Biomedical subjects

Makoto Hamasaki

Publications and source records attributed to Makoto Hamasaki.

At least 19 recordsLinked to original sources

PubMed2007

Emmprin in epithelioid sarcoma: expression in tumor cell membrane and stimulation of MMP-2 production in tumor-associated fibroblasts.

Emmprin is a transmembrane glycoprotein on tumor cells that stimulates peritumoral fibroblasts to produce matrix metalloproteinases (MMPs). Emmprin and the induced MMPs play a crucial role in tumor progression, invasion and metastasis of human carcinomas (epithelial malignancies). However, only a few reports have addressed its role in soft tissue sarcomas. This study investigated the expression and role of emmprin in epithelioid sarcoma (ES). Immunoblot studies of 2 ES cell lines showed that they express emmprin, and co-culture of these ES cells with dermal fibroblasts resulted in upregulation of gelatinase A (MMP-2) in fibroblasts, as shown by zymography, immunoblotting and enzyme immunoassay. This stimulation was inhibited by an activity-blocking peptide against emmprin and by antiemmprin antibody. In addition, in vivo, immunohistochemical analysis of 5 ES patient cases demonstrated diffuse emmprin expression in ES cells and MMP-2 expression in both ES cells and peritumoral fibroblasts. The histopathological findings that peritumoral fibroblasts that were not in direct contact with emmprin-expressing ES cells exhibit upregulated MMP-2 prompted us to look for a soluble form of emmprin. Soluble full-length emmprin released from ES cells was detected in conditioned medium and shown to stimulate MMP-2 production by fibroblasts. In conclusion, emmprin is expressed in ES in both membrane and soluble forms and stimulates MMP-2 production via interactions with fibroblasts, which could play a role in ES cell stromal invasion and vascular involvement.

Adult↗

PubMed2006

Expression of hypoxia-inducible factor-1 alpha and its prognostic significance in small-sized adenocarcinomas of the lung.

OBJECTIVE: To analyze the prognostic value of hypoxia-inducible factor-1 (HIF-1) alpha expression and its correlation with clinicopathologic variables and the expression of vascular endothelial growth factor-A and -C in patients with lung adenocarcinomas of small size. METHODS: The expression of hypoxia-inducible factor-1 alpha was immunohistochemically determined in 78 cases of small-sized adenocarcinoma (maximum dimension < or = 2 cm) using antibody against a recombinant protein corresponding to amino acids 575-780 of hypoxia-inducible factor-1 alpha. Data regarding patient survival, clinicopathologic factors, and immunohistochemical studies of vascular endothelial growth factors were also collected. RESULTS: Strong expression of hypoxia-inducible factor-1 alpha was observed in 23 of 78 cases; absent or minimal expression was found in the localized bronchioloalveolar carcinomas. Strong expression of hypoxia-inducible factor-1 alpha was significantly higher in cases with vascular invasion, lymph node involvement, and vascular endothelial growth factor-A expression. The 5-year survival rate was 63.2% if expression of hypoxia-inducible factor-1 alpha was strong and 85.1% if expression was weak (p < 0.05). CONCLUSION: Immunohistochemical staining of HIF-1 alpha, along with examination of metastatic potential via vascular pathways, may be valid defining a subpopulation of patients with small-sized adenocarcinoma of the lung whose tumors have aggressive angiogenesis potential.

Adenocarcinoma↗

PubMed2006

Establishment of three malignant peripheral nerve sheath tumor cell lines, FU-SFT8611, 8710 and 9817: conventional and molecular cytogenetic characterization.

