Cell Renal Cell Cancer Research Articles

DNA Methylation as Drug Sensitivity Marker in RCC: A Systematic Review.

Patient response after treatment of renal cell cancer (RCC) with systemic agents, which include various drug categories, is generally poor and unpredictable. In this context, the ideal drug administration includes tools to predict the sensitivity of the disease to therapy. The aim of this study was to systematically summarize the reports on the predictive value of the methylation status in the systemic therapy of RCC. Only original articles reporting on the association of promoter methylation with the response of patients or cell lines to systemic agents were included in this review. We applied PRISMA recommendations to the structure and methodology of this systematic review. Our literature search concluded with 31 articles conducted on RCC cell lines and patient tissues. The majority of the studies demonstrated a methylation-dependent response to systemic agents. This correlation suggests that the methylation pattern can be used as a predictive tool in the management of RCC with various classes of systemic agents. However, although methylation biomarkers show promise for predicting response, the evidence of such correlation is still weak. More studies on the gene methylation pattern in patients under systemic therapy and its correlation with different degrees of response are needed.

TIGIT may Serve as a Potential Target for the Immunotherapy of Renal Cell Carcinoma.

This study aims to explore whether TIGIT is an effective target for the immunotherapy of renal cell cancer (RCC) with PD-1 as a positive control. The expression of TIGIT and PD-1 in RCC and peripheral blood mononuclear cells (PBMC) and the correlation between TIGIT and PD-1 are evaluated. The expression of TIGIT and PD-1 is inhibited, and then the proliferation, apoptosis, and migration are assessed. TIGIT expression is positively related to the expression of PDCD1, BTLA, ICOS, and FOXP3 (p<0.05). TIGIT expression in the PBMC, TIL, RCC, and adjacent normal tissues is higher than PD-1 expression. Blocking the TIGIT and PD-1 signaling pathways significantly inhibits the proliferation, migration, and invasion of RCC cells and promotes their apoptosis. These effects are more evident in TIGIT inhibitors than in PD-1 inhibitors. TIGIT inhibitor mainly regulates the expression of differential genes to achieve the reconstruction of immune killing and restore the killing effect on the RCC, and its mechanism by which TIGIT functions overlap that of PD-1 inhibitor. TIGIT may become a target for the immunotherapy of RCC, and there is a theoretical basis for the combination of TIGIT inhibitors and PD-1 inhibitors for the treatment of RCC.

18F-fluoro-2-deoxy-2-d-glucose PET-CT (FDG PET-CT) in staging of high-risk renal and urothelial bladder cancers (COPPER-T) trial protocol.

Role of 18F-fluoro-2-deoxy-2-d-glucose positron emission tomography-computed tomography (FDG PET-CT) in evaluation of renal cell cancers (RCC) and urinary bladder cancers is not standardized, and the COPPER-T trial, which is a single centre prospective randomized study, was designed to compare it with conventional imaging for staging of clinically localized high risk RCC and urinary bladder carcinoma (Stage T2 and above). There will be two subgroups of patients: RCC and urinary bladder carcinoma. In each of these, the patients will be randomized to either Arm A or Arm B. In each of the arms, each patient will be subjected to diagnostic imaging by FDG PET-CT. The CT scan will be a contrast-enhanced scan like that in conventional staging. A radiologist and nuclear medicine specialist will report the scan independently. The radiologist will not have access to the PET scan sequences and will only review the contrast-enhanced computed tomography (CECT) images. In Arm A, the report of the conventional imaging modality, that is, CECT and bone scan if done, will be reviewed first by the clinician, and based on this report, a management plan will be made. Then, the PET-CT report will be reviewed, and change in the management plan will be noted. New findings or equivocal findings if any in the PET-CT report would be noted. In Arm B, the report of the PET-CT report will be reviewed first by the clinicians, and a management plan will be made. Then, the CECT and/or bone scan reports will be reviewed, and any change in the management plan will be noted. Final analysis of the data after completion of the trial will help in clarifying the role of FDG PET-CT in high risk RCC and transitional cell carcinoma (TCC) of the bladder, its diagnostic accuracy compared with conventional imaging and the impact of using it on patient management.

