Renal Cell Carcinoma Tumorigenesis Research Articles

Androgen Receptor and Non-Coding RNAs’ Interaction in Renal Cell Carcinoma

Renal cell carcinoma (RCC), the most prevalent among the urogenital cancers, accounts for around 3% of new cancer cases worldwide. Significantly, the incidence of RCC has doubled in developed world countries, ranking it as the sixth most common cancer in males, who represent two-thirds of RCC cases. Males with RCC exhibit a higher mortality rate and tend to develop a more aggressive form of the disease than females. Sex-related risk factors, including lifestyle and biological variations, explain this difference. The androgen receptor (AR) oncogenic signaling pathway has been extensively studied among the biological factors that affect RCC. Recent advancements in high-throughput RNA sequencing techniques have underscored the significant roles played by noncoding-RNAs (ncRNAs), previously dismissed as “junk”. The oncogenic potential of AR is manifested through its dysregulation of the ncRNAs’ availability and function, promoting RCC tumorigenesis. This review offers a summary of the most recent findings on the role and molecular mechanisms of the AR in dysregulating the ncRNAs that play a role in the progression of RCC and the possibility of utilizing ncRNAs to target AR as a potential therapeutic strategy.

SRSF3 suppresses RCC tumorigenesis and progression via regulating SP4 alternative splicing

Abnormal alternative splicing (AS) caused by dysregulated expression of splicing factors plays a crucial role in tumorigenesis and progression. The serine/arginine-rich (SR) RNA-binding protein family is a major class of splicing factors regulating AS. However, their roles and mechanisms in renal cell carcinoma (RCC) development and progression are not fully understood. Here, we found that SR splicing factor 3 (SRSF3) was an important splicing factor affecting RCC progression. SRSF3 was downregulated in RCC tissues and its low level was associated with decreased overall survival time of RCC patients. SRSF3 overexpression suppressed RCC cell malignancy. Mechanistically, the binding of SRSF3 to SP4 exon 3 led to the inclusion of SP4 exon 3 and the increase of long SP4 isoform (L-SP4) level in RCC cells. L-SP4, but not S-SP4 overexpression suppressed RCC cell malignancy. Meanwhile, L-SP4 participated in SRSF3-mediated anti-proliferation by transcriptionally promoting SMAD4 expression. Taken together, our findings provide new insights into the anticancer mechanism of SRSF3, suggesting that SRSF3 may serve as a novel potential therapeutic target for RCC.

The Role of the PAX Genes in Renal Cell Carcinoma.

Renal cell carcinoma (RCC) is a significant oncological challenge due to its heterogeneous nature and limited treatment options. The PAX developmental gene family encodes nine highly conserved transcription factors that play crucial roles in embryonic development and organogenesis, which have been implicated in the occurrence and development of RCC. This review explores the molecular landscape of RCC, with a specific focus on the role of the PAX gene family in RCC tumorigenesis and disease progression. Of the various RCC subtypes, clear cell renal cell carcinoma (ccRCC) is the most prevalent, characterized by the loss of the von Hippel-Lindau (VHL) tumor suppressor gene. Here, we review the published literature on the expression patterns and functional implications of PAX genes, particularly PAX2 and PAX8, in the three most common RCC subtypes, including ccRCC, papillary RCC (PRCC), and chromophobe RCC (ChRCC). Further, we review the interactions and potential biological mechanisms involving PAX genes and VHL loss in driving the pathogenesis of RCC, including the key signaling pathways mediated by VHL in ccRCC and associated mechanisms implicating PAX. Lastly, concurrent with our update regarding PAX gene research in RCC, we review and comment on the targeting of PAX towards the development of novel RCC therapies.

Shared chromosome 21q loss in a mixed subtype renal cell carcinoma: composite or collision tumor?

