l-Dopa decarboxylase (DDC) constitutes an emerging biomarker in predicting patients’ survival with stomach adenocarcinomas

Purpose

Stomach adenocarcinoma represents a major health problem and is regarded as the second commonest cause of cancer-associated mortality, universally, since it is still difficult to be perceived at a curable stage. Several lines of evidence have pointed out that the expression of l-Dopa decarboxylase (DDC) gene and/or protein becomes distinctively modulated in several human neuroendocrine neoplasms as well as adenocarcinomas.

Methods

In order to elucidate the clinical role of DDC on primary gastric adenocarcinomas, we determined qualitatively and quantitatively the mRNA levels of the gene with regular PCR and real-time PCR by using the comparative threshold cycle method, correspondingly, and detected the expression of DDC protein by immunoblotting in cancerous and normal stomach tissue specimens.

Results

A statistically significant association was disclosed between DDC expression and gastric intestinal histotype as well as tumor localization at the distal third part of the stomach (p = 0.025 and p = 0.029, respectively). Univariate and multivariate analyses highlighted the powerful prognostic importance of DDC in relation to disease-free survival and overall survival of gastric cancer patients. According to Kaplan–Meier curves, the relative risk of relapse was found to be decreased in DDC-positive (p = 0.031) patients who, also, exhibited higher overall survival rates (p = 0.016) than those with DDC-negative tumors.

Conclusions

This work is the first to shed light on the potential clinical usefulness of DDC, as an efficient tumor biomarker in gastric cancer. The provided evidence underlines the propitious predictive value of DDC expression in the survival of stomach adenocarcinoma patients.     

Splenic marginal-zone lymphoma: one or more entities? A histologic, immunohistochemical, and molecular study of 42 cases

We analyzed 42 splenic marginal-zone lymphoma (SMZL) cases diagnosed on splenectomy specimens after established World Health Organization criteria. A predominantly nodular growth pattern was observed in 24 cases; the remainder showed predominantly (11/42) or exclusively (7/42) diffuse infiltration. Twenty-one cases showed the "classic" biphasic appearance; 13 cases exhibited marginal-zone morphology; finally, 8 cases were composed predominantly of small cells. CD21 and CD35 were expressed by 12/42 and 17/38 cases, respectively. DBA.44 was detected in 24/42 cases. Seventeen of 37 cases were surface IgD (SIgD)-positive. Twenty-one of 22 analyzed cases were SIgM-positive (12/21 coexpressed SIgD). Five of 37 cases were SIgG-positive. CD27 staining was observed in 21/35 cases; 7/18 CD27-positive cases coexpressed SIgD; 7/14 CD27-negative cases were SIgD-positive. Forty IGHV-D-J rearrangements were amplified in 34/42 cases: the IGHV4-34 gene predominated, followed by IGHV1-2. Using the 98% homology cut-off, 25/40 (62.5%) IGHV sequences were considered as "mutated": 10/11 cases with monomorphous, marginal-zone morphology were IGHV-mutated; in contrast, 4/6 cases with monomorphous, small-cell morphology were IGHV-unmutated. Five of 7 cases expressing IGHV1 subgroup genes had biphasic morphology, whereas 6/9 IGHV3-expressing cases had monomorphous, marginal-zone morphology. Most IGHV-mutated cases (14/20; 70%) were SIgD-negative; in contrast, 8/11 IGHV-unmutated cases expressed SIgD. CD27 was detected in 10/17 IGHV-mutated and 6/10 IGHV-unmutated cases. Seven of 11 CD27-negative cases were IGHV-mutated; 5/7 CD27-negative/IGHV-mutated cases expressed DBA.44. These results confirm the considerable histologic, immunohistochemical, and molecular heterogeneity of SMZL and indicate an origin from the diverse resident B-cell populations of the normal SMZ.     

