RESUMO
INTRODUCTION: Prolactinomas are the most frequent pituitary tumor subtype. Despite most of them respond to medical treatment, a proportion are resistant and become a challenge in clinical management. Wnt/ß-Catenin pathway has been implicated in several cancers including pituitary tumors and other sellar region malignancies. Interestingly, Wnt/ß-Catenin inhibition augments the cytotoxicity of the chemotherapeutic agent Temozolomide (TMZ) in different cancers. TMZ is now being implemented as rescue therapy for aggressive pituitary adenoma treatment. However, the molecular mechanisms associated with TMZ action in pituitary tumors remain unclear. OBJECTIVES: Our aims in the present study were to evaluate differential ß-Catenin expression in human resistant prolactinomas and Wnt/ß-Catenin signaling activation and involvement in Prolactin (PRL) secreting experimental models treated with TMZ. RESULTS: We first evaluated by immunohistochemistry ß-Catenin localization in human resistant prolactinomas in which we demonstrated reduced membrane ß-Catenin in prolactinoma cells compared to normal pituitaries, independently of the Ki-67 proliferation indexes. In turn, in vivo 15âmg/kg of orally administered TMZ markedly reduced PRL production and increased prolactinoma cell apoptosis in mice bearing xenografted prolactinomas. Intratumoral ß-Catenin strongly correlated with Prl and Cyclin D1, and importantly, TMZ downregulated both ß-Catenin and Cyclin D1, supporting their significance in prolactinoma growth and as candidates of therapeutic targets. When tested in vitro, TMZ directly reduced MMQ cell viability, increased apoptosis and produced G2/M cell cycle arrest. Remarkably, ß-Catenin activation and VEGF secretion were inhibited by TMZ in vitro. CONCLUSIONS: We concluded that dopamine resistant prolactinomas undergo a ß-Catenin relocalization in relation to normal pituitaries and that TMZ restrains experimental prolactinoma tumorigenicity by reducing PRL production and ß-Catenin activation. Together, our findings contribute to the understanding of Wnt/ß-Catenin implication in prolactinoma maintenance and TMZ therapy, opening the opportunity of new treatment strategies for aggressive and resistant pituitary tumors.
Assuntos
Neoplasias Hipofisárias , Prolactinoma , Animais , Ciclina D1 , Humanos , Camundongos , Modelos Teóricos , Neoplasias Hipofisárias/patologia , Prolactina/metabolismo , Prolactina/uso terapêutico , Prolactinoma/tratamento farmacológico , Prolactinoma/metabolismo , Prolactinoma/patologia , Temozolomida/farmacologia , Temozolomida/uso terapêutico , beta CateninaRESUMO
RESEARCH QUESTION: Does resveratrol exert a potent inhibitory effect on the development of endometriosis by interfering with some pivotal processes? DESIGN: In-vitro cultures of primary endometriotic stromal cells, immortalized endometrial stromal (St-T1b) and endometriotic epithelial (12Z) cells were used to assess the effects of resveratrol on endometrial cell mechanisms. The effects of resveratrol on 12Z and St-T1b cell viability were assessed by MTT assay, apoptosis by FITC Annexin V assay and cleaved caspase-3 levels and cell migration by wound healing assay. The effect of resveratrol on the expression of genes related to cell migration, angiogenesis and cell stemness was evaluated by qRT-PCR. RESULTS: Resveratrol significantly decreased cell viability (P= 0.0065 to Pâ¯=â¯0.0180), cell migration (P < 0.001 to Pâ¯=â¯0.0225) and increased the number of apoptotic cells (Pâ¯=â¯0.0031 to Pâ¯=â¯0.0432) in both cell lines. In cell lines and primary culture, the treatment reduced MMP-2/TIMP-1 (P < 0.001 to Pâ¯=â¯0.0180), VEGF (Pâ¯=â¯0.0052 to Pâ¯=â¯0.0243) and Ang-1 mRNA (P < 0.001 to Pâ¯=â¯0.0382) expression. Among the stem cell phenotype markers, resveratrol 100 µM increased mRNA expression levels of Notch-1 (P < 0.001 to Pâ¯=â¯0.0018), KLF-4 (Pâ¯=â¯0.0011 to Pâ¯=â¯0.0137), SOX-2 (P < 0.001 to Pâ¯=â¯0.0070) and TERT (P < 0.001 to Pâ¯=â¯0.0193) in both cell lines and primary cultures. The mRNA expression level of Snail-1 increased in the cell lines (P < 0.001 to Pâ¯=â¯0.0087), whereas OCT-4 mRNA expression increased in St-T1b (Pâ¯=â¯0.0396) and primary cultures (Pâ¯=â¯0.0148). Vimentin mRNA expression showed a significant upregulation in primary cultures (P < 0.001). The expression of Msi-1 (Pâ¯=â¯0.0145) and NANOG (Pâ¯=â¯0.0080) decreased only in St-T1b cells. CONCLUSION: Resveratrol showed inhibitory effects on cell behaviour related to the development of endometriosis by differentially affecting growth, apoptosis, migration and stem cell phenotype of endometrial and endometriotic cells in vitro.
Assuntos
Endometriose , Endometriose/patologia , Endométrio/metabolismo , Feminino , Humanos , RNA Mensageiro/metabolismo , Resveratrol/farmacologia , Células Estromais/metabolismoRESUMO
Glycosaminoglycans (GAGs) and proteoglycans (PGs) are major components of the glycocalyx. The secreted GAG and CD44 ligand hyaluronic acid (HA), and the cell surface PG syndecan-1 (Sdc-1) modulate the expression and activity of cytokines, chemokines, growth factors, and adhesion molecules, acting as critical regulators of tumor cell behavior. Here, we studied the effect of Sdc-1 siRNA depletion and HA treatment on hallmark processes of cancer in breast cancer cell lines of different levels of aggressiveness. We analyzed HA synthesis, and parameters relevant to tumor progression, including the stem cell phenotype, Wnt signaling constituents, cell cycle progression and apoptosis, and angiogenic markers in luminal MCF-7 and triple-negative MDA-MB-231 cells. Sdc-1 knockdown enhanced HAS-2 synthesis and HA binding in MCF-7, but not in MDA-MB-231 cells. Sdc-1-depleted MDA-MB-231 cells showed a reduced CD24-/CD44+ population. Furthermore, Sdc-1 depletion was associated with survival signals in both cell lines, affecting cell cycle progression and apoptosis evasion. These changes were linked to the altered expression of KLF4, MSI2, and miR-10b and differential changes in Erk, Akt, and PTEN signaling. We conclude that Sdc-1 knockdown differentially affects HA metabolism in luminal and triple-negative breast cancer model cell lines and impacts the stem phenotype, cell survival, and angiogenic factors.