Objective:

2

To investigate the effects and underlying mechanism of action of dihydroartemisinin (DHA) on ferroptosis in ovarian cancer (OC).

Methods:

2

In vitro

SKOV3 and A2780 cells were treated with different concentrations of DHA. The proliferative capacity of DHA-treated OC cells was determined using cell counting kit-8 assay

scratch test and clone formation assay. In addition

OC cells were treated with the ferroptosis inhibitor (ferrostatin-1; Fer-1) in combination with DHA to observe the changes in cell viability. To confirm the oxidative stress-inducing effect of DHA

levels of Fe

2+

glutathione (GSH) and reactive oxygen species (ROS) were detected using Fe

2+

GSH and ROS kits

respectively. Western blotting and quantitative PCR analyses were performed to detect the expressions of signal transducer and activator of transcription 3 (STAT3)

recombinant solute carrier family 7 member 11 (SLC7A11)

and glutathione peroxidase 4 (GPX4) at the protein and gene expression levels to determine stimulatory effects on ferroptosis.

In vivo

in accordance with the random number table approach

nude mice with successful tumor loading were divided into vehicle and DHA (150 mg/kg) groups

with 3 mice in each group. Throughout the 10-day treatment period

the body weight

s and tumor volumes of the mice were documented. The STAT3

SLC7A11

and GPX4 protein expression levels were determined using Western blotting and immunohistochemistry

respectively.

Results:

2

DHA significantly reduced the viability of OC cells

and treatment with Fer-1 significantly increased the survival rate of OC cells (

P

<

0.05 or

P

<

0.01). Subsequent to the administration of DHA

the migration rate and clone formation ability of OC cells decreased significantly (

P

<

0.01). Compared with control cells

DHA-treated OC cells exhibited increased Fe

2+

and ROS levels (

P

<

0.05 or

P

<

0.01)

whereas the GSH level decreased with DHA treatment (

P

<

0.05 or

P

<

0.01). DHA-treated OC cells exhibited significantly lower levels of STAT3

SLC7A11 and GPX4 mRNA and protein than control cells (

P

<

0.05 or

P

<

0.01). In nude mice

treatment with DHA significantly reduced tumor volume (

P

<

0.05). According to Western blotting and immunohistochemistry results

DHA treatment downregulated the expressions of STAT3

SLC7A11

and GPX4 (

P

<

0.05 or

P

<

0.01).

Conclusion:

2

Treatment with DHA can inhibit OC cell proliferation and induce ferroptosis in OC

and these effects may be predominantly mediated via STAT3/GPX4 signaling pathway.