Alcohol promotes epithelial mesenchymal transformation-mediated premetastatic niche formation of colorectal cancer by activating interaction between laminin-γ2 and integrin-β1

BACKGROUND Colorectal cancer(CRC) is a common malignant tumor. Alcohol consumption is positively correlated with CRC malignant metastasis;however, the mechanism is unclear. The interaction between laminin-γ2(LAMC2) and integrin-β1(ITGB1) plays a role in premetastatic niche signaling, which may induce epithelial mesenchymal transformation(EMT) and lead to metastasis.AIM To investigate the effects of alcohol on CRC metastasis from the molecular mechanism of the premetastatic niche.METHODS The interaction between LAMC2 and ITGB1 was measured by Duolink assay, and the expression levels of LAMC2, ITGB1 and focal adhesion kinase(FAK), snail, fibronectin, N-cadherin and special AT-rich sequence binding protein 1(SATB1) were measured by quantitative real-time polymerase chain reaction, immunohistochemistry and western blotting. Interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α) and IL-6 levels were measured via enzyme-linked immunosorbent assay, histopathological assessment via hematoxylin eosin staining, and determination of aberrant crypt foci via methylene blue.RESULTS The lymph node metastasis rate was higher in the alcohol group than non-alcohol group. There was a significant increase in interaction signals between LAMC2 and ITGB1, and an increase in phosphorylate-FAK/FAK, snail, fibronectin, N-cadherin and SATB1, whereas E-cadherin was reduced in the alcohol group compared to the non-alcohol group in both animal and clinical samples. Serum IL-1β, TNF-α and IL-6 were higher in alcohol group than in non-alcohol group. Alcohol may promote CRC metastasis by influencing the molecular mechanism of the premetastatic niche.CONCLUSION Our study suggests that alcohol promotes EMT-mediated premetastatic niche formation of CRC by activating the early interaction between LAMC2 and ITGB1 and lead to CRC metastasis.

Effects of exogenous recombinant human bone morphogenic protein-7 on the corneal epithelial mesenchymal transition and fibrosis

AIM：To evaluate the effect of exogenous recombinant human bone morphogenic protein-7（rhBMP-7）on transforming growth factor-β（TGF-β）-induced epithelial mesenchymal cell transition（EMT）and assessed its antifibrotic effect via topical application.METHODS：The cytotoxic effect of rhBMP-7 was evaluated and the EMT of human corneal epithelial cells（HECEs）was induced by TGF-β. HECEs were then cultured in the presence of rhBMP-7 and/or hyaluronic acid（HA）. EMT markers,fibronectin,E-cadherin,α-smooth muscle actin（α-SMA）,and matrix metaloproteinase-9（MMP-9）,were evaluated. The level of corneal fibrosis and the reepithelization rate were evaluated using a rabbit keratectomy model. Expression of α-SMA in keratocytes were quantified following treatment with different concentrations of rhBMP-7.RESULTS：Treatment with rhBMP-7 attenuated TGF-β-induced EMT in HECEs. It significantly attenuated fibronectin secretion（31.6%; P〈0.05）,the α-SMA protein level（72.2%; P〈0.01）,and MMP-9 expression（23.6%,P〈0.05）in HECEs compared with cells grown in the presence of TGF-β alone. E-cadherin expression was significantly enhanced（289.7%; P〈0.01）in the presence of rhBMP-7. Topical application of rhBMP-7 combined with 0.1% HA significantly reduced the amount of α-SMA~＋ cells by 43.18%（P〈0.05）at a concentration of 2.5 μg/mL and by 47.73%（P〈0.05）at 25 μg/mL,compared with the control group,without disturbing corneal reepithelization.CONCLUSION：rhBMP-7 attenuates TGF-β-induced EMT in vitro,and topical application of rhBMP-7 reduces keratocyte myodifferentiation during the early wound healing stages in vivo without hindering reepithelization. Topical rhBMP-7 application as biological eye drops seems to be feasible in diseases involving TGF-β-related corneal fibrosis with corneal reepithelization disorders.

