Discovery of ellagic acid as a competitive inhibitor of Src homology phosphotyrosyl phosphatase 2 (SHP2) for cancer treatment: In vitro and in silico study.

Targeting SHP2 has become a potential cancer treatment strategy. In this study, ellagic acid was first reported as a competitive inhibitor of SHP2, with an IC50 value of 0.69 ± 0.07 µM, and its inhibitory potency was 34.86 times higher that of the positive control NSC87877. Ellagic acid also had high inhibitory activity on the SHP2-E76K and SHP2-E76A mutants, with the IC50 values of 1.55 ± 0.17 µM and 0.39 ± 0.05 µM, respectively. Besides, the IC50 values of ellagic acid on homologous proteins SHP1, PTP1B, and TCPTP were 0.93 ± 0.08 µM, 2.04 ± 0.28 µM, and 11.79 ± 0.83 µM, with selectivity of 1.35, 2.96, and 17.09 times, respectively. The CCK8 proliferation experiment exhibited that ellagic acid would inhibit the proliferation of various cancer cells. It was worth noting that the combination of ellagic acid and KRASG12C inhibitor AMG510 would produce a strong synergistic effect in inhibiting NCI-H358 cells. Western blot experiment exhibited that ellagic acid would downregulate the phosphorylation levels of Erk and Akt in NCI-H358 and MDA-MB-468 cells. Molecular docking and molecular dynamics studies revealed the binding information between SHP2 and ellagic acid. In summary, this study provides new ideas for the development of SHP2 inhibitors.

Follow-up Results and Clinical Significance of Magnetic Resonance Spectroscopy Combined with Fluorescence Microscopy in Resection of High Grade Supra-tentoria Gliomas.

Objective To investigate the clinical effectiveness of magnetic resonance spectroscopy (MRS) combined with sodium fluorescein(FL) in the treatment of high grade gliomas(HGG). Methods From August 2013 to 2015 November,the clinical data of 72 supratentorial HGG(WHO grade Ⅲ-Ⅳ) patients who had received surgical treatment in our hospital were retrospectively studied,among whom 43 cases received MRS combined with intra-perative FL navigation(observation group),and 29 cases only received conventional surgery(control group). Post-operative radiotherapy and chemotherapy were applied for more than 3 months. Routine enhanced MRI were performed 24-48 hours after the operation to investigate the extent of tumor resection. Six months after the operation,the quality of life of patients was evaluated by using the Karnofsky score,and 1-year postoperative survival rate and progression-free survival(PFS) were observed. Results Postoperative MRI showed that the rate of gross total resection(GTR) in observation group was significantly higher than that in control group(72.09%vs.51.72%;χ2=23.88,P=0.001),and the GTR rate of WHO grade Ⅳ tumors was significantly higher than that of WHO grade Ⅲ tumors in observation group(92.86% vs.62.07%;χ2=6.06,P=0.042). The postoperative Karnofsky score in the observation group was significantly higher than that in control group(µ=2.34,P=0.021). The mean time of follow-up was(16.4±2.4) months(8-21 months) and there was no statistical significant difference between observation group and control group in 1-year survival rate(74.07% vs.77.50%;χ2=4.90,P=0.165) and PFS [(13.2±1.2) months vs.(12.7±2.0) months;χ2=7.26,P=0.067]. In observation group,the PFS of WHO grade Ⅳ patients was significantly higher than that in control group [(14.2±0.3) months vs.(10.0±1.1) months;χ2=11.03,P=0.031]. There was also no statistical significant difference between WHO grade Ⅳ tumors in two groups in terms of 1-year survival rate(71.43% vs.72.54%;χ2=5.33,P=0.089),and there was no statistical significant difference between WHO grade Ⅲ tumors in two groups in 1-year survival rate(75.86% vs. 72.22%;χ2=3.78,P=0.250) and in PFS [(13.7±1.4) months vs.(12.4±0.8) months;χ2=4.85,P=0.083]. Conclusions MRS combined with intraoperative FL navigation technology can improve the resection rate and improve survival quality of patients,and there is no evidence that MRS combined with intraoperative FL navigation prolong the overall survival of patients with high-grade gliomas. Different outcome may be found with longer follow-up and increased simple size.

