Cytarabine prevents neuronal damage by enhancing AMPK to stimulate PINK1 / Parkin-involved mitophagy in Parkinson's disease model.

Parkinson's disease (PD) is a common age-related neurodegenerative disorder, which may be largely due to the mitochondrial dysfunction and impaired mitophagy. Thus, it is of great importance to seek novel therapeutic strategies for PD targeting mitochondrial function and mitophagy. Cytarabine is a marine-derived antimetabolite used in the treatment of acute leukemia, which is also used in the study of the nervous system. In this study, we found that cytarabine pretreatment significantly inhibited the apoptosis and necrosis in the ROT-induced SH-SY5Y cell PD model and reduced the oxidative stress, as evidenced by the reduced MDA levels and the increased levels of SOD, GSH, and total antioxidant capacity. Cytarabine can also enhance mitochondrial vitality, improve mitochondrial respiratory function, and preserve mitochondrial morphology. Cytarabine also enhanced the expression of the mitophagy-related proteins PINK1, Parkin, VDAC1, and DJ-1, and its actions can be reversed by treatment with AMPK inhibitor - Compound C (CC), suggesting that AMPK activation may be involved in cytarabine-enhanced mitophagy. Furthermore, cytarabine can also ameliorate the motor symptoms in the MPTP-induced PD-like mice model, and attenuate the neuropathy in the substantia nigra (SN) of PD mice, while Compound C antagonized cytarabine's beneficial effects. In summary, marine-derived compound cytarabine could resist neurological damage both in vitro and in vivo by activating AMPK to increase PINK1/Parkin-induced mitophagy, serving as a promising disease modulator for treating neurodegenerative disease.

Prognostic value of eight immune gene signatures in pancreatic cancer patients.

BACKGROUND: Pancreatic cancer is one of the most common malignant tumors of the digestive tract, and it has a poor prognosis. Traditional methods are not effective to accurately assess the prognosis of patients with pancreatic cancer. Immunotherapy is a new promising approach for the treatment of pancreatic cancer; however, some patients do not respond well to immunotherapy, which may be related to tumor microenvironment regulation. In this study, we use gene expression database to mine important immune genes and establish a prognostic prediction model for pancreatic cancer patients. We hope to provide a feasible method to evaluate the prognosis of pancreatic cancer and provide valuable targets for pancreatic cancer immunotherapy. RESULTS: We used univariate COX proportional hazard regression analysis, the least absolute shrinkage and selection operator, and multivariate COX regression analysis to screen 8 genes related to prognosis from the 314 immune-related genes, and used them to construct a new clinical prediction model in the TCGA pancreatic cancer cohort. Subsequently, we evaluated the prognostic value of the model. The Kaplan-Meier cumulative curve showed that patients with low risk scores survived significantly longer than patients with high risk scores. The area under the ROC curve (AUC value) of the risk score was 0.755. The univariate COX analysis showed that the risk score was significantly related to overall survival (HR 1.406, 95% CI 1.237-1.598, P < 0.001), and multivariate analysis showed that the risk score was an independent prognostic factor (HR 1.400, 95% CI 1.287-1.522, P < 0.001). Correlation analysis found that immune genes are closely related to tumor immune microenvironment. CONCLUSIONS: Based on the TCGA-PAAD cohort, we identified immune-related markers with independent prognostic significance, validated, and analyzed their biological functions, to provide a feasible method for the prognosis of pancreatic cancer and provide potentially valuable targets for pancreatic cancer immunotherapy.

Occupational exposure to carbon black nanoparticles increases inflammatory vascular disease risk: an implication of an ex vivo biosensor assay.

