Targeted induction of apoptosis in glioblastoma multiforme cells by an MRP3-specific TRAIL fusion protein in vitro.

Single-chain Fv fragments (scFvs) consist of the variable heavy-chain (VH) and variable light-chain (VL) domains, which are the smallest immunoglobulin fragments containing the whole antigen-binding site. Human soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) proves to acquire a potent pro-apoptotic activity only after selective binding to a predefined tumor cell surface antigen and has no off-target effects towards normal cells. Glioblastoma multiforme (GBM) is the most frequent and aggressive type of brain tumor and overexpresses human multidrug resistance protein 3 (MRP3). In this study, we designed a novel fusion protein, termed scFvM58-sTRAIL, in which the MRP3-specific scFv antibody M58 was genetically fused to the N-terminus of human soluble TRAIL (sTRAIL). The recombinant scFvM58-sTRAIL fusion protein, expressed in Escherichia coli, was purified by chromatography and tested for cytotoxicity. scFvM58-sTRAIL showed a significant apoptosis-inducing activity towards MRP3-positive GBM cells in vitro. The pro-apoptotic activity of scFvM58-sTRAIL towards GBM cells was strongly inhibited in the presence of the parental scFvM58 antibody, suggesting that cytotoxic activity is MRP3-restricted. In a control experiment with MRP3-negative Jurkat cells, scFvM58-sTRAIL did not induce apparent apoptosis. In addition, through target antigen-restricted binding, scFvM58-sTRAIL was capable of activating not only TRAIL-R1 but also TRAIL-R2. In conclusion, our results suggest that fusion protein scFvM58-sTRAIL with specificity for MRP3 is a highly selective therapeutic agent and may provide an alternative therapy for human GBM.

Identifying FGA peptides as nasopharyngeal carcinoma-associated biomarkers by magnetic beads.

Early diagnosis and treatment is known to improve prognosis for nasopharyngeal carcinoma (NPC). The study determined the specific peptide profiles by comparing the serum differences between NPC patients and healthy controls, and provided the basis for the diagnostic model and identification of specific biomarkers of NPC. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) can be used to detect the molecular mass of peptides. Mass spectra of peptides were generated after extracting and purification of 40 NPC samples in the training set, 21 in the single center validation set and 99 in the multicenter validation set using weak cationic-exchanger magnetic beads. The spectra were analyzed statistically using FlexAnalysis™ and ClinProt™ bioinformatics software. The four most significant peaks were selected out to train a genetic algorithm model to diagnose NPC. The diagnostic sensitivity and specificity were 100% and 100% in the training set, 90.5% and 88.9% in the single center validation set, 91.9% and 83.3% in the multicenter validation set, and the false positive rate (FPR) and false negative rate (FNR) were obviously lower in the NPC group (FPR, 16.7%; FNR, 8.1%) than in the other cancer group (FPR, 39%; FNR, 61%), respectively. So, the diagnostic model including four peptides can be suitable for NPC but not for other cancers. FGA peptide fragments identified may serve as tumor-associated biomarkers for NPC.

CT-diagnosed severe skull base bone destruction predicts distant bone metastasis in early N-stage nasopharyngeal carcinoma.

Bone metastasis is the most frequent type of distant metastasis in nasopharyngeal carcinoma (NPC). In this study, we investigated the correlation between the skull base bone destruction and the distant bone metastasis in patients with NPC. A total of 449 cases with NPC who were diagnosed and had definitive radiotherapy from 2001 to 2006 were enrolled in this study. The skull base bone destruction was diagnosed by computed tomography (CT) in all cases, and 191 patients also underwent magnetic resonance imaging scan. Kaplan-Meier method was adopted to perform the univariate analysis; Cox regression model was used to perform multivariate analysis to determine whether the skull base bone destruction when diagnosed by CT was an independent impact factor of the distant bone metastases. The group with skull base bone destruction had a distant bone metastases rate of 9.0% (14/155), whereas the group without skull base bone destruction had rate of 4.1% (12/294). The multivariate analysis showed that the skull base bone destruction, when diagnosed by CT, was an independent impact factor of the distant bone metastases-free survival in the early N-staging cases, but was not an independent impact factor when diagnosed by MRI. The skull base bone destruction diagnosed by CT in patients with NPC had predictive value for the distant bone metastases, especially for the early N-staging cases.

In vivo tracking of human adipose-derived stem cells labeled with ferumoxytol in rats with middle cerebral artery occlusion by magnetic resonance imaging.

Ferumoxytol, an iron replacement product, is a new type of superparamagnetic iron oxide approved by the US Food and Drug Administration. Herein, we assessed the feasibility of tracking transplanted human adipose-derived stem cells labeled with ferumoxytol in middle cerebral artery occlusion-injured rats by 3.0 T MRI in vivo. 1 × 10(4) human adipose-derived stem cells labeled with ferumoxytol-heparin-protamine were transplanted into the brains of rats with middle cerebral artery occlusion. Neurologic impairment was scored at 1, 7, 14, and 28 days after transplantation. T2-weighted imaging and enhanced susceptibility-weighted angiography were used to observe transplanted cells. Results of imaging tests were compared with results of Prussian blue staining. The modified neurologic impairment scores were significantly lower in rats transplanted with cells at all time points except 1 day post-transplantation compared with rats without transplantation. Regions with hypointense signals on T2-weighted and enhanced susceptibility-weighted angiography images corresponded with areas stained by Prussian blue, suggesting the presence of superparamagnetic iron oxide particles within the engrafted cells. Enhanced susceptibility-weighted angiography image exhibited better sensitivity and contrast in tracing ferumoxytol-heparin-protamine-labeled human adipose-derived stem cells compared with T2-weighted imaging in routine MRI.

