Cytoplasmic expression of pontin in renal cell carcinoma correlates with tumor invasion, metastasis and patients' survival

RUVBL1 in Clear-Cell Renal Cell Carcinoma: Unraveling Prognostic Significance and Correlation with HIF1A

This study investigates the roles of RUVBL1 and HIF1A in ccRCC development and explores their clinical significance as prognostic biomarkers. mRNA and protein expressions were analyzed using TCGA data and an institutional tissue cohort, respectively. Correlations with clinicopathological parameters and patient outcomes were assessed. TCGA data revealed significantly elevated RUVBL1 mRNA expression in ccRCC tissues, associated with advanced histological grade, T stage, lymph node metastasis, and clinical stage. High RUVBL1 mRNA expression correlated with inferior overall survival and served as an adverse prognostic factor. Similarly, HIF1A mRNA expression was significantly higher in ccRCC tissues, correlating with worse overall survival and acting as an adverse prognostic factor for treatment outcomes. Simultaneous evaluation of RUVBL1 and HIF1A mRNA expression demonstrated enhanced prognostic capacity, surpassing the predictive power of individual markers. Immunohistochemical staining confirmed substantial upregulation of both RUVBL1 and HIF-1α proteins in ccRCC tissues. Furthermore, high expression of both RUVBL1 and HIF-1α proteins was significantly associated with shorter patient survival time. Our findings underscore the significance of RUVBL1 and HIF-1α as potential prognostic markers in ccRCC, paving the way for further research to translate these insights into clinically relevant applications.

High expression of RUVBL1 and HNRNPU is associated with poor overall survival in stage I and II non-small cell lung cancer patients

The present study aimed to investigate expression levels and prognostic significance of RUVBL1 and HNRNPU in stage I and II non-small-cell lung cancer (NSCLC) patients. Therefore, we evaluated immunohistochemical staining of RUVBL1 and HNRNPU, as well as RNA-seq data from public sources, and the results were evaluated concerning overall survival (OS) and clinicopathological features. We found that RUVBL1 and HNRNPU proteins and mRNA levels were higher in tumor tissues as compared to adjacent/normal tissues. RUVBL1 (p = 0.013) and HNRNPU (p = 0.021) high protein levels were independent prognostic factors for poor OS. Also, the multivariate analysis in the TCGA dataset revealed that high RUVBL1 (p = 0.064) and HNRNPU (p = 0.181) mRNA levels were not significantly associated with prognosis. However, the co-expression status of these markers (R + H +) was independently associated with poor OS both in the TCGA dataset (p = 0.027) and in our cohort (p = 0.001). In conclusion, combined and individual expression of RUVBL1 and HNRNPU proteins, as well as R + H + mRNA status, may serve as potential prognostic biomarkers for NSCLC. This study adds to the previous observations that RUVBL1 and HNRNPU might be novel and promising therapeutic targets and markers for prognostic evaluation.

Ecdysoneless Overexpression Drives Mammary Tumorigenesis through Upregulation of C-MYC and Glucose Metabolism

Ecdysoneless (ECD) protein is essential for embryogenesis, cell-cycle progression, and cellular stress mitigation with an emerging role in mRNA biogenesis. We have previously shown that ECD protein as well as its mRNA are overexpressed in breast cancer and ECD overexpression predicts shorter survival in patients with breast cancer. However, the genetic evidence for an oncogenic role of ECD has not been established. Here, we generated transgenic mice with mammary epithelium-targeted overexpression of an inducible human ECD transgene (ECDTg). Significantly, ECDTg mice develop mammary hyperplasia, preneoplastic lesions, and heterogeneous tumors with occasional lung metastasis. ECDTg tumors exhibit epithelial to mesenchymal transition and cancer stem cell characteristics. Organoid cultures of ECDTg tumors showed ECD dependency for in vitro oncogenic phenotype and in vivo growth when implanted in mice. RNA sequencing (RNA-seq) analysis of ECDTg tumors showed a c-MYC signature, and alterations in ECD levels regulated c-MYC mRNA and protein levels as well as glucose metabolism. ECD knockdown-induced decrease in glucose uptake was rescued by overexpression of mouse ECD as well as c-MYC. Publicly available expression data analyses showed a significant correlation of ECD and c-MYC overexpression in breast cancer, and ECD and c-MYC coexpression exhibits worse survival in patients with breast cancer. Taken together, we establish a novel role of overexpressed ECD as an oncogenesis driver in the mouse mammary gland through upregulation of c-MYC-mediated glucose metabolism.

