Analysis of differential membrane proteins related to matrix stiffness-mediated metformin resistance in hepatocellular carcinoma cells.

BACKGROUND: Our previous work shows that increased matrix stiffness not only alters malignant characteristics of hepatocellular carcinoma (HCC) cells, but also attenuates metformin efficacy in treating HCC cells. Here, we identified differential membrane proteins related to matrix stiffness-mediated metformin resistance for better understand therapeutic resistance of metformin in HCC. METHODS: Differential membrane proteins in HCC cells grown on different stiffness substrates before and after metformin intervention were screened and identified using isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with the liquid chromatography-tandem mass spectrometry (LC-MS/MS), then bioinformatic analysis were applied to determine candidate membrane protein and their possible signaling pathway. RESULTS: A total of 5159 proteins were identified and 354 differential membrane proteins and membrane associated proteins, which might be associated with matrix stiffness-mediated metformin resistance were discovered. Then 94 candidate membrane proteins including 21 up-regulated protein molecules and 73 down-regulated protein molecules were further obtained. Some of them such as Annexin A2 (ANXA2), Filamin-A (FLNA), Moesin (MSN), Myosin-9 (MYH9), Elongation factor 2 (eEF2), and Tax1 binding Protein 3 (TAX1BP3) were selected for further validation. Their expressions were all downregulated in HCC cells grown on different stiffness substrates after metformin intervention. More importantly, the degree of decrease was obviously weakened on the higher stiffness substrate compared with that on the lower stiffness substrate, indicating that these candidate membrane proteins might contribute to matrix stiffness-mediated metformin resistance in HCC. CONCLUSIONS: There was an obvious change in membrane proteins in matrix stiffness-mediated metformin resistance in HCC cells. Six candidate membrane proteins may reflect the response of HCC cells under high stiffness stimulation to metformin intervention, which deserve to be investigated in the future.

An SCD1-dependent mechanoresponsive pathway promotes HCC invasion and metastasis through lipid metabolic reprogramming.

Matrix stiffness promotes hepatocellular carcinoma (HCC) metastasis. This study examined the contribution of lipid metabolic reprogramming to matrix stiffness-induced HCC metastasis. HCC cells were cultured on mechanically tunable polyacrylamide gels and subjected to lipidomic analysis. The key enzyme that responded to matrix stiffness and regulated lipid metabolism was identified. The comparative lipidomic screening revealed that stearoyl-CoA desaturase 1 (SCD1) is a mechanoresponsive enzyme that reprogrammed HCC cell lipid metabolism. The genetic and pharmacological inhibition of SCD1 expression/activity altered the cellular lipid composition, which in turn impaired plasma membrane fluidity and inhibited in vitro invasive motility of HCC cells in response to high matrix stiffness. Knockdown of SCD1 suppressed HCC invasion and metastasis in vivo. Conversely, the overexpression of SCD1 or exogenous administration of its product oleic acid augmented plasma membrane fluidity and rescued in vitro invasive migration in HCC cells cultured on soft substrates, mimicking the effects imposed by high matrix stiffness. In human HCC tissues, collagen content, a marker of increasing matrix stiffness, and increased expression of SCD1 together predicted poor survival of HCC patients. An SCD1-dependent mechanoresponsive pathway that responds to increasing matrix stiffness in the tumor microenvironment promotes HCC invasion and metastasis through lipid metabolic reprogramming.

Treatment-damaged hepatocellular carcinoma promotes activities of hepatic stellate cells and fibrosis through GDF15.

The aim of this study was to investigate whether treatment-damaged hepatocellular carcinoma (HCC) would accelerate liver cirrhosis through promoting the activities of hepatic stellate cells (HSCs). HCC cells were exposed to chemotherapeutic agent or hypoxia to mimic the transarterial chemoembolization (TACE)-like treatment. Growth differentiation factor 15 (GDF15) expression was increased in cisplatin- or hypoxia-treated HCC cells. Treatment-induced GDF15 increase in HCC cells was mediated by p38MAPK, JNK, ERK1/2 activation. GDF15 from treatment-damaged HCC cells enhanced the proliferation and collagen synthesis of HSCs through ERK1/2- and Smad3-dependent pathways. Metformin significantly reduced the GDF15 production from treatment-damaged HCC cells by targeting JNK. The use of metformin could attenuate the in vivo fibrotic activities of HSCs promoted by treatment-damaged HCC cells and inhibit GDF15 expression. In conclusion, treatment-damaged HCC accelerates fibrosis by promoting the activities of HSCs via GDF15 secretion, which could be reversed by metformin. This provides a potential therapeutic target for alleviating TACE-aggravated liver cirrhosis.

