Renal Cell Carcinoma Cell Migration Research Articles

Poria acid inhibit the growth and metastasis of renal cell carcinoma by inhibiting the PI3K/akt/NF-κb signaling pathway

BackgroundPoria acid (PAC) is a triterpene compound found in Poria cocos, a traditional Chinese medicine (TCM). The current study aims to explore the therapeutic effects and potential mechanisms of PAC on the migration and proliferation of human renal cell carcinoma (RCC) cells as well as tumor growth in animal model. MethodsCell viability and proliferative capacity of normal renal cells and RCC cells were investigated by MTT assay. In addition, 786-O cells were divided into four groups and treated with different concentrations of PAC (0, 20, 40, and 60 μM) for 48 h. Cell scratch test and cell invasion assay were performed to evaluate the effects of PAC on the invasion and migration of RCC cells, respectively. The effects of PAC on apoptosis of RCC cells and expression levels of PI3K/Akt/NF-kB signaling pathway-related biomarkers were investigated using TUNEL staining and Western blotting methods, respectively. Effects of PAC on the inhibitory activity of RCC tumor in mice were evaluated in a 786-O CDX model. ResultsThe study found that PAC inhibited the viability of RCC cells in a dose-dependent manner, as demonstrated by in vitro cell assays (p < 0.05). However, PAC showed no significant inhibitory effect on normal renal cells (p > 0.05). PAC also significantly inhibited the migration and invasion of RCC via EMT/MMP signaling pathways (p < 0.05). Immunofluorescence and immunoblotting results showed that PAC induced the apoptosis of RCC, which was accompanied by changes in the expression levels of apoptosis-related proteins (p < 0.05). Moreover, PAC significantly downregulated the PI3K/Akt/NF-kB signaling pathway in a concentration-dependent manner (p < 0.05). The effect of PAC on RCC apoptosis was dramatically reversed by 740Y–P (PI3K agonist) (p < 0.05) but significantly enhanced in the presence of LY294002 (PI3K inhibitor) (p < 0.05). The results of in vivo experiment also demonstrated that the antitumor activity of PAC was achieved by affecting the PI3K/Akt/NF-kB signaling pathway. ConclusionsPAC can effectively suppress the proliferation, invasion and migration of RCC cells, and exhibit anti-tumor effects in RCC model by inhibiting the PI3K/Akt/NF-kB signaling pathway.

Pachymic acid activates TP53INP2/TRAF6/caspase-8 pathway to promote apoptosis in renal cell carcinoma cells.

While pachymic acid (PA), a key component of Poria cocos (Schw.), has demonstrated anti-tumor effects in lung, breast, and pancreatic cancers, its impact on renal cell carcinoma (RCC) is unclear. This study evaluated the effect of PA on proliferation, migration, and apoptosis in human renal cancer A498 and ACHN cells as well as in cancer xenograft mice using wound scratch test, Western blotting, and co-immunoprecipitation assays. In a dose- and time-dependent manner, PA exhibited significant inhibition of RCC cell proliferation, migration, and invasion, accompanied by the induction of apoptosis. Additionally, PA upregulated the expression of tumor protein p53-inducible nuclear protein 2 (TP53INP2) and tumor necrosis factor receptor-associated factor 6 (TRAF6), which were downregulated in renal papillary and chromophobe carcinoma, resulting in inhibited tumor growth in mice. PA treatment elevated cleaved-caspase 3 and 8, and PARP levels, and facilitated TP53INP2 and TRAF6 binding to caspase 8, promoting its ubiquitination. Molecular docking revealed interactions between PA and TP53INP2, TRAF6. In summary, PA inhibits RCC development by upregulating TP53INP2 and promoting TRAF6-induced caspase 8 ubiquitination, activating apoptotic pathways.

