Renal Cell Proliferation Research Articles

Preliminary study on the role of the C5orf46 gene in renal cancer

BackgroundC5orf46 has been found to have antibacterial and anti-inflammatory effects via sequencing and microarray technologies, but its effects on cancer are unclear. MethodsC5orf46 expression in renal cancer patients and cell lines was measured by quantitative polymerase chain reaction (qPCR). RNA sequencing data and clinicopathological information from renal cancer patients extracted from The Tumor Genome Atlas (TCGA) were analyzed to evaluate the prognostic value of C5orf46. The role of C5orf46 in vitro was verified by migration, proliferation and apoptosis experiments in renal cancer cell lines. Furthermore, the transcriptome of renal cancer cell lines with C5orf46 knocked down was sequenced to analyze potential signaling network pathways. Finally, the possible mechanisms of C5orf46 involvement in renal cancer development were analyzed by evaluating the immune microenvironment, mutation status and methylation levels. ResultsC5orf46 was highly expressed in renal cancer and was an independent prognostic factor. In vitro cell experiments showed that inhibition of C5orf46 expression could reduce renal cancer cell proliferation and migration and increase apoptosis. Transcriptomic sequencing after knockdown of C5orf46 in renal cancer cells revealed that it is involved in the malignant phenotype and immune microenvironment regulation of renal cancer. Finally, public databases suggest that C5orf46-related immune cell infiltration, mutational potential, and low methylation levels may contribute to poor prognosis in renal cancer. ConclusionThese findings suggest that C5orf46 is associated with renal cancer progression and could be a potential target for improving renal cancer prognosis.

Curcumin Inhibits the Proliferation of Renal Cancer 786-O Cells through MTOR Signaling Pathway and Its Mechanism.

Objectives The mechanism of curcumin inhibiting renal cancer 786-O cells proliferation through MTOR signaling pathway was investigated. Methods Human renal cancer 786-O cells were cultured with curcumin for 48 h. The OD values were measured by the MTT method, and the growth inhibition rate of 786-O cells was calculated. The cell cycle distribution and apoptosis rate were detected by flow cytometry (FCM). Transwell chamber was introduced to detect cell invasion ability. Cell migration ability was detected by the cell scratch test. The protein expression was assessed by Western blot. Results With curcumin concentration increasing, the expressions of MMP2, MMP9, MTOR, and p-MTOR proteins and the number of cells in the S phase decreased gradually, while number of cells in G1 and G2/M phases and cells apoptosis rate increased continuously. With the increasing of concentration and time, growth of 786-O cells in each treatment group was inhibited to varying degrees. The higher the inhibition rate was, the cells migration and transmembrane cells proportion decreased significantly. Conclusions Curcumin inhibits the proliferation, migration, and invasion and induces apoptosis of renal cancer 786-O cells by blocking the MTOR signaling pathway. It may be related to the downregulation of MMP2 and MMP9 proteins.

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.

Comparison of the treatment efficacy of umbilical mesenchymal stem cell transplantation via renal subcapsular and parenchymal routes in AKI-CKD mice

BackgroundMesenchymal stem cells (MSCs) have emerged as a promising cell-based therapy for acute kidney injury (AKI). However, the optimal route of MSC transplantation remains controversial, and there have been no comparisons of the therapeutic benefits of MSC administration through different delivery routes.MethodsIn this study, we encapsulated MSCs into a collagen matrix to help achieve local MSC retention in the kidney and assessed the survival of MSCs in vitro and in vivo. After transplanting collagen matrix-encapsulated-MSCs (Col-MSCs) under the renal capsule or into the parenchyma using the same cell dose and suspension volume in an ischemia/reperfusion injury model, we evaluated the treatment efficacy of two local transplantation routes at different stages of AKI.ResultsWe found that Col-MSCs could be retained in the kidney for at least 14 days. Both local MSC therapies could reduce tubular injury, promote the proliferation of renal tubular epithelial cells on Day 3 and alleviate renal fibrosis on Day 14 and 28. MSC transplantation via the subcapsular route exerts better therapeutic effects for renal functional and structural recovery after AKI than MSC administration via the parenchymal route.ConclusionsSubcapsular MSC transplantation may be an ideal route of MSC delivery for AKI treatment, and collagen I can provide a superior microenvironment for cell–cell and cell–matrix interactions to stabilize the retention rate of MSCs in the kidney.

