1Used to introduce or emphasize what follows, often summarizing or getting to the main point — similar to "anyway" or "in any case."
何しろ初めての海外旅行なので、少し緊張している。
Anyway, since this is my first trip abroad, I'm a bit nervous.
何しろ人手が足りないから、みんなで手伝ってほしい。
In any case, we're short-staffed, so I'd like everyone to help.
何しろ急いでいたので、忘れ物をしてしまった。
Anyhow, I was in a hurry, so I ended up forgetting something.
2Used when giving a reason, similar to "because" or "after all"; common in spoken Japanese.
何しろ田舎なので、夜になるとお店がほとんど閉まってしまう。
Since it's the countryside, after all, most shops close once night falls.
何しろ子供が小さいので、なかなか外出できない。
Since the kids are still small, we can't really go out much.