Distinct mutation spectrum, clinical outcome and therapeutic responses of typical complex/monosomy karyotype acute myeloid leukemia carrying TP53 mutations.

The present study aimed to define a subtype of complex/monosomal karyotype (CK/MK) acute myeloid leukemia (AML) by its distinct clinical features, p53 signaling and responses to p53 targeting agents. Ninety-eight young adults (range: 21-60 years; median: 49 years) with CK/MK AML were studied. They received standard induction, consolidation and allogeneic hematopoietic stem cell transplantation from siblings or matched unrelated donors if available. Chromosomal abnormalities most commonly affected chromosome 5 (30%), 7 (22%) and 17 (21%). Next generation sequencing of a 54-myeloid gene panel were available in 76 patients. Tumor protein 53 (TP53) mutations were most common (49%) and associated with the presence of -5/5q- (P < .001) and -17/17p- (P < .001), but not -7/7q- (P = .370). This "typical" CK/MK AML subtype was associated with significantly lower presenting white cell counts, higher number of karyotypic abnormalities, and inferior leukemia-free and overall survivals, compared with CK/MK AML without the typical features. Blood or bone marrow samples from typical CK/MK AML patients showed defective p53 signaling upon induction by etoposide. In vitro drug sensitivity analysis showed that they were sensitive to APR-246 that targeted mutant p53, but resistant to MDM2 antagonist MI-77301. Novel therapeutic strategies targeting TP53 mutations in CK/MK AML should be developed and tested in clinical trials.

Rapid versus gradual lung function decline in bronchiolitis obliterans syndrome after haematopoietic stem cell transplantation is associated with survival outcome.

BACKGROUND AND OBJECTIVE: Bronchiolitis obliterans syndrome (BOS) after haematopoietic stem cell transplantation (HSCT) presents with lung function decline. The pattern of lung function decline after BOS diagnosis could impact prognostication of BOS as a complication after HSCT. The aim of this study was to assess the impact of lung function decline on overall survival (OS) in BOS subjects. METHODS: Subjects with BOS were compared to those without BOS and matched for age, gender, primary diagnoses, conditioning regimes and chronic graft versus host disease. Lung function tests at baseline, at BOS diagnosis and every 3 months after HSCT were evaluated. RESULTS: Of the 1461 subjects undergoing allogeneic HSCT (allo-HSCT) between 1998 and 2015, 95 (6.5%) were diagnosed with BOS. A total of 159 matched HSCT recipients without BOS were identified. A 25% decline in FEV1 within the first 3 months after BOS diagnosis would separate BOS subjects into a subgroup with initial rapid decline and another subgroup with initial gradual decline in lung function. The rapid decline group showed lower subsequent lung function parameters and significantly worse OS compared to the gradual decline group (P = 0.013). CONCLUSION: Post-HSCT BOS subjects with initial rapid lung function decline within 3 months after BOS diagnosis will have significantly poorer lung function and worse OS compared to those with initial gradual decline in lung function after BOS diagnosis. HSCT BOS patients with rapid initial decline in lung function warrant closer monitoring for the development of other post-HSCT complications that could affect their survival.

Gene hypermethylation in multiple myeloma: lessons from a cancer pathway approach.

Multiple myeloma (MM) is an incurable plasma cell neoplasm. Pathogenesis involves upregulation of D-type cyclins and activation of oncogenes, but little is known about the role of tumor suppressor genes. Gene hypermethylation is an alternative mechanism of tumor suppressor gene inactivation. Various approaches have been used to elucidate the role of gene hypermethylation in MM, including a candidate gene approach, microarray approach for genes upregulated by hypomethylating agents, and a cancer pathway approach, which enables a comprehensive picture of the involvement of multiple tumor suppressor genes in MM. Based on the cancer pathway approach, the following data on the involvement of cell cycle control, intrinsic tumor suppressor, and cell signaling were derived. First, among the INK4 and CIP/KIP families of cyclin-dependent kinase inhibitors, only CDKN2B and CDKN2A are frequently hypermethylated. Second, methylation of SHP1 and soluble Wnt inhibitors is associated with constitutive activation of JAK/STAT and Wnt signaling. Importantly, downregulation of the signaling pathways can be restored by demethylation and re-expression of SHP1 and soluble Wnt inhibitors, which is potentially important therapeutically. Third, of the tumor suppressor genes involved in the DAPK/P14/HDM2/P53/Apaf-1 pathway, only DAPK is frequently methylated, which appeared to be an adverse prognostic factor to survival. Lastly, apart from being implicated in the progression from monoclonal gammopathy of unknown significance to MM, aberrant gene promoter methylation might also account for late disease progression in MM. Future studies are needed to delineate the biologic consequence of gene hypermethylation, the prognostic effect of gene methylation, and the possibility of hypomethylation therapy.

