AIM: To monitor the early responses to irradiation in primary and metastatic colorectal cancer (CRC) with 18 Ffluorothymidine ( 18 F-FLT) and 18 F-fluorodeoxyglucose ( 18 F-FDG) small-animal position emission tomograp...AIM: To monitor the early responses to irradiation in primary and metastatic colorectal cancer (CRC) with 18 Ffluorothymidine ( 18 F-FLT) and 18 F-fluorodeoxyglucose ( 18 F-FDG) small-animal position emission tomography (micro-PET). METHODS: The primary and metastatic CRC cell lines, SW480 and SW620, were irradiated with 5, 10 and 20, l l l , Gy. After 24 h, the cell cycle phases were analyzed. A dual-tumor-bearing mouse model of primary and metastatic cancer was established by injecting SW480 and SW620 cells into mice. micro-PET with 18 F-FLT and 18 F-FDG was performed before and 24 h after irradiation with 5, 10 and 20 Gy. The region of interest (ROI) was drawn over the tumor and background to calculate the ratio of tumor to non-tumor (T/NT) in tissues. Immunohistochemical assay and Western blotting were used to examine the levels of integrin β3, Ki-67, vascular endothelial growth factor receptor 2 (VEGFR2) and heat shock protein 27 (HSP27). RESULTS: The proportion of SW480 and SW620 cells in the G 2 -M phase was decreased with an increasing radiation dose. The proportion of SW480 cells in the G 0 -G 1 phase was increased from 48.33% ± 4.55% to 87.09% ± 7.43% (P < 0.001) and that of SW620 cells in the S-phase was elevated from 43.57% ± 2.65% to 66.59% ± 7.37% (P = 0.021). In micro-PET study, with increasing dose of radiation, 18 F-FLT uptake was significantly reduced from 3.65 ± 0.51 to 2.87 ± 0.47 (P = 0.008) in SW480 tumors and from 2.22 ± 0.42 to 1.76 ± 0.45 (P = 0.026) in SW620 tumors. 18 F-FDG uptake in SW480 and SW620 tumors was reduced but not significantly (F = 0.582, P = 0.633 vs F = 0.273, P = 0.845). Dose of radiation was negatively correlated with 18 F-FLT uptake in both SW480 and SW620 tumors (r = -0.727, P = 0.004; and r = -0.664, P = 0.009). No significant correlation was found between 18 F-FDG uptake and radiation dose in SW480 or SW620 tumors. HSP27 and integrin β3 expression was higher in SW480 than in SW620 tumors. The T/NT ratio for 18 F-FLT uptake was positively correlated with HS展开更多
Positron emission tomography (PET) imaging has emerged as an important clinical tool for cancer management, and specifically targeted radiopharmaceuticals play critical roles on PET molecular imaging. Solid cancers ha...Positron emission tomography (PET) imaging has emerged as an important clinical tool for cancer management, and specifically targeted radiopharmaceuticals play critical roles on PET molecular imaging. Solid cancers have highly complex and heterogeneous microenvironment, this review focused on those microenvironmental factors such as hypoxia, proliferation and perfusion and, accordingly, a novel test system for validation of current and novel targeted imaging radiopharmaceuticals. In this review, we have introduced the establishment of cancer and metastases models in nude mice, visualization of microenvironmental components of hypoxia, proliferation, perfusion, stroma and necrosis in cancers and metastases for establishing the microenvironment based model system, and validation of several radio- pharmaceuticals such as 18F-fluoro-2-deoxyglucose (18F-FDG) 18F-fluorothymidine (18F-FLT), 18F-misonidazole (18F- FMISO) using the system. We found that 18F-FLT accumulates in proliferating cancer cells, while 18F-FMISO and 18F-FDG mostly accumulate in hypoxic and non-proliferative cancer cells, 18F-FDG shares roughly similar intratumoral distribution pattern with 18F-FMISO and IAZGP, but mutually excludes 18F-FLT. This model system validated current tracers for imaging glucose metabolism, hypoxia and proliferation in cancer and metastases, therefore, can be used for novel targeted radiopharmaceuticals validation.展开更多
AIM To establish patient-individual tumor models of rectal cancer for analyses of novel biomarkers, individual response prediction and individual therapy regimens.METHODS Establishment of cell lines was conducted by d...AIM To establish patient-individual tumor models of rectal cancer for analyses of novel biomarkers, individual response prediction and individual therapy regimens.METHODS Establishment of cell lines was conducted by direct in vitro culturing and in vivo xenografting with subsequent in vitro culturing. Cell lines were in-depth characterized concerning morphological features, invasive and migratory behavior, phenotype, molecular profile including mutational analysis, protein expression, and confirmation of origin by DNA fingerprint. Assessment of chemosensitivity towards an extensive range of current chemotherapeutic drugs and of radiosensitivity was performed including analysis of a combined radioand chemotherapeutic treatment. In addition, glucose metabolism was assessed with 18 F-fluorodeoxyglucose(FDG) and proliferation with 18 F-fluorothymidine.RESULTS We describe the establishment of ultra-low passage rectal cancer cell lines of three patients suffering from rectal cancer. Two cell lines(HROC126, HROC284 Met) were established directly from tumor specimens while HROC239 T0 M1 was established subsequent to xenografting of the tumor. Molecular analysis classified all three cell lines as CIMP-0/non-MSI-H(sporadic standard) type. Mutational analysis revealed following mutational profiles: HROC126: APC^(wt), TP53^(wt), KRAS^(wt), BRAF^(wt), PTEN^(wt); HROC239 T0 M1: APC^(mut), P53^(wt), KRAS^(mut), BRAF^(wt), PTEN^(mut) and HROC284 Met: APC^(wt), P53^(mut), KRAS^(mut), BRAF^(wt), PTEN^(mut). All cell lines could be characterized as epithelial(EpCAM+) tumor cells with equivalent morphologic features and comparable growth kinetics. The cell lines displayed a heterogeneous response toward chemotherapy, radiotherapy and their combined application. HROC126 showed a highly radio-resistant phenotype and HROC284 Met was more susceptible to a combined radiochemotherapy than HROC126 and HROC239 T0 M1. Analysis of 18 F-FDG uptake displayed a markedly reduced FDG uptake of all three cell lines after combined radiochemotherapy.展开更多
