Preliminary Study of Whole-Genome Bisulfite Sequencing and Transcriptome Sequencing in VHL Disease-Associated ccRCC.

BACKGROUND: Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary tumor syndrome with an incidence of approximately 1/36,000. VHL disease-associated clear cell renal cell carcinoma (ccRCC) is the most common congenital RCC. Although recent advances in treating RCC have improved the long-term prognosis of patients with VHL disease, kidney cancer is still the leading cause of death in these patients. Therefore, finding new targets for diagnosing and treating VHL disease-associated ccRCC is still essential. METHODS: In this study, we collected matched tumor tissues and normal samples from 25 patients with VHL disease-associated ccRCC, diagnosed and surgically treated in the Department of Urology, Peking University First Hospital. After screening, we performed whole genome bisulfite sequencing (WGBS) on 23 pairs of tissues and RNA-seq on 6 pairs of tissues. And we also compared the VHL disease-associated ccRCC transcriptome data with the sporadic ccRCC transcriptome data from the The Cancer Genome Atlas (TCGA) public database RESULTS: We found that the methylation level of VHL disease-associated ccRCC tumor tissues was significantly lower than that of normal tissues. The tumor tissues showed a difference in the copy number of 3p loss and 5q and 7q gain compared with normal tissues. We integrated RNA-seq and WGBS data to reveal methylation candidate genes associated with VHL disease-associated ccRCC; our results showed 124 hypermethylated and downregulated genes, and 245 hypomethylated and upregulated genes. By comparing the VHL disease-associated ccRCC transcriptome data with the sporadic ccRCC transcriptome data from the TCGA public database, we found that the major pathways of differential gene enrichment differed between them. CONCLUSIONS: Our study mapped the multiomics of copy number variation, methylation and mRNA level changes in tumor and normal tissues of clear cell renal cell carcinoma with VHL syndrome, which provides a solid foundation for the mechanistic study, biomarker screening, and therapeutic target discovery of clear cell renal cell carcinoma.

Genotype-phenotype correlations and clinical outcomes of patients with von Hippel-Lindau disease with large deletions.

BACKGROUND: Approximately 20%-40% of patients with von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary disease, exhibit large deletions (LDs). Few studies have focused on this population. Hence, we aimed to elucidate the genotype-phenotype correlations and clinical outcomes in VHL patients with LDs. METHODS: In this retrospective study, we included 119 patients with VHL disease from 50 unrelated families in whom LDs were detected using traditional and next-generation sequencing methods. Other germline mutations were confirmed by Sanger sequencing. Genotype-phenotype correlations and survival were analysed in different groups using Kaplan-Meier and Cox regression. We also evaluated therapeutic response to tyrosine kinase inhibitor (TKI) therapy. RESULTS: The overall penetrance of patients aged <60 was 95.2%. Two VHL patients with LDs also carried CHEK2 and FLCN germline mutations. An earlier age of onset of retinal haemangioblastoma was observed in the next generation. Patients with exon 2 deletion of VHL had an earlier onset age of renal cell carcinoma and pancreatic lesions. The risk of renal cell carcinoma was lower in VHL patients with LDs and a BRK1 deletion. The group with earlier age of onset received poorer prognosis. Four of eight (50%) patients showed partial response to TKI therapy. CONCLUSION: The number of generations and the status of exon 2 could affect age of onset of VHL-related manifestations. Onset age was an independent risk factor for overall survival. TKI therapy was effective in VHL patients with LDs. Our findings would further support clinical surveillance and decision-making processes.

