RESUMO
Progesterone and progestins have been demonstrated to enhance breast cancer cell migration, although the mechanisms are still not fully understood. The protease-activated receptors (PARs) are a family of membrane receptors that are activated by serine proteases in the blood coagulation cascade. PAR1 (F2R) has been reported to be involved in cancer cell migration and overexpressed in breast cancer. We herein demonstrate that PAR1 mRNA and protein are upregulated by progesterone treatment of the breast cancer cell lines ZR-75 and T47D. This regulation is dependent on the progesterone receptor (PR) but does not require PR phosphorylation at serine 294 or the PR proline-rich region mPRO. The increase in PAR1 mRNA was transient, being present at 3â h and returning to basal levels at 18 âh. The addition of a PAR1-activating peptide (aPAR1) to cells treated with progesterone resulted in an increase in focal adhesion (FA) formation as measured by the cellular levels of phosphorylated FA kinase. The combined but not individual treatment of progesterone and aPAR1 also markedly increased stress fiber formation and the migratory capacity of breast cancer cells. In agreement with in vitro findings, data mining from the Oncomine platform revealed that PAR1 expression was significantly upregulated in PR-positive breast tumors. Our observation that PAR1 expression and signal transduction are modulated by progesterone provides new insight into how the progestin component in hormone therapies increases the risk of breast cancer in postmenopausal women.
Assuntos
Neoplasias da Mama/patologia , Carcinoma/patologia , Movimento Celular/efeitos dos fármacos , Adesões Focais/efeitos dos fármacos , Progesterona/farmacologia , Receptor PAR-1/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Avaliação Pré-Clínica de Medicamentos , Feminino , Adesões Focais/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes erbB-1/fisiologia , Humanos , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 1/fisiologia , Pós-Menopausa/genética , Pós-Menopausa/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismo , Proteínas Proto-Oncogênicas pp60(c-src)/fisiologia , Receptor PAR-1/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
2-Methoxyestradiol (2ME) is an endogenous metabolite of 17ß-estradiol with antiangiogenic and antitumor properties, although its mechanisms of action remain unclear. Progestins in hormone replacement therapy increase the risk of breast cancer. Progesterone also enhances the procoagulant activity and invasive potential of progesterone receptor (PR)-positive breast cancer cell lines, an effect largely mediated by induction of tissue factor (TF), the cellular activator of the coagulation cascade. Here we show that 2ME abrogates the induction TF expression in progesterone-treated breast cancer cells via a mechanism that does not involve the estrogen receptor. Instead, we demonstrate that by selectively antagonizing ERK1/2 signaling in breast cancer cells, 2ME limits the transactivation potential of ligand-bound PR and inhibits the expression of endogenous progesterone targets, such as TF and signal transducer and activator of transcription 5. We further demonstrate that 2ME can alter the phosphorylation status of PR. Thus, 2ME prevents progesterone-dependent increase in breast cancer cell invasiveness and procoagulant activity by uncoupling PR from the ERK1/2 signal transduction pathway.
Assuntos
Neoplasias da Mama/metabolismo , Estradiol/análogos & derivados , Progesterona/metabolismo , Tromboplastina/biossíntese , Moduladores de Tubulina/farmacologia , 2-Metoxiestradiol , Western Blotting , Linhagem Celular Tumoral , Estradiol/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ativação Transcricional/efeitos dos fármacos , TransfecçãoRESUMO
Cancers of the reproductive tract account for 12% of all malignancies in women. As previous studies have shown that oestrogen metabolites can cause apoptosis, we characterised the effect of oestrogen and oestrogen metabolites on non-cancerous and cancerous human endometrial cells. Herein, we demonstrate that 2-methoxyoestradiol (2ME), but not 17beta-oestradiol, induces apoptosis in cancer cell lines and primary cultured tumours of endometrial origin. In contrast, 2ME had no effect on cell viability of corresponding normal tissue. This ability of 2ME to induce apoptosis does not require oestrogen receptor activation, but is associated with increased entry into the G2/M phases of the cell cycle and the activation of both the intrinsic and the extrinsic apoptotic pathways. The selective behaviour of 2ME on cancerous as opposed to normal tissue may be due to a reduction in 17beta-hydroxysteroid dehydrogenase type II levels in cancer cells and to a differential down-regulation of superoxide dismutase. Furthermore, we demonstrate that pre-treatment with 2ME enhances the sensitivity of reproductive tract cancer cells to the apoptotic drug tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), without the loss in cell viability to normal cells incurred by currently chemotherapeutic drugs. In conclusion, 2ME, alone or in combination with TRAIL, may be an effective treatment for cancers of uterine origin with minimal toxicity to corresponding healthy female reproductive tissue.
Assuntos
Apoptose , Neoplasias do Endométrio/enzimologia , Estriol/análogos & derivados , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , 17-Hidroxiesteroide Desidrogenases/metabolismo , Antineoplásicos/farmacologia , Caspases/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Endométrio/efeitos dos fármacos , Endométrio/enzimologia , Estriol/farmacologia , Estrogênios/metabolismo , Estrogênios/farmacologia , Feminino , Humanos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismoRESUMO
Progesterone in hormonal preparations increases the incidence of breast cancer. Tissue factor (TF), the initiator of the extrinsic coagulation pathway, is associated with metastasis in a wide variety of cancers. We demonstrate herein that TF mRNA and protein are up-regulated by progesterone in the breast cancer cell line ZR-75. Epidermal growth factor, also associated with increased breast cancer risk, did not regulate TF. The increase in TF is both rapid and transient; increasing after 6 h, reaching a maximum at 24 h, before decreasing to basal levels at 72 h. Sucrose gradient experiments demonstrated that TF is located in the heavy fraction of the plasma membrane, although caveolin-1 is not expressed in ZR-75. To understand the physiological implications of an increase in TF, we performed coagulation and invasion assays. An increase in TF corresponded to an increase in procoagulant activity. Furthermore, progesterone increased the invasion of ZR-75 cells through a matrigel, an effect that was blocked by an antibody against TF. Because TF expression is associated with an enhanced risk of metastasis, we postulate that the progesterone-dependent up-regulation of TF provides a survival advantage to burgeoning breast cancer cells and may contribute to the increased risk of cancer associated with combined hormone replacement therapy.