Enhanced anti-cancer effects of oestrogen and progesterone co-therapy against colorectal cancer in males

Abstract

Although ovarian sex steroids could have protective roles against colorectal cancer (CRC) in women, little is currently known about their potential anti-tumorigenic effects in men. Hence, this study measured the therapeutic effects of 17β-oestradiol (E2) and/or progesterone (P4) against azoxymethane-induced CRC in male mice that were divided into (n = 10 mice/group): negative (NC) and positive (PC) controls, E2 (580 µg/Kg/day; five times/week) and P4 (2.9 mg/Kg/day; five times/week) monotherapies, and concurrent (EP) and sequential (E/P) co-therapy groups. Both hormones were injected intraperitoneally to the designated groups for four consecutive weeks. Similar treatment protocols with E2 (10 nM) and/or P4 (20 nM) were also used in the SW480 and SW620 human male CRC cell lines. The PC group showed abundant colonic tumours alongside increased colonic tissue testosterone levels and androgen (AR) and oestrogen (ERα) receptors, whereas E2 and P4 levels with ERβ and progesterone receptor (PGR) decreased significantly compared with the NC group. E2 and P4 monotherapies equally increased ERβ/PGR with p21/Cytochrome-C/Caspase-3, reduced testosterone levels, inhibited ERα/AR and CCND1/survivin and promoted apoptosis relative to the PC group. Both co-therapy protocols also revealed better anti-cancer effects with enhanced modulation of colonic sex steroid hormones and their receptors, with E/P the most prominent protocol. In vitro, E/P regimen showed the highest increases in the numbers of SW480 (2.1-fold) and SW620 (3.5-fold) cells in Sub-G1 phase of cell cycle. The E/P co-therapy also disclosed the lowest percentages of viable SW480 cells (2.8-fold), whilst both co-therapy protocols equally showed the greatest SW620 apoptotic cell numbers (5.2-fold) relative to untreated cells. Moreover, both co-therapy regimens revealed maximal inhibitions of cell cycle inducers, cell survival markers, and AR/ERα alongside the highest expression of cell cycle suppressors, pro-apoptotic molecules, and ERβ/PGR in both cell lines. In conclusion, CRC was associated with abnormal levels of colonic sex steroid hormones alongside aberrant protein expression of their receptors. While the anti-cancer effects of E2 and P4 monotherapies were equal, their combination protocols showed boosted tumoricidal actions against CRC in males, possibly by promoting ERβ and PGR-mediated androgen deprivation together with inhibition of ERα-regulated oncogenic pathways.

Profiling estrogen, progesterone, and androgen receptors in colorectal cancer in relation to gender, menopausal status, clinical stage, and tumour sidedness

“…Collectively, Our findings correlate with earlier studies reporting gender-dependent expression of ERs ( 14 – 16 ), PGR ( 17 – 19 ), and AR ( 20 – 22 ) in normal colon, which supports the notion that sex steroid hormones contribution to colon biology could, at least in part, be gender-specific. Moreover, our data and prior studies advocate that ERβ ( 33 – 36 ) and PGR ( 30 , 36 , 52 ) mediate tumor suppressive actions, whereas overexpressed ERα ( 23 – 25 ) and AR ( 37 – 40 ) could incite oncogenicity in colon. The present findings also provide additional support for the potential prognostic values of sex steroid receptors in CRC ( 23 – 30 , 32 ).…”

“…The importance of sex steroid hormones in colon cancer has gained greater attention, since the rates of CRC in premenopausal, as well as post-menopausal women using HRT, were markedly lower than nonuser post-menopausal women and age-matched men ( 6 , 8 , 9 , 44 ). The risk of CRC also increased significantly in women after oophorectomy ( 45 , 46 ), and 17β-estradiol treatment in vivo and in vitro inhibited CRC progression via ERβ-mediated actions ( 33 – 36 ), whilst promoted cancer progression through ERα ( 47 – 49 ). Others have likewise reported lower CRC incidence in menopausal women using P4 ( 50 , 51 ), and the hormone also triggered cell cycle arrest and apoptosis in several human CRC cell lines, including SW480 and HT29 cells ( 30 , 36 , 52 ).…”

“…The risk of CRC also increased significantly in women after oophorectomy ( 45 , 46 ), and 17β-estradiol treatment in vivo and in vitro inhibited CRC progression via ERβ-mediated actions ( 33 – 36 ), whilst promoted cancer progression through ERα ( 47 – 49 ). Others have likewise reported lower CRC incidence in menopausal women using P4 ( 50 , 51 ), and the hormone also triggered cell cycle arrest and apoptosis in several human CRC cell lines, including SW480 and HT29 cells ( 30 , 36 , 52 ). Furthermore, ERβ expression declined significantly in malignant relative to non-malignant colonic tissues and coincided with drastically elevated ERα ( 48 , 53 – 55 ), and the expression linked with lower survival and higher recurrence rates, advanced stages, and distant metastasis ( 23 – 25 , 27 – 29 ).…”

“…However, the protein expression of ERα ( 23 – 25 ) and AR ( 26 ) increases, whereas ERβ ( 27 – 29 ) and PGR ( 23 , 30 – 32 ) decline, markedly in cancerous colonic tissues, and they correlated with the tumor clinicopathological characteristics and/or prognosis. Experimental studies have also shown that E2 induced ERβ-mediated anti-cancer actions, whilst promoting oncogenic effects through ERα in colonic cells, both in vivo and in vitro ( 33 – 36 ). Moreover, treatment with P4 induced apoptosis and inhibited cancer progression ( 30 , 36 ), whereas testosterone therapy triggered cell growth and colon carcinogenesis ( 37 – 40 ), in vitro and in animal models.…”

“…Experimental studies have also shown that E2 induced ERβ-mediated anti-cancer actions, whilst promoting oncogenic effects through ERα in colonic cells, both in vivo and in vitro ( 33 – 36 ). Moreover, treatment with P4 induced apoptosis and inhibited cancer progression ( 30 , 36 ), whereas testosterone therapy triggered cell growth and colon carcinogenesis ( 37 – 40 ), in vitro and in animal models. Hence, the authors suggested that E2, through ERβ ( 33 – 36 ), and P4 via PGR ( 30 , 36 ) could act as tumor suppressors, whilst activation of ERα by E2 ( 33 – 36 ) and AR by testosterone ( 37 – 40 ) could promote the development and progression of colon neoplasia.…”