Expression of matrix metalloproteinases 2 and 9 in human gastric cancer and superficial gastritis

Lipocalin 2-not only a biomarker: a study of current literature and systematic findings of ongoing clinical trials

Lipocalin 2 (Lcn2), also known as neutrophil gelatinase-associated lipocalin, is an innate immune protein encoded by the LCN2 gene. In this study, we investigated various roles and functions of Lcn2 characterized in a systems-based format and evaluated its therapeutic potentials and clinical relevance for diagnosis and prognosis. An additional systematic presentation was presented for 70 ongoing clinical trials utilizing Lcn2 in the diagnostic and prognostic setting as a key outcome measure. With trials being conducted through December 2030, Lcn2 will become all the more relevant given its associations with diseases as a prognostic biomarker. Data also suggests that it plays a role in pathological conditions. The gaps in our understanding of Lcn2, once filled, may improve the immune mediation of acute and chronic disease.

Quantification of the presence of enzymes in gelatin zymography using the Gini index

Gel zymography quantifies the activity of certain enzymes in tumor processes. These enzymes are widely used in medical diagnosis. In order to analyze them, experts classify the zymography spots into various classes according to their tonalities. This classification is done by visual analysis, which is what makes it a subjective process. This work proposes a methodology to carry out this classifications with a process that involves an unsupervised learning algorithm in the images, denoted as the GI algorithm. With the experiments shown in this paper, this methodology could constitute a tool that bioinformatics scientists can trust to perform the desired classification since it is a quantitative indicator to order the enzymatic activity of the spots in a zymography.

Total saponins from Tupistra chinensis baker inhibits growth of human gastric cancer cells in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tupistra chinensis Baker (syn. Rohdea chinensis), an antitumor folk herb mainly distributed in China, its rhizome has been historically used to treat gastric cancer. Studies showed that the steroidal saponins were the main bioactive components in the rhizome of T. chinensis. Our previous studies have confirmed that the steroidal saponins have a variety of anti-tumor activities. However, the underlying anti-tumor mechanism of the total steroidal saponins of T. chinensis (TCS) remains to be revealed.

AIM OF THE STUDY

In the present study, we studied the potential anti-proliferative activity and anti-tumor mechanism of TCS on gastric cancer in vitro and in vivo.

METHODS

In vitro, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to detect the proliferation ability of TCS on SGC-7901 cells and AGS cells. Flow cytometry were performed to analyze cell apoptosis, cell cycle, mitochondrial membrane potential and reactive oxygen species expression level. Western blotting was performed to validate the expression of proteins in related pathways. In vivo, a xenograft model was established by injecting SGC-7901 cells into nude mice.

RESULTS

In vitro, TCS inhibited the proliferation of gastric cancer cells. TCS effectively induced apoptosis by PI3K/Akt/mTOR signaling pathway in SGC-7901 cells, and promoted apoptosis via p53-mediated pathway in AGS cells. TCS also exhibited inhibitory activity in blocking the migration of gastric cancer cells. In vivo, TCS significantly inhibited the growth of xenograft tumor.

CONCLUSION

These results indicated that TCS exhibited significant anti-gastric cancer effects in vitro and in vivo.

Ketogenic Diet in Cancer Prevention and Therapy: Molecular Targets and Therapeutic Opportunities

Although cancer is still one of the most significant global challenges facing public health, the world still lacks complementary approaches that would significantly enhance the efficacy of standard anticancer therapies. One of the essential strategies during cancer treatment is following a healthy diet program. The ketogenic diet (KD) has recently emerged as a metabolic therapy in cancer treatment, targeting cancer cell metabolism rather than a conventional dietary approach. The ketogenic diet (KD), a high-fat and very-low-carbohydrate with adequate amounts of protein, has shown antitumor effects by reducing energy supplies to cells. This low energy supply inhibits tumor growth, explaining the ketogenic diet's therapeutic mechanisms in cancer treatment. This review highlights the crucial mechanisms that explain the ketogenic diet's potential antitumor effects, which probably produces an unfavorable metabolic environment for cancer cells and can be used as a promising adjuvant in cancer therapy. Studies discussed in this review provide a solid background for researchers and physicians to design new combination therapies based on KD and conventional therapies.

Expression of Vascular Endothelial Growth Factor, Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 in Polycystic Ovarian Syndrome Rats and Its Implication

Polycystic ovary syndrome (PCOS) is a female endocrine disorder and frequently leads to infertility. Vascular endothelial growth factor (VEGF) has crucial roles and matrix metalloproteinase (MMPs) is correlated with cell migration. Both of them are involved in the occurrence and progression of PCOS. This study established a rat PCOS model using letrozole to measure the expression of VEGF, MMP-2 and MMP-9 (MMP-2/9), to analyze its correlation with PCOS. Letrozole was applied by gavage to establish rat PCOS model. General condition and ovarian tissue morphology were observed under a light field microscope. ELISA and immunohistochemistry (IHC) were used to detect serum or tissue expression of VEGF, MMP-2/9. Estrous cycle of rats was disrupted after 12 d for using letrozole. Vaginal smear showed abundant leukocytes with sparse keratinocytes. Ovary showed whitening and increased volume, with early phase small follicles plus lower granular cells or corpus luteum. Compared to control group, experimental group had significantly higher VEGF, MMP-2/9 (P < 0.05), which were higher in antral follicles than those in preantral follicle with higher expressions than primordial follicle (P < 0.05). In conclusion, VEGF, MMP-2/9 are abundantly expressed in both serum and tissues of PCOS rats.