AURKA promotes renal cell carcinoma progression via regulation of CCNB1 transcription

AURKA is a member of the serine/threonine kinase family and its kinase activity is crucial for the progression of mitosis. Recent studies have highlighted the therapeutic significance of AURKA inhibition in multiple cancer types. However, the specific mechanisms by which AURKA contributes to the progression of renal cell carcinoma (RCC) have not been fully elucidated. In this study, AURKA expression level was identified in human RCC tissues by immunohistochemical (IHC) staining. The function of AURKA on cell malignant phenotypes was evaluated in vitro after AURKA inhibition. The subcutaneous xenograft was conducted to confirm the in vivo effect of AURKA knockdown on growth of RCC cells. Finally, Co-IP, luciferase assay and ChIP experiments were performed to reveal the regulatory mechanism of AURKA on CCNB1. Our results showed a significant upregulation of AURKA in RCC tissues and cell lines, and a high AURKA expression was associated with poor prognosis. AURKA knockdown inhibited RCC cell proliferation and migration, induced cell apoptosis, and led to G1/G2 phase arrest. This effect was further confirmed by the use of an AURKA inhibitor. Mechanistically, AURKA interacted with E2F1, and subsequently recruited it to the promoter region of CCNB1. CCNB1 expression was essential for AURKA-induced RCC progression. Collectively, our results suggested that AURKA plays an important role in development of RCC via regulating CCNB1 transcription.

METTL3 facilitates renal cell carcinoma progression by PLOD2 m6A-methylation under prolonged hypoxia

N6-methyladenosine (m6A) is the most prevalent reversible modification in eukaryotic mRNA, and it plays a critical role in tumor progression. The purpose of this study was to investigate the function and regulatory mechanisms of the methyltransferase METTL3 in renal cell carcinoma (RCC). METTL3 expression was upregulated and predicted a poor prognosis in patients with advanced RCC. METTL3 facilitated the proliferation, migration, and invasion of RCC cells, depending on its methylase activity. METTL3 positively regulated the expression of PLOD2, and both genes were triggered under prolonged hypoxia. Mechanistically, hypoxia-induced the binding of HIF-1α to the METTL3 promoter, which enhanced its transcriptional activity. METTL3-mediated m6A modifications of PLOD2 mRNA at 3’UTR region, promoting the translation of PLOD2 protein. Furthermore, silencing METTL3 impaired RCC progression in vitro. In vivo, administration of highly potent and selective METTL3 inhibitor STM2457 showed anti-tumor effects, whereas AAV9-mediated re-transduction of PLOD2 largely abolished the above phenomenon in a subcutaneous mouse model. These findings reveal that hypoxia and HIF-driven METTL3 transcription promote RCC progression by increasing PLOD2 expression in an m6A-dependent manner, suggesting that METTL3 may serve as a novel pharmaceutical intervention for RCC.

Ropivacaine suppresses the progression of renal cell carcinoma through regulating the lncRNA RMRP/EZH2/CCDC65 axis.

Renal cell carcinoma (RCC) is a common malignancy. Local anesthetics were displayed powerful effects against various cancers. This study aims to probe the functions and molecular mechanism of ropivacaine in RCC. Different concentrations of ropivacaine were performed to administrate RCC cells including 786-O and Caki-1 cells. Cell viability and cell apoptosis were examined using CCK-8 and flow cytometry, respectively. Cell migration and invasion were determined by transwell assay. RMRP and CCDC65 expression was firstly predicted using TCGA dataset and further validated in RCC cells using qRT-PCR and western blot. The interactions among RMRP, EZH2 and CCDC65 were verified by RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays. Ropivacaine effectively suppressed RCC cell viability, migration and invasion and enhanced cell apoptosis rate. Aberrantly elevated RMRP expression in RCC tissues was predicted by TCGA database. Interestingly, overexpressed RMRP observed in RCC cells could be also blocked upon the administration of ropivacaine. Likewise, RMRP knockdown further strengthened ropivacaine-mediated tumor suppressive effects on RCC cells. In terms of mechanism, RMRP directly interacted with EZH2, thereby modulating the histone methylation of CCDC65 to silence its expression. Moreover, ropivacaine inhibited tumor growth in mice bearing RCC tumor through regulating RMRP/EZH2/CCDC65 axis. In sum up, our work revealed that ropivacaine suppressed capacities of RCC cell viability, migration and invasion through modulating the RMRP/EZH2/CCDC65 axis, which laid the experimental foundation of ropivacaine for clinical application in the future.