BACKGROUND: Among manufactured or engineered nanoparticles, carbon black (CB) has largest production worldwide and is also an occupational respiratory hazard commonly seen in rubber industry. Few studies have assessed the risk for cardiovascular disease in carbon black exposed populations. An endothelial biosensor assay was used to quantify the capacity of sera from 82 carbon black packers (CBP) and 106 non-CBPs to induce endothelial cell activation ex vivo. The mediation effect of circulatory proinflammatory factors on the association between carbon black exposure and endothelial cell activation was assessed and further validated using in vitro intervention experiments. RESULTS: The average elemental carbon level inside carbon black bagging facilities was 657.0 µg/m3, which was 164-fold higher than that seen in reference areas (4.0 µg/m3). A global index was extracted from mRNA expression of seven candidate biosensor genes using principal component analysis and used to quantify the magnitude of endothelial cell activation. This global index was found to be significantly altered in CBPs compared to non-CBPs (P < 0.0001), however this difference did not vary by smoking status (P = 0.74). Individual gene analyses identified that de novo expression of key adhesion molecules (e.g., ICAM and VCAM) and chemotactic factors (e.g., CCL2, CCL5, and CXCL8) responsible for the recruitment of leukocytes was dramatically induced in CBPs with CXCL8 showing the highest fold of induction (relative quantification = 9.1, P < 0.0001). The combination of mediation analyses and in vitro functional validation confirmed TNF-α, IL-1ß, and IL-6 as important circulatory factors mediating the effects of carbon black exposure on endothelial cell activation responses. CONCLUSIONS: Inflammatory mediators in sera from CBPs may bridge carbon black exposure and endothelial cell activation response assessed ex vivo. CBPs may have elevated risk for cardiovascular diseases when comorbidity exists. Our study may serve as a benchmark for understanding health effects of engineered carbon based nanoparticles with environmental and occupational health relevance.

NHE1 Mediates 5-Fu Resistance in Gastric Cancer via STAT3 Signaling Pathway.

BACKGROUND: Several recent studies have addressed the role of Na+/H+ exchanger isoform 1 (NHE1) in tumor cell growth and apoptosis, including in gastric cancer. However, the role of NHE1 expression related to the 5-Fu resistance in gastric cancer has not been investigated. METHODS: The expression of NHE1 was examined by qPCR in the SGC7901/5-FU cell line and its parental cell line. pcDNA3.1-NHE1 and NHE1-siRNA were transfected to SGC7901/5-FU resistance cells and cell apoptosis was detected via TUNEL assay. The upstream activators in NHE1 mediated 5-Fu resistant gastric cancer cells were detected by Western blot and immunofluorescent. RESULTS: A significant increase of the expression of NHE1 was observed in SGC7901 5-FU resistance cells compared to the GES-1 and SGC7901 cell line. NHE1 can suppress the cell apoptosis of SGC7901 5-FU resistance cells and involved in cell cycle. Also, the migration and invasion of SGC7901 5-FU resistance cells were promoted by NHE1. NHE1 also increases the intracellular pH. The results of Western blot analysis showed that NHE1 overexpression induced an increase in the expression of phosphorylated activator transcription factor 3 (pSTAT3). The more obvious phosphorylated level was shown in the phosphorylated STAT3 at pSTAT3tyr705. Further investigations revealed that the constitutive activation of STAT3 may be induced by JAK1 and JAK2, and thus effect the 5-FU resistance by regulating NHE1. DISCUSSION: In summary, our findings provided evidence that NHE1 contributed to 5-Fu resistance in gastric cancer cells by regulating the JAK/STAT3 pathway. Therefore, NHE1 can be a useful marker for predicting and monitoring 5-Fu resistance.

