PBX4 belongs to the pre-B-cell leukemia homeobox (PBX) transcription factors family and acts as a transcriptional cofactor of HOX proteins participating in several pathophysiological processes. Recent studies have revealed that the dysregulation of PBX4 is closely related to multiple diseases, especially cancers. However, the research on PBX4’s potential roles in 33 cancers from the Cancer Genome Atlas (TCGA) is still insufficient. Therefore, we performed a comprehensive pan-cancer analysis to explore the roles of PBX4with multiple public databases. Our results showed that PBX4 was differentially expressed in 17 types of human cancer and significantly correlated to the pathological stage, tumor grade, and immune and molecular subtypes. We used the Kaplan–Meier plotter and PrognoScan databases to find the significant associations between PBX4 expression and prognostic values of multiple cancers. It was also found that PBX4 expression was statistically related to mutation status, DNA methylation, immune infiltration, drug sensitivity, and immune checkpoint blockade (ICB) therapy. Additionally, we found that PBX4 was involved in different functional states of multiple cancers from the single-cell resolution perspective. Enrichment analysis results showed that PBX4-related genes were enriched in the cell cycle process, MAPK cascade, ncRNA metabolic process, positive regulation of GTPase activity, and regulation of lipase activity and mainly participated in the pathways of cholesterol metabolism, base excision repair, herpes simplex virus 1 infection, transcriptional misregulation in cancer, and Epstein–Barr virus infection. Altogether, our integrative analysis could help in better understanding the potential roles of PBX4 in different human cancers.

Background Transcription factor Dp-1 (TFDP1) was overexpressed and interacted with other genes to impact multiple signaling pathways in various human cancers. However, there is less research about the TFDP1 specific roles in lung adenocarcinoma (LUAD). Methods We first explored TFDP1 expression levels and relative diseases from a pan-cancer perspective using the ONCOMINE, TIMER, and Open Targets Platform databases. Then, we used UALCAN, GEPIA 2, TCGA-LUAD data, and Kaplan-Meier plotter to examine TFDP1 clinicopathological features and prognosis in LUAD patients. Genomic alterations and DNA methylation analysis were performed by cBioPortal and MethSurv, respectively. Then, we used a cancer single-cell state atlas (CancerSEA) to find TFDP1 functions at a single-cell resolution. LinkedOmics was used to find TFDP1 coexpressed genes, biological processes, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Then, Gene Set Cancer Analysis (GSCA) was used to examine the drug resistence of TFDP1 in LUAD. Results We found that TFDP1 was overexpressed in most human cancers and related to various diseases, including LUAD. Moreover, LUAD patients with high TFDP1 expression levels might be significantly associated with individual cancer stages and have a poor prognosis. Multivariate analysis revealed that the American Joint Committee on Cancer (AJCC) pathologic stage, AJCC stage T, and AJCC stage N were the independent prognostic factors. LUAD patients with TFDP1 alterations suggested poor overall survival (OS), and disease-free survival (DFS), while hypermethylation might lead to a good prognosis. TFDP1 and its coexpressed genes were enriched in multiple signaling pathways and biological processes involved in the cell cycle, spliceosome, and DNA replication. Furthermore, TFDP1 was strongly positively related to the half-maximal inhibitory concentration (IC50) values of multiple drugs. Conclusions In summary, TFDP1 was a possible biomarker and potential therapeutic target for LUAD patients.

Rac Family Small GTPase 3 (Rac3) is a member of the Rho family of small GTP-binding proteins which play critical roles in the occurrence, progression, and metastasis of various tumors. Nevertheless, previous studies have focused on a single type of human cancer, so that the roles of Rac3 in different cancer types have not been sufficiently clarified. With the progress of biological detection and bioinformatics technology, the emerging cancer genomics databases make it possible to perform a pancancer analysis. Therefore, for the first time, we performed multiple omics analysis to investigate the roles of Rac3 in differential expression, survival prognosis, mutative status, DNA methylation, functions, immune infiltration, and immunotherapy across 33 human cancer types. We found that Rac3 expression was abnormal in 17 cancer types and significantly different in both molecular and immune subtypes of 10 cancers (p<0.05). These Rac3 expression dysregulations in cancer tissues significantly affected their corresponding survival prognosis. Our results also indicated that genetic alterations of Rac3 occurred in 27 cancer types and were significantly associated with prognosis. Moreover, methylation of Rac3 was associated with dysfunctional T-cell phenotypes and affected the prognosis of the brain, melanoma, and breast tumors, and Rac3 Copy Number Alterations (CNA) might affect the infiltration levels of different immune cells in nine cancers. Rac3 and Rac3-related genes were enriched in the axon guidance, actin cytoskeleton regulation, and neurotrophin signaling pathway, and involved the regulation of cellular localization and actin cytoskeleton organization, and small GTPase mediated signal transduction. Then, we further explored the correlations between Rac3 expression and 25 immune cells and cancer-associated fibroblasts across 33 human cancers. Furthermore, we found that Rac3 achieved higher predictive power (AUC>0.5) than three standardized biomarkers of tumor immune responses and was associated with cytotoxic T-cell levels (CTLs) and the risk of immunotherapeutic responses in three cancer types. Collectively, our study contributes to a comprehensive and integrative understanding of the oncogenic roles of Rac3 across human cancers and offers a new clue for treatment strategies.INDEX TERMS Rac3, human cancer, multiple omics, cancer prognosis, immune infiltrating.