Chromosome ideograms of the laboratory rat (Rattus norvegicus) based on high-resolution banding, and anchoring of the cytogenetic map to the DNA sequence by FISH in sample chromosomes

A detailed banded ideogram representation of the rat chromosomes was constructed based on actual G-banded prometaphase chromosomes. The approach yielded 535 individual bands, a significant increase compared to previously presented ideograms. The new ideogram was adapted to the existing band nomenclature. The gene locus positions in the rat draft DNA sequence were compared to the chromosomal positions as determined by dual-color FISH, using rat (RNO) chromosomes 6 and 15 and a segment of RNO4 as sample regions. It was found that there was generally an excellent correlation in the chromosome regions tested between the relative gene position in the DNA molecules and the sub-chromosomal localization by FISH and subsequent information transfer on ideograms from measurements of chromosomal images. However, in the metacentric chromosome (RNO15), the correlation was much better in the short arm than in the long arm, suggesting that the centromeric region may distort the linear relationship between the chromosomal image and the corresponding DNA molecule.

Analysis of chromosomal aberrations involving chromosome 1q31-->q53 in a DMBA-induced rat fibrosarcoma cell line: amplification and overexpression of Jak2

In a study of DMBA-induced rat fibrosarcomas we repeatedly found deletions and/or amplifications in the long arm of rat chromosome 1 (RNO1). Comparative genome hybridization showed that there was amplification involving RNO1q31-->q53 in one of the DMBA-induced rat fibrosarcoma tumors (LB31) and a cell culture derived from it. To identify the amplified genes we physically mapped rat genes implicated in cancer and analyzed them for signs of amplification. The genes were selected based on their locations in comparative maps between rat and man. The rat proto-oncogenes Ccnd1, Fgf4, and Fgf3 (HSA11q13.3), were mapped to RNO1q43 by fluorescence in situ hybridization (FISH). The Ems1 gene was mapped by radiation hybrid (RH) mapping to the same rat chromosome region and shown to be situated centromeric to Ccnd1 and Fgf4. In addition, the proto-oncogenes Hras (HSA11p15.5) and Igf1r (HSA15q25-->q26) were mapped to RNO1q43 and RNO1q32 by FISH and Omp (HSA11q13.5) was assigned to RNO1q34. PCR probes for the above genes together with PCR probes for the previously mapped rat genes Bax (RNO1q31) and Jak2 (RNO1q51-->q53) were analyzed for signs of amplification by Southern blot hybridization. Low copy number increases of the Omp and Jak2 genes were detected in the LB31 cell culture. Dual color FISH analysis of tumor cells confirmed that chromosome regions containing Omp and Jak2 were amplified and were situated in long marker chromosomes showing an aberrant banding pattern. The configuration of the signals in the marker chromosomes suggested that they had arisen by a break-fusion-bridge (BFB) mechanism.

Cutaneous T-cell lymphomas

OBJECTIVES

To describe the current state of the knowledge regarding the pathology, clinical presentation, treatment strategies, and nursing management of patients with cutaneous T-cell lymphoma, specifically, mycosis fungoides and the Sezary syndrome.

DATA SOURCES

Book chapters, review articles, published research studies, proceedings from professional meetings.

CONCLUSIONS

Although mycosis fungoides and the Sezary syndrome are rare, epidemiologic studies suggest an increasing incidence. Advances in cellular biology and immunology result in continuously changing diagnostic and treatment strategies aimed at this illness.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses need an understanding of the current state of the knowledge of cutaneous T-cell lymphoma to meet the extensive needs of patients confronted with this chronic, progressively devastating malignancy.

Interleukin-1 alpha increases the preferential cytotoxicity of an interleukin-2-diphtheria toxin fusion protein against neoplastic lymphocytes from patients with the Sezary syndrome compared to normal lymphocytes

DAB389IL-2 is a recombinant fusion toxin composed of the diphtheria A chain and a protion of the translocating region of the diphtheria B chain, replacing the receptor binding domain with human IL-2. DAB389IL-2 can be safely administered to humans with mycosis fungoides (MF) or Sezary syndrome (SS), and antineoplastic effects occur. This agent binds optimally to the high-affinity IL-2R. The decreased efficiency of uptake by neoplastic cells which do not express the high-affinity IL-2R represents a potential limitation. Treatment of the HUT-78 cutaneous T-cell lymphoma with IL-1 alpha preceding exposure to DAB389IL-2 overcame their resistance to the toxin, IL-1 alpha inducing high-affinity IL-2R expression. Similarly, pretreatment with IL-1 alpha of SS patient lymphocytes demonstrated increased cytotoxicity compared to treatment with the fusion toxin alone. Normal lymphocytes and monocytes were not sensitive to DAB389IL-2 when pretreated with IL-1 alpha, suggesting a differential sensitivity which may be exploited clinically in the treatment of lymphomas.