A Novel Cuproptosis-Related Prognostic Model and the Hub Gene FDX1 Predict the Prognosis and Correlate with Immune Infiltration in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is a common malignancy of the urological system with poor prognosis. Cuproptosis is a recently discovered novel manner of cell death, and the hub gene FDX1 could promote cuproptosis. However, the potential roles of cuproptosis-related genes (CRGs) and FDX1 for predicting prognosis, the immune microenvironment, and therapeutic response have been poorly studied in ccRCC. In the present study, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) data were downloaded. CRGs were subjected to prognosis analysis, and three of them were used to construct the prognostic model by least absolute shrinkage and selection operator (LASSO) regression. The CRGs prognostic model showed excellent performance. Moreover, based on the risk score of the model, the nomogram was developed to predict 1-year, 3-year, and 5-year survival. Furthermore, the hub gene of cuproptosis, FDX1, was an independent prognostic biomarker in multivariate Cox regression analysis. The pan-cancer analysis showed that FDX1 was significantly downregulated and closely related to prognosis in ccRCC among 33 cancer types. Lower FDX1 was also correlated with worse clinicopathologic features. The lower expression of FDX1 in ccRCC was verified in the external database and our own database, which may be caused by DNA methylation. We further demonstrated that the tumor mutational burden (TMB) and immune cell infiltration were related to the expression of FDX1. Immune response and drug sensitivity analysis revealed that immunotherapy or elesclomol may have a favorable treatment effect in the high FDX1 expression group and sunitinib or axitinib may work better in the low FDX1 expression group. In conclusion, we constructed a CRGs prognostic model and revealed that FDX1 could serve as a prognostic biomarker and predict therapeutic response in ccRCC. The study will provide a novel, precise, and individual treatment strategy for ccRCC patients.

FTO-mediated autophagy promotes progression of clear cell renal cell carcinoma via regulating SIK2 mRNA stability.

The progression of clear cell renal cell carcinoma (ccRCC) remains a major challenge in clinical practice, and elucidation of the molecular drivers of malignancy progression is critical for the development of effective therapeutic targets. Recent studies have demonstrated that N6-methyladenosine (m6A) is the most abundant modification of eukaryotic mRNA and plays a key role in tumorigenesis and progression. However, the biological roles and underlying mechanisms of m6A-mediated autophagy in cancers especially in ccRCC remain poorly elucidated. m6A dot blot assay, m6A RNA methylation assay kit and immunofluorescence analysis were used to profile m6A levels in tissue samples and their correlation with autophagic flux. Expression patterns and clinical significance of fat mass and obesity-associated protein (FTO) were determined through bioinformatics analysis, real-time PCR, western blotting, immunohistochemistry. RNA-seq, MeRIP-seq, MeRIP-qRT-PCR, RIP-qRT-PCR, transmission electron microscopy, immunofluorescence analysis and luciferase reporter assay were used to investigate the underlying mechanism of the FTO-autophagy axis. The role of FTO and autophagy in ccRCC progression was evaluated both in vitro and in vivo. Here we found that m6A modification was suppressed and closely related to autophagic flux in ccRCC. Elevated FTO was inhibited by rapamycin, whereas silencing FTO enhanced autophagic flux and impaired ccRCC growth and metastasis. SIK2 was identified as a functional target of m6A-mediated autophagy, thereby prompting FTO to play a conserved and important role in inhibiting autophagy and promoting tumorigenesis through an m6A-IGF2BP2 dependent mechanism. Moreover, the small molecule inhibitor FB23-2 targeting FTO inhibited tumor growth and prolonged survival in the patient-derived xenograft (PDX) model mice, suggesting that FTO is a potential effective therapeutic target for ccRCC. Our findings uncovered the crucial role of FTO/autophagy/SIK2 axis in modulating the progression of ccRCC, suggesting that FTO may serve as a valuable prognostic biomarker and promising therapeutic target in ccRCC.

Downregulation of FXYD2 Is Associated with Poor Prognosis and Increased Regulatory T Cell Infiltration in Clear Cell Renal Cell Carcinoma.

