the eurotarget cohort: a european collaborative project on targeted therapy in renal cell cancer using genetic and tumour-related biomarkers for response and toxicity
I can't recall seeing a title with more than one colon in a carefully edited publication. In the revised example above, the colon indicates that what follows it elaborates on what precedes it. In the recast elaboration, the word "using" removes any need for a second colon in the title.
Thanks again to @sven for suggesting I explain the revised example.