Tumor-delivered multi-target therapeutics for colon cancer

Abstract

The present disclosure relates to genetically modified strains of Salmonella, engineered to be tumor navigating, self-eradicating, and armed with decoy polypeptides that bind endogenous ligand and block activation of signal transduction cascades associated with cancer cell proliferation and tumor growth. Also provided herein are methods of producing and methods of using such genetically modified Salmonella strains to treat cancer.

1 - 6 . (canceled) 
     
     
         7 . A genetically modified  Salmonella  bacterium comprising:
 (i) a recombinant gene encoding a human decoy polypeptide;   (ii) the following mutations ΔP murA ::TT araC P BAD  murA ΔasdA::TT araC P BAD  c2 Δ(wza-wcaM) Δpmi ΔrelA recF ΔsifA ΔendA ΔsseL ΔtlpA ΔP hilA ::P trc ΔlacO888 hilA; and   (iii) one or more of mutations selected from ΔP tar ::P trc ΔlacO  tar, ΔP tsr ::P trc ΔlacO  tsr, and Δtrg.   
     
     
         8 . The genetically modified  Salmonella  bacterium of  claim 7 , wherein the decoy polypeptide disrupts Wnt/β-catenin signaling. 
     
     
         9 . The genetically modified  Salmonella  bacterium of  claim 7 , wherein the decoy polypeptide is selected from a soluble form of human frizzled (FZD) receptor, a soluble form of human LRP6, a soluble form of human PD-1, and a soluble form of human SIRP-alpha. 
     
     
         10 . The genetically modified  Salmonella  bacterium of  claim 7 , wherein the bacterium comprises mutation ΔP tar ::P trc ΔlacO  tar. 
     
     
         11 . The genetically modified  Salmonella  bacterium of  claim 7 , wherein the bacterium comprises mutations ΔP tar ::P trc ΔlacO  tar, ΔP tsr ::P trc ΔlacO  tsr, and Δtrg. 
     
     
         12 . The genetically modified  Salmonella  bacterium of  claim 7 , wherein the bacterium is a  Salmonella  strain selected from GMS525(pK-DFZD), GMS525(pK-DLRP6), GMS525(pK-DPD-1), and GMS525(pK-DSIRPa). 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . A method for stimulating tumoricidal activity in a host comprising:
 transforming a first recombinant gene into a strain of  Salmonella  forming a strain B, the first recombinant gene encoding a decoy polypeptide;   introducing the following mutations ΔP murA ::TT araC P BAD  murA Δasd::TT araC P BAD  c2 Δ(araC P BAD )::P22 P R  araBAD Δ(wza-wcaM) Δpmi ΔrelA::araC P BAD  lacI TT ΔpagP::P lpp  lpxE ΔendA into strain B, thereby forming strain C;   introducing one or more mutations selected from ΔP tar ::P trc ΔlacO  tar, ΔP tsr ::P trc ΔlacO  tsr, and Δtrg into strain C, thereby forming strain D; and   administering strain D to the host.   
     
     
         16 . The method of  claim 15 , wherein the decoy polypeptide disrupts Wnt/β-catenin signaling. 
     
     
         17 . The method of  claim 15 , wherein the decoy polypeptide is selected from a soluble form of human frizzled (FZD) receptor, a soluble form of human LRP6, a soluble form of human PD-1, and a soluble form of human SIRP-alpha. 
     
     
         18 . The method of  claim 15 , wherein administering comprises oral administration or intra-tumoral injection of strain D into the host. 
     
     
         19 . The method of  claim 15 , wherein strain D is a  Salmonella  strain selected from GMS515(pK-FZD), GMS515(pK-LRP6), GMS515(pK-PD-1), GMS515(pK-SIRPα), GMS515(pK-VEGFR2), GMS515(pK-PDGFRα), and GMS515(pK-FGFR-1). 
     
     
         20 . A method for stimulating tumoricidal activity in a host comprising:
 introducing the following mutations ΔP murA ::TT araC P BAD  murA ΔasdA::TT araC P BAD  c2 Δ(wza-wcaM) Δpmi ΔrelA ΔrecF ΔsifA ΔendA ΔsseL ΔtlpA ΔP hilA ::P trc ΔlacO888 hilA into a strain of  Salmonella , whereby strain E is formed;   introducing one or more mutations selected from ΔP tar ::P trc ΔlacO  tar, ΔP tsr ::P trc ΔlacO  tsr, and Δtrg into strain E, whereby strain F is formed;   transforming a recombinant gene into strain F, the recombinant gene encoding a decoy polypeptide; whereby strain G is formed; and   administering strain G to the host.   
     
     
         21 . The method of  claim 20 , wherein the decoy polypeptide disrupts Wnt/β-catenin signaling. 
     
     
         22 . The method of  claim 20 , wherein the decoy polypeptide is selected from a soluble form of human frizzled (FZD) receptor, a soluble form of human LRP6, a soluble form of human PD-1, and a soluble form of human SIRP-alpha. 
     
     
         23 . The method of  claim 20 , wherein administering comprises oral administration or intra-tumoral injection of strain G into the host. 
     
     
         24 . The method of  claim 20 , wherein strain G is a  Salmonella  strain selected from GMS525(pK-DFZD), GMS525(pK-DLRP6), GMS525(pK-DPD-1), and GMS525(pK-DSIRPa). 
     
     
         25 . A method of treating a tumor in a subject in need thereof comprising administering a genetically modified  Salmonella  bacterium of  claim 7  to the subject, whereby the genetically modified  Salmonella  bacterium treats tumor cells in the subject. 
     
     
         26 . The method of  claim 25 , wherein administering comprises oral administration or intra-tumoral injection of the genetically modified  Salmonella  bacterium.