Effect of BDNF-AS/miR-145-5p axis on renal tubular epithelial cell injury induced by high glucose

To investigate the effect and possible mechanism of BDNF-AS on renal tubular epithelial cell injury induced by high glucose. Human renal tubular epithelial cells HK-2 were cultured in vitro and transfected with BDNF-AS small interfering RNA or miR-145-5p mimic, or co-transfected with BDNF-AS small interfering RNA and miR-145-5p inhibitor, respectively. The cells were then intervened with 30 mmol/L glucose for 24 hours. The expression of BDNF-AS and miR-145-5p were detected by RT-qPCR. Cell proliferation was detected by CCK-8, and apoptosis was detected by flow cytometry. The expression of Bcl-2 and Bax proteins were detected by Western blotting, and the levels of IL-1β and IL-6 in cell culture supernatant were detected by enzyme-linked immunosorbent assay. Dual luciferase reporter gene experiment was used to verify the regulatory relationship of BDNF-AS with miR-145-5p. High glucose promoted the expression of BDNF-AS in HK-2 cells (P<0.05), but inhibited that of miR-145-5p (P<0.05). Interfering with BDNF-AS or overexpression of miR-145-5p decreased the inhibition rate, apoptosis rate and expression of Bax protein, IL-1β and IL-6 of HK-2 cells induced by high glucose (P<0.05), but promoted the expression of Bcl-2 protein (P<0.05). Interfering with miR-145-5p reversed the effect of interfering with BDNF-AS on the proliferation, apoptosis rate and the expression of IL-1β and IL-6 of HK-2 cells induced by high glucose. BDNF-AS could target and down-regulate miR-145-5p. Interfering with BDNF-AS may promote the proliferation of renal tubular epithelial cells induced by high glucose and inhibit cell apoptosis and the expression of inflammatory factor by down-regulating miR-145-5p.

Icariin Attenuation of Diabetic Kidney Disease Through Inhibition of Endoplasmic Reticulum Stress via G Protein-Coupled Estrogen Receptors.

Diabetic kidney disease (DKD) is the most common complication of diabetes mellitus and has become the primary cause of End-Stage Renal Disease (ESRD) globally. Icariin (ICA), an effective component extracted from Epimedium, has antiosteoporosis effect, antitumor effects, anti-ischemia effects, and other effects. In this study, a mouse DKD model was established, and Icariin solid nanoliposomes were administered to determine whether ICA had a protective effect on the renal function of DKD mice by regulating estrogen level and endoplasmic reticulum (ER) stress pathway. The results showed that the microalbumin/creatinine in urine, serum urea nitrogen, and CHOL in ICA cultured DKD mice significantly decreased, and mice nephropathy improved significantly. rat renal tubule epithelial cells were further tested, and the rat renal tubule epithelial cells were modeled by cultured cells with high glucose. The results showed that high glucose could promote the proliferation of renal tubular epithelial cells. Simultaneously, ICA can inhibit the proliferation of renal tubular epithelial cells and induce cell apoptosis. Furthermore, the expression of ER stress-related proteins IRE1 and XBP-1S was further detected. Additionally, to ICA intervention, a GPER antagonist (G-15) was added for intervention, the inhibitory effects of IRE1 and XBP-1S were reversed, and the ER stress pathway was activated. Cell experiments showed that ICA could promote GPER expression, while inhibiting GPER expression promoted the activation of ER stress pathway, and GPER expression was negatively correlated with ER stress protein expression. Therefore, the experiment proved that in DKD tissues, a high concentration of ICA can inhibit the ER stress response by promoting the expression of GPER, reducing the proliferation of diabetic nephropathy, and increasing the rate of tissue apoptosis.

