Canonical NF-κB Promotes Lung Epithelial Cell Tumour Growth by Downregulating the Metastasis Suppressor CD82 and Enhancing Epithelial-to-Mesenchymal Cell Transition

Background: The development of non-small cell lung cancer (NSCLC) involves the progressive accumulation of genetic and epigenetic changes. These include somatic oncogenic KRAS and EGFR mutations and inactivating TP53 tumour suppressor mutations, leading to activation of canonical NF-κB. However, the mechanism(s) by which canonical NF-κB contributes to NSCLC is still under investigation. Methods: Human NSCLC cells were used to knock-down RelA/p65 (RelA/p65KD) and investigate its impact on cell growth, and its mechanism of action by employing RNA-seq analysis, qPCR, immunoblotting, immunohistochemistry, immunofluorescence and functional assays. Results: RelA/p65KD reduced the proliferation and tumour growth of human NSCLC cells grown in vivo as xenografts in immune-compromised mice. RNA-seq analysis identified canonical NF-κB targets mediating its tumour promoting function. RelA/p65KD resulted in the upregulation of the metastasis suppressor CD82/KAI1/TSPAN27 and downregulation of the proto-oncogene ROS1, and LGR6 involved in Wnt/β-catenin signalling. Immunohistochemical and bioinformatics analysis of human NSCLC samples showed that CD82 loss correlated with malignancy. RelA/p65KD suppressed cell migration and epithelial-to-mesenchymal cell transition (EMT), mediated, in part, by CD82/KAI1, through integrin-mediated signalling involving the mitogenic ERK, Akt1 and Rac1 proteins. Conclusions: Canonical NF-κB signalling promotes NSCLC, in part, by downregulating the metastasis suppressor CD82/KAI1 which inhibits cell migration, EMT and tumour growth.

Download Full-text

Different translation dynamics of β-and γ-actin regulates cell migration

eLife ◽

10.7554/elife.68712 ◽

2021 ◽

Vol 10 ◽

Author(s):

Pavan Vedula ◽

Satoshi Kurosaka ◽

Brittany MacTaggart ◽

Qin Ni ◽

Garegin Papoian ◽

...

Keyword(s):

Cell Migration ◽

Amino Acid ◽

Single Molecule ◽

Amino Acid Level ◽

Focal Adhesions ◽

Mesenchymal Cell ◽

Cell Periphery ◽

Pronounced Difference ◽

Coding Sequence

β- and γ-cytoplasmic actins are ubiquitously expressed in every cell type and are nearly identical at the amino acid level but play vastly different roles in vivo. Their essential roles in embryogenesis and mesenchymal cell migration critically depend on the nucleotide sequences of their genes, rather than their amino acid sequence, however it is unclear which gene elements underlie this effect. Here we address the specific role of the coding sequence in β- and γ-cytoplasmic actins' intracellular functions, using stable polyclonal populations of immortalized mouse embryonic fibroblasts with exogenously expressed actin isoforms and their 'codon-switched' variants. When targeted to the cell periphery using the β-actin 3′UTR, β-actin and γ-actin have differential effects on cell migration. These effects directly depend on the coding sequence. Single molecule measurements of actin isoform translation, combined with fluorescence recovery after photobleaching, demonstrate a pronounced difference in β- and γ-actins' translation elongation rates in cells, leading to changes in their dynamics at the focal adhesions, impairments in actin bundle formation, and reduced cell anchoring to the substrate during migration. Our results demonstrate that coding sequence-mediated differences in actin translation play a key role in cell migration.

Download Full-text

YAP1 mediates gastric adenocarcinoma peritoneal metastases that are attenuated by YAP1 inhibition

Gut ◽

10.1136/gutjnl-2019-319748 ◽

2020 ◽

Vol 70 (1) ◽

pp. 55-66

Author(s):

Jaffer A Ajani ◽

Yan Xu ◽

Longfei Huo ◽

Ruiping Wang ◽

Yuan Li ◽

...

Keyword(s):