Myocyte-specific enhancer factor 2D promotes tumorigenesis and progression in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (TSCC) ranks as one of the most common cancers worldwide and has a poor prognosis. Myocyte-specific enhancer factor 2 (MEF2D) has recently been considered as a novel factor involved in cancer development. In the present study, the function and underlying mechanism of MEF2D in TSCC were investigated. The levels of MEF2D mRNA and protein were determined in human TSCC samples by RT-qPCR and western blot, respectively. The interaction between MEF2D expression and clinicopathologic features was evaluated by IHC and analysis of clinical information. MEF2D-mediated effects on proliferation, migration, and invasion were explored in TSCC cells after transfection with MEF2D-siRNA. The results showed higher expression of MEF2D at both the mRNA and protein levels in TSCC carcinoma tissues than in paracarcinoma tissues. Furthermore, high expression of MEF2D was positively correlated with tumor differentiation and lymphatic metastasis. MEF2D knocked down TSCCA cells also had reduced proliferative, migratory, and invasive abilities compared to those of control cells. Together, these data confirmed that knockdown of MEF2D might suppress the growth and metastasis of TSCC, which further indicated that MEF2D might serve as a therapeutic target for TSCC treatment.

[Effect of Polyvinyl Alcohol/Graphene Oxide Aerogel on the Biological Characteristics of Acute Leukemia Cell Lines].

OBJECTIVE: To investigate the effects of polyvinyl alcohol (PVA) + graphene oxide (GO, weight content 1 wt%) aerogel three-dimensional (3D) scaffolds culture system on the proliferation, phenotype and drug resistance of ALL cell line Jurkat and AML cell line HL-60. METHODS: Jurkat cells and HL-60 cells were seeded in PVA+GO aerogel scaffolds for culture, and the structure of cells were observed by the scanning electron microscopy. Cell proliferation activity was measured by Cell Counting Kit-8 (CCK-8), cell phenotypes were analyzed by flow cytometry after fluorescent staining, then were compared with 2D cultured cells. Ara-C was used in drug resistance experiment, and CCK8 was used to detected cell proliferation activity. RESULTS: The proliferation activity of Jurkat cells grown in aerogel scaffolds was higher than that by 2D cultured in long-term culture. However, in HL-60 cells, the proliferation activity on 3D scaffold only at the 8th to 20th day was higher than that on the traditional 2D culture. Expression of CD4 in Jurkat cells increased after culture for 30 days, but the cell phenotypes in the 3D aerogel scaffolds were similar to 2D cultured cells. Phenotype of HL-60 cells was certainly changed after culture for 30 days, the cells can be divided into CD13+CD14-CD45+HLA-DR+,CD13-CD14--CD45+HLA-DR+ and CD13-CD14-CD45+HLA-DR- groups, and a new CD13+CD14-CD45-HLA-DR+ group of cells appeared in the cells cultured in 3D scaffolds, but not in 2D cultured cells. Drug resistance experiments showed that Jurkat cells in aerogel scaffolds have stronger drug resistance than those in 2D culture. CONCLUSION: PVA+GO (1 wt%) aerogel scaffolds can improve the proliferation and drug resistance of leukemia cells, and the phenotypes were the same as those in 2D culture, which can be used for cell amplification and biology characteristics studies and drug experiments. However, cell phenotypes should be analyzed before culture, and the effects of phenotypes changes on drug resistance should be eliminated.

lncRNA PTAR promotes NSCLC cell proliferation, migration and invasion by sponging microRNA­101.

MicroRNA (miR)­101 copy loss is an early event in the development of human lung cancer, and it occurs in 29% of all lung cancer incidences. In addition, miR­101 expression in non­small cell lung cancer (NSCLC) is known to be downregulated. The aim of the present study was to explore the roles and mechanisms of the long non­coding (lnc)­RNA pro­transition associated RNA (PTAR) on NSCLC cell proliferation, migration and invasion in association with miR­101. Reverse transcription­quantitative PCR analysis was performed to detect the expression of lncRNA PTAR in 30 paired human NSCLC tissues and the corresponding para­tumor tissues. PTAR was amplified and cloned into the expression vector pCDNA3.1. Then, PTAR­overexpression plasmids or small interfering (si)­RNA­PTAR was transfected into A549 cells for 48 h, after which cell proliferation and the cell cycle distribution were evaluated. In addition, Transwell chamber and cell scratch­wound assays were conducted to analyze A549 cell migration and invasion. A luciferase activity assay was evaluated to determine the interaction between PTAR and miR­101. Furthermore, our results demonstrated that in human NSCLC tissues and cell lines, lncRNA PTAR expression was upregulated compared with normal lung tissues and cell lines, respectively. Additionally, PTAR transfection was observed to promote A549 cell proliferation, migration and invasion; opposing effects were observed with siRNA­PTAR transfection. The luciferase activity assay revealed that PTAR could act as a sponge to bind miR­101. Thus, miR­101 plays a role in NSCLC tumorigenesis and progression. In conclusion, lncRNA PTAR was proposed to promote NSCLC cell growth through sponging and inactivating miR­101, which may be a possible mechanism underlying miR­101 copy loss in human NSCLC.

