Comparison of BCR-ABL1 quantification in peripheral blood and bone marrow using an International Scale-standardized assay for assessment of deep molecular response in chronic myeloid leukemia.

Background Monitoring of molecular response (MR) using quantitative polymerase chain reaction (PCR) for BCR-ABL1 is a pivotal tool for guiding tyrosine kinase inhibitor therapy and the long-term follow-up of patients with chronic myeloid leukemia (CML). Results of MR monitoring are standardized according to the International Scale (IS), and specific time-dependent molecular milestones for definition of optimal response and treatment failure have been included in treatment recommendations. The common practice to use peripheral blood (PB) instead of bone marrow (BM) aspirate to monitor the MR monitoring in CML has been questioned. Some studies described differences between BCR-ABL1 levels in paired PB and BM specimens. Methods We examined 631 paired PB and BM samples from 283 CML patients in a retrospective single-center study using an IS normalized quantitative reverse transcription (qRT)-PCR assay for quantification of BCR-ABL1IS. Results A good overall concordance of BCR-ABL1IS results was found, a systematic tendency towards higher BCR-ABL1IS levels in PB was observed in samples of CML patients in a major MR. This difference was most pronounced in patients treated with imatinib for at least 1 year. Importantly, the difference resulted in a significantly lower rate of deep MR when BCR-ABL1IS was assessed in the PB compared to BM aspirates. Conclusions In summary, our data suggest that the classification of deep MR in patients with CML is more stringent in PB than in BM. Our study supports the current practice to primarily use PB for long-term molecular follow-up monitoring in CML.

Circulating Free Methylated Tumor DNA Markers for Sensitive Assessment of Tumor Burden and Early Response Monitoring in Patients Receiving Systemic Chemotherapy for Colorectal Cancer Liver Metastasis.

BACKGROUND: Neoadjuvant chemotherapy (neoCTx) followed by hepatic resection is the treatment of choice for patients with colorectal cancer liver metastasis (CLM). Treatment response is generally assessed using radiologic imaging after several cycles of chemotherapy. However, earlier assessment of response would be desirable since nonresponders could be switched early to an alternative chemotherapy regimen. Recent evidence suggests that circulating free methylated tumor DNA is a highly sensitive biomarker and may more accurately reflect tumor burden and treatment response than conventional markers for CRC. PATIENTS AND METHODS: Thirty-four patients with CLM who received neoCTx prior to intended hepatic resection were included in this prospective nonrandomized study. Peripheral blood plasma was collected at baseline and before each cycle of neoCTx and was then analyzed for aberrant methylation of 48 CRC-associated genes. Methylation marker levels were correlated with baseline tumor volume and treatment response and compared with the standard tumor markers CEA and CA 19-9. RESULTS: The methylation markers SEPT9, DCC, BOLL, and SFRP2 were present in all patients at baseline and displayed a stronger correlation with tumor volume than CEA and CA 19-9. Serial measurement of these methylation markers allowed for discrimination between operated and nonoperated patients already after 1 cycle of neoCTx with high sensitivity and specificity. The early dynamic changes of SEPT9 and DCC also seemed to correlate with pathohistological response. CONCLUSION: Our data suggest that serial measurements of CRC-associated methylation markers could be a particularly valuable tool for early response assessment in patients receiving neoCTx for CLM.

Phenotyping and Target Expression Profiling of CD34+/CD38- and CD34+/CD38+ Stem- and Progenitor cells in Acute Lymphoblastic Leukemia.