Clear cell renal cell carcinoma (CCRCC) and papillary renal cell carcinoma (PRCC) are the two most frequentlyencountered subtypes of renal cell carcinoma (RCC). Rarely, these two entities are identified intermingled within thesame mass and have been labeled either collision tumors juxtaposed by random chance or composite tumors thathave arisen from a common tumorigenic precursor cell. Regarding this distinction, authors have commonly reliedupon macroscopic, histologic, and clinicopathologic findings, which may be prone to subjectivity. Objectivemolecular evidence has been lacking. We present a renal tumor showing a mixed CCRCC and PRCC withcorroborating histologic, immunophenotypic, chromosomal microarray analysis (CMA), and next-generationsequencing (NGS) analysis for the respective tumor components, including classic findings of chromosome 3p lossand VHL mutation within the CCRCC component and gain of chromosomes 7 and 17 within the PRCC component.Of novel interest, CMA revealed a shared loss of chromosome 21q in both components with no other identifiableshared or overlapping mutations. This report adds unique evidence supporting the possibility of a true compositerenal cell carcinoma composed of two commonly recognized subtypes. This finding may help to inform earlymolecular pathogenetic mechanism of RCC tumorigenesis.

Can platelet distribution width lymphocyte ratio be a novel biomarker for predicting survival in metastatic renal cell cancer?

Renal cell carcinoma (RCC) constitutes 3% of all malignant tumors in the adult patient population (1). As in other cancer processes, inflammation affects each step of tumor formation, including initiation of tumorigenesis, tumor promotion, and metastatic progression in RCC (2,3). It is widely accepted that C-reactive protein, fibrinogen, neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio, and platelet-lymphocyte ratio (PLR) are markers of inflammation in both inflammatory diseases and malignant disease processes (2,3). Furthermore, a relatively high NLR was reported to be associated with an unfavorable prognosis and reduced overall survival in urological cancers (4,5). Platelets can secrete active metabolites and proteins and take a significant role in various processes such as inflammation, sepsis, and tissue regeneration (5). In addition, it is known that they can release growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-beta, and vascular endothelial growth factor (VEGF), which may all induce tumor angiogenesis and growth (6). In line with these findings, Tsujino et al. reported that platelet count could be an independent prognostic marker of overall survival and recurrence-free survival for patients with localized RCC (7). Additionally, Wang et al. stated that a high PLR value indicated an unfavorable prognosis in all urological cancers (8). Although several studies investigated the significance of hematological indices such as NLR and PLR in localized or metastatic RCC (mRCC), none focused on the platelet distribution width-lymphocyte ratio (PDWLR) (7,9,10). Therefore, this study aimed to analyze the prognostic significance of these platelet parameters in patients with mRCC.

Pan-Cancer Analysis Identifies BCLAF1 as a Potential Biomarker for Renal Cell Carcinoma.

B-cell lymphoma-2-associated transcription factor 1 (BCLAF1) is a versatile protein involved in the regulation of gene transcription and post-transcriptional processing. Although BCLAF1 exerts a broad tumor suppressor effect or tumor promoter effect in many cancer types, the specific roles concerning its expression levels, and its impact on tumorigenesis in Renal cell carcinoma (RCC) remain unclear. Here, we utilized the Cancer Genome Atlas (TCGA) and Genotype Tissue Expression (GTEx) datasets alongside R software and online tools to unravel the specific roles of BCLAF1 in 33 cancer types, including its expression levels, tumor immune and molecular subtypes, and its correlation with prognosis, diagnosis, DNA methylation, and immune microenvironment. Additionally, we carried out cell biology experiments to independently investigate the expression of BCLAF1 in RCC and its effects on tumor progression. BCLAF1 was differentially expressed in tumor tissues compared to normal tissues across various cancer types and was also differentially expressed in different immune and molecular subtypes. In RCC, patients with high BCLAF1 expression had a better prognosis and BCLAF1 was tightly correlated with the stage, gender, and histological grade of patients. Furthermore, BCLAF1 had higher DNA methylation levels and higher immune infiltration levels in tumor tissues. Additionally, cell functional experiments confirmed the low expression of BCLAF1 in RCC and that BCLAF1 significantly inhibited the proliferation, migration, and invasion, while inducing apoptosis and cell cycle arrest in RCC cells in vitro. Our study under-scored the potential of BCLAF1 as an important actor in tumorigenesis, especially concerning RCC where it may serve as an effective prognostic marker.

