Impact of Tumor Stem Cells in Propensity to Recurrence in Benign Salivary Gland Tumors

Introduction The aim is to clarify whether stem cell-like cells in pleomorphic adenomas (PA) can be responsible for the development of recurrences. Warthin tumors (WT) and normal tissue (N) serve as comparison groups.

Material and Methods A total of 47 tissue samples (N: n = 13, PA: n = 21, WT: n = 14, 30% male, average age 59.9 ± 13.1 years) were examined for stem cell markers using qPCR. 53 samples obtained intraoperatively were processed to isolate stem cell-like cells (N: n = 23, PA: n = 16, WT n = 14).

Results PA showed an increased relative expression for MSI1 (p = 0.001) and a clearly decreased expression for CD44 (p < 0.001) and SOX9 (p < 0.05). If the group of PA and PA recurrences were considered separately, a reduced expression of SOX9 could only be found in the recurring tumors (p < 0.05). There was no difference between the primary tumors and the relapses in the relative expression of other markers. WT showed an increased expression for CXCR4 (p < 0.05) and a decreased expression for SOX9 (p <0.05), CD44 (p < 0.001) and ITGA6 (p < 0.05). The isolation efficiency of the primary spheroid cells was 68% with no difference between the entities (N = 57%, PA = 75% and WT = 79%). PA and WT showed a higher maximum degree of sphericity compared to the N (p < 0.05 for both). 42% of the PA and 55% of the WT formed grade 3 spheres.

Conclusion Relapse-associated stem cell markers can be detected in benign salivary gland tumors. Primarily spheroid cultures can be obtained from the surgical samples. These are examined for stem cell properties and the expression of marker proteins. The presence of grade 3 spheres may indicate the presence of highly potent cell properties.

Interdisziplinäres Zentrum für Klinische Forschung (IZKF) des Universitätsklinikum Jena und Deutsche Forschungsgemeinschaft (DFG) – Clinician Scientist-Program OrganAge (WI 830/12-1)

Conflict of Interest

The author declares that there is no conflict of interest.

Publikationsverlauf

Artikel online veröffentlicht:
24. Mai 2022