RESUMO
Progesterone receptors (PRs) ligands are being tested in luminal breast cancer. There are mainly two PR isoforms, PRA and PRB, and their ratio (PRA/PRB) may be predictive of antiprogestin response. Our aim was to investigate: the impact of the PR isoform ratio on metastatic behaviour, the PR isoform ratio in paired primary tumours and lymph node metastases (LNM) and, the effect of antiprogestin/progestins on metastatic growth. Using murine and human metastatic models, we demonstrated that tumours with PRB > PRA (PRB-H) have a higher proliferation index but less metastatic ability than those with PRA > PRB (PRA-H). Antiprogestins and progestins inhibited metastatic burden in PRA-H and PRB-H models, respectively. In breast cancer samples, LNM retained the same PRA/PRB ratio as their matched primary tumours. Moreover, PRA-H LNM expressed higher total PR levels than the primary tumours. The expression of NDRG1, a metastasis suppressor protein, was higher in PRB-H compared to PRA-H tumours and was inversely regulated by antiprogestins/progestins. The binding of the corepressor SMRT at the progesterone responsive elements of the NDRG1 regulatory sequences, together with PRA, impeded its expression in PRA-H cells. Antiprogestins modulate the interplay between SMRT and AIB1 recruitment in PRA-H or PRB-H contexts regulating NDRG1 expression and thus, metastasis. In conclusion, we provide a mechanistic interpretation to explain the differential role of PR isoforms in metastatic growth and highlight the therapeutic benefit of using antiprogestins in PRA-H tumours. The therapeutic effect of progestins in PRB-H tumours is suggested.
Assuntos
Neoplasias da Mama , Proteínas de Ciclo Celular , Peptídeos e Proteínas de Sinalização Intracelular , Receptores de Progesterona , Animais , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/metabolismo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Metástase Neoplásica , Progesterona/farmacologia , Progestinas/metabolismo , Isoformas de Proteínas/metabolismo , Receptores de Progesterona/metabolismoRESUMO
Endocrine resistance may develop as a consequence of enhanced growth factor signaling. Fibroblast growth factor 2 (FGF2) consists of a low and several high molecular weight forms (HMW-FGF2). We previously demonstrated that antiprogestin-resistant mammary carcinomas display lower levels of progesterone receptor A isoforms (PRA) than B isoforms (PRB). Our aim was to evaluate the role of FGF2 isoforms in breast cancer progression. We evaluated FGF2 expression, cell proliferation, and pathway activation in models with different PRA/PRB ratios. We performed lentiviral infections of different FGF2 isoforms using the human hormone-responsive T47D-YA cells, engineered to only express PRA, and evaluated tumor growth, metastatic dissemination, and endocrine responsiveness. We assessed FGF2 expression and localization in 81 human breast cancer samples. Antiprogestin-resistant experimental mammary carcinomas with low PRA/PRB ratios and T47D-YB cells, which only express PRB, displayed higher levels of HMW-FGF2 than responsive variants. HMW-FGF2 overexpression in T47D-YA cells induced increased tumor growth, lung metastasis, and antiprogestin resistance compared to control tumors. In human breast carcinomas categorized by their PRA/PRB ratio, we found nuclear FGF2 expression in 55.6% of tumor cells. No differences were found between nuclear FGF2 expression and Ki67 proliferation index, tumor stage, or tumor grade. In low-grade tumor samples, moderate to high nuclear FGF2 levels were associated to carcinomas with low PRA/PRB ratio. In conclusion, we show that HMW-FGF2 isoforms are PRB targets which confer endocrine resistance and are localized in the nuclei of breast cancer samples. Hence, targeting intracellular FGF2 may contribute to overcome tumor progression.