IMPLICATIONS

We demonstrate ECD overexpression in the mammary gland of mice led to the development of a tumor progression model through upregulation of c-MYC signaling and glucose metabolism.

RUVBL1 promotes enzalutamide resistance of prostate tumors through the PLXNA1-CRAF-MAPK pathway

Although enzalutamide improves the overall survival of patients with metastatic prostate cancers, enzalutamide resistance (ENZR) will be inevitably developed. Emerging evidence support that alternative oncogenic pathways may bypass the androgen receptor (AR) signaling to promote ENZR progression, however, the underpinning mechanisms remain poorly defined. Here, we report that the expression of RuvB like AAA ATPase 1 (RUVBL1) is upregulated in ENZR cells and xenograft models and prostate tumors in patients. Enzalutamide increases RUVBL1 accumulation in the cytoplasm, which in turn enhances the recruitment of CRAF proto-oncogene serine/threonine kinase protein to plexin A1 (PLXNA1) and the subsequent activation of the downstream MAPK pathway. Co-overexpression of RUVBL1 and PLXNA1 defines a subgroup of prostate cancer (PCa) patients with a poor prognosis. Furthermore, pharmacological inhibition of RUVBL1 by CB-6644 suppresses ENZR cell proliferation and xenograft growth and allows re-sensitization of ENZR cells and xenografts to enzalutamide, indicating that RUVBL1 may act to substitute the AR signaling to promote cancer cell survival and ENZR development. Together, these findings may lead to the identification of RUVBL1 as a potential therapeutic target for ENZR tumors.

Bioinformatic gene analysis for possible biomarkers and therapeutic targets of hypertension-related renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is one of the most prevalent malignant tumors of the urinary system. Hypertension can cause hypertensive nephropathy (HN). Meanwhile, Hypertension is considered to be related to kidney cancer. We analyzed co-expressed genes to find out the relationship between hypertension and RCC and show possible biomarkers and novel therapeutic targets of hypertension-related RCC.

METHODS

We identified the differentially expressed genes (DEGs) of HN and RCC through analyzing Gene Expression Omnibus (GEO) datasets GSE99339, GSE99325, GSE53757 and GSE15641 by means of bioinformatics analysis, respectively. Then we evaluated these genes with protein-protein interaction (PPI) networks, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and CTD database. Subsequently, we verified co-expressed DEGs with Gene Expression Profiling Interactive Analysis (GEPIA) database. Finally, corresponding predicted miRNAs of co-expressed DEGs were identified and verified via mirDIP database and Starbase, respectively.

RESULTS

We identified 9 co-expressed DEGs, including BCAT1, CORO1A, CRIP1, ESRRG, FN1, LYZ, PYCARD, SAP30, and PTRF. CRIP1 and ESRRG and their corresponding predicted miRNAs, especially hsa-miR-221-5p, hsa-miR-205-5p, hsa-miR-152-3p and hsa-miR-137 may be notably related to hypertension-related RCC.

CONCLUSIONS

CRIP1 and ESRRG genes have great potential to become novel biomarkers and therapeutic targets concerning hypertension-related RCC.

Deregulated levels of RUVBL1 induce transcription-dependent replication stress

Chromatin regulators control transcription and replication, however if and how they might influence the coordination of these processes still is largely unknown. RUVBL1 and the related ATPase RUVBL2 participate in multiple nuclear processes and are implicated in cancer. Here, we report that both the excess and the deficit of the chromatin regulator RUVBL1 impede DNA replication as a consequence of altered transcription. Surprisingly, cells that either overexpressed or were silenced for RUVBL1 had slower replication fork rates and accumulated phosphorylated H2AX, dependent on active transcription. However, the mechanisms of transcription-dependent replication stress were different when RUVBL1 was overexpressed and when depleted. RUVBL1 overexpression led to increased c-Myc-dependent pause release of RNAPII, as evidenced by higher overall transcription, much stronger Ser2 phosphorylation of Rpb1- C-terminal domain, and enhanced colocalization of Rpb1 and c-Myc. RUVBL1 deficiency resulted in increased ubiquitination of Rpb1 and reduced mobility of an RNAP subunit, suggesting accumulation of stalled RNAPIIs on chromatin. Overall, our data show that by modulating the state of RNAPII complexes, RUVBL1 deregulation induces replication-transcription interference and compromises genome integrity during S-phase.

