Effect of miR-22 secreted by macrophage exosomes on cardiomyocyte autophagy under uremic toxin stimulation

AIM To investigate the effect of microRNA-22 (miR-22) secreted by macrophage exosomes on the autophagy of H9c2 cardiomyocytes under uremic toxin stimulation. METHODS The macrophage-derived exosomes stimulated by indoxyl sulfate (IS) were collected and co-cultured with H9c2 cells. The levels of miR-22 in the macrophages, macrophage-derived exosomes and H9c2 cells were detected by RT-qPCR. The viability of H9c2 cells was measured by CCK-8 assay. The expression of exosome surface marker protein CD63 and autophagy-related proteins LC3 and P62 was determined by Western blot. RESULTS Under IS stimulation, the expression of exosome surface marker protein CD63 in the macrophages was significantly higher than that in control group (P<0.05), and the levels of miR-22 in the macrophages and macrophage-derived exosomes were significantly increased (P<0.01). With the increase in macrophage exosome concentration, the viability of H9c2 cells was decreased gradually (P<0.05), and the stimulation of macrophage exosomes reduced P62 expression and promoted the conversion of LC3-I to LC3-II in a dose-dependent manner (P<0.05). Macrophage-derived exosomes increased the ratio of LC3-II to LC3-I but decreased P62 protein expression in the H9c2 cells transfected with miR-22 mimic compared with the cells transfected with corresponding negative control miRNAs (P<0.05). However, miR-22 inhibitor yielded contrasting results. CONCLUSION IS-stimulated macrophages increase expression of miR-22 in cardiomyocytes through exosomes, and promote autophagy of the cardiomyocytes.     

siRNA targeting TRIM29 gene induces apoptosis of nasopharyngeal carcinoma cells by inhibiting PI3K/AKT signaling pathway

AIM:To investigate the effect of TRIM29 gene expression silencing on the apoptosis and PI3K/AKT signaling pathway in human nasopharyngeal carcinoma 5-8F cells. METHODS:The 5-8F cells were divided into blank group, negative control (NC) group (transfected negative control siRNA) and si-TRIM29 group (transfected TRIM29 specific siRNA). The viability of the 5-8F cells transfected with si-TRIM29 for 0~96 h was measured by CCK-8 assay. The apoptotic rate and the protein levels of TRIM29, cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, t-AKT and p-AKT in the 5-8F cells transfected with si-TRIM29 for 48 h were determined by flow cytometry and Western blot, respectively. PI3K/AKT signal specific inhibitor LY294002 at 10 μmol/L and si-TRIM29 alone or in combination were treated with the 5-8F cells, and the cells were divided into blank group, LY294002 group and LY294002+si-TRIM29 group. The apoptotic rates in the 3 groups were detected by flow cytometry. RESULTS:The protein expression of TRIM29 in the 5-8F cells transfected with TRIM29 siRNA was significantly lower than that in blank group (P<0.05). Compared with blank group, the cell viability was significantly decreased, the apoptotic rate was significantly increased, the protein levels of cleaved caspase-3, cleaved caspase-9 and Bax were significantly increased, and the protein levels of Bcl-2 and p-AKT were significantly decreased in si-TRIM29 group (P<0.05). The apoptotic rate in LY294002 group was higher than that in blank group, while that in LY294002+si-TRIM29 group was even higher than that in LY294002 group (P<0.05). CONCLUSION:Silencing of TRIM29 gene expression induces apoptosis of nasopharyngeal carcinoma 5-8F cells by inhibiting PI3K/AKT signaling pathway.     

Preliminary study of bone marrow mesenchymal stem cell-derived exosomes in repair of spinal cord injury in rats

