Objective: To study the role of pancreatic cancer stem cells in radiotherapy resistance of pancreatic cancer. Methods: CD133+ pancreatic cancer stem cells were obtained by using magnetic cell sorting. MTT and flow cytometry were used to observe the proliferation activity and apoptosis of different cell subsets of pancreatic cancer after radiation treatment. Then flow cytometry, Western blot and qRT-PCR were used to observe the expression changes of CD133 in pancreatic cancer cells after radiation treatment. Finally, the cell cycle distribution of different subgroup cells was observed by flow cytometry. Results: Compared with unselected cells and CD133- cells, CD133+ stem cells had the highest survival rate and the lowest apoptosis rate after radiation treatment. The proportion of CD133+ stem cells increased and the expressions of CD133 protein and RNA increased in pancreatic cancer cells. CD133+ stem cells had the highest ratio of G0/G1 phase compared with unsorted cells and CD133- cells, and the difference was statistically significant. Conclusion: CD133+ pancreatic cancer stem cells are one of the important causes of radiotherapy resistance in pancreatic cancer cells, and the increased proportion of G0/G1 phase may be one of the mechanisms.

Objective To determine the expression of Caspase 8 and phospho-Akt(p-Akt)in condyloma acuminatum(CA)lesions, and to evaluate their significance. Methods Skin lesion samples were collected from 30 patients with CA, cancer tissue samples from 20 with cervical cancer, and normal skin samples from 20 healthy controls. All the samples were subjected to paraffin embedding. An immunohistochemical study was conducted to determine the expression and distribution of Caspase 8 and p-Akt in the above samples. Results The expression rate of Caspase 8 was significantly lower in CA lesions (23.33%)than in normal skin samples(90%, P < 0.01)and cervical cancer lesions(80%, P < 0.001). Moreover, the expression rate of p-Akt in CA lesions(93.33%)was significantly higher than that in the normal skin samples(90%, P<0.001), but lower than that in the cervical cancer lesions(95%, P<0.001). No significant correlations were observed between the expression of Caspase 8 and p-Akt in either CA lesions or normal skin samples. However, the expression of Caspase 8 was positively correlated with the expression of p-Akt in cervical cancer lesions(r=0.369, P<0.05). Conclusion Both suppressed apoptosis initiation of Caspase 8 and anti-apoptotic effect of p-Akt may be involved in the occurrence and development of CA.

Objective To screen the active components of Bushen Huoxue Decoction ( BSHXD) involved in promoting the proliferation of bone marrow mesenchymal stem cells ( MSCs). Methods BSHXD and its subdivisions were extracted with petroleum ether, ethyl acetate, water-free ethanol and water respectively. MSCs were isolated and cultured by the bone marrow adherent method. At the third passage, MSCs were identified by the specific surface markers with immunofluorescence, and their osteogenic and adipogenic differentiation were tested by alizarin red staining and oil red “O” staining. After treated with the extracts of BSHXD and its subdivisions at gradient concentrations for 24 hours, cell viability was detected by methyl thiazolyl tetrazolium (MTT) assay for the screening of active components and optimal concentration. MTT assay was used to describe the growth curve of MSCs treated with the most effective components, and cell cycle was analyzed by flow cytometry. Results Compared with the blank control group, the extracts of BSHXD and its subdivisions could protect MSCs from death to various degrees. Of all the extracts, the ethyl acetate extract of Bushen Division ( BSD) , ethyl acetate extract of BSHXD, ethyl acetate extract of Huoxue Division ( HXD) had the strongest effect, and the effect was dose-dependent, 100 μg/mL being the optimal active concentration while having no any cytotoxic reaction. The results of MTT assay revealed that BSD extracts promoted the proliferation of MSCs significantly and was the most effective component, and then came BSHXD. The results of flow cytometry indicated that BSD extract had the most strongest effect on increasing the amount of MSCs at proliferative phase, and then came BSHXD. Conclusion BSD ethyl acetate extract is the active component of BSHXD for promoting the proliferation of MSCs, showing an effect on increasing the proportion of MSCs at proliferative phase.

Objective:To evaluate the effect and possible mechanism of B-cell-specific moloney murine leukemia virus insertion site 1(BMI-1) on the radiosensitivity of pancreatic cancer SW1990 cell line.Methods:According to our previous study results, 4 Gy X-ray and down-regulation of BMI-1 expression were adopted as intervention conditions. The effect on the proliferation of SW1990 cells was assessed by clony formation assay. The effect on cell apoptosis and cell cycle was evaluated by flow cytometry. The effect upon the epithelial-mesenchymal transition (EMT) was determined by Western blot.Results:Clony formation assay and flow cytometry found that the lowest cell proliferation ability and the highest apoptotic rate were obtained after BMI-1 down-regulation and 4 Gy X-ray compared with other groups (all P<0.05). Flow cytometry revealed that the proportion of G 0/G 1 phase was significantly decreased, whereas the G 2/M phase was remarkably increased in pancreatic cancer stem cells treated with 4 Gy X-ray compared with the control group (both P<0.05). Nevertheless, opposite results were obtained after down-regulation of BMI-1 expression. Western blot showed that the expression of E-cadherin was up-regulated, whereas that of Vimentin was down-regulated following 4 Gy X-ray (both P<0.05). Conclusion:Downregulation of BMI-1 expression can enhance the radiosensitivity of pancreatic cancer SW1990 cells, and its mechanism may be related to cell cycle and EMT.