ObjectiveTo explore the effects of silencing the expression of ubiquitin-conjugating enzyme E2T (UBE2T) gene on proliferation, apoptosis, migration and invasion abilities of A549 cells.MethodsA549 cells were cultured in vitro. Three sets of shRNA-UBE2T plasmid vectors (UBE2T-shRNA1 group, UBE2T-shRNA2 group, UBE2T-shRNA3 group) and shRNA-NC (shRNA-NC group) were constructed, respectively. A549 cells were transfected with lipofection transfection. The cells transfected with empty vector were enrolled as control (control group). The transfection efficiency was detected by RT-PCR. The effects of silencing the expression of UBE2T gene on biological behaviors (proliferation, apoptosis, migration, and invasion) of lung cancer A549 cells were detected by clone formation assay, flow cytometry, Transwell assay and scratch test. The expression of proliferation and apoptosis related proteins, and expression of PI3K/AKT signaling pathway proteins were detected by Western blot. ResultsAfter transfection, expression level of UBE2T mRNA in UBE2T-shRNA1 group, UBE2T-shRNA2 group and UBE2T-shRNA3 group was significantly down-regulated (all P<0.05), whose down-regulation was the most significant in UBE2T-shRNA3 group (P<0.05). Compared with control group and shRNA-NC group, clone formation rate, number of invasion A549 cells, scratch healing rate, Ki67 expression, PCNA expression, p-PI3K/PI3K ratio and p-AKT/AKT ratio were significantly decreased in UBE2T-shRNA3 group (P<0.05), while A549 apoptosis rate, Bax/Bcl-2 ratio and cleaved caspase-3/caspase-3 ratio were significantly increased (P<0.05). There were no significant differences in the above indexes between control group and shRNA-NC group (P>0.05). ConclusionsThe shRNA interfering with UBE2T is reliable to construct the model of A549 cells with stable low-expression UBE2T. Down-regulation of UBE2T expression can promote apoptosis of A549 cells, inhibit their proliferation, invasion and migration abilities. The mechanism may be related to inhibiting the activation of PI3K/AKT signaling pathway.
【 Abstract 】 Objective Overexpressions of epidermal growth factor (EGF) and EGF receptor have been associated with progression and invasive phenotype of pancreatic cancer. However, the underlying molecular mechanism by which EGF worked in pancreatic cancer cells has not been completely understood. In this study, effect of EGF on the invasion and metastasis of pancreatic cancer cells and its regulatory mechanism were investigated. Methods The effects of EGF on the proliferation, adhesion and invasion of pancreatic cancer cells were detected by WST-1 proliferation assay, adhesion assay and invasive assay, respectively. The activity and expression of MMP-2 and MMP-9 were examined by zymography, Western blot and RT-PCR, respectively. The activity of NF- κ B was examined by EMSA. Results EGF could significantly promote the invasiveness of pancreatic cancer cells but did not affect cell proliferation or adhesion. The expressions of NF- κ B and MMP-9 were significantly increased by EGF, but EGF did not affect the activity and expression of MMP-2. Furthermore, EGF stimulated the NF- κ B binding activity. Pretreatment with NF- κ B inhibitors, pyrrolidine dithiocarbamate (PDTC), could significantly inhibit the activity of NF- κ B induced by EGF. Meanwhile, the EGF-induced expression and activity of MMP-9, as well as cell invasiveness were also inhibited by NF- κ B inhibitor. Conclusion EGF could increase the expression and promote the invasiveness of MMP-9 via the activation of NF- κ B in pancreatic cancer cells, which implies that NF- κ B inhibitant, such as PDTC, may diminish the invasiveness of pancreatic cancer cells.
Objective To study the expressions of Wnt5a, MMP2, and MMP14 in the primary lesions of gastric cancer and the influences on clinicopathologic features. Methods The expressions of Wnt5a, MMP2, and MMP14 in the specimens of 106 patients with gastric cancer and 39 patients from the adjacent normal gastric tissues were detected by immunohistochemical staining, χ2 test and non-parametric test were used to analyze the relationships among them and between them and their influences on the clinicopathologic features. Results Extensive expressions of Wnt5a, MMP2, and MMP14 were demonstrated in the gastric cancer, which were significantly higher than those in the normal gastric tissues respectively (Plt;0.05). Positive expression of Wnt5a was associated with larger tumor diameter, deeper depth of invasion, higher degree of regional lymph node metastasis, later TNM stage, and higher rate of lymph node metastasis (Plt;0.05). In addition, Wnt5a expression was also associated with lymphatic infiltration and vascular infiltration (Plt;0.05). The expressions of MMP2 and MMP14 were associated with lymphatic infiltration, but not with vascular infiltration. Higher expressions of MMP2 and MMP14 were correlated with deeper tumor invasion, higher degree of regional lymph node metastasis, later TNM stage, and higher rate of lymph node metastasis (Plt;0.05). In addition, higher expression of MMP2 possesed greater tumor diameter (Plt;0.05). Spearman rank correlation analysis revealed the positive relation between Wnt5a and MMP2 （rs=0.240, P=0.014）, Wnt5a and MMP14 （rs=0.251, P=0.010）, as well as MMP2 and MMP14 （rs=0.444, P=0.000）. Conclusion Higher expressions of Wnt5a, MMP2, and MMP14 seem to promote invasion and metastasis of gastric cancer, and there are positive relations among their expressions.
