F-box and WD repeat domain-containing 7 (FBXW7) mediates the hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway to affect hypoxic-ischemic brain damage in neonatal rats

Mechanism of HIF-1α promoting proliferation, invasion and metastasis of nasopharyngeal carcinoma by regulating MMP-2 in hypoxic microenvironment

Objective

To explore the mechanism of HIF-1α promoting the proliferation, invasion and metastasis of nasopharyngeal carcinoma cells by regulating the expression of MMP-2.

Methods

30 nasopharyngeal carcinoma tissues and 30 normal nasopharyngeal epithelial tissues were collected, and the expression of HIF-1α and MMP-2 in the nasopharyngeal carcinoma, normal nasopharyngeal epithelial tissues and their hypoxic environment were systematically analyzed by qRT-PCR and western blot techniques. Lentivirus transfection technology was used to regulate the expression of HIF-1α and MMP-2 genes in the HONE1 cell line under hypoxic environment, and to explore the interaction mechanism of HIF-1α and MMP-2 genes and their role in the proliferation, invasion and metastasis of nasopharyngeal carcinoma. Furthermore, the cytological behavior changes regulated by HIF-1α and MMP-2 genes were further explored by gene chip technology.

Results

The expressions of HIF-1α and MMP-2 in nasopharyngeal carcinoma tissues were significantly higher than those in normal nasopharyngeal epithelial tissues (P < 0.05). Compared with normoxic group, the expression of HIF-1α and MMP-2 in the nasopharyngeal carcinoma cell line HONE1 increased in hypoxic group (P < 0.05). Compared with NC-siRNA group, the expression of HIF-1α in si-HIF-1α group decreased, and the cell proliferation ability and invasion and metastasis ability decreased (P < 0.05). PCR array analysis revealed that the mRNA expressions of FAS, BRCA1, TIMP-1 genes were up-regulated in nasopharyngeal carcinoma HONE1 cells with HIF-1α gene silencing. AKT1, VEGFA, MET, MMP-2, MMP-9 and MTA2 were down-regulated. Compared with NC-siRNA group, the expression of MMP-2 in si-MMP-2 group decreased, and the ability of cell proliferation and invasion and metastasis decreased (P < 0.05).

Conclusion

HIF-1α could inhibit the proliferation, invasion and metastasis of nasopharyngeal carcinoma by regulating the expression of MMP-2, thus inhibiting tumor growth. Therefore, HIF-1α and MMP-2 might become important therapeutic targets to inhibit the growth, invasion and metastasis of nasopharyngeal carcinoma.

Protein Stability Regulation in Osteosarcoma: The Ubiquitin-like Modifications and Glycosylation as Mediators of Tumor Growth and as Targets for Therapy

The identification of new therapeutic targets and the development of innovative therapeutic approaches are the most important challenges for osteosarcoma treatment. In fact, despite being relatively rare, recurrence and metastatic potential, particularly to the lungs, make osteosarcoma a deadly form of cancer. In fact, although current treatments, including surgery and chemotherapy, have improved survival rates, the disease's recurrence and metastasis are still unresolved complications. Insights for analyzing the still unclear molecular mechanisms of osteosarcoma development, and for finding new therapeutic targets, may arise from the study of post-translational protein modifications. Indeed, they can influence and alter protein structure, stability and function, and cellular interactions. Among all the post-translational modifications, ubiquitin-like modifications (ubiquitination, deubiquitination, SUMOylation, and NEDDylation), as well as glycosylation, are the most important for regulating protein stability, which is frequently altered in cancers including osteosarcoma. This review summarizes the relevance of ubiquitin-like modifications and glycosylation in osteosarcoma progression, providing an overview of protein stability regulation, as well as highlighting the molecular mediators of these processes in the context of osteosarcoma and their possible targeting for much-needed novel therapy.

The Ubiquitin-Proteasome System in Tumor Metabolism

Metabolic reprogramming, which is considered a hallmark of cancer, can maintain the homeostasis of the tumor environment and promote the proliferation, survival, and metastasis of cancer cells. For instance, increased glucose uptake and high glucose consumption, known as the "Warburg effect," play an essential part in tumor metabolic reprogramming. In addition, fatty acids are harnessed to satisfy the increased requirement for the phospholipid components of biological membranes and energy. Moreover, the anabolism/catabolism of amino acids, such as glutamine, cystine, and serine, provides nitrogen donors for biosynthesis processes, development of the tumor inflammatory environment, and signal transduction. The ubiquitin-proteasome system (UPS) has been widely reported to be involved in various cellular biological activities. A potential role of UPS in the metabolic regulation of tumor cells has also been reported, but the specific regulatory mechanism has not been elucidated. Here, we review the role of ubiquitination and deubiquitination modification on major metabolic enzymes and important signaling pathways in tumor metabolism to inspire new strategies for the clinical treatment of cancer.

