Long interspersed nuclear element-1 (LINE-1) is the only self-transposable non-terminal repeat retrotransposon in the human genome, which can copy and paste to new sites in the genome. To ensure evolutionary success, heritable new LINE-1 inserts accumulate in germ cells and embryonic stem cells, which carry genetic information. However, the reduction of LINE-1 inhibition in early embryo development may lead to genomic mutations induced by reverse transposon insertion. Increased LINE-1 mRNA and protein expression may indirectly cause early embryo damage or even pregnancy loss by inducing oocyte wear, DNA damage and immune inflammatory response. This paper summarized and analyzed the research progress on the role of LINE-1 epigenetic regulation in gametogenesis and early embryo development and the causes of early pregnancy loss.

Long interspersed nuclear element-1 (LINE-1) is the only self-transposable non-terminal repeat retrotransposon in the human genome, which can copy and paste to new sites in the genome. To ensure evolutionary success, heritable new LINE-1 inserts accumulate in germ cells and embryonic stem cells, which carry genetic information. However, the reduction of LINE-1 inhibition in early embryo development may lead to genomic mutations induced by reverse transposon insertion. Increased LINE-1 mRNA and protein expression may indirectly cause early embryo damage or even pregnancy loss by inducing oocyte wear, DNA damage and immune inflammatory response. This paper summarized and analyzed the research progress on the role of LINE-1 epigenetic regulation in gametogenesis and early embryo development and the causes of early pregnancy loss.

Recurrent spontaneous abortion (RSA) is a common disease in women of reproductive age, and the pathogenesis is not fully understood. In recent years, with in-depth research in the field of epigenetics, DNA methylation has gradually become a new perspective on the pathophysiology of RSA. Studies have shown that the regulation of DNA methylation modification is closely related to RSA. Abnormal DNA methylation and its imprinting disorders, dysregulated gene expression disorders, sperm defects and immune system abnormalities directly or indirectly affect embryo implantation. The growth and development process eventually lead to the occurrence of RSA. The role of DNA methylation in the pathogenesis of RSA and its regulatory pathways are reviewed.

Recurrent spontaneous abortion (RSA) is a common disease in women of reproductive age, and the pathogenesis is not fully understood. In recent years, with in-depth research in the field of epigenetics, DNA methylation has gradually become a new perspective on the pathophysiology of RSA. Studies have shown that the regulation of DNA methylation modification is closely related to RSA. Abnormal DNA methylation and its imprinting disorders, dysregulated gene expression disorders, sperm defects and immune system abnormalities directly or indirectly affect embryo implantation. The growth and development process eventually lead to the occurrence of RSA. The role of DNA methylation in the pathogenesis of RSA and its regulatory pathways are reviewed.

Objective To investigate the invasion situation of cardinal ligaments(CL) in stage Ⅰ A2 - ⅡA2 cervical cancer and to find the high risk clinicopathological factors affecting its invasion .Methods The retrospective analysis was performed on the clinicopathological data in 2 982 patients with cervical cancer treated by operation extracted in 5 hospitals from January 2004 to De‐cember 2014 .Results (1) Totally 855 cases according with the research condition were included .The CL invasion was found in 20 cases(2 .3% ) .No CL invasion occurred in the stage ⅠA2 ,the CL invasion rate in the stage ⅠB1 was 1 .7% ,in the stage ⅠB2 was 1 .2% ,in the stage ⅡA1 was 5 .7% and in the stage ⅡA2 was 2 .9% .With the increase of FIGO staging ,the CL invasion rate had no significant increase(P=0 .269) .(2) The infiltration rate of left CL and right CL had no statistical difference among the stageⅠA2- ⅡA2(P=1 .000) .And the invasion rate of the left CL with different FIGO stages had no statistical difference(P=0 .286) , while the right one had statistical difference(P=0 .005) ,in which the highest was in the stage ⅡA1 (4 .3% ) .(3)The univariate a‐nalysis found that lymph‐vascular invasion ,cervical stroma infiltration depth ,pelvic lymph node metastasis ,uterus body infiltration and vaginal fornix infiltration were the risk factors of CL invasion(P<0 .01);the further multivariate analysis determined that the invasion of uterine body(OR=11 .858) ,pelvic lymph node metastasis(OR=6 .359 ,) ,vaginal fornix infiltration(OR=6 .012 ,) were the risk factors for CL invasion(P<0 .05) .Conclusion The invasion rate of CL invasion in early stage cervcial cancer is low .The invasion of uterine body ,pelvic lymph node metastasis and vaginal fornix filtration are the risk factors for CL invasion in the stageⅠA2- ⅡA2 cervical cancer .