Leukemic stem cells (LSCs) are an emerging target of curative anti-leukemia therapy. In acute lymphoblastic leukemia (ALL), LSCs frequently express CD34 and often lack CD38. However, little is known about markers and targets expressed in ALL LSCs. We have examined marker- and target expression profiles in CD34+/CD38- LSCs in patients with Ph+ ALL (n = 22) and Ph- ALL (n = 27) by multi-color flow cytometry and qPCR. ALL LSCs expressed CD19 (B4), CD44 (Pgp-1), CD123 (IL-3RA), and CD184 (CXCR4) in all patients tested. Moreover, in various subgroups of patients, LSCs also displayed CD20 (MS4A1) (10/41 = 24%), CD22 (12/20 = 60%), CD33 (Siglec-3) (20/48 = 42%), CD52 (CAMPATH-1) (17/40 = 43%), IL-1RAP (13/29 = 45%), and/or CD135 (FLT3) (4/20 = 20%). CD25 (IL-2RA) and CD26 (DPPIV) were expressed on LSCs in Ph+ ALL exhibiting BCR/ABL1p210, whereas in Ph+ ALL with BCR/ABL1p190, LSCs variably expressed CD25 but did not express CD26. In Ph- ALL, CD34+/CD38- LSCs expressed IL-1RAP in 6/18 patients (33%), but did not express CD25 or CD26. Normal stem cells stained negative for CD25, CD26 and IL-1RAP, and expressed only low amounts of CD52. In xenotransplantation experiments, CD34+/CD38- and CD34+/CD38+ cells engrafted NSG mice after 12-20 weeks, and targeting with antibodies against CD33 and CD52 resulted in reduced engraftment. Together, LSCs in Ph+ and Ph- ALL display unique marker- and target expression profiles. In Ph+ ALL with BCR/ABL1p210, the LSC-phenotype closely resembles the marker-profile of CD34+/CD38- LSCs in chronic myeloid leukemia, confirming the close biologic relationship of these neoplasms. Targeting of LSCs with specific antibodies or related immunotherapies may facilitate LSC eradication in ALL.

Circulating cell-free DNA in plasma of colorectal cancer patients - A potential biomarker for tumor burden.

BACKGROUND: Measurement of cell-free DNA (cfDNA) in plasma - the so called liquid biopsy - is a novel method for early detection of cancer. Necrotic cancer cells release various DNA fragments that can be detected in plasma or serum. The aim of our study was to investigate the concentration of circulating ALU115, LINE79 and LINE297 fragments in plasma from venous and arterial blood of colorectal cancer (CRC) patients before, during and 5 days after surgical intervention. PATIENTS AND METHODS: Thirty patients (16 female, 14 male, median age 56 years), undergoing surgery for colorectal and appendix cancer, and 17 healthy volunteers were included in this study. Plasma samples were collected from patients and healthy individuals. Qualitative polymerase chain reaction (PCR) and quantitative real-time PCR analyses were conducted using specific primers for ALU115, LINE79 and LINE297. RESULTS: The concentration of ALU115 was significantly increased in plasma of CRC patients compared to the control group (p = 0.002). Interestingly, the concentration of LINE297 was significantly higher in healthy individuals than patients (p = 0.031). We did not find any difference regarding LINE79 between the two groups (p = 0.893). The total cfDNA concentration was slightly increased in plasma after the surgery (p < 0.056), however, the difference was not significant. Interestingly, no correlation was detected between the peritoneal carcinosis index (PCI) and conventional tumor markers. CONCLUSION: According to our results, the concentration of ALU115 in cfDNA could be a potential biomarker for diagnosis of CRC. LINE79 or the conventional tumor markers CEA or CA19-9 do not seem useful for the detection of malignant tumors. Whether the amount of LINE297 in cfDNA represents a reliable biomarker for early diagnosis has yet to be confirmed.

Swarm Intelligence-Enhanced Detection of Non-Small-Cell Lung Cancer Using Tumor-Educated Platelets.

Blood-based liquid biopsies, including tumor-educated blood platelets (TEPs), have emerged as promising biomarker sources for non-invasive detection of cancer. Here we demonstrate that particle-swarm optimization (PSO)-enhanced algorithms enable efficient selection of RNA biomarker panels from platelet RNA-sequencing libraries (n = 779). This resulted in accurate TEP-based detection of early- and late-stage non-small-cell lung cancer (n = 518 late-stage validation cohort, accuracy, 88%; AUC, 0.94; 95% CI, 0.92-0.96; p < 0.001; n = 106 early-stage validation cohort, accuracy, 81%; AUC, 0.89; 95% CI, 0.83-0.95; p < 0.001), independent of age of the individuals, smoking habits, whole-blood storage time, and various inflammatory conditions. PSO enabled selection of gene panels to diagnose cancer from TEPs, suggesting that swarm intelligence may also benefit the optimization of diagnostics readout of other liquid biopsy biosources.