Evidence for the significant role of immunoglobulin light chains in antigen recognition and selection in chronic lymphocytic leukemia

We analyzed somatic hypermutation (SHM) patterns and secondary rearrangements involving the immunoglobulin (IG) light chain (LC) gene loci in 725 patients with chronic lymphocytic leukemia (CLL). Important differences regarding mutational load and targeting were identified in groups of sequences defined by IGKV/IGLV gene usage and/or K/LCDR3 features. Recurrent amino acid (AA) changes in the IGKV/IGLV sequences were observed in subsets of CLL cases with stereotyped B-cell receptors (BCRs), especially those expressing IGHV3-21/IGLV3-21 and IGHV4-34/IGKV2-30 BCRs. Comparison with CLL LC sequences carrying heterogeneous K/LCDR3s or non-CLL LC sequences revealed that distinct amino acid changes appear to be "CLL-biased." Finally, a significant proportion of CLL cases with monotypic LC expression were found to carry multiple potentially functional LC rearrangements, alluding to active, (auto)antigen-driven receptor editing. In conclusion, SHM targeting in CLL LCs is just as precise and, likely, functionally driven as in heavy chains. Secondary LC gene rearrangements and subset-biased mutations in CLL LC genes are strong indications that LCs are crucial in shaping the specificity of leukemic BCRs, in association with defined heavy chains. Therefore, CLL is characterized not only by stereotyped HCDR3 and heavy chains but, rather, by stereotyped BCRs involving both chains, which generate distinctive antigen-binding grooves.     

Overexpression of CXCR4 predicts adverse overall and event-free survival in patients with unmutated FLT3 acute myeloid leukemia with normal karyotype

BACKGROUND: CXC chemokine receptor 4 (CXCR4) expression in acute myeloid leukemia (AML) is reported to correlate with FLT3 gene mutation and poorer prognosis. The prognostic significance of CXCR4 expression in patients with AML that have a normal karyotype and no evidence of FLT3 gene mutations was examined. METHODS: The prognostic significance of CXCR4 expression in 122 AML patients with normal karyotype and no evidence of FLT3 gene mutation treated at our institution between 1997 and 2003 was analyzed. All patients received intensive chemotherapy according to institutional protocols; 84% received cytarabine-containing regimens. Bone marrow biopsy or clot specimens obtained before treatment were immunostained for CXCR4. RESULTS: There were 70 men and 52 women with a median age of 62 years (range, 22-82 years). Median follow-up was 18 months (range, <1-97 months). Seventy-six patients achieved complete remission (CR); 39 had recurrence. Sixty-six patients died, including 9 with no evidence of disease. CXCR4 was positive in 70 and negative in 52 patients, with CR rates of 58% and 71%, respectively (P = .09). Multivariate analysis demonstrated that CXCR4 expression, presence of multilineage dysplasia, and high creatinine level predicted poorer overall (OS) and event-free (EFS) survival. CONCLUSIONS.: The results suggest that CXCR4 expression is associated with poor prognosis in AML patients with an unmutated FLT3 gene.     

Folate and vitamin B12 levels in levodopa-treated Parkinson's disease patients: their relationship to clinical manifestations, mood and cognition

We tested the hypothesis that mood, clinical manifestations and cognitive impairment of levodopa-treated Parkinson's disease (PD) patients are associated with vitamin B12 and folate deficiency. To this end, we performed this cross-sectional study by measuring serum folate and vitamin B12 blood levels in 111 consecutive PD patients. Levodopa-treated PD patients showed significantly lower serum levels of folate and vitamin B12 than neurological controls, while depressed patients had significantly lower serum folate levels as compared to non-depressed. Cognitively impaired PD patients exhibited significantly lower serum vitamin B12 levels as compared to cognitively non-impaired. In conclusion, lower folate levels were associated with depression, while lower vitamin B12 levels were associated with cognitive impairment. The effects of vitamin supplementation merit further attention and investigation.     

