Preparation and Characterization of Fe3O4@MTX Magnetic Nanoparticles for Thermochemotherapy of Primary Central Nervous System Lymphoma in vitro and in vivo.

BACKGROUND: Primary central nervous system lymphomas (PCNSL) are extranodal malignant non-Hodgkin lymphomas (NHL) that arise exclusively in central nervous system (CNS). Diffuse large B-cell lymphoma (DLBCL) is the most common histological subtype. PURPOSE: To evaluate whether nano drug-loading system-mediated magnetic-targeted thermochemotherapy could produce a better therapeutic effect than single chemotherapy while reducing the use of chemotherapeutic drugs. METHODS: Six groups (control, Fe3O4, MTX, Fe3O4@MTX, Fe3O4 with hyperthermia and Fe3O4@MTX with hyperthermia) were set. Tumor cell apoptosis in each treatment group was detected by flow cytometry. Apoptosis-related gene expressions Caspase-3, Bax and Bcl-2 were detected by qPCR and Western blot; intracranial tumor model of PCNSL was established by intracranial injection of OCI-LY18 tumor cells into BALB/c-Nude mice. Magnetic resonance imaging (MRI) was used to monitor tumor progression and H&E staining was used to observe pathological changes of the tumor tissue. RESULTS: In vitro, compared with chemotherapy alone, apoptosis rate of Fe3O4@MTX mediated thermochemotherapy group was significantly increased, and expression of apoptosis-inducing gene Caspase-3 and Bax were significantly upregulated in OCI-LY18 cells, while expression of apoptosis-inhibiting Bcl-2 gene was significantly downregulated. In vivo, MRI showed successful generation of intracranial tumor, and tumor volume was significantly smaller in combined thermochemotherapy group than in single chemotherapy group. H&E staining result of tumor tissues in each group was consistent with MRI; tumor cells were significantly reduced in thermochemotherapy group. Expression of apoptosis-related gene Caspase-3 and Bax were significantly upregulated in tumor tissues, while expression of Bcl-2 gene was significantly downregulated. CONCLUSION: These results demonstrated in vivo and in vitro that the combined thermochemotherapy of Fe3O4@MTX MNPs was superior to the single MTX chemotherapy with less dosage, which may promote apoptosis of DLBCL cells through the mitochondrial apoptotic pathway and provided a new way for the treatment of PCNSL.

Fe3O4@Au composite magnetic nanoparticles modified with cetuximab for targeted magneto-photothermal therapy of glioma cells.

BACKGROUND: Thermoresponsive nanoparticles have become an attractive candidate for designing combined multimodal therapy strategies because of the onset of hyperthermia and their advantages in synergistic cancer treatment. In this paper, novel cetuximab (C225)-encapsulated core-shell Fe3O4@Au magnetic nanoparticles (Fe3O4@Au-C225 composite-targeted MNPs) were created and applied as a therapeutic nanocarrier to conduct targeted magneto-photothermal therapy against glioma cells. METHODS: The core-shell Fe3O4@Au magnetic nanoparticles (MNPs) were prepared, and then C225 was further absorbed to synthesize Fe3O4@Au-C225 composite-targeted MNPs. Their morphology, mean particle size, zeta potential, optical property, magnetic property and thermal dynamic profiles were characterized. After that, the glioma-destructive effect of magnetic fluid hyperthermia (MFH) combined with near-infrared (NIR) hyperthermia mediated by Fe3O4@Au-C225 composite-targeted MNPs was evaluated through in vitro and in vivo experiments. RESULTS: The inhibitory and apoptotic rates of Fe3O4@Au-C225 composite-targeted MNPs-mediated combined hyperthermia (MFH+NIR) group were significantly higher than other groups in vitro and the marked upregulation of caspase-3, caspase-8, and caspase-9 expression indicated excellent antitumor effect by inducing intrinsic apoptosis. Furthermore, Fe3O4@Au-C225 composite-targeted MNPs-mediated combined hyperthermia (MFH+NIR) group exhibited significant tumor growth suppression compared with other groups in vivo. CONCLUSION: Our studies illustrated that Fe3O4@Au-C225 composite-targeted MNPs have great potential as a promising nanoplatform for human glioma therapy and could be of great value in medical use in the future.

Polymorphism of methylenetetrahydrofolate reductase gene is associated with response to fluorouracil-based chemotherapy in Chinese patients with gastric cancer.

