Invasion and metastasis of renal cell carcinoma

Integration of basement membrane-related genes in a risk signature for prognosis in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is characterized by high heterogeneity and recurrence rates, posing significant challenges for stratification and treatment. Basement membrane-related genes (BMGs) play a crucial role in tumor initiation and progression. Clinical and transcriptomic data of ccRCC patients were extracted from TCGA and GEO databases. We employed univariate regression and LASSO-Cox stepwise regression analysis to construct a BMscore model based on BMGs expression level. A nomogram combining clinical features and BMscore was constructed to predict individual survival probabilities. Further enrichment analysis and immune-related analysis were conducted to explore the enriched pathways and immune features associated with BMGs. High-risk individuals predicted by BMscore exhibited poorer overall survival, which was consistent with the validation dataset. BMscore was identified as an independent risk factor for ccRCC. Functional analysis revealed that BMGs were related to cell-matrix and tumor-associated signaling pathways. Immune profiling suggests that BMGs play a key role in immune interactions and the tumor microenvironment. BMGs serve as a novel prognostic predictor for ccRCC and play a role in the immune microenvironment and treatment response. Targeting the BM may represent an alternative therapeutic approach for ccRCC.

Identification of Comprehensive Biomarkers in Patients With Mismatch Repair-Deficient Colon Adenocarcinoma Based on Parallel Multiomics

Immunocheckpoint inhibitors have shown impressive efficacy in patients with colon cancer and other types of solid tumor that are mismatch repair-deficient (dMMR). Currently, PCR-capillary electrophoresis is one of the mainstream detection methods for dMMR, but its accuracy is still limited by germline mismatch repair (MMR) mutations, the functional redundancy of the MMR system, and abnormal methylation of MutL Homolog 1 promoter. Therefore, this study aimed to develop new biomarkers for dMMR based on artificial intelligence (AI) and pathologic images, which may help to improve the detection accuracy. To screen for the differential expression genes (DEGs) in dMMR patients and validate their diagnostic and prognostic efficiency, we used the expression profile data from the Cancer Genome Atlas (TCGA). The results showed that the expression of Immunoglobulin Lambda Joining 3 in dMMR patients was significantly downregulated and negatively correlated with the prognosis. Meanwhile, our diagnostic models based on pathologic image features showed good performance with area under the curves (AUCs) of 0.73, 0.86, and 0.81 in the training, test, and external validation sets (Jiangsu Traditional Chinese Medicine Hospital cohort). Based on gene expression and pathologic characteristics, we developed an effective prognosis model for dMMR patients through multiple Cox regression analysis (with AUC values of 0.88, 0.89, and 0.88 at 1-, 3-, and 5-year intervals, respectively). In conclusion, our results showed that Immunoglobulin Lambda Joining 3 and nucleus shape-related parameters (such as nuclear texture, nuclear eccentricity, nuclear size, and nuclear pixel intensity) were independent diagnostic and prognostic factors, suggesting that they could be used as new biomarkers for dMMR patients.

ANKRD49 promotes the metastasis of NSCLC via activating JNK-ATF2/c-Jun-MMP-2/9 axis

BACKGROUND

Ankyrin repeat domain 49 (ANKRD49) has been found to be highly expressed in multiple cancer including lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC). However, the function of ANKRD49 in the pathogenesis of NSCLC still remains elusive. Previously, ANKRD49 has been demonstrated to promote the invasion and metastasis of A549 cells, a LUAD cell line, via activating the p38-ATF-2-MMP2/MMP9 pathways. Considering the heterogeneity of tumor cells, the function and mechanism of ANKRD49 in NSCLC need more NSCLC-originated cells to clarify.

METHODS

Real-time qPCR was employed to test ANKRD49 expression levels in nine pairs of fresh NSCLC tissues and the corresponding adjacent normal tissues. The function of ANKRD49 was investigated using overexpression and RNA interference assays in lung adenocarcinoma cell line (NCI-H1299) and lung squamous carcinoma cell line (NCI-H1703) through gelatin zymography, cell counting kit-8, colony formation, wound healing, migration and invasion assays mmunoprecipitation was performed to in vitro. Immunoprecipitation was performed to test the interaction of c-Jun and ATF2. Chromatin immunoprecipitation was conducted to assess the transcriptional regulation of ATF2/c-Jun on MMP-2/9. Moreover, the tumorigenicity of ANKRD49 was evaluated in nude mice models and the involved signal molecular was also measured by immunohistochemical method.

RESULTS

We found that the levels of ANKRD49 in cancerous tissues were higher than those in adjacent normal tissues. in vitro assay showed that ANKRD49 promoted the migration and invasion of NCI-H1299 and NCI-H1703 cells via enhancing the levels of MMP-2 and MMP-9. Furthermore, ANKRD49 elevated phosphorylation of JNK and then activated c-Jun and ATF2 which interact in nucleus to promote the binding of ATF2:c-Jun with the promoter MMP-2 or MMP-9. In vivo assay showed that ANKRD49 promoted lung metastasis of injected-NSCLC cells and the high metastatic rate was positively correlated with the high expression of ANKRD49, MMP-2, MMP-9, p-JNK, p-c-Jun and p-ATF2.

CONCLUSION

The present study indicated that ANKRD49 accelerated the invasion and metastasis of NSCLC cells via JNK-mediated transcription activation of c-Jun and ATF2 which regulated the expression of MMP-2/MMP-9. The molecular mechanisms of ANKRD49's function is different from those found in A549 cells. The current study is a supplement and improvement to the previous research.

Formin-related protein 1 facilitates proliferation and aggressive phenotype of clear cell renal cell carcinoma through MAPK/MMP2 pathway

BACKGROUND

Formin-related protein-1(FRL1) has reportedly been overexpressed in a variety of malignancies, such as clear cell renal cell carcinoma (ccRCC). However, the clinical value and molecular mechanisms underlying ccRCC tumorigenesis and progression in association with FRL1 remain poorly understood.

METHODS

Immunohistochemical analysis was performed on 119 paraffin-embedded RCC tissue samples to detect FRL1 expression and analyze its prognostic value. Colony formation, the CCK-8 assay, flow cytometry, and in vivo nude mice subcutaneous experiments were used to identify the effects of FRL1 on growth and proliferation. In vitro tests for wound healing, migration, and invasion were used to assess the involvement of FRL1 in invasion and metastatic potential. The process of epithelial-mesenchymal transition process (EMT) and the MMP2 expression were detected in stably transfected RCC cells via western blotting, as well as in tumor tissue paraffin sections from xenograft model.

RESULTS

Both FRL1 mRNA and protein levels were noticeably elevated in ccRCC cell lines and samples. Aberrant overexpression of FRL1 was associated with unfavorable clinicopathological features of ccRCC and indicated poor prognosis. Ectopic overexpression of FRL1 increased the growth-promoting traits of ccRCC cells as well as the migratory and invasive capacity of RCC cells, whereas FRL1-silencing caused the opposite results. In addition, FRL1 promoted epithelial-mesenchymal transition (EMT) and upregulated the expression of matrix metalloproteinase 2 (MMP2). Finally, overexpression of FRL1 upregulated phosphorylation level of ERK1/2 with no effect on total level of ERK1/2 in the RCC cells. MAPK/ERK inhibitor reversed the promotional effects of FRL1.

CONCLUSION

FRL1 was overexpressed in ccRCC tissues and predicted poor prognosis. FRL1 contributes to invasion and aggressive phenotype of ccRCC by facilitating EMT through MAPK/MMP2 axis.

