Fas Gene Mutation in the Progression of Adult T Cell Leukemia

Fas antigen (Apo-1/CD95) is an apoptosis-signaling cell surface receptor belonging to the tumor necrosis factor receptor superfamily. Adult T cell leukemia (ATL) cells express Fas antigen and show apoptosis after treatment with an anti-Fas monoclonal antibody. We established the ATL cell line KOB, which showed resistance to Fas-mediated apoptosis, and found that KOB expressed two forms of Fas mRNA, the normal form and a truncated form. The truncated transcript lacked 20 base pairs at exon 9, resulting in a frame shift and the generation of a premature stop codon at amino acid 239. The same mutation was detected in primary ascitic cells and peripheral blood cells. The mutation was not detected in lymph node cells, however, although all of the primary ATL cells were of the same clonal origin. A retroviral-mediated gene transfer of the truncated Fas to Jurkat cells rendered the cells resistant to Fas-mediated apoptosis, suggesting a dominant negative interference mechanism. These results indicate that an ATL subclone acquires a Fas mutation in the lymph nodes, enabling the subclone to escape from apoptosis mediated by the Fas/Fas ligand system and proliferate in the body. Mutation of the Fas gene may be one of the mechanisms underlying the progression of ATL.

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Mutation of CD95 (Fas/Apo-1) Gene in Adult T-Cell Leukemia Cells

Blood ◽

10.1182/blood.v91.10.3935 ◽

1998 ◽

Vol 91 (10) ◽

pp. 3935-3942 ◽

Cited By ~ 101

Author(s):

Sadahiro Tamiya ◽

Ken-ichiro Etoh ◽

Hitoshi Suzushima ◽

Kiyoshi Takatsuki ◽

Masao Matsuoka

Keyword(s):

T Cell ◽

Anticancer Drugs ◽

Fas Ligand ◽

The Other ◽

Silent Mutation ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Fas Antigen ◽

Adult T Cell Leukemia ◽

Exon 4

Abstract CD95 antigen (also known as Fas or Apo-1) and Fas ligand play key roles in apoptosis of cells of the immune system, function as effector molecules of cytotoxic T lymphocytes, and function in the elimination of activated lymphocytes during the downregulation of the immune response. The critical roles of the Fas-Fas ligand system in apoptosis suggest that its inactivation may be involved in malignant transformation. We analyzed the expression of Fas antigen on adult T-cell leukemia (ATL) cells by flow cytometry and found that Fas antigen expression was absent in a case of ATL and markedly decreased in another case among 47 cases examined. Apoptosis could not be induced in the Fas-negative ATL cells by antibody against Fas antigen. Sequencing of reverse transcription-polymerase chain reaction products of the Fas genes in the Fas negative cells showed two types of aberrant transcripts: one had a 5-bp deletion and a 1-bp insertion in exon 2, and the other transcript lacked exon 4. These mutations caused the premature termination of both alleles, resulting in the loss of expression of surface Fas antigen. These aberrant transcripts were not detected in a nonleukemic B-cell line from the same patient. An RNase protection assay of the Fas gene showed mutations in 2 additional cases with Fas-positive ATL cells of 35 cases examined: 1 case lacked exon 4 and the other was a silent mutation. In the Fas antigen-negative case, leukemic cells were resistant to anticancer drugs in vivo, indicating that the loss of expression of Fas antigen may be associated with a poor response to anticancer drugs. Indeed, Fas-negative ATL cells were resistant to adriamycin-induced apoptosis in vitro, which is consistent with the finding that ATL in this case was resistant to chemotherapy. These findings indicate that mutation of the Fas gene may be associated with the progression of ATL and with resistance to anticancer drugs.

