Background: The VHL-HIF pathway and lipid droplet accumulation are the main characteristics of clear cell renal cell carcinoma (ccRCC). However, the connection between the two features is largely unknown. Methods: We used transcriptional sequencing and TCGA database analysis to identify APOL1 as a novel therapeutic target for ccRCC. The oncogenic functions of APOL1 were investigated by cell proliferation, colony formation, migration and invasion assays in ccRCC cells in vitro and xenografts derived from ccRCC cells in vivo. Oil red O staining and quantification were used to detect lipid droplets. Chromatin immunoprecipitation (ChIP) assays and luciferase reporter assays were carried out to identify HIF-2α bound to the promoter of APOL1 and lncRNA LINC02609. RNA-FISH and luciferase reporter assays were performed to determine that LncRNA LINC02609 functions as a competing endogenous RNA to regulate APOL1 expression by sponging miR-149-5p. Findings: RNA-seq data revealed that HIF2α can regulate APOL1 and lncRNA LINC02609 expression. We also found that HIF-2α can bind to the promoter of APOL1 and lncRNA LINC02609 and transcriptionally regulate their expression directly. We further demonstrated that LncRNA LINC02609 functions as a competing endogenous RNA to regulate APOL1 expression by sponging miR-149-5p in ccRCC. Mechanistically, APOL1-dependent lipid storage is required for endoplasmic reticulum (ER) homeostasis and cell viability and metastasis in ccRCC. We also showed that high APOL1 expression correlated with worse clinical outcomes, and knockdown of APOL1 inhibited tumor cell lipid droplet formation, proliferation, metastasis and xenograft tumor formation abilities. Together, our studies identify that HIF2α can regulate the expression of the lipid metabolism related gene APOL1 by direct and indirect means, which are essential for ccRCC tumorigenesis. Interpretation: Based on the experimental data, in ccRCC, the HIF-2α/LINC02609/APOL1 axis can regulate the expression of APOL1, thus interfering with lipid storage, promoting endoplasmic reticulum homeostasis and regulating tumor progression in ccRCC. Together, our findings provide potential biomarkers and novel therapeutic targets for future studies in ccRCC.

Emerging evidence has highlighted that dysregulation of lipid metabolism in clear cell renal cell carcinoma (ccRCC) is associated with tumor development and progression. HIF-2α plays an oncogenic role in ccRCC and is involved in abnormal lipid accumulation. However, the underlying mechanisms between these two phenomena remain unknown. Here, MED15 was demonstrated to be a dominant factor for HIF-2α-dependent lipid accumulation and tumor progression. HIF-2α promoted MED15 transcriptional activation by directly binding the MED15 promoter region, and MED15 overexpression significantly alleviated the lipid deposition inhibition and malignant tumor behavior phenotypes induced by HIF-2α knockdown. MED15 was upregulated in ccRCC and predicted poor prognosis. MED15 promoted lipid deposition and tumor progression in ccRCC. Mechanistic investigations demonstrated that MED15 acts as SREBP coactivator directly interacting with SREBPs to promote SREBP-dependent lipid biosynthesis enzyme expression, and promotes SREBP1 and SREBP2 activation through the PLK1/AKT axis. Overall, we describe a molecular regulatory network that links MED15 to lipid metabolism induced by the SREBP pathway and the classic HIF-2α pathway in ccRCC. Efforts to target MED15 or inhibit MED15 binding to SREBPs as a novel therapeutic strategy for ccRCC may be warranted.

The current research revealed a strong link between lipid reprogramming and dysregulated lipid metabolism to the genesis and development of clear cell renal cell carcinoma (ccRCC). Pathologically, ccRCC exhibits a high concentration of lipid droplets within the cytoplasm. HIF-2α expression has previously been demonstrated to be elevated in ccRCC caused by mutations in the von Hippel-Lindau (VHL) gene, which plays a vital role in the development of renal cell carcinoma. Nevertheless, the mechanisms by which HIF-2α influences lipid metabolism reprogramming are unknown. Our investigation demonstrated that HIF-2α directly binds to the promoter region of LPCAT1, promoting its transcription. RNA-seq and lipidomics mass spectrometry studies showed that knocking down LPCAT1 significantly reduced triglyceride production. Research suggests that KD-LPCAT1 involves activation of the NF-κB signaling pathway, which activates F-Box/WD Repeat-Containing Protein 7 (FBXW7). FBXW7, an E3 ubiquitin ligase involved in lipid metabolism, interacts with ATP Citrate Lyase (ACLY) to promote its degradation, lowering fatty acid production and contributing to the lipid content reduction.

