AIM: To investigate the protective effect of sodium selenite ( Na2 SeO3 ) on human keratinocytes under ultraviolet-B (UVB) irradiation.METHODS: The cultured HaCaT cells were divided into 4 groups: (1) normal control group;(2) Na2 SeO3 group:pretreated with Na2 SeO3 at doses of 10 nmol/L, 50 nmol/L, 100 nmol/L, 200 nmol/L and 1 μmol/L for 24 h;(3) UVB group: irradiated with UVB at doses of 300, 600 and 900 J/m2; (4) Na2SeO3 +UVB group:after pretreated with Na2SeO3 for 24 h, irradiated with UVB at doses of 300, 600 and 900 J/m2.The cell pro-liferation was detected by MTT assay .The apoptotic rates of HaCaT cells treated with UVB at dose of 300 J/m2 were as-sessed by flow cytometry .RESULTS:Compared with normal control group , the cell proliferation activity in UVB group de-creased significantly ( P<0.05 ) .The cell activity was inversely correlated with the irradiation intensity .No significant difference of the cell activity between Na 2 SeO3 group and normal control group was observed .The cell proliferation in Na2SeO3 +UVB group was higher than that in UVB group significantly (P<0.05).Na2SeO3 at concentration of 100 nmol/L showed the strongest activity to promote cell proliferation .After 300 J/m2 UVB irradiation, the apoptotic rate in Na2SeO3+UVB group decreased significantly ( P<0.05) compared with UVB group .The inhibitory effect of Na 2 SeO3 at concentra-tion of 100 nmol/L on apoptosis was the strongest .CONCLUSION: The damage of human keratinocytes by UVB irradia-tion is in a dose-dependent manner .The photoprotection performance of Na 2 SeO3 reduces the damage of human keratino-cytes induced by UVB irradiation .

Objective To investigate the effects of intense pulsed light (IPL) irradiation on the content of collagen fibers, elastic fibers and hyaluronic acid in Kunming mouse skin. Methods The dorsal skin of mice was divided into two areas: the right area was irradiated with IPL, and the left remaining unirradiated served as the control. Skin specimens were taken from the back of mice on day 1, 3, week 1, 2, 4 and 8 after the irradiation and subjected to staining with HE, sirius red and Gomori aldehyde-fuchsin for examinations of histological changes, type Ⅰ and Ⅲ collagen fibers and elastic fibers. The hydroxyproline and hyaluronic acid content in skin tissues of mice was determined with ultraviolet spectrophotometry and radioimmunoassay respectively. Results After irradiation, a significant increase was observed in dermal thickness on week 2 (t =4.623, P＜ 0.05), 4, and 8 (t = 3.904, P＜ 0.05), in type Ⅲ collagen fiber (t = 5.129, P＜ 0.05) on week 1,in type Ⅰ and Ⅲ collagen fibers on week 2, 4 and 8 (both P＜ 0.05), in elastic fibers from week 2 to 8 (P ＜0.05), and in hydroxyproline content from week 1 to 8 (all P ＜ 0.05) in the skin of mice compared with unirradiated mice. In detail, dermal thickness increased by 18.71% on week 4, and type Ⅲ collagen fiber by 40.54% in irradiated mice compared with unirradiated mice. Further more, the hyaluronic acid content was elevated from day 1 to 3, but gradually declined from week 1 to 8, and remained statistically higher from day 1 to week 8 (P ＜ 0.05) in irradiated mice compared to unirradiated mice. Conclusion IPL irradiation could induce an increase in the content of collagen fiber, elastic fiber and hyaluronic acid in the dorsal skin of mice.