AIM:To study the influence of bone marrow mesenchymol stem cell-drived exosomes (BMSC-exosomes) on hindlimb activity, and the numbers of reactive astrocytes and residual neurons in spinal cord injury (SCI) rats. METHODS:BMSCs were cultured using the whole bone marrow adherent culture method and surface markers CD90 and CD34 were verified by flow cytometry. Exosomes were isolated by ultracentrifugation and the morphology of exosomes was observed under transmission electron microscope. The protein markers CD63 and CD9 were verified by Western blot. After exosomes were applied to SCI rats, the Basso, Beattie and Bresnahan locomotor rating scale score, the Nissl staining of the lesion site, and the numbers of reactive astrocytes and residual neurons were assessed at various time points. RESULTS:Transmission electron microscopic observation revealed the presence of saucer-shaped vesicles. BMSC-exosomes were found to express high levels of CD63 and CD9. Compared with injury group, significant improvement of hindlimb activity scores from day 14 after injury in treatment group was observed (P<0.05), and less reactive astrocytes and more residual neurons from day 7 after injury were also observed (P<0.05). CONCLUSION:BMSC-exosomes inhibit reactive astrocytes and death of neurons, and improve hindlimb activity in the rats after SCI.     

Pancreatic cancer cell-secreted exosomes promote apoptosis of β cells via activation of mitochondrial apoptotic pathways

AIM: To investigate the effects of exosomes secreted by pancreatic cancer cells on the viability and function of β cells and the possible mechanism. METHODS: ExoQuick-TC kit was used to extract exosomes in the supernatants of mouse pancreatic cancer Pan02 and MPC-83 cells, and the extracted exosomes were identified by transmission electron microscopy. Fluorescence-labeled exosomes were incubated with mouse insulinoma MIN6 cells for 48 h to detect whether exosomes secreted by pancreatic cancer cells were uptaken by MIN6 cells. MTT and glucose-stimulated insulin secretion (GSIS) assays were conducted to examine cell viability and insulin secretion of MIN6 cells after incubating with exosomes. The expression of miR-204 and Bcl-2 mRNA in MIN6 cells was detected by qPCR. The protein expression of Bcl-2, Bax, caspase-3 and cytochrome C (Cyt-C) in MIN6 cells was determined by Western blot. RESULTS: The results of transmission electron microscopy showed that both Pan02 cells and MPC-83 cells secreted exosomes, and Pan02 cells secreted more. The co-incubation results of fluorescence-labeled exosomes and MIN6 cells confirmed that MIN6 cells were able to ingest large amounts of exosomes secreted by pancreatic cancer cells. The results of MTT and GSIS assays showed that the viability and the level of high glucose-stimulated insulin secretion of MIN6 cells in exosome treatment group significantly decreased compared with nontreatment group (P<0.01). The results of qPCR showed that the exosomes secreted by pancreatic cancer cells were rich in miR-204, and the mRNA expression of Bcl-2 in MIN6 cells was significantly down-regulated by exosome incubation (P<0.01). The results of Western blot showed that the protein expression of Bcl-2 in the MIN6 cells treated with exosomes was significantly down-regulated (P<0.05), and the protein levels of Bax, cleaved caspase-3 and Cyt-C in exosomes treatment group were significantly up-regulated (P<0.01). CONCLUSION: Pancreatic cancer cells secrete exosomes. The exosomes secreted by pancreatic cancer cells are ingested by β cells, and reduce the viability and insulin secretion of β cells. The mechanism may be related to the increase in exosomal miR-204 in the β cells. Increasing miR-204 may inhibit the expression of Bcl-2 and promote the activation of mitochondrial apoptosis in β cells.     

CaMKII aggravates hypoxia/reoxygenation injury in H9c2 cells by activating apoptosis

AIM: To investigate the effect of Ca²⁺/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ) on hypoxia/reoxygenation (H/R) injury in H9c2 cells. METHODS: H9c2 cells were randomized into 4 groups:control group, KN-93 (an inhibitor of CaMKⅡ; 1 μmol/L) treatment group, H/R group and H/R+KN-93 (1 μmol/L) treatment group. The cells in KN-93 group and KN-93+H/R group were pretreated with KN-93 for 2 h before the other treatment was performed. The viability of H9c2 cells in each group was measured by CCK-8 assay. Lactate dehydrogenase (LDH) activity in the culture medium was detected. The protein levels of phosphorylated CaMKⅡ (p-CaMKⅡ), phosphorylated phospholamban (p-PLN) and cleaved caspase-3 were determined by Western blot. The apoptosis was analyzed by TUNEL staining and the flow cytometry. RESULTS: No significant difference of all indexes tested between control group and KN-93 group was observed. H/R treatment significantly reduced the cell viability, and increased the activity of LDH (P<0.01), the protein levels of p-CaMKⅡ, p-PLN and cleaved caspase-3 (P<0.05), and the apoptotic rate (P<0.01). KN-93 (1 μmol/L) significantly increased the cell viability, and decreased the activity of LDH (P<0.01), the protein levels of p-CaMKⅡ, p-PLN and cleaved caspase-3 (P<0.05), and the apoptotic rate (P<0.01). CONCLUSION: CaMKⅡ aggravates hypoxia/reoxygenation injury in the H9c2 cells by activating apoptosis.     

