Genome-Wide Transcriptional and Functional Analysis of Endoglin Isoforms in the Human Promonocytic Cell Line U937
JOURNAL OF CELLULAR PHYSIOLOGY
Authors: Blanco, Francisco J.; Ojeda-Fernandez, Luisa; Aristorena, Mikel; Gallardo-Vara, Eunate; Benguria, Alberto; Dopazo, Ana; Langa, Carmen; Botella, Luisa M.; Bernabeu, Carmelo
Abstract
Endoglin is an auxiliary cell surface receptor for TGF-beta family members. Two different alternatively spliced isoforms, long (L)-endoglin and short (S)-endoglin, have been reported. S-endoglin and L-endoglin proteins vary from each other in their cytoplasmic tails that contain 14 and 47 amino acids, respectively. A critical role for endoglin in vascular development has primarily been studied in endothelial cells. In addition, endoglin expression is upregulated during monocyte-to-macrophage differentiation; however, little is known about its role in this myeloid context. To investigate the function of endoglin in monocytes, stable transfectants expressing the two endoglin isoforms in the promonocytic human cell line U937 were generated. The differential gene expression fingerprinting of these endoglin transfectants using DNA microarrays and further bioinformatics analysis showed a clear alteration in essential biological functions, mainly those related to "Cellular Movement", including cell adhesion and transmigration. Interestingly, these cellular functions are highly dependent on adhesion molecules, including integrins alpha 1 (CD49a, ITGA1 gene), alpha L (CD11a, ITGAL gene), alpha M(CD11b, ITGAM gene) and beta 2 (CD18, ITGB2 gene) and the chemokine receptor CCR2 (CD192, CCR2 gene), which are downregulated in endoglin transfectants. Moreover, activin A (INHBA gene), a TGF-beta superfamily member involved in macrophage polarization, was distinctly affected in each endoglin transfectant, and may contribute to the regulated expression of integrins. These data were confirmed by quantitative PCR, flow cytometry and functional tests. Taken together, these results provide new insight into endoglin function in monocytes. (C) 2014 Wiley Periodicals, Inc.
CLIC1 Promotes the Progression of Gastric Cancer by Regulating the MAPK/AKT Pathways
CELLULAR PHYSIOLOGY AND BIOCHEMISTRY
Authors: Li, Bo-pei; Mao, Yuan-tian; Wang, Zhen; Chen, Ye-yang; Wang, Ye; Zhai, Chong-yu; Shi, Bo; Liu, Si-yu; Liu, Jin-lu; Chen, Jun-qiang
Abstract
Background/Aims: Chloride intracellular channel 1 (CLIC1), which is a member of the chloride channel protein family, is associated with various human tumors. Recent studies have shown that CLIC1 is involved in the occurrence and development of gastric cancer (GC). However, the exact mechanism remains unclear in GC. Methods: Effects of CLIC1 on the progression of GC in vivo and in vitro and the potential underlying mechanisms have been investigated by analysing 54 patients with GC, as well as human gastric cell lines SGC-7901 and MGC-803, utilizing proteomics, RT-PCR, Western blotting, flow cytometry, Cell invasion and migration assays and xenograft tumor models. Results: Our study shows that CLIC1 knockdown by targeted-siRNA markedly inhibits GC cell invasion and migration and induces apoptosis in vitro. In total, 54 differentially expressed proteins were identified in GC cells SGC-7901 after CLIC1 silencing by isobaric tags for relative isotope labeled and absolute quantitation (iTRAQ) technology, including integrin alpha 1 (ITG alpha 1) and ITG alpha 3. The expression levels of ITG alpha 3, ITG alpha v, ITG beta 1 and Bcl-2 mRNA and protein were decreased significantly in GC cells after CLIC1 knockdown; ITGa1 and Fas were upregulated, but the level of survivin was not significantly different. GC growth and metabolism were decreased in vivo after CLIC1 silencing, but apoptosis was markedly increased. Further study showed that the expression levels of ITG alpha 3, ITG alpha v and ITG beta 1, as well as AKT-phosphorylation, ERK-phosphorylation and p38-phosphorylation, were reduced in vivo after CLIC1 knockdown, while ITG alpha 1 was upregulated. Conclusions: We speculate that CLIC1 may play an important role in the progression of GC, and its mechanism may be related to the regulation of integrin family proteins, which leads to the sequential regulation of the PI3K/AKT, MAPK/ERK and MAPK/p38 pathways. (C) 2018 The Author(s) Published by S. Karger AG, Basel