The CXCL12-3′A allele plays a favourable role in patients with multiple myeloma

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.

Expression and role of MIG/CXCR3 axis in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a unique subtype of B-cell non-Hodgkin lymphoma with a generally aggressive and heterogeneous clinical course. Chemokines are one of the complex components in the tumor microenvironment (TME), and they play a vital role in tumor progression and metastasis. There is no information about the monokine induced by gamma interferon (MIG)/CXC chemokine receptor 3 (CXCR3) axis in patients with MCL. In the present study, we discovered that CXCR3 was highly expressed in MCL tissues and some cell lines including Maver, Z138, and Jeko-1, and significantly associated with clinical factors reflecting high tumor burden in MCL patients. Moreover, elevated serum MIG at diagnosis showed a close relationship with advanced disease and poor prognosis in MCL patients. Additionally, the role of CXCR3 in promoting the proliferation and inhibiting the apoptosis of primary MCL cells and Jeko-1 cells was validated by in vitro experiments. Further research indicated that the MIG/CXCR3 axis mediated MCL cell migration to the TME through the PI3K/AKT signaling pathway. Therefore, the MIG/CXCR3 axis might be a potential target with fewer off-target side effects than other targets in MCL.

High expression of CC chemokine receptor 5 (CCR5) promotes disease progression in patients with B-cell non-Hodgkin lymphomas

Chemokines are small proteins, that regulate cell migration in many physiological and pathologic processes in human body. They are also responsible for cancer progression. CC chemokine receptor 5 (CCR5) is responsible for cell recruitment in inflammation and may be involved in antitumor immune response controlling. Aberrant CCR5 can be found in different kind of cancers, not only hematological, but also solid tumors. Non-Hodgkin lymphomas consist of many lymphoma subtypes. They predominantly derive from B cells and can have very heterogenous clinical course. That is why new prognostic factors are still needed to predict and select high-risk patients. We evaluated CCR5 expression in lymph nodes derived from B-cell lymphomas in comparison to reactive lymphatic tissue (reactive lymph nodes): samples of lymphoma lymph nodes, peripheral blood, and bone marrow aspirates of patients with B-cell non-Hodgkin lymphoma were taken at diagnosis and after completed chemotherapy. Gene expression was determined by the reverse transcription-polymerase chain reaction method. Expression was estimated from 0AU (no amplificate signal) to 3AU (maximal amplificate signal). We found low CCR5 expression in lymphomas and reactive lymph nodes. Higher CCR5 gene expression in lymphoma patients was correlated with advanced stage of the disease, high proliferation index (Ki-67), and international prognostic index. Patients with higher CCR5 expression had shorter survival. CCR5 high expression may have a role in non-Hodgkin's lymphomas progression and can influence patients' survival. CCR5 also can become an immunotherapeutic target for novel treatment options in the future as well as new prognostic factor.

SDF1-3'A polymorphism is associated with increased risk of hematological malignancy: a meta-analysis

CXCL12 (also named SDF1), a member of the chemokine family, has been demonstrated to play an important role in the progression of multiple types of hematological malignancy. Several recent studies have shown that SDF1-3′A polymorphism (rs1801157) is associated with susceptibility to hematological malignancy, but published studies’ results are disputed. Therefore, we performed a meta-analysis to evaluate the relationship between SDF1-3′A polymorphism and the risk of hematological malignancy based on the existing literature. We carried out a comprehensive literature search using the Web of Science, PubMed, Cochrane Library, Chinese Wan Fang, and Chinese National Knowledge Infrastructure databases. And the raw data were extracted and calculated in standard steps of meta-analysis. Overall, nine qualified studies containing 1,576 cases and 1,674 controls were included in the ultimate meta-analysis. The pooled results displayed that AA genotype significantly increased the risk of hematological malignancy. The result of subgroup analysis further indicated that SDF1-3′A polymorphism was significantly associated with increased risk of chronic myeloid leukemia, Hodgkin’s lymphoma and multiple myeloma, but was not associated with increased risk of acute myeloid leukemia and non-Hodgkin’s lymphoma. In addition, SDF1-3′A polymorphism was associated with increased risk of hematological malignancy in Africans and Asians, but not in Caucasians. In conclusion, our meta-analysis firstly demonstrated that SDF1-3′A polymorphism may be associated with increased risk of hematological malignancy, especially for chronic myeloid leukemia, Hodgkin’s lymphoma, multiple myeloma and the non-Caucasian population. Nevertheless, these conclusions should be reconfirmed by more evidence from large sample sized studies.