Activated hepatic stellate cells promote progression of post-heat residual hepatocellular carcinoma from autophagic survival to proliferation.

BACKGROUND: Microscopic residual tumor often occurs after thermal ablation for medium-large hepatocellular carcinoma (HCC), leading to early aggressive recurrence or late relapse during follow-up. The mechanism how microscopic residual HCC cells survive sublethal heat stress and develop rapid outgrowth remains poorly understood. METHODS: HCC cells were exposed to sublethal heat treatment and co-cultured with conditioned media from activated HSCs (HSC-CM). Changes of cell proliferation, parameters of cell autophagy and activation of signaling pathways in heat-treated residual HCC cells were analyzed. An HCC orthotopic model was subjected to partial thermal ablation and antitumor effects of a combined treatment regimen were studied. RESULTS: HCC cells survived sublethal heat stress via activation of autophagy. HSC-CM enhanced autophagic survival within 24 h and then promoted proliferation of heat-treated residual HCC cells through HGF/c-Met signaling. Inhibition of autophagy or c-Met increased apoptosis of heat-treated residual HCC cells and reversed the protective effect of HSC-CM. HGF modulated biological status in autophagic survival or proliferation of heat-treated residual HCC through HGF/c-Met/ERK signaling and downstream components of ATG5/Beclin1 or cyclinD1. In an animal model, inhibiting autophagy in combination with c-Met inhibitor significantly thwarted tumor progression of residual HCC after incomplete thermal ablation via the suppressed autophagy, the decreased proliferation and the increased apoptosis. CONCLUSIONS: Activated HSCs promote progression of residual HCC cells after sublethal heat treatment from autophagic survival to proliferation via HGF/c-Met signaling. A combined treatment regimen of inhibiting autophagy and c-Met signaling could be used to suppress tumor progression of residual HCC after incomplete thermal ablation.

Periostin involved in the activated hepatic stellate cells-induced progression of residual hepatocellular carcinoma after sublethal heat treatment: its role and potential for therapeutic inhibition.

BACKGROUND: Incomplete thermal ablation may induce invasiveness of hepatocellular carcinoma (HCC). Here, we investigated whether activated hepatic stellate cells (HSCs) would accelerate the progression of residual HCC after sublethal heat treatment, and thus sought to identify the potential targets. METHODS: Hepatocellular carcinoma cells were exposed to sublethal heat treatment and then cultured with the conditioned medium from activated HSCs (HSC-CM). The cell proliferation, migration, invasion and parameters of epithelial-mesenchymal transition (EMT) were analyzed. In vivo tumor progression of heat-treated residual HCC cells inoculated with activated HSCs was studied in nude mice. RESULTS: HSC-CM significantly enhanced the proliferation, motility, invasion, prominent EMT activation and decreased apoptosis of heat-exposed residual HCC cells. These increased malignant phenotypes were markedly attenuated by neutralizing periostin (POSTN) in HSC-CM. Furthermore, exogenous POSTN administration exerted the similar effects of HSC-CM on heat-treated residual HCC cells. POSTN induced the prominent activation of p52Shc and ERK1/2 via integrin ß1 in heat-exposed residual HCC cells. Vitamin D analog calcipotriol blocked POSTN secretion from activated HSCs. Calcipotriol plus cisplatin significantly suppressed the activated HSCs-enhanced tumor progression of heat-treated residual HCC cells via the inhibited POSTN expression and the increased apoptosis. CONCLUSIONS: Activated HSCs promote the tumor progression of heat-treated residual HCC through the release of POSTN, which could be inhibited by calcipotriol. Calcipotriol plus cisplatin could be used to thwart the accelerated progression of residual HCC after suboptimal heat treatment.

Extracellular matrix collagen I promotes the tumor progression of residual hepatocellular carcinoma after heat treatment.