2-Chlorodeoxyadenosine in cutaneous T-cell lymphoproliferative disorders

The efficacy and toxicity of 2-chlorodeoxyadenosine (2-CdA) in cutaneous T-cell lymphoproliferative disorders was examined. Between February 1991 and April 1996, 25 patients with relapsed or refractory cutaneous T-cell lymphoproliferative disorders (24 mycosis fungoides or Sezary syndrome, one Ki-1+ anaplastic large cell lymphoma) were treated with 2-CdA initially administered by continuous intravenous infusion at a dose of 0.1 mg/kg/d for 7 days (13 patients). The infusion duration was subsequently reduced to 5 days (9 patients) because of prohibitive hematologic toxicity. Three patients were treated at the same daily dose by bolus injection over two hours for 5 days. Cycles were administered at 28 day intervals. Seventeen patients received more than one cycle. An overall response rate of 24% was achieved. Three patients (12%) had a complete response with a median duration of 4.5 months (range, 2.5 to 16). Three (12%) had a partial response with a median duration of 2 months (range, 2 to 4). Nineteen patients (76%) had no response. The most significant toxicities encountered were myelosuppression (64%) and infectious complications (64%). 2-CdA has activity as a single agent in patients with previously treated relapsed T-cell lymphoproliferative disorders.

Recurring structural chromosome abnormalities in peripheral blood lymphocytes of patients with mycosis fungoides/Sézary syndrome

Cytogenetic analysis was performed on peripheral blood lymphocyte cultures from 19 patients with mycosis fungoides (MF)/Sézary syndrome (SS) stimulated with either phytohemagglutinin, a conventional mitogen, or a combination of interleukin-2 (IL-2) plus IL-7. The use of both PHA-stimulated and IL-2 plus IL-7-stimulated cultures enhanced the ability to identify clonal abnormalities. Clonal abnormalities were observed in 11 patients (53%) including one with monosomy for the sex chromosome as the sole abnormality. Five of the 11 patients with clonal abnormalities had normal peripheral white blood cell counts, indicating detectability of clones in the absence of frankly leukemic disease. The presence of clonal abnormalities correlated with advanced stage disease and a significantly reduced survival duration from the time of cytogenetic studies. Clonal abnormalities involving chromosomes 1 and 8 were observed in six cases. In five cases with aberrations of chromosome 1, loss of material involved the region between 1p22 and 1p36. In an additional case, a reciprocal translocation involving 1p33 was observed. Clonal abnormalities involving chromosomes 10 and 17 were observed in 5 cases, clonal abnormalities involving chromosome 2 in 4 cases, and clonal abnormalities involving chromosomes 4, 5, 6, 9, 13, 15, 19, and 20 in 3 cases. In 2 cases a der(8)t(8;17)(p11;q11) was observed. Regions of the genome that encode T-cell receptors were not involved in abnormalities. The region between 1p22 and 1p36 is identified as a region of the genome that requires detailed analysis toward the identification of potential gene(s) involved in the process of malignant transformation and/or progression in MF/SS.

Phase II trial of 2-chlorodeoxyadenosine for the treatment of cutaneous T-cell lymphoma

We investigated the efficacy of 2-chlorodeoxyadenosine (2-CdA) therapy in patients with mycosis fungoides (MF) and the Sezary syndrome (SS). Between February 1991 and November 1993, 21 patients with relapsed or refractory MF/SS were treated with 2-CdA. 2-CdA was administered by continuous intravenous infusion at a dose of 0.1 mg/kg/d for 7 days initially (13 patients), but was subsequently reduced to 5 days (nine patients) due to hematologic toxicity. All patients had failed to respond to at least one prior treatment for MF/SS (median number of total prior therapies, five; median number of systemic prior therapies, three) and had an Eastern Cooperative Oncology Group performance status of two or better. Cycles were administered at 28-day intervals. Assessable patients received at least 5 days of 2-CdA. Fourteen patients received more than one cycle of 2-CdA. An overall response rate of 28% was achieved. Three patients (14%) had a complete response with a median duration of 4.5 months (range, 2.5 to 16). Three (14%) had a partial response with a median duration of 2 months (range, 2 to 4). Fifteen patients (72%) had no response. The most significant toxicities encountered were bone marrow suppression (62% of patients) and infectious complications (62% of patients). Thirty-eight percent of patients experienced no toxicity from 2-CdA. 2-CdA has activity as a single agent in patients with previously treated relapsed MF/SS. Studies in less heavily pretreated individuals with 2-CdA alone or in combination will be undertaken.

Treatment of mycosis fungoides with photochemotherapy (PUVA): long-term follow-up

BACKGROUND

Mycosis fungoides (MF) is a non-Hodgkin's T-cell lymphoma of the skin that often begins as limited patches and plaques with slow progression to systemic involvement. No studies have been published comparing photochemotherapy (PUVA) with other topical therapies in the treatment of early-stage disease.