Major Metabolite Levels of Preoperative Proton Magnetic Resonance Sectroscopy and Intraoperative Fluorescence Intensity in Glioblastoma.

Objective To compare the intraoperative major metabolite level of preoperative proton magnetic resonance spectroscopy(1H-MRS)and fluorescence intensity marked with fluorescein sodium(FLs)in glioblastoma(GBM)and thus provide an objective basis for fluorescence surgical treatment of GBM. Methods All newly diagnosed patients by plain and enhanced magnetic resonance imaging from the April 1,2014 to December 31,2015 were enrolled in this study.All of them received 1H-MRS and marked with FLs.The expression of Ki67 in tumor boundary were confirmed by postoperative pathology and determined by immunostaining assay.The relationship between 1H-MRS metabolite levels and tumor fluorescence intensity was analyzed. Results Totally 33 patients were included in the study.Preoperative 1H-MRS revealed high-grade gliomas in 25 cases.The N-acetylaspartate(NAA)decreased significantly and choline(Cho)increased significantly in high-grade gliomas.The ratios of Cho/NAA,NAA/creatine(Cr),and Cho/Cr significantly differed in different tumor regions(P=0.02,P=0.01,and P=0.00,respectively).Surgical results were marked with FLs intraoperatively.Tissue fluorescence were clearly seen.There were 29 patients undergoing total resection and 4 cases undergoing subtotal resection.No acute encephalocele occured after operation,while 2 patients suffered from epilepsy.Postoperative pathology results included:28 cases were diagnosed as GBM(22 cases consistent with 1H-MRS diagnosis).The results of GBM fluorescence imaging included:the level of fluorescence intensity in tumor parenchyma was significantly higher than that in tumor boundary and peritumoral edema(P=0.01).The result of 1H-MRS metabolite analysis included:The kurtosis of NAA and of Cho and the ratio of Cho/NAA were significantly different according the fluorescence intensity in tumor parenchyma(P=0.01,P=0.02,and P=0.01).While there was no difference in the kurtosis of NAA,the kurtosis of Cho and the ratio of Cho/NAA were significantly different according the fluorescence intensity in tumor boundary(P=0.02, P=0.00).In peritumoral edema,there was no significant different in kurtosis of NAA and of Cho and in the ratio of Cho/NAA(P=0.23,P=0.09,P=0.14).Immunohistochemistry in GBM tumor boundary showed different Ki67 expressions according to different fluorescence imaging(P=0.03). Conclusions The fluorescence intensity in GBM parenchyma is higher than that in other tumor regions,and there are different metabolic levels in different fluorescence intensity.The metabolic information marked by FLs and provided by 1H-MRS before operationis are important,and the correlation between them should be further investigated.

LRIG1 enhances the radiosensitivity of radioresistant human glioblastoma U251 cells via attenuation of the EGFR/Akt signaling pathway.

The radiotherapy as a local and regional modality is widely applied in treatment of glioma, but most glioblastomas are commonly resistant to irradiation treatment. It remains challengeable to seek out efficient strategies to conquer the resistance of human glioblastoma cells to radiotherapy. Leucine-rich repeats and immunoglobulin-like domains protein 1 (LRIG1) is a newly discovered tumor suppressor which involved in regulation of chemosensitivity in various human cancer cells. In the present study, we established a radioresistant U251 cell line (U251R) to investigate the role of LRIG1 in regulation of radiosensitivity in human glioblastoma cells. Significantly decreased expression level of LRIG1 and enhanced expression of EGFR and phosphorylated Akt were detected in U251R cells compared with the parental U251 cells. U251R cells exhibited an advantage in colony formation ability, which accompanied by remarkably reduced X-ray-induced γ-H2AX foci formation and cell apoptosis. LRIG1 overexpression significantly inhibited the colony formation ability of U251R cells and obviously enhanced X-ray-inducedγ-H2AX foci formation and cell apoptosis. In addition, up-regulated expression of LRIG1 suppressed the expression level of EGFR and phosphorylated Akt protein. Our results demonstrated that LRIG1 expression was related to the radiosensitivity of human glioblastoma cells and may play an important role in the regulation of cellular radiosensitivity of human glioblastoma cells through the EGFR/Akt signaling pathway.