Effect of p53 agonist nutlin-3 on proliferation of mesangial cells cultured in high glucose

AIM:To observe the effect of p53 agonist nutlin-3 on the proliferation, apoptosis and expression of extracellular matrix in the glomerular mesangial cells (MCs) cultured in high glucose, and to explore its possible mechanism. METHODS:After successful modeling of diabetic nephropathy (DN), PAS staining was performed on the kidney tissues to observe pathological changes. In addition, the p53 expression in the kidney tissue was detected by immunohistochemical staining. The mesangial cell SV40 was cultured in vitro and divided into mannitol (Motl) group, normal glucose (NG) group, high glucose (HG) group, high glucose plus nutlin-3 (HG+Nut) group and nutlin-3 control (Nut) group. The cell viability was detected by CCK-8 assay, and the living cell counting was performed by the method of Trypan blue exclusion. The apoptosis was analyzed by flow cytometry. The protein levels of collagen type IV (Col-IV), p53, p-p53, Bcl-2 and Bax were determined by Western blot. RESULTS:The significant increases in the proliferation of mesangial cells and the levels of p53 in renal tissue of diabetic nephropathy mice were observed. The results of CCK-8 assay showed that high glucose promoted the viability of mesangial cells, and nutlin-3 at 40 μmol/L inhibited the viability of mesangial cells in high glucose environment. Western blot analysis showed that the protein levels of p53, Bax and p-p53 were significantly increased (P<0.05), and the protein levels of Bcl-2 and Col-IV was decreased in HG+Nut group compared with HG group (P<0.05). Furthermore, the ratio of Bax/Bcl-2 was greater than 1. The results of flow cytometry showed that compared with HG group, nutlin-3 promoted the apoptosis of mesangial cells in high glucose environment, the apoptotic rate was significantly increased (P<0.05).CONCLUSION:High glucose promotes the proliferation of mesangial cells. p53 agonist inhibits the viability and promotes apoptosis of mesangial cells under high glucose.     

Influence of maxadilan on human adipose-derived stem cells

AIM: To investigate the effect of maxadilan, which specifically activates pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1 receptor), on the proliferation, apoptosis and differentiation potential of human adipose-derived stem cells (ASCs). METHODS: ASCs from human adipose tissue were isolated by enzymatic digestion and cultured. ASCs were confirmed by the analysis of the markers for cell phenotypes by flow cytometry (FCM) and adipogenic/osteogenic induction. The effect of maxadilan on ASCs viability was analyzed by CCK-8 assay and FCM. ASCs were irradiated by ultraviolet C (UVC) at 254 nm and the absorbance of apoptotic ASCs induced by various doses of UVC was measured by CCK-8 assay. ASCs were exposed to 702 J/m² UVC for 24 h to induce apoptosis. The effect of maxadilan on ASC apoptosis was analyzed by FCM and the determination of caspase 3 and caspase 9 levels. RESULTS: Adipose-derived stem cells were confirmed by the detection of the positive expression of cell phenotypes including CD29, CD44, CD59 and CD105 by FCM. The data of CCK-8 assay revealed that ASCs treated with maxadilan (80 nmol/L) had the strongest ability of proliferation. The data of FCM also demonstrated that the addition of 80 nmol/L maxadilan to ASCs in experimental group markedly improved the proliferation capacity of the cells compared with control group (P<0.05). The apoptosis of ASCs exposed to 702 J/m² UVC was dramatically inhibited by the treatment with maxadilan (80 nmol/L). Such process involved the caspase signaling pathway including caspase 3 and caspase 9. There was statistical significance (P<0.05) between experiment group (ASCs irradiated by UVC and supplemented with maxadilan) and control group (ASCs only irradiated by UVC). Meanwhile, adipogenic and osteogenic differentiation potentials were both positive in experiment group and control group. CONCLUSION: Maxadilan promotes proliferation and inhibits apoptosis of the ASCs. The differentiation potential of ASCs toward adipogenic and osteogenic lineages wouldn't be altered by maxadilan. Maxadilan would benefit to growth and expansion of ASCs in vitro.     

