Single-cell protein activity analysis identifies recurrence-associated renal tumor macrophages.

Clear cell renal carcinoma (ccRCC) is a heterogeneous disease with a variable post-surgical course. To assemble a comprehensive ccRCC tumor microenvironment (TME) atlas, we performed single-cell RNA sequencing (scRNA-seq) of hematopoietic and non-hematopoietic subpopulations from tumor and tumor-adjacent tissue of treatment-naive ccRCC resections. We leveraged the VIPER algorithm to quantitate single-cell protein activity and validated this approach by comparison to flow cytometry. The analysis identified key TME subpopulations, as well as their master regulators and candidate cell-cell interactions, revealing clinically relevant populations, undetectable by gene-expression analysis. Specifically, we uncovered a tumor-specific macrophage subpopulation characterized by upregulation of TREM2/APOE/C1Q, validated by spatially resolved, quantitative multispectral immunofluorescence. In a large clinical validation cohort, these markers were significantly enriched in tumors from patients who recurred following surgery. The study thus identifies TREM2/APOE/C1Q-positive macrophage infiltration as a potential prognostic biomarker for ccRCC recurrence, as well as a candidate therapeutic target.

Proteomic profiling of ovarian clear cell carcinomas identifies prognostic biomarkers for chemotherapy.

Clear cell ovarian carcinoma (CCOC) is a relatively rare subtype of ovarian cancer (OC) with high degree of resistance to standard chemotherapy. Little is known about the underlying molecular mechanisms, and it remains a challenge to predict its prognosis after chemotherapy. Here, we first analyzed the proteome of 35 formalin-fixed paraffin-embedded (FFPE) CCOC tissue specimens from a cohort of 32 patients with CCOC (H1 cohort) and characterized 8697 proteins using data-independent acquisition mass spectrometry (DIA-MS). We then performed proteomic analysis of 28 fresh frozen (FF) CCOC tissue specimens from an independent cohort of 24 patients with CCOC (H2 cohort), leading to the identification of 9409 proteins with DIA-MS. After bioinformatics analysis, we narrowed our focus to 15 proteins significantly correlated with the recurrence free survival (RFS) in both cohorts. These proteins are mainly involved in DNA damage response, extracellular matrix (ECM), and mitochondrial metabolism. Parallel reaction monitoring (PRM)-MS was adopted to validate the prognostic potential of the 15 proteins in the H1 cohort and an independent confirmation cohort (H3 cohort). Interferon-inducible transmembrane protein 1 (IFITM1) was observed as a robust prognostic marker for CCOC in both PRM data and immunohistochemistry (IHC) data. Taken together, this study presents a CCOC proteomic data resource and a single promising protein, IFITM1, which could potentially predict the recurrence and survival of CCOC.

Multiorgan Toxicity from Dual Checkpoint Inhibitor Therapy, Resulting in a Complete Response-A Case Report.

Immunotherapy treatment with checkpoint inhibitors (ICIs) has led to a breakthrough in the treatment of oncological diseases. Despite its clinical effectiveness, this treatment differs from others, such as cytotoxic chemotherapy, in that it causes immune-related adverse events. This type of toxicity can affect any organ or organ system of the body. We present a literature review and a rare clinical case from our clinical practice, in which a patient with metastatic clear cell renal carcinoma was treated with a single dose of dual checkpoint blockade (cytotoxic T-lymphocyte-4 (CTLA-4) and programmed death-1 (PD-1)) and simultaneously diagnosed with colitis, hepatitis, and nephritis. After early immunosuppressive treatment with the glucocorticoids, complete organ function recovery was achieved. The follow-up revealed a sustained complete response lasting more than a year.

Renal enhanced CT images reveal the tandem mechanism between tumor cells and immunocytes based on bulk/single-cell RNA sequencing.

