Yes - but it's not easy because of the following:

1) You can only do roundtrip upgrades - one way is not possible
2) You cannot waitlist
3) Both outbound and return flights have to have award availability open at the same time, otherwise you cannot issue the upgrade
4) Upgrades must be done at least 48 hours before departure

I've done it successfully for HKG-LHR-HKG runs twice before. At 30K miles for Y+ to J it's great value.

However, I've noticed that miles will not credit automatically and you will probably need to claim for missing mileage.