Background： The detection of solitary pulmonary nodules （SPNs） that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed t...Background： The detection of solitary pulmonary nodules （SPNs） that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed tomography （CT） imaging results remains a significant challenge. The 2-[^18F]-fluoro-2-deoxy-D-glucose （^18F-FDG） positron emission tomography （PET）/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18F-FDG and 3-deoxy-3-[^18F]-fluorothymidine （^18F-FLT） in lung cancer PET/CT imaging. Methods： The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established （n = 12）, and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values （SUVs）, and Ki-67 proliferation marker expression were investigated. Results： The cell-tracer binding ratio for the A549 cells using the ^18F-FDG was greater than the ratio using 18F-FLT （P 〈 0.05）. The Ki-67 expression showed a significant positive correlation with the ^18F-FLT binding ratio （r = 0.824, P〈 0.01）. The tumor-to-nontumor uptake ratio of ^18F-FDG imaging in xenografts was higher than that of ^18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of ^18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of ^18F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of ^18F-FDG and ^18F-FLT （r = 0.658, P〈 0.05 and r = 0.724, P〈 0.01, respectively）. Conclusions： The ^18F-FDG uptake ratio is higher than that of ^18F-FLT in A549 cells at the cellular level.^18F-FLT imaging might be superior for the quantitative diagnosis展开更多
基金Supported by Grants from the China Postdoctoral Science Foundation, No. 20070420569the Special Fund, China Postdoctoral Science Foundation No. 200902679the National Natural Science Foundation of China No. 30770607
文摘AIM: To monitor the early responses to irradiation in primary and metastatic colorectal cancer (CRC) with 18 Ffluorothymidine ( 18 F-FLT) and 18 F-fluorodeoxyglucose ( 18 F-FDG) small-animal position emission tomography (micro-PET). METHODS: The primary and metastatic CRC cell lines, SW480 and SW620, were irradiated with 5, 10 and 20, l l l , Gy. After 24 h, the cell cycle phases were analyzed. A dual-tumor-bearing mouse model of primary and metastatic cancer was established by injecting SW480 and SW620 cells into mice. micro-PET with 18 F-FLT and 18 F-FDG was performed before and 24 h after irradiation with 5, 10 and 20 Gy. The region of interest (ROI) was drawn over the tumor and background to calculate the ratio of tumor to non-tumor (T/NT) in tissues. Immunohistochemical assay and Western blotting were used to examine the levels of integrin β3, Ki-67, vascular endothelial growth factor receptor 2 (VEGFR2) and heat shock protein 27 (HSP27). RESULTS: The proportion of SW480 and SW620 cells in the G 2 -M phase was decreased with an increasing radiation dose. The proportion of SW480 cells in the G 0 -G 1 phase was increased from 48.33% ± 4.55% to 87.09% ± 7.43% (P < 0.001) and that of SW620 cells in the S-phase was elevated from 43.57% ± 2.65% to 66.59% ± 7.37% (P = 0.021). In micro-PET study, with increasing dose of radiation, 18 F-FLT uptake was significantly reduced from 3.65 ± 0.51 to 2.87 ± 0.47 (P = 0.008) in SW480 tumors and from 2.22 ± 0.42 to 1.76 ± 0.45 (P = 0.026) in SW620 tumors. 18 F-FDG uptake in SW480 and SW620 tumors was reduced but not significantly (F = 0.582, P = 0.633 vs F = 0.273, P = 0.845). Dose of radiation was negatively correlated with 18 F-FLT uptake in both SW480 and SW620 tumors (r = -0.727, P = 0.004; and r = -0.664, P = 0.009). No significant correlation was found between 18 F-FDG uptake and radiation dose in SW480 or SW620 tumors. HSP27 and integrin β3 expression was higher in SW480 than in SW620 tumors. The T/NT ratio for 18 F-FLT uptake was positively correlated with HS
文摘Positron emission tomography (PET) imaging has emerged as an important clinical tool for cancer management, and specifically targeted radiopharmaceuticals play critical roles on PET molecular imaging. Solid cancers have highly complex and heterogeneous microenvironment, this review focused on those microenvironmental factors such as hypoxia, proliferation and perfusion and, accordingly, a novel test system for validation of current and novel targeted imaging radiopharmaceuticals. In this review, we have introduced the establishment of cancer and metastases models in nude mice, visualization of microenvironmental components of hypoxia, proliferation, perfusion, stroma and necrosis in cancers and metastases for establishing the microenvironment based model system, and validation of several radio- pharmaceuticals such as 18F-fluoro-2-deoxyglucose (18F-FDG) 18F-fluorothymidine (18F-FLT), 18F-misonidazole (18F- FMISO) using the system. We found that 18F-FLT accumulates in proliferating cancer cells, while 18F-FMISO and 18F-FDG mostly accumulate in hypoxic and non-proliferative cancer cells, 18F-FDG shares roughly similar intratumoral distribution pattern with 18F-FMISO and IAZGP, but mutually excludes 18F-FLT. This model system validated current tracers for imaging glucose metabolism, hypoxia and proliferation in cancer and metastases, therefore, can be used for novel targeted radiopharmaceuticals validation.