Metabolic reprogramming is essential for establishing the tumor microenvironment (TME). Glutamine has been implicated in cancer metabolism, but its role in clear cell renal carcinoma (ccRCC) remains unknown. Transcriptome data of patients with ccRCC and single-cell RNA sequencing (scRNA-seq) data were obtained from The Cancer Genome Atlas (TCGA, 539 ccRCC samples and 59 normal samples) database and GSE152938 (5 ccRCC samples). Differentially expressed genes related to glutamine metabolism (GRGs) were obtained from the MSigDB database. Consensus cluster analysis distinguished metabolism-related ccRCC subtypes. LASSO-Cox regression analysis was used to construct a metabolism-related prognostic model. The ssGSEA and ESTIMATE algorithms evaluated the level of immune cell infiltration in the TME, and the immunotherapy sensitivity score was obtained from TIDE. Cell-cell communication analysis was used to observe the distribution and effects of the target genes in the cell subsets. An image genomics model was constructed using imaging feature extraction and a machine learning algorithm. Results: Fourteen GRGs were identified. Overall survival and progression-free survival rates were lower in metabolic cluster 2, compared with those in cluster 1. The matrix/ESTIMATE/immune score in C1 decreased, but tumor purity in C2 increased. Immune cells were more active in the high-risk group, in which CD8 + T cells, follicular helper T cells, Th1 cells, and Th2 cells were significantly higher than those in the low-risk group. The expression levels of immune checkpoints were also significantly different between the two groups. RIMKL mainly appeared in epithelial cells in the single-cell analysis. ARHGAP11B was sparsely distributed. The imaging genomics model proved effective in aiding with clinical decisions. Glutamine metabolism plays a crucial role in the formation of immune TMEs in ccRCC. It is effective in differentiating the risk and predicting survival in patients with ccRCC. Imaging features can be used as new biomarkers for predicting ccRCC immunotherapy.

ZNF692 promote proliferation through transcriptional repression of essential genes in clear cell renal carcinoma.

Transcription deregulation is recognized as a prominent hallmark of carcinogenesis. However, our understanding of the transcription factors implicated in the dysregulated transcription network of clear cell renal carcinoma (ccRCC) remains incomplete. In this study, we present evidence that ZNF692 drives tumorigenesis in ccRCC through the transcriptional repression of essential genes. We observed overexpression of ZNF692 in various cancers, including ccRCC, and found that the knockdown or knockout of ZNF692 suppressed the growth of ccRCC. Genome-wide binding site analysis using ChIP-seq revealed that ZNF692 regulates genes associated with cell growth, Wnt signaling, and immune response in ccRCC. Furthermore, motif enrichment analysis identified a specific motif (5'-GCRAGKGGAKAY-3') that is recognized and bound by ZNF692. Subsequent luciferase reporter assays demonstrated that ZNF692 transcriptionally represses the expression of IRF4 and FLT4 in a ZNF692 binding motif-dependent manner. Additionally, we observed MYC binding to the promoter regions of ZNF692 in most cancer types, driving ZNF692 overexpression specifically in ccRCC. Overall, our study sheds light on the functional significance of ZNF692 in ccRCC and provides valuable insights into its therapeutic potential as a target in cancer treatment.

Cell-cell communications shape tumor microenvironment and predict clinical outcomes in clear cell renal carcinoma.

