Lack of association between the TNF-alpha promoter gene polymorphism and susceptibility to B-cell chronic lymphocytic leukaemia

Association of TNF-α rs1800629 with Adult Acute B-Cell Lymphoblastic Leukemia

TNF−α influences lymphomagenesis by upregulating proinflammatory and antiapoptotic pathways. In this study, we evaluated the frequency of TNF−α rs1800629 (−308 G>A) polymorphism in newly diagnosed adult patients with acute lymphoblastic leukemia (ALL) and its correlation with age at diagnosis, gender and subtype of ALL. In this case control study, a total of 330 individuals were recruited, including 165 newly diagnosed adult patients with ALL, from the Radiation and Isotope Center in Khartoum (RICK) and 165 healthy normal controls. TNF−α rs1800629 polymorphism was tested through allele-specific polymerase chain reaction (PCR) assay. The frequency of the rs1800629 GA genotype was high (70.9% vs. 60%, OR = 1.84) in the patient group as compared to healthy controls, whereas GG and AA genotypes did not exhibit any statistically significant difference between controls and patients. Based on subtype, GG and GA rs1800629 genotypes showed increased risk of B-ALL (OR 0.46 and 2.12, respectively), whereas rs1800629 GG, GA and AA genotypes did not show any disease association with T-ALL (p > 0.05). Age at diagnosis and gender did not exhibit any association of rs1800629 with ALL in the patient group. In conclusion, rs1800629 is associated with high risk of adult B-ALL, with an insignificant effect of age at diagnosis and gender.

Current Trends in Management of Oral Mucositis in Cancer Treatment

Oral Mucositis (OM) is among the most common and dreaded toxicities of cancer therapy. It occurs in almost all patients who receive radiation therapy in which areas of oral and oropharyngeal mucosa are included in the treatment field. With the advent of chemotherapy in 1940 and its extended clinical legacy, it is only within the past two decade or so that mucositis’ complex pathobiology has become fully appreciated. There are still many unanswered questions about the risk factors for developing OM, but historically, risk factors have been attributed to both therapy and patient m characteristics. One thing that has been consistent from the initial descriptions of its clinical manifestations has been the frustration on the part of clinicians and patients with the scarcity of therapeutic options to prevent or treat the condition, or effectively ameliorate the symptoms. Clinicians, researchers and those involved in oral and periodontal medicine should join hand in hand in persuit of understanding and developing treatment strategies for treatment of inflammatory conditions like OM in oncology. This will lead to development of effective treatments and reducing the burden of OM and other inflammatory conditions in oncology.

TNF-α and LT-α polymorphisms and the risk of leukemia: a meta-analysis

AIM

The aim of this study is to investigate whether TNF-α or LT-α polymorphisms are associated with the risk of leukemia.

METHODS

A meta-analysis was performed to examine the association between the TNF-α -308 G>A and LT-α +252 A>G polymorphisms and the incidence of leukemia. We also performed subgroup analyses based on the classification of leukemias. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the association.

RESULTS

A total of 19 publications comprising 1,509 cases and 4,075 controls were selected in the study. An association between the risk of leukemia and the LT-α +252 AA genotype was found (GG + AG vs. AA, OR = 0.485, 95% CI 0.368-0.639, p = 0.000). After multivariable analysis TNF-α polymorphism showed no consistent association with leukemia.

CONCLUSIONS

This meta-analysis suggests that the LT-α +252 AA polymorphism is associated with the risk of leukemia.

Pharmacotherapy for the management of cancer regimen-related oral mucositis

INTRODUCTION

Oral mucositis is a frequent and devastating toxicity secondary to cancer treatment, which may affect 20-40% of patients receiving conventional chemotherapy and 60-85% of patients undergoing hematopoietic stem cell transplantation. The pathobiology of mucositis includes a complex cascade of biologic events in which pro-inflammatory cytokines, ROS, second messengers, and the oral microbiome contribute to tissue damage of the oral mucosa. Management strategies to oral mucositis secondary to chemotherapy include preventative measures and therapeutic approaches.

AREA COVERED

A literature search of published animal and clinical studies was perform to review the epidemiology, pathophysiology and treatment options for cancer regimen-induced mucositis. We also discuss new data coming from recent pertinent clinical trials.