Ubiquitin-specific peptidase 2 inhibits epithelial-mesenchymal transition in clear cell renal cell carcinoma metastasis by downregulating the NF-κB pathway

ABSTRACT Clear cell renal cell carcinoma, the most common type of renal cancer, is associated with poor survival. Ubiquitin-specific peptidase 2 regulates the molecular mechanisms of cancer cells. However, its mechanism in clear cell renal cell carcinoma remains unclear. Quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry were performed to assess ubiquitin-specific peptidase 2 expression in human clear cell renal cell carcinoma samples. Ubiquitin-specific peptidase 2 was weakly expressed in clear cell renal cell carcinoma samples and associated with poor patient outcomes. Ubiquitin-specific peptidase 2 inhibition promoted clear cell renal cell carcinoma cell proliferation, migration, and invasion. Ubiquitin-specific peptidase 2 overexpression inhibited clear cell renal cell carcinoma cell proliferation, migration, and invasion in vitro and in vivo. RNA-sequencing showed significant changes in the epithelial-mesenchymal transition-related pathways following ubiquitin-specific peptidase 2 knockdown. Western blotting was performed to detect the protein expression levels. Expression of p-nuclear factor-κB p65, N-cadherin, Vimentin, and Snail, which were markedly increased, as well as E-cadherin, which was decreased following ubiquitin-specific peptidase 2 knockdown. Rescue experiments using the nuclear factor-κB inhibitor BAY 11–7082 revealed that the migration and invasion abilities and the expression of epithelial-mesenchymal transition pathway proteins were inhibited in both the short hairpin RNA (shRNA) for ubiquitin-specific peptidase 2 and shRNA for negative control groups. Ubiquitin-specific peptidase 2 is a potential biomarker to distinguish clear cell renal cell carcinoma patients from healthy individuals. Ubiquitin-specific peptidase 2-mediated inhibition of epithelial-mesenchymal transition in clear cell renal cell carcinoma cells is dependent on the nuclear factor-κB pathway.

Apigenin inhibits renal cell carcinoma cell proliferation through G2/M phase cell cycle arrest.

Apigenin is a flavonoid widely presented in fruits and vegetables, and is known to possess anti‑inflammatory, antioxidant, and anticancer properties. The present study was designed to investigate the effects of apigenin on renal cell carcinoma (RCC) cells. These effects on cell growth were evaluated using a cell counting kit, while cell cycle distribution was investigated by flow cytometry following propidium iodide DNA staining. The human RCC cell lines, Caki‑1, ACHN, and NC65, were each treated with 1‑100µM apigenin for 24h, which resulted in concentration‑dependent cell growth inhibition, with the effects confirmed by trypan blue staining. Furthermore, even when the apigenin treatment period was shortened to 3h, the same cytostatic effect on RCC cells was noted. Similarly, a concentration‑dependent cell growth inhibitory effect was also observed in primary RCC cells, as apigenin induced G2/M phase cell cycle arrest and reduced the expression levels of cyclinA, B1, D3, andE in RCC cells in both dose‑ and time‑dependent manners. These findings suggest the possibility of the use of apigenin as a novel therapeutic strategy for treatment of RCC due to its anticancer activity and ability to function as a cell cycle modulating agent.

Effect of L-carnitine on potassium dichromate-induced nephrotoxicity in rats: modulation of PI3K/AKT signaling pathway.