BACKGROUND: Cell-cell communications of various cell populations within tumor microenvironment play an essential role in primary tumor growth, metastasis evolution, and immune escape. Nevertheless, comprehensive investigation of cell-cell communications in the ccRCC (Clear cell renal carcinoma) microenvironment and how this interplay affects prognosis still remains limited. METHODS: Intercellular communications were characterized by single-cell data. Firstly, we employed "CellChat" package to characterize intercellular communications across all types of cells in microenvironment in VHL mutated and non-mutated samples from 8 patients, respectively. And pseudotime trajectory analyses were performed with monocle analyses. Finally clinical prognosis and immunotherapy efficacy with different landscapes of intercellular interplay are evaluated by TCGA-KIRC and immunotherapy cohort. RESULTS: Firstly, the VHL phenotype may be related to the intercellular communication landscape. And trajectory analysis reveals the potential relationship of cell-cell communication molecules with T cells and Myeloid cells differentiation. Furthermore, those molecules also correlate with the infiltration of T cells and Myeloid cells. A tumor cluster with highly expressed ligands was defined by quantitative analysis and transcription factor enrichment analysis, which was identified to be pivotal for intercellular communications in tumor microenvironment. Finally, bulk data indicates bulk that different clusters with different intercellular communications have significant predictive value for prognosis and distinguished immunotherapy efficiency. CONCLUSIONS: The intercellular communication landscapes of VHL wild and VHL mutant ccRCC vary. Intercellular communications within the tumor microenvironment also influence T cell and myeloid cell development and infiltration, as well as predict clinical prognosis and immunotherapy efficacy in ccRCC.

A New Signature That Predicts Progression-Free Survival of Clear Cell Renal Cell Carcinoma with Anti-PD-1 Therapy.

Immunotherapy has greatly improved the survival time and quality of life of patients with renal cell carcinoma, but the benefits are limited to a small portion of patients. There are too few new biomarkers that can be used to identify molecular subtypes of renal clear cell carcinoma and predict survival time with anti-PD-1 treatment. Single-cell RNA data of clear cell renal cell carcinoma (ccRCC) treated with anti-PD-1 were obtained from public databases, then 27,707 high-quality CD4 + T and CD8 + T cells were obtained for subsequent analysis. Firstly, genes set variation analysis and CellChat algorithm were used to explore potential molecular pathway differences and intercellular communication between the responder and non-responder groups. Additionally, differentially expressed genes (DEGs) between the responder and non-responder groups were obtained using the "edgeR" package, and ccRCC samples from TCGA-KIRC (n = 533) and ICGA-KIRC (n = 91) were analyzed by the unsupervised clustering algorithm to recognize molecular subtypes with different immune characteristics. Finally, using univariate Cox analysis, least absolute shrinkage and selection operator (Lasso) regression, and multivariate Cox regression, the prognosis model of immunotherapy was established and verified to predict the progression-free survival of ccRCC patients treated with anti-PD-1. At the single cell level, there are different signal pathways and cell communication between the immunotherapy responder and non-responder groups. In addition, our research also confirms that the expression level of PDCD1/PD-1 is not an effective marker for predicting the response to immune checkpoint inhibitors (ICIs). The new prognostic immune signature (PIS) enabled the classification of ccRCC patients with anti-PD-1 therapy into high- and low-risk groups, and the progression-free survival times (PFS) and immunotherapy responses were significantly different between these two groups. In the training group, the area under the ROC curve (AUC) for predicting 1-, 2- and 3-year progression-free survival was 0.940 (95% CI: 0.894-0.985), 0.981 (95% CI: 0.960-1.000), and 0.969 (95% CI: 0.937-1.000), respectively. Validation sets confirm the robustness of the signature. This study revealed the heterogeneity between the anti-PD-1 responder and non-responder groups from different angles and established a robust PIS to predict the progression-free survival of ccRCC patients receiving immune checkpoint inhibitors.

The Metastasis Pattern of Renal Cell Carcinoma Is Influenced by Histologic Subtype, Grade, and Sarcomatoid Differentiation.