Objective To detect the expression of KiSS-1 protein in papillary thyroid carcinoma, and to analyze its significance. Methods Paraffin-embedded specimens of 32 patients with thyroid papillary carcinoma and its adjacent cancer tissues were included in this study. Then the expression of KiSS-1 protein was detected by munohistochemistry and its relationship with clinical pathological features was analyzed. Results KiSS-1 protein mainly expressed in the cell membrane and cytoplasm. The expression of KiSS-1 protein was positive in adjacent tissues, but decreased or absent in cancer tissues in 32 patients. In the latter, there were 11 cases with positive expression (34.4%) and 21 cases with negative expression (65.6%), and the difference was statistically significant (χ2=31.256, Plt;0.001). The average value of KiSS-1 protein expression represented by absorbance (A) value (119.595 2) in cancer tissues was higher than that in adjacent tissues (174.805 0), t=34.429, Plt;0.001. The expression of KiSS-1 protein in cancer tissues was not related to patient gender (P=0.618) and age (P=0.061), but except TNM staging (P=0.034). The expression rate of KiSS-1 protein in cancer tissues with lymph node metastasis (4/4, 100%) was significantly higher than that without lymph node metastasis (7/28, 25.0%)， P=0.003. Conclusion The expression of KiSS-1 protein is decreased or absent in papillary thyroid carcinoma, which may be involved in tumorigenesis, invasion, and metastasis.
Objective To observe the effect of epidermal growth factor (EGF) on the proliferation, adhesion, invasiveness and the activation of nuclear factor-κB (NF-κB), matrix metalloproteinases (MMPs) expression and explore related mechanisms in pancreatic cancer cells. Methods Cell invasion assay, proliferation assay and adhesion assay were used to examine the proliferation, adhesion and invasiveness of pancreatic cancer cells, respectively. NF-κB activity was detected by electrophoretic mobility shift assay (EMSA), and MMPs protein and mRNA expressions were investigated by gelatin zymography, Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Results EGF increased the invasiveness of pancreatic cancer cell in a dose-dependent manner (P＜0.05), but did not affect cell proliferation or adhesion. The expressions of MMP-9 mRNA and protein significantly increased after induction by EGF and were highest when EGF concentration was 50 ng/ml, while there was no effect on the expressions of MMP-2 mRNA and protein. Furthermore, NF-κB activity increased with increased concentration of EGF in a concentration-dependent manner (P＜0.05). In addition, NF-κB activity and the expressions of MMP-9 mRNA and protein by pretreatment with both pyrrolidine dithiocarbamate (PDTC) and EGF decreased when compared that by pretreatment with EGF alone. The invasiveness of pancreatic cancer cell by pretreatment with both PDTC and EGF decreased when compared that by pretreatment with EGF alone and nothing (P＜0.05).Conclusion The findings indicate that the NF-κB-mediated MMP-9 induction is essential for EGF-induced invasiveness in pancreatic cancer cells, which can be inhibited by PDTC.
Objective To explore the effect of interfering RNA (shRNA) on biological activity of A549 cells and tumor growth in nude mice after knockdown of estrogen receptor α (ERα) gene. Methods The ERα gene in A549 cells was knocked down by shRNA. RT-PCR and Western blot were used to detect the gene expression and protein expression after knockdown; colony formation experiment was used to detect the proliferation of cells, and RT-PCR was used to detect the expression of Ki-67 and PCNA; flow cytometry was used to detect apoptosis rate; transwell assay was used to detect cell invasion ability; Western blot was used to detect the expression of epithelial cadherin (E-cad) and neuropathic cadherin (N-cad) protein. The control group and A549 cells transfected with ERα-shRNA1 were injected subcutaneously in nude mice to construct transplanted tumors. Immunohistochemistry was used to detect the expression of Ki-67 and N-cad in tumor tissues. Results Compared with the control group, after transfection of ERα-shRNA1 and ERα-shRNA2, the mRNA and protein expressions of ERα were reduced significantly (P<0.05), and shRNA1 with high interference efficiency was used for subsequent experiments. Compared with the control group, the A549 cells were transfected with ERα-shRNA1, the colony formation rate was down-regulated significantly (P<0.05), the apoptosis rate was increased significantly (P<0.05), the expression of Ki-67 and PCNA were down-regulated significantly (P<0.05), the number of invasive cells was reduced significantly, the expression of E-cad was increased, and the expression of N-cad was decreased (P<0.05). The results of tumor formation in nude mice showed that interfering with ERα expression can significantly inhibit tumor growth (P<0.05), and down-regulate the rate of Ki-67 and N-cad positive cells (P<0.05). Conclusion Knockdown of ERα inhibits the proliferation and migration ability of NSCLC cells and the occurrence and development of transplanted tumors in nude mice.
