“…The contrast enhancement and increased K trans value indicated that the original tumors exhibited significant angiogenic activity and high vascular permeability (36), which may be attributed to the increased expression levels of the angiogenesis-associated genes in the original tumors (37)(38)(39). The rADC values of the original tumors were significantly lower compared with the xenografts, which may be attributed with the higher expression levels of the cell adhesion and extracellular matrix-associated genes noted in the original tumors, which in turn resulted in a higher cell density (40,41). Therefore, the differences noted in gene expression levels may underlie the differences noted in the MRI features between the original tumors and the corresponding xenografts.…”
Patient-derived orthotopic glioma xenograft models are important platforms used for pre-clinical research of glioma. In the present study, the diagnostic ability of magnetic resonance imaging (MRI) was examined with regard to the identification of biomarkers obtained from patient-derived glioma xenografts and human tumors. Conventional MRI, diffusion weighted imaging and dynamic contrast-enhanced (DCE)-MRI were used to analyze seven pairs of high grade gliomas with their corresponding xenografts obtained from non-obese diabetic-severe-combined immunodeficiency nude mice. Tumor samples were collected for transcriptome sequencing and histopathological staining, and differentially expressed genes were screened between the original tumors and the corresponding xenografts. Gene Ontology (GO) analysis was performed to predict the functions of these genes. In 6 cases of xenografts with diffuse growth, the degree of enhancement was significantly lower compared with the original tumors. Histopathological staining indicated that the microvascular area and microvascular diameter of the xenografts were significantly lower compared with the original tumors (P=0.009 and P=0.007, respectively). In one case, there was evidence of nodular tumor growth in the mouse. Both MRI and histopathological staining showed a clear demarcation between the transplanted tumors and the normal brain tissues. The relative apparent diffusion coefficient values of the 7 cases examined were significantly higher compared with the corresponding original tumors (P=0.001) and transfer coefficient values derived from DCE-MRI of the tumor area was significantly lower compared with the original tumors (P=0.016). GO analysis indicated that the expression levels of extracellular matrix-associated genes, angiogenesis-associated genes and immune function-associated genes in the original tumors were higher compared with the corresponding xenografts. In conclusion, the data demonstrated that the MRI features of patient-derived xenograft glioma models in mice were different compared with those of the original patient tumors. Differential gene expression may underlie the differences noted in the MRI features between original tumors and corresponding xenografts. The results of the present study highlight the precautions that should be taken when extrapolating data from patient-derived xenograft studies, and their applicability to humans.
“…The contrast enhancement and increased K trans value indicated that the original tumors exhibited significant angiogenic activity and high vascular permeability (36), which may be attributed to the increased expression levels of the angiogenesis-associated genes in the original tumors (37)(38)(39). The rADC values of the original tumors were significantly lower compared with the xenografts, which may be attributed with the higher expression levels of the cell adhesion and extracellular matrix-associated genes noted in the original tumors, which in turn resulted in a higher cell density (40,41). Therefore, the differences noted in gene expression levels may underlie the differences noted in the MRI features between the original tumors and the corresponding xenografts.…”
Patient-derived orthotopic glioma xenograft models are important platforms used for pre-clinical research of glioma. In the present study, the diagnostic ability of magnetic resonance imaging (MRI) was examined with regard to the identification of biomarkers obtained from patient-derived glioma xenografts and human tumors. Conventional MRI, diffusion weighted imaging and dynamic contrast-enhanced (DCE)-MRI were used to analyze seven pairs of high grade gliomas with their corresponding xenografts obtained from non-obese diabetic-severe-combined immunodeficiency nude mice. Tumor samples were collected for transcriptome sequencing and histopathological staining, and differentially expressed genes were screened between the original tumors and the corresponding xenografts. Gene Ontology (GO) analysis was performed to predict the functions of these genes. In 6 cases of xenografts with diffuse growth, the degree of enhancement was significantly lower compared with the original tumors. Histopathological staining indicated that the microvascular area and microvascular diameter of the xenografts were significantly lower compared with the original tumors (P=0.009 and P=0.007, respectively). In one case, there was evidence of nodular tumor growth in the mouse. Both MRI and histopathological staining showed a clear demarcation between the transplanted tumors and the normal brain tissues. The relative apparent diffusion coefficient values of the 7 cases examined were significantly higher compared with the corresponding original tumors (P=0.001) and transfer coefficient values derived from DCE-MRI of the tumor area was significantly lower compared with the original tumors (P=0.016). GO analysis indicated that the expression levels of extracellular matrix-associated genes, angiogenesis-associated genes and immune function-associated genes in the original tumors were higher compared with the corresponding xenografts. In conclusion, the data demonstrated that the MRI features of patient-derived xenograft glioma models in mice were different compared with those of the original patient tumors. Differential gene expression may underlie the differences noted in the MRI features between original tumors and corresponding xenografts. The results of the present study highlight the precautions that should be taken when extrapolating data from patient-derived xenograft studies, and their applicability to humans.
“…DWI in soft tissue tumors (STTs) is generally used with at least three b -values (from b = 50 to b = 1000) [ 103 , 104 ]. According to some authors, minimum ADC may be more accurate for characterization compared to mean ADC, while mean ADC should be preferred for tumor follow-up and treatment response evaluation [ 105 ].…”
Section: Soft Tissue Tumorsmentioning
confidence: 99%
“…To overcome this limitation, perfusion-insensitive ADC values can be used. Myxoid STTs show higher intrinsic diffusion coefficients due to their elevated mucin contents, and the difference in ADC between benign and malignant myxoid STTs was reported to be not statistically significant in some studies [ 103 , 104 ]. Similarly, both benign and malignant fatty STTs have very low ADC [ 106 ] ( Figure 13 A–D).…”
Section: Soft Tissue Tumorsmentioning
confidence: 99%
“…Similarly, both benign and malignant fatty STTs have very low ADC [ 106 ] ( Figure 13 A–D). Concerning tumor characterization, several studies reported significantly lower ADC of malignant STTs than benign ones, although a variable degree of overlap has been always reported [ 104 , 107 , 108 ]. According to a recent study by Choi et al, this overlap seems to be especially due to the high ADCs of myxoid malignant STTs and the low ADCs of giant cell tumors, fibromas, and schwannomas [ 107 ].…”
To date, diffusion weighted imaging (DWI) is included in routine magnetic resonance imaging (MRI) protocols for several cancers. The real additive role of DWI lies in the “functional” information obtained by probing the free diffusivity of water molecules into intra and inter-cellular spaces that in tumors mainly depend on cellularity. Although DWI has not gained much space in some oncologic scenarios, this non-invasive tool is routinely used in clinical practice and still remains a hot research topic: it has been tested in almost all cancers to differentiate malignant from benign lesions, to distinguish different malignant histotypes or tumor grades, to predict and/or assess treatment responses, and to identify residual or recurrent tumors in follow-up examinations. In this review, we provide an up-to-date overview on the application of DWI in oncology.
“…Without recurrent haemorrhages and concentration of haemoglobin derivatives (deoxyhaemoglobin and methaemoglobin), viscosity of the cyst remains lower and shading sign is unlikely to be observed (17). Diffusion weighted imaging is a MR sequence which provides functional information by probing the random motion of water molecules in biological tissues, also with a quantitative assessment of diffusivity calculated on the ADC map (18)(19)(20)(21)(22)(23). Endometriomas tipically show low ADC values mainly due to "T2 blackout effects", related to the low T2-weigthed signal intensity of the lesions (24).…”
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