Acylglycerol kinase promotes paclitaxel resistance in nasopharyngeal carcinoma cells by regulating FOXM1 via the JAK2/STAT3 pathway.

OBJECTIVE: Drug resistance is an important factor that impedes the treatment of nasopharyngeal cancer (NPC). Acylglycerol kinase (AGK) has been found to be overexpressed in NPC and correlates with poor prognosis. Our objective was to demonstrate the effect of AGK on paclitaxel resistance in NPC and determine the underlying mechanisms. METHODS: MTT assay was employed to determine the IC50 of paclitaxel in NPC cells after different treatments. Flow cytometry assays were employed to evaluate cell apoptosis. RT-qPCR and Western blot assays were used to detect alterations in mRNA and protein expression, respectively. Luciferase assays and chromatin immunoprecipitation (ChIP) assays were used to determine the relationship between and the regulatory effect of STAT3 on the promoter of FOXM1. RESULTS: AGK was elevated in paclitaxel-resistant NPC cells, and knockdown of AGK suppressed the resistance of CNE1-TR and CNE2-TR cells to paclitaxel. Moreover, upregulation of FOXM1 rescued the effects of AGK knockdown. Furthermore, the JAK2/STAT3 signalling pathway was overactivated in CNE1-TR and CNE2-TR cells, and knockdown of AGK suppressed JAK2/STAT3 signalling. STAT3 was verified to bind to and activate the promoter region of FOXM1. An in vivo tumour xenograft assay also verified that AGK knockdown inhibited tumour growth and mitigated paclitaxel resistance by regulating the JAK2/STAT3/FOXM1 axis. CONCLUSION: AGK levels were increased in paclitaxel-resistant NPC cells. AGK activates JAK2/STAT3 signalling, thus promoting FOXM1 transcription and eventually enhancing the drug resistance of NPC cells.

Malignant meningioma with jugular vein invasion and carotid artery extension: A case report and review of the literature.

BACKGROUND: Grade II and III meningiomas [World Health Organization (WHO) classification] rarely have extracranial metastases via the blood circulation; however, we experienced a case with a metaplastic atypical meningioma and local de-differentiation that metastasized to the jugular vein, carotid artery and subclavian artery at the cervicothoracic junction. Such cases have seldom been reported before. CASE SUMMARY: The patient was a 30-year-old man who developed right neck masses with dysphagia, labored breathing, dizziness, and occasional earaches. Eight months earlier the patient was diagnosed with a right parietal lobe neoplasm and hemorrhage at a local hospital due to the sudden onset of headaches and left limb weakness, and the post-operative pathology was a metaplastic atypical meningioma (WHO grade II) with local de-differentiation (WHO III). Magnetic resonance imaging revealed a calcified mass at the root of the neck on the right and a large cystic mass in the right parapharyngeal space. Head and neck angiography showed that the right common carotid artery was compressed and completely occluded, and the jugular vein was enveloped by the tumor and occluded. A balloon occlusion test showed no perfusion in the right common carotid artery. Tumor resection, carotid artery ligation, and subclavian artery reconstruction were performed. The tumor was a malignant meningioma. Post-operatively, the patient had Horner's syndrome and hoarseness. CONCLUSION: This case highlights the importance of the link between a large cervical mass and a primary intracranial tumor. Malignant meningioma should not be considered merely as an intracranial metastasis spread through cerebrospinal fluid, it can also be transferred through the circulation to the parapharyngeal space and the cervical great vessels.

[A study on toxic effects of sodium salicylate on rat cochlear spiral ganglion neurons: dopamine receptors mediate expressions of NMDA and GABAA receptors].

The aim of the present study was to observe whether dopamine receptor (DR) was involved in the effects of sodium salicylate (SS) on the expressions of N-methyl-D-aspartic acid (NMDA) and γ-aminobutyric acid (GABA) receptors in rat cochlear spiral ganglion neurons (SGNs). Forty-eight hours after primary culture of rat SGNs, immunofluorescence technique was applied to detect expressions of DR1 and DR2, the two subtypes of dopamine receptors. Western blot was performed to assess NMDA receptor NR1 subunit and GABAA receptor subunit α2 (GABRα2) protein expressions in the SGNs after the treatments of SS alone or in combination with DR antagonists. The results demonstrated that: (1) The DR1 and DR2 were expressed in the bodies and axons of the SGN; (2) After the treatment with SS, the surface protein expressions of GABRα2 and NR1 were decreased by 44.69% and 21.57%, respectively, while the total protein expressions showed no significant changes; (3) Neither SS + SCH23390 (DR1 antagonist) group nor SS + Eticlopride (DR2 antagonist) group showed significant differences in GABRα2 and NR1 surface protein expressions compared with the control group. These results suggest that SS regulates the surface GABAA and NMDA receptors trafficking on SGN, and the mechanism may involve DR mediation.

[Interactions between dopamine receptor and NMDA/type A γ-aminobutyric acid receptors].

Type A γ-aminobutyric acid receptors (GABAAR) and N-methyl-D-aspartate receptors (NMDAR) are the major inhibitory and excitatory receptors in the central nervous system, respectively. Co-expression of the receptors in the synapse may lead to functional influence between receptors, namely receptor interaction. The interactions between GABAAR and NMDAR can be either positive or negative. However, the mechanisms of interaction between the two receptors remain poorly understood, and potential mechanisms include (1) through a second messenger; (2) by receptors trafficking; (3) by direct interaction; (4) by a third receptor-mediation. Dopamine is the most abundant catecholamine neurotransmitter in the brain, and its receptors, dopamine receptors (DR) can activate multiple signaling pathways. Earlier studies on the interaction between DR and GABAAR/NMDAR have shown some underlying mechanisms, suggesting that DR could mediate the interaction between GABAAR and NMDAR. This paper summarized some recent progresses in the studies of the interaction between DR and NMDAR/GABAAR, providing a further understanding on the interaction between NMDAR and GABAAR mediated by DR.

[Characteristics of hearing loss in 299 high-risk neonates].

OBJECTIVE: To compare the occurrence of hearing loss in neonates with hyperbilirubinemia, hypoxic-ischemic encephalopathy (HIE) and very low-birth weight infant (VLBW) body mass, and to provide evidence for early intervention. METHODS: Totally 299 high-risk neonates (598 ears) were divided into six groups: pure hyperbilirubinemia group, pure HIE group, hyperbilirubinemia with HIE group, hyperbilirubinemia with VLBW group, HIE with LBWI group, hyperbilirubinemia with VLBW and HIE mass group. Auditory brainstem response (ABR) was detected in all groups. RESULTS: The hearing threshold of ABR and the abnormal rate of hyperbilirubinemia with LBWI and HIE were much higher than that of pure hyperbilirubinemia and pure HIE neonates. CONCLUSIONS: Of the three high-risk factors, hearing loss occurs more often and more serious in neonates with hyperbilirubinemia and with VLBW while as HIE body mass. So the babies should receive hearing screening with ABR and be treated in time or following up as early as possible.