Determinants of renal cell carcinoma invasion and metastatic competence

Deep learning-based pathological prediction of lymph node metastasis for patient with renal cell carcinoma from primary whole slide images

BACKGROUND

Metastasis renal cell carcinoma (RCC) patients have extremely high mortality rate. A predictive model for RCC micrometastasis based on pathomics could be beneficial for clinicians to make treatment decisions.

METHODS

A total of 895 formalin-fixed and paraffin-embedded whole slide images (WSIs) derived from three cohorts, including Shanghai General Hospital (SGH), Clinical Proteomic Tumor Analysis Consortium (CPTAC) and Cancer Genome Atlas (TCGA) cohorts, and another 588 frozen section WSIs from TCGA dataset were involved in the study. The deep learning-based strategy for predicting lymphatic metastasis was developed based on WSIs through clustering-constrained-attention multiple-instance learning method and verified among the three cohorts. The performance of the model was further verified in frozen-pathological sections. In addition, the model was also tested the prognosis prediction of patients with RCC in multi-source patient cohorts.

RESULTS

The AUC of the lymphatic metastasis prediction performance was 0.836, 0.865 and 0.812 in TCGA, SGH and CPTAC cohorts, respectively. The performance on frozen section WSIs was with the AUC of 0.801. Patients with high deep learning-based prediction of lymph node metastasis values showed worse prognosis.

CONCLUSIONS

In this study, we developed and verified a deep learning-based strategy for predicting lymphatic metastasis from primary RCC WSIs, which could be applied in frozen-pathological sections and act as a prognostic factor for RCC to distinguished patients with worse survival outcomes.

Molecular underpinnings of dedifferentiation and aggressiveness in chromophobe renal cell carcinoma

Sarcomatoid dedifferentiation is common to multiple renal cell carcinoma (RCC) subtypes, including chromophobe RCC (ChRCC), and is associated with increased aggressiveness, resistance to targeted therapies, and heightened sensitivity to immunotherapy. To study ChRCC dedifferentiation, we performed multiregion integrated paired pathological and genomic analyses. Interestingly, ChRCC dedifferentiates not only into sarcomatoid but also into anaplastic and glandular subtypes, which are similarly associated with increased aggressiveness and metastases. Dedifferentiated ChRCC shows loss of epithelial markers, convergent gene expression, and whole genome duplication from a hypodiploid state characteristic of classic ChRCC. We identified an intermediate state with atypia and increased mitosis but preserved epithelial markers. Our data suggest that dedifferentiation is initiated by hemizygous mutation of TP53, which can be observed in differentiated areas, as well as mutation of PTEN. Notably, these mutations become homozygous with duplication of preexisting monosomes (i.e., chromosomes 17 and 10), which characterizes the transition to dedifferentiated ChRCC. Serving as potential biomarkers, dedifferentiated areas become accentuated by mTORC1 activation (phospho-S6) and p53 stabilization. Notably, dedifferentiated ChRCC share gene enrichment and pathway activation features with other sarcomatoid RCC, suggesting convergent evolutionary trajectories. This study expands our understanding of aggressive ChRCC, provides insight into molecular mechanisms of tumor progression, and informs pathologic classification and diagnostics.

Mining and validation of prognosis of various visceral metastasis in renal cell carcinoma: a study based on SEER database

Our study was aimed to analyze a substantial of renal cell carcinoma (RCC) patients, research the high-risk factors and prognostic factors of metastasis, and thoroughly examine the effects of primary site surgery, lymph node dissection (LND), and chemotherapy on the prognosis of different visceral metastases. The baseline characteristics were characterized, and logistic regression was used to predict the risk factors for metastasis. Prognostic factors of metastatic RCC were assessed using batch univariate and multivariate Cox regression, with adjustments made through PSM. Next, the Kaplan-Meier method was employed to assess OS and create the survival curve. Logistic regression identified risk factors for metastasis: male gender [OR, 1.223; P < 0.001], Hist clear (OR, 9.37; P < 0.001), Hist papillary (OR, 2.49; P < 0.001), and TTX (OR, 23.33; P < 0.001). We found several independent prognostic variables: among which chemotherapy (HR, 0.64), local LND (HR, 0.67), and primary site surgery (HR, 0.97) were associated with better OS. Further study results demonstrated that all kinds of visceral metastasis except for liver metastasis in the operation group had substantially better prognoses than those in the non-operation group (P < 0.05). Regional LND had no discernible impact on survival. Patients with liver, lung, and distant lymph node (LN) metastasis benefited from chemotherapy (P < 0.05), but the bone and brain metastasis did not significantly benefit from treatment (P > 0.05). We recommend primary surgery for different types of visceral metastases except liver metastasis. Routine regional LND is not recommended. Chemotherapy should be considered for patients with lung, distant LN, and liver metastases, but not for those with bone and brain metastases.