EXPERT OPINION

Mucositis is one of the most common debilitating toxicities secondary to cancer treatment and can adversely affect patients' quality of life. Epidemiological data for mucositis are often under-reported. Research efforts have shown that genetics plays a major role in the development of this toxicity. Although few therapeutic agents are available, several promising drugs are under investigations.

New frontiers in mucositis

Mucositis is among the most debilitating side effects of radiotherapy, chemotherapy, and targeted anticancer therapy. Research continues to escalate regarding key issues such as etiopathology, incidence and severity across different mucosae, relationships between mucosal and nonmucosal toxicities, and risk factors. This approach is being translated into enhanced management strategies. Recent technology advances provide an important foundation for this continuum. For example, evolution of applied genomics is fostering development of new algorithms to rapidly screen genomewide single-nucleotide polymorphisms (SNPs) for patient-associated risk prediction. This modeling will permit individual tailoring of the most effective, least toxic treatment in the future. The evolution of novel cancer therapeutics is changing the mucositis toxicity profile. These agents can be associated with unique mechanisms of mucosal damage. Additional research is needed to optimally manage toxicity caused by agents such as mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors, without reducing antitumor effect. There has similarly been heightened attention across the health professions regarding clinical practice guidelines for mucositis management in the years following the first published guidelines in 2004. New opportunities exist to more effectively interface this collective guideline portfolio by capitalizing upon novel technologies such as an Internet-based Wiki platform. Substantive progress thus continues across many domains associated with mucosal injury in oncology patients. In addition to enhancing oncology patient care, these advances are being integrated into high-impact educational and scientific venues including the National Cancer Institute Physician Data Query (PDQ) portfolio as well as a new Gordon Research Conference on mucosal health and disease scheduled for June 2013.

Mucositis: pathobiology and management

PURPOSE OF REVIEW

Oral mucositis remains a frequent debilitating toxicity associated with drug and radiation regimens used to treat cancer. This review highlights the recent understanding of the biological basis, risk factors for, and management for oral mucositis.

RECENT FINDINGS

Prevalence and incidence data for mucositis are inconsistent and often underreported. The pathogenesis of mucositis encompasses a sequence of biological events possibly influenced by the oral microbiome and environment. Despite its frequency and severity, there is currently no effective treatment available for the majority of patients at risk. However, with the better understanding of the pathogenesis of mucositis a number of new drugs and biological agents are under investigation. Genome-wide risk prediction tools will allow the identification of patients at risk of developing mucositis.

SUMMARY

Oral mucositis is a common complication of cancer treatment that may negatively impact the patient's cancer treatment outcome. Despite its frequency and consequences, the lack of effective interventions has frustrated patients and caregivers. Fortunately, a broad range of mechanistically targeted compounds are being developed.

Oral Mucositis Induced By Anticancer Therapies

Oral mucositis induced by conventional cytotoxic cancer therapies is a common and significant clinical problem in oncology. Mucositis symptoms, which include severe pain, may lead to dose reductions and unplanned interruptions of chemotherapy and/or radiotherapy, and often affect patients' quality of life. In addition, ulcerative mucositis represents a risk factor for local or systemic infectious complications that may be life-threatening in immunosuppressed patients. The development of biologically based targeted cancer therapies, which aim to block the growth, spread, and survival of tumors by interfering with specific molecular targets, may have reduced mucosal injury, but did not eliminate it. This article will review the epidemiology, pathobiology, and management of oral mucositis associated with conventional cytotoxic therapies for malignant diseases and will briefly summarize emerging information on oral mucosal injury associated with targeted therapies. Considerations for future research aimed at the development of more efficient and effective supportive care approaches will be presented, with emphasis on the contribution of dental researchers and clinicians in these efforts.

The association between the polymorphisms of TNF-α and non-Hodgkin lymphoma: a meta-analysis