3D culture enhances chemoresistance of ALL Jurkat cell line by increasing DDR1 expression.

Three dimensional (3D) culture has gradually become a research hotspot in the field of drug screening, stem cell research, and tissue engineering due to its more physiological-like morphology and function. In this study, we compared the differences of cell proliferation, population, protein expression and chemoresistance profiles between two dimensional (2D) and 3D culture of acute lymphoblastic leukemia (ALL) Jurkat cell line. Polycaprolactone (PCL) is used for 3D culture owing to its biochemical properties and compatibility. Culturing of ALL Jurkat cell line in collagen type I coated polycaprolactone scaffold for 168 h increased cell proliferation, attachment, as well as the drug resistance to cytarabine (Ara-C) and daunorubicin (DNR) without changing the original CD2+CD3+CD4+dimCD8-CD34-CD45+dim phenotype, compared to uncoated PCL scaffold and tissue culture plate systems. Molecularly, increased chemoresistance is associated with the upregulation of discoidin domain receptor 1 (DDR1) and transcription factor STAT3. Inhibition of DDR1 activity by DDR1-specific inhibitor DDR-IN-1 accelerated cell death in the presence of Ara-C, DNR or their combination. These results demonstrated that 3D culture enhances chemoresistance of ALL Jurkat cell line by increasing DDR1 expression. Importantly, the cell adhesion-mediated drug resistance induced by DDR1 in the scaffold was similar to the clinical situation, indicating the 3D culture of cancer cells recapitulate the in vivo tumor environment and this platform can be used as a promising pre-clinic drug-screen system.

The miR-3127-5p/p-STAT3 axis up-regulates PD-L1 inducing chemoresistance in non-small-cell lung cancer.

It is less known about miRNA3127-5p induced up-regulation of PD-L1, immune escape and drug resistance caused by increased PD-L1 in lung cancer. In this study, lentivirus was transduced into lung cancer cells, and quantitative PCR and Western blot were used to detect the expression of PD-L1. Then immunofluorescence assay was applied to detect autophagy, finally we explored the relationship between PD-L1 expressions and chemoresistance in patients. As a result, we found that microRNA-3127-5p promotes pSTAT3 to induce the expression of PD-L1; microRNA-3127-5p promotes STAT3 phosphorylation through suppressing autophagy, and autophagy could retaine pSTAT3 into the nucleus in miRNA-3127-5p knocked cells, and immune escape induced by elevated level of PD-L1 results in chemoresistance of lung cancer. In conclusion, microRNA-3127-5p induces PD-L1 elevation through regulating pSTAT3 expression. We also demonstrate that immune escape induced by PD-L1 can be dismissed by corresponding monoclonal antibody.

CRM1, a novel independent prognostic factor overexpressed in invasive breast carcinoma of poor prognosis.

