Purpose
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by recurrent genetic aberration in leukemic stem cells, namely Philadelphia chromosome caused by reciprocal ...translocation t(9;22)(q34;q11). In our study, we analyzed the telomeric complex expression and function in the molecular pathogenesis of CML.
Methods
We employed CD34+ primary leukemic cells, comprising both leukemic stem and progenitor cell populations, isolated from peripheral blood or bone marrow of CML patients in chronic and blastic phase to analyze the telomere length and telomeric-associated proteins.
Results
The reduction in telomere length during disease progression was correlated with increased expression of
BCR::ABL1
transcript and the dynamic changes were neither associated with the enzymatic activity of telomerase nor with gene copy number and expression of telomerase subunits. Increased expression of
BCR::ABL1
was positively correlated with expression of
TRF2
,
RAP1
,
TPP1
,
DKC1
,
TNKS1
, and
TNKS2
genes.
Conclusions
The dynamics of telomere length changes in CD34+ CML cells is dependent on the expression level of
BCR::ABL
, which promotes the expression of certain shelterins including
RAP1
and
TRF2
, as well as
TNKS
, and
TNKS2
, and results in telomere shortening regardless of telomerase activity. Our results may allow better understanding of the mechanisms responsible for the genomic instability of leukemic cells and CML progression.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Here we perform the first genome-wide association study (GWAS) of multiple myeloma (MM) survival. In a meta-analysis of 306 MM patients treated at UCSF and 239 patients treated at the Mayo clinic, we ...find a significant association between SNPs near the gene FOPNL on chromosome 16p13 and survival (rs72773978; P=6 × 10(-10)). Patients with the minor allele are at increased risk for mortality (HR: 2.65; 95% CI: 1.94-3.58) relative to patients homozygous for the major allele. We replicate the association in the IMMEnSE cohort including 772 patients, and a University of Utah cohort including 318 patients (rs72773978 P=0.044). Using publicly available data, we find that the minor allele was associated with increased expression of FOPNL and increased expression of FOPNL was associated with higher expression of centrosomal genes and with shorter survival. Polymorphisms at the FOPNL locus are associated with survival among MM patients.
Summary
Over the past four decades, remarkable progress has been made in the treatment and prognosis of multiple myeloma (MM), although it remains an incurable disease. Chemotherapy resistance is a ...major hurdle for treatment efficacy. Drug resistance can be innate and so driven by genes involved in the drug metabolism pathways. We performed an association study of 71 germline variants within the major genes in those pathways (ABCB1, ABCC2, ABCG2, and their regulators NR1I2/PXR and NR1I3/CAR) in the International Multiple Myeloma rESEarch (IMMEnSE) consortium, consisting of 1365 MM cases with survival information recruited in 5 European countries. Two of the SNPs showed a significant association with the survival of MM patients, namely rs2235013, located in ABCB1 Hazard ratio (HR) = 1·52, 95% confidence interval (CI) = 1·18–1·95, P = 0·00087, and rs4148388, located in ABCC2 (HR = 2·15, 95% CI = 1·44–3·22, P = 0·0001). ABCC2 plays an essential role in transporting various anticancer drugs, including several used against MM, out of the cell. In silico analyses predict that the variant alleles of four SNPs in linkage disequilibrium with ABCC2‐rs4148388 are associated with increased gene expression. Overexpression of ABCC2 increases drug clearance and therefore may induce drug resistance mechanisms. In conclusion, we found a promising association between ABCC2‐rs4148388 and MM outcome that is supported by a plausible biological explanation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Pyoderma gangrenosum (PG) is an uncommon, serious, ulcerating skin disease of uncertain etiology. It manifests as a noninfectious, progressive necrosis of the skin characterized by sterile ...neutrophilic infiltrates. It seems to be a disorder of the immune system. PG is associated with certain underlying conditions in at least 50% of cases. Therefore, it is important to look carefully for comorbidities in every patient with PG and treat them adequately to improve the prognosis. Here, we demonstrate a 35-year-old man diagnosed with multifocal PG and hemophagocytic lymphohistiocytosis (HLH) with fatal outcome, despite combined, long-term, intensive dermatological and hematological treatment with high doses of steroids, cyclosporin, intravenous immunoglobulins (IVIG), HLH-2004 protocol with intravenously administered etoposide, and anakinra. This case is presented owing to the extremely rare coexistence of PG and HLH and the related diagnostic and therapeutic difficulties. It is also worth underlying that the diagnosis of HLH should perhaps be considered in the presence of a high percentage of double-negative T lymphocytes (DNTs) in flow cytometry, after excluding the diagnosis of lymphoma and leukemia. In this article we have also performed and present the critical literature review of local and systemic options in the management of PG lesions based on a detailed search of the PubMed database.
Compelling biological and epidemiological evidences point to a key role of genetic variants of the TERT and TERC genes in cancer development. We analyzed the genetic variability of these two gene ...regions using samples of 2,267 multiple myeloma (MM) cases and 2,796 healthy controls. We found that a TERT variant, rs2242652, is associated with reduced MM susceptibility (OR = 0.81; 95% CI: 0.72–0.92; p = 0.001). In addition we measured the leukocyte telomere length (LTL) in a subgroup of 140 cases who were chemotherapy‐free at the time of blood donation and 468 controls, and found that MM patients had longer telomeres compared to controls (OR = 1.19; 95% CI: 0.63–2.24; ptrend = 0.01 comparing the quartile with the longest LTL versus the shortest LTL). Our data suggest the hypothesis of decreased disease risk by genetic variants that reduce the efficiency of the telomerase complex. This reduced efficiency leads to shorter telomere ends, which in turn may also be a marker of decreased MM risk.
