LAURENCE ELIAS | None - Academia.edu (original) (raw)

Papers by LAURENCE ELIAS

Biology of Blood and Marrow Transplantation, 1998

Blood, 2012

4039 Introduction: Bruton tyrosine kinase (Btk) is essential in the development and function of B... more 4039 Introduction: Bruton tyrosine kinase (Btk) is essential in the development and function of B cells through normal B cell receptor signaling, and it is down-regulated in non-malignant plasma cells. This is not the case in malignant plasma cells of patients with MM where robust Btk gene expression is usual. In addition, Btk is expressed and functional in osteoclasts and their precursors, which play a pathogenic role in MM-related bone disease, as well as growth and survival of MM in the microenvironment. Researchers in our group (Tai, Chang et al, Blood, 2012) recently demonstrated that the Btk inhibitor ibrutinib (PCI-32765) inhibited the interaction of MM cells with stromal cells, and inhibited the growth in vitro of MM colony forming cells from patient explants. Ibrutinib suppressed in vitro osteoclast differentiation and production of multiple cytokines and chemokines including CCL3, CCL4, IL-8, and TGF-β. Ibrutinib furthermore decreased MM progression and accompanying bone d...

Blood, 2014

Introduction: Multiple myeloma (MM) remains an incurable disease in need of new therapies with un... more Introduction: Multiple myeloma (MM) remains an incurable disease in need of new therapies with unique targets. Ibrutinib is a first-in-class, once-daily, oral, covalent inhibitor of Bruton’s tyrosine kinase (BTK), an essential enzyme in the B-cell receptor signaling pathway. While BTK is essential for the development and function of B cells and is down-regulated in plasma cells, the expression of BTK in malignant plasma cells is increased 4-fold and comparable to BTK expression levels in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). In addition, pre-clinical models show that BTK inhibition with ibrutinib led to direct inhibition of both osteoclast bone resorption and the release of osteoclast-derived tumor growth factors (Tai et al, Blood 2012). Taken together these data suggest that ibrutinib may have a role in the treatment of MM. Methods: This open label phase 2 dose escalation study was designed to enroll patients in 4 cohorts (Figure) to evaluate efficacy (...

Molecular cancer therapeutics, Dec 27, 2016

Ibrutinib is a potent, small-molecule Bruton's tyrosine kinase (BTK) inhibitor developed for ... more Ibrutinib is a potent, small-molecule Bruton's tyrosine kinase (BTK) inhibitor developed for the treatment of B-cell malignancies. Ibrutinib covalently binds to Cys481 in the ATP-binding domain of BTK. This cysteine residue is conserved among 9 other tyrosine kinases, including HER2 and EGFR, which can be targeted. Screening large panels of cell lines demonstrated that ibrutinib was growth inhibitory against some solid tumor cells, including those inhibited by other HER2/EGFR inhibitors. Among sensitive cell lines, breast cancer lines with HER2 overexpression were most potently inhibited by ibrutinib (<100 nM); additionally the IC50s were lower than that of lapatinib and dacomitinib. Inhibition of cell growth by ibrutinib coincided with downregulation of phosphorylation on HER2 and EGFR and their downstream targets, AKT and ERK. Irreversible inhibition of HER2 and EGFR in breast cancer cells was established after 30-minute incubation above 100 nM or following 2-hour incubatio...

Molecular Cancer Therapeutics, 2009

Background: Telomerase maintains telomere length (TL) of dividing cells, and is essential for cel... more Background: Telomerase maintains telomere length (TL) of dividing cells, and is essential for cell immortalization. Telomerase is upregulated in tumors, particularly in cancer progenitor cells. Imetelstat (GRN163L), the first targeted telomerase inhibitor in clinical trials, is a 13-mer lipidated oligonucleotide that binds to the template RNA strand of telomerase. With weekly dosing, thrombocytopenia was dose limiting and MTD was 4.8 mg/kg. To increase drug exposure and maintain tolerability, we tested an intermittent dosing schedule of imetelstat. Methods: Patients (pts) with advanced solid cancers were given imetelstat as a single agent by 2 hr. i.v. infusions on D1 and D8 of 21-Day cycles (Cy), starting at 4.8 mg/kg. A 3+3 dose escalation was used. Pre-treatment granulocyte TL (PMN TL), a surrogate of hematopoietic progenitor TL, was measured by Flow-FISH. Results: 31 pts have been treated, with 4 currently on study. Mean number of prior cytotoxic regimens reported for 26 pts was...