ObjectiveTo study the expression of matrilysin in gastric cancer and to evaluate the correlation between its expression and invasion, metastasis, and prognosis. MethodsA total of 52 patients with gastric cancer were selected and followed up. The expressions of matrilysin in gastric primary focus, normal gastric mucosa, and metastatic lymph nodes were examined by reverse transcriptionpolymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry, respectively. The correlations between matrilysin expression and tumor invasion, metastasis, and prognosis were assessed. ResultsThe expressions of matrilysin in gastric primary focus and metastatic lymph nodes significantly increased, while decreased or loss in normal gastric mucosa (Plt;0.001). The higher concordance was seen between the levels of mRNA and protein (Plt;0.001). Among patients with infiltrating type, penetrated serosa, area of serosa involved more than 20 cm2, and metastatic lymph nodes more than 7, the expression of matrilysin was significantly higher (Plt;0.01). The survival rate of patients with matrilysin higher expression (34.1%) was significantly lower than that with matrilysin lower expression (55.6%), χ2=9.778， P=0.002. Conclusions Up-regulated expression of matrilysin plays an important role in tumor invasion, metastasis, and poor prognosis, and it is a good molecular marker to reflect the biological behaviors of gastric cancer.
ObjectiveTo study the expression of c-Met in colorectal carcinoma cells and the effect of hepatocyte growth factor (HGF) on proliferation and invasion of colon carcinoma cells SW480.
MethodsReal-time PCR and Western blot methods were respectively used to detect the expressions of c-Met mRNA and protein in the different colorectal carcinoma cells in order to screen the high c-Met expression cells. The SW480 cells were incubated with different concentrations (0, 20, 40, and 70 ng/mL) HGF. MTT assay and Transwell test were used to evaluate the effects of proliferation and invasion in the SW480 cells.
Results①The c-Met was expressed in each colorectal carcinomar cells, especially highly expressed in the colon carcinoma cells SW480 in vitro.②MTT assay showed that the HGF could promote the proliferation of SW480 cells in a dose-dependent manner with some extent.③Transwell test showed that the HGF could increase the invasion of SW480 cells.
ConclusionThe c-Met is highly expressed in colorectal carcinoma cells and HGF could promote proliferation and increase invasion of colorectal carcinoma cells in vitro.
ObjectiveTo explore the expression of MSI2 in gastric cancer and its association with clinical significance.
MethodsThe expression level of MSI2 mRNA in gastric cancer tissues and para-carcinoma tissues was detected by Real-time PCR to explore its clinical significance. The expression level of MSI2 protein was detected by Western blotting. The prognosis of patients with the ratio of MSI2 mRNA expression level in gastric cancer tissues and adjacent normal tissues was more than 2 times and below 2 times were compared.
ResultsThere was no significant difference between the expressions of MSI2 mRNA in cancer tissues and para-carcinoma tissues(P > 0.05). The expression level of MSI2 mRNA were associated with the invasion depth (P=0.017), TNM stage (P=0.028), differentiation (P=0.020), and size (P=0.030) of tumor, but no association with other clinical factors such as gender, age, and location were found. The overall survival of the patients with high expression of MSI2 mRNA was significantly shorter than that of the patients with low expression of MSI2 mRNA (χ2=4.221, P=0.040).
ConclusionMSI2 expression is associated with the gastric cancer invasion, TNM stage and differentiation, and the patients with higher expression of MSI2 mRNA have poor prognosis, which makes it possible to be a potential therapeutic target.
ObjectiveTo explore the influence mechanism of proliferation and invasion in colon cancer cell after silence of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) gene.
MethodsRT-PCR or Western blot method was used to detect the expression of PTEN mRNA or protein among four colon cancer cell lines (HT-29, WiDr, CaCo-2, and Colo320 cell lines). small interfering RNA (siRNA) was used to synthetize PTEN siRNA and transfect it into colon cancer cells. The expression of PTEN protein after transfecting was detected by Western blot. WsT-1 and invasion assay were used to examine the effects of PTEN siRNA silence on proliferation and invasion in colon cancer cells.
ResultsPTEN mRNA and protein were expressed in all the four colon cancer cell lines. After PTEN siRNA transfected into the colon cancer cells, the expressions of PTEN proteins were inhibited in all the four colon cancer cell lines (P < 0.01), and the proliferation and invasion of colon cancer cells were enhanced significantly (P < 0.01).
ConclusionsPTEN siRNA play an important role in metastasis process of colon cancer via enhanced its proliferation and invasion. Therefore, the understanding biologic mechanisms for regulation of PTEN might enable better molecular target therapy of treating the colon cancer patients with metastasis.
