Hexosaminidase‐altered Aberrant Crypts, Carrying Decreased Hexosaminidase α and β Subunit mRNAs, in Colon of 1,2‐Dimethylhydrazine‐treated Rats

Abstract

Aberrant crypt foci (ACF), consisting of morphologically irregular crypts, are thought to be precancerous lesions for colon cancers. For their molecular analysis, it is necessary to avoid contamination with adjacent normal crypts and stromal cells. Decreased hexosaminidase activity in ACF, which has been histochemically demonstrated, was used in the present study to classify isolated crypts in combination with morphological changes. The length, rim diameter, and width (average±SD, μm) of hexosaminidase‐positive (Hex+) crypts were 238.6±40.4, 89.5±22.9, and 57.6±14.0, respectively. For hexosaminidase‐negative (Hex‐) crypts, the values were 314.4±77.8, 140.3±45.7, and 97.3±34.7, the width being 1.69 tunes greater (PHexa and Hexb, respectively), real‐tune relative quantitative reverse transcription‐polymerase chain reaction (RT‐PCR) analysis was performed using the LightCycler system. In aberrant crypts, both Hexa and Hexb were significantly down‐regulated to 0.266 (P‐actin as the internal standard. This decrease could be a molecular marker for precancerous enzyme‐altered ACF.