Small Molecule Amiloride Modulates Oncogenic RNA Alternative Splicing to Devitalize Human Cancer Cells

Chang, Jui‐Hsing; Yang, Da; Chang, Wen Hsin; Chow, Lu-Ping; Chan, Wen Ling; Lin, Hui Hua; Huang, Hsien Da; Chang, Yaotsu; Hung, Cheng Hao; Yang, Wen

doi:10.1371/journal.pone.0018643

Cited by 56 publications

(44 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Amiloride is known to suppress the Na + /H + exchanger protein (NHE) activity to disturb membrane ruffling, 22 but it is also associated with the suppression of pAkt expression. 38 Moreover, we found that non-IPF and IPF fibroblasts on collagen showed significantly decreased pAkt expression along with reduced uptake of CNPs in the presence of amiloride. Thus, it may be possible that amiloride can inhibit the Na + /H + exchanger protein-dependent signaling pathway via the PI3K/Akt axis.…”

Section: Discussionmentioning

confidence: 76%

The effects of collagen-rich extracellular matrix on the intracellular delivery of glycol chitosan nanoparticles in human lung fibroblasts

Yhee¹,

Yoon²,

Kim³

et al. 2017

IJN

View full text Add to dashboard Cite

Recent progress in nanomedicine has shown a strong possibility of targeted therapy for obstinate chronic lung diseases including idiopathic pulmonary fibrosis (IPF). IPF is a fatal lung disease characterized by persistent fibrotic fibroblasts in response to type I collagen-rich extracellular matrix. As a pathological microenvironment is important in understanding the biological behavior of nanoparticles, in vitro cellular uptake of glycol chitosan nanoparticles (CNPs) in human lung fibroblasts was comparatively studied in the presence or absence of type I collagen matrix. Primary human lung fibroblasts from non-IPF and IPF patients (n=6/group) showed significantly increased cellular uptake of CNPs (>33.6–78.1 times) when they were cultured on collagen matrix. To elucidate the underlying mechanism of enhanced cellular delivery of CNPs in lung fibroblasts on collagen, cells were pretreated with chlorpromazine, genistein, and amiloride to inhibit clathrin-mediated endocytosis, caveolae-mediated endocytosis, and macropinocytosis, respectively. Amiloride pretreatment remarkably reduced the cellular uptake of CNPs, suggesting that lung fibroblasts mainly utilize the macropinocytosis-dependent mechanism when interacted with collagen. In addition, the internalization of CNPs was predominantly suppressed by a phosphoinositide 3-kinase (PI3K) inhibitor in IPF fibroblasts, indicating that enhanced PI3K activity associated with late-stage macropinocytosis can be particularly important for the enhanced cellular delivery of CNPs in IPF fibroblasts. Our study strongly supports the concept that a pathological microenvironment which surrounds lung fibroblasts has a significant impact on the intracellular delivery of nanoparticles. Based on the property of enhanced intracellular delivery of CNPs when fibroblasts are made to interact with a collagen-rich matrix, we suggest that CNPs may have great potential as a drug-carrier system for targeting fibrotic lung fibroblasts.

show abstract

Section: Discussionmentioning

confidence: 76%

The effects of collagen-rich extracellular matrix on the intracellular delivery of glycol chitosan nanoparticles in human lung fibroblasts

Yhee¹,

Yoon²,

Kim³

et al. 2017

IJN

View full text Add to dashboard Cite

show abstract

“…Similarly, this study showed that amiloride treatment had an antiproliferative effect and increased radiosensitivity in irradiated GBM8401 glioblastoma cells. Earlier studies have shown that the antiproliferative effects of amiloride in several cancer cell types may result from apoptosis (Park et al, 2009;Chang et al, 2011aChang et al, , 2011b. In contrast, other agents, for example, lactate and gemcitabine, are reported to, respectively, increase radioresistance (Hirschhaeuser et al, 2011) and decrease radiosensitivity (Salem et al, 2012).…”

Section: Discussionmentioning

confidence: 99%

“…Amiloride (Sigma Chemical) treatment was performed as previously described (Chang et al, 2011a). At specified times, cells were irradiated with a single dose of 5 Gy at room temperature by a Varian 2100 C/D linear accelerator (Varian Medical System) at a dose rate of 300 MU/min (3 Gy/min) and at a source-to-target distance of 100 cm.…”

Section: Cell Culture and Ionizing Radiation Exposurementioning

confidence: 99%

Modulating Roles of Amiloride in Irradiation-Induced Antiproliferative Effects in Glioblastoma Multiforme Cells Involving Akt Phosphorylation and the Alternative Splicing of Apoptotic Genes