Systematic pan-cancer analysis identifies APOC1 as an immunological biomarker which regulates macrophage polarization and promotes tumor metastasis

Apolipoprotein C1 (APOC1) has been found to play an essential part in proliferation and metastasis of numerous cancers, but related mechanism has not been elucidated, especially its function and role in tumor immunity. Through systematic pan-cancer analysis, we identified that APOC1 was closely associated with the infiltration of various immune cells in multiple cancers. Besides, APOC1 was significantly co-expressed with the immune checkpoints, major histocompatibility complex (MHC) molecules, chemokines and other immune-related genes. Furthermore, single-cell sequencing analysis suggested that the vast majority of APOC1 was expressed in macrophages or tumor-associated macrophages (TAMs). Additionally, the expression of APOC1 was significantly related to the prognosis of different cancers. Since APOC1 was most significantly abnormally expressed in renal cell cancer (RCC), subsequent experiments were carried out in RCC to explore the role of APOC1 in tumor immunity. The expression of APOC1 was significantly elevated in the tumor and serum of RCC patients. Besides, APOC1 was mainly expressed in the macrophage and it was closely related to the immune cell infiltration of RCC. Co-culture with RCC cells could induce the generation of TAMs with M2 phenotype which be blocked by silencing APOC1. The expression of APOC1 was elevated in the M2 or TAMs and APOC1 promoted M2 polarization of macrophages through interacting with CD163 and CD206. Furthermore, macrophages overexpressing APOC1 promoted the metastasis of RCC cells via secreting CCL5. Together, these data indicate that APOC1 is an immunological biomarker which regulates macrophage polarization and promotes tumor metastasis.

Precision Medicine: An Optimal Approach to Patient Care in Renal Cell Carcinoma.

Renal cell cancer (RCC) is a heterogeneous tumor that shows both intra- and inter-heterogeneity. Heterogeneity is displayed not only in different patients but also among RCC cells in the same tumor, which makes treatment difficult because of varying degrees of responses generated in RCC heterogeneous tumor cells even with targeted treatment. In that context, precision medicine (PM), in terms of individualized treatment catered for a specific patient or groups of patients, can shift the paradigm of treatment in the clinical management of RCC. Recent progress in the biochemical, molecular, and histological characteristics of RCC has thrown light on many deregulated pathways involved in the pathogenesis of RCC. As PM-based therapies are rapidly evolving and few are already in current clinical practice in oncology, one can expect that PM will expand its way toward the robust treatment of patients with RCC. This article provides a comprehensive background on recent strategies and breakthroughs of PM in oncology and provides an overview of the potential applicability of PM in RCC. The article also highlights the drawbacks of PM and provides a holistic approach that goes beyond the involvement of clinicians and encompasses appropriate legislative and administrative care imparted by the healthcare system and insurance providers. It is anticipated that combined efforts from all sectors involved will make PM accessible to RCC and other patients with cancer, making a tremendous positive leap on individualized treatment strategies. This will subsequently enhance the quality of life of patients.