Background: FXYD2, a gene coding for the γ subunit of Na+/K+-ATPase, was demonstrated to involve in carcinogenesis recently. However, the specific role of FXYD2 in clear cell renal cell carcinoma (ccRCC) remains unknown. The current study was conducted to investigate the expression, biological function, and potentially immune-related mechanisms of FXYD2 in ccRCC. Materials and methods. The data from TCGA-KIRC, ICGC, GEO, Oncomine, ArrayExpress, TIMER, HPA datasets, and our clinical samples were used to determine and validate the expression level, prognostic roles, and potentially immune-related mechanisms in ccRCC. Cell function assays were performed to investigate the biological role of FXYD2 in vitro. Results: FXYD2 was identified to be downregulated in ccRCC tissue compared to normal tissue, which was confirmed by our RT-PCR, WB, and IHC analyses. Kaplan-Meier survival analysis and Cox regression analysis suggested that downregulated FXYD2 could independently predict poor survival of ccRCC patients. Through the ESTIMATE algorithm, ssGSEA algorithm, CIBERSORT algorithm, TIMER database, and our laboratory experiment, FXYD2 was found to correlate with the immune landscape, especially regulatory T cells (Treg), in ccRCC. Gain-of-function experiment revealed that FXYD2 could restrain cell proliferation, migration, and invasion in vitro. Functional enrichment analysis illustrated that TGF-ß-SMAD2/3, Notch, and PI3K-Akt-mTOR signaling pathways may be potential signaling pathways of FXYD2 in ccRCC. Conclusions: Downregulation of FXYD2 is associated with ccRCC tumorigenesis, poor prognosis, and increased Treg infiltration in ccRCC, which may be related to TGF-ß-SMAD2/3, Notch, and PI3K-Akt-mTOR signaling pathways. This will probably provide a novel prognostic marker and potential therapeutic target for ccRCC.

VHL Ser65 mutations enhance HIF2α signaling and promote epithelial-mesenchymal transition of renal cancer cells.

BACKGROUND: Von Hippel-Lindau (VHL) disease is an autosomal dominant genetic neoplastic disorder caused by germline mutation or deletion of the VHL gene, characterized by the tendency to develop multisystem benign or malignant tumors. The mechanism of VHL mutants in pathogenicity is poorly understand. RESULTS: Here we identified heterozygous missense mutations c.193T > C and c.194C > G in VHL in several patients from two Chinese families. These mutations are predicted to cause Serine (c.193T > C) to Proline and Tryptophan (c.194C > G) substitution at residue 65 of VHL protein (p.Ser65Pro and Ser65Trp). Ser65 residue, located within the ß-domain and nearby the interaction sites with hypoxia-inducing factor α (HIFα), is highly conserved among different species. We observed gain of functions in VHL mutations, thereby stabilizing HIF2α protein and reprograming HIF2α genome-wide target gene transcriptional programs. Further analysis of independent cohorts of patients with renal carcinoma revealed specific HIF2α gene expression signatures in the context of VHL Ser65Pro or Ser65Trp mutation, showing high correlations with hypoxia and epithelial-mesenchymal transition signaling activities and strong associations with poor prognosis. CONCLUSIONS: Together, our findings highlight the crucial role of pVHL-HIF dysregulation in VHL disease and strengthen the clinical relevance and significance of the missense mutations of Ser65 residue in pVHL in the familial VHL disease.

Clinical characteristics and risk factors for survival in affected offspring of von Hippel-Lindau disease patients.

BACKGROUND: Von Hippel-Lindau (VHL) disease is an autosomal dominant genetic tumour syndrome with poor prognosis. The clinical manifestation was found to be more serious in affected offspring of patients with VHL disease, but the risk factors and survival for them have never been reported before. We aimed to explore how these patients were influenced by genetic and clinical factors. METHODS: In this retrospective study, we collected 372 affected offspring of VHL patients from 118 unrelated VHL families. Patients were stratified into different groups based on sets of variables. The age-related risk, overall survival and central nervous systemhaemangioblastoma (CHB)-specific survival were analysed between different groups using Kaplan-Meier survival analysis and Cox regression analysis. RESULTS: The estimated median life expectancy and median age of onset for affected offspring of VHL patients were 66 years and 28 years, respectively. The later generation and patients with mutations in exon 3 had an earlier onset age. The first presenting symptom was the only independent risk factor influencing overall survival and CHB-specific survival. Patients that the first presenting symptom is central nervous system (CNS) significantly had a lower life expectancy both in overall survival and CHB-specific survival analysis than abdominal lesions group. CONCLUSION: This study indicated that affected offspring of VHL patients with CNS as the first presenting symptom was an independent risk factor for overall survival and CHB-specific survival. Generation and mutation region only had an effect on the onset age, which is helpful to clinical decision-making and generate a more precise surveillance protocol.

