Objective To summarize the roles of tumor initiating cells （TICs） and epithelial-mesenchymal transition （EMT） in tumor metastasis and drug resistance. Methods Domestic and international publications online which involving TICs，EMT，and its roles in tumor metastasis and drug resistance in recent years were reviewed. Results TICs were self-renewal cells and had the ability to give rise to more differentiated cell types，and played an important role in tumor metastasis and drug resistance. Various markers had been used to identify TICs，such as CD133，CD44，and so on. EMT was the process by which epithelial cells losed polarity and detach from the epithelial sheet， and acquired a motile mesenchymal phenotype，usually observed in embryo development and wound healing. It also could promote tumor progression and metastasis，and may also be responsible for the ability of tumors to evade the body’s immune response. EMT may be the reasons of TICs that drived tumor metastasis and recurrence. TICs or EMT as a target for treatments may effectively prevent tumor recurrence and improve patient’s survival. Conclusions EMT is probably the mechanism that TICs promote tumor metastasis and drug resistance. More effective target therapies for cancer may be found if we know more about TICs and EMT.
Objective To examine the effects of TGF-β1 on epithelial-myofibroblast transition ( EMT) of A549 cells and its relationship with extracellular regulating kinase1/2 ( ERK1/2) signaling system. Methods Cultured A549 cells were divided into one negative control group and four groups incubated with TGF-β1 for 48 hours at different concentration ( 0.05, 0. 5, 5, 10 μg/L, respectively) . The protein expressions of E-cadherin, α-smooth muscle actin ( α-SMA) , vimentin and fibronectin were assessed by indirect immunofluorescence and Western blot. In the other experiment, cultured A549 cells were incubated with TGF-β1 for different time. The protein and mRNA expressions of E-cadherin and α-SMA were assessed by Western blot and RT-PCR. The protein expressions of vimentin, fibronectin, ERK1 /2, and p-ERK1 /2 were detected by Western blot. Results By indirect immunofluorescence, Western blot, and RT-PCR analysis, E-cadherin expression significantly decreased and α-SMA expression significantly increased in A549 cells treated with TGF-β1 compared with negative controls in a time- and concentrationdependent manner ( Plt;0.05 ) . Vimentin and fibronectin protein expressions significantly increased simultaneously ( Plt;0.05) . The concentration of 5 ng/mL of TGF-β1 was most effective. The ratio of p-ERK1 /2 and ERK1/2 was significantly increased in the TGF-β1 treated cells in a time-dependent manner ( P lt;0. 05) . Conclusions TGF-β1 can induced EMT in A549 cells in vitro in a time- and concentrationdependant manner. This effect may involve in upregulation of ERK1/2 signaling system.
Objective To investigate the structure characteristics， functions， and research progress of Notch signaling pathway in digestive tumors. Methods The related literatures about the molecular genetic mechanism of Notch signaling pathway were reviewed. Results The Notch signaling pathway plays an important role not only in normal cells’ growth， differentiation， proliferation， and apoptosis but also in a variety of tumors’ occurrence and development. Conclusion The reasonable regulation to Notch signaling pathway may open up new ways to the treatment of the tumor.