Background and purpose:Kidney diseases impose significant global health challenges. Potassium dichromate (PD) is a heavy metal frequently associated with nephrotoxicity. PD prompts oxidative and inflammatory injuries in renal tissues. L-carnitine is a naturally-occurring amino acid commonly used as a supplement.Experimental approach:Forty rats were randomly allocated into 5 groups. Group 1 (normal) received only saline. Nephrotoxicity was induced in the remaining groups by PD (15 mg/kg; i.p). Group 2 served as a nephrotoxic group. Groups 3-5 received L-carnitine (25, 50, and 100 mg/kg; p.o.), respectively for 4 weeks.Findings/Results:PD administration resulted in elevated serum creatinine and blood urea nitrogen accompanied by diminished reduced glutathione and elevated malondialdehyde, tumor necrosis factor-alpha, and transforming growth factor-beta renal tissue contents relative to normal rats. PD also produced apoptotic histopathological injuries and down-regulated PI3K/Akt signaling pathway; signifying ongoing apoptosis. In the current work, L-carnitine use in the selected dose levels resulted in improvement of all the aforementioned serum, renal tissue, and histological parameters relative to nephrotoxic rats. L-carnitine up-regulated PI3K/Akt signaling pathway that was down-regulated post PD use.Conclusion and implications:Collectively, the study highlighted that the possible mechanisms beyond the beneficial effects of L-carnitine are mainly through its antioxidant as well as anti-inflammatory actions. L- carnitine significantly abrogated apoptosis via up-regulation of PI3K/Akt signaling pathway and signified restoration of normal renal cell proliferation and functionality.

Silencing lncRNA SLC16A1-AS1 Induced Ferroptosis in Renal Cell Carcinoma Through miR-143-3p/SLC7A11 Signaling.

Introduction: Renal cancer is one of the most common cancers in the world, but the effect of therapies on advanced renal cancer has not improved for decades. Ferroptosis is an emerging type of programmed cell death and has been proved to play a vital role in many kinds of cancers. However, the mechanisms of ferroptosis regulated by long noncoding RNA (lncRNA) in the context of renal cancer was still unknown. Methods: We used bioinformation analysis to identify SLC16A1-AS1 as a survival-related lncRNA in renal cancer. The expression levels of SLC16A1-AS1 and microRNA-143-3p (miR-143-3p) were detected by quantitative reverse transcription–polymerase chain reaction. Cell counting kit-8 assay, 5-bromo-2′-deoxyuridine proliferation assay, and colony-formation assay were performed to evaluate cell viability and proliferation. Wound-healing assay and transwell assay were used to examine cell invasive and migration capacity. Dual-luciferase reporter assay and RNA-binding protein immunoprecipitation were used to identify the interaction among SLC16A1-AS1, miR-143-3p, and the target protein solute carrier family 7 membrane 11 (SLC7A11). Reduced glutathione and glutathione and lipid peroxidation measurements were carried out to evaluate the level of ferroptosis, and the expression levels of ferroptosis-related proteins were analyzed by western blot. Results: Our study revealed that SLC16A1-AS1 has high expression and was associated with overall survival in renal cancer. Knockdown SLC16A1-AS1 inhibited cell viability, proliferation, and migration of renal cancer cells. Furthermore, it was demonstrated that SLC16A1-AS1 served as a sponge of miR-143-3p, and knockdown SLC16A1-AS1 significantly increased the enrichment of miR-143-3p. And then, SLC7A11 was identified as the target protein of miR-143-3p, and overexpression miR-143-3p remarkably inhibited the expression of SLC7A11. Moreover, knockdown SLC16A1-AS1 could aggravate this effect. Finally, through inhibiting SLC7A11 expression, silencing SLC16A1-AS1 induced ferroptosis via increasing miR-143-3p. Conclusion: The present results suggest that silencing lncRNA SLC16A1-AS1 can induce ferroptosis through miR-143-3p/SLC7A11 signaling in renal cancer. Our study provided a novel view into the pathogenesis and treatment strategy of RCC.

Calbindin S100A16 Promotes Renal Cell Carcinoma Progression and Angiogenesis via the VEGF/VEGFR2 Signaling Pathway.

