Hose, L. | bioRxiv Science

bioRxiv2024

HPV-positive head and neck squamous cell carcinoma cells lose viability during triggered myocyte lineage differentiation

Head and neck squamous cell carcinoma (HNSCC) is a highly malignant disease, and death rates have remained at approximately 50% for decades. New tumor-targeting treatment strategies are desperately needed. Using patient-derived tumor cells, we created an HNSCC differentiation model of HPV+ tumor cells from two patients. We observed a loss of malignant characteristics in differentiating cell culture conditions, including irregularly enlarged cell morphology, cell cycle arrest with downregulation of Ki67, and reduced cell viability. RNA-seq showed myocyte-like differentiation with upregulation of markers of myofibril assembly, including TPM1, TAGLN, and ACTA1. Immunofluorescence staining of differentiated and undifferentiated primary HPV+ HNSCC cells confirmed an upregulation of these markers and the formation of parallel actin fibers reminiscent of myoblast-lineage cells. Moreover, immunofluorescence of HPV+ tumor tissue revealed areas of cells co-expressing the identified markers of myofibril assembly, HPV surrogate marker p16, and stress-associated basal keratinocyte marker KRT17, indicating that the observed myocyte-like in vitro differentiation occurs in human tissue. A recent sarcoma study was able to turn rhabdomyosarcoma into muscle-like cells. We are the first to report that carcinoma cells can undergo a triggered myocyte differentiation. Our study suggests that the targeted myo-differentiation of tumor cells might be therapeutically valuable in HPV+ HNSCCs.

cancer biology↗

bioRxiv2023

Head and neck cancer cells terminally differentiate reflecting their tissue of origin: a rationale for differentiation therapies

BackgroundHuman papillomavirus-negative head and neck squamous cell carcinoma (HNSCC) is a highly malignant disease with high death rates that have remained substantially unaltered for decades. Therefore, new treatment approaches are urgently needed. Human papillomavirus-negative tumors harbor areas of terminally differentiated tissue that are characterized by cornification. Dissecting this intrinsic ability of HNSCC cells to irreversibly differentiate into non-malignant cells may have striking tumor-targeting potential. MethodsWe modeled the cornification of HNSCC cells in a primary spheroid model and analyzed the mechanisms underlying differentiation by RNA-seq and ATAC-seq. Results were verified by immunofluorescence using human HNSCC tissue of distinct anatomical locations. ResultsHNSCC cell differentiation was accompanied by cell adhesion, proliferation stop, diminished tumor-initiating potential in immunodeficient mice, and activation of a wound healing-associated signaling program. Small promoter accessibility increased despite overall chromatin closure. Differentiating cells upregulated KRT17 and cornification markers. Although KRT17 represents a basal stem-cell marker in normal mucosa, we confirm KRT17 to represent an early differentiation marker in HNSCC tissue and dysplastic mucosa. Cornification was observed to frequently surround necrotic and immune-infiltrated areas in human tumors, indicating an involvement of pro-inflammatory stimuli. Indeed, inflammatory mediators were found to activate the HNSCC cell differentiation program. ConclusionsDistinct cell differentiation states create a common tissue architecture in normal mucosa and HNSCCs. Our data demonstrate a loss of cell malignancy upon HNSCC cell differentiation, indicating that targeted differentiation approaches may be therapeutically valuable. Moreover, we describe KRT17 to be a candidate biomarker for HNSCC cell differentiation and early tumor detection.

cancer biology↗