sirolimus and Lymphoma--T-Cell--Peripheral

We performed a phase I study to determine the dose and safety of everolimus as a combination chemotherapy in peripheral T-cell lymphoma (PTCL).. Four dose levels (2.5 to 10 mg) of everolimus from days 1 to 14 with CHOP (750 mg/m(2) cyclophosphamide, 50 mg/m(2) doxorubicin, and 1.4 mg/m(2) (maximum 2 mg) vincristine on day 1, and 100 mg/day prednisone on days 1 to 5) every 21 days were planned.. Fifteen patients newly diagnosed with stage III/IV PTCL were enrolled. One of 6 patients at dose level 2 (5 mg everolimus) had grade 3 hepatotoxicity and 3 of 6 patients at level 3 (7.5 mg everolimus) had grade 4 hematologic toxicities (two grade 4 thrombocytopenia and one grade 4 neutropenia with fever lasting more than 3 days). The recommended dose of everolimus for combination was 5 mg. There were no differences in steady state trough concentrations of everolimus between cycles 1 and 2 for all three dose levels. All evaluable patients achieved response (8 complete and 6 partial).. Everolimus (5 mg) can be safely combined with CHOP leading to a feasible and effective regimen for PTCL. The subsequent phase II is now in progress.

Topics: Antineoplastic Combined Chemotherapy Protocols; Cyclophosphamide; Doxorubicin; Drug Administration Schedule; Everolimus; Humans; Lymphoma, T-Cell, Peripheral; Maximum Tolerated Dose; Prednisone; Sirolimus; Vincristine

HTLV-I-associated adult T-cell leukemia/lymphoma (ATL) and human T-cell lymphotropic virus type I (HTLV-I)-negative peripheral T-cell lymphomas carry poor prognosis mainly because of acquired resistance to chemotherapy. We have shown that this disease is responsive to the combination of zidovudine and interferon-α. However, long-term maintenance therapy with this combination is associated with side effects affecting patient quality of life and hence more tolerated alternatives are needed. In this submission, we explored the effect of the mammalian target of rapamycin (mTOR) complex-1 (mTORC1) inhibitor everolimus (RAD001) on ATL and HTLV-negative malignant T-cell lines. We demonstrate that, at clinically achievable concentrations, long-term treatment with everolimus resulted in a dramatic inhibitory effect on the growth of HTLV-I-positive and -negative malignant T-cells, while normal resting or activated T-lymphocytes were resistant. Everolimus specifically induced oncoprotein Tax degradation and senescence in ATL cells and cell cycle arrest and apoptosis in HTLV-I-negative malignant T-cells. Everolimus-mediated apoptosis was also associated with an upregulation of p53 upregulated modulator of apoptosis (PUMA-α) proteins, an increase in Bax proteins and downregulation of Bcl-x(L) proteins in all tested HTLV-I-positive and -negative malignant cell lines. These results support a therapeutic role for everolimus, particularly as long-term maintenance therapy in patients with ATL and other HTLV-I-negative peripheral T-cell lymphomas.

Topics: Adult; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Cells, Cultured; Cellular Senescence; Everolimus; G1 Phase; Human T-lymphotropic virus 1; Humans; Leukemia-Lymphoma, Adult T-Cell; Lymphoma, T-Cell, Peripheral; Proto-Oncogene Proteins; Signal Transduction; Sirolimus; T-Lymphocytes; TOR Serine-Threonine Kinases; Tumor Suppressor Protein p53

Recurrent chromosomal aberrations in hematopoietic tumors target genes involved in pathogenesis. Their identification and functional characterization are therefore important for the establishment of rational therapies. Here, we investigated genomic amplification at 7q22 in the T-cell lymphoma cell line SU-DHL-1 belonging to the subtype of anaplastic large-cell lymphoma (ALCL). Cytogenetic analysis mapped this amplicon to 86-95 Mb. Copy-number determination quantified the amplification level at 5- to 6-fold. Expression analysis of genes located within this region identified cyclin-dependent kinase 6 (CDK6) as a potential amplification target. In comparison with control cell lines, SU-DHL-1 expressed considerably higher levels of CDK6. Functionally, SU-DHL-1 cells exhibited reduced sensitivity to rapamycin treatment, as indicated by cell growth and cell cycle analysis. Rapamycin reportedly inhibits degradation of the CDK inhibitor p27 with concomitant downregulation of cyclin D3, implying a proliferative advantage for CDK6 overexpression. Amplification of the CDK6 locus was analyzed in primary T-cell lymphoma samples and, while detected infrequently in those classified as ALCL (1%), was detected in 23% of peripheral T-cell lymphomas not otherwise specified. Taken together, analysis of the 7q22 amplicon identified CDK6 as an important cell cycle regulator in T-cell lymphomas, representing a novel potential target for rational therapy.

Topics: Cell Line, Tumor; Chromosome Aberrations; Chromosomes, Human, Pair 7; Cyclin-Dependent Kinase 6; Cytogenetic Analysis; Drug Resistance; Gene Dosage; Gene Expression Regulation, Neoplastic; Humans; Lymphoma, Large-Cell, Anaplastic; Lymphoma, T-Cell; Lymphoma, T-Cell, Peripheral; Sirolimus; Tumor Cells, Cultured

Natural killer (NK) lymphomas occurring more frequently in the Far East and South America respond poorly to anthracycline-based regimens. Here we report an in vivo NK lymphoma xenograft (NK-S1) derived from the testicular metastasis of a patient with an extranodal NK lymphoma (nasal type). The NK-S1 xenograft, established in severe combined immune deficient (SCID) mice retained the same imunophenotypic features as the original tumor. NK-S1 disseminated intra-abdominally to the testis, intestine and liver. Although doxorubicin, rapamycin, bevacizumab, rapamycin-doxorubicin, and bevacizumab-doxorubicin had no effects on the growth of subcutaneous NK-S1 xenografts, intraperitoneal (IP) delivery of cyclophosphamide caused complete tumor regression; this tumor regression was associated with apoptosis, upregulation of activated caspase-3, and cleaved Poly(ADP-ribose) polymerase (PARP). In an IP model of NK lymphoma, cyclophosphamide also prolonged the survival of mice and potently inhibited tumor dissemination and ascites formation. Our data suggest that the NK-S1 xenograft is a useful tool for screening preclinical drugs, and cyclophosphamide may be a useful drug for the treatment of this disease.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bevacizumab; Blotting, Western; Caspase 3; Cyclophosphamide; Doxorubicin; Enzyme Activation; Epstein-Barr Virus Infections; Herpesvirus 4, Human; Humans; Injections, Intraperitoneal; Killer Cells, Natural; Lymphoma, T-Cell, Peripheral; Male; Mice; Mice, SCID; Middle Aged; Neoplasm Transplantation; Poly(ADP-ribose) Polymerases; Sirolimus; Transplantation, Heterologous; Tumor Cells, Cultured