PCR array analysis identified hyperproliferation but not autophagy or apoptosis in fibrous epulis

• Main Authors: Fang, B. (Author), Jiang, Y. (Author), Xu, B. (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2021
• Subjects: adult; Adult; apoptosis; Apoptosis; Article; ATG family; autophagy; Autophagy; autophagy (cellular); autophagy related protein; Autophagy-Related Proteins; Bcl-2 family; BCL2 gene; BCL2L1 gene; BCL2L1 protein, human; bcl-X Protein; caspase; caspase family; Caspases; cell proliferation; Cell Proliferation; controlled study; CXCR4 gene; female; Female; fibrous epulis; gene; gene expression; gene expression profiling; Gene Expression Profiling; genetics; gingiva; Gingiva; gingiva disease; Gingival Diseases; HSP90AA1 gene; HSPA8 gene; human; human tissue; Humans; IGF1 gene; major clinical study; male; Male; middle aged; Middle Aged; pathogenesis; pathology; PCR array; peptides and proteins; physiology; polymerase chain reaction; Polymerase Chain Reaction; procedures; protein bcl 2; protein bcl x; protein LC3 I; protein LC3 II; Proto-Oncogene Proteins c-bcl-2; unclassified drug
• Online Access: View Fulltext in Publisher

 Background: The pathogenesis of fibrous epulis is still quite unclear. Our recent genome-wide RNA sequencing analysis revealed that in fibrous epulis, RAS-PI3K-AKT-NF-κB pathway regulates the expression of Bcl-2 family and IAP family genes, leading to increased proliferation and the inhibition of apoptosis. The PI3K/AKT signaling pathway can promote autophagy in human gingival fibroblasts; therefore, the purpose of the present study was to identify whether autophagy is involved in the pathogenesis of fibrous epulis. Methods: Differentially expressed genes (DEGs) between fibrous epulis lesions and normal gingival tissues were identified using the PCR array. The expression levels of eighteen autophagy-related (ATG) family genes, twelve B-cell lymphoma 2 (Bcl-2) family genes, and eleven cysteine-dependent aspartate-directed protease (caspase) family genes were validated using quantitative real-time PCR (qRT-PCR). Autophagy induction was determined by measuring microtubule-associated protein light chain 3 (LC3) conversion (LC3-I to LC3-II) by immunoblot analysis. Results: The PCR array identified six upregulated genes, whereas no genes were expressed at significantly lower levels. The upregulated genes were BCL2, BCL2L1, CXCR4, HSP90AA1, HSPA8, and IGF1, which all belong to the “regulation of autophagy” group but not the “autophagy machinery components” group. qRT-PCR verified that the expression levels of BCL2, BCL2L1 (also known as BCL-XL), and BCL2L2 (also known as BCL-W) were significantly increased in fibrous epulis. No LC3-I to LC3-II conversion was observed. Conclusions: The present study reveals that in fibrous epulis, Bcl-2 and Bcl-xL coordinately mediate gingival cell escape from apoptosis, leading to uncontrolled proliferation. Moreover, ATG family genes are not activated, and autophagy is not involved in this process. © 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC