Ok, so the Pym Particles grants a single based figure to become a giant or tiny size by possessing that ability.
So, let's say you have someone with Telekinesis and you have normal, single-based, Mary Jane Watson. And let's say Mary Jane picks up the Pym Particles and now is either a giant or tiny sized. She still have the , so I would say she could be Telekinesised. Yet, she also possesses either the giant or tiny size.
So, I don't know how the wording rules this. Would a Mary Jane who picks up the Pym Particles and changes size be able to be TKed or not?

If Mary Jane uses Pym Particles to become , the is replaced and she no longer possesses it. She could not be TK'd, because she is now . If she becomes she can be TK'd, because nothing prevent Tiny sized characters from being TK'd.

From the 2014 Rule Book, pg 19: