Cryptome discovers novel compounds to treat cancer

Melbourne biopharma Cryptome's (ASX:CRP) proprietary drug-screening technology has struck a highly prospective vein just 12 months after beginning its first major dig into the human proteome in search of novel anti-cancer drugs.

Using a melanoma cell line to screen a range of human proteins, Cryptome researchers have identified a family of small proteins with promising anti-cancer activity.

Cryptome's chief scientific officer, Vic Ilag, said that conventionally, cancer researchers start by identifying a drug target, then screen compounds for promising activity, Cryptome's approach inverts this activity.

It employs in vitro cultures of tumour cells - in this case, a melanoma cell line - to screen naturally occurring proteins in human cells, and purifies any that show promising activity.

Researchers then cleave the proteins into peptide fragments with Cryptome's proprietary protease enzymes, to dissect out the active peptide elements, or 'crypteines', hidden within the parent proteins.

Ilag calls it a "shoot first, ask questions later" strategy, likening the process to the development of aspirin. "Aspirin has been used for well over a century, but it wasn't until 15 years ago that we understood how it works."

Armed with the 'sharp bits' of the active proteins, researchers can then fish for the target molecule on the cancerous cells.

The identify of the target molecule, and the crypteines that bind to it, remain secret, but Ilag said Cryptome has a cluster of closely related proteins and peptide molecules that exhibit varying degrees of anti-cancer activity.

All exhibit anti-coagulant activity, but Ilag said they also appear to disrupt the growth of cancerous cells both directly and indirectly, by killing the cells, or blocking angiogenesis - the growth of new blood cells.

Why don't these proteins or peptides act naturally to prevent cancer in the body? Ilag said the mode of action is unclear, but the molecules are synthesized as an early response to stresss, and the body may not amplify their expression sufficiently for them to kill cancerous cells.

If they make it to market, the new compounds would probably be formulated for intranasal delivery, rather than by the oral or subcutaneous route.

The company has already filed patents on the compounds' anti-coagulant properties, and will now select several compounds as leads for animal trials.

Ilag said human proteins have natural advantages as drugs - they are safer and easier to get through the Food and Drug Administration's and Therapeutic Goods Administration's regulatory process.

It has taken Cryptome only a year to get to its first anti-cancer molecules, where it typically takes three years by the conventional route.