Inhibitory effect on subretinal fibrosis by anti-placental growth factor treatment in a laser-induced choroidal neovascularization model in mice

AIM:To investigate whether anti-placental growth factor(PGF) can inhibit subretinal fibrosis and whether this effect is mediated by the inhibitory effect of PGF on epithelial-mesenchymal transition(EMT) of retinal pigment epithelial(RPE) cells.METHODS:Subretinal fibrosis model was established in laser induced choroidal neovascularization(CNV) mice on day 21 after laser photocoagulation.Immunofluorescence staining(IFS) of cryosections and enzyme-linked immunosorbent assay(ELISA) were used to detect the expression of PGF.IFS of whole choroidal flat-mounts was used to detect the degree of subretinal fibrosis.IFS of cryosections and ELISA were used to detect the expression of EMT related indicators in subretinal fibrosis lesions.RESULTS:The expression of PGF protein in subretinal fibrosis lesions was significantly up-regulated(P<0.05),and mainly co-stained with pan-cytokeratin labeled RPE cells.Intravitreal injection of anti-PGF neutralizing antibody reduced the area of subretinal fibrosis and the ratio of fibrotic/angiogenic area significantly at the concentrations of 0.25,0.5,1.0,and 2.0 μg/μL(all P<0.05).The expression of E-cadherin in the local RPE cells decreased,while α-SMA increased significantly in subretinal fibrosis lesions,and the application of anti-PGF neutralizing antibody could reverse these changes(P<0.05).CONCLUSION:The expression of PGF is up-regulated in the lesion site of subretinal fibrosis and mainly expressed in RPE cells.Intravitreal injection of anti-PGF neutralizing antibody can significantly inhibit the degree of subretinal fibrosis in CNV mice,and this effect may be mediated by the inhibition of PGF on EMT of RPE cells.

Research progress on circulating tumor cell detection in brain gliomas

Glioma,the most common primary intracranial tumor,has high morbidity and mortality.The detection of circulating tumor cells(CTCs)is an important part of the liquid biopsy of gliomas.CTCs,carrying the genetic and biological information of tumor tissue,provide a new perspective and dimension for the study of tumor metastasis,progression,chemotherapy sensitivity and drug resistance.Cerebrospinal fluid(CSF)circulates through the ventricle and spinal cord cistern,which can better maintain the original information of tumor cells compared with the complicated environments of tissues and plasma.Study on the dynamic changes of CTCs in the CSF of the central nervous system(CNS)is relatively rare.However,the analysis of CTCs in CSF can be used to guide the treatment of gliomas and reveal the patho-physiological and genetic mechanisms of tumor cell metastasis to the CSF.This paper reviews the progress in the research on CTC detection in gliomas.

Matrix metalloproteinases contribute to kidney fibrosis in chronic kidney diseases

Matrix metalloproteinases(MMPs) are members of the neutral proteinase family. They were previously thought to be anti-fibrotic because of their ability to degrade and remodel of extracellular matrix. However, recent studies have shown that MMPs are implicated in initiation and progression of kidney fibrosis through tubular cell epithelial–mesenchymal transition(EMT) as well as activation of resident fibroblasts, endothelial-mesenchymal transition(Endo MT) and pericyte-myofibroblast transdifferentiation. Interstitial macrophage infiltration has also been shown to correlate with the severity of kidney fibrosis in various chronic kidney diseases. MMPs secreted by macrophages, especially MMP-9, hasbeen shown by us to be profibrotic by induction of tubular cells EMT. EMT is mainly induced by transforming growth factor-β(TGF-β). However, MMP-9 was found by us and others to be up-regulated by TGF-β1 in kidney tubular epithelial cells and secreted by activated macrophages, resulting in EMT and ultimately kidney fibrosis. Therefore, MMP-9 may serve as a potential therapeutic target to prevent kidney fibrosis in chronic kidney disease. This review, by a particular focus on EMT, seeks to provide a comprehensive understanding of MMPs, especially MMP-9, in kidney fibrosis.