Objective To investigate the prognostic value of epithelial-mesenchymal transition （EMT） related proteins （Snail， E-cadherin， and N-cadherin） in gastric cancer and its relationship with tumor initiating cells （TICs） marker （CD133）. Methods The expressions of EMT-related proteins and CD133 protein in the gastric cancer tissues and normal gastric mucosa tissues adjacent to gastric cancer were detected by Western blot method. The relations between the expressions of EMT-related factors proteins and CD133 protein and the clinicopathologic characters were analyzed. The correlations between EMT-related factors and CD133 were analyzed by Spearman. The correlations between EMT-related factors expressions and CD133 expression and survival were analyzed by Kaplan-Meier method and Log-rank test. Results ① The protein expression levels of Snail， N-cadherin， and CD133 in the gastric cancer tissues were significantly higher than those in the normal gastric mucosa tissues adjacent to gastric cancer （Snail：0.599±0.114 versus 0.259±0.108， P=0.020；N-cadherin：0.754±0.154 versus 0.329±0.134， P=0.001；CD133：0.635±0.119 versus 0.485±0.116， P=0.029）， while the protein expression level of E-cadherin was lower than that in the normal gastric mucosa tissues adjacent to gastric cancer （0.378±0.123 versus 0.752±0.156， P=0.003）.② The expression levels of Snail and N-cadherin in the gastric cancer patients with vascular invasion， lymphatic vessel invasion，N3 lymph node metastasis， diameter more than 5 cm， and Ⅲ＋Ⅳ staging were significantly higher than those in the patients without vascular invasion， lymphatic vessel invasion， N0-N2 lymph node metastasis， diameter less than 5 cm， andⅠ＋Ⅱ staging（P＜0.05）， while E-cadherin protein expression was lower than that in the patients without vascular invasion， lymphatic vessel invasion， N0-N2 lymph nodes metastasis， andⅠ＋Ⅱstaging （P＜0.05）. The expression levels of CD133 in the gastric cancer patients with lymphatic vessel invasion， diameter more than 5 cm， and Ⅲ＋Ⅳ staging were significantly higher than those in the patients without lymphatic vessel invasion， diameter less than 5 cm， andⅠ＋Ⅱ staging （P＜0.05）. ③The Snail and N-cadherin protein expressions were significantly positive correlated with CD133 protein expression， respectively （rs=0.278， P=0.048；rs=0.406， P=0.003）， while E-cadherin protein expression was significantly negative correlated with CD133 protein expression （rs=-0.504， P=0.000）.④ The survival time in the patients with lower expressions of Snail， N-cadherin， and CD133 were significantly longer than those in the patients with higher expressions of Snail， N-cadherin， and CD133 （P＜0.05）. The combination of Snail， N-cadherin， E-cadherin， and CD133 could effectively predict survival. Conclusions There is a significant correlation between EMT and gastric cancer TICs， and which are correlated with aggressive clinicopathologic features of gastric cancer. The combination of Snail， E-cadherin， N-cadherin， and CD133 may be effectively predict the prognosis of gastric cancer patients.
ObjectiveTo summarize the role of epithelial-mesenchymal-transition （EMT） in occurrence and development of gastrointestinal cancer. MethodsDomestic and international publications online involving EMT of gastrointestinal cancer in recent years were collected and reviewed. ResultsEMT was a highly conserved process that has been well characterised in embryogenesis. Studies had shown that the aberrant activation of EMT in adult epithelia could promote tumour metastasis by repressing cell adhesion molecules. E-cadherin， one of the epithelial cell markers, maybe involved in the process of the EMT, especially of the Ecadherin transcriptional repressors， these transcriptional repressors significantly increased in the gastrointestinal cancer. Further more， EMT might involve in the process of gastrointestinal cancer stem cells formation. ConclusionsEMT and it’s regulators play a very important role in gastrointestinal cancer， and may provide a newsight into the gastrointestinal cancer. It also can provide a novel clinical targets to treat the gastrointestinal cancer.
ObjectiveTo understand research progress of influence of claudins on proliferation and activation for breast cancer. MethodThe relevant literatures of influence of claudins on proliferation and activation for breast cancer were retrieved and reviewed. ResultsThe claudins had 24 members in mammals,claudin-13 was missing in human beings.Expression and distribution mode of the claudins possessed highly tissue-specific,and multiple proteins were expressed in many organizations.The expressions of claudins could be regulated from the levels of transcription and post-transcription,coordinately regulated by the transcription factor and post-synthetic modifications.Claudins were related to epithelial-mesenchymal transition.Now the studies were relatively clear those focused on claudin-1,-2,-4,-6,and other subtypes,and the expression of claudin-1 indicated the poor prognosis of tumor;claudin-2 was closely related to liver metastasis of breast cancer;claudin-4 was closely related to triple negative breast cancer;the function of claudin-6 in the breast cancer was controversial.In addition to the claudins mentioned above,other claudin members also played certain roles in normal breast and malignant breast tumors.Claudin-5 might participate in metastasis of breast cancer through N-WASP and ROCK signal pathway;CD-24 and claudin-7 immunodepression had a certain guiding significance on prognosis of invasive ductal carcinoma;the expressions of claudin-16 and HAPLN3 gene were remarkably increased in human breast cancer;Claudin-20 induced breast cancer cells into a subtype that possessed the high invasiveness and weakened the resis-tance of epithelial-mesenchymal transition.Recently,the claudin-low subtype was proposed,and it differed from other types of breast cancer in many aspects,and also it had a better prognosis than other types of triple negative breast cancer. ConclusionsClaudin,being an important member of tight junction protein,is confirmed to be related to epithelial-mesenchymal transition.Claudins play important roles in dissociaton,activation,invasiveness,and metastasis of breast cancer,but there is no final conclusion which member contributes to invasiveness and metastasis of breast cancer.Moreover,there are opposite conclusions on some certain claudins members in breast cancer which might due to the different subtypes of breast cancer,so,further studies about the function of claudins in different subtypes are needed eagerly.