Malignant peripheral nerve sheath tumor (MPNST) is a rare malignant tumor, for which only a few cultured cell lines are available to date. In the present study, we established three new MPNST cell lines, FU-SFT8611, FU-SFT8710 and FU-SFT9817, from a 40-year-old Japanese man without neurofibromatosis 1 (NF1), a 43-year-old Japanese woman with NF1, and a 61-year-old Japanese woman without NF1, respectively. These cell lines were in culture for more than 3 years in vitro, and exhibit complex karyotypes lacking a common characteristic pattern. Two of the cell lines, FU-SFT8611 and FU-SFT9817, were tumorigenic in nude mice, with the resultant tumors showing an immunohistochemical phenotype similar to the original tumors. Comparative genomic hybridization analysis revealed that chromosomal imbalances were very similar between the original tumors and the established cell lines, but no consistent imbalances among the three cell lines as reported so far. As for chromosomal imbalances that have been reported to be associated with poor survival, FU-SFT8611 exhibited a gain of chromosome 17q22-qter, and FU-SFT9817 showed a loss of 17q22-qter, while gains of 17q24 and 7p15-p21 were observed in none of the cell lines. These newly established cell lines provide a valuable resource for biological and pathological investigations into new treatment regimes for MPNST.

Adult↗

PubMed2005

Novel inosine monophosphate dehydrogenase inhibitor VX-944 induces apoptosis in multiple myeloma cells primarily via caspase-independent AIF/Endo G pathway.

Inosine monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme required for the de novo synthesis of guanine nucleotides from IMP. VX-944 (Vertex Pharmaceuticals, Cambridge, MA, USA) is a small-molecule, selective, noncompetitive inhibitor directed against human IMPDH. In this report, we show that VX-944 inhibits in vitro growth of human multiple myeloma (MM) cell lines via induction of apoptosis. Interleukin-6, insulin-like growth factor-1, or co-culture with bone marrow stromal cells (BMSCs) do not protect against VX-944-induced MM cell growth inhibition. VX-944 induced apoptosis in MM cell lines with only modest activation of caspases 3, 8, and 9. Furthermore, the pan-caspase inhibitor z-VAD-fmk did not inhibit VX-944-induced apoptosis and cell death. During VX-944-induced apoptosis, expressions of Bax and Bak were enhanced, and both apoptosis-inducing factor (AIF) and endonuclease G (Endo G) were released from the mitochondria to cytosol, suggesting that VX-944 triggers apoptosis in MM cells primarily via a caspase-independent, Bax/AIF/Endo G pathway. Importantly, VX-944 augments the cytotoxicity of doxorubicin and melphalan even in the presence of BMSCs. Taken together, our data demonstrate a primarily non-caspase-dependent apoptotic pathway triggered by VX-944, thereby providing a rationale to enhance MM cell cytotoxicity by combining this agent with conventional agents which trigger caspase activation.

Antineoplastic Agents↗

PubMed2005

FTY720 induces apoptosis in multiple myeloma cells and overcomes drug resistance.

The novel immunomodulator FTY720 down-modulates sphingosine-1-phosphate receptor 1 on lymphocytes at low nanomolar concentrations, thereby inhibiting sphingosine-1-phosphate receptor 1-dependent egress of lymphocytes from lymph nodes into efferent lymphatics and blood. At high micromolar concentration, FTY720 has been shown to induce growth inhibition and/or apoptosis in human cancer cells in vitro. In this study, we investigated the biological effects of FTY720 on multiple myeloma cells. We found that FTY720 induces potent cytotoxicity against drug-sensitive and drug-resistant multiple myeloma cell lines as well as freshly isolated tumor cells from multiple myeloma patients who do not respond to conventional agents. FTY720 triggers activation of caspase-8, -9, and -3, followed by poly(ADP-ribose) polymerase cleavage. Interestingly, FTY720 induces alterations in mitochondrial membrane potential (DeltaPsim) and Bax cleavage, followed by translocation of cytochrome c and Smac/Diablo from mitochondria to the cytosol. In combination treatment studies, both dexamethasone and anti-Fas antibodies augment anti-multiple myeloma activity induced by FTY720. Neither interleukin-6 nor insulin-like growth factor-I, which both induce multiple myeloma cell growth and abrogate dexamethasone-induced apoptosis, protect against FTY720-induced growth inhibition. Importantly, growth of multiple myeloma cells adherent to bone marrow stromal cells is also significantly inhibited by FTY720. Finally, it down-regulates interleukin-6-induced phosphorylation of Akt, signal transducers and activators of transcription 3, and p42/44 mitogen-activated protein kinase; insulin-like growth factor-I-triggered Akt phosphorylation; and tumor necrosis factor alpha-induced IkappaBalpha and nuclear factor-kappaB p65 phosphorylation. These results suggest that FTY720 overcomes drug resistance in multiple myeloma cells and provide the rationale for its clinical evaluation to improve patient outcome in multiple myeloma.