Tang

Chang

2013

DNA and Cell Biology

Self Cite

View full text Add to dashboard Cite

Apoptosis is a key mechanism for enhanced cellular radiosensitivity in radiation therapy. Studies suggest that Akt signaling may play a role in apoptosis and radioresistance. This study evaluates the possible modulating role of amiloride, an antihypertensive agent with a modulating effect to alternative splicing for regulating apoptosis, in the antiproliferative effects induced by ionizing radiation (IR) in glioblastoma multiforme (GBM) 8401 cells. Analysis of cell viability showed that amiloride treatment significantly inhibited cell proliferation in irradiated GBM8401 cells ( p < 0.05) in a time-dependent manner, especially in cells treated with amiloride with IR posttreatment. In comparison with GBM8401 cells treated with amiloride alone, with GBM8401 cells treated with IR alone, and with human embryonic lung fibroblast control cells (HEL 299), GBM8401 cells treated with IR combined with amiloride showed increased overexpression of phosphorylated Akt, regardless of whether IR treatment was performed before or after amiloride administration. The alternative splicing pattern of apoptotic proteaseactivating factor-1 (APAF1) in cells treated with amiloride alone, IR alone, and combined amiloride-IR treatments showed more consistent cell proliferation compared to that in other apoptosis-related genes such as baculoviral IAP repeat containing 5 (BIRC5), Bcl-X, and homeodomain interacting protein kinase-3 (HIPK3). In GBM8401 cells treated with amiloride with IR post-treatment, the ratio of prosurvival (-XL,-LC) to proapoptotic (-LN,-S) splice variants of APAF1 was lower than that seen in cells treated with amiloride with IR pretreatment, suggesting that proapoptotic splice variants of APAF1 (APAF1-LN,-S) were higher in the glioblastoma cells treated with amiloride with IR post-treatment, as compared to glioblastoma cells and fibroblast control cells that had received other treatments. Together, these results suggest that amiloride modulates cell radiosensitivity involving the Akt phosphorylation and the alternative splicing of APAF1, especially for the cells treated with amiloride with IR posttreatment. Therefore, amiloride may improve the effectiveness of radiation therapy for GBMs.

show abstract

“…However, it has been discovered in a screen to potently affect splicing of several apoptotic genes and to be able to decrease tumor growth in animal models. 61,62 Recently, a class of small molecule compounds that inhibit SRPK1 (SRPIN340, SPHINX), a major regulator of AS through SR-protein phosphorylation, has been shown to switch VEGF-A splicing toward the VEGF-A xxx b isoforms, and therefore inhibit angiogenesis in several mouse models including ocular neovascularization, 63 melanoma xenografts, 64 and orthotopic prostate cancer. 65 Administration of rhVEGF 165 b is therapeutic in mouse models of DN.…”

Section: Manipulation Of As As a Potential Therapeutic Avenue In Ckdmentioning

confidence: 99%

Alternative Splicing in CKD

Stevens

Oltean

2016

JASN

View full text Add to dashboard Cite

Alternative splicing (AS) has emerged in the postgenomic era as one of the main drivers of proteome diversity, with $94% of multiexon genes alternatively spliced in humans. AS is therefore one of the main control mechanisms for cell phenotype, and is a process deregulated in disease. Numerous reports describe pathogenic mutations in splice factors, splice sites, or regulatory sequences. Additionally, compared with the physiologic state, disease often associates with an abnormal proportion of splice isoforms (or novel isoforms), without an apparent driver mutation. It is therefore essential to study how AS is regulated in physiology, how it contributes to pathogenesis, and whether we can manipulate faulty splicing for therapeutic advantage. Although the disease most commonly linked to deregulation of AS in several genes is cancer, many reports detail pathogenic splice variants in diseases ranging from neuromuscular disorders to diabetes or cardiomyopathies. A plethora of splice variants have been implicated in CKDs as well. In this review, we describe examples of these CKD-associated splice variants and ideas on how to manipulate them for therapeutic benefit.

show abstract

Small Molecule Amiloride Modulates Oncogenic RNA Alternative Splicing to Devitalize Human Cancer Cells

Cited by 56 publications

References 54 publications

The effects of collagen-rich extracellular matrix on the intracellular delivery of glycol chitosan nanoparticles in human lung fibroblasts

The effects of collagen-rich extracellular matrix on the intracellular delivery of glycol chitosan nanoparticles in human lung fibroblasts

Modulating Roles of Amiloride in Irradiation-Induced Antiproliferative Effects in Glioblastoma Multiforme Cells Involving Akt Phosphorylation and the Alternative Splicing of Apoptotic Genes

Alternative Splicing in CKD

Contact Info

Product

Resources

About