Bauhinia Protease Inhibitors Attenuate Gastric Ulcer by Blocking Neutrophil Enzymes

Proteases play a pivotal role in many signaling pathways; inhibitors of well-established proteases have shown a substantial therapeutic success. This study aimed to examine the in vivo effects of 3 protease inhibitors isolated from Bauhinia species: i) Bauhinia mollis elastase inhibitor, which blocks human neutrophil elastase (Ki_app 2.8 nM) and cathepsin G (Ki_app 1.0 nM) activities; ii) Bauhinia mollis trypsin inhibitor, a trypsin inhibitor (Ki_app 5.0 nM); and iii) Bauhinia bauhinioides cruzipain inhibitor, which inhibits elastase (Ki_app 2.6 nM), cathepsin G (Ki_app 160.0 nM), and the cysteine proteases cathepsin L (Ki_app 0.2 nM). Bauhinia bauhinioides cruzipain inhibitor, Bauhinia mollis elastase inhibitor, and Bauhinia mollis trypsin inhibitor were isolated using acetone and ammonium sulfate fractionations, DEAE-Sephadex, trypsin-Sepharose, and Resource-Q chromatographies. Mice and rats were treated intraperitoneally with 1 dose of inhibitor; gastric mucosal lesions were induced by cold-restraint stress. Oral pretreatment of mice with Bauhinia mollis elastase inhibitor or Bauhinia mollis trypsin inhibitor (1 - 10 mg/kg) did not show anti-ulcer effect, while Bauhinia bauhinioides cruzipain inhibitor (0.1 - 1.0 mg/kg) produced a similar reduction of the index of mucosal damage at all effective doses (30 to 33% < control). In rats at doses lower than those used in mice, Bauhinia mollis elastase inhibitor and Bauhinia bauhinioides cruzipain inhibitor reduced the index of mucosal damage by 66% and 54% of controls, respectively. The results indicate a protective effect against gastric mucosal lesions associated with elastase inhibition but not inhibition of trypsin activities. Moreover, the lack of Bauhinia mollis elastase inhibitor efficacy observed in mice may possibly be related to the reported structural differences of elastase in mice and rats.

Differential Effects of Purinergic Signaling in Gastric Cancer-Derived Cells Through P2Y and P2X Receptors

Gastric cancer (GC) is the one of the most prevalent cancers and one of the leading causes of cancer-induced deaths. Previously, we found that the expression of purinergic P2Y₂ receptor (P2Y₂R) is increased in GC samples as compared to adjacent healthy mucosa taken from GC-diagnosed patients. In this work, we studied in detail purinergic signaling in the gastric adenocarcinoma-derived cell lines: AGS, MKN-45, and MKN-74, and compared them to a nontumoral epithelial cell line: GES-1. In GC-derived cells, we detected the expression of several purinergic receptors, and found important differences as compared to GES-1 cells. Functional studies revealed a strong contribution of P2Y₂Rs in intracellular calcium increases, elicited by adenosine-triphosphate (ATP), uridine-triphosphate (UTP), and the P2Y₂R agonist MRS2768. Responses were preserved in the absence of extracellular calcium and inhibited by P2Y₂R antagonists. In GES-1 cells, ATP and UTP induced similar responses and the combination of P2X and P2Y receptor antagonists was able to block them. Proliferation studies showed that ATP regulates AGS and MKN-74 cells in a biphasic manner, increasing cell proliferation at 10–100 μM, but inhibiting at 300 μM ATP. On the other hand, 1–300 μM UTP, a P2Y₂R agonist, increased concentration-dependent cell proliferation. The effects of UTP and ATP were prevented by both wide-range and specific purinergic antagonists. In contrast, in GES-1 cells ATP only decreased cell proliferation in a concentration-dependent manner, and UTP had no effect. Notably, the isolated application of purinergic antagonists was sufficient to change the basal proliferation of AGS cells, indicating that nucleotides released by the cells can act as paracrine/autocrine signals. Finally, in tumor-derived biopsies, we found an increase of P2Y₂R and a decrease in P2X4R expression; however, we found high variability between seven different biopsies and their respective adjacent healthy gastric mucosa. Even so, we found a correlation between the expression levels of P2Y₂R and P2X4R and survival rates of GC patients. Taken together, these results demonstrate the involvement of different purinergic receptors and signaling in GC, and the pattern of expression changes in tumoral cells, and this change likely directs ATP and nucleotide signaling from antiproliferative effects in healthy tissues to proliferative effects in cancer.

TO901317 inhibits the development of hepatocellular carcinoma by LXRα/Glut1 decreasing glycometabolism

This study was conducted to observe the effect and possible mechanism of TO901317 in vivo and in vitro to provide a new basis for the targeted therapy of hepatocellular carcinoma (HCC). The expressions of liver X receptor (LXR)-α, glucose transporter (Glut)-1, proliferating cell nuclear antigen (PCNA), and matrix metalloproteinase (MMP)-9 were analyzed from HCC public database (NCBI PubMed database). The result showed that LXRα was downregulated, whereas Glut1, PCNA, and MMP9 were upregulated in human HCC compared with normal liver. Furthermore, LXRα mRNA was negatively correlated with Glut1 mRNA. At the same time, HCC cells were cultivated in vitro and axillary injected in nude mice to establish the xenograft model. The xenograft in the TO901317-treated group was slower and smaller than the control group. The protein expression of LXRα, Glut1, and MMP9 could be detected by Western blot and glucose level. As a result, TO901317 could inhibit the cell proliferation of HCC in a dose-dependent manner by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. With the increase of TO901317 concentration, the cellular glucose concentration and ATP level were gradually decreased. Western blot results showed TO901317 could upregulate LXRα expression but downregulate MMP9 and Glut1 expression. Transwell and wound-healing analysis confirmed that, by increasing the concentration of TO901317, the cell invasion and migration were both decreased. LXRα small-interfering RNA (siRNA) could relieve the suppression effect of TO901317 on the cell invasion and migration and the expression of LXRα, Glut1, and MMP9. The glucose concentration was also raised. TO901317 could repress the progress of HCC cells by reducing the glucose concentration, upregulating LXRα expression, but downregulating the expression of Glut1 and MMP9. NEW & NOTEWORTHY This subject confirmed that TO901317, a specific liver X receptor agonist, could inhibit the progression of liver cancer through upregulating liver X receptor-α, downregulating the expression of glucose transporter-1 and matrix metalloproteinase-9, and decreasing the glucose content in SMMC-7721 and HepG2 cells.