Purpose Recent research has indicated that the calcium-binding protein S100A16 promotes carcinogenesis and tumor growth in several forms of cancer. The objective of this study was to examine the relationship between S100A16 and renal cell cancer. Methods By using The Cancer Genome Atlas (TCGA) database, the differentially expressed gene S100A16 was identified, and its appearance and link to the prognosis of persons with renal cancer were confirmed. Cox regression was used in multivariate analysis, and a nomogram was developed for internal validation. The correlation between S100A16 and immune cells was analyzed in the TIMER database. Moreover, the potential mechanism of action was investigated utilizing GO and KEGG enrichment analyses. Proliferation, migration, and angiogenesis were investigated in vitro, and the involvement of S100A16 in the undesirable biological events of renal cell carcinoma (RCC) was further explored. Results S100A16 was the differentially expressed molecule identified through database screening. Malignant tissues showed higher S100A16 expression than noncancerous tissues, and S100A16 expression was mostly localized in the cytoplasm. According to the TCGA and KM-plotter datasets, patients with RCC and low S100A16 expression had superior OS, PFI, and DSS. The C-index of the nomogram was 0.754 (0.726–0.782), and the accuracy of the prediction model was high. The TIMER database shows that the expression of S100A16 is associated with immune infiltration and may play an important role in promoting tumor cell immune escape in the RCC tumor microenvironment. S100A16 may influence the biological processes of RCC via the VEGF/VEGFR2 signaling route and PI3K-Akt signaling pathway and through P53 alteration and cell cycle according to the gene enrichment technique. In vitro cytological experiments demonstrated that S100A16 knockdown can inhibit the proliferation and migration of renal cancer cells and the expression levels of VEGF, VEGFR2, and phosphorylated AKT within renal cancer cells, thereby inhibiting angiogenesis in renal cancer cells and resulting in a poor prognosis of RCC. Conclusion A decrease in S100A16 expression may dramatically increase the OS, PFI, and DSS of patients with RCC and may thus be used as a biomarker for predicting RCC. It may be associated with the immune infiltration of RCC and play a crucial role in the immune evasion of tumor cells within the RCC microenvironment. Intervention of s100a16 can promote the progression and angiogenesis of renal cell carcinoma through the VEGF/VEGFR2 signal transduction pathway and lead to poor prognosis of renal cell carcinoma. These findings suggest a potential target for the development of anticancer strategies for renal cancer.

Nc886 promotes renal cancer cell drug-resistance by enhancing EMT through Rock2 phosphorylation-mediated β-catenin nuclear translocation

ABSTRACT Drug resistance is a significant challenge in the present treatment regimens of renal cell carcinoma (RCC). Our previous study confirmed that nc886 functions as an oncogene in RCC. Nevertheless, the role and underlying mechanism of nc886 in RCC drug resistance are unclear. In the present study, Sunitinib and Everolimus treatment, respectively, downregulated nc886 expression in a dose-dependent manner in all four renal cancer cell lines. Nc886 overexpression in 786-O cells and ACHN cells significantly reduced the sensitivity of cancer cells to both Sunitinib and Everolimus treatment, respectively, by promoting cell viability and inhibiting cell apoptosis, whereas nc886 silencing increased cancer cell sensitivity. In renal cancer cell line with the highest drug-resistance, 786-O cells, Sunitinib, or Everolimus treatment enhanced the cellular EMT and was further enhanced by nc886 overexpression while attenuated by nc886 silencing. In 786-O cells, nc886 overexpression significantly promoted EMT, ROCK2 phosphorylation, and β-catenin nucleus translocation under Sunitinib or Everolimus treatment. Moreover, ROCK2 silencing significantly reversed the effects of nc886 overexpression on EMT, ROCK2 phosphorylation, and β-catenin nucleus translocation, as well as drug-resistant renal cancer cell viability and apoptosis. In conclusion, it was demonstrated that nc886 promotes renal cancer cell proliferation, migration, and invasion, as demonstrated previously. nc886 also promotes renal cancer cell drug-resistance to Sunitinib or Everolimus by promoting EMT through Rock2 phosphorylation-mediated nuclear translocation of β-catenin.