Embryonic Program Activated during Blast Crisis of Chronic Myelogenous Leukemia (CML) Implicates a TCF7L2 and MYC Cooperative Chromatin Binding

Chronic myeloid leukemia (CML) is characterized by an inherent genetic instability, which contributes to the progression of the disease towards an accelerated phase (AP) and blast crisis (BC). Several cytogenetic and genomic alterations have been reported in the progression towards BC, but the precise molecular mechanisms of this event are undetermined. Transcription Factor 7 like 2 (TFC7L2) is a member of the TCF family of proteins that are known to activate WNT target genes such as Cyclin D1. TCF7L2 has been shown to be overexpressed in acute myeloid leukemia (AML) and represents a druggable target. We report here that TCF7L2 transcription factor expression was found to be correlated to blast cell numbers during the progression of the disease. In these cells, TCF7L2 CHIP-sequencing highlighted distal cis active enhancer, such as elements in SMAD3, ATF5, and PRMT1 genomic regions and a proximal active transcriptional program of 144 genes. The analysis of CHIP-sequencing of MYC revealed a significant overlapping of TCF7L2 epigenetic program with MYC. The β-catenin activator lithium chloride and the MYC-MAX dimerization inhibitor 10058-F4 significantly modified the expression of three epigenetic targets in the BC cell line K562. These results suggest for the first time the cooperative role of TCF7L2 and MYC during CML-BC and they strengthen previous data showing a possible involvement of embryonic genes in this process.

Functional genetic variants of RUVBL1 predict overall survival of Chinese patients with epithelial ovarian cancer

To date, the 5-year overall survival of epithelial ovarian cancer (EOC) remains poor. Because studies suggest that RUVBL1 may be a chemotherapeutic target for the treatment of cancer, in this study, therefore, we investigated the role of potentially functional single nucleotide polymorphisms (SNPs) of RUVBL1 in the survival of Chinese patients with EOC, and we subsequently performed functional prediction and validation of the identified significant SNPs. We found that RUVBL1 rs1057156 A>G and RUVBL1 rs149652370 A>G were associated with survival of EOC patients in the multivariate Cox proportional hazards regression analysis. Specifically, the RUVBL1 rs149652370 AG genotype was associated with a shorter progression-free survival ([adjusted hazards ratio (HR)] = 3.32, 95% confidence interval (CI) = 1.76-6.25 and P = 2.01E-04), compared with the AA genotype. The RUVBL1 rs1057156 AG (only nine had GG) genotype was also associated with a poor overall survival (adjusted HR = 1.73, 95% CI = 1.19-2.52, P = 0.004), compared with the AA genotype. Further experiments showed that the RUVBL1 rs1057156 A>G change lowered its binding affinity to microRNA-4294 and led to upregulation of the RUVBL1 expression. We further found that overexpression of RUVBL1 promoted cell proliferation and metastatic potential. Overall, RUVBL1 enhanced EOC cell proliferation, invasion and migration presumably by stimulating the process of glycolysis. Thus, this study provides evidence that functional variants of RUVBL1 may regulate its gene expression, a possible mechanism affecting survival of EOC patients and that RUVBL1 may be a potential chemotherapeutic target for the treatment of EOC patients.

The Emerging Roles of ATP-Dependent Chromatin Remodeling Complexes in Pancreatic Cancer

Pancreatic cancer is an aggressive cancer with low survival rates. Genetic and epigenetic dysregulation has been associated with the initiation and progression of pancreatic tumors. Multiple studies have pointed to the involvement of aberrant chromatin modifications in driving tumor behavior. ATP-dependent chromatin remodeling complexes regulate chromatin structure and have critical roles in stem cell maintenance, development, and cancer. Frequent mutations and chromosomal aberrations in the genes associated with subunits of the ATP-dependent chromatin remodeling complexes have been detected in different cancer types. In this review, we summarize the current literature on the genomic alterations and mechanistic studies of the ATP-dependent chromatin remodeling complexes in pancreatic cancer. Our review is focused on the four main subfamilies: SWItch/sucrose non-fermentable (SWI/SNF), imitation SWI (ISWI), chromodomain-helicase DNA-binding protein (CHD), and INOsitol-requiring mutant 80 (INO80). Finally, we discuss potential novel treatment options that use small molecules to target these complexes.