Hypoxic preconditioning alleviates oxygen-glucose deprivation in PC12 cells:the involvement of autophagy

AIM: To examined the effects of hypoxic preconditioning(HPC) on oxygen-glucose deprivation(OGD)-induced PC12 cells, and to investigate its possible mechanisms of autophagy.METHODS: Cultured PC12 cells were randomly divided into control group, HPC group, 3-methyladenine(3-MA) group, HPC+OGD group, 3-MA+HPC+OGD group and OGD group. CCK-8 assay was used to detect the cell viability. The caspase-3 activity was also tested. TUNEL staining and flow cytometry were used to detect the cell apoptosis. The protein levels of apoptosis-related protein caspase-3 and autophagy-marked protein LC3-2 and beclin-1 were determined by Western blot.RESULTS: Compared with control group, the viability of PC12 cells was significantly reduced, and the activity of caspase-3 was significantly increased in OGD group. Compared with 3-MA+ HPC+OGD group and OGD group, the viability of PC12 cells was significantly increased, and the activity of caspase-3 was significantly reduced in HPC+OGD group(P<0.05). The PC12 cell injury was apparent after OGD with a great increase in the apoptotic rate(P<0.05). Compared with OGD group, the apoptotic rate significantly decreased in HPC+OGD group(P<0.05). Compared with control group, the protein level of cleaved caspase-3 was significantly increased in OGD group(P<0.05). Compared with OGD group, the protein level of cleaved caspase-3 was significantly decreased, and the levels of LC3-2 and beclin-1 were significantly increased in HPC+OGD group(P<0.05).CONCLUSION: OGD decreases cell survival and induces apoptosis.Activation of cell autophagy may be the mechanism by which hypoxic preconditioning protects the PC12 cells from OGD induced injury.     

CCK-8 up-regulats signal pathway of LPS-induced HO-1 expression in rat lungs

AIM: To study the signal pathway involved in up-regulation of LPS-induced HO-1 expression by CCK-8. METHODS: Forty-two SD rats were divided into 7 groups (six rats each) randomly as follows: control group, LPS group, LPS+SP600125 (JNK-specific inhibitor) group, CCK-8+LPS group, CCK-8+LPS+SP600125 group, CCK-8 group and CCK-8 +SP600125 group. Lungs from the rats in these 7 groups were excised 6 h after the agents were administered. HO-1 mRNA expression was examined by RT-PCR. The protein expression of HO-1 was detected by Western blotting and immunofluorescence flow cytometry (FCM). RESULTS: There were significant positive expression of HO-1 mRNA in LPS group compared to control group. CCK-8 enhanced LPS-induced HO-1 mRNA expression and CCK-8 alone induced HO-1 mRNA expression as well. The mRNA expressions of HO-1 in LPS group, CCK-8+LPS group and CCK-8 group were 3.01 (P<0.01), 5.88 (P<0.01) and 3.45 (P<0.01) times as many as that in control group, respectively. SP600125 inhibited the mRNA expression of HO-1 induced by CCK-8 and (or) LPS. The change of HO-1 protein expression was in accordance with that of HO-1 mRNA expression by Western blotting and immunofluorescence FCM. CONCLUSION: These results suggest that JNK/c-Jun signal pathway plays an important role in the up-regulation of LPS-induced HO-1 expression by CCK-8.     