RNA-binding protein MEX3A controls G1/S transition via regulating the RB/E2F pathway in clear cell renal cell carcinoma

MEX3A is an RNA-binding protein that mediates mRNA decay through binding to 3′ untranslated regions. However, its role and mechanism in clear cell renal cell carcinoma remain unknown. In this study, we found that MEX3A expression was transcriptionally activated by ETS1 and upregulated in clear cell renal cell carcinoma. Silencing MEX3A markedly reduced clear cell renal cell carcinoma cell proliferation in vitro and in vivo. Inhibiting MEX3A induced G1/S cell-cycle arrest. Gene set enrichment analysis revealed that E2F targets are the central downstream pathways of MEX3A. To identify MEX3A targets, systematic screening using enhanced cross-linking and immunoprecipitation sequencing, and RNA-immunoprecipitation sequencing assays were performed. A network of 4,000 genes was identified as potential targets of MEX3A. Gene ontology analysis of upregulated genes bound by MEX3A indicated that negative regulation of the cell proliferation pathway was highly enriched. Further assays indicated that MEX3A bound to the CDKN2B 3′ untranslated region, promoting its mRNA degradation. This leads to decreased levels of CDKN2B and an uncontrolled cell cycle in clear cell renal cell carcinoma, which was confirmed by rescue experiments. Our findings revealed that MEX3A acts as a post-transcriptional regulator of abnormal cell-cycle progression in clear cell renal cell carcinoma.

CircCHST15 is a novel prognostic biomarker that promotes clear cell renal cell carcinoma cell proliferation and metastasis through the miR-125a-5p/EIF4EBP1 axis

BackgroundCircular RNAs (circRNAs) have been indicated as potentially critical mediators in various types of tumor progression, generally acting as microRNA (miRNA) sponges to regulate downstream gene expression. However, the aberrant expression profile and dysfunction of circRNAs in human clear cell renal cell carcinoma (ccRCC) need to be further investigated. This study mined key prognostic circRNAs and elucidates the potential role and molecular mechanism of circRNAs in regulating the proliferation and metastasis of ccRCC.MethodscircCHST15 (hsa_circ_0020303) was identified by mining two circRNA microarrays from the Gene Expression Omnibus database and comparing matched tumor versus adjacent normal epithelial tissue pairs or matched primary versus metastatic tumor tissue pairs. These results were validated by quantitative real-time polymerase chain reaction and agarose gel electrophoresis. We demonstrated the biological effect of circCHST15 in ccRCC both in vitro and in vivo. To test the interaction between circCHST15 and miRNAs, we conducted a number of experiments, including RNA pull down assay, dual-luciferase reporter assay and fluorescence in situ hybridization.ResultsThe expression of circCHST15 was higher in ccRCC tissues compared to healthy adjacent kidney tissue and higher in RCC cell lines compared to normal kidney cell lines. The level of circCHST15 was positively correlated with aggressive clinicopathological characteristics, and circCHST15 served as an independent prognostic indicator for overall survival and progression-free survival in patients with ccRCC after surgical resection. Our in vivo and in vitro data indicate that circCHST15 promotes the proliferation, migration, and invasion of ccRCC cells. Mechanistically, we found that circCHST15 directly interacts with miR-125a-5p and acts as a microRNA sponge to regulate EIF4EBP1 expression.ConclusionsWe found that sponging of miR-125a-5p to promote EIF4EBP1 expression is the underlying mechanism of hsa_circ_0020303-induced ccRCC progression. This prompts further investigation of circCHST15 as a potential prognostic biomarker and therapeutic target for ccRCC.

Identification of Pax protein inhibitors that suppress target gene expression and cancer cell proliferation

The Pax family of developmental control genes are frequently deregulated in human disease. In the kidney, Pax2 is expressed in developing nephrons but not in adult proximal and distal tubules, whereas polycystic kidney epithelia or renal cell carcinoma continues to express high levels. Pax2 reduction in mice or cell culture can slow proliferation of cystic epithelial cells or renal cancer cells. Thus, inhibition of Pax activity may be a viable, cell-type-specific therapy. We designed an unbiased, cell-based, high-throughput screen that identified triazolo pyrimidine derivatives that attenuate Pax transactivation ability. We show that BG-1 inhibits Pax2-positive cancer cell growth and target gene expression but has little effect on Pax2-negative cells. Chromatin immunoprecipitation suggests that these inhibitors prevent Pax protein interactions with the histone H3K4 methylation complex at Pax target genes in renal cells. Thus, these compounds may provide structural scaffolds for kidney-specific inhibitors with therapeutic potential.

