<?php
$string ="
Text-Text
Abc-123
123-Abc
A2C-def4gk
Ab-3
Abc!-ajr4
a-bc3-25aj
a?c-b%";

$regex='~
        ^\w{3,}  # at last three word characters at the beginning of the line
        -        # a dash
        \w{3,}$  # three word characters at the end of the line
        ~xm';    # multiline and freespacing mode (for this explanation)
preg_match_all($regex, $string, $matches);
print_r($matches);
?>