Testicular Metastasis from Renal Cell Carcinoma: A Systematic Review

Approximately one-third of renal cell carcinoma (RCC) is recognized in its metastatic stage. This systematic review aimed to summarize knowledge on the occurrence and treatment of testicular RCC metastasis. The literature search was performed by two authors independently, with the use of main electronic medical databases (Science Direct, Web of Science, and PubMed) until March 2023 to identify relevant articles that could potentially contribute to this review. Neither language nor publication dates were set as limits. Although we found a total of 51 case reports, only 31 of them contained all the required information. Testicular metastasis in patients with RCC suggests a late stage of the disease. Moreover, it usually does not present typical systemic or specific symptoms except for swelling and enlargement of the affected testis. Knowledge of the possibility of such variants of RCC metastases will allow a clinician to make an appropriate diagnosis and implement adequate treatment without delay, which is crucial in the management of neoplastic disease.

Development and External Validation of Machine Learning-Based Models for Predicting Lung Metastasis in Kidney Cancer: A Large Population-Based Study

The accuracy of indices widely used to evaluate lung metastasis (LM) in patients with kidney cancer (KC) is insufficient. Therefore, we aimed at developing a model to estimate the risk of developing LM in KC based on a large population size and machine learning algorithms. Demographic and clinicopathologic variables of patients with KC diagnosed between 2004 and 2017 were retrospectively analyzed. We performed a univariate logistic regression analysis to identify risk factors for LM in patients with KC. Six machine learning (ML) classifiers were established and tuned using the ten-fold cross-validation method. External validation was performed using clinicopathologic information from 492 patients from the Southwest Hospital, Chongqing, China. Algorithm performance was estimated by analyzing the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, precision, recall, F1 score, clinical decision analysis (DCA), and clinical utility curve (CUC). A total of 52,714 eligible patients diagnosed with KC were enrolled, of whom 2,618 developed LM. Variables of age, sex, race, T stage, N stage, tumor size, histology, and grade were identified as important for the prediction of LM. The extreme gradient boosting (XGB) algorithm performed better than other models in both the internal validation (AUC: 0.913, sensitivity: 0.873, specificity: 0.809, and F1 score: 0.325) and the external validation (AUC: 0.904, sensitivity: 0.750, specificity: 0.878, and F1 score: 0.364). This study established a predictive model for LM in KC patients based on ML algorithms which showed high accuracy and applicative value. A web-based predictor was built using the XGB model to help clinicians make more rational and personalized decisions.

Identification of basement membrane-related prognostic signature for predicting prognosis, immune response and potential drug prediction in papillary renal cell carcinoma

Papillary renal cell carcinoma (PRCC) is a malignant neoplasm of the kidney and is highly interesting due to its increasing incidence. Many studies have shown that the basement membrane (BM) plays an important role in the development of cancer, and structural and functional changes in the BM can be observed in most renal lesions. However, the role of BM in the malignant progression of PRCC and its impact on prognosis has not been fully studied. Therefore, this study aimed to explore the functional and prognostic value of basement membrane-associated genes (BMs) in PRCC patients. We identified differentially expressed BMs between PRCC tumor samples and normal tissue and systematically explored the relevance of BMs to immune infiltration. Moreover, we constructed a risk signature based on these differentially expressed genes (DEGs) using Lasso regression analysis and demonstrated their independence using Cox regression analysis. Finally, we predicted 9 small molecule drugs with the potential to treat PRCC and compared the differences in sensitivity to commonly used chemotherapeutic agents between high and low-risk groups to better target patients for more precise treatment planning. Taken together, our study suggested that BMs might play a crucial role in the development of PRCC, and these results might provide new insights into the treatment of PRCC.

Tat-hspb1 Suppresses Clear Cell Renal Cell Carcinoma (ccRCC) Growth via Lysosomal Membrane Permeabilization

Clear cell renal cell carcinoma (ccRCC) is the most prevalent kidney cancer, of which the incidence is increasing worldwide with a high mortality rate. Bioactive peptides are considered a significant class of natural medicines. We applied mass spectrometry-based peptidomic analysis to explore the peptide profile of human renal clear cell carcinoma and adjacent normal tissues. A total of 18,031 peptides were identified, of which 105 unique peptides were differentially expressed (44 were up-regulated and 61 were down-regulated in ccRCC tissues). Through bioinformatic analysis, we finally selected one peptide derived from the HSPB1 protein (amino acids 12-35 of the N-terminal region of HSPB1). Next, we fused this peptide to the HIV-Tat, generated a novel peptide named Tat-hspb1, and found that Tat-hspb1 inhibited ccRCC cells' viability while being less cytotoxic to normal epithelial cells. Furthermore, Tat-hspb1 induced apoptosis and inhibited the proliferation and migration of ccRCC cells. Furthermore, we demonstrated that Tat-hspb1 was predominantly localized in lysosomes after entering the ccRCC cell and induced lysosomal membrane permeabilization (LMP) and the release of cathepsin D from lysosomes. Taken together, Tat-hspb1 has the potential to serve as a new anticancer drug candidate.

BACH1 promotes clear cell renal cell carcinoma progression by upregulating oxidative stress-related tumorigenicity

The carcinogenesis and progression of renal cell carcinoma (RCC), a heterogeneous cancer derived from renal tubular epithelial cells, is closely related to oxidative stress responses (OSRs). Oxidative stress responses participate in various biological processes related to the metabolism and metastatic potential of cancer such as inflammation, epithelial-mesenchymal transition (EMT), and angiogenesis. In this study, we investigated the role of broad complex-tramtrack-bric-a-brac and cap 'n' collar homology 1 (BACH1), a key transcription factor for OSRs, in clear cell RCC (ccRCC) development and prognosis. The poor prognosis and elevation of serum inflammation markers in nephrectomized ccRCC patients were correlated with the intratumor expression of BACH1 accompanied by a downregulation of heme oxygenase-1. BACH1 contributes to the invasion and migration abilities of RCC cell lines without affecting their proliferation in vitro. In contrast, BACH1 contributes to tumor progression in vivo, in relation to OSRs with the activation of EMT-related pathways. BACH1 involvement in other OSR-linked pathways, including inflammatory responses, angiogenesis, and mTOR signaling, was further revealed by RNA sequencing analysis of BACH1-knockdown cells. In conclusion, the crucial role of BACH1 in the pathogenesis and poor prognosis of ccRCC through the promotion of OSRs is suggested.

IFI35 Promotes Renal Cancer Progression by Inhibiting pSTAT1/pSTAT6-Dependent Autophagy

Interferon-induced protein 35 (IFI35), is currently acknowledged to govern the virus-related immune inflammatory responses. However, the biological significance and function of IFI35 in renal cell cancer (RCC) is still not well understood. Here, IFI35 expression and function were investigated in RCC tissues, renal cancer cells, and animal models. The results showed that IFI35 expression was significantly increased in 200 specimens of RCC patients. We found that higher IFI35 levels were significantly correlated with poor RCC prognosis. In human cell lines, the knockdown of IFI35 suppressed the malignant behavior of renal cancer cells. Similarly, the IFI35 knockdown resulted in significant inhibition of tumor progression in the subcutaneous or lung metastasis mouse model. Furthermore, the knockdown of IFI35 promoted the induction of autophagy by enhancing the autophagy-related gene expression (LC3-II, Beclin-1, and ATG-5). Additionally, blockade of STAT1/STAT6 phosphorylation (pSTAT1/pSTAT6) abrogated the induced autophagy by IFI35 knockdown in renal cancer cells. The autophagy inhibitor 3-MA also abolished the prevention of tumor growth by deleting IFI35 in renal cancer models. The above results suggest that the knockdown of IFI35 suppressed tumor progression of renal cancer by pSTAT1/pSTAT6-dependent autophagy. Our research revealed that IFI35 may serve as a potential diagnosis and therapeutic target for RCC.