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Mutation of CD95 (Fas/Apo-1) Gene in Adult T-Cell Leukemia Cells

Blood ◽

10.1182/blood.v91.10.3935.3935_3935_3942 ◽

1998 ◽

Vol 91 (10) ◽

pp. 3935-3942 ◽

Cited By ~ 4

Author(s):

Sadahiro Tamiya ◽

Ken-ichiro Etoh ◽

Hitoshi Suzushima ◽

Kiyoshi Takatsuki ◽

Masao Matsuoka

Keyword(s):

T Cell ◽

Anticancer Drugs ◽

Fas Ligand ◽

The Other ◽

Silent Mutation ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Fas Antigen ◽

Adult T Cell Leukemia ◽

Exon 4

CD95 antigen (also known as Fas or Apo-1) and Fas ligand play key roles in apoptosis of cells of the immune system, function as effector molecules of cytotoxic T lymphocytes, and function in the elimination of activated lymphocytes during the downregulation of the immune response. The critical roles of the Fas-Fas ligand system in apoptosis suggest that its inactivation may be involved in malignant transformation. We analyzed the expression of Fas antigen on adult T-cell leukemia (ATL) cells by flow cytometry and found that Fas antigen expression was absent in a case of ATL and markedly decreased in another case among 47 cases examined. Apoptosis could not be induced in the Fas-negative ATL cells by antibody against Fas antigen. Sequencing of reverse transcription-polymerase chain reaction products of the Fas genes in the Fas negative cells showed two types of aberrant transcripts: one had a 5-bp deletion and a 1-bp insertion in exon 2, and the other transcript lacked exon 4. These mutations caused the premature termination of both alleles, resulting in the loss of expression of surface Fas antigen. These aberrant transcripts were not detected in a nonleukemic B-cell line from the same patient. An RNase protection assay of the Fas gene showed mutations in 2 additional cases with Fas-positive ATL cells of 35 cases examined: 1 case lacked exon 4 and the other was a silent mutation. In the Fas antigen-negative case, leukemic cells were resistant to anticancer drugs in vivo, indicating that the loss of expression of Fas antigen may be associated with a poor response to anticancer drugs. Indeed, Fas-negative ATL cells were resistant to adriamycin-induced apoptosis in vitro, which is consistent with the finding that ATL in this case was resistant to chemotherapy. These findings indicate that mutation of the Fas gene may be associated with the progression of ATL and with resistance to anticancer drugs.

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Expression of functional Fas antigen on adult T-cell leukemia

Leukemia Research ◽

10.1016/0145-2126(94)90034-5 ◽

1994 ◽

Vol 18 (4) ◽

pp. 305-310 ◽

Cited By ~ 13

Author(s):

Tomio Kotani ◽

Yatsuki Aratake ◽

Seiji Kondo ◽

Kazuo Tamura ◽

Sachiya Ohtaki

Keyword(s):

T Cell ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Fas Antigen ◽

Adult T Cell Leukemia

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Interleukin-10 gene expression in adult T-cell leukemia

Blood ◽

10.1182/blood.v88.3.1035.bloodjournal8831035 ◽

1996 ◽

Vol 88 (3) ◽

pp. 1035-1045 ◽

Cited By ~ 55

Author(s):

N Mori ◽

PS Gill ◽

T Mougdil ◽

S Murakami ◽

S Eto ◽

...

Keyword(s):

