Background Clear cell renal cell carcinoma (CCRCC) is characterized by a highly metastatic potential. The stromal communication between stem cells and cancer cells critically influences metastatic dissemination of cancer cells. Methods The effect of exosomes isolated from cancer stem cells (CSCs) of CCRCC patients on the progress of epithelial-mesenchymal transition (EMT) and lung metastasis of CCRCC cells were examined. Results CSCs exosomes promoted proliferation of CCRCC cells and accelerated the progress of EMT. Bioactive miR-19b-3p transmitted to cancer cells by CSC exosomes induced EMT via repressing the expression of PTEN. CSCs exosomes derived from CCRCC patients with lung metastasis produced the strongest promoting effect on EMT. Notably, CD103+ CSC exosomes were enriched in tumor cells and in lung as well, highlighting the organotropism conferred by CD103. In addition, CD103+ exosomes were increased in blood samples from CCRCC patients with lung metastasis. Conclusions CSC exosomes transported miR-19b-3p into CCRCC cells and initiated EMT promoting metastasis. CD103+ acted to guide CSC exosomes to target cancer cells and organs, conferring the higher metastatic capacity of CCRCC to lungs, suggesting CD103+ exosomes as a potential metastatic diagnostic biomarker. Graphical abstract ᅟ

While the androgen receptor (AR) may influence the progression of clear cell renal cell carcinoma (ccRCC), its role to impact vasculogenic mimicry (VM) to alter the ccRCC progression and metastasis remains obscure. Here, we demonstrated that elevated AR expression was positively correlated with tumor-originated vasculogenesis in ccRCC patients. Consistently, in vitro research revealed AR promoted VM formation in ccRCC cell lines via modulating lncRNA-TANAR/TWIST1 signals. Mechanism dissection showed that AR could increase lncRNA-TANAR (TANAR) expression through binding to the androgen response elements (AREs) located in its promoter region. Moreover, we found that TANAR could impede nonsense-mediated mRNA decay (NMD) of TWIST1 mRNA by direct interaction with TWIST1 5′UTR. A preclinical study using in vivo mouse model with orthotopic xenografts of ccRCC cells further confirmed the in vitro data. Together, these results illustrated that AR-mediated TANAR signals might play a crucial role in ccRCC VM formation and metastasis, and targeting this newly identified AR/TANAR/TWIST1 signaling may help in the development of a novel anti-angiogenesis therapy to better suppress the ccRCC progression.

Background/Aims: Emerging novel optical imaging techniques with cancer-specific molecular imaging agents offer a powerful and promising platform for cancer detection and resection. White-light cystoscopy and random bladder biopsies remain the most appropriate but nonetheless suboptimal diagnostic technique for bladder cancer, which is associated with high morbidity and recurrence. However, white-light cystoscopy has intrinsic shortcomings. Although current optical imaging technologies hold great potential for improved diagnostic accuracy, there are few imaging agents for specific molecular targeting. Carbonic anhydrase IX (CAIX) plays a pivotal role in tumorigenesis and tumor progression with potential value as an imaging target. Here, we investigated the feasibility of CAIX as a target and validated the diagnostic performance and significance of CAIX as an imaging agent. Methods: We first analyzed the data from The Cancer Genome Atlas (TCGA). Pairs of samples comprising bladder cancer and adjacent normal tissue were collected. All tissue samples were used for real-time PCR and immunohistochemistry to compare CAIX expression in normal and cancer tissue. Using blue-light cystoscopy, we observed the optical distribution of fluorescently labeled CAIX antibody in freshly excised human bladders and obtained random bladder biopsies to assess sensitivity and specificity. Results: The TCGA data revealed that CAIX expression was significantly higher in bladder cancer specimens than in normal tissue. The outcome was similar in quantitative real-time PCR analysis. In immunohistochemical analysis, bladder cancer specimens classified in four pathological subtypes presented a variety of positive staining intensities, whereas no benign specimens showed CAIX staining. Using blue-light cystoscopy, we distinguished bladder cancers that were mainly papillary, some variants of urothelial carcinoma, and less carcinoma in situ, from benign tissue, despite the presence of suspicious-appearing mucosa. The sensitivity and specificity for CAIX-targeted imaging were 88.00% and 93.75%, respectively. Conclusions: CAIX-targeted molecular imaging could be a feasible and adaptive alternative approach for the accurate diagnosis and complete resection of bladder cancer.

Bladder cancer (BC) is the most common malignancy involving the urinary system, and is characterized by a high recurrence rate. It is important to identify potential lncRNA signatures capable of predicting tumour recurrence risk and assessing recurrence prognosis in BC patients. We extracted data from The Cancer Genome Atlas and identified 381 differentially expressed lncRNAs, 855 mRNAs and 70 miRNAs between non-recurrent and recurrent BC tissues. Subsequently, a competing endogenous RNA (ceRNA) network composed of 29 lncRNAs, 13 miRNAs and 4 mRNAs was established. We used univariate and multivariate Cox regression to analyse the relationship between the 29 lncRNAs and recurrence-free survival (RFS) in BC patients. Six lncRNAs had significant prognostic values, and their cumulative risk score indicated that this 6-lncRNA signature independently predicted RFS in BC patients. We applied a receiver operating characteristic (ROC) analysis to assess the efficiency of our prognostic models. High-risk patients exhibited a poorer prognosis than low-risk patients did. Additionally, the 6-lncRNA signature showed a significant correlation with BC clinicopathological characteristics, which indicates that it could be used for effective risk stratification. The current study provides novel insights into the lncRNA-related ceRNA network and this 6-lncRNA signature may be an independent prognostic factor in predicting the recurrence of BC patients.