A PROTEIN INHIBITOR, EXTRACTED FROM HELA-CELLS, WHICH RECOGNIZES A CELL-SURFACE PROTEASE ON PRENEOPLASTIC CELLS OBTAINED FROM CERVICAL SMEARS

Hela cells originate from a clone of cervical carcinoma cells. The cyt oplasm of Hela cells contains a protein which recognises and inhibits a proteolytic enzyme (guanidino-benzoatase) on the surface of Hela cel ls. This same protease is present on the surface of abnormal epithelia l cells obtained from cervical smears, enabling a rhodamine labelled i nhibitor extracted from Hela cells to locate abnormal cervical cells i n monolayer spreads.