Background and Objectives: Metastasis is a major cause of death in renal cell carcinoma (RCC) patients; therefore, a better understanding of the metastatic process and the ability to predict metastasis in advance is important for treating patients with RCC. This study aimed to investigate whether histological subtypes of RCC and other factors, such as nuclear grade and sarcomatoid differentiation, could predict the probability and location of metastases in patients with RCC. Materials and Methods: Cases of clear-cell, papillary, chromophobe, and sarcomatoid RCC were retrieved and analyzed from the Surveillance, Epidemiology, and End Results databases. Results: When comparing the metastatic patterns among the three histologic subtypes, patients with clear-cell RCC were significantly more likely to have brain and lung metastases. Moreover, patients with papillary RCC were significantly less likely to develop bone metastases and more likely to develop lymph node metastases. Patients with chromophobe RCC are significantly more likely to develop liver metastases. As the nuclear grade increased, there was also a significantly increased tendency for clear-cell RCC to metastasize to the lungs. Patients with sarcomatoid RCC had a higher rate of metastasis, with a significantly higher probability of metastasis to the bone and lungs, than those with all three histological subtypes did. Conclusions: Histological subtype, nuclear grade, and sarcomatoid differentiation were significant predictors of metastasis in patients with RCC.

Overexpression of CYP11A1 recovers cell cycle distribution in renal cell carcinoma Caki-1.

BACKGROUND: Clear cell renal carcinoma is commonly known for its metastasis propensity to outspread to other organs and is asymptomatic in the early stage. Recent studies have shown that deficiencies in CYP11A1 expression can lead to fatal adrenal failure if left untreated and are associated with downstream regulation in various cancer types. However, the molecular mechanisms of CYP11A1 and kidney cancer proliferation remain unclear. METHODS: Normal and renal carcinoma cell lines (HEK293 and Caki-1) were transfected with plasmid encoding CYP11A1 to overexpress the P450scc protein. Cell cycle distribution was investigated using flow cytometry. The expression of proteins related to C-Raf/ERK/JNK/p38 signaling pathways was examined using western blot. RESULTS: We observed that CYP11A1 overexpression suppressed the cyclin B1 and cell-division cycle 2 expression while cyclin-dependent kinases 2 and 4 were unaffected. Cancer cell migration and invasion were suppressed along with epithelial-intermediate metastatic markers Snail and Vimentin. In addition, in CYP11A1-overexpressing Caki-1 cells, cdc2/cyclinB1 was downregulated while the phosphorylation of cdc25c, a G2/M arrest-related upstream signal, was increased. The intrinsic-mitochondrial apoptosis markers were not significantly altered. We also identified that the C-Raf/ERK/JNK/p38 pathway is an important pro-apoptotic mechanism in CYP11A1-overexpressing cell-based models. Our results suggest that CYP11A1 overexpression recovered the disturbed cell cycle arrest distribution in renal carcinoma cell line Caki-1 through G2/M arrest and C-Raf/ERK/JNK pathway. CONCLUSIONS: Our findings may suggest promising new therapeutic targets to suppress kidney cancer proliferation without affecting normal cells, eventually improving the survival of patients with cancer.

Construction and validation of a prognostic model of RNA binding proteins in clear cell renal carcinoma.

BACKGROUND: The dysfunction of RNA binding proteins (RBPs) is associated with various inflammation and cancer. The occurrence and progression of tumors are closely related to the abnormal expression of RBPs. There are few studies on RBPs in clear cell renal carcinoma (ccRCC), which allows us to explore the role of RBPs in ccRCC. METHODS: We obtained the gene expression data and clinical data of ccRCC from the Cancer Genome Atlas (TCGA) database and extracted all the information of RBPs. We performed differential expression analysis of RBPs. Risk model were constructed based on the differentially expressed RBPs (DERBPs). The expression levels of model markers were examined by reverse transcription-quantitative PCR (RT-qPCR) and analyzed for model-clinical relevance. Finally, we mapped the model's nomograms to predict the 1, 3 and 5-year survival rates for ccRCC patients. RESULTS: The results showed that the five-year survival rate for the high-risk group was 40.2% (95% CI = 0.313 ~ 0.518), while the five-year survival rate for the low-risk group was 84.3% (95% CI = 0.767 ~ 0.926). The ROC curves (AUC = 0.748) also showed that our model had stable predictive power. Further RT-qPCR results were in accordance with our analysis (p < 0.05). The results of the independent prognostic analysis showed that the model could be an independent prognostic factor for ccRCC. The results of the correlation analysis also demonstrated the good predictive ability of the model. CONCLUSION: In summary, the 4-RBPs (EZH2, RPL22L1, RNASE2, U2AF1L4) risk model could be used as a prognostic indicator of ccRCC. Our study provides a possibility for predicting the survival of ccRCC.

