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BACKGROUND@#To observe the effect of linear alkylbenzenesulfonate (LAS) on oxidative stress and collagen fiber in skin tissue of mice and to explore the correlation between oxidative stress and collagen metabolism. @*METHODS@#Forty healthy Kunming mice (male) were randomly divided into 4 groups: a control group, a low-, middle- and high-dose group of LAS (LD, MD and HD groups), treated with LAS at 150, 300 and 600 mg/L respectively (n=10 per group). The skin on the back of mice was smeared with distilled water or different dosage of LAS for 60 days. The measured indexes included general condition of mice, HE and Masson staining of skin, the content of hydroxyproline (Hyp) in skin tissue, the activity of super oxidase dismutase (SOD) and the content of malondialdehyde (MDA) in skin tissue and serum, and the activity of lactate dehydrogenase (LDH) in serum. @*RESULTS@#Compared with the control group, the changes of diet, daily activities and mental state of mice with different dose of LAS were not obvious during the experiment, but the body weight of mice in the experimental groups reduced obviously after 4 weeks of experiment (P<0.01), and their skin tissue was thinner, some of epidermis of skin contained areas with cellular necrosis and abscission. Superficial layer of dermis was infiltrated by inflammatory cells. The collagen fibers were looser and dimmer. At the same time, the content of MDA and the activity of LDH increased remarkably (P<0.01), while the activity of SOD and the content of Hyp decreased obviously (P<0.01). @*CONCLUSIONS@#LAS can induce oxidative stress in the skin tissue of mice, which can destroy the integrity of skin structure and collagen fiber and reduce the content of collagen fiber. The oxidative damage might be the primary cause for disorders of collagen fiber. .
Subject(s)
Animals , Male , Mice , Alkanesulfonic Acids , Pharmacology , Collagen , Metabolism , Malondialdehyde , Metabolism , Oxidative Stress , Skin , MetabolismABSTRACT
Objective To compare the reversal effects of short hairpin RNA (shRNA) interference and tetrandrine on multidrug resistance (MDR) of human colorectal cancer cell line LoVo/5-fluorouracil(5-FU ).Methods An eukaryotic expression plasmid of shRNA targeting MDR1 was constructed and transfected into human colorectal cancer cell line LoVo/5-FU (transfection group).LoVo/5-FU was also pretreated with tetrandrine (tetrandrine group).Drug sensitivity was detected by methyl thiazolyltetrazolium colorimetric method.Cell cycle,apoptosis of cells and positive expression rate of P-glycoprotein (P-gp) were determined by flow cytometry assay.The expressions of MDR1 mRNA and P-gp were detected by real-time polymerase chain reaction and Western blot,respectively.All data were analyzed by analysis of variance and SNK-q test.Results (1)Drug sensitivity:the 50％ concentration of inhibition(IC50)of the control group,tetrandrine group and transfection group were (7.3 ± 0.3),(4.4 ±0.7) and (2.4 ±0.4) mmol/L,respectively,a significant difference between the 3 groups was found(F =65.27,P ＜ 0.05 ).There was a significant difference in the IC50 between the tetrandrine group and the transfection group (q =6.67,P ＜ 0.05 ).(2) Changes of cell cycle:the proportion of cells in the G1 phase and S phase of the control group,tetrandrine group and transfection group were 38.13％ ± 3.75％,51.36％ ± 2.76％,59.24％±4.31％ and 20.46％±2.23％,14.32％± 1.91％,9.40％± 1.65％,respectively,a significant difference between the 3 groups was found(F =25.23,24.37,P ＜ 0.05 ).There were significant differences in the proportion of cells in the G1 phase and S phase between the tetrandrine group and the transfection group(q =3.67,4.35,P ＜ 0.05 ).(3) Cell apoptosis:the cell apoptotic rates of the control group,tetrandrine group and transfection group were 1.32％ ± 0.47％,3.24％ ± 0.26％,5.88％ ±- 0.44％,respectively,a significant difference between the 3 groups was found(F =99.26,P ＜ 0.05 ).There was a significant difference in the cell apoptotic rate between the tetrandrine group and transfection group(q =11.48,P ＜ 0.05 ).(4)The expression of P-gp:the positive expression rates of P-gp of the control group,tetrandrine group and transfection group were 96.9％ ± 2.3％,61.6％ ± 4.9％,76.6％ ± 3.6％,respectively,a significant difference between the 3 groups was found(F =67.83,P ＜ 0.05 ).There was a significant difference in the positive expression rate of P-gp between the tetrandrine group and transfection group (q =6.97,P ＜ 0.05 ).(5)The mRNA expression of MDR1:the mRNA expressions of MDR1 of the control group,tetrandrine group and transfection group were 1462 ±161,570 ±85,233 ± 81,respectively,a significant difference between the 3 groups was found(F =90.59,P ＜ 0.05 ).There was a significant difference in the mRNA expression of MDR1 between the tetrandrine group and transfection group (q =5.12,P ＜ 0.05 ).Conclusions MDR1 shRNA and tetrandrine could reverse M DR1 gene-mediated m.ultidrug resistance in human colon cancer cell line LoVo/5-FU,but the effect of MDR1 shRNA is better than that of tetrandrine.MDR1 shRNA and tetrandrine might take effect by inhibiting P-gp expression and down-regulating mRNA expression of MDR1.