BACKGROUND: Accelerated malignant behaviors induced by insufficient thermal ablation have been increasingly reported, however, the exact mechanisms are still unclear. Here, we investigated the importance of the extracellular matrix (ECM) in modulating the progression of residual hepatocellular carcinoma (HCC) after heat treatment. METHODS: Heat-exposed residual HCC cells were cultured in different ECM gels. We used basement membrane gel (Matrigel) to simulate the normal microenvironment and collagen I to model the pathological stromal ECM. The alterations of morphology and parameters of proliferation, epithelial-mesenchymal transition (EMT) and stemness were analyzed in vitro and in vivo. RESULTS: Increased collagen I deposition was observed at the periablational zone after incomplete RFA of HCC in a xenograft model. The markers of cell proliferation, EMT, motility and progenitor-like traits of heat-exposed residual HCC cells were significantly induced by collagen I as compared to Matrigel (p values all < 0.05). Importantly, collagen I induced the activation of ERK phosphorylation in heat-exposed residual HCC cells. ERK1/2 inhibitor reversed the collagen I-promoted ERK phosphorylation, cell proliferative, protrusive and spindle-like appearance of heat-treated residual HCC cells in vitro. Moreover, collagen I promoted the in vivo tumor progression of heat-exposed residual HCC cells, and sorafenib markedly reversed the collagen I-mediated protumor effects. CONCLUSIONS: Our findings demonstrate that collagen I could enhance the aggressive progression of residual HCC cells after suboptimal heat treatment and sorafenib may be a treatment approach to thwart this process.

Increased matrix stiffness promotes tumor progression of residual hepatocellular carcinoma after insufficient heat treatment.

Aggravated behaviors of hepatocellular carcinoma (HCC) will occur after inadequate thermal ablation. However, its underlying mechanisms are not fully understood. Here, we assessed whether the increased matrix stiffness after thermal ablation could promote the progression of residual HCC. Heat-treated residual HCC cells were cultured on tailorable 3D gel with different matrix stiffness, simulating the changed physical environment after thermal ablation, and then the mechanical alterations of matrix stiffness on cell phenotypes were explored. Increased stiffness was found to significantly promote the proliferation of the heat-treated residual HCC cells when the cells were cultured on stiffer versus soft supports, which was associated with stiffness-dependent regulation of ERK phosphorylation. Heat-exposed HCC cells cultured on stiffer supports showed enhanced motility. More importantly, vitamin K1 reduced stiffness-dependent residual HCC cell proliferation by inhibiting ERK phosphorylation and suppressed the in vivo tumor growth, which was further enhanced by combining with sorafenib. Increased matrix stiffness promotes the progression of heat-treated residual HCC cells, proposing a new mechanism of an altered biomechanical environment after thermal ablation accelerates HCC development. Vitamin K1 plus sorafenib can reverse this protumor effect.

Effects of extremely low frequency electromagnetic fields on human fetal scleral fibroblasts.

This study investigated the effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human fetal scleral fibroblasts (HFSFs). HFSFs were subjected to 50 Hz artificial ELF-EMFs generated by Helmholtz coils with 0.1, 0.2, 0.5, and 1.0 mT field intensities for 6 to 48 h. The viability and factors involved in scleral structuring of HFSFs were determined. The growth rate of HFSFs significantly decreased after only 24 h of exposure to ELF-EMFs (0.2 mT). The messenger RNA (mRNA) expression of collagen type I (COL1A1) decreased and expression of matrix metalloproteinase-2 (MMP-2) increased significantly. There was a decrease in tissue inhibitor of MMP-2 mRNA levels between treated and control cells only at the 1.0 mT intensity level. Transforming growth factor beta-2 mRNA increased in exposed cells, and, simultaneously, fibroblast growth factor-2 mRNA levels decreased. The protein expressions of COL1A1 and MMP-2 were also significantly altered subsequent to exposure (p < 0.05). This study shows that ELF-EMFs had biological effects on HFSFs and could cause abnormality in scleral collagen.

Sex-determination gene SRY potentially associates with poor prognosis but not sex bias in hepatocellular carcinoma.

BACKGROUND: Gender disparity is well known in hepatocellular carcinoma (HCC). SRY is a critical sex-determination gene involved in embryonic development. AIM: The potential relevance of SRY to HCC progression was evaluated. METHODS: SRY expression in HCC cell lines and tissues was evaluated. Invasion and wound healing assays were used to evaluate the role of SRY in HCC cell migration. The prognostic value of SRY for HCC patient survival was evaluated. RESULTS: SRY was highly expressed in HCC cell lines and tumor tissues. Downregulation of SRY expression decreased migration and invasion potential of HCC cells. High SRY levels correlated with poor HCC patient survival. Additionally, neither spatial position nor expression intensity of SRY was correlated with HCC gender disparity. CONCLUSIONS: High levels of SRY expression correlated with cancer progression and poor HCC patient survival. However, high SRY levels are not significantly correlated with HCC sex bias.

