Lactate dehydrogenase A promotes the invasion and proliferation of pituitary adenoma

Lactate dehydrogenase A (LDHA) has been reported to be involved in the initiation and progression of tumors. However, the potential role of LDHA in pituitary adenoma (PA) remains unknown. In this study, we showed that the expression levels of LDHA mRNA and protein were significantly elevated in invasive PA samples, and positively correlated with higher Ki-67 index. Overexpression of LDHA in a PA cell line (GH3) promoted glucose uptake through the upregulation of glucose transporter-1 (Glut1), lactate secretion and induced cellular invasion by upregulation of matrix metalloproteinase2 (MMP2). LDHA also promoted GH3 cell proliferation through induction of cell cycle progression via activation of the Akt-GSK-3β-cyclinD1 pathway. Accordingly, oxamate-induced inhibition of LDHA suppressed glucose uptake, lactate secretion, invasion and proliferation in GH3 cells via down regulation of Glut1 and MMP2 expression and inhibition of the Akt-GSK-3β-cyclinD1 pathway. Moreover, oxamate induced GH3 cell apoptosis by increasing mitochondrial reactive oxygen species (ROS) generation. In vivo, LDHA overexpression promoted tumor growth, and oxamate delayed tumor growth. In primary PA cell cultures, oxamate also effectively suppressed invasion and proliferation. Our data indicate that LDHA is involved in promoting the progression of PA, and oxamate might be a promising therapeutic agent for the treatment of PA.


Supplementary
. Laser scanning confocal microscope examination one week after LDHA transfection with lentivirus, indicating high transfection efficiencies in GH3 cells.
Supplementary Figure S2. Cell cycle distributions of GH3 cells transfected with empty vector or LDHA over expression vector were analyzed using flow cytometry.
. Laser scanning confocal microscope examination one week after LDHA transfection with lentivirus, indicating high transfection efficiencies in GH3 cells.
Cell cycle distributions of GH3 cells transfected with empty vector or LDHA over expression vector were analyzed using flow cytometry.
. Laser scanning confocal microscope examination one week after LDHA transfection with lentivirus, indicating high transfection efficiencies in GH3 cells.
Cell cycle distributions of GH3 cells transfected with empty vector or Supplementary Figure S3. GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, and cell cycle distributions were analyzed using flow cytometry.
Supplementary Figure S4. GH3 cells were pretreated with or without Licl and then treated with oxamate for 48 h, then cell cycle were analyzed using flow cytometry.
. GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, and s were analyzed using flow cytometry.
. GH3 cells were pretreated with or without Licl and then treated with , then cell cycle were analyzed using flow cytometry.
. GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, and . GH3 cells were pretreated with or without Licl and then treated with Supplementary Figure S5. A, GH3 cells were treated and cell apoptosis were analyzed using flow cytometry. B, GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, and intracellular ROS levels were analyzed by DCFH using flow cytometry. C, GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, mitochondrial membrane potential were measured by JC Supplementary . A, GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, and cell apoptosis were analyzed using flow cytometry. B, GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, and intracellular ROS levels were analyzed by DCFH , GH3 cells were treated with oxamate (0, 60 and 100 mM) for 48 h, mitochondrial membrane potential were measured by JC-1 staining using flow cytometry.