I'm not an electrician but I do know that if you can buy cable that's coded for burial in the ground, it doesn't matter whether you run it through PVC or pipe. If you're thinking of running indoor-rated wire through ANYTHING outside, DON'T. It's probably a code violation and probably unsafe too.
If want to bury any wire, make sure it's code-compliant and safe. Hopefully, an electrician will add more here. My best to ya and hope this helps.