Solitary Contralateral Adrenal Metastasis of Renal Cell Carcinoma: 68Ga-DOTATATE PET/CT Findings

ABSTRACT

68Ga-DOTATATE PET/CT is an imaging technique used in the diagnosis of neuroendocrine tumors. Since renal cell carcinoma (RCC) expresses the somatostatin receptors, 68Ga-DOTATATE PET/CT could be used in the surveillance of RCC. However, limited cases showing 68Ga-DOTATATE uptake in the metastases of RCC have been reported before. Herein, we report a case of a 55-year-old woman with a history of left nephrectomy for clear cell renal cell carcinoma 2 years before, and referred to 68Ga-DOTATATE PET/CT for the evaluation of adrenal mass. 68Ga-DOTATATE PET/CT showed intense 68Ga-DOTATATE uptake on the adrenal mass. Histopathology of the adrenal mass confirmed the diagnosis of clear cell renal cell carcinoma metastasis.

All bone metastases are not created equal: Revisiting treatment resistance in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common malignancy of the kidney, representing 80-90% of renal neoplasms, and is associated with a five-year overall survival rate of approximately 74%. The second most common site of metastasis is bone. As patients are living longer due to new RCC targeting agents and immunotherapy, RCC bone metastases (RCCBM) treatment failure is more prevalent. Bone metastasis formation in RCC is indicative of a more aggressive disease and worse prognosis. Osteolysis is a prominent feature and causes SRE, including pathologic fractures. Bone metastasis from other tumors such as lung, breast, and prostate cancer, are more effectively treated with bisphosphonates and denosumab, thereby decreasing the need for palliative surgical intervention. Resistance to these antiresportives in RCCBM reflects unique cellular and molecular mechanisms in the bone microenvironment that promote progression via inhibition of the anabolic reparative response. Identification of critical mechanisms underlying RCCBM induced anabolic impairment could provide needed insight into how to improve treatment outcomes for patients with RCCBM, with the goals of minimizing progression that necessitates palliative surgery and improving survival.

LncRNAs in the Regulation of Genes and Signaling Pathways through miRNA-Mediated and Other Mechanisms in Clear Cell Renal Cell Carcinoma

The fundamental novelty in the pathogenesis of renal cell carcinoma (RCC) was discovered as a result of the recent identification of the role of long non-coding RNAs (lncRNAs). Here, we discuss several mechanisms for the dysregulation of the expression of protein-coding genes initiated by lncRNAs in the most common and aggressive type of kidney cancer-clear cell RCC (ccRCC). A model of competitive endogenous RNA (ceRNA) is considered, in which lncRNA acts on genes through the lncRNA/miRNA/mRNA axis. For the most studied oncogenic lncRNAs, such as HOTAIR, MALAT1, and TUG1, several regulatory axes were identified in ccRCC, demonstrating a number of sites for various miRNAs. Interestingly, the LINC00973/miR-7109/Siglec-15 axis represents a novel agent that can suppress the immune response in patients with ccRCC, serving as a valuable target in addition to the PD1/PD-L1 pathway. Other mechanisms of action of lncRNAs in ccRCC, involving direct binding with proteins, mRNAs, and genes/DNA, are also considered. Our review briefly highlights methods by which various mechanisms of action of lncRNAs were verified. We pay special attention to protein targets and signaling pathways with which lncRNAs are associated in ccRCC. Thus, these new data on the different mechanisms of lncRNA functioning provide a novel basis for understanding the pathogenesis of ccRCC and the identification of new prognostic markers and targets for therapy.

Shoulder pain in a patient with renal cell carcinoma? Suprascapular neuropathy caused by bone metastasis of renal cell carcinoma: A case report

BACKGROUND

Pain management is crucial in palliative care for patients with advanced cancer. Here, we report a case of shoulder pain in a patient with renal cell carcinoma.

CASE PRESENTATION

A 36-year-old male diagnosed metastatic renal cell carcinoma presented with pain and weakness on left shoulder for more than 6 months. Physical examination showed limited range of motion and atrophic changes on supraspinatus and infraspinatus muscles. Weakness in shoulder abduction and external rotation was also noted.

POSSIBLE COURSES OF ACTION

In this case, suprascapular neuropathy, adhesive capsulitis of shoulder and metastatic lesions involving shoulder joint were suspected.

FORMULATION OF A PLAN

We planned imaging studies including X-ray, bone scan, magnetic resonance imaging, and electrodiagnostic studies.

OUTCOME

Imaging and electrodiagnostic studies showed suprascapular neuropathy by bone metastasis. Conservative treatment including injection and rehabilitation therapy reduced the patient's pain and improved the range of motion limitation.

LESSONS FROM THE CASE

Clinicians should be aware that bone metastasis in patients with advanced cancer can cause suprascapular neuropathy, shoulder pain and shoulder dysfunction.

VIEW ON RESEARCH PROBLEMS, OBJECTIVES, OR QUESTIONS GENERATED BY THE CASE

More research is expected on development of an early surveillance model, barriers to cancer pain management, communication from patients' perspectives.

SMAD4 Expression in Renal Cell Carcinomas Correlates With a Stem-Cell Phenotype and Poor Clinical Outcomes

Renal cell carcinoma (RCC) is the most lethal neoplasm of common urologic cancers with poor prognoses. SMAD4 has a principal role in TGF-β (Transformis growth factorβ)-induced epithelial to mesenchymal transition (EMT) as a key factor in gaining cancer stem cell (CSC) features and tumor aggressiveness. This study aimed to evaluate the expression patterns and clinical significance of SMAD4 in RCC and the impact of its targeting on stem cell/mesenchymal cells and EMT characteristics in renal spheroid derived cells (SDCs) compared to parental cells (PCs) in RCC. The expression pattern and clinical significance of SMAD4 was evaluated in RCC. SDCs were enriched using a sphere culture system. Then SDCs and their PCs were compared with respect to their sphere and colony formation, expression of putative CSC markers, invasiveness as well as expression of genes, including stemness/mesenchymal, SMAD4 and TGFβ1genes. Finally, the effect of SMAD4 knockdown on SDCs was analyzed. We demonstrated that SMAD4 is positively correlated with decreased disease specific survival (DSS) in RCC patients and clear cell RCC (ccRCC) subtype and associates with poor DSS in patients with RCC, especially in ccRCC as the most metastatic RCC subtype. SDCs exhibited higher stem cell/mesenchymal properties. Inhibition of SMAD4 in PCs accelerated the dissociation of SDCs and decreased their clonogenicity, invasiveness, expression of mesenchymal markers and expression of SMAD4 and TGFβ1 genes compared to SDCs before transfection. We suggest that targeting SMAD4 may be useful against renal CSCs and may improve RCC prognosis.

