BackgroundSkin cutaneous melanoma (SKCM) is the most lethal skin cancer with an increasing incidence worldwide. The poor prognosis of SKCM urgently requires us to discover prognostic biomarkers for accurate therapy. As a regulator of DNA replication, TIMELESS (TIM) has been found to be highly expressed in various malignancies but rarely reported in SKCM. The objective of this study was to evaluate the relationship between TIM and SKCM tumorigenesis and prognosis.MethodsWe obtained RNA sequencing data from TCGA and GTEx to analyze TIM expression and differentially expressed genes (DEGs). Subsequently, GO/KEGG, GSEA, immune cell infiltration analysis, and protein-protein interaction (PPI) network were used to perform the functional enrichment analysis of TIM-related DEGs. Moreover, the receiver operating characteristic (ROC) curves, Cox regression analysis, Kaplan–Meier (K-M) analysis, and nomograms were applied to figure out the clinical significance of TIM in SKCM. In addition, we investigated the relationship between TIM promoter methylation and SKCM prognosis through the UALCAN database. Finally, the immunohistochemical (IHC) results of normal skin and SKCM were analyzed to determine expression differences.ResultsTIM was significantly elevated in various malignancies, including SKCM, and high expression of TIM was associated with poor prognosis. Moreover, a total of 402 DEGs were identified between the two distinct TIM expression groups, and functional annotation showed enrichment with positive regulation of cell cycle and classic oncogenic pathways in the high TIM expression phenotype, while keratinization pathways were negatively regulated and enriched. Further analysis showed that TIM was correlated with infiltration of multiple immune cells. Finally, IHC validated the differential expression of TIM in SKCM.ConclusionTIM might play a pivotal role in tumorigenesis of SKCM and is closely related to its prognosis.

Owing to the persistent inflammatory microenvironment and unsubstantial dermal tissues, chronic diabetic wounds do not heal easily and their recurrence rate is high. Therefore, a dermal substitute that can induce rapid tissue regeneration and inhibit scar formation is urgently required to address this concern. In this study, we established biologically active dermal substitutes (BADS) by combining novel animal tissue‐derived collagen dermal‐replacement scaffolds (CDRS) and bone marrow mesenchymal stem cells (BMSCs) for the healing and recurrence treatments of chronic diabetic wounds. The collagen scaffolds derived from bovine skin (CBS) displayed good physicochemical properties and superior biocompatibility. CBS loaded with BMSCs (CBS‐MCSs) could inhibit M1 macrophage polarization in vitro. Decreased MMP‐9 and increased Col3 at the protein level were detected in CBS‐MSCs‐treated M1 macrophages, which may be attributed to the suppression of the TNF‐α/NF‐κB signaling pathway (downregulating phospho‐IKKα/β/total IKKα/β, phospho‐IκB/total IκB, and phospho‐NFκB/total NFκB) in M1 macrophages. Moreover, CBS‐MSCs could benefit the transformation of M1 (downregulating iNOS) to M2 (upregulating CD206) macrophages. Wound‐healing evaluations demonstrated that CBS‐MSCs regulated the polarization of macrophages and the balance of inflammatory factors (pro‐inflammatory: IL‐1β, TNF‐α, and MMP‐9; anti‐inflammatory: IL‐10 and TGF‐β3) in db/db mice. Furthermore, CBS‐MSCs facilitated the noncontractile and re‐epithelialized processes, granulation tissue regeneration, and neovascularization of chronic diabetic wounds. Thus, CBS‐MSCs have a potential value for clinical application in promoting the healing of chronic diabetic wounds and preventing the recurrence of ulcers.