BACKGROUND: The importance of polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene for the prediction of the response to fluorouracil-based adjuvant chemotherapy in gastric cancer patients remains unclear. The aim of this study is to assess the predictive value of several polymorphisms of the MTHFR gene for clinical outcomes of gastric cancer patients treated with fluorouracil-based adjuvant chemotherapy in Chinese population. METHODS: Three hundred and sixty-two Chinese patients with gastric cancer were treated with fluorouracil-based adjuvant chemotherapy. DNA samples were isolated from peripheral blood collected before treatment. The three single nucleotide polymorphisms (SNPs) (rs1801131, rs1801133, rs2274976) genotypes of the MTHFR gene were determined by matrixassisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). RESULTS: The average response rate for chemotherapy was 46.7%. Homozygous genotypes rs2274976G/G (χ(2) = 22.7, P < 0.01) and rs1801131A/A (χ(2) = 14.3, P = 0.008) were over-represented in responsive patients. Carriers of the rs2274976A allele genotypes (G/A and A/A) and of the rs1801131C allele genotypes (A/C and C/C) were prevalent in nonresponsive patients. In the haplotype association analysis, there was a significant difference in global haplotype distribution between the groups (χ(2) = 20.69, P = 0.000 124). CONCLUSIONS: These results suggest that polymorphisms of the MTHFR gene may be used as predictors of the response to fluorouracil-based chemotherapy for gastric cancer patients in Chinese population. Well-designed, comprehensive, and prospective studies on determining these polymorphisms of MTHFR gene as clinical markers for predicting the response to fluorouracil-based therapy in gastric cancer patients is warranted.

Polymorphisms of dihydropyrimidine dehydrogenase gene and clinical outcomes of gastric cancer patients treated with fluorouracil-based adjuvant chemotherapy in Chinese population.

BACKGROUND: Dihydropyrimidine dehydrogenase (DPD), a key enzyme involved in the catabolism of 5-fluorouracil (5-FU), is the attractive candidate for pharmacogenetic research on efficacies and toxicities of 5-FU. The aim of this study is to explore the association between polymorphisms of dihydropyrimidine dehydrogenase gene (DPYD) and clinical outcomes of gastric cancer patients treated with fluorouracil-based adjuvant chemotherapy in the Chinese population. METHODS: Three hundred and sixty-two patients with gastric cancer in the Chinese population were treated with fluorouracil-based adjuvant chemotherapy. The single nucleotide polymorphic genotypes of DPYD were determined by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) using DNA samples isolated from peripheral blood collected before treatment. RESULTS: The average response rate for chemotherapy was 46.7%. A significantly different distribution of the rs1801159 (c2=8.76, P=0.012) genotypes was observed. Homozygous genotype rs1801159A/A was over-represented in responsive patients. Conversely, carriers of the rs1801159A/G genotype were prevalent in non-responsive patients. In the haplotype association analysis, there was significant difference in global haplotype distribution between the groups (c2=3.96, P=0.0465). CONCLUSIONS: These results suggest that polymorphisms of rs1801159 in DPYD may be used as valuable predictors of the response to fluorouracil-based chemotherapy for gastric cancer patients in the Chinese population. Well-designed, comprehensive, and prospective studies on determining these polymorphisms of DPYD as predictive markers for gastric cancer in response to fluorouracil-based therapies are warranted.

Biocompatibility of Fe3O4@Au composite magnetic nanoparticles in vitro and in vivo.

PURPOSE: This research was conducted to assess the biocompatibility of the core-shell Fe(3)O(4)@ Au composite magnetic nanoparticles (MNPs), which have potential application in tumor hyperthermia. METHODS: Fe(3)O(4)@Au composite MNPs with core-shell structure were synthesized by reduction of Au(3+) in the presence of Fe(3)O(4)-MNPs prepared by improved co-precipitation. Cytotoxicity assay, hemolysis test, micronucleus (MN) assay, and detection of acute toxicity in mice and beagle dogs were then carried out. RESULTS: The result of cytotoxicity assay showed that the toxicity grade of this material on mouse fibroblast cell line (L-929) was classified as grade 1, which belongs to no cytotoxicity. Hemolysis rates showed 0.278%, 0.232%, and 0.197%, far less than 5%, after treatment with different concentrations of Fe(3)O(4)@Au composite MNPs. In the MN assay, there was no significant difference in MN formation rates between the experimental groups and negative control (P > 0.05), but there was a significant difference between the experimental groups and the positive control (P < 0.05). The median lethal dose of the Fe(3)O(4)@Au composite MNPs after intraperitoneal administration in mice was 8.39 g/kg, and the 95% confidence interval was 6.58-10.72 g/kg, suggesting that these nanoparticles have a wide safety margin. Acute toxicity testing in beagle dogs also showed no significant difference in body weight between the treatment groups at 1, 2, 3, and 4 weeks after liver injection and no behavioral changes. Furthermore, blood parameters, autopsy, and histopathological studies in the experimental group showed no significant difference compared with the control group. CONCLUSION: The results indicate that Fe(3)O(4)@Au composite MNPs appear to be highly biocompatible and safe nanoparticles that are suitable for further application in tumor hyperthermia.