Objective To study the correlation of cleft lip and palate transmembrane 1 like(CLPTM1L)expression and radiosensitivity of lung cancer cells.Methods Thiazolyl blue tetrazolium bromide(MTT) and cell colony formation assays were used to determine cell growth and survival.Western Blot assay was employed to measure protein expression.Results The results demonstrated a negative correlation between the CLPTM1L expression level and radiosensitivity of lung cancer cells.A lower radiosensitivity in lung cancer cells containing high level of CLPTM1L expression,and vice versa.Enforced expression of CLPTM1L resulted in a significant reduction of radiosensitivity in lung cancer cells irradiated with γ-rays.On the contrary,a marked elevation of radiosensitivity was observed in lung cancer cells transfected with CLPTM1L siRNA.Conclusions CLPTM1L may be a novel target gene in mediating radiosensitivity of lung cancer cells.

Objective To study the nuclear protein association of high-mobility group box-1 (HMGB1) and histone deacetylase 1 (HDAC1),and the effect of interaction on radiosensitivity in human breast cancer cells.Methods The protein-protein interaction was determined by immunoprecipitationWestern blot and glutathione-S-transferase capture assays.Cell growth was examined by MTT (methyl thiazolyl tetrazolium)assay and clonogenic assay.Histone deacetylase activity was analyzed by histone deacetylase assay.Results A significant increase of HMGB1 protein and radiosensitivity was observed in MDA-MB-231 and MDA-MB-468 cells transfected with a pCMV-Tag2B expression vector carrying with a full-length of HMGB1 cDNA.HMGB1 binding to HDAC1 was demonstrated as GST (glutathione Stransferase)-pull down and immunoprecipitation Western blot assay,and the association was elevated by irradiation.An LXCXE motif was required for the HMGB1-HADC1 interaction and HMGB1 radiosensitization.A significant difference of IC50 value was observed,for example,1.8 and 2.2 Gy (wtHMGB1 transfectants,P ＜ 0.05),3.6 and 3.8 Gy (HMGB1/C103F transfectants,P ＞ 0.05),both compared with 3.9 and 4.1 Gy (pCMV-Tag2B transfectants) in MDA-MB-231 and MDA-MB-468 cells,respectively.A specific HDAC1 inhibitor trichostatin A markedly reduced the HMGB1-mediated radiosensitivity,0.5 Gy in the presence of trichostatin A versus 1.8 Gy in absence of trichostatin A in MDA-MB-231 transfectants,1.2 Gy (with trichostatin A) versus 2.2 Gy (without trichostatin A) in MDA-MB-468 transfectants,P ＜ 0.05.Histone deacetylase activity was also detected in immunoprecipitates prepared from these cells with antibodies to HMGB1,and this activity was abolished by the histone trichostatin A.Conclusions These results suggest a previous unanticipated role for HDAC1 in modification of HMGB1-mediated radiosensitivity by its direct interaction with HMGB1.

