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Objective To explore the role of integrin αvβ6 in mediating the tolerance of gastric cancer AGS cells to 5-fluorouracil, and to determine whether direct β6-extracellular signal-regulated protein kinase(ERK) binding is involved. Methods Gastric cancer AGS cells in the logarithmic phase were incubated with either 5-fluorouracil for 24 hours ( control group), with 0.1 g/L of mouse anti-αvβ6 monoclonal antibody 10D5 for 6 hours and then with 5-fluorouracil for24 hours ( 10D5 group), with IgG2a and 5-fluorouracil ( IgG2a group), or with 5-fluorouracil and 20 μnol/L of ERK inhibitor PD98059 for 24 hours ( PD98059 group). Cell proliferation,apoptosis and the expression of Bcl-2 and caspase-3 protein were detected by MTT assay, flow cytometry and western blotting, respectively. All data were analysed by one-way analysis of variance and LSD test. Results The cell inhibition rates of the control group, 10D5 group, IgG2a group and PD98059 group were 28.1% ±2.7%,84.5% ± 1.6%, 31.4% ±5.2%, 86.7% ±5.2%, respectively, with a significant difference ( F = 342. 5, P ＜0.05). The apoptosis rates of the control group, 10D5 group, IgG2a group, and PD98059 group were 6.6% ±1.4%, 30.6% ± 2.4%, 8.1% ± 1.3%, 36.0% ±4.0%, respectively, with a significant difference among the four groups (F = 105.4, P ＜0.05 ). There was a significant difference in the expression of caspase-3 and Bcl-2 among the four groups (F=292.1, 181.6, P＜0.05). Conclusion Integrin αvβ6 can mediate the tolerance of gastric cancer AGS cells to 5-fluorouracil through direct β6-ERK binding.
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Objective To investigate the roles of integrin ανβ6 in the invasion of colon cancer cells and its molecular mechanisms for regulation of the extracellular matrix (ECM) degradation.Methods The RNA interfering technique was used to downregulate the expression of ανβ6 in colon cancer cells. The expression of ανβ6 in transfected cells was determined by RT-PCR and Western blot.The cell invasive capacity was evaluated by reconstituted basement membrane invasion assay. Western blot and gelatin zymography were used to determine whether the reduced αvβ6 expression affects extracellular signal-regulated kinase (ERK), P-ERK, urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs) expressions. [3H]-labelled type Ⅳ collagen degradation assay was performed to asess if supression of integrin ανβ6 inhibits extracellular matrix degradation.Results Specific siRNA inhibited the expression of ανβ6 in both the protein and mRNA levels in HT29 cells. Down regulation of integrin ανβ6 inhibited ERK, P-ERK1/2 expressions, and the secretion of uPA. pro-MMP-9 and pro-MMP-2 in tumor conditioned medium. Supression of integrin ανβ6 inhibited MAPK dependent [3H]-labelled type Ⅳ collagen degradation. Conclusions These data in our study demonstrats that integrin ανβ6 plays important roles in the invasion of colon cancer cells. The ανβ6 regulates the secretion levels of uPA, pro-MMP-9, pro-MMP-2 and the ECM degradation through the MAPK pathway.
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Objective:To investigate the feasibility and safety of a new method of natural orifice transluminal endoscopic surgery(NOTES) -totally transtracheal endoscopic thyroidectomy(TTET) .Methods:Three miniature swines and 6 beagle dogs were underwent TTET.Under general anesthesia,special designed endotracheal tube with 2-channel was used and endoscope and instruments were inserted through the respective channel.Incision of tracheal anterior wall was accomplished and partial or subtotal thyroidectomy was performed.Finally,the defects in the trachea were sutured with ENDO STITCH instrument.Results:Partial thyroidectomy was successfully accomplished on 3 pigs and subtotal thyroidectomy was done on 6 dogs.No serious complications such as anoxia,asphyxia,airway obstruction and death occurred during the operation.Animals were sacrificed 2h after the procedure and incision of trachea was found to be closely sutured.There were no subcutaneous emphysema and haematoma formation.Conclusion:Preliminary experimental results showed the feasibility and safety of TTET.Transtracheal access maintains the integrity of cervical tissues and achieves an optimal cosmetic outcome.TTET may open up a new field of NOTES on thyroid surgery.
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Objective To investigate the inducing effect of acitrotin on the growth and apoptosis of human cutaneous squamous cell carcinoma cell line SCC13 and on caspases expression.Methods Human cutaneous squa-mous cell carcinoma cell line SCC13 was treated with five different concentrations of acitrefin [5×10-7,1×10-6,5×10-6,1×10-5,5×10-5mol/L].Cell proliferation was evaluated by MTT assay.Apoptosis was assessed by en-zyme-linked immunosorbent assay.The cell cycle was assessed by flow cytometry.The protein expressions of caspase-8 and caspase-9 were examined with Western blot.Results Acitretin inhibited the growth ( F = 83.64,96.34 and 123.17, respectively on the first, third and fifth day)and induced the apoptosis of SCC13 cells(F=74.45,107.37,and 64.28, respectively on the first, third and fifth day) in a dose- and time-dependent manner(P<0.05).Acitretin altered cell cycle distribution of SCC13 cells as compared with controls, the G1-phase population increased by 77.66% 72 hours after acitretin treatment, while the control increased only by 63.55%.An active fragment of caspase-8 occurred following 12 hours treatment of acitretin on SCC13 cells, whereas the caspase-9 active fragment occurred 24 hours after acitretin treatment, which increased time-dependently (P<0.01).Conclusion Acitretin plays an important role on the growth inhibition and apoptosis of cutaneous squamous cell carcinoma cells, which may be affected through both Fas receptor way and mitochondria way.
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Objective: To explore the role of integrin ?v?6 in proliferation and apoptosis of gastric cancer AGS cells. Methods: Gastric cancer AGS cells were treated with ?v?6 monoclonal antibody 10D5 or the negative control mouse immunogloblins IgG2a. Cell viability was measured by MTT assay, cell apoptosis was detected by FCM, and caspase-3 activity was examined by Western blot. Results: Compared with the control and IgG2a group, the apoptotic rate and caspase-3 activity of AGS cells treated with 10D5 increased, meanwhile cells survival rate decreased. There were significant differences of the indexes between the 10D5 group and the other two groups (P0.05). Conclusion: Integrin ?v?6 plays an important role in the proliferation and apoptosis of gastric cancer AGS cells.