GATA3 suppresses human fibroblasts-induced metastasis of clear cell renal cell carcinoma via an anti-IL6/STAT3 mechanism

The integrate profiling of single-cell and spatial transcriptome RNA-seq reveals tumor heterogeneity, therapeutic targets, and prognostic subtypes in ccRCC

Clear-cell renal cell carcinoma (ccRCC) is the most common type of RCC; however, the intratumoral heterogeneity in ccRCC remains unclear. We first identified markers and biological features of each cell cluster using bioinformatics analysis based on single-cell and spatial transcriptome RNA-sequencing data. We found that gene copy number loss on chromosome 3p and amplification on chromosome 5q were common features in ccRCC cells. Meanwhile, NNMT and HILPDA, which are associated with the response to hypoxia and metabolism, are potential therapeutic targets for ccRCC. In addition, CD8+ exhausted T cells (LAG3+ HAVCR2+), CD8+ proliferated T cells (STMN+), and M2-like macrophages (CD68+ CD163+ APOC1+), which are closely associated with immunosuppression, played vital roles in ccRCC occurrence and development. These results were further verified by whole exome sequencing, cell line and xenograft experiments, and immunofluorescence staining. Finally, we divide patients with ccRCC into three subtypes using unsupervised cluster analysis. and generated a classifier to reproduce these subtypes using the eXtreme Gradient Boosting algorithm. Our classifier can help clinicians evaluate prognosis and design personalized treatment strategies for ccRCC. In summary, our work provides a new perspective for understanding tumor heterogeneity and will aid in the design of antitumor therapeutic strategies for ccRCC.

FMNL1 Exhibits Pro-Metastatic Activity via CXCR2 in Clear Cell Renal Cell Carcinoma

Formin-like (FMNL) proteins are responsible for cytoskeletal remodeling and have been implicated in the progression and spread of human cancers. Yet the clinical significance and biological function of FMNL1 in clear cell renal cell carcinoma (ccRCC) remain unclear. In this study, the expression of FMNL1 in ccRCC and its clinical value were determined by tissue microarray-based IHC and statistical analyses. The role of FMNL1 in ccRCC metastasis and the underlying mechanism were investigated via in vitro and in vivo models using gene regulation detection, ChIP, Luciferase reporter assays, and rescue experiments. We show that FMNL1 is upregulated in ccRCC and exhibits pro-metastatic activity via induction of CXCR2. High expression of FMNL1 is significantly correlated with advanced tumor stage, higher pathological tumor grade, tumor metastasis, and unfavorable prognosis in two independent cohorts containing over 800 patients with ccRCC. The upregulation of FMNL1 in ccRCC is mediated by the loss of GATA3. Ectopic expression of FMNL1 promotes, whereas FMNL1 depletion inhibits cell migration in vitro and tumor metastasis in vivo. The FMNL1-enhanced cell mobility is markedly attenuated by the knockdown of CXCR2. Further studies demonstrate that FMNL1 increases the expression of CXCR2 via HDAC1. In clinical samples, FMNL1 expression is positively associated with CXCR2, and is negatively connected to GATA3 expression. Collectively, our data suggest FMNL1 serve as a potential prognostic factor and function as an oncogene. The axis of GATA3/FMNL1/CXCR2 may present a promising therapeutic target for tumor metastasis in ccRCC.

Fingolimod inhibits proliferation and epithelial-mesenchymal transition in sacral chordoma by inactivating IL-6/STAT3 signalling

Purpose: To explore the sensitivity of the immunosuppressive agent fingolimod (FTY720) in chordoma and determine whether it can serve as an appropriate alternate treatment for unresectable tumours in patients after incomplete surgery.

Methods: Cell viability assays, colony formation assays and EdU assays were performed to evaluate the sensitivity of chordoma cell lines to FTY720. Transwell invasion assays, wound healing assays, flow cytometry, cell cycle analysis, immunofluorescence analysis, Western blotting analysis and enzyme-linked immunosorbent assays (ELISAs) were performed to evaluate cell invasion, epithelial–mesenchymal transition (EMT) and activation of related pathways after treatment with FTY720. The effect of FTY720 was also evaluated in vivo in a xenograft model.

Results: We found that FTY720 inhibited the proliferation, invasion and metastasis of sacral chordoma cells (P < 0.01). FTY720 also inhibited the proliferation of tumour cells in a xenograft model using sacral chordoma cell lines (P < 0.01). The mechanism was related to the EMT and apoptosis of chordoma cells and inactivation of IL-6/STAT3 signalling in vitro and in vivo.

Conclusions: Our findings indicate that FTY720 may be an effective therapeutic agent against chordoma. These findings suggest that FTY720 is a novel agent that can treat locally advanced and metastatic chordoma.