Department of Molecular Oncology, Cancer Institute (WIA), 38, Sardar Patel Road, Chennai, 600036, India.
Cell Oncol (Dordr). 2013 Dec;36(6):459-67. doi: 10.1007/s13402-013-0150-8. Epub 2013 Sep 27.
The objective of this study was to determine radiation, doxorubicin, tamoxifen and letrozole sensitivity of breast cancer cells in response to functional inhibition of the ubiquitin conjugating enzyme UBE2C.
Taqman Real time PCR was performed to measure UBE2C levels in breast cancer cell lines and control HBL100 and HEK293T cells. A dominant negative form of UBE2C (DN-UBE2C) was used to functionally inhibit wild type UBE2C. Cell proliferation and anchorage independent growth were measured by colorimetric and soft agar assays, respectively. Radiation, doxorubicin, tamoxifen and letrozole responses of the cell lines were assessed by colorimetric and clonogenic assays.
Overexpression of UBE2C was observed in all breast cancer cell lines tested using quantitative real time PCR. UBE2C expression was found to be highest in MDAMB231 and relatively lowest in MCF7 cells, compared to control cells. Both the growth rate and the anchorage independent growth of MCF7 and MDAMB231 cells transfected with DN-UBE2C were significantly reduced compared to cells transfected with vector alone. MCF7 and MDAMB231 cells expressing DN-UBE2C were significantly more sensitive to different doses of radiation and doxorubicin compared to both wild type and vector alone transfected cells. In addition, DN-UBE2C transfected MCF7 cells were more sensitive to inhibition by tamoxifen and letrozole compared to wild type and vector alone transfected cells.
Our results show that inhibition of UBE2C sensitizes breast cancer cells to radiation, doxorubicin and hormone blocking agents. UBE2C may, therefore, serve as a potential therapeutic target aimed at inducing radiation and chemo sensitization.
本研究旨在确定通过泛素连接酶 UBE2C 的功能抑制，乳腺癌细胞对辐射、多柔比星、他莫昔芬和来曲唑的敏感性。
采用 Taqman 实时 PCR 检测乳腺癌细胞系和对照 HBL100 和 HEK293T 细胞中 UBE2C 的水平。使用泛素连接酶 UBE2C 的显性失活形式（DN-UBE2C）来功能性抑制野生型 UBE2C。通过比色法和软琼脂测定分别测量细胞增殖和锚定独立生长。通过比色法和集落形成测定评估细胞系对辐射、多柔比星、他莫昔芬和来曲唑的反应。
使用定量实时 PCR 观察到所有测试的乳腺癌细胞系中均过表达 UBE2C。与对照细胞相比，UBE2C 在 MDAMB231 中的表达最高，而在 MCF7 细胞中相对最低。与单独转染载体的细胞相比，转染 DN-UBE2C 的 MCF7 和 MDAMB231 细胞的生长速度和锚定独立生长均显著降低。与野生型和单独转染载体的细胞相比，表达 DN-UBE2C 的 MCF7 和 MDAMB231 细胞对不同剂量的辐射和多柔比星更敏感。此外，与野生型和单独转染载体的细胞相比，转染 DN-UBE2C 的 MCF7 细胞对他莫昔芬和来曲唑的抑制作用更敏感。
我们的结果表明，UBE2C 的抑制使乳腺癌细胞对辐射、多柔比星和激素阻断剂敏感。因此，UBE2C 可能成为一种潜在的治疗靶点，旨在诱导辐射和化疗增敏。
