Progression Of Renal Cell Carcinoma Research Articles

Cancer-associated fibroblasts promote the stemness and progression of renal cell carcinoma via exosomal miR-181d-5p

The mechanisms underlying the effects of cancer-associated fibroblasts (CAFs) on cancer stemness and tumor progression in renal cell carcinoma (RCC) have not been elucidated yet. In the present study, we found that the enrichment of CAFs was positively associated with tumor progression and cancer stemness in RCC. Further investigation revealed that CAFs could enhance cancer stemness through delivering exosomes to RCC cells, and miR-181d-5p was identified as the critical exosomal miRNA in CAF-secreted exosomes by small RNA sequencing and subsequent screening assays. Mechanistically, exosomal miR-181d-5p transferred from CAFs to RCC cells directly suppressed the expression of ring finger protein 43 (RNF43) and activated Wnt/β-catenin signaling pathway, thus promoted cancer stemness and tumor progression. Overexpression of RNF43 strongly suppressed stemness properties and the effects could be reverted by miR-181d-5p. Overall, our findings revealed a crucial mechanism by which CAF-secreted exosomal miRNAs to enhance cancer stemness and thus promote RCC progression, suggesting a new avenue based on CAF-secreted miRNAs for more effective targeted therapies.

BACH1 promotes clear cell renal cell carcinoma progression by upregulating oxidative stress-related tumorigenicity.

The carcinogenesis and progression of renal cell carcinoma (RCC), a heterogeneous cancer derived from renal tubular epithelial cells, is closely related to oxidative stress responses (OSRs). Oxidative stress responses participate in various biological processes related to the metabolism and metastatic potential of cancer such as inflammation, epithelial-mesenchymal transition (EMT), and angiogenesis. In this study, we investigated the role of broad complex-tramtrack-bric-a-brac and cap 'n' collar homology 1 (BACH1), a key transcription factor for OSRs, in clear cell RCC (ccRCC) development and prognosis. The poor prognosis and elevation of serum inflammation markers in nephrectomized ccRCC patients were correlated with the intratumor expression of BACH1 accompanied by a downregulation of heme oxygenase-1. BACH1 contributes to the invasion and migration abilities of RCC cell lines without affecting their proliferation in vitro. In contrast, BACH1 contributes to tumor progression in vivo, in relation to OSRs with the activation of EMT-related pathways. BACH1 involvement in other OSR-linked pathways, including inflammatory responses, angiogenesis, and mTOR signaling, was further revealed by RNA sequencing analysis of BACH1-knockdown cells. In conclusion, the crucial role of BACH1 in the pathogenesis and poor prognosis of ccRCC through the promotion of OSRs is suggested.

Hypoxia-inducible factor pathway genes predict survival in metastatic clear cell renal cell carcinoma.

Hypoxia inducible factor (HIF) pathway alterations drive progression of clear cell renal cell carcinoma (ccRCC). We aim to evaluate genes within the canonical and non-canonical HIF pathways as predictors of survival in metastatic ccRCC. Gene expression was determined from 324 archival pretreatment nephrectomy specimens from CALGB90206, a phase III trial of patients treated with interferon alpha (INF-α) vs. INF-α plus bevacizumab. TaqMan RT-qPCR was performed using RNA from tumors macrodissected based on review by genitourinary pathology. A total of 35 HIF-related genes were assessed by Cox regression analysis. After adjusting for sex and Memorial Sloan Kettering Cancer Center risk score (MSKCC-RS), 11 genes predicted OS: HIF2A (HR 1.059, P = 0.012), EGLN3 (HR 1.089, P = 0.012), VEGFC (HR 0.904, P = 0.039), VEGFD (HR 1.085, P = 0.016), FLT4 (HR 1.093, P = 0.038), CCND1 (HR 1.077, P = 0.026), TGFA (HR 1.127, P = 0.003), EGFR (HR 1.151, P = 0.028), VHL (HR 0.764, P = 0.002), HSP90AA1 (HR 0.845, P = 0.002), and PTEN (HR 1.163, P = 0.050); 7 genes predicted PFS: HIF2A (HR 1.060, P = 0.011), CCND1 (HR 1.082, P = 0.016), TGFA (HR 1.096, P = 0.026), EP300 (HR 1.171, P = 0.031), VHL (HR 0.775, P = 0.007), HSP90AA1 (HR 0.871, P = 0.015), and TP53 (HR 1.119, P = 0.050). Most of these genes validated as significant predictors of survival in the external, TCGA dataset. In multivariate analysis of all externally validated genes, VEGFC (HR 0.906, P = 0.043), TGFA (HR 1.122, P = 0.003), CITED2 (HR 1.113, P = 0.035) and EP300 (HR 1.136, P = 0.049) predicted OS; and HIF2A (HR 1.049, P = 0.036) and EP300 (HR 1.199, P = 0.010) predicted PFS. EGLN3 (HR 1.156, P = 0.045) and BNIP3 (HR 1.254, P = 0.049) significantly interacted with treatment status and predicted PFS in patients treated with IFN-α and IFN-α+bevacizumab, respectively. We identified specific gene isoforms in both the canonical and non-canonical HIF pathways associated with metastatic RCC survival. EGLN3 and BNIP3 showed significant interaction with treatment arm and may be predictive of treatment response. We have identified genes for future prospective investigation as predictive biomarkers and novel drug targets.