Breast cancer (BC) is the most commonly diagnosed cancer in females globally and is more aggressive at later stages. Chromosome region maintenance 1 (CRM1) is involved in the nuclear export of proteins and RNAs and has been associated with a number of malignancies. However, the clinicopathological significance of its expression in BC remains to be elucidated therefore this was investigated in the present study. CRM1 expression in 280 breast cancer tissues and 60 normal tissues was retrospectively analyzed using immunohistochemistry (IHC) and western blotting. IHC investigation demonstrated that CRM1 expression was significantly increased in BC compared with the normal breast epithelium (P<0.0001). Overexpression of CRM1 was markedly associated with poor prognostic characteristics, including larger tumor size (P=0.024), positive lymph node metastasis (P=0.032), invasive histological type (P=0.004) and distant metastasis (P=0.026). Significant associations were also observed between increased CRM1 expression and the progesterone receptor (P=0.028) and Ki67 (P=0.019). Kaplan-Meier survival analysis demonstrated that patients with high CRM1 expression exhibited a reduced disease-free survival and overall survival compared with those with low CRM1 expression (P=0.013). In the multivariate analysis, CRM1 expression (P=0.011), tumor size (P=0.001) and lymph node metastasis (P<0.001) were independent prognostic markers of BC. In conclusion, CRM1 serves an important role in BC and may serve as a predictive and prognostic factor for a poor outcome in patients with BC.

Anticancer effect of fufang yiliu yin on human hepatocellular carcinoma SMMC-7721 cells.

Chinese herbal medicine utilizes clinically effective adjuvants that can potentiate the effects of hepatectomy and molecule-targeted drugs for the treatment of hepatocellular carcinoma (HCC). The aim of this study was to investigate the possible molecular mechanisms underlying the antitumor effect of fufang yiliu yin (FYY) on HCC cells. We investigated the effects of FYY on the proliferation, migration, invasion, and apoptosis of SMMC-7721 cells in vitro and in mouse subcutaneous xenograft models in vivo. FYY significantly inhibited the proliferation of SMMC-7721 cells compared to that of normal hepatocytes; cell proliferation was blocked at the G2/M phase in accordance with reduced expression of proliferating cell nuclear antigen. FYY treatment resulted in the activation of caspase-8, caspase-3 and poly (ADP-ribose) polymerase, with reduced protein levels of tumor necrosis factor receptor-associated factor 2, indicating an induction of cell apoptosis. In addition, we observed decreases in the protein expression of matrix metalloproteinase-2 and -9 along with an inhibition of cell migration and invasion after FYY treatment. Furthermore, FYY treatment significantly inhibited the growth of tumors in vivo. These data demonstrate the strong inhibitory effects of FYY on SMMC-7721 cells, and we propose FYY as a novel potential anticancer adjuvant.

Trichostatin A reverses the chemoresistance of lung cancer with high IGFBP2 expression through enhancing autophagy.

Insulin-like growth factor (IGF) signaling plays an important role in tumorigenesis and metastasis. Here, we analyzed insulin-like growth factor (IGF) binding protein-2 (IGFBP2) expression in 81 lung cancer patients and 36 controls consisting of healthy and benign pulmonary lesion participants for comparison, then validated the IGFBP2 expression in additional 84 lung cancer patients, and evaluated the prognostic and chemoresistant significance of IGFBP2 in two cohorts respectively. Next we detected the reversal effect of trichostatin A (TSA) on chemoresistance in cell lines with high IGFBP2 expression. As a result, the mean expression of IGFBP2 in lung cancer patients was significantly higher than that in controls and increased with lung cancer progressed to advanced stage. In addition, high IGFBP2 expression was independently predictive for chemoresistance; over-expressed IGFBP2 enhances cell activity and TSA can reverse the chemoresistance induced by high IGFBP2 expression through enhancing autophagy. Furthermore, multivariate analysis showed that lung cancer patients whose blood IGFBP2 was higher had a poor survival outcome, with a hazard ratio of 8.22 (95%CI 1.78-37.92, P = 0.007) after adjustment for stage, histopathology, EGFR mutation, age, smoking and surgery.