Alteration of pro-carcinogenic gut microbiota is associated with clear cell renal cell carcinoma tumorigenesis.

Increasing evidence suggests that gut microbiota is involved in the occurrence and progression of urinary system diseases such as clear cell renal cell carcinoma (ccRCC). However, the mechanism of how alteration of gut metagenome promotes ccRCC remains unclear. Here we aim to elucidate the association of specific gut bacteria and their metabolites with ccRCC. In a pilot case-control study among 30 ccRCC patients (RCC group) and 30 healthy controls (Control group), 16S ribosomal RNA (rRNA) gene sequencing were analyzed from fecal samples collected prior to surgery or hospitalization. Alpha diversity and beta diversity analysis of the gut microbiota were performed, and differential taxa were identified by multivariate statistics. Meanwhile, serum metabolism was measured by UHPLC-MS, and differential genes were identified based on the TCGA database. Alpha diversity found there were no significant microbial diversity differences of gut microbiota between the RCC group and the Control group. However, beta diversity analysis showed that the overall structures of the two groups were significantly separated (p = 0.008). Random Forests revealed the relative abundances of 20 species differed significantly between the RCC group and the Control group, among which nine species were enriched in the RCC group such as Desulfovibrionaceae, and 11 species were less abundant such as four kinds of Lactobacillus. Concomitantly, serum level of taurine, which was considered to be consumed by Desulfovibrionaceae and released by Lactobacillus, has decreased in the RCC group. In addition, macrophage-related genes such as Gabbr1 was upregulated in ccRCC patients. Reduction of protective bacteria, proliferation of sulfide-degrading bacteria Desulfovibrionaceae, reduction of taurine, and enrichment of macrophage related genes might be the risk predictors of ccRCC.

RP11-367G18.1V2 enhances clear cell renal cell carcinoma progression via induction of epithelial-mesenchymal transition.

Metastasis is the end stage of renal cell carcinoma (RCC), and clear cell renal cell carcinoma (ccRCC) is the most common malignant subtype. The hypoxic microenvironment is a common feature in ccRCC and plays an essential role in the regulation of epithelial-mesenchymal transition (EMT). Accumulating evidence manifests that long non-coding RNAs (lncRNAs) participate in RCC tumorigenesis and regulate hypoxia-induced EMT. Here, we identified a lncRNA RP11-367G18.1 induced by hypoxia, that was overexpressed in ccRCC tissues. A total of 216 specimens, including 149 ccRCC tumor samples and 67 related normal kidney parenchyma tissue samples, were collected. To investigate the biological fucntions of RP11.367G18.1 in ccRCC, migration, invasion, soft agar colony formation, xenograft tumorigenicity assays, and tail vein and orthotopic metastatic mouse models were performed. The relationship between RP11-367G18.1 and downstream signaling was analyzed utilizing reporter assay, RNA pull-down, chromatin immunopreciptation, and chromatin isolation by RNA purification assays. Hypoxic conditions and overexpression of HIF-1α increased the level of RP11-367G18.1. RP11-367G18.1 induced EMT and enhanced cell migration and invasion through variant 2. Inhibition of RP11-367G18.1 variant 2 reversed hypoxia-induced EMT phenotypes. An in vivo study revealed that RP11-367G18.1 variant 2 was required for hypoxia-induced tumor growth and metastasis in ccRCC. Mechanistically, RP11-367G18.1 variant 2 interacted with p300 histone acetyltransferase to regulate lysine 16 acetylation on histone 4 (H4K16Ac), thus contributing to hypoxia-regulated gene expression. Clinically, RP11-367G18.1 variant 2 was upregulated in ccRCC tissues, particularly metastatic ccRCC tissues, and it is linked to poor overall survival. These findings demonstrate the prognostic value and EMT-promoting role of RP11-367G18.1 and indicate that this lncRNA may provide a therapeutic target for ccRCC.

