Genetic variation in cell cycle and apoptosis related genes and multiple myeloma risk

RIPK1 polymorphisms and expression levels: impact on genetic susceptibility and clinical outcome of epithelial ovarian cancer

BACKGROUND

The aim of this study was to explore the associations of RIPK1 polymorphisms, plasma levels and mRNA expression with susceptibility to epithelial ovarian cancer (EOC) and clinical outcome.

METHODS

Three hundred and nineteen EOC patients included in a 60-month follow-up program and 376 controls were enrolled. Two tag SNPs (rs6907943 and rs9392453) of RIPK1 were genotyped using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. Plasma levels of RIPK1 and RIPK1 mRNA expression in white blood cells were determined by ELISA and qPCR, respectively.

RESULTS

For rs9392453, significantly increased EOC risk was found to be associated with C allele (P = 0.002, OR = 1.49, 95%CI  1.15-1.92), and with CT/CC genotypes in the dominant genetic model (P = 0.006, OR = 1.54, 95%CI  1.12-2.08). CC haplotype (rs6907943-rs9392453) was associated with increased EOC susceptibility. CC genotype of rs6907943 and CT/CC genotypes of rs9392453 were associated with early onset (age ≤ 50 years) of EOC (OR = 2.5, 95%CI  1.03-5.88, and OR = 1.64, 95%CI  1.04-2.63, respectively). AC genotype of rs6907943 was associated with better overall survival of EOC patients in the over-dominant genetic model (P = 0.035, HR = 0.41, 95%CI  0.18-0.94). Multivariate survival analysis identified the AC genotype of rs6907943 as an independent protective factor for survival of early onset patients (P = 0.044, HR = 0.12, 95%CI  0.02-0.95). Compared to controls, significantly increased plasma levels of RIPK1 and reduced RIPK1 mRNA expression were observed in patients.

CONCLUSIONS

Our results suggest that tag SNPs of RIPK1, increased plasma levels of RIPK1 protein and reduced RIPK1 mRNA expression in white blood cells, may influence the susceptibility to EOC. SNP rs6907943 may be a useful marker to distinguish EOC patients with high risk of death.

Current perspectives on interethnic variability in multiple myeloma: Single cell technology, population pharmacogenetics and molecular signal transduction

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This review discusses the emerging single cell technologies and applications in Multiple myeloma (MM), population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction.

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The role(s) of epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of MM are also discussed.

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It is understood that ethnic component acts as a driver of variable response to chemotherapy in different sub-populations globally.

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This review augments our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, myeloma microenvironment at the molecular and cellular level, and developing precision medicine strategies to combat this malignancy.

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The emerging single cell technologies hold great promise for enhancing our understanding of MM tumor heterogeneity and clonal diversity.

Multiple myeloma (MM) is an aggressive cancer characterised by malignancy of the plasma cells and a rising global incidence. The gold standard for optimum response is aggressive chemotherapy followed by autologous stem cell transplantation (ASCT). However, majority of the patients are above 60 years and this presents the clinician with complications such as ineligibility for ASCT, frailty, drug-induced toxicity and differential/partial response to treatment. The latter is partly driven by heterogenous genotypes of the disease in different subpopulations. In this review, we discuss emerging single cell technologies and applications in MM, population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction, as well as the role(s) played by epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of the disease. Taken together, our discussions further our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, augment our understanding of the myeloma microenvironment at the molecular and cellular level and provide a basis for developing precision medicine strategies to combat this malignancy.

Association of CASP9, CASP10 gene polymorphisms and tea drinking with colorectal cancer risk in the Han Chinese population

