Potential Role of the GPI Anchor of Thy-1 in Expanding Ovarian Cancer Stem Cells
Abstract
Introduction and Objective. Ovarian cancer is usually detected at late stage. Screening for specific biomarkers may facilitate detection and improve prognoses. One biomarker of interest is the glycosylphosphatidylinositol-anchor (GPI-anchor), which serves as an anchor for various glycoproteins on the cell’s surface and has higher expression in cancer stem cells. Thy-1 (CD90) is a GPI-anchored protein that has been associated with a poorer prognosis in ovarian cancer. The goal of this project is to investigate if the GPI-anchor is the component of the Thy-1 protein contributing to an increased cancer stem cell population. Methods. Two ovarian cancer cell lines, A1847 (cisplatin-sensitive) and C30 (cisplatin-resistant), were transfected with a lentivirus to express three different versions of the GPI anchor + Thy1 amino acids (six total cell groups). Construct I contains truncated Thy-1 protein with the GPI anchor, Construct II has truncated Thy-1 without the GPI anchor, and Construct III has the full Thy-1 protein and the GPI anchor. The cell lines grew on non-adherent six well plates to allow formation of spheroids, which is dependent on the number of cancer stem cells. The density of spheroids was calculated using ImageJ software every 24 hours for three days. Results. After growing spheroids for 72 hours, the A1847 Construct I maintained a significantly higher growth than Construct II (p=0.002), but there was no significant difference between Construct I and III. In the C30 group, Construct III both maintained higher density than Constructs I and II at 72 hours (p < 0.001). When comparing cell lines, constructs I and II from the A1847 cells had higher density than C30 cells (p < 0.001), while constructs III showed no difference in proliferation. Conclusions-Implications. GPI anchor may be the component of the CD-90 protein contributing to ovarian cancer proliferation. It may have a greater role in growth of chemoresistant cells, and thus can be leveraged to target patients with ovarian cancer who have failed conventional therapy.
Keywords
ovarian cancer, spheroids, biomarkers, GPI anchor, CD90
Presentation Type
Poster Presentation
Potential Role of the GPI Anchor of Thy-1 in Expanding Ovarian Cancer Stem Cells
Introduction and Objective. Ovarian cancer is usually detected at late stage. Screening for specific biomarkers may facilitate detection and improve prognoses. One biomarker of interest is the glycosylphosphatidylinositol-anchor (GPI-anchor), which serves as an anchor for various glycoproteins on the cell’s surface and has higher expression in cancer stem cells. Thy-1 (CD90) is a GPI-anchored protein that has been associated with a poorer prognosis in ovarian cancer. The goal of this project is to investigate if the GPI-anchor is the component of the Thy-1 protein contributing to an increased cancer stem cell population. Methods. Two ovarian cancer cell lines, A1847 (cisplatin-sensitive) and C30 (cisplatin-resistant), were transfected with a lentivirus to express three different versions of the GPI anchor + Thy1 amino acids (six total cell groups). Construct I contains truncated Thy-1 protein with the GPI anchor, Construct II has truncated Thy-1 without the GPI anchor, and Construct III has the full Thy-1 protein and the GPI anchor. The cell lines grew on non-adherent six well plates to allow formation of spheroids, which is dependent on the number of cancer stem cells. The density of spheroids was calculated using ImageJ software every 24 hours for three days. Results. After growing spheroids for 72 hours, the A1847 Construct I maintained a significantly higher growth than Construct II (p=0.002), but there was no significant difference between Construct I and III. In the C30 group, Construct III both maintained higher density than Constructs I and II at 72 hours (p < 0.001). When comparing cell lines, constructs I and II from the A1847 cells had higher density than C30 cells (p < 0.001), while constructs III showed no difference in proliferation. Conclusions-Implications. GPI anchor may be the component of the CD-90 protein contributing to ovarian cancer proliferation. It may have a greater role in growth of chemoresistant cells, and thus can be leveraged to target patients with ovarian cancer who have failed conventional therapy.