AIM: To investigate the effect of tamoxifen (TAM) on multidrug resistance (MDR) of colorectal carcinoma in vivo and its relationship with estrogen receptor (ER). METHODS: Multidrug resistance was determined by means o...AIM: To investigate the effect of tamoxifen (TAM) on multidrug resistance (MDR) of colorectal carcinoma in vivo and its relationship with estrogen receptor (ER). METHODS: Multidrug resistance was determined by means of semi-quantitative retro-transcription polymerase chain reaction (RT-PCR) to test mdr1 gene mRNA and ER expression was studied by immunohistochemistry. Tumor tissues from three cases of human colon carcinoma, which had mdr1(+)/ER(+),mdr1(+)/ER(-), mdr1(-) expressions, were planted subcutaneously in the neck of nude mice to establish three xenograft models. These models were subdivided into four subgroups randomly: Doxorubicin (DOX)-treated group, TAM-treated group, DOX and TAM group and control group. The dimensions of these xenografts were measured after each course of treatment and the xenografts were removed at the end of the experiments for measurements of weight and the variation of mdr1 mRNA level with RT-PCR. In each course, TAM [15 mg/(kg/d)] was administrated orally per day in the first seven days and DOX (3.6 mg/kg) was injected peritoneally on the first day. Data was evaluated by q and t tests. RESULTS: In the animal models with mdr1(-) tumor, the weights and volumes of the planted tumor in DOX group [(39.1±2.29) mg, (31.44±1.61) mm3] and TAM and DOX group [(38.72±2.56) mg, (31.31v1.74) mm3], which were lesser than that of control group [(45.48±3.92) mg, (36.42±2.77) mm3, P= 0.037, P= 0.016 respectively] significantly. In the animal models with mdr1(+)/ER(+) tumor, the weights and volumes of planted tumor were not affected by DOX or TAM treatment; however, in TAM and DOX group [(425.5±28.58) mg, (340.35±22.28) mm3], they were significantly less than that of control group [(634.23±119.41) mg, (507.45±93.34) mm3, P= 0.022, P = 0.045 respectively], which are similar to that in the models with mdr1(+)/ER(-) tumor. No significant changes were found in the expressive level of mdr1 mRNA following these treatments. CONCLUSION: The expression of mdr1 gene corresponds to the sensitivity of colon cancer to anti-tumor drugs in vivo. TAM can reverse the MDR of colorectal carcinoma in nude mice, which is independent of the expression of ER; however, no change was observed in the expressive level of mdr1 mRNA.展开更多
AIM： To investigate the effects of catalytically superior gene-directed enzyme prodrug therapy systems on a rat hepatoma model. METHODS： To increase hepatoma cell chemosensitivity for the prodrug 5-fluorocytosine （...AIM： To investigate the effects of catalytically superior gene-directed enzyme prodrug therapy systems on a rat hepatoma model. METHODS： To increase hepatoma cell chemosensitivity for the prodrug 5-fluorocytosine （5-FC）, we generated a chimeric bifunctional SuperCD suicide gene, a fusion of the yeast cytosine deaminase （YCD） and the yeast uracil phosphoribosyltransferase （YUPRT） gene. RESULTS： In vitro stably transduced Morris rat hepatoma cells （MH） expressing the bifunctional SuperCD suicide gene （MH SuperCD） showed a clearly marked enhancement in cell killing when incubated with 5-FC as compared with MH cells stably expressing YCD solely （MH YCD） or the cytosine deaminase gene of bacterial origin （MH BCD）, respectively. In vivo, MH SuperCD tumors implanted both subcutaneously as well as orthotopically into the livers of syngeneic ACI rats demonstrated significant tumor regressions （P〈0.01） under both high dose as well as low dose systemic 5-FC application, whereas MH tumors without transgene expression （MH naive） showed rapid progression. For the first time, an order of in vivo suicide gene effectiveness （SuperCD〉〉 YCD〉〉BCD〉〉〉negative control） was defined as a result of a direct in vivo comparison of all three suicide genes. CONCLUSION： Bifunctional SuperCD suicide gene expression is highly effective in a rat hepatoma model, thereby significantly improving both the therapeutic index and the efficacy of hepatocellular carcinoma killing by fluorocytosine.展开更多
