Multicellular compositions of pluripotent human embryonic stem cells and cancer cells

Abstract

Methods are provided for producing novel multicellular compositions comprising cancer cells together with pluripotent human stem cells, which are capable of proliferating and differentiating into various normal cell lines and tissue structures. These novel multicellular compositions are useful for investigating the properties of cancer cells in a normal human tissue microenvironment, and for studying interventions that will modulate these properties including devising, testing and screening therapeutic drugs.

1 . A method of screening therapeutic agents using a multicellular composition comprising human cancer cells within and surrounded by a microenvironment of non-malignant human cells selected from pluripotent human embryonic stem cells and non-malignant human tissue derived from differentiated human embryonic stem cells and wherein the cancer cells maintain their abnormal phenotype, the method comprising contacting the multicellular composition with at least one candidate therapeutic agent, and determining the effect of the at least one therapeutic agent on the multicellular composition. 
     
     
         2 . The method according to  claim 1 , comprising: (a) culturing human embryonic stem cells in conditions which promote generation of embryoid bodies; (b) determining the formation of at least one embryoid body in the culture of (a); (c) injecting cancer cells into the at least one embryoid body thereby obtaining at least one multicellular composition; optionally, (d) determining the presence of cancer cells within said at least one multicellular composition; (e) contacting said at least one multicellular composition obtained in (d) to a therapeutic agent; and (f) determining the effect of the therapeutic agent on said at least one multicellular composition. 
     
     
         3 . The method according to  claim 1 , wherein determining the effect of the therapeutic agent on said at least one multicellular composition comprises evaluating one or more parameters selected from the group consisting of: cell proliferation, cell differentiation, invasiveness of the cancer cells, angiogenesis and apoptosis. 
     
     
         4 . The method according to  claim 1 , comprising: (a) injecting undifferentiated human embryonic stem cells into a host animal; (b) determining the formation of at least one teratoma in the host animal; (c) injecting cancer cells into the at least one teratoma thereby obtaining at least one multicellular composition; (d) determining the presence of cancer cells within the at least one multicellular composition; (e) treating the host animal having said at least one multicellular composition obtained in (d) with a therapeutic agent; and (f) determining the effect of the therapeutic agent on said at least one multicellular composition. 
     
     
         5 . The method of  claim 1 , comprising: (a) culturing undifferentiated human embryonic stem cells in conditions which promote generation of embryoid bodies; (b) determining the formation of at least one embryoid body in the culture of (a); (c) injecting cancer cells into the at least one embryoid body thereby obtaining at least one multicellular composition; optionally, (d) determining the presence of cancer cells within said at least one multicellular composition; (e) implanting said at least one multicellular composition into a host animal; optionally, (f) treating the host animal with a composition comprising a therapeutic agent; and (g) determining the effect of therapeutic agent on said at least one multicellular composition. 
     
     
         6 . The method of  claim 5 , wherein step (e) further comprises occluding said at least one multicellular composition within a barrier membrane prior to implanting said at least one multicellular composition in a host animal. 
     
     
         7 . The method of  claim 5 , wherein said at least one multicellular composition is injected into a site in the host animal selected from the peritoneal cavity and a predefined locus. 
     
     
         8 . The method of  claim 4 , wherein treating the host animal is performed by topical administration of said therapeutic agent to said at least one multicellular composition. 
     
     
         9 . The method of  claim 4 , wherein the host animal is immunodefficient. 
     
     
         10 . The method of  claim 1 , wherein the therapeutic agent is selected from the group consisting of: a cytotoxic compound, a cytostatic compound, anticancer drug, an antisense compound, an anti-viral agent, an agent inhibitory of DNA synthesis and function and an immunotherapeutic agent. 
     
     
         11 . The method of  claim 10 , wherein the at least one therapeutic agent is conjugated to an agent selected from the group consisting of: a fluorescent marker, chemiluminescent marker, imaging agent and a carrier. 
     
     
         12 . The method of  claim 11 , wherein the imaging agent is selected from the group consisting of: gadolinium, yttrium, lutetium and gallium; radioactive moieties, such as, radioactive indium, rhenium and technetium, fluorescein isothiocyanate (FITC), green fluorescent protein (GFP), cyan fluorescent protein (CFP), rhodamine I, II, III and IV, rhodamine B, and rosamine. 
     
     
         13 . The method of  claim 10 , wherein the immunotherapeutic agent is of human origin. 
     
     
         14 . The method of  claim 10 , wherein the immunotherapeutic agent is selected from the group consisting of: an antibody or any active fragment thereof, a cytokine, a chemokine, a polynucleotide encoding same and a cell of the immune system. 
     
     
         15 . The method of  claim 10 , wherein the therapeutic agent comprises at least one oligonucleotide, selected from the group consisting of: antisense, sense nucleotide sequence, short interfering RNA, ribozyme and aptamer. 
     
     
         16 . A method for evaluating treatment efficacy of a therapeutic agent, comprising assessing the effect of the therapeutic agent on cancer cells within and surrounded by a microenvironment of non-malignant human cells selected from pluripotent human embryonic stem cells and non-malignant human tissue derived from differentiated human embryonic stem cells; wherein the cancer cells maintain their abnormal phenotype. 
     
     
         17 . The method of  claim 16 , comprising contacting a plurality of multicellular compositions with a therapeutic agent and assessing the damage caused by the therapeutic agent to the non-malignant human cells. 
     
     
         18 . The method of  claim 16 , comprising contacting a plurality of multicellular compositions with a therapeutic agent and assessing the damage caused by the therapeutic agent to the cancer cells. 
     
     
         19 . The method of  claim 17 , wherein the damaged caused by the therapeutic agent is assessed by evaluating at least one of the parameters selected from the group consisting of: cell proliferation, cell differentiation, invasiveness of the cancer cells, angiogenesis and apoptosis. 
     
     
         20 . The method of  claim 16 , wherein the therapeutic agent is selected from the group consisting of: a cytotoxic compound, a cytostatic compound, anticancer drug, an antisense compound, an anti-viral agent, an agent inhibitory of DNA synthesis, an agent inhibitory for DNA function and an immunotherapeutic agent. 
     
     
         21 . The method of  claim 20 , wherein the therapeutic agent is selected from the group consisting of: adriamycin, bleomycin, chlorambucil, cisplatin, daunomycin, ifosfamide and melphalan; agents inhibitory of microtubule (mitotic spindle) formation and function: vinblastine, vincristine, vinorelbine, paclitaxel (taxol) and docetaxel; anti metabolites: cytarabine, fluorouracil, fluoroximidine, mercaptopurine, methotrexate, gemcitabin and thioquanine; alkylating agents: mechlorethamine, chlorambucil, cyclophosphamide, melphalan and methotrexate; antibiotics: bleomycin and mitomycin; nitrosoureas: carmustine (BCNU) and lomustine; inorganic ions: carboplatin, oxaloplatin; interferon and asparaginase; hormones: tamoxifen, leuprolide, flutamide, daunomycin and megestrol acetate.