Human Ovarian Surface Epithelial Cells

Cell Viability/Cytotoxicity and Morphological Changes in HOSE Cells following OCPs Exposure

Exposure to organochlorine pesticides (OCPs) may contribute to the risk of epithelial ovarian cancer, but the underlying mechanisms remain unclear. In the present study, Shah et al. investigated the effects of dichlorodiphenyldichloroethylene (DDE), endosulfan, and heptachlor on E-cadherin and proinflammatory mediators in human ovary surface epithelial (HOSE) cells.

HOSE cells treated with increasing concentrations of DDE, endosulfan, and heptachlor had a decreased cell viability (Fig. 1). The IC₅₀ for DDE, endosulfan, and heptachlor was 74.27, 69.53, and 68.34 µM, respectively. They used concentrations up to 10 µM for OCPs exposure, which resulted in over 100% cell viability. Dose at 20 µM was approximately 100% viability for all OCPs. Concentrations at 30 µM for DDE, endosulfan, and heptachlor were cytotoxic (Fig. 1). Therefore, the highest noncytotoxic concentration (10 µM) was chosen for DDE, endosulfan, and heptachlor in this study. HOSE cells with 72 h exposure to 10 µM of DDE, endosulfan, and heptachlor retained cobblestone (cuboidal) cell structures (Fig. 2A). DDE, endosulfan, and heptachlor-exposed HOSE cells formed aggregates and clumps (Fig. 2B–D). This indicated that OCPs exposure may promote epithelial differentiation and inhibit mesenchymal transition in HOSE cells.

Fig. 1. Effect of OCPs on HOSE cell viability. Cells were treated with increasing concentrations (1 µM to 200 µM) of DDE, endosulfan, and heptachlor for 72 h (Shah H K, Banerjee B D, et al., 2022).

Fig. 2. The morphology of HOSE cells. HOSE cells were treated with (A) 0.25% DMSO (control), 10 µM of (B) DDE, (C) endosulfan, and (D) heptachlor for 72 h (Shah H K, Banerjee B D, et al., 2022).

Antagonistic Effect of Melatonin Against OIS in Human Ovarian Surface Epithelial Cells

Ovarian aging, as an organ senescence, is the pathophysiological basis of various diseases of the reproductive system. As ovarian aging progresses, the loss of surface epithelial integrity and depletion of human ovarian surface epithelial cells (HOSEpiCs) is its typical manifestation. The following studies were conducted to investigate the epigenetic protective effect of melatonin on HOSEpiCs.

HOSEpiCs were transfected with H-RasV12 or an empty vector (as control) and treated with melatonin at 10 nM, 100 nM, 1 μM, 10 μM or 100 μM. Ras treatment caused an increase in SA-β-galactosidase-positive cells, yet 1 μM melatonin successfully blocked the senescence triggered by Ras (Fig. 3A). Telomere length was reduced in the Ras-treated group but was restored by 1 μM melatonin treatment (Fig. 3B). Ras-induced growth arrest was also blocked by 1 μM melatonin treatment over a course of 8 days (Fig. 3C). The BrdU incorporation assay showed that melatonin significantly abrogated Ras-induced cell cycle arrest (0.11% in Ras-treated vs. 0.36% in Ras + melatonin, P < 0.05) (Fig. 3D). In addition, the expression of senescence markers p53, p21 and p16, upregulated by Ras, was reduced by melatonin treatment (Fig. 3E). Collectively, melatonin antagonizes Ras-induced senescence in HOSEpiCs.

Fig. 3. Antagonistic effect of melatonin against OIS-induced senescence of human ovarian surface epithelial cells (Zhu R X, Ji X, et al., 2022)