Abstract 2963: The Foxp3 transcription factor expression in human gynecologic cancer cell lines

Abstract Objectives: The forkhead box protein 3 (Foxp3) transcription factor is considered as a master control gene for the function of regulatory T cells. However, recently some publications revealed that Foxp3 in cancer expressed higher than other tissues. A very recent publication describes the expression of Foxp3 in pancreatic carcinoma cells providing evidence that this could be an important tumor escape mechanism. As a result, some research considered that Foxp3 is associated with carcinogenesis, and cancer progression. To this end, This study was scheduled to investigate whether the expression of Foxp3 transcription factor can occur in gynecologic tumor types. Materials and methods: Ten tumor cell lines of cervical, ovarian, breast cancer origins were selected. The cell lines of cervical cancer were SiHa, HeLa, and Caski. Ovarian cancers were OV-CAR-3, SK-OV-3, SNU-8, and SNU-251. MDA-MB-231, MCF-7,and T47-D were selected as breast cancer cell lines. They were maintained in specific medium (RPM1640, DMEM (Dulbecco's modified Eagle's medium)). The cell lines were cultured for a period of 2 weeks. Detection of Foxp3 mRNA was performed using both conventional quantitative real-time PCR, the RT2 PCR Primer Set for Foxp3 (SuperArray, USA, forward 5’ GGCATCGTGATGGACTCCG 3’ and reverse 5’ GCTGGAAGGTGGACAGCGA 3′). β-Actin was used as a reference gene. All experiments were repeated three times. Results: The expression of Foxp3 mRNA was revealed in all tumor cell lines studied. This expression did not relate to the tissue of origin of each line. Relative expression values for tumor cells varied widely between 0.21 and 4.97 (1.71±0.09). Cervical cancer cell lines expressed highly Foxp3 mRNA in relative expression values for tumor cells. The highest expression level of Foxp3 in cervical cancer cell lines were with the SiHa cell lines. OV-CAR-3 cell lines expressed highly in ovarian cancer cell lines. In breast cancer cell lines, Foxp3 mRNA expression revealed the highest levels in T47-D cell lines. Conclusion: Foxp3 mRNA was detected in all tumor cell lines, albeit in variable levels, not related to the origins of tissue. We offer evidence that Foxp3 mRNA expression, characterizes tumor cells of various tissue origins. The biological significance of these findings warrants further investigation in the context of tumor immune escape, and especially under the light of current anti-cancer efforts interfering with Foxp3 expression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2963.