Antineoplastic Agents↗

PubMed2005

Honokiol overcomes conventional drug resistance in human multiple myeloma by induction of caspase-dependent and -independent apoptosis.

Honokiol (HNK) is an active component purified from magnolia, a plant used in traditional Chinese and Japanese medicine. Here we show that HNK significantly induces cytotoxicity in human multiple myeloma (MM) cell lines and tumor cells from patients with relapsed refractory MM. Neither coculture with bone marrow stromal cells nor cytokines (interleukin-6 and insulin-like growth factor-1) protect against HNK-induced cytotoxicity. Although activation of caspases 3, 7, 8, and 9 is triggered by HNK, the pan-caspase inhibitor z-VAD-fmk does not abrogate HNK-induced apoptosis. Importantly, release of an executioner of caspase-independent apoptosis, apoptosis-inducing factor (AIF), from mitochondria is induced by HNK treatment. HNK induces apoptosis in the SU-DHL4 cell line, which has low levels of caspase 3 and 8 associated with resistance to both conventional and novel drugs. These results suggest that HNK induces apoptosis via both caspase-dependent and -independent pathways. Furthermore, HNK enhances MM cell cytotoxicity and apoptosis induced by bortezomib. In addition to its direct cytotoxicity to MM cells, HNK also represses tube formation by endothelial cells, suggesting that HNK inhibits neovascurization in the bone marrow microenvironment. Taken together, our results provide the preclinical rationale for clinical protocols of HNK to improve patient outcome in MM.

Antineoplastic Agents, Phytogenic↗

PubMed2005

SDX-101, the R-enantiomer of etodolac, induces cytotoxicity, overcomes drug resistance, and enhances the activity of dexamethasone in multiple myeloma.

In this study we report that R-etodolac (SDX-101), at clinically relevant concentrations, induces potent cytotoxicity in drug-sensitive multiple myeloma (MM) cell lines, as well as in dexamethasone (MM.1R)-, doxorubicin (Dox40/RPMI8226)-, and bortezomib (DHL4)-resistant cell lines. Immunoblot analysis demonstrates that R-etodolac induces apoptosis characterized by caspase-8, -9, and -3 and PARP (poly-ADP [adenosine diphosphate]-ribose polymerase) cleavage and down-regulation of cyclin D1 expression. Subcytotoxic doses of R-etodolac up-regulate myeloid cell leukemia-1 proapoptotic variant (Mcl-1S), while enhancing dexamethasone (Dex)-induced caspase activation and apoptosis. The combination of R-etodolac with Dex results in a highly synergistic cytotoxic effect. R-etodolac also induces apoptosis against primary cells isolated from patients with MM refractory to chemotherapy. Although interleukin 6 (IL-6) and insulin-like growth factor-1 (IGF-1) abrogate Dex-induced MM cell cytotoxicity, neither IL-6 nor IGF-1 protects against R-etodolac-induced cytotoxicity in MM cells. R-etodolac also inhibits viability of MM cells adherent to bone marrow stromal cells (BMSCs), thereby overcoming a mechanism of drug resistance commonly observed with other conventional chemotherapeutic agents. Our data, therefore, indicate that R-etodolac circumvents drug resistance in MM cells at clinically relevant concentrations, targets Mcl-1, and can be synergistically combined with Dex.

Antineoplastic Agents↗

PubMed2005

Azaspirane (N-N-diethyl-8,8-dipropyl-2-azaspiro [4.5] decane-2-propanamine) inhibits human multiple myeloma cell growth in the bone marrow milieu in vitro and in vivo.