Immunogenicity moderation effect of interleukin-24 on myelogenous leukemia cells

Previous studies have shown that interleukin-24 (IL-24) has tumor-suppressing activity by multiple pathways. However, the immunogenicity moderation effect of IL-24 on malignant cells has not been explored extensively. In this study, we investigated the role of IL-24 in immunogenicity modulation of the myelogenous leukemia cells. Data show that myelogenous leukemia cells express low levels of immunogenicity molecules. Treatment with IL-24 could enhance leukemia cell immunogenicity, predominantly regulate leukemia cells to produce immune-associated cytokines, and improve the cytotoxic sensitivity of these cells to immune effector cells. IL-24 expression could retard transplanted leukemia cell tumor growth in vivo in athymic nude mice. Moreover, IL-24 had marked effects on downregulating the expression of angiogenesis-related proteins vascular endothelial growth factor, cluster of differentiation (CD) 31, CD34, collagen IV and metastasis-related factors CD147, membrane type-1 matrix metalloproteinase (MMP), and MMP-2 and MMP-9 in transplanted tumors. These findings indicated novel functions of this antitumor gene and characterized IL-24 as a promising agent for further clinical trial for hematologic malignancy immunotherapy.

Silibinin inhibits the migration and invasion of human gastric cancer SGC7901 cells by downregulating MMP-2 and MMP-9 expression via the p38MAPK signaling pathway

The objective of the present study was to observe the effects of silibinin and the p38 mitogen-activated protein kinase (MAPK) signaling pathway inhibitor SB203580 on the migration and invasion capabilities of SGC7901 cells, and to explore the underlying associated mechanisms. Scratch, Transwell and Matrigel invasion assays were performed to study the effects of silibinin on cell migration and invasion. Western blot analysis was used to determine the expression levels of p38MAPK, phosphorylated (p-)p38MAPK, matrix metalloproteinase (MMP)-2 and MMP-9. At the genomic level, quantitative polymerase chain reaction was performed to evaluate the expression levels of MMP-2 and MMP-9. The results of scratch assay indicated that silibinin inhibited the migration capabilities of human gastric cancer SGC7901 cells in a dose-dependent manner. Additionally, Matrigel invasion and Transwell migration assays revealed that silibinin and SB203580 combined treatment significantly reduced the number of invasive cells. Western blot analysis indicated a reduced phosphorylation of p38MAPK without marked changes in p38MAPK expression. In addition, the expression of MMP-2 and MMP-9 significantly decreased in the presence of silibinin, SB203580, and the combination of silibinin and SB203580. In summary, silibinin decreased the invasion and migration abilities of SGC7901 cells by downregulating the expression of MMP-2 and MMP-9 through inhibiting p38MAPK signaling cascades.

Insulin-like growth factor binding protein-1 (IGFBP-1) upregulated by Helicobacter pylori and is associated with gastric cancer cells migration

Insulin-like growth factor binding protein-1 (IGFBP-1), a secreted protein, implicated of various cells in mediating the proliferation, migration, invasion, adhesion, survival and so on. In this study, we assessed the expression and release of IGFBP-1 from gastric cancer cells with H. pylori 26695 infection and the biological functions of IGFBP-1 in gastric cancer cells. The results showed that the expression and release of IGFBP-1 were increased in gastric cancer cells (MGC-803, BGC-823, SGC-7901) infected with H. pylori 26695. In addition, the upregulation of IGFBP-1 was dose-dependent in BGC-823 cells infected with H. pylori 26695 but not time-dependent. The upregulation of IGFBP-1 got to peak at 12h after H. pylori 26695 infection and then decreased over time. Subsequently, we measured its functions by silencing and overexpressing IGFBP1 which suggested that overexpression of IGFBP-1 could inhibit the migration of BGC-823 and SGC-7901 cells. However, knocking down the IGFBP-1 could increase the migration of BGC-823 and SGC-7901 cells. Functional findings illustrated that IGFBP-1 was implicated in H. pylori 26695-induced MMP-9 expression in BGC-823 cells. In addition, overexpressing IGFBP1 reduce the promoting effect of MMP-9 on the BGC-823 cells migration. In summary, we demonstrated that IGFBP-1 suppress the migration of BGC-823 cells and play a protective role in the process of H. pylori-induced gastric cancer.

Association of Urinary Activity of MMP-2 with Microalbuminuria in an Isolated Sample of Subjects Living in High Altitude Rural Locations in México

Hernández-Hernández, Magda Elena, Jaime Morales-Romero, Clara Luz Sampieri, Diego Jesús Luna Lozano, Isidra del Carmen Valencia Lezama, Mónica Janett Muñoz Contreras, and Arturo Rodríguez Hernández. Association of urinary activity of MMP-2 with microalbuminuria in an isolated sample of subjects living in high altitude rural locations in México. High Alt Med Biol. 18:209-218, 2017.-Matrix metalloproteinases (MMP) are implicated in remodeling of the renal extracellular matrix. In a cross-sectional study we evaluated renal impairment in general population of high-altitude rural locations in México. Multivariable analysis was performed to identify the association between MMP-2 and MMP-9 and microalbuminuria. Twenty-eight (20.9%) subjects with renal impairment (WRI) and 106 (79.1%) without renal impairment were included. No differences were found relating to sex, location, marital status, current habits, weight, height, body mass index, waist size in males, creatinine in males, and uric acid. In contrast, differences were found among age, level of education, waist size in general and in females, creatinine in general and in females, urinary albumin, urea, glucose, total cholesterol, and triglycerides. Proportions of hypertension, type 2 diabetes mellitus, central abdominal obesity, hypertriglyceridemia, and hypercholesterolemia were greater in the group WRI. Presence of urinary MMP-2 or of both urinary gelatinases and arbitrary unit (AU) values ≥P₉₀ were associated with microalbuminuria. We conclude that AU values ≥P₉₀ of urinary MMP-2 (OR = 20.1, p = 0.002) is associated with microalbuminuria.