TKI rotation-induced persistent deep molecular response in multi-resistant blast crisis of Ph+ CML.

In chronic myeloid leukemia (CML) resistance against one or more BCR-ABL1 tyrosine kinase inhibitors (TKI) remains a clinical challenge. Preclinical data suggest that TKI combinations may overcome resistance. We report on a heavily pre-treated 78 year-old female patient with CML who developed multi-resistant blast crisis with bone marrow fibrosis and a Ph- clone. Treatment with ponatinib resulted in blast cell clearance, decrease in fibrosis, and disappearance of BCR-ABL1, but also in severe thrombocytopenia with bleedings requiring platelet transfusions. We therefore switched from ponatinib to bosutinib. During bosutinib, platelet counts recovered. However, after 6 months, BCR-ABL1 mRNA levels increased to > 1%. Therefore, we ´switched back´ to ponatinib, and this was again followed by disappearance of BCR-ABL1 and a decrease in platelets. During the next 2 years, we applied ponatinib and bosutinib in continuous rotation-cycles and added hydroxyurea in order to suppress all sub-clones and to balance between efficacy and potential side effects following the principle of personalized medicine. With this approach the patient remained in complete molecular response and reached normal blood counts and a normal quality of life without vascular or other side effects. In conclusion, TKI rotation is a novel potent approach to suppress multiple resistant sub-clones and to balance between clinical efficacy and side effects in patients with advanced CML. Clinical trials are now warranted to show that TKI-rotation is in general safe and effective in these patients.

Identification of CD25 as STAT5-Dependent Growth Regulator of Leukemic Stem Cells in Ph+ CML.

PURPOSE: In chronic myelogenous leukemia (CML), leukemic stem cells (LSC) represent a critical target of therapy. However, little is known about markers and targets expressed by LSCs. The aim of this project was to identify novel relevant markers of CML LSCs. EXPERIMENTAL DESIGN: CML LSCs were examined by flow cytometry, qPCR, and various bioassays. In addition, we examined the multipotent CD25(+)CML cell line KU812. RESULTS: In contrast to normal hematopoietic stem cells, CD34(+)/CD38(-)CML LSCs expressed the IL-2 receptor alpha chain, IL-2RA (CD25). STAT5 was found to induce expression of CD25 in Lin(-)/Sca-1(+)/Kit(+)stem cells in C57Bl/6 mice. Correspondingly, shRNA-induced STAT5 depletion resulted in decreased CD25 expression in KU812 cells. Moreover, the BCR/ABL1 inhibitors nilotinib and ponatinib were found to decrease STAT5 activity and CD25 expression in KU812 cells and primary CML LSCs. A CD25-targeting shRNA was found to augment proliferation of KU812 cellsin vitroand their engraftmentin vivoin NOD/SCID-IL-2Rγ(-/-)mice. In drug-screening experiments, the PI3K/mTOR blocker BEZ235 promoted the expression of STAT5 and CD25 in CML cells. Finally, we found that BEZ235 produces synergistic antineoplastic effects on CML cells when applied in combination with nilotinib or ponatinib. CONCLUSIONS: CD25 is a novel STAT5-dependent marker of CML LSCs and may be useful for LSC detection and LSC isolation in clinical practice and basic science. Moreover, CD25 serves as a growth regulator of CML LSCs, which may have biologic and clinical implications and may pave the way for the development of new more effective LSC-eradicating treatment strategies in CML.

Increased expression of transient receptor potential canonical 6 (TRPC6) in differentiating human megakaryocytes.

Members of the transient receptor potential (TRP) family of cation conducting channels are found in several tissues and cell types where they have different physiological functions. The canonical TRP channel 6 (TRPC6) is present on the platelet membrane and appears to participate in calcium influx during platelet activation. However, limited information is available on the importance of TRPC channels in megakaryocytes (MKs), the precursor cells of platelets. We determined the mRNA and protein expression of TRPC family members and investigated the role of TRPC6 for proliferation and differentiation of human MKs derived from CD34+ progenitor cells. TRPC6 transcripts were highly expressed during the differentiation of MKs and TRPC6 protein was detectable in MK cytoplasm by confocal staining. TRPC6 channel activity was modulated by pharmacological approaches using flufenamic acid (FFA) for activation and SKF96365 for inhibition. Upon FFA stimulation in MKs, an increase in intracellular calcium was observed, which was blocked by SKF96365 at 10 µM concentration. Incubation of MKs with SKF96365 resulted in a reduction in thrombopoietin-stimulated cell proliferation. Our results suggest a role of TRPC6 in calcium homeostasis during MK development, particularly for cell proliferation.