Correlation between Tissue Characterization and Dynamic Expression of Matrix Metalloproteinase-2 and Its Tissue Inhibitor in Conjunctival Filtering Bleb of Rats.

PURPOSE: Using rat conjunctival bleb model, we correlated changes morphology and histology in the bleb with changes in MMP-2 and TIMP-2 levels. METHODS: Filtering surgeries were performed on rats. Dynamic changes in morphology and histopathology were observed using HE staining. Expression of MMP-2 and TIMP-2 was determined by immunofluorescence microscopy and western blotting. RESULTS: Well-elevated filtering blebs formed and persisted for an average of 12 days. Histological examination showed that inflammatory was dominant in postoperative days 1-3, and proliferating manifestation became the main sign 5 days later. Western blot showed that MMP-2 was downregulated 1 day after surgery, upregulated at 3 days, and observed with a peak at 7 days; then it persisted until 28 days. The difference was statistically significant (F = 280.18, p < 0.01).TIMP-2 was upregulated 1 day after surgery and observed with a peak at 5 days; then it persisted until 28 days. The difference was statistically significant (F = 145.34, p < 0.01). CONCLUSIONS: During the processes of conjunctival filtering bleb and scar formation in rats, the changes in MMP-2 and TIMP-2 levels in the filtering area, together with a corresponding proliferation of fibroblasts and the accumulation of collagen fibres, resulted in scarring of filtering blebs.

P53 prevent tumor invasion and metastasis by down-regulating IDO in lung cancer.

In present study, we are to clear demonstrate the genetic evidence of IDO signaling's impact on invasion and metastasis in lung cancer. Here we examined IDO1 expression levels in non-small cell lung cancer (NSCLC) patients (64) tumor/normal pairs underwent RT-PCR and comprehensive histological, immunohistochemica and clinical analysis. The NSCLC cells stably expressing IDO1 was analyzed for migration and invasion assays and the regulatory mechanism in vitro and metastasis assays in vivo. As results, we reported that IDO1 expression increased by more than 3.2-fold in lung cancer compared with their corresponding non-tumor tissues, and the up-regulation of IDO1 is significantly correlated to TNM stage and lymph node-metastasis. The over-expression of IDO1 significantly encouraged the metastasis and invasion of lung cancer cells, and IDO1 could promote metastasis formation in vivo. Furthermore, we further found that p53 could attenuate IDO signaling in lung cancer cell migration partly. In conclusion, these results demonstrate that the IDO signaling's impact on invasion and metastasis and the suppressive effect of p53 on IDO1 in lung cancer, present one novel therapeutic strategy for early metastatic lung cancer in clinical.

Rnf2 knockdown reduces cell viability and promotes cell cycle arrest in gastric cancer cells.

Rnf2 is a fundamental component of the polycomb repressive complex 1and acts as the really interesting new gene finger E3 ligase, which is responsible for histone 2A modification. Previous studies have shown that the ring finger protein 2 (Rnf2) is overexpressed in various types of tumor and has a close association with tumor development. However, few studies have been carried out into the expression and biological function of Rnf2 in gastric cancer cells. The present study measured the expression of Rnf2 in gastric cancer cells and normal epithelial gastric cells. The results demonstrate that Rnf2 is upregulated in gastric cancer cells. In addition, the knockdown of Rnf2 inhibited the cell viability and induced increased G1 phase followed by a substantial reduction of the G2/M phase. The expression levels of p21 and p27 were also significantly elevated by the knockdown of Rnf2. These results provide evidence of the oncogenic function of Rnf2 in gastric cancer, possibly through an inhibition of cellular proliferation and a delay of the G2/M phase. Therefore, Rnf2 may be a novel target for the prognosis and therapy of gastric cancer.

Downregulation of NPM expression by Her-2 reduces resistance of gastric cancer to oxaliplatin.

