TGFβ promotes YAP‐dependent AXL induction in mesenchymal‐type lung cancer cells

The acquisition of chemoresistance remains a major cause of cancer mortality due to the limited accessibility of targeted or immune therapies. However, given that severe alterations of molecular features during epithelial‐to‐mesenchymal transition (EMT) lead to acquired chemoresistance, emerging studies have focused on identifying targetable drivers associated with acquired chemoresistance. Particularly, AXL, a key receptor tyrosine kinase that confers resistance against targets and chemotherapeutics, is highly expressed in mesenchymal cancer cells. However, the underlying mechanism of AXL induction in mesenchymal cancer cells is poorly understood. Our study revealed that the YAP signature, which was highly enriched in mesenchymal‐type lung cancer, was closely correlated to AXL expression in 181 lung cancer cell lines. Moreover, using isogenic lung cancer cell pairs, we also found that doxorubicin treatment induced YAP nuclear translocation in mesenchymal‐type lung cancer cells to induce AXL expression. Additionally, the concurrent activation of TGFβ signaling coordinated YAP‐dependent AXL expression through SMAD4. These data suggest that crosstalk between YAP and the TGFβ/SMAD axis upon treatment with chemotherapeutics might be a promising target to improve chemosensitivity in mesenchymal‐type lung cancer.

Abbreviations

AUC

area under the curve

AXL

AXL receptor tyrosine kinase

BCL2

B‐cell lymphoma 2

CTD2

cancer target discovery and development

CTGF

connective tissue growth factor

DEG

differentially expressed genes

DOXO

doxorubicin

EMT

epithelial–mesenchymal transition

Eto

etoposide

FDA

Food and Drug Administration

ITGB3

integrin beta‐3

MAPK

mitogen‐activated protein kinase

MMP2

matrix metalloproteinase‐2

MMP9

matrix metalloproteinase‐9

mRNA

messenger RNA

NF‐κB

nuclear factor kappa‐light‐chain‐enhancer of activated B cells

SBE

SMAD binding element

SERPINE1

serpin family E member 1

siRNA

small interfering RNA

ssGSEA

single‐sample gene set enrichment analysis

TCGA

The Cancer Genome Atlas

TGFβ

transforming growth factor beta

YAP

Yes‐associated protein

YAP8SA

mutants of inhibitory phosphorylation site at eight serine to Alanine of YAP

ZEB1

zinc finger E‐box binding homeobox 1

ZEB2

zinc finger E‐box‐binding homeobox 2

     

NCOA5通过调控上皮间质转化促进卵巢癌细胞的侵袭转移能力

目的 研究核受体共激活因子5 (NCOA5)对卵巢癌细胞侵袭和转移能力的作用及分子机制。方法 常规培养卵巢癌细胞株SKOV-3、A2780、OC3、HO-8910和正常卵巢上皮细胞系IOSE80,Western blot检测各细胞中NCOA5蛋白的表达水平。选取高表达NCOA5的卵巢癌细胞SKOV-3 和A2780,各分为si-NC组、si-NCOA5组,并分别转染NC siRNA和NCOA5 siRNA。Boyden实验检测各组细胞侵袭能力,Transwell实验检测各组细胞转移能力,Western blot检测各组细胞上皮间质转（EMT）相关蛋白E-cadherin、N-cadherin、vimentin和Slug蛋白的表达水平。结果 Western blot结果显示NCOA5在卵巢癌细胞中的表达显著上调(P<0.05)。在SKOV-3和A2780细胞中干扰NCOA5的表达均显著抑制卵巢癌细胞侵袭和转移能力 (P<0.05),并促进EMT相关蛋白E-cadherin的表达,抑制细胞中EMT相关蛋白N-cadherin、vimentin和Slug蛋白的表达(P<0.05)。结论 NCOA5促进卵巢癌侵袭转移能力,具有作为卵巢癌新型预后生物标志物和治疗分子靶点的潜力。     