DLEU7-AS1 promotes renal cell cancer by silencing the miR-26a-5p/coronin-3 axis

ABSTRACTLong non-coding RNAs (lncRNAs) have been implicated in the progression and development of many types of cancer by interacting with RNA, DNA and proteins, including DLEU7-AS1. However, the function of DLEU7-AS1 in renal cell cancer (RCC) remains unclear. In this study, two in silico prediction algorithms were used to discover the potential target of miR-26a-5p, which was determined to be a tumor suppressor gene, possibly DLEU7-AS1, through the downregulation of coronin-3 in RCC. Thus, we hypothesized that DLEU7-AS1 promotes RCC by silencing the miR-26a-5p/coronin-3 axis. To test our hypothesis, we confirmed that DLEU7-AS1 directly targets miR-26a-5p using the pmirGLO dual-luciferase reporter assay. Next, we observed that DLEU7-AS1 expression was markedly upregulated in RCC samples and inversely correlated with clinical prognosis and miR-26a-5p levels. Knockdown of DLEU7-AS1 significantly suppressed the growth and metastasis of RCC cells in vitro and attenuated tumor growth in vivo. Interestingly, exogenous expression of coronin-3 or miR-26a-5p inhibitor treatment almost completely rescued the DLEU7-AS1 knockdown-induced inhibitory effects on cell proliferation, migration and invasion. In conclusion, our data demonstrate that DLEU7-AS1 is an oncogene in RCC capable of regulating the growth and metastasis of RCC by silencing the miR-26a-5p/coronin-3 axis, suggesting that DLEU7-AS1 can be employed as a potential therapeutic target and prognostic biomarker for RCC.

PBRM1 loss in kidney cancer unbalances the proximal tubule master transcription factor hub to repress proximal tubule differentiation

SUMMARYPBRM1, a subunit of the PBAF coactivator complex that transcription factors use to activate target genes, is genetically inactivated in almost all clear cell renal cell cancers (RCCs). Using unbiased proteomic analyses, we find that PAX8, a master transcription factor driver of proximal tubule epithelial fates, recruits PBRM1/PBAF. Reverse analyses of the PAX8 interactome confirm recruitment specifically of PBRM1/PBAF and not functionally similar BAF. More conspicuous in the PAX8 hub in RCC cells, however, are corepressors, which functionally oppose coactivators. Accordingly, key PAX8 target genes are repressed in RCC versus normal kidneys, with the loss of histone lysine-27 acetylation, but intact lysine-4 trimethylation, activation marks. Re-introduction of PBRM1, or depletion of opposing corepressors using siRNA or drugs, redress coregulator imbalance and release RCC cells to terminal epithelial fates. These mechanisms thus explain RCC resemblance to the proximal tubule lineage but with suppression of the late-epithelial program that normally terminates lineage-precursor proliferation.

Trim21-mediated HIF-1α degradation attenuates aerobic glycolysis to inhibit renal cancer tumorigenesis and metastasis.

Tripartite motif-containing 21 (Trim21) is mainly involved in antiviral responses and autoimmune diseases. Although Trim21 has been reported to have a cancer-promoting or anticancer effect in various tumours, its role in renal cell cancer (RCC) remains to be elucidated. In this study, we demonstrate that Trim21 is downregulated in primary RCC tissues. Low Trim21 expression in RCC is correlated with poor clinicopathological characteristics and short overall survival. Moreover, we illustrate that Trim21 inhibits RCC cells glycolysis through the ubiquitination-mediated degradation of HIF-1α, which inhibits the proliferation, tumorigenesis, migration, and metastasis of RCC cells in vitro and in vivo. Our findings show that Trim21 may become a promising predictive biomarker for the prognosis of patients with RCC.

Identifying the novel key genes in renal cell carcinoma by bioinformatics analysis and cell experiments