CircMYO10 promotes osteosarcoma progression by regulating miR-370-3p/RUVBL1 axis to enhance the transcriptional activity of β-catenin/LEF1 complex via effects on chromatin remodeling

Background

CircMYO10 is a circular RNA generated by back-splicing of gene MYO10 and is upregulated in osteosarcoma cell lines, but its functional role in osteosarcoma is still unknown. This study aimed to clarify the mechanism of circMYO10 in osteosarcoma.

Methods

CircMYO10 expression in 10 paired osteosarcoma and chondroma tissues was assessed by quantitative reverse transcription polymerase chain reaction (PCR). The function of circMYO10/miR-370-3p/RUVBL1 axis was assessed regarding two key characteristics: proliferation and endothelial–mesenchymal transition (EMT). Bioinformatics analysis, western blotting, real-time PCR, fluorescence in situ hybridization, immunoprecipitation, RNA pull-down assays, luciferase reporter assays, chromatin immunoprecipitation, and rescue experiments were used to evaluate the mechanism. Stably transfected MG63 cells were injected via tail vein or subcutaneously into nude mice to assess the role of circMYO10 in vivo.

Results

CircMYO10 was significantly upregulated, while miR-370-3p was downregulated, in osteosarcoma cell lines and human osteosarcoma samples. Silencing circMYO10 inhibited cell proliferation and EMT in vivo and in vitro. Mechanistic investigations revealed that miR-370-3p targets RUVBL1 directly, and inhibits the interaction between RUVBL1 and β-catenin/LEF1 complex while circMYO10 showed a contrary effect via the inhibition of miR-370-3p. RUVBL1 was found to be complexed with chromatin remodeling and histone-modifying factor TIP60, and lymphoid enhancer factor-1 (LEF1) to promote histone H4K16 acetylation (H4K16Ac) in the vicinity of the promoter region of gene C-myc. Chromatin immunoprecipitation methods showed that miR-370-3p sponge promotes H4K16Ac in the indicated region, which is partially abrogated by RUVBL1 small hairpin RNA (shRNA) while circMYO10 showed a contrary result via the inhibition of miR-370-3p. Either miR-370-3p sponge or ShRUVBL1 attenuated circMYO10-induced phenotypes in osteosarcoma cell lines. MiR-370-3p inhibition abrogated the inhibition of proliferation, EMT of osteosarcoma cells in vitro and in vivo seen upon circMYO10 suppression via Wnt/β-catenin signaling.

Conclusions

CircMYO10 promotes osteosarcoma progression by regulating miR-370-3p/RUVBL1 axis to promote chromatin remodeling and thus enhances the transcriptional activity of β-catenin/LEF1 complex, which indicates that circMYO10 may be a potential therapeutic target for osteosarcoma treatment.

MicroRNA-375 Suppresses the Tumor Aggressive Phenotypes of Clear Cell Renal Cell Carcinomas through Regulating YWHAZ

Background:

MicroRNAs (miRNAs) are key regulators during tumor initiation and progression. MicroRNA-375 (MiR-375) has been proven to play a tumor-suppressive role in various types of human malignancies; however, its biological role in clear cell renal cell carcinoma (ccRCC) remains unclear. The purpose of this study was to explore the biologic role as well as the underlying mechanism of miR-375 in ccRCC progression.

Methods:

Quantitative polymerase chain reaction (qPCR) was applied to test the expression of miR-375 in tissues and cell lines by t-test. Functional experiments were used to investigate the biological role of miR-375 utilizing a gain-of-function strategy. The target of miR-375 was investigated by bioinformatic analysis and further verified by luciferase reporter assay, qPCR, Western blotting, and functional experiments in vitro.

Results:

Our study demonstrated that miR-375 was significantly downregulated in ccRCC tissues (cancer vs. normal, 0.804 ± 0.079 vs. 1.784 ± 0.200, t = 5.531 P < 0.0001) and cell lines, and loss of miR-375 expression significantly associated with advanced Fuhrman nuclear grades (Grade III and IV vs. Grade I and II, 1.000 ± 0.099 vs. 1.731 ± 0.189, t = 3.262 P = 0.003). Functional studies demonstrated that miR-375 suppressed ccRCC cell proliferation, migration, and invasion (all P < 0.05 in both 786-O and A498 cell lines). Multiple miRNA target prediction algorithms indicated the well-studied oncogene YWHAZ as a direct target of miR-375, which was further confirmed by the luciferase reporter assay, qPCR, and Western blotting. Moreover, restoration of YWHAZ could rescue the antiproliferation effect of miR-375.

