You can still cast it for the Indestructible effect. Spells and effects always do as much as they can when they resolve. If they can't perform something, they simply move on
The exception to this is if the spell has single Target. If a spell no longer has any legal targets, it will be countered when it tries to resolve. Take Volt Charge . If you cast it targeting my Grizzly Bears and I sacrifice my bears in response, Volt Charge will be countered and you won't be able to proliferate. If a spell has multiple targets (Hunt the Weak ), as long as it still has one legal target it will try to resolve the best it can. If you cast Hunt the Weak targeting my poor bears and I sac them again, you will still get your +1/+1 counter on your creature.