What's new?
A critical element of cancer cell immortality is the maintenance of telomere length, a process that is influenced in part by genetic variations in telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC). At the TERT locus in particular, certain variations are linked with either increased or decreased risk of a variety of malignancies. In the present study, a variant of TERT known as rs2242652 was associated with reduced risk of multiple myeloma. Compared with controls, patients with multiple myeloma were found to possess longer telomeres, suggesting an association between increased telomere length and increased multiple myeloma risk.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Genetic variants in genes acting during the maturation process of immature B-cell to differentiated plasma cell could influence the risk of developing multiple myeloma (MM). During B-cell maturation, ...several programmed genetic rearrangements occur to increase the variation of the immunoglobulin chains. Class switch recombination (CSR) is one of the most important among these mechanisms. Germline polymorphisms altering even subtly this process could play a role in the etiology and outcome of MM. We performed an association study of 30 genetic variants in the key CSR genes, using 2632 MM patients and 2848 controls from the International Multiple Myeloma rESEarch (IMMEnSE) consortium, the Heidelberg MM Group and the ESTHER cohort. We found an association between LIG4-rs1555902 and decreased MM risk, which approached statistical significance, as well as significant associations between AICDA-rs3794318 and better outcome. Our results add to our knowledge on the genetic component of MM risk and survival.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Cereblon (CRBN) is crucial for antiproliferative and immunomodulatory properties of immunomodulatory drugs. The objective of this study was to verify whether germline single nucleotide polymorphisms ...(SNPs) in the CRBN gene may influence response to lenalidomide in multiple myeloma (MM). Fourteen tagging SNPs covering the genetic variability in the CRBN gene region were genotyped in 167 Polish patients with refractory/relapsed MM treated with lenalidomide-based regimens. We found that carriers of minor alleles of two studied CRBN SNPs rs1714327G > C (OR = 0.26; 95% CI = 0.1-0.67; p = .0055, Bonferroni corrected p = .033) and rs1705814T > C (OR = 0.22; 95% CI = 0.07-0.65; p = .0063, Bonferroni corrected p = .037) were significantly associated with lower probability of achievement at least partial remission while treated with lenalidomide-based regimens, using the dominant inheritance model. Moreover, one of these SNPs, namely rs1705814T > C, was correlated with shorter progression-free survival (HR = 2.49; 95%CI = 1.31-4.74, p = .0054, Bonferroni corrected p = .033). It is suggested that selected germline CRBN allelic variants (rs1714327G > C and rs1705814T > C) affect lenalidomide efficacy in patients with relapsed/refractory MM.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The idiopathic hypereosinophilic syndrome (HES) comprises a heterogenous group of disorders characterized by marked blood eosinophilia with eosinophilia-associated organ damage. Eight patients with a ...median age at diagnosis of 42 years (range 19–67) received imatinib mesylate (IM) for FIP1L1-PDGFRα-negative HES resistant to previous conventional treatment. Median number of prior therapies was 3 (range 2–4). Median time from diagnosis to IM initiation was 112 months (range 2–293). Four patients were treated daily with 100 mg IM, whereas the remaining four patients were treated daily with 400 mg IM. Four male patients (50%) achieved complete haematologic response (CHR) after median of 7 days (range 3–150) using 100 mg daily IM (
n
= 2) and 400 mg (
n
= 2). Median duration of IM treatment for IM responders was 18 months (range 2–88). No adverse events were reported throughout the treatment duration. Two patients maintained CHR while on 100 mg weekly IM. Four patients (2 men and 2 women) failed IM treatment. Median duration of IM for non-responding patients was 3 weeks (range 3–12). Non-responding HES patients were significantly older and had lower percentage of blood eosinophilia when compared with IM responders. Our results suggest that IM, even at lower than conventional doses, may induce and maintain long-term remission for FIP1L1-PDGFRα-negative HES.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Genetic background plays a role in multiple myeloma susceptibility. Several single-nucleotide polymorphisms (SNP) associated with genetic susceptibility to multiple myeloma were identified in the ...last years, but only a few of them were validated in independent studies.
With the aim to conclusively validate the strongest associations so far reported, we selected the polymorphisms rs2227667 (SERPINE1), rs17501108 (HGF), rs3136685 (CCR7), rs16944 (IL1B), rs12147254 (TRAF3), rs1805087 (MTR), rs1800629 (TNF-α), rs7516435 (CASP9), rs1042265 (BAX), rs2234922 (mEH), and rs1801133 (MTHFR). We genotyped them in 1,498 multiple myeloma cases and 1,934 controls ascertained in the context of the International Multiple Myeloma rESEarch (IMMEnSE) consortium, and meta-analyzed our results with previously published ones.
None of the selected SNPs were significantly associated with multiple myeloma risk (P value range, 0.055-0.981), possibly with the exception of the SNP rs2227667 (SERPINE1) in women.
We can exclude that the selected polymorphisms are major multiple myeloma risk factors.
Independent validation studies are crucial to identify true genetic risk factors. Our large-scale study clarifies the role of previously published polymorphisms in multiple myeloma risk.
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