Conclusions:

The data provide the solid evidence that miR-375 plays a tumor-suppressive role in ccRCC progression, partially through regulating YWHAZ. This study expands the antitumor profile of miR-375, and supports its role as a potential therapeutic target in ccRCC treatment.

Hypoxia-regulated lncRNA CRPAT4 promotes cell migration via regulating AVL9 in clear cell renal cell carcinomas

Introduction

Long noncoding RNAs (lncRNAs) are proven to be key regulators in cancer biology. Our screening effort for clear cell renal cell carcinoma (ccRCC) prognosis-associated lncRNAs identified a novel lncRNA, ccRCC prognosis-associated transcript 4 (CRPAT4), as one of the top candidates that was previously uncharacterized. The aim of this study was to verify the clinical significance of CRPAT4 in ccRCC patients and to explore its biological role as well as the underlying mechanisms, in ccRCC cell lines.

Materials and methods

Quantitative real-time polymerase chain reaction (PCR) was performed to demonstrate that CRPAT4 was differentially expressed between ccRCC and the normal controls and that high CRPAT4 expression significantly associated with advanced Fuhrman nuclear grades.

Results

Kaplan–Meier survival analysis with The Cancer Genome Atlas KIRC RNA sequencing data indicated that high CRPAT4 expression was significantly associated with poor overall survival and progression-free survival. Functional studies indicated that CRPAT4 was an HIF-1α regulated gene, and CRPAT4 knockdown significantly inhibited cell migration and proliferation in the absence of HIF-1α. In addition, a mechanistic study revealed that CRPAT4 could regulate the expression of the migration-associated protein AVL9.

Conclusion

Collectively, our study first identified CRPAT4 as a hypoxia-regulated lncRNA, acting as an oncogene in ccRCC progression via regulating AVL9 protein, thus expanding our knowledge on the hypoxia pathway in ccRCC biology from a noncoding perspective. Moreover, CRPAT4 has the potential to be a prognostic marker in ccRCC patients.

Betulinic acid induces apoptosis and inhibits metastasis of human renal carcinoma cells in vitro and in vivo

Betulinic acid (BA), a natural product with a broad range of biological properties, is a lupane-type pentacyclic triterpene isolated from various plants. Evidence is accumulating that BA is cytotoxic against multiple types of human cancer cells; however, its effects on renal carcinoma cells remain obscure. This study aimed to evaluate the anticancer activity of BA in human renal cancer cells in vitro and in vivo. In the current study, we found that BA inhibited renal cancer cell proliferation in a time-dependent and dose-dependent manner in vitro. Moreover, flow cytometry analysis revealed that BA affected the survival of renal cancer cells via the induction of apoptosis. Western blot analysis showed that the occurrence of apoptosis was associated with upregulation of Bcl2-associated X protein and cleaved caspase-3 and downregulation of B-cell lymphoma 2 in renal cancer cells. Additionally, BA treatment augmented the production of reactive oxygen species and induced a significant loss of mitochondrial membrane potential in renal cancer cells, suggesting that BA may trigger apoptosis via the mitochondria-mediated apoptotic pathway. Furthermore, the migrative and invasive capabilities of renal cancer cells were markedly repressed by BA treatment, which was related to upregulation of matrix metalloproteinase (MMP)2, MMP9, and vimentin, and downregulation of tissue inhibitor of metalloproteinase 2 and E-cadherin. Notably, administration of BA retarded tumor growth in 786-O-bearing mice in vivo. Taken together, our results demonstrated the anticancer potential of BA in human renal cancer cells by triggering apoptosis and suppressing migration and invasion.

AAA+ ATPases Reptin and Pontin as potential diagnostic and prognostic biomarkers in salivary gland cancer - a short report

PURPOSE

Salivary gland cancer (SGC) is a rare and heterogeneous disease with significant differences in recurrence and metastasis characteristics. As yet, little is known about the mechanisms underlying the initiation and/or progression of these diverse tumors. In recent years, the AAA+ ATPase family members Pontin (RuvBL1, Tip49a) and Reptin (RuvBL2, Tip49b) have been implicated in various processes, including transcription regulation, chromatin remodeling and DNA damage repair, that are frequently deregulated in cancer. The aim of this study was to assess the clinical and functional significance of Reptin and Pontin expression in SGC.

