N-cadherin expression in human adult T-cell leukemia cell line.

Abstract

Adult T-cell leukemia/lymphoma (ATL) has been reported as a new category of T-cell malignancy [1]. Human T-cell lymphotropic virus I (HTLV-I) has been linked etiologically with the disease [2]. Both ATL and cutaneous T-cell lymphoma (CTCL) show a helper/inducer T-cell phenotype (CD4+CD8–), but there are differences between these phenotypes, e.g. the expression of IL-2 receptor (CD25) is higher in ATL than in CTCL [3]. Aiba et al. [4] reported that some populations of T cell express E-cadherin, and Cepek et al. [5] and Ashton et al. [6] have shown that a cadherin molecule other than E-cadherin is expressed in T-cell lymphoma and T lymphocytes by immunoblotting using anti-pan-cadherin and anti-E-cadherin antibodies. Recently N-cadherin expression in some human leukemia cell lines has been reported by Tsutsui et al. [7]. ATL cells sometimes infiltrate into the epidermis and form microabscesses as well as T-cell lymphoma, which suggests the existence of a cadherin molecule, but the type of cadherin expressed in ATL cells is still unclear. To identify the cadherin molecule expressed in ATL cell lines, we performed a polymerase chain reaction (PCR) using the degenerate primers 5′-GAATTCACNGCNCCNCCNTAYGA and 5′-GAATTCTCNGCNARYTTYTTRAA to amplify multiple cadherin subtypes with the first strand of cDNAs generated by reverse transcription of the mRNAs of Hut102 cells [8]. The PCR conditions were essentially the same as those described by Matsuyoshi et al. [9]. After PCR, the reaction products were separated by 2% agarose gel electrophoresis, and the DNA of about 160 bp in size was extracted using a Geneclean Kit (Funakoshi, Tokyo, Japan) and ligated with a TA vector (Invitrogen, San Diego, Calif.) for sequencing. The sequencing of the DNA was done using an ALFred DNA Sequencer (Pharmacia Biotech, Uppsala, Sweden) which is designed for the automated electrophoresis and analysis of sequencing reactions by the direct detection of fluorescently labeled DNA molecules. We identified a fragment homologous with cadherins from Hut102. The deduced amino acid sequence of the fragment was identical to human N-cadherin (Fig. 1A,B). To confirm the expression of N-cadherin at the mRNA level and to confirm the existence of E-cadherin mRNA in Hut102, we carried out RT-PCR with the first strand of cDNA generated by reverse transcription of the mRNA of Hut102 cells, normal human epidermal keratinocytes and human fibroblasts using specific primers for N-cadherin (5′-GTGCCATTAGCCAAGGGAATTCAGC) and (5′-GCGTTCCTGTTCCACTCATAGGAGG), and E-cadherin Norihisa Matsuyoshi · Ken-ichi Toda · Sadao Imamura