Downregulation of matrix metalloproteinases contributes to the inhibition of cell migration and invasion in HepG2 cells by sodium valproate

Proteomic analysis of small extracellular vesicles from the plasma of patients with hepatocellular carcinoma

PURPOSE

Liver cancer is one of the most common tumors with the seventh-highest incidence and the third-highest mortality. Many studies have shown that small extracellular vesicles (sEVs) play an important role in liver cancer. Here, we report comprehensive signatures for sEV proteins from plasma obtained from patients with hepatocellular carcinoma (HCC), which might be valuable for the evaluation and diagnosis of HCC.

METHODS

We extracted sEVs from the plasma of controls and patients with HCC. Differentially expressed proteins in the sEVs were analyzed using label-free quantification and bioinformatic analyses. Western blotting (WB) was used to validate the abovementioned sEV proteins.

RESULTS

Proteomic analysis was performed for plasma sEVs from 21 patients with HCC and 15 controls. Among the 335 identified proteins in our study, 27 were significantly dysregulated, including 13 upregulated proteins that were involved predominantly in the complement cascade (complement C1Q subcomponent subunit B (C1QB), complement C1Q subcomponent subunit C (C1QC), C4B-binding protein alpha chain (C4BPA), and C4B-binding protein beta chain (C4BPB)) and the coagulation cascade (F13B, fibrinogen alpha chain (FGA), fibrinogen beta chain (FGB), and fibrinogen gamma chain (FGG)). We verified increased levels of the C1QB, C1QC, C4BPA, and C4BPB proteins in the plasma sEVs from patients with HCC in both the discovery cohort and validation cohort.

CONCLUSIONS

The complement cascade in sEVs was significantly involved in HCC progression. C1QB, C1QC, C4BPA, and C4BPB were highly abundant in the plasma sEVs from patients with HCC and might represent molecular signatures.

"Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.

Association of surfactant protein D with pulmonary metastases from colon cancer

Surfactant protein D (SP-D) is a member of the collectin family of proteins, which is secreted by airway epithelial cells. SP-D serves an important role in the immune system and in the inflammatory regulation of the lung. SP-D was recently found to suppress lung cancer progression by downregulating epidermal growth factor signaling. However, the relationship between SP-D and pulmonary metastases from colon cancer remains unknown. The present study aimed to determine whether SP-D may suppress the development of the mouse rectal carcinoma cell line, CMT93, in vitro. The present study investigated the effect of SP-D on pulmonary metastases from colon cancer in vivo using SP-D knockout mice. A wound healing assay and cell invasion assay revealed that SP-D suppressed the proliferation, migration and invasion of CMT-93 cells. After injection of CMT-93 cells into the tail vein, SP-D knockout mice were significantly more susceptible to developing pulmonary metastases than C57/BL6 mice (control). Moreover, a novel cell line (CMT-93 pulmonary metastasis; CMT-93 PM) was established from the lesions of pulmonary metastases in C57/BL6 mice following injection of CMT93 into the tail vein. CMT-93 PM exhibited more robust invasion and proliferation compared to CMT93, which was unaffected by exposure to SP-D. A higher incidence of pulmonary metastases was detected following injection of CMT93 PM into the tail vein of C57/BL6 mice compared with CMT-93. Consequently, SP-D may be involved in the pathogenesis of pulmonary metastases from colon cancer.

Predictive Significance of Serum MMP-9 in Papillary Thyroid Carcinoma

Objective

The incidence of papillary thyroid carcinoma (PTC) is increasing, and there are no reliable serum biomarkers for the diagnosis and prognosis of PTC. This study aimed to assess whether serum matrix metalloproteinase-9 (MMP-9) could serve as an auxiliary diagnostic/prognostic marker for PTC after total and partial thyroidectomy.

Material and Methods

Postoperative serum MMP-9 concentrations were measured in 182 male patients with PTC, 86 male patients with benign thyroid nodule (BTN), and 62 male healthy controls (HCs). Multivariate logistic regression and Cox regression were applied to evaluate the correlation between variables. The performance of serum MMP-9 in diagnosing PTC and predicting structural persistent/recurrent disease (SPRD) during 48 months of follow-up after initial surgery was evaluated by receiving operating characteristic curve analysis.

