Východiska: Folikulární lymfom (FL) je nejčastějším indolentním non-Hodgkinským lymfomem v západním světě. U většiny pacientů se jedná o indolentní onemocnění, ale u cca 20 % případů dochází po úvodní léčbě k časnému relapsu, což je spojeno s kratším celkovým přežitím. Další prognosticky závažnou událostí je histologická transformace FL do agresivního lymfomu, nejčastěji do difuzního velkobuněčného B-lymfomu. Díky genomickým studiím a myším modelům se nám lépe daří chápat molekulární podstatu vzniku FL a evoluci „agresivních“ subklonů buněk. Zároveň se také v posledních letech podařilo popsat deregulace molekulárních drah přispívajících k histologické transformaci FL. Cíl: V tomto přehledovém článku shrnujeme komplexní mechanizmy, které jsou na molekulární úrovni zodpovědné za vznik, progresi a agresivitu FL a jeho transformaci. Domníváme se, že tato pozorování u FL mají obecnější přesah pro pochopení mechanizmů, které vedou k evoluci „agresivity“ nádorového onemocnění jako je divergentní evoluce, intraklonální variabilita a nádorová plasticita.
Background: Follicular lymphoma (FL) is the most common indolent non-Hodgkin‘s lymphoma in the Western world. It is an indolent disease in most patients, but about 20% of patients experience an early relapse after initial treatment, which is associated with shorter overall survival. A histological transformation into an aggressive lymphoma, most frequently diffuse large-cell B-lymphoma, represents another prognostically unfavorable event in the course of the disease. Thanks to recent genomic studies and mouse models, we are able to better understand the molecular nature of the FL onset and evolution of “aggressive” subclones of cells. Recently, deregulation of several molecular pathways associated with the histological transformation has also been described. Purpose: This review summarizes the complex molecular mechanisms responsible for FL onset, progression, aggressiveness, and transformation. We believe that the observations in FL have some general implications for understanding the mechanisms leading to the evolution of cancer “aggressiveness,” such as divergent evolution, intraclonal variability and tumor plasticity.
- Klíčová slova
- histologická transformace, transformovaný folikulární lymfom,
- MeSH
- difúzní velkobuněčný B-lymfom genetika patologie MeSH
- folikulární lymfom * genetika patologie MeSH
- lidé MeSH
- nádorová transformace buněk * genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
BACKGROUND: A previous International Lymphoma Epidemiology (InterLymph) Consortium evaluation of joint associations between five immune gene variants and autoimmune conditions reported interactions between B-cell response-mediated autoimmune conditions and the rs1800629 genotype on risk of B-cell non-Hodgkin lymphoma (NHL) subtypes. Here, we extend that evaluation using NHL subtype-specific polygenic risk scores (PRS) constructed from loci identified in genome-wide association studies of three common B-cell NHL subtypes. METHODS: In a pooled analysis of NHL cases and controls of Caucasian descent from 14 participating InterLymph studies, we evaluated joint associations between B-cell-mediated autoimmune conditions and tertile (T) of PRS for risk of diffuse large B-cell lymphoma (DLBCL; n = 1,914), follicular lymphoma (n = 1,733), and marginal zone lymphoma (MZL; n = 407), using unconditional logistic regression. RESULTS: We demonstrated a positive association of DLBCL PRS with DLBCL risk [T2 vs. T1: OR = 1.24; 95% confidence interval (CI), 1.08-1.43; T3 vs. T1: OR = 1.81; 95% CI, 1.59-2.07; P-trend (Ptrend) < 0.0001]. DLBCL risk also increased with increasing PRS tertile among those with an autoimmune condition, being highest for those with a B-cell-mediated autoimmune condition and a T3 PRS [OR = 6.46 vs. no autoimmune condition and a T1 PRS, Ptrend < 0.0001, P-interaction (Pinteraction) = 0.49]. Follicular lymphoma and MZL risk demonstrated no evidence of joint associations or significant Pinteraction. CONCLUSIONS: Our results suggest that PRS constructed from currently known subtype-specific loci may not necessarily capture biological pathways shared with autoimmune conditions. IMPACT: Targeted genetic (PRS) screening among population subsets with autoimmune conditions may offer opportunities for identifying those at highest risk for (and early detection from) DLBCL.
- MeSH
- autoimunitní nemoci * epidemiologie genetika MeSH
- B-lymfocyty MeSH
- celogenomová asociační studie MeSH
- difúzní velkobuněčný B-lymfom * epidemiologie genetika MeSH
- folikulární lymfom * epidemiologie genetika MeSH
- lidé MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Ig gene (IG) clonality analysis has an important role in the distinction of benign and malignant B-cell lymphoid proliferations and is mostly performed with the conventional EuroClonality/BIOMED-2 multiplex PCR protocol and GeneScan fragment size analysis. Recently, the EuroClonality-NGS Working Group developed a method for next-generation sequencing (NGS)-based IG clonality analysis. Herein, we report the results of an international multicenter biological validation of this novel method compared with the gold standard EuroClonality/BIOMED-2 protocol, based on 209 specimens of reactive and neoplastic lymphoproliferations. NGS-based IG clonality analysis showed a high interlaboratory concordance (99%) and high concordance with conventional clonality analysis (98%) for the molecular conclusion. Detailed analysis of the individual IG heavy chain and kappa light chain targets showed that NGS-based clonality analysis was more often able to detect a clonal rearrangement or yield an interpretable result. NGS-based and conventional clonality analysis detected a clone in 96% and 95% of B-cell neoplasms, respectively, and all but one of the reactive cases were scored polyclonal. We conclude that NGS-based IG clonality analysis performs comparable to conventional clonality analysis. We provide critical parameters for interpretation and discuss a first step toward a quantitative scoring approach for NGS clonality results. Considering the advantages of NGS-based clonality analysis, including its high sensitivity and possibilities for accurate clonal comparison, this supports implementation in diagnostic practice.