The initiators caspase-9 (CASP9) and caspase-10 (CASP10) are two key controllers of apoptosis and play important roles in carcinogenesis. This study aims to explore the association between CASPs gene polymorphisms and colorectal cancer (CRC) susceptibility in a population-based study. A two-stage designed population-based case-control study was carried out, including a testing set with 300 cases and 296 controls and a validation set with 206 cases and 845 controls. A total of eight tag selected single nucleotide polymorphisms (SNPs) in CASP9 and CASP10 were chosen based on HapMap and the National Center of Biotechnology Information (NCBI) datasets and genotyped by restriction fragment length polymorphism (RFLP) assay. Multivariate logistic regression models were applied to evaluate the association of SNPs with CRC risk. In the first stage, from eight tag SNPs, three polymorphisms rs4646077 (odds ratio (OR)(AA+AG): 0.654, 95% confidence interval (CI): 0.406-1.055; P=0.082), rs4233532 (OR(CC): 1.667, 95% CI: 0.967-2.876; OR(CT): 1.435, 95% CI: 0.998-2.063; P=0.077), and rs2881930 (OR(CC): 0.263, 95% CI: 0.095-0.728, P=0.036) showed possible association with CRC risk. However, none of the three SNPs, rs4646077 (OR(AA+AG): 1.233, 95% CI: 0.903-1.683), rs4233532 (OR(CC): 0.892, 95% CI: 0.640-1.243; OR(CT): 1.134, 95% CI: 0.897-1.433), and rs2881930 (OR(CC): 1.096, 95% CI: 0.620-1.938; OR(CT): 1.009, 95% CI: 0.801-1.271), remained significant with CRC risk in the validation set, even after stratification for different tumor locations (colon or rectum). In addition, never tea drinking was associated with a significantly increased risk of CRC in testing set together with validation set (OR: 1.755, 95% CI: 1.319-2.334). Our results found that polymorphisms of CASP9 and CASP10 genes may not contribute to CRC risk in Chinese population and thereby the large-scale case-control studies might be in consideration. In addition, tea drinking was a protective factor for CRC.

Evolution and impact of subclonal mutations in chronic lymphocytic leukemia

Clonal evolution is a key feature of cancer progression and relapse. We studied intratumoral heterogeneity in 149 chronic lymphocytic leukemia (CLL) cases by integrating whole-exome sequence and copy number to measure the fraction of cancer cells harboring each somatic mutation. We identified driver mutations as predominantly clonal (e.g., MYD88, trisomy 12, and del(13q)) or subclonal (e.g., SF3B1 and TP53), corresponding to earlier and later events in CLL evolution. We sampled leukemia cells from 18 patients at two time points. Ten of twelve CLL cases treated with chemotherapy (but only one of six without treatment) underwent clonal evolution, predominantly involving subclones with driver mutations (e.g., SF3B1 and TP53) that expanded over time. Furthermore, presence of a subclonal driver mutation was an independent risk factor for rapid disease progression. Our study thus uncovers patterns of clonal evolution in CLL, providing insights into its stepwise transformation, and links the presence of subclones with adverse clinical outcomes.

Familial monoclonal gammopathy of undetermined significance and multiple myeloma: epidemiology, risk factors, and biological characteristics

Monoclonal gammopathy of undetermined significance (MGUS), a precursor to multiple myeloma (MM), is one of the most common premalignant conditions in the general population. The cause of MGUS is largely unknown. Recent studies show that there is an increased prevalence of MGUS in blood relatives of persons with lymphoproliferative and plasma cell proliferative disorders, suggesting presence of shared underlying genetic influences. In the past few years, additional studies have examined risk factors and biologic characteristics that may contribute to the increased prevalence of MGUS among relatives of probands with MGUS, MM, and other blood malignancies. This article reviews the known epidemiology and risk factors for familial MGUS and myeloma, the risk of lymphoproliferative disorders and other malignancies among blood-relatives of patients with MGUS and MM, and discusses future directions for research.

MyelomA Genetics International Consortium

While the etiology of multiple myeloma (MM) is largely unknown, evidence for an inherited genetic susceptibility is provided by the two-fold increased risk of the disease seen in first-degree relatives of cases of MM. It is likely that part of this heritable risk is a consequence of the co-inheritance of low-risk genetic variants. The accumulated experience to date in identifying risk variants for other tumors has highlighted difficulties in conducting statistically and methodologically rigorous studies. The MyelomA Genetics International Consortium (MAGIC) includes 16 research groups in Europe, Asia, Australasia, the Middle East and the Americas engaged in studying the genetics of MM. The first goal of MAGIC is to identify and characterize common genetic variants for MM through association-based analyses. Here, we review the rationale for identifying genetic risk variants for MM and our proposed strategy for establishing MAGIC.

