Tumor-Specific Delivery of Therapeutic Agents via Liposomase/US

Abstract

Clostridium novyi is an obligate anaerobe that can infect hypoxic regions within experimental tumors. We found that mice bearing large, established tumors were often cured when treated with C. novyi plus a single dose of liposomal doxorubicin. The secreted factor responsible for this phenomenon was identified and, surprisingly, proved to be a member of the lipase family. The gene encoding this protein, called liposomase, has the potential to be incorporated into diverse therapeutic methods to deliver specifically a variety of chemotherapeutic agents to tumors.

1 - 54 . (canceled) 
     
     
         55 . A kit comprising:
 a  Clostridium novyi  liposomase according to SEQ ID NO: 1 with a substitution mutation in the GXSXG lipase motif at residues 160-164; and   a liposome comprising an anti-tumor drug or biological agent.   
     
     
         56 . The kit of  claim 55  wherein the anti-tumor drug or biological agent is doxorubicin. 
     
     
         57 . The kit of  claim 55  wherein the anti-tumor drug or biological agent is irinotecan. 
     
     
         58 . The kit of  claim 55  wherein the anti-tumor drug or biological agent is an antibody. 
     
     
         59 . The kit of  claim 55  wherein the anti-tumor drug or biological agent is a polynucleotide. 
     
     
         60 . The kit of  claim 55  wherein the anti-tumor drug or biological agent is a polynucleotide in a viral vector. 
     
     
         61 . The kit of  claim 55  wherein the anti-tumor drug or biological agent is a polynucleotide in a non-viral vector. 
     
     
         62 . A method of treating a tumor bearing mammal, comprising:
 administering to the tumor bearing mammal a first agent which is a  Clostridium novyi  liposomase according to SEQ ID NO: 1 with a substitution mutation in the GXSXG lipase motif at residues 160-164 and a second agent which is a liposome comprising an anti-tumor drug or biological agent, whereby the tumor regresses or its growth is slowed or arrested.   
     
     
         63 . The method of  claim 62  wherein the first agent and the second agent are administered sequentially. 
     
     
         64 . The method of  claim 62  wherein the first agent and the second agent are administered simultaneously. 
     
     
         65 . The method of  claim 62  wherein the anti-tumor drug or biological agent is doxorubicin. 
     
     
         66 . The method of  claim 62  wherein the anti-tumor drug or biological agent is irinotecan. 
     
     
         67 . The method of  claim 62  wherein the anti-tumor drug or biological agent is an antibody. 
     
     
         68 . The method of  claim 62  wherein the anti-tumor drug or biological agent is a polynucleotide. 
     
     
         69 . The method of  claim 62  wherein the anti-tumor drug or biological agent is a polynucleotide in a viral vector. 
     
     
         70 . The method of  claim 62  wherein the anti-tumor drug or biological agent is a polynucleotide in a non-viral vector. 
     
     
         71 . The method of  claim 62  wherein the administration is intratumoral. 
     
     
         72 . The method of  claim 62  wherein the tumor bearing mammal is a human. 
     
     
         73 . The method of  claim 62  wherein the tumor bearing mammal is a pet. 
     
     
         74 . The method of  claim 62  wherein the tumor bearing mammal is an agricultural animal. 
     
     
         75 . The method of  claim 62  wherein the tumor bearing mammal is a laboratory animal. 
     
     
         76 . The method of  claim 73  wherein the pet is a dog. 
     
     
         77 . A composition comprising an isolated and purified  Clostridium novyi  liposomase protein according to SEQ ID NO: 1 with a substitution mutation in the GXSXG lipase motif at residues 160-164.