RUNX1/miR-582-5p Pathway Regulates the Tumor Progression in Clear Cell Renal Cell Carcinoma by Targeting COL5A1

Recent evidences indicated that miRNAs played core role in the progression of clear cell renal cell carcinoma (ccRCC). However, its molecular mechanism in ccRCC is still remained unclear. The study was designed to identify the role and regulatory mechanism of miR-582-5p in ccRCC. In this study, the low expression level of miR-582-5p were detected by qRT-PCR in ccRCC patient tumor samples and ccRCC cell lines, respectively. The expression level of miR-582-5p was associated with tumor stage and metastasis. In vivo and in vitro experiments found miR-582-5p inhibit tumor growth via suppressing COL5A1 expression. Additionally, RUNX1 was identified as the negative regulator of miR-582-5p through database prediction and chromatin immunoprecipitation. Finally, the negative relation of RUNX1 and miR-582-5p was verified through rescue experiment both in vitro and in vivo. In summary, miR-582-5p, which was regulated by RUNX1, inhibited tumor growth and invasion by targeting COL5A1, indicating that miR-582-5p may act as a biomarker and that the RUNX1/miR-582-5p/COL5A1 axis could be a potential therapeutic target for ccRCC.

Recurrent renal cell carcinoma to the breast and thigh soft tissues. A case report and review of the literature

The breast seldom harbors secondary malignant lesions and is rarer for the kidney to be the origin of the metastatic lesion. Keen Imaging analysis, as well as a high index of suspicion, are critical to differentiate a primary tumor from a metastatic lesion. We describe an unusual case of a recurrent RCC presenting as metastatic lesions to the breast and soft tissue of the right thigh in a 51-year-old patient referred to our breast-imaging unit 10 months after therapeutic surgery. An adequate and close follow-up accompanied by a thorough physical exam and appropriate imaging methods is essential to identify these types of cases.

Identification of a novel cancer stem cell subpopulation that promotes progression of human fatal renal cell carcinoma by single-cell RNA-seq analysis

Background: Cancer stem cells (CSCs) are biologically characterized by self-renewal, multi-directional differentiation and infinite proliferation, inducing anti-tumor drug resistance and metastasis. In the present study, we attempted to depict the baseline landscape of CSC-mediated biological properties, knowing that it is vital for tumor evolution, anti-tumor drug selection and drug resistance against fatal malignancy.

Methods: We performed single-cell RNA sequencing (scRNA-seq) analysis in 15208 cells from a pair of primary and metastatic sites of collecting duct renal cell carcinoma (CDRCC). Cell subpopulations were identified and characterized by t-SNE, RNA velocity, monocle and other computational methods. Statistical analysis of all single-cell sequencing data was performed in R and Python.

Results: A CSC population of 1068 cells was identified and characterized, showing excellent differentiation and self-renewal properties. These CSCs positioned as a center of the differentiation process and transformed into CDRCC primary and metastatic cells in spatial and temporal order, and played a pivotal role in promoting the bone destruction process with a positive feedback loop in the bone metastasis microenvironment. In addition, CSC-specific marker genes BIRC5, PTTG1, CENPF and CDKN3 were observed to be correlated with poor prognosis of CDRCC. Finally, we pinpointed that PARP, PIGF, HDAC2, and FGFR inhibitors for effectively targeting CSCs may be the potential therapeutic strategies for CDRCC.

Conclusion: The results of the present study may shed new light on the identification of CSCs, and help further understand the mechanism underlying drug resistance, differentiation and metastasis in human CDRCC.

Contrast-enhanced magnetic resonance (MR) T1 mapping with low-dose gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) is promising in identifying clear cell renal cell carcinoma histopathological grade and differentiating fat-poor angiomyolipoma

Background

This study aimed to identify clear cell renal cell carcinoma (ccRCC) histopathological grade and differentiate it from fat-poor angiomyolipoma (AML). This was achieved through contrast-enhanced magnetic resonance (MR) T1 mapping with intravenous low-dose gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA).

Methods

In total, 56 consecutive patients received MR scanning between January 2016 and December 2018 using the pre- and post- contrast-enhanced T1 mapping sequences with low-dose Gd-DTPA (0.036 mmol/kg). RCCs were pathologically proven in 40 patients after surgery and graded according to the International Society of Urological Pathology (ISUP) classification system. Ten AMLs were pathologically proven by surgery histopathology and six AMLs were diagnosed by magnetic resonance imaging (MRI). Patients were followed up for more than half a year. The mean T1 values of the renal lesion and ipsilateral normal renal parenchyma were measured before and after Gd-DTPA administration (T1p and T1e). The reduction of T1 value (T1d) and the ratio of its reduction (T1d %) were calculated and compared.

Results

In 40 ccRCCs, higher-grade [International Society of Urologic Pathology (ISUP) grade 3 and 4] and lower-grade (ISUP grade 1 and 2) ccRCCs were noted in 13 and 27 patients, respectively. The mean T1p was 1,514.8±139.4 ms and the mean T1d was 907.7±193.7 ms in the higher-grade ccRCCs, which were significantly higher than in the lower-grade ccRCCs (T1p =1,251.7±151.5 ms and T1d =648.5±218.2 ms, respectively; P<0.001). Fat-poor AMLs had higher T1p (1,677.3±104.8 ms) and T1e (865.6±251.5 ms) as compared to ccRCCs (P<0.001). Combined T1p + T1d showed the highest area under the curve (AUC) (0.912) in the differentiation of higher-grade ccRCCs from lower-grade ccRCCs (P=0.010). Combined T1p + T1e had the highest AUC (0.956) in the differentiation between ccRCCs and fat-poor AMLs (P=0.010). All T1 mapping metrics could discriminate between normal renal parenchyma and renal lesions (P<0.001). No significant difference was found in the T1p and T1e at different parts of the ipsilateral normal renal parenchyma. Interobserver agreement for quantitative longitudinal relaxation time in the T1 maps was excellent.

Conclusions

Contrast-enhanced T1 mapping with low-dose Gd-DTPA may provide a more reliable and accurate approach in identifying ccRCCs histopathological grade and differentiating ccRCCs from fat-poor AMLs.

Integrative Radiogenomics Approach for Risk Assessment of Post-Operative Metastasis in Pathological T1 Renal Cell Carcinoma: A Pilot Retrospective Cohort Study

Despite the increasing incidence of pathological stage T1 renal cell carcinoma (pT1 RCC), postoperative distant metastases develop in many surgically treated patients, causing death in certain cases. Therefore, this study aimed to create a radiomics model using imaging features from multiphase computed tomography (CT) to more accurately predict the postoperative metastasis of pT1 RCC and further investigate the possible link between radiomics parameters and gene expression profiles generated by whole transcriptome sequencing (WTS). Four radiomic features, including the minimum value of a histogram feature from inner regions of interest (ROIs) (INNER_Min_hist), the histogram of the energy feature from outer ROIs (OUTER_Energy_Hist), the maximum probability of gray-level co-occurrence matrix (GLCM) feature from inner ROIs (INNER_MaxProb_GLCM), and the ratio of voxels under 80 Hounsfield units (Hus) in the nephrographic phase of postcontrast CT (Under80HURatio), were detected to predict the postsurgical metastasis of patients with pathological stage T1 RCC, and the clinical outcomes of patients could be successfully stratified based on their radiomic risk scores. Furthermore, we identified heterogenous-trait-associated gene signatures correlated with these four radiomic features, which captured clinically relevant molecular pathways, tumor immune microenvironment, and potential treatment strategies. Our results of accurate surrogates using radiogenomics could lead to additional benefit from adjuvant therapy or postsurgical metastases in pT1 RCC.

Spindle cell renal cell carcinoma diagnosed after sunitinib treatment for chromophobe renal cell carcinoma

INTRODUCTION

Chromophobe renal cell carcinoma presents in early pathological stages with a lower risk of metastasis. However, aggressive features and metastasis can occur. A rare case of rapidly progressive disease with histological changes is presented.

