Ovarian epithelial cancer: a role for PGE2-synthesis and signalling in malignant transformation and progression

Abstract

Background: The involvement of the cyclooxygenases (COX), in particular COX-2, is well documented for many tumours, e.g. colon, breast and prostate cancer, by both experimental and clinical studies. There are epidemiological data from subjects using NSAIDs, and experimental evidence supporting the hypothesis of prostaglandins (PGs) as regulators of tumourigenesis in the ovary. One of the end products of PG-synthesis, PGE 2 , regulates several key-processes, which are characteristic for tumour growth, e.g. angiogenesis, proliferation and apoptosisis. The present study investigated the pathway for PGE 2 -synthesis and signalling in ovarian tumourigenesis by analysing specimen from normal ovaries (n = 18), benign (B) (n = 8), borderline type (BL) (n = 6) and malignant tumours (AC) (n = 22). The expression and cell-specific localization of COX-1, COX-2, microsomal prostaglandin E synthase-1 (mPGES-1) and two of the receptors for PGE 2 , EP 1 and EP 2 , were examined by immunoblotting (IB) and immunohistochemistry (IHC).

Prostaglandin E2 (PGE2) promotes proliferation and invasion by enhancing SUMO-1 activity via EP4 receptor in endometrial cancer

“…Secreted PGE2 acts in either an autocrine or paracrine manner through its four cognate G protein-coupled receptors, EP1 to EP4. Many studies have found PGE2 associated with tumors of the colorectal organs, lung, and breast [5–7]. In some before studies of our research teams, we have found some cytokines high expressed in endometrial cancers [8, 9], and PGE2 is one of them.…”

“…Recent studies have suggested that PGE2 may be a mitogen associated with a variety of tumors [5–7, 20]. We performed immunohistochemistry (IHC) in normal endometrium and endometrial cancer tissues.…”

The Role of the Tumor Stroma in Ovarian Cancer

“…Analysis of proteins related to the prostaglandin synthesis pathway using IHC showed expression of COX-2, microsomal prostaglandin E synthase-I (mPGES-I), and the prostaglandin E 2 receptors EP 1 and EP 2 to the OC stroma, particularly in tumors of higher histological grade (117). …”

Role of macrophage secretions on rat polycystic ovary: its effect on apoptosis

“…Also, it has been shown that androgen and androgen receptors promote Bax-mediated apoptosis in prostate cancer cells (Lin et al 2006). Furthermore, it is known that PGE 2 promotesthe proliferation and survival of cells through apoptosis inhibition (Sheng et al 1998, Rask et al 2006.…”