Effects of arsenic trioxide on the cellular proliferation, apoptosis and differentiation of human neuroblastoma cells.

A human neuroblastoma cell line, IMR-32, was used as an in vitro model system to study the effects of arsenic trioxide (As(2)O(3)) on aggressive human neuroblastoma. From 0.5 micro M, As(2)O(3) exhibited a dose-dependent inhibition of IMR-32 proliferation. At concentrations of 1.5 micro M or higher, As(2)O(3) up-regulated caspase 3, leading to cellular apoptosis. However, neurofilament-200 kDa and tyrosine hydroxylase were not up-regulated, implying minimal neuronal differentiation. Concomitantly, TrkA was down-regulated and TrkB up-regulated. Pre-treatment with the protein kinase C (PKC) inhibitor Ro-31-8220 partially blocked As(2)O(3)-mediated apoptosis, meaning that As(2)O(3) might signal through PKC activation. The results suggest that As(2)O(3) might be potentially useful in neuroblastoma.

Polymorphisms of the GSTM1, GSTP1, MPO, XRCC1, and NQO1 genes in Chinese patients with non-small cell lung cancers: relationship with aberrant promoter methylation of the CDKN2A and RARB genes.

An association between functional polymorphisms of genes resulting in decreased detoxification of carcinogens or DNA repair and aberrant promoter methylation is an attractive hypothesis in lung carcinogenesis. The genotypes at polymorphic sites of the glutathione S-transferase (GST) M1 (null/wildtype) and P1 (nucleotide 2627 A/G), myeloperoxidase (MPO) (nucleotide -463 G/A), X-ray repair cross-complementing group 1 (XRCC1) (nucleotides 26304 C/T; 28152 G/A), and NADPH quinine oxidoreductase (NQO1) (nucleotide 609 C/T) genes in 75 Chinese patients with non-small cell lung cancer (NSCLC) were characterized with polymerase chain reaction-restriction fragment length polymorphism. Results were correlated with aberrant methylation of the CDKN2A (alias p16(INK4A)), retinoic acid receptor beta (RARB), methylguanine-DNA methyltransferase (MGMT), and death-associated-protein (DAP) kinase genes in the tumors. In comparison with an age-matched control, none of the polymorphisms were associated with increased lung cancer risks. In male patients, however, the MPO -463 GG homozygous state was associated with CDKN2A (alias p16(INK4A)) methylation (odds ratio OR=3.63, 95% confidence interval CI=1.26-10.51), and the XRCC1 26304 T allele in the heterozygous/homozygous state was associated with methylation of CDKN2A (OR=6.13, 95% CI=1.55-24.16) and RARB (OR=7.67, 95% CI=1.62-36.18). In female patients, the GSTP1 G allele in the heterozygous/homozygous state was associated with RARB methylation (OR=18.0, 95% CI=0.76-427.29). These results showed that functional deficiencies in metabolic pathways that protect cells from carcinogen induced DNA damage might be linked to aberrant promoter methylation of the CDKN2A and RARB genes during lung carcinogenesis.

Aberrant promoter methylation in Chinese patients with non-small cell lung cancer: patterns in primary tumors and potential diagnostic application in bronchoalevolar lavage.

This study was aimed at defining patterns of aberrant gene methylation in non-small cell lung cancer (NSCLC) in Chinese patients and its use in detecting cancer cells in bronchoalveolar lavage (BAL). The methylation-specific PCR (MSP) was used to study methylation of the p16, retinoic acid receptor-beta (RARbeta), death-associated protein (DAP) kinase, and O(6)-methylguanine-DNA-methyltransferase (MGMT) genes in 75 NSCLCs [44 adenocarcinomas and 31 squamous cell carcinomas (SCCs)] and 68 BALs from suspected lung cancers. More females had adenocarcinoma than SCC (11 of 44 versus 2 of 31, P = 0.04). Aberrant methylation in at least one gene was found in 63 of 75 (84%) NSCLCs. p16, RARbeta, DAP kinase, and MGMT methylation was similar in adenocarcinoma and SCC. However, females with NSCLC showed more frequent p16 methylation than males (12 of 13 versus 36 of 62, P = 0.02), because of more frequent p16 methylation in female adenocarcinomas (10 of 11 versus 17 of 33, P = 0.02). This sexual difference was not observed in RARbeta, DAP kinase, and MGMT. At 92%, the frequency of p16 methylation in Chinese female NSCLC is one of the highest known. For BAL, MSP and cytological analysis showed concordant and discordant results in 25 of 68 and 43 of 68 samples. Of 41 MSP+/cytology- cases, 35 were eventually shown to have malignant lung lesions, 4 were at high risk but had no evidence of lung cancer, and 2 were lost to follow-up. There were two MSP-/cytology+ cases. Frequent gene methylations were seen in Chinese NSCLC patients. More frequent p16 methylation was seen in female patients. MSP is a useful molecular adjunct for cancer cell detection in BAL samples.