Many genetic variations in the promoter region of tumor necrosis factor alpha (TNF-α) may confer host susceptibility to cancer by influencing TNF-α expression. Nevertheless, the results remain inconclusive. The current meta-analysis was performed to investigate the association between three common TNF-α promoter polymorphisms and the risk of non-Hodgkin lymphoma (NHL). A literature search was conducted mainly from PubMed for all eligible studies. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were used to assess the association of TNF-α polymorphisms with the risk of NHL. TNF-α -308 A allele showed a statistically significant increased risk for NHL under the homozygous (AA vs. GG, OR = 1.51, 95 % CI = 1.26-1.80) and recessive (OR = 1.47, 95 % CI = 1.23-1.75) models, respectively. The stratified analyses showed an increased risk of NHL with the presence of TNF-α -308 A allele among Africans and Caucasians, but a decreased risk among Asians. No association was observed between -238 G/A polymorphism and NHL risk either in the overall analysis or in the stratified analysis. Similarly, pooled analysis did not reveal an altered risk of NHL with -857 C/T polymorphism. Nonetheless, a statistically significant association was observed among Asians when stratified by ethnicity. Among the three genetic variations of interest, TNF-α -308 G/A polymorphism was significantly associated with the risk of NHL; neither -238 G/A nor -857 C/T polymorphism was shown to alter the overall NHL risk; however, stratified analysis by ethnicity observed a statistically significant association between -857 C/T polymorphism and the risk of NHL among Asians.

Candidate gene association studies and risk of chronic lymphocytic leukemia: a systematic review and meta-analysis

To evaluate the contribution of association studies of candidate polymorphisms to inherited predisposition to chronic lymphocytic leukemia (CLL), we conducted a systematic review and meta-analysis of published case-control studies. We identified 36 studies which reported on polymorphic variation in 19 genes and CLL risk. Out of the 23 polymorphic variants, significant associations (p < 0.05) were seen in pooled analyses for only four variants: MDR1, rs1045642; LTA, rs2239704; CD38, rs6449182; and IFNGR1, rs4896243. These findings should be interpreted cautiously, as the estimated false positive report probabilities (FPRPs) for each association were not noteworthy (i.e. FPRP > 0.2). While studies of candidate polymorphisms may be an attractive means of identifying risk factors for CLL, the limited power of published studies to demonstrate statistically significant associations makes it essential that future analyses be based on sample sizes well-powered to identify variants having modest effects on CLL risk.

Recent advances in microRNA-mediated gene regulation in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the western world and is a very clinically heterogeneous disease for which better prognostic biomarkers are needed. Current prognostic markers exhibit both biological and technical limitations. MicroRNAs (miRNAs) are small endogenous, non-coding 22-nucleotide regulatory RNAs that have been shown to modulate hematopoietic lineage differentiation and play important gene-regulatory roles in disease processes. In this manuscript, we review miRNA biology and the association of specific miRNAs with CLL.

Polymorphisms of TNF and IL-10 genes and clinical outcome of patients with chronic lymphocytic leukemia

Genetic variations in tumor necrosis factor (TNF) and interleukin-10 (IL-10) were reported to influence susceptibility to and outcome of patients with non-Hodgkin lymphoma. Therefore, we investigated whether single nucleotide polymorphisms in TNF and IL-10 may play a role in the clinical course of patients with chronic lymphocytic leukemia (CLL). TNF-308G>A, IL-10-3575T>A, and IL-10-1082A>G seem to be functionally relevant, were genotyped in 292 previously untreated patients with CLL. The control group consisted of 192 randomly selected blood donors. The patients carrying TNF-308GG and IL-10-1082AA genotypes presented a higher 3-year treatment-free survival (56.6 vs. 40.6%, P = 0.05) as well as a 10-year overall survival (OS) rates (92.3 vs. 57.6%, P = 0.005) than those with other TNF-308 and IL-10-1082 genotype combinations. Multivariate analysis demonstrated the Rai stage (P = 0.0002), IGHV mutation status (P = 0.01), TNF-308G>A (P = 0.03), and TNF/IL-10 polymorphism-based risk groups (P = 0.05) to be independent factors predicting OS. When the mutated IGHV patients were analyzed, the homozygotes TNF-308GG and IL-10-1082AA presented a higher 10-year OS rate than those carrying other TNF-308 and IL-10-1082 genotypes (100 vs. 67.7%, P = 0.01). In the unmutated IGHV patients, only the TNF-308G>A polymorphism influenced OS. The genetic variations in TNF and IL-10 genes work as independent predictors of survival and may play a role in the clinical course of CLL. It suggests inherited ability of the host to shift the balance between the Th1 and Th2 response, which in turn might contribute to the pathogenesis and prognosis of B-cell malignancies.