Increasing matrix stiffness upregulates vascular endothelial growth factor expression in hepatocellular carcinoma cells mediated by integrin ß1.

Matrix stiffness as a novel regulation factor involves in modulating the pathogenesis of hepatocellular carcinoma (HCC) invasion or metastasis. However, the mechanism by which matrix stiffness modulates HCC angiogenesis remains unknown. Here, using buffalo rat HCC models with different liver matrix stiffness backgrounds and an in vitro cell culture system of mechanically tunable Collagen1 (COL1)-coated polyacrylamide gel, we investigated the effects of different matrix stiffness levels on vascular endothelial growth factor (VEGF) expression in HCC cells and explored its regulatory mechanism for controlling HCC angiogenesis. Tissue microarray analysis showed that the expression levels of VEGF and CD31 were gradually upregulated in tumor tissues with increasing COL1 and lysyl oxidase (LOX) expression, indicating a positive correlation between tumor angiogenesis and matrix rigidity. The expression of VEGF and the phosphorylation levels of PI3K and Akt were all upregulated in HCC cells on high-stiffness gel than on low-stiffness gel. Meanwhile, alteration of intergrin ß1 expression was found to be the most distinctive, implying that it might mediate the response of HCC cells to matrix stiffness simulation. After integrin ß1 was blocked in HCC cells using specific monoclonal antibody, the expression of VEGF and the phosphorylation levels of PI3K and Akt at different culture times were accordingly suppressed and downregulated in the treatment group as compared with those in the control group. All data suggested that the extracellular matrix stiffness stimulation signal was transduced into HCC cells via integrin ß1, and this signal activated the PI3K/Akt pathway and upregulated VEGF expression. This study unveils a new paradigm in which matrix stiffness as initiators to modulate HCC angiogenesis.

MiR-612 suppresses the stemness of liver cancer via Wnt/ß-catenin signaling.

Previous research showed that microRNA-612 (miR-612) has inhibitory effects on cell proliferation, migration, invasion, and metastasis of hepatocellular carcinoma (HCC). AKT2 was confirmed to be a direct target of miR-612, through which the epithelial-mesenchymal transition (EMT) and metastasis of HCC were inhibited. Our present findings reveal that miR-612 is able to suppress the stemness of HCC by reducing the number and size of tumorspheres as well as clone formation in soft agar, and to relieve drug resistance to cisplatin and 5-fluorouracil. In addition, miR-612 hampered the capacity of tumorigenesis in NOD/SCID mice and redistributed the tumor invasive frontier of miR-612-modulating cells. Finally, our findings suggest that Wnt/ß-catenin signaling is required in the regulation of EMT-associated stem cell-like traits by miR-612.

Increased ARPP-19 expression is associated with hepatocellular carcinoma.

The cAMP-regulated phosphoprotein 19 (ARPP-19) plays a key role in cell mitotic G2/M transition. Expression of ARPP-19 was increased in human hepatocellular carcinoma (HCC) compared to adjacent non-tumorous liver tissues in 36 paired liver samples, and the level of ARPP-19 in HCC tissues was positively correlated with the tumor size. To determine the interrelationship between ARPP-19 expression and HCC, we silenced ARPP-19 expression in the human hepatocarcinoma HepG2 and SMMC-7721 cells using lentivirus encoding ARPP-19 siRNA. HepG2 and SMMC-7721 cells with ARPP-19 knockdown displayed lowered cell growth rate, retarded colony formation and increased arrest at the G2/M phase transition. Silencing ARPP-19 in HCC cells resulted in decreased protein levels of phospho-(Ser) CDKs substrates and increased levels of inactivated cyclin division cycle 2 (Cdc2). Therefore, ARPP-19 may play a role in HCC pathogenesis through regulating cell proliferation.

[Real-world analysis of concurrent diseases and medicine use among patients with insomnia].