Identification and validation of the clinical roles of the VHL-related LncRNAs in clear cell renal cell carcinoma.

Accumulating evidence suggests that lncRNAs (long non-coding RNAs) function as oncogenes or tumor suppressor genes in ccRCC (clear cell renal cell carcinoma). Although VHL (Von Hippel-Lindau) gene inactivation is by far the most common carcinogenic driving event in ccRCC, the roles of VHL-related lncRNAs in ccRCC remain unknown. In this study, using RNA-seq and clinical data in TCGA-KIRC (the Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma), we identified VHL-related lncRNAs through WGCNA (Weighted Gene Co-expression Network Analysis), correlation analysis and catRAPID algorithm, and explored their clinical characteristics in ccRCC. Results showed that 10 lncRNAs (AC112220.2, AL391121.1, USP46-AS1, AL450326.1, MID1IP1-AS1, SUCLG2-AS1, RAP2C-AS1, FGD5-AS1, AC018647.2 and AC015922.2) were identified as VHL-related lncRNAs, and they were down-regulated in ccRCC tissues. Survival analysis results indicated that high expression groups of AC112220.2, AL391121.1, USP46-AS1, AL450326.1, SUCLG2-AS1, RAP2C-AS1, FGD5-AS1, AC018647.2 and AC015922.2 had significantly longer OS (Overall Survival) than their respective low expression groups. Meanwhile high AC112220.2, USP46-AS1, AL450326.1, SUCLG2-AS1, FGD5-AS1, AC018647.2 and AC015922.2 expression groups had remarkably longer DFS (Disease Free Survival) than their respective low expression groups. Besides, FGD5-AS1 and AL391121.1 expression were decreased in VHL mutant tissues compared with VHL non-mutant tissues. Moreover, high expression group of FGD5-AS1 had significantly longer OS and DFS than their respective low expression groups in VHL mutant ccRCC. In addition, we found that DNA hypermethylation may also play an important role in decreased FGD5-AS1 expression. Furthermore, we validated the expression of FGD5-AS1 in VHL mutant and non-mutant ccRCC tissues and cell lines. In conclusion, our results demonstrated that lncRNA FGD5-AS1 was significantly associated with VHL and can serve as a novel biomarker of ccRCC.

Association between vasectomy and risk of prostate cancer: a meta-analysis.

BACKGROUND: The debate over the association between vasectomy and prostate cancer has been lasted about 40 years and there is no sign of stopping. In the present study, we aimed to evaluate whether vasectomy is associated with prostate cancer based on the most comprehensive and up-to-date evidence available. METHODS: The PubMed, Cochrane Library, and EMBASE databases were systematically searched inception to March 14, 2021 without year or language restriction. Multivariable adjusted risk ratios (RRs) were used to assess each endpoint. Risk of bias was assessed using the Newcastle-Ottawa scale. RESULTS: A total of 58 studies involving 16,989,237 participants fulfilled inclusion criteria. There was significant association of vasectomy with risk of any prostate cancer (risk ratio, 1.18, 95% CI, 1.07-1.31). Association between vasectomy and advanced prostate cancer (risk ratio, 1.06, 95% CI, 1.01-1.12), low-grade prostate cancer (risk ratio, 1.06, 95% CI, 1.02-1.10), and intermediate-grade prostate cancer (risk ratio, 1.12, 95% CI, 1.03-1.22) were significant. There was no significant association between vasectomy and prostate cancer-specific mortality (risk ratio, 1.01, 95% CI, 0.93-1.10). CONCLUSIONS: This study found that vasectomy was associated with the risk of any prostate cancer and advanced prostate cancer. From the current evidence, patients should be fully informed of the risk of prostate cancer before vasectomy.