Cereblon and IRF4 Variants Affect Risk and Response to Treatment in Multiple Myeloma

Multiple myeloma (MM) is a plasma-cell malignancy derived from an early precursor of the B-cell lineage characterised by bone-marrow infiltration, lytic bone lesions, and the presence of a monoclonal protein in serum and/or urine. Interferon regulatory factor 4 (IRF4) is a critical transcriptional regulator in B-cell development and function that is required during immune response for lymphocyte activation and the generation of immunoglobulin-secreting plasma cells. Immunomodulatory drugs, derivatives of thalidomide, are commonly used in therapy against MM. They are known to target a protein called cereblon (CRBN); however, the exact mechanism remains unknown. The present study aimed to assess the association of two (rs12203592 and rs872071) polymorphisms within the IRF4 gene and two (rs711613 and rs1045433) in the CRBN gene with MM susceptibility, progression, and response to treatment. For this purpose, 144 MM patients and 126 healthy individuals were genotyped for the IRF4 and CRBN alleles. The presence of the IRF4 (rs872071) G allele was more frequently detected in patients than healthy individuals (OR 1.78; P = 0.034), and this relationship was especially pronounced in women (OR 2.83; P = 0.012). The CRBN (rs711613) A allele-carriers were better responders to the treatment (P = 0.012), in particular to thalidomide including therapy (P = 0.023). These results underline the prognostic significance of the IRF4 and CRBN polymorphisms in patients with MM.

SDF1-3'A polymorphism is associated with size but not occurrence of abdominal aortic aneurysm in a Chinese population

OBJECTIVE

Previous studies have suggested that stromal-derived factor 1 (SDF1) plays a pivotal role in abdominal aortic aneurysm (AAA) development. The SDF1-3'A polymorphism (G to A, rs1801157), located in the 3' untranslated region, could influence the expression of SDF1. The aim of our study was to investigate the relationship of SDF1-3'A polymorphism with the risk of AAA occurrence and size.

METHODS

A total of 205 AAA patients and 216 age- and sex-matched controls were recruited. The SDF1-3'A polymorphism was evaluated by polymerase chain reaction, followed by restriction enzyme analysis.

RESULTS

The frequency of A allele was similar between groups. The genotype distribution also displayed no statistically significant differences under both the dominant model (odds ratio [OR], 0.922; P = .678) and the recessive model (OR, 1.617; P = .300). The multiple logistic regression analysis indicated that the association between the polymorphism and AAA remained insignificant when applied to the dominant model. However, AAA patients with GG genotype were more likely to develop aneurysms larger than 50 mm (OR, 0.497; P = .014). AAA patients with SDF1-3'A allele have reduced plasma SDF1α levels. In addition, plasma SDF1α levels were positively correlated with AAA size.

CONCLUSIONS

Our study suggests that SDF1-3'A polymorphism is associated with size but not occurrence of AAA, providing further evidence that SDF1 is implicated in AAA progression.

The SDF-1 rs1801157 Polymorphism is Associated with Cancer Risk: An Update Pooled Analysis and FPRP Test of 17,876 Participants

The stromal cell derived factor-1 (SDF-1) rs1801157 gene polymorphism has been implicated in susceptibility to cancer, but the results were inconclusive. The current study was to precisely investigate the association between SDF-1 rs1801157 polymorphism and cancer risk using meta-analysis and the false positive report probability (FPRP) test. All 17,876 participants were included in the study. The meta-analysis results indicated a significant association between the SDF-1 rs1801157 polymorphism and cancer risk. By subgroup analyses, the results detected that the SDF-1 rs1801157 polymorphism was associated with cancer susceptibility among Asians and Caucasians. Additionally, we also found significant associations between the SDF-1 rs1801157 polymorphism and susceptibility to different types of cancer. However, to avoid a "false positive report", we further investigated the significant associations observed in the present meta-analysis using the FPRP test. Interestingly, the results of the FPRP test indicated that only 4 gene models were truly associated with cancer risk, especially in Asians. Moreover, we confirmed that the SDF-1 rs1801157 gene polymorphism was only associated with lung and urologic cancer risk. In summary, this study suggested that the SDF-1 rs1801157 polymorphism may serve as a risk factor for cancer development among Asians, especially an increased risk of urologic and lung cancers.

The role of polymorphisms of stromal-derived factor-1 and CXC receptor 4 in acute myeloid leukemia and leukemia cell dissemination

BACKGROUND

Acute myeloid leukemia (AML) is a form of cancer characterized by infiltration of the bone marrow, blood, and other tissues by proliferative, clonal, abnormally differentiated cells of the hematopoietic system. Chemokine stromal cell-derived factor 1 (SDF-1) and its receptor CXC receptor 4 (CXCR4) play crucial roles in malignant cell invasion. Genetic polymorphisms may contribute to the differences in the expression level and activities associated with the SDF-1/CXCR4 pathway. This study aimed to determine the associations between the polymorphisms located on the SDF-1 (rs1801157, G>A) and CXCR4 (rs2228014, C>T) encoding genes and susceptibility and leukemia cell dissemination in AML.