This study aims to explore and analyze the condition of concurrent diseases and medicine use of traditional Chinese medicine (TCM) and western medicine among the patients with insomnia. One thousand and sxity seven cases of data from 20 national hospitals' hospital information system (HIS) databases were collected. The frequent concurrent diseases included hypertension (26.9%), brain blood supply insufficiency (24.93%), cerebral infarction (19.49%), blood lipoprotein disturbance (15.28%), coronary heart disease (14.15%), headache (10.68%), chronic gastritis (8.81%), type 2 diabetes mellitus (7.87%), depressive disorder (7.4%) and anxiety disorder (6.65%). The 10 most frequently-used western drugs included alprazolam (35.99%), aspirin (25.4%), olanzapine (24.18%), cinepazide (23.06%), flupentixol & melitracen (18.74%), zolpidem (18.37%), oxiracetam (15.65%), estazolam (15%), aniracetam (13.4%) and piracetam (13.31%). The 10 most frequently-used TCM included Shuxuening injection (16.4%), Shuxuetong injection (15.18%), extract of ginkgo biloba leaf (14.71%), gastrodin (12.46%), Dengzanxixin injection (11.34%), Xueshuantong (8.53%), Danhong injection (6.37%), compound liquorice tablet (5.81%), Sanqi Tongshu capsule (5.72%) and sowthistle-leaf ixeridium injection (5.34%). Among all combined uses, the most frequent western drug use was alprazolam and olanzapine, while combined use of hypnotic drug and Huoxuehuayu formula is the most frequent. This study concludes that the concurrent diseases mainly include cardio-cerebrovascular diseases, metabolic disorders and anxiety-depression disorders, with increasing tendency of diseases types by ages, especially for cardio-cerebrovascular diseases. The most frequently-used hypnotic is alprazolam in the insomnia patients, and it is worth being concerned about the off-label use of olanzapine as an antipsychotic for the treatment of insomnia However, due to the fact that all cases data are from the inpatients, these findings have some limitations.

Nuclear translocation of metabolic enzyme PKM2 participates in high glucose-promoted HCC metastasis by strengthening immunosuppressive environment.

Although some cohort studies have indicated a close association between diabetes and HCC, the underlying mechanism about the contribution of diabetes to HCC progression remains largely unknown. In the study, we applied a novel HCC model in SD rat with diabetes and a series of high glucose-stimulated cell experiments to explore the effect of a high glucose environment on HCC metastasis and its relevant mechanism. Our results uncovered a novel regulatory mechanism by which nuclear translocation of metabolic enzyme PKM2 mediated high glucose-promoted HCC metastasis. Specifically, high glucose-increased PKM2 nuclear translocation downregulates chemerin expression through the redox protein TRX1, and then strengthens immunosuppressive environment to promote HCC metastasis. To the best of our knowledge, this is the first report to elucidate the great contribution of a high glucose environment to HCC metastasis from a new perspective of enhancing the immunosuppressive microenvironment. Simultaneously, this work also highlights a previously unidentified non-metabolic role of PKM2 and opens a novel avenue for cross research and intervention for individuals with HCC and comorbid diabetes.

A synergistic regulation works in matrix stiffness-driven invadopodia formation in HCC.

Growing evidence has suggested that increased matrix stiffness can significantly strengthen the malignant characteristics of hepatocellular carcinoma (HCC) cells. However, whether and how increased matrix stiffness regulates the formation of invadopodia in HCC cells remain largely unknown. In the study, we developed different experimental systems in vitro and in vivo to explore the effects of matrix stiffness on the formation of invadopodia and its relevant molecular mechanism. Our results demonstrated that increased matrix stiffness remarkably augmented the migration and invasion abilities of HCC cells, upregulated the expressions of invadopodia-associated genes and enhanced the number of invadopodia. Two regulatory pathways contribute to matrix stiffness-driven invadopodia formation together in HCC cells, including direct triggering invadopodia formation through activating integrin ß1 or Piezo1/ FAK/Src/Arg/cortactin pathway, and indirect stimulating invadopodia formation through improving EGF production to activate EGFR/Src/Arg/cortactin pathway. Src was identified as the common hub molecule of two synergistic regulatory pathways. Simultaneously, activation of integrin ß1/RhoA/ROCK1/MLC2 and Piezo1/Ca2+/MLCK/MLC2 pathways mediate matrix stiffness-reinforced cell migration. This study uncovers a new mechanism by which mechanosensory pathway and biochemical signal pathway synergistically regulate the formation of invadopodia in HCC cells.