Ang(1-7) attenuates palmitic acid-induced injury of Min6 cells

AIM: To investigate the effect of angiotensin (1-7)[Ang (1-7)] on palmitic acid (PA)-induced injury of Min6 cells and the potential protective mechanisms of autophagy. METHODS: Cultured Min6 cells were divided into 7 groups:control group, PA group, PA+Ang(1-7) group, PA+Ang(1-7)+A779 group, PA+Ang(1-7)+rapamycin group, Ang(1-7) group and A779 group. The function of Min6 cells was detected by glucose-stimulated insulin release test. Intracellular reactive oxygen species (ROS) production was measured by ROS assay kit. Apoptosis was analyzed by flow cytometry with Annexin V/PI staining. Autophagy-related proteins were determined by Western blot. RESULTS: Compared with control group, the secretion of insulin from Min6 cells in PA group was significantly decreased (P<0.05), and the apoptotic rate was increased (P<0.05). The ratio of LC3-Ⅱ/LC3-I was significantly increased (P<0.05). Compared with PA group, the insulin secretion in PA+Ang(1-7) group was increased (P<0.05). The intracellular ROS level and the A779 and LC3-Ⅱ/LC3-I were significantly decreased (P<0.05). This protective effect of Ang(1-7) was partially blocked by A779 and rapamycin. CONCLUSION: Ang(1-7) attenuates PA-induced Min6 cell injury, and its protective mechanism may be related to inhibiting the activity of autophagy.     

Berberine enhances mitomycin C-induced cell cycle arrest and apoptosis of T24 bladder cancer cells

AIM: To observe the effects of the combination of berberin (Ber) and mitomycin C (MMC) on the cell cycle arrest and apoptosis of T24 bladder cancer cells and the underlying mechanisms. METHODS: The T24 cells were exposed to MMC in the presence or absence of difference concentrations of Ber. The viability of the T24 cells was determined by CCK-8 assay. The cell cycle distribution was detected by flow cytometry. The apoptosis was analyzed by flow cytometry with Annexin V-FITC/PI staining, and the protein expression levels of cyclin D1, survivin, CDK2, CDK4, p21 and p27 were determined by Western blot. RESULTS: CCK-8 experiments showed that Ber enhanced the inhibitory effect of MMC on the viability of T24 cells. The results of flow cytometry showed that Ber also enhanced the blockade effect of MMC on T24 cells in G₀/G₁ phase (P<0.05). Compared with the MMC group, Ber increased the expression of p21 and p27 up-regulated by MMC, and decreased the expression of cynlin D1, CDK2 and CDK4 (P<0.05). Meanwhile, Ber promoted MMC to inhibit the expression of survivin (P<0.05). Ber increased the apoptosis of T24 cells induced by MMC (P<0.05). CONCLUSION: Ber significantly enhances the inhibitory effect of MMC on the viability of T24 cells. The mechanism may be related to up-regulation of p21 and p27, thereby inhibiting the expression of cyclin D1, CDK-2 and CDK-4. At the same time, Ber inhibits the protein expression of survivin, which eventually leads to cell arrest in G₀/G₁ phase and promotes apoptosis.     

Effects of fibulin-3 expression on malignant pleural mesothelioma cells

AIM: To observe the effects of over-expression and silencing of fibulin-3 on malignant pleural mesothelioma (MPM) cell line SMC-1, and to search for a new method for the treatment of MPM. METHODS: The vectors for fibulin-3 over-expression and short hairpin RNA (shRNA) were constructed, and control vector, fibulin-3 over-expression vector (Exp), over-expression control vector (Exp-NC), interference vector (shRNA1, shRNA2, shRNA3 and shRNA4), and interference control vector (shRNA-NC) were transfected into the SMC-1 cells. The cell cycle distribution and apoptosis were analyzed by flow cytometry. The expression of fibulin-3 before and after interference was determined by real-time PCR and Western blot. RESULTS: Compared with control group, the number of the SMC-1 cells in G₂ phase in Exp group was increased (P<0.05), while that in shRNA2 group was decreased (P<0.05). The results of apoptosis analyzed by flow cytometry showed that compared with control group, the apoptotic rate in Exp group was decreased (P<0.05), while that in shRNA2 group was increased (P<0.05). The mRNA and protein expression levels of fibulin-3 and mesothelin in Exp group were up-regulated, while those in shRNA group were down-regulated (P<0.05).CONCLUSION: The vectors for over-expression and silencing of fibulin-3 are successfully constructed, proving that transfection of Exp and shRNA effectively changes fibulin-3 expression and the SMC-1 cell growth. Fibulin-3 may be a target molecule for MPM treatment.     