Brusatol enhances MEF2A expression to inhibit RCC progression through the Wnt signalling pathway in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most aggressive subtype of kidney tumour with a poor prognosis and an increasing incidence rate worldwide. Brusatol, an essential active ingredient derived from Brucea javanica, exhibits potent antitumour properties. Our study aims to explore a novel treatment strategy for RCC patients. We predicted 37 molecular targets of brusatol based on the structure of brusatol, and MEF2A (Myocyte Enhancer Factor 2A) was selected as our object through bioinformatic analyses. We employed various experimental techniques, including RT-PCR, western blot, CCK8, colony formation, immunofluorescence, wound healing, flow cytometry, Transwell assays and xenograft mouse models, to investigate the impact of MEF2A on RCC. MEF2A expression was found to be reduced in patients with RCC, indicating a close correlation with MEF2A deubiquitylation. Additionally, the protective effects of brusatol on MEF2A were observed. The overexpression of MEF2A inhibits RCC cell proliferation, invasion and migration. In xenograft mice, MEF2A overexpression in RCC cells led to reduced tumour size compared to the control group. The underlying mechanism involves the inhibition of RCC cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) through the modulation of Wnt/β-catenin signalling. Altogether, we found that MEF2A overexpression inhibits RCC progression by Wnt/β-catenin signalling, providing novel insight into diagnosis, treatment and prognosis for RCC patients.

Corosolic acid inhibits metastatic response of human renal cell carcinoma cells by modulating ERK/MMP2 signaling.

Corosolic acid (CA), a plant-derived pentacyclic triterpenoid, has potent anti-inflammatory, anti-metabolic, and anti-neoplastic actions against a variety of human cancers. However, the specific mechanism by which CA inhibits the progression of renal cell carcinoma (RCC) is yet unclear. We found that CA (≤8 μM) had no influence on either the growth or viability of RCC cell lines (786-O, ACHN, and Caki-1) or normal HK2 cells. However, in a dose-dependent manner, CA prevented the invasion and migration of RCC cells. Human protease array analysis showed that CA reduced MMP2 expression. At increasing concentrations of CA, the expression of MMP2 was dose-dependently reduced, as shown by western blot and RT-PCR analyses as well as immunofluorescence staining. CA also stimulated ERK1/2 phosphorylation in 786-O and Caki-1 cells. Transfection of CA-treated RCC cells with siRNA-ERK restored MMP2 protein expression and the motility and invasion capabilities of RCC cells. Molecular docking study results showed that CA and MMP2 interact strongly. These findings elucidate the mechanism by which CA prevents RCC cells from migrating and invading, and these findings indicate that CA may be a potential anti-metastatic therapy for RCC.

HOXD8 suppresses renal cell carcinoma growth by upregulating SHMT1 expression.

Amplification of amino acids synthesis is reported to promote tumorigenesis. The serine/glycine biosynthesis pathway is a reversible conversion of serine and glycine catalyzed by cytoplasmic serine hydroxymethyltransferase (SHMT)1 and mitochondrial SHMT2; however, the role of SHTM1 in renal cell carcinoma (RCC) is still unclear. We found that low SHMT1 expression is correlated with poor survival of RCC patients. The in vitro study showed that overexpression of SHMT1 suppressed RCC proliferation and migration. In the mouse tumor model, SHMT1 significantly retarded RCC tumor growth. Furthermore, by gene network analysis, we found several SHMT1-related genes, among which homeobox D8 (HOXD8) was identified as the SHMT1 regulator. Knockdown of HOXD8 decreased SHMT1 expression, resulting in faster RCC growth, and rescued the SHMT1 overexpression-induced cell migration defects. Additionally, ChIP assay found the binding site of HOXD8 to SHMT1 promoter was at the -456~-254 bp region. Taken together, SHMT1 functions as a tumor suppressor in RCC. The transcription factor HOXD8 can promote SHMT1 expression and suppress RCC cell proliferation and migration, which provides new mechanisms of SHMT1 in RCC tumor growth and might be used as a potential therapeutic target candidate for clinical treatment.

MiR-183-5p promotes renal cell carcinoma metastasis by targeting TET1.