O5 - Effect of EphA2 silencing on inhibiting the progression of non-metastatic renal cell carcinoma in an orthotopic mouse model of renal cell carcinoma

O5 - Effect of EphA2 silencing on inhibiting the progression of non-metastatic renal cell carcinoma in an orthotopic mouse model of renal cell carcinoma

MiR-378a-3p promotes renal cell carcinoma proliferation, migration, and invasion by targeting TOB2.

Renal cell carcinoma (RCC) is one of the most common malignant tumors of the urinary system, which has high metastasis. MicroRNAs (miRNAs) have been reported to participate in RCC progression. The present study aimed to understand the biological role and mechanism of miR-378a-3p in RCC. RT-qPCR assay was used to assess miR-378a-3p and transducer of ERBB2 (TOB2) expression in RCC tissues and cell lines. CCK-8, clone formation, scratch, and transwell assays were carried out to evaluate cell proliferation, migration, and invasion. Furthermore, the target genes of miR-378a-3p were predicted by the online bioinformatics databases. Dual-luciferase reporter assay was used to validate the relationship between miR-378a-3p and TOB2. miR-378a-3p was highly expressed in RCC tissues and RCC cell lines. Besides, miR-378a-3p accelerated the progression of RCC by mediating cell proliferation, migration and invasion. More importantly, TOB2 was confirmed as a potential target gene of miR-378a-3p. The results of loss-of-function experiments showed that inhibition of TOB2 reversed the inhibitory roles of miR-378a-3p inhibitor on RCC progression. miR-378a-3p promoted cell proliferation, migration and invasion through regulating TOB2 in RCC, which indicated a promising target for the treatment of RCC.

The significance of CD14 in clear cell renal cell carcinoma progression and survival prognosis

Purpose: CD14-positive tumour and immune cells have been implicated in cancer progression. This study evaluated the prognostic significance of CD14 immunostaining in clear cell renal cell carcinoma (ccRCC) compared to the adjacent non-cancer kidney, and serum soluble CD14 (sCD14) levels in patients versus controls. Methods: Immunohistochemistry was performed for CD14 on ccRCC and the corresponding adjacent non-cancer kidney tissue from 88 patients. Staining intensity was determined using Aperio ImageScope morphometry. Serum sCD14 was evaluated for 39 ccRCC patients and 38 non-cancer controls using ELISA. CD14 levels were compared with tumour characteristics and survival status. Results: CD14 overall and nuclear immunostaining was higher in ccRCC compared to the adjacent non-cancer kidney tissue. CD14 nuclear immunostaining in the adjacent non-cancer kidney was significantly associated with advanced stage and adverse RCC survival prognosis. Serum sCD14 concentration was elevated in ccRCC patients compared to non-cancer controls and was also significantly associated with tumour stage and worse survival prognosis. Higher CD14 expression, in particular CD14 positive immune cell infiltrates found in the adjacent non-RCC kidney tissue, were associated with tumour progression and poorer prognosis. Conclusion: The levels of CD14 in non-RCC adjacent kidney and serum could be potential prognostic indicators.

Interaction of RARRES1 with ICAM1 modulates macrophages to suppress the progression of kidney renal clear cell carcinoma.