Results

The median serum MMP-9 concentration in the PTC group (79.45 ng/ml) was significantly higher than those in the BTN group (47.35 ng/ml) and HC group (47.71 ng/ml). The area under the curve (AUC) for predicting PTC from BTN was 0.852 at a cut-off value of 60.59 ng/ml. Serum MMP-9 was negatively correlated with disease-free survival (OR 1.026, P=0.001). Serum MMP-9 exhibited good performance in predicting SPRD at a cutoff value of 99.25 ng/ml with an AUC of 0.818. Advanced TNM stage (OR 31.371, P=0.019) and serum MMP-9 ≥99.25 ng/ml (OR 4.103, P=0.022) were independent risk factors for SPRD.

Conclusions

Serum MMP-9 potentially represents a good predictive biomarker for PTC diagnosis and prognosis after thyroidectomy in Chinese male patients for whom radio-imaging indicates suspected PTC.

Cigarette Smoke Extract Activates Tartrate-Resistant Acid Phosphatase-Positive Macrophage

BACKGROUND

It has been reported that smoking is one of the strongest positive risk factors for abdominal aortic aneurysms (AAAs). Although many studies have been directed to decipher the effect of smoking on AAA, its effect on macrophage activation has not yet been explored.

OBJECTIVES

We have reported the importance of osteoclastogenesis (OCG) in aneurysm formation. Therefore, we examined the effect of cigarette smoking on OCG and arterial aneurysmal formation by using cigarette smoke extract (CSE) in this study.

METHODS

Macrophage cell lines were stimulated with CSE, and their activation and differentiation were examined in vitro. Since macrophages activated through the OCG pathway are identified by tartrate-resistant acid phosphatase (TRAP) expression, these cells are referred to as TRAP-positive macrophages (TPMs) in this study. We also applied CSE-contained PBS in the calcium chloride-induced mouse carotid aneurysm model in vivo.

RESULTS

Macrophages stimulated with CSE expressed significantly higher levels of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), TRAP, cathepsin K, matrix metalloproteinase-9 and membrane-type metalloproteinase (MT1-MMP). CSE-treated mouse aneurysms showed increased aneurysm size with increased TPM infiltration and protease expression compared to non-CSE-treated mouse aneurysms.

CONCLUSIONS

These results suggest that CSE intensifies OCG in macrophages and promotes arterial aneurysmal progression.

Benzo(a)pyrene promotes Hep-G2 cell migration and invasion by upregulating phosphorylated extracellular signal-regulated kinase expression

Benzo(a)pyrene (BaP), a carcinogenic component of cigarette smoke, has been reported to activate extracellular signal-regulated kinase (ERK) in cancer cells. Furthermore, activated ERK is associated with liver cancer cell invasion and metastasis. Therefore, the aim of the present study was to investigate the potential role of phosphorylated (p)-ERK in BaP-induced Hep-G2 cell migration and invasion. An MTT assay was used to determine the effects of BaP treatment on Hep-G2 cell proliferation. Wound-healing and Transwell invasion assays were employed to assess the migration and invasion abilities of Hep-G2 cells. Western blot analysis was applied to detect the expression of proteins. The results of the present study demonstrated that BaP treatment was able to increase the level of p-ERK protein expression in Hep-G2 cells. BaP treatment promoted Hep-G2 cell migration and invasion. The ERK inhibitor, U0126, was able to block the migration and invasion abilities of Hep-G2 cells induced by BaP. The results of the present study demonstrated that BaP treatment promoted the migration and invasion of Hep-G2 cells by upregulating p-ERK expression.

The Protein Extract of Chlorella minutissima Inhibits The Expression of MMP-1, MMP-2 and MMP-9 in Cancer Cells through Upregulation of TIMP-3 and Down Regulation of c-Jun

Objective

Considering the bioactivities exhibited by microalgae, the effect of protein extract of Chlorella minutissimma (CP extract) was investigated on the expression of human matrix metalloproteinases-1 (MMP-1) in the breast cancer cell line MDA-MB231, and that of MMP-2 and -9 in hepatocellular cancer cell line HepG2 at different expression levels. The study aimed identification and analysis of inhibitory activity of microalgal components extracted from Chlorella minutissima against human MMPs.

Materials and Methods

In this experimental study, we analysed the effect of Chlorella extracts on MMP-1, -2, and -9 expression at various levels. Gelatin zymography was performed to study the inhibitory effect of Chlorella exracts on human gelatinases at the activity level, followed by western blotting to analyse the expression of all three MMPs at the protein level. The similar effect at the mRNA level along with the probable mechanism underlying inhibition of MMPs was assessed using real-time polymerase chain reaction (PCR).