Azaspirane (N-N-diethyl-8,8-dipropyl-2-azaspiro [4.5] decane-2-propanamine; trade name, Atiprimod) is an orally bioavailable cationic amphiphilic compound that significantly inhibits production of interleukin 6 (IL-6) and inflammation in rat arthritis and autoimmune animal models. We here characterize the effect of atiprimod on human multiple myeloma (MM) cells. Azaspirane significantly inhibited growth and induced caspase-mediated apoptosis in drug-sensitive and drug-resistant MM cell lines, as well as patient MM cells. IL-6, insulin-like growth factor 1 (IGF-1), or adherence of MM cells to bone marrow stromal cells (BMSCs) did not protect against atiprimod-induced apoptosis. Both conventional (dexamethasone, doxorubicin, melphalan) and novel (arsenic trioxide) agents augment apoptosis induced by atiprimod. Azaspirane inhibits signal transducer activator of transcription 3 (STAT3) and a PI3-K (phosphatidylinositol 3-kinase) target (Akt), but not extracellular signal-regulated kinase 1 and 2 (ERK1/2), inhibits phosphorylation triggered by IL-6, and also inhibits inhibitorkappaBalpha (IkappaBalpha) and nuclear factor kappaB (NFkappaB) p65 phosphorylation triggered by tumor necrosis factor alpha (TNF-alpha). Of importance, azaspirane inhibits both IL-6 and vascular endothelial growth factor (VEGF) secretion in BMSCs triggered by MM cell binding and also inhibits angiogenesis on human umbilical vein cells (HUVECs). Finally, azaspirane demonstrates in vivo antitumor activity against human MM cell growth in severe combined immunodeficient (SCID) mice. These results, therefore, show that azaspirane both induces MM cell apoptosis and inhibits cytokine secretion in the BM milieu, providing the framework for clinical trials to improve patient outcome in MM.

Animals↗

PubMed2005

Differential expression of cytokines, chemokines and their receptors in follicular lymphoma and reactive follicular hyperplasia: assessment by complementary DNA microarray.

Follicular lymphoma (FL) is pathologically categorised as a low-grade B-cell lymphoma and histopathologically shows follicular proliferation of neoplastic B cells. In the neoplastic follicles of FL, the presence of T cells, macrophages and follicular dendritic cells (FDCs) suggests that these cells may promote a favourable environment for the growth of FL cells. Because FL cells are generally associated with FDCs, FDCs may be considered an important source of cytokines and chemokines. FDCs form the framework for germinal centres and also provide networks for nodules of FL. To evaluate the gene expression in neoplastic follicles of FL and reactive follicles of reactive follicular hyperplasia (RFH), we performed gene expression profiling of FL (n=5) and RFH (n=5) using complementary DNA (cDNA) microarray of cytokines/chemokines and their receptors. FL and RFH exhibited a diffuse down-regulated profile compared with normal peripheral blood cells, which were used as controls, although some genes displayed up-regulated profiles. Hierarchical clustering analysis separated FL and RFH into two distinct groups based on their gene expression profiles. FL cases exhibited significantly higher expression of interleukin 3 receptor alpha (IL-3Ralpha) than RFH. Immunohistochemically, neoplastic follicles of FL frequently expressed IL-3Ralpha, especially in FDCs, but not in FL cells. However, IL-3Ralpha expression was rare or weak in the reactive follicles of RFH. These findings suggest the importance of the micro-environment for FL cell growth. Further studies of cDNA microarray should provide new insight into the molecular pathology of FL and may allow the design of improved therapies.

Adult↗

PubMed2004

p38 MAPK inhibition enhances PS-341 (bortezomib)-induced cytotoxicity against multiple myeloma cells.