基金the German Cancer Foundation to Oliver H Kr?mer,No.KR 2291/7-1
文摘AIM To establish patient-individual tumor models of rectal cancer for analyses of novel biomarkers, individual response prediction and individual therapy regimens.METHODS Establishment of cell lines was conducted by direct in vitro culturing and in vivo xenografting with subsequent in vitro culturing. Cell lines were in-depth characterized concerning morphological features, invasive and migratory behavior, phenotype, molecular profile including mutational analysis, protein expression, and confirmation of origin by DNA fingerprint. Assessment of chemosensitivity towards an extensive range of current chemotherapeutic drugs and of radiosensitivity was performed including analysis of a combined radioand chemotherapeutic treatment. In addition, glucose metabolism was assessed with 18 F-fluorodeoxyglucose(FDG) and proliferation with 18 F-fluorothymidine.RESULTS We describe the establishment of ultra-low passage rectal cancer cell lines of three patients suffering from rectal cancer. Two cell lines(HROC126, HROC284 Met) were established directly from tumor specimens while HROC239 T0 M1 was established subsequent to xenografting of the tumor. Molecular analysis classified all three cell lines as CIMP-0/non-MSI-H(sporadic standard) type. Mutational analysis revealed following mutational profiles: HROC126: APC^(wt), TP53^(wt), KRAS^(wt), BRAF^(wt), PTEN^(wt); HROC239 T0 M1: APC^(mut), P53^(wt), KRAS^(mut), BRAF^(wt), PTEN^(mut) and HROC284 Met: APC^(wt), P53^(mut), KRAS^(mut), BRAF^(wt), PTEN^(mut). All cell lines could be characterized as epithelial(EpCAM+) tumor cells with equivalent morphologic features and comparable growth kinetics. The cell lines displayed a heterogeneous response toward chemotherapy, radiotherapy and their combined application. HROC126 showed a highly radio-resistant phenotype and HROC284 Met was more susceptible to a combined radiochemotherapy than HROC126 and HROC239 T0 M1. Analysis of 18 F-FDG uptake displayed a markedly reduced FDG uptake of all three cell lines after combined radiochemotherapy.
基金This study was supported by grants from the National Natural Science Foundation of China （No. 81271607）, and the National Postdoctoral Science Foundation of China （No. 2015M572810）.
文摘Background： The detection of solitary pulmonary nodules （SPNs） that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed tomography （CT） imaging results remains a significant challenge. The 2-[^18F]-fluoro-2-deoxy-D-glucose （^18F-FDG） positron emission tomography （PET）/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18F-FDG and 3-deoxy-3-[^18F]-fluorothymidine （^18F-FLT） in lung cancer PET/CT imaging. Methods： The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established （n = 12）, and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values （SUVs）, and Ki-67 proliferation marker expression were investigated. Results： The cell-tracer binding ratio for the A549 cells using the ^18F-FDG was greater than the ratio using 18F-FLT （P 〈 0.05）. The Ki-67 expression showed a significant positive correlation with the ^18F-FLT binding ratio （r = 0.824, P〈 0.01）. The tumor-to-nontumor uptake ratio of ^18F-FDG imaging in xenografts was higher than that of ^18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of ^18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of ^18F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of ^18F-FDG and ^18F-FLT （r = 0.658, P〈 0.05 and r = 0.724, P〈 0.01, respectively）. Conclusions： The ^18F-FDG uptake ratio is higher than that of ^18F-FLT in A549 cells at the cellular level.^18F-FLT imaging might be superior for the quantitative diagnosis
