Retrieve RNA sequencing data for human p53 colon cancer cell lines I want to download the next generation RNA sequencing data in different cell lines. I want the data (alongwith normal) for p53 wild type, p53 knock-out and p53 null cell lines (human colon cancer). From where do I download this data? In fastq format if possible.

Currently, I am going through SRA, to look for the datasets, using their search engine. But the process is extremely tedious. 

Also can someone please hint about how to download the data from SRA, in case that's the only way to get data. I'm getting very confused.
I suggest you to try difference resources, including ArrayExpress. 
A simple search at ArrayExpress returns multiple experiments which might be of your interest. Just a pointer, ArrayExpress is also synced with GEO.