public class User
{
   public int Id {get;set;}

   public string Name {get;set;}

   public string Surname{get;set;}
}

public class News
{
   public int Id {get;set;}

   public string Content {get;set;}

   [ForeignKey("OwnerUser")]
   public int OwnerUserId{ get; set; }

   public virtual User OwnerUser{ get; set; }
}

public News InsertNews(News instance)
{
    instance = RealInsertionCode(instance);
    User usr = GetObjectById(OwnerUserId);
    instance.OwnerUser = usr;
    return instance;
}