Histologic tumor necrosis rate as a predictor of recurrence after surgical treatment for localized clear cell renal cell carcinoma.

INTRODUCTION: Coagulative tumor necrosis (TN) is a potential negative prognostic marker in clear cell renal cell carcinoma (ccRCC). Our study assessed the significance of the TN rate in histological specimens in terms of the risk of recurrence in patients after surgical treatment for localized disease. METHODS: Our study included 149 subjects surgically treated for ccRCC from 2011 to 2014. Mean postoperative follow-up was 538 days. Presence of TN was assessed by a physician - pathologist in histological specimens. The following findings were described: without necrosis (79 samples), TN rate below 50% (46 samples) and TN rate higher or equal to 50% of the specimen (24 samples). The Kaplan-Meier method, log-rank test and Cox regression analysis were used to evaluate the disease-free survival (DFS). RESULTS: Seventeen patients experienced recurrence - with no TN detected in 3, TN rate below 50% in 6 and TN rate above 50% in 8 patients. There was a significant difference in DSF in patients with proven TN compared to patients without TN (HR 3.83; CI95% 1.489.94%; p=0.006; in multivariate analysis: p=0.031). Evaluation according to the proportion of TN showed a significant difference in DFS in patients with the TN rate below or equal to 50% compared to patients without TN (HR 16.27; CI95% 4.0066.15; p=0.0001; in multivariate analysis: p=0.041). The difference of DSF between patients without TN and with the TN rate higher than 50%, and patients with the TN rate below 50% and higher than 50% was not statistically significant. CONCLUSION: Our study confirmed TN as a risk factor of disease recurrence. Additionally, a higher TN rate is associated with a significantly higher risk of recurrence.

Myc-associated zinc-finger protein promotes clear cell renal cell carcinoma progression through transcriptional activation of the MAP2K2-dependent ERK pathway.

BACKGROUND: The dysfunction of myc-related zinc finger protein (MAZ) has been proven to contribute to tumorigenesis and development of multiple cancer types. However, the biological roles and clinical significance of MAZ in clear cell renal carcinoma (ccRCC) remain unclear. METHODS: MAZ expression was examined in ccRCC and normal kidney tissue by quantitative real-time PCR and Western blot. Statistical analysis was used to evaluate the clinical correlation between MAZ expression and clinicopathological characteristics to determine the relationship between MAZ expression and the survival of ccRCC patients. The biological roles of MAZ in cells were investigated in vitro using MTT and colony assays. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to investigate the relationship between MAZ and its potential downstream signaling molecules. RESULTS: MAZ expression is elevated in ccRCC tissues, and higher levels of MAZ were correlated with poor survival of patients with ccRCC. MAZ upregulation elevates the proliferation ability of ccRCC cells in vitro, whereas silencing MAZ represses this ability. Our results further reveal that MAZ promotes cell growth, which is dependent on ERK signaling. Importantly, we found that MAZ positively regulates MAP2K2 expression in ccRCC cells. Mechanistically, MAZ binds to the MAP2K2 promoter and increases MAP2K2 transcription. Furthermore, MAP2K2 levels were shown to be increased in ccRCC tissues and to be associated with a poor prognosis of ccRCC patients. MAP2K2 upregulation activates the ERK signaling pathway and promotes ccRCC progression. CONCLUSION: These results reveal that the MAZ/MAP2K2/ERK signaling axis plays a crucial role in promoting ccRCC progression, which suggests the potential therapeutic utility of MAZ in ccRCC.