Objective To evaluate the effect of selenomethionine (Se-Met) against ultraviolet B (UVB)-induced oxidative damage to human HaCaT keratinocytes,and to explore its possible mechanisms.Methods Cultured HaCaT cells were divided into several groups:normal control group receiving no treatment,Se-Met groups treated with Se-Met at concentrations of 1,10,50,100,200 nmol/L and 1 μmol/L for 24 hours respectively,UVB groups irradiated with UVB of 30,60 and 90 mJ/cm2 respectively,Se-Met + UVB groups treated with Se-Met at concentrations of 1,10,50,100,200 nmol/L and 1 μmol/L for 24 hours firstly,then irradiated with UVB of 30,60 and 90 mJ/cm2 respectively.Subsequently,methyl thiazolyl tetrazolium (MTT) assay was performed to estimate cellular proliferative activity,flow cytometry to detect cell apoptosis,colorimetry to evaluate superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and to determine malondialdehyde (MDA) levels.Statistical analysis was carried out by using factorial design analysis of variance (ANOVA),one-way ANOVA and least significant difference (LSD) test.Results Factorial design ANOVA showed that UVB radiation had an inhibitory effect on the proliferative activity of HaCaT cells (F =128.04,P ＜ 0.05),which significantly decreased along with the increase of UVB doses,with significant differences between the three UVB groups (P ＜ 0.05).Se-Met pretreatment also affected cellular proliferative activity (F =5.95,P ＜ 0.05),which was significantly increased in Se-Met (10 nmol/L-1 μmol/L) + UVB groups compared with the UVB groups at corresponding doses (all P ＜ 0.05).There was no significant interaction effect on cellular proliferative activity between UVB radiation and Se-Met pretreatment (F =1.65,P ＞ 0.05).The apoptosis rate of HaCaT cells in the 30-mJ/cm2 UVB group was 31.9％ ± 2.67％,significantly higher than that in the normal control group (4.1％ ± 0.67％,P＜ 0.05) and in the 10-,50-,100-,200-nmol/L and 1-μmol/L Se-Met + 30-mJ/cm2 UVB groups (21.9％ ± 3.72％,17.2％ ± 1.67％,4.6％ ±-0.85％,7.5％ ± 1.86％ and 13.5％ ± 1.95％ respectively,all P ＜ 0.05).Similarly,SOD and GSH-Px activities were significantly weaker (both P ＜ 0.05),while MDA levels were higher (all P ＜ 0.05) in the 30-mJ/cm2 UVB group than in the normal control group;however,there was a significant increase in SOD and GSH-Px activities but a decrease in MDA levels in the Se-Met (10 nmol/L-1 μmol/L) + 30-mJ/cm2 UVB groups compared with the 30-mJ/cm2 UVB group (all P ＜ 0.05).Conclusions Se-Met can reduce UVB-induced oxidative damage to HaCaT cells,likely by enhancing antioxidase activity and decreasing oxygen radicals.

Objective To investigate the radiosensitizing effects of dihydroartemisinin(DHA)on human HeLa cells of cervical cancer irradiated by X rays.Methods Cell growth kinetics was determined using MTF assay.Cell survival was analyzed by elonogenic assay.The change of cell cycle and apeptosis was measured by flow cytometry.Results Dihydroartemisinin inhibited the growth of HeLa cells of human cervical cancer and showed a dose-dependent and time-dependent manner.Dihydroartemisinin(20 μmol/L)showed the radiosensitizing effects on HeLa cells,and the sensitizing enhancement ratio(SER)was 1.47.Dihydroartemisinin abrogated radiation-induced G2 arrest of the tested HeLa cells,the G2 ratio of medicine + radiation group dechned from 73.58% to 48.31%.Dihydroartemisinin enhanced the apoptosis of HeLa cells by X-irradiation,the apoptosis rates of medicine + radiation group significantly increased from 29.46%,48.04%,70.21% to 45.79%,66.36% and 79.58%,respectively for 2,4 and 6 Gy.Conclusions Dihydroartemisinin could increase the radiesensitivity of HeLa cells of human cervical cancer.Abrogation of radiation-induced C2 arrest could be part of the mechanism.

Objective To study the radiosensitizing effect of caffic acid phenethyl ester(CAPE)on human cervical cancer HeLa cells.Methods MTT assay was used to measure the relation between the inhibition effect and CAPE concentrations by CAPE with different concentrations on HeLa cells for 24 hours.HeLa cells were divided into the control and experimental groups,both of which were given 0,2,4,6 and 8 Gy of 60Co γ-irradiation,respectively.The cell clones were counted.Meanwhile HeLa cells were divided into the control,CAPE,irradiation and combination groups.Flow cytometric analysis was adopted to detect the changes of cell cycle distribution induced by CAPE.Results The inhibition rate of CAPE acting on Hela cells increased with concentrations(F=126.49～3654.88,P＜0.01).HeLa cells cloning survival decreased with the increase of radiation dose(F=174.42～9422.81,P＜0.01).At the game radiation dose,HeLa cells cloning survival was less in experimental group than conlrol group(F=120.14～251.91,P＜0.01).The mean lethal dose(D0)(1.45 and 1.82 Gy)and the quasi-threshold dose(Dq)(1.89 and 3.21 Gy)of HeLa cells in experimental group decreased comparing with control group,SER was 1.26.Compared with the sole irradiation group,cells in G2/M phase of the CAPE group and the sole irradiation group increased(P＜0.01)while the combination group decreased(P＜0.01).Conclusions CAPE could increase the radiation sensitivity of HeLa cells by G2/M arrest and may be related to the inhibition of the sub-lethal damage repair.

