SIRT1 downregulated FGB expression to inhibit RCC tumorigenesis by destabilizing STAT3

Therapeutic applications of exercise in neurodegenerative diseases: focusing on the mechanism of SIRT1

Neurodegenerative diseases comprise a group of central nervous system disorders marked by progressive neuronal degeneration and dysfunction. Their pathogenesis is multifactorial, involving oxidative stress, mitochondrial dysfunction, excitotoxicity, and neuroinflammation. Recent research has highlighted the potential of exercise as a non-pharmacological intervention for both the prevention and treatment of these disorders. In particular, exercise has received growing attention for its capacity to upregulate the expression and activity of SIRT1, a critical mediator of neuroprotection via downstream signaling pathways. SIRT1, a key member of the Sirtuin family, is a nicotinamide adenine dinucleotide (NAD +)-dependent class III histone deacetylase. It plays an essential role in regulating cellular metabolism, energy homeostasis, gene expression, and cellular longevity. In the context of neurodegenerative diseases, SIRT1 confers neuroprotection by modulating multiple signaling cascades through deacetylation, suppressing neuronal apoptosis, and promoting neural repair and regeneration. Exercise enhances SIRT1 expression and activity by increasing NAD + synthesis and utilization, improving intracellular redox balance, alleviating oxidative stress-induced inhibition of SIRT1, and thereby promoting its activation. Moreover, exercise may indirectly modulate SIRT1 function by influencing interacting molecular networks. This review summarizes recent advances in the therapeutic application of exercise for neurodegenerative diseases, with a focus on SIRT1 as a central mechanism. It examines how exercise mediates neuroprotection through the regulation of SIRT1 and its associated molecular mechanisms and signaling pathways. Finally, the paper discusses the potential applications and challenges of integrating exercise and SIRT1-targeted strategies in the management of neurodegenerative diseases, offering novel perspectives for the development of innovative treatments and improvements in patients' quality of life.

METTL14-mediated m6A modification of ZFP14 inhibits clear cell renal cell carcinoma progression via promoting STAT3 ubiquitination

Therapeutic options for advanced clear cell renal cell carcinoma (ccRCC) are currently inadequate. Earlier research has shown that the enzyme methyltransferase-like 14 (METTL14) can suppress ccRCC development through the modification of N6-methyladenosine (m6A). This study further explored its complex biological functions and underlying molecular mechanisms. Here, we identified zinc finger protein 14 (ZFP14) as a novel target of METTL14-mediated m6A, and its under-expression was associated with ccRCC tumourigenesis and progression. Detailed investigations revealed that METTL14 interacted directly with the 3' untranslated region of ZFP14 mRNA, promoting m6A modification at two specific sites. These modifications were recognised by the protein insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), which stabilised and enhanced the expression of ZFP14 mRNA. Functionally, the METTL14/ZFP14 axis suppressed in vitro growth, migration and invasiveness and in vivo proliferation and metastasis of ccRCC cells. ZFP14 potentially regulated numbers of transcripts, among which matrix metalloproteinase 1/3 (MMP1/3) were validated to be under-expressed by ZFP14. Crucially, ZFP14 interacted with the signal transducer and activator of transcription 3 (STAT3), augmenting its K48-linked ubiquitination and destabilising it via the proteasome pathway. Moreover, ZFP14 repressed ccRCC cell in vivo growth and metastasis as well as decreasing MMP1/3 levels by under-expressing STAT3. These observations confirmed that ZFP14 served as both a novel target for METTL14-mediated m6A modification and a significant tumour suppressor in ccRCC, shedding light on the cellular and molecular operations in ccRCC and opening up possibilities for novel therapeutic strategies. KEY POINTS: ZFP14 under-expression is associated with ccRCC tumourigenesis and progression. METTL14-mediated m6A enhances ZFP14 mRNA stability and expression with IGF2BP2 as the reader in ccRCC. ZFP14 promotes the degradation of STAT3 by enhancing its K48-linked ubiquitination, inhibiting ccRCC progression.