Hepatitic graft-versus-host disease after hematopoietic stem cell transplantation: clinicopathologic features and prognostic implication.

BACKGROUND: Graft-versus-host disease (GVHD) of the liver after allogeneic hematopoietic stem cell transplantation classically presents with increased bilirubin and alkaline phosphatase (ALP) levels. A hepatitic variant was recently recognized, with more than a 10-fold increase in aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. This study defines the clinicopathologic features and prognostic implications of hepatitic GVHD compared with classic liver GVHD. METHOD: A total of 38 cases of hepatitic GVHD, 68 cases of classic liver GVHD, and 13 cases of hepatitis B virus (HBV)-related hepatitis after hematopoietic stem cell transplantation were analyzed. RESULTS: Hepatitic GVHD cases showed significantly higher ALT, AST, and ALP levels compared with classic liver GVHD cases (at onset, mean ALT: 154 vs. 58 U/L, P <0.001; AST: 167 vs. 77 U/L, P <0.001; at peak, ALT: 435 vs. 112 U/L, P <0.001; AST: 587 vs. 150 U/L, P <0.001; ALP: 416 vs. 238 U/L, P =0.001), persisted longer (74 vs. 32 days, P =0.006), and showed more lobular pathologic changes in biopsy (lobular changes: 16/26 vs. 4/19, P =0.007; hepatocyte necrosis: 16/26 vs. 6/19, P =0.008; acidophil bodies: 15/26 vs. 4/19, P =0.014) but less cholestasis (4/26 vs. 8/19, P =0.045). However, cumulative doses of immunosuppressants prescribed, response, and outcome were similar. Compared with hepatitic GVHD, HBV-related hepatitis occurred later (95 vs. 184 days, P =0.049), but clinical and biochemical profiles were similar, requiring liver biopsies for their distinction. CONCLUSIONS: Hepatitic and classic liver GVHD differed biochemically and pathologically, but these differences showed no obvious impact on outcome. The distinction of hepatitic GVHD from other hepatitis is mandatory.

Caveolin-1 gene is coordinately regulated with the multidrug resistance 1 gene in normal and leukemic bone marrow.

Caveolin-1 is a structural protein that may function as a scaffold for plasma membrane proteins, one of which is P-glycoprotein (P-gp), product of the multidrug resistance-1 (MDR-1) gene. We tested the hypothesis that if P-gp and caveolin-1 interacted physically, caveolin-1 and MDR-1 genes might be coordinately regulated; by quantifiying their gene expression with quantitative-polymerase chain reaction. MDR-1 and caveolin-1 gene expressions were normalized to an internal control and related to a fixed calibrator by a comparative cycle-threshold (CT) method. In four different groups of marrow samples (20 normal, 56 acute myeloid leukemias (AML) at diagnosis, 48 AMLs at relapse, and 51 regenerating marrows), caveolin-1 and MDR-1 gene expressions were positively correlated. In 65 samples with MDR-1 over-expression, caveolin-1 and MDR-1 expressions were also correlated. The coordinate expression of caveolin-1 and MDR-1 suggests that they may either interact physically, or are involved in the same aberrant pathway(s) activated during MDR-1 up-regulation.

T-cell large granular lymphocyte leukemia of donor origin after allogeneic bone marrow transplantation.

