Disclaimer: I am not a lawyer.
You won't find an absolute answer to this question anywhere, but the general consensus seems to be, "Yes, with attribution, depending on your jurisdiction."
The CC0 is not a copyleft license, so it does not require re-licensing under the same license for derivative works. In my (non-lawyerly) opinion, as long as you are attributing the creator/owner of the work, there shouldn't be an issue with you publishing your modified version of the code under the MIT license.
From the CC0 FAQ:
Just like anything in the public domain, it will be possible for others to use or adapt it however they wish without attribution.
Just like anything already in the public domain today, anybody will be able to use your work for any purpose, even in ways you may find distasteful or objectionable. They can also make money off of your work, and they may give you credit or they may not.
From answers to the question linked to above by @unor:
consider the author's moral rights. In some jurisdictions, this include the right to be attributed properly, and this is a legal requirement.
There's no legal requirement [in the USA] that the CC0 license and authorship information be retained.
The answers so far assume that it is definitely unmoral to not attribute work published with CC0 and it will be seen as such at court (given appropriate jurisdictions).