Genetic variations in multiple myeloma I: effect on risk of multiple myeloma

Few risk factors have been established for the plasma cell disorder multiple myeloma, but some of these like African American ethnicity and a family history of B-cell lymphoproliferative diseases suggest a genetic component for the disease. Genetic variation represents the genetic basis of variability in a population. The complex interplay between environment and genes for the development of cancer may therefore be influenced by genetic variations. A genetic variation may change the function of the gene, and if the genetic variation is associated with the risk of disease, that particular gene may be involved in the pathogenesis of disease. Genes of interest are genes involved in the normal development and function of the plasma cell and genes that protect us against exposures from the environment, for example, genes involved in the metabolism of xenobiotics, metabolism of folate and methionine, as well as genes involved in inflammation and DNA repair. Identification of genes with potential influence on cancer risk may help us to establish relevant laboratory studies on exposure and dose-response assessment and may help us to test the hypothesis in epidemiological studies. Knowledge of individual at high risk of cancer may offer promising insight for the prevention of cancer.

Variations in suppressor molecule ctla-4 gene are related to susceptibility to multiple myeloma in a polish population

Various phenotype and functional T-cell abnormalities are observed in multiple myeloma (MM) patients. The aim of this study was to investigate the association between polymorphisms in the gene encoding cytotoxic T-lymphocyte antigen-4 (CTLA-4), a negative regulator of the T-lymphocyte immune response and susceptibility to multiple myeloma in a Polish population. Two hundred MM patients and 380 healthy subjects were genotyped for the following polymorphisms: CTLA-4c.49A>G, CTLA-4g.319C>T, CTLA-4g.*642AT(8_33), CT60 (CTLA-4g.*6230G>A), Jo31 (CTLA-4g.*10223G>T). Our study is the largest and most comprehensive evaluation to date of the association between genetic polymorphisms in the CTLA-4 molecule and multiple myeloma. It was found that CTLA-4c.49A>G[G], CT60[G], and Jo31[G] alleles were more frequently observed in MM patients than in controls (0.50 vs. 0.44, p = 0.03, 0.65 vs. 0.58, p = 0.04, and 0.63 vs. 0.57, p = 0.03, respectively). Moreover, the haplotype CTLA-4c.49A>G[G], CTLA-4g.319C>T[C], CTLA-4g.*642AT(8_33) [8], CT60[G], Jo31[G] including all susceptibility alleles increases the risk of MM about fourfold (OR: 3.79, 95%CI: 2.08–6.89, p = 0.00001). These findings indicate that genetic variations in the CTLA-4 gene play role in susceptibility to multiple myeloma and warrant further investigation through replication studies.

Gender disparities in the tumor genetics and clinical outcome of multiple myeloma

BACKGROUND

Several cancer types have differences in incidence and clinical outcome dependent on gender, but these are not well described in myeloma. The aim of this study was to characterize gender disparities in myeloma.

METHODS

We investigated the association of gender with the prevalence of tumor genetic lesions and the clinical outcome of 1,960 patients enrolled in the phase III clinical trial MRC Myeloma IX. Genetic lesions were characterized by FISH.

RESULTS

Disparities were found in the prevalence of primary genetic lesions with immunoglobulin heavy chain gene (IGH) translocations being more common in women (50% of female patients vs. 38% of male patients, P < 0.001) and hyperdiploidy being more common in men (50% female vs. 62% male, P < 0.001). There were also differences in secondary genetic events with del(13q) (52% female vs. 41% male, P < 0.001) and +1q (43% female vs. 36% male, P = 0.042) being found more frequently in female myeloma patients. Female gender was associated with inferior overall survival (median: 44.8 months female vs. 49.9 months male, P = 0.020).