Endocan reduces the malign grade of gastric cancer cells by regulating associated protein expression

Endocan, which has been identified to be low expressed in gastric cancer, was found to be positively related to the differentiation level of gastric cancer in vivo and in vitro. In the present study, we aimed to investigate the role of endocan in gastric adenocarcinoma cell line SGC7901 by artificially upregualting or downregulating endocan expression using endocan recombinant vector or specific small interfering RNA (siRNA)-targeting endocan gene, respectively. The effects of endocan recombinant vector-mediated over-expressing and siRNA-mediated endocan silencing on the differentiation, migration, and apoptosis of SGC7901 cells were assessed. Furthermore, the primary molecular mechanisms of endocan were explored by testing the expression alterations of associated protein in SGC7901 along endocan over-expression or knockdown. We found that over-expression of endocan reduced the migration but promoted the differentiation and apoptosis of SGC7901 cells. While, knockdown of endocan did just the opposite. Some molecules were found to participate in endocan-mediated anti-tumor effects, such as p53, caspase 3, and MMP-9. In conclusion, our findings suggest that endocan plays an anti-carcinogenic role in gastric cancer development and progression and might serve as a prognostic biomarker as well as a potential therapeutic target for gastric cancer.

The role of MMP genes in recurrent depressive disorders and cognitive functions

OBJECTIVE

Among the 28 metalloproteinases described so far, 23 can be found in the human organism, but only few are expressed in the human brain. The main objective of this study was to analyse the relationship between MMP-2, MMP-9 and TIMP-2 gene expression and cognitive performance.

METHODS

The study comprised 234 subjects: patients suffering from recurrent depressive disorder (rDD, n=139) and healthy subjects (HS, n=95). The cognitive function assessment was carried out with the help of the following tests: Trail Making Test, The Stroop Test, Verbal Fluency Test and Auditory Verbal Learning Test. Gene expression on the mRNA and protein level was evaluated for MMP-2, MMP-9 and TIMP-2 in both groups using RNA extraction, reverse transcription and enzyme-linked immunosorbent assay.

RESULTS

Both mRNA and protein expression levels of all the genes were significantly lower in rDD subjects as compared with HS. Having analysed the entire experimental group (N=234), significant interrelations were found between the expression of the analysed genes and the results of the tests used to measure cognitive functions. Increased expression on both the mRNA and the protein level was associated in each case with better performance of all the tests conducted. After carrying out a separate analysis on the people from the rDD group and the HS group, similar dependencies were still observed.

CONCLUSIONS

The results of our study show decreased expression of MMP-2, MMP-9 and TIMP-2 genes on both mRNA and protein levels in depression. Elevated expression of MMP-2, MMP-9, TIMP-2 positively affects cognitive efficiency: working memory, executive functions, attention functions, direct and delayed auditory-verbal memory, the effectiveness of learning processes and verbal fluency. The study highlights the important role of peripheral matrix metalloproteinases genes in depression and cognitive functions.

RABEX-5 overexpression in gastric cancer is correlated with elevated MMP-9 level

OBJECTIVE

This study aimed to investigate mRNA and protein expression levels of RABEX-5 and matrix metalloproteinase-9 (MMP-9), their mutual correlation, and biological behavior in gastric cancer (GC) patients.

METHODS

The expression levels of RABEX-5 and MMP-9 were determined by real-time quantitative PCR and Western blotting in cell lines, GC tissues, and adjacent normal tissues. In addition, RABEX-5 and MMP-9 expression was analyzed by immunohistochemistry in formalin-fixed tissues from 113 GC patients.

RESULTS

The mRNA and protein expression levels of RABEX-5 and MMP-9 in GC cell lines and GC tissues were higher than those in normal gastric mucosa cell line and adjacent normal tissues. RABEX-5 expression and MMP-9 expression in GC tissues were significantly and positively correlated. In addition, the size of tumor (p<0.001), Lauren's classification (p=0.009), and N stage (p<0.001) were identified as the relative factors of RABEX-5 expression, whereas the expression of MMP-9 was correlated with N stage (p=0.003). The results of the multivariate analysis revealed that the independent predictive factors of overall survival were T stage (hazard ratio (HR)=2.382; p=0.028), N stage (HR=1.755; p<0.001), RABEX-5 expression (HR=0.452; p=0.004), and MMP-9 expression (HR=0.561; p=0.032).

CONCLUSIONS

RABEX-5 and MMP-9 expression levels were elevated in GC tissues and were associated with tumor invasion, metastasis, and prognosis. Therefore, they may be promising prognostic indicators of survival in GC patients.

Expression and Activity of Metalloproteinases in Depression

BACKGROUND Depression is one of the most common mental disorders and often co-exists with somatic diseases. The most probable cause of comorbidity is a generalized inflammatory process that occurs in both depression and somatic diseases. Matrix metalloproteinases MMPs play a role in modulating inflammation and their impact in many inflammatory diseases has been investigated. The purpose of this study was to evaluate gene expression for selected polymorphisms of MMP-2 (C-735T), MMP-7 (A-181G), and MMP-9 (T-1702A, C1562T), which have been confirmed to participate in development of depression, and TIMP-2 (G-418C, tissue inhibitor of MMP). Activity variability of pro-MMP-2 and pro-MMP-9 was measured in a group of people with depression and a group of healthy individuals. MATERIAL AND METHODS The examined population comprised 142 individuals suffering from depression and 100 individuals who formed a control group (CG). Designations were carried out for MMP-2 (C-735T), MMP-7 (A-181G), MMP-9 (T-1702A, C1562T), and TIMP-2 (G-418C). RESULTS For all examined and tested MMPs and for TIMP-2, gene expression at the mRNA level was higher in patients with depression than in the CG. Similar results were recorded for gene expression at the protein level, while expression on the protein level for TIMP-2 was higher in the CG. Change in activity of MMP-2 and pro-MMP-2 was statistically more significant in the group with depression. The opposite result was recorded for MMP-9 and pro-MMP-9, in which the change in activity was statistically more significant in the CG. CONCLUSIONS Changes in MMPs and TIMP expression may be a common element in, or perhaps even a marker for, recurrent depressive disorders and somatic diseases.