Ferroptosis and autophagy, playing significant roles in tumor treatment, are two typical forms of the programmed cell death. However, the rational combination of ferroptosis and autophagy for synergistic tumor therapy...Ferroptosis and autophagy, playing significant roles in tumor treatment, are two typical forms of the programmed cell death. However, the rational combination of ferroptosis and autophagy for synergistic tumor therapy is still highly challenging. Herein, we report on an intriguing nanomedicine strategy for achieving autophagy-enhanced ferroptosis on efficiently combating cancer, which was based on the construction of trehalose-loaded mSiO_(2)@MnO_(x)-mPEG(Tre MMM) nanoparticles with satisfactory biocompatibility. The nanoparticles are endowed with high glutathione(GSH) consumption efficiency, thereby inducing cancer-cell ferroptosis via inactivating glutathione peroxidases 4(GPX4). Subsequently, the Tre MMM degradation due to the GSH depletion and p H sensitivity contributed to the trehalose release for inducing autophagy, promoting/enhancing ferroptosis by NCOA4-mediated degradation of ferritin.A substantial in vitro and in vivo antitumor effect was achieved by such an intriguing autophagyenhanced ferroptosis. Therefore, the rational combination of GSH-consumption-induced ferroptosis and trehalose-induced autophagy by nanomedicine design provides an alternative but effective strategy for tumor treatment.展开更多
Hypoxia severely impedes the therapeutic efficacies of tumor chemotherapy, radiotherapy and conventional photodynamic therapy(type Ⅱ PDT). Herein, we proposed a nonplanar near-infrared(NIR)-absorbing hyperthermia and...Hypoxia severely impedes the therapeutic efficacies of tumor chemotherapy, radiotherapy and conventional photodynamic therapy(type Ⅱ PDT). Herein, we proposed a nonplanar near-infrared(NIR)-absorbing hyperthermia and superoxide radical(O^(-)_(2)) photogenerator(TB) against hypoxic tumors. TB particularly possessed a favorable O^(-)_(2) generation capability under 808 nm laser irradiation with the donoracceptor-donor(D-A-D) molecular structure. Moreover, owing to molecular rotation, potent hyperthermia was realized under continuous laser irradiation. For the usage of hypoxic tumor treatment, TB was encapsulated by a block copolymer,poly(ethylene glycol)-b-poly(latic acid)(PEG_(45)-b-PLA_(24)), to fabricate phototheranostic nanoparticles(TB NPs). Due to the twisted molecular structure and the shielding effect of long alkyl chains, the π-π stacking-induced quenching of O^(-)_(2) could be reduced after the fabrication of nano-assemblies. Significantly, TB NPs exhibited satisfactory O^(-)_(2) generation for type I PDT and a simultaneously distinct photothermal conversion efficiency(PCE, 62%) for photothermal therapy(PTT)to combat hypoxic tumor cells. Moreover, the high PCE endowed TB NPs with high-performance photoacoustic(PA)and photothermal imaging capability. In vivo experiments demonstrated that TB NPs possessed an outstanding phototherapeutic efficacy for eradicating hypoxic tumors. This study established a novel approach for constructing oxygenindependent phototherapeutic reagent against hypoxic tumors.展开更多
Peroxynitrite （ONOO-） is a powerful oxidant and nitrosative agent and has in vivo existence. The half life of ONOO- at physiological pH is less than 1 s. It can react with nucleic acids, proteins, lipoproteins, sacc...Peroxynitrite （ONOO-） is a powerful oxidant and nitrosative agent and has in vivo existence. The half life of ONOO- at physiological pH is less than 1 s. It can react with nucleic acids, proteins, lipoproteins, saccharides, cardi- olipin, etc., and can modify their native structures. Action of ONOO-, synthesized in the authors＇ laboratory by a rapid quenched flow process, on structural changes of commercially available RNA was studied by ultraviolet （UV）, fluo- rescence, and agarose gel electrophoresis. Compared to native RNA, the ONOO--modified RNA