BackgroundAlthough major driver gene have been identified, the complex molecular heterogeneity of renal cell cancer (RCC) remains unclear. Therefore, more relevant genes need to be identified to explain the pathogenesis of renal cancer.MethodsMicroarray datasets GSE781, GSE6344, GSE53000 and GSE68417 were downloaded from Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified by employing GEO2R tool, and function enrichment analyses were performed by using DAVID. The protein-protein interaction network (PPI) was constructed and the module analysis was performed using STRING and Cytoscape. Survival analysis was performed using GEPIA. Differential expression was verified in Oncomine. Cell experiments (cell viability assays, transwell migration and invasion assays, wound healing assay, flow cytometry) were utilized to verify the roles of the hub genes on the proliferation of kidney cancer cells (A498 and OSRC-2 cell lines).ResultsA total of 215 DEGs were identified from four datasets. Six hub gene (SUCLG1, PCK2, GLDC, SLC12A1, ATP1A1, PDHA1) were identified and the overall survival time of patients with RCC were significantly shorter. The expression levels of these six genes were significantly decreased in six RCC cell lines(A498, OSRC-2, 786- O, Caki-1, ACHN, 769-P) compared to 293t cell line. The expression level of both mRNA and protein of these genes were downregulated in RCC samples compared to those in paracancerous normal tissues. Cell viability assays showed that overexpressions of SUCLG1, PCK2, GLDC significantly decreased proliferation of RCC. Transwell migration, invasion, wound healing assay showed overexpression of three genes(SUCLG1, PCK2, GLDC) significantly inhibited the migration, invasion of RCC. Flow cytometry analysis showed that overexpression of three genes(SUCLG1, PCK2, GLDC) induced G1/S/G2 phase arrest of RCC cells.ConclusionBased on our current findings, it is concluded that SUCLG1, PCK2, GLDC may serve as a potential prognostic marker of RCC.

LncRNA SNHG7 promotes the proliferation and inhibits apoptosis of renal cell cancer cells by downregulating CDKN1A.

Recent studies have revealed that long non-coding RNAs (lncRNAs) have a crucial role in tumor progression. Renal cell cancer (RCC) is a common type of fatal gynecological cancer worldwide. This study aims to identify the role of lncRNA Small nucleolar RNA host gene 7 (SNHG7) in the progression of RCC. Expression of lncRNA SNHG7 in both RCC cells and 50 pairs of tissue samples was detected by Real-time quantitative polymerase chain reaction (RT-qPCR). Moreover, the function of SNHG7 was identified by performing cell apoptosis assay, colony formation assay and proliferation assay in vitro. The underlying mechanism assays including RT-qPCR and Western blot assay were conducted. SNHG7 expression was remarkably upregulated in tumor tissues when compared with adjacent tissues. Moreover, RCC cell proliferation was inhibited and cell apoptosis was promoted after knockdown of SNHG7 in vitro. Moreover, after knockdown of SNHG7, CDKN1A was upregulated at mRNA and protein level in vitro. Furthermore, the expression of CDKN1A in tumor tissues was negatively correlated to the expression of SNHG7. These results above suggest that SNHG7 could promote cell proliferation and inhibit cell apoptosis in RCC through downregulating CDKN1A, which may offer a new therapeutic intervention for RCC patients.

MicroRNA-Mediated Metabolic Reprograming in Renal Cancer.

Metabolic reprogramming is one of the hallmarks of renal cell cancer (RCC). We hypothesized that altered metabolism of RCC cells results from dysregulation of microRNAs targeting metabolically relevant genes. Combined large-scale transcriptomic and metabolic analysis of RCC patients tissue samples revealed a group of microRNAs that contribute to metabolic reprogramming in RCC. miRNAs expressions correlated with their predicted target genes and with gas chromatography-mass spectrometry (GC-MS) metabolome profiles of RCC tumors. Assays performed in RCC-derived cell lines showed that miR-146a-5p and miR-155-5p targeted genes of PPP (the pentose phosphate pathway) (G6PD and TKT), the TCA (tricarboxylic acid cycle) cycle (SUCLG2), and arginine metabolism (GATM), respectively. miR-106b-5p and miR-122-5p regulated the NFAT5 osmoregulatory transcription factor. Altered expressions of G6PD, TKT, SUCLG2, GATM, miR-106b-5p, miR-155-5p, and miR-342-3p correlated with poor survival of RCC patients. miR-106b-5p, miR-146a-5p, and miR-342-3p stimulated proliferation of RCC cells. The analysis involving >6000 patients revealed that miR-34a-5p, miR-106b-5p, miR-146a-5p, and miR-155-5p are PanCancer metabomiRs possibly involved in global regulation of cancer metabolism. In conclusion, we found that microRNAs upregulated in renal cancer contribute to disturbed expression of key genes involved in the regulation of RCC metabolome. miR-146a-5p and miR-155-5p emerge as a key “metabomiRs” that target genes of crucial metabolic pathways (PPP (the pentose phosphate pathway), TCA cycle, and arginine metabolism).

