Anthrax may be ally in cancer war
Jan 04,2008 00:00 by Bend_Weekly_News_Sources

Most peo­ple would­n’t con­sid­er an­thrax tox­in to be help­ful—but this bac­te­ri­al poi­son may some­day be a can­cer ther­a­py, sci­en­tists claim. 

The tox­in has been shown to be fairly se­lec­tive in tar­get­ing mel­a­no­ma, or skin can­cer, cells, ac­cord­ing to Ste­phen Lep­pla of the Na­t­ional In­sti­tute of Al­ler­gy and In­fec­tious Dis­eases in Be­thes­da, Md.

In a new stu­dy, Lep­pla and col­leagues mod­i­fied the tox­in to make it tar­get tu­mor cells even more pre­cise­ly, while spar­ing healthy cells. To work, the re­search­ers said, the new poi­son re­quires the pres­ence of pro­teins over­pro­duced only in can­cer cells. The pro­teins are called ma­trix met­al­lo­pro­tein­ases.

The team found that all mice tested with the mu­tat­ed tox­in tol­er­ated doses that would be oth­er­wise le­thal. The mu­tat­ed poi­son was al­so bet­ter at kill­ing mel­a­no­ma tu­mors than nat­u­ral tox­in, they said, due to its high­er spe­cif­i­city and long­er pres­ence in the blood.

Even bet­ter, Lep­pla and col­leagues said, the molecule’s an­ti-can­cer ac­ti­vity was­n’t lim­it­ed to mel­a­no­ma: the poi­son could al­so kill oth­er tu­mors like co­lon and lung. This abil­ity was due, they re­ported, to its power to in­hib­it an­gio­gen­esis, or the forma­t­ion of new blood ves­sels that nour­ish tu­mors.

“These en­cour­ag­ing mouse re­sults sug­gest that mod­i­fied an­thrax tox­in could be clin­ic­ally vi­a­ble, and this po­tent kill­er might some­day be put to good use,” said an an­nounce­ment of the find­ings this week from the Ame­ri­can So­ciety for Bio­chem­is­try and Mo­l­e­cu­lar Bio­logy. The org­a­ni­za­tion pub­lishes the Jour­nal of Bi­o­log­i­cal Chem­is­try, which reports the new study in its Jan. 4 is­sue.

Courtesy American Society for Biochemistry and Molecular Biology