I doubt tree frogs live long enough for the bacteria to have evolved to fight cancer as such. They are quite small.

They also produce of range of drugs secreted on their skin, including anti-virals for hiv, antibiotics (russian one,) one containing a super opiate, (south american desert one,) the poison dart ones, what else, there are others.

The toxins are not alkaloids but peptides, and tend to have a much shorter half time as active ingredients as I'm aware.