High-Grade Malignant Non-Hodgkin’s Lymphomas Differ from Low-Grade Lymphomasin the Extent of Apoptosis andTheir Expression of bcl-2, mcl-1,bax and p53

Abstract

In this study, we investigated the extent of apoptosis in 82 non-Hodgkin’s lymphoma and 4 reactive follicular hyperplasias and correlated the findings with the extent of apoptosis as determined by the 3′-end labelling method of the apoptotic DNA. To study the influence of apoptosis-regulating proteins bcl-2, bax, mcl-1 and p53 on the extent of apoptosis, we also immunostained the samples with antibodies to them. The results show that there is a significant difference in the extent of apoptosis between low- and high-grade non-Hodgkin’s lymphomas, the latter on average showing considerably more apoptotic cells (0.38 ± 0.30 and 1.44 ± 1.35%, respectively; p = 0.001). In line with this difference, high-grade lymphomas had significantly more cases with a weak expression of bcl-2 and strong expression of bax (p = 0.00008 and p = 0.016, respectively). They also showed significantly more cases with a positive p53 immunoreactivity (p < 0.00001) and strong mcl-1 immunoreactivity (p = 0.018). The results suggest that apoptosis-affecting genes bcl-2, bax, mcl-1 and p53 all take part in the regulation of apoptosis in malignant non-Hodgkin’s lymphomas and contribute to a different level of apoptosis between high- and low-grade non-Hodgkin’s lymphomas.

Hodgkin and Reed-Sternberg cells harbor alterations in the major tumor suppressor pathways and cell-cycle checkpoints: analyses using tissue microarrays

“…The pattern of expression of Bcl2, Bax, Bcl-X L , survivin, and Bcl6 in lymphoid tissue has been described elsewhere. 28,29 In the HL-derived cell lines, overexpression and/or loss of some oncogenes, tumor suppressor genes, STAT proteins, and p65/RelA have been previously described. 7,30,31 Our results from the TMAs confirmed these observations and also revealed the frequent expression of PTEN, cyclins A, B1, and E, CDK1, 2, and 6, and Rb.…”

Immunohistochemical Detection of Bcl-2 in Kaposi's Sarcoma Lesions Varies According to Histopathologic Stage, Whereas Expression of Bcl-x and Mcl-1 Differs According to Human Immunodeficiency Virus Serologic Status of Patients

“…The intracellular distribution of Mcl-1 is essentially mitochondrial (41), being physiologically expressed in many types of long-lived cells (13) and frequently overexpressed in neoplasms. Mcl-1 expression in neoplasms does not follow an obvious pattern, so although it increases with stage or histologic grade in tumors of the thymus (18) and prostate (15) and non-Hodgkin lymphomas (17), it decreases in the more poorly differentiated neuroblastomas (14) and colorectal carcinomas (42).…”

Apoptosis and Proliferation in Subcutaneous Panniculitis-Like T-Cell Lymphoma

“…For example, nodal peripheral T-cell lymphomas are reported to have an AI that ranges from 0.3 to 1.8%, depending on histologic type. In general, peripheral T-cell lymphomas of large cell type have higher AI than peripheral T-cell lymphomas of small cell type (20,27). Various types of small cell and large cell B-cell lymphomas of different types also show a much lower median or mean AI than in SPTCL.…”