Similarly, the three MALT lymphoma associated chromosome translocations, namely t(1;14)(p22;q32)/BCL10-IGH, t(14;18)(q32;q21)/IGH-MALT1,and t(11;18)(q21;q21)/BIRC3 (API2)-MALT1, are also capable of activating both canonical and non-canonical NF-κB pathways.
Few cases of breast MALT lymphomas in the literature have been assessed for MALT lymphoma-associated translocations and BCL10 expression, underlying their rarity in primary breast MALT lymphomas.
As we observed MALT1-API2 to be an efficient target of its own E3 ubiquitin ligase activity, our data suggest that this inherent instability of MALT1-API2 prevents its accumulation and renders a potential effect on MALT lymphoma development via destabilization of BCL10 unlikely.
Translocations involving IGH were detected in 36 (32%) of 111 cases; their partner genes included BCL6 (n = 10), c-MYC (n = 5), and FOXP1 (n = 3) but remained unknown in the remaining 18 cases. t(14;18)/IGH-BCL2, t(14;18)/IGH-MALT1, and t(1;14)/BCL10-IGH were not detected in any case. t(11;18)/API2-MALT1 was detected in none of the cases, except for one case of DLBCL with MALT lymphoma, which showed positive signals only in MALT lymphoma cells.
We investigated the efficacy of H. pylori eradication and assessed the predictive value of BCL10 nuclear expression and t(11;18)(q21;q21) regarding resistance to H. pylori eradication in primary gastric mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) patients from mainland China.
We assessed the incidence and clinical significance of the MALT lymphoma-associated genetic abnormalities t(11;18)/API2-MALT1, t(1;14)/BCL10-IGH, t(14;18)/IGH-MALT1, t(3;14)/FOXP1-IGH, and extra copies of MALT1 and FOXP1 in gastric MALT lymphomas from Japan.
Our results showed five key findings, which are (a) higher detection rates of t(11;18) (21.13%) in Chinese patients with transformed MALT lymphoma, (b) lower detection rates of t(11;18) in stomach MALT lymphoma, (c) different organ localizations of MALT lymphoma in Chinese patients, (d) higher nuclear expression rates of Bcl-10 in low grade MALT (51.72%), and (e) lower response rates (50% CR, and 50% PR) to anti-H.-pylori therapy.
This study further supports the close interaction between the MALT1 and BCL10 proteins in the pathogenesis of MALT lymphomas and may indicate that BCL10 immunohistochemistry is a simple technique to identify those MALT lymphoma cases with an underlying genetic aberration.
In this study, MALT1 and BCL10 expression was examined in normal lymphoid tissues and 423 cases of MALT lymphoma from eight sites, and their expression was correlated with the above translocations, which were detected by molecular and molecular cytogenetic methods.
Borrelia burgdorferi infection has been suggested as a possible causative agent in European cutaneous cases of marginal zone B-cell lymphoma, whereas API2-MALT1 fusion and BCL10 mutation are highly associated with MALT lymphoma.
We therefore screened 51 cases of pulmonary MALT lymphoma for API2-MALT1 fusion, and studied its relationship with clinicopathologic factors including the immunohistochemical expression of BCL10, another MALT lymphoma-associated molecule.
BCL10, a gene involved in the chromosomal translocation t(1;14)(p22;q32) found in mucosa-associated lymphoid tissue lymphoma (MALT lymphoma), has shown mutation in not only MALT lymphomas but also other lymphold tumors.
Specific molecular events have been associated with the development of MALT lymphoma including t(11;18) and alterations in Bcl-10 protein expression, and these appear to be interlinked.
We investigated the role of Bcl10 in MALT lymphoma by analyzing its expression, rearrangement and somatic mutation, by immunostaining, reverse transcriptase-polymerase chain reaction (RT-PCR), Southern blot and PCR in 20 cases of MALT lymphoma.
These results indicate that both t(11;18)(q21;q21) and BCL10 nuclear expression are associated with advanced MALT lymphoma and that their oncogenic activities may be related to each other.(Blood.2001;98:1182-1187)
Another gene involved in the regulation of apoptosis, the BCL10 gene, has been cloned from a MALT lymphoma cytogenetically characterized by the t(1;14)(p22;q32).
Mutations within the BCL10 coding region resulting in truncated BCL10 proteins with loss of their proapoptotic function and preservation of their NF-kappaB activating function were detected in MALT lymphoma.
Gastrectomy specimens of four MALT lymphoma cases were studied by microdissection and clone-specific polymerase chain reaction (CS-PCR) and of a further case with t(1;14)(p22;q32) by immunohistochemistry for BCL10 protein, which acted as a tumour marker for tumour cells carrying the translocation.