The
phosphoprotein phosphatase catalytic subunit (PPPCs) family has been shown to play an important role in the development and progression of various
malignancies, but its expression patterns and biological functions in
breast cancer (BC) remain unclear. Therefore, we aimed to investigate the clinical significance and biological functions of the PPPCs family to understand its possible significance in the diagnosis, prognosis and treatment of
breast cancer. We comprehensively investigated the expression levels, diagnostic accuracy, prognostic outcomes, biological functions and effects on immune cell infiltration of the PPPCs family in
breast cancer using online databases. Except for PPP1CB, PPP1CC, PPP5C and PPEF1, the
mRNA expression levels of the PPPCs family in
breast cancer tissues were significantly different from those in paracancerous tissues. The differentially expressed genes (DEGs) were associated with the clinicopathological parameters and prognosis of
breast cancer. The DEGs were mainly associated with the WNT signaling pathway, antigen presentation and DNA repair. In addition, the DEGs significantly affected the infiltration of immune cells in
breast cancer tissues. Among the PPPCs family, PPP1CA and PPP4C played a prominent role in the progression of
breast cancer, and inhibition of PPP1CA and PPP4C expression by
siRNA can significantly inhibit
breast cancer cells proliferation and migration. In conclusion, the PPPCs family, especially PPP1CA and PPP4C, could be used as new
biomarkers to improve diagnostic accuracy, predict prognosis and novel targets for the treatment of
breast cancer.