CASE PRESENTATION

A 56-year-old woman had a right renal tumor with multiple lymph node metastases, and the pathological diagnosis of the biopsy specimens from the primary tumor was chromophobe renal cell carcinoma. After sunitinib treatment, the metastatic lymph node had decreased in size and the numbers of circulating tumor cells were decreased, consequently, cytoreductive nephrectomy was performed. However, rapid progression of lymph node metastases was observed. Histopathological examination showed that the renal tumor was diagnosed as spindle cell renal carcinoma.

CONCLUSION

It appears that the primary tumor underwent epithelial-mesenchymal transition; further tissue specimen collection and analysis might be needed.

6-Shogaol Suppresses 2-Amino-1-Methyl-6-Phenylimidazo [4,5-b] Pyridine (PhIP)-Induced Human 786-O Renal Cell Carcinoma Osteoclastogenic Activity and Metastatic Potential

2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) which can be detected in processed meats and red meats, is a potential carcinogen for renal cell carcinoma (RCC). Approximately 30% of patients with metastatic RCC have bone metastases, and the prognosis of RCC with bone metastases is poor. Thus, the aim of the present study was to investigate whether PhIP induced bone metastases and to develop novel therapeutic agents. Our data revealed that PhIP pre-treatment increased the production of parathyroid hormone-related protein (PTHrP) in human 786-O renal cell carcinoma cells. Subsequently, the cultures of human osteoblasts with PhIP-stimulated condition medium of 786-O increased the expression of the macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL), and decreased the expression of osteoprotegerin (OPG). In addition, PhIP-mediated PTHrP up-regulated as well as increased IL-8 secretion in 786-O cells, and then contributed to 786-O-mediated bone resorption. Furthermore, 6-shogaol, which is an active ingredient in ginger, showed suppressive effects on PhIP-mediated bone resorption. In summary, this is the first study to demonstrate that PhIP pre-treatment increases the stimulatory effect of human renal cell carcinoma 786-O on osteoclastogenesis activity directly by PTHrP. In addition, 6-shogaol treatment reverses PhIP-mediated bone resorption. It suggests that 6-shogaol treatment results in bone resorption activity in the RCC model in vitro.

Overexpression of COL5A1 promotes tumor progression and metastasis and correlates with poor survival of patients with clear cell renal cell carcinoma

Background and aims

COL5A1 has been identified to be involved in metastasis of clear cell renal cell carcinoma (ccRCC) by bioinformatic analysis. This study aimed to investigate COL5A1 expression and its clinical significance in ccRCC. The function of COL5A1 in ccRCC was further investigated.

Methods

COL5A1 expression was examined in 256 ccRCC tissues and paired adjacent normal renal tissues by immunohistochemistry and real-time quantitative PCR. The clinical significance of COL5A1 expression was evaluated. Downregulation of COL5A1 was achieved using siRNA. The effects of COL5A1 silencing on cell proliferation, apoptosis, migration, invasion in vitro, and tumor growth in vivo were investigated.

Results

COL5A1 expression was upregulated in the majority of the ccRCC tissues at both protein and mRNA levels. COL5A1 expression was significantly correlated with tumor diameter, tumor stage, tumor grade, distant metastasis, recurrence, necrosis, and sarcomatoid (all P<0.05). COL5A1 expression was also significantly associated with overall survival of ccRCC patients (HR 1.876; P=0.027) and recurrence-free survival of localized ccRCC patients (HR 4.751; P<0.001). The accuracy of TNM, University of California Los Angeles Integrated Staging System, and Mayo clinic stage, size, grade, and necrosis prognostic models was improved when COL5A1 expression was added.

Conclusion

COL5A1 knockdown significantly inhibited cell proliferation, induced cell apoptosis, inhibited cell migration and invasion in vitro, and inhibited tumor growth in vivo. Therefore, COL5A1 may be a novel prognostic biomarker and a promising therapeutic target for ccRCC.

NLRC5 mediates cell proliferation, migration, and invasion by regulating the Wnt/β-catenin signalling pathway in clear cell renal cell carcinoma

NLRC5, a newly discovered member of the NLR family, has been reported to regulate immune responses and promote cell proliferation, migration, and invasion in hepatocellular carcinoma. However, to date, the potential regulatory roles and molecular mechanisms by which NLRC5 affects the development and progression of clear cell renal cell carcinoma (ccRCC) remain largely unknown. In this study, human clinical data from The Cancer Genome Atlas database revealed that increased NLRC5 expression was associated with advanced stage and poor prognosis in ccRCC patients. Moreover, experimental results showed that NLRC5 is aberrantly overexpressed in human ccRCC tissues and cell lines. Depletion of NLRC5 attenuated ccRCC cell proliferation, migration, and invasion and suppressed ccRCC growth in a nude mouse model. By contrast, overexpression of NLRC5 promoted the proliferation, migration, and invasion of ccRCC cells in vitro. Additionally, NLRC5 expression is not only positively correlated with β-catenin but also coordinates the activation of the downstream Wnt/β-catenin signalling pathway. Together, our data suggest that NLRC5 may be a potential therapeutic target for ccRCC therapy.

Calcium-sensing receptor (CaSR) promotes development of bone metastasis in renal cell carcinoma

Bone metastasis is an important prognostic factor in renal cell carcinoma (RCC). The calcium-sensing receptor (CaSR) has been associated with bone metastasis in several different malignancies. We analyzed the impact of CaSR in bone metastasis in RCC in vitro and in vivo. The RCC cell line 786-O was stably transfected with the CaSR gene and treated with calcium alone or in combination with the CaSR antagonist NPS2143. Afterwards migration, adhesion, proliferation and prominent signaling molecules were analyzed. Calcium treated CaSR-transfected 768-O cells showed an increased adhesion to endothelial cells and the extracellular matrix components fibronectin and collagen I, but not to collagen IV. The chemotactic cell migration and proliferation was also induced by calcium. The activity of SHC, AKT, ERK, P90RSK and JNK were enhanced after calcium treatment of CaSR-transfected cells. These effects were abolished by NPS2143. Development of bone metastasis was evaluated in vivo in a mouse model. Intracardiac injection of CaSR-transfected 768-O cells showed an increased rate of bone metastasis. The results indicate CaSR as an important component in the mechanism of bone metastasis in RCC. Therefore, targeting CaSR might be beneficial in patients with bone metastatic RCC with a high CaSR expression.

TCF21 hypermethylation regulates renal tumor cell clonogenic proliferation and migration

We recently identified hypermethylation at the gene promoter of transcription factor 21 (TCF21) in clear cell sarcoma of the kidney (CCSK), a rare pediatric renal tumor. TCF21 is a transcription factor involved in tubular epithelial development of the kidney and is a candidate tumor suppressor. As there are no in vitro models of CCSK, we employed a well-established clear cell renal cell carcinoma (ccRCC) cell line, 786-O, which also manifests high methylation at the TCF21 promoter, with consequent low TCF21 expression. The tumor suppressor function of TCF21 has not been functionally addressed in ccRCC cells; we aimed to explore the functional potential of TCF21 expression in ccRCC cells in vitro. 786-O clones stably transfected with either pBABE-TCF21-HA construct or pBABE vector alone were functionally analyzed. We found that ectopic expression of TCF21 in 786-O cells results in a trend toward decreased cell proliferation (not significant) and significantly decreased migration compared with mock-transfected 786-O cells. Although the number of colonies established in colony formation assays was not different between 786-O clones, colony size was significantly reduced in 786-O cells expressing TCF21. To investigate whether the changes in migration were due to epithelial-to-mesenchymal transition changes, we interrogated the expression of selected epithelial and mesenchymal markers. Although we observed upregulation of mRNA and protein levels of epithelial marker E-cadherin in clones overexpressing TCF21, this did not result in surface expression of E-cadherin as measured by fluorescence-activated cell sorting and immunofluorescence. Furthermore, mRNA expression of the mesenchymal markers vimentin (VIM) and SNAI1 was not significantly decreased in TCF21-expressing 786-O cells, while protein levels of VIM were markedly decreased. We conclude that re-expression of TCF21 in renal cancer cells that have silenced their endogenous TCF21 locus through hypermethylation results in reduced clonogenic proliferation, reduced migration, and reduced mesenchymal-like characteristics, suggesting a tumor suppressor function for transcription factor 21.

