Exposure to Select PFAS and PFAS Mixtures Alters Response to Platinum-Based Chemotherapy in Endometrial Cancer Cell Lines

Brittany P. Rickard, Marta Overchuk, Justin Tulino, Xianming Tan, Frances S. Ligler, Victoria L. Bae-Jump, Suzanne E. Fenton, and Imran Rizvi

DOI: https://doi.org/10.22427/NTP-DATA-500-009-001-000-5

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Publication

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Abstract

Background: Exposure to per- and poly-fluoroalkyl substances (PFAS) has been associated with significant alterations in female reproductive health. These include changes in menstrual cyclicity, timing of menarche and menopause, and fertility outcomes, as well as increased risk of endometriosis, all of which may contribute to an increased risk of endometrial cancer. The effect of PFAS on endometrial cancer cells, specifically altered treatment response and biology, however, remains poorly studied. Like other gynecologic malignancies, a key contributor to lethality in endometrial cancer is resistance to chemotherapeutics, specifically to platinum-based agents that are used as the standard of care for patients with advanced-stage and/or recurrent disease.

Objectives: To explore the effect of environmental exposures, specifically PFAS, on platinum-based chemotherapy response and mitochondrial function in endometrial cancer.

Methods: HEC-1 and Ishikawa endometrial cancer cells were exposed to sub-cytotoxic nanomolar and micromolar concentrations of PFAS/PFAS mixtures and were treated with platinum-based chemotherapy. Survival fraction was measured 48-hours post-chemotherapy treatment. Mitochondrial membrane potential was evaluated in both cell lines following exposure to PFAS  chemotherapy treatment.

Results: HEC-1 and Ishikawa cells displayed differing outcomes after PFAS exposure and chemotherapy treatment. Cells exposed to PFAS appeared to be less sensitive to carboplatin, with instances of increased survival fraction, indicative of platinum resistance, observed in HEC-1 cells. In Ishikawa cells treated with cisplatin, PFAS mixture exposure significantly decreased survival fraction. In both cell lines, increases in mitochondrial membrane potential were observed post-PFAS exposure ± chemotherapy treatment.

Discussion: Exposure of endometrial cancer cell lines to PFAS/PFAS mixtures had varying effects on response to platinum-based chemotherapies. Increased survival fraction post-PFAS + carboplatin treatment suggests platinum resistance, while decreased survival fraction post-PFAS mixture + cisplatin exposure suggests enhanced therapeutic efficacy. Regardless of chemotherapy sensitivity status, mitochondrial membrane potential findings suggest that PFAS exposure may affect endometrial cancer cell mitochondrial functioning and should be explored further.

Figures

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Figures

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)

Figure 1. Chemotherapy dose-response in HEC-1 and Ishikawa cells.

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)
• Figure 1 09182023 (17 MB)

Figure 2. Exposure to PFAS impacts survival fraction in HEC-1 cells.

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)
• Figure 2 09182023 (16 MB)

Figure 3. Exposure to PFAS mixtures impacts survival fraction in Ishikawa cells.

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)
• Figure 3 09182023 (18 MB)

Figure 4. ΔΨm increases after exposure to PFAS in HEC-1 and Ishikawa cells but decreases after treatment with platinum-based chemotherapy.

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)
• Figure 4 10.10.2023 (29 MB)

Figure 5. ΔΨm increases in HEC-1 and Ishikawa cells following exposure to PFAS or PFAS mixtures + carboplatin treatment.

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)
• Figure 5 07312023 (30 MB)

Figure 6. ΔΨm increases in Ishikawa, but not HEC-1, cells following exposure to PFAS or PFAS mixtures + cisplatin treatment.

• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript Data (123 KB)
• Figure 6 07312023 (29 MB)

Supplemental Materials

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Supplemental Materials

• 10.10.2023 Supplemental Figures (64 MB)
• CEBS Endometrial Cancer PFAS Chemotherapy Response Manuscript Environ Health (3 MB)
• Environ Health Endometrial Cancer Manuscript SuppMat Data (69 KB)
• PDT-analysis 20230113[21] (965 KB)
• PDT-analysis 20230531ab[45] (931 KB)
• PDT-analysis 20230531c[13] (950 KB)

Supplemental Figures

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Figure S1: Optimal seeding densities of HEC-1 and Ishikawa cells based on the linear dynamic range of the CellTiter Glo Luminescent Cell Viability Assay.

Figure S2: HEC-1 and Ishikawa survival fraction post-methanol exposure.

Figure S3: Select nanomolar and micromolar concentrations of PFAS are sub-cytotoxic in HEC-1 cells.

Figure S4: Select nanomolar and micromolar concentrations of PFAS are sub-cytotoxic in Ishikawa cells.

Figure S5: Survival fraction increased after PFAS exposure + platinum-based chemotherapy treatment in HEC-1 cells.

Figure S6: Survival fraction was unchanged in Ishikawa cells exposed to PFAS then treated with platinum-based chemotherapy.

Figure S7: Select nanomolar and micromolar concentrations of PFAS mixtures are sub-cytotoxic in HEC-1 cells.

Figure S8: Select nanomolar and micromolar concentrations of PFAS mixtures are sub-cytotoxic in Ishikawa cells.

Figure S9: Survival fraction was unchanged in HEC-1 cells exposed to PFAS mixtures then treated with platinum-based chemotherapy.

Figure S10: Survival fraction decreased after PFAS mixture exposure + cisplatin, but not carboplatin, treatment in Ishikawa cells.

Figure S11: ΔΨm increased in HEC-1 cells exposed to PFAS then treated with carboplatin, but not cisplatin.

Figure S12: ΔΨm increased in Ishikawa cells exposed to PFAS then treated with platinum-based chemotherapy.