Comparative genomics incorporating translocation renal cell carcinoma mouse model reveals molecular mechanisms of tumorigenesis

Translocation renal cell carcinoma (tRCC) most commonly involves an ASPSCR1-TFE3 fusion, but molecular mechanisms remain elusive and animal models are lacking. Here, we show that human ASPSCR1-TFE3 driven by Pax8-Cre (a credentialed clear cell RCC driver) disrupted nephrogenesis and glomerular development, causing neonatal death, while the clear cell RCC failed driver, Sglt2-Cre, induced aggressive tRCC (as well as alveolar soft part sarcoma) with complete penetrance and short latency. However, in both contexts, ASPSCR1-TFE3 led to characteristic morphological cellular changes, loss of epithelial markers, and an epithelial-mesenchymal transition. Electron microscopy of tRCC tumors showed lysosome expansion, and functional studies revealed simultaneous activation of autophagy and mTORC1 pathways. Comparative genomic analyses encompassing an institutional human tRCC cohort (including a hitherto unreported SFPQ-TFEB fusion) and a variety of tumorgraft models (ASPSCR1-TFE3, PRCC-TFE3, SFPQ-TFE3, RBM10-TFE3, and MALAT1-TFEB) disclosed significant convergence in canonical pathways (cell cycle, lysosome, and mTORC1) and less established pathways such as Myc, E2F, and inflammation (IL-6/JAK/STAT3, interferon-γ, TLR signaling, systemic lupus, etc.). Therapeutic trials (adjusted for human drug exposures) showed antitumor activity of cabozantinib. Overall, this study provides insight into MiT/TFE-driven tumorigenesis, including the cell of origin, and characterizes diverse mouse models available for research.

Prognostic Significance of Grade Discrepancy Between Primary Tumor and Venous Thrombus in Nonmetastatic Clear-cell Renal Cell Carcinoma: Analysis of the REMEMBER Registry and Implications for Adjuvant Therapy

BACKGROUND

Further stratification of the risk of recurrence of clear-cell renal cell carcinoma (ccRCC) with venous tumor thrombus (VTT) will facilitate selection of candidates for adjuvant therapy.

OBJECTIVE

To assess the impact of tumor grade discrepancy (GD) between the primary tumor (PT) and VTT in nonmetastatic ccRCC on disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS).

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective analysis of a multi-institutional nationwide data set for patients with pT3N0M0 ccRCC who underwent radical nephrectomy and thrombectomy.

OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS

Pathology slides were centrally reviewed. GD, a bidirectional variable (upgrading or downgrading), was numerically defined as the VTT grade minus the PT grade. Multivariable models were built to predict DFS, OS, and CSS.

RESULTS AND LIMITATIONS

We analyzed data for 604 patients with median follow-up of 42 mo (excluding events). Tumor GD between VTT and PT was observed for 47% (285/604) of the patients and was an independent risk factor with incremental value in predicting the outcomes of interest (all p < 0.05). Incorporation of tumor GD significantly improved the performance of the ECOG-ACRIN 2805 (ASSURE) model. A GD-based model (PT grade, GD, pT stage, PT sarcomatoid features, fat invasion, and VTT consistency) had a c index of 0.72 for DFS. The hazard ratios were 8.0 for GD = +2 (p < 0.001), 1.9 for GD = +1 (p < 0.001), 0.57 for GD = -1 (p = 0.001), and 0.22 for GD = -2 (p = 0.003) versus GD = 0 as the reference. According to model-converted risk scores, DFS, OS, and CSS significantly differed between subgroups with low, intermediate, and high risk (all p < 0.001).

CONCLUSIONS

Routine reporting of VTT upgrading or downgrading in relation to the PT and use of our GD-based nomograms can facilitate more informed treatment decisions by tailoring strategies to an individual patient's risk of progression.

PATIENT SUMMARY

We developed a tool to improve patient counseling and guide decision-making on other therapies in addition to surgery for patients with the clear-cell type of kidney cancer and tumor invasion of a vein.

Regulator of G protein signaling-1 regulates immune infiltration and macrophage polarization in clear cell renal cell carcinoma

OBJECTIVE

To better understand how to clear cell renal cell cancer (ccRCC) is affected by the regulator of G protein signaling-1 (RGS1), its effect on immune infiltration, macrophage polarization, tumor proliferation migration, and to explore whether RGS1 may serve as a marker and therapeutic target for ccRCC.