The role of acetylation and deacetylation in cancer metabolism

As a hallmark of cancer, metabolic reprogramming adjusts macromolecular synthesis, energy metabolism and redox homeostasis processes to adapt to and promote the complex biological processes of abnormal growth and proliferation. The complexity of metabolic reprogramming lies in its precise regulation by multiple levels and factors, including the interplay of multiple signalling pathways, precise regulation of transcription factors and dynamic adjustments in metabolic enzyme activity. In this complex regulatory network, acetylation and deacetylation, which are important post-translational modifications, regulate key molecules and processes related to metabolic reprogramming by affecting protein function and stability. Dysregulation of acetylation and deacetylation may alter cancer cell metabolic patterns by affecting signalling pathways, transcription factors and metabolic enzyme activity related to metabolic reprogramming, increasing the susceptibility to rapid proliferation and survival. In this review, we focus on discussing how acetylation and deacetylation regulate cancer metabolism, thereby highlighting the central role of these post-translational modifications in metabolic reprogramming, and hoping to provide strong support for the development of novel cancer treatment strategies. KEY POINTS: Protein acetylation and deacetylation are key regulators of metabolic reprogramming in tumour cells. These modifications influence signalling pathways critical for tumour metabolism. They modulate the activity of transcription factors that drive gene expression changes. Metabolic enzymes are also affected, altering cellular metabolism to support tumour growth.

Fibrinogen and tumors

Elevated plasma fibrinogen (Fg) levels consistently correlate with an unfavorable prognosis in various tumor patient cohorts. Within the tumor microenvironment, aberrant deposition and expression of Fg have been consistently observed, interacting with multiple cellular receptors and thereby accentuating its role as a regulator of inflammatory processes. Specifically, Fg serves to stimulate and recruit immune cells and pro-inflammatory cytokines, thereby contributing to the promotion of tumor progression. Additionally, Fg and its fragments exhibit dichotomous effects on tumor angiogenesis. Notably, Fg also facilitates tumor migration through both platelet-dependent and platelet-independent mechanisms. Recent studies have illuminated several tumor-related signaling pathways influenced by Fg. This review provides a comprehensive summary of the intricate involvement of Fg in tumor biology, elucidating its multifaceted role and the underlying mechanisms.

Overexpression of miR-506-3p reversed doxorubicin resistance in drug-resistant osteosarcoma cells

Background and objective: Osteosarcoma is a common primary malignant tumor of bone, and doxorubicin is one of the most widely used therapeutic drugs. While the problem of doxorubicin resistance limits the long-term treatment benefits in osteosarcoma patients. The role of miRNAs and their target genes in osteosarcoma have become increasingly prominent. Currently, there is no report on miR-506-3p reversing doxorubicin resistance by targeting STAT3 in osteosarcoma. The purpose of this study was to investigate the molecular mechanism that overexpression of miR-506-3p reverses doxorubicin resistance in drug-resistant osteosarcoma cells. Methods: Doxorubicin-resistant osteosarcoma cells (U-2OS/Dox) were constructed by intermittent stepwise increasing stoichiometry. The target genes of miR-506-3p were predicted by bioinformatics approach and the targeting relationship between miR-506-3p and STAT3 was detected using dual luciferase reporter assay. U-2OS/Dox cells were treated with miR-506-3p overexpression and STAT3 silencing respectively. Then Western blot and RT-qPCR were used to detect the protein and mRNA expression levels of JAK2/STAT3 signaling pathway, drug-resistant and apoptotic associated molecules. The migration and invasion were assessed by cell scratch assay and transwell assay. The cell proliferative viability and apoptosis were investigated by CCK8 assay and flow cytometry assay. Results: U-2OS/Dox cells were successfully constructed with a 14.4-fold resistance. MiR-506-3p is directly bound to the 3'-UTR of STAT3 mRNA. Compared with U-2OS cells, the mRNA expression of miR-506-3p was reduced in U-2OS/Dox cells. Overexpression of miR-506-3p decreased the mRNA expression levels of JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and decreased the protein expression levels of p-JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and conversely increased Bax expression. It also inhibited the proliferation, migration and invasion of U-2OS/Dox cells and promoted cells apoptosis. The results of STAT3 silencing experiments in the above indicators were consistent with that of miR-506-3p overexpression. Conclusion: Overexpression of miR-506-3p could inhibit the JAK2/STAT3 pathway and the malignant biological behaviors, then further reverse doxorubicin resistance in drug-resistant osteosarcoma cells. The study reported a new molecular mechanism for reversing the resistance of osteosarcoma to doxorubicin chemotherapy and provided theoretical support for solving the clinical problems of doxorubicin resistance in osteosarcoma.