Cytoplasmic expression of Twist1, an EMT-related transcription factor, is associated with higher grades renal cell carcinomas and worse progression-free survival in clear cell renal cell carcinoma

Twist1 is a key transcription factor, which confers tumor cells with cancer stem cell (CSC)-like characteristics and enhances epithelial-mesenchymal transition in pathological conditions including tumor malignancy and metastasis. This study aimed to evaluate the expression patterns and clinical significance of Twist1 in renal cell carcinoma (RCC). The cytoplasmic and nuclear expression of Twist1 were examined in 252 well-defined renal tumor tissues, including 173 (68.7%) clear cell renal cell carcinomas (ccRCC), 45 (17.9%) papillary renal cell carcinomas (pRCC) and 34 (13.5%) chromophobe renal cell carcinoma, by immunohistochemistry on a tissue microarray. The association between expression of this marker and clinicopathologic parameters and survival outcomes were then analyzed. Twist1 was mainly localized to the cytoplasm of tumor cells (98.8%). Increased cytoplasmic expression of Twist1 was associated with higher grade tumors (P = 0.045), renal vein invasion (P = 0.031) and microvascular invasion (P = 0.044) in RCC. It was positively correlated with higher grade tumors (P = 0.026), shorter progression-free survival time (P = 0.027) in patients with ccRCC, and also with higher stage in pRCC patients (P = 0.036). Significantly higher cytoplasmic expression levels of Twist1 were found in ccRCC and pRCC subtypes, due to their more aggressive tumor behavior. Increased cytoplasmic expression of Twist1 had a critical role in worse prognosis in ccRCC. These findings suggest that cytoplasmic, rather than nuclear expression of Twist1 can be considered as a prognostic and therapeutic marker for targeted therapy of RCC, especially for ccRCC patients.

Early identification and intervention matters: A comprehensive review of current evidence and recommendations for the monitoring of bone health in patients with cancer

Bone metastases are common in patients with advanced solid tumors, and many individuals experience debilitating skeletal-related events (SREs; e.g. pathologic fracture, hypercalcemia, radiotherapy or surgery to bone, and spinal cord compression). These events substantially affect disease outcomes, including survival and quality of life, and healthcare systems. Plain radiography is the most widely used imaging modality for the detection of bone metastases; skeletal scintigraphy, computed tomography, positron emission tomography and magnetic resonance imaging offer greater sensitivity but their use in routine practice is restricted by high costs and limited availability. Biomarkers of bone turnover may also have a role in the early detection of bone metastases and can provide valuable prognostic information on disease progression. SREs can be delayed or prevented using agents such as the receptor activator of nuclear factor kappa B ligand (RANKL) inhibitor, denosumab, and bisphosphonates. Painful bone metastases can be treated with radiofrequency ablation, radiotherapy, or radionuclides such as radium-223 dichloride, which has been shown to delay the onset of SREs in men with castration-resistant prostate cancer. Close monitoring of bone health in patients with advanced cancer may lead to early identification of individuals with bone metastases who could benefit from early intervention to prevent SREs. This review examines current guideline recommendations for assessing and monitoring bone health in patients with advanced cancer, use of biomarkers and treatment of patients with bone metastases. The emerging evidence for the potential survival benefit conferred by early intervention with denosumab and bisphosphonates is also discussed, together with best practice recommendations.

The significance of TIMD4 expression in clear cell renal cell carcinoma

T-cell immunoglobulin and mucin domain (TIMD) family genes are related to innate immune responses. TIMD4 is a receptor for phosphatidylserine and is involved in the phagocytosis of apoptotic cells by macrophages. In the present study, we found that TIMD4 is expressed on the cancer cells of patients with clear cell renal cell carcinoma (ccRCC). TIMD4 was immunostained in the resected samples of 89 patients diagnosed as ccRCC. High expression of TIMD4 in cancer cells was closely related to short progression free survival time; however, it was not correlated with other clinicopathological factors. Intracellular expression of TIMD4 was observed in the RCC cell line, 786-O. In vitro studies using 786-O cells and shRNA targeting TIMD4 indicated that TIMD4 expression was associated with resistance to sorafenib but not with cell proliferation. TIMD4 might be useful as a prognostic factor and may also be a new target for therapy of ccRCC.

Manifestation of osteoblastic phenotypes in the sarcomatous component of epithelial carcinoma and sarcomatoid carcinoma

Epithelial carcinomas occasionally have sarcomatous components that consist primarily of spindle and cuboidal cells, which often resemble osteoblasts. Sarcomatoid carcinomas consist of similar cells. Recent studies have characterized these phenomena as a manifestation of epithelial-mesenchymal transition in carcinoma cells, but the mesenchymal phenotypes that manifest in sarcomatous cells of epithelial carcinomas are not well understood. Here, we examined the expression profiles of four osteoblastic differentiation biomarkers in the sarcomatous components of multiple carcinoma types, including five renal clear cell, four breast invasive ductal, two esophageal, one maxillary squamous cell, three larynx, three lung, one liver, and one skin sarcomatoid carcinoma. Expression was analyzed by immunohistochemistry using antibodies against cell adhesion molecule 1, a member of the IgCAM superfamily, osterix transcription factor (Osterix), cluster of differentiation 151, a transmembrane 4 superfamily member, and alkaline phosphatase. Immunostaining intensity was rated in scale 0 (negative), 0.5 (weak), and 1 (strong) for each marker, and the four scale values were summed to calculate osteoblastic scores. In all, 10 cases had a osteoblastic score ≥3, and all of these 10 cases were cell adhesion molecule 1- and Osterix-positive. Eight and five of the nine samples with a osteoblastic score <3 were negative for cell adhesion molecule 1 ( p < 0.0001) and Osterix ( p = 0.006), respectively. The other markers showed no statistical significance. These results indicate that osteoblastic differentiation can occur in carcinoma cells and that cell adhesion molecule 1 could be a useful marker for identifying this phenomenon in carcinoma tissues.

Knockdown of Collagen Triple Helix Repeat Containing-1 Inhibits the Proliferation and Epithelial-to-Mesenchymal Transition in Renal Cell Carcinoma Cells

Collagen triple helix repeat containing-1 (CTHRC1), a secreted glycoprotein, is frequently upregulated in human cancers. However, the functional role of CTHRC1 in renal cell carcinoma (RCC) remains unclear. Thus, the aim of this study was to explore the role of CTHRC1 in RCC. Our results demonstrated that CTHRC1 was upregulated in RCC tissues and cell lines. Knockdown of CTHRC1 significantly inhibits the proliferation in RCCs. Furthermore, knockdown of CTHRC1 significantly inhibited the epithelial-to-mesenchymal transition (EMT) process in RCCs, as well as suppressed RCC cell migration and invasion. Mechanistically, knockdown of CTHRC1 inhibited the expression of β-catenin, c-Myc, and cyclin D1 in RCC cells. In conclusion, the results of the present study indicated that CTHRC1 downregulation inhibited proliferation, migration, EMT, and β-catenin expression in RCC cells. Therefore, CTHRC1 may be a potential therapeutic target for the treatment of RCC.

miRNA-21 promotes renal carcinoma cell invasion in a microfluidic device

MicroRNAs (miR) play important roles in cancer invasion.

