Can black still use the Sicilian against Queen's Pawn?

After some study on the Sicilian (plus using it), I found it to be an (small) improvement for me as black when my opponent plays King's Pawn. Now I have another question: Is it possible for black to still play the Sicilian when white plays Queen's Pawn Opening (other than the d4 pawn attacking my Nc6 knight if I play that)? Thanks!

You mean, 1. d4, c5? Yes this is possible, but it is not a Sicilian, it is an old benoni, and the positions are competely different from typical sicilian positions. It is possible for white to reply with 2. e4 which transposes to a sicilian smith-morra gambit, but most of the time white will play 2. d5

So it still does work for black I see, thank you very much.

No, it really doesn't.  White gets a significant advantage, and scores almost 65% in the old benonis, specifically those where White does not play c4, like the line mentioned above, 1.d4 c5 2.d5 e6 3.e4 Nf6 4.Nc3!.  Also common is 3...exd5 4.exd5 Nf6, after which White should play 5.Nc3, NOT 5.c4.

If you want to play the Benoni, play 1.d4 Nf6 and if 2.c4, only then 2...c5!

What's wrong with 2. dxc5?

Nothing. It's playable, but no more than that.

A friend of mine once lost playing this:

He was rather disappointed with his own performance
 

Even in King's Pawn, its necessary to keep the c-pawn unless you're done with developing (Dragon Variation) or defending yourself.

But to the OP- if you want to play c5 against d4, playing Nf6 first is better.

and black will fianchetto on the kingside, try to prepare a6, b5 and use the queenside majority. If white locks up the queenside black can sometimes get a nice kingside attack. You will have to do some opening prep though as there are a lot of ways for black to go wrong if you don't know what's going on.