AIM: To investigate the possibility of transfecting siRNA into rabbit cervical cells in transformation zone by the method of solid phase in vivo and to verify the effectivity of siRNA transfection by modifying the permeability of the cervical epithelium. METHODS: A sense strand small-interference RNA (siRNA) for human papillomavirus type 16 (21 bp) was designed and labeled with Cy3. siRNA-Lipo2000-carbomer gum was prepared. Twelve rabbits were included in the study and divided into experimental group and control group. In order to modify the permeability of cervical epithelium, hypertonic saline solution at concentration of 200 mmol/L was used to infuse the cervix in the experimental rabbits for 10 min, and normal saline was used for the control animals. The siRNA-Lipo2000-carbomer gum was applied to the surface of the rabbit cervix. Twenty-four hours later, the rabbits were sacrificed, and the cervix was isolated, cut into 2 parts, one part was for rapid frozen sectioning and the efficiency of transfection was observed under fluorescence microscope, another part was prepared by paraffin embedding and sectioning, and the form of cervical histiocytes was observed. Twelve SCID mice with SiHa cell cervical tumor, divided into experimental group and control group, were also used in the study. The mice in experimental group were treated with siRNA-Lipo2000-carbomer gum for 7 d. The control mice were treated with Lipo2000-carbomer gum only. Five days later, the mice were sacrificed and the tumor was collected, and the HPV16-DNA was measured by PCR. RESULTS: (1) Red fluorescence (Cy3) in cervical epithelium was observed in all rabbits. However, no different effect of siRNA transfection was found between the ways of modifying the cervical epithelium permeability. (2) No abnormal change such as flare, swelling and ulcer at all cervical tissue was observed, the cervical cell form was normal. (3) The titer of HPV16-DNA was decreased significantly after siRNA transfection (P<0.05). CONCLUSION: Transfection of siRNA into rabbit cervical epithelium in vivo is successful by using the method of solid phase and inhibits the processes of HPV-DNA, indicating that using RNAi is a practical way to treat HPV infection in human cercix and to decrease the incidence of cercical carcinoma.

Objective To evaluate the efficacy,bleeding profile and safety of low-dose levonorgestrel-releasing intrauterine system (LNG-IUS 8) in Chinese healthy women of childbearing age.Methods A multi-center,open-label,single-arm clinical trial conducted at 16 centres in China enrolled 773 healthy women of childbearing age (mean age 31.6 years old,range 18 to 40 years old),who demanded contraception,from April 2006 to June 2013.All women placed LNG-IUS 8 for 3 years and then been followed up at 3,6,9,12,18,24,30,36 months.The efficacy variables including pregnancy rate and expulsion rate were analyzed using life table,while observing adverse events (AE) to evaluate the safety.The bleeding profile happened during the study was assessed using 90-day reference intervals (World Health Organization criteria).Results Eight pregnancies occurred among 773 women,resulting in a overall Pearl index of 0.42 per 100 women years.The 3-year cumulative pregnancy rate was 0.37 per 100 women years and the 3-year cumulative expulsion rate was 1.99 per 100 women years.The number of women with bleeding/spotting reduced and the bleeding/spotting days declined over time.Totally 219 AE were reported related to LNG-IUS 8 placements.The most common AE were vaginal bleeding (8.2％,63/773)and the ovarian cyst (6.2％,52/773).LNG-IUS 8 had an improving effect on dysmenorrhea that the percentage of women with dysmenorrhea as well as the days of dysmenorrhea decreased over time.The percentage of women satisfied or very satisfied with LNG-IUS 8 was 87.2％ (622/713).Conclusion LNG-IUS 8 is highly effective and safe for Chinese healthy women of childbearing age.