Non-Contact Electric Field May Induced Higher CD4, CD8, Caspase-8, and Caspase-9 Protein Expression in Breast Tumor Tissue of Rats (Rattus norvegicus Berkenhout, 1769)

Abstract

Non-contact electric field therapy has been studied as one of less invasive and safe alternative method in cancer therapy. Some studies reported that non-contact electric field therapy with low intensity (50 - 60 V/m) and medium frequency (150 kHz) could slower the rat’s breast tumor growth and did not cause significant damage on the rat's kidney and liver. However, further study needed to evaluate the potency of non-contact electric field to be developed into effective cancer therapy. Thus, we investigated the immune response of non-contact electric field therapy through the detection of CD4 and CD8 protein expression and the mechanism of apoptosis through the detection of caspase-8 and caspase-9 proteins on breast tumor tissue of rats. Twenty four rats were divided into 4 groups: 1. non-induction - non-therapy (NINT), 2. non-induction - therapy (NIT), 3. induction - non-therapy (INT), and 4. induction - therapy (IT). DMBA (7,12-dimethylbenz(α)anthracene) 20 mg/kg body weight was used to induced breast tumor formation. Rats with breast nodules that had reached 1 cm in size were exposed to an ECCT device with 150 kHz and 50 - 60 V/m electric fields. Further, the breast tissues were collected for routine histological and immunohistochemistry preparation for CD4, CD8, caspase 8, as well as caspase 9 detection. The data were statistically analyzed using Mann-Whitney U-Test method, with a significance level of p < 0.05 using the SPSS 16.0 version. The scoring results were compared between the INT and IT groups. Our results showed that non-contact electric field therapy could suppress breast tumor growth and improved its histological structure. Interestingly, the breast tissue of IT group qualitatively had slightly more necrotic and apoptotic cells than that of INT group. Moreover, the IT group showed by higher CD4 and CD8 as well as higher caspase 8 and caspase 9 expression. Collecting all the data together, we concluded that non-contact electric field therapy potent to improve histological structure of breast tumor.