Single cell analysis reveals intra-tumor heterogeneity and microenvironment for clear cell renal cell carcinoma
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ABSTRACT: Here we performed 3’ transcriptome single cell sequencing on 7 ccRCC patients’ tumor and matched 5 adjacent normal samples. We identified two different functional subgroups in ccRCC tumor epithelial cells and two different gene transcriptional programs that were associated with survival across a TCGA cohort. We found important transcriptional factor regulons that played roles in ccRCC progression. We identified macrophage and T cell clusters whose higher infiltration in tumor was associated with overall survival. We also discovered some potentially targetable inhibitory interactions among tumor epithelial cells, the infiltrating T cell and myeloid compartments. Collectively, our data provided cell clusters and gene sets for predict clinical outcome and potential targets for ccRCC therapy.
Project description:Clear cell Renal Cell Carcinoma (ccRCC) is the third most common and most malignant urological cancer, with a 5-year survival rate of 10% for patients with advanced tumors. Here, we identified 10,160 unique proteins by in-depth quantitative proteomics, of which 955 proteins were significantly regulated between tumor and normal adjacent tissues. We verified 4 putatively secreted biomarker candidates, namely PLOD2, FERMT3, SPARC and SIRPα, as highly expressed proteins that are not affected by intra- and inter-tumor heterogeneity. Moreover, SPARC displayed a significant increase in urine samples of ccRCC patients, making it a promising marker for clinical screening assays. Furthermore, based on molecular expression profiles, we propose a biomarker panel for the robust classification of ccRCC tumors into two main clusters, which significantly differed in patient outcome with an almost three times higher risk of death for cluster 1 tumors compared to cluster 2 tumors. Moreover, among the most significant clustering proteins, 13 were targets of repurposed inhibitory FDA-approved drugs. Our rigorous proteomics approach identified promising diagnostic and tumor-discriminative biomarker candidates which can serve as therapeutic targets for the treatment of ccRCC.
Project description:Clear cell renal cell carcinomas (ccRCC) are characterized by arm-wide chromosomal alterations. Loss at 14q is associated with disease aggressiveness in ccRCC, which responds poorly to chemotherapeutics. The 14q locus contains one of the largest miRNA clusters in the human genome; however, little is known about the contribution of these miRNAs to ccRCC pathogenesis. In this regard, we investigated the expression pattern of selected miRNAs at the 14q32 locus in TCGA kidney tumors and in ccRCC cell lines. We validated that the miRNA cluster is downregulated in ccRCC (and cell lines) as well as in papillary kidney tumors relative to normal kidney tissues and primary renal proximal tubule epithelial (RPTEC) cells. We demonstrated that agents modulating expression of DNMT1 (e.g., 5-Aza-deoxycytidine) could modulate miRNA expression in ccRCC cell lines. Lysophosphatidic acid (LPA, a Lysophospholipid mediator elevated in ccRCC) not only increased labile iron content but also modulated expression of 14q32 miRNAs. Through an overexpression approach targeting a subset of 14q32 miRNAs (specifically at subcluster A: miR-431, miR-432, miR-127, and miR-433) in 769-P cells, we uncovered changes in cellular viability and claudin-1, a tight junction marker. A global proteomic approach was implemented using these miRNA overexpressing cell lines which uncovered ATXN2 as a highly downregulated target, which has a role in chronic kidney disease pathogenesis. Collectively, these findings support a contribution of miRNAs at 14q32 in ccRCC pathogenesis.
Project description:Clear cell renal cell carcinoma (ccRCC) is a metabolic disease that is believed to arise from renal proximal convoluted tubule (PCT) epithelial cells. However, the signaling events leading to ccRCC development are not completely understood. Here, we report that a carnitine synthesis enzyme predominantly expressed in PCT cells, γ-butyrobetaine hydroxylase 1 (BBOX1), is a novel ccRCC tumor suppressor. BBOX1 expression is lost in transformed primary renal epithelial cells and ccRCC patient tumors. Restoring BBOX1 expression in ccRCC tumor cells suppresses cell viability in physiological conditions as well as tumor growth and metastasis in xenograft models. Conversely, BBOX1 inhibition increases ccRCC tumor growth. To dissect the mechanism, we performed mass spectrometry analysis of BBOX1 interacting proteins and identified TANK-binding kinase 1 (TBK1). Binding was abrogated by introducing a mutation in BBOX1 that rendered the enzyme inactive. Mechanistically, BBOX1 loss leads to TBK1-dependent mTORC1 activation and increased glycolysis. Thus, the BBOX1-TBK1 axis represents a novel mechanism of dysregulated metabolic signaling offering potential new therapeutic strategies to target ccRCC.