Influence of IL10 (G1082A) and TNFα (G308A) Polymorphisms on the Survival of Pediatric Patients with ALL

Interleukin 10 (IL10) is a pleiotropic cytokine that stimulates various hematopoietic cells. The tumor necrosis factor alpha (TNFα) is a cytokine that may influence the transcriptional activity induced by glucocorticoids. This study examined the impact of TNFα (G308A) and IL10 (G1082A) polymorphisms at promoter regions in relation to the overall survival of 105 children (0 ≤ 18 years) with acute lymphoblastic leukemia (ALL) for a period of 126 months, treated according to the protocol GBTLI99. The G1082A and G308A polymorphisms were identified by allele-specific PCR and PCR-RFLP, respectively. Patients with IL10AA genotype had a higher death ratio (44%, P = 0.0089). Patients with both IL10AA and TNFAA genotypes showed the worst survival when compared with the IL10GG and TNFGA genotypes (P = 0.0043). The results of this study revealed a lower survival among patients with IL10AA genotype and the concomitant occurrence of IL10AA and TNFAA genotypes.

Inherited predisposition to chronic lymphocytic leukemia

Inherited susceptibility to chronic lymphocytic leukemia (CLL) has been recognized for decades. Approximately 10% of individuals with CLL report a family history of CLL or a related lymphoproliferative disorder, and genetic predisposition is the best understood risk factor for CLL. Studies of familial CLL have suggested that the disease features are largely similar to sporadic CLL, although recent data suggest that familial CLL may more commonly show somatic hypermutation of the immunoglobulin heavy-chain variable region, suggesting a more indolent disease course. Monoclonal B-cell lymphocytosis (MBL) has been identified recently as a likely precursor to CLL; it is found in the general population with increasing age and enriched in unaffected relatives of individuals with familial CLL. Studies of MBL as well as mouse models of CLL may lead to better understanding of early CLL pathogenesis that is relevant to familial predisposition. To date, the identification of genes that predispose to familial CLL has been slow, primarily due to the relatively few families available for study, the small size of those families and disease causation most likely by multiple genes that each confer smaller risks. In the coming years, the application of systematic genomics approaches to familial CLL should, hopefully, lead to the identification of novel loci involved in the disease.

Role of decreased production of interleukin-10 and interferon-gamma in spontaneous apoptosis of B-chronic lymphocytic leukemia lymphocytes in vitro

BACKGROUND AND AIMS

B-chronic lymphocytic leukemia (B-CLL) is characterized by the progressive accumulation of small B lymphocytes that do not undergo apoptosis due to an underlying defect. One potential mechanism of defective apoptosis may be irregular cytokine production. The goal of our investigation was to determine in vitro production of relevant cytokines by lymphocytes of B-CLL patients.

METHODS

Thirty untreated (stage A) B-CLL patients, as well as 20 stage B and C patients and 30 healthy volunteers as a control group were examined. Interleukin-4 (IL-4), interferon-gamma (IFN-gamma), interleukin-10 (IL-10) and tumor necrosis factor-alpha (TNF-alpha) were measured by enzyme-linked immunosorbent assay (ELISA) in supernatants of lymphocyte cultures of all three investigated groups. The method applied for detecting apoptosis was fluorescence microscopic analysis using acridine orange/ethidium bromide (AO/EB) double staining.

RESULTS

Investigation showed that in vitro lymphocyte production of IL-10 and IFN-gamma were significantly decreased in B-CLL patients, whereas there were no statistically significantly differences of IL-4 and TNF-alpha production among the tested groups. Compared with the spontaneous apoptosis observed in control subjects' lymphocytes, B-CLL lymphocytes showed increased percentages of apoptotic cells after incubation for 24h. Interestingly, increased spontaneous apoptosis of B-CLL lymphocytes was followed by decreased IL-10 and IFN-gamma production. Stage of disease did not influence B-CLL lymphocyte spontaneous apoptosis in vitro.

CONCLUSIONS

These changes in cytokine production in cultures of B-CLL lymphocytes may be one of the potential mechanisms in the pathogenesis of abnormal apoptosis.

IFN gamma gene polymorphism may contribute to the susceptibility to CLL

The pathogenesis of B-cell chronic lymphocytic leukemia (B-CLL) has been linked with the production and activity of certain growth factors. However a significant proportion of CLL patients display immune abnormalities suggestive of aberrant cytokine secretion and/or response. In contrast to B lymphocytes, T cells of B-CLL patients characterise with the increased production of interferon-gamma (IFN-gamma) and this cytokine has been indicated to prevent malignant cells from entering apoptosis including the slowly expanding population of CD5+ B cells that characterizes chronic lymphocytic leukemia. The aim of the present study was to assess whether functionally relevant interferon-gamma gene (IFNG) polymorphism (+847 A/T) contributes to the pathogenesis of B-CLL. In total 110 individuals was investigates, including 61 CLL patients and 50 healthy individuals. The presence of the IFNG AA genotype was found to be associated with susceptibility to CLL (23/61 vs. 7/50, p < 0.005, for patients and controls, respectively). This results suggest that individuals rather prone to the lower level of IFN-gamma production (associated with the presence of the A allele) appear to be more susceptible to this malignant disease.