Naringenin inhibits proliferation, migration, and invasion as well as induces apoptosis of gastric cancer SGC7901 cell line by downregulation of AKT pathway

The preliminary anti-cancer activity of Naringenin (Nar) has been proven in several cancers. However, the therapeutic activity of Nar on gastric cancer SGC-7901 cell line is not yet well understood. The aim of the present study was to investigate the effect and mechanisms of Nar on proliferation, apoptosis, migration, and invasion of SGC-7901 cells. In this in vitro study, SGC-7901 cells were treated with Nar at serial concentrations. Our data showed that Nar efficiently inhibited SGC-7901 cell proliferation in a time- and concentration-dependent manner, as well as downregulated proliferating cell nuclear antigen (PCNA) levels in a concentration-dependent manner. Meanwhile, the cell migration and invasion also dramatically decreased after Nar incubation, and the expressions of MMP2 and MMP9 were significantly downregulated. In addition, a strong proapoptotic effect was observed in the SGC-7901 cells after Nar treatment. Apoptosis-related proteins Bax and cleaved caspase-3 were up-regulated, whereas Bcl-2 and Survivin were downregulated. After administration with Nar, we found that phosphorylation of AKT was inhibited, and this inhibitory action could be mildly enhanced by the combination treatment of Nar and AKT inhibitor LY294002. In conclusion, our study confirmed that Nar could inhibit SGC-7901cell proliferation, migration, and invasion as well as induces apoptosis, and Nar might provide a new potential therapeutic strategy for treating gastric cancer.

Silencing profilin-1 inhibits gastric cancer progression via integrin β1/focal adhesion kinase pathway modulation

AIM: To investigate the role of profilin-1 (PFN1) in gastric cancer and the underlying mechanisms.

METHODS: Immunohistochemical analysis, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to detect PFN1 expression in clinical gastric carcinoma and adjacent tissues, and the association of PFN1 expression with patient clinicopathological characteristics was analyzed. PFN1 was knocked down to investigate the role of this protein in cell proliferation and metastasis in the SGC-7901 cell line. To explore the underlying mechanisms, the expression of integrin β1 and the activity of focal adhesion kinase (FAK) and the downstream proteins extracellular-regulated kinase (ERK)1/2, P38 mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K), AKT and mammalian target of rapamycin (mTOR) were measured through Western blot or qRT-PCR analysis. Fibronectin (FN), a ligand of integrin β1, was used to verify the correlation between alterations in the integrin β1/FAK pathway and changes in tumor cell aggressiveness upon PFN1 perturbation.

RESULTS: Immunohistochemical, Western blot and qRT-PCR analyses revealed that PFN1 expression was higher at both the protein and mRNA levels in gastric carcinoma tissues compared with the adjacent tissues. In addition, high PFN1 expression (53/75, 70.4%) was correlated with tumor infiltration, lymph node metastasis and TNM stage in gastric cancer, but not with gender, age, location, tumor size, or histological differentiation. In vitro experiments showed that PFN1 knockdown inhibited the proliferation of SGC-7901 cells through the induction G₀/G₁ arrest. Silencing PFN1 inhibited cell migration and invasion and down-regulated the expression of matrix metalloproteinase (MMP)-2 and MMP9. Moreover, silencing PFN1 reduced the expression of integrin β1 at the protein level and inhibited the activity of FAK, and the downstream effectors ERK1/2, P38MAPK, PI3K, AKT and mTOR. FN-promoted cell proliferation and metastasis via the integrin β1/FAK pathway was ameliorated by PFN1 silencing.

CONCLUSION: These findings suggest that PFN1 plays a critical role in gastric carcinoma progression, and these effects are likely mediated through the integrin β1/FAK pathway.

Overexpression of SMYD3 and matrix metalloproteinase-9 are associated with poor prognosis of patients with gastric cancer

SET and MYND domain-containing protein 3 (SMYD3) plays a key role in the progression of human cancer. Matrix metalloproteinase (MMP)-9 is being related to tumor progression. It has been reported that SMYD3 and MMP-9 are overexpressed in human cancers. However, the exact roles of SMYD3 and MMP-9 in the metastasis and prognosis of gastric cancer (GC) remain unclear. The expressions of SMYD3 and MMP-9 were detected by semiquantitative reverse transcription polymerase chain reaction and Western blotting in gastric cancer and adjacent nontumor tissues. In addition, SMYD3 and MMP-9 expressions were analyzed by immunohistochemistry in formalin-fixed samples from 186 gastric cancer patients. The messenger RNA (mRNA) and protein expression levels of SMYD3 and MMP-9 in gastric cancer tissues were both significantly higher than those in adjacent nontumor tissues. In addition, the expression of SMYD3 was correlated with size of primary tumor and lymph node metastasis, while size of primary tumor and serosal invasion were identified as the independently relative factors of MMP-9 expression in GC tissues. SMYD3 expression and MMP-9 expression in GC tissues were significantly and positively correlated. Multivariate analysis results demonstrated that degree of differentiation, lymph node metastasis, TNM stage, SMYD3 expression, and MMP-9 expression were the independent prognostic indicators of gastric cancer. SMYD3 and MMP-9 may play important roles in tumor invasion, metastasis, and prognosis and could work as promising targets for prognostic prediction in gastric cancer.

Overexpression of twist and matrix metalloproteinase-9 with metastasis and prognosis in gastric cancer

OBJECTIVE

Twist, a basic helix-loop-helix transcription factor, plays a key role in the metastatic progression of human cancer. Matrix metalloproteinase (MMP)-9 is an endopeptidase that digests basement membrane type IV collagen, therefore being possibly related to tumor progression. It has been reported that Twist and matrix metalloproteinase-9 (MMP-9) are expressed in gastric cancers. However, the exact roles of Twist and MMP-9 in tumor metastasis and prognosis remain unclear. The aim of this study was to casts light on this question.

METHODS

Twist and MMP-9 expression in tissue sections of 37 gastric carcinomas was evaluated with immunohistochemistry. The staining results were compared with clinicopathologic features and to patients'outcome.

