Resistant Renal Cell Carcinoma Research Articles

Calcium saccharate/DUSP6 suppresses renal cell carcinoma glycolytic metabolism and boosts sunitinib efficacy via the ERK-AKT pathway

Current therapeutic options for renal cell carcinoma (RCC) are very limited, which is largely due to inadequate comprehension of molecular pathological mechanisms as well as RCC's resistance to chemotherapy. Dual-specificity phosphatase 6 (DUSP6) has been associated with numerous human diseases. However, its role in RCC is not well understood. Here, we show that diminished DUSP6 expression is linked to RCC progression and unfavorable prognosis. Mechanistically, DUSP6 serves as a tumor suppressor in RCC by intervening the TAF10 and BSCL2 via the ERK-AKT pathway. Further, DUSP6 is also transcriptionally regulated by HNF-4a. Moreover, docking experiments have indicated that DUSP6 expression is enhanced when bound by Calcium saccharate, which also inhibits RCC cell proliferation, metabolic rewiring, and sunitinib resistance. In conclusion, our study identifies Calcium saccharate as a prospective pharmacological therapeutic approach for RCC.

Abstract 4555: c-Met/AXL crosstalk in mediating therapeutic resistance in renal cell carcinoma

Abstract Receptor Tyrosine Kinase (RTK), c-Met, is overexpressed in renal cancer and correlates with a decreased survival rate. Upon binding with its specific ligand, Hepatocyte Growth Factor (HGF), c-Met activates pro-tumorigenic signaling. c-Met/RTK inhibitors are used for the treatment of advanced renal cell carcinoma (RCC). However, acquired therapeutic resistance is a major clinical problem and the underlying mechanisms are largely unknown. Hence, novel therapeutic targets are needed to overcome the clinical hurdles; and the RTK, AXL, can be a potential target. AXL is overexpressed and a poor prognostic marker in RCC. AXL overexpression drives wide-ranging processes, including epithelial-to-mesenchymal transition (EMT), tumor angiogenesis, and resistance to chemotherapeutics. Cabozantinib (XL184/Cabo), is approved for advanced-stage RCC and can inhibit c-Met and VEGFR2 activation (including AXL and a few other RTKs); however, it is not a specific/potent inhibitor of AXL. Hence, inhibiting c-Met alone may not be sufficient when AXL remains active. Therefore, the pro-tumorigenic role of AXL and its cross-talk with c-Met in renal cancer need to be thoroughly investigated. We compared the expression of c-Met and AXL in TCGA and found significantly high expression of both c-Met and AXL in primary renal tumor tissues compared to normal tissues. Our data showed that AXL forms a complex with c-Met and may have a significant cross-talk which can be involved in therapeutic resistance. We have also found that prolonged treatment of c-Met inhibitor Cabo, (including Crizotinib and PF-4217903) induced c-Met and AXL overexpression in RCC cells. Interestingly, c-Met inhibitor(s)-induced overexpressed c-Met can also be increasingly phosphorylated (at low concentrations) in the presence of HGF, which may cause enhanced downstream tumor-promoting signaling. To understand the role of AXL in tumor-promoting pathways and therapeutic resistance, we have generated CRISPR/Cas9-mediated AXL knock-out cells (AXL-KO) and found that silencing AXL can prevent c-Met-inhibitor(s)-mediated c-Met overexpression. Furthermore, to identify the effect of AXL-KO on pro-tumorigenic signaling, transcriptional profiles of control clones and AXL-KO cells were compared. The gene set enrichment analysis (GSEA) showed that genes involved in ‘EMT’, ‘Hypoxia’, and ‘K-Ras’ signaling pathways were significantly downregulated. We have also utilized an AXL-specific small molecule inhibitor, TP-0903, in combination with Cabo and validated our data. We have also generated a Cabo-resistant cell line (Caki-1) and found high expression of c-Met and AXL in these cells. Furthermore, either silencing of AXL (using siRNA) or inhibiting AXL (using TP0903) induced significant apoptosis in these Cabo-resistant cells. Together, our data suggest that inhibition of AXL along with c-Met can be beneficial in preventing acquired therapeutic resistance in RCC. Citation Format: Akash Sabarwal, Laxminarayan Rawat, Johannes Wedel, Murugabaskar Balan, Gwo-Shu Mary Lee, Toni K. Choueiri, Soumitro Pal. c-Met/AXL crosstalk in mediating therapeutic resistance in renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4555.

