Angiogenic protein synthesis after photobiomodulation therapy on SHED: a preliminary study.

This study evaluated the viability, proliferation, and protein expression after photobiomodulation (PBM) of stem cell from human exfoliated deciduous teeth (SHED). The groups were the following: G1 (2.5 J/cm2), G2 (3.7 J/cm2), and control (not irradiated). According to the groups, cells were irradiated with InGaAlP diode laser at 660 nm wavelength, continuous mode, and single time application. After 6 h, 12 h, and 24 h from irradiation, the cell viability and proliferation, and the protein expression were analyzed by MTT, crystal violet, and ELISA multiplex assay, respectively. Twenty-four hours after PBM, SHED showed better proliferation. Over time in the supernatant, all groups had an increase at the levels of VEGF-C, VEGF-A, and PLGF. In the lysate, the control and G2 exhibited a decrease of the VEGF-A, PECAM-1, and PLGF expression, while control and G3 decreased VEGF-C, VEGF-A, and PDGF expression. The dosimetries of 2.5 J/cm2 and 3.7 J/cm2 maintained viability, improved proliferation, and synthesis of the angiogenic proteins in the supernatant in the studied periods on SHED.

PROX1 gene is differentially expressed in oral cancer and reduces cellular proliferation.

Homeobox genes are a family of transcription factors that play a pivotal role in embryogenesis. Prospero homeobox 1 (PROX1) has been shown to function as a tumor suppressor gene or oncogene in various types of cancer, including oral squamous cell carcinoma (OSCC). We have previously identified PROX1 as a downregulated gene in OSCC. The aim of this study is to clarify the underlying mechanism by which PROX1 regulates tumorigenicity of OSCC cells. PROX1 mRNA and protein expression levels were first investigated in 40 samples of OSCC and in nontumor margins. Methylation and amplification analysis was also performed to assess the epigenetic and genetic mechanisms involved in controlling PROX1 expression. OSCC cell line SCC9 was also transfected to stably express the PROX1 gene. Next, SCC9-PROX1-overexpressing cells and controls were subjected to proliferation, differentiation, apoptosis, migration, and invasion assays in vitro. OSCC samples showed reduced PROX1 expression levels compared with nontumor margins. PROX1 amplification was associated with better overall survival. PROX1 overexpression reduces cell proliferation and downregulates cyclin D1. PROX1-overexpressing cells also exhibited reduced CK18 and CK19 expression and transcriptionally altered the expression of WISP3, GATA3, NOTCH1, and E2F1. Our results suggest that PROX1 functions as a tumor suppressor gene in oral carcinogenesis.

Comparative immunohistochemical study of the presence of mast cells in apical granulomas and periapical cysts: possible role of mast cells in the course of human periapical lesions.

Cells other than macrophages and lymphocytes have recently been shown capable of producing cytokines and mediators. Among these are mast cells, a cell population now recognized for its immunoregulatory properties. Little is known about the complex interactions between cells, cytokines, and other inflammatory elements in periapical lesions. The objective of this investigation was to determine the immunohistochemical pattern of expression of mast cells tryptase in periapical lesions based on study of 20 apical granulomas and 20 periapical cysts. Microscopic analysis revealed mast cells to be present in greater numbers in periapical cysts than in apical granulomas, and in cysts were more numerous in regions of active inflammation. Mast cells tended to be more common in the peripheral regions of both periapical lesions, and were often found in close proximity to lymphocytes. These findings lead us to propose a functional relationship between these two cell populations that may facilitate elicitation of an immune response contributory to the pathogenesis of periapical lesions.