Mesenchymal Stem Cells Accelerate Recovery of Acetic Acid-Induced Chronic Gastric Ulcer by Regulating Ekt/Akt/TRIM29 Axis

Chronic gastric ulcer (CGU), a prevalent digestive disease, has a high incidence and is seriously harmful to human health. Mesenchymal stem cells (MSCs) have been proven to have beneficial therapeutic effects in many human diseases. Here, a CGU model induced by acetic acid in mice was used to evaluate the repair effects and potential mechanism of human umbilical cord-derived MSCs (hUC-MSCs) and hUC-MSCs derived conditioned medium (hUC-MSC-CM). We found that hUC-MSCs and hUC-MSC-CM treatment significantly repaired morphological characteristics of CGU, improved proliferation and decreased apoptosis of gastric cells, and promoted the generation of new blood vessels in granulation tissues. In addition, we could detect the homing of MSCs in gastric tissue, and MSCs may differentiate into Lgr5-positive cells. As well as this, in vitro experiments showed that hUC-MSC-CM could promote cell proliferation, stimulate cell cycle progression, and reduce the incidence of apoptosis. The transcriptome of cells and the iTRAQ proteome of gastric tissues suggest that MSCs may play a therapeutic role by increasing the expression of TRIM29. Additionally, it was found that knocking down TRIM29 significantly decreased the ameliorative effects of hUC-MSC-CM on cell apoptosis. As a result of further molecular experiments, it was found that TRIM29 is capable of phosphorylating Erk/Akt in specific cell type. As a whole, it appears that hUC-MSCs can be an effective therapeutic approach for promoting gastric ulcer healing and may exert therapeutic effects in the form of paracrine and differentiation into gastric cells.

Proliferation, migration and phenotypic transformation of VSMC induced via Hcy related to up-expression of WWP2 and p-STAT3

To provide a theoretical basis for the prevention and treatment of atherosclerosis (AS), the current study aimed to investigate the mechanism underlying the effect of homocysteine (Hcy) on regulating the proliferation, migration and phenotypic transformation of vascular smooth muscle cells (VSMC) via sirtuin-1 (SIRT1)/signal transducer and activator of transcription 3 (STAT3) through Nedd4-like E3 ubiquitin-protein ligase WWP2 (WWP2). Here, Based on the establishment of ApoE-/- mouse models of high Hcy As and the model of Hcy stimulation of VSMC in vitro to observe the interaction between WWP2 and STAT3 and its effect on the proliferation, migration, and phenotypic transformation of Hcy-induced VSMC, which has not been previously reported. This study revealed that WWP2 could promote the proliferation, migration, and phenotype switch of Hcy-induced VSMC by up-regulating the phosphorylation of SIRT1/STAT3 signaling. Furthermore, Hcy might up-regulate WWP2 expression by inhibiting histone H3K27me3 expression through up-regulated UTX. These data suggest that WWP2 is a novel and important regulator of Hcy-induced VSMC proliferation, migration, and phenotypic transformation.

Insights on the molecular mechanisms of cytotoxicity induced by AS1411 linked to folate-functionalized DNA nanocages in cancer cells

Self-assembled multivalent DNA nanocages are an emerging class of molecules useful for biomedicine applications. Here, we investigated the molecular mechanisms of cytotoxicity induced by AS1411 free aptamer, AS1411-linked nanocages (Apt-NCs) and nanocages harboring both folate and AS1411 functionalization (Fol-Apt-NCs) in HeLa and MDA-MB-231 cancer cell lines. The three treatments showed different cytotoxic efficacy and Fol-Apt-NCs resulted the most effective in inhibiting cell proliferation and inducing apoptotic pathways and ROS activation in both HeLa and MDA-MB-231 cells. RNA-seq analysis allowed to identify biological functions and genes altered by the various treatments, depending on the AS1411 route of intracellular entry, highlighting the different behavior of the two cancer cell lines. Notably, Fol-Apt-NCs altered the expression of a subset of genes associated to cancer chemoresistance in MDA-MB-231, but not in HeLa cells, and this may explain the increased chemosensitivity to drugs delivered through DNA nanocages of the triple-negative breast cancer cells.