GPX8 regulates clear cell renal cell carcinoma tumorigenesis through promoting lipogenesis by NNMT

BackgroundClear cell renal cell carcinoma (ccRCC), with its hallmark phenotype of high cytosolic lipid content, is considered a metabolic cancer. Despite the implication of this lipid-rich phenotype in ccRCC tumorigenesis, the roles and regulators of de novo lipid synthesis (DNL) in ccRCC remain largely unexplained.MethodsOur bioinformatic screening focused on ccRCC-lipid phenotypes identified glutathione peroxidase 8 (GPX8), as a clinically relevant upstream regulator of DNL. GPX8 genetic silencing was performed with CRISPR-Cas9 or shRNA in ccRCC cell lines to dissect its roles. Untargeted metabolomics, RNA-seq analyses, and other biochemical assays (e.g., lipid droplets staining, fatty acid uptake, cell proliferation, xenograft, etc.) were carried out to investigate the GPX8’s involvement in lipid metabolism and tumorigenesis in ccRCC. The lipid metabolic function of GPX8 and its downstream were also measured by isotope-tracing-based DNL flux measurement.ResultsGPX8 knockout or downregulation substantially reduced lipid droplet levels (independent of lipid uptake), fatty acid de novo synthesis, triglyceride esterification in vitro, and tumor growth in vivo. The downstream regulator was identified as nicotinamide N-methyltransferase (NNMT): its knockdown phenocopied, and its expression rescued, GPX8 silencing both in vitro and in vivo. Mechanically, GPX8 regulated NNMT via IL6-STAT3 signaling, and blocking this axis suppressed ccRCC survival by activating AMPK. Notably, neither the GPX8-NNMT axis nor the DNL flux was affected by the von Hippel Lindau (VHL) status, the conventional regulator of ccRCC high lipid content.ConclusionsTaken together, our findings unravel the roles of the VHL-independent GPX8-NNMT axis in ccRCC lipid metabolism as related to the phenotypes and growth of ccRCC, which may be targeted for therapeutic purposes.Graphical abstract

TRPC Channels in the Physiology and Pathophysiology of the Renal Tubular System: What Do We Know?

The study of transient receptor potential (TRP) channels has dramatically increased during the past few years. TRP channels function as sensors and effectors in the cellular adaptation to environmental changes. Here, we review literature investigating the physiological and pathophysiological roles of TRPC channels in the renal tubular system with a focus on TRPC3 and TRPC6. TRPC3 plays a key role in Ca2+ homeostasis and is involved in transcellular Ca2+ reabsorption in the proximal tubule and the collecting duct. TRPC3 also conveys the osmosensitivity of principal cells of the collecting duct and is implicated in vasopressin-induced membrane translocation of AQP-2. Autosomal dominant polycystic kidney disease (ADPKD) can often be attributed to mutations of the PKD2 gene. TRPC3 is supposed to have a detrimental role in ADPKD-like conditions. The tubule-specific physiological functions of TRPC6 have not yet been entirely elucidated. Its pathophysiological role in ischemia-reperfusion injuries is a subject of debate. However, TRPC6 seems to be involved in tumorigenesis of renal cell carcinoma. In summary, TRPC channels are relevant in multiples conditions of the renal tubular system. There is a need to further elucidate their pathophysiology to better understand certain renal disorders and ultimately create new therapeutic targets to improve patient care.

ER export signals mediate plasma membrane localization of transmembrane protein TMEM72.

Transmembrane protein 72 (TMEM72) is involved in normal kidney development and tumorigenesis in renal cell carcinoma. However, the function of TMEM72 has not been experimentally examined; therefore, the role of TMEM72 is incompletely understood. In this study, we initially demonstrated that TMEM72 has four transmembrane domains (TMDs) and a long C-terminal tail. Immunofluorescence analysis showed that TMEM72 is localized on the plasma membrane but not on the outer mitochondrial membrane. Experiments performed with a series of TMEM72 deletion mutants and an evaluation of the unfolded protein response indicated that these TMDs are needed for proper protein folding or assembly. In contrast, domain-specific replacement analysis indicated the essential role of the C-terminal region of TMEM72 in protein transport. Spatial colocalization and immunoprecipitation assays showed that the proximal C-terminal region is responsible for anterograde protein transport. An amino acid sequence analysis and an immunocytochemical evaluation revealed that KRKKRKAAPEVLA, whichcorresponds to amino acid positions 132-144 in TMEM72, participates in efficient cellular transport. The motifs 132KRKKRK137 and 139APEVLA144 are associated with COPII and are considered to cooperate with membrane trafficking. Because efficient membrane trafficking is crucial for cells to maintain normal function, our data may contribute to elucidating the pathogenesis of membrane trafficking-associated diseases, particularly renal carcinoma and chronic kidney disease.

CircSCNN1A is a tumor suppressor in renal cell carcinoma via inducing the upregulation of MPP7 by the sponge effect on miR-421

BackgroundCircular RNAs (circRNAs) function as oncogenic factors or tumor repressors in variety of human malignancies. CircRNA Sodium Channel Epithelial 1 Subunit Alpha (circSCNN1A, hsa_circ_0025135) was downregulated in renal cell carcinoma (RCC). This study performed further research of circSCNN1A in RCC. MethodsThe level detection for circSCNN1A, microRNA-421 (miR-421) or Membrane Palmitoylated Protein 7 (MPP7) was conducted by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell behaviors were analyzed by Cell counting kit-8 (CCK-8) assay for cell viability, EDU assay for cell proliferation, flow cytometry for cell apoptosis, transwell assay for cell invasion and tube formation assay for angiogenesis. The protein expression was determined using western blot. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and pull-down assay were applied to validate the interaction between targets. In vivo research was performed by xenograft tumor assay. ResultsThe level of circSCNN1A was significantly downregulated in RCC tissues and cells. RCC cell proliferation, invasion and angiogenesis were reduced but apoptosis was promoted by circSCNN1A overexpression. Interestingly, circSCNN1A could interact with miR-421. Overexpression of miR-421 has reversed the anti-tumor function of circSCNN1A in RCC cells. MPP7 served as a target of miR-421, and MPP7 inhibited the malignant phenotypes of RCC cells. In addition, miR-421 downregulation induced the inhibitory effect on the RCC development via elevating the MPP7 level. Moreover, RCC tumorigenesis was suppressed by circSCNN1A through the miR-421/MPP7 axis in vivo. ConclusionThe experimental data revealed that circSCNN1A upregulated the expression of MPP7 via sponging miR-421, then inhibiting the progression of RCC.

Integrated analysis of transcriptomics, proteomics and metabolomics data reveals the role of SLC39A1 in renal cell carcinoma.

Purpose: Accumulating evidence suggests that solute carrier family 39 member 1 (SLC39A1) conceivably function as a tumor suppressor, but the underlying mechanism in renal cell carcinoma (RCC) is poorly understood. Methods: OSRC-2 renal cancer cells were first transfected with SLC39A1 overexpressed vectors and empty vectors and then used in transcriptomics, proteomics, and metabolomics integrated analyses. Results: SLC39A1 significantly altered several metabolisms at transcriptional, protein and metabolic levels, including purine and pyrimidine metabolism, amino acids and derivatives metabolism, lactose metabolism, and free fatty acid metabolism. Additionally, SLC39A1 could promote ferroptosis, and triggered significant crosstalk in PI3K-AKT signal pathway, cAMP signal pathway, and peroxisome proliferators-activated receptor (PPAR) signal pathway. Conclusion: We found SLC39A1 transfection impaired tumor metabolism and perturbed tumor metabolism-related pathways, which was a likely cause of the alteration in cell proliferation, migration, and cell cycle progression in RCC cells. These multi-omics analyses results provided both a macroscopic picture of molecular perturbation by SLC39A1 and novel insights into RCC tumorigenesis and development.