Synopsis and synthesis of candidate-gene association studies in chronic lymphocytic leukemia: the CUMAGAS-CLL information system

A comprehensive and systematic assessment of the current status of candidate-gene association studies for chronic lymphocytic leukemia (CLL) was conducted. Data from 989 candidate-gene association studies (1992-2009) involving 905 distinct genetic variants were analyzed and cataloged in CUMAGAS-CLL, a Web-based information system which allows the retrieval and synthesis of data from candidate-gene association studies on CLL (http://biomath.med.uth.gr). Nine genetic variants (BAX (rs4645878), GSTM1 (null/present), GSTT1 (null/present), IL10 (rs1800896), LTA (rs909253), MTHFR (rs1801131), MTHFR (rs1801133), P2RX7 (rs3751143), and TNF (rs1800629)) were investigated in 4 or more studies, and their results were meta-analyzed. In individual studies, 147 variants showed a significant association with CLL risk under any genetic model. For 53 variants, the association was significant at P < 0.01 with an increased risk greater than 40%. Only 0.3% of studies had statistical power greater than 80%. In meta-analyses, none of the variants showed significant results, and heterogeneity ranged from none to high. Large and rigorous genetic studies (candidate-gene association studies and genome-wide association studies) designed to investigate epistatic and gene-environment interactions may produce more conclusive evidence about the genetic etiology of CLL. CUMAGAS-CLL would be a useful tool for current genomic epidemiology research in the field of CLL.

Susceptibility genes and B-chronic lymphocytic leukaemia

Common genetic variants are thought to increase the risk of chronic lymphocytic leukaemia (CLL), and case-control studies provide an approach to detect these variants. There have been multiple candidate gene studies published to date, but relatively few disease pathway studies or large genomic association studies. We summarize the results of these previous studies, as well as present results from our recent large pathway study of 9412 single nucleotide polymorphisms from 1253 immunity and inflammation genes in a study of 126 CLL cases and 484 frequency-matched controls. Several promising genes have been identified as susceptibility genes for risk of CLL across all of these association studies. However, a number of candidate gene studies have not been replicated in follow-up studies, whereas the results from disease pathway and large genomic studies have yet to be replicated in an independent sample. The challenge of future studies of this type will be overcoming study design issues, including definition of CLL, sample size limitations and multiple testing issues.

Functional variations in the JWA gene are associated with increased odds of leukemias

The association between the -76G>C in the 5'-flanking region and 723T>G in JWA exon three variants were examined for risk of leukemia development in a hospital-based case-control study of 201 leukemia patients and 243 cancer-free controls in a Chinese population. Studies showed that the -76C allele was associated with significantly increased odds of leukemia but the 723G allele was correlated with marked decreased odds of leukemia. Variation in the -76C allele resulted in almost complete loss of oxidative stress stimulated transcription activities of the promoter fragment.

Single nucleotide polymorphism of the JWA gene is associated with risk of leukemia: a case-control study in a Chinese population

The JWA gene was initially cloned as a novel cell differentiation-associated gene and was subsequently found to be an environmental responsive gene. The JWA gene also produced a marked effect during chemical-induced multidirectional differentiations of primary and human myeloid leukemia cells. Recently, a novel single nucleotide polymorphism (SNP) in exon2 of the JWA gene (454CA) was identified that may play a role in risk of bladder cancer. The aim of this study was to investigate the association between the 454CA (NM_006407.2) in JWA exon2 variants and risk of leukemia in a hospital-based case-control study of 202 leukemia patients and 289 cancer-free controls. Results indicated that 454A allele was found to associate with significantly increased risk of leukemia, although the 454CA is a synonymous polymorphism in coding region of the JWA gene. In conclusion, the potentially functional genetic polymorphism 454CA of the JWA gene appears to contribute to the risk of multiple kinds of leukemia in a south Chinese population.