Effects of TRPC1 on TGF-β1-induced migration of human bronchial epithelial cells

AIM: To investigate the role of canonical transient receptor potential channel 1 (TRPC1) in the migration of human bronchial epithelial cells (16HBE) induced by transforming growth factor-β1 (TGF-β1). METHODS: Silencing of TRPC1 gene expression was performed by siRNA. The cell activity and apoptosis were measured by CCK-8 assay and flow cytometry, respectively. The migration and invasion abilities of the 16HBE cells were detected by wound- healing assay and Transwell assay. The protein expression of E-cadherin and vimentin was determined by Western blot. RESULTS: TGF-β1 treatment significantly enhanced the cell migration distance compared with control groups (P < 0.01). The results of CCK-8 assay and flow cytometry indicated that there were no significant difference in proliferation and apoptosis among TRPC1 siRNA group, TGF-β1 group and control group (P > 0.05). The results of wound-healing and Transwell assays showed that migration and invasion abilities in TRPC1 siRNA + TGF-β1 group were markedly suppressed compared with TGF-β1 group (P < 0.01). The protein expression of E-cadherin and vimentin induced by TGF-β1 was inhibited by TRPC1 silencing compared with TGF-β1 group (P < 0.05). CONCLUSION: TRPC1 is involved in the migration of human bronchial epithelial cells induced by TGF-β1 through regulating the protein expression of E-cadherin and vimentin.     

PI3K/Akt/GSK-3β pathway mediates ABC transporter regulating multidrug resistance in human colon cancer HCT-15 cells

AIM: To investigate whether the PI3K/Akt signaling pathway regulates the expression of ABC transporter through the downstream glycogen synthase kinase-3β (GSK-3β) pathway and participates in the multidurg resistance of colorectal cancer (CRC) HCT-15 cells. METHODS: Colorectal cancer HCT-15 cells were cultured and then treated with GSK-3β inhibitor (HY-19807) and PI3K/Akt pathway inhibitor (HY-13898), respectively. The median inhibitory concentration (IC₅₀) of oxaliplatin for HCT-15 cells in each group was detected by CCK-8 assay, the inhibition rate and resistance index were also calculated. The protein levels of Akt, p-Akt, GSK-3β, p-GSK3β-Ser9 and ABC transporters P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP-2) in the HCT-15 cells were determined by Western blot. The mRNA expression of ABC transporter in the HCT-15 cells was detected by RT-qPCR. The cell cycle distributions were analyzed by flow cytometry assasy. RESULTS: After GSK-3β inhibitor HY-19807 was used in the HCT-15 cells, the median inhibitory concentration of oxaliplatin was significantly increased, the protein levels of p-GSK3β-Ser9, P-gp and MRP-2 were up-regulated compared with control group (P<0.05), the changes of Akt and p-Akt were not obvious compared with control group (P>0.05). The results of RT-qPCR also showed that the mRNA levels of ABCB1 and ABCC2 were increased (P<0.01). Meanwhile, analysis of the cell cycle distribution showed that GSK-3β inhibitor HY-19807 promoted HCT-15 cell transition from G₁ phase to S phase, and cell proliferation was vigorous. After the PI3K/Akt pathway inhibitor HY-13898 was applied to HCT-15 cells, the IC₅₀ of oxaliplatin was decreased compared with control group (P<0.05). Moreover, the protein levels of p-Akt, p-GSK3β-Ser9, P-gp and MRP-2 were down-regulated (P<0.01). RT-qPCR results also showed that the mRNA expression of ABCB1 and ABCC2 was decreased (P<0.01). At the same time, G₁ phase was prolonged, which inhibited cell transition from G₁ phase to S phase, and inhibited cell proliferation. The protein expression of total GSK-3β was consistent in each group. CONCLUSION: The PI3K/Akt signaling pathway is involved in the proliferation and multidrug resistance of colorectal cancer HCT-15 cells by regulating the phosphorylation of GSK-3β and changing the expression of ABC transporter.     