RESULTS

Twist positive expression was significantly increased in gastric cancer cases with lymph node metastasis (P=0.023). But no correlations were found between MMP-9 overexpression and clinicopathologic features, such as recurrence, TNM stage, and lymph node metastasis. Overall survival (OS) was significantly correlated with recurrence, serosa invasion, TNM stages, distant metastasis, and MMP-9 (P=0.027, 0.021, 0.000, 0.024 and 0.036, respectively). Disease-free survival (DFS) was prominently related to recurrence location, serosa invasion and TNM stages (P=0.000, 0.038 and 0.003, respectively). In the Cox regression multivariate analysis, TNM stage, distant metastasis and MMP-9 were significantly associated with prognosis of gastric cancer (P=0.002, 0.019, and 0.032, respectively).

CONCLUSIONS

This study showed Twist positive expression to be significantly correlated with lymph node metastasis in gastric cancer. MMP-9 overexpression is associated with OS, suggesting that MMP-9 is a prognostic indicator for survival in patients with gastric cancer.

Increased expression of P2RY2, CD248 and EphB1 in gastric cancers from Chilean patients

BACKGROUND

Gastric cancer (GC) ranks as one of the major causes of mortality due to cancer worldwide. In Chile, it is currently the leading cause of cancer death. Identification of novel molecular markers that may help to improve disease diagnosis at early stages is imperative.

MATERIALS AND METHODS

Using whole-genome DNA microarrays we determined differential mRNA levels in fresh human GC samples compared to adjacent healthy mucosa from the same patients. Genes significantly overexpressed in GC were validated by RT-PCR in a group of 14 GC cases.

RESULTS

The genes CD248, NSD1, RAB17, ABCG8, Ephb1 and P2RY2 were detected as the top overexpressed in GC biopsies. P2RY2, Ephb1 and CD248 showed the best sensitivity for GC detection with values of 92.9%, 85.7% and 64.3% (p<0.05), respectively. Specificity was 85.7%, 71.4% and 71.4% (p<0.05), for each respectively.

Expression of the matrix metalloproteases 2, 14, 24, and 25 and tissue inhibitor 3 as potential molecular markers in advanced human gastric cancer

Background. During progression of gastric cancer (GC), degradation of the extracellular matrix is mediated by the matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs): changes in the expression of these have been related to unfavorable prognosis in GC. Objective. To analyze the expression of certain MMPs and TIMPs in chronic superficial gastritis (SG) and GC. Methods. The expression of MMPs and TIMPs was determined using qRT-PCR; the expression was classified, using threshold cycle (C_T) values, as very high (C_T ≤ 25), high (C_T = 26–30), moderate (C_T = 31–35), low (C_T = 36–39), or not detected (C_T = 40). Strength of association was estimated between the proteins, which were detected by Western blot, and the risk of developing GC. Results. We found a high expression of MMP1, MMP2, MMP14, TIMP1, and TIMP3; moderate one of MMP9 and MMP25, and low one of MMP13 and MMP24 in both tissues. In absolute mRNA levels, significant differences were found in expression of MMP2, MMP24, and MMP25, which are overexpressed in GC compared with SG. The presence of the proteins MMP-14 and TIMP-3 was associated with the risk of developing GC. Conclusions. We consider that MMP2, MMP24, and MMP25 and the proteins MMP-14 and TIMP-3 could be candidates for prognostic molecular markers in GC.

Characterization of microRNA-29 family expression and investigation of their mechanistic roles in gastric cancer

Increasing evidence shows that abnormal microRNAs (miRNAs) expression is involved in tumorigenesis. They might be the novel biomarkers or therapeutic targets in disease treatment. miR-29 family was previously reported to act as tumor suppressors or oncogenes in diverse cancers. However, their accurate expression, function and mechanism in gastric cancer (GC) are not well known. Here, we found that the expression of miR-29 family members was significantly reduced in GC compared with adjacent controls. Among them, miR-29c had the most reduced percentage in GC and was associated with aggressive and progressive phenotypes of GC. We further demonstrated that miR-29 family acted as tumor suppressors through targeting CCND2 and matrix metalloproteinase-2 genes in GC. Moreover, the inverse relationship between miR-29 family and their targets was verified in patients and xenograft mice. Finally, reintroduction of miR-29 family significantly inhibited tumor formation of GC cells in the xenograft mice. Take together, our finding characterized the expression properties of miR-29 family, contributed to the function and molecular mechanism of miR-29 family in GC and implied that miR-29 family might be employed as novel prognostic markers and therapeutic targets of GC.

MYC, FBXW7 and TP53 copy number variation and expression in gastric cancer

BACKGROUND

MYC deregulation is a common event in gastric carcinogenesis, usually as a consequence of gene amplification, chromosomal translocations, or posttranslational mechanisms. FBXW7 is a p53-controlled tumor-suppressor that plays a role in the regulation of cell cycle exit and reentry via MYC degradation.

METHODS

We evaluated MYC, FBXW7, and TP53 copy number, mRNA levels, and protein expression in gastric cancer and paired non-neoplastic specimens from 33 patients and also in gastric adenocarcinoma cell lines. We also determined the invasion potential of the gastric cancer cell lines.

RESULTS

MYC amplification was observed in 51.5% of gastric tumor samples. Deletion of one copy of FBXW7 and TP53 was observed in 45.5% and 21.2% of gastric tumors, respectively. MYC mRNA expression was significantly higher in tumors than in non-neoplastic samples. FBXW7 and TP53 mRNA expression was markedly lower in tumors than in paired non-neoplastic specimens. Moreover, deregulated MYC and FBXW7 mRNA expression was associated with the presence of lymph node metastasis and tumor stage III-IV. Additionally, MYC immunostaining was more frequently observed in intestinal-type than diffuse-type gastric cancers and was associated with MYC mRNA expression. In vitro studies showed that increased MYC and reduced FBXW7 expression is associated with a more invasive phenotype in gastric cancer cell lines. This result encouraged us to investigate the activity of the gelatinases MMP-2 and MMP-9 in both cell lines. Both gelatinases are synthesized predominantly by stromal cells rather than cancer cells, and it has been proposed that both contribute to cancer progression. We observed a significant increase in MMP-9 activity in ACP02 compared with ACP03 cells. These results confirmed that ACP02 cells have greater invasion capability than ACP03 cells.