PATIENTS AND METHODS

In this study, a total of 20 surgical specimens of patients with pathological diagnosis of ccRCC admitted to the Department of Urology of the Second Affiliated Hospital of Anhui Medical University from November 2021 to June 2022 were selected for pathological and protein testing, while the expression of RGS1 in tumors, immune infiltration, and macrophage polarization, particularly M2 macrophage linked to the development of tumor microenvironment (TME), were combined with TGCA database and GO analysis. We also further explored and studied the expression and function of RGS1 in TME, investigated how RGS1 affected tumor growth, migration, apoptosis, and other traits, and initially explored the signaling pathways and mechanisms that RGS1 may affect.

RESULTS

RGS1 was found to be expressed at higher quantities in ccRCC than in normal cells or tissues, according to bioinformatics analysis and preliminary experimental data from this work. Using the TCGA database and GO analysis to describe the expression of RGS1 in a range of tumors, it was found that ccRCC had a much higher level of RGS1 expression than other tumor types. The results of gene enrichment analysis indicated that overexpression of RGS1 may be associated with immune infiltration. The outcomes of in vitro tests revealed that RGS1 overexpression in ccRCC did not significantly alter the proliferation and migration ability of ccRCC, but RGS1 overexpression promoted apoptosis in ccRCC. By in vitro co-culture experiments, RGS1 overexpression inhibited M2 macrophage polarization and also suppressed the Jagged-1/Notch signaling pathway.

CONCLUSIONS

RGS1 is highly expressed in ccRCC, while overexpression of RGS1 may increase immune infiltration in the TME and reduce the polarization of M2 macrophages while promoting apoptosis in ccRCC.

Single-cell analysis of immune and stroma cell remodeling in clear cell renal cell carcinoma primary tumors and bone metastatic lesions

BACKGROUND

Despite therapeutic advances, once a cancer has metastasized to the bone, it represents a highly morbid and lethal disease. One third of patients with advanced clear cell renal cell carcinoma (ccRCC) present with bone metastasis at the time of diagnosis. However, the bone metastatic niche in humans, including the immune and stromal microenvironments, has not been well-defined, hindering progress towards identification of therapeutic targets.

METHODS

We collected fresh patient samples and performed single-cell transcriptomic profiling of solid metastatic tissue (Bone Met), liquid bone marrow at the vertebral level of spinal cord compression (Involved), and liquid bone marrow from a different vertebral body distant from the tumor site but within the surgical field (Distal), as well as bone marrow from patients undergoing hip replacement surgery (Benign). In addition, we incorporated single-cell data from primary ccRCC tumors (ccRCC Primary) for comparative analysis.

RESULTS

The bone marrow of metastatic patients is immune-suppressive, featuring increased, exhausted CD8 + cytotoxic T cells, T regulatory cells, and tumor-associated macrophages (TAM) with distinct transcriptional states in metastatic lesions. Bone marrow stroma from tumor samples demonstrated a tumor-associated mesenchymal stromal cell population (TA-MSC) that appears to be supportive of epithelial-to mesenchymal transition (EMT), bone remodeling, and a cancer-associated fibroblast (CAFs) phenotype. This stromal subset is associated with poor progression-free and overall survival and also markedly upregulates bone remodeling through the dysregulation of RANK/RANKL/OPG signaling activity in bone cells, ultimately leading to bone resorption.

CONCLUSIONS

These results provide a comprehensive analysis of the bone marrow niche in the setting of human metastatic cancer and highlight potential therapeutic targets for both cell populations and communication channels.

Convergent insights into intratumor heterogeneity

Mathematics, conventional histology, and genomics converge to confirm that highly aggressive clear cell renal cell carcinomas (CCRCCs) display low levels of intratumor heterogeneity (ITH). We hypothesize that therapeutic strategies aimed at maintaining high ITH levels would be advisable to slow down cancer evolution and to improve survival.

Early Evolution in Cancer: A Mathematical Support for Pathological and Genomic Evidence in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (CCRCC) is an aggressive form of cancer and a paradigmatic example of intratumor heterogeneity (ITH). The hawk-dove game is a mathematical tool designed to analyze competition in biological systems. Using this game, the study reported here analyzes the early phase of CCRCC development, comparing clonal fitness in homogeneous (linear evolutionary) and highly heterogeneous (branching evolutionary) models. Fitness in the analysis is a measure of tumor aggressiveness. The results show that the fittest clone in a heterogeneous environment is fitter than the clone in a homogeneous context in the early phases of tumor evolution. Early and late periods of tumor evolution in CCRCC are also compared. The study shows the convergence of mathematical, histological, and genomics studies with respect to clonal aggressiveness in different periods of the natural history of CCRCC. Such convergence highlights the importance of multidisciplinary approaches for obtaining a better understanding of the intricacies of cancer.

