From the title, I read this expecting another lame observational study which I would probably distrust on the basis that it doesn't show anything causal. It's not that! Rather, if I understand it, they (1) took mice and introduced leukemia cells and (2) took human leukemia cell lines. In both cases, they found biomarkers related to leukemia growth.
(I welcome corrections to that understanding from experts!)
Personally, this seems far from convincing evidence that taurine in energy drinks is actually causing cancer. But it is suggestive and it seems like one might reasonably avoid taurine out of an "abundance of caution".
The inverse of this study, in which a nutrient that helps cells grow, including cancer cells, is the cause of cancer is that every substance they find that kills cells, but is slightly more likely to kill cancer cells than regular cells is suddenly the cure for cancer.
The paper (an extremely difficult one to comprehend, reminding us how complex this field of research has become) only glancingly mentions energy drinks because apparently they are sometimes used to offset the effects of chemotherapy. That is, the context in which they are mentioned is people who already have leukemia. The entire rest of the paper is about how taurine produced by the body's own cells contributes to the advancement of the established disease.
Taurine deficiency has been claimed to be a driver of aging [1]. The claim from the news article about it possibly being related to cancer seems like it needs a much stronger justification.
(I welcome corrections to that understanding from experts!)
Personally, this seems far from convincing evidence that taurine in energy drinks is actually causing cancer. But it is suggestive and it seems like one might reasonably avoid taurine out of an "abundance of caution".