showed hyper- chromicity at 260 nm. Furthermore, the ethidium bromide （EtBr） assisted emission intensities of ONOO--modified RNA samples were found to be lower than the emission intensity of native RNA-EtBr complex. Agarose gel electrophoresis of ONOO--modifled RNA showed a gradual decrease in band intensities compared to native RNA, an observation clearly due to the poor intercalation of EtBr with ONOO--modified RNA. Native and ONOO--modified RNA samples were used as an antigen to detect autoantibodies in sera of patients with clinically defined breast cancer. Both direct binding and inhibition enzyme-linked immunosorbent assay （ELISA） confirmed the prevalence of native and 0.8 mmol/L ONOO--modified RNA specific autoantibodies in breast cancer patients. Moreover, the progressive retarda- tion in the mobility of immune complexes formed with native or 0.8 mmol/L ONOO--modified RNA and affinity purified immunoglobulin G （IgG） from sera of breast cancer patients supports the findings of the direct binding and inhibition ELISAs. The peroxynitrite treatment to RNA at a higher concentration appears to have damaged or destroyed the typical epitopes on RNA and thus there was a sharp decrease in autoantibodies binding to 1.4 mmol/L ONOO--modified RNA. It may be interpreted that cellular nitrosative stress can modify and confer immunogenicity on RNA molecules. Higher concentrations of nitrogen reactive species can be detrimental to RNA. However, the emergence of native as well as 0.8 mmol/L ONOO--modified RNA as a novel antigen/substrate for autoantibodies in breast cancer patients indicates that, in future, these molecules might find a place on the panel of antigens for early diagnosis of breast cancer.展开更多
基金Supported by Scientific Foundation of Education Committee of Jiangsu Province. No.96039
文摘AIM: To investigate the effect of tamoxifen (TAM) on multidrug resistance (MDR) of colorectal carcinoma in vivo and its relationship with estrogen receptor (ER). METHODS: Multidrug resistance was determined by means of semi-quantitative retro-transcription polymerase chain reaction (RT-PCR) to test mdr1 gene mRNA and ER expression was studied by immunohistochemistry. Tumor tissues from three cases of human colon carcinoma, which had mdr1(+)/ER(+),mdr1(+)/ER(-), mdr1(-) expressions, were planted subcutaneously in the neck of nude mice to establish three xenograft models. These models were subdivided into four subgroups randomly: Doxorubicin (DOX)-treated group, TAM-treated group, DOX and TAM group and control group. The dimensions of these xenografts were measured after each course of treatment and the xenografts were removed at the end of the experiments for measurements of weight and the variation of mdr1 mRNA level with RT-PCR. In each course, TAM [15 mg/(kg/d)] was administrated orally per day in the first seven days and DOX (3.6 mg/kg) was injected peritoneally on the first day. Data was evaluated by q and t tests. RESULTS: In the animal models with mdr1(-) tumor, the weights and volumes of the planted tumor in DOX group [(39.1±2.29) mg, (31.44±1.61) mm3] and TAM and DOX group [(38.72±2.56) mg, (31.31v1.74) mm3], which were lesser than that of control group [(45.48±3.92) mg, (36.42±2.77) mm3, P= 0.037, P= 0.016 respectively] significantly. In the animal models with mdr1(+)/ER(+) tumor, the weights and volumes of planted tumor were not affected by DOX or TAM treatment; however, in TAM and DOX group [(425.5±28.58) mg, (340.35±22.28) mm3], they were significantly less than that of control group [(634.23±119.41) mg, (507.45±93.34) mm3, P= 0.022, P = 0.045 respectively], which are similar to that in the models with mdr1(+)/ER(-) tumor. No significant changes were found in the expressive level of mdr1 mRNA following these treatments. CONCLUSION: The expression of mdr1 gene corresponds to the sensitivity of colon cancer to anti-tumor drugs in vivo. TAM can reverse the MDR of colorectal carcinoma in nude mice, which is independent of the expression of ER; however, no change was observed in the expressive level of mdr1 mRNA.