Alternative endpoints to the 5-year overall survival and locoregional control for nasopharyngeal carcinoma: A retrospective analysis of 2,450 patients.

The purpose of the present study was to investigate alternative endpoints to the 5-year overall survival (OS) and locoregional control (LRC) for nasopharyngeal carcinoma (NPC). A total of 2,450 NPC patients were enrolled in this study, including 1,842 patients treated with two-dimensional (2D) radiotherapy (RT), 451 treated with 3D conformal RT (CRT) and 157 treated with intensity-modulated RT (IMRT). We sequentially calculated the 1-, 2-, 3- and 4-year survival rates using a life table and compared these with the 5-year survival rate using the McNemar method, with the survival rate of the last indifferent comparison being considered as the alternative endpoint. For 2D RT, stage I patients exhibited similar survival rates at 1 and 5 years (98.9 vs. 94.4%, respectively; P=0.125 for both OS and LRC); stage N3 patients exhibited similar 4-year OS (55.2 vs. 53.5%; P=1.000) and 2-year LRC (78.3 vs. 71.2%; P=0.125) to the 5-year OS and LRC. For IMRT, the 1-, 2-, 3-, 4- and 5-year OS and LRC rates in stage I/II NPC patients were 100, 98, 96, 94 and 94% for OS and 100, 98, 96, 96 and 96% for LRC, respectively. No significant differences were observed for all the comparisons. For stage III/IV NPC patients treated with IMRT, the 1-, 2-, 3-, 4- and 5-year rates were 99.1, 96.3, 92.5, 88.8 and 85.0% for OS and 98.1, 97.2, 95.3, 90.7 and 89.7% for LRC, respectively. Only the 4-year OS and LRC rates were indifferent from those at 5 years (P=0.125 for OS and P=1.00 for LRC). In conclusion, the 1-year OS and LRC for stage I NPC patients treated with 2D RT or stage I/II NPC patients treated with IMRT, the 4-year OS and 2-year LRC for stage N3 NPC patients treated with 2D RT and the 4-year OS and LRC for stage III/IV NPC patients treated with IMRT were determined as the alternative endpoints to the 5-year OS and LRC for NPC patients.

Relationship between CYP1A1 genetic polymorphisms and renal cancer in China.

AIM: To study the potential role of cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) polymorphisms in the risk of renal cell cancer in Chinese. METHODS: A total of 181 pathologically-proven renal cancers and 350 controls from the second Xiangya Hospital in Changsha were collected during the period from May 2007 to December 2010. CYP1A1 genetic polymorphisms were genotyped using PCRRFLP. Unconditional logistic regression analysis was performed to analyze their relationship with risk of RCC. RESULTS: Individuals with Val/Val genotypes had a significantly increased risk of RCC compared those with CYP1A1 IIe/IIe (OR=1.69, 95%CI=1.03-2.85). We also found CYP1A1 Wt/Vt and Vt/Vt to confer a significantly greater risk than CYP1A1 Wt/Wt (Wt/Vt: OR=2.14, 95%CI=1.24-3.45; Vt/Vt: OR=1.78, 95%CI=1.31-3.96). In smokers, a high increase risk of RCC was observed in those with CYP1A1 Val allele and Vt allele (Val allele: OR=2.13, 95%CI=1.40-2.57; Vt allele: OR=3.75, 95%CI=2.43-6.79), but no other significant interactions were found. CONCLUSION: Our study found suggestive evidence that CYP1A1 polymorphisms may play an important role in the etiology of RCC. Cigarette smoking may increase the susceptibility to RCC carcinogenesis in individuals with a high-risk genotype.

[Effect of DNA-PKcs antisense oligodeoxynucleotides on radiosensitivity of nasopharyngeal carcinoma cell lines with different p53 function statuses].

BACKGROUND & OBJECTIVE: DNA-dependent protein kinase (DNA-PK) can repair DNA double-strand break. This study was to observe the effect of DNA-PKcs antisense oligodeoxynucleotides (ASODN) on the radiosensitivity of nasopharyngeal carcinoma (NPC) cell lines with normal or abnormal p53 functions. METHODS: DNA-PKcs ASODN was transfected into CNE-1 and CNE-1-wtp53 cells. These cells were irradiated with 0, 0.5, 1, 2, 4, 6, or 8 Gy X-ray. Cell survival was determined by clonogenic assay. The parameters D0, Dq, and N for the single-hit multitarget model and the parameters alpha, beta, alpha/beta, and SF2 for the linear-quadratic model were calculated to evaluate the changes of radiosensitivity. RESULTS: The alpha values before DNA-PKcs ASODN transfection were 0.03 in CNE-1 cells and 0.05 in CNE-1-wtp53 cells; the alpha values after transfection were 0.04 in CNE-1 cells and 0.27 in CNE-1-wtp53 cells. The SF2 before transfection were 0.73 in CNE-1 cells and 0.50 in CNE-1-wtp53 cells; the SF2 after transfection were 0.45 in CNE-1 cells and 0.21 in CNE-1-wtp53 cells. The D0 before transfection were 2.08 Gy in CNE-1 cells and 1.13 Gy in CNE-1-wtp53 cells; the D0 after transfection were 1.07 Gy in CNE-1 cells and 0.83 Gy in CNE-1-wtp53 cells. The Dq before transfection were 2.04 Gy in CNE-1 cells and 1.36 Gy in CNE-1-wtp53 cells; the Dq after transfection were 1.24 Gy in CNE-1 cells and 0.73 Gy in CNE-1-wtp53 cells. The parameter alpha of CNE-1 cells was increased after DNA-PKcs ASODN transfection, but the parameters SF2, D0, and Dq were decreased after transfection. CONCLUSION: DNA-PKcs ASODN could enhance the radiosensitivity of CNE-1 cells regardless of p53 function status.