RARRES1 is a tumor suppressor protein, and its expression is suppressed in various tumor cells. However, whether it participates in the immune response in kidney renal clear cell carcinoma (KIRC) is unknown, and the defined mechanism is not clear. Therefore, the mechanism of RARRES1 in KIRC is worthy of investigation. We analysed the expression and function of RARRES1 with The Cancer Genome Atlas (TCGA) database. The Kaplan-Meier curve was adopted to estimate survival. RARRES1-correlated genes were obtained from the UALCAN database and subjected to Gene Ontology (GO) enrichment and protein-protein interaction (PPI) network analyses. The correlation analysis between tumor-infiltrating immune cells and selected genes were performed with TIMER database. We also investigated the possible function of RARRES1 in KIRC by coculturing Caki-1 cells with THP-1 cells. Immunofluorescence assay was performed to study the RARRES1 expression in difference grade KIRC tissues. The expression of RARRES1 was negatively correlated with survival in KIRC patients. The GO biological process term most significantly enriched with the RARRES1-correlated genes was regulation of cell adhesion. ICAM1, which exhibited a relatively highest correlation with RARRES1, is positively correlated with the infiltration level of macrophages. RARRES1 could enhance the expression of ICAM1 in Caki-1 cells and then induce the activation of M1 THP-1 cells to decrease the viability and induce the apoptosis of Caki-1 cells. RARRES1 plays an antitumor role by promoting ICAM1 expression and inducing the activation of M1 macrophages. We offer insights into the molecular mechanism of KIRC and reveal a potential therapeutic target.

PDCD5 inhibits progression of renal cell carcinoma by promoting T cell immunity: with the involvement of the HDAC3/microRNA-195-5p/SGK1

BackgroundEpigenetics exerts a vital role in the onset and development of renal cell carcinoma (RCC). Mounting evidence has shed light on the significance of human immune system in response to tumor infiltrating T cells. Hereby, we sought to unmask the immunomodulatory role of histone deacetylase 3 (HDAC3) and its potential upstream molecule, programmed cell death 5 (PDCD5) in RCC.MethodsRCC and adjacent non-cancerous tissues were clinically resected from 58 patients, in which the expression profile of microRNA-195-5p (miR-195-5p), PDCD5, HDAC3, and serum glucocorticoid-inducible kinase 1 (SGK1) was determined by RT-qPCR and Western blot analysis. Their relations were investigated by a series of luciferase assays in combination with ChIP and co-IP. RCC cells (A498) were intervened using gain- and loss-of-function approaches, followed by cell proliferation evaluation. After co-culture with CD3+ T cells, flow cytometry and interferon-γ (IFN-γ) determination were performed. A xenograft tumor mouse model was developed for in vivo validation.ResultsPDCD5 was downregulated in RCC tissues and A498 cells. Upregulation of HDAC3, as well as of SGK1, resulted in suppression of A498 cell proliferation and promotion of T cell activation as evidenced by higher IFN-γ expression. Re-expression of PDCD5 downregulated HDAC3, causing a subsequent upregulation of miR-195-5p, while miR-195-5p could inversely modulate its target gene, SGK1. The regulatory mechanism appeared to be functional in vivo.ConclusionOur results highlight the possible manipulation by PDCD5 on RCC cell proliferation and T cell activation, which provides new clues to better understand the immune balance in RCC progression.

Roles of DNA damage repair and precise targeted therapy in renal cancer (Review).

The primary subtypes of renal cell carcinoma (RCC) include clear cell, papillary and chromophobe RCC. RCC occurs often due to loss of von Hippel-Lindau (VHL) and accumulation of lipids and glycogen, and RCC cells may exhibit sensitivity to the disruption of normal metabolism or homologous recombination gene defect. Although the application of molecular-targeted drugs (tyrosine kinase inhibitors) and immune checkpoint inhibitors has been recommended for the treatment of advanced RCC, more targets of DNA damage repair (DDR) signaling pathway involved in the synthetic lethal effect have been investigated. However, although achievements has been made in the exploration of the roles of DDR genes on RCC progression, their association has not been systematically summarized. Poly (ADP-ribose) polymerase (PARP) 1 inhibitors are used in tumors with BRCA1/2 DNA repair-associated mutations. PARP family enzymes perform post-translational modification functions and participate in DDR and cell death. Inhibitors of PARP, ataxia telangiectasia mutant gene and polymerase θ serve key roles in the treatment of specific RCC subtypes. PARP1 may serve as an important biological marker to predict the therapeutic effect of immune checkpoint inhibitors and evaluate the prognosis of patients with ccRCC with polybromo 1 mutation. Therefore, the roles of DDR pathway on RCC progression or treatment may hold promises for the treatment of certain specific types of RCC.

Construction of a novel prognostic signature based on the composition of tumor-infiltrating immune cells in clear cell renal cell carcinoma.

Emerging evidence has uncovered that tumor-infiltrating immune cells (TIICs) play significant roles in regulating the tumorigenesis and progression of clear cell renal cell carcinoma (ccRCC). However, the exact composition of TIICs and their prognostic values in ccRCC have not been well defined. A total of 534 ccRCC samples with survival information and TIIC data from The Cancer Genome Atlas (TCGA) dataset were included in our research. The ImmuCellAI tool was employed to estimate the abundance of 24 TIICs and further survival analysis explored the prognostic values of TIICs in ccRCC. In addition, the expression levels of immunosuppressive molecules (PDL1, PD1, LAG3, and CTLA4) in the high- and low-risk groups were explored. Various subtypes of TIICs had distinct infiltrating features and most TIICs exhibited dysregulated abundance between normal and tumor tissues. Moreover, specific kinds of TIICs had encouraging prognostic values in ccRCC. Further analysis constructed a 4-TIICs signature to evaluate the prognosis of ccRCC patients. Cox regression analyses confirmed the independent prognostic role of the signature in ccRCC. Moreover, immunosuppressive molecules, including PD1, LAG3, and CTLA4, were significantly upregulated in the high-risk group and predicted poor prognosis. However, PDL1 was not changed between high- and low-risk groups and could not predict poor prognosis. To sum up, our research explored the landscape of TIICs in ccRCC and established a novel 4-TIIC prognostic signature, which could effectively predict the prognosis for patients with ccRCC. Based on this signature, we also concluded that PDL1 may not predict prognosis in ccRCC.

Circ_0008717 promotes renal cell carcinoma progression by upregulating FBXO17 via targeting miR-217.

Renal cell carcinoma (RCC) is a common lethal urological malignancy. Circular RNAs are assumed to play important roles in cancer development. The objective of the present study was to investigate the role and action mechanism of circ_0008717 in RCC. The expression of circ_0008717, miR-217 and F-box protein 17 (FBXO17) mRNA was detected by a real-time quantitative polymerase chain reaction. Cell proliferation was examined using a cell counting kit-8 assay and an 5-ethynyl-2'-deoxyuridine assay. Cell apoptosis was assessed by a flow cytometry assay. Cell migration and cell invasion were investigated using a transwell assay. Glycolysis progression was assessed according to the levels of glucose uptake and lactate production. The expression of glycolysis-related proteins and FBXO17 protein was quantified by western blotting. The targets were analyzed by the bioinformatics tools (starBase and circinteractome) and validated by a dual-luciferase reporter assay, RNA pull-down assay and RNA immunoprecipitation assay. A xenograft model was established to monitor the role of circ_0008717 in vivo. Circ_0008717 was upregulated in RCC tissues and cells. Silencing circ_0008717 suppressed RCC cell proliferation, migration, invasion and glycolysis but promoted cell apoptosis. MiR-217 was a target of circ_0008717 and bound to the FBXO17 3' untranslated region. The expression of FBXO17 was positively regulated by circ_0008717 but impaired by miR-217 reintroduction. The inhibitory effects of circ_0008717 knockdown on RCC cell malignant behaviors were reversed by miR-217 inhibition or FBXO17 overexpression. Circ_0008717 knockdown inhibited tumor growth in vivo by regulating miR-217 and FBXO17. Circ_0008717 aggravated the progression of RCC by activating FBXO17 through targeting miR-217, which provided a novel mechanism for circ_0008717 to participate in RCC progression.