Downregulation of lncRNA ZNF582-AS1 due to DNA hypermethylation promotes clear cell renal cell carcinoma growth and metastasis by regulating the N(6)-methyladenosine modification of MT-RNR1.

BACKGROUND: Emerging evidence confirms that lncRNAs (long non-coding RNAs) are potential biomarkers that play vital roles in tumors. ZNF582-AS1 is a novel lncRNA that serves as a potential prognostic marker of cancers. However, the specific clinical significance and molecular mechanism of ZNF582-AS1 in ccRCC (clear cell renal cell carcinoma) are unclear. METHODS: Expression level and clinical significance of ZNF582-AS1 were determined by TCGA-KIRC data and qRT-PCR results of 62 ccRCCs. DNA methylation status of ZNF582-AS1 promoter was examined by MSP, MassARRAY methylation and demethylation analysis. Gain-of-function experiments were conducted to investigate the biological roles of ZNF582-AS1 in the phenotype of ccRCC. The subcellular localization of ZNF582-AS1 was detected by RNA FISH. iTRAQ, RNA pull-down and RIP-qRT-PCR were used to identify the downstream targets of ZNF582-AS1. rRNA MeRIP-seq and MeRIP-qRT-PCR were utilized to examine the N(6)-methyladenosine modification status. Western blot and immunohistochemistry assays were used to determine the protein expression level. RESULTS: ZNF582-AS1 was downregulated in ccRCC, and decreased ZNF582-AS1 expression was significantly correlated with advanced tumor stage, higher pathological stage, distant metastasis and poor prognosis. Decreased ZNF582-AS1 expression was caused by DNA methylation at the CpG islands within its promoter. ZNF582-AS1 overexpression inhibited cell proliferative, migratory and invasive ability, and increased cell apoptotic rate in vitro and in vivo. Mechanistically, we found that ZNF582-AS1 overexpression suppressed the N(6)-methyladenosine modification of MT-RNR1 by reducing rRNA adenine N(6)-methyltransferase A8K0B9 protein level, resulting in the decrease of MT-RNR1 expression, followed by the inhibition of MT-CO2 protein expression. Furthermore, MT-RNR1 overexpression reversed the decreased MT-CO2 expression and phenotype inhibition of ccRCC induced by increased ZNF582-AS1 expression. CONCLUSIONS: This study demonstrates for the first time that ZNF582-AS1 functions as a tumor suppressor gene in ccRCC and ZNF582-AS1 may serve as a potential biomarker and therapeutic target of ccRCC.

Cell-cycle arrest and senescence in TP53-wild type renal carcinoma by enhancer RNA-P53-bound enhancer regions 2 (p53BER2) in a p53-dependent pathway.

TP53 is a classic tumor suppressor, but its role in kidney cancer remains unclear. In our study, we tried to explain the role of p53 in kidney cancer through the p53-related enhancer RNA pathway. Functional experiments were used to explore whether P53-bound enhancer regions 2 (p53BER2) has a role in the cell cycle and senescence response of TP53-wild type (WT) renal cancer cells in vitro or vivo. RNA-sequencing was used to identify the potential target of p53BER2. The results showed that the expression level of P53BER2 was downregulated in renal cancer tissues and cell lines, further dual-luciferase experiments and APR-256-reactivated experiments showed p53BER2 expresses in a p53-dependent way. Moreover, knockdown p53BER2 could reverse nutlin-3-induced cytotoxic effect in TP53-WT cell lines. Further exploration showed the downregulation of p53BER2 could reverse nutlin-3-induced G1-arrest and senescence in TP53-WT cell lines. What is more, the knockdown of p53BER2 showed resistance to nutlin-3 treatment in vivo. Additionally, we found BRCA2 could be regulated by p53BER2 in vitro and vivo; further experiment showed p53BER2 could induce cell-cycle arrest and DNA repair by mediating BRCA2. In summary, the p53-associated enhancer RNA-p53BER2 mediates the cell cycle and senescence of p53 in TP53-WT renal cancer cells.

