Establishment and Characterization of Two Novel Olfactory Neuroblastoma Cell Lines

Background: Olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma, is a malignant neoplasm of the sinonasal cavity accounting for approximately 6% of all sinonasal malignancies. ONBs are locally aggressive neoplasms and can metastasize to the neck, central nervous system, and bone. Currently, there are no effective systemic therapies available for ONB patients and there is little progress in understanding the pathogenesis of ONB, largely due to the lack of model systems which accurately maintain the genetic and pathophysiologic characteristics of ONB. In this study, we aim to establish and characterize two ONB cell lines, to develop novel therapies with translational potential.

Methods: Specimens were obtained from patients with ONB including both intranasal and/or intracranial components of tumors. Specimens were transported directly from the operating room to the laboratory and were minced and digested with collagenase IV. After passing through a 70-µm nylon mesh, the cells were maintained in growth medium at 37°C, 5% CO₂ in a humidified incubator. Short tandem repeat (STR) analysis was used to characterize established ONB cell lines and their parental ONB tumors, while immunofluorescence staining in ONB cell lines and immunohistochemical staining in their parental tumors were used to compare the expression of ONB molecular markers.

Results: Cell lines were established from two patients, with one line derived from an intranasal specimen (JHH_ONB_1903) and the other from an intracranial specimen (JHH_ONB_1904). Genomic analysis using STR profiling revealed that the intranasal ONB cell line showed 100% identity and the intracranial ONB cell line showed 98.4% identity to their parental ONB samples, respectively. In addition, the expression of ONB molecular markers, including synaptophysin, INSM1 and neuron-specific enolase, were detected in both ONB cell lines and their parental ONB samples in similar patterns: the expression of synaptophysin was detected in a punctate pattern; the expression of INSM1 was detected in nucleus; and the expression of neuron-specific enolase was detected diffusely throughout the cytoplasm.

Conclusion: Two novel ONB cell lines were established. These lines accurately maintain the genetic and immunohistochemical characteristics of their parental ONB samples. These lines provide reliable models to further study the pathophysiology underlying ONB and to evaluate therapeutic strategies.