Ten-eleven translocation 1 (TET1) is a member of the DNA demethylase family that regulates the methylation level of the genome. Dysregulation of TET1 in renal cell carcinoma (RCC) may be associated with RCC progression, but the mechanism of TET1 down-regulation in RCC is not yet known. MiR-183-5p is up-regulated in various tumor tissues and acts as an oncogene. We used Transwell and wound healing assays to test cell invasion and migration. To investigate DNA methylation, we used dot blot, which indicates TET1 enzyme activity. We verified the binding of miR-183-5p and TET1 3'-UTR (untranslated region) using dual-luciferase reporter assay. Our study demonstrated, for the first time, that miR-183-5p can directly repress TET1 expression in RCC. We observed a significant decrease in TET1 expression in RCC specimens, as reported in the literature, and a significant decrease in the concentration of 5hmC in RCC. By aligning the microRNA with a database and using the luciferase reporter gene method, we found that miR-183-5p can inhibit luciferase activity by binding to 453-459 bp of TET1 3'-UTR, leading to inhibition of TET1 expression. Furthermore, down-regulation of TET1 inhibited miR-200c expression and promoted RCC cell invasion and migration. Our findings suggest that in RCC, increased expression of miR-183-5p inhibits the expression of TET1, which in turn inhibits the expression of miR-200c and E-cadherin, both of which are associated with cell adhesion. This leads to the promotion of cell invasion and migration.

Synergistic anti-tumour activity of sorafenib in combination with pegylated resveratrol is mediated by Akt/mTOR/p70S6k-4EBP-1 and c-Raf7MEK/ERK signaling pathways

IntroductionTo investigate the inhibitory effect of sorafenib combined with PEGylated resveratrol on renal cell carcinoma (RCC) and its potential mechanism. MethodsMTT assay was used to detect the inhibitory effects of PEGylated resveratrol and sorafenib alone or combination on proliferation of RCC cells. Scratch and transwell assays were performed to examine the effects on the in vitro migration and invasion of RCC cells, respectively. The anti-tumor activity as well as splenic lymphocyte proliferation of the combination therapy was evaluated in the RCC xenograft mouse model. Western blotting method was used to detect changes in proteins involved in the antitumor efficacy related signaling pathways. ResultsInhibitory effects of PEGylated resveratrol combined with sorafenib incubation on the proliferation of Renca cells was synergistically enhanced compared with the mono-incubation group (both P < 0.01, CI < 1). Scratch and transwell assays revealed that combined incubation could significantly inhibit the migration and invasion of 786-O cells in vitro. Combined PEGylated resveratrol with sorafenib could significantly inhibit the growth of Renca renal carcinoma in mice with the tumor growth inhibition (TGI) of 85.5% and one achieved complete remission on D14, while the two monotherapies were both below 43% on D14, suggesting that current combination may have synergistic anti-renal carcinoma activity. Compared with the control group, PEGylated resveratrol combined with sorafenib in vivo promoted the proliferation of unactivated splenic lymphocytes and the proliferation of lymphocytes stimulated with concanavalin A and lipopolysaccharide. Western blotting results showed that combination therapy may suppress the growth of renal cell carcinoma by inhibiting AKT/mTOR/p70S6k-4EBP-1 and c-Raf7MEK/ERK signaling pathways. ConclusionPEGylated resveratrol combined with sorafenib can achieve synergistic anti-RCC activity, and the mechanism may be related to the inhibition of Akt/mTOR/p70S6k-4EBP-1 and c-Raf7MEK/ERK signaling pathways.

Hsa_circ_0057105 modulates a balance of epithelial-mesenchymal transition and ferroptosis vulnerability in renal cell carcinoma.

The incidence of renal cell carcinoma (RCC) has increased in recent years. Metastatic RCC is common and remains a major cause of mortality. A regulatory role for circular RNAs (circRNAs) in the occurrence and progression of RCC has been identified, but their function, molecular mechanisms, and potential clinical applications remain poorly understood. High-throughput RNA sequencing was used to explore the differential expression of circRNAs and their related pathways in RCC patients. Transwell and CCK-8 assays were used to assess the function of hsa_circ_0057105 in RCC cells. The clinical relevance of hsa_circ_0057105 was evaluated in a cohort of RCC patients. The hsa_circ_0057105 regulatory axis was defined using RNA pull-down, luciferase reporter assays, and fluorescence in situ hybridization assays, and the in vivo effect of hsa_circ_0057105 was validated using animal experiments. Single-sample gene set enrichment analysis and correlation analysis of RNA-seq data showed that hsa_circ_0057105 was potentially oncogenic and may serve to regulate epithelial-mesenchymal transition (EMT) activation in RCC. Hsa_circ_0057105 expression was associated with advanced TNM stages and was an independent prognostic factor for poor RCC patient survival. Phenotypic studies show that hsa_circ_0057105 can enhance the migration and invasion abilities of RCC cells. Further, hsa_circ_0057105 was shown to inhibit the expression of miR-577, a miRNA that regulated the expression of both COL1A1, which induced EMT activation, and VDAC2, which modulated ferroptosis sensitivity. The dual regulatory roles of hsa_circ_0057105 on EMT and ferroptosis sensitivity were verified using rescue experiments. Animal studies confirmed that hsa_circ_0057105 increased the metastatic ability and ferroptosis sensitivity of RCC cells in vivo. In RCC, hsa_circ_0057105 regulates COL1A1 and VDAC2 expression through its sponge effect on miR-577, acting like a 'double-edged sword'. These findings provide new insight into the relationship between EMT and ferroptosis in RCC and provide potential biomarkers for RCC surveillance and treatment.