CONCLUSION

In conclusion, FBXW7 and MYC mRNA may play a role in aggressive biologic behavior of gastric cancer cells and may be a useful indicator of poor prognosis. Furthermore, MYC is a candidate target for new therapies against gastric cancer.

Both macrophages and hypoxia play critical role in regulating invasion of gastric cancer in vitro

BACKGROUND

As previously demonstrated, tumor associated macrophages (TAMs) infiltration is associated with some cancers invasion and metastasis. However, the role of TAMs in the gastric cancer remains unclear.

METHODS

Three- dimensional dynamic migration imaging system and real time RT-PCR were used to quantitatively investigate the effect of macrophages on the cancer cell mobility and gene expression related to cancer invasion and metastasis, including ADAM8, ADAM9, MMP9, TIMP3, VEGF-A and IL8 genes, in AGS, HGC-27, Hs-746T and NCI-N87 gastric cancer cell lines under normal or hypoxic conditions.

RESULTS

Under normal conditions, the cancer cell invasion rate was increased significantly and all six gene expressions were upregulated in all four cancer cell lines by macrophages. Under hypoxia the changes in the cancer cell invasion rate induced by macrophages was negatively correlated to the TIMP3 expression. In non- metastatic cell line AGS, the increase in migration rate induced by macrophages was further elevated under hypoxia with increased ADAM8 and ADAM9 expression and decreased MMP9 and TIMP3 expressions. Under hypoxia, the induction by macrophages for IL-8 expression was increased significantly in distant metastatic cell lines NCI-N87 and HS-746T, VEGF-A was increased in HGC-27 cell line.

CONCLUSIONS

Both macrophages and hypoxia play an indispensable role in regulating the invasion of gastric cancer cells in vitro; ADAMs, MMP9 and TIMP3 might be involved in TAM induced invasive power of gastric cancer cells.

Suppressive effects of an ethanol extract of Gleditsia sinensis thorns on human SNU-5 gastric cancer cells

The thorns of Gleditsia sinensis are a traditional Oriental medicine used for the treatment of swelling, suppuration, carbuncle and skin diseases. In the present study, we identified a novel molecular mechanism by which an ethanol extract of Gleditsia sinensis thorns (EEGS) inhibits the growth of the SNU-5 human gastric cancer cell line. EEGS treatment inhibited cell growth and was associated with G1 phase cell cycle arrest at a concentration of 400 µg/ml (IC50) in SNU-5 cells. Treatment with EEGS also stimulated p21WAF1 expression, which significantly decreased the expression of cyclins and cyclin-dependent kinases (CDKs). Further study suggested that p38 MAP kinase pathways may be involved in the inhibition of cell proliferation through p21WAF1‑dependent G1 phase cell cycle arrest in EEGS-treated cells. In addition, NF-κB and AP-1 transcription factor binding sites were identified as the cis-elements for tumor necrosis factor-α (TNF-α)-induced matrix metalloproteinase-9 (MMP-9) expression in SNU-5 cells, as determined by gel-shift assay. Treatment of cells with EEGS suppressed MMP-9 expression induced by TNF-α via a decrease in the binding activity of both NF-κB and AP-1 motifs. These data demonstrate that EEGS-mediated inhibition of cell growth appears to involve the activation of p38 MAP kinase, subsequently leading to the induction of p21WAF1 and the downregulation of cyclin D1/CDK4 and cyclin E/CDK2 complexes. Moreover, EEGS strongly inhibited TNF-α-induced MMP-9 expression by impeding the DNA binding activity of NF-κB and AP-1. Overall, these results provide a potential mechanism for EEGS in the treatment of gastric cancer.

Molecular imaging of gastric neoplasia with near-infrared fluorescent activatable probes

Gastric cancer is the second leading cause of cancer mortality worldwide and is projected to rise to tenth in all-cause mortality in the near term. Early detection requires improved sensitivity and specificity of endoscopic imaging with novel methods. The objective of this study was to evaluate the utility of activatable molecular probes for the detection of gastric cancer both in vivo and ex vivo in a preclinical model. Smad4⁺/⁻ mice, which develop spontaneous gastric neoplasia, were compared to normal wild-type controls. Cathepsin-activatable and matrix metalloproteinase (MMP)-activatable molecular probes were injected 24 hours and 6 hours before imaging, respectively. In vivo imaging was performed using quantitative tomographic near-infrared fluorescence (NIRF) imaging. For validation, ex vivo imaging and histologic examination were performed. Molecular imaging in vivo of Smad4⁺/⁻ gastric cancer murine models revealed intense activation of both cathepsin B and MMP probes. Ex vivo imaging and histology confirmed that the detected neoplasms were adenocarcinomas and hyperplastic lesions. This study provides proof of principle that the cathepsin- and MMP-activatable molecular probes are activated in the Smad4⁺/⁻ murine model of spontaneous gastric adenocarcinoma and can be imaged by both in vivo and ex vivo NIRF methods. The cathepsin probe also detects hyperplastic lesions.

mRNA profiling of the cancer degradome in oesophago-gastric adenocarcinoma

Background:

Degradation of the extracellular matrix is fundamental to tumour development, invasion and metastasis. Several protease families have been implicated in the development of a broad range of tumour types, including oesophago–gastric (OG) adenocarcinoma. The aim of this study was to analyse the expression levels of all core members of the cancer degradome in OG adenocarcinoma and to investigate the relationship between expression levels and tumour/patient variables associated with poor prognosis.

Methods:

Comprehensive expression profiling of the protease families (matrix metalloproteinases (MMPs), members of the ADAM metalloproteinase-disintegrin family (ADAMs)), their inhibitors (tissue inhibitors of metalloproteinase), and molecules involved in the c-Met signalling pathway, was performed using quantitative real-time reverse transcription polymerase chain reaction in a cohort of matched malignant and benign peri-tumoural OG tissue (n=25 patients). Data were analysed with respect to clinico-pathological variables (tumour stage and grade, age, sex and pre-operative plasma C-reactive protein level).

