Low Expression of PLAT in Breast Cancer Infers Poor Prognosis and High Immune Infiltrating Level

Purpose: Breast cancer accounts for the highest incidence of tumors in women. Immune infiltrating of the tumor microenvironment positively correlates with the overall survival of breast cancer patients. PLAT can affect the development of many cancers, but its mechanism in breast cancer is unclear. We assessed the correlation between PLAT and immune infiltrating in breast cancer based on the TCGA database. Patients and Methods: The expression and DNA methylation of PLAT in breast cancer with different clinical characteristics was tested by Wilcoxon signed rank test and displayed by box plot. Sequentially, Kaplan-Meier plot was employed to compare the difference in overall survival rates between patients with different expressed levels. Univariate and multivariate Cox regression analyses were used to validate whether PLAT is an independent prognostic factor of breast cancer. After that, GO, KEGG, and gene-set enrichment analysis were employed to do functional enrichment analysis. Finally, TIMER, TISIDB database, and ssGSEA algorithm were used to assess the correlation between PLAT expression and various immune characteristics. The correlation between PLAT expression and DNA methylation was examined by Pearson correlation coefficient. Results: PLAT displays differential expression levels in breast cancer patients with various clinical characteristics. As an independent protective factor for breast cancer, PLAT may significantly correlate with the immune status of breast cancer by adjusting many immune molecules and affecting the immune infiltration in the tumor microenvironment. DNA methylation of PLAT downregulates the gene expression and affects the prognosis of breast cancer. Conclusion: PLAT can be considered a potential biomarker to predict breast cancer prognosis and might contribute to the development of immunological treatment strategies.