Protein acetylation and related potential therapeutic strategies in kidney disease

Kidney disease can be caused by various internal and external factors that have led to a continual increase in global deaths. Current treatment methods can alleviate but do not markedly prevent disease development. Further research on kidney disease has revealed the crucial function of epigenetics, especially acetylation, in the pathology and physiology of the kidney. Histone acetyltransferases (HATs), histone deacetylases (HDACs), and acetyllysine readers jointly regulate acetylation, thus affecting kidney physiological homoeostasis. Recent studies have shown that acetylation improves mechanisms and pathways involved in various types of nephropathy. The discovery and application of novel inhibitors and activators have further confirmed the important role of acetylation. In this review, we provide insights into the physiological process of acetylation and summarise its specific mechanisms and potential therapeutic effects on renal pathology.

TTC13 expression and STAT3 activation may form a positive feedback loop to promote ccRCC progression

Background

Renal cell carcinoma (RCC) originates from renal tubular epithelial cells and is mainly classified into three histological types, including clear cell renal cell carcinoma (ccRCC) which accounts for about 75% of all kidney cancers and is characterized by its strong invasiveness and poor prognosis. Hence, it is imperative to understand the mechanisms underlying the occurrence and progression of ccRCC to identify effective biomarkers for the early diagnosis and the prognosis prediction.

Methods

The mRNA level of TTC13 was quantified by RT-PCR, while the protein level was determined by western blot and immunohistochemistry (IHC) staining. Cell proliferation was measured by cck-8, and cell apoptosis was detected by flow cytometry. The binding of STAT3 to the promoter region of TTC13 was determined by the luciferase reporter assay and chip experiments. STAT3 nuclear translocation was assessed by immunofluorescence staining.

Results

We found that TTC13 was up-regulated in ccRCC, and TTC13 promoted cell proliferation as well as inhibited cell apoptosis and autophagy of ccRCC through wnt/β-catenin and IL6-JAK-STAT3 signaling pathways. Furthermore, TTC13 might play a role in the immune infiltration and immunotherapy of ccRCC. Mechanistically, STAT3 activated the transcription of TTC13 gene.

Conclusions

STAT3 directly regulated TTC13 expression through a positive feedback loop mechanism to promote ccRCC cell proliferation as well as reduce cell apoptosis and autophagy. These findings suggested new and effective therapeutic targets for more accurate and personalized treatment strategies.

Exploring the material basis and mechanism of action of clinacanthus nutans in treating renal cell carcinoma based on metabolomics and network pharmacology

BACKGROUND

Clinacanthus nutans (for abbreviation thereafter) is often used as medicine in the form of fresh juice in the folk to treat many kinds of cancers, including renal cell carcinoma (RCC). It is speculated that its active ingredient may have heat sensitivity, but there are currently no reports on this aspect. Therefore, based on the folk application for fresh juice of C nutans, this study used metabonomics and network pharmacology to explore the material basis and mechanism of action of C nutans against RCC.

METHODS

Firstly, untargeted metabolomics profiling was performed by Liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry to screen the metabolites down-regulated by heat in the extract of C nutans. Secondly, we collected the targets of metabolites in the Swiss Target Prediction platform. In addition, the targets of RCC were obtained in the GeneCards database. The "component-target-disease" network was established by Cytoscape3.9.0 software. Then we constructed a protein-protein interaction network in the STRING network platform to screen core targets. The gene ontology and kyoto encyclopedia of genes and genomes enrichment analysis of core targets were carried out to predict the relevant pathway of C nutans in the treatment of RCC. Finally, the molecular docking verification of the core targets were carried out.

