Related Experiment Videos
Density-dependent induction of apoptosis by transforming growth factor-beta 1 in a human ovarian carcinoma cell line
Abstract:
Transforming growth factor-beta 1 inhibited proliferation of a human ovarian carcinoma cell line (NIH-OVCAR-3). The inhibition of NIH-OVCAR-3 cell proliferation was accompanied by a decrease in clonogenic potential, evidenced by the reduced ability of TGF-beta 1-treated NIH-OVCAR-3 cells to form colonies on a plastic substratum. This rapid decrease of clonogenic potential, which was detected 6 h after addition of TGF-beta 1 was dose-dependent (IC50 = 4 pM). Fluorescence microscopy of DAPI-stained cells supported by electron-microscopic examination showed that TGF-beta 1 induced chromatin condensation and nuclear fragmentation. In addition, oligonucleosomal-sized fragments were detected in the TGF-beta 1-treated cells. These features indicated that TGF-beta 1 induced NIH-OVCAR-3 cell death by an apoptosis-like mechanism. This TGF-beta 1 apoptotic effect was subject to modulation by cell density. It was observed that an increase in cell density (up to 20 x 10(3) cells/cm2) protected NIH-OVCAR-3 cells against apoptosis induced by TGF-beta 1. Conditioned medium from high-density cultures of NIH-OVCAR-3 cells did not inhibit apoptosis induced by TGF-beta 1 on NIH-OVCAR-3 cells cultured at low density, suggesting that the protective effect of cell density was not related to the cell secretion of a soluble survival factor.
Insights
Transforming growth factor-beta 1 (TGF-β1) halts ovarian cancer cell growth and triggers apoptosis, a programmed cell death. Higher cell density protects these cancer cells from TGF-β1-induced apoptosis.
Area of Science:
- Cell Biology
- Molecular Biology
- Cancer Research
Background:
- Transforming growth factor-beta 1 (TGF-β1) is a cytokine with diverse cellular functions.
- Ovarian carcinoma is a significant cause of cancer-related mortality in women.
- Understanding TGF-β1's role in ovarian cancer is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the effect of TGF-β1 on the proliferation and survival of NIH-OVCAR-3 human ovarian carcinoma cells.
- To elucidate the mechanism by which TGF-β1 affects these cancer cells.
- To examine the influence of cell density on TGF-β1's effects.
Main Methods:
- Cell proliferation assays using NIH-OVCAR-3 cells.
- Clonogenic assays to assess colony formation.
- Fluorescence and electron microscopy to examine cellular morphology.
- Detection of DNA fragmentation to identify apoptosis.
Main Results:
- TGF-β1 significantly inhibited NIH-OVCAR-3 cell proliferation and clonogenic potential in a dose-dependent manner (IC50 = 4 pM).
- TGF-β1 induced morphological changes indicative of apoptosis, including chromatin condensation and nuclear fragmentation.
- Oligonucleosomal DNA fragments were detected, confirming apoptosis.
- Increased cell density protected NIH-OVCAR-3 cells from TGF-β1-induced apoptosis.
Conclusions:
- TGF-β1 induces apoptosis in human ovarian carcinoma cells (NIH-OVCAR-3).
- The anti-proliferative and apoptotic effects of TGF-β1 are modulated by cell density.
- Cell density confers protection against TGF-β1-induced apoptosis, independent of soluble survival factors.