Abstract 7584: The solute transported xCT (SLC7A11) modulates lysosome biogenesis and microRNA trafficking in drug resistant renal cell carcinoma

Abstract Multi-tyrosine kinase inhibitors (TKIs) like sunitinib bind to over 50 kinases and inhibit several receptors such as VEGFR-1, VEGFR-2, and VEGFR-3 receptors, PDGFRa and PDGFRb, RET, cKIT, and FLT3. TKIs are effective drugs for the treatment of renal cell carcinoma (RCC) but intrinsic/acquired resistance remains a major hurdle. One of the proposed models for TKI resistance is drug sequestration by lysosomes. The solute transporter xCT is a cystine/glutamate antiporter that plays a role in the production of antioxidants in cancer cells. Our lab has found that SLC7A11, the gene that encodes xCT, is overexpressed in sunitinib resistant RCC cells. LAMP1 expression was also increased in sunitinib resistant RCC cells, suggesting an upregulation of lysosome biogenesis. The biochemical knock down of SLC7A11 by shRNA showed a decrease in LAMP1 expression, suggesting a decrease in lysosome biogenesis. SEC24D is a key catalytic component of COPII complex involved in formation of exosomes and secretory pathways. Our preliminary data showed that reduction in xCT expression was associated with a decrease in SEC24D protein levels which was associated with a reduction in the extracellular export and, consequently, an increase in intracytoplasmic levels of miRNA 605, a known tumor suppressor. We are currently testing the hypothesis that xCT may modulate lysosomes biogenesis and micro-RNA trafficking in several clear cell and translation renal cell carcinoma models. In summary, a better understanding of the role of xCT in the regulation of intracytoplasmic organelles may lead to the identification of a novel therapeutic strategy to overcome TKI resistance in RCC. Citation Format: Abbas Jawadwala, Christopher Rupert, Remi Adelaiye-Ogala, Roberto Pili, Sreenivasulu Chintala, Ashley Orillion, May Elbanna, Nur Damayanti, Ilaria Delle Fontane. The solute transported xCT (SLC7A11) modulates lysosome biogenesis and microRNA trafficking in drug resistant renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7584.

Reversing Sunitinib Resistance Facilitated by ITGA1 Through the PI3K/Akt/Bcl-2 Pathway Using Nano Co-Delivery System in Renal Cell Carcinoma

For genitourinary cancers, renal cell carcinoma (RCC) is the third leading cause of death, while target drug resistance has always been a difficult problem. Integrin alpha 1 (ITGA1) is a member of the integrin family, which is significant for the pathogenesis, development, and drug resistance of various malignant tumors. However, it remains unclear for the ITGA1 functions in renal cell carcinoma sunitinib resistance. In this study, we found that the ITGA1 gene facilitates renal cell carcinoma sunitinib resistance through the PI3K/Akt/Bcl-2 signaling pathway. Based on this, we developed a co-delivery system designated as Su/Si-PEAL NPs for the synergistic delivery of ITGA1 small interfering RNA (siRNA) and sunitinib using monomethoxy polyethylene glycol-polylactic acid/glycolic acid-poly-L-lysine triblock copolymer (mPEG-PLGA-PLL, PEAL) as the backbone material. Furthermore, the results of a series of functional experiments confirmed that this codelivery system was capable of downregulating the expression of ITGA1 and enhancing the sensitivity of 786-O-R cells to sunitinib. This co-delivery system could be an efficient approach for reversing sunitinib resistance in renal cell carcinoma.

Nilotinib in combination with sunitinib renders MCL-1 for degradation and activates autophagy that overcomes sunitinib resistance in renal cell carcinoma.

