Medroxyprogesterone acetate (MPA) is a synthetic progestin[1]. Medroxyprogesterone acetate can be used for contraception, endometriosis, endometrial bleeding, and can also be used to treat endometrial cancer and breast cancer[2, 3].
In vitro, treatment of human colon cancer cell lines HT29 and HCT116 cells with Medroxyprogesterone acetate (20nM) for 48h reduced the level of cyclin E and led to G1 phase arrest of cells[4]. Treatment of human endothelial cells with Medroxyprogesterone acetate (0.5, 10nM) for 16h inhibited the expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and reduced the adhesion of endothelial cells to leukocytes[5].
In vivo, oral treatment of ovariectomized mice with Medroxyprogesterone acetate (0.05, 0.1, and 0.2mg/kg/day) for 14 days increased allopregnanolone levels in all tissues except the adrenal glands and affected β-END levels in the hippocampus and interneuronal lobe[6]. Intramuscular treatment of mice with KPL-4 cell xenografts with Medroxyprogesterone acetate (100mg/kg) significantly reduced serum IL-6 levels but did not affect tumor growth[7].
References:
[1] Mattson R H, Cramer J A, Caldwell B V, et al. Treatment of seizures with medroxyprogesterone acetate: preliminary report[J]. Neurology, 1984, 34(9): 1255-1255.
[2] Kaunitz A M. Long-acting injectable contraception with depot medroxyprogesterone acetate[J]. American journal of obstetrics and gynecology, 1994, 170(5): 1543-1549.
[3] Kim J J, Kurita T, Bulun S E. Progesterone action in endometrial cancer, endometriosis, uterine fibroids, and breast cancer[J]. Endocrine reviews, 2013, 34(1): 130-162.
[4] Tanaka Y, Kato K, Mibu R, et al. Medroxyprogesterone acetate inhibits proliferation of colon cancer cell lines by modulating cell cycle-related protein expression[J]. Menopause, 2008, 15(3): 442-453.
[5] Simoncini T, Mannella P, Fornari L, et al. Differential signal transduction of progesterone and medroxyprogesterone acetate in human endothelial cells[J]. Endocrinology, 2004, 145(12): 5745-5756.
[6] Bernardi F, Pluchino N, Pieri M, et al. Progesterone and medroxyprogesterone acetate effects on central and peripheral allopregnanolone and beta-endorphin levels[J]. Neuroendocrinology, 2006, 83(5-6): 348-359.
[7] Kurebayashi J, Yamamoto S, Otsuki T, et al. Medroxyprogesterone acetate inhibits interleukin 6 secretion from KPL-4 human breast cancer cells both in vitro and in vivo: a possible mechanism of the anticachectic effect[J]. British journal of cancer, 1999, 79(3): 631-636.