CD15 Is a Risk Predictor and a Novel Target in Clear Cell Renal Cell Carcinoma

INTRODUCTION

Tumor cells use adhesion molecules like CD15 or sialylCD15 (sCD15) for metastatic spreading. We analyzed the expression of CD15 and sCD15 in clear cell renal cell carcinoma (ccRCC) regarding prognosis.

METHODS

A tissue microarray containing tissue specimens of 763 patients with ccRCC was immunohistochemically stained for CD15 and sCD15, their expression quantified using digital image analysis, and the impact on patients' survival analyzed. The cell lines 769p and 786o were stimulated with CD15 or control antibody in vitro and the effects on pathways activating AP-1 and tumor cell migration were examined.

RESULTS

ccRCC showed a broad range of CD15 and sCD15 expression. A high CD15 expression was significantly associated with favorable outcome (p < 0.01) and low-grade tumor differentiation (p < 0.001), whereas sCD15 had no significant prognostic value. Tumors with synchronous distant metastasis had a significantly lower CD15 expression compared to tumors without any (p < 0.001) or with metachronous metastasis (p < 0.01). Tumor cell migration was significantly reduced after CD15 stimulation in vitro, but there were no major effects on the activating pathways of AP-1.

CONCLUSION

CD15, but not sCD15, qualifies as a biomarker for risk stratification and as an interesting novel target in ccRCC. Moreover, the data indicate a contribution of CD15 to metachronous metastasis. Further research is warranted to decipher the intracellular pathways of CD15 signaling in ccRCC in order to characterize the CD15 effects on ccRCC more precisely.

Spatio-temporal heterogeneity in cancer evolution and tumor microenvironment of renal cell carcinoma with tumor thrombus

Metastasis is the most fatal aspect of cancer, often preceded by a tumor thrombus (TT) which forms within the vascular system. Renal cell carcinoma (RCC), the predominant form of kidney cancer, witnesses a venous system invasion in 4-10% of cases, resulting in venous tumor thrombus (RCC-TT). This variant represents a formidable clinical challenge due to its escalated surgical complexity, heightened risk of progression and metastasis, and an adverse prognosis. However, recent trials addressing RCC-TT face significant barriers stemming from the profound inter- and intra-tumoral heterogeneity, patient-specific treatment variations, and distinct therapeutic resistance patterns between the primary tumor (PT) and the TT. This review delves into the unique evolutionary pathway of RCC-TT, the relationship between the staging and grading of RCC-TT invasion patterns, and the spatial molecular profiling of RCC-TT. Additionally, we assess the temporal heterogeneity among TT, PT, and distant metastases, as well as the functional phenotypes of TME components. An outlook for future research on RCC-TT is also provided.

Mesenchymal-like Tumor Cells and Myofibroblastic Cancer-Associated Fibroblasts Are Associated with Progression and Immunotherapy Response of Clear Cell Renal Cell Carcinoma

Immune checkpoint inhibitors (ICI) represent the cornerstone for the 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 the plasticity of cancer cells and their cross-talk 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 data sets and data from the BIONIKK clinical trial (NCT02960906) revealed a strong correlation between mesenchymal-like ccRCC cells and myofibroblastic cancer-associated fibroblasts (myCAF), which are both enriched in metastases and correlate with poor patient survival. Spatial transcriptomics and multiplex immune staining uncovered the 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. These data highlight 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.

SIGNIFICANCE

Single-cell and spatial transcriptomics reveal the proximity of mesenchymal tumor cells to myofibroblastic cancer-associated fibroblasts and their association with disease outcome and immune checkpoint inhibitor response in clear cell renal cell carcinoma.