Although PS-341 (bortezomib) is a promising agent to improve multiple myeloma (MM) patient outcome, 65% of patients with relapsed and refractory disease do not respond. We have previously shown that heat shock protein (Hsp)27 is upregulated after PS-341 treatment, that overexpression of Hsp27 confers PS-341 resistance, and that inhibition of Hsp27 overcomes PS-341 resistance. Since Hsp27 is a downstream target of p38 mitogen-activated protein kinase (MAPK)/MAPK-mitogen-activated protein kinase-2 (MAPKAPK2), we hypothesized that inhibition of p38 MAPK activity could augment PS-341 cytotoxicity by downregulating Hsp27. Although p38 MAPK inhibitor SCIO-469 (Scios Inc, CA, USA) alone did not induce significant growth inhibition, it blocked baseline and PS-341-triggered phosphorylation of p38 MAPK as well as upregulation of Hsp27, associated with enhanced cytotoxicity in MM.1S cells. Importantly, SCIO-469 enhanced phosphorylation of c-Jun NH2-terminal kinase (JNK) and augmented cleavage of caspase-8 and poly(ADP)-ribose polymerase. Moreover, SCIO-469 downregulated PS-341-induced increases in G2/M-phase cells, associated with downregulation of p21Cip1 expression. Importantly, SCIO-469 treatment augmented cytotoxicity of PS-341 even against PS-341-resistant cell lines and patient MM cells. These studies therefore provide the framework for clinical trials of SCIO-469 to enhance sensitivity and overcome resistance to PS-341, thereby improving patient outcome in MM.

Antineoplastic Agents↗

PubMed2004

Transforming growth factor beta receptor I kinase inhibitor down-regulates cytokine secretion and multiple myeloma cell growth in the bone marrow microenvironment.

PURPOSE: Transforming growth factors (TGFs) have pleiotropic biological effects on tumor cells and their environment. In multiple myeloma (MM), we have reported that bone marrow stromal cells (BMSCs) from MM patients produce more TGF-beta1 than BMSCs from healthy donors, which in turn induces interleukin (IL)-6 secretion. We show here that the TGF-beta receptor I kinase inhibitor SD-208 significantly decreases secretion of both IL-6 and vascular endothelial growth factor (VEGF) from BMSCs, as well as tumor cell growth triggered by MM cell adhesion to BMSCs. EXPERIMENTAL DESIGN: Cytokine production and MM cell proliferation triggered by TGF-beta1 or adhesion to BMSCs were examined in the presence or absence of SD-208. Effects of SD-208 on TGF-beta1-induced signaling pathways triggering IL-6 and VEGF transcription in BMSCs were also delineated. RESULTS: SD-208 significantly inhibits not only transcription but also secretion of both IL-6 and VEGF from BMSCs triggered by either TGF-beta1 or adhesion of MM cells to BMSCs. Moreover, SD-208 decreased tumor cell growth triggered by MM cell adhesion to BMSCs. SD-208 works, at least in part, by blocking TGF-beta1-triggered nuclear accumulation of Smad2/3 and hypoxia-inducible factor 1alpha, as well as related production of IL-6 and VEGF, respectively. CONCLUSIONS: These studies indicate that SD-208 inhibits production of cytokines mediating MM cell growth, survival, drug resistance, and migration in the BM milieu, thereby providing the preclinical rationale for clinical evaluation of SD-208 to improve patient outcome in MM.

Antineoplastic Agents↗

PubMed2004

Mechanisms by which SGN-40, a humanized anti-CD40 antibody, induces cytotoxicity in human multiple myeloma cells: clinical implications.

CD40 is expressed on B-cell malignancies, including human multiple myeloma (MM) and a variety of carcinomas. We examined the potential therapeutic utility of SGN-40, the humanized anti-CD40 monoclonal antibody, for treating human MM using MM cell lines and patient MM cells (CD138(++), CD40(+)). SGN-40 (0.01-100 micro g/ml) induces modest cytotoxicity in MM cell lines and patient MM cells. In the presence of de novo protein synthesis inhibitor cycloheximide, SGN-40 significantly induced apoptosis in Dexamethasone (Dex)-sensitive MM.1S and Dex-resistant MM.1R cells and in patient MM cells. SGN-40-mediated cytotoxicity is associated with up-regulation of cytotoxic ligands of the tumor necrosis factor family (Fas/FasL, tumor necrosis factor-related apoptosis-inducing ligand, and tumor necrosis factor alpha). SGN-40 treatment also induces a down-regulation of CD40 dependent on an endocytic pathway. Consequently, pretreatment of MM cells with SGN-40 blocked sCD40L-mediated phosphatidylinositol 3'-kinase/AKT and nuclear factor kappaB activation. Importantly, pretreatment of MM.1S and MM.1R cells with SGN-40 inhibited proliferation triggered by interleukin 6 (IL-6) but not by insulin-like growth factor-I. In addition, SGN-40 pretreatment of MM.1S cells blocked the ability of IL-6 to protect against Dex-induced inhibition of DNA synthesis. This was associated with a 2-4-fold reduction of IL-6 receptor at protein and mRNA levels in SGN-40-treated MM.1S cells and patient MM cells. Taken together, these results provide the preclinical rationale for the evaluation of SGN-40 as a potential new therapy to improve patient outcome in MM.

