GSTP1, PRDX2 and NFE2L2: Potential Markers for Primary Stage Breast Cancer

Breast cancer incidence and mortality have continued to rise over the past few decades. Despite advancements made in clinical research, the most imperative feature of breast cancer management is the diagnosis at the earliest stages. The current focus of the study is to identify and quantify differentially expressed oxidative stress-related proteins as putative early- stage markers for breast cancer.

Normal and cancerous breast tissue samples (n = 40) were collected after approval from the institutional bioethics committee (IBC) and with patient's consent. A label-free proteomic approach was used to quantify oxidative stress-related proteins. Gene expression of GSTP1, PRDX2, HSP90, NFE2L2, and miR-365a was quantified using RT-qPCR in all samples. Protein expression of PRDX2 and GSTP1 was further analyzed using immunohistochemistry.

The protein and gene expression of PRDX2, GSTP1, and HSP90 were significantly upregulated (p < 0.05) in cancerous samples as compared to normal. However, gene and protein expression of the transcription factor NFE2L2 was significantly downregulated (p < 0.05) in diseased samples. OncomiR-365a was also significantly upregulated (p < 0.05) in cancerous samples. Immunohistochemical analysis also confirmed the upregulated expression of GSTP1 and PRDX2 in cancer tissues.

Our study provides insight into the significant role of GSTP1, PRDX2, and NFE2L2 in the pathophysiology of the disease as early-stage breast cancer markers. It is suggested that altered expression of these key proteins could play a protective role in reducing the damage.

It can be concluded that GSTP1, PRDX2, and NFE2L2 may serve as predictive early- stage markers for diagnosis and potential therapeutic targets for breast cancer.