Project description:Identifying tumor-cell-specific markers and elucidating their epigenetic regulation and spatial heterogeneity provides mechanistic insights into cancer etiology. Here, we have performed snRNA-seq and snATAC-seq in 34 and 28 human clear cell renal cell carcinoma (ccRCC) specimens, respectively, with matched bulk proteogenomics data. By identifying 20 tumor-specific markers through a multi-omics tiered approach, we reveal an association between higher ceruloplasmin (CP) expression and reduced survival. CP knockdown, combined with spatial transcriptomics, suggests a role for CP in regulating hyalinized stroma and tumor-stroma interactions in ccRCC. Intratumoral heterogeneity analysis portrays tumor cell-intrinsic inflammation and epithelial-mesenchymal transition (EMT) as two distinguishing features of tumor subpopulations. Finally, BAP1 mutations are associated with widespread reduction of chromatin accessibility, while PBRM1 mutations generally increase accessibility, with the former affecting five times more accessible peaks than the latter. These integrated analyses reveal the cellular architecture of ccRCC, providing insights into key markers and pathways in ccRCC tumorigenesis.
Project description:Clear cell renal cell carcinoma (ccRCC) is the most prevalent form of renal cancer, accounting for over 75% of cases. The asymptomatic nature of the disease contributes to late-stage diagnoses and poor survival. Highly vascularized and immune infiltrated microenvironment are prominent features of ccRCC, yet the interplay between vasculature and immune cells, disease progression and response to therapy remains poorly understood. Using droplet-based single-cell RNA sequencing we profiled 50,236 transcriptomes from paired tumor and healthy adjacent kidney tissues. Our analysis revealed significant heterogeneity and inter-patient variability of the tumor microenvironment. Notably, we discovered a previously uncharacterized vasculature subpopulation associated with epithelial-mesenchymal transition. The cell-cell communication analysis revealed multiple modes of immunosuppressive interactions within the tumor microenvironment, including clinically relevant interactions between tumor vasculature and stromal cells with immune cells. The upregulation of the genes involved in these interactions was associated with worse survival in the TCGA KIRC cohort. Our findings demonstrate the role of tumor vasculature and stromal cell populations in shaping the ccRCC microenvironment and uncover a subpopulation of cells within the tumor vasculature that is associated with an invasive phenotype.
Project description:Immune checkpoint inhibitors (ICI) represent the cornerstone for treatment of patients with metastatic clear-cell renal cell carcinoma (ccRCC). Despite a favorable response for a subset of patients, others experience primary progressive disease highlighting the need to precisely understand plasticity of cancer cells and their crosstalk with the microenvironment to better predict therapeutic response and personalize treatment. Single-cell RNA sequencing of ccRCC at different disease stages and normal adjacent tissue (NAT) from patients identified 46 cell populations, including 5 tumor subpopulations, characterized by distinct transcriptional signatures representing an epithelial to mesenchymal transition gradient and a novel inflamed state. Deconvolution of the tumor and microenvironment signatures in public datasets and in data from the BIONIKK clinical trial (NCT02960906) revealed a strong correlation between mesenchymal-like ccRCC cells and myofibroblastic cancer-associated fibroblasts (myCAFs), which are both enriched in metastases and correlate with poor patient survival. Spatial transcriptomics and multiplex immune staining uncovered spatial proximity of mesenchymal-like ccRCC cells and myCAFs at the tumor-NAT interface. Moreover, enrichment in myCAFs was associated with primary resistance to ICI therapy in the BIONIKK clinical trial. This data highlights the epithelial-mesenchymal plasticity of ccRCC cancer cells and their relationship with myCAFs, a critical component of the microenvironment associated with poor outcome and ICI resistance.