Sunitinib is a recommended drug for metastatic renal cell carcinoma (RCC). However, the therapeutic potential of sunitinib is impaired by toxicity and resistance. Therefore, we seek to explore a combinatorial strategy to improve sunitinib efficacy of low-toxicity dose for better clinical application. We screen synergistic reagents of sunitinib from a compound library containing 1374 FDA-approved drugs by in vitro cell viability evaluation. The synergistically antiproliferative and proapoptotic effects were demonstrated on in vitro and in vivo models. The molecular mechanism was investigated by phosphoproteomics, co-immunoprecipitation, immunofluorescence and western-blot assays, etc. RESULTS: From the four-step screening, nilotinib stood out as a potential synergistic killer combined with sunitinib. Subsequent functional evaluation demonstrated that nilotinib and sunitinib synergistically inhibit RCC cell proliferation and promote apoptosis in vitro and in vivo. Mechanistically, nilotinib activates E3-ligase HUWE1 and in combination with sunitinib renders MCL-1 for degradation via proteasome pathway, resulting in the release of Beclin-1 from MCL-1/Beclin-1 complex. Subsequently, Beclin-1 induces complete autophagy flux to promote antitumor effect. Our findings revealed that a novel mechanism that nilotinib in combination with sunitinib overcomes sunitinib resistance in RCC. Therefore, this novel rational combination regimen provides a promising therapeutic avenue for metastatic RCC and rationale for evaluating this combination clinically.

Interaction between Wnt/β-catenin signaling pathway and EMT pathway mediates the mechanism of sunitinib resistance in renal cell carcinoma

BackgroundTargeted drugs are the main methods of RCC treatment. However, drug resistance is common in RCC patients, in-depth study of the drug-resistant mechanism is essential.MethodsWe constructed sunitinib resistant and Twist overexpressed A498 cells, and studied its mechanisms in vitro and in vivo.ResultsIn cell research, we found that either sunitinib resistance or Twist overexpression can activate Wnt/β-catenin and EMT signaling pathway, and the sunitinib resistance may work through β-catenin/TWIST/TCF4 trimer. In zebrafish research, we confirmed the similarity of Twist overexpression and sunitinib resistance, and the promoting effect of Twist overexpression on drug resistance.ConclusionsSunitinib resistance and Twist overexpression can activate Wnt/β-catenin signaling pathway and EMT to promote the growth and metastasis of RCC cells.

Glutamine metabolism and VEGF analysis to elucidate and overcome the mechanism of tyrosine kinase inhibitor resistance in renal cell carcinoma.

Glutamine metabolism and VEGF analysis to elucidate and overcome the mechanism of tyrosine kinase inhibitor resistance in renal cell carcinoma.

Underlying mechanisms of novel cuproptosis-related dihydrolipoamide branched-chain transacylase E2 (DBT) signature in sunitinib-resistant clear-cell renal cell carcinoma.

Renal cell carcinoma (RCC) is the predominant form of malignant kidney cancer. Sunitinib, a primary treatment for advanced, inoperable, recurrent, or metastatic RCC, has shown effectiveness in some patients but is increasingly limited by drug resistance. Recently identified cuproptosis, a copper-ion-dependent form of programmed cell death, holds promise in combating cancer, particularly drug-resistant types. However, its effectiveness in treating drug resistant RCC remains to be determined. Exploring cuproptosis's regulatory mechanisms could enhance RCC treatment strategies. Our analysis of data from the GEO and TCGA databases showed that the cuproptosis-related gene DBT is markedly under expressed in RCC tissues, correlating with worse prognosis and disease progression. In our study, we investigated copper CRGs in ccRCC, noting substantial expression differences, particularly in advanced-stage tumors. We established a connection between CRG expression levels and patient survival, positioning CRGs as potential therapeutic targets for ccRCC. In drug resistant RCC cases, we found distinct expression patterns for DBT and GLS CRGs, linked to treatment resistance. Our experiments demonstrated that increasing DBT expression significantly reduces RCC cell growth and spread, underscoring its potential as a therapeutic target. This research sheds new light on the role of CRGs in ccRCC and their impact on drug resistance.

Mechanisms of tyrosine kinase inhibitor resistance in renal cell carcinoma.

