High speed train from Beijing to Guangzhou with two 50 lb. suitcases

1. Can we bring our 50 lb suitcases on it with us and store them on the it. or
2. Is there a place to check in these suitcases and they will be some where on the it and arrive with us, we don't want them on another rail trip because we have to transfer to another trip to Hong Kong...
3. If this check in is possible what is the cost to do this?