RESULTS

In this study, 35 potential active ingredients and 125 potential targets were obtained. And the core targets were Cellular tumor antigen p53, Signal transducer and activator of transcription 3, and so on. Then, 48 biological processes, 30 cell components, and 36 molecular functions were obtained by gene ontology enrichment analysis. Besides, 44 pathways were obtained by Kyoto encyclopedia of genes and genomes enrichment analysis, including Pathway in cancer, PI3K-Akt signal pathway, P53 signal pathway, and so on. The docking model between the core target and its corresponding components was stable.

CONCLUSION

This research is based on the folk application of C nutans, showed its potential active ingredients by metabonomics, and predicted the potential mechanism of C nutans in the treatment of RCC by network pharmacology. It provides new references for follow-up research and new drug development.

Single-Cell Sequencing Identifies the Heterogeneity of CD8+ T Cells and Novel Biomarker Genes in Hepatocellular Carcinoma

CD8+ T cells are required for the establishment of antitumor immunity, and their substantial infiltration is associated with a good prognosis. However, CD8+ T cell subsets in the tumor microenvironment may play distinct roles in tumor progression, prognosis, and immunotherapy. In this study, we used the scRNA-seq data of hepatocellular carcinoma (HCC) to reveal the heterogeneity of different CD8+ T cell subsets. The scRNA-seq data set GSE149614 was obtained from the GEO database, and the transcriptome and sample phenotypic data of TCGA-LIHC were obtained from the TCGA database. CD8+ T cell subtypes and metabolic gene sets were obtained from published reports. The data processing and analysis of CD8+ T cell groups was performed by R language. The PPI network was constructed to obtain the hub genes, and the KM survival curve of the hub genes was further plotted to determine the hub genes with differences in survival. CD8+ T cells in HCC were divided into 7 subsets, and the cytotoxic CD8 T cells 4 subset showed considerable differences between the TP53-mutant and nonmutant groups, as well as between different degrees of cirrhosis, HCC grades, stages, ages, and body weights. Cytotoxic CD8 T cells 4 differential genes were analyzed by TCGA-LIHC data and single-cell sequencing data set. 10 hub genes were found: FGA, ApoA1, ApoH, AHSG, FGB, HP, TTR, TF, HPX, and APOC3. Different subsets of CD8+ T cells were found to contribute to heterogeneous prognosis and pathway activity in HCC. Alterations in the cytotoxic and immune checkpoint gene expression during CD8+ T cell differentiation were also identified. We found that cytotoxic CD8 T cells 4 is closely associated with survival and prognosis of HCC and identified four differential genes that can be used as biological markers for survival, prognosis, and clinically relevant characteristics of HCC. Results of this study could help finding targets for immunotherapy of HCC and aid in the accelerated development of immunotherapy for HCC.

The Histone Acetyltransferase MOF Regulates SIRT1 Expression to Suppress Renal Cell Carcinoma Progression

BACKGROUND

Renal cell carcinoma (RCC) is one of the most common and lethal human urological malignancies around the world. Although many advancements in diagnostic and therapeutic strategies have been acquired, the prognosis of patients with metastatic RCC was poor. Thus, there is an urgent need to understand the molecular mechanism of RCC.

METHODS

The quantitative real-time PCR (qRT-PCR) was used to detect the RNA expression of MOF in human RCC tissues and cell lines. The protein expression of MOF was analyzed with immunohistochemistry (IHC) and Western blot. To understand the regulatory mechanism of MOF in liver cancer, ChIP-qPCR assay and dual-luciferase assay were performed. Moreover, a series of in vivo and in vitro experiments were conducted to evaluate the effect of MOF on renal cell carcinoma progression.

RESULTS

In the present study, we found that Males absent on the first (MOF), a histone acetyltransferase involved in transcription activation, was significantly decreased in both RCC tissues and RCC cells compared to normal tissues and non-cancer cells. Moreover, MOF downregulation was associated with advanced histological grade, pathologic stage and distant metastasis of RCC patients. Ectopic expression of MOF could significantly attenuate cell proliferation and promote cell apoptosis. Besides, MOF overexpression also suppressed migration of RCC cells through inhibiting epithelial-mesenchymal transition (EMT). Importantly, the inhibition of tumor growth by MOF was further confirmed by in vivo studies. Mechanism dissection revealed that MOF could transcriptionally upregulate the expression of SIRT1, leading to attenuated STAT3 signaling, which was involved in cell proliferation and migration. Moreover, SIRT1 knockdown could restore the biological function induced by MOF overexpression.

