Human interferon-inducible protein 10: expression and purification of recombinant protein demonstrate inhibition of early human hematopoietic progenitors.

Human interferon-inducible protein 10 (IP-10), a member of the family of the small secreted proteins called intercrine cytokines or chemokines, is secreted by interferon gamma-stimulated T cells, monocytes, endothelial cells, and keratinocytes. We have begun to explore the biological properties of IP-10 by cloning and overexpression in baculovirus and in bacterial protein expression systems. A 9.9-kD protein was secreted by infected insect cells, which on sodium dodecyl sulfate-polyacrilamide gel electrophoresis comigrated with keratinocyte IP-10 and with f(22-98), a bacterial recombinant fragment lacking the signal sequence but containing all other residues of IP-10. All three reacted with antibodies recognizing residues 10-98 (alpha IP-10) and 77-98 of IP-10 (alpha 22), demonstrating that it is secreted by keratinocytes and insect cells after removal of the signal sequence but without proteolysis of the COOH-terminal end. Purified rIP-10 suppresses in vitro colony formation by early human bone marrow progenitor cells which need r-steel factor (rSLF) and rGM-CSF or rSLF and r-erythropoeitin (rEPO). The inhibition is dose dependent, is complete at concentrations > or = 50 ng/ml, is prevented by preincubation of rIP-10 with alpha IP-10, but not by alpha 22, and is seen with highly purified CD34+ cells, suggesting direct effect of rIP-10 on the progenitors. Combination of rIP-10 and other chemokines at inactive concentrations inhibited colony formation in a synergistic manner. rIP-10 did not affect colony formation in the absence of any growth factors or in the presence of rEPO or rGM-CSF but in absence of rSLF. The effects of IP-10 may be relevant to normal marrow function and might be harnessed to protect human hematopoietic progenitors from the cytotoxic effects of chemotherapy.

Isolation and partial characterization of the sialoglycoprotein fraction of murine erythrocyte ghosts.

With the lithium diiodosalicylate (LIS1) extraction-phenol partition method, we have isolated a sialoglycoprotein fraction from DBA/2 mouse erythrocyte ghosts. We have demonstrated that the Laemmeli system for SDS PAGE can resolve this fraction into four monomers of which two (gp-2.1 and gp-3.1) appear to be authentic, whereas the other two (gp-2.2 and gp-3.2) are probably generated from gp-2.1 and gp-3.1, by limited proteolysis during the isolation procedure. All four components contain O-acetylated neuraminic acid residues, can be stained with Periodic acid-Schiff reagent (PAS) and with Coomassie Brilliant Blue (CB), and can be radioiodinated with the lactoperoxidase-glucose oxidase (LPO-GO) method. All monomers but especially gp-2.1 and gp-3.1 generate characteristic aggregates during solubilization in SDS. The aggregation is enhanced by boiling at high concentrations, and can be reversed by boiling at low concentrations. In addition, the fraction contains a diffuse component present also in ghosts which stains poorly with CB and with PAS and cannot be radioiodinated by the LPO-GO technique. SDS PAGE in the Steck and Yu gel system does not give an accurate separation of the sialoglycoprotein monomers.

Immunofluorescent detection of erythrocyte sialoglycoprotein antigens on murine erythroid cells.

A sialoglycoprotein fraction isolated from murine (DBA/2) erythrocytic ghosts (see companion article, Sarris and Palade, 1982, J. Cell. Biol. 93:583-590) was used to raise antibodies in rabbits. By immune-IgG (serum)-[125I] protein A overlays, the antibodies were found to react positively with the four sialoglycoprotein monomers (gp-2.1, gp-2.2, gp-3.1, and gp-3.2) of the original fraction, with the sialoglycoproteins detected in erythrocytic ghosts (gp-2.1 and gp-3.1), with a diffuse component (probably a macroglycolipid) trailing around gp-3.1 in SDS polyacrylamide gel electrophoretograms of solubilized ghosts, and with a minor sialoglycoprotein hidden under this trail. IgG's isolated from immune and nonimmune rabbit sera were conjugated to tetramethylrhodamine isothiocyanate and used to survey, by fluorescence microscopy, the distribution of the cognate antigens on the three different erythroid lines known to succeed each other during the life span of the mouse. In the peripheral blood of the adult, the antibodies recognized only mature erythrocytes; they did not crossreact with either platelets, monocytes, or different types of granulocytes. In the spleen of adult anemic mice, the antibodies reacted weakly with proerythroblasts and strongly with all types of erythroblasts. In enucleating erythroblasts, antigens were preferentially segregated on the cell membrane of the nascent reticulocyte. In the 10-day-old embryo, antigens were already present on the primitive nucleated erythrocytes (produced by the blood islets of the yolk sack), and in the 14-d fetus they were found on all hepatic erythroblasts and derived non-nucleated erythrocytes. A positive immunoreaction was also obtained on Friend erythroleukemic cells, before or after induction by dimethyl sulfoxide. Nonimmune serum, or nonimmune IgGs gave negative reactions in all cases. The antibodies were species-specific: they did not crossreact with either human or rat erythrocytes.