Ursolic acid-downregulated long noncoding RNA ASMTL-AS1 inhibits renal cell carcinoma growth via binding to HuR and reducing vascular endothelial growth factor expression.

It has been reported ursolic acid (UA), one of the naturally abundant pentacyclic triterpenes, possesses a wide range of biological activities including anti-inflammatory, anti-atherosclerotic, and anticancer properties. Renal cell carcinoma (RCC) is a severe malignancy due to its asymptomatically spreading ability. Our study aimed to investigate the role and molecular mechanism of UA in RCC. RCC cell proliferation, migration, invasion, and angiogenesis were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Transwell, and tube formation assays. Xenograft tumor models were established to confirm the role of UA and long noncoding RNA ASMTL antisense RNA 1 (ASMTL-AS1) in vivo. Expression levels of ASMTL-AS1 and vascular endothelial growth factor (VEGF) were measured using reverse transcriptase quantitative polymerase chain reaction and western blot analysis. The interaction probabilities of ASMTL-AS1 or VEGF with RNA-binding protein human antigen R (HuR) were verified by RNA immunoprecipitation experiment. The half-life period of messenger RNA (mRNA) was determined using actinomycin D. UA inhibited RCC cell growth in vivo and tumorigenesis in vitro. ASMTL-AS1 was highly expressed in RCC cell lines. Of note, UA downregulated ASMTL-AS1 expression, and overexpressed ASMTL-AS1 reversed the UA-induced suppression on RCC cell migration, invasion, and tube formation. Additionally, ASMTL-AS1 bound to HuR to maintain the stability of VEGF mRNA. Rescue experiments showed that the suppressed malignancy of RCC cells mediated by ASMTL-AS1 knockdown was counteracted by overexpression of VEGF. Moreover, silenced ASMTL-AS1 inhibited RCC tumor growth and metastasis in vivo. The obtained data suggest UA as a promising therapeutic agent to attenuate the development of RCC via regulation of the targeted molecules.

CircZBTB44 promotes renal carcinoma progression by stabilizing HK3 mRNA structure

CircZBTB44 (hsa_circ_0002484) has been identified to be upregulated in renal cell carcinoma (RCC) tissues, while its role and contribution in RCC remain elusive. We confirmed the overexpression of circZBTB44 in RCC cells compared to normal kidney cell HK-2. CircZBTB44 knockdown suppressed the viability, proliferation, and migration of RCC cells and inhibited tumorigenesis in xenograft mouse models. Heterogeneous Nuclear Ribonucleoprotein C (HNRNPC) and Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) are two RNA binding proteins of circZBTB44. HNRNPC facilitated the translocation of circZBTB44 from nuclei to cytoplasm via m6A modification, facilitating the interaction of IGF2BP3 and circZBTB44 in the cytoplasm of RCC cells. Furthermore, circZBTB44 upregulated Hexokinase 3 (HK3) expression by binding to IGF2BP3 in RCC cells. HK3 exerted oncogenic effects on RCC cell malignant behaviors and tumor growth. In the co-culture of RCC cells with macrophages, circZBTB44 promoted M2 polarization of macrophages by up-regulating HK3. In summary, HNRNPC mediated circZBTB44 interaction with IGF2BP3 to up-regulate HK3, promoting the proliferation and migration of RCC cells in vitro and tumorigenesis in vivo. The results of the study shed new light on the targeted therapy of RCC.