Dysregulation and implications of N6-methyladenosine modification in renal cell carcinoma.

Increasing evidence indicates that N6-methyladenosine (m6A) methylation modification serves important functions in biological metabolism. Dysregulation of m6A regulators is related to the progression of different malignancies, including renal cell carcinoma (RCC). Recent studies have reported preliminary findings on the influence of m6A regulator dysregulation on RCC tumorigenesis and development. However, no comprehensive review that integrates and analyzes the roles of m6A modification in RCC has been published to date. In this review, we focus on the dysregulation of m6A regulators as it relates to RCC tumorigenesis and development, as well as possible applications of m6A modification in RCC diagnosis and therapeutics.

Iron accumulation typifies renal cell carcinoma tumorigenesis but abates with pathological progression, sarcomatoid dedifferentiation, and metastasis.

Iron is a potent catalyst of oxidative stress and cellular proliferation implicated in renal cell carcinoma (RCC) tumorigenesis, yet it also drives ferroptosis that suppresses cancer progression and represents a novel therapeutic target for advanced RCC. The von Hippel Lindau (VHL)/hypoxia-inducible factor-α (HIF-α) axis is a major regulator of cellular iron, and its inactivation underlying most clear cell (cc) RCC tumors introduces both iron dependency and ferroptosis susceptibility. Despite the central role for iron in VHL/HIF-α signaling and ferroptosis, RCC iron levels and their dynamics during RCC initiation/progression are poorly defined. Here, we conducted a large-scale investigation into the incidence and prognostic significance of total tissue iron in ccRCC and non-ccRCC patient primary tumor cancer cells, tumor microenvironment (TME), metastases and non-neoplastic kidneys. Prussian Blue staining was performed to detect non-heme iron accumulation in over 1600 needle-core sections across multiple tissue microarrays. We found that RCC had significantly higher iron staining scores compared with other solid cancers and, on average, >40 times higher than adjacent renal epithelium. RCC cell iron levels correlated positively with TME iron levels and inversely with RCC levels of the main iron uptake protein, transferrin receptor 1 (TfR1/TFRC/CD71). Intriguingly, RCC iron levels, including in the TME, decreased significantly with pathologic (size/stage/grade) progression, sarcomatoid dedifferentiation, and metastasis, particularly among patients with ccRCC, despite increasing TfR1 levels, consistent with an increasingly iron-deficient tumor state. Opposite to tumor iron changes, adjacent renal epithelial iron increased significantly with RCC/ccRCC progression, sarcomatoid dedifferentiation, and metastasis. Lower tumor iron and higher renal epithelial iron each predicted significantly shorter ccRCC patient metastasis-free survival. In conclusion, iron accumulation typifies RCC tumors but declines toward a relative iron-deficient tumor state during progression to metastasis, despite precisely opposite dynamics in adjacent renal epithelium. These findings raise questions regarding the historically presumed selective advantage for high iron during all phases of cancer evolution, suggesting instead distinct tissue-specific roles during RCC carcinogenesis and early tumorigenesis versus later progression. Future study is warranted to determine how the relative iron deficiency of advanced RCC contributes to ferroptosis resistance and/or introduces a heightened susceptibility to iron deprivation that might be therapeutically exploitable.

