Cancer stem cells （CSCs） are a rare subpopulation of phenotypically distinct cancer cells exhibiting stem cell characteristics. They are tumourigenic, meanwhile capable of self-renewal and forming differentiated pro...Cancer stem cells （CSCs） are a rare subpopulation of phenotypically distinct cancer cells exhibiting stem cell characteristics. They are tumourigenic, meanwhile capable of self-renewal and forming differentiated progenies. CSCs are believed to be resistant to the standard therapeutics, and provide the cell reservoir for tumour initiation.1 Understanding CSCs or in another word, tumour-initiating cells, is of critical therapeutic importance.展开更多
To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-bo...To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-body autoradiography(QWBA) and LC–MS/MS following i.v.administration of BMS-753493 or its active moiety,BMS-748285 in mice bearing FRt(98M109) and FR–(M109) tumors.QWBA showed [3H]BMS-753493–derived radioactivity was extensively distributed to various tissues.The FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors(i.e.,M109 tumors) up to 48 h post dose of [3H]BMS-753493,despite the magnitude of difference between the tumors is relatively small(generally 3 5-fold).The radioactivity level in 98M109 tumors was 2 12-fold of normal tissues except intestine/content at 48 h post dose.No selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after i.v.administration of the active epothilone,[3H]BMS-748285.LC–MS/MS measurements demonstrated that the concentrations of BMS-748285,presumably from hydrolysis of the folate conjugate,in 98M109 tumors were greater than those in M109 tumors after i.v.administration of BMS-753493(2–3-fold) whereas no differential uptake in the tumors following BMS-748285 administration.Those data were consistent with radioactivity determinations.Those results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR overexpressing 98M109 tumors,thereby supporting targeted delivery of cytotoxics through the folate receptor.展开更多
文摘Cancer stem cells （CSCs） are a rare subpopulation of phenotypically distinct cancer cells exhibiting stem cell characteristics. They are tumourigenic, meanwhile capable of self-renewal and forming differentiated progenies. CSCs are believed to be resistant to the standard therapeutics, and provide the cell reservoir for tumour initiation.1 Understanding CSCs or in another word, tumour-initiating cells, is of critical therapeutic importance.
文摘To assess targeting of an epothilone folate conjugate(BMS-753493) to the folate receptor(FR)-overexpressed tumor in mice bearing both FRt and FR– tumors,a series of experiments were conducted by quantitative whole-body autoradiography(QWBA) and LC–MS/MS following i.v.administration of BMS-753493 or its active moiety,BMS-748285 in mice bearing FRt(98M109) and FR–(M109) tumors.QWBA showed [3H]BMS-753493–derived radioactivity was extensively distributed to various tissues.The FR over-expressing 98M109 tumors showed consistently higher level of radioactivity than FR-negative tumors(i.e.,M109 tumors) up to 48 h post dose of [3H]BMS-753493,despite the magnitude of difference between the tumors is relatively small(generally 3 5-fold).The radioactivity level in 98M109 tumors was 2 12-fold of normal tissues except intestine/content at 48 h post dose.No selective radioactivity uptake into 98M109 tumors over M109 or normal tissues was observed after i.v.administration of the active epothilone,[3H]BMS-748285.LC–MS/MS measurements demonstrated that the concentrations of BMS-748285,presumably from hydrolysis of the folate conjugate,in 98M109 tumors were greater than those in M109 tumors after i.v.administration of BMS-753493(2–3-fold) whereas no differential uptake in the tumors following BMS-748285 administration.Those data were consistent with radioactivity determinations.Those results demonstrated that the folate conjugation in BMS-753493 enabled moderately preferential distribution of the active epothilone to FR overexpressing 98M109 tumors,thereby supporting targeted delivery of cytotoxics through the folate receptor.
