If you want an exact match, that's easy:

while (<DATA>){
    print "matched\n" if /publish/ and /date/;
}
[download]

But note that this would also match "the date was published on"...

If the order in which the words must occur is relevant, you could do

while (<DATA>){
    print "matched\n" if /publish.*date/;
}
[download]