Long-term treatment with imatinib results in profound mast cell deficiency in Ph+ chronic myeloid leukemia.

Although mast cells (MC) play an important role in allergic reactions, their physiologic role remains unknown. In mice, several models of MC-deficiency have been developed. However, no comparable human model is available. We examined the in vitro- and in vivo effects of the KIT-targeting drug imatinib on growth and development of human MC. Imatinib was found to inhibit stem cell factor (SCF)-induced differentiation of MC in long-term suspension cultures (IC50: 0.01 µM). Correspondingly, long-term treatment of chronic myeloid leukemia (CML) patients with imatinib (400 mg/day) resulted in a marked decrease in MC. In patients with continuous complete molecular response during therapy, bone marrow MC decreased to less than 5% of pre-treatment values, and also serum tryptase concentrations decreased significantly (pre-treatment: 32.0 ± 11.1 ng/ml; post-therapy: 3.4 ± 1.8, p<0.01). Other myeloid lineages, known to develop independently of KIT, were not affected by imatinib-therapy. Imatinib also produced a substantial decrease in MC-development in mice. However, no clinical syndrome attributable to drug-induced MC-deficiency was recorded in our CML patients. Together, imatinib suppresses MC production in vitro and in vivo. However, drug-induced MC depletion is not accompanied by adverse clinical events, suggesting that MC are less relevant to homeostasis in healthy tissues than we assumed so far.

Serum-tryptase at diagnosis: a novel biomarker improving prognostication in Ph(+) CML.

Basophilia is an established prognostic variable in Ph-chromosome+ chronic myeloid leukemia (CML). However, in CML, basophils are often immature and thus escape microscopic quantification. We have previously shown that tryptase is produced and secreted by immature CML basophils. In the current study, serum samples of 79 CML patients (chronic phase=CP, n=69; accelerated/blast phase=AP/BP, n=10) treated with BCR/ABL inhibitors, were analyzed for their tryptase content. Serum-tryptase levels at diagnosis were found to correlate with basophil counts and were higher in AP/BP patients (median tryptase: 29.9 ng/mL) compared to patients with CP (11.7 ng/mL; p<0.05). In 20/69 patients with CP, progression occurred. The progression-rate was higher in patients with tryptase >15 ng/mL (31%) compared to those with normal tryptase levels (9%, p<0.05). To validate tryptase as new prognostic variable, we replaced basophils by tryptase levels in the EUTOS score. This modified EUTOS-T score was found to predict progression-free and event-free survival significantly better, with p values of 0.000064 and 0.00369, respectively, compared to the original EUTOS score (progression-free survival: p=0.019; event-free survival: p=0.156). In conclusion, our data show that the serum-tryptase level at diagnosis is a powerful prognostic biomarker in CML. Inclusion of tryptase in prognostic CML scores may improve their predictive value.

Chronic mast cell leukemia (MCL) with KIT S476I: a rare entity defined by leukemic expansion of mature mast cells and absence of organ damage.

Mast cell leukemia (MCL) is a rare, life-threatening malignancy defined by a substantial increase in neoplastic mast cells (MCs) in bone marrow (BM) smears, drug-resistance, and a poor prognosis. In most patients, the survival time is less than 1 year. However, exceptional cases may present with a less malignant course. We report on a 49-year-old female patient with MCL diagnosed in 2013. In February 2013, first symptoms, including flushing, headache, and diarrhea, were recorded. In addition, mild anemia was detected. The disease was characterized by a massive increase in well-granulated, mature, and often spindle-shaped MCs (80 %) in BM smears. The serum tryptase level amounted to 332 ng/mL. Like in most other MCL patients, no skin lesions were detected. However, unlike in other patients, tryptase levels remained stable, and no other signs or symptoms of MCL-induced organ damage were found. Sequencing studies revealed an isolated S476I point mutation in KIT but no mutation in codon 816. The patient received histamine receptor blockers but refused cytoreductive therapy. After 9 months, still no progression or organ damage was detected. However, progression with transformation to acute MCL occurred after 12 months. We propose that the chronic type of MCL with stable conditions, absence of organ damage, and a mature MC morphology is recognized as a distinct entity that should be distinguished from the acute variant of MCL.

