RESUMEN
BACKGROUND: Dynamic transitions of tumour cells along the epithelial-mesenchymal axis are important in tumorigenesis, metastasis and therapy resistance. METHODS: In this study, we have used cell lines, 3D spheroids and tumour samples in a variety of cell biological and transcriptome analyses to highlight the cellular and molecular dynamics of OSCC response to ionising radiation. RESULTS: Our study demonstrates a prominent hybrid epithelial-mesenchymal state in oral squamous cell carcinoma cells and tumour samples. We have further identified a key role for levels of E-cadherin in stratifying the hybrid cells to compartments with varying levels of radiation response and radiation-induced epithelial-mesenchymal transition. The response to radiation further entailed the generation of a new cell population with low expression levels of E-cadherin, and positive for Vimentin (ECADLow/Neg-VIMPos), a phenotypic signature that showed an enhanced capacity for radiation resistance and invasion. At the molecular level, transcriptome analysis of spheroids in response to radiation showed an initial burst of misregulation within the first 30 min that further declined, although still highlighting key alterations in gene signatures. Among others, pathway analysis showed an over-representation for the Wnt signalling pathway that was further confirmed to be functionally involved in the generation of ECADLow/Neg-VIMPos population, acting upstream of radiation resistance and tumour cell invasion. CONCLUSION: This study highlights the functional significance and complexity of tumour cell remodelling in response to ionising radiation with links to resistance and invasive capacity. An area of less focus in conventional radiotherapy, with the potential to improve treatment outcomes and relapse-free survival.
Asunto(s)
Carcinoma de Células Escamosas/patología , Transición Epitelial-Mesenquimal , Neoplasias de la Boca/patología , Tolerancia a Radiación/genética , Carcinoma de Células Escamosas/genética , Línea Celular Tumoral , Movimiento Celular/genética , Transición Epitelial-Mesenquimal/genética , Transición Epitelial-Mesenquimal/efectos de la radiación , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Genes de Cambio/fisiología , Genes de Cambio/efectos de la radiación , Estudios de Asociación Genética , Humanos , Neoplasias de la Boca/genética , Invasividad Neoplásica , Fenotipo , Radiación Ionizante , Transcriptoma/efectos de la radiación , Vía de Señalización Wnt/genética , Vía de Señalización Wnt/efectos de la radiaciónRESUMEN
The development and growth of the vertebrate ocular lens is dependent on the regulated proliferation of an anterior monolayer of epithelial cells, and their subsequent differentiation into elongate fiber cells. The growth factor rich ocular media that bathes the lens mediates these cellular processes, and their respective intracellular signaling pathways are in turn regulated to ensure that the proper lens architecture is maintained. Recent studies have proposed that Cysteine Rich Motor Neuron 1 (Crim1), a transmembrane protein involved in organogenesis of many tissues, might influence cell adhesion, polarity and proliferation in the lens by regulating integrin-signaling. Here, we characterise the lens and eyes of the Crim1KST264 mutant mice, and show that the loss of Crim1 function in the ocular tissues results in inappropriate differentiation of the lens epithelium into fiber cells. Furthermore, restoration of Crim1 levels in just the lens tissue of Crim1KST264 mice is sufficient to ameliorate most of the dysgenesis observed in the mutant animals. Based on our findings, we propose that tight regulation of Crim1 activity is required for maintenance of the lens epithelium, and its depletion leads to ectopic differentiation into fiber cells, dramatically altering lens structure and ultimately leading to microphthalmia and aphakia.
