GOL/ Across the border, U.S. stock index futures dropped on Amazon.com Inc's AMZN.O warning about a slowdown in its cloud business, and downbeat forecasts from social media companies Snap Inc SNAP.N and Pinterest Inc PINS.N. April 28 (Reuters) - Futures for Canada's main stock index fell on Friday, as gold lost ground and downbeat mood on Wall Street after disappointing overnight forecasts spilled over. .N Markets await the U.S. personal consumption expenditures index data, the Fed's preferred inflation gauge, later in the day, ahead of the central bank's key policy meeting next week.