SHMT2 promotes the tumorigenesis of renal cell carcinoma by regulating the m6A modification of PPAT

ObjectiveSerine hydroxymethyltransferase 2 (SHMT2) is the first rate-limiting enzyme for serine/glycine biosynthesis and one carbon metabolism. Here, we explore the underlying mechanism of how SHMT2 functions in renal cell carcinoma (RCC) initiation. MethodsIn this study, SHMT2 expression was assessed in RCC tissues. In vitro experiments were performed to investigate the functional role of SHMT2. The detailed mechanisms of SHMT2-mediated PPAT were addressed. ResultsIncreased SHMT2 facilitated RCC cell proliferation by inducing the G1/S phase transition. And SHMT2 promoted the expression of PPAT. Mechanism dissection revealed that SHMT2 enhanced the m6A modification through the endogenous methyl donor SAM mediated by SHMT2 via serine/glycine one carbon metabolic networks. SHMT2-catalyzed serine/glycine conversion regulated PPAT expression in an m6A-IGF2BP2-dependent manner. SHMT2 promoted RCC cell proliferation by upregulating PPAT expression. ConclusionsSHMT2 promotes RCC tumorigenesis by increasing PPAT expression. Thus, SHMT2 may be a novel potential therapeutic target for RCC.

The Role of P4HA1 in Multiple Cancer Types and its Potential as a Target in Renal Cell Carcinoma.

Background: Prolyl 4-hydroxylase subunit alpha 1 (P4HA1) provides the majority of the catalytic site of the active P4H enzyme. Emerging evidence has revealed that P4HA1 participates in the initiation and development of several malignant tumors. However, a pan-cancer analysis of P4HA1 has not been performed. Methods: In this study, we carried out an in-depth analysis of the expression patterns and prognostic value of P4HA1 using the datasets of The Cancer Genome Atlas (TCGA) and Kaplan–Meier Plotter. Genomic and epigenetic alterations of P4HA1 and the correlation of P4HA1 with DNA methylation in different cancers were also analyzed across multiple databases. In addition, the purity-adjusted partial Spearman’s correlation test was utilized to evaluate the correlation between P4HA1 expression and immune cell infiltration. We also further explored the biological function and mechanism of P4HA1 in renal cell carcinoma (RCC). Results: We characterized the expression profiles and prognostic values of P4HA1 in multiple cancer types. P4HA1 expression was increased in clear cell renal cell carcinoma (RCC) compared to adjacent normal tissues, and P4HA1 positively correlated with the overall survival (OS) and disease-free survival (DFS) in papillary RCC. In addition, a positive correlation between P4HA1 expression and immune cell infiltration was observed in clear cell RCC. We also identified a strong correlation between P4HA1 expression and immune checkpoint gene expression, microsatellite instability, and tumor mutation burden in chromophobe RCC. Finally, the results of in vitro experiments verified that overexpression of P4HA1 promoted the proliferation, migration, invasion, and epithelial–mesenchymal transition of RCC cells. Conclusion: Overall, our study has suggested that P4HA1 might play a significant role in tumorigenesis in RCC and may be a prognostic biomarker and therapeutic target for several malignant tumors, including RCC.

NF-κB and EGFR participate in S1PR3-mediated human renal cell carcinomas progression

The bioactive lipid sphingosine 1-phosphate (S1P) is implicated in many pivotal processes for the physiological and pathological actions via activating five types of G-protein-coupled S1P receptors (S1PR1‐5). The role of S1P in renal cell carcinoma (RCC) and its receptor subtype specific mediating mechanism are poorly studied. So we focus on the regulatory role of S1P in RCC progression and the receptor subtypes involved in S1P-induced actions, intending to further clarify a novel therapeutic target for RCC. Analysis of The Cancer Genome Atlas (TCGA) databases showed that the patients with high expression of S1PR3 had significantly worse overall than with low expression. We further demonstrated that S1P could promote proliferation, migration, and epithelial-mesenchymal transition (EMT) of renal cancer cells in vitro, and the actions were enhanced with the increase of S1PR3 expression. Meanwhile, the results in animal experiments also showed that S1PR3 could accelerate tumorigenesis and metastasis of RCC. Our study also clarified the mechanism for S1P induced cell proliferation is mediated by S1PR3/Gi/p38/Akt/p65/cyclin D1-CDK4 pathway and the main pathway for migration is S1PR3/Gi/q/ERK/p38/p65. In addition, S1PR3 was involved in epidermal growth factor (EGF)-induced actions by enhancing protein expression, not by transactivation of epidermal growth factor receptor (EGFR). These results also further supported our conclusion that the carcinogenic role of S1P/S1PR3 axis. Thus, our findings provide that S1PR3 may be a promising small molecular therapeutic target for S1PR3 expressed cancers.