Clinical significance of miRNA-326 expression in gastric cancer and effect of up-regulation of its expression on viability and apoptosis of gastric cancer cells

AIM: To investigate the clinical significance of microRNA-326 (miRNA-326) expression in gastric carcinoma and the effect of up-regulation of its expression on the viability and apoptosis of gastric cancer cells. METHODS: The expression of miRNA-326 in 55 tissue samples of gastric cancer was detected by RT-qPCR, and the relationship between the expression and the clinicopathological features was analyzed. The expression of miRNA-326 in gastric cancer BGC-823 cells was detected by RT-qPCR. The BGC-823 cells were transfected by liposome method, and randomly divided into normal control group (untransfected), mimic-NC group (transfected with negative control mimic) and miRNA-326 mimic group (transfected with miRNA-326 mimic). After up-regulation of miRNA-326 expression, the cell viability was measured by CCK-8 assay, and the apoptosis of the cells was analyzed by flow cytometry. The protein levels of matrix metalloprotein 9 (MMP-9), p21, cyclin D1, Bcl-2 and cleaved caspase-3 were determined by Western blot, and the mRNA expression of cyclin D1 was detected by RT-qPCR. Whether CCND1 (the gene of cyclin D1) was the target gene of miRNA-326 was evaluated by dual-luciferase reporter assay. RESULTS: The expression of miRNA-326 in the gastric cancer tissues was significantly lower than that in the adjacent tissues (P<0.05). The miRNA-326 expression had a significant correlation with the tumor size, lymph node metastasis, differentiation, and clinical stages (P<0.05), but it had no correlation with the age and sex of the patients. Moreover, the expression of miRNA-326 was also closely related to the survival rate of the patients (P<0.05). The expression of miRNA-326 in the BGC-823 cells was significantly lower than that in the normal gastric mucosa GES-1 cells (P<0.05). Compared with normal control group, the expression of miRNA-326 in mimic-NC group did not change significantly, while that in miRNA-326 mimic group was increased significantly (P<0.05). Compared with normal control group, the cell viability in miRNA-326 mimic group was significantly decreased, and the apoptosis was increased (P<0.05). In addition, compared with normal control group, the protein levels of MMP-9, cyclin D1 and Bcl-2, and the mRNA expression of cyclin D1 in miRNA-326 mimic group were decreased, while the protein levels of p21 and cleaved caspase-3 were increased (P<0.05). However, no significant difference of above protein and mRNA levels between mimic-NC group and normal control group was observed. Compared with mimic-NC+miR-326 mimic group, the activity of luciferase in the cells transfected with pmiR-CCND1-WT plasmid was significantly decreased (P<0.05), but that in the cells transfected with pmiR-CCND1-Mut plasmid did not change significantly. CONCLUSION: The expression level of miRNA-326 in gastric cancer tissues is low, and it may promote cell viability and inhibit cell apoptosis by targeting CCND1.     

miRNA-101-3p inhibits proliferation and migration of gastric cancer cells by targeting EZH2

AIM: To investigate the role of microRNA-101-3p (miRNA-101-3p) on the proliferation, apoptosis and invasion of gastric cancer cells and the possible regulatory mechanisms. METHODS: The expression of miRNA-101-3p in two kinds of gastric cancer cells and a gastric mucosal cell line was detected by real-time PCR. The miRNA-101-3p was overexpressed by Lipofectamine 2000 transfection with miRNA-101-3p mimics. The effects of miRNA-101-3p on cell cycle distribution and apoptosis were analyzed by flow cytometry. The effects of miRNA-101-3p on cell proliferation and migration abilities were detected by CCK-8 assay, trypan blue exclusion test and Transwell assay. The protein expression of enhancer of zeste homolog 2 (EZH2) was determined by Western blot. RESULTS: The expression of miRNA-101-3p in gastric cancer cells was lower than that in gastric mucosal cells (P<0.05). The gastric cancer cell MGC-803 had the lowest expression level of miRNA-101-3p. The result of flow cytometry showed that the population of S phase was reduced, and the population of G₀/G₁ phase and the early stage apoptotic rate were increased after the expression of miRNA-101-3p was overexpressed (P<0.05). The results of CCK-8 assay, trypan blue exclusion test and Transwell assay showed that overexpression of miRNA-101-3p significantly reduced the proliferation and migration abilities of gastric cancer cells (P<0.05). Overexpression of miRNA-101-3p decreased the protein level of EZH2 (P<0.05). CONCLUSION: miRNA-101-3p may suppresses the gastric cancer cell proliferation and migration, and promotes the gastric cancer cell apotosis by down-regulation of EZH2.     