Renal cell carcinoma (RCC), the most prevalent type of kidney cancer, is a significant cause of cancer morbidity and mortality worldwide. Antiangiogenic tyrosine kinase inhibitors (TKIs), in combination with immune checkpoint inhibitors (ICIs), are among the first-line treatment options for patients with advanced RCC. These therapies target the vascular endothelial growth factor receptor (VEGFR) tyrosine kinase pathway and other kinases crucial to cancer proliferation, survival, and metastasis. TKIs have yielded substantial improvements in progression-free survival (PFS) and overall survival (OS) for patients with advanced RCC. However, nearly all patients eventually progress on these drugs as resistance develops. This review provides an overview of TKI resistance in RCC and explores different mechanisms of resistance, including upregulation of alternative proangiogenic pathways, epithelial-mesenchymal transition (EMT), decreased intracellular drug concentrations due to efflux pumps and lysosomal sequestration, alterations in the tumor microenvironment including bone marrow-derived cells (BMDCs) and tumor-associated fibroblasts (TAFs), and genetic factors such as single nucleotide polymorphisms (SNPs). A comprehensive understanding of these mechanisms opens the door to the development of innovative therapeutic approaches that can effectively overcome TKI resistance, thereby improving outcomes for patients with advanced RCC.

Mechanisms of sunitinib resistance in renal cell carcinoma and associated opportunities for therapeutics.

Sunitinib is the first-line drug for renal cell carcinoma (RCC) treatment. However, patients who received sunitinib treatment will ultimately develop drug resistance after 6-15 months, creating a huge obstacle to the current treatment of renal cell carcinoma. Therefore, it is urgent to clarify the mechanisms of sunitinib resistance and develop new strategies to overcome it. In this review, the mechanisms of sunitinib resistance in renal cell carcinoma have been summarized based on five topics: activation of bypass or alternative pathway, inadequate drug accumulation, tumour microenvironment, metabolic reprogramming and epigenetic regulation. Furthermore, present and potential biomarkers, as well as potential treatment strategies for overcoming sunitinib resistance in renal cell carcinoma, are also covered.

DIRAS2 promotes radiation resistance in renal cell carcinoma via autophagy induction and MKK4-JNK1 pathway activation

DIRAS2 promotes radiation resistance in renal cell carcinoma via autophagy induction and MKK4-JNK1 pathway activation

Site-specific detection of circulating tumor DNA methylation in biological samples utilizing phosphorothioated primer-based loop-mediated isothermal amplification

DNA methylation, a kind of epigenetic alteration, plays a vital role in tumorigenesis and offers a new class of targets for cancer treatment. DNA hypermethylation at the E-Box site (CACGTG, −288 bp) in the SLC22A2 promoter was related to multidrug resistance of renal cell carcinoma (RCC), which can provide the target for both treatment and monitoring. Herein, we developed a novel phosphorothioated primer based loop-mediated isothermal amplification (PS-LAMP) assay to detect circulating tumor DNA (ctDNA) methylation levels in E-Box sites in tumor tissue, urine, and plasma samples from patients with RCC. Bisulfite treatment converted methylated/unmethylated discrepancy to a single base discrepancy (C/U). PS-LAMP amplified the templates to a tremendous amount. One-step strand displacement (OSD) probe provided single base resolution in amplified products and finally realized the specific site methylation detection. Our proposed method provided a linear range from 0% to 100% for methylation levels and was available in samples at low concentrations (102 copies/μL). Visually observable colorimetric detection can be achieved by incorporating the OSD probe with gold nanoparticles (AuNP). Our assay performed better than traditional methods in biological samples with low ctDNA concentration. Further, we found a potential consistency of methylation levels between tumor tissue and plasma sample from the same patient (Spearman's ρ = 0.886, P = 0.019, n = 6). In general, this work provides a PS-LAMP assay combining OSD probes for site-specific methylation detection in various biological samples, offering a method for noninvasive detection.