ACE2 Correlated With Immune Infiltration Serves As A Novel Prognostic Biomarker In Clear Cell Renal Cell Carcinoma: Implication For COVID-19.

The current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global infection, and is seriously threatening human life, especially cancer patients. Thus, we sought to determine the clinical roles of ACE2 (the cell entry receptor of SARS-CoV-2) in ccRCC (clear cell renal cell carcinoma). TCGA, GEO and TIP datasets, and immunohistochemistry and western blot results were used to determine the prognostic and clinicopathological characteristics of ACE2. ACE2 expression was down-regulated in ccRCC tissues and cell lines. The multivariate Cox regression analysis results indicated that increased ACE2 expression was independent predictor of longer OS (HR: 0.8259, 95%CI: 0.7734-0.8819, P<0.0001) and RFS (HR: 0.8023, 95%CI: 0.7375-0.8729, P<0.0001) in ccRCC patients. Lower ACE2 expression was also associated with advanced tumor stage, higher histological grade and pathological stage, and metastasis. Besides, ACE2 expression was significantly positively and negatively correlated with CD4 Naïve infiltration and CD4 Memory infiltration, respectively. Moreover, higher CD4 Naïve and lower CD4 Memory infiltration levels were associated with better pathological features and longer OS and RFS. Furthermore, high ACE2 expression group in decreased CD4 Naïve, enriched CD4 Naïve and enriched CD4 memory cohort had favorable prognosis. These findings identified that AEC2 was significantly reduced in ccRCC, and decreased ACE2 was related to worse pathological features and poor prognosis. Low ACE2 expression in ccRCC may partially affect the prognosis due to altered immune cells infiltration levels.

CLDN10 associated with immune infiltration is a novel prognostic biomarker for clear cell renal cell carcinoma.

Aims: To identify the clinical roles of CLDN10 in clear cell renal cell carcinoma (ccRCC). Materials & methods: Using data from TCGA-KIRC, GEO DataSets and laboratory experiments to determine the prognostic and clinicopathological characteristics of CLDN10. Results: CLDN10 expression was remarkably reduced in ccRCC. Downregulated CLDN10 was related to metastasis and poor prognosis. Multivariate Cox analysis determined that elevated CLDN10 expression was independently correlated with longer OS and DFS. Moreover, CLDN10 expression was negatively associated with the methylation levels of cg10305311 and cg16275739. CLDN10 expression was also associated with naive CD4 and memory T-cell and dendritic cell infiltration. Conclusions: Immune-related CLDN10 is an independent prognostic biomarker of ccRCC. DNA hypermethylation plays an important role in decreased CLDN10 expression.

The Genotype-Phenotype Association of Von Hipple Lindau Disease Based on Mutation Locations: A Retrospective Study of 577 Cases in a Chinese Population.