Biomarkers predictive of venous thromboembolism in patients with newly diagnosed high-grade gliomas.

BACKGROUND: High-grade gliomas (HGGs) are among the most prothrombotic of malignancies. METHODS: We performed a prospective study to investigate 11 potential biomarkers for prediction of venous thromboembolism (VTE) in newly diagnosed HGG patients who had undergone a neurosurgical intervention. In addition, we tested 2 VTE risk assessment models (RAMs). The strongest predictors of VTE, which were identified by statistical forward selection, were used for the first RAM. The parameters used for the second RAM were both predictive of VTE and available in routine clinical practice. RESULTS: One hundred forty-one HGG patients were included in this study, and 24 (17%) of them developed VTE during follow-up. An association with the risk of future VTE was found for the following parameters: leukocyte count, platelet count, sP-selectin, prothrombin-fragment 1 + 2, FVIII activity, and D-dimer. The first RAM included low platelet count (<25th percentile of the study population) and elevated sP-selectin (≥75th percentile). The cumulative VTE probability after 12 months was 9.7% for score 0 (n = 76), 18.9% for score 1 (n = 59), and 83.3% for score 2 (n = 6). The second RAM included low platelet count (<25th percentile), elevated leukocyte count, and elevated D-dimer (≥75th percentile). The probability of VTE was 3.3% for score 0 (n = 63), 23.0% for score 1 (n = 53), and 37.7% for score 2 (n = 22) or score 3 (n = 3). CONCLUSIONS: We identified biomarkers suitable for assessing the VTE risk in newly diagnosed HGG patients. The application of 2 RAMs allowed identification of patients at high risk of developing VTE. We could also define patients at low risk of VTE, who would most probably not benefit from extended primary thromboprophylaxis.

Dipeptidylpeptidase IV (CD26) defines leukemic stem cells (LSC) in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a stem cell (SC) neoplasm characterized by the BCR/ABL1 oncogene. Although mechanisms of BCR/ABL1-induced transformation are well-defined, little is known about effector-molecules contributing to malignant expansion and the extramedullary spread of leukemic SC (LSC) in CML. We have identified the cytokine-targeting surface enzyme dipeptidylpeptidase-IV (DPPIV/CD26) as a novel, specific and pathogenetically relevant biomarker of CD34(+)/CD38(─) CML LSC. In functional assays, CD26 was identified as target enzyme disrupting the SDF-1-CXCR4-axis by cleaving SDF-1, a chemotaxin recruiting CXCR4(+) SC. CD26 was not detected on normal SC or LSC in other hematopoietic malignancies. Correspondingly, CD26(+) LSC decreased to low or undetectable levels during successful treatment with imatinib. CD26(+) CML LSC engrafted NOD-SCID-IL-2Rγ(-/-) (NSG) mice with BCR/ABL1(+) cells, whereas CD26(─) SC from the same patients produced multilineage BCR/ABL1(-) engraftment. Finally, targeting of CD26 by gliptins suppressed the expansion of BCR/ABL1(+) cells. Together, CD26 is a new biomarker and target of CML LSC. CD26 expression may explain the abnormal extramedullary spread of CML LSC, and inhibition of CD26 may revert abnormal LSC function and support curative treatment approaches in this malignancy.

FLAG-induced remission in a patient with acute mast cell leukemia (MCL) exhibiting t(7;10)(q22;q26) and KIT D816H.