Blood

2647 Poster Board II-623 Background/Aims: Reflecting their proliferative history, malignant cells... more 2647 Poster Board II-623 Background/Aims: Reflecting their proliferative history, malignant cells generally have shorter telomeres compared to their normal counterparts. We have reported that leukemic cells from patients with T-prolymphocytic leukaemia (T-PLL) have exceptionally short telomeres (telomere lengths around 1 kb) compared to other malignancies, and high levels of telomerase activity (Roeth et al., Leukemia, 2007). We have also previously presented (Roeth et al., ASCO 2008) cytotoxic effects of the telomerase inhibitory agent imetelstat sodium (GRN163L), which is currently in clinical trials. The objective of this study was to further characterize the relationship between mean telomere length (TL), the single chromosome telomeric size distributions (single TL), telomerase levels and imetelstat-induced telomerase inhibition and cytotoxicity in T-PLL, B-CLL, and normal cells. Methods: Cells were obtained from peripheral blood of normal donors and patients with T-PLL and B-C...

Journal of Clinical Oncology

e15014 Background: Tissue factor (TF) up-regulation is associated with increased tumor invasivene... more e15014 Background: Tissue factor (TF) up-regulation is associated with increased tumor invasiveness and progression, worsened prognosis and increased thromboembolism (VTE). Activation of protease activated receptors by TF:FVIIa complex leads to increases in IL-8, VEGF and other invasiveness promoting factors. PCI-27483 (P), a selective FVIIa inhibitor, reduced pancreatic adenocarcinoma (PCa) xenograft growth in mice at doses producing 2.5 - 3.0 x PT changes. Methods: Escalating doses of P combined with gemcitabine (G) targeting peak (2 hr post) INR = 3.0 was studied in Phase I preceding randomization to G+P at the determined dose vs. G alone in Phase II. Eligible patients (pts) had measurable locally advanced or metastatic PCa, ECOG PS 0-1, and normal PT/aPTT, and no history of VTE. G was given IV at 1 G/m2 q wk X3 every 4 wks, and P was self-administered SC bid continuously. Tumor evaluation including spiral CTs were performed at baseline and q 8 wks. Results: In phase I, 8 pts wer...

British journal of haematology, 2018

Novel therapies with unique new targets are needed for patients who are relapsed/refractory to cu... more Novel therapies with unique new targets are needed for patients who are relapsed/refractory to current treatments for multiple myeloma. Ibrutinib is a first-in-class, once-daily, oral covalent inhibitor of Bruton tyrosine kinase, which is overexpressed in the myeloma stem cell population. This study examined various doses of ibrutinib ± low-dose dexamethasone in patients who received ≥2 prior lines of therapy, including an immunomodulatory agent. Daily ibrutinib ± weekly dexamethasone 40 mg was assessed in 4 cohorts using a Simon 2-stage design. The primary objective was clinical benefit rate (CBR; ≥minimal response); secondary objectives included safety. Patients (n = 92) received a median of 4 prior regimens. Ibrutinib + dexamethasone produced the highest CBR (28%) in Cohort 4 (840 mg + dexamethasone; n = 43), with median duration of 9·2 months (range, 3·0-14·7). Progression-free survival was 4·6 months (range, 0·4-17·3). Grade 3-4 haematological adverse events included anaemia (1...

