RESUMO
N6-methyladenosine (m6A) modification, the most abundant methylation modification on eukaryotic mRNAs, was implicated in the tumourigenesis. This study aimed to explore the role of methyltransferase like 3 (METTL3) in triple-negative breast cancer progression and its underlying mechanisms. FAM83D was markedly elevated in triple-negative breast cancer tissues and cells, and high expression of FAM83D was related to the poor prognosis of triple-negative breast cancer patients. FAM83D knockdown significantly retarded cell proliferation, invasion, stemness, and accelerated cell apoptosis in triple-negative breast cancer cells. On the contrary, overexpression of FAM83D promoted the malignant behaviors. METTL3 could interact with FAM83D and mediate m6A modification of FAM838D. Moreover, METTL3 positively regulated FAM83D expression, and FAM83D overexpression could block the inhibition effects of MRTTL3 knockdown on the malignant behaviors. METTL3 knockdown decreased FAM83D expression to inhibit the Wnt/ß-catenin pathway. In addition, knockdown of FAM83D also showed the repressive effects on tumor growth in triple-negative breast cancer in vivo. These findings suggested that METTL3 could modulate FAM83D protein expression through m6A modification to aggravate triple-negative breast cancer progression via the Wnt/ß-catenin pathway.
Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Linhagem Celular Tumoral , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , beta Catenina/genética , beta Catenina/metabolismo , Transformação Celular Neoplásica , Via de Sinalização Wnt , Metiltransferases/genética , Metiltransferases/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Ciclo Celular/metabolismoRESUMO
Most cancer cells preferentially metabolize glucose by glycolysis rather than oxidative phosphorylation to proliferate efficiently. LncRNAs have been proposed as crucial regulators in pathophysiological processes including cell growth, apoptosis and glucose metabolism. However, little is known regarding the specific role of LINC00346 in regulating glucose metabolism in breast cancer. LINC00346 and miR-148a/b expression in breast cancer cells was detected by qRT-PCR. The relationships between LINC00346, glucose transporter 1 (GLUT1) and miR-148a/b in breast cancer cells were explored by luciferase reporter assay. Cell proliferation and apoptosis were evaluated by CCK-8 and flow cytometry analysis, respectively. Glycolysis was detected by measuring the glucose uptake and lactate production. Results showed that LINC00346 was over-expressed while miR-148a/b was low-expressed in breast cancer cells. miR-148a/b were direct targets of LINC00346 in breast cancer cells. LINC00346 knockdown inhibited cell proliferation and glycolysis, and induced apoptosis by upregulating miR-148a/b in breast cancer cells. Furthermore, we found that LINC00346 knockdown repressed GLUT1 expression in breast cancer cells by upregulating miR-148a/b. In conclusion, LINC00346 knockdown suppressed breast cancer cell glycolysis by upregulating miR-148a/b and repressing GLUT1 expression.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Glicólise/genética , RNA Longo não Codificante/metabolismo , Apoptose/genética , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , Regulação para Cima/genéticaRESUMO
Multidrug resistance remains a major challenge in the chemotherapy of breast cancer. Guajadial, a natural meroterpenoid, has been found to possess anti-tumor activity. However, the role of guajadial in drug resistance has not been investigated. The aim of this study was to evaluate the effect of guajadial on drug resistance in drug-resistant breast cancer cells. Cell viability was measured by MTT assay, and the IC50 values were calculated. The expression of ATP-binding cassette (ABC) transporters including P-glycoprotein (P-gp) and the breast cancer resistance protein (BCRP) was detected by qRT-PCR and western blot. The expression of Akt, p-Akt, p70S6K, and p-p70S6K was determined by western blot. We found that guajadial significantly inhibited cell viability of parental non-resistant cell line MCF-7, adriamycin (ADR)-resistant cell line MCF-7/ADR, and paclitaxel (PTX)-resistant cell line MCF-7/PTX in a dose-dependent manner. Guajadial enhanced ADR and PTX sensitivity of MCF-7/ADR and MCF-7/PTX cells, and inhibited the expression of P-gp and BCRP. Guajadial treatment resulted in an inactivation of PI3K/Akt pathway in drug-resistant MCF-7â¯cells. In conclusion, guajadial acted as an inhibitor of drug resistance, which might be mediated by the inhibition of ABC transporter expression and PI3K/Akt pathway in drug-resistant breast cancer cells. These findings suggested that guajadial treatment might be a new approach to overcome the drug resistance in the chemotherapy of breast cancer.