MiRNA Signatures Related to Invasiveness and Recurrence in Patients With Non-Functioning Pituitary Neuroendocrine Tumors.

PURPOSE: This preliminary study aimed to analyze and identify differentially expressed miRNAs in Bulgarian patients with non-functioning pituitary neuroendocrine tumors (NFPitNET). The relationship between deregulated miRNAs and tumor invasiveness, recurrence, and size was determined. METHODS: Twenty patients with NFPitNET were selected and fresh pituitary tumor tissues were collected. RNA containing miRNAs were isolated using miRNAeasy mini kit and analyzed by quantitative real-time polymerase chain reaction (PCR) using LNA miRNA Cancer-Focus PCR Panel (Qiagen). RESULTS: Three miRNAs (miR-210-3p, miR-149-3p, and miR-29b-3p) were deregulated in invasive compared to non-invasive NFPitNETs. Differential expression of four-miRNA signatures - miRNA-17, miR-19, miR-106a, and miR-20, correlated with patient recurrence. CONCLUSION: This prospective pilot study selected a unique miRNA expression profile, that correlates with invasiveness and recurrence in non-functioning pituitary neuroendocrine tumors. Moreover, some of the selected miRNAs are reported for the first time in patients with this disease, shedding light on the molecular mechanisms involved in pituitary pathogenesis. The identified miRNAs demonstrate potential as biomarkers, deserving further investigation in a larger cohort to validate their clinical applicability.

Proteome response of dental pulp cells to exogenous FGF8.

FGF8 specifies early tooth development by directing the migration of the early tooth founder cells to the site of tooth emergence. To date the effect of the FGF8 in adult dental pulp has not been studied. We have assessed the regenerative potential of FGF8 by evaluating changes in the proteome landscape of dental pulp following short- and long-term exposure to recombinant FGF8 protein. In addition, we carried out qRT PCR analysis to determine extracellular/adhesion gene marker expression and assessed cell proliferation and mineralization in response to FGF8 treatment. 2D and mass spectrometry data showed differential expression of proteins implicated in cytoskeleton/ECM remodeling and migration, cell proliferation and odontogenic differentiation as evidenced by the upregulation of gelsolin, moesin, LMNA, WDR1, PLOD2, COPS5 and downregulation of P4HB. qRT PCR showed downregulation of proteins involved in cell-matrix adhesion such as ADAMTS8, LAMB3 and ANOS1 and increased expression of the angiogenesis marker PECAM1. We have observed that, FGF8 treatment was able to boost dental pulp cell proliferation and to enhance dental pulp mineralization. Collectively, our data suggest that, FGF8 treatment could promote endogenous healing of the dental pulp via recruitment of dental pulp progenitors as well as by promoting their angiogenic and odontogenic differentiation. SIGNIFICANCE: Dental pulp cells (DP) have been studied extensively for the purposes of mineralized tissue repair, particularly for the reconstruction of hard and soft tissue maxillofacial defects. Canonical FGF signaling has been implicated throughout multiple stages of tooth development by regulating cell proliferation, differentiation, survival as well as cellular migration. FGF8 expression is indispensible for normal tooth development and particularly for the migration of early tooth progenitors to the sites of tooth emergence. The present study provides proteome and qRT PCR data with regard to the future application and biological relevance of FGF8 in dental regenerative medicine. AUTHORS WITH ORCID: Rozaliya Tsikandelova - 0000-0003-0178-3767 Zornitsa Mihaylova - 0000-0003-1748-4489 Sébastien Planchon - 0000-0002-0455-0574 Nikolay Ishkitiev - 0000-0002-4351-5579.

Bacterial lipopolysaccharide induces proliferation of IL-6-dependent plasmacytoma cells by MAPK pathway activation.

Mouse plasmacytomas are appropriate models to study the biology of human multiple myeloma (MM). Growth of murine interleukin-6 (IL-6)-dependent hybridoma/plasmacytoma lines can be stimulated by bacterial lipopolysaccharides (LPS). However, the molecular mechanisms of this phenomenon are still not elucidated. In this study the in vitro action of bacterial LPS on the mouse IL-6-dependent B9 hybridoma/plasmacytoma cell line and two IL-6-dependent hybridomas was investigated. The involvement of different signal transduction pathways was established using specific kinase inhibitors in proliferation assays and immunoblotting analysis of the kinase activity. Selective mitogen-activated protein kinase (MAPK) kinase inhibitor PD989059 inhibited both IL-6- and LPS-induced B9 cell proliferation. In contrast, in H187 and H188 cells, PD98059 inhibited only LPS-, but not IL-6-stimulated cell growth. The kinetics of MAPK activation in all cell lines showed that phosphorylation of p42 MAPK (encoded as ERK2) but not of p44 MAPK (ERK1), was considerably increased after treatment with LPS. We found that in H187 and H188 hybridomas IL-6 induced proliferation by a different STAT3-dependent mechanism. This study demonstrates the key role of the MAPK pathway in LPS-stimulated growth of mouse IL-6-dependent plasmacytoma cells. These findings suggest the presence of signaling mechanism in MM cells inducible by bacterial mitogens and possibly mediated by Toll-like receptors (TLR)--evolutionarily conserved molecules playing a central role in the microbial recognition and initiation of the cellular innate immune response.

The effect of chemical blockade of PKC with Gö6976 and Gö6983 on proliferation and MAPK activity in IL-6-dependent plasmacytoma cells.

Interleukin-6 (IL-6) mediates growth of murine B9 hybridoma/plasmacytoma cells via Ras-dependent mitogen-activated protein kinase (MAPK) pathway. Preincubation of cells with selective protein kinase C (PKC) inhibitors Gö6976 and Gö6983 leads to enhancement of IL-6-induced p44/p42 MAPK activity. The basal p44/p42 MAPK activity is also stimulated in the presence of both inhibitors. On the other hand, Gö6976 completely blocks proliferation, but Gö6983 which does not inhibit PKC(mu) has no effect on the cell growth. These findings suggest that PKC(mu) is required for proliferation and other PKC isoenzymes are involved in regulation of IL-6-dependent growth of B9 cells by negative regulation of the MAPK pathway.