Zinc Oxide Nanoparticle Inhibits Tumorigenesis of Renal Cell Carcinoma by Modulating Lipid Metabolism Targeting miR-454-3p to Repressing Metabolism Enzyme ACSL4.

Background Renal cell carcinoma (RCC) affects the life quality of patients with advanced diseases despite good prognosis and exhibits abnormal lipid metabolism. Zinc oxide nanoparticles (ZONs) are metal oxide nanoparticles that are regarded as promising therapeutic candidate for multiple diseases. This study was for exploring the function of ZONs in RCC. Methods We established in vitro cell model and in vivo xenograft model to determine the antitumor effect of ZONs. Cell viability and proliferation were evaluated via the cell counting kit-8 (CCK-8), colony formation, and 5-ethynyl-2'-deoxyuridine (EDU) assay. Protein and RNA levels were checked by using immunohistochemistry (IHC) and qRT-PCR assay. ROS, malondialdehyde (MDA), triglyceride, and total cholesterol were quantified to assess lipid oxidation and synthesis. Oil red O staining was performed to check lipid droplets accumulation. The ACSL4 and miR-454-3p expression in tumor samples and normal tissues were evaluated. The luciferase reporter gene assay was performed for checking the interaction between miR-454-3p and ACSL4 3'UTR region. Results ZONs suppressed the proliferation and viability of RCC cells both in vitro and in vivo. ZONs suppressed accumulation of ROS, MDA, triglyceride, total cholesterol, and lipid droplets in RCC cells, along with upregulated miR-454-3p. miR-454-3p targeted the 3'UTR region to suppress its expression. In patient samples, ACSL4 expression was notably elevated and indicated poor prognosis of RCC patients. Conclusion ZONs treatment notably impeded proliferation, lipid accumulation, and oxidation in RCC cells, through upregulating miR-454-3p to suppression the function of ACSL4. Our data suggested that ZONs are promising and effective agent for RCC treatment.

Propofol Disrupts Clear Cell Renal Cell Carcinoma Tumorigenesis by Regulating circFBXW7/miR-942 Axis

Background: Propofol is a commonly used intravenous anesthetic and has been found to perform anticancer effects in many cancers. However, the effects and mechanisms of propofol in clear cell renal cell carcinoma (ccRCC) remain largely undefined. Methods: The expression of circular RNA FBXW7 (circFBXW7) and miR-942 was detected by qRT-PCR. Cell proliferation, apoptosis, migration, and invasion capacities were analyzed using cell counting kit-8, colony formation, flow cytometry, and transwell assays, respectively. Western blot was used to detect the expression levels of PCNA, Cleaved-caspase 3 and MMP protein. The bindings between miR-942 and circFBXW7 were verified using RNA pull-down, dual-luciferase reporter, and RIP assays. Xenograft tumor analysis was employed to detect tumorigenesis in vivo. Results: Propofol alleviated cell proliferation, migration, invasion, and induced apoptosis in vitro and impeded tumor growth in vivo in ccRCC. Propofol elevated the level of circFBXW7, which knockdown reversed the anticancer effects of propofol on ccRCC cell tumorigenesis. CircFBXW7 directly bound to miR-942, and suppressed ccRCC cell malignant biological behaviors via targeting miR-942. Besides that, propofol decreased miR-942 expression, and miR-942 overexpression attenuated the effects of propofol on ccRCC cells. Moreover, propofol could regulate miR-942 expression through circFBXW7. Conclusion: Propofol suppressed the growth, migration, and invasion of ccRCC cells by regulating circFBXW7/miR-942 axis, suggesting a potential therapeutic strategy for the intervention of human ccRCC development.