Epithelial to Mesenchymal Transition in Renal Cell Carcinoma: Implications for Cancer Therapy

Epithelial-to-mesenchymal transition (EMT) is a developmentally vital reversible process by which fully differentiated cells lose their epithelial features and acquire a migratory mesenchymal phenotype. EMT contributes to the metastatic potential of tumors. The expression profile and other biological properties of EMT suggest potential targets for cancer therapy, including in renal-cell carcinoma (RCC). The preclinical and clinical results have substantiated the promises that dysregulated elements leading to EMT can be a potential target in RCC patients. In this study, we illustrated the pathogenic and prognostic role of EMT in RCC. In addition, we reconstructed, by literature analysis, the different pathways implicated in the EMT process, thus supporting the rational for future EMT-directed therapeutic approaches for RCC patients.

The interplay between HPIP and casein kinase 1α promotes renal cell carcinoma growth and metastasis via activation of mTOR pathway

Hematopoietic pre-B cell leukemia transcription factor (PBX)-interacting protein (HPIP) was shown to be crucial during the development and progression of a variety of tumors. However, the role of HPIP in renal cell carcinoma (RCC) is unknown. Here we report that HPIP is upregulated in most RCC patients, positively correlates with tumor size, high Fuhrman grade and preoperative metastasis, and predicts poor clinical outcomes. Mechanistically, we identified casein kinase 1α (CK1α), a critical regulator of tumorigenesis and metastasis, as a novel HPIP-interacting protein. HPIP facilitates RCC cell growth, migration, invasion and epithelial–mesenchymal transition depending on its interaction with CK1α. Activation of mammalian target of rapamycin pathways by HPIP is partly dependent on CK1α and is required for HPIP modulation of RCC cell proliferation and migration. HPIP knockdown suppresses renal tumor growth and metastasis in nude mice through CK1α. Moreover, expression of CK1α is positively correlated with HPIP in RCC samples, and also predicts poor clinical outcome-like expression of HPIP. Taken together, our data demonstrate the critical regulatory role of the HPIP–CK1α interaction in RCC, and suggest that HPIP and CK1α may be potential targets for RCC therapy.

Recent advances in renal cell carcinoma from a pathological point of view

The purpose of this article is to review the recent advances in renal cell carcinoma (RCC) from a pathological point of view. Because the genetic features and morphological characteristics have become major criteria for the classification of RCC, special techniques, such as immunohistochemistry, are essential to the differential diagnosis of renal tumors. Metastasis is frequently observed among the RCC patients with curative nephrectomy, and extracellular matrix-degrading enzymes, such as matrix metalloproteinases (MMP) and heparanase, play a key role in invasion and metastasis of RCC. Snail and Slug, transcription factors of epithelial-mesenchymal transition (EMT), accelerate cancer cell invasion through downregulation of E-cadherin and up-regulation of MMP. Therapies targeted at the vascular endothelial growth factor pathway have become the standard treatment of metastatic RCC. Although they lead to tumor shrinkage mainly by inhibiting angiogenesis, they have typically been associated with drug resistance. The mechanism of the resistance remains largely unknown, but complex events including re-activation of angiogenesis, EMT and cancer stem cells, and immune escape are implicated in the refractory response to the therapy. Recent advances of the research on RCC have caused the changes of classification and therapy, and pathologists should take overall view of these as integrated pathology.

IL-8 induces the epithelial-mesenchymal transition of renal cell carcinoma cells through the activation of AKT signaling

The epithelial-mesenchymal transition (EMT) process has increasingly been examined due to its role in the progression of human tumors. Renal cell carcinoma (RCC) is one of the most common urological tumors that results in patient mortality. Previous studies have demonstrated that the EMT process is closely associated with the metastasis of RCC; however, the underlying molecular mechanism has not been determined yet. The present study revealed that interleukin (IL)-8 was highly expressed in metastatic RCC. IL-8 could induce the EMT of an RCC cell line by enhancing N-cadherin expression and decreasing E-cadherin expression. Furthermore, IL-8 could induce AKT phosphorylation, and the phosphatidylinositol-4,5-bisphosphate 3-kinase inhibitor LY294002 could inhibit the EMT of RCC cells that was induced by IL-8. Therefore, these results suggest that IL-8 is able to promote the EMT of RCC through the activation of the AKT signal transduction pathway, and this may provide a possible molecular mechanism for RCC metastasis.

Synchronous Metastatic Clear-Cell Renal Cell Carcinoma: A Distinct Morphologic, Immunohistochemical, and Molecular Phenotype

INTRODUCTION

Clear cell renal cell carcinomas (ccRCCs) are highly metastatic tumors with metastases detected at diagnosis (synchronous) or during follow-up (metachronous). To date, there have been no reports comparing primary ccRCC of patients with synchronous and metachronous metastases, who are different in terms of prognosis. Determining whether there is a phenotypic difference between these 2 groups could have important clinical implications.

PATIENTS AND METHODS

In a retrospective consecutive cohort of 98 patients with ccRCC, 48 patients had metastases, including 28 synchronous and 20 metachronous presentations, with a follow-up of 10 years. For each primary tumor in these metastatic patients, pathologic criteria, expression of vascular endothelial growth factor, partitioning-defective 3, CAIX, and programmed death ligand 1 as detected by immunohistochemistry, and complete VHL status were analyzed. Univariate analysis was performed, and survival was assessed using Kaplan-Meier curves compared by log-rank test.

RESULTS

Compared with primary ccRCC in patients with metachronous metastases, primary ccRCC in patients with synchronous metastases were significantly associated with a poorer Eastern Cooperative Oncology Group performance (P = .045), higher pT status (P = .038), non-inactivated VHL gene (P = .01), sarcomatoid component (P = .007), expression of partitioning-defective 3 (P = .007), and overexpressions of vascular endothelial growth factor (> 50%) (P = .017) and programmed death ligand 1 (P = .019). Patients with synchronous metastases had a worse cancer-specific survival than patients with metachronous metastases even from metastatic diagnosis (median survival, 16 months vs. 46 months, respectively; P = .01).

CONCLUSION

This long-term study is the first to support the notion that synchronous m-ccRCC has a distinct phenotype. This is probably linked to the occurrence of oncogenic events that could explain the worse prognosis. These particular patients with metastases could benefit from specific therapy.

Application of single-cell RNA sequencing in optimizing a combinatorial therapeutic strategy in metastatic renal cell carcinoma

BACKGROUND

Intratumoral heterogeneity hampers the success of marker-based anticancer treatment because the targeted therapy may eliminate a specific subpopulation of tumor cells while leaving others unharmed. Accordingly, a rational strategy minimizing survival of the drug-resistant subpopulation is essential to achieve long-term therapeutic efficacy.

