Proteomic analysis reveals important role of 14-3-3σ in anoikis resistance of cholangiocarcinoma cells

Abstract

Cholangiocarcinoma (CCA), a high-prevalence cancer in Thailand, is highly metastatic and has high mortality rates. Anoikis resistance or the ability of cells to survive after detachment from extracellular matrix is a necessary property of metastatic cancer. Here, we report differential protein expression of an anoikis-resistant CCA cell line culture, under attachment conditions compared to nonattachment conditions, studied using 2DE coupled with protein identification by LC-MS/MS. Our data reveal the deregulation of proteins involved in stress response, cytoskeleton rearrangement, proapoptosis, cell proliferation, and glycolysis. Interestingly, 14-3-3σ (14-3-3 sigma) protein was intensely upregulated in detached CCA cells. Real-time RT-PCR analysis confirmed that only the sigma isotype was the most abundant transcript among 14-3-3 genes in CCA cells. Furthermore, silencing 14-3-3σ expression by small interfering RNA in CCA cells resulted in significantly increased percentage of cell death in detached culture. Our findings provide the first evidence showing that 14-3-3σ protein plays a crucial role in anoikis resistance of CCA cells. Therefore, 14-3-3σ might be a potential target in CCA therapy.

Anoikis‐resistant cholangiocarcinoma cells display aggressive characteristics and increase STAT3 activation

“…Previous study demonstrated that CCA cells managed to survive under nonattachment condition by upregulating 14–3‐3σ protein . Our present study further explored biological properties of anoikis‐resistant CCA cells, as well as examined signaling pathways that underlie the resistance.…”

Decreasing O-GlcNAcylation affects the malignant transformation of MCF-7 cells via Hsp27 expression and its O-GlcNAc modification

“…Anoikis resistance and anchorage-independence are therefore crucial steps in a series of changes that tumor cells undergo during malignant transformation. Extensive studies on anoikis resistance mechanisms have been performed in cancers to identify molecular targets for preventing metastasis (1)(2)(3). Moreover, anchorage-independent growth of cancer cells in vitro (colony forming capacity in soft agar media) has been used to predict the tumor phenotype, particularly with respect to the potential for metastasis in primary breast and lung tumors (4).…”

Secretomic profiling of cells from hollow fiber bioreactor reveals PSMA3 as a potential cholangiocarcinoma biomarker

“…Increasing number of studies suggest that 14-3-3 play a critical role during cancer metastasis in HCC (40). We recently reported the upregulation of 14-3-3σ protein that plays an important role in anoikis resistance of human CCA cells (41). In addition, the secretory 14-3-3σ protein in the conditioned media of 3D culture systems is significantly increased compared to those of MNC culture system (11,12).…”