Robotic Partial vs Radical Nephrectomy for Clinical T3a Tumors: A Narrative Review

Introduction: T3a renal masses include a diverse group of tumors that invade the perirenal and/or sinus fat, pelvicaliceal system, or renal vein. The majority of cT3a renal masses represent renal cell carcinoma (RCC) and have historically been treated with radical nephrectomy (RN) given their aggressive nature. With the adoption of minimally invasive approaches to renal surgery, the combination of improved observation, pneumoperitoneum, and robotic articulation has allowed urologists to consider partial nephrectomy (PN) for more complex tumors. Herein, we review the existing literature regarding robot-assisted PN (RAPN) and robot-assisted RN (RARN) in the management of T3a renal masses. Methods: A literature search was performed using PubMed for articles evaluating the role of RARN and RAPN for T3a renal masses. Search parameters were limited to English language studies. Applicable studies were abstracted and included in this narrative review. Results: T3a RCC caused by renal sinus fat or venous involvement is associated with ∼50% lower cancer-specific survival than those with perinephric fat invasion alone. CT and MRI can both be used to stage cT3a tumors, however, MRI is more accurate when assessing venous involvement. Upstaging to pT3a RCC during RAPN does not confer a worse prognosis than pT3a tumors treated with RARN; however, patients who undergo RAPN for T3a RCC with venous involvement have relatively higher rates of recurrence and metastasis. Intraoperative tools including drop-in ultrasound, near-infrared fluorescence, and 3D virtual models improve the ability to perform RAPN for T3a tumors. In well-selected cases, warm ischemia times remain reasonable. Conclusions: cT3a renal masses represent a diverse group of tumors. Depending on substratification of cT3a, RARN or RAPN can be employed for treatment of such masses.

Presurgical immune-oncology/tyrosine kinase inhibitor combination therapy for renal cell carcinoma with a vena cava tumor thrombus: a single-institution case series

Background

Although current guidelines recommend administering adjuvant immunotherapy following resection of advanced primary renal cell carcinoma (RCC), the clinical benefit of presurgical immunotherapy for patients with RCC remains uncertain.

Case Description

We conducted a retrospective analysis of five patients diagnosed with RCC who developed inferior vena cava (IVC) tumor thrombus and were treated with radical nephrectomy following combined immunotherapy with a tyrosine kinase inhibitor. The median follow-up after nephrectomy was 23 months (range, 19-30 months). In all cases, the size of the IVC tumor thrombus decreased, and three of the cases demonstrated a decrease in the tumor thrombus level. Surgical margins were negative in all cases, and none of the patients experienced any major intraoperative complications. However, adhesions were encountered at the operative sites during surgery in all cases. One patient required a lymphatic intervention due to abdominal lymphatic leakage (Clavien IIIa) within 90 days after operation. Our case series demonstrated a median progression-free survival (PFS) of 11 months [95% confidence interval (CI)]: 5.5-22.5 months). No patient died during the follow-up period.

Conclusions

Presurgical therapy combined with immunotherapy and tyrosine kinase inhibitors warrants consideration. Nevertheless, surgeons should be mindful of the difficulties that may arise beyond the clinical stage.

Establishing a prognostic model based on five starvation-related long non-coding RNAs for clear cell renal cell carcinoma

BACKGROUND

Starvation-induced tumor microenvironment significantly alters genetic profiles including long non-coding RNAs (lncRNAs), further regulating the malignant biological characteristics (invasion and migration) of clear cell renal cell carcinoma (ccRCC).

METHODS

Transcriptome RNA-sequencing data of 539 ccRCC tumors and 72 normal tissues were acquired from the TCGA and paired clinical samples of 50 ccRCC patients. In vitro experiments, such as qPCR, migration and invasion assays were applied to reveal the clinical relevance of LINC-PINT, AC108449.2 and AC007637.1.

RESULTS

170 lncRNAs were verified as starvation-related lncRNAs (SR-LncRs), of which 25 lncRNAs were associated with overall survival in ccRCC patients. Furthermore, a starvation-related risk score model (SRSM) was built based on the expression levels of LINC-PINT, AC108449.2, AC009120.2, AC008702.2 and AC007637.1. ccRCC patients with high level of LINC-PINT expression were divided into high-risk group and led to higher mortality, but AC108449.2 and AC007637.1 were contrary. Analogously, LINC-PINT was highly expressed in ccRCC cell lines and tumor tissues, especially in patients with advanced stage, T-stage and M-stage, while AC108449.2 and AC007637.1 showed the opposite results. In addition, the increased levels of AC108449.2 and AC007637.1 were significantly correlated with grade. Silencing LINC-PINT reduced the invasion and migration characteristics of ccRCC cells. SiR-AC108449.2 and siR-AC007637.1 enhanced the ability of invasion and migration in ccRCC cells.

CONCLUSIONS

In this study, we find the clinical significance of LINC-PINT, AC108449.2 and AC007637.1 in predicting the prognosis of ccRCC patients and verify their correlation with various clinical parameters. These findings provide an advisable risk score model for ccRCC clinical decision-making.