OBJECTIVE

The purpose of the study was to examine our long-term experience using PUVA to treat early-stage MF and to compare its effectiveness and side-effect profile with other previously reported topical therapies.

METHODS

Eighty-two patients with MF (83% stage IA or IB) were treated with PUVA. Clinical and histologic features were observed for a period from 2 months to 15 years (median, 43 months).

RESULTS

A response was noted in 78 patients (95%) with complete clinical and histologic clearing in 53 patients (65%) for all stages. The mean duration of total complete response to PUVA for all stages was 43 months (3.6 years). The mean survival of our study group for all stages was 8.5 years. Signs of chronic actinic skin damage were found in 10% of patients, including three patients with basal cell carcinomas and three patients with squamous cell carcinomas. In a nonrandomized comparison with previously reported data for other topical therapies, the efficacy and side-effect profile of PUVA compared favorably.

CONCLUSION

PUVA is an effective and safe therapy for MF with prolonged disease-free remissions being achieved. Patients with stage I and II MF respond best to PUVA. Palliative therapy with PUVA is useful in more advanced cases of MF.

Effectiveness of interferon alfa-2a combined with phototherapy for mycosis fungoides and the Sézary syndrome

PURPOSE

To investigate the efficacy of combined topical therapy and systemic interferon alfa-2a in patients with mycosis fungoides (MF) and the Sézary syndrome (SS).

PATIENTS AND METHODS

Between December 1987 and April 1993, 39 patients with all stages of MF and SS were treated with combined phototherapy and systemic interferon alfa-2a as part of two institutional studies. The initial phase I study of 15 patients established the maximum-tolerated dose of interferon and has been previously reported. Subsequently, 24 patients have been entered onto a phase II trial. Long-term follow-up data are provided for both studies.

RESULTS

The median follow-up duration for the entire cohort is 28 months. Patients with all stages of disease were enrolled (stage IB, n = 14; IIA, n = 5; IIB, n = 6; III, n = 8; IVA, n = 5; IVB, n = 1). Thirty-four patients had received previous therapy. Overall, 36 of 39 patients achieved a complete response (CR; 62%) or partial response (28%) to therapy. The median response duration is 28 months (range, 1 to 64). Twenty-nine of 39 patients are alive, with a median survival duration of 62 months (range, 1 to 66).

CONCLUSION

Interferon alfa-2a combined with phototherapy is an effective, safe, durable therapy for MF and SS.

Minimal-change glomerulopathy and glomerular visceral epithelial hyperplasia associated with alpha-interferon therapy for cutaneous T-cell lymphoma

A 44-year-old man was diagnosed with cutaneous T-cell lymphoma characterized by a proliferation of CD4-positive cells. In response to alpha-interferon therapy, he experienced rapid regression of his cutaneous disease. This improvement was associated with development of renal failure, characterized by nephrotic-range proteinuria with interstitial nephritis and minimal-change nephropathy. The remarkable finding of renal biopsy was marked proliferation of visceral epithelial cells (podocytes). Renal disease improved significantly in response to discontinuation of interferon and initiation of prednisone therapy. Nephrotic range proteinuria regressed, but never completely resolved. This case is illustrative of the probable role for lymphokine-mediated nephrotoxicity in the setting of lymphoproliferative disease.

Phase I trial of the diphtheria toxin/interleukin-2 fusion protein DAB486IL-2: efficacy in mycosis fungoides and other non-Hodgkin's lymphomas

The purpose of this study was to investigate the biologic activity of DAB486IL-2 when administered three times daily, in terms of toxicity, pharmacokinetics, and anti-tumor effects in patients with IL-2R expressing hematologic malignancies, especially mycosis fungoides. 20 patients were enrolled in this dose escalation phase I trial. Patient cohorts were treated at levels of 0.03 mg/kg, 0.05 mg/kg, 0.07 mg/kg and 0.09 mg/kg every 8 hours for a total of 12 doses, every 21 days as toxicity and response warranted. Eight patients experienced transient fevers associated with DAB486IL-2 administration. One patient experienced grade 3 hypotension, and a second developed fluid retention manifested as weight gain/pedal edema. Dose limiting toxicity consisted of one episode of transient grade 4 hepatic transaminase elevation, and 8 episodes of transient asymptomatic grade 3 hepatic transaminase elevation. At the maximum tolerated dose DAB486IL-2 exhibited biphasic clearance kinetics; transient receptor saturation may be one mechanism for this observation. Initial serum concentration and apparent steady state level (plateau) directly correlated with the dose administered, but no difference in area under the concentration curve with greater dose was observed. Biologic activity was noted in patients with mycosis fungoides with skin lesion clearing and relief of pruritus. One patient with mycosis fungoides, and one patient with a relapsed intermediate grade non-Hodgkin's lymphoma achieved partial responses. The novel mechanism of action, toxicity profile, and evidence of biologic activity in refractory cancer patients, support development of more active constructs of this agent; such trials are underway.