Cancer research, Jan 15, 2015

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense stromal fibroinflammatory rea... more Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense stromal fibroinflammatory reaction that is a major obstacle to effective therapy. The desmoplastic stroma comprises many inflammatory cells, in particular mast cells as key components of the PDAC microenvironment, and such infiltration correlates with poor patient outcome. Indeed, it has been hypothesized that stromal ablation is critical to improve clinical response in patients with PDAC. Ibrutinib is a clinically approved Bruton's tyrosine kinase inhibitor that inhibits mast cells and tumor progression in a mouse model of β-cell tumorigenesis. Here, we show that ibrutinib is highly effective at limiting the growth of PDAC in both transgenic mouse and patient-derived xenograft models of the disease. In these various experimental settings, ibrutinib effectively diminished fibrosis, extended survival, and improved the response to clinical standard-of-care therapy. Our results offer a preclinical rationale to imme...

The Journal of clinical investigation, Jan 3, 2014

Chronic graft-versus-host disease (cGVHD) is a life-threatening impediment to allogeneic hematopo... more Chronic graft-versus-host disease (cGVHD) is a life-threatening impediment to allogeneic hematopoietic stem cell transplantation, and current therapies do not completely prevent and/or treat cGVHD. CD4+ T cells and B cells mediate cGVHD; therefore, targeting these populations may inhibit cGVHD pathogenesis. Ibrutinib is an FDA-approved irreversible inhibitor of Bruton's tyrosine kinase (BTK) and IL-2 inducible T cell kinase (ITK) that targets Th2 cells and B cells and produces durable remissions in B cell malignancies with minimal toxicity. Here, we evaluated whether ibrutinib could reverse established cGVHD in 2 complementary murine models, a model interrogating T cell-driven sclerodermatous cGVHD and an alloantibody-driven multiorgan system cGVHD model that induces bronchiolar obliterans (BO). In the T cell-mediated sclerodermatous cGVHD model, ibrutinib treatment delayed progression, improved survival, and ameliorated clinical and pathological manifestations. In the alloantib...

Journal of Cellular Physiology, 1988

The effect of human tumor necrosis factor (TNF) on early-passage HL-60 cells was studied. A trans... more The effect of human tumor necrosis factor (TNF) on early-passage HL-60 cells was studied. A transient phase of increased [3H]thymidine (TdR) incorporation was noted at 20-24 hr of exposure to TNF. This increase was disproportionate to the much slighter stimulation of the percentage of S-phase cells, which was measured by flow cytometry. Evidence for increased metabolic trapping of [3H]TdR following TNF treatment was apparent from whole cell uptake experiments. The salvage pathway enzyme TdR kinase was therefore measured and was found to be elevated comparably to [3H]TdR uptake. The mechanism of TNF regulation of TdR kinase was further investigated by a series of combination treatment experiments using other biologic factors and pharmacologic inhibitors of various intracellular steps. The response to TNF was not potentiated or reproduced by IL-1, IL-2, IL-3, IL-4, G-CSF, M-CSF, GM-CSF or alpha- or gamma-interferon. Blockers of early signal transduction steps, including H7, W7, sphingosine, and pertussis toxin, failed to inhibit TNF stimulation of [3H]TdR incorporation. mRNA synthesis inhibition with alpha-amanitin blocked this TNF effect, as did cAMP but not cGMP analogues. A sensitizing effect was noted with amiloride or cytochalasin B, characterized by greater relative increases of [3H]TdR incorporation and TdR kinase activity in response to TNF. In the presence of cytochalasin B, TNF treatment resulted in no change or slight decreases in the percentage of S-phase cells. Regulation of TdR kinase could thereby be dissociated from the usual cell cycle control. This study thus documents a unique example of stimulation of thymidine salvage pathway metabolism by a biologic factor, dissociable from overall cell cycle regulation.