Objective To investigate the radiosensitizing effects of artesunate on human HeLa cells of cervical cancer in vitro.Methods Hela cells were irradiated with 60Co γ-rays.The dose rate was 0.635 Gy/min and the radiation dose was 0,1,2,4,6 Gy,respectively.The anti-proliferation activities of artesunate on HeLa cells were evaluated with MTT assay,to determine the most appropriate drug concentration.The effect of radiosensitivity was observed by using clonogenic assay.The single-hit multitarget model was used to plot the HeLa cell's dose-survival curve,to calculate mean lethal dose,quasithreshold dose and sensitization enhancement rate,and to evaluate its radiosensitization effect.The apoptosis was analyzed with flow cytometry (FCM) to further test the radiation senseitization of artesunate on HeLa cells.Results The inhibition of artesunate on HeLa cells increased with concentration.In radiation group,the cell cloning efficiency were 91.67% ,82.02% ,58.60% ,25.01%,respectively,and in artesunate (2.0 μ mol/L) + radiation group,the cell cloning efficiency were 74.93% ,60.53% ,22.38% ,5.05%.In radiation group and artesunate (2.0 μmol/L) + radiation group,the mean lethal dose(D0) was 2.95 and 2.07 Gy,respectively,while the qusai-threshold dose (Dq) were 2.01 and 1.24 Gy,respectively,and SER was 1.43.Compared with 2 and 6 Gy radiation group,the apoptosis rate of drug + radiation group increased from 12.26% ,40.08% to 22.71% ,59.92%.Conclusions The inhibiting effect of artesunate on HeLa cells is concentration-dependent.Artesunate has radiosensitizing effect on HeLa cells in vitro.

Objective To evaluate the effect of artemether on the cell cycle and the radiosensitivity in human nasopharyngeal carcinoma cell line CNE-1.Methods Cell growth inhibition was assessed with MTT.The method of colony-forming was used to detect the radiation sensitivity.Cell cycle distribution was analyzed by using flow cytometry.The protein expressions of clyclin B1 and Weei were detected by using Western blot.Results The growth of CNE-1 cells was inhibited in a dose-dependent manner.The concentration of 20 μmol/L artemether had radiosensitive effect on CNE-1 cells at 24 h after administration,and SER was 1.481.When CNE-1 cell was irradiated,the G2/M cells increased (t =4.59,P ＜ 0.05).After exposure to combination of artemether and irradiation,the G2/M cells were decreased (t= 10.60,P ＜ 0.05).Western blot showed that artemether increased the level of cyclin B1 expression and inhibited the level of Weel expression.Conclusions The noncytotoxic concentration of artemether could enhance radiosensitization of CNE-1 cells.The radiosensitivity enhancement of artemether might depend on the exposure time.The effect is most obvious when radiation is delivered 24 h after expose to artemetherr.The radiosensitizing effect could be related to apoptosis.

A 22-year-old female patient presented with skin flushing in the bilateral legs for 4 years, which gradually spread throughout the whole lower limbs and forearms 6 months ago. Skin examination showed diffuse flushing and dilated capillaries in the lower limbs and both forearms, and the flushing faded after a press. Histopathological examination of the skin lesion on the leg showed hyperkeratosis in a basket-like shape, increased pigmentation in the basal layer, infiltration of the superficial dermis with scattered lymphocytes, with no obvious red blood cell overflow; periodic acid-Schiff staining showed thickened and homogeneous deposits around the blood vessels; immunohistochemical staining showed thickened blood vessel walls and positive staining for type Ⅳ collagen. Diagnosis: cutaneous collagenous vasculopathy.