The mechanism of inhibition of bacteriophage T7 RNA synthesis by acridines, diacridines and actinomycin D.

A homologous series of diacridines, as well as 9-amino acridine, were assayed for their ability to interfere with the synthesis of RNA (bands U-VI) by bacteriophage T7 DNA-dependent RNA polymerase transcribing T7 DNA in vitro; their action was compared to that of actinomycin D. It was found that, in contrast to actinomycin D which inhibits chain elongation, the acridines tested inhibited chain initiation only; no evidence for inhibition of chain elongation was noted. No clear-cut differentiation between single and double intercalators on the mechanism of inhibition of RNA synthesis could be determined, except that the latter are more potent inhibitors. However, it appears that diacridines connected with a diethyldiamine and a butyldiamine chain are less inhibitory to the synthesis of the RNA of Bands III and IV. The results furthermore indicate that the estimation of the number average molecular weight alone, without identification of the product RNA, is a potentially misleading method of determining the mode of action of these drugs.

Testicular lymphoma: late relapses and poor outcome despite doxorubicin-based therapy.

PURPOSE: To determine the significance of the International Prognostic Index (IPI) score in adults with testicular lymphoma treated with doxorubicin-based regimens. PATIENTS AND METHODS: Untreated adults with testicular lymphoma who presented between 1969 and 1993 were studied. Those with Ann Arbor stages III and IV were included if they had a testicular mass at presentation. RESULTS: We identified 22 patients, 21 with intermediate-grade and one with high-grade lymphoma. All 10 patients with an IPI score < or = 1 had Ann Arbor stage I disease, whereas the 12 with an IPI score more than 1 had Ann Arbor stage II to IV disease. Complete remission (CR) was achieved in 73% of patients. At 153 months, 22% of all complete responders and 40% and 0% of those with IPI scores < or = 1 and more than 1, respectively, remained in CR (P = .01). With a median follow-up time of 113 months for survivors, the failure-free survival (FFS) rate at 153 months was 16% for all patients or 32% and 0% for those with IPI scores < or = 1 and more than 1, respectively (P = .02). The CNS or contralateral testis were involved in all patients who failed to respond to primary therapy and in 50% of those who relapsed from CR. CONCLUSION: The prognosis of patients with testicular lymphoma appears poor despite doxorubicin-based chemotherapy. On the basis of failures in the CNS and contralateral testis, we recommend prophylactic intrathecal chemotherapy and scrotal radiotherapy for all patients. Those with an IPI score < or = 1 can be treated with conventional doxorubicin-based regimens, but those with an IPI score more than 1 should be considered for investigational systemic therapy.

Fludarabine, mitoxantrone, and dexamethasone: an effective new regimen for indolent lymphoma.

