Project description:We describe changes to the transcriptomes of 4t1 mammary gland carcinoma cells in different matrix environments and with and without T cells
Project description:Extracellular biophysical cues such as matrix stiffness are key stimuli tuning cell fate and affecting tumor progression in vivo. However, it remains unclear how spheroids in a 3D microenvironment perceive matrix mechanical stiffness stimuli and translate them into intracellular signals driving cancer. Mechanosensitive Piezo1 and TRPV4 ion channels, upregulated in many malignancies, are major transducers of such physical stimuli into biochemical responses. Most mechanotransduction studies probing the reception of changing stiffness cues by cells are, however, still limited to 2D culture systems or cell-extracellular matrix models which lack the major cell-cell interactions prevalent in 3D cancer tumors. Here, we engineered a 3D spheroid culture environment with varying mechanobiological properties to study the effect of static matrix stiffness stimuli on mechanosensitive and malignant phenotypes in oral squamous cell carcinoma spheroids. We find that spheroid growth is enhanced when cultured in stiff extracellular matrix. Using flow cytometry, we show that the expression of mechanoreceptor Piezo1 and stemness marker CD44 is upregulated in stiff matrix. We also report the upregulation of a selection of genes with associations to mechanoreception, ion channel transport, extracellular matrix organization, and tumorigenic phenotypes in stiff matrix spheroids. Together, our results indicate that cancer cells in 3D spheroids utilize mechanosensitive ion channels Piezo1 and TRPV4 to sense changes in static extracellular matrix stiffness and that stiffness drives pro-tumorigenic phenotypes in oral squamous cell carcinoma.
Project description:Approximately 80%-90% of hepatocellular carcinomas (HCC) occur in a premalignant environment of fibrosis and abnormal extracellular matrix (ECM), predicting an essential role of abnormal matrix in the tumorigenesis and progress of HCC. However, the determinants of ECM in HCC are poorly defined. Here, we show that nuclear receptor RORγ is highly expressed and amplified in HCC tumors. RORγ functions as an essential activator of the matrisome program via directly driving the expression of major ECM genes in HCC cells. The elevated RORγ increased Fibronectin-1 deposition, cell-matrix adhesion, collagen production and cross-linkling, creating a favorable microenvironment to boost liver cancer metastasis. Moreover, RORγ antagonists effectively inhibit tumor growth and metastasis via ECM remodeling in multiple HCC xenografts and immune-intact models, and they effectively sensitize HCC tumors to sorafenib therapy in mice. Notably, the elevated RORγ expression is associated with ECM remodeling and metastasis in patients with HCC. Taken together, we identify RORγ as a key player in HCC progression by remodeling ECM and as an attractive therapeutic target for advanced HCC.
Project description:Visual processing depends on sensitive and balanced synaptic neurotransmission. Extracellular matrix proteins in the environment of cells are key modulators in synaptogenesis and synaptic plasticity. In the present study, we provide evidence that the combined loss of the four extracellular matrix components brevican, neurocan, tenascin-C and tenascin-R in quadruple knockout mice leads to severe retinal dysfunction and diminished visual motion processing in vivo. Remarkably, impaired visual motion processing was accompanied by a developmental loss of cholinergic direction-selective starburst amacrine cells. Additionally, we noted imbalance of inhibitory and excitatory synaptic signaling in the quadruple knockout retina. Collectively, the study offers novel insights into the functional importance of four key extracellular matrix proteins for retinal function, visual motion processing and synaptic signaling.
Project description:A major problem in cancer research is the lack of a tractable model for delayed metastasis. Herein we show that cancer cells suppressed by SISgel, a gel-forming normal ECM material derived from Small Intestine Submucosa, in flank xenografts show properties of suppression and re-activation that are very similar to normal delayed metastasis and suggest they can serve as a novel model for developing therapeutics to target micrometastases or suppressed cancer cells. Co-injection with SISgel suppressed the malignant phenotype of highly invasive J82 and T24 bladder cancer cells and highly metastatic JB-V cells in flank xenografts. Cells could remain viable up to 120 days without forming tumors and appeared much more highly differentiated and less atypical than tumors from cells co-injected with Matrigel. In 40% of SISgel xenografts, growth resumed in the malignant phenotype after a period of suppression or dormancy for at least 30 days and was more likely with implantation of 3 million cells or more cells. Ordinary Type I collagen did not suppress malignant growth, and tumors developed about as well with collagen as with Matrigel. A clear signal in gene expression over different cell lines was not seen, but in contrast, Reverse Phase Protein Analysis of 250 proteins across 4 cell lines identified a clear signal at the protein level involving Integrin Linked Kinase (ILK) signaling that was confirmed by an ILK inhibitor. We suggest that cancer cells suppressed on SISgel could serve as a model for dormancy and re-awakening to develop therapeutic targets for micrometastases. Earlier we demonstrated that the phenotype of bladder cancer cells was radically different in 3-dimensional organotypic culture when grown on a normal extracellular matrix preparation (SISgel) as compared to that observed on a cancer-modulated permissive extracellular matrix preparation (Matrigel). SISgel is a gel-forming material derived from acellular small intestine submucosa, whereas Matrigel is a basement membrane preparation obtained from a mouse sarcoma. On Matrigel the bladder cancer cells recapitulated the phenotype reported for the original tumor; in sharp contrast, most of the malignant properties were lost when the cells were grown on SISgel. Cell lines derived from papillomas formed a layered structure reminiscent of normal urothelium, whereas cell lines derived from higher grade tumors formed a noninvasive layer of cells. These findings suggested that growth of cancer cells on normal ECM could provide a model to investigate the phenomenon of suppression of malignancy by normal ECM in metastasis and recurrence. In this study we explored whether the phenotypic suppression seen in organotypic culture of bladder cancer cells on SISgel also is observed in vivo. Positive findings support the use of SISgel as a model for investigations of the dormant or suppressed tumor cell phenotype and of mechanisms by which the normal ECM exerts an inhibitory influence on tumorigenesis and metastasis. The findings strongly suggest that interactions of cancer cells with normal ECM play an important role in recurrence and metastasis and further suggest that targeting suppressed cells could represent a heretofore unexploited point of vulnerability in cancer therapy.