PMC

Immunofluorescent staining of NQO1 in MCF-7 human breast cancer cells. NQO1 protein located in the cytoplasm of breast cancer cells (red indicates NQO1 staining; Blue indicates DAPI).

Kaplan–Meier survival curves in patients with high and low NQO1 expression. (A) and (B) show comparison of DFS and 10-year OS, respectively, in NQO1 low-expression (L) and high-expression (H) patients.

Kaplan–Meier survival curves of in early and late stage patients. (A) and (B) show comparison of DFS and 10-year OS, respectively, in NQO1 (L) and (H) patients of early stage. (C) and (D) show comparison of DFS and 10-year OS, respectively in NQO1 (L) and (H) patients of late stage.

Kaplan–Meier survival curves in patients with Her2 positive and negative expression. (A) and (B) show comparison of DFS and 10-year OS, respectively, in NQO1 (L) and (H) patients with Her2 negative expression. (C) and (D) show comparison of DFS and 10-year OS, respectively, in NQO1 (L) and (H) patients with Her2 positive expression.

Immunohistochemical staining for NQO1 protein expression. (A) NQO1 staining is negative in non-tumor tissue. (B) Weakly positive NQO1 protein signals in breast hyperplasia. (C) Strongly positive NQO1 protein signal in breast cancer cases with metastasis. (D) Weakly positive NQO1 protein signal in invasive ductal breast cancers without metastasis. (E) Strongly positive NQO1 protein in the cancer cells metastatic to blood vessels (arrows). (F) Strongly positive NQO1 protein signal in the metastatic cancer loci in lymph node. Original magnification, A: ×100; B–F: ×200.

Overexpression of NQO1 mRNA and protein in breast cancer tissues. Expression of NQO1 mRNA and protein in breast cancers tissues (T) and adjacent non-tumor tissues (ANT) were examined by qPCR (A) and western blotting (B). Data in (A) represent fold change of relative NQO1 mRNA expression normalized to GAPDH levels. Error bars represent the standard deviation of the mean (SD) calculated from three parallel experiments. *P < 0.05.