PURPOSE: Although most patients with indolent lymphomas respond to initial therapy, virtually all experience relapse. Secondary therapy is often beneficial, but responses are rarely, if ever, durable. We conducted this phase II trail to evaluate the therapeutic efficacy and toxicity of fludarabine, mitoxantrone, and dexamethasone (FND) in patients with relapsed indolent lymphoma. PATIENTS AND METHODS: Fifty-one patients with recurrent or refractory indolent lymphoma were treated with a regimen of fludarabine 25 mg/m2/d intravenously (IV) on days 1 to 3, mitoxantrone 10 mg/m2 IV on day 1, and dexamethasone 20 mg/d IV or orally on days 1 to 5. Treatment was repeated at 4-week intervals for a maximum of eight courses. Late in the course of this trial, trimethoprim-sulfamethoxazole (TMP-SMX) was incorporated for Pneumocystis carinii (PCP) prophylaxis. RESULTS: Responses were complete (CR) in 24 patients (47%) and partial (PR) in 24 (47%). The median failure-free survival time was 21 months for CR patients and 9 months for PR patients. Notable activity of FND was seen even in the elderly, in those with high serum lactate dehydrogenase (LDH) or beta2-microglobulin levels, and in those with multiple prior treatment regimens. The predominant toxic effects were myelosuppression and infections; other toxic effects were modest. Infections occurred in 12% of courses. Almost half of the infections were proven or suspected opportunistic infections, including six cases of dermatomal herpes zoster and two cases of proven PCP pneumonia. CONCLUSION: The FND combination is highly active in patients with recurrent or relapsed indolent lymphoma and results in a high percentage of CRs. Because of the risk of opportunistic infections, we currently recommend prophylaxis with TMP-SMX and advise deletion of corticosteroids for patients who develop opportunistic infections.

Primary cutaneous non-Hodgkin's lymphoma of Ann Arbor stage I: preferential cutaneous relapses but high cure rate with doxorubicin-based therapy.

PURPOSE: Establish frequency, presenting features, response and relapse patterns, and outcome of primary cutaneous non-Hodgkin's lymphoma (PCNHL). PATIENTS AND METHODS: Review of untreated patients, older than 16 years, presenting between 1971 and 1993 with cutaneous lymphoma, not mycosis fungoides, and Ann Arbor stage I. RESULTS: We identified 46 patients, 27 males, with median age of 57 years. Treatment was radiotherapy in 10 patients, doxorubicin-based therapy in 33 patients that was followed by radiotherapy in 25 patients, and other combination with radiotherapy in one patient. The complete response rate was 95%. After a median follow-up of 140 months (range, 61 to 284 months), 18 patients have relapsed, and 14 have died from lymphoma. The first failure was exclusively cutaneous in 50% of relapses. For the 44 treated patients, progression-free survival (PFS; actuarial +/- SE) was 61% +/- 7% and survival was 58% +/- 9% at 12 years. For the 18 patients with diffuse large B-cell lymphoma, after doxorubicin-based regimens, PFS was 71% +/- 12% (P = .0003) versus 0% after radiotherapy; survival was 77% +/- 12% versus 25% +/- 22% (P = 004), respectively. For the nine patients with follicular center-cell lymphoma treated with combined modality, the 12-year PFS was 89% +/- 11% and survival 70% +/- 18%. CONCLUSION: PCNHL is rare, and its first relapse is exclusively cutaneous in 50% of patients. Patients with diffuse large B-cell lymphoma are curable with doxorubicin-based regimens but not with radiotherapy. Prospective studies in PCNHL should define the cytogenetics, the basis for cutaneous tropism, the prognosis of histologic subtypes, and the role of radiotherapy.

Trimetrexate in relapsed T-cell lymphoma with skin involvement.

PURPOSE: Methotrexate (MTX) is active against lymphomas, but transport or polyglutamylation mutations confer MTX resistance. Because trimetrexate (TMTX) enters cells by passive diffusion and is not polyglutamylated, its activity in relapsed T-cell lymphoma was investigated. PATIENTS AND METHODS: Eligible patients had histologically confirmed relapsed T-cell lymphoma involving the skin, had received more than one previous regimen, were older than 16 years, had normal organ function, and had no CNS disease or serious infections, including human immunodeficiency virus. TMTX (200 mg/m(2)) was given intravenously every 14 days without topical or systemic corticosteroids. Patients who responded received up to 12 doses. RESULTS: Twenty patients were assessable for response. Median age was 59 years (range, 45 to 87 years); 13 patients were men. Three patients had anaplastic large-cell lymphoma, 15 had mycosis fungoides or Sézary syndrome (14 with large-cell transformation), and two had peripheral T-cell lymphoma. Serum lactate dehydrogenase was high in 35%, and beta-2 microglobulin was more than 3.0 mg/L in 35% of patients. The median number of previous regimens was three (range, two to 15) and included MTX in five patients. Disease was refractory to the regimen immediately preceding TMTX in 85% of patients. Responses were complete in one and partial in eight patients (overall response rate, 45%). Two of five patients previously treated with MTX responded. Grade 3 or 4 mucositis was observed after 4%, infection after 3%, neutropenic fever after 6%, neutrophils less than 100/microL after 4%, and platelets less than 10,000/microL after 3% of TMTX doses. CONCLUSION: TMTX is active with acceptable toxicity in this population and merits further investigation.

