Abstract:

Objective To study the inhibitory effect of recombinant plasmid pSilencer1.0-U6-siRNA-STAT3  on ovarian cancer in nude mice and clarify the the role of RNA interference(RNAi) technique in the field of biological therapy of ovarian cancer.Methods The subcutaneous transplantated tumor models in 15 nude mice were established with  cell line SKOV3 of human ovarian cancer. The model mice were randomly divided into 3 groups: control group(physiologic saline)，control group of vacancy plasmid,and  recombinant plasmid group (pSilencer1.0-U6-siRNA-STAT3).The recombinant plasmid was transferred into transplanted tumor in nude mice by electron piercing instrument.The growth status of subcutaneous transplanted tumor in nude mice after injection was observed.The protein expression of STAT3 was detected by Western blotting.The morphological changes and apoptosis of tumor cells were observed by HE and TUNEL staining.Results The growth of transplanted tumor had an obvious suppression after transferred.Compared with two control groups,the growth velocity of transplanted tumor in  recombinant plasmid group was decreased(P<0.01),the protein levels of Stat3,CyclinD1,VEGF,Survivin,c-myc in recombinant plasmid group were reduced(P<0.01).HE staining showed the tumor cells in recombinant plasmid group had nuclei pyknosis,fragmentation and other signs of apoptosis.The TUNEL test results confirmed that the tumor tissues in recombinant plasmid group had a large amount of apoptotic cells.Conclusion The recombinant plasmid pSilencer1.0-U6-siRNA-STAT3 can obviously inhibit the growth of ovarian cancer in nude mice.

Key words: RNA interfere；SKOV3；STAT3；ovarian neoplasms