Pan-Cancer Analysis of Pentraxin 3: A Potential Biomarker of COVID-19

SIMPLE SUMMARY: We clarified the expression patterns, genetic alterations, prognostic significance, and the underlying mechanisms of the COVID-19 biomarker PTX3 across TCGA cancers. Importantly, we linked PTX3 to immunotherapy, synthetically underscoring its importance in human cancers and providing the prospect of PTX3 and immunotherapy for tumor patients. In addition the function of PTX3 in kidney renal clear cell carcinoma (KIRC) was explored with in vitro assays. Collectively, we suggest that clinicians should pay particular attention to tumor patients with high PTX3 expression and should make specific and deliberative treatment choices. ABSTRACT: Pentraxin 3 (PTX3), a potential biomarker of the severity and mortality of COVID-19 patients, is aberrantly expressed in human tumors. However, a comprehensive pan-cancer analysis of PTX3 remains to be elucidated. PTX3 data profiles and clinical information in TCGA cancers were obtained from different public databases to clarify the expression levels, genetic alterations, prognostic significance, underlying mechanisms, and the predicted role in immunotherapy of PTX3 across TCGA cancers. Our analyses showed that PTX3 was aberrantly expressed in most tumors and was significantly related to prognosis and tumor stage. Interaction network and enrichment analyses revealed that PTX3 participated in tumor immuno-related progression. In addition, PTX3 levels were critically associated with immune cell components and immune scores, and PTX3 strongly coexpressed with immune-related genes in TCGA cancers. Meanwhile, PTX3 expression was associated with immune checkpoint genes, and immunotherapy potential biomarkers in multiple cancers, predicting special immunotherapy responses in different tumor types. In kidney renal clear cell carcinoma (KIRC), PTX3 emerged as an independent prognostic factor through multivariable Cox regression analyses. Blocking PTX3 with siRNA could suppress the growth of KIRC cells and invasion. Conclusively, our study shows a comprehensive bioinformatic analysis of PTX3, which might serve as a pan-cancer prognostic biomarker.