Detection of cyclin D1 mRNA by reverse transcription-polymerase chain reaction in paraffin-embedded tissues and its diagnostic significance for mantle cell lymphoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of detecting cyclin D1 mRNA in paraffin-embedded tissues by reverse transcriptase polymerase chain reaction (RT-PCR) and competitive RT-PCR and its diagnostic and differential diagnostic significance for mantle cell lymphoma (MCL).</p><p><b>METHODS</b>Paraffin-embedded samples of 36 cases of MCL, 71 cases of other small B-cell lymphomas and 20 cases of lymphoid reactive hyperplasia as control group were retrieved from archival materials. Cyclin D1 protein and its mRNA was detected by EnVision and RT-PCR and competitive RT-PCR in all samples. House-keeping gene PGK was choosen as internal control.</p><p><b>RESULTS</b>(1) Cyclin D1 protein was expressed in 27 of the 38 MCL (71.1%). No cyclin D1 expression was found in the control group. (2) PGK was detected in 103 of the 116 cases (88.8%) and also detected in 34 of 36 MCL cases (94.7%). (3) cyclin D1 mRNA was detected in 34 nodal mantle cell lymphoma cases by RT-PCR in paraffin-embedded tissues. The positive rate of cyclin D1 mRNA was 94.4% in mantle cell lymphomas after exclusion of the 2 cases which were negative for both cyclin D1 mRNA and PGK. cyclin D1 mRNA was not detected in other nodal small B-cell lymphomas or lymphoid reactive hyperplasia, except 1 case of B-SLL. Sequencing analysis showed that sequences were identical to cyclin D1. (4) Cyclin D1 mRNA overexpression was detected in 27 cases of nodal mantle cell lymphoma by competitive RT-PCR in paraffin-embedded tissues. The positive rate of cyclin D1 mRNA overexpression was 75.0% in mantle cell lymphomas after exclusion of 2 cases which were negative for both cyclin D1 mRNA and PGK. cyclin D1 mRNA overexpression was not detected in other nodal small B-cell lymphomas or lymphoid reactive hyperplasia.</p><p><b>CONCLUSION</b>RT-PCR and competitive RT-PCR detection of cyclin D1 mRNA overexpression could be used for the diagnosis and differential diagnosis of mantle cell lymphoma in paraffin-embedded blocks.</p>

Mutation of 5'noncoding region of the bcl-6 gene in diffuse large B cell lymphomas / 中华病理学杂志

<p><b>OBJECTIVE</b>To observe the mutation of 5'noncoding region of bcl-6 gene in diffuse large B cell lymphoma (DLBCL) and its effect on lymphoma pathogenesis.</p><p><b>METHODS</b>38 DLBCL, 2 reactive hyperplasias, 5 follicular lymphomas and 5 T cell lymphomas were chosen for PCR direct sequence analysis using two sets of primers in 5'noncoding region of the bcl-6 gene.</p><p><b>RESULTS</b>No mutation was found in the marginal region of reactive hyperplasias, T cell lymphomas, and follicular lymphomas but detected in 1/2 of the follicular center cells, and 7/38 cases of DLBCL. The incidence is less than that seen in other reports. Basepairs substitution and point insertion were the main mutation types.</p><p><b>CONCLUSIONS</b>The positive rate of mutation of 5'noncoding region of bcl-6 gene in DLBCL is 18.7%, less frequent than the published data of DLBCL reported in other countries. It may, in some extent, participate in the pathogenesis and progression of DLBCL.</p>