CONCLUSIONS

We found gender-dependent differences in the prevalence of the primary genetic events of myeloma, with IGH translocations being more common in women and hyperdiploidy more common in men. This genetic background may impact subsequent genetic events such as +1q and del(13q), which were both more frequent in women. The higher prevalence of lesions associated with poor prognosis in the female myeloma population, such as t(4;14), t(14;16) and +1q, may adversely affect clinical outcome.

IMPACT

These differences suggest that gender influences the primary genetic events of myeloma.

Risk of Japanese carriers of hyperphosphorylated paratarg-7, the first autosomal-dominantly inherited risk factor for hematological neoplasms, to develop monoclonal gammopathy of undetermined significance and multiple myeloma

Hyperphosphorylated paratarg-7 (pP-7) is a frequent target of paraproteins in German patients with monoclonal gammopathy of undetermined significance (MGUS)/multiple myeloma (MM). The frequency of MGUS/MM is lower in Japan than in Europe. As pP-7, the first molecularly defined autosomal-dominant risk factor for any hematological neoplasm, is inherited in a dominant fashion, we determined the incidence of the pP-7 carrier state in a Japanese population, and compared the frequency of pP-7-specific paraproteins and the pP-7 carrier state in Japanese and German patients with MGUS/MM. Peripheral blood from 111 Japanese patients with MGUS/MM and 278 healthy blood donors was analyzed for the pP-7 carrier state by isoelectric focusing and for pP-7-specific antibodies by ELISA. The Japanese group was compared with 252 German MGUS/MM patients and 200 healthy controls. Five of 111 (4.5%) Japanese and 35/252 (13.9%) German IgA/IgG MGUS/MM patients had a pP-7-specific paraprotein (P=0.009). The prevalence of healthy pP-7 carriers in the Japanese study group was 1/278 (0.36%), whereas it was 4/200 in the German group (P=0.166). The relative risk for pP-7 carriers developing MGUS/MM had an odds ratio of 13.1 in the Japanese and 7.9 in the German group. In conclusion, the fraction of pP-7 carriers with a pP-7-specific paraprotein is lower among Japanese than in German patients with MGUS/MM, but pP-7 carriers in both ethnic groups have a high risk of developing MGUS/MM.

Association of a dominantly inherited hyperphosphorylated paraprotein target with sporadic and familial multiple myeloma and monoclonal gammopathy of undetermined significance: a case-control study

BACKGROUND

Chronic antigenic stimulation might have a role in the pathogenesis of monoclonal gammopathy of unknown significance (MGUS) and multiple myeloma. The aim of this study was to search for factors underlying the autoimmunogenicity of paratarg-7, a frequent antigenic target of paraproteins in MGUS and multiple myeloma.

METHODS

Between January, 2005, and February, 2009, serum and peripheral blood cells were obtained from consecutive patients with MGUS or multiple myeloma and healthy blood donors, and paratarg-7 was analysed by DNA sequencing, SDS-PAGE, isoelectric focusing, and western blotting.

FINDINGS

Mutations or polymorphisms of paratarg-7 were not noted, but hyperphosphorylation was detected in 35 (13.9%) of 252 patients with MGUS or multiple myeloma, all of whom had an anti-paratarg-7-specific paraprotein. Analysis of eight families showed that hyperphosphorylated paratarg-7 is inherited in a dominant fashion, and that carriers of hyperphosphorylated paratarg-7 have an increased risk of developing MGUS and multiple myeloma (odds ratio [OR] 7.9, 95% CI 2.8-22.6; p=0.0001).

INTERPRETATION

Familial MGUS and multiple myeloma were associated with a dominant inheritance of hyperphosphorylated paratarg-7, enabling family members at increased risk for MGUS or multiple myeloma to be identified. That only patients with MGUS or multiple myeloma who are carriers of hyperphosphorylated paratarg-7 had a paratarg-7-specific paraprotein suggests that the hyperphosphorylation of paratarg-7 induces auto-immunity and is involved in the pathogenesis of MGUS and multiple myeloma; for example, by chronic antigenic stimulation.

FUNDING

Förderverein Krebsforschung Saar-Pfalz-Mosel e.V. (eingetragener Verein: officially registered charity) and HOMFOR (the research programme of the Saarland University Faculty of Medicine).