Objective:To investigate the clinical and pathological characteristics and prognosis of upper tract urothelial carcinoma (UTUC) with concurrent other histological variants.Methods:The clinical data of 566 UTUC patients admitted to Peking University People's Hospital from January 2007 to April 2021 were retrospectively analyzed. Among them, 289 were males and 277 were females, with an average age of (67.3±10.0)years old. Among the patients, 97 had a history of smoking, 29 had undergone kidney transplantation, 120 had diabetes, 76 had coronary heart disease, 146 had hyperlipidemia, 271 had hypertension, and 50 had a history of chronic kidney disease. Among the UTUC cases, 366 had concurrent hydronephrosis, 55 had concurrent bladder cancer, and 43 had a history of previous bladder cancer. The distribution included 210 cases of renal pelvis carcinoma, 5 cases of carcinoma at the renal pelvis-ureter junction, 226 cases of ureteral carcinoma, and 125 cases of multifocal tumors. Patients were classified into the pure UTUC group and the UTUC with concurrent other histological variants group based on postoperative pathology, and their clinical and pathological features were compared. Logistic regression analysis was used to explore risk factors for the occurrence of histological variations in UTUC. The log-rank test was employed to compare the overall survival (OS) and cancer-specific survival (CSS) between the two groups, while Cox regression analysis was performed to investigate prognostic factors.Results:Among the 566 cases, 511 were pure UTUC and 55 were UTUC with concurrent other histological variants. Among the latter, 30 cases had squamous differentiation, 6 had glandular differentiation, 5 had mucinous differentiation, 5 had sarcomatoid carcinoma, 2 had micropapillary carcinoma, 2 had neuroendocrine carcinoma, 1 had giant cell carcinoma, and 4 had other mixed histological variations. The proportion of patients with a history of kidney transplantation was higher in the UTUC with concurrent histological variants group than that in the pure UTUC group [14.5% (8/55) vs. 4.1% (21/511)], with statistically significant difference ( P=0.003). In the UTUC with concurrent histological variants group, the proportion of postoperative high-grade tumors [98.2% (54/55) vs. 80.2% (410/511)], muscle-invasive tumors [89.1% (49/55) vs. 68.1% (348/511)], lymph node metastasis tumors [10.9% (6/55) vs. 2.3% (12/511)], and maximum tumor diameter [(3.60±2.64) cm vs. (2.96±1.98) cm] were higher than those in the pure UTUC group ( P<0.05). Multivariate logistic regression analysis showed that a history of kidney transplantation ( OR=4.991, 95% CI 1.749-13.615, P=0.002) was an independent predictive factor for the occurrence of histological variants. Follow-up was conducted for 1 to 174 months, with a median follow-up time of 32.8 months. UTUC with concurrent histological variants was significantly associated with worse OS and CSS ( P<0.05). Multivariate Cox regression analysis indicated that histological variants were an independent risk factor for OS ( HR=1.860, 95% CI 1.228-2.816, P=0.003) and CSS ( HR=2.146, 95% CI 1.349-3.412, P=0.001). Conclusions:UTUC with concurrent other histological variants exhibited higher postoperative tumor grade and stage compared to pure UTUC, and UTUC with concurrent other histological variants was an independent risk factor for worse prognosis.

Objective·To explore the relationship between osteoarthritis and nicotinamide metabolism-related genes using bioinformatics analysis,and identify key genes with diagnostic value and therapeutic potential.Methods·By using"Osteoarthritis"as a search term,GSE12021,GSE55235,and GSE55457 were obtained from the GEO database,with GSE55457 being used as the validation set.After removing batch effects from the GSE12021 and GSE55235 datasets,the standardized combined dataset was obtained and used as the training dataset.Differentially expressed genes(DEGs)were identified from the training dataset.All nicotinamide metabolism-related genes(NMRGs)were obtained from the GeneCards and MSigDB databases.The intersection of DEGs and NMRGs was taken to obtain nicotinamide metabolism-related differentially expressed genes(NMRDEGs).Gene set enrichment analysis(GSEA)was performed on the training dataset,while gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)analysis were performed on NMRDEGs.Key genes were selected by using least absolute shrinkage and selection operator(LASSO)and support vector machine(SVM)analysis in NMRDEGs to build an osteoarthritis diagnosis model which was validated by using the GSE55457 dataset.Single sample gene set enrichment analysis(ssGSEA)was used to analyze the immune cell infiltration type.Interactions networks and drug molecule predictions were obtained for these key genes'mRNA with the DGIdb,ENCORI,and CHIPBase databases.siRNA was used to knock down the key genes in chondrocytes,and then real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)was used to detect the expression of chondrogenesis-related genes.Results·Seven NMRDEGs,including NAMPT,TIPARP,were discovered.GO and KEGG analysis enriched some signaling pathways,such as nuclear factor-κB signaling pathway and positive regulation of interleukin-1-mediated signaling pathway.GSEA enriched pathways such as Hif1 Tfpathway and syndecan 1 pathway.Key genes NPAS2,TIPARP,and NAMPT were identified through LASSO and SVM analysis,and used to construct an osteoarthritis diagnostic model.The validated results showed that the diagnostic model had high accuracy.Immune infiltration analysis results obtained by ssGSEA showed significant differences(all P<0.05)in 15 types of immune cells,including macrophages.Seven potential small molecules targeting key genes were identified,along with 19 miRNAs with the sum of upstream and downstream>10,19 transcription factors with upstream and downstream>7,and 27 RNA binding proteins with clusterNum>19.The results of RT-qPCR showed that knocking down key genes reduced the expression of chondrogenesis-related genes.Conclusion·Through bioinformatics analysis,key genes related to nicotinamide metabolism,NPAS2,TIPARP,and NAMPT,are discovered,and an osteoarthritis diagnostic model is constructed.