基金Supported by grants from German Research Foundation (LA649-20-2)Federal Ministry of Education, Science, Research and Technology (Fo. 01KS9602, Fo. 01KV9532)Interdisciplinary Clinical Research Center (IZKF) Tubingen, and the fortune-program of the Medical Faculty of Eberhard-Karls-University Tubingen (F. 1281127)W.A.W. supported by a scholarship from Pinguin Foundation (Henkel KGaA)
文摘AIM： To investigate the effects of catalytically superior gene-directed enzyme prodrug therapy systems on a rat hepatoma model. METHODS： To increase hepatoma cell chemosensitivity for the prodrug 5-fluorocytosine （5-FC）, we generated a chimeric bifunctional SuperCD suicide gene, a fusion of the yeast cytosine deaminase （YCD） and the yeast uracil phosphoribosyltransferase （YUPRT） gene. RESULTS： In vitro stably transduced Morris rat hepatoma cells （MH） expressing the bifunctional SuperCD suicide gene （MH SuperCD） showed a clearly marked enhancement in cell killing when incubated with 5-FC as compared with MH cells stably expressing YCD solely （MH YCD） or the cytosine deaminase gene of bacterial origin （MH BCD）, respectively. In vivo, MH SuperCD tumors implanted both subcutaneously as well as orthotopically into the livers of syngeneic ACI rats demonstrated significant tumor regressions （P〈0.01） under both high dose as well as low dose systemic 5-FC application, whereas MH tumors without transgene expression （MH naive） showed rapid progression. For the first time, an order of in vivo suicide gene effectiveness （SuperCD〉〉 YCD〉〉BCD〉〉〉negative control） was defined as a result of a direct in vivo comparison of all three suicide genes. CONCLUSION： Bifunctional SuperCD suicide gene expression is highly effective in a rat hepatoma model, thereby significantly improving both the therapeutic index and the efficacy of hepatocellular carcinoma killing by fluorocytosine.
基金This work was supported by the National Key R&D Program of China(2016YFA0203700)the National Natural Science Foundation of China(51722211,51672303,and 51902334)+1 种基金Program of Shanghai Academic Research Leader(18XD1404300)the National Science Foundation for Young Scientists of China(81903178)。
文摘Ferroptosis and autophagy, playing significant roles in tumor treatment, are two typical forms of the programmed cell death. However, the rational combination of ferroptosis and autophagy for synergistic tumor therapy is still highly challenging. Herein, we report on an intriguing nanomedicine strategy for achieving autophagy-enhanced ferroptosis on efficiently combating cancer, which was based on the construction of trehalose-loaded mSiO_(2)@MnO_(x)-mPEG(Tre MMM) nanoparticles with satisfactory biocompatibility. The nanoparticles are endowed with high glutathione(GSH) consumption efficiency, thereby inducing cancer-cell ferroptosis via inactivating glutathione peroxidases 4(GPX4). Subsequently, the Tre MMM degradation due to the GSH depletion and p H sensitivity contributed to the trehalose release for inducing autophagy, promoting/enhancing ferroptosis by NCOA4-mediated degradation of ferritin.A substantial in vitro and in vivo antitumor effect was achieved by such an intriguing autophagyenhanced ferroptosis. Therefore, the rational combination of GSH-consumption-induced ferroptosis and trehalose-induced autophagy by nanomedicine design provides an alternative but effective strategy for tumor treatment.