Mast cell leukemia (MCL) is a life-threatening disease associated with high mortality and drug-resistance. Only few patients survive more than 12 months. We report on a 55-year-old female patient with acute MCL diagnosed in May 2012. The disease was characterized by a rapid increase in white blood cells and mast cells (MC) in the peripheral blood, and a rapid increase of serum tryptase levels. The KIT D816H mutation was detected in the blood and bone marrow (BM). Induction chemotherapy with high-dose ARA-C and fludarabine (FLAG) was administered. Unexpectedly, the patient entered a hematologic remission with almost complete disappearance of neoplastic MC and a decrease of serum tryptase levels to normal range after 2 cycles of FLAG. Consecutively, the patient was prepared for allogeneic stem cell transplantation. However, shortly after the third cycle of FLAG, tryptase levels increased again, immature MC appeared in the blood, and the patient died from cerebral bleeding. Together, this case shows that intensive chemotherapy regimens, like FLAG, may induce remission in acute MCL. However, treatment responses are short-lived and the overall outcome remains dismal in these patients. We propose to separate this acute type of MCL from more subacute or chronic variants of MCL.

Mean platelet volume predicts outcome in patients with asymptomatic carotid artery disease.

BACKGROUND AND OBJECTIVE: Platelets play a pivotal role in atherothrombosis and are potentially involved in the pathogenesis of atherosclerosis. We investigated whether mean platelet volume (MPV) predicts clinical outcome and progression of atherosclerosis in patients with asymptomatic carotid artery disease. METHODS: We studied 1006 of 1268 prospectively collected consecutive patients with asymptomatic carotid atherosclerosis who were evaluated by duplex sonography. Patients were followed up clinically for the occurrence of a major adverse cardiovascular event (MACE), a composite of myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft, stroke and death. RESULTS: During a median follow-up of 3.1 years (interquartile range, 2.5-3.5), a total of 316 (31.5%) MACEs were recorded. Increased levels of MPV were significantly associated with increased risk of the occurrence of MACEs (adjusted hazard ratio [HR] for an increase in one standard deviation [SD] of MPV 1.22, confidence interval [CI] 1.05-1.35, P < 0.01). Patients with MPV levels above 11.8 femtolitre (= fifth quintile) had a significantly higher event rate (41.3% vs. 29.3%, P < 0.001) with an adjusted HR for MACEs of 1.65 (95% CI 1.26-2.16, P < 0.001) compared with patients with MPV levels in the first to fourth quintile. No significant association was found between baseline MPV levels with either baseline degree or progression during a 6-month follow-up of carotid stenosis. CONCLUSION: Mean platelet volume was independently and significantly associated with adverse cardiovascular outcome in patients with asymptomatic carotid atherosclerosis.

Morphine decreases clopidogrel concentrations and effects: a randomized, double-blind, placebo-controlled trial.

OBJECTIVES: This study sought to examine the possible drug-drug interactions between clopidogrel and morphine. BACKGROUND: Because morphine-the recommended treatment for pain of myocardial infarction-is associated with poor clinical outcome, we hypothesized that morphine lowers the plasma levels of clopidogrel active metabolite as well as its effects on platelets. METHODS: Twenty-four healthy subjects received a loading dose of 600 mg clopidogrel together with placebo or 5 mg morphine intravenously in a randomized, double-blind, placebo-controlled, cross-over trial. Pharmacokinetics was determined by liquid chromatography tandem mass spectrometry, and clopidogrel effects were measured by platelet function tests. RESULTS: Morphine injection delayed clopidogrel absorption (p = 0.025) and reduced the area under the curve levels of its active metabolite by 34% (p = 0.001). Morphine delayed the maximal inhibition of platelet aggregation on average by 2 h (n = 24; p < 0.001). Residual platelet aggregation was higher 1 to 4 h after morphine injection (n = 24; p < 0.005). Furthermore, morphine delayed the inhibition of platelet plug formation under high shear rates (P2Y-Innovance; n = 21; p < 0.004) and abolished the 3-fold prolongation in collagen adenosine diphosphate-induced closure times seen in extensive and rapid metabolizers (n = 16; p = 0.001). CONCLUSIONS: Morphine delays clopidogrel absorption, decreases plasma levels of clopidogrel active metabolite, and retards and diminishes its effects, which can lead to treatment failure in susceptible individuals. (Drug/Drug Interactions of Aspirin and P2Y12-inhibitors; NCT01369186).