PD17-07 COMBINATION THERAPY FOR TKI RESISTANT KIDNEY CANCER VIA BLOCKING ERΒ/CIRCRNA-DGKD/MIR-125-5P/VE-CADHERIN SIGNAL INDUCED VASCULOGENIC MIMICRY

You have accessJournal of UrologyCME1 Apr 2023PD17-07 COMBINATION THERAPY FOR TKI RESISTANT KIDNEY CANCER VIA BLOCKING ERΒ/CIRCRNA-DGKD/MIR-125-5P/VE-CADHERIN SIGNAL INDUCED VASCULOGENIC MIMICRY Jie Ding, Yixi Hu, Chawnshang Chang, Edward M. Messing, Jean Joseph, and Shuyuan Yeh Jie DingJie Ding More articles by this author , Yixi HuYixi Hu More articles by this author , Chawnshang ChangChawnshang Chang More articles by this author , Edward M. MessingEdward M. Messing More articles by this author , Jean JosephJean Joseph More articles by this author , and Shuyuan YehShuyuan Yeh More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003272.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Tyrosine kinase inhibitors (TKIs), pazopanib and sunitinib, are widely used in renal cell carcinoma (RCC) therapy by inhibiting tumor angiogenesis. However, most patients become insensitive or develop resistance toward TKI therapy eventually, and the underlying mechanisms have not yet been fully elucidated. Our goal is to reveal the molecular mechanisms of TKI resistant RCC to find a potential combination therapy for TKI-resistant RCC. METHODS: The human RCC cell lines: 786-O, A498, Caki-1, and SW-839 were used. Lentiviral plasmids were used to generate gene engineering tools. The qPCR and Western blot were used to evaluate the gene expressions at RNA and protein levels, respectively. Vasculogenic mimicry (VM) assays were performed to examine vascular-like structure formation ability of cancer cells. Protein-DNA binding complexes were detected by Chromatin immunoprecipitation (ChIP) assays. The human DGKD promoter region was cloned into pGL3 vector for Luciferase Assays. Preclinical mouse RCC model was used to evaluate the anti-cancer effect of pazopanib and circRNA-DGKD blockage in TKI resistant RCC. RESULTS: TKI resistant RCC cells showed increased ability of forming VM to counteract the TKI-suppression function both in vivo and in vitro. Mechanism dissection revealed that pazopanib (or sunitinib)-resistant RCC cells had an increased ERβ, consequently enhancing the circRNA-DGKD expression. In turn, circRNA-DGKD could increase VE-cadherin expression via sponging the miR-125-5p. Supportively, targeting circRNA-DGKD intercepted the RCC VM formation, reduced metastases and improved survival in an orthotopic RCC mouse model. Collectively, the findings may aid in the development of novel therapies for metastatic or TKI-resistant RCC. CONCLUSIONS: Our study reveals that the resistance to TKIs (pazopanib or sunitinib) occurs by increasing vasculogenic mimicry (VM) ability to counteract the TKI angiogenesis suppression function. Furthermore, we find a potential therapy to more effectively treat TKI resistant RCC by blocking ERβ/circRNA-DGKD/miR-125-5p/VE-cadherin pathway together with pazopanib administration. Source of Funding: This work was partially supported by URMC Urology Department Research fund and George H. Whipple Professorship Endowment © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e498 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jie Ding More articles by this author Yixi Hu More articles by this author Chawnshang Chang More articles by this author Edward M. Messing More articles by this author Jean Joseph More articles by this author Shuyuan Yeh More articles by this author Expand All Advertisement PDF downloadLoading ...

Sunitinib resistance in renal cell carcinoma: From molecular mechanisms to predictive biomarkers.

Currently, renal cell carcinoma (RCC) is the most prevalent type of kidney cancer. Targeted therapy has replaced radiation therapy and chemotherapy as the main treatment option for RCC due to the lack of significant efficacy with these conventional therapeutic regimens. Sunitinib, a drug used to treat gastrointestinal tumors and renal cell carcinoma, inhibits the tyrosine kinase activity of a number of receptor tyrosine kinases, including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), c-Kit, rearranged during transfection (RET) and fms-related receptor tyrosine kinase 3 (Flt3). Although sunitinib has been shown to be efficacious in the treatment of patients with advanced RCC, a significant number of patients have primary resistance to sunitinib or acquired drug resistance within the 6-15 months of therapy. Thus, in order to develop more efficacious and long-lasting treatment strategies for patients with advanced RCC, it will be crucial to ascertain how to overcome sunitinib resistance that is produced by various drug resistance mechanisms. In this review, we discuss: 1) molecular mechanisms of sunitinib resistance; 2) strategies to overcome sunitinib resistance and 3) potential predictive biomarkers of sunitinib resistance.