Research progress of long non-coding RNA in the development and progression of renal cell carcinoma

肾细胞癌是泌尿系统常见的恶性肿瘤之一，由于早期临床无症状或缺乏特异性的生物标志物，诊断时肿瘤常已发生局部侵袭或远处转移，错过最佳的治疗机会，预后较差。长链非编码RNA（lncRNA）是一类长度超过200个核苷酸的RNA分子。lncRNA可通过表观遗传调控、转录调控、转录后调控等方面参与基因的表达调控，广泛参与肿瘤发生发展的过程，如细胞增殖、迁移、侵袭和凋亡，在肾细胞癌的早期诊断、预后评估和治疗等方面发挥重要作用。本文就lncRNA在肾细胞癌发生和发展中的作用进行综述。.

RUNX2 interacts with SCD1 and activates Wnt/β-catenin signaling pathway to promote the progression of clear cell renal cell carcinoma.

Previous studies have demonstrated that Runt-associated transcription factor 2 (RUNX2) serves as the main transcription factor for osteoblast differentiation and chondrocyte maturation. RUNX2 is related to a variety of tumors, particularly tumor invasion and metastasis, while the expression and molecular mechanisms of RUNX2 in clear cell renal cell carcinoma (ccRCC) keep to be determined. Stearyl CoA desaturase 1 (SCD1), an endoplasmic reticulum fatty acid desaturase, transfers saturated fatty acids to monounsaturated fatty acids, is expressed highly in numerous malignancies. The Cancer Genome Atlas (TCGA) datebase and Western blot was used to analyzed the mRNA and protein levels of the target gene in ccRCC tissues and adjacent tissues. The proliferation ability of ccRCC cells was tested by colony forming and EdU assay. The migration ability of cells was detected by transwell assay. Immunoprecipitation was utilized to detect protein-protein interaction. Cycloheximide chase assay was used to measure the half-life of SCD1 protein. In this study, the expressions of RUNX2 and SCD1 are increased in ccRCC tissues as well as ccRCC cell lines. Both RUNX2 and SCD1 could promote proliferation and migration in ccRCC cells. Furthermore, RUNX2 could physically interact with SCD1. In addition, the functional degradation and the inactivation of Wnt/β-catenin signaling pathway triggered by the downregulation of RUNX2 could be partly offset by the overexpression of SCD1. The findings indicate that the RUNX2/SCD1 axis may act as a potential therapeutic target via the Wnt/β-catenin signaling pathway of ccRCC.

Circular RNA circSDHC (hsa_circ_0015004) regulates tumor growth and angiogenesis via regulating centrosomal protein 55 expression in renal cell carcinoma.

Renal cell carcinoma (RCC) is the main aggressive subtype of kidney cancer. Circular RNAs have been shown to exert critical roles in RCC. However, little is known about the regulatory mechanism of hsa_circ_0015004 (circSDHC) in RCC. 35 patients with RCC were recruited in the research. Expression changes of circSDHC were determined by real-time quantitative polymerase chain reaction (RT-qPCR). The effects of circSDHC inhibition on cell proliferation, apoptosis, angiogenesis, migration, and invasion were analyzed. The regulation mechanism of circSDHC was surveyed by bioinformatics analysis. The effect of circSDHC on tumorigenesis was validated by xenograft assay. We observed an observable elevation in circSDHC expression in RCC tissues and cell lines. Functionally, circSDHC silencing decreased xenograft tumor growth and induced RCC cell apoptosis, repressed RCC cell proliferation, angiogenesis, migration, and invasion in vitro. Mechanically, circSDHC modulated centrosomal protein 55 (CEP55) expression by functioning as a miR-130a-3p sponge. Also, miR-130a-3p silencing offset circSDHC knockdown-mediated impacts on malignant phenotypes and angiogenesis of RCC cells. Furthermore, exogenetic expression of CEP55 counteracted miR-130a-3p overexpression-mediated effects on malignant phenotypes and angiogenesis of RCC cells. Silencing of circSDHC restrained cell malignant phenotypes and angiogenesis via reducing CEP55 expression by releasing miR-130a-3p in RCC, providing a new mechanism for understanding the progression of RCC.

RENAL CELL CARCINOMA PRESENTING AS LUNG COLLAPSE

RENAL CELL CARCINOMA PRESENTING AS LUNG COLLAPSE

Genetic Analysis Implicates Dysregulation of SHANK2 in Renal Cell Carcinoma Progression.