Mutation E522K in human DNA topoisomerase IIbeta confers resistance to methyl N-(4'-(9-acridinylamino)-phenyl)carbamate hydrochloride and methyl N-(4'-(9-acridinylamino)-3-methoxy-phenyl) methane sulfonamide but hypersensitivity to etoposide

Human cells express two isoforms of topoisomerase II, alpha and beta, that are both targeted by anticancer drugs. To investigate acridine resistance mediated by topoisomerase IIbeta, we used a forced molecular evolution approach. A library of mutated topoisomerase IIbeta cDNAs was generated by hydroxylamine mutagenesis and was transformed into the yeast JN394 top2-4. Methyl N-(4'-(9-acridinylamino)-phenyl)carbamate hydrochloride (AMCA) selection identified a resistant transformant able to grow in media containing 76 microg/ml AMCA. Topoisomerase IIbeta with a glutamic acid-to-lysine substitution at position 522 was responsible for the approximately 10-fold resistance to AMCA. The transformant was cross-resistant to methyl N-(4'-(9-acridinylamino)-3-methoxy-phenyl) methane sulfonamide (mAMSA) and mAMCA but hypersensitive to etoposide and ellipticine. In vitro, the betaE522K protein was unable to support acridine-stimulated DNA cleavage, suggesting that resistance to these acridines is caused by reduced drug-stimulated DNA cleavage. However, betaE522K showed DNA cleavage with etoposide, and the cleavable complexes formed with etoposide showed greater stability, thus accounting for the hypersensitivity to etoposide. Drug-independent cleavage of an oligonucleotide by betaE522K was reduced compared with the wild-type enzyme. Decatenation and relaxation activities were reduced to 52 and 61% of the wild-type levels, which may explain the slower growth of yeast strain JN394top2-4 expressing betaE522K at the nonpermissive temperature. This study confirms that topoisomerase IIbeta is a target for AMCA and that resistance to AMCA can be mediated by a point mutation at Glu522 in topoisomerase IIbeta. Residue 522 lies within a Rossmann fold in the B' subfragment of topoisomerase II, a region previously implicated in drug interactions.     

The Bellagio Report: Cardiovascular risks of spaceflight: implications for the future of space travel

BACKGROUND: Long-duration space missions, as well as emerging civilian tourist space travel activities, prompted review and assessment of data available to date focusing on cardiovascular risk and available risk mitigation strategies. The goal was the creation of tools for risk priority assessments taking into account the probability of the occurrence of an adverse cardiovascular event and available and published literature from spaceflight data as well as available risk mitigation strategies. METHODS: An international group of scientists convened in Bellagio, Italy, in 2004 under the auspices of the Aerospace Medical Association to review available literature for cardiac risks identified in the Bioastronautics Critical Path Roadmap (versions 2000, 2004). This effort led to the creation of a priority assessment framework to allow for an objective assessment of the hazard, probability of its occurrence, mission impact, and available risk mitigation measures. RESULTS/CONCLUSIONS: Spaceflight data are presented regarding evidence/ no evidence of cardiac dysrhythmias, cardiovascular disease, and cardiac function as well as orthostatic intolerance, exercise capacity, and peripheral resistance in presyncopal astronauts compared to non-presyncopal astronauts. Assessment of the priority of different countermeasures was achieved with a tabular framework with focus on probability of occurrence, mission impact, compliance, practicality, and effectiveness of countermeasures. Special operational settings and circumstances related to sensitive portions of any mission and the impact of environmental influences on mission effectiveness are addressed. The need for development of diagnostic tools, techniques, and countermeasure devices, food preparation, preservation technologies and medication, as well as an infrastructure to support these operations are stressed. Selected countermeasure options, including artificial gravity and pharmacological countermeasures need to be systematically evaluated and validated in flight, especially after long-duration exposures. Data need to be collected regarding the emerging field of suborbital and orbital civilian space travel, to allow for sound risk assessment.