Background: The success of using glycolytic inhibitors for cancer treatment relies on better understanding the roles of each frequently deregulated glycolytic genes in cancer. This report analyzed the involvement of a key glycolytic enzyme, alpha-enolase (ENO1), in tumor progression and prognosis of human glioma.Methods: ENO1 expression levels were examined in glioma tissues and normal brain (NB) tissues. The molecular mechanisms of ENO1 expression and its effects on cell growth, migration and invasion were also explored by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, Transwell chamber assay, Boyden chamber assay, Western blot and in vivo tumorigenesis in nude mice.Results: ENO1 mRNA and protein levels were upregulated in glioma tissues compared to NB. In addition, increased ENO1 was associated disease progression in glioma samples. Knocking down ENO1 expression not only significantly decreased cell proliferation, but also markedly inhibited cell migration and invasion as well as in vivo tumorigenesis. Mechanistic analyses revealed that Cyclin D1, Cyclin E1, pRb, and NF-κB were downregulated after stable ENO1 knockdown in glioma U251 and U87 cells. Conversely, knockdown of ENO1 resulted in restoration of E-cadherin expression and suppression of mesenchymal cell markers, such as Vimentin, Snail, N-Cadherin, β-Catenin and Slug. Furthermore, ENO1 suppression inactivated PI3K/Akt pathway regulating the cell growth and epithelial-mesenchymal transition (EMT) progression.Conclusion: Overexpression of ENO1 is associated with glioma progression. Knockdown of ENO1 expression led to suppressed cell growth, migration and invasion progression by inactivating the PI3K/Akt pathway in glioma cells.

BACKGROUND: Simultaneous intracranial and testicular germ cell tumors (GCTs) are extremely rare, leading to a lack of adequate experience in their treatment. Therefore, the authors report a case of this kind of GCT. OBSERVATIONS: A 5-year-old boy was admitted to the hospital with headache and vomiting. Computed tomography and magnetic resonance imaging suggested the possibility of a GCT in the pineal region. The value of the serum tumor marker alpha-fetoprotein (AFP) was 5,396.1 μg/L, and β-human chorionic gonadotropin levels were within the normal range. Subsequently, the tumor was removed, and the final pathological result was a mixed GCT. Therefore, chemotherapy and radiation were added. However, the authors found a testicular tumor on ultrasound at the same time, and pathology after surgery suggested a mature cystic teratoma. Following treatment, the patient recovered well, and AFP levels dropped to normal values. LESSONS: To the authors’ knowledge, this report is the fourth case of simultaneous intracranial and testicular GCTs and the first case of a simultaneous mixed GCT in the pineal region and mature teratoma of the testis. A combination of surgery, chemotherapy, and radiation therapy for mixed GCTs in the pineal region and surgical excision for testicular reproductive cell tumors are effective in these patients, but long-term monitoring is required.