Effects of marrow stromal cell-mediated microenvironment on human hepatocellular carcinoma cell line SMMC-7721

AIM: To investigate the effects of marrow stromal HS-5 cells on hepatocellular carcinoma SMMC-7721 cells in the tumor microenvironment. METHODS: The effects of HS-5 cell-conditioned medium (HS-5-CM) on the proliferation, migration and invasion abilities of SMMC-7721 cells were detected by MTT, wound-healing and Transwell assays. After co-culture of SMMC-7721 cells with HS-5 cells in the Transwell chamber, the expression of chemokine CCL5 and its receptor CCR5 at mRNA and protein levels in SMMC-7721 cells was examined by quantitative real-time PCR (qRT-PCR), ELISA or Western blotting. Akt and p-Akt473 protein levels in SMMC-7721 cells treated with PI3K inhibitor LY294002 were observed by Western blotting. RESULTS: HS-5-CM promoted the proliferation, migration and invasion abilities of SMMC-7721 cells. The expression of CCL5 and CCR5 at mRNA and protein levels in SMMC-7721 cells was increased after co-cultured with HS-5 cells. PI3K inhibitor LY294002 inhibited the activation of PI3K-Akt signaling pathway and the secretion of CCL5 in SMMC-7721 cells after co-cultured with HS-5 cells. CONCLUSION: HS-5 cells significantly promote the proliferation, migration and invasion abilities of SMMC-7721 cells. Co-culture of SMMC-7721 cells with HS-5 cells activates PI3K-Akt signaling pathway to increase the secretion of CCL5 in SMMC-7721 cells.     

Effect of biological clock gene Timeless silencing on apoptosis and invasion of ovarian cancer SKOV3 cells

AIM:To evaluate the effect of biological clock gene Timeless (TIM) silencing on the apoptosis and invasion ability of human ovarian cancer SKOV3 cells. METHODS:The protein expression of TIM in the ovarian cancer tissues and normal ovarian tissues was detected by immunohistochemistry, and the correlation between the protein expression of TIM in ovarian cancer tissues and the pathological features was analyzed. The ovarian cancer SKOV3 cells were transfected with PBS (blank control group), control siRNA (siRNA control group) or TIM siRNA (TIM siRNA group). The protein expression of TIM, Bcl-2, Bax, MMP-2, MMP-9, caspase-3 and caspase-9 was determined by Western blot. The apoptosis was detected by flow cytometry. The invasion ability was measured by Transwell chamber test. RESULTS:The positive expression rate of TIM in the ovarian cancer tissues (84.0%) was significantly higher than that in the normal ovarian tissues (10.0%; P<0.01). TIM expression was associated with ovarian cancer differentiation, depth of invasion, lymph node metastasis and TNM stage (P<0.05), but was not associated with age and pathological type (P>0.05). The protein expression levels of TIM, MMP-2, MMP-9 and Bcl-2 in TIM siRNA group were significantly decreased as compared with control group and siRNA control group (P<0.01), and the protein expression of Bax, caspase-3 and caspase-9 in TIM siRNA group was significantly increased as compared with blank control group and siRNA control group (P<0.01). No significant difference of the protein expression of TIM, MMP-2, MMP-9, Bcl-2, Bax, caspase-3 and caspase-9 between blank control group and siRNA control group was observed (P>0.05). The apoptotic rate in TIM siRNA group was significantly higher than that in blank control group and siRNA control group (P<0.01), and that in blank control group and siRNA control group was not significantly different (P>0.05). The penetrated cell number in TIM siRNA group was significantly less than that in blank control group and siRNA control group (P<0.01), and that in blank control group and siRNA control group was not significantly different (P>0.05). CONCLUSION:Silencing of TIM gene in ovarian cancer SKOV3 cells by siRNA promotes apoptosis, and inhibits cell invasion.