PBRM1 Loss in Kidney Cancer Unbalances the Kidney Lineage Master Transcription Factor Hub to Repress Terminal Epithelial Fates

PBRM1 is the 2nd-most frequently deleted and mutated gene in clear cell renal cell cancers (RCC). How this loss promotes malignancy is poorly understood. PBRM1 is a subunit of the PBAF coactivator complex that transcription factors recruit to reposition nucleosomes for gene activation. Identifying transcription factors using PBRM1/PBAF might therefore indicate gene expression programs repressed by PBRM1 loss. We therefore used affinity-purification mass spectrometry to identify, in unbiased fashion, transcription factors recruiting PBRM1 in kidney lineage cells. These unbiased proteomic analyses identified PAX8, a master transcription factor essential for kidney epithelial fates, as the most prominent PBRM1 interaction partner. Reverse proteomic analyses of the PAX8 protein hub confirmed recruitment specifically of PBRM1/PBAF, and not the BAF coactivator complex. More conspicuous in the PAX8 hub in RCC cells, however, were several corepressors, e.g. DNMT1, which oppose coactivators to repress instead of activate genes. Accordingly, key PAX8 target genes, e.g., GATA3, LHX1, WT1, and >500 other kidney epithelial genes, were repressed and hyper-methylated in RCC versus normal kidney, with the greatest repression in cases with bi-allelic PBRM1 inactivation. PBRM1 re-introduction into RCC cells, or depletion of the corepressor DNMT1 using a clinical drug decitabine, rebalanced both composition and function of the PAX8 transcription factor hub toward coactivators, activating terminal epithelial fates in vitro and in vivo. Thus, PBRM1 coactivator loss skews composition of the PAX8 kidney lineage master transcription factor hub toward corepressors and repression instead of activation of kidney epithelial-fates. Sensitivity of the transcription factor hub to coactivator/corepressor stoichiometry, however, also enables correction by pharmacologic corepressor inhibition.

Long noncoding RNA ZFPM2-AS1 promotes the tumorigenesis of renal cell cancer via targeting miR-137.

Recently, long noncoding RNAs (lncRNAs) have attracted more attention for their roles in tumor progression. The aim of this study was to investigate the role of lncRNA ZFPM2 antisense RNA 1 (ZFPM2-AS1) in the progression of renal cell cancer (RCC), and to explore the possible underlying mechanism. Expression levels of ZFPM2-AS1 in both RCC cells and 50 paired tissue samples were detected by Real Time-quantitative Polymerase Chain Reaction (RT-qPCR). Moreover, the relationship between lncRNA ZFPM2-AS1 expression level and clinic-pathological characteristics as well as patients' disease-free survival rate was explored, respectively. Furthermore, cell proliferation assay, wound healing assay and transwell assay were performed to investigate the role of lncRNA ZFPM2-AS1 in vitro. In addition, Western blot assay, Luciferase reporter gene assay and RNA immunoprecipitation assay were used to explore the possible underlying mechanism. The expression level of ZFPM2-AS1 in tumor tissues was significantly higher than that of corresponding normal tissues. ZFPM2-AS1 expression was associated with lymph node metastasis, tumor stage and survival time of RCC patients. Moreover, the overexpression of ZFPM2-AS1 significantly promoted the growth, invasion and migration of tumor cells, whereas remarkably inhibited cell apoptosis in vitro. Further experiments revealed that miR-137 was a direct target of ZFPM2-AS1. In addition, miR-137 expression in tumor tissues was negatively correlated with ZFPM2-AS1 expression. Our findings indicated that ZFPM2-AS1 could promote metastasis and proliferation, whereas inhibiting the apoptosis of RCC via targeting miR-137. This study might provide a new vision for interpreting the mechanism of RCC development.