Integrative transcriptome and proteome analyses of clear cell renal cell carcinoma develop a prognostic classifier associated with thrombus

Clear cell renal cell carcinoma (ccRCC) with venous tumor thrombus (VTT) is associated with poor prognosis. Our integrative analyses of transcriptome and proteome reveal distinctive molecular features of ccRCC with VTT, and yield the development of a prognostic classifier to facilitate ccRCC molecular subtyping and treatment. The RNA sequencing and mass spectrometry were performed in normal-tumor-thrombus tissue triples of five ccRCC patients. Statistical analysis, GO and KEGG enrichment analysis, and protein-protein interaction network construction were used to interpret the transcriptomic and proteomic data. A six-gene-based classifier was developed to predict patients' survival using Cox regression, which was validated in an independent cohort. Transcriptomic analysis identified 1131 tumorigenesis-associated differentially expressed genes (DEGs) and 856 invasion-associated DEGs. Overexpression of transcription factor EGR2 in VTT indicated its important role in tumor invasion. Furthermore, proteomic analysis showed 597 tumorigenesis-associated differentially expressed proteins (DEPs) and 452 invasion-associated DEPs. The invasion-associated DEPs showed unique enrichment in DNA replication, lysine degradation, and PPAR signaling pathway. Integration of transcriptome and proteome reveals 142 tumorigenesis-associated proteins and 84 invasion-associated proteins displaying changes consistent with corresponding genes in transcriptomic profiling. Based on their different expression patterns among normal-tumor-thrombus triples, RAB25 and GGT5 were supposed to play a consistent role in both tumorigenesis and invasion processes, while SHMT2 and CADM4 might play the opposite roles in tumorigenesis and thrombus invasion. A prognostic classifier consisting of six DEGs (DEPTOR, DPEP1, NAT8, PLOD2, SLC7A5, SUSD2) performed satisfactorily in predicting survival of ccRCC patients (HR = 4.41, P < 0.001), which was further validated in an independent cohort of 40 cases (HR = 5.52, P = 0.026). Our study revealed the transcriptomic and proteomic profiles of ccRCC patients with VTT, and identified the distinctive molecular features associated with VTT. The six-gene-based prognostic classifier developed by integrative analyses may facilitate ccRCC molecular subtyping and treatment.

TTI1 promotes non-small-cell lung cancer progression by regulating the mTOR signaling pathway

The role of TELO2-interacting protein 1 (TTI1) in the progression of several types of cancer has been reported recently. The aim of this study was to estimate the expression and potential value of TTI1 in non-small-cell lung cancer (NSCLC) patients. The expression of TTI1 and its prognostic value in NSCLC from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO) database were analyzed. To verify the bioinformatics findings, a tissue microarray containing 160 NSCLC and paired peritumoral tissues from NSCLC patients was analyzed by immunohistochemistry for TTI1. Subsequently, the roles of TTI1 in NSCLC cells were investigated in vivo by establishing xenograft models in nude mice and in vitro by transwell, CCK-8, wound healing, and colony formation assays. In addition, quantitative real-time polymerase chain reaction and western blot were applied to explore the underlying mechanism by which TTI1 promotes tumor progression. Finally, the relationship between TTI1 and Ki67 expression level in NSCLC was probed, and Kaplan-Meier and Cox analyses were performed to assess the prognostic merit of TTI1 and Ki67 in NSCLC patients. We found that the expression of TTI1 was significantly upregulated in NSCLC tissues compared to paired peritumoral tissues, which coincides with the bioinformatics findings from the TCGA and GEO databases. TTI1 was highly expressed in NSCLC patients with large tumors, advanced tumor stage, and lymphatic metastasis. In addition, the prognostic analysis identified TTI1 as an independent indication for poor prognosis of NSCLC patients. In vitro, upregulation of TTI1 in NSCLC cells could facilitate cell invasion, metastasis, viability, and proliferation. Mechanistically, our study verified that TTI1 could regulate mTOR activity, which has a pivotal role in human cancer. Consistently, the expressions of TTI1 and Ki67 had a positive relationship in NSCLC cells and tissues. Notably, patients with overexpression of TTI1 or Ki67 had a shorter overall survival rate and a higher disease-free survival rate compared to patients with low expression of TTI1 or Ki67, and the combination of TTI1 and Ki67 was an independent parameter predicting the prognosis and recurrence of NSCLC patients. We conclude that TTI1 promotes NSCLC cell proliferation, metastasis, and invasion by regulating mTOR activity, and the combination of TTI1 and Ki67 is a valuable molecular biomarker for the survival and recurrence of NSCLC patients.