Long-lasting complete response to imatinib in a patient with systemic mastocytosis exhibiting wild type KIT.

Systemic mastocytosis (SM) is a hematopoietic disorder characterized by abnormal expansion of mast cells (MCs) in visceral organs. The skin is involved in most cases. In adult patients the transforming KIT mutation D816V is usually present and confers resistance against imatinib. Therefore, imatinib is not recommended for patients with KIT D816V+ SM. Nonetheless, imatinib may work in patients with SM lacking KIT D816V. However, little is known about long-term efficacy and safety of this drug in SM. We report on a 62-year-old female patient with indolent SM (ISM) who suffered from severe debilitating skin involvement despite therapy with anti-mediator-type drugs, psoralen and ultraviolet-A-radiation. Although multifocal MC infiltrates were detected in the bone marrow by immunohistochemistry, no KIT mutation was found by sequencing analysis. In 2003, treatment with imatinib (induction, 400 mg/day; maintenance, 200 mg/day) was initiated. During therapy, skin lesions and tryptase levels decreased. Treatment was well tolerated without any side effects. After 10 years, skin lesions have disappeared and the tryptase level is within normal range. This case-study confirms the long-term efficacy and safety of imatinib in patients with SM lacking activating KIT mutations. Imatinib should be considered in select cases of SM in whom MCs exhibit wild-type KIT.

UDP-glucuronosyltransferase 2B17 genotype and the risk of lung cancer among Austrian Caucasians.

BACKGROUND: The enzyme uridine diphospho glucuronosyltansferase 2B17 (UGT2B17) glucuronidates several endogenous and exogenous compounds, including carcinogens from tobacco smoke like 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanl (NNAL). UGT2B17 shows a remarkable copy number variation (CNV) and an association between deletion genotype and increased risk of lung adenocarcinoma in women has been previously reported. METHODS: We investigated the UGT2B17 CNV by PCR in 453 Austrian lung cancer patients and in 449 healthy donors and analyzed the impact on lung cancer susceptibility and outcome. RESULTS: Copy numbers of UGT2B17 were 44.4% (+/+), 42.2% (+/-) and 13.5% (-/-) in lung cancer patients and 43.0% (+/+), 46.3% (+/-) and 10.7% (-/-) among healthy donors. The null genotype was not significantly more frequent among women with adenocarcinoma compared to healthy women (p=0.59). There was no association with overall survival (p=0.622) and no significant sex-associated (p=0.423) or histology-related impact on development of lung cancer. CONCLUSION: UGT2B17 deletion genotype was not associated with a significant risk for lung cancer development or outcome in our Central European patient cohort. Our study indicates that UGT2B17 is not a crucial factor in lung carcinogenesis among Caucasians and shows the importance of investigating such markers in large cohorts from different populations.

Overexpression of uridine diphospho glucuronosyltransferase 2B17 in high-risk chronic lymphocytic leukemia.

Uridine diphospho glucuronosyltransferase 2B17 (UGT2B17) glucuronidates androgens and xenobiotics including certain drugs. The UGT2B17 gene shows a remarkable copy number variation (CNV), which predisposes for solid tumors and influences drug response. Here, we identify a yet undescribed UGT2B17 mRNA overexpression in poor-risk chronic lymphocytic leukemia (CLL). In total, 320 CLL patients and 449 healthy donors were analyzed. High (above median) UGT2B17 expression was associated with established CLL poor prognostic factors and resulted in shorter treatment-free and overall survival (hazard ratio ([death] 2.18; 95% CI 1.18-4.01; P = .013). The prognostic impact of mRNA expression was more significant than that of UGT2B17 CNV. UGT2B17 mRNA levels in primary CLL samples directly correlated with functional glucuronidation activity toward androgens and the anticancer drug vorinostat (R > 0.9, P < .001). After treatment with fludarabine containing regimens UGT2B17 was up-regulated particularly in poor responders (P = .030). We observed an exclusive involvement of the 2B17 isoform within the UGT protein family. Gene expression profiling of a stable UGT2B17 knockdown in the CLL cell line MEC-1 demonstrated a significant involvement in key cellular processes. These findings establish a relevant role of UGT2B17 in CLL with functional consequences and potential therapeutic implications.