DNA methylation profiles of 22 apoptosis-related genes in odontogenic keratocysts before and after marsupialization

Comparing the characteristics of recurrent versus primary odontogenic keratocysts - A single center retrospective cohort study

The high recurrence rate of odontogenic keratocysts (OKC) entails a large number of follow-up interventions after primary surgery. This study aimed to compare recurrent with primary OKC in regard to recurrence rate, treatment modality, radiographic and clinical findings. A single center retrospective cohort study with surgically treated OKC between 2012 and 2021 was conducted. The primary predictor was recurrence type of the lesion: primary (P-OKC), first recurrence (R1-OKC) and second recurrence (R2-OKC). The primary outcome variables were recurrence and time to recurrence. 68 surgeries were identified. Recurrence was not significantly associated with recurrence type (p = 0.906) but with the method of surgery (p < 0.001). Marsupialized R1-OKC recurred earlier than marsupialized P-OKC. Diameter was significantly associated with recurrence type (p = 0.002). R1-OKC had a smaller median diameter than P-OKC and R2-OKC were smaller than R1-and P-OKC. P-OKC were associated with teeth in 79% of surgeries, R1-OKC in 61% and R2-OKC in 27% (p = 0.007). Postoperative numbness was present after 40% of surgeries and decreased to 15% at follow-up, independently of recurrence type. Time to recurrence may be shorter for recurrent marsupialized OKC. Recurrent OKC are smaller and less often associated with teeth. Postoperative numbness after OKC surgery has a good prognosis.

A review of the molecular profile of benign and malignant odontogenic lesions

Odontogenic cysts and tumors are heterogeneous lesions, originating from elements or remnants of the odontogenic apparatus. Although the majority of these lesions are benign and never undergo malignant transformation, rare malignant tumors may arise de novo or from benign precursors. The molecular basis of these lesions is still poorly understood. This article summarizes and discusses studies using small, medium, and large-scale and/or "-omic" techniques to describe the molecular characteristics of benign and malignant odontogenic lesions and briefly debates strategies to increase the use of "-omic" and multi-omic approaches or integrative analyses in the research of these lesions. A comprehensive understanding of the molecular aspects of odontogenic lesions by using large-scale approaches will enable us to refine the classification of this heterogeneous group of disorders and provide more accurate biomarkers for precise diagnosis, prognosis, and development of molecular tools in the management of patients with these conditions.

Identification of key genes in invasive clinically non-functioning pituitary adenoma by integrating analysis of DNA methylation and mRNA expression profiles

BACKGROUND

Tumor surrounding the internal carotid artery or invading to the cavernous sinus is an important characteristic of invasive pituitary adenoma, and a pivotal factor of tumor residue and regrowth. Without specific changes in serum hormone related to the adenohypophyseal cell of origin, clinically non-functioning pituitary adenoma is more likely to be diagnosed at invasive stages compared with functioning pituitary adenoma. The underlying mechanism of tumor invasion remains unknown. In this study, we aimed to identify key genes in tumor invasion by integrating analyses of DNA methylation and gene expression profiles.

METHOD

Genome-wide DNA methylation and mRNA microarray analysis were performed for tumor samples from 68 patients at the Beijing Tiantan Hospital. Differentially expressed genes and methylated probes were identified based on an invasive vs non-invasive grouping. Differentially methylated probes in the promoter region of targeted genes were assessed. Pearson correlation analysis was used to identify genes with a strong association between DNA methylation status and expression levels. Pyrosequencing and RT-PCR were used to validate the methylation status and expression levels of candidate genes, respectively.

RESULTS

A total of 8842 differentially methylated probes, located on 4582 genes, and 661 differentially expressed genes were identified. Both promoter methylation and expression alterations were observed for 115 genes with 58 genes showing a negative correlation between DNA methylation status and expression level. Nineteen genes that exhibited notably negative correlations between DNA methylation and gene expression levels, are involved in various gene ontologies and pathways, or played an important role in different diseases, were regarded as candidate genes. We found an increased methylation with a decreased expression of PHYHD1, LTBR, C22orf42, PRR5, ANKDD1A, RAB13, CAMKV, KIFC3, WNT4 and STAT6, and a decreased methylation with an increased expression of MYBPHL. The methylation status and expression levels of these genes were validated by pyrosequencing and RT-PCR.

CONCLUSIONS

The DNA methylation and expression levels of PHYHD1, LTBR, MYBPHL, C22orf42, PRR5, ANKDD1A, RAB13, CAMKV, KIFC3, WNT4 and STAT6 are associated with tumor invasion, and these genes may become the potential genes for targeted therapy.