Low expression of ferritinophagy-related NCOA4 gene in relation to unfavorable outcome and defective immune cells infiltration in clear cell renal carcinoma.

BACKGROUND: Clear cell renal cell carcinoma is susceptible to ferroptosis, and immunotherapy is recently recommended as a priority for the initial treatment of metastatic clear cell renal carcinoma. Increased ferroptosis and immune activation can synergistically reinforce each other in killing cancer cells. NCOA4 depletion can eliminate iron accumulation and thus weaken ferroptosis. Here, we aim to identify and validate the association between NCOA4 expression, clinicopathologic characteristics, and overall survival in ccRCC by using The Cancer Genome Atlas and Gene Expression Omnibus databases. We further analyze the interacted proteins of NCOA4 and infiltrated immune cells via TIMER and GEPIA databases. METHODS: NCOA4 expression in clear cell renal carcinoma (ccRCC) tissues and normal adjacent tissues in The Cancer Genome Atlas (TCGA) data were primarily screened, and further validated in another independent cohort from the gene expression omnibus (GEO) database and human protein atlas. The relationships of NCOA4 expression and clinicopathologic parameters and overall survival (OS) were assessed using multivariate methods and Kaplan-Meier survival curves. And the proteins network with which NCOA4 interacted were also built using the online STRING website. Meanwhile, we use TIMER and GEPIA databases to investigate the relationships between NCOA4 expression and infiltrated immune cells and their corresponding gene marker sets. RESULTS: Contrast to normal tissue, NCOA4 expression was lower in ccRCC tumor tissue(p < 0.05). Lower NCOA4 expression was closely associated with high-grade malignancy and advanced TNM stage. Univariate and multivariate analysis indicated the overall survival of ccRCC cases with low NCOA4 level is shorter than those of patients with high NCOA4 expression (p < 0.05). FTL and FTH1 were the important proteins interacting with NCOA4. ccRCC with NCOA4 deficiency presented the paucity of infiltrated immune cells and their matching marker sets, including CD8+ T cells. CONCLUSION: Deficient NCOA4 expression was related to disease progression and poor prognosis, as well as impaired infiltration of immune cells in ccRCC.

ABAT and ALDH6A1, regulated by transcription factor HNF4A, suppress tumorigenic capability in clear cell renal cell carcinoma.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is a malignancy characterized by metabolic reprogramming. ABAT and ALDH6A1 are metabolic enzymes. In this study, we aim to investigate the associations of ABAT and ALDH6A1 with the malignancy of ccRCC cells. METHODS: The gene expression levels of ABAT and ALDH6A1 in ccRCC were analyzed from gene expression microarray datasets and RNA sequencing data. Clinical information was analyzed from The Cancer Genome Atlas (TCGA) data. The distributions of ABAT and ALDH6A1 in ccRCC clinical tissues were screened by reverse transcription-quantitative polymerase chain reaction (RT-QPCR) and immunohistochemical assays. The effect of overexpression of ABAT or ALDH6A1 was measured by detecting the cell viability, migration ability, and the ratio of lactate and nicotinamide adenine dinucleotide phosphate (NADPH). Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were carried out to investigate the transcript regulation of HNF4A in ABAT and ALDH6A1. RESULTS: Remarkable downregulated ABAT and ALDH6A1 expression levels were observed in ccRCC patients and low expression of ABAT and ALDH6A1 was correlated with poor survival. Overexpression of ABAT or ALDH6A1 significantly attenuated cell proliferation and migration, and impaired lactate production. In ABAT increased ccRCC cells, the ratio of NADPH/NADP+ was reduced. Finally, we demonstrated that ABAT and ALDH6A1 were directly regulated by a tumor suppressor, HNF4A. CONCLUSIONS: These observations identified HNF4A-regulated low-expressed ABAT and ALDH6A1 as promising diagnostic and prognostic biomarkers for ccRCC.

The different expression of glycogen phosphorylases in renal clear cell renal carcinoma and chromophobe renal carcinoma.