ORP8 inhibits renal cell carcinoma progression by accelerating Stathmin1 degradation and microtubule polymerization

ORP8 has been reported to suppress tumor progression in various malignancies. However, the functions and underlying mechanisms of ORP8 are still unknown in renal cell carcinoma (RCC).Here, decreased expression of ORP8 was detected in RCC tissues and cell lines. Functional assays verified that ORP8 suppressed RCC cell growth, migration, invasion, and metastasis. Mechanistically, ORP8 attenuated Stathmin1 expression by accelerating ubiquitin-mediated proteasomal degradation and led to an increase in microtubule polymerization. Lastly, ORP8 knockdown partly rescued microtubule polymerization, as well as aggressive cell phenotypes induced by paclitaxel. Our findings elucidated that ORP8 suppressed the malignant progression of RCC by increasing Stathmin1 degradation and microtubule polymerization, thus suggesting that ORP8 might be a novel target for the treatment of RCC.

Abstract 3702: Serine promotes aggressive phenotype in renal cancer

Abstract Tumor cells are known to have increased demand for nutrients to support proliferation. Among the most highly utilized nutrients by tumor cells are nonessential amino acids (NEAAs). While the role of NEAAs in supporting tumor growth is well-established, their role in supporting aggressive phenotypes such as migration and invasion is poorly understood. Yet, the major cause of morbidity from malignancies such as renal cell carcinoma (RCC) is metastasis. Through an unbiased approach, we assayed the role of NEAAs in promoting the migration of RCC cells. We demonstrate that exogenous serine and glutamine are essential and sufficient to support aggressive phenotypes in RCC. Moreover, the availability of both NEAAs is critical for the expression of the proinvasive transcription factor SNAIL. Our data converge on the role of these two NEAAs in supporting the translation of this factor. Perturbations that limit the availability and/or synthesis of either result in translational reprogramming through the integrated stress response (ISR) that leads to loss of SNAIL1 expression and attenuates aggressive phenotypes. Our findings associate nutrient status to the ISR including ER stress. Collectively, our study highlights new insights for NEAA metabolism in supporting aggressive tumor phenotypes and could reveal novel approaches to mitigate metastasis by targeting NEAA availability and/or utilization. Citation Format: Suman Karki, Anirban Kundu, Garret Brinkley, Hyeyoung Nam, Kayla Goliwas, Jessy Deshane, Sunil Sudarshan. Serine promotes aggressive phenotype in renal cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3702.

KLF9 inhibits the proliferation, invasion, and migration of renal cell carcinoma through the SDF-1/CXCR4 axis.

Altered Krüppel-like factor 9 (KLF9) expression can regulate the progression of several cancers, including renal cell carcinoma (RCC). This study was conducted to investigate the role of KLF9 in the proliferation, invasion, and migration of RCC cells via regulation of stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4). The expression patterns of KLF9, SDF-1, and CXCR4 in the experimental cell lines were determined by real-time quantitative polymerase chain reaction and Western blotting. After transfection of the KLF9 siRNA and KLF9 pcDNA, cell proliferation, invasion, and migration were evaluated by experiments including cell counting kit-8, colony formation, and Transwell assays. The binding of KLF9 to the SDF-1 promoter was analyzed by chromatin immunoprecipitation and dual-luciferase assay. The rescue experiment was performed using the recombinant SDF-1 protein and KLF9 pcDNA. KLF9 was downregulated in the RCC cells. KLF9 knockdown induced the proliferation, invasion, and migration of RCC cells, whereas KLF9 overexpression elicited the opposite roles. Mechanically, KLF9 bound to the SDF-1 promoter, repressed SDF-1 transcription, and reduced the SDF-1/CXCR4 expression levels. Activation of the SDF-1/CXCR4 axis attenuated the inhibitory role of KLF9 overexpression in RCC cell growth. Ordinarily, KLF9 suppressed the proliferation, invasion, and migration of RCC cells by repressing the SDF-1/CXCR4 signaling.