Gene Expression ◽

T Cell ◽

Cell Lines ◽

Interleukin 10 ◽

Jurkat Cells ◽

Leukemic Cells ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Nf Kappa B ◽

Adult T Cell Leukemia

We studied the serum levels of interleukin-10 (IL-10), in patients with adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) infection. Elevated IL-10 levels were observed in 33 of 45 patients with ATL. Fresh leukemic cells from ATL patients as well as HTLV-I-infected T-cell lines MT-2, SLB-1, and C10/MJ expressed IL-10 mRNA by reverse transcription-polymerase chain reaction analysis, whereas IL-10 mRNA was not detected in normal peripheral mononuclear cells and an uninfected T-cell line Jurkat. IL-10 protein was also detected in the culture medium of leukemic cells from ATL patients as well as these HTLV-I-infected cell lines, and in the extracellular fluids of ATL patients. Interestingly, MT-4 cells, which did not express Tax although transformed by HTLV-I, did not express IL-10 at either the mRNA or protein level. To elucidate the role of the HTLV-I encoded transactivator Tax in IL-10 gene expression, Jurkat cells were transfected with a Tax expression plasmid. In transiently transfected Jurkat cells, endogenous IL-10 mRNA expression was induced by Tax. Stably transfected Jurkat cell lines expressed IL-10 mRNA and secreted IL-10 protein into the culture medium. The nuclear factor (NF)-kappa B pathway is a target for Tax transactivation. We treated MT-2 cells with phosphorothioate antisense oligonucleotides to the p65 subunit of NF- kappa B. A reduction in the expression of p65 was accompanied by a reduction in IL-10 gene expression and IL-10 production. We showed that the IL-10 kappa B-like sites ( kappa B1,-2,034 to -2,025; kappa B2, - 1,961 to -1,952; kappa B3, -452 to -443) specifically formed a complex with NF-kappa B-containing nuclear extract from MT-2 cells and that NF- kappa B bound with the highest affinity to the kappa B2 element (kappa B2 > kappa B3 > kappa B1). These data suggest a general role for NF- kappa B activation in the induction of IL-10 gene transcription. Activation of IL-10 in HTLV-I-infected cells may contribute to the pathology associated with HTLV-I infection.

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Interleukin-10 gene expression in adult T-cell leukemia

Blood ◽

10.1182/blood.v88.3.1035.1035 ◽

1996 ◽

Vol 88 (3) ◽

pp. 1035-1045 ◽

Cited By ~ 5

Author(s):

N Mori ◽

PS Gill ◽

T Mougdil ◽

S Murakami ◽

S Eto ◽

...

Keyword(s):

Gene Expression ◽

T Cell ◽

Cell Lines ◽

Interleukin 10 ◽

Jurkat Cells ◽

Leukemic Cells ◽

T Cell Leukemia ◽

Cell Leukemia ◽

Nf Kappa B ◽

Adult T Cell Leukemia

Abstract We studied the serum levels of interleukin-10 (IL-10), in patients with adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) infection. Elevated IL-10 levels were observed in 33 of 45 patients with ATL. Fresh leukemic cells from ATL patients as well as HTLV-I-infected T-cell lines MT-2, SLB-1, and C10/MJ expressed IL-10 mRNA by reverse transcription-polymerase chain reaction analysis, whereas IL-10 mRNA was not detected in normal peripheral mononuclear cells and an uninfected T-cell line Jurkat. IL-10 protein was also detected in the culture medium of leukemic cells from ATL patients as well as these HTLV-I-infected cell lines, and in the extracellular fluids of ATL patients. Interestingly, MT-4 cells, which did not express Tax although transformed by HTLV-I, did not express IL-10 at either the mRNA or protein level. To elucidate the role of the HTLV-I encoded transactivator Tax in IL-10 gene expression, Jurkat cells were transfected with a Tax expression plasmid. In transiently transfected Jurkat cells, endogenous IL-10 mRNA expression was induced by Tax. Stably transfected Jurkat cell lines expressed IL-10 mRNA and secreted IL-10 protein into the culture medium. The nuclear factor (NF)-kappa B pathway is a target for Tax transactivation. We treated MT-2 cells with phosphorothioate antisense oligonucleotides to the p65 subunit of NF- kappa B. A reduction in the expression of p65 was accompanied by a reduction in IL-10 gene expression and IL-10 production. We showed that the IL-10 kappa B-like sites ( kappa B1,-2,034 to -2,025; kappa B2, - 1,961 to -1,952; kappa B3, -452 to -443) specifically formed a complex with NF-kappa B-containing nuclear extract from MT-2 cells and that NF- kappa B bound with the highest affinity to the kappa B2 element (kappa B2 > kappa B3 > kappa B1). These data suggest a general role for NF- kappa B activation in the induction of IL-10 gene transcription. Activation of IL-10 in HTLV-I-infected cells may contribute to the pathology associated with HTLV-I infection.

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