[The expression of API2-MALT1 fusion gene and its influence on the cellular apoptosis and proliferation in gastrointestinal MALT lymphoma].

Objective: To investigate the expression of API2-MALT1 fusion gene mRNA and its effect on protein of API2, Caspase3 and Ki67 in gastrointestinal MALT lymphoma (Extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue).

Methods: The mRNA of API2-MALT1 fusion transcript was assayed in 33 archival cases of gastrointestinal MALT lymphoma by RT-PCR and nested PCR. According to the expression of API2-MALT1 mRNA or not, 33 cases of MALT lymphoma were divided into two groups. Ki67, API2 and Caspase3 were detected by immunohistochemical technique and analyzed by the microsoft Image-Pro plus.

Results: API2-MALT1 fusion gene mRNA was found in 16 of specimens with gastrointestinal MALT lymphoma. The expression rate was 48.4%. The average area (21177.30 +/- 6171.72) micron 2 and single cell average area (29.81 +/- 7.40) micron 2 of API2 were decreased in the group with the expression of API2-MALT1 mRNA, compared with those in the group without the expression of API2-MALT1 mRNA [(34325.65 +/- 6577.00) micron 2, (37.84 +/- 8.55) micron 2]. The integrated optical density(IOD) of API2 showed no significant difference between the two groups, neither did the expression of Ki67 and Caspase3.

Conclusion: The expression of API2-MALT1 is related to the down-regulated expression of protein of API2, its effect on apoptosis of MALT lymphoma remains to be detected further. The expression of API2-MALT1 mRNA is unrelated to the cellular proliferation.