CONCLUSIONS

Our findings indicated that MOF serves as a tumor suppressor via regulation of SIRT1 in the development and progression of RCC, and MOF might be a potent biomarker for diagnosis and prognosis prediction of RCC patients.

Integrative Analysis of Epigenome and Transcriptome Data Reveals Aberrantly Methylated Promoters and Enhancers in Hepatocellular Carcinoma

DNA methylation is a key transcription regulator, whose aberration was ubiquitous and important in most cancers including hepatocellular carcinoma (HCC). Whole-genome bisulfite sequencing (WGBS) was conducted for comparison of DNA methylation in tumor and adjacent tissues from 33 HCC patients, accompanying RNA-seq to determine differentially methylated region-associated, differentially expressed genes (DMR-DEGs), which were independently replicated in the TCGA-LIHC cohort and experimentally validated via 5-aza-2-deoxycytidine (5-azadC) demethylation. A total of 9,867,700 CpG sites showed significantly differential methylation in HCC. Integrations of mRNA-seq, histone ChIP-seq, and WGBS data identified 611 high-confidence DMR-DEGs. Enrichment analysis demonstrated activation of multiple molecular pathways related to cell cycle and DNA repair, accompanying repression of several critical metabolism pathways such as tyrosine and monocarboxylic acid metabolism. In TCGA-LIHC, we replicated about 53% of identified DMR-DEGs and highlighted the prognostic significance of combinations of methylation and expression of nine DMR-DEGs, which were more efficient prognostic biomarkers than considering either type of data alone. Finally, we validated 22/23 (95.7%) DMR-DEGs in 5-azadC-treated LO2 and/or HepG2 cells. In conclusion, integration of epigenome and transcriptome data depicted activation of multiple pivotal cell cycle-related pathways and repression of several metabolic pathways triggered by aberrant DNA methylation of promoters and enhancers in HCC.

Deacetylation of Transcription Factors in Carcinogenesis

Reversible Nε-lysine acetylation/deacetylation is one of the most common post-translational modifications (PTM) of histones and non-histone proteins that is regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). This epigenetic process is highly involved in carcinogenesis, affecting histone and non-histone proteins' properties and their biological functions. Some of the transcription factors, including tumor suppressors and oncoproteins, undergo this modification altering different cell signaling pathways. HDACs deacetylate their targets, which leads to either the upregulation or downregulation of proteins involved in the regulation of cell cycle and apoptosis, ultimately influencing tumor growth, invasion, and drug resistance. Therefore, epigenetic modifications are of great clinical importance and may constitute a new therapeutic target in cancer treatment. This review is aimed to present the significance of HDACs in carcinogenesis through their influence on functions of transcription factors, and therefore regulation of different signaling pathways, cancer progression, and metastasis.

Targeting Canonical and Non-Canonical STAT Signaling Pathways in Renal Diseases

Signal transducer and activator of transcription (STAT) plays an essential role in the inflammatory reaction and immune response of numerous renal diseases. STATs can transmit the signals of cytokines, chemokines, and growth factors from the cell membrane to the nucleus. In the canonical STAT signaling pathways, upon binding with their cognate receptors, cytokines lead to a caspase of Janus kinases (JAKs) and STATs tyrosine phosphorylation and activation. Besides receptor-associated tyrosine kinases JAKs, receptors with intrinsic tyrosine kinase activities, G-protein coupled receptors, and non-receptor tyrosine kinases can also activate STATs through tyrosine phosphorylation or, alternatively, other post-translational modifications. Activated STATs translocate into the nucleus and mediate the transcription of specific genes, thus mediating the progression of various renal diseases. Non-canonical STAT pathways consist of preassembled receptor complexes, preformed STAT dimers, unphosphorylated STATs (U-STATs), and non-canonical functions including mitochondria modulation, microtubule regulation and heterochromatin stabilization. Most studies targeting STAT signaling pathways have focused on canonical pathways, but research extending into non-canonical STAT pathways would provide novel strategies for treating renal diseases. In this review, we will introduce both canonical and non-canonical STAT pathways and their roles in a variety of renal diseases.