METHODS

Immunohistochemical staining of Pontin, Reptin, β-catenin, Cyclin D1, TP53 and MIB-1 was performed on a collection of 94 SGC tumor samples comprising 13 different histological subtypes using tissue microarrays.

RESULTS

We found that Reptin and Pontin were expressed in the majority of SGC samples across all histological subtypes. Patients with a high Reptin expression showed a significantly inferior 5-year overall survival rate compared to patients with a low Reptin expression (47.7% versus 78.3%; p = 0.033), whereas no such difference was observed for Pontin. A high Reptin expression strongly correlated with a high expression of the proliferation marker MIB-1 (p = 0.003), the cell cycle regulator Cyclin D1 (p = 0.006), accumulation of TP53 as a surrogate p53 mutation marker (p = 0.042) and cytoplasmic β-catenin expression (p = 0.002). Increased Pontin expression was found to significantly correlate with both cytoplasmic and nuclear β-catenin expression (p = 0.037 and p = 0.018, respectively), which is indicative for its oncogenic function.

CONCLUSIONS

Our results suggest a role of Reptin and Pontin in SGC tumor progression and/or patient survival. Therefore, SGC patients exhibiting a high Reptin expression may benefit from more aggressive therapeutic regimens. Future studies should clarify whether such patients may be considered for more radical surgery, extended adjuvant therapy and/or targeted therapy.

Pontin Acts as a Potential Biomarker for Poor Clinical Outcome and Promotes Tumor Invasion in Hilar Cholangiocarcinoma

Hilar cholangiocarcinoma (HC) is a devastating malignancy that carries a poor overall prognosis. As a member of the AAA+ superfamily, Pontin becomes highly expressed in several malignant tumors, which contributes to tumor progression and influences tumor prognosis. In our research, Pontin expression in tumor specimens resected from 86 HC patients was detected by immunohistochemistry. Interestingly, high expression of Pontin was significantly associated with lymph node metastasis (p = 0.011) and tumor node metastasis (TNM) stage (p = 0.005). The Kaplan–Meier overall survival rate and multivariate analyses were performed to evaluate the prognosis of patients with HC. Patients with high Pontin expression had significantly poorer overall survival outcomes. Multivariate analyses found that Pontin was an independent prognostic factor (p = 0.001). Moreover, bioinformatics analysis confirmed the increase in Pontin mRNA expression levels in cholangiocarcinoma tissues. In addition, in vitro experiments showed that Pontin expression was inhibited at the mRNA as well as protein levels after transfection with Pontin siRNA in human cholangiocarcinoma cell lines. Moreover, significant suppression of cell invasion was observed after the downregulation of Pontin. Taken together, the present study suggested that Pontin could act as a potential prognostic predictor, which might be a new valuable molecular candidate for the prevention and treatment of HC.

The Role of Pontin and Reptin in Cellular Physiology and Cancer Etiology

Pontin (RUVBL1, TIP49, TIP49a, Rvb1) and Reptin (RUVBL2, TIP48, TIP49b, Rvb2) are highly conserved ATPases of the AAA+ (ATPases Associated with various cellular Activities) superfamily and are involved in various cellular processes that are important for oncogenesis. First identified as being upregulated in hepatocellular carcinoma and colorectal cancer, their overexpression has since been shown in multiple cancer types such as breast, lung, gastric, esophageal, pancreatic, kidney, bladder as well as lymphatic, and leukemic cancers. However, their exact functions are still quite unknown as they interact with many molecular complexes with vastly different downstream effectors. Within the nucleus, Pontin and Reptin participate in the TIP60 and INO80 complexes important for chromatin remodeling. Although not transcription factors themselves, Pontin and Reptin modulate the transcriptional activities of bona fide proto-oncogenes such as MYC and β-catenin. They associate with proteins involved in DNA damage repair such as PIKK complexes as well as with the core complex of Fanconi anemia pathway. They have also been shown to be important for cell cycle progression, being involved in assembly of telomerase, mitotic spindle, RNA polymerase II, and snoRNPs. When the two ATPases localize to the cytoplasm, they were reported to promote cancer cell invasion and metastasis. Due to their various roles in carcinogenesis, it is not surprising that Pontin and Reptin are proving to be important biomarkers for diagnosis and prognosis of various cancers. They are also current targets for the development of new therapeutic anticancer drugs.

