Medroxyprogesterone effects on colony growth, autophagy and mitochondria of C6 glioma cells are augmented with tibolone and temozolomide: Cell kinetic and electron microscopical studies with a broad review of the literature.

•We previously showed antitumor efficacy of medroxyprogesterone acetate (MPA) in experimental glioma models.•Tibolone, an estrogenic progesterone derivative enhanced anti-glioma efficacy of MPA.•MPA and temozolomide also synergized in blocking C6 glioma colony growth.•MPA and tibolone suppressed C6 glioma spheroid DNA-Synthesis as potent as temozolomide.•Mutual interactions between progestins and temozolomide involved mitophagy and autophagy.