Cyclosporin A does not reverse clinical resistance to paclitaxel in patients with relapsed non-Hodgkin's lymphoma.

PURPOSE: Cyclosporin A has been shown to reverse paclitaxel resistance in vitro by inhibiting P-gp function. Therefore, we determined whether addition of cyclosporine to paclitaxel reversed clinical paclitaxel resistance in patients with non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients with relapsed NHL were eligible if they had no intervening treatment after failure to respond to paclitaxel (200 mg/m2 over 3 hours), and if they had adequate marrow, renal, and hepatic function, no serious cardiac disease, no CNS involvement, and no antibodies to human immunodeficiency virus-1. A cyclosporin A bolus dose (5 mg/kg over 3 hours) was followed by intravenous infusion (15 mg/kg) over 24 hours. Six hours after the beginning of cyclosporin A, the immediately preceding paclitaxel dose was administered over 3 hours. All patients were premedicated with dexamethasone, diphenhydramine, and cimetidine. Response was assessed after two cycles, and those patients who achieved at least a partial response received a maximum of six courses. RESULTS: All 26 patients entered were assessable for toxicity and 25 were assessable for response. One patient whose disease had progressed during paclitaxel treatment had a partial remission after the addition of cyclosporin A (response rate, 4%; 95% confidence interval, 1% to 20%). Disease progressed in 17 patients (71%) and did not respond in seven (25%). Serum cyclosporin A A levels measured at the time of initiation of paclitaxel infusion were greater than 2,000 ng/mL during 81% of cycles. Treatment toxicity included peripheral neuropathy in 57%, myalgia or arthralgia in 30%, neutropenia in 53%, neutropenic fever in 8%, and thrombocytopenia in 42% of patients. One patient with preexisting asthma had an acute bronchospasm during the first cycle and was removed from the study. There were no renal or hepatic toxicity and no infectious or hemorrhagic deaths. CONCLUSION: Cyclosporin A administered on this schedule did not reverse established clinical resistance to paclitaxel, which suggests that P-gp-mediated drug efflux is unlikely to be the only cause of paclitaxel resistance in this patient population.

Patterns of outcome and prognostic factors in primary large-cell lymphoma of the testis in a survey by the International Extranodal Lymphoma Study Group.

PURPOSE: To determine clinical features and patterns of outcome of primary testicular diffuse large B-cell lymphomas (DLCL). PATIENTS AND METHODS: A retrospective international survey of 373 patients with primary testicular DLCL. RESULTS: Most patients presented with localized disease (stage I to II), and the median age at diagnosis was 66 years (range, 19 to 91 years). Anthracycline-based chemotherapy was administered to 255 patients (68%), and prophylactic intrathecal chemotherapy was given to 68 patients (18%); 133 patients (36%) received prophylactic scrotal radiotherapy. Median overall survival was 4.8 years, and median progression-free survival was 4 years. The survival curves showed no clear evidence of a substantial proportion of cured patients. A favorable international prognostic index score (IPI), no B-symptoms, the use of anthracyclines, and prophylactic scrotal radiotherapy were significantly associated with longer survival at multivariate analysis. However, even for patients with stage I disease and good-risk IPI, the outcome seems worse than what was reported for DLCL at other sites. At a median follow-up of 7.6 years, 195 patients (52%) had relapsed. Extranodal recurrence was reported in 140 cases. Relapses in CNS were detected in 56 patients (15%) up to 10 years after presentation. A continuous risk of recurrence in the contralateral testis was seen in patients not receiving scrotal radiotherapy. CONCLUSION: Testicular DLCL is characterized by a particularly high risk of extranodal relapse even in cases with localized disease at diagnosis. Anthracycline-based chemotherapy, CNS prophylaxis, and contralateral testicular irradiation seem to improve the outcome. Their efficacy is under evaluation in a prospective clinical trial.

Human recombinant interferon-inducible protein-10 inhibits the proliferation of normal and acute myelogenous leukemia progenitors.

Recombinant human interferon-inducible protein-10 (rIP-10) has been recently identified, purified and shown to suppress the multiplication of normal marrow early hemopoietic progenitors. In the present study we investigated the effect of rIP-10 on different normal and acute myelogenous leukemia (AML) progenitor populations. We first studied hematologically normal bone marrow using the delta culture assay, in which marrow low-density cells were incubated in liquid culture with recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) for 1 week, to allow the differentiation of mature progenitors, and thereafter cultured in methylcellulose in the presence of rGM-CSF and recombinant erythropoietin (rEPO). In this assay rIP-10 significantly inhibited the proliferation of normal marrow hemopoietic progenitors in a dose-dependent fashion. However, when fresh normal marrow cells were cultured in methylcellulose without preincubation in liquid culture, rIP-10 did not affect the growth of colony-forming cells. In contrast, when recombinant c-kit ligand (rKL) was added to rGM-CSF and rEPO, an increment in colony numbers was observed that was eliminated by rIP-10. Similar experiments performed with low-density, non-adherent, T cell-depleted AML marrow cells, obtained from 12 untreated adult AML patients, revealed qualitatively similar results: rIP-10 inhibited the proliferation of AML progenitors in the AML delta assay but did not affect the growth of rGM-CSF-responsive AML colony-forming cells when plated in semisolid media in the presence of rGM-CSF. When rKL was added to rGM-CSF during plating in an effort to recruit additional AML progenitor populations, there was an increment in leukemic blast colony numbers that was eliminated by rIP-10. As observed with normal progenitors, the effect of rIP-10 on these AML progenitors was concentration-dependent, statistically significant and reversible with a rIP-10-neutralizing antiserum. To delineate the mechanism of action of rIP-10 we used the thymidine suicide assay and found that rIP-10 significantly reduced the fraction of leukemic progenitors synthesizing DNA. Our data suggest the rIP-10 inhibits the proliferation of (probably immature) AML progenitor populations by reducing the fraction of cells undergoing DNA synthesis. Additional studies are needed to further elucidate the mechanism of this inhibition and to determine the potential clinical benefits of rIP-10 in future therapies for AML.

Interferon-inducible protein 10 as a possible factor in the pathogenesis of cutaneous T-cell lymphomas.

Human IFN-gamma-inducible protein 10 (IP-10), a C-X-C chemokine secreted by IFN-gamma-stimulated keratinocytes, is chemotactic for normal CD4-positive lymphocytes and inhibits the proliferation of early subsets of normal and of leukemic hemopoietic progenitors. Cutaneous T-cell lymphoma (CTCL) is an indolent lymphoproliferative disorder of CD4-positive lymphocytes that remain confined to the skin for many years before visceral dissemination. Because IFN-gamma mRNA was detected in the epidermis of CTCL lesions, we decided to investigate the role of IP-10 in the epidermotropism of CTCL by determining its expression in normal skin and in CTCL lesions. Using purified recombinant IP-10 (rIP-10) or a recombinant fusion protein between IP-10 and the straight phi10 protein of phage T7, we generated rabbit antisera that recognized and neutralized rIP-10. Immunoperoxidase staining of normal epidermis demonstrated that IP-10 was expressed by basal keratinocytes but not by the more differentiated cells. In the often hyperplastic epidermis overlying CTCL lesions, IP-10 immunostaining was enhanced compared to normal skin and extended to the suprabasal keratinocytes in 28 of 29 patients for a frequency of 97% and a 95% confidence interval of 82-100%. However, IP-10 was detectable in the dermal or epidermal lymphoid infiltrates in only 3 of 29 patients (10%; 95% confidence interval, 2-29%). Skin clinically free of CTCL demonstrated normal IP-10 immunostaining. In one patient who had matching biopsies performed before and after treatment, IP-10 was overexpressed before treatment but was normally expressed at remission. The in vitro proliferation of primary normal human keratinocytes was inhibited in a dose-dependent manner by rIP-10. These results suggest that IP-10 plays a role in the epidermotropism of CTCL. Additional work is needed to determine whether IP-10 stimulates or inhibits CTCL proliferation. A better understanding of the growth controls operating in CTCL may be useful in the development of curative strategies for this disorder.

beta(2)-microglobulin in Hodgkin's lymphoma: prognostic significance in patients treated with ABVD or equivalent regimens.