BACKGROUND: The various pathogenesis between Clear cell renal carcinoma (CCRCC) and Chromophobe renal carcinoma (CHRCC) contributes to the different tumor growth rate and metastasis. In this study, we explored the distinct proteomic profiles between these two cancers and found different expression of glycogen phosphorylases in two cancers. METHODS: We explored novel targets by proteomics. Five CCRCC cases and five CHRCC cases were selected for tandem mass tag-labeling liquid chromatography-mass spectroscopy (LC-MS). Gene ontology and KEGG pathway were applied for bioinformatic analysis. Glycogen phosphorylases were detected by Western blotting. RESULTS: CHRCC were younger, more commonly female, and had larger tumors compared to those with CCRCC. 101 differentially expressed proteins (DEPs) in CCRCC and 235 DEPs in CHRCC were detected by LC-MS. It was found that disruption of metabolic pathways, epithelial cell differentiation, and cell response were the common characters for two tumor types. Activation of cell-cell adhesion and oxidation-reduction process stimulate CCRCC growth and epithelial cell differentiation and transferrin transport was involved in CHRCC growth, We also found that oxidative phosphorylation is activated in CHRCC and inhibited in CCRCC. More importantly, we found and confirmed that upregulation of glycogen phosphorylase liver type in CCRCC and glycogen phosphorylase brain type in CHRCC mediated differential glycogenolysis in the two tumor types, which could serve as potential therapeutic targets. CONCLUSION: We found different expression of glycogen phosphorylases in CCRCC and CHRCC by quantitative proteomics, which provides potential therapeutic targets in the future.

Clear cell renal carcinoma metastases to the pancreas.

INTRODUCTION: To date, clear cell renal carcinoma (Grawitz tumour) remains the most frequent malignant tumour of the kidney in adults. It metastasises in more than 25% of cases, most frequently to the bones (osteolytic metastases), lungs, brain, liver, adrenal glands and the contralateral kidney. Metastases to the pancreas are rare and represent 1-4% of all malignant tumours of the pancreas. METHODS: This is a retrospective analysis of patients who were operated at the Department of Surgery in Pilsen between 2010 and 2018 for histologi-cally verified metastasis of clear cell carcinoma (Grawitz tumour) to the pancreas. RESULTS: We operated 12 patients (8 men and 4 women). The metastases appeared on average 8 years and 8 months following the primary urolo-gical surgery. The mean age of the male patients was 66.5 years and that of the female patients was 67.4 years. In our sample, the diagnostic specificity of the CT scan was 50%, the diagnostic specificity of endoscopic ultrasound (EUS) was 75% and subsequent EUS-guided fine needle aspiration biopsy performed in 100% of cases yielded a specificity of 75%. Resectability was 92%. The average length of hospitalisation was 11.5 days. Post-operative complications according to Clavien-Dindo were grade 1 in 66%, grade 2 in 1.25% and grade 5 in 8.3% of the cases. The 30-day post-operative mortality was 8.3% (one patient).  Conclusion: Clear cell renal carcinoma metastases to the pancreas are very rare. However, if radically removed, the patient has a good prognosis with regards to long-term survival.

Personalized Treatment Response Assessment for Rare Childhood Tumors Using Microcalorimetry-Exemplified by Use of Carbonic Anhydrase IX and Aquaporin 1 Inhibitors.

We present a novel approach to a personalized therapeutic concept for solid tumors. We illustrate this on a rare childhood tumor for which only a generalized treatment concept exists using carbonic anhydrase IX and aquaporin 1 inhibitors. The use of microcalorimetry as a refined in vitro method for evaluation of drug susceptibility in organotypic slice culture has not previously been established. Rapid microcalorimetric drug response assessment can refine a general treatment concept when it is applied in cases in which tumors do not respond to conventional chemo-radiation treatment. For solid tumors, which do not respond to classical treatment, and especially for rare tumors without an established protocol rapid microcalorimetric drug response testing presents an elegant novel approach to test alternative therapeutic approaches. While improved treatment concepts have led to improved outcome over the past decades, the prognosis of high risk disease is still poor and rethinking of clinical trial design is necessary. A small patient population combined with the necessity to assess experimental therapies for rare solid tumors rather at the time of diagnosis than in relapsed or refractory patients provides great challenges. The possibility to rapidly compare established protocols with innovative therapeutics presents an elegant novel approach to refine and personalize treatment.

