Objective

2

To study the effect-enhancing and toxicity-reducing activities of astragalus polysaccharide injection （APS） on U14 cervical cancer in model mice receiving X-ray treatment.

Method

2

U14 mouse cervical cancer cells were cultured

in vitro

and injected into the right forelimb armpit of Kunming mice for constructing a subcutaneous tumor-bearing model of cervical cancer. The tumor-bearing mice were randomly divided into the model group， X-ray intervention（IR， 6 Gy） group， APS （10 mL·kg

-1

·d

-1

） group， and IR + APS group. Following the observation of the state， body mass， and food intake of mice in each group， the volume of the tumor was measured. The tumor cell cycle and apoptosis were determined by flow cytometry. The protein and mRNA expression levels of apoptosis-related proteins p53， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and cleaved cysteine-dependent aspartate-directed protease-3 （Caspase-3） in tumor tissues were assayed by Western blot and real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）.

Result

2

The comparison with the model group showed that mice in the IR group had poor mental status and reduced mobility. The IR group and IR + APS group exhibited reduced food intake and body mass since the 8

th

d （

P

<

0.05，

P

<

0.01） and narrowed tumor volume since the 9

th

d （

P

<

0.01）. In the IR group， the proportion of cells in the G

1

phase was increased， while the proportion of those in the S phase was decreased （

P

<

0.01）. In the IR + APS group， the proportion of cells in the G

1

phase rose， whereas the proportion of those in the G

2

and S phases cells declined （

P

<

0.05，

P

<

0.01）. The apoptotic rates in both the IR group and IR + APS group were elevated significantly （

P

<

0.01）. Compared with the model group， the IR group and IR + APS group displayed up-regulated cleaved Caspase-3 and Bax protein and mRNA expression in tumor tissues， but down-regulated Bcl-2 and p53 protein and mRNA expression （

P

<

0.05，

P

<

0.01）. Compared with the IR group， the mice in the IR + APS group had better mobility and hair， normal body mass， and increased food intake （

P

<

0.05）. The tumor volume in the IR + APS group was reduced （

P

<

0.05）. The proportion of cells in the G

2

phase was reduced， but the proportion of those in the S phase was raised （

P

<

0.05）. The apoptosis rate was increased （

P

<

0.05）. The apoptosis-related protein Bax protein expression in the tumor tissue was up-regulated， while the protein expression levels of Bcl-2 and p53 were down-regulated （

P

<

0.05，

P

<

0.01）.

Conclusion

2

APS maintains the life state of U14 cervical cancer model mice treated with X-ray and promotes tumor cell apoptosis， thus enhancing the efficiency and reducing toxicity.