A 39-year-old man with chronic myeloid leukemia in accelerated phase underwent allogeneic bone marrow transplantation (BMT). At 6 months after BMT, lymphocytosis (WBC count, 23,100/microL [23.1 x 10(9)/L]; 80% (0.80) large granular lymphocytes [LGLs]) occurred. The LGLs were CD3+CD4-CD8+, with clonally rearranged T-cell receptor gamma gene, and of donor origin, as shown by analysis of polymorphic microsatellite markers. Epstein-Barr virus was not present. The diagnosis, therefore, was consistent with T-cell large granular lymphocytic (T-LGL) leukemia. Corticosteroids controlled the LGL count, but progressive pancytopenia led to death 4 months later. Retrospective analysis showed that the T-LGL leukemia apparently had arisen as early as 3 months after BMT. The distinguishing features of this case included donor origin, neoplastic nature, and the aggressive fatal outcome.

Differential effects of 9-cis, 13-cis and all-trans retinoic acids on the neuronal differentiation of human neuroblastoma cells.

A human neuroblastoma cell line IMR-32 was used as an in vitro model to examine three naturally occurring retinoic acid (RA) isomers, 9-cis (9c), 13-cis (13c) and all-trans (AT) RA, in mediating growth differentiation and neuronal differentiation. All RA isomers inhibited cellular proliferation, with 13c-RA being most effective. Cyclic AMP-responsive-element-binding-protein (CREB) was activated during RA treatment. AT-RA was a better differentiating agent in inducing the highest expression of the neurotrophic factor receptor TrkA. After prolonged RA treatment, the expression of RA receptors (RARs) was comparable for the three isomers, but retinoid X receptors (RXRs) were differentially regulated. These results imply that distinctive molecular pathways might be involved in the in vitro differentiation of neuroblastoma with different RA isomers.

Low frequency of FLT3 gene internal tandem duplication and activating loop mutation in therapy-related acute myelocyticleukemia and myelodysplastic syndrome.

FLT3 gene internal tandem duplication (ITD) and activating loop mutations (D835) were determined in 22 cases of therapy-related acute myelocytic leukemia/myelodysplastic syndrome (t-AML/MDS) and 102 cases of de novo AML/MDS. In t-AML/MDS, FLT3 ITD was absent, and D835 was found in only one case of therapy-related acute promyelocytic leukemia (APL). In de novo AML/MDS, however, FLT3 ITD and D835 were significantly more frequent (28 of 102 cases, P=0.024) and were associated with high peripheral blood and marrow blast counts. Our results suggest that different pathogenetic pathways might be involved in t-AML/MDS and de novo AML/MDS.

Aberrant gene promoter methylation in acute promyelocytic leukaemia: profile and prognostic significance.

Acute promyelocytic leukaemia (APL) has distinct clinicopathological and molecular features. However, the profile of aberrant gene promoter methylation is undefined. In this study, methylation-specific polymerase chain reaction (MSP) was used to define the methylation status of a panel of nine genes, comprising p15, p16, RARbeta, oestrogen receptor (ER), E-cadherin (E-CAD), p73, caspase 8 (CASP8), VHL and MGMT, in 29 patients with APL. Aberrant methylation of p15, ER, RARbeta, p16 and E-CAD occurred, respectively, in 23 (79%), 14 (48%), six (21%), six (21%) and two (7%) patients at diagnosis, but p73, VHL, CASP8 and MGMT were not methylated in any patients. There was methylation of one gene in 13 patients (45%), two genes in four patients (14%), three genes in six patients (21%) and four genes in three patients (10%). Concurrent methylation of two or more genes occurred in 13 patients (45%). No association was identified between gene methylation and presenting clinicopathological features. However, p15 methylation was significantly associated with an inferior disease-free survival (DFS, P = 0.008), and remained the only poor prognostic factor in multivariate analysis (P = 0.019). In APL, p15, p16, ER and RARbeta were most frequently methylated. This profile is distinct from other types of myeloid leukaemias. p15 methylation has a poor prognostic impact on DFS.

Aberrant promoter CpG methylation as a molecular marker for disease monitoring in natural killer cell lymphomas.