RESULTS

Using single-cell RNA sequencing (RNA-seq), we examine the intratumoral heterogeneity of a pair of primary renal cell carcinoma and its lung metastasis. Activation of drug target pathways demonstrates considerable variability between the primary and metastatic sites, as well as among individual cancer cells within each site. Based on the prediction of multiple drug target pathway activation, we derive a combinatorial regimen co-targeting two mutually exclusive pathways for the metastatic cancer cells. This combinatorial strategy shows significant increase in the treatment efficacy over monotherapy in the experimental validation using patient-derived xenograft platforms in vitro and in vivo.

CONCLUSIONS

Our findings demonstrate the investigational application of single-cell RNA-seq in the design of an anticancer regimen. The approach may overcome intratumoral heterogeneity which hampers the success of precision medicine.

Renal Cell Carcinoma Presenting as Radiating Rib Pain: A 65-Year-Old Woman

OBJECTIVE

The purpose of this case report is to describe chiropractic management and referral of a patient with rib pain who was subsequently diagnosed with renal cell carcinoma.

CLINICAL FEATURES

A 65-year-old woman presented with radiating rib pain to a chiropractic clinic. She was treated with a 2-week course of conservative care. On follow-up evaluation, she reported a deep ache over her lower ribs, wrapping around to her abdomen. Palpation under the anterior rib cage reproduced her pain, and she also had a positive Murphy Sign. She was referred for an abdominal ultrasonography.

INTERVENTION AND OUTCOME

Ultrasonography showed a 12-cm solid vascular mass of the right kidney. Further imaging studies using computerized tomography and magnetic resonance imaging confirmed the ultrasonography findings. She was referred to a cancer center for staging of the cancer and subsequent surgical treatment. The involved tissue, as well as the kidney and part of the inferior vena cava, was removed, and the pathology report determined that the mass was clear cell carcinoma.

CONCLUSION

This case describes an unusual presentation of a patient with rib pain that had previously undiagnosed renal cancer. Referral by her doctor of chiropractic resulted in detection of the tumor and treatment.

Discoidin domain receptor 1 (DDR1), a promising biomarker, induces epithelial to mesenchymal transition in renal cancer cells

Discoidin domain receptor I (DDR1) is confirmed as a receptor tyrosine kinase (RTK), which plays a consequential role in a variety of cancers. Nevertheless, the influence of DDR1 expression and development in renal clear cell carcinoma (RCCC) are still not well corroborated. In our research, we firstly discovered that the expression level of DDR1 was remarkable related to TNM stage (p = 0.032), depth of tumor invasion (p = 0.047), and lymph node metastasis (p = 0.034) in 119 RCCC tissue samples using tissue microarray. The function of DDR1 was then evaluated in vitro using collagen I and DDR1 small interfering RNA (siRNA) to regulate the expression of DDR1 in OS-RC-2 and ACHN renal cancer cells (RCC). DDR1 expression correlated with increased RCC cell migration, invasion, and angiogenesis. Further study revealed that high expression of DDR1 can result in epithelial to mesenchymal transition (EMT) activation. Western blot assay showed that the N-cadherin protein and vimentin were induced while E-cadherin was reduced after DDR1 over expression. Our results suggest that DDR1 is both a prognostic marker for RCCC and a potential functional target for therapy.

Unconventional Functions of Mitotic Kinases in Kidney Tumorigenesis

Human tumors exhibit a variety of genetic alterations, including point mutations, translocations, gene amplifications and deletions, as well as aneuploid chromosome numbers. For carcinomas, aneuploidy is associated with poor patient outcome for a large variety of tumor types, including breast, colon, and renal cell carcinoma. The Renal cell carcinoma (RCC) is a heterogeneous carcinoma consisting of different histologic types. The clear renal cell carcinoma (ccRCC) is the most common subtype and represents 85% of the RCC. Central to the biology of the ccRCC is the loss of function of the Von Hippel–Lindau gene, but is also associated with genetic instability that could be caused by abrogation of the cell cycle mitotic spindle checkpoint and may involve the Aurora kinases, which regulate centrosome maturation. Aneuploidy can also result from the loss of cell–cell adhesion and apical–basal cell polarity that also may be regulated by the mitotic kinases (polo-like kinase 1, casein kinase 2, doublecortin-like kinase 1, and Aurora kinases). In this review, we describe the “non-mitotic” unconventional functions of these kinases in renal tumorigenesis.

Does the onset of bone metastasis in sunitinib-treated renal cell carcinoma patients impact the overall survival?

PURPOSE

To evaluate the impact of bone metastasis (BM) onset toward prognosis in metastatic renal cell carcinoma (mRCC) patients treated with sunitinib.

METHODS

mRCC patients with BM and sunitinib as first targeted therapy between May 2005 and December 2012 were retrospectively analyzed. Patients with synchronous (s) BM or metachronous (m) BM were compared with regard to treatment and outcome [time to clinical progression (TTcP), overall survival (OS), skeletal-related events (SRE)]. Descriptive statistics, Kaplan-Meier estimation of TTcP and OS, Cox regression analyses, and a landmark analysis were administered.

RESULTS

BM was identified in 127 mRCC patients; thereof, 82 sunitinib-treated patients were analyzed [sBM n = 57 (69.5 %), mBM n = 25 (30.5 %)]. Higher tumor grading (p = 0.029), male predominance (p = 0.02), and less second-line therapy (p = 0.001) were detected in sBM compared to mBM. SRE remained similar between subgroups (p = 0.462). TTcP during sunitinib was similar [median sBM 8.1 (95 % CI 3.9-12.3) vs. mBM 8.7 (95 % CI 2.7-14.8) months, p = 0.903]. OS remained significantly inferior in sBM patients compared to mBM [median sBM 21.1 (95 % CI 16-26.2) months vs. mBM 38.5 (95 % CI 15-62) months, p = 0.001], which was confirmed by landmark analyses at 1.5, 3, 6, 9, and 12 months. However, OS after occurrence of BM was similar in both groups [median sBM 24.2 (95 % CI 17.3-31.1) months vs. mBM 17.2 (95 % CI 8.4-26) months, p = 0.519].

CONCLUSIONS

mBM is associated with an improved OS compared to sBM in mRCC with sunitinib treatment, despite similar efficacy of sunitinib treatment in both groups of patients.

Tumor size, stage and grade alterations of urinary peptidome in RCC

Background

Several promising biomarkers have been found for RCC, but none of them has been used in clinical practice for predicting tumour progression. The most widely used features for predicting tumour aggressiveness still remain the cancer stage, size and grade. Therefore, the aim of our study is to investigate the urinary peptidome to search and identify peptides whose concentrations in urine are linked to tumour growth measure and clinical data.

Methods

A proteomic approach applied to ccRCC urinary peptidome (n = 117) based on prefractionation with activated magnetic beads followed by MALDI-TOF profiling was used. A systematic correlation study was performed on urinary peptide profiles obtained from MS analysis. Peptide identity was obtained by LC–ESI–MS/MS.

Results

Fifteen, twenty-six and five peptides showed a statistically significant alteration of their urinary concentration according to tumour size, pT and grade, respectively. Furthermore, 15 and 9 signals were observed to have urinary levels statistically modified in patients at different pT or grade values, even at very early stages. Among them, C1RL, A1AGx, ZAG2G, PGBM, MMP23, GP162, ADA19, G3P, RSPH3, DREB, NOTC2 SAFB2 and CC168 were identified.

Conclusions

We identified several peptides whose urinary abundance varied according to tumour size, stage and grade. Among them, several play a possible role in tumorigenesis, progression and aggressiveness. These results could be a useful starting point for future studies aimed at verifying their possible use in the managements of RCC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0693-8) contains supplementary material, which is available to authorized users.