PURPOSE: Serum beta-2 microglobulin (sbeta(2)m) is an established prognostic factor for several lymphoproliferative disorders. Because its significance in Hodgkin's lymphoma (HL) is controversial, we determined sbeta(2)m levels in pretreatment serum samples of patients with HL in order to elucidate its prognostic value in this condition. PATIENTS AND METHODS: Pretreatment sbeta(2)m levels were determined in 379 HL patients who were treated with ABVD or equivalent regimens with or without radiotherapy (RT), using a radioimmunoassay (upper normal limit 2.4 mg/l). Sbeta(2)m levels were correlated with several clinical and laboratory parameters. RESULTS: Elevated sbeta(2)m levels were detected in 138/379 (36%) patients and correlated with all clinical and laboratory baseline features except gender, lung involvement and mediastinal bulk. They also correlated with serum soluble CD30 and interleukin-10 levels. The 8-year failure-free survival (FFS) was 78 -/+ 4% for patients with normal versus 65 -/+ 7% for patients with elevated sbeta(2)m levels (p=0.003). The corresponding rates among early-stage patients were 83 -/+ 53% versus 71 -/+ 9% (p=0.003), while for advanced stages they were 70 -/+ 6% versus 64 -/+ 8% (p=0.54). In multivariate analysis of the whole patient population elevation of sbeta(2)m levels was not predictive of FFS, but it was strongly predictive among early-stage patients. The 8-year overall survival (OS) rates were 91 -/+ 3% for patients with normal versus 59 -/+ 11% (p <0,0001) for patients with elevated sbeta(2)m levels, while unrelated mortality at 8 years was 1 -/+ 1% versus 27 -/+ 12% (p<0.0001). CONCLUSION: Our data suggest that sbeta(2)m levels may be a potent prognostic factor for FFS in patients with early stage HL treated with ABVD and equivalent regimens. Their effect on OS is confounded by the higher unrelated mortality in patients with elevated baseline sbeta(2)m levels, probably due to the strong association between sbeta(2)m and older age.

Safety of fludarabine, mitoxantrone, and dexamethasone combined with rituximab in the treatment of stage IV indolent lymphoma.

Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA and IDEC Pharmaceutical Corporation, San Diego, CA) is an effective agent for the treatment of CD20-positive B-cell lymphomas. Because its toxicities are minimal and do not overlap with the toxicities of standard chemotherapy, it is an appealing agent to use in combination with chemotherapy. Moreover, there is evidence for synergy between rituximab and some chemotherapeutic agents. The combination of fludarabine/ mitoxantrone/dexamethasone (FND) has been a well-tolerated and effective regimen for the treatment of indolent lymphomas. When given together with prophylaxis for Pneumocystis carinii, infectious complications with FND have been modest. We report on preliminary safety data using FND in conjunction with rituximab, along with maintenance alpha interferon. Toxicity has been modest. The concurrent use of rituximab with FND modestly increases neutropenia, but has not resulted in any change in the pattern of infectious or other toxicity that occurs with FND alone.

Immunofluorescent localization and immunochemical determination of cyclophilin-A with specific rabbit antisera.

We raised rabbit antisera against homogeneous bovine cyclophilin A (CypA) and we report their use for its immunofluorescent and immunochemical detection without resorting to cyclosporine binding. Indirect immunofluorescence demonstrated that in tissue culture cells CypA is present in the cytoplasm diffusely and also associated with vesicles and the Golgi apparatus. In mitotic cells CypA is increased in amount and redistributed away from cytoplasmic organelles. High levels of CypA were demonstrated in murine splenic erythroblasts and myeloblasts, but they became undetectable during differentiation to mature erythrocytes and granulocytes. Large, often granular, lymphocytes stained very intensely, but small lymphocytes demonstrated variable staining. Dot blot immunoassays demonstrated that murine tissues contain similar amounts of CypA. During CsA treatment murine liver can increase its CypA content much more than spleen. In summary, we demonstrated that cells known to be resistant to the effects of CsA have high levels of CypA. Also tissues that are resistant to CsA can increase their levels more than sensitive tissues upon CsA exposure. Taken together these results suggest that CypA plays a role in cell cycle progression and that sensitivity to CsA may not be simply a reflection of the baseline CypA levels, but may also be affected by the regulation of these levels. Further work is needed in order to delineate the role of CypA in the cell cycle and its relation to the action of CsA.