基金supported by the National Natural Science Foundation of China (21875063 and 21871006)the Science and Technology Commission of Shanghai Municipality for Shanghai International Cooperation Program (19440710600)the Open Funding Project of the State Key Laboratory of Bioreactor Engineering。
文摘Hypoxia severely impedes the therapeutic efficacies of tumor chemotherapy, radiotherapy and conventional photodynamic therapy(type Ⅱ PDT). Herein, we proposed a nonplanar near-infrared(NIR)-absorbing hyperthermia and superoxide radical(O^(-)_(2)) photogenerator(TB) against hypoxic tumors. TB particularly possessed a favorable O^(-)_(2) generation capability under 808 nm laser irradiation with the donoracceptor-donor(D-A-D) molecular structure. Moreover, owing to molecular rotation, potent hyperthermia was realized under continuous laser irradiation. For the usage of hypoxic tumor treatment, TB was encapsulated by a block copolymer,poly(ethylene glycol)-b-poly(latic acid)(PEG_(45)-b-PLA_(24)), to fabricate phototheranostic nanoparticles(TB NPs). Due to the twisted molecular structure and the shielding effect of long alkyl chains, the π-π stacking-induced quenching of O^(-)_(2) could be reduced after the fabrication of nano-assemblies. Significantly, TB NPs exhibited satisfactory O^(-)_(2) generation for type I PDT and a simultaneously distinct photothermal conversion efficiency(PCE, 62%) for photothermal therapy(PTT)to combat hypoxic tumor cells. Moreover, the high PCE endowed TB NPs with high-performance photoacoustic(PA)and photothermal imaging capability. In vivo experiments demonstrated that TB NPs possessed an outstanding phototherapeutic efficacy for eradicating hypoxic tumors. This study established a novel approach for constructing oxygenindependent phototherapeutic reagent against hypoxic tumors.
文摘Peroxynitrite （ONOO-） is a powerful oxidant and nitrosative agent and has in vivo existence. The half life of ONOO- at physiological pH is less than 1 s. It can react with nucleic acids, proteins, lipoproteins, saccharides, cardi- olipin, etc., and can modify their native structures. Action of ONOO-, synthesized in the authors＇ laboratory by a rapid quenched flow process, on structural changes of commercially available RNA was studied by ultraviolet （UV）, fluo- rescence, and agarose gel electrophoresis. Compared to native RNA, the ONOO--modified RNA showed hyper- chromicity at 260 nm. Furthermore, the ethidium bromide （EtBr） assisted emission intensities of ONOO--modified RNA samples were found to be lower than the emission intensity of native RNA-EtBr complex. Agarose gel electrophoresis of ONOO--modifled RNA showed a gradual decrease in band intensities compared to native RNA, an observation clearly due to the poor intercalation of EtBr with ONOO--modified RNA. Native and ONOO--modified RNA samples were used as an antigen to detect autoantibodies in sera of patients with clinically defined breast cancer. Both direct binding and inhibition enzyme-linked immunosorbent assay （ELISA） confirmed the prevalence of native and 0.8 mmol/L ONOO--modified RNA specific autoantibodies in breast cancer patients. Moreover, the progressive retarda- tion in the mobility of immune complexes formed with native or 0.8 mmol/L ONOO--modified RNA and affinity purified immunoglobulin G （IgG） from sera of breast cancer patients supports the findings of the direct binding and inhibition ELISAs. The peroxynitrite treatment to RNA at a higher concentration appears to have damaged or destroyed the typical epitopes on RNA and thus there was a sharp decrease in autoantibodies binding to 1.4 mmol/L ONOO--modified RNA. It may be interpreted that cellular nitrosative stress can modify and confer immunogenicity on RNA molecules. Higher concentrations of nitrogen reactive species can be detrimental to RNA. However, the emergence of native as well as 0.8 mmol/L ONOO--modified RNA as a novel antigen/substrate for autoantibodies in breast cancer patients indicates that, in future, these molecules might find a place on the panel of antigens for early diagnosis of breast cancer.
