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Transformation of the indolent follicular lymphoma (FL) to the aggressive diffuse large B-cell lymphoma (DLBCL) results in resistance to therapy with shortened survival. It has been demonstrated that the 12q12-14 region was mainly amplified in DLBCL cases but not in their FL counterparts. Therefore, we examined the DNA copy number and protein expression profiles for CDK2, CDK4 and GADD153, three genes that map to 12q12-14, in a set of 44 paired FL/DLBCL samples from 22 patients. The concordant amplification of these genes occurred in seven of 22 (32%) of FL cases, compared with 15 of 22 (68%) of DLBCL cases. At the protein level, 15 of 22 of the DLBCL samples (68%) showed strong staining for the CDK2 protein, compared with five of 21 of FL samples (24%). The majority of the DLBCL samples (16/22, 72%) expressed the CDK4 protein, whereas the majority of the FL samples (12/21, 57%) showed no expression of this protein. Except for one DLBCL case, no expression of the GADD153 protein could be detected. The deregulation of the CDK2 and CDK4 genes at the genetic and protein levels suggest a functional role for these genes in the transformation process and could potentially provide targets for prognostic tests or therapeutic interventions.

The aim of this study was to determine whether administration of BB-10010, a synthetic stem cell inhibitor, would allow more intensive chemotherapy to be administered to patients with newly diagnosed high grade NHL. Thirteen patients were randomised to receive BB-10010 concurrently with dose-intensified BEMOP/CA chemotherapy (7 patients) or chemotherapy alone (6 patients). Although the mean neutrophil count of BB-10010 treated patients was higher following cycles 1, 2 and 3 of chemotherapy compared with those receiving chemotherapy alone, there was no difference in the mean number of cycles tolerated, blood component usage and hospital admissions due to infections. No specific toxicity of BB-10010 was identified. Whilst BB-10010 can be administered safely, it does not improve the ability of patients to tolerate intensive chemotherapy for high grade NHL.

The purpose of this study was to identify novel areas of genomic copy number change associated with transformation from follicular lymphoma (FL) to diffuse large B cell lymphoma (DLBL). DNA was extracted from tumour cells micro-dissected from paraffin- embedded tissue sections in 24 patients with FL and subsequent transformation to DLBL and 18 patients with de novo DLBL. Tumour DNA was compared to reference DNA using comparative genomic hybridization. Abnormalities common to all 3 groups were gains on chromosomes 4q, 5q, 7q, 11q and X and losses on 3p, 8p and 10q. Copy number changes seen in both transformed and de novo DLBL and not seen in FL were gains on 2p and losses on 1q, 15q and Xq. Gains on 2q, 6p, 7p and 17q and losses on 5p and 8q were specific to transformed DLBL cases. Gain on 12q12-14 was found in 52% of the transformed DLBL cases and was never seen in its follicular counterpart. Patterns of genomic copy number change associated with specific clinical events in NHL have been demonstrated and suggest that gains on 2q, 6p, 7p, 12q and 17q and losses on 5p and 8q may be important in the transformation from low to high-grade disease., (Copyright 2001 Cancer Research Campaign.)

We have investigated the expression of the MYC gene at both the mRNA and protein levels to determine how these parameters are related in lymphoma cells and in nonmalignant lymphoid cells. To do this we have adopted a multicolor fluorescence in situ hybridization methodology, which has allowed us to investigate the expression of different genes at the same time in the same cell. We have made use of the digital imaging capabilities of a charge-coupled device camera system to quantify the hybridization signals for the MYC gene and, by comparing these to the expression of a control gene (glyceraldehyde-3-phosphate dehydrogenase; GAPDH), have obtained relative quantitations of MYC mRNA and protein levels. In this study we have compared cells both within and outside the germinal centers in control tissues (reactive lymph nodes and tonsils) and in low-grade follicular center lymphomas, as well as cells in high-grade diffuse large cell lymphomas. The MYC/GAPDH mRNA hybridization signal ratios were calculated and found to be higher in cell populations containing a majority of malignant cells (p < 0.04). However, when the myc/GAPDH protein hybridization signal ratios were calculated, these were significantly higher in malignant cells from all lymphomas than the ratios observed in the nonmalignant cells (p < 0.0005). These observations indicate that the environment in a malignant cell may contribute to the stabilization of the myc protein, thus enabling it to function for a longer time period than in nonmalignant cells.