Suppression of SREBP-1 Expression by Simvastatin Decreases Visfatin-Induced Chemoresistance to Sunitinib in Human Renal Carcinoma 786-O Cells.

The resistance of renal cell carcinoma (RCC) to sunitinib impedes the success of chemotherapy in cancer treatment. Although several sunitinib resistance mechanisms have been proposed, little is known concerning the impact of obesity and adipokines in RCC cells. The upregulation of sterol-regulatory element-binding protein-1 (SREBP-1) has been reported to modulate the progression of tumor cells. The present study investigated the effect of visfatin on sunitinib-induced cytotoxicity in RCC cells through SREBP-1 expression. We found that visfatin-induced Akt and p70S6K activation increased SREBP-1 expression in 786-O cells. The visfatin-induced SREBP-1 mRNA and protein levels were attenuated through the inactivation of Akt and p70S6K by pharmacological inhibitors. In addition, the SREBP-1 knockdown using siRNA enhanced the cytotoxic effects of sunitinib. Our results also revealed the roles of simvastatin in attenuating the effects of visfatin on 786-O cells by inhibiting the production of reactive oxygen species. In particular, simvastatin co-treatment increased the cell cytotoxicity of sunitinib in visfatin-treated 786-O cells, which were associated with down-regulation of SREBP-1 expression. Our results suggest an important role of SREBP-1 in visfatin-induced drug resistance of RCC cells to sunitinib. The cytotoxic mechanism of simvastatin on RCC cells may provide a new strategy to improve therapeutic outcomes for the RCC treatment.

Extracellular Vesicle-Mediated Transfer of LncRNA IGFL2-AS1 Confers Sunitinib Resistance in Renal Cell Carcinoma.

Extracellular vesicle-packaged IGFL2-AS1 promotes sunitinib resistance by regulating TP53INP2-triggered autophagy, implicating this lncRNA as a potential therapeutic target in renal cell carcinoma.

Downregulation of long noncoding RNA HCP5/miR-216a-5p/ZEB1 axis inhibits the malignant biological function of laryngeal squamous cell carcinoma cells.

Previous studies find that long noncoding RNA human leukocyte antigen complex P5 (HCP5) is regarded as an oncogene via accelerating cancer cell growth, invasion, metastasis, vascularization, and drug resistance in renal cell carcinoma, gastric cancer, and colorectal cancer. Nevertheless, the effect and regulatory mechanism of HCP5 in laryngeal squamous cell carcinoma (LSCC) remains unknown. In this study, HCP5 expression levels were confirmed to be prominently raised in LSCC cell lines. HCP5 knockdown reduced cell proliferation and migration and invasive ability of LSCC cell lines. Furthermore, miR-216a-5p was confirmed to sponge HCP5, and its expression was prominently downregulated in LSCC cell lines and upregulated in HCP5-silenced LSCC cell lines. miR-216a-5p overexpression downregulated the cell proliferation and migration and invasive ability of LSCC cells. Additionally, the protein level of zinc finger E-box binding homeobox 1 (ZEB1), one target gene of miR-216a-5p, was highly expressed in LSCC cell lines, and its expression level was downregulated by HCP5 knockdown and miR-216a-5p overexpression. An miR-216a-5p inhibitor reversed the effect of HCP5 knockdown on the proliferation and migration and invasive ability of LSCC cells. In conclusion, knocking down HCP5 may be a strategy to suppress the malignant biological function via regulating miR-216a-5p/ZEB1. Therefore, HCP5 may become a prospective therapeutic target for LSCC.

Plasma CD27, a Surrogate of the Intratumoral CD27-CD70 Interaction, Correlates with Immunotherapy Resistance in Renal Cell Carcinoma.

CD70 is a costimulatory molecule known to activate CD27-expressing T cells. CD27-CD70 interaction leads to the release of soluble CD27 (sCD27). Clear-cell renal cell carcinoma (ccRCC) expresses the highest levels of CD70 among all solid tumors; however, the clinical consequences of CD70 expression remain unclear. Tumor tissue from 25 patients with ccRCC was assessed for the expression of CD27 and CD70 in situ using multiplex immunofluorescence. CD27+ T-cell phenotypes in tumors were analyzed by flow cytometry and their gene expression profile were analyzed by single-cell RNA sequencing then confirmed with public data. Baseline sCD27 was measured in 81 patients with renal cell carcinoma (RCC) treated with immunotherapy (35 for training cohort and 46 for validation cohort). In the tumor microenvironment, CD27+ T cells interacted with CD70-expressing tumor cells. Compared with CD27- T cells, CD27+ T cells exhibited an apoptotic and dysfunctional signature. In patients with RCC, the intratumoral CD27-CD70 interaction was significantly correlated with the plasma sCD27 concentration. High sCD27 levels predicted poor overall survival in patients with RCC treated with anti-programmed cell death protein 1 in both the training and validation cohorts but not in patients treated with antiangiogenic therapy. In conclusion, we demonstrated that sCD27, a surrogate marker of T-cell dysfunction, is a predictive biomarker of resistance to immunotherapy in RCC. Given the frequent expression of CD70 and CD27 in solid tumors, our findings may be extended to other tumors.

Mitochondrial metabolic reprogramming by SIRT3 regulation ameliorates drug resistance in renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) alters metabolic signals frequently, leading to mitochondrial dysfunction, such as increase of glycolysis and accumulation of lipid. Sirtuin3 (SIRT3) is a key factor for the regulation of both mitochondrial integrity and function. SIRT3 is downregulated and contributes in both cancer development and progression in ccRCC. The aim of this study is to investigate SIRT3-regulated mitochondrial biogenesis in ccRCC. SIRT3 overexpression alone reduced glucose uptake rate and enhanced membrane potential in mitochondria. ccRCC with overexpressed SIRT3 further improved the lethal effects when combined with anticancer drugs (Resveratrol, Everolimus and Temsirolimus). Cell viability was markedly decreased in a dose-dependent manner when treated with resveratrol or mTOR inhibitors in SIRT3 overexpressing ccRCC. In conclusion, SIRT3 improved mitochondrial functions in ccRCC through metabolic reprogramming. Mitochondrial reprogramming by SIRT3 regulation improves the sensitivity to anticancer drugs. The combination of SIRT3 and resveratrol functioned synergistically lethal effect in ccRCC.

TOPK/PBK is phosphorylated by ERK2 at serine 32, promotes tumorigenesis and is involved in sorafenib resistance in RCC

TOPK/PBK (T-LAK Cell-Originated Protein Kinase) is a serine/threonine kinase that is highly expressed in a variety of human tumors and is associated with poor prognosis in many types of human malignancies. Its activation mechanism is not yet fully understood. A bidirectional signal transduced between TOPK and ERK2 (extracellular signal-regulated kinase 2) has been reported, with ERK2 able to phosphorylate TOPK at the Thr9 residue. However, mutated TOPK at Thr9 cannot repress cellular transformation. In the present study, Ser32 was revealed to be a novel phosphorylated site on TOPK that could be activated by ERK2. Phospho-TOPK (S32) was found to be involved in the resistance of renal cell carcinoma (RCC) to sorafenib. Herein, combined a TOPK inhibitor with sorafenib could promoted the apoptosis of sorafenib-resistant RCC. High expression of HGF/c-met contributes to activation of p-TOPK (S32) during the development of sorafenib resistance in RCC. The current research presents a possible mechanism of sorafenib resistance in RCC and identifies a potential diagnostic marker for predicting sorafenib resistance in RCC, providing a valuable supplement for the clinically targeted treatment of advanced RCC.