上皮间质转化(EMT)及其分子机制

上皮细胞受到细胞外因子刺激后向间质细胞转化的现象与肿瘤的浸润转移密切相关。在此过程中上皮细胞的极性丧失，迁移和运动能力增强，同时上皮表型丢失而逐渐获得间质表型。参与这一过程的细胞内信号转导途径有受体酪氨酸激酶Ras-MAPK途径，Src激酶，Rho家族激酶，PI3K/AKT途径，Wnt信号通路，转录因子等。     

Mucosal bromodomain-containing protein 4 mediates aeroallergen-induced inflammation and remodeling

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Genetic variability of the extraneuronal monoamine transporter EMT (SLC22A3)

The extraneuronal monoamine transporter EMT (HGNC Nomenclature SLC22A3) is the molecular correlate of the classical uptake₂ system responsible for the non-neuronal inactivation of circulating and centrally released catecholamines. Because of its functional profile and expression pattern, EMT is regarded as a candidate gene for diseases related to the sympathetic nervous system and neuropsychiatric disorders. We describe the first investigation of the genetic variability of the EMT gene in human. Six single-nucleotide substitutions and one deletion were detected within the assumed core promoter, the exonic and flanking intronic sequences and the 3'-untranslated region in 100 Caucasian individuals. No amino acid changes were found and Tajima's D was positive (D=2.91; P<0.01). However, the synonymous nucleotide substitution 1233G→A might serve as a cryptic splice acceptor site. Analysis of linkage disequilibrium between polymorphisms yielded 12 possible haplotypes accounting for more than 90% of all haplotypes. Knowledge of the sequence variation and frequency of the underlying polymorphisms in this member of the amphiphilic solute facilitator family of transporters provides the basis for subsequent association studies and candidate gene approaches. Electronic Publication     

Expression of c-ets-1 mRNA is associated with an invasive, EMT-derived phenotype in breast carcinoma cell lines

We have previously observed in vitro that some stromal proteinases (MMP-2, MT1-MMP) were expressed or activated by invasive carcinoma cell lines exhibiting mesenchymal features, presumably acquired through an epithelial to mesenchymal transition (EMT). To examine the potential contribution of c-ets-1 to this phenotype, we have compared here the expression of c-ets-1 with invasiveness in vitro and expression of vimentin, E-cadherin, uPA, MMP-1 and MMP-3 in a panel of human breast cancer cell lines. Our results clearly demonstrate an association between c-ets-1 expression and the invasive, EMT-derived phenotype, which is typified by the expression of vimentin and the lack of E-cadherin. While absent from the two non-invasive, vimentin-negative cell lines, c-ets-1 was abundantly expressed in all the four vimentin-positive lines. However, we could not find a clear quantitative or qualitative relationship between the expression of c-ets-1 and the three proteinases known to be regulated by c-ets-1, except that when they were expressed, it was only in the invasive c-ets-1-positive lines. UPA mRNAs were found in three of the four vimentin-positive lines, MMP-1 in two of the four, and MMP-3 could not be detected in any of the cell lines. Intriguingly, MDA-MB-435 cells, which exhibit the highest metastatic potential of these cell lines in nude mice, expressed vimentin and c-ets-1, but lacked expression of these three proteinases, at least under the culture conditions employed. Taken together, our results show that c-ets-1 expression is associated with an invasive, EMT-derived phenotype in breast cancer cells, although it is apparently not sufficient to ensure the expression of uPA, MMP-1 or MMP-3, in the vimentin-positive cells. Such proteases regulation is undoubtedly qualified by the cellular context. This study therefore advances our understanding of the molecular regulation of invasiveness in EMT-associated carcinoma progression, and suggests that c-ets-1 may contribute to the invasive phenotype in carcinoma cells.     