Gastric Adenocarcinoma ◽

Tumour Growth ◽

Malignant Ascites ◽

Tumour Cells ◽

Rna Seq ◽

Molecular Events ◽

Advanced Gastric Adenocarcinoma

ObjectivePeritoneal carcinomatosis (PC; malignant ascites or implants) occurs in approximately 45% of advanced gastric adenocarcinoma (GAC) patients and associated with a poor survival. The molecular events leading to PC are unknown. The yes-associated protein 1 (YAP1) oncogene has emerged in many tumour types, but its clinical significance in PC is unclear. Here, we investigated the role of YAP1 in PC and its potential as a therapeutic target.MethodsPatient-derived PC cells, patient-derived xenograft (PDX) and patient-derived orthotopic (PDO) models were used to study the function of YAP1 in vitro and in vivo. Immunofluorescence and immunohistochemical staining, RNA sequencing (RNA-Seq) and single-cell RNA-Seq (sc-RNA-Seq) were used to elucidate the expression of YAP1 and PC cell heterogeneity. LentiCRISPR/Cas9 knockout of YAP1 and a YAP1 inhibitor were used to dissect its role in PC metastases.ResultsYAP1 was highly upregulated in PC tumour cells, conferred cancer stem cell (CSC) properties and appeared to be a metastatic driver. Dual staining of YAP1/EpCAM and sc-RNA-Seq revealed that PC tumour cells were highly heterogeneous, YAP1high PC cells had CSC-like properties and easily formed PDX/PDO tumours but also formed PC in mice, while genetic knockout YAP1 significantly slowed tumour growth and eliminated PC in PDO model. Additionally, pharmacologic inhibition of YAP1 specifically reduced CSC-like properties and suppressed tumour growth in YAP1high PC cells especially in combination with cytotoxics in vivo PDX model.ConclusionsYAP1 is essential for PC that is attenuated by YAP1 inhibition. Our data provide a strong rationale to target YAP1 in clinic for GAC patients with PC.

Download Full-text

Overexpression of RSK4 reverses doxorubicin resistance in human breast cancer cells via PI3K/AKT signalling pathway

The Journal of Biochemistry ◽

10.1093/jb/mvaa009 ◽

2020 ◽

Vol 167 (6) ◽

pp. 603-611

Author(s):

Yan Mei ◽

Xiaoming Liao ◽

Lingyu Zhu ◽

Huawei Yang

Keyword(s):

Breast Cancer ◽

Drug Resistance ◽

Cell Migration ◽

Western Blot ◽

Tumour Growth ◽

Metastatic Breast ◽

Signalling Pathway ◽

Chemotherapy Drugs ◽

Mcf 7

Abstract Doxorubicin (DOX) is one of the most effective chemotherapy drugs for the treatment of metastatic breast cancer (BC), but drug resistance becomes an obstacle to treatment. This study aims to investigate the role of Ribosomal S6 protein kinase 4 (RSK4) in regulating BC resistance to DOX. We first used Kaplan–Meier Plotter to identify the prognostic roles of RSK4 in BC. DOX-resistant BC cells (MCF-7/DOX) were constructed and the expression of RSK4 was determined by reverse transcript polymerase chain reaction and western blot. Subsequently, we overexpressed the RSK4 in MCF-7/DOX cells, and measured drug resistance, colony formation, cell migration, invasion ability and cell apoptosis after transfection. In addition, western blot was used to explore the expression of apoptosis-related proteins and BC-resistance protein. Effects of RSK4 on activation of the PI3K/AKT signalling pathway were also tested. Furthermore, tumour xenograft in nude mice was constructed to observe the effect of RSK4 overexpression on tumour growth in vivo. In conclusion, RSK4 was positively correlated with survival rate in BC patients, which is lowly expressed in MCF-7/DOX. Meanwhile, the overexpression of RSK4 may inhibit drug resistance, cell migration, invasion, apoptosis and tumour growth. RSK4 may effectively attenuate DOX resistance in BC by inhibiting the PI3K/AKT signalling pathway.

Download Full-text

FSMP-11. TARGETING CHOLESTEROL HOMEOSTASIS DYSREGULATION FOR THE TREATMENT OF GLIOBLASTOMA

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab024.075 ◽

2020 ◽

Vol 3 (Supplement_1) ◽

pp. i18-i18

Author(s):

Mingzhi Han

Keyword(s):

Tumour Growth ◽

Cholesterol Metabolism ◽

Ectopic Expression ◽

Cholesterol Homeostasis ◽

Normal Brain ◽

Rna Seq ◽

Specific Enzyme ◽

Normal Brain Tissue ◽

Potential Therapeutic Target

Abstract Dysregulated cholesterol metabolism is a hallmark of many cancers, including glioblastoma (GBM), but its role in disease progression is not well understood. Here, we identified cholesterol 24-hydroxylase (CYP46A1), a brain-specific enzyme responsible for elimination of cholesterol through conversion of cholesterol to 24(S)-hydroxycholesterol (24OHC), as one of the most dramatically dysregulated cholesterol metabolism genes in GBM. CYP46A1 was significantly decreased in GBM samples compared to normal brain tissue. In gliomas, a reduction in CYP46A1 expression was associated with increasing tumour grade and poor prognosis. Functionally, ectopic expression of CYP46A1 suppressed cell proliferation and in vivo tumour growth by increasing 24OHC levels. RNA-seq revealed that treatment of GBM cells with 24OHC suppressed tumour growth through regulation of LXR and SREBP signaling. Efavirenz (EFV), an activator of CYP46A1 that is known to penetrate the blood-brain barrier (BBB), inhibited GBM growth in vivo. Our findings demonstrate that CYP46A1 is a critical regulator of cellular cholesterol in GBM and that the CYP46A1/24OHC axis is a potential therapeutic target.

