Call method x times using linq

You can System.Linq.Enumerable to repeat an Action multiple times.

                Enumerable.Repeat<Action>(() =>
            {
                lstNews.Add(CollectNews);
            }, 3);

This would run the Add method on the list 3 times. Docs on Enumerable.Repeat here.

var lstNews = Enumerable.Repeat(0, 3).Select(_ => CollectNews()).ToList();

As I understand you want to end up with a list of three News objects. You can do something like

Enumerable.Repeat(1, 3).Select(_ => CollectNews()).ToList();

You could use any value in place of 1 in that example.

While this approach works, it's sort of abusing the idea of LINQ. In particular, you should not assume any order of executing CollectNews() calls. While the standard Select implementation will execute in sequence this may not always be true.