Combined treatment of Nimotuzumab and rapamycin is effective against temozolomide-resistant human gliomas regardless of the EGFR mutation status.

BACKGROUND: The treatment of glioblastoma multiforme (GBM) is an unmet clinical need. The 5-year survival rate of patients with GBM is less than 3%. Temozolomide (TMZ) remains the standard first-line treatment regimen for gliomas despite the fact that more than 90% of recurrent gliomas do not respond to TMZ after repeated exposure. We have also independently shown that many of the Asian-derived glioma cell lines and primary cells derived from Singaporean high-grade glioma patients are indeed resistant to TMZ. This issue highlights the need to develop new effective anti-cancer treatment strategies. In a recent study, wild-type epidermal growth factor receptor (wtEGFR) has been shown to phosphorylate a truncated EGFR (known as EGFRvIII), leading to the phosphorylation of STAT proteins and progression in gliomagenesis. Despite the fact that combination of EGFR targeting drugs and rapamycin has been used before, the effect of mono-treatment of Nimotuzumab, rapamycin and combination therapy in human glioma expressing different types of EGFR is not well-studied. Herein, we evaluated the efficacy of dual blockage using monoclonal antibody against EGFR (Nimotuzumab) and an mTOR inhibitor (rapamycin) in Caucasian patient-derived human glioma cell lines, Asian patient-derived human glioma cell lines, primary glioma cells derived from the Mayo GBM xenografts, and primary short-term glioma culture derived from high-grade glioma patients. METHODS: The combination effect of Nimotuzumab and rapamycin was examined in a series of primary human glioma cell lines and glioma cell lines. The cell viability was compared to TMZ treatment alone. Endogenous expressions of EGFR in various GBM cells were determined by western blotting. RESULTS: The results showed that combination of Nimotuzumab with rapamycin significantly enhanced the therapeutic efficacy of human glioma cells compared to single treatment. More importantly, many of the Asian patient-derived glioma cell lines and primary cells derived from Singaporean high-grade gliomas, which showed resistance to TMZ, were susceptible to the combined treatments. CONCLUSIONS: In conclusion, our results strongly suggest that combination usage of Nimotuzumab and rapamycin exert higher cytotoxic activities than TMZ. Our data suggest that this combination may provide an alternative treatment for TMZ-resistant gliomas regardless of the EGFR status.

Utility of the sendai consensus guidelines for branch-duct intraductal papillary mucinous neoplasms: a systematic review.

INTRODUCTION: The Sendai Consensus Guidelines (SCG) was formulated in 2006 to guide the management of intraductal papillary mucinous neoplasms (IPMN). The main area of controversy is the criteria for selection of branch duct (BD)-IPMN for resection. Although these guidelines have gained widespread acceptance, there is limited data to date supporting its use. This systematic review is performed to evaluate the utility of the Sendai Consensus Guidelines (SCG) for BD-IPMN. METHODS: Studies evaluating the clinical utility of the SCG in surgically resected neoplasms were identified. The SCG were retrospectively applied to all resected neoplasms in these studies. BD-IPMNs which met the criteria for resection were termed SCG+ve and those for surveillance were termed SCG-ve. RESULTS: Twelve studies were included, of which, 9 were suitable for pooled analysis. There were 690 surgically resected BD-IPMNs, of which, 24% were malignant. Five hundred one BD-IPMNs were classified as SCG+ve and 189 were SCG-ve. The positive predictive value (PPV) of SCG+ve neoplasms ranged from 11 to 52% and the NPV of SCG-ve neoplasms ranged from 90 to 100%. Overall, there were 150/501 (29.9%) of malignant BD-IPMNs in the SCG+ve group and 171/189 (90%) of benign BD-IPMNs in the SCG-ve group. Of the 18 reported malignant (11 invasive) BD-IPMNs in the SCG-ve group, 17 (including all 11 invasive) were from a single study. When the results from this single study were excluded, 170/171 (99%) of SCG-ve BD-IPMNs were benign. CONCLUSION: The results of this review confirm the limitations of the SCG for BD-IPMN. The PPV of the SCG in predicting a malignant BD-IPMN was low and some malignant lesions may be missed based on these guidelines.