Single-cell RNA-seq integrated with multi-omics reveals SERPINE2 as a target for metastasis in advanced renal cell carcinoma

Tumor growth, metastasis and therapeutic response are believed to be regulated by the tumor and its microenvironment (TME) in advanced renal cell carcinoma (RCC). However, the mechanisms underlying genomic, transcriptomic and epigenetic alternations in RCC progression have not been completely defined. In this study, single-cell RNA-sequencing (scRNA-seq) data were obtained from eight tissue samples of RCC patients, including two matched pairs of primary and metastatic sites (lymph nodes), along with Hi-C, transposable accessible chromatin by high-throughput (ATAC-seq) and RNA-sequencing (RNA-seq) between RCC (Caki-1) and human renal tubular epithelial cell line (HK-2). The identified target was verified in clinical tissue samples (microarray of 407 RCC patients, TMA-30 and TMA-2020), whose function was further validated by in vitro and in vivo experiments through knockdown or overexpression. We profiled transcriptomes of 30514 malignant cells, and 14762 non-malignant cells. Comprehensive multi-omics analysis revealed that malignant cells and TME played a key role in RCC. The expression programs of stromal cells and immune cells were consistent among the samples, whereas malignant cells expressed distinct programs associated with hypoxia, cell cycle, epithelial differentiation, and two different metastasis patterns. Comparison of the hierarchical structure showed that SERPINE2 was related to these NNMF expression programs, and at the same time targeted the switched compartment. SERPINE2 was highly expressed in RCC tissues and lowly expressed in para-tumor tissues or HK-2 cell line. SERPINE2 knockdown markedly suppressed RCC cell growth and invasion, while SERPINE2 overexpression dramatically promoted RCC cell metastasis both in vitro and in vivo. In addition, SERPINE2 could activate the epithelial-mesenchymal transition pathway. The above findings demonstrated that the role of distinct expression patterns of malignant cells and TME played a distinct role in RCC progression. SERPINE2 was identified as a potential therapeutic target for inhibiting metastasis in advanced RCC.

Cell Competition Shapes Metastatic Latency and Relapse

Cell competition, a fitness-sensing process, is essential for tissue homeostasis. Using cancer metastatic latency models, we show that cell competition results in the displacement of latent metastatic (Lat-M) cells from the primary tumor. Lat-M cells resist anoikis and survive as residual metastatic disease. A memodeled extracellular matrix facilitates Lat-M cell displacement and survival in circulation. Disrupting cell competition dynamics by depleting secreted protein and rich in cysteine (SPARC) reduced displacement from orthotopic tumors and attenuated metastases. In contrast, depletion of SPARC after extravasation in lung-resident Lat-M cells increased metastatic outgrowth. Furthermore, multiregional transcriptomic analyses of matched primary tumors and metachronous metastases from patients with kidney cancer identified tumor subclones with Lat-M traits. Kidney cancer enriched for these Lat-M traits had a rapid onset of metachronous metastases and significantly reduced disease-free survival. Thus, an unexpected consequence of cell competition is the displacement of cells with Lat-M potential, thereby shaping metastatic latency and relapse.

SIGNIFICANCE

We demonstrate that cell competition within the primary tumor results in the displacement of Lat-M cells. We further show the impact of altering cell competition dynamics on metastatic incidence that may guide strategies to limit metastatic recurrences. This article is highlighted in the In This Issue feature, p. 1.

Pathology and the evolutionary dynamics of clear cell renal cell carcinoma

Cancer is an ecosystem whose intrinsic mechanisms do not show up under the microscope of pathologists. However, the information provided by pathologists is absolutely necessary for the correct implementation of personalized treatments. This short paper seeks to analyze this apparent paradox, i.e. static snapshots for making crucial decisions in essentially dynamic diseases, taking clear cell renal cell carcinoma as a paradigmatic example of tumor variability. We seek to call the attention of pathologists and other cancer-related medical specialists to extend knowledge of the evolutionary features of the disease to help obtain a better understanding of why cancer behaves as it does.

Cellular milieu in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is globally the most prevalent renal cancer. The cells of origin in ccRCC have been identified as proximal tubular epithelial cells (PTEC); however, the transcriptomic pathways resulting in the transition from normal to malignant PTEC state have remained unclear. Immunotherapy targeting checkpoints have revolutionized the management of ccRCC, but a sustained clinical response is achieved in only a minority of ccRCC patients. This indicates that our understanding of the mechanisms involved in the malignant transition and resistance to immune checkpoint therapy in ccRCC is unclear. This review examines recent single-cell transcriptomics studies of ccRCC to clarify the transition of PTEC in ccRCC development, and the immune cell types, states, and interactions that may limit the response to targeted immune therapy, and finally suggests stromal cells as key drivers in recurrent and locally invasive ccRCC. These and future single-cell transcriptomics studies will continue to clarify the cellular milieu in the ccRCC microenvironment, thus defining actional clinical, therapeutic, and prognostic characteristics of ccRCC.