Metformin induces lactate accumulation and accelerates renal cyst progression in Pkd1-deficient mice.

Metabolic reprogramming is a potential treatment strategy for autosomal dominant polycystic kidney disease (ADPKD). Metformin has been shown to inhibit the early stages of cyst formation in animal models. However, metformin can lead to lactic acidosis in diabetic patients with advanced chronic kidney disease, and its efficacy in ADPKD is still not fully understood. Here, we investigated the effect of metformin in an established hypomorphic mouse model of PKD that presents stable and heritable knockdown of Pkd1. The Pkd1 miRNA transgenic mice of both genders were randomized to receive metformin or saline injections. Metformin was administrated through daily intraperitoneal injection from postnatal day 35 for 4weeks. Unexpectedly, metformin treatment at a concentration of 150mg/kg increased disease severity, including kidney-to-body weight ratio, cystic index and plasma BUN levels, and was associated with increased renal tubular cell proliferation and plasma lactate levels. Functional enrichment analysis for cDNA microarrays from kidney samples revealed significant enrichment of several pro-proliferative pathways including β-catenin, hypoxia-inducible factor-1α, protein kinase Cα and Notch signaling pathways in the metformin-treated mutant mice. The plasma metformin concentrations were still within the recommended therapeutic range for type 2 diabetic patients. Short-term metformin treatment in a second Pkd1 hypomorphic model (Pkd1RC/RC) was however neutral. These results demonstrate that metformin may exacerbate late-stage cyst growth associated with the activation of lactate-related signaling pathways in Pkd1 deficiency. Our findings indicate that using metformin in the later stage of ADPKD might accelerate disease progression and call for the cautious use of metformin in these patients.

The Sigma-2 Receptor/TMEM97 Agonist PB28 Suppresses Cell Proliferation and Invasion by Regulating the PI3K-AKT-mTOR Signalling Pathway in Renal Cancer.

Sigma‐2 receptor/TMEM97 is overexpressed in many tumours, and sigma‐2 receptor ligands are under investigation for cancer therapy. We intended to evaluate the effect of PB28 on renal cancer in proliferation, migration and invasion in vitro and in vivo. Invasive renal cancer cell lines treated with PB28 (or sigma‐2 receptor antagonist 1) were subjected to cell proliferation, migration and invasion assays. The therapeutic effect of PB28 was performed on nude mice. Western blot for proteins in the PI3K‐AKT‐mTOR signalling pathway was conducted. A CCK‐8 assay was used to examine the effect of the combination of PB28 and cisplatin on renal cancer cells. Significant inhibitory effects were observed on proliferation, migration and invasion of 786‐O and ACHN cells after culturing with PB28. But, the outcomes of sigma‐2 receptor antagonist 1 presented the opposite tendency. PB28 significantly inhibited the proliferative and invasive ability of OS‐RC‐2 cells in vivo. Treatment resulted in decreased phosphorylation of constituents of the PI3K‐AKT‐mTOR pathway. The combination of PB28 and cisplatin showed enhanced efficacy in the inhibition of renal cancer cell proliferation. Taken together, PB28 inhibited the tumorigenic behaviours of renal cancer cells by regulating the PI3K‐AKT‐mTOR signalling pathway and was expected to be a sensitizer of cisplatin.

The roles of ferroptosis regulatory gene SLC7A11 in renal cell carcinoma: A multi-omics study.

