Activation of the TCL1 protein in B cell lymphomas.
The TCL1 gene, localized near the break point of chromosome 14q32.1 often involved in T cell leukemias, is also expressed in normal precursor T and B cells, and B cell lymphoma cell lines. We investigated the expression of the TCL1 protein in various types of B cell lymphomas according to the Revised European-American Classification of Lymphoid neoplasms. Paraffin-embedded tissue sections of lymphoma specimens were subjected to TCL1 immunohistochemistry, and positivity was scored on a three-tiered scale: - (< 25% cells), + (25-50% cells), and ++ (> 50% cells). The TCL1 protein was expressed in low-grade B cell lymphomas including mucosa-associated lymphoid tissue type in ocular adnexa (18/20, 90%). It was also expressed in follicular, lymphoplasmacytic, and mantle cell lymphoma, but not in high-grade diffuse large B cell lymphoma (2/11, 18%). These data suggest that the expression of the TCL1 gene characterizes low-grade B cell lymphomas, and may be involved in certain processes of lymphomatogenesis.
Nakayama
I
I
Departments of Pathology and; Ophthalmology, Kobe University School of Medicine, Kobe, Japan.
Murao
S
S
Kitazawa
S
S
Azumi
A
A
Yamamoto
M
M
Maeda
S
S
D004268:DNA-Binding Proteins / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000235:genetics* / Q000473:pathology; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors / Q000235:genetics*; D015854:Up-Regulation
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C090851:TCL1A protein, human; D014157:Transcription Factors