MiR-33a inhibits cell growth in renal cancer by downregulation of MDM4 expression.

Background MicroRNA‐33a (miR‐33a) plays the role of the tumor suppressor gene by regulating the expression level of downstream genes. However, the effects of miR‐33a in renal cell cancer (RCC) remain unknown. Our study was designed to investigate the expression level and potential function of miR‐33a in RCC.MethodsRT‐qPCR was applied to measure the levels of miR‐33a in RCC tissues and cell lines. Western blotting and luciferase reporter assay were used to detect the relationship between miR‐33a and Mouse double minute 4 (MDM4) in RCC cells. CCK‐8 and flow cytometry were applied to detected cell viability and cell cycle. Animal models and TUNEL assay were applied to detect the effect of miR‐33a on the growth of RCC and cell apoptosis.ResultsWe found that the levels of miR‐33a were significantly decreased in RCC tissues and cell lines. Moreover, the low expression of miR‐33a in RCC patients indicated a shorter overall survival (OS). Notably, MDM4 as a direct target of miR‐33a in RCC, the expression level of MDM4 was significantly increased in RCC cells group than the control group. Furthermore, miR‐33a overexpression significantly inhibited RCC cells growth than the control group, while the inhibitory effects of miR‐33a were reversed upon the overexpression of MDM4. Luciferase reporter assays showed that there was a direct interaction between miR‐33a and 3′ UTR of MDM4 mRNA. In vivo, tumor volumes and weight were significantly decreased in the transfected miR‐33a mimics group than the control group.ConclusionTaken together, our study indicates that miR‐33a inhibits RCC cell growth by targeting MDM4.

MiR-1-3p suppresses the epithelial-mesenchymal transition property in renal cell cancer by downregulating Fibronectin 1.

PurposeRenal cell cancer (RCC) is one of the primary causes of malignancy deaths all over the world. The most important cause of RCC-related mortality is metastasis. Epithelial-mesenchymal transition (EMT) plays an important role in metastasis of malignant tumors including RCC. miR-1-3p is confirmed to be decreased in many types of cancer. Nevertheless, the function of miR-1-3p in RCC metastasis and EMT process was still unclear.Materials and methodsIn this study, information from clinical investigation, in vitro study, and in vivo study discovered miR-1-3p expression character and its status in RCC. The character of miR-1-3p in invasive and metastatic properties in vitro and in vivo was also inspected in RCC cells and xenograft tumor model, and expression levels of EMT markers were evaluated in RCC cells and tissues.ResultsmiR-1-3p was proved to be decreased in RCC cell lines and tissues compared with normal renal cells and tissues. miR-1-3p expression level in RCC tissues was closely related with capsulation, lymph node metastasis, and vascular invasion. miR-1-3p was found to be able to block the EMT process in A498 and CAKI-1 RCC cells and tumors. Luciferase reporter assay and expression level rescue assays were employed to reveal that miR-1-3p inhibited the invasion and migration property of RCC cells by directly targeting Fibronectin 1. Upregulation of Fibronectin 1 partially reversed the suppressive effect of miR-1-3p on EMT process.ConclusionIn brief, this study has verified that miR-1-3p blocked the EMT process of RCC cells by reducing Fibronectin 1 expression. miR-1-3p/Fibronectin 1 axis may be considered as a new target for drug development of RCC.

SGK2 promotes renal cancer progression via enhancing ERK 1/2 and AKT phosphorylation.