Genetic ablation of FLRT3 reveals a novel morphogenetic function for the anterior visceral endoderm in suppressing mesoderm differentiation

During early mouse development, the anterior visceral endoderm (AVE) secretes inhibitor and activator signals that are essential for establishing the anterior–posterior (AP) axis of the embryo and for restricting mesoderm formation to the posterior epiblast in the primitive streak (PS) region. Here we show that AVE cells have an additional morphogenetic function. These cells express the transmembrane protein FLRT3. Genetic ablation of FLRT3 did not affect the signaling functions of the AVE according to the normal expression pattern of Nodal and Wnt and the establishment of a proper AP patterning in the epiblast. However, FLRT3^−/− embryos showed a highly disorganized basement membrane (BM) in the AVE region. Subsequently, adjacent anterior epiblast cells displayed an epithelial-to-mesenchymal transition (EMT)-like process characterized by the loss of cell polarity, cell ingression, and the up-regulation of the EMT and the mesodermal marker genes Eomes, Brachyury/T, and FGF8. These results suggest that the AVE acts as a morphogenetic boundary to prevent EMT and mesoderm induction in the anterior epiblast by maintaining the integrity of the BM. We propose that this novel function cooperates with the signaling activities of the AVE to restrict EMT and mesoderm induction to the posterior epiblast.     

慢病毒载体MicroRNA-375过表达调控EMT通路抑制结直肠癌细胞侵袭和迁移

目的:通过慢病毒载体构建microRNA-375过表达的结直肠癌细胞HCT116,研究microRNA-375通过调控EMT通路抑制结直肠癌细胞在人体中侵袭、迁移的作用。方法:通过慢病毒载体转染构建并培养出HCT116细胞的microRNA-375过表达实验组(过表达组)、设立空载体对照组(空载体组)、空白对照组(空白组)。实时逆转录PCR检测3组细胞中microRNA-375的表达情况。Trans-well小室模型检测3组细胞的侵袭能力。划痕实验检测3组细胞的迁移能力。Western blot蛋白质印迹法检测3组细胞EMT通路中蛋白质的相对含量。结果:慢病毒载体转染成功,构建并培养出microRNA-375过表达实验组和空载体对照组的HCT116细胞。过表达组细胞的microRNA-375相对表达量较空载体组和空白组明显升高(P<0.05);空载体组和空白组细胞的microRNA-375相对表达量差异无统计学意义(P>0.05)。过表达组细胞的侵袭、迁移能力较空载体组和空白组减弱(P<0.05);空载体组和空白组细胞的侵袭、迁移能力差异无统计学意义(P>0.05)。过表达组细胞的EMT过程较空载体组和空白组受抑制(P<0.05);空载体组和空白组细胞的EMT过程差异无统计学意义(P>0.05)。结论:MicroRNA-375作为抑癌因子,可通过抑制EMT通路,发挥抑制结直肠癌细胞在人体中侵袭和迁移的作用。     

TGF-β信号通路促进小鼠乳腺癌活检相关性肺转移的实验研究

目的探讨空芯针穿刺活检(core needle biopsy,CNB)对乳腺癌远处转移的影响及其可能机制。方法 30只BALB/c小鼠采用乳腺癌4T1细胞乳腺脂肪垫接种,分成活检与非活检两组,活检组应用CNB建立活检相关肺转移模型,采用流式细胞术、qPCR及形态学等检测技术从肿瘤组织局部和整体水平评价其生物学行为。结果成功建立稳定而可靠的乳腺癌肺转移模型,活检组小鼠肺转移结节数显著高于非活检组(P0.05);与非活检组相比,活检组小鼠TGF-β1、SOX-4及EZH2的m RNA表达上调(P0.05),流式细胞术检测的NK细胞增加,但差异无统计学意义(P0.05)。结论 CNB可通过TGF-β信号通路介导的上皮-间质转化(epithelial-mesenchymal transition,EMT)等机制促进乳腺癌的肺转移。