The Role of the SOX9/lncRNA ANXA2P2/miR-361-3p/SOX9 Regulatory Loop in Cervical Cancer Cell Growth and Resistance to Cisplatin

Cervical cancer is a highly prevalent female malignancy. Presently, cisplatin (DDP) is a first-line agent for cervical cancer chemotherapy. However, its curative effect is limited because of chemo-resistance. It has been previously reported that SOX9 targeted and activated oncogenic genes, enhancing cervical cancer cell resistance to DDP. The effects of the SOX9/lncRNA ANXA2P2/miR-361-3p/SOX9 regulatory loop on cervical cancer cell growth and resistance to DDP have been demonstrated. miR-361-3p expression was decreased in DDP-resistant cervical cancer cells and tissues. Moreover, miR-361-3p overexpression inhibited the growth of resistant cervical cancer cells and the resistance to DDP, whereas miR-361-3p inhibition exerted opposite effects. miR-361-3p inhibited SOX9 expression through binding; the effects of miR-361-3p inhibition were partially reversed by SOX9 knockdown. LncRNA ANXA2P2 expression was elevated in DDP-resistant cervical cancer cells and tissues. LncRNA ANXA2P2 inhibited miR-361-3p expression by binding, thereby upregulating SOX9. LncRNA ANXA2P2 knockdown inhibited DDP-resistant cervical cancer cell growth and resistance to DDP, whereas the effects of lncRNA ANXA2P2 knockdown were partially reversed by miR-361-3p inhibition. SOX9 expression was elevated in DDP-resistant cervical cancer cells and tissues, and SOX9 activated lncRNA ANXA2P2 transcription by binding. Collectively, SOX9, lncRNA ANXA2P2, and miR-361-3p form a regulatory loop, modulating DDP-resistant cervical cancer cell growth and response to DDP treatment.

ANXA2P2/miR-9/LDHA axis regulates Warburg effect and affects glioblastoma proliferation and apoptosis

BACKGROUND

Aerobic glycolysis is a unique tumor cell phenotype considered as one of the hallmarks of cancer. Aerobic glycolysis can accelerate tumor development by increasing glucose uptake and lactate production. In the present study, lactate dehydrogenase A (LDHA) is significantly increased within glioma tissue samples and cells, further confirming the oncogenic role of LDHA within glioma.

METHODS

Hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining were applied for histopathological examination. The protein levels of LDHA, transporter isoform 1 (GLUT1), hexokinase 2 (HK2), phosphofructokinase (PFK) in target cells were detected by Immunoblotting. The predicted miR-9 binding to lncRNA Annexin A2 Pseudogene 2 (ANXA2P2) or the 3' untranslated region (UTR) of LDHA was verified using Luciferase reporter assay. Cell viability or apoptosis were examined by MTT assay or Flow cytometry. Intracellular glucose and Lactate levels were measured using glucose assay kit and lactate colorimetric assay kit.

RESULTS

The expression of ANXA2P2 showed to be dramatically upregulated within glioma tissue samples and cells. Knocking down ANXA2P2 within glioma cells significantly inhibited cell proliferation and aerobic glycolysis, as manifested as decreased lactate and increased glucose in culture medium, and downregulated protein levels of glycolysis markers, GLUT1, HK2, PFK, as well as LDHA. miR-9 was predicted to target both lncRNA ANXA2P2 and LDHA. The overexpression of miR-9 suppressed the cell proliferation and aerobic glycolysis of glioma cells. Notably, miR-9 could directly bind to LDHA 3'UTR to inhibit LDHA expression and decrease the protein levels of LDHA. ANXA2P2 competitively targeted miR-9, therefore counteracting miR-9-mediated repression on LDHA. Within tissues, miR-9 exhibited a negative correlation with ANXA2P2 and LDHA, respectively, whereas ANXA2P2 and LDHA exhibited a positive correlation with each other.

CONCLUSIONS

In conclusion, ANXA2P2/miR-9/LDHA axis modulates the aerobic glycolysis progression in glioma cells, therefore affecting glioma cell proliferation.