CircPTPN12 promotes the progression and sunitinib resistance of renal cancer via hnRNPM/IL-6/STAT3 pathway

Renal cell carcinoma (RCC) is characterized by the difficulties in early diagnosis and the propensity to metastases. For advanced RCC, sunitinib targeted therapy is the clinically recommended first-line drug and the major challenge of sunitinib treatment is adaptive resistance. Therefore, it is imperative to research the mechanisms underlying sunitinib resistance. In this study, we discovered that circPTPN12 was highly expressed in RCC tissues and was associated with poorer clinical outcomes. circPTPN12 could promote the proliferation, migration, invasion, and sunitinib resistance of RCC cells. Mechanistically, circPTPN12 was found to form a complex with hnRNPM, which was involved in the regulation of mRNA processing. The combination with circPTPN12 enhanced the ability of hnRNPM to maintain the stability of IL-6 mRNA and further activated the STAT3 signaling pathway. The study revealed that circPTPN12/hnRNPM/IL-6/STAT3 axis promoted RCC progression and sunitinib resistance, which might be a promising therapeutic target for relieving sunitinib resistance in RCC.

Licochalcone A Suppresses Renal Cancer Cell Proliferation and Metastasis by Engagement of Sp1-Mediated LC3 Expression

Licochalcone A (LicA) is a strong anti-inflammatory, antioxidant, and anticarcinogenic substance that is useful against a variety of human malignancies. However, its precise mechanism in mediating the development of renal cell carcinoma (RCC) is not entirely understood. In this work, LicA was discovered to limit cell growth and survival, induce cell cycle arrest, promote autophagy and LC3B expression, and inhibit the migration and invasion of RCC cells. In addition, the proliferation, migration, and invasion inhibited by LicA were restored by the transfection of siRNA-LC3. The effects of LC3B on the metastatic phenotype of ACHN cells was enhanced with the overexpression of Sp1 or suppressed by inhibiting the phosphorylation of FAK and Src. Finally, LicA showed antitumor properties against RCC in an in vivo xenograft model. In conclusion, our study demonstrated the chemotherapeutic potential of LicA on proliferation, migration, invasion, and autophagy through the activation of LC3B expression, ultimately modulating FAK/Src signaling pathway-mediated Sp1 expression. These findings illustrate the novel role and molecular mechanisms of LicA against RCC cells.

Tumor Cell-Derived Exosomal circ-PRKCI Promotes Proliferation of Renal Cell Carcinoma via Regulating miR-545-3p/CCND1 Axis

Renal cell carcinoma (RCC) originates from the epithelial cells of the renal tubules and has a high degree of malignancy and heterogeneity. Recent studies have found that exosomes regulate intercellular communication via transferring various bioactive molecules, such as circular RNAs (circRNAs), which are critical for cancer progression. However, the role of tumor cell-derived exosomal circRNAs in RCC remains unclear. In this study, we reported the high expression of circ-PRKCI in RCC tissues and serum exosomes. We also found that circ-PRKCI could be transferred exosomally from highly malignant RCC cells to relatively less malignant RCC cells. Tumor cell-derived exosomal circ-PRKCI promoted the proliferation, migration, and invasion of RCC cells, while inhibiting their apoptosis. Mechanistically, we found that circ-PRKCI promoted the proliferation of RCC via the miR-545-3p/CCND1 signaling pathway. Our study is the first to report the potential mechanisms of tumor cell-derived exosomal circ-PRKCI in RCC. In conclusion, this study will provide a new understanding about the molecular mechanisms of RCC progression.

BTG2 suppresses renal cell carcinoma progression through N6-methyladenosine.

The biological functions of N6-methyladenosine (m6A) modification of mRNA have recently received a great deal of attention. In previous studies, m6A methylation modification has been shown to regulate mRNA fate and to be crucial for the progression and development of tumors. BTG2 (B-cell translocation gene 2) is a member of BTG/TOB anti-proliferative protein family. BTG2 could inhibit cell proliferation and migration and regulate the cell cycle progression. In this study, we confirm that BTG2 is frequently down-regulated in renal cell carcinoma (RCC) tissues and its low expression is associated with unfavorable prognosis and decreased m6A level. Moreover, we found that m6A methylation modifies the 5'UTR of BTG2 to promote its mRNA stability by binding to IGF2BP2. It has been shown that CRISPR/dCas13b-METLL3 can specifically increase BTG2 m6A modification to significantly increase its m6A and expression levels. Then m6A hypermethylation in BTG2 mRNA could dramatically inhibit RCC cells proliferation and migration, and induce cells apoptosis. Taken together, our data show that BTG2 functions as a tumor suppressor and is frequently silenced via m6A modification in RCC.