Antibodies, Monoclonal↗

PubMed2004

Apoptosis- and cell cycle-associated gene expression profiling of histiocytic necrotising lymphadenitis.

Cell death is of two types; necrosis and apoptosis. In histiocytic necrotising lymphadenitis (HNL), apoptosis is the main form of cell death. Apoptosis results in the formation of nuclear debris, which is one of the characteristic features of HNL. We previously reported that in HNL it is predominantly CD8-positive cytotoxic T cells that undergo apoptosis; however, the majority of proliferating cells are also CD8-positive T cells. Recent advances in technical and analytical methods have facilitated the parallel quantitation of expression of numerous genes using DNA microarrays. The technology is particularly well suited to compare differences in gene expression between normal tissues and inflammatory disease. To investigate the apoptosis- and cell cycle-associated gene expression in HNL, we analysed five cases each of HNL and non-specific lymphadenitis (NSL), using ready-made microarrays, including cyclins and caspases, and immunohistochemical staining of caspase-3, ssDNA, bcl-2 and NF-kappaB. Caspase-3- and ssDNA-positive apoptotic cells were frequently detected in HNL, but were rare in NSL. However, bcl-2- and NF-kappaB-positive cells were rare in HNL. Gene expression tree analysis of DNA microarrays showed different clustering of HNL and NSL. In comparison with NSL, HNL exhibited diffuse upregulation of these gene profiles, particularly of cyclins and caspases (ratio; cyclin A2, 2.72; caspase-6, 2.43; caspase-3, 2.02); whereas, Mcl-1, which has been shown to delay apoptosis, was downregulated (ratio, 0.71), as confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR). Almost all apoptosis-associated genes, especially caspases, were upregulated, and apoptosis inhibitory genes, including bcl-2 by immunohistochemistry, were downregulated in all five cases with HNL. In addition, cell cycle-associated genes were upregulated in all. These findings confirm that both apoptosis and proliferation are simultaneously present in HNL lesions.

Apoptosis↗

PubMed2004

Differential expression of chemokines, chemokine receptors, cytokines and cytokine receptors in diffuse large B cell malignant lymphoma.

Host immunity, particularly T cell immunity (Th1/Th2 balance), plays an important role in clinicopathological features of malignant disease. However, the T cell immunity has not been fully investigated in patients with lymphoid malignancies. Recent studies suggested the important role of dysregulation of the endogenous immune system in lymphomagenesis. The relationships between cytokines/chemokines and their receptors, are important in determining the selectivity of local immunity. To investigate differences in the endogenous immune system of diffuse large B cell lymphoma (DLBL), we performed gene expression profiling using cDNA microarrays of cytokines/chemokines and their receptors. We studied 5 cases each of primary central nervous system lymphomas (PCNSL), extranodal and nodal lymphomas. PCNSL exhibited diffuse down-regulated profiles, compared to normal peripheral blood lymphocytes. While extranodal and nodal lymphomas also exhibited diffuse down-regulated profiles, some genes displayed up-regulated profiles. Hierarchical clustering analysis separated PCNSL and extranodal lymphomas into distinct groups based on their gene expression profiles, as well as extranodal and nodal, but not PCNSL and nodal. PCNSL exhibited significantly lower expression of BLC/BCA-1 and CCR-3 (Th2 type), and higher expression of IL-8 and MIP-1beta (Th1 type) than extranodal lymphomas. Immunohistochemistry and RT-PCR revealed frequent CCR-3 and BLC/BCA-1 expression in extranodal lymphomas, compared with PCNSL. Our results provide new insights into the pathogenesis of each DLBL. A better understanding of the immune response in each DLBL could help in the design of novel therapeutic strategies based on cytokines/chemokines and their receptors.