Protein aggregation mediated by cysteine oxidation during the stacking phase of discontinuous buffer SDS-PAGE.

The resolution of complex protein mixtures by discontinuous buffer SDS-PAGE is accomplished by their concentration into thin bands in the stacking gel, followed by their separation during migration through the resolving gel. Recombinant human interferon-inducible protein-10 (IP-10), a 10-kDa C-X-C chemokine with four cysteines, aggregated during the stacking phase of SDS-PAGE and generated a band with an apparent molecular mass of 18 kDa. This aggregation depended on the presence of reduced sulfhydryl residues on IP-10, on the amount of loaded protein, and on the concentration of the ammonium persulfate used to polymerize the stacking gel. The aggregation of IP-10 could be prevented by reduction of its sulfhydryls with dithiothreitol followed by irreversible blockade with iodoacetamide. These methods may be useful in the prevention of aggregation of sulfhydryl-containing proteins during SDS-PAGE, especially when large quantities are analyzed to assess their purity.

Real-time 5'-->3' exonuclease-based PCR assay for detection of the t(11;14)(q13;q32).

We describe the usefulness of a real-time polymerase chain reaction (PCR) assay for detection of the t(11;14)(q13;q32), most commonly present in mantle cell lymphoma (MCL). This assay is based on the 5'-->3' exonuclease activity of Taq polymerase, which cleaves an internal probe labeled with a reporter dye at its 5' end and a quencher dye at its 3' end during PCR. The real-time t(11;14) PCR assay was established using DNA from a case of MCL with the t(11;14), amplifiable using conventional PCR and primers specific for the major translocation cluster (MTC) region of the bcl-1 locus and the immunoglobulin heavy chain joining region gene (JH). The specificity was determined by analyzing DNA from 82 cases: 50 MCL, 27 other types of non-Hodgkin lymphoma (NHL), and 5 reactive lymphoid proliferations. The real-time t(11;14) PCR results were correlated with data obtained by a conventional PCR assay. By using the real-time assay, bcl-1 MTC/JH DNA fusion sequences were detected in 25 of 50 MCLs but not in other NHLs or reactive lymphoid proliferations. Concordance between real-time and conventional PCR methods for MCL was 96% and for all samples was 98%. The results demonstrate that this real-time PCR method to detect bcl-1 MTC/JH DNA fusion sequences is specific and reliable. In addition, the results are available immediately following amplification, without standard post-PCR manipulations.

Non-Hodgkin's lymphoma affecting the testis: is it curable with doxorubicin-based therapy?

This study was designed to determine response, outcome, and patterns of failure of patients with non-Hodgkin's lymphoma who presented with a testicular mass. Consecutive patients presenting to M.D. Anderson Cancer Center between 1969 and 1999 treated with doxorubicin-based regimens and with radiotherapy and/or intrathecal therapy were considered for this study. We identified 43 patients whose median age was 61 years. Ann Arbor stage (AAS) was I in 22 patients, II in 7 patients, III in 1 patient, and IV in 13 patients. All 43 patients had intermediate-grade lymphomas according to the Working Formulation, and all 31 tumors assessed immunophenotypically were large B-cell lymphoma according to the World Health Organization classification. The International Prognostic Index score was > or = 2 in 18 patients (42%). Thirty-four patients achieved complete remission, 19 of whom relapsed, and 5 failed initial therapy. At 10 years, progression-free survival (PFS) was 20% +/- 9% and survival was 33% +/- 9%. Progression-free survival for patients with AAS I/II vs. III/IV was 36% +/- 13% vs. 0%, respectively (P = 0.004). At 10 years, the actuarial probability of failure in the central nervous system was 34% +/- 9% and was 21% +/- 9% in contralateral testis. Using the intent-to-treat method, patients receiving cyclophosphamide/doxorubicin/ vincristine/prednisone (CHOP), with additional scrotal radiotherapy and intrathecal methotrexate, had a 5-year PFS of 91% +/- 9% vs. 30% +/- 15% vs. 41% +/- 12% for those receiving only one or neither of these additional modalities (P = 0.053). Doxorubicin-based regimens alone appear unable to cure most patients with lymphoma involving the testis, but CHOP with prophylactic intrathecal therapy and adjuvant scrotal radiotherapy appears promising. This should be confirmed with prospective clinical trials and longer follow-up.