Cancer Research, Jun 1, 1981

Determination of levels and isozymic patterns of protein kinase activities was performed upon ext... more Determination of levels and isozymic patterns of protein kinase activities was performed upon extracts from two human leukemia cell lines (K562 and HL-60) and blast cells from five untreated patients with acute myeloblastic leukemia and com pared to activities from normal human peripheral blood granulocytes and bone marrow samples enriched for proliferative myeloid cells. The leukemic cells studied were found to have higher specific activities of cytosol cyclic adenosine 3':5'monophosphate (cAMP)-independent casein kinase and lower activation by cAMP of their cytosol histone kinase compared to the normal myeloid cells studied. Diethylaminoethyl-cellulose chromatography revealed correspondingly higher amounts of cAMP-independent protein kinase isoenzymes (two casein ki nase and one histone kinase peaks) in the leukemic cells, as well as altered ratios of the two cAMP-dependent isozymes. Casein phosphorylating activities extracted from the nuclei of the leukemic cell lines were also high compared to normal myeloid cells. Further purification and estimation of molecular weights of the isoenzymes present in leukemia were accom plished by gel filtration, using Sephacryl S-200. Resolution of the acute myeloblastic leukemia cell line nuclear casein kinase activity into two peaks was also thereby accomplished. The nuclear peaks eluted earlier than the corresponding cytoplasmic peaks; thus, the nuclear isoenzymes may not be identical to those from the cytoplasm. The increased protein kinase activity noted in such cells may be an important biochemical concomitant of transformation. stitute, Kirtland Air Force Base, Albuquerque. N. M. 87116. " The abbreviations used are: cAMP, cyclic adenosine 3':5'-monophosphate; AML, acute myeloblastic leukemia; PBS, phosphate buffered saline [0.118 M NaCI-0.01 M Na2HPO4 • NaH2PO4 (pH 7.4)]; HB, hypotonie buffer[0.005 MKH2PO4 • K2HPO4 (pH 7.5HO% glycerol-0.1% 2-mercaptoethanol];

Cancer treatment reports

In an attempt to improve remissions and survivals in previously treated patients with adult acute... more In an attempt to improve remissions and survivals in previously treated patients with adult acute leukemia, we gave Adriamycin, vincristine, and prednisone for induction therapy, followed by 6-mercaptopurine and methotrexate for maintenance therapy to patients attaining complete remission (CR). The study group consisted of 18 patients with acute myeloblastic leukemia (AML), ten with acute lymphoblastic leukemia, and one with acute undifferentiated leukemia. Only one patient had previously received Adriamycin. Overall, there were ten CRs and two partial remissions. The five CRs and one partial remission in patients with AML occurred among those with one prior induction attempt; none of the eight AML patients with more than one prior induction attempt responded. The actuarial median duration of CR was 15 weeks and was similar for AML and acute lymphoblastic leukemia patients. Responders had a longer median survival (30 weeks) than nonresponders (9 weeks). Thus, although a reasonable number of responses in previously treated patients were obtained with this program, improvements in maintenance therapy are clearly needed.

Western Journal of Medicine

Because no conclusive evidence as to the efficacy of maintenance chemotherapy in acute myelogenou... more Because no conclusive evidence as to the efficacy of maintenance chemotherapy in acute myelogenous leukemia (AML) existed, a study to obtain such information was done. Twenty-six adult patients with AML in whom complete remission had been achieved following induction chemotherapy were randomly assigned to receive either maintenance chemotherapy consisting of cytarabine and 6-thioguanine for two days each month or to receive no maintenance therapy. The data showed a significant difference in remission duration between the two groups, with median remission lengths for the maintained and unmaintained groups being 10.3 and 6.7 months, respectively (p<.05). In 46 percent of the maintained patients there were remissions lasting longer than 11 months, whereas in none of the unmaintained patients was there such a prolonged remission. No significant drug-induced toxicity was observed. That the prolonged exposure to these chemotherapeutic agents, which were also used in our induction program, did not adversely affect the rate of successful reinduction therapy was shown by identical 50 percent complete remission rates for second inductions in both groups. In patients with palpable splenomegaly at the time of diagnosis, there was no prolongation of remission with maintenance therapy. These data indicate the potential utility of maintenance chemotherapy for prolonging remission duration in acute myelogenous leukemia. DESPITE a lack of conclusive evidence, it has been assumed that maintenance chemotherapy is useful in the management of acute myelogenous leukemia (AML). This assumption is related to