SH3 and multiple ankyrin repeat domains (SHANK) is a family of scaffold proteins that were first identified to be involved in balancing synaptic transmission via regulation of intracellular signalling crosstalk and have been linked to various cancers. However, the role of the SHANK genes in renal cell carcinoma (RCC) remains to be elucidated. In this study, we aimed to evaluate whether genetic variants in SHANK family genes affect the risk of RCC and survival of patients. A genetic association study was conducted using logistic regression and Cox regression analyses, followed by the correction for a false discovery rate (FDR), in 630 patients with RCC and controls. A pooled analysis was further performed to summarise the clinical relevance of SHANK gene expression in RCC. After adjustment for known risk factors and the FDR, the SHANK2 rs10792565 T allele was found to be associated with an increased risk of RCC (adjusted odds ratio = 1.79, 95% confidence interval = 1.32–2.44, p = 1.96 × 10−4, q = 0.030), whereas no significant association was found with RCC survival. A pooled analysis of 19 independent studies, comprising 1509 RCC and 414 adjacent normal tissues, showed that the expression of SHANK2 was significantly lower in RCC than in normal tissues (p < 0.001). Furthermore, low expression of SHANK2 was correlated with an advanced stage and poor prognosis for patients with clear cell and papillary RCC. This study suggests that SHANK2 rs10792565 is associated with an increased risk of RCC and that SHANK2 may play a role in RCC progression.

Organic Anion Transporters (OAT) and Other SLC22 Transporters in Progression of Renal Cell Carcinoma.

Simple SummaryKidney cancer diagnoses make up over 2% of newly identified cancers each year. SoLute Carrier 22 (SLC22) genes are expressed in normal functioning kidneys and are responsible for transport of myriad metabolites, xenobiotics, antioxidants and other small molecules, but their role in kidney cancer is not well understood. We assessed the relationship between the expression of SLC22 genes and survival in patients with kidney cancer and found expression patterns of multiple SLC22 genes to be associated with overall survival as well as with disease progression. We sought to interpret this data in the context of physiological information from previous studies by us and others. Furthermore, network analysis indicated the importance of SLC22 genes and identified additional genes that might be therapeutic targets.(1) Background: Many transporters of the SLC22 family (e.g., OAT1, OAT3, OCT2, URAT1, and OCTN2) are highly expressed in the kidney. They transport drugs, metabolites, signaling molecules, antioxidants, nutrients, and gut microbiome products. According to the Remote Sensing and Signaling Theory, SLC22 transporters play a critical role in small molecule communication between organelles, cells and organs as well as between the body and the gut microbiome. This raises the question about the potential role of SLC22 transporters in cancer biology and treatment. (2) Results: In two renal cell carcinoma RNA-seq datasets found in TCGA, KIRC and KIRP, there were multiple differentially expressed (DE) SLC22 transporter genes compared to normal kidney. These included SLC22A6, SLC22A7, SLC22A8, SLC22A12, and SLC22A13. The patients with disease had an association between overall survival and expression for most of these DE genes. In KIRC, the stratification of patient data by pathological tumor characteristics revealed the importance of SLC22A2, SLC22A6, and SLC22A12 in disease progression. Interaction networks combining the SLC22 with ADME genes supported the centrality of SLC22 transporters and other transporters (ABCG2, SLC47A1) in disease progression. (3) Implications: The fact that many of these genes are uric acid transporters is interesting because altered uric acid levels have been associated with kidney cancer. Moreover, these genes play key roles in processing metabolites and chemotherapeutic compounds, thus making them potential therapeutic targets. Finally, our analyses raise the possibility that current approaches may undertreat certain kidney cancer patients with low SLC22 expression and only localized disease while possibly overtreating more advanced disease in patients with higher SLC22 expression. Clinical studies are needed to investigate these possibilities.

MicroRNA Associated with the Invasive Phenotype in Clear Cell Renal Cell Carcinoma: Let-7c-5p Inhibits Proliferation, Migration, and Invasion by Targeting Insulin-like Growth Factor 1 Receptor.