Genomic DNA amplification and the detection of t(2;5)(p23;q35) in lymphoid neoplasms.

Anaplastic large cell lymphoma (ALCL) is an intermediate grade Non-Hodgkin's lymphoma (NHL) characterized by the frequent presence of the t(2;5)(p23;q35). This translocation fuses the nucleophosmin (NPM) gene on chromosome 5q35 to a protein kinase gene (Anaplastic Lymphoma Kinase, ALK) on chromosome 2p23. In order to determine the frequency of t(2;5) we used a DNA polymerase chain reaction (PCR) amplification using genomic DNA, 5'-primers derived from the NPM gene, and 3'-primers derived from the ALK gene. The presence of amplifiable DNA in the samples was established with PCR and oligonucleotide primers designed to amplify a 3,016 bp fragment from the beta-globin locus. The t(2;5) PCR assay was established using DNA isolated from three t(2;5)-positive ALCL cell lines. Its ability to amplify genomic DNA prepared for routine molecular diagnostic use was validated using archival DNA from four ALCL tumors known to be t(2;5)-positive. Its sensitivity was established by serially diluting t(2;5)-positive DNA in normal DNA: amplicons were generated in 100% of reactions diluted 10(4)-fold (6-8 cells per tube) and in 30% of those diluted 10(5)-fold (0.6-0.8 cells per tube.) We subsequently analyzed archival genomic DNA extracted from 38 ALCL, 77 NHLs, 37 Hodgkin's lymphomas, and 9 lymphomatoid papuloses. The t(2;5) was detected in 6 ALCLs (16%, 95% confidence intervals 6%-31%), but not in any other lymphoma, or in lymphomatoid papulosis. By using the published sequence of the fourth NPM intron that is involved in t(2;5) and by sequencing the individual tumor amplicons and also the normal ALK intron that is involved in t(2;5), we established that all breakpoints involve the same introns in the ALK and NPM loci. Detailed analysis demonstrated that each translocation generates a unique breakpoint sequence, and suggested that sequence homology between the ALK and NPM intron sequences may be involved in the translocation. We conclude that genomic DNA-PCR is useful for the detection of t(2;5) that in our patient population is restricted to ALCL and is not detectable in other NHL, Hodgkin's disease, or lymphomatoid papulosis. More work is needed to determine the prognostic significance of t(2;5), and to establish the utility of the genomic DNA PCR in monitoring minimal residual disease.

Interferon-inducible protein-10 and the pathogenesis of cutaneous T-cell lymphomas.

Human interferon-g inducible protein-10 (IP-10), a small basic protein secreted by interferon (INF)-g stimulated keratinocytes, is chemotactic for normal CD4-positive lymphocytes and inhibits early normal and leukemic hemopoietic progenitor proliferation. Cutaneous T-cell lymphoma (CTCL) is an indolent CD4-positive lymphoma characterized by multiple skin relapses before visceral dissemination. We investigated the role of IP-10 in the biology of CTCL by using immunocytochemistry to define IP-10 expression in normal and CTCL skin biopsies. Using purified recombinant (r) IP-10, we generated a rabbit antiserum that recognized and neutralized rIP-10 but did not cross-react with any keratinocyte proteins or any other chemokine. Immunoperoxidase staining of normal epidermis demonstrated that IP-10 was expressed by basal but not by differentiated keratinocytes. The epidermis overlying CTCL lesions was often hyperplastic, IP-10 immunostaining was enhanced compared to normal skin, and extended to the suprabasal keratinocytes in 25 of 26 patients for a frequency of 96%; and 95% confidence interval (CI) of 80% to 100%. However, IP-10 was detectable in the dermal or epidermal lymphoid infiltrates in only three of these 26 patients (12%; 95% Cl, 2% to 39%). Skin clinically free of CTCL demonstrated normal IP-10 immunostaining. In one patient who had matching biopsies performed before and after treatment, IP-10 was initially overexpressed before treatment but was normally expressed when he achieved remission. These results suggest that IP-10 may play a role in the epidermotropism of CTCL. More work is required to determine whether IP-10 stimulates or inhibits CTCL proliferation. A better understanding of the growth controls operating in CTCL may be used to develop curative therapies for this disorder.