In continuation of my update on Platinum compounds as anticancer drugs, I find this one more interesting info to share with. MIT chemists have developed a new platinum compound that is as powerful as the commonly used anticancer drug cisplatin but better able to destroy tumor cells.
As per the claim by the researchers, glycolytic metabolism of most solid tumors, known as the Warburg effect, is associated with resistance to apoptosis that enables cancer cells to survive. Dichloroacetate (DCA) is an anticancer agent that can reverse the Warburg effect by inhibiting a key enzyme in cancer cells, pyruvate dehydrogenase kinase (PDK), that is required for the process. DCA is currently not approved for cancer treatment in the USA. With this idea behind researchers have prepared the new compound by combining dichloroacetate, DCA and cisplatin. Mitaplatin, thus obtained has two DCA units which are appended to the axial positions of a six-coordinate Pt (IV) center.
As per the claim by the authors, the negative intracellular redox potential reduces the platinum to release cisplatin, a Pt (II) compound, and two equivalents of DCA. By a unique mechanism, mitaplatin thereby attacks both nuclear DNA with cisplatin and mitochondria with DCA selectively in cancer cells. The cytotoxicity of mitaplatin in a variety of cancer cell lines equals or exceeds that of all known Pt (IV) compounds and is comparable to that of cisplatin.
Mitaplatin alters the mitochondrial membrane potential gradient of cancer cells, promoting apoptosis by releasing cytochrome c and translocating apoptosis inducing factor from mitochondria to the nucleus. Cisplatin formed upon cellular reduction of mitaplatin enters the nucleus and targets DNA to form 1,2-intrastrand d(GpG) cross-links characteristic of its own potency as an anticancer drug. These properties of mitaplatin are manifest in its ability to selectively kill cancer cells cocultured with normal fibroblasts and to partially overcome cisplatin resistance. Further studies like mice transplanted with human tissues are to be substantiated, in my opinion its a good achievement...
Ref : http://www.pnas.org/content/early/2009/12/09/0912276106.abstract?related-urls=yes&legid=pnas;0912276106v1
As per the claim by the authors, the negative intracellular redox potential reduces the platinum to release cisplatin, a Pt (II) compound, and two equivalents of DCA. By a unique mechanism, mitaplatin thereby attacks both nuclear DNA with cisplatin and mitochondria with DCA selectively in cancer cells. The cytotoxicity of mitaplatin in a variety of cancer cell lines equals or exceeds that of all known Pt (IV) compounds and is comparable to that of cisplatin.
Mitaplatin alters the mitochondrial membrane potential gradient of cancer cells, promoting apoptosis by releasing cytochrome c and translocating apoptosis inducing factor from mitochondria to the nucleus. Cisplatin formed upon cellular reduction of mitaplatin enters the nucleus and targets DNA to form 1,2-intrastrand d(GpG) cross-links characteristic of its own potency as an anticancer drug. These properties of mitaplatin are manifest in its ability to selectively kill cancer cells cocultured with normal fibroblasts and to partially overcome cisplatin resistance. Further studies like mice transplanted with human tissues are to be substantiated, in my opinion its a good achievement...
Ref : http://www.pnas.org/content/early/2009/12/09/0912276106.abstract?related-urls=yes&legid=pnas;0912276106v1
nice information, there is nice video showing the mechanism of action of cisplatin.
ReplyDeletehttp://medchemblog.blogspot.com/2009/08/cisplatin-cisplatinum-or-cis.html
Thanx for comments and the video link (mech. of action)....
ReplyDelete