Role of SIRT1/AMPK signaling in the proliferation, migration and invasion of renal cell carcinoma cells

Renal cell carcinoma (RCC) is a lethal urologic tumor commonly seen in men that best responds to partial nephrectomy. An enhanced understanding of the molecular pathogenesis of RCC can broaden treatment options and tumor prevention strategies. Sirtuin 1 (SIRT1) is a NAD+‑dependent deacetylase that regulates several bioactive substances, and the present study aimed to identify the role of SIRT1/AMP‑activated protein kinase (AMPK) signaling in RCC progression. SIRT1 expression was detected in 100 patients with RCC using tissue microarray immunohistochemistry. SIRT1‑knockdown and overexpression were performed via RNA interference and plasmid transfection. Inhibition of AMPK was used for the phenotypic rescue assays to verify whether AMPK was a downstream target of SIRT1. Reverse transcription‑quantitative PCR was performed to verify transfection efficiency. Transwell, MTT and flow cytometry apoptosis assays were performed to evaluate the migration, invasion, proliferation and early apoptosis level of RCC cells. SIRT1 and AMPK protein expression in human RCC tissues and cell lines (786‑O and ACHN) was detected using western blotting and immunofluorescence staining. The current results, combined with data from The Cancer Genome Atlas database, revealed that SIRT1 expression in RCC tissues was downregulated compared with in adjacent normal tissues. Additionally, high SIRT1 expression was associated with an improved prognosis in patients with RCC. Overexpression of SIRT1 inhibited the proliferation, migration and invasion of RCC cell lines and induced apoptosis, while inhibition of SIRT1 expression had the opposite effects. Further experiments indicated that SIRT1 may serve an anticancer role by upregulating the expression levels of downstream AMPK, thus revealing a potential therapeutic target for RCC.

RB1CC1 functions as a tumor-suppressing gene in renal cell carcinoma via suppression of PYK2 activity and disruption of TAZ-mediated PDL1 transcription activation

Rb1-inducible coiled-coil 1 (RB1CC1) has been demonstrated to function as an inhibitor of proline-rich/Ca-activated tyrosine kinase 2 (PYK2) by binding to the kinase domain of PYK2, which promotes the proliferation, invasion, and migration of renal cell carcinoma (RCC) cells. Additionally, in breast cancer, PYK2 positively regulates the expression of transcriptional co-activator with PDZ-binding motif (TAZ) which in turn can enhance PDL1 levels in breast and lung cancer cells. The current study was performed to decipher the impact of RB1CC1 in the progression of RCC via regulation of the PYK2/TAZ/PDL1 signaling axis. Expression of RB1CC1 and PYK2 was quantified in clinical tissue samples from RCC patients. The relationship between TAZ and PYK2, TAZ and PDL1 was then validated. The cellular processes of doxorubicin (DOX)-induced human RCC cell lines including the abilities of proliferation, colony formation, sphere formation and apoptosis, as well as the tumorigenicity of transfected cells, were evaluated after the alteration of RB1CC1 expression. RB1CC1 exhibited decreased expression in RCC tissues and was positively correlated with patient survival. RB1CC1 could inhibit the activity of PYK2, which in turn stimulated the stability of TAZ protein by phosphorylating TAZ. Meanwhile, TAZ protein activated PDL1 transcription by binding to the promoter region of PDL1. RB1CC1 overexpression or PYK2 knockdown could help everolimus (EVE) to inhibit tumor proliferation and activate immune response. Taken together, RB1CC1 can potentially augment the response of RCC cells to immunotherapy by suppressing the PYK2/TAZ/PDL1 signaling axis.

