The genetic circuits that allow cancer cells to evade immune killing via epithelial mesenchymal plasticity remain poorly understood. Here, we showed that mesenchymal-like (Mes) KPC3 pancreatic... Show moreThe genetic circuits that allow cancer cells to evade immune killing via epithelial mesenchymal plasticity remain poorly understood. Here, we showed that mesenchymal-like (Mes) KPC3 pancreatic cancer cells were more resistant to cytotoxic T lymphocyte (CTL)–mediated killing than the parental epithelial–like (Epi) cells and used parallel genome-wide CRISPR screens to assess the molecular underpinnings of this difference. Core CTL-evasion genes (such as IFN-γ pathway components) were clearly evident in both types. Moreover, we identified and validated multiple Mes-specific regulators of cytotoxicity, such as Egfr and Mfge8. Both genes were significantly higher expressed in Mes cancer cells, and their depletion sensitized Mes cancer cells to CTL-mediated killing. Notably, Mes cancer cells secreted more Mfge8 to inhibit proliferation of CD8+ T cells and production of IFN-γ and TNFα. Clinically, increased Egfr and Mfge8 expression was correlated with a worse prognosis. Thus, Mes cancer cells use Egfr-mediated intrinsic and Mfge8-mediated extrinsic mechanisms to facilitate immune escape from CD8+ T cells. Show less
Rotteveel, L.; Kurakula, K.; Kooijman, E.J.M.; Schuit, R.C.; Verlaan, M.; Schreurs, M.; ... ; Windhorst, A.D. 2022
The transforming growth factor beta (TGF beta) pathway plays a complex role in cancer biology, being involved in both tumour suppression as well as promotion. Overactive TGF beta signalling has... Show moreThe transforming growth factor beta (TGF beta) pathway plays a complex role in cancer biology, being involved in both tumour suppression as well as promotion. Overactive TGF beta signalling has been linked to multiple diseases, including cancer, pulmonary arterial hypertension, and fibrosis. One of the key meditators within this pathway is the TGF beta type I receptor, also termed activin receptor-like kinase 5 (ALK5). ALK5 expression level is a key determinant of TGF beta signalling intensity and duration, and perturbation has been linked to diseases. A validated ALK5 positron emission tomography (PET) tracer creates an opportunity, therefore, to study its role in human diseases. To develop ALK5 PET tracers, two small molecule ALK5 kinase inhibitors were selected as lead compounds, which were labelled with carbon-11 and fluorine-18, respectively. [C-11]LR111 was synthesized with a yield of 17 +/- 6%, a molar activity of 126 +/- 79 GBq. mol(-1) and a purity of > 95% (n = 44). [18F]EW-7197 was synthesized with a yield of 10 +/- 5%, a molar activity of 183 & PLUSMN; 126 GBq. mol(-1) and a purity of > 95% (n = 11). Metabolic stability was evaluated in vivo in mice, showing 39 +/- 2% of intact [11C]LR111 and 21 +/- 2% of intact [F-18]EW-7197 in blood plasma at 45 min p.i. In vitro binding experiments were conducted in breast cancer MDAMB-231 and lung cancer A431 cell lines. In addition, both tracers were used for PET imaging in MDA-MB-231 xenograft models. Selective uptake of [F-18]EW-7197 and [C-11]LR111 was observed in MDA-MB-231 cells, in the MDA-MB-231 tumour xenografts in vivo and in the autoradiograms. As [C-11]LR111 and [F-18]EW-7197 showed selectivity of binding to ALK5 in vivo and in vitro. Both tracers are thereby valuable tools for the detection of ALK5 activity. Show less
Rotteveel, L.; Poot, A.J.; Bogaard, H.J.; Dijke, P. ten; Lammertsma, A.A.; Windhorst, A.D. 2019
The transforming growth factor beta (TGF beta) family of cytokines achieves homeostasis through a careful balance and crosstalk with complex signalling pathways. Inappropriate activation or... Show moreThe transforming growth factor beta (TGF beta) family of cytokines achieves homeostasis through a careful balance and crosstalk with complex signalling pathways. Inappropriate activation or inhibition of this pathway and mutations in its components are related to diseases such as cancer, vascular diseases, and developmental disorders. Quantitative imaging of expression levels of key regulators within this pathway using positron emission tomography (PET) can provide insights into the role of this pathway in vivo, providing information on underlying pathophysiological processes. PET imaging can also be used to study the drug targeting of this pathway and to detect diseases in which this pathway is disturbed. In this review, we provide an overview of PET tracers available to study the TGF beta signalling pathway. In addition, we discuss future imaging targets for this pathway and possible leads for new PET tracers. Show less
![Synthesis and preclinical evaluation of [C-11]LR111 and [F-18]EW-7197 as PET tracers of the activin-receptor like kinase-5](/sites/all/modules/custom/islandora_solr_search/images/defaultimg.png?solr_nav%5Bid%5D=418d8cd9ee79fb024faa&solr_nav%5Bpage%5D=0&solr_nav%5Boffset%5D=1)