Download Full-text

An ultrastructural and morphometric analysis of an in vivo contact guidance system

Development ◽

10.1242/dev.101.2.363 ◽

1987 ◽

Vol 101 (2) ◽

pp. 363-381

Author(s):

A. Wood ◽

P. Thorogood

Keyword(s):

Cell Migration ◽

Morphometric Analysis ◽

Mesenchymal Cell ◽

Mesenchymal Cells ◽

Contact Guidance ◽

Cell Phenotype ◽

Cell Processes ◽

Computer Based ◽

The Mean

The pectoral fin bud of the developing teleost embryo contains a highly ordered extracellular matrix of collagenous fibrils, called ‘actinotrichia’. During invasion of the fin fold, mesenchymal cells, migrating distally from the base of the fin, become contact aligned by the actinotrichial fibrils. Behavioural aspects of this response have previously been studied using Nomarski differential interference contrast microscopy and time-lapse video recording (Wood & Thorogood, 1984). Here we present an ultrastructural description of these cells and their matrix associations and a computer- based morphometric analysis of selected parameters within the migration substratum, relevant to this in vivo ‘contact guidance’ phenomenon. The study shows that a differentiated and aligned matrix of actinotrichial fibrils can be detected before invasion of the fin fold, at levels up to 40μm distal to the advancing mesenchymal cell margin. Subsequently, during invasion of the fin fold, aligned mesenchymal cells and processes are almost exclusively associated with actinotrichia and not the intervening surface of the epithelial basal lamina. However, aligned cell processes appear to avoid the smaller actinotrichia and at late stages of development 87á0% of actinotrichia without cell process contacts are distributed at the lower end of the size range. Study of cell ultrastructure revealed a complete absence of cytoskeletal organization within this mesenchymal cell population, although cytoskeletal components are clearly visible in adjacent epithelia. The computer-based morphometric survey of the migration substratum has shown a gradual but progressive increase in the mean diameter of actinotrichia at a level at which distal cell processes are first detectable in sections of fins. However, at similar levels over the same period the mean value for interactinotrichial spacings remained virtually constant. These results suggest that the spacing between actinotrichia is not significant in contributing to progressive changes in mesenchymal cell phenotype, but that the actinotrichia themselves are strongly implicated in providing the guidance cues to direct cell migration within the developing fin and the initiation of cell migration. These findings are discussed in the general context of cell movement and contact guidance both in vivo and in vitro.

Download Full-text

Patterns of fibronectin gene expression and splicing during cell migration in chicken embryos

Development ◽

10.1242/dev.104.3.369 ◽

1988 ◽

Vol 104 (3) ◽

pp. 369-382 ◽

Cited By ~ 7

Author(s):

C. Ffrench-Constant ◽

R.O. Hynes

Keyword(s):

Cell Migration ◽

Neural Crest ◽

Neural Crest Cell ◽

Mesenchymal Cell ◽

Endocardial Cushion ◽

Chicken Embryos ◽

Relative Contribution ◽

Area Vasculosa ◽

Neural Crest Cell Migration

A variety of evidence suggests that fibronectin (FN) promotes cell migration during embryogenesis, and it has been suggested that the deposition of FN along migratory pathways may also play a role in cell guidance. In order to investigate such a role for FN, it is important to determine the relative contribution of migrating and pathway-forming cells to the FN in the migratory track, as any synthesis of FN by the migrating cells might be expected to mask guidance cues provided by the exogenous FN from pathway-forming cells. We have therefore used in situ hybridization to determine in developing chicken embryos the distribution and alternative splicing of FN mRNA during three different cell migrations known to occur through FN-rich environments; neural crest cell migration, mesenchymal cell migration in the area vasculosa and endocardial cushion cell migration in the heart. Our results show that trunk neural crest cells do not contain significant FN mRNA during their initial migration. In contrast, migrating mesenchymal cells of the area vasculosa and endocardial cushion cells both contain abundant FN mRNA. Furthermore, the FN mRNA in these migrating mesenchymal and endocardial cells appears to be spliced in a manner identical with that present in the cells adjacent to their pathways. This in vivo evidence for FN synthesis by migrating and pathway cells argues against a generalized role for exogenously produced FN as a guidance mechanism for cell migration.

Download Full-text