Assuntos
Neoplasias da Mama/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Peso MolecularRESUMO
Background: Compelling evidence shows that progestins regulate breast cancer growth. Using preclinical models, we demonstrated that antiprogestins are inhibitory when the level of progesterone receptor isoform A (PR-A) is higher than that of isoform B (PR-B) and that they might stimulate growth when PR-B is predominant. The aims of this study were to investigate ex vivo responses to mifepristone (MFP) in breast carcinomas with different PR isoform ratios and to examine their clinical and molecular characteristics. Methods: We performed human breast cancer tissue culture assays (n = 36) to evaluate the effect of MFP on cell proliferation. PR isoform expression was determined by immunoblotting (n = 282). Tumors were categorized as PRA-H (PR-A/PR-B ≥ 1.2) or PRB-H (PR-A/PR-B ≤ 0.83). RNA was extracted for Ribo-Zero-Seq sequencing to evaluate differentially expressed genes. Subtypes and risk scores were predicted using the PAM50 gene set, the data analyzed using The Cancer Genome Atlas RNA-seq gene analysis and other publicly available gene expression data. Tissue microarrays were performed using paraffin-embedded tissues (PRA-H n = 53, PRB-H n = 24), and protein expression analyzed by immunohistochemistry. All statistical tests were two-sided. Results: One hundred sixteen out of 222 (52.3%) PR+ tumors were PRA-H, and 64 (28.8%) PRB-H. Cell proliferation was inhibited by MFP in 19 of 19 tissue cultures from PRA-H tumors. A total of 139 transcripts related to proliferative pathways were differentially expressed in nine PRA-H and seven PRB-H tumors. PRB-H and PRA-H tumors were either luminal B or A phenotypes, respectively ( P = .03). PRB-H cases were associated with shorter relapse-free survival (hazard ratio [HR] = 2.70, 95% confidence interval [CI] = 1.71 to 6.20, P = .02) and distant metastasis-free survival (HR = 4.17, 95% CI = 2.18 to 7.97, P < .001). PRB-H tumors showed increased tumor size ( P < .001), Ki-67 levels ( P < .001), human epidermal growth factor receptor 2 expression ( P = .04), high grades ( P = .03), and decreased total PR ( P = .004) compared with PRA-H tumors. MUC-2 ( P < .001) and KRT6A ( P = .02) were also overexpressed in PRB-H tumors. Conclusion: The PRA/PRB ratio is a prognostic and predictive factor for antiprogestin responsiveness in breast cancer.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Mifepristona/uso terapêutico , Progestinas/antagonistas & inibidores , Receptores de Progesterona/metabolismo , Adulto , Idoso , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proliferação de Células/efeitos dos fármacos , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Antagonistas de Hormônios/uso terapêutico , Humanos , Immunoblotting , Imuno-Histoquímica , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Valor Preditivo dos Testes , Progestinas/metabolismo , Prognóstico , Análise Serial de Tecidos , Resultado do Tratamento , Células Tumorais CultivadasRESUMO
While changes in heme oxygenase (HO-1) in lung cancer have already been reported, conflicting results were obtained for enzyme expression in human lung cancer specimens. Therefore, the aim of this work was to study HO-1 expression in a large collection of human lung cancer samples. For this purpose, we analyzed the expression of HO-1 in an organized tissue microarray (TMA) and investigated its correlation with clinicopathological data. Ninety-six percent of tumor samples were positive for HO-1, and the expression of HO-1 was significantly higher in cancerous than in non-cancerous tissues. Importantly, HO-1 expression correlated with advanced stages and lymph node involvement. Additionally, quantitative RT-PCR in 18 pairs of human lung carcinomas and their adjacent non-malignant tissues was performed. Our results demonstrate that HO-1 protein is upregulated in epithelial malignant cells in NSCLC and its expression is associated with higher stages of the disease. Additionally, different subcellular localization is observed between tumor and adjacent non-malignant tissues.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/enzimologia , Expressão Gênica , Heme Oxigenase-1/metabolismo , Neoplasias Pulmonares/enzimologia , Animais , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/secundário , Linhagem Celular Tumoral , Células Epiteliais/enzimologia , Células Epiteliais/patologia , Feminino , Heme Oxigenase-1/genética , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Metástase Linfática , Masculino , Camundongos , Células NIH 3T3 , Reação em Cadeia da Polimerase em Tempo Real , Análise Serial de Tecidos , Regulação para CimaRESUMO
Fibroblast growth factor receptors (FGFRs) are tyrosine kinase receptors which have been implicated in breast cancer. The aim of this study was to evaluate FGFR-1, -2, -3, and -4 protein expressions in normal murine mammary gland development, and in murine and human breast carcinomas. Using immunohistochemistry and Western blot, we report a hormonal regulation of FGFR during postnatal mammary gland development. Progestin treatment of adult virgin mammary glands resulted in changes in localization of FGFR-3 from the cytoplasm to the nucleus, while treatment with 17-ß-estradiol induced changes in the expressions and/or localizations of FGFR-2 and -3. In murine mammary carcinomas showing different degrees of hormone dependence, we found progestin-induced increased expressions, mainly of FGFR-2 and -3. These receptors were constitutively activated in hormone-independent variants. We studied three luminal human breast cancer cell lines growing as xenografts, which particularly expressed FGFR-2 and -3, suggesting a correlation between hormonal status and FGFR expression. Most importantly, in breast cancer samples from 58 patients, we found a strong association (P < 0.01; Spearman correlation) between FGFR-2 and -3 expressions and a weaker correlation of each receptor with estrogen receptor expression. FGFR-4 correlated with c-erbB2 over expression. We conclude that FGFR-2 and -3 may be mechanistically linked and can be potential targets for treatment of estrogen receptor-positive breast cancer patients.