ObjectiveTo explore the effectiveness of Ovol2 gene for epithelial-mesenchymal transition (EMT) to offer some theory evidences for the targeted therapy in lung adenocarcinoma. MethodsA549 cells were treated with control and Ovol2 overexpressioned by lentivirus infection. Real-time PCR were performed to test the mRNA level of genes correlated to EMT. Western Blot was performed for protein level of the following makers:E-cadherin, N-cadherin, vimentin, ect. Moreover, we tested the migration and invasion ability of A549 cells by transwell and wound healing experiment. ResultsAfter treated with Ovol2 overexpressed, the expression level of E-cadherin raised, while the expression level of N-cadherin, vimentin and Twist1 declined in both mRNA and protein expression level. The results of wound healing and transwell experiment indicated that the migration and invasion ability of A549 cells weakened. ConclusionOverexpression of Ovol2 gene can suppress the distant metastasis ability and invasion ability of A549 cells by inhibiting the EMT.
ObjectiveTo investigate the role of GOLPH3 in esophageal squamous cell carcinoma (ESCC). MethodsWound healing assays, transwell invasion assays and 3D culture were carried out to analyze the cell migration and invasion ability of GOLPH3 overexpression and knockdown KYSE-140 cells. The relationship between GOLPH3 expression and CYR61, CD44 and Snail mRNA expression was further examined through qRT-PCR, to identify the mechanisms involved. ResultsGOLPH3-promoted ESCC cell migration and invasion. CYR61, CD44 and Snail mRNA expression levels were correlated with GOLPH3 protein expression level. ConclusionGOLPH3 overexpression promotes ESCC metastasis through epithelial-mesenchymal transition (EMT), and plays an oncogenesis role in ESCC.
ObjectiveTo systematically review the prognostic value of E-cadherin expression in stage I non-small cell lung cancer (NSCLC). MethodsDatabases including PubMed, EMbase, The Cochrane Library (Issue 1, 2015), CNKI, CBM and WanFang Data were searched to collect cohort studies about the prognostic value of E-cadherin expression in stage I NSCLC from inception to Jun. 2015. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then meta-analysis was performed by using RevMan 5.3 software. ResultsA total of 9 cohort studies, involving 1028 patients were included. The results of meta-analysis showed that, the lower E-cadherin expression group had a lower overall survival rate than that of the higher E-cadherin expression group (HR=1.74, 95%CI 1.36 to 2.24, P＜0.00001). However, there was no significant difference between two groups in disease free survival (HR=2.08, 95%CI 0.8 to 5.40, P=0.13). Subgroup analysis showed that, the lower E-cadherin expression group had a worse overall survival when groups were divided by different cut-off values, E-cadherin location site or different nations (all value P＜0.05). ConclusionCurrent evidence shows that, reduced E-cadherin expression could predict poor prognostic outcome in patients with stage I NSCLC. Due to the limited quantity and quality of included studies, the above conclusions need to be verified by more high quality studies.
ObjectiveTo investigate the influence of hypoxia on pro-metastasis induced by epithelial-mesenchymal transition (EMT) of human lung adenocarcinoma. MethodsThe human lung cancer cell line H460 was cultured in hypoxic condition and the morphologic changes of the cells were observed under the microscope. The EMT-related markers including E-cadherin and vimentin were detected by Western blot. Transwell migration assay and transwell invasion assay were employed to detect the migratory and invasive activity of cancer cells. ResultsHypoxic induced morphological changes were consistent with the mesenchymal phenotype, such as an elongated fibroblastic morphology, and conversion from a tightly packed epithelial cobblestone pattern to a loosely packed scattered phenotype. Compared with the control group, hypoxic attenuated the quantity of E-cadhenrin, but increased vimentin, which resulted in promotion of migration and invasion of H460. ConclusionHypoxia induces EMT in H460 and enhances the invasive and migratory abilities of lung cancer cells.