Biology of Blood and Marrow Transplantation, 1998

Blood, 2012

4039 Introduction: Bruton tyrosine kinase (Btk) is essential in the development and function of B... more 4039 Introduction: Bruton tyrosine kinase (Btk) is essential in the development and function of B cells through normal B cell receptor signaling, and it is down-regulated in non-malignant plasma cells. This is not the case in malignant plasma cells of patients with MM where robust Btk gene expression is usual. In addition, Btk is expressed and functional in osteoclasts and their precursors, which play a pathogenic role in MM-related bone disease, as well as growth and survival of MM in the microenvironment. Researchers in our group (Tai, Chang et al, Blood, 2012) recently demonstrated that the Btk inhibitor ibrutinib (PCI-32765) inhibited the interaction of MM cells with stromal cells, and inhibited the growth in vitro of MM colony forming cells from patient explants. Ibrutinib suppressed in vitro osteoclast differentiation and production of multiple cytokines and chemokines including CCL3, CCL4, IL-8, and TGF-β. Ibrutinib furthermore decreased MM progression and accompanying bone d...

Blood, 2014

Introduction: Multiple myeloma (MM) remains an incurable disease in need of new therapies with un... more Introduction: Multiple myeloma (MM) remains an incurable disease in need of new therapies with unique targets. Ibrutinib is a first-in-class, once-daily, oral, covalent inhibitor of Bruton’s tyrosine kinase (BTK), an essential enzyme in the B-cell receptor signaling pathway. While BTK is essential for the development and function of B cells and is down-regulated in plasma cells, the expression of BTK in malignant plasma cells is increased 4-fold and comparable to BTK expression levels in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). In addition, pre-clinical models show that BTK inhibition with ibrutinib led to direct inhibition of both osteoclast bone resorption and the release of osteoclast-derived tumor growth factors (Tai et al, Blood 2012). Taken together these data suggest that ibrutinib may have a role in the treatment of MM. Methods: This open label phase 2 dose escalation study was designed to enroll patients in 4 cohorts (Figure) to evaluate efficacy (...

Molecular cancer therapeutics, Dec 27, 2016

Ibrutinib is a potent, small-molecule Bruton's tyrosine kinase (BTK) inhibitor developed for ... more Ibrutinib is a potent, small-molecule Bruton's tyrosine kinase (BTK) inhibitor developed for the treatment of B-cell malignancies. Ibrutinib covalently binds to Cys481 in the ATP-binding domain of BTK. This cysteine residue is conserved among 9 other tyrosine kinases, including HER2 and EGFR, which can be targeted. Screening large panels of cell lines demonstrated that ibrutinib was growth inhibitory against some solid tumor cells, including those inhibited by other HER2/EGFR inhibitors. Among sensitive cell lines, breast cancer lines with HER2 overexpression were most potently inhibited by ibrutinib (<100 nM); additionally the IC50s were lower than that of lapatinib and dacomitinib. Inhibition of cell growth by ibrutinib coincided with downregulation of phosphorylation on HER2 and EGFR and their downstream targets, AKT and ERK. Irreversible inhibition of HER2 and EGFR in breast cancer cells was established after 30-minute incubation above 100 nM or following 2-hour incubatio...

Molecular Cancer Therapeutics, 2009

Background: Telomerase maintains telomere length (TL) of dividing cells, and is essential for cel... more Background: Telomerase maintains telomere length (TL) of dividing cells, and is essential for cell immortalization. Telomerase is upregulated in tumors, particularly in cancer progenitor cells. Imetelstat (GRN163L), the first targeted telomerase inhibitor in clinical trials, is a 13-mer lipidated oligonucleotide that binds to the template RNA strand of telomerase. With weekly dosing, thrombocytopenia was dose limiting and MTD was 4.8 mg/kg. To increase drug exposure and maintain tolerability, we tested an intermittent dosing schedule of imetelstat. Methods: Patients (pts) with advanced solid cancers were given imetelstat as a single agent by 2 hr. i.v. infusions on D1 and D8 of 21-Day cycles (Cy), starting at 4.8 mg/kg. A 3+3 dose escalation was used. Pre-treatment granulocyte TL (PMN TL), a surrogate of hematopoietic progenitor TL, was measured by Flow-FISH. Results: 31 pts have been treated, with 4 currently on study. Mean number of prior cytotoxic regimens reported for 26 pts was...

