ABSTRACT
Background The key enzymes of serine synthesis pathway (SSP) play an important role in tumor growth, proliferation, and invasion, but their roles in arsenic carcinogenesis are unclear. Objective To observe the effects of NaAsO2 treatment on the expressions of key enzymes [such as phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH)] of SSP and on the ability to proliferate and migrate in human immortalized skin keratinocytes (HaCaT) and NaAsO2-induced malignantly transformed HaCaT (T-HaCaT), and to explore the roles of SSP key enzymes in arsenic carcinogenesis. Methods (1) The T-HaCaT cells constructed earlier by our research team were divided into a passage control (0 μmol·L−1 NaAsO2) group, a T-HaCaT (0.5 μmol·L−1 NaAsO2) group, a NCT503 (PHGDH inhibitor, 25 μmol·L−1) group, and a NCT503 (25 μmol·L−1) + T-HaCaT (0.5 μmol·L−1 NaAsO2) group. Western blotting was used to detect the protein expression levels of SSP key enzymes in the passage control group and the T-HaCaT group. CCK8 assay and cell scratch test were used to detect the proliferation and migration rates of cells in each group respectively. (2) Well-grown logarithmic-phase HaCaT cells were treated with 0, 0.625, 1.25, and 2.5 μmol·L−1 NaAsO2 for 0, 24, 48, and 72 h to detect cell proliferation rate and protein expression levels of SSP key enzymes. In the subsequent experiment, HaCaT cells were pretreated with 25 μmol·L−1 NCT503 for 6 h, and then treated with 2.5 μmol·L−1 NaAsO2 for 72 h continuously. The experimental groups included a control (0 μmol·L−1 NaAsO2) group, an exposure (2.5 μmol·L−1 NaAsO2) group, a pretreatment (25 μmol·L−1 NCT503) group, and a pretreatment (25 μmol·L−1 NCT503) + exposure (2.5 μmol·L−1 NaAsO2) group, to detect the proliferation rate of cells in each group. Results The protein expression level of PHGDH in the T-HaCaT group were 1.60 times higher than that in the passage control group (P<0.05), and its proliferation rate (177.51%±14.69%) and migration rate (53.85%±0.94%) were also higher than the passage control group’s (100.00%±0.00% and 24.30%±2.26%) (both Ps<0.05), respectively. After the NCT503 intervention, the proliferation rate (144.97%±8.08%) and migration rate (35.80%±0.99%) of cells in the NCT503 + T-HaCaT group were lower than those in the T-HaCaT group (both P<0.05). The proliferation rate of HaCaT cells after NaAsO2 exposure for 72 h increased with the increase of exposure concentration (r=0.862, P<0.05), and consistently, the protein levels of SSP key enzymes in HaCaT cells in each exposure group were higher than those in the control group (all P<0.05). The proliferation rate of HaCaT cells treated with 2.5 μmol·L−1 NaAsO2 increased with the extension of exposure time (r=0.775, P<0.05), which was consistent with the changes of PHGDH levels in cells. After the NCT503 intervention, the proliferation rate of the pretreatment + exposure group was significantly lower than that of the exposure group (P<0.05). Conclusion The key enzymes of SSP may play an important role in the proliferation of T-HaCaT cells induced by NaAsO2.
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Objective To evaluate the value of chorionic villus cells karyotype analysis in prenatal diagnosis during the first tri-mester of pregnancy.Methods Pregnant women with prenatal diagnosis indications were punctured by guiding abdominal B-mode ultrasound to get villi tissue which was then to develop cell culture,chromosome preparation and karyotype analysis.Results A to-tal of 1 140 cases were successfully cultured,and the successful cultivating rate was 98.2% (1 140/1 160).Among them,chromo-somes of 62 cases were detected to be non-polymorphic structural abnormalities,including 32 abnormal chromosome number,5 chro-mosome balanced translocation,3 chromosome deletion,and 22 chimeras.What′s more,20 cases were detected to be chromosomal inversion,19 cases of chromosome 9 were inversion,and one with chromosome Y was inversion.Conclusion Karyotype analysis of villus cell could help to detect fetal chromosomal abnormalities during early pregnancy and get early intervention.It was significant to reduce the child′s birth with chromosome abnormalities.
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Objective To prepare insulin-containing chitosan-thioglycollic acid conjugates microspheres and evaluate their hypoglycemic effect.Methods The insulin-containing chitosan-thioglycollic acid conjugates microspheres were prepared by the dry-in-oil method using the chitosan-thioglycollic acid conjugates which the content of thiol group was 983?mol?g-1.The hypoglycemic effect of the microsphere was evaluated by drug release test in vitro and hypoglycemic test on hyperglycemic rats.Results The insulin-containing chitosan-thioglycollic acid conjugates microspheres with an average diameter of 13?m were administered by intraduodenal and intraileal application,and gave visible decrease in plasma glucose level in 4h at a dose of 20IU?kg-1.The relative bioavailability of the latter compared to hypodermic injection was 29.9%.Couclusion The results showed that the bioavailability of oral insulin could be facilitated by insulin-containing chitosan-thioglycollic acid conjugates microspheres,and good biological availability was obtained when the microspheres were administered by intraileal application.
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Objective To prepare a new bioadhesive material-chitosan-thioglycolic acid conjugates from chitosan,and analysed the structure moreover.Methods Preparing chitosan-thioglycolic acid conjugates with a new synthesis method under catalytic reaction by NHS,and the contents of thiol groups in the conjugates were determined.Furthermore,elemental analysis and the IR spectrum of the polymer were determined.Results The content of thiol groups in the chitosan-thioglycolic acid conjugates was 1034?mol?g~(-1),and the structure was elucidated.Conclusion The new synthesis method was feasible,and the structure can be elucidated by IR spectrum.
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Objective Research on the relation between the content of thiol group in chitosan-thioglycolic acid conjugates and in vitro adhesion. Methods Prepared chitosan-thioglycolic acid conjugates with different content of thiol group,and determined the swelling behavior,instant detachment force between test disc and mucosa,recorded the maximum detachment force(MDF),and calculated the total work of adhesion(TWA)of these samples.Results The relation between the content of thiol groups and in vitro adhesion of the chitosan-thioglycolic acid conjugates was positive correlation, the adhesion of the polymer increased along with the content of thiol group,but the rate decreased.Conclusion The adhesion of chitosan-thioglycolic acid conjugates with higher content of thiol gyoup was far more stronger than chitosan.