BackgroundThe ferroptosis inhibitory gene Solute carrier family 7 member 11 (SLC7A11) provides a new strategy for anticancer treatment. However, its function in renal cell carcinoma (RCC) remains elusive.MethodsThe expression and somatic mutation information of SLC7A11 in RCC samples were determined using The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC), Gene Expression Omnibus (GEO), Oncomine, and cBioPortal databases. The prognostic value of SLC7A11 was assessed through survival analysis, Receiver operating characteristic curve (ROC) analysis, independent prognostic analysis, clinical subgroup analysis, and nomogram. Its prognostic value was also validated in the ICGC and GSE29607 cohorts. Gene set enrichment analysis (GSEA) was employed to investigate the effects of SLC7A11 on multiple metabolic pathways. The CIBERSORT algorithm and single‐sample gene set enrichment analysis (ssGSEA) method were applied to evaluate the effects of SLC7A11 on the tumor immune microenvironment (TIM). SLC7A11’s therapeutic correlations were analyzed using the GSE87121, GSE67501, and GSDC datasets. Finally, the biofunctions of SLC7A11 in renal cancer cells and ferroptosis were ascertained by MTT, wound healing, transwell, and western blot assays.ResultsThrough multiple datasets, SLC7A11 was found to be markedly upregulated in RCC. In terms of prognosis, SLC7A11 overexpression conferred a worse prognosis and was identified as an independent prognostic factor. Its prognostic value was validated in ICGC cohort. Moreover, high SL7CA11 expression could stimulate nucleotides, fatty acids, and amino acid metabolism to meet the proliferative consumption of tumor cells. As for the immune effect, SLC7A11 suppressed antitumor immunity by reducing the abundances of CD8+ T and NK cells. Regarding the therapeutic response, SLC7A11 expression was not correlated with the sensitivities of most chemotherapy and targeted drugs. Finally, SLC7A11 promoted the proliferation, migration, and invasion of renal cancer cells by enhancing GPX4 output, which in turn inhibits ferroptosis.ConclusionsSLC7A11 not only deeply influences RCC prognosis and TIM, but also promotes RCC progression by inhibiting ferroptosis and inducing metabolic reprogramming. In addition, SLC7A11 weakly affects the therapeutic effect and sensitivities of multiple chemotherapy and targeted drugs.

Confounders for kidney carcinogenesis in rodent cancer bioassays.

In the long-term safety testing of chemicals for carcinogenicity the toxicologist needs to be aware of a number of scenarios where renal tubule tumors, or their precursors, arise that are not due to a carcinogenic action of the test article. Situations producing false positive results in the kidney include exacerbation of chronic progressive nephropathy (CPN) in rats, confusion of atypical tubule hyperplasia (the obligate precursor of renal tubule tumor) with foci of benign CPN-related renal tubule cell proliferation, inclusion of spontaneous tumor entities, such as the amphophilic-vacuolar tumor, in the test article tumor count, the possibility of a link between spontaneous forms of tubule dilatation and renal tubule tumor formation in mice, and the supposed predictivity of chemically-induced karyomegaly for renal carcinogenicity in both rats and mice. Examples of these misleading situations are described and discussed.

MicroRNAs in Lupus Nephritis-Role in Disease Pathogenesis and Clinical Applications.

MicroRNAs (miRs) are non-coding small RNAs that act as epigenetic modulators to regulate the protein levels of target mRNAs without modifying the genetic sequences. The role of miRs in the pathogenesis of lupus nephritis (LN) is increasingly recognized and highly complex. Altered levels of different miRs are observed in the blood, urine and kidney tissues of murine LN models and LN patients. Accumulating evidence suggests that these miRs can modulate immune cells and various key inflammatory pathways, and their perturbations contribute to the aberrant immune response in LN. The dysregulation of miRs in different resident renal cells and urinary exosomes can also lead to abnormal renal cell proliferation, inflammation and kidney fibrosis in LN. While miRs may hold promise in various clinical applications in LN patients, there are still many potential limitations and safety concerns for their use. Further studies are worthwhile to examine the clinical utility of miRs in the diagnosis, disease activity monitoring, prognostication and treatment of LN.