Effect Of Pulsed Eelectric Field On Invasion And Metastasis Of Human Cervical Cancer Hela Cells In Vitro

Cervical cancer is one of commonest genital tract malignant tumor and is the second malignant tumor to breast malignant tumor in female. In recent years it is a serious threat to women's health and lives because of its obviously rising and younger trend of incidence. The main treatments include surgery, radiotherapy, and chemotherapy, immune therapy, and heat treatment. Although the patients in very earlier stage may be recovered by resection, but the quality of life drops, the incidence of abortion and premature delivery increases, even they lose the reproductive function, so the therapeutic effect is still dissatisfied and new treatments are needed. Pulsed electric field is a new technology which is combined with biomedicine, electrotechnics, microelectronics in tumor treatment filed, and it has been studied as a individual tumor treatment by domestic and overseas scholars. The cervix can be exposured and fixed easily and it is possible for pulsed electric field to treat cerical cancer. Previous studies have confirmed that pulsed electric field had good anti-tumor effects, it could kill tumor cells and inhibit the growth of tumors effectively. But we also found in the edge of pulsed electric field, there were inevitably residual tumor cells and their changes of invasion and metastasis ability were significant for clinical teatment by pulsed electric field safely and effectively. There is little research about the effect of pulsed electric field on the invasion and metastasis ability of tumor cells at present. In this study, we discuss the effect of pulsed electric field with different intensity on the invasion and metastasis ability of cerical cancer Hela cells and its possible mechanism. PART ONE INFLUENCE OF PULSED ELECTRIC FIELD ON INVASION AND METASTASIS OF CERVICAL CANCER HELA CELLSObjective To observe the changes and analysis the influence and correlation of the invasion and metastasis ability in cervical cancer Hela cells treated by pulsed electric field with different intensity.Methods Hela cells were cultivated in vitro and divided into four groups according to acceptable different intensity of pulsed electric field: control group; 500V/cm group; 1000V/cm group; 1500V/cm group. The clone ability was measured with flat clone formation experiment; the adhesion ability was measured by mechanical method; the invasion and migrating ability was determined by transwell cave.Results Treated by different intensity of pulsed electric field, the ability of clone,adhesion, invasion and migration in Hela cells declined, and it declined obviously when the intensity of pulsed electric field increased, especially when the intensity of pulsed electric field exceeded 1000V/cm, the difference between each experiment group and control group was significant(P<0.05), the differences among experiment groups also were significant(P<0.05).Conclusion Pulsed electric field can inhibit the invasion and metastasis ability of Hela cells and the inhibition was positively correlated with the intensity of pulsed electric field. PART TWO INFLUENCE OF PULSED ELECTRIC FIELD ON THE EXPRESSION OF CORRELATION FACTORS WITH INVASION AND METASTASIS: RHOC, MMP-2 AND TIMP-2 IN CERVICAL CANCER HELA CELLSObjective To observe the changes and analysis the influence and correlation of the expression of factors correlated with invasion and metastasis: RhoC, MMP-2 and TIMP-2 in cerical cancer Hela cells treated with different intensity of pulsed electric field.Methods Hela cells wered cultivated in vitro and divided into four groups according to acceptable different intensity of pulsed electric field: control group; 500V/cm group; 1000V/cm group; 1500V/cm group. The expression of mRNA in RhoC, MMP-2 and TIMP-2 mRNA was detected by RT-PCR method; The expression of RhoC, MMP-2 and TIMP-2 was detected by Immunofluorescence test .Results The expression of RhoC and MMP-2 and their mRNA of Hela cells in each experiment group was lower than that in control group , especially when the intensity of pulsed electric field exceeded 1000V/cm, the difference was significant(P<0.05), the differences among experiment groups also were significan(tP<0.05). But the expression of TIMP- 2 and its mRNA was higher in each experiment group than that in control group, when the intensity of pulsed electric field exceeded 1000V/cm, the difference was significant(P<0.05), the differences among experiment groups also were significant(P<0.05).Conclusion The expression of RhoC and MMP - 2 being inhibited and the expression TIMP - 2 being enhanced in Hela cells treated with pulsed electric field, may be one of mechanisms of the invasion and metastasis ability's being inhibited by pulsed electric field.