Natural killer (NK) cell lymphomas lack suitable clonal markers for tumour cell detection, making the monitoring of minimal residual lymphoma difficult. Aberrant promoter CpG methylation occurs frequently in NK cell lymphomas. The objective of this study was to assess the potential of aberrant methylation as a surrogate tumour marker. Twenty-five primary tumours and 105 serial biopsies taken at various time points after treatment were examined using a methylation-specific polymerase chain reaction (MSP) for a panel of genes, comprising p73, p16, hMLH1, RARbeta and p15, previously shown to be methylated in NK cell lymphomas. All samples underwent independent morphological examination, supplemented by immunostaining for CD56 and in-situ hybridization for Epstein-Barr-virus-encoded RNA. Primary tumours showed the frequent methylation of the genes p73 (92%), p16 (71%), hMLH1 (61%), RARbeta (56%) and p15 (48%). MSP results in serial post-treatment biopsies were correlated with clinicopathological findings. Results were concordant in 89 follow-up samples (18 samples, histology positive/MSP positive; 71 samples, histology negative/MSP negative) and discordant in 16. Fifteen samples were histology negative/MSP positive, and tumour involvement was subsequently confirmed (positive re-biopsies or relapses at the same sites), indicating that MSP was more sensitive for minimal lymphoma detection. One sample was histology positive/MSP negative; a subsequent histological review and continuous clinical remission of the patient did not support tumour involvement. Our findings suggest that MSP for aberrantly methylated genes is a potentially valuable molecular marker for detecting either residual or relapsed disease in NK cell lymphoma patients.

Squamous cell carcinoma of the tongue complicating chronic oral mucosal graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Two patients underwent allogeneic hematopoietic stem cell transplantation (HSCT) for acute myeloid leukemia. Chronic graft-versus-host disease (GVHD) developed, with persistent symptomatic oral lesions. At 2 and 6 years post-HSCT, both patients developed squamous cell carcinoma (SCC) of the tongue in areas previously involved by chronic GVHD. None had any known risk factor for SCC. Histologically, moderate to severe dysplasia was present in noncancerous oral mucosa. Oral SCC is rarely described after HSCT, and a review of the reported cases showed chronic GVHD to be a common risk, suggesting that the chronic inflammation associated with GVHD might be of pathogenetic significance.

Fludarabine, mitoxantrone and dexamethasone in the treatment of indolent B- and T-cell lymphoid malignancies in Chinese patients.

The treatment results of indolent lymphoid malignancies in Chinese are poorly reported. The efficacy of FND (fludarabine 25 mg/m2/d, x3; mitoxantrone 10 mg/m2/d, x1; dexamethasone 20 mg/d, x5; monthly cycles, x6) in 95 Chinese patients with indolent B-cell malignancies (at diagnosis: 55, relapse/refractory disease: 40) and nine Chinese patients with T-cell large granular lymphocyte leukaemia (T-LGL leukaemia) (at diagnosis: two, refractory disease: seven) was evaluated. For B-cell malignancies, the complete response (CR), partial response (PR) and overall response (OR) rates were 50.5%, 18% and 68.5% respectively. Better results were obtained for primary versus relapse/refractory disease (CR: 60% vs. 37.5%, P = 0.03; OR: 84% vs. 47.5%, P < 0.001; median progression-free survival (PFS): 44 months vs. 22 months; 2-year PFS: 66% vs. 47%, P = 0.039; overall survival (OS): not reached vs. 32%; 2-year OS: 92% vs. 58%, P < 0.001). Responsive patients (CR/PR) had a better median PFS (44 months vs. 5 months, P < 0.001) and OS (67 months vs. 13 months, P < 0.001) than unresponsive patients. For T-LGL leukaemia, the CR and molecular-remission rates were 56% and 67% (median follow-up: 23 months). FND is an active regimen for the treatment of indolent B- and T-cell malignancies in Chinese patients, with results comparable with Western patients with similar indolent lymphomas.

FLT-3 aberrations in acute promyelocytic leukaemia: clinicopathological associations and prognostic impact.

FLT-3 aberrations that occur as an internal tandem duplication (ITD) or a mutation at the activation-loop position 835, D835, are common in acute promyelocytic leukaemia (APL). We investigated the clinicopathological associations and prognostic impact of FLT-3 aberrations in a cohort of APL patients. FLT-3 exons 11 and 12 were amplified by polymerase chain reaction (PCR), and the ITD was recognized as an increase in the size of the PCR product. FLT-3 exon 17 was amplified, and D835 mutation was identified by loss of an EcoRV site, followed by DNA sequencing. Of 82 patients studied, FLT-3 aberrations were detected in 35 cases (43%) at diagnosis (ITD: 16; D835 mutation: 18; ITD + D835 mutation: 1). FLT-3 ITD, but not D835 mutations, was significantly associated with higher presentation white blood cell count (WBC) and microgranular morphology. Early/induction deaths were related to male sex and high presentation WBC. There was a trend for FLT-3 ITD to be associated with non-remission (P = 0.06). For disease-free survival, high WBC was the only significant adverse factor. Male sex, high WBC and FLT-3 ITD were significant adverse factors for overall survival. These findings have important implications on the possible use of FLT-3 inhibitors in the treatment of APL.