Adult↗

PubMed2004

Expression and alternative splicing pattern of human telomerase reverse transcriptase in human lung cancer cells.

Telomerase activity is generally considered to be necessary for cancer cells to avoid senescence. The expression of human telomerase reverse transcriptase (hTERT) is believed to be a rate-limiting step in telomerase activation. Recently, it has been proposed that the alternative splicing of hTERT is also involved in regulation of telomerase activity. However, the regulatory mechanism of telomerase in cancer cells has not been thoroughly investigated. To clarify it in lung cancer cells, we measured the expression of the hTERT transcript, analyzed its alternative splicing by RT-PCR, and compared it with telomerase activity and telomere length. The expression of the hTERT transcript was positively correlated with telomerase activity in lung cancer cells. Cancer cells with high telomerase activity contained 4 splicing variants of hTERT, and the full-length variant was 31.3-54.2% of the total transcripts. Cells of the TKB-20 cell line, which has extremely low telomerase activity, showed a different splicing pattern of hTERT in addition to low expression. The functional full-length variant was scarcely detected in TKB-20 cells, suggesting that the telomerase activity was repressed by alternative splicing of hTERT. Telomere length was not necessarily correlated with telomerase activity or hTERT expression in lung cancer cells. Cells of the TKB-4 cell line that also showed relatively low telomerase activity (as TKB-20 cells) had long telomeres. In conclusion, hTERT expression is regulated at both the transcriptional and post-transcriptional levels in lung cancer cells, and the alternative splicing of hTERT is involved in the control of telomerase activity.

Alternative Splicing↗

PubMed2003

Effects of oligonucleotide N3'-->P5' thio-phosphoramidate (GRN163) targeting telomerase RNA in human multiple myeloma cells.

Telomeres are specialized nucleoprotein complexes that protect against fusion and degradation of linear chromosomes. Critical shortening of telomeres leads to irreversible cessation of cell division, whereas telomerase elongates telomere sequences to compensate for losses that occur with each round of DNA replication. Continued proliferation of tumor cells requires this enzyme to maintain chromosomal stability and to counteract the cellular mitotic clock. In this study, we evaluated the effect of oligonucleotide N3'-->P5' thio-phosphoramidate (NP), which targets template RNA component, in human multiple myeloma (MM) cell lines and patient MM cells. Fluorescein staining at 24 h confirmed NP uptake in 84.7 and 86.1% of MM.1S cells and MM patient cells, respectively, without any transfection enhancer. High transfection efficiency was observed into both CD138(+) and CD138(-) MM patient cells. Match NP (7S), but not mismatch NP (30S), inhibited telomerase activity in MM.1S cells, U266 cells, and RPMI 8226 cells, as well as in patient MM cells. Moreover, 7S inhibited cytokine-induced telomerase activity in MM.1S cells. 7S treatment-induced progressive telomere shortening was associated with growth inhibition and cell death in MM.1S cells with short telomeres (2.5 kb), but not in U266 cells with long telomeres (9.0 kb), at 56 days of culture. Progressive telomere shortening leading to growth inhibition and cell death in MM.1S cells was associated with up-regulation of p21 and phosphorylation of p53 (Ser-15). These studies, therefore, identify the molecular sequelae of NP oligonucleotide (GRN163) against human telomerase RNA component as a telomerase inhibitor and provide the rationale for the development of telomerase-targeted therapies to improve patient outcome in MM.

Amides↗

PubMed2003

Imbalances of chemokines, chemokine receptors and cytokines in Hodgkin lymphoma: classical Hodgkin lymphoma vs. Hodgkin-like ATLL.