Nucleophosmin (NPM) and human epidermal growth factor receptor-2 (Her-2) are abnormally expressed in various types of human malignant tumors, including gastric cancer, and have been closely associated with cancer chemoresistance. However, their interaction and roles in oxaliplatin resistance are not fully understood. Therefore, the present study aimed to elucidate the relationship between NPM and Her-2 in gastric cancer cell lines and clinical samples, and further investigated their role in the resistance of gastric cancer to oxaliplatin. Western blotting and reverse transcription-quantitative polymerase chain reaction confirmed that NPM and Her-2 expression were significantly upregulated in gastric cancer cells and clinical samples, and that their expression levels were strongly correlated. However, Her-2 expression was not affected by upregulation or downregulation of NPM expression in gastric cancer cells. Cell counting kit-8 assays demonstrated that the cell sensitivity to oxaliplatin decreased simultaneously with an increase in NPM expression. Furthermore, inhibition of Her-2 expression using trastuzumab significantly increased the sensitivity of the cells to oxaliplatin, which occurred simultaneously with the downregulation of NPM. These results indicated that inhibition of NPM, as a Her-2 downstream signal, may be a novel strategy to overcome oxaliplatin-resistant gastric cancer, and that trastuzumab and oxaliplatin may exhibit a synergistic antitumor effect in Her-2-positive gastric cancer cells.

Upregulated microRNA-429 inhibits the migration of HCC cells by targeting TRAF6 through the NF-κB pathway.

Increasing evidence indicates that miR-429 is involved in tumor suppression in various human cancers. however, its role in hepatocellular carcinoma (HCC) remains unclear. In the present study, we found that miR-429 was significantly downregulated in HCC tissue samples and cell lines. Upregulation of miR-429 markedly suppressed proliferation and migration of HCC cells. Moreover, we identified TRAF6 as a direct target of miR-429. Downregulation of TRAF6 partially attenuated the oncogenic effect of anti­miR-429 on HCC cells. Ectopic expression of miR-429 in HCC cells inhibited TCF-4 activity as well as nuclear accumulation of P65 and expression of the NF-κB targets c-Myc and phosphorylation of TAK1. In a nude xenograft model, miR-429 upregulation significantly decreased HCC growth. In conclusion, by targeting TRAF6, miR-429 is downregulated in HCC and inhibits HCC cell proliferation and motility. Our data suggest that miR-429 may serve as a potential anticancer target for the treatment of HCC.

ATP-induced cardioprotection against myocardial ischemia/reperfusion injury is mediated through the RISK pathway.

The aim of the present study was to examine the post-infarct acute effect of adenosine-5'-triphosphate (ATP) on myocardial infarction (MI) size as well as its precise molecular mechanism. Sixty New Zealand white male rabbits were exposed to 40 min of ischemia followed by 180 min of reperfusion. The rabbits were intravenously administered 3 mg/kg of ATP (ATP group) or saline (control group) immediately after reperfusion and maintained throughout the first 30 min. The wortmannin+ATP, PD-98059+ATP, and 5-hydroxydecanoic acid (5-HD) sodium salt+ATP groups were separately injected with wortmannin (0.6 mg/kg), PD-98059 (0.3 mg/kg), and 5-HD (5 mg/kg) 5 min prior to ATP administration. MI size was calculated as the percentage of the risk area in the left ventricle. Myocardial apoptosis was determined using a TUNEL assay. Western blot analysis was performed to examine the levels of protein kinase B (Akt)/p-Akt and extracellular signal-regulated kinase (ERK)/p-ERK in the ischemic myocardium, 180 min after reperfusion. The infarct size was significantly smaller in the ATP group than in the control group (p<0.05). The infarct size-reducing effect of ATP was completely blocked by wortmannin, PD-98059 and 5-HD. Compared with the control group, cardiomyocyte apoptosis was significantly reduced in the ATP group, while this did not occur in the wortmannin+ATP, PD-98059+ATP and 5-HD+ATP groups. Western blot analysis revealed a higher myocardial expression of p-Akt and p-ERK 180 min following reperfusion in the ATP versus the control group. In conclusion, cardioprotection by postischemic ATP administration is mediated through activation of the reperfusion injury salvage kinase (RISK) pathway and opening of the mitochondrial ATP-dependent potassium channels.