PBX1 promotes the cell proliferation via JAK2/STAT3 signaling in clear cell renal carcinoma.

PBX1 was abnormally overexpressed and its intracellular localization was found to be frequently amplified in many types of cancer, including renal clear cell carcinoma. PBX1 displays oncogenic activity in several different types of cells, but little is known about how signaling pathways are altered, and the function of PBX1 in renal clear cell carcinoma has not been well investigated. In this study, we demonstrate that the expression of PBX1 was significantly upregulated in 30 pairs of human tissues compared to adjacent normal tissues and the overall survival rate of PBX1-high group was significantly worse than that of PBX1-low group. Furthermore, JAK2 expression is significantly correlated to PBX1 expression in human clinical specimen and PBX1 knockdown inhibits STAT3 phosphorylation and reduced transcription of STAT3 target genes Cyclin D1. More interestingly, PBX1 knockdown inhibits ccRCC cell viability, proliferation and cell cycle progression in vivo and in vitro. Thus, our results demonstrate that PBX1 plays an oncogenic role in ccRCC via JAK2/STAT3 pathway and indicate its potential application for the treatment of human ccRCC in future.

Tumour response in metastatic renal cell carcinoma treated with tyrosine kinase inhibitors - assessment of intra-tumour heterogeneity.

Intra-tumour heterogeneity is a common molecular phenomenon in metastatic clear cell renal carcinoma (mRCC), representing the genetic complexity of a tumour with multiple metastatic sites. The present commentary discusses the observed phenomena of phenotypic intra-tumour heterogeneity in mRCC patients treated with the tyrosine kinase inhibitors sunitinib or pazopanib. Here, drug response can be different on the level of each evaluated metastasis in the individual patient. This questions the currently used radiologic staging systems of RECIST criteria and demands for a modification of radiologic response assessment with the consequence of a patient-tailored therapy in the clinical setting.Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0729-9 .

Overexpression of BTG2 suppresses growth, migration, and invasion of human renal carcinoma cells in vitro.

The objective of the study was to investigate the impact of BTG2 on growth, migration and invasion of human clear cell renal cell carcinoma (ccRCC) cells. Endogenous expression of BTG2 was evaluated in the ccRCC cell lines (Caki-1, 786-O and Caki-2) and noncancerous human renal proximal tubular cell lines (HKC, HK-2 and RPTEC). BTG2 expression was decreased in the ccRCC cells compared with the noncancerous cells (P < 0.01). Then Caki-1 and 786-O cells described as suitable transfection hosts were used in transfection to carry out biological function studies. The three experimental groups were as follows: BTG2-ORF (transfected with BTG2-ORF plasmid), blank-Vector (transfected with pCMV6-Entry), and Cell-alone group (no DNA transfected in). BTG2 expression in the BTG2-ORF groups was significantly higher than that in the controls (P < 0.01). Cell growth was remarkably reduced and the number of migrating or invading cells was reduced in the BTG2-ORF groups compared with the controls (P < 0.01). Furthermore, Matrix Metalloproteinase-9 (MMP-9), Cyclin D1 and Cyclin E expression were reduced in the BTG2-ORF groups compared with the controls. Here, we have provided data for attenuated BTG2 expression in the ccRCC cells. Overexpressed BTG2 could inhibit cell proliferation, migration and invasion of human ccRCC, and the suppressive effects might be due to down-regulation of MMP-9, Cyclin D1 and Cyclin E expression.