By Abigail Summerville and Sukriti Gupta (Reuters) - Wall Street's three main stock indexes ended lower in choppy trading on Tuesday as caution set in ahead of an anticipated interest rate cut from the Federal Reserve. Investors are largely still pricing in a 25 basis-point cut from the U.S. central bank at the conclusion of its two-day meeting on Wednesday, to offset the deterioration in the U.S. labor market, evidenced by numerous recent economic indicators. Data on Tuesday showed that U.S. retail sal ...