Results

The results reveal that the treatment with CP extract decreased the mRNA expression of MMP-1, MMP-2, and MMP-9 by 0.26-, 0.29-, and 0.40-fold, respectively, at 20 μg/ml concentration as well as inhibited the activity of MMP-2 and MMP-9 by 37.56 and 42.64%, respectively, at 15 μg/ml concentration. Additionally, upregulated mRNA expression of tissue inhibitor of metalloproteinases-3 (TIMP-3) by 1.68-fold was seen in HepG2 cells at 20 μg/ml concentration treatment group. However, CP extract did not induce any change in the mRNA expression of the TIMP-1, -2 and -4 in HepG2 and TIMP-1, -2, -3 and -4 in MDA-MB231 cells. Activator protein-1 (AP-1)-dependent c-Jun-mediated transcriptional regulation of MMP-1, -2, and -9 was also studied to elucidate the appropriate mechanism involved in the inhibition of MMPs.

Conclusion

The CP extract successfully inhibited MMP-1, -2, and -9 at different expression levels through TIMP-3 upregulation and c-Jun downregulation.

Valproate Attenuates Endoplasmic Reticulum Stress-Induced Apoptosis in SH-SY5Y Cells via the AKT/GSK3β Signaling Pathway

Endoplasmic reticulum (ER) stress-induced apoptosis plays an important role in a range of neurological disorders, such as neurodegenerative diseases, spinal cord injury, and diabetic neuropathy. Valproate (VPA), a typical antiepileptic drug, is commonly used in the treatment of bipolar disorder and epilepsy. Recently, VPA has been reported to exert neurotrophic effects and promote neurite outgrowth, but its molecular mechanism is still unclear. In the present study, we investigated whether VPA inhibited ER stress and promoted neuroprotection and neuronal restoration in SH-SY5Y cells and in primary rat cortical neurons, respectively, upon exposure to thapsigargin (TG). In SH-SY5Y cells, cell viability was detected by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, and the expression of ER stress-related apoptotic proteins such as glucose‑regulated protein (GRP78), C/EBP homologous protein (CHOP), and cleaved caspase-12/-3 were analyzed with Western blot analyses and immunofluorescence assays. To explore the pathway involved in VPA-induced cell proliferation, we also examined p-AKT, GSK3β, p-JNK and MMP-9. Moreover, to detect the effect of VPA in primary cortical neurons, immunofluorescence staining of β-III tubulin and Anti-NeuN was analyzed in primary cultured neurons exposed to TG. Our results demonstrated that VPA administration improved cell viability in cells exposed to TG. In addition, VPA increased the levels of GRP78 and p-AKT and decreased the levels of ATF6, XBP-1, GSK3β, p-JNK and MMP-9. Furthermore, the levels of the ER stress-induced apoptosis response proteins CHOP, cleaved caspase-12 and cleaved caspase-3 were inhibited by VPA treatment. Meanwhile, VPA administration also increased the ratio of Bcl-2/Bax. Moreover, VPA can maintain neurite outgrowth of primary cortical neurons. Collectively, the neurotrophic effect of VPA is related to the inhibition of ER stress-induced apoptosis in SH-SY5Y cells and the maintenance of neuronal growth. Collectively, our results suggested a new approach for the therapeutic function of VPA in neurological disorders and neuroprotection.

Inhibition of cancer migration and invasion by knocking down delta-5-desaturase in COX-2 overexpressed cancer cells

We recently reported that knockdown of delta-5-desaturase (a key enzyme that converts dihomo-γ-linolenic acid, DGLA, to the downstream ω-6 arachidonic acid) promotes formation of an anti-cancer byproduct 8-hydroxyoctanoic acid from cyclooxygenase (COX)-catalyzed DGLA peroxidation. 8-hydroxyoctanoic acid can exert its growth inhibitory effect on cancer cells (e.g. colon and pancreatic cancer) by serving as a histone deacetylase inhibitor. Since histone deacetylase inhibitors have been well-known to suppress cancer cell migration and invasion, we thus tested whether knockdown of delta-5-desaturase and DGLA treatment could also be used to inhibit cancer migration and invasion of colon cancer and pancreatic cancer cells. Wound healing assay, transwell assay and western blot were used to assess cell migration and invasion as well as the associated molecular mechanisms. Formation of threshold level of 8-hydroxyoctanoic acid was quantified from COX-catalyzed DGLA peroxidation in the cancer cells that overexpress COX-2 and their delta-5-desaturases were knocked down by shRNA transfection. Our results showed that knockdown of delta-5-desaturase along with DGLA supplement not only significantly inhibited cell migration, but also improved the efficacies of 5-flurouracil and gemcitabine, two frontline chemotherapy drugs currently used in the treatment of colon and pancreatic cancer, respectively. The molecular mechanism behind these observations is that 8-hydroxyoctanoic acid inhibits histone deacetylase, resulting in downregulation of cancer metastasis promotors, e.g., MMP-2 and MMP-9 as well as upregulation of cancer metastasis suppressor, e.g. E-cadherin. For the first time, we demonstrated that we could take the advantage of the common phenomenon of COX-2 overexpression in cancers to inhibit cancer cell migration and invasion. With the shifting paradigm of COX-2 cancer biology, our research outcome may provide us a novel cancer treatment strategy.