Classical Hodgkin lymphoma (HL) is characterized by the presence of Hodgkin and Reed-Sternberg cells (H&RS) and a prominent lymphocytic infiltration. We previously reported Hodgkin-like adult T-cell leukemia/lymphoma (HL-like ATLL) (new WHO classification). Various CXC and CC chemokines are expressed on H&RS cells and the relationships between chemokines and the chemokine receptor (R) are thought to be important for selectivity of local immunity of Th1 and Th2 T cells. To clarify the role of T-cell immunity in classical HL and Hodgkin-like ATLL, we performed gene expression profiling (chemokine, chemokine R and cytokine DNA chips) in 12 cases [classical HL, 8 cases [mixed cellularity (MC) type, 4; nodular sclerosis (NS) type, 4]; Hodgkin-like ATLL, 4 cases] and immunohistochemical staining in 29 cases (MC, 10; NS, 10; Hodgkin-like ATLL, 9). EBV-infected H&RS cells were detected in 9 of 10 cases of HL MC, 5 of 9 of HL-like ATLL and 2 of 10 HL NS. T-cell-directed chemokine thymus- and activation-regulated chemokine (TARC)- and/or macrophage-derived chemokine (MDC)-positive H&RS cells were detected in all 20 cases of HL MC and HL NS but only in 5 of 9 cases of HL-like ATLL. Interferon-gamma-inducible protein-10 (IP10)- and monokine induced by interferon-gamma (MIG)-positive H&RS cells were detected in all 10 HL MC but only in 5 of 10 cases of HL NS and 2 of 9 cases of HL-like ATLL. However, 2 of 5 cases of HL-like ATLL with EBV infection and 2 of 2 HL NS with EBV had IP10/MIG-positive H&RS cells. The chemokine expressions in H&RS cells seemed to be associated with EBV infection rather than histologic subtypes. In the DNA chip expression analysis, classical HL and HL-like ATLL had a mixed Th1/Th2-type profile, and HL MC (EBV-positive) and HL NS (EBV-negative) were differentially clustered. However, 2 cases of HL-like ATLL clustered with HL MS and the other 2 cases of HL-like ATLL clustered with HL NS. The former HL-like ATLL had EBV infection in H&RS cells, whereas the latter did not have EBV infection. This finding also suggests that EBV might influence local expression of chemokines rather than HL subtypes. Our results indicate that local immunologic disorder or imbalance appears to influence the formation of H&RS cells and that in HL-like ATLL, HTLV-1 infection might not be necessary for H&RS cell formation.

Chemokines↗

PubMed2003

Th1, Th2, and activated T-cell marker and clinical prognosis in peripheral T-cell lymphoma, unspecified: comparison with AILD, ALCL, lymphoblastic lymphoma, and ATLL.

A new World Health Organization classification was recently proposed. However, classification of peripheral T-cell lymphomas remains to be clarified. Particularly, unspecified type was considered as a heterogeneous category. Here we studied the expressions of chemokine receptors, Th1-associated CXCR3 and CCR5 and Th2-associated marker ST2(L), and activated T-cell receptor OX40/CD134 in 185 patients with nodal T-cell lymphoma, and evaluated the relationship to prognosis. Their expression patterns correlated with the specific subtype of nodal T-cell lymphoma, such as angioimmunoblastic T-cell lymphoma (AILD), anaplastic large cell lymphoma (ALCL), and in peripheral T-cell lymphoma (PTCL), unspecified. In AILD, almost all cases were immunoreactive for OX40/CD134 (96%) and for CXCR3 (89%). In ALCL, all cases were immunonegative for OX40/CD134, and only a few cases (24%) were immunoreactive for CXCR3, whereas almost all cases (94%) were positive for ST2(L). Cases of PTCL, unspecified, were divided into 2 groups; group 1 (cases positive for either ST2(L), CCR5, or CXCR3) tended to show favorable prognosis compared with group 2 (cases negative for ST2(L), CCR5, and CXCR3). Our results indicate that further subtyping of PTCL, unspecified, into groups 1 and 2 could be significant for evaluating prognosis and understanding the functional role of these tumors.

Biomarkers, Tumor↗