The relationship between proteoglycan inhibition via xylosyltransferase II silencing and the implantation of salivary pleomorphic adenoma

Heterogeneity and versatility of the extracellular matrix during the transition from pleomorphic adenoma to carcinoma ex pleomorphic adenoma: cumulative findings from basic research and new insights

Pleomorphic adenoma (PA) is the most common salivary gland tumor, accounting for 50%-60% of these neoplasms. If untreated, 6.2% of PA may undergo malignant transformation to carcinoma ex-pleomorphic adenoma (CXPA). CXPA is a rare and aggressive malignant tumor, whose prevalence represents approximately 3%-6% of all salivary gland tumors. Although the pathogenesis of the PA-CXPA transition remains unclear, CXPA development requires the participation of cellular components and the tumor microenvironment for its progression. The extracellular matrix (ECM) comprises a heterogeneous and versatile network of macromolecules synthesized and secreted by embryonic cells. In the PA-CXPA sequence, ECM is formed by a variety of components including collagen, elastin, fibronectin, laminins, glycosaminoglycans, proteoglycans, and other glycoproteins, mainly secreted by epithelial cells, myoepithelial cells, cancer-associated fibroblasts, immune cells, and endothelial cells. Like in other tumors including breast cancer, ECM changes play an important role in the PA-CXPA sequence. This review summarizes what is currently known about the role of ECM during CXPA development.

Comprehensive network map of interferon gamma signaling

Interferon gamma (IFN-γ), is a cytokine, which is an important regulator of host defense system by mediating both innate and adaptive immune responses. IFN-γ signaling is primarily associated with inflammation and cell-mediated immune responses. IFN-γ is also represented as antitumor cytokine which facilitates immunosurveillance in tumor cells. In addition, IFN-γ mediated signaling also elicits pro-tumorigenic transformations and promotes tumor progression. Impact of IFN-γ signaling in mammalian cells has been widely studied which indicate that IFN-γ orchestrates distinct cellular functions including immunomodulation, leukocyte trafficking, apoptosis, anti-microbial, and both anti- and pro-tumorigenic role. However, a detailed network of IFN-γ signaling pathway is currently lacking. Therefore, we systematically curated the literature information pertaining to IFN-γ signaling and develop a comprehensive signaling network to facilitate better understanding of IFN-γ mediated signaling. A total of 124 proteins were catalogued that were experimentally proven to be involved in IFN-γ signaling cascade. These 124 proteins were found to participate in 81 protein-protein interactions, 94 post-translational modifications, 20 translocation events, 54 activation/inhibiton reactions. Further, 236 differential expressed genes were also documented in IFN-γ mediated signaling. IFN-γ signaling pathway is made freely available to scientific audience through NetPath at ( http://www.netpath.org/pathways?path_id=NetPath_32 ). We believe that documentation of reactions pertaining to IFN-γ signaling and development of pathway map will facilitate further research in IFN-γ associated human diseases including cancer.

Effect of Xylosyltransferase-I Silencing on Implanting Growth of Salivary Pleomorphic Adenoma

BACKGROUND Salivary pleomorphic adenoma is one of the most common salivary gland tumors. It has a relatively high tendency to recur and a high risk of malignant transformation. The present study aimed to study the effect of XT-I gene silencing on the implanting growth of salivary pleomorphic adenoma. MATERIAL AND METHODS Primary cultures of SPA cells and fibroblasts from the same patient were assessed. The adenovirus vector Ad-shRNA-XT-I was constructed and transfected into SPA cells. The expression of XT-I gene and XT-I protein was detected by real-time PCR and Western blot. The contents of proteoglycans were detected. The SPA cells transfected with Ad-shRNA-XT-I (group SPA-XT-I) and Ad-shRNA-HK (group SPA-HK), as well as without transfection (group SPA), were implanted into ADM scaffold with fibroblasts and then transferred into 18 BALB/C-nu nude mice for 3 months. RESULTS Primary cultures showed SPA cells were positive for human CK and S-100 protein and the fibroblasts were positive for human vimentin. The expressions of XT-I gene and protein were decreased by 51% and 51.31%, respectively. The content of proteoglycans was reduced by 48.45%. The results of the implanting growth in vitro and in vivo of nude mice indicated that no tumors grew in the SPA-XT-I group, whereas SPA grew in groups SPA-HK and SPA positive for human a-SMA, S-100 protein, and calponin. CONCLUSIONS XT-I gene silencing effectively inhibited the implanting growth of SPA.