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High level of COX-2 could be used to inhibit cancer cell migration and invasion.

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8-hydroxyoctanoic acid suppresses cancer migration and invasion via inhibiting HDAC.

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D5D knockdown and DGLA improves efficacy of chemotherapy to inhibit cancer metastasis.

HDAC inhibitors suppress c-Jun/Fra-1-mediated proliferation through transcriptionally downregulating MKK7 and Raf1 in neuroblastoma cells

Activator protein 1 (AP-1) is a transcriptional factor composed of the dimeric members of bZIP proteins, which are frequently deregulated in human cancer cells. In this study, we aimed to identify an oncogenic AP-1 dimer critical for the proliferation of neuroblastoma cells and to investigate whether histone deacetylase inhibitors (HDACIs), a new generation of anticancer agents, could target the AP-1 dimer. We report here that HDACIs including trichostatin A, suberoylanilidehydroxamic acid, valproic acid and M344 can transcriptionally suppress both c-Jun and Fra-1, preceding their inhibition of cell growth. c-Jun preferentially interacting with Fra-1 as a heterodimer is responsible for AP-1 activity and critical for cell growth. Mechanistically, HDACIs suppress Fra-1 expression through transcriptionally downregulating Raf1 and subsequently decreasing MEK1/2-ERK1/2 activity. Unexpectedly, HDACI treatment caused MKK7 downregulation at both the protein and mRNA levels. Deletion analysis of the 5′-flanking sequence of the MKK7 gene revealed that a major element responsible for the downregulation by HDACI is located at −149 to −3 relative to the transcriptional start site. Knockdown of MKK7 but not MKK4 remarkably decreased JNK/c-Jun activity and proliferation, whereas ectopic MKK7-JNK1 reversed HDACI-induced c-Jun suppression. Furthermore, suppression of both MKK-7/c-Jun and Raf-1/Fra-1 activities was involved in the tumor growth inhibitory effects induced by SAHA in SH-SY5Y xenograft mice. Collectively, these findings demonstrated that c-Jun/Fra-1 dimer is critical for neuroblastoma cell growth and that HDACIs act as effective suppressors of the two oncogenes through transcriptionally downregulating MKK7 and Raf1.

Associations of Promoter Methylations and mRNA Expressions of MMP-2, MMP-7 and MMP-9 with Primary Fallopian Tube Carcinoma

OBJECTIVE

To explore the associations of matrix metalloprotease-2 (MMP-2), MMP-7 and MMP-9 methylations and messenger ribonucleic acid (mRNA) expressions with primary fallopian tube carcinoma (PFTC) development and prognosis.

METHODS

We recruited 48 patients with PFTC into the case group and 48 healthy individuals into the control group; PFTC tissues and normal fallopian tube tissues were obtained from subjects in both groups. Methylation specific polymerase chain reaction (PCR), reverse transcription PCR and the immunohistochemical method were used to examine methylation, mRNA expressions and protein expressions of MMP-2, MMP-7 and MMP-9, respectively.

RESULTS

The methylation rates of MMP-2, MMP-7 and MMP-9 in the case group were significantly lower than those in the control group (all p < 0.05); MMP-2, MMP-7 and MMP-9 protein and mRNA expressions of PFTC tissues were enormously higher than those of normal tissues (all p < 0.05); univariate survival analysis indicated that MMP-2 and MMP-9 methylations and their protein expressions were associated with PFTC prognosis (all p < 0.05), which was further confirmed by the Cox regression model (all p < 0.05).

CONCLUSION

The protein and mRNA expressions of MMP-2, MMP-7 and MMP-9 might be related to PFTC, while the methylations and protein expressions of MMP-2 and MMP-9 might be associated with PFTC progression and prognosis.