Increasing studies reported that the serum- and glucocorticoid-inducible kinases (SGKs) contributed to the tumorigenesis of various cancer. In this article, we are aiming to explore the function of SGK2 in renal cell cancer (RCC). In this study, the SGK2 expression was quantified by Western blot (WB) in multiple RCC cell lines. And in vitro SGK2 knockdown and overexpression experiments were also performed. In addition, molecular function analysis was performed using FunRich software V3. The Cancer Genome Atlas (TCGA) database was retrieved to verify the association between the SGK2 expression and the prognosis of RCC patients. We found that SGK2 was up-regulated in RCC tissues compared with adjacent normal tissues, and the SGK2 expression also increased in various RCC cell lines compared to that in the normal epithelial cell line HK-2. Meanwhile, the SGK2 expression was significantly associated with the survival rate of RCC patients. Functional experiments showed that silencing SGK2 expression inhibited RCC cells proliferation, migration, colony formation and invasion abilities in vitro, whereas opposite results were uncovered after overexpressing SGK2 in RCC cells. Furthermore, functional analyses showed that SGK2 related genes were associated with protein serine/threonine kinase activity, guanosine triphosphatase (GTPase) activity, guanyl-nucleotide exchange factor activity, and motor activity. Protein interaction analysis identified that growth factor receptor-bound protein 2 (GRB2), one of the most important upstream components in the growth factor signaling pathway, was significantly enriched in SGK2 related genes. In addition, the WB assay validated that SGK2 could promote the phosphorylation of ERK 1/2 and AKT. Our results suggested that SGK2 promoted RCC progression by mediating the phosphorylation of extracellular regulated protein kinases (ERK) 1/2 and Protein kinase B (AKT/PKB), indicating that SGK2 might serve as a potential prognostic marker and therapeutic target for renal cancer patients.

Thymoquinone inhibits the metastasis of renal cell cancer cells by inducing autophagy via AMPK/mTOR signaling pathway.

Thymoquinone (TQ, 2‐methyl‐5‐isopropyl‐1,4‐benzoquinone), a bioactive constituent extracted from the seeds of Nigella sativa, has been proved to exert anti‐tumor efficiency in various cancers. Autophagy is a self‐digestion phenomenon, and its role in tumor formation and progression remains controversial. In the present study, we investigated the effects of TQ on renal cell cancer (RCC) cell lines (786‐O and ACHN) using wound healing assay, transwell assay and western blot analysis. We found that TQ effectively inhibited the metastatic capacity of RCC cells in vitro, which was also verified in a xenograft model. Meanwhile, we observed LC3 puncta and detected the expression of LC3 in TQ‐treated RCC cells, and then found that autophagy was induced by TQ in 786‐O and ACHN cell lines. In addition, TQ inhibited the migration and invasion as well as the EMT in RCC cells in an autophagy‐dependent manner. To further explore the underlying mechanism, we detected the AMPK/mTOR signaling pathway. The results indicated that TQ inhibited the metastasis of RCC cells by inducing autophagy via AMPK/mTOR signaling pathway. In conclusion, our findings provide a novel therapeutic strategy that aims at TQ‐induced autophagy in RCC treatment.

NT5E inhibition suppresses the growth of sunitinib-resistant cells and EMT course and AKT/GSK-3β signaling pathway in renal cell cancer.

We aimed to explore the mechanisms of sunitinib-resistance in renal cell cancer (RCC) and provide new therapeutic evidence and biomarkers for RCC treatment using human clear-cell renal cell carcinoma (ccRCC) cell line, 786-O. Microarray analysis, quantitative real time PCR (qRT-PCR), Western blot, and immunohistochemistry were used to detect Ecto-5'-nucleotidase (NT5E) expressions in sunitinib-resistant tissues in RCC. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Thiazolyl Blue Tetrazolium Bromide (MTT), cell-count kit 8 (CCK-8), wound healing, and Transwell assays were used to investigate the influences of sunitinib and NT5E on 786-O cell line and sunitinib-resistant 786-O cell line (S786-O). Protein expressions related to epithelial-mesenchymal transition (EMT) and AKT/GSK-3β signaling pathway in 786-O cells and S786-O cells were determined by Western blot. In vivo experiment was performed using NCr-nu/nu mice to explore the effects of NT5E on cell growth and EMT signal in sunitinib environment. NT5E expression was upregulated in sunitinib-resistant RCC tissues and cells. NT5E downregulation repressed RCC cell proliferation, migration as well as invasion. EMT course and AKT/GSK-3β signal pathway both in vitro and in vivo in sunitinib environment was suppressed to varying degrees via NT5E inhibition. NT5E inhibition could suppress the growth of sunitinib-resistant RCC cells and restrain EMT course and AKT/GSK-3β signal pathway in sunitinib environment in RCC. © 2018 IUBMB Life, 71(1):113-124, 2019.