Relationship Between HSP70 and ERBB2 Expression in Breast Cancer Cell Lines Regarding Drug Resistance.

BACKGROUND: Heat shock protein 70 (HSP70) is known to be downstream of human epidermal growth factor receptor-2 (ERBB2), but little is known regarding the relationship between HSP70 and drug resistance mediated by ERBB2 in breast cancer. MATERIALS AND METHODS: After infecting breast cancer cells with lentivirus-mediated Lenti-ShHSP70 and Lenti-ShERBB2, we examined the expression of HSP70 and ERBB2 by real-time polymerase chain reaction and western blotting. RESULTS: Compared to the control groups, mRNA expression of HSP70 was decreased in lentivirus-infected, and western blotting indicated a concordant reduction of HSP70 protein. On the other hand, ERBB2 was significantly down-regulated by HSP70 silencing in SK-BR-3 cells at both the mRNA and protein levels. Expression of HSP70 in transfected cells was also reduced by Lenti-ShERBB2. CCK8 viability assay indicated that inhibition of HSP70 increased the sensitivity of SK-BR-3 cells to fluorouracil treatment. CONCLUSION: HSP70 affects ERBB2 and ERBB2-mediated drug-resistance in breast cancer cells.

DNA hypermethylation of the vimentin gene inversely correlates with vimentin expression in intestinal- and diffuse-type gastric cancer.

The vimentin gene is a hallmark of epithelial-to-mesenchymal transition and has been observed to be overexpressed in various types of tumor cell line and tissue. Previous studies have reported correlations between vimentin DNA methylation levels and subsequent vimentin expression levels in solid tumors, including breast and colorectal cancer; however, to the best of our knowledge, such a correlation has not been reported for gastric cancer (GC) using Lauren classification. Therefore, the present study aimed to quantify DNA methylation levels of the vimentin gene using quantitative (q) methylation-specific polymerase chain reaction (PCR) in intestinal-type GC cell lines (MKN-28, AGS and MKN-1), diffuse-type GC cell lines (SGC-7901, SNU-5 and KATO III), the GES-1 immortalized human non-neoplastic gastric epithelial cell line, as well as in tumor and paratumor normal tissue samples. Furthermore, the present study analyzed the messenger RNA expression of the vimentin gene in these cell lines and tissues by reverse transcription-qPCR. A comparison of the clinicopathological features was conducted between patients, grouped according to the Lauren classification. The present study identified that the vimentin promoter region was hypermethylated in all GC cell lines and tumor tissue samples when compared with immortalized normal gastric epithelial cells and paratumor normal tissues. In addition, vimentin promoter methylation levels were observed to be higher in intestinal-type cell lines when compared with those of diffuse-type lines and tissues. Correspondingly, vimentin expression levels were lower in intestinal-type gastric cell lines compared with those of diffuse-type cell lines and tissues, and were lowest in the non-neoplastic gastric cell line and paratumor normal tissues. Patients with diffuse-type GC were on average younger (P=0.023), and exhibited higher tumor (P=0.020), node (P=0.032) and TNM classification of malignant tumor stage (P=0.039) than those with intestinal-type GC. Following treatment of AGS cells (which demonstrated the highest methylation level of the vimentin gene) with 5-aza-2'-deoxycytidine, vimentin expression was restored significantly. Thus, the present study revealed that vimentin promoter methylation levels are inversely correlated with vimentin expression levels in GC (according to Lauren classification). High levels of methylation in the vimentin gene promoter region may be involved in carcinogenesis and the development of GC, and may provide a novel molecular classification for GC.