Further Evidence of Neuroprotective Effects of Recombinant Human Erythropoietin and Growth Hormone in Hypoxic Brain Injury in Neonatal Mice

Experimental in vivo data have recently shown complementary neuroprotective actions of rhEPO and growth hormone (rhGH) in a neonatal murine model of hypoxic brain injury. Here, we hypothesized that rhGH and rhEPO mediate stabilization of the blood−brain barrier (BBB) and regenerative vascular effects in hypoxic injury to the developing brain. Using an established model of neonatal hypoxia, neonatal mice (P7) were treated i.p. with rhGH (4000 µg/kg) or rhEPO (5000 IU/kg) 0/12/24 h after hypoxic exposure. After a regeneration period of 48 h or 7 d, cerebral mRNA expression of Vegf-A, its receptors and co-receptors, and selected tight junction proteins were determined using qRT-PCR and ELISA. Vessel structures were assessed by Pecam-1 and occludin (Ocln) IHC. While Vegf-A expression increased significantly with rhGH treatment (p < 0.01), expression of the Vegfr and TEK receptor tyrosine kinase (Tie-2) system remained unchanged. RhEPO increased Vegf-A (p < 0.05) and Angpt-2 (p < 0.05) expression. While hypoxia reduced the mean vessel area in the parietal cortex compared to controls (p < 0.05), rhGH and rhEPO prevented this reduction after 48 h of regeneration. Hypoxia significantly reduced the Ocln+ fraction of cortical vascular endothelial cells. Ocln signal intensity increased in the cortex in response to rhGH (p < 0.05) and in the cortex and hippocampus in response to rhEPO (p < 0.05). Our data indicate that rhGH and rhEPO have protective effects on hypoxia-induced BBB disruption and regenerative vascular effects during the post-hypoxic period in the developing brain.

The effect and mechanism of dl-3-n-butylphthalide on angiogenesis in a rat model of chronic myocardial ischemia

OBJECTIVE

To assess the effect of dl-3-n-butylphthalide (NBP) on angiogenesis and its underlying mechanism in a rat model of chronic myocardial ischemia (CMI).

METHODS

Forty Sprague-Dawley rats were randomly divided into four groups: model, low-dose NBP (L-NBP), middle-dose NBP (M-NBP), or high-dose NBP (H-NBP) (n=10/group). All groups received intraperitoneal injections of isoprinosine hydrochloride daily for 14 days. Additionally, the L-NBP, M-NBP, and H-NBP groups received NBP at 3, 6, and 12 mg per kg body weight, respectively, by intraperitoneal injection. An additional 10 rats (control group) received 0.9% sodium chloride via intraperitoneal injection for 14 consecutive days. Echocardiography was used for the measurement of heart function. Immunohistochemical staining for factor VIII-related antigen and microvascular density determination were performed. The protein and mRNA expression of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) in CMI areas were measured by western blot and RT-PCR, respectively.

RESULTS

Electrocardiograms showed that NBP improved cardiac function by regulating left ventricular end-diastolic and end-systolic diameters, ejection fraction, and fractional shortening. Compared with the control and model groups, the L-NBP, M-NBP, and H-NBP groups showed increased mRNA and protein expression of VEGFA and HIF-1α in myocardial tissue. The mRNA and protein expression of VEGFA and HIF-α in the H-NBP group were the highest.

CONCLUSION

NBP treatment promotes VEGF and HIF-1α protein expression during myocardial ischemia, which may represent useful biomarkers for coronary collateral establishment and offer potential targets for therapeutic induction of angiogenesis in patients with CMI.

Research advances in the role of endogenous neurogenesis on neonatal hypoxic-ischemic brain damage

Hypoxic-ischemic brain damage (HIBD) is the main cause of perinatal mortality and neurologic complications in neonates, but it remains difficult to cure due to scarce treatments and complex molecular mechanisms remaining incompletely explained. Recent, mounting evidence shows that endogenous neurogenesis can improve neonatal neurological dysfunction post-HIBD. However, the capacity for spontaneous endogenous neurogenesis is limited and insufficient for replacing neurons lost to brain damage. Therefore, it is of great clinical value and social significance to seek therapeutic techniques that promote endogenous neurogenesis, to reduce neonatal neurological dysfunction from HIBD. This review summarizes the known neuroprotective effects of, and treatments targeting, endogenous neurogenesis following neonatal HIBD, to provide available targets and directions and a theoretical basis for the treatment of neonatal neurological dysfunction from HIBD.