Characterizing Tumor Thrombus Arising from Non–Clear Cell Renal Cell Carcinoma

Background

Renal cell carcinoma (RCC) can exhibit a unique vascular tropism that enables tumor thrombus extension into the inferior vena cava (IVC). While most RCC subtypes that form tumor thrombi are of clear cell (cc) histology, non–clear cell (ncc) subtypes can also exhibit this unique growth pattern.

Objective

To characterize clinicopathologic differences and survival outcomes among patients with IVC tumor thrombus arising from ccRCC versus nccRCC.

Design, setting, and participants

Patients diagnosed with IVC tumor thrombus secondary to RCC in our institutional experience from 2003 to 2021 were identified.

Outcome measurements and statistical analysis

Clinicopathologic characteristics were compared by histology. Perioperative and oncologic outcomes including recurrence-free (RFS), overall (OS), and cancer-specific (CSS) survival were assessed using multivariable Cox regression analyses.

Results and limitations

The analyzed cohort included 103 patients (82 ccRCC and 21 nccRCC). There were no significant differences in baseline demographic parameters. Patients with nccRCC were more likely to have regional lymph node involvement (42.9% vs 20.7%, p = 0.037). No differences in perioperative outcomes, IVC resection, or IVC reconstruction were observed between groups. The median follow-up time was 30 mo. The median RFS was 30 (nccRCC) versus 53 (ccRCC) mo (p = 0.1). There was no significant difference in OS or CSS. This study was limited by its small sample size.

Conclusions

Patients with IVC tumor thrombus arising from ccRCC and nccRCC exhibit similar perioperative and oncologic outcomes. While surgical appropriateness was not impacted by histologic subtype, multimodal strategies are needed to improve outcomes for patients with tumor thrombus.

Patient summary

Renal cell carcinoma (RCC) can uniquely invade vasculature and form a tumor thrombus. This study examined the difference in outcomes of patients with tumor thrombus based on RCC subtype (clear cell vs non–clear cell). We found that patients exhibited similar surgical and survival outcomes regardless of RCC type.

Decoding the multicellular ecosystem of vena caval tumor thrombus in clear cell renal cell carcinoma by single-cell RNA sequencing

Background

Vascular invasion with tumor thrombus frequently occurs in advanced renal cell carcinoma (RCC). Thrombectomy is one of the most challenging surgeries with high rate of perioperative morbidity and mortality. However, the mechanisms driving tumor thrombus formation are poorly understood which is required for designing effective therapy for eliminating tumor thrombus.

Results

We perform single-cell RNA sequencing analysis of 19 surgical tissue specimens from 8 clear cell renal cell carcinoma (ccRCC) patients with tumor thrombus. We observe tumor thrombus has increased tissue resident CD8⁺ T cells with a progenitor exhausted phenotype compared with the matched primary tumors. Remarkably, macrophages, malignant cells, endothelial cells and myofibroblasts from TTs exhibit enhanced remodeling of the extracellular matrix. The macrophages and malignant cells from primary tumors represent proinflammatory states, but also increase the expression of immunosuppressive markers compared to tumor thrombus. Finally, differential gene expression and interaction analyses reveal that tumor-stroma interplay reshapes the extracellular matrix in tumor thrombus associated with poor survival.

Conclusions

Our comprehensive picture of the ecosystem of ccRCC with tumor thrombus provides deeper insights into the mechanisms of tumor thrombus formation, which may aid in the design of effective neoadjuvant therapy to promote downstaging of tumor thrombus and decrease the perioperative morbidity and mortality of thrombectomy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13059-022-02651-9.

The changing role of natural killer cells in cancer metastasis

Natural killer (NK) cells are innate immune cells that are critical to the body's antitumor and antimetastatic defense. As such, novel therapies are being developed to utilize NK cells as part of a next generation of immunotherapies to treat patients with metastatic disease. Therefore, it is essential for us to examine how metastatic cancer cells and NK cells interact with each other throughout the metastatic cascade. In this Review, we highlight the recent body of work that has begun to answer these questions. We explore how the unique biology of cancer cells at each stage of metastasis alters fundamental NK cell biology, including how cancer cells can evade immunosurveillance and co-opt NK cells into cells that promote metastasis. We also discuss the translational potential of this knowledge.