Blood

2647 Poster Board II-623 Background/Aims: Reflecting their proliferative history, malignant cells... more 2647 Poster Board II-623 Background/Aims: Reflecting their proliferative history, malignant cells generally have shorter telomeres compared to their normal counterparts. We have reported that leukemic cells from patients with T-prolymphocytic leukaemia (T-PLL) have exceptionally short telomeres (telomere lengths around 1 kb) compared to other malignancies, and high levels of telomerase activity (Roeth et al., Leukemia, 2007). We have also previously presented (Roeth et al., ASCO 2008) cytotoxic effects of the telomerase inhibitory agent imetelstat sodium (GRN163L), which is currently in clinical trials. The objective of this study was to further characterize the relationship between mean telomere length (TL), the single chromosome telomeric size distributions (single TL), telomerase levels and imetelstat-induced telomerase inhibition and cytotoxicity in T-PLL, B-CLL, and normal cells. Methods: Cells were obtained from peripheral blood of normal donors and patients with T-PLL and B-C...

Journal of Clinical Oncology

e15014 Background: Tissue factor (TF) up-regulation is associated with increased tumor invasivene... more e15014 Background: Tissue factor (TF) up-regulation is associated with increased tumor invasiveness and progression, worsened prognosis and increased thromboembolism (VTE). Activation of protease activated receptors by TF:FVIIa complex leads to increases in IL-8, VEGF and other invasiveness promoting factors. PCI-27483 (P), a selective FVIIa inhibitor, reduced pancreatic adenocarcinoma (PCa) xenograft growth in mice at doses producing 2.5 - 3.0 x PT changes. Methods: Escalating doses of P combined with gemcitabine (G) targeting peak (2 hr post) INR = 3.0 was studied in Phase I preceding randomization to G+P at the determined dose vs. G alone in Phase II. Eligible patients (pts) had measurable locally advanced or metastatic PCa, ECOG PS 0-1, and normal PT/aPTT, and no history of VTE. G was given IV at 1 G/m2 q wk X3 every 4 wks, and P was self-administered SC bid continuously. Tumor evaluation including spiral CTs were performed at baseline and q 8 wks. Results: In phase I, 8 pts wer...

British journal of haematology, 2018

Novel therapies with unique new targets are needed for patients who are relapsed/refractory to cu... more Novel therapies with unique new targets are needed for patients who are relapsed/refractory to current treatments for multiple myeloma. Ibrutinib is a first-in-class, once-daily, oral covalent inhibitor of Bruton tyrosine kinase, which is overexpressed in the myeloma stem cell population. This study examined various doses of ibrutinib ± low-dose dexamethasone in patients who received ≥2 prior lines of therapy, including an immunomodulatory agent. Daily ibrutinib ± weekly dexamethasone 40 mg was assessed in 4 cohorts using a Simon 2-stage design. The primary objective was clinical benefit rate (CBR; ≥minimal response); secondary objectives included safety. Patients (n = 92) received a median of 4 prior regimens. Ibrutinib + dexamethasone produced the highest CBR (28%) in Cohort 4 (840 mg + dexamethasone; n = 43), with median duration of 9·2 months (range, 3·0-14·7). Progression-free survival was 4·6 months (range, 0·4-17·3). Grade 3-4 haematological adverse events included anaemia (1...