Suppression of type I collagen in human scleral fibroblasts treated with extremely low-frequency electromagnetic fields.

PURPOSE: To investigate the expression differences of type I collagen (COL1A1) and its underlying mechanisms in human fetal scleral fibroblasts (HFSFs) that were treated with conditioned medium from retinal pigment epithelial (RPE) cells under extremely low-frequency electromagnetic fields (ELF-EMFs). METHODS: The ELF-EMFs used in this study were established by slidac and artificial coils. Growth of the treated HFSFs was evaluated by a cell-counting kit-8 assay. The expression of COL1A1 and matrix metalloproteinases-2 (MMP-2) in the treated HFSFs was detected by reverse transcription PCR (RT-PCR) and western blot, and the expression of transforming growth factor-ß2 (TGF-ß2) and basic fibroblast growth factor-2 (FGF-2) in RPE cells exposed to EMFs was detected by RT-PCR. The expression of COL1A1 and MMP-2 in HFSFs was further confirmed by immunofluorescence staining. Activation of extracellular signal-regulated kinase 1/2 (ERK1/2 also called p44/p42 mitogen-activated protein kinases [MAPK]) and p38 in HFSFs was measured by western blot. RESULTS: We found that exposure to ELF-EMFs resulted in a decreased proliferation rate of HFSFs and that addition of RPE supernatant medium could enhance this effect. Compared with that of the control cells, a significant decrease in collagen synthesis was detected in HFSFs under ELF-EMFs. However, the expression of MMP-2 was upregulated, which could be further enhanced via an RPE supernatant additive. The activities of ERK1/2 and p38 were significantly increased in HFSFs exposed to ELF-EMFs, and this effect could be enhanced by RPE supernatant medium additive. CONCLUSIONS: Our results suggested that ELF-EMFs can inhibit the expression of type I collagen in HFSFs and contribute to the remodeling of the sclera.

The significance of MMP-9 over MMP-2 in HCC invasiveness and recurrence of hepatocellular carcinoma after curative resection.

BACKGROUND: The extracellular matrix metalloproteases MMP-9 and MMP-2 are critical for the invasive potential of tumors. However, it is not clear which of the two plays the predominant role in tumor invasion and progression. In the present study, we compared the clinical efficacy of MMP-9 and MMP-2 overexpression for predicting tumor recurrence and survival after surgical resection in HCC patients. MATERIALS AND METHODS: MMP-9 and MMP-2 expression in HCC cell lines and in vitro HCC invasion model were detected by quantitative RT-PCR and immunofluorescence. The expression levels of MMP-9 and MMP-2 were assessed by immunohistochemistry in HCC tissue microarrays from HCC patients (study set) who underwent curative resection. The clinicopathological data were retrospectively analyzed. The results were further verified in an independent cohort of 92 HCC patients (validation set). RESULTS: Univariate analysis demonstrated that high expression of MMP-9 was associated with both time to recurrence (TTR, P = .015) and overall survival (OS, P = .024), whereas high expression of MMP-2 was only correlated with TTR (P = .041). Multivariate analysis confirmed that MMP-9 expression was an independent predictor of TTR and OS. The coindex of MMP-9 and preoperative serum AFP levels was significantly correlated with TTR and OS (P = .036 and P = .040), but the coindex of MMP-2 and AFP did not show prognostic significance for either TTR or OS (P = .067 and P = .053). The prognostic value of MMP-9 overexpression was validated in the independent data set. CONCLUSION: MMP-9 is superior to MMP-2 for the prediction of tumor recurrence and survival in HCC patients after surgical resection.

Activation of Piezo1 contributes to matrix stiffness-induced angiogenesis in hepatocellular carcinoma.

BACKGROUND: Despite integrin being highlighted as a stiffness-sensor molecule in matrix stiffness-driven angiogenesis, other stiffness-sensor molecules and their mechanosensory pathways related to angiogenesis in hepatocellular carcinoma (HCC) remain obscure. Here, we explored the interplay between Piezo1 and integrin ß1 in the mechanosensory pathway and their effects on HCC angiogenesis to better understand matrix stiffness-induced angiogenesis. METHODS: The role of Piezo1 in matrix stiffness-induced angiogenesis was investigated using orthotopic liver cancer SD rat models with high liver stiffness background, and its clinical significance was evaluated in human HCC tissues. Matrix stiffness-mediated Piezo1 upregulation and activation were assayed using an in vitro fibronectin (FN)-coated cell culture system with different stiffness, Western blotting and Ca2+ probe. The effects of shPiezo1-conditioned medium (CM) on angiogenesis were examined by tube formation assay, wound healing assay and angiogenesis array. The underlying mechanism by which Piezo1 participated in matrix stiffness-induced angiogenesis was analyzed by microRNA quantitative real-time polymerase chain reaction (qRT-PCR), matrix stiffness measurement, dual-luciferase reporter assay, ubiquitination assay and co-immunoprecipitation. RESULTS: Increased matrix stiffness significantly upregulated Piezo1 expression at both cellular and tissue levels, and high expression of Piezo1 indicated an unfavorable prognosis. High matrix stiffness also noticeably enhanced the activation level of Piezo1, similar to its expression level. Piezo1 knockdown significantly suppressed tumor growth, angiogenesis, and lung metastasis of HCC rat models with high liver stiffness background. shPiezo1-CM from HCC cells attenuated tube formation and migration abilities of vascular endothelial cells remarkably, and analysis of differentially expressed pro-angiogenic factors revealed that Piezo1 promoted the expression and secretion of vascular endothelial growth factor (VEGF), CXC chemokine ligand 16 (CXCL16) and insulin-like growth factor binding protein 2 (IGFBP2). Matrix stiffness-caused Piezo1 upregulation/activation restrained hypoxia inducible factor-1α (HIF-1α) ubiquitination, subsequently enhanced the expression of downstream pro-angiogenic factors to accelerate HCC angiogenesis. Besides, collagen 1 (COL1)-reinforced tissue stiffening resulted in more expression of Piezo1 via miR-625-5p. CONCLUSIONS: This study unravels a new mechanism by which the integrin ß1/Piezo1 activation/Ca2+ influx/HIF-1α ubiquitination/VEGF, CXCL16 and IGFBP2 pathway participates in matrix stiffness-driven HCC angiogenesis. Simultaneously, a positive feedback regulation loop as stiff matrix/integrin ß1/miR-625-5p/Piezo1 and COL1/stiffer matrix mediates matrix stiffness-caused Piezo1 upregulation.

A three-dimensional cell biology model of human hepatocellular carcinoma in vitro.

We established an in vitro 3-D model of metastatic hepatocellular carcinoma (HCC) by culturing MHCC97H cells on molecular scaffolds within a rotating wall vessel bioreactor. Morphological and biochemical analyses revealed that the 3-D HCC model mirrored many clinical pathological features of HCC in vivo, including cancer cell morphology, tissue ultrastructure, protein production and secretion, glucose metabolism, tissue-specific gene expression, and apoptosis. Xenografts into livers of nude mice resulted in tumorigenesis and distant metastasis. This 3-D HCC spheroid is a promising model for HCC tumor biology, anticancer drug screening, and for the establishment of HCC animal models.

[TNFα induced IL-8 production through p38 MAPK- NF-kB pathway in human hepatocellular carcinoma cells].

OBJECTIVE: To identify the role of p38 MAPK- NF-kB signaling pathway in TNF-α induced IL-8 production in human hepatocellular carcinoma cells. METHODS: The concentrations of IL-8 from MHCC-97H cells were measured by an enzyme-linked immunosorbent assay (ELISA). The phosphorylation of p38 MAPK was analyzed by Western blot and immunofluorescence. NF-kB p65 protein nuclear translocation was determined by non-radioactive NF-kB p50 / p65 transcription factor activity kit and immunofluorescence. RESULTS: The IL-8 production from MHCC-97H cells challenged with TNFa significantly increased in a time-dependent (F = 144.04, P < 0.01) and dose-dependent (F = 364.14, P < 0.01) manners, as compared with those without TNFa challenge. TNFa up-regulated the phosphorylation levels of p38 MAPK and increased the translocation of NF-kB p65 protein into the nucleus, also proved by immunofluorescence staining. p38 MAPK inhibitor (SB203580) could significantly inhibit IL-8 production in a dose-dependent manners (F = 65.47, P < 0.01), and partially inhibited NF-kB p65 nuclear translocation in a dose-dependent manner (F=141.20, P < 0.05). CONCLUSION: TNF-α could increase the production of IL-8 in MHCC-97H cells and p38 MAPK- NF-kB pathways seem to play a central role in the regulation of IL-8 production.