Differential microRNA (miRNA) expression can portend clear cell renal cell carcinoma (ccRCC) progression. In a previous study, we identified a subset of dysregulated miRNA in small renal masses, pT1 ccRCC (≤5 cm) that are associated with an aggressive phenotype. The present study investigated miRNA expression in clinical stage I (cT1) tumors (≤5 cm), comparing pathologic stage I (pT1) tumors to those upstaged to pathologic stage 3 (pT3) after surgery following identification of renal vein invasion or invasion into adjacent fat tissue within Gerota’s fascia. Twenty cT1 tumors were examined in an miRNA screening, 10 pT1 and 10 pT3 tumors. The ccRCC cell lines 786-O and Caki-1 were used to assess the impact of let-7c-5p and its protein target insulin-like growth factor 1 receptor (IGF1R). Cells were transfected with pre-let-7c-5p and assessed through cell proliferation, migration, and invasion assays. IGF1R expression was evaluated through Simple Western, and interaction between let-7c-5p and IGF1R was confirmed via luciferase reporter assay. Screening identified 20 miRNA, including let-7c-5p, that were dysregulated between pT1 and pT3 upstaged tumors. This miRNA was also downregulated in our previous study of pT1 tumors that progressed to metastatic disease. Transfection of ccRCC cells with pre-let-7c-5p significantly inhibited proliferation, migration, invasion, and IGF1R expression. These findings suggest that miRNA dysregulation is involved in ccRCC progression, specifically through invasion, and that let-7c-5p downregulation contributes to the aggressiveness of small ccRCC tumors, in part, through its regulation of IGF1R.

Human herpesvirus 6A and 6B and polyomavirus JC and BK infections in renal cell carcinoma and their relationship with p53, p16INK4a, Ki-67, and nuclear factor-kappa B expression.

There are a limited number of studies regarding the involvement of viruses in the development and pathogenesis of renal cell carcinoma (RCC). In this study, we aimed to discover whether human herpesvirus 6A (HHV-6A) and 6B (HHV-6B) and human polyomavirus JC (JCV) and BK (BKV) are associated with RCC and the expression of p53, p16INK4a, Ki-67, and nuclear factor-κB (NF-κB) in patients with RCC. A total of 122 histologically confirmed RCC tissue specimens and 96 specimens of their corresponding peritumoral tissues were included in this prospective study. Nested PCR was performed to amplify viral DNA sequences. Restriction endonuclease analysis was carried out to discriminate between HHV-6A and HHV-6B. p53, p16INK4a, Ki-67, and NF-κB immunostaining data of the studied tissue specimens were available from our previous study. Statistical analysis was performed to demonstrate the potential associations. HHV-6B and JCV were detected in 10.7% and 13.9% of patients with RCC, respectively. We did not detect HHV-6A and BKV in any of RCC tissue specimens. Moreover, no association was found between either of these viruses and RCC. Our study revealed a significant association between HHV-6B and p53 overexpression. No other associations were found between cellular biomarkers p53, p16INK4a, Ki-67, and NF-κB and the studied viruses. The data of this study, though very limited, disprove the involvement of HHV-6A, HHV-6B, BKV, and JCV in the initiation or progression of RCC.

GLUD1 suppresses renal tumorigenesis and development via inhibiting PI3K/Akt/mTOR pathway.

Growing cancer cells are addicted to glutamine. Glutamate dehydrogenase 1 (GLUD1) is one of key enzymes in glutamine metabolism and plays a critical role in the malignancy of diverse tumors. However, its role and molecular mechanism in clear cell renal cell carcinoma (ccRCC) development and progression remain unknown. In this study, analysis results of the GEO/TCGA/UALCAN database showed that GLUD1 level was downregulated in ccRCC tissues. Immunohistochemistry and western blotting results further validated the downregulation of GLUD1 level in ccRCC tissues. GLUD1 level was gradually decreased as ccRCC stage and grade progressed. Low GLUD1 level was associated with a shorter survival and higher IC50 value for tyrosine kinase inhibitors (TKIs) in ccRCC, reminding that GLUD1 level could predict the prognosis and TKIs sensitivity of ccRCC patients. High level of methylation in GLUD1 promoter was positively correlated with the downregulation of GLUD1 level and was negatively correlated with survival of ccRCC patients. GLUD1 overexpression suppressed RCC cell proliferation, colony formation and migration by inhibiting PI3K/Akt/mTOR pathway activation. Low GLUD1 level correlated with suppressive immune microenvironment (TIME) in ccRCC. Together, we found a novel tumor-suppressing role of GLUD1 in ccRCC which was different from that in other tumors and a new mechanism for inhibiting PI3K/Akt/mTOR activation and TIME in ccRCC. These results provide a theoretical basis for GLUD1 as a therapeutic target and prognostic marker in ccRCC.