Cancer research, Jan 15, 2015

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense stromal fibroinflammatory rea... more Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dense stromal fibroinflammatory reaction that is a major obstacle to effective therapy. The desmoplastic stroma comprises many inflammatory cells, in particular mast cells as key components of the PDAC microenvironment, and such infiltration correlates with poor patient outcome. Indeed, it has been hypothesized that stromal ablation is critical to improve clinical response in patients with PDAC. Ibrutinib is a clinically approved Bruton's tyrosine kinase inhibitor that inhibits mast cells and tumor progression in a mouse model of β-cell tumorigenesis. Here, we show that ibrutinib is highly effective at limiting the growth of PDAC in both transgenic mouse and patient-derived xenograft models of the disease. In these various experimental settings, ibrutinib effectively diminished fibrosis, extended survival, and improved the response to clinical standard-of-care therapy. Our results offer a preclinical rationale to imme...

The Journal of clinical investigation, Jan 3, 2014

Chronic graft-versus-host disease (cGVHD) is a life-threatening impediment to allogeneic hematopo... more Chronic graft-versus-host disease (cGVHD) is a life-threatening impediment to allogeneic hematopoietic stem cell transplantation, and current therapies do not completely prevent and/or treat cGVHD. CD4+ T cells and B cells mediate cGVHD; therefore, targeting these populations may inhibit cGVHD pathogenesis. Ibrutinib is an FDA-approved irreversible inhibitor of Bruton's tyrosine kinase (BTK) and IL-2 inducible T cell kinase (ITK) that targets Th2 cells and B cells and produces durable remissions in B cell malignancies with minimal toxicity. Here, we evaluated whether ibrutinib could reverse established cGVHD in 2 complementary murine models, a model interrogating T cell-driven sclerodermatous cGVHD and an alloantibody-driven multiorgan system cGVHD model that induces bronchiolar obliterans (BO). In the T cell-mediated sclerodermatous cGVHD model, ibrutinib treatment delayed progression, improved survival, and ameliorated clinical and pathological manifestations. In the alloantib...

Journal of Cellular Physiology, 1988

The effect of human tumor necrosis factor (TNF) on early-passage HL-60 cells was studied. A trans... more The effect of human tumor necrosis factor (TNF) on early-passage HL-60 cells was studied. A transient phase of increased [3H]thymidine (TdR) incorporation was noted at 20-24 hr of exposure to TNF. This increase was disproportionate to the much slighter stimulation of the percentage of S-phase cells, which was measured by flow cytometry. Evidence for increased metabolic trapping of [3H]TdR following TNF treatment was apparent from whole cell uptake experiments. The salvage pathway enzyme TdR kinase was therefore measured and was found to be elevated comparably to [3H]TdR uptake. The mechanism of TNF regulation of TdR kinase was further investigated by a series of combination treatment experiments using other biologic factors and pharmacologic inhibitors of various intracellular steps. The response to TNF was not potentiated or reproduced by IL-1, IL-2, IL-3, IL-4, G-CSF, M-CSF, GM-CSF or alpha- or gamma-interferon. Blockers of early signal transduction steps, including H7, W7, sphingosine, and pertussis toxin, failed to inhibit TNF stimulation of [3H]TdR incorporation. mRNA synthesis inhibition with alpha-amanitin blocked this TNF effect, as did cAMP but not cGMP analogues. A sensitizing effect was noted with amiloride or cytochalasin B, characterized by greater relative increases of [3H]TdR incorporation and TdR kinase activity in response to TNF. In the presence of cytochalasin B, TNF treatment resulted in no change or slight decreases in the percentage of S-phase cells. Regulation of TdR kinase could thereby be dissociated from the usual cell cycle control. This study thus documents a unique example of stimulation of thymidine salvage pathway metabolism by a biologic factor, dissociable from overall cell cycle regulation.