PURPOSE: Von Hippel-Lindau (VHL) disease is a hereditary kidney cancer syndrome, with which patients are more likely to get affected by renal cell carcinoma (RCC), pancreatic cyst or tumor (PCT), central nervous system hemangioblastoma (CHB), retinal angiomas (RA), and pheochromocytoma (PHEO). Mutations of VHL gene located in 3p25 may impair the function of the VHL protein and lead to the disease. It's unclear why obvious phenotype varieties exist among VHL patients. Here we aimed to ascertain whether the mutation types and locations affect the phenotype. METHODS: We enrolled 577 Chinese VHL patients from 211 families and divided them into three groups and six subgroups according to their mutation types and locations. Cox survival analysis and Kaplan-Meier analysis were used to compare intergroup age-related tumor risks. RESULTS: Patients with nonsense or frameshift mutations that were located before residues 117 of VHL protein (NoF1 subgroup) hold lower age-related risks of VHL associated tumors (HR = 0.638, 95%CI 0.461-0.883, p = 0.007), CHB (HR = 0.596, 95%CI 0.409-0.868, p = 0.007) or PCT (HR = 0.595, 95%CI 0.368-0.961, p = 0.034) than patients whose mutations were located after residues 117 (NoF2 subgroup). Patients in NoF1 subgroup still had lower age-related risks of CHB (HR = 0.652, 95%CI 0.476-0.893, p = 0.008) and PCT (HR = 0.605, 95%CI 0.398-0.918, p = 0.018) compared with those in combined NoF2 subgroup and other truncating mutation patients. NoF1 subgroup correspondingly had a longer estimated median lifespan (64 vs. 55 year, p = 0.037) than NoF2 subgroup. Among patients with missense mutations of VHL, only a small minority (23 of 286 missense mutations carriers) carried mutations involving neither HIF-α binding region nor elongin C binding region, who were grouped in MO subgroup. MO subgroup seemed to have a higher age-related risk of PHEO. In the whole cohort (n = 577), PHEO was an independent protective factor for CHB (p = 0.001) and survival (p = 0.005). RA and CHB failed to predict the age-related risk of each other. CONCLUSION: The mutation types and locations of VHL gene are associated with phenotypes. Genetic counselors could predict phenotypes more accurately based on more detailed genotype-phenotype correlations. Further genotype-phenotype studies should focus on the prediction of tumor recurrence, progression, and metastasis. The deep molecular mechanism of genotype-phenotype correlation is worth further exploring.

Novel genetic characterisation and phenotype correlation in von Hippel-Lindau (VHL) disease based on the Elongin C binding site: a large retrospective study.

BACKGROUND: Von Hippel-Lindau (VHL) disease is an autosomal dominant genetic tumour syndrome resulting from mutations in the VHL gene lineage, and its prognosis is generally poor. This study aimed to provide a more valuable genotype-phenotype correlation based on the Elongin C binding site in VHL disease. METHODS: This study included 553 patients (194 families) who were diagnosed with VHL disease in our centre from September 2010 to February 2019. According to the type of gene mutation, the patients were divided into the Elongin C binding site missense mutation (EM) group, the non-Elongin C binding site missense mutation (nEM) group and the truncation mutation (TR) group. We analysed and compared the age-related tumour risk and prognosis of the three groups. RESULTS: A total of 14 new intragenic mutations were found in this cohort. The age-related risk of central nervous system haemangioblastoma (CHB) and pancreatic tumour in the EM group was lower than in the combined nEM-TR group, while the corresponding risk of pheochromocytoma (PHEO) was higher. Additionally, the prognoses of EM and nEM-TR were analysed. The median survival period in the EM group was longer than that in the nEM-TR group, and both the total survival and the CHB-specific survival of the EM group were better than those of the nEM-TR group. CONCLUSION: In conclusion, our study demonstrated that the EM was an independent risk factor for PHEO. The EM is also an independent protective factor for CHB age-related risk, overall survival and CHB-specific survival in VHL disease. This modified genotype-phenotype correlation integrates gene mutation, the Elongin B binding site, and phenotypic diversity and provides a reference for clinical diagnosis.

Discovery and validation of the prognostic value of the lncRNAs encoding snoRNAs in patients with clear cell renal cell carcinoma.