Role of the KEAP1-NRF2 Axis in Renal Cell Carcinoma

NRF2 is a transcription factor that coordinates the antioxidant response in many different tissues, ensuring cytoprotection from endogenous and exogenous stress stimuli. In the kidney, its function is essential in appropriate cellular response to oxidative stress, however its aberrant activation supports progression, metastasis, and resistance to therapies in renal cell carcinoma, similarly to what happens in other nonrenal cancers. While at the moment direct inhibitors of NRF2 are not available, understanding the molecular mechanisms that regulate its hyperactivation in specific tumor types is crucial as it may open new therapeutic perspectives. Here, we focus our attention on renal cell carcinoma, describing how NRF2 hyperactivation can contribute to tumor progression and chemoresistance. Furthermore, we highlight the mechanism whereby the many pathways that are generally altered in these tumors converge to dysregulation of the KEAP1-NRF2 axis.

Impact of inflammation and immunotherapy in renal cell carcinoma

Substantial research attention has been directed at exploring the mechanisms and treatment of renal cell carcinoma (RCC). Indeed, the association between inflammation and tumor phenotypes has been at the center of cancer research. Concomitant with research on the inflammation response and inflammatory molecules involved in RCC, new breakthroughs have emerged. A large body of knowledge now shows that treatments targeting inflammation and immunity in RCC provide substantial clinical benefits. Adequate analysis and a better understanding of the mechanisms of inflammatory factors in the occurrence and progression of RCC are highly desirable. Currently, numerous RCC treatments targeted at inflammation and immunotherapy are available. The current review describes in detail the link between inflammation and RCC.

Integrative Analysis of Sirtuins and Their Prognostic Significance in Clear Cell Renal Cell Carcinoma

Sirtuins, class III histone deacetylases, are involved in multiple biological processes in cancer initiation and progression. However, the diverse expression patterns and prognostic values of sirtuins in cancers have yet to be elucidated. In this study, we first evaluated the expression and prognostic values of sirtuins in multiple cancer cohorts using publicly available TCGA pan-cancer datasets. Pan-cancer survival analysis indicated that 6 out of 7 sirtuin family members were significant associated with prognosis of clear cell renal cell carcinoma (KIRC) patients. SIRT1, SIRT3, SIRT4, and SIRT5 were associated with favorable prognosis of KIRC patients, while SIRT6 and SIRT7 were associated with unfavorable prognosis. The expression levels of SIRT4 and SIRT5 in KIRC tissues were lower than that in normal tissues, while SIRT6 and SIRT7 were higher in KIRC tissues. The expression levels of SIRT1, SIRT3, SIRT5, SIRT6, and SIRT7 were significantly correlated with tumor stage and histological grade. DNA methylation may contribute to the dysregulation of sirtuins. Finally, GSEA was conducted to predict the potential functions of sirtuins in KIRC. Our results may provide novel insights for the development of sirtuins-based cancer therapy in KIRC.

Dynasore suppresses cell proliferation, migration, and invasion and enhances the antitumor capacity of cisplatin via STAT3 pathway in osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor. The prognosis of metastatic and recurrent OS patients still remains unsatisfactory. Cisplatin reveals undeniable anti-tumor effect while induces severe side effects that threatening patients’ health. Dynasore, a cell-permeable small molecule that inhibits dynamin activity, has been widely studied in endocytosis and phagocytosis. However, the anti-tumor effect of dynasore on OS has not yet been ascertained. In the present study, we suggested that dynasore inhibited cell proliferation, migration, invasion, and induced G0/G1 arrest of OS cells. Besides, dynasore repressed tumorigenesis of OS in xenograft mouse model. In addition, we demonstrated that dynasore improved the anti-tumor effect of cisplatin in vitro and in vivo without inducing nephrotoxicity and hepatotoxicity. Mechanistically, dynasore repressed the expression of CCND1, CDK4, p-Rb, and MMP-2. Furthermore, we found that dynasore exerts anti-tumor effects in OS partially via inhibiting STAT3 signaling pathway but not ERK-MAPK, PI3K-Akt or SAPK/JNK pathways. P38 MAPK pathway served as a negative regulatory mechanism in dynasore induced anti-OS effects. Taken together, our study indicated that dynasore does suppress cell proliferation, migration, and invasion via STAT3 signaling pathway, and enhances the antitumor capacity of cisplatin in OS. Our results suggest that dynasore is a novel candidate drug to inhibit the tumor growth of OS and enhance the anti-tumor effects of cisplatin.