydrogenase; Prx I, peroxiredoxin I; qRT-PCR, quantitative real-time polymerase chain reaction; Trx1, thioredoxin 1.