Project description:Immune checkpoint inhibitors (ICI) represent the cornerstone for treatment of patients with metastatic clear-cell renal cell carcinoma (ccRCC). Despite a favorable response for a subset of patients, others experience primary progressive disease highlighting the need to precisely understand plasticity of cancer cells and their crosstalk with the microenvironment to better predict therapeutic response and personalize treatment. Single-cell RNA sequencing of ccRCC at different disease stages and normal adjacent tissue (NAT) from patients identified 46 cell populations, including 5 tumor subpopulations, characterized by distinct transcriptional signatures representing an epithelial to mesenchymal transition gradient and a novel inflamed state. Deconvolution of the tumor and microenvironment signatures in public datasets and in data from the BIONIKK clinical trial (NCT02960906) revealed a strong correlation between mesenchymal-like ccRCC cells and myofibroblastic cancer-associated fibroblasts (myCAFs), which are both enriched in metastases and correlate with poor patient survival. Spatial transcriptomics and multiplex immune staining uncovered spatial proximity of mesenchymal-like ccRCC cells and myCAFs at the tumor-NAT interface. Moreover, enrichment in myCAFs was associated with primary resistance to ICI therapy in the BIONIKK clinical trial. This data highlights the epithelial-mesenchymal plasticity of ccRCC cancer cells and their relationship with myCAFs, a critical component of the microenvironment associated with poor outcome and ICI resistance.
Project description:Renal cell carcinoma (RCC) is the most common neoplasm of the adult kidney. Currently, there are no biomarkers for the diagnostic, prognostic, or predictive applications in RCC. MicroRNAs (miRNAs) are short non protein-coding RNAs that negatively regulate gene expression and have been shown to be involved in cancer. We analyzed a total of 70 matched pairs of clear cell RCC (ccRCC) and normal kidney tissues from the same patients by microarray analysis and validated our results by quantitative real time PCR. We identified 166 miRNAs significantly dysregulated in ccRCC. MiR-122, miR-155 and miR-210 had the highest fold changes of overexpression while miR-200c, miR-335, and miR-218 were the most downregulated. We performed extensive bioinformatics analysis including a combinatorial analysis of previously reported miRNAs dysregulated in RCC and extensive target prediction analysis. Many miRNAs were predicted to target a number of genes involved in RCC pathogenesis. Our results showed that miRNA dysregulation in RCC can be attributed in part, to chromosomal aberrations, the co-regulation of miRNA clusters, and co-expression with host genes. We also correlated miRNA expression with clinical characteristics and found miR-155 expression was correlated with ccRCC tumor size. In conclusion, our analysis showed that a number of miRNAs are dysregulated in ccRCC and may contribute to kidney cancer pathogenesis by targeting more than one key molecule. We identified mechanisms that may contribute to miRNA dysregulation in ccRCC. Dysregulated miRNAs represent potential biomarkers for kidney cancer. We preformed a miRNA microarray on 20 pairs of matched primary clear cell renal cell carcinoma (ccRCC) and normal kidney tissue from the same patient (St. Michael's Hospital, Toronto, Canada). One matched pair was used per array for a total of 20 arrays. Microarray results were validated by quantitative real time PCR using an independent set of 50 matched pairs of ccRCC and normal kidney tissue from the same patient.
Project description:Detailed genetic profiling of clear cell Renal Cell Carcinoma (ccRCC) has shown that these tumors are characterized by large genetic heterogeneity with some genomic regions commonly affected by structural changes. Loss on chromosomes 3p and 14q, and gain on 5q and 7 are examples of alterations commonly reported in ccRCC. However, there is no consensus regarding the potential prognostic information carried by the identified alterations. We report on poorer outcome for patients with gain on 5q and 7, and loss on 9p, 9q and 14q. These aberrations were in addition found more frequently in metastasized tumors, suggesting that they are markers for advanced disease. Furthermore, the presence of M-bM-^IM-% 4 common aberrations was associated with decreased survival time. Shorter relative telomere length (RTL) has been associated with loss of chromosomal regions in ccRCC tumors, but we found no significant associations between tumor RTL and chromosomal deletions. However, significantly lower tumor-to-nontumor (T/N) RTL ratio was detected for patients with loss on 4q and 9p. Finally, we found a minimum region (MR) of genetic loss of 1.4 Mbp on chromosome 9p and this region contains only one gene, the tumor suppressor candidate 1 gene (TUSC1). TUSC1 has been implicated in lung carcinogenesis and our result further strengthens its role in tumorigenesis. Seventy-four ccRCC tumors and 22 paired normal kidney cortex and blood samples were genotyped on Illuminas HumanCytoSNP-12 bead chips.
Project description:This study investigates the genes that promote clear cell renal cell carcimoma (ccRCC) metastasis using 4 primary metastatic and 5 non-metastatic tumor samples. U133 plus 2.0 array was used to identify the diffrently expressed genes between the primary metastatic and non metastatic ccRCC samples To identify differences in gene expression assoctiated with ccRCC metastasis, 4 primary metastatic and 5 non-metastatic ccRCC samples were used to perform expression profiling.