Some lncRNAs can encode small nucleolar RNAs (snoRNAs), called small nucleolar RNA host genes (SNHGs), which have exerted certain predictive values for the prognosis of some cancer patients. In this study, using RNA-seq and survival data in TCGA-KIRC, we examined the expression profile of 20 SNHGs and explored their prognostic values in ccRCC. Results showed that SNHG1, GAS5, SNHG3-8, SNHG11, SNHG12, SNHG15-17, SNHG20, SNHG22 and SNHG25 were significantly upregulated in ccRCC tissues compared with adjacent normal tissues. After adjustment for confounding factors, the multivariate analysis confirmed that increased SNHG3 expression was independently associated with shorter OS, while increased SNHG15 expression was an independent predictor of shorter RFS. Using the methylation data, the methylation status of 2 CpG sites (cg07807470 and cg15161854) and 2 CpG sites (cg00953154 and cg16459265) were negatively correlated with SNHG3 and SNHG15 expression, respectively. Moreover, low methylation levels of the 4 CpG sites were significantly associated with shorter OS. Furthermore, we validated the expression patterns, methylation status and prognostic value of SNHG3 and SNHG15 using clinical ccRCC samples. Taken together, SNHG3 and SNHG15 might be valuable prognostic markers in ccRCC, and DNA hypomethylation might play an important role in elevated SNHG3 and SNHG15 transcription in ccRCC.

The Efficacy and Safety of Tyrosine Kinase Inhibitors for Von Hippel-Lindau Disease: A Retrospective Study of 32 Patients.

Background: Von Hippel-Lindau (VHL) disease is an autosomal-dominant hereditary cancer syndrome. Currently, studies on tyrosine kinase inhibitor (TKI) therapy for VHL disease are scarce. In this study, we retrospectively evaluated the efficacy and safety of four TKIs in patients with VHL disease. Methods: Patients diagnosed with VHL disease who were receiving TKIs were recruited. Patients were treated with sunitinib (n = 12), sorafenib (n = 11), axitinib (n = 6), or pazopanib (n = 3). The therapeutic response was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Results: From July 2009 to September 2018, 32 patients with VHL disease were eligible and included in this study. The median duration of TKI therapy was 22 months (IQR 8.5-44.75), and the median follow-up period was 31.5 months (IQR 13.5-63.5). According to the RECIST, 9 (28%) of 32 patients showed a partial response, 15 (47%) achieved stable disease, and eight exhibited continued disease progression. A partial response was observed in 11 (31%) of 36 renal cell carcinomas, 4 (27%) of 15 pancreatic lesions, and 1 (20%) of five central nervous system (CNS) hemangioblastomas. The average tumor size decreased significantly for renal cell carcinomas (P = 0.0001), renal cysts (P = 0.027), and pancreatic lesions (P = 0.003) after TKI therapy. Common side effects included hand-foot skin reactions, diarrhea, alopecia, thrombocytopenia, and fatigue. Conclusions: Partial alleviation of VHL disease-related tumors can be achieved by TKI therapies in some patients, providing an alternative treatment strategy, and the side effects of TKIs are acceptable. Larger prospective studies are warranted to further evaluate the efficacy and safety of TKIs in patients with VHL disease.

Frequent Mutations of VHL Gene and the Clinical Phenotypes in the Largest Chinese Cohort With Von Hippel-Lindau Disease.

Von Hippel-Lindau (VHL) disease is a rare autosomal-dominant inherited tumor syndrome. We aimed to analyze the correlations between frequent VHL mutations and phenotypes in Chinese VHL families. We screened 540 patients from 187 unrelated Chinese VHL families for 19 frequent VHL mutations. The penetrance and mean age at onset for VHL-associated susceptible organs were calculated and compared. The overall survival of VHL patients was described with Kaplan-Meier curves. Among the 19 frequent germline mutations, there were four hotspot mutation sites (194, 481, 499, and 500). Missense mutations were the most common types of mutations (70.0%) followed by nonsense mutations (20.0%) and splicing mutations (10.0%). Due to the diversity of these mutations, the penetrance for each organ and the age at onset are distinct. Even in cases of similar mutations, variance in the penetrance and age at onset was observed. The mean age at death for the patients in this cohort was 42.4 ± 13.5 years, and variability was observed in the Kaplan-Meier curves. We present a precise summary of the phenotypes for the frequent VHL mutations in the largest Chinese VHL cohort, which provides valuable strategies for genetic counseling and clinical surveillance of VHL individuals.