Results:

Gene expression of MMP1, 3, 7, 9, 10, 11, 12, 16 and 24 was upregulated by factors >4-fold in OG adenocarcinoma samples compared with matched benign tissue (P<0.01). Expression of ADAM8 and ADAM15 correlated significantly with tumour stage (P=0.048 and P=0.044), and ADAM12 expression correlated with tumour grade (P=0.011).

Conclusion:

This study represents the first comprehensive quantitative analysis of the expression of proteases and their inhibitors in human OG adenocarcinoma. These findings implicate elevated ADAM8, 12 and 15 mRNA expression as potential prognostic molecular markers.

Inhibition of neutrophil elastase and metalloprotease-9 of human adenocarcinoma gastric cells by chamomile (Matricaria recutita L.) infusion

This study investigated whether the antiinflammatory effect of chamomile infusion at gastric level could be ascribed to the inhibition of metalloproteinase-9 and elastase. The infusions from capitula and sifted flowers (250-1500 µg/mL) and individual flavonoids (10 µM) were tested on phorbol 12-myristate 13-acetate-stimulated AGS cells and human neutrophil elastase. The results indicate that the antiinflammatory activity associated with chamomile infusions from both the capitula and sifted flowers is most likely due to the inhibition of neutrophil elastase and gastric metalloproteinase-9 activity and secretion; the inhibition occurring in a concentration dependent manner. The promoter activity was inhibited as well and the decrease of metalloproteinase-9 expression was found to be associated with the inhibition of NF-kB driven transcription. The results further indicate that the flavonoid-7-glycosides, major constituents of chamomile flowers, may be responsible for the antiinflammatory action of the chamomile infusion observed here.

The selected genetic polymorphisms of metalloproteinases MMP2, 7, 9 and MMP inhibitor TIMP2 in sarcoidosis

BACKGROUND

Increased activity of metalloproteinases may play a role in the initiation and propagation of inflammation in sarcoidosis, and may also be one of the factors responsible for the development of lung fibrosis. The aim of this study was to verify whether polymorphisms of MMP2 C-735T, MMP7 A-181G, MMP9 T-1702A and tissue inhibitor of metalloproteinase (TIMP)2 G-418C predispose to sarcoidosis.

MATERIAL/METHODS

The study included 139 patients with sarcoidosis and 100 healthy subjects. MMPs and TIMP2 mRNA were measured in peripheral blood lysate using real-time RT-PCR. DNA for genetic polymorphism was extracted from peripheral blood by GTC method. Protein concentrations in peripheral blood lysates were measured by ELISA, and MMP2 and 9 activities in BAL fluid were estimated by gel zymography.

RESULTS

TT genotype in MMP9 T-1702A was more frequent in sarcoidosis (p<0.0001, OR = 13.71, 95% CI 7.02-26.80) and resulted in higher expression of MMP9 mRNA (p<0.0001). No differences were found between TT and AT/AA patients in terms of radiological stage, lung function test parameters, activity markers and the presence/absence of Löfgren syndrome. There were no differences in the distribution of MMP2, MMP7 and TIMP2 polymorphisms. Messenger RNAs, as well as protein concentrations of MMP2, 7, 9, and TIMP2 were elevated in patients with sarcoidosis (p<0.0001 for each).

CONCLUSIONS

The TT homozygotes of MMP9 T-1702A genotype may be predisposed to sarcoidosis. Elevated MMP2, 7, 9, and TIMP2 mRNAs suggest their inducibility.

Effect of HMGB1 silencing on cell proliferation, invasion and apoptosis of MGC-803 gastric cancer cells

High-mobility group box 1 (HMGB1) is a multifunctional protein with intranuclear and extracellular functions. Although HMGB1 is overexpressed in approximately 85% of gastric cancers, the role of HMGB1 in gastric cancer biology remains unclear. In this study, we investigate the effect of downregulation of HMGB1 on the biological behavior of gastric cancer cells. MGC-803 gastric cancer cells were transduced with HMGB1-specific RNAi lentiviral vectors. Real-time polymerase chain reaction and Western blot analysis of HMGB1 mRNA and protein, respectively, validated the silencing effects. HMGB1-specific silencing significantly decreased cell proliferation. The impact on proliferation was observed at the cell cycle level--the number of cells in the G0/G1 phase increased, whereas that in S and G2/M phases decreased. Cell cycle changes were accompanied by decreases in cyclin D1 expression. Furthermore, HMGB1 silencing sensitized cells to apoptosis that was induced by oxaliplatin and mediated by the caspase-3 pathway. Finally, silencing of HMGB1 expression significantly reduced cellular metastatic ability and MMP-9 expression in MGC-803 cells. In summary, HMGB1 not only plays an essential role in the proliferation and invasion of MGC-803 cells but also represents a potential target for the therapeutic intervention of gastric cancer.

Role of STAT3 in the development and progression of gastroenteric tumors

STAT3 is a member of the signal transducers and activators of transcription (STATs) family of proteins. Cytoplasmic STAT3 is phosphorylated by JAK to form STAT3-STAT3 dimers. After dimerization, the dimers translocate to the nucleus, where they bind to specific DNA response elements in the promoters of target genes to regulate the transcription of these genes. Recently it has been found that STAT3 plays a significant role in gastroenteric tumorigenesis, especially gastric cancer and colorectal carcinoma. STAT3 regulates the expression of genes that mediate survival & anti-apoptosis (Bcl-2, survivin, cyclin D1), invasion & metastasis (matrix metalloproteinases), and angiogenesis (vascular endothelial growth factor). Multiple mechanisms are involved in regulating the STAT3 signaling pathway. Two major groups of direct negative modulators of STAT3 signaling are the suppressors of cytokine signaling (SOCS) and the protein inhibitors of activated STATs (PIAS). STAT3 inhibitors are promising agents for the therapy of gastroenteric tumors.