Costimulatory molecules have been proven to enhance antitumor immune responses, but their roles in clear cell renal cell carcinoma (ccRCC) remain unexplored. In this study, we aimed to explore the gene expression profiles of costimulatory molecule genes in ccRCC and construct a prognostic signature to improve treatment decision-making and clinical outcomes. We performed the first comprehensive analysis of costimulatory molecules in patients with ccRCC and identified 13 costimulatory molecule genes with prognostic values and diagnostic values. Consensus clustering analysis based on these 13 costimulatory molecular genes showed different distribution patterns and prognostic differences for the two clusters identified. Then, a costimulatory molecule-related signature was constructed based on these 13 costimulatory molecular genes, and validated in an external dataset, showing good performance for predicting a patient’s prognosis. The signature was an independent risk factor for ccRCC patients and was significantly correlated with patients’ clinical factors, which could be used as a complement for clinical factors. In addition, the signature was associated with the tumor immune microenvironment and the response to immunotherapy. Patients identified as high-risk based on our signature exhibited a high mutation frequency, a high level of immune cell infiltration, and an immunosuppressive microenvironment. High-risk patients tended to have high cytolytic activity scores and immunophenoscore of CTLA4 and PD1/PD-L1/PD-L2 blocker than low-risk patients, suggesting these patients may be more suitable for immunotherapy. Therefore, our signature could provide clinicians with prognosis predictions and help guide treatment for ccRCC patients.

Background: The development and implementation of telesurgery are of significant strategic importance for the future expansion and evolution of the surgical robotics industry. Telesurgery has been demonstrated to improve access to advanced medical care but also enhances the overall healthcare delivery in these underserved regions. Here, we presented a telesurgery system that optimized surgical signals via a telesurgery host using real-time signal processing and multi-source signal interaction systems. Additionally, a telesurgery network solution was developed to ensure seamless network switching. Materials and methods: We present the results of the first multi-center human study of robot-assisted laparoscopic telesurgery. Specifically, telesurgeries were performed on 18 patients across four hospitals in China utilizing EDGE MP 1000 tele-surgical systems. The distances between each pair of cities ranged from 450 km to 2200 km. Results: The telesurgery success rate was 100%. The mean real-time round-trip network latency, network jitter, video encoding/decoding latency, code rate, and video display latency were 38.38 ± 13.25 ms, 0.39 ± 0.29 ms, 20.02 ± 0.06 ms, and 12.77 ± 0.57 Mbps, 21.35 ± 3.42 ms, respectively. There was no frame loss during all telesurgeries. Conclusion: Our results indicated that telesurgery using 5G and dedicated line technology was a safe and feasible treatment option for patients with urologic oncology.

Background: Eukaryotic initiation factor 3a (EIF3A), a “reader” protein for RNA methylation, has been found to be involved in promoting tumorigenesis in a variety of cancers. The impact of EIF3A in clear cell renal cell carcinoma (ccRCC) has yet to be reported. This study aimed to identify the prognostic value of EIF3A in ccRCC and investigate the relationship between EIF3A expression and immune infiltration. Methods: We collected 29 m6A-related mRNA data and clinicopathological parameters from The Cancer Genome Atlas (TCGA) database. Logistic regression analyses were used to analyse the correlation between EIF3A expression and clinical characteristics. Immunohistochemistry (IHC) was applied to examine EIF3A levels in normal and ccRCC tissues. Univariate and multivariate analyses were conducted to recognize independent factors associated with overall survival (OS) and disease-free survival (DFS). The nomogram aimed to predict the 1-, 3- and 5-year survival probabilities. Gene set enrichment analysis (GSEA) was carried out to determine the potential functions and related signalling pathways of EIF3A expression. To investigate EIF3A of coexpressed genes, we used LinkedOmics, and the results were subjected to enrichment analysis. Simultaneously, LinkedOmics and STRING datasets were used to identify EIF3A coexpressed genes that were visualized via Cytoscape. Finally, we evaluated whether EIF3A expression correlated with the infiltration of immune cells and the expression of marker genes in ccRCC by Tumour Immune Estimation Resource (TIMER) and Gene Expression Profiling Interactive Analysis (GEPIA). Result: EIF3A expression was significantly different between ccRCC tissues and normal tissues. EIF3A expression was correlated with poor prognostic clinicopathological factors, and K–M analyses revealed that low EIF3A expression was correlated with a poor prognosis. The results of univariate and multivariate analyses proved that EIF3A was a prognostic factor in ccRCC patients. GSEA results indicated that EIF3A high expression was enriched in the renal cell carcinoma pathway. EIF3A expression was significantly positively correlated with B cells, CD8 + T cells, CD4 + T cells, neutrophils, macrophages, and dendritic cells. Furthermore, EIF3A expression was associated with most marker genes of immune cells. Conclusions: EIF3A could serve as a potential biomarker for prognostic and diagnostic stratification of ccRCC and is related to immune cell infiltrates.