DNA methylation of neural EGFL like1 (NELL1) is associated with advanced disease and the metastatic state of renal cell cancer patients.

Recent studies have shown that NELL1 expression is silenced epigenetically in human renal cell cancer (RCC) tissues and in RCC cell lines. However, it remains unknown whether NELL1 promoter methylation observed in clinical specimens might be associated with the clinicopathology or survival of patients with RCC. We analyzed NELL1 DNA methylation in tissues from patients with RCC and in adjacent normal renal tissues. In addition, we evaluated NELL1 methylation in cell lines derived from different urogenital tumors (prostate cancer, urothelial cancer and RCC). We performed regression analyses to determine whether NELL1 methylation is associated with clinicopathological parameters and recurrence‑free survival (RFS). This cross‑sectional study included 98patients with RCC and 63 paired tumor and adjacent normal tissue samples. We analyzed a locus in the intron 1 region of NELL1 with pyrosequencing. We performed insilico analysis of NELL1 methylation in the TCGA Kidney Renal Clear Cell Carcinoma (KIRC) data set (n=284patients), which served as a validation study. Statistical analyses were performed with the two‑sided paired t‑test for paired tumor and adjacent normal samples. We used logistic regression for subgroup comparisons and Cox regression for RFS comparisons. The mean methylation level was 6.8% higher in RCC tissues compared to paired adjacent normal tissues (paired t‑test, P<0.001). Methylation levels in RCC were associated with advanced disease (P=0.002), the presence of distant metastases (P=0.004), and shorter RFS (P=0.035, HR: 4.15). Insilico validation with TCGA KIRC data for adjacent loci also demonstrated that high relative methylation levels were associated with adverse clinicopathology and shortened RFS. Our results suggest that NELL1 methylation contributes to RCC disease progression. This finding could provide a clinical marker to complement recent functional analyses in tumor models.

PTBP1 knockdown in renal cell carcinoma inhibits cell migration, invasion and angiogenesis in vitro and metastasis in vivo via the hypoxia inducible factor-1α pathway

Polypyrimidine tract-binding protein 1 (PTBP1), a heterogeneous nuclear ribonucleoprotein, is a multi-functional RNA-binding protein. PTBP1 participates in a number of biological processes, including maintaining cell structure and motility, immunity, protein metabolism and the cell cycle. The present study aimed to investigate the association between PTBP1 expression and the prognosis and clinicopathological characteristics of patients with renal cell cancer(RCC). The potential mechanism of action of PTBP1 in the metastasis of RCC was also investigated. The results demonstrated that PTBP1 was overexpressed in RCC tissues compared with normal renal tissues. Furthermore, PTBP1 expression was negatively associated with patient prognosis and positively associated with tumor size, pathological tumor(pT) and pathological metastasis(pM) status and tumor lymph node metastasis(TNM) stage. PTBP1 knockdown invitro inhibited RCC cell migration, invasion, proliferation and angiogenesis, and it was demonstrated that PTBP1 affected RCC cells primarily via the hypoxia inducible factor-1α pathway. Furthermore, PTBP1 knockdown decreased RCC lung metastasis invivo. The present study demonstrated that PTBP1 knockdown suppresses tumor progression and metastasis, indicating that PTBP1 is an important prognostic factor in RCC and that it may be developed as a novel method of treating patients with RCC.