Composition and method for modulating fibroblast growth factor receptor 3 activation

Abstract

A method of inhibiting an overactive fibroblast growth factor receptor 3 (FGFR3) in a cell by contacting the cell with a composition that contains an effective amount of Pheophorbide a, Pyropheophorbide a, or an active derivative thereof. Also disclosed is a method for treating a disorder associated with an overactive FGFR3 with a composition containing an effective amount of Pheophorbide a, Pyropheophorbide a, or an active derivative thereof. Further, a composition for treating a disorder associated with an overactive FGFR3 is described. The composition contains an ethanol extract of Amaranthus viridis.

1 . A method of inhibiting an overactive fibroblast growth factor receptor 3 (FGFR3) in a cell, comprising contacting the cell with a composition containing an effective amount of Pheophorbide a, Pyropheophorbide a, or an active derivative thereof. 
     
     
         2 . A method of treating a disorder associated with an overactive FGFR3 in a subject, comprising:
 identifying a subject in need thereof, and   administering to the subject a composition containing an effective amount of Pheophorbide a, Pyropheophorbide a, or an active derivative thereof.   
     
     
         3 . The method of  claim 2 , wherein the disorder is a skeletal dysplasia or a cancer. 
     
     
         4 . The method of  claim 3 , wherein the skeletal dysplasia is achondroplasia, hypochondroplasia, severe achondroplasia with developmental delay and acanthosis nigricans, thanatophoric dysplasia type I, or thanatophoric dysplasia type II, and wherein the cancer is multiple myeloma, bladder cancer, cervical cancer, or any type of cancer associated with FGFR3 activation. 
     
     
         5 . The method of  claim 1 , wherein the composition is an extract of a green plant or green algae. 
     
     
         6 . The method of  claim 5 , wherein the plant is  Amaranthus viridis.    
     
     
         7 . A mammalian cell, comprising a first exogenous nucleic acid encoding a human FGFR3 protein and a second exogenous nucleic acid encoding a fusion protein that includes a green fluorescent protein (GFP) and a FGFR3 effector protein, wherein the cell expresses the human FGFR3 protein and the fusion protein, and wherein the effector protein is capable of binding to an activated FGFR3. 
     
     
         8 . The mammalian cell of  claim 7 , wherein the effector protein is the Src homology 2 (SH2) domain of human SH2-Bβ. 
     
     
         9 . The mammalian cell of  claim 8 , wherein the human FGFR3 protein is a wild-type protein or an overactive mutant. 
     
     
         10 . The mammalian cell of  claim 9 , wherein the overactive mutant is FGFR3(Y373C), FGFR3(G380R), FGFR3(N540K), FGFR3(K650E), FGFR3(R248C), FGFR3(S371C), FGFR3(Y373C), FGFR3(G375C), FGFR3(G380R), FGFR3(N540K), FGFR3(K650M), FGFR3(K650E), FGFR3(X807G), FGFR3(X807R), or FGFR3(X807C). 
     
     
         11 . The mammalian cell of  claim 10 , wherein the cell exhibits a punctate pattern of cytoplasmic GFP spots. 
     
     
         12 . A method of identifying a modulator of FGFR3 activation, comprising:
 providing a mammalian cell, comprising a first exogenous nucleic acid encoding a human FGFR3 protein and a second exogenous nucleic acid encoding a fusion protein that includes a green fluorescent protein (GFP) and a FGFR3 effector protein, wherein the cell expresses the human FGFR3 protein and the fusion protein, and wherein the effector protein is capable of binding to an activated FGFR3,   contacting the cell with a test agent,   imaging the cell for cytoplasmic GFP signals, and   obtaining a count of individual cytoplasmic GFP spots,   
       wherein obtaining a count that is lower or higher than a control count indicates that the test agent is a modulator of FGFR3 activation. 
     
     
         13 . The method of  claim 12 , wherein obtaining a count that is lower than the control count indicates that the test agent is an inhibitor of FGFR3 activation. 
     
     
         14 . The method of  claim 13 , wherein obtaining a count that is higher than the control count indicates that the test agent is an activator of FGFR3 activation. 
     
     
         15 . A composition for treating a disorder associated with an overactive FGFR3, the composition comprising an effective amount of an ethanol extract of a plant belonging to the family Amaranthaceae, Sapotaceae, or Zingiberaceae. 
     
     
         16 . The composition of 15, wherein the ethanol extract is from  Amaranthus viridis.    
     
     
         17 . The composition of  claim 16 , wherein the ethanol extract includes Pheophorbide a or Pyropheophorbide a. 
     
     
         18 . The method of  claim 2 , wherein the composition is an extract of a green plant or green algae. 
     
     
         19 . The mammalian cell of  claim 7 , wherein the cell endogenously express mRNA for FGFR1, 2 and 4, but not FGFR3. 
     
     
         20 . The mammalian cell of  claim 7 , wherein the cell is osteosarcoma cells (U20S). 
     
     
         21 . The method of  claim 12 , wherein the cell endogenously express mRNA for FGFR1, 2 and 4, but not FGFR3. 
     
     
         22 . The method of  claim 21 , wherein the cell is osteosarcoma cells (U2OS).