METHODS

A total of 926 individuals, including 466 de novo AML patients and 460 healthy controls were genotyped for rs1801157 and rs2228014 using DNA Sanger sequencing.

RESULTS

Genotype distributions of CT and CT+TT for rs2228014 were significantly increased in AML patients compared with healthy controls [OR: 1.36, p=0.04; OR: 1.34, p=0.04; respectively]. However, rs1801157 demonstrated no significant differences in genotype distributions and allele frequency between AML patients and healthy controls. For the two combined SNPs, there was no significant proportional difference between the wild type GG-CC genotypes and non-GG-CC genotypes in AML patients and healthy controls. Additionally, peripheral blood leukemia-cell (PBLC) count was not statistically influenced by the genotypes of either rs1801157 or rs2228014.

CONCLUSION

Genotype CT of rs2228014 appeared to correlate with AML risk, but played no role in leukemia cells invading the bloodstream, while rs1801157 and the two combined SNPs were not associated with either increased AML risk or extramedullary leukemia-cell dissemination.

Beneficial effect of the CXCL12-3'A variant for patients undergoing hematopoietic stem cell transplantation from unrelated donors

The present study aimed to assess the impact of the CXCL12 gene polymorphism (rs1801157) on clinical outcome of hematopoietic stem cell transplantation from unrelated donors. Toxic complications were less frequent among patients transplanted from donors carrying the CXCL12-3'-A allele (42/79 vs. 105/151, p=0.014 and 24/79 vs. 73/151, p=0.009, for grade II-IV and III-IV, respectively). Logistic regression analyses confirmed a role of donor A allele (OR=0.509, p=0.022 and OR=0.473, p=0.013 for grade II-IV and III-IV toxicity). In addition, age of recipients (OR=0.980, p=0.036 and OR=0.981, p=0.040, respectively) was independently protective while female to male transplantation and HLA compatibility were not significant. The incidence of aGvHD (grades I-IV) was lower in patients having A allele (52/119 vs. 113/204, p=0.043) and AA homozygous genotype (6/25 vs. 159/298, p=0.005). Independent associations of both genetic markers with a decreased risk of aGvHD were also seen in multivariate analyses (A allele: OR=0.591, p=0.030; AA homozygosity: OR=0.257, p=0.006) in which HLA compatibility seemed to play less protective role (p<0.1) while recipient age and donor-recipient gender relation were not significant. Moreover, CXCL12-3'-A-positive patients were less prone to early HHV-6 reactivation (2/34 vs. 19/69, p=0.026). The presence of the CXCL12-3'-A variant was found to facilitate outcome of unrelated HSCT.

Decreased expression of CXCR4 chemokine receptor in bone marrow after chemotherapy in patients with non-Hodgkin lymphomas is a good prognostic factor

Background

CXCR4 chemokine receptor is constitutively expressed on normal and malignant B lymphocytes derived from patients with B-cell lymphoproliferative disorders and has a significant role in cell migration to lymph nodes and bone marrow. Non-Hodgkin's lymphomas (NHL) constitute a heterogeneous group of lymphoproliferative diseases, which can localize not only to lymph nodes, but also can migrate to peripheral blood and metastase to other organs, including bone marrow.

Aim

The purpose of this study was to determine CXCR4 gene expression in peripheral blood and bone marrow of NHL patients before and after treatment.

Methods

Samples of lymphoma lymph nodes, peripheral blood and bone marrow aspirates of patients with B-cell NHL were taken at diagnosis and after chemotherapy. Gene expression was determined by the reverse transcription (RT)-polymerase chain reaction method. Expression was estimated from 0 AU (no amplificate signal) to 3 AU (maximal amplificate signal).

Results

No significant difference in the level of CXCR4 expression was found in reactive lymph nodes compared to lymphoma samples We observed high level of CXCR4 expression in most patients before treatment: in bone marrow: 3 AU-10 pts, 2 AU–8 pts, 1 AU–2 pts. In peripheral blood: 3 AU–14 pts, 2 AU–4 pts, 1 AU–1 pts, 0 AU–1 pts. After chemotherapy, significant decrease in CXCR4 expression was observed. Bone marrow: 3 AU–5 pts, 2 AU–7 pts, 1 AU–5 pts, 0 AU–3 pts (p = 0.03). Peripheral blood: 3 AU–2 pts, 2 AU–6 pts, 1 AU–10 pts, 0 AU–2 pts (p = 0.0002). There was a good response to treatment in patients with significant decrease of CXCR4 expression in the bone marrow after treatment with 10-fold lower risk of death (p = 0.03).

Conclusions

Decrease in CXCR4 expression in the bone marrow of NHL patients after chemotherapy may be a good prognostic factor.