Cancer Research, Jun 1, 1981

Determination of levels and isozymic patterns of protein kinase activities was performed upon ext... more Determination of levels and isozymic patterns of protein kinase activities was performed upon extracts from two human leukemia cell lines (K562 and HL-60) and blast cells from five untreated patients with acute myeloblastic leukemia and com pared to activities from normal human peripheral blood granulocytes and bone marrow samples enriched for proliferative myeloid cells. The leukemic cells studied were found to have higher specific activities of cytosol cyclic adenosine 3':5'monophosphate (cAMP)-independent casein kinase and lower activation by cAMP of their cytosol histone kinase compared to the normal myeloid cells studied. Diethylaminoethyl-cellulose chromatography revealed correspondingly higher amounts of cAMP-independent protein kinase isoenzymes (two casein ki nase and one histone kinase peaks) in the leukemic cells, as well as altered ratios of the two cAMP-dependent isozymes. Casein phosphorylating activities extracted from the nuclei of the leukemic cell lines were also high compared to normal myeloid cells. Further purification and estimation of molecular weights of the isoenzymes present in leukemia were accom plished by gel filtration, using Sephacryl S-200. Resolution of the acute myeloblastic leukemia cell line nuclear casein kinase activity into two peaks was also thereby accomplished. The nuclear peaks eluted earlier than the corresponding cytoplasmic peaks; thus, the nuclear isoenzymes may not be identical to those from the cytoplasm. The increased protein kinase activity noted in such cells may be an important biochemical concomitant of transformation. stitute, Kirtland Air Force Base, Albuquerque. N. M. 87116. " The abbreviations used are: cAMP, cyclic adenosine 3':5'-monophosphate; AML, acute myeloblastic leukemia; PBS, phosphate buffered saline [0.118 M NaCI-0.01 M Na2HPO4 • NaH2PO4 (pH 7.4)]; HB, hypotonie buffer[0.005 MKH2PO4 • K2HPO4 (pH 7.5HO% glycerol-0.1% 2-mercaptoethanol];

Cancer treatment reports

In an attempt to improve remissions and survivals in previously treated patients with adult acute... more In an attempt to improve remissions and survivals in previously treated patients with adult acute leukemia, we gave Adriamycin, vincristine, and prednisone for induction therapy, followed by 6-mercaptopurine and methotrexate for maintenance therapy to patients attaining complete remission (CR). The study group consisted of 18 patients with acute myeloblastic leukemia (AML), ten with acute lymphoblastic leukemia, and one with acute undifferentiated leukemia. Only one patient had previously received Adriamycin. Overall, there were ten CRs and two partial remissions. The five CRs and one partial remission in patients with AML occurred among those with one prior induction attempt; none of the eight AML patients with more than one prior induction attempt responded. The actuarial median duration of CR was 15 weeks and was similar for AML and acute lymphoblastic leukemia patients. Responders had a longer median survival (30 weeks) than nonresponders (9 weeks). Thus, although a reasonable number of responses in previously treated patients were obtained with this program, improvements in maintenance therapy are clearly needed.

Western Journal of Medicine

Because no conclusive evidence as to the efficacy of maintenance chemotherapy in acute myelogenou... more Because no conclusive evidence as to the efficacy of maintenance chemotherapy in acute myelogenous leukemia (AML) existed, a study to obtain such information was done. Twenty-six adult patients with AML in whom complete remission had been achieved following induction chemotherapy were randomly assigned to receive either maintenance chemotherapy consisting of cytarabine and 6-thioguanine for two days each month or to receive no maintenance therapy. The data showed a significant difference in remission duration between the two groups, with median remission lengths for the maintained and unmaintained groups being 10.3 and 6.7 months, respectively (p<.05). In 46 percent of the maintained patients there were remissions lasting longer than 11 months, whereas in none of the unmaintained patients was there such a prolonged remission. No significant drug-induced toxicity was observed. That the prolonged exposure to these chemotherapeutic agents, which were also used in our induction program, did not adversely affect the rate of successful reinduction therapy was shown by identical 50 percent complete remission rates for second inductions in both groups. In patients with palpable splenomegaly at the time of diagnosis, there was no prolongation of remission with maintenance therapy. These data indicate the potential utility of maintenance chemotherapy for prolonging remission duration in acute myelogenous leukemia. DESPITE a lack of conclusive evidence, it has been assumed that maintenance chemotherapy is useful in the management of acute myelogenous leukemia (AML). This assumption is related to