Transcriptome Sequencing (RNAseq) Enables Utilization of Formalin-Fixed, Paraffin-Embedded Biopsies with Clear Cell Renal Cell Carcinoma for Exploration of Disease Biology and Biomarker Development

Formalin-fixed, paraffin-embedded (FFPE) tissues are an underused resource for molecular analyses. This proof of concept study aimed to compare RNAseq results from FFPE biopsies with the corresponding RNAlater^® (Qiagen, Germany) stored samples from clear cell renal cell carcinoma (ccRCC) patients to investigate feasibility of RNAseq in archival tissue. From each of 16 patients undergoing partial or full nephrectomy, four core biopsies, such as two specimens with ccRCC and two specimens of adjacent normal tissue, were obtained with a 16g needle. One normal and one ccRCC tissue specimen per patient was stored either in FFPE or RNAlater^®. RNA sequencing libraries were generated applying the new Illumina TruSeq^® Access library preparation protocol. Comparative analysis was done using voom/Limma R-package. The analysis of the FFPE and RNAlater^® datasets yielded similar numbers of detected genes, differentially expressed transcripts and affected pathways. The FFPE and RNAlater datasets shared 80% (n = 1106) differentially expressed genes. The average expression and the log2 fold changes of these transcripts correlated with R² = 0.97, and R² = 0.96, respectively. Among transcripts with the highest fold changes in both datasets were carbonic anhydrase 9 (CA9), neuronal pentraxin-2 (NPTX2) and uromodulin (UMOD) that were confirmed by immunohistochemistry. IPA revealed the presence of gene signatures of cancer and nephrotoxicity, renal damage and immune response. To simulate the feasibility of clinical biomarker studies with FFPE samples, a classifier model was developed for the FFPE dataset: expression data for CA9 alone had an accuracy, specificity and sensitivity of 94%, respectively, and achieved similar performance in the RNAlater dataset. Transforming growth factor-ß1 (TGFB1)-regulated genes, epithelial to mesenchymal transition (EMT) and NOTCH signaling cascade may support novel therapeutic strategies. In conclusion, in this proof of concept study, RNAseq data obtained from FFPE kidney biopsies are comparable to data obtained from fresh stored material, thereby expanding the utility of archival tissue specimens.

Amygdalin inhibits the growth of renal cell carcinoma cells in vitro

Although amygdalin is used by many cancer patients as an antitumor agent, there is a lack of information on the efficacy and toxicity of this natural compound. In the present study, the inhibitory effect of amygdalin on the growth of renal cell carcinoma (RCC) cells was examined. Amygdalin (10 mg/ml) was applied to the RCC cell lines, Caki-1, KTC-26 and A498, for 24 h or 2 weeks. Untreated cells served as controls. Tumor cell growth and proliferation were determined using MTT and BrdU tests, and cell cycle phases were evaluated. Expression of the cell cycle activating proteins cdk1, cdk2, cdk4, cyclin A, cyclin B, cyclin D1 and D3 as well as of the cell cycle inhibiting proteins p19 and p27 was examined by western blot analysis. Surface expression of the differentiation markers E- and N-cadherin was also investigated. Functional blockade by siRNA was used to determine the impact of several proteins on tumor cell growth. Amygdalin treatment caused a significant reduction in RCC cell growth and proliferation. This effect was correlated with a reduced percentage of G2/M-phase RCC cells and an increased percentage of cells in the G0/1-phase (Caki-1 and A498) or cell cycle arrest in the S-phase (KTC-26). Furthermore, amygdalin induced a marked decrease in cell cycle activating proteins, in particular cdk1 and cyclin B. Functional blocking of cdk1 and cyclin B resulted in significantly diminished tumor cell growth in all three RCC cell lines. Aside from its inhibitory effects on growth, amygdalin also modulated the differentiation markers, E- and N-cadherin. Hence, exposing RCC cells to amygdalin inhibited cell cycle progression and tumor cell growth by impairing cdk1 and cyclin B expression. Moreover, we noted that amygdalin affected differentiation markers. Thus, we suggest that amygdalin exerted RCC antitumor effects in vitro.