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Objective To explore the reversal effect on MDR1 gene-mediated multidrug resistance in human colon carcinoma LOVO/5-Fu cells by tetrandrine ( Tet) and to clarify its molecular mechanism.Methods LOVO/5-Fu cells were treated for 48 h with Tet.Drug sensitivity was measured by MTT.The cell cycle, apoptosis of cells and expression of P-glycoprotein (P-gp) were determined by flow cytometry assay.Expression of MDR1 mRNA was detected by real-time quantitative PCR (real-time PCR).P-gp expression was detected by Western blot.Results After LOVO/5-Fu cells were treated for 48 h with Tet, the IC50 of 5-Fu decreased to ( 4.15 ± 0.31 ) μg/ml ( P ＜ 0.05 ) ; and the apoptotic rate increased to (3.44% ± 0.28% ) ( P ＜ 0.05) ; the expression of MDR1 mRNA reduced to (570 ± 85) (P ＜ 0.05 ).Conclusions Tetrandrine reverses MDR1 gene-mediated multidrug resistance in human colon carcinoma LOVO/5-Fu cells possibly by inhibiting the expression of MDR1, decreasing the expression of P-gp, thus enhancing the sensitivity of LOVO/5-Fu cells to 5-fluorouracil.
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Objective To compare the efficacy of XELOX and FOLFOX4 in the treatment of locally advanced unresectable gastric cancer. Methods The clinical data of 72 patients with gastric cancer who were admitted to the Shandong Provincial Hospital from July 2006 to October 2009 were prospectively analyzed. Of all the patients, 3 lost follow-up, and 69 patients with locally advanced unresectable gastric cancer were randomly divided into XELOX group ( n = 36 ) and FOLFOX4 group ( n = 33 ) according to the random number table.All patients received chemotherapy for six weeks. The efficacy of the two regimens were evaluated by the multidiscipline team six weeks later. The cell cycle of patients with complete or partial remission and received surgical treatment was detected by flow cytometry. All data were analyzed using the Pearson chi-square test, Levene test or t test. Results The curative rates of XELOX and FOLFOX4 were 53% (19/36) and 52% (17/33), respectively,with no significant difference between the two groups ( x2= 0. 01 , P ＞ 0. 05 ). The incidences of nausea and vomiting, phlebitis and hand-foot syndrome were 25% (9/36), 6% (2/36) and 19% (7/36) in the xELOX group, and 55% ( 18/33), 39% (13/33) and 3% (1/33) in the FOLFOX4 group, respectively, with significant difference between the two groups ( x2 = 6.31, 11.59, 4.53, P ＜ 0.05 ). Nineteen patients in the XELOX group and 17 patients in the FOLFOX4 group received surgical resection of the gastric cancer, and no complications such as anastomotic leakage and hemorrhage occurred postoperatively. In the XELOX group, the s-phase fraction (SPF),proliferation index (PI) and G2/M of the gastric cancer cells were 5.89% ± 0.79%, 9.22% ± 1.99% and 5.19% ± 1. 66% after neoadjuvant chemotherapy, which were significantly lower than 6.76% ± 1.21%, 10.44% ±2.12% and 6. 04% ± 0. 57% before neoadjuvant chemotherapy, while the ratio of gastric cancer cells in the G0/G1 phase after neoadjuvant chemotherapy was 90.39% ±4.78%, which was significantly higher than 87.54%±6.34% before neoadjuvant chemotherapy (x2 =3.61, 2.52, 2. 15, 2.91, P ＜0.05). In the FOLFOX4group, the SPF, PI and G2/M of the gastric cancer cells were 6.09% ± 0.96%, 10.65 % ± 2.47% and 4.88% ±0.87% after neoadjuvant chemotherapy, which were significantly lower than 7.15% ± 1.45%, 11.87% ± 2.33%and 5.67% ± 1.03% before neoadjuvant chemotherapy, while the ratio of gastric cancer cells in the G0/G1 phase after neoadjuvant chemotherapy was 91.45% ± 5.22%, which was significantly higher than 88.01% ± 4.23%before neoadjuvant chemotherapy ( x2 = 3.50, 2.06, 3.37, 2.94, P ＜ 0.05 ). There was a significant difference in PI between XELOX group and FOLFOX4 group after neoadjuvant chemotherapy ( x2 = 2.66, P ＜ 0.05 ).Conclusions XELOX and FOLFOX4 are safe and effective in the treatment of locally advanced unresectable gastric cancer, and they can significantly restrain the proliferation of gastric cancer cells. XELOX regimen is more effective than FOLFOX4 regimen.