- MeSH
- B-buněčný lymfom genetika MeSH
- B-lymfocyty imunologie MeSH
- buněčné klony imunologie MeSH
- fenotyp MeSH
- folikulární lymfom genetika MeSH
- genová přestavba * MeSH
- geny pro imunoglobuliny * MeSH
- imunoglobuliny - kappa-řetězce genetika MeSH
- lidé MeSH
- multiplexová polymerázová řetězová reakce metody MeSH
- senzitivita a specificita MeSH
- správnost dat MeSH
- těžké řetězce imunoglobulinů genetika MeSH
- vysoce účinné nukleotidové sekvenování metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
- validační studie MeSH
Follicular lymphoma (FL) is a common indolent B-cell malignancy with a variable clinical course. An unfavorable event in its course is histological transformation to a high-grade lymphoma, typically diffuse large B-cell lymphoma. Recent studies show that genetic aberrations of MYC or its overexpression are associated with FL transformation (tFL). However, the precise molecular mechanisms underlying tFL are unclear. Here we performed the first profiling of expression of microRNAs (miRNAs) in paired samples of FL and tFL and identified 5 miRNAs as being differentially expressed. We focused on one of these miRNAs, namely miR-150, which was uniformly downmodulated in all examined tFLs (∼3.5-fold), and observed that high levels of MYC are responsible for repressing miR-150 in tFL by binding in its upstream region. This MYC-mediated repression of miR-150 in B cells is not dependent on LIN28A/B proteins, which influence the maturation of miR-150 precursor (pri-miR-150) in myeloid cells. We also demonstrated that low miR-150 levels in tFL lead to upregulation of its target, namely FOXP1 protein, which is a known positive regulator of cell survival, as well as B-cell receptor and NF-κB signaling in malignant B cells. We revealed that low levels of miR-150 and high levels of its target, FOXP1, are associated with shorter overall survival in FL and suggest that miR-150 could serve as a good biomarker measurable in formalin-fixed paraffin-embedded tissue. Overall, our study demonstrates the role of the MYC/miR-150/FOXP1 axis in malignant B cells as a determinant of FL aggressiveness and its high-grade transformation.
- MeSH
- aktivace transkripce MeSH
- difúzní velkobuněčný B-lymfom genetika patologie MeSH
- down regulace MeSH
- folikulární lymfom diagnóza genetika patologie MeSH
- forkhead transkripční faktory genetika MeSH
- lidé MeSH
- mikro RNA genetika MeSH
- nádorová transformace buněk genetika patologie MeSH
- prognóza MeSH
- protoonkogenní proteiny c-myc genetika MeSH
- regulace genové exprese u nádorů * MeSH
- represorové proteiny genetika MeSH
- upregulace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- histologická transformace, protein FOXP1,
- MeSH
- difúzní velkobuněčný B-lymfom * genetika metabolismus MeSH
- folikulární lymfom * genetika metabolismus MeSH
- forkhead transkripční faktory genetika MeSH
- lidé MeSH
- mikro RNA * genetika metabolismus MeSH
- nádorová transformace buněk MeSH
- nádorové biomarkery genetika metabolismus MeSH
- progrese nemoci MeSH
- represorové proteiny genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Klíčová slova
- histonmetyltransferázy, BCL2, epigenetické regulátory,
- MeSH
- B-lymfocyty fyziologie patologie MeSH
- chromozomální aberace MeSH
- cytokiny MeSH
- folikulární lymfom * genetika patofyziologie patologie MeSH
- histonacetyltransferasy genetika MeSH
- lidé MeSH
- lymfocyty patologie MeSH
- mikro RNA MeSH
- mutace MeSH
- protoonkogenní proteiny fyziologie MeSH
- signální transdukce MeSH
- transkripční faktory genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- MeSH
- B-lymfocyty imunologie patologie MeSH
- buňky kostní dřeně imunologie patologie MeSH
- chronická lymfatická leukemie genetika imunologie patologie MeSH
- difúzní velkobuněčný B-lymfom genetika imunologie patologie MeSH
- folikulární lymfom genetika imunologie patologie MeSH
- hematopoetické kmenové buňky imunologie patologie MeSH
- hematopoéza genetika imunologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- lymfom z plášťových buněk genetika imunologie patologie MeSH
- mnohočetný myelom genetika imunologie patologie MeSH
- nádorové proteiny genetika imunologie MeSH
- regulace genové exprese u nádorů MeSH
- senioři MeSH
- stanovení celkové genové exprese MeSH
- studie případů a kontrol MeSH
- věkové faktory MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- práce podpořená grantem MeSH
The physiology of B cells is intimately connected with the function of their B-cell receptor (BCR). B-cell lymphomas frequently (dys)regulate BCR signalling and thus take advantage of this pre-existing pathway for B-cell proliferation and survival. This has recently been underscored by clinical trials demonstrating that small molecules (fosfamatinib, ibrutinib, idelalisib) inhibiting BCR-associated kinases (SYK, BTK, PI3K) have an encouraging clinical effect. Here we describe the current knowledge of the specific aspects of BCR signalling in diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, chronic lymphocytic leukaemia (CLL) and normal B cells. Multiple factors can contribute to BCR pathway (dys)regulation in these malignancies and the activation of 'chronic' or 'tonic' BCR signalling. In lymphoma B cells, the balance of initiation, amplitude and duration of BCR activation can be influenced by a specific immunoglobulin structure, the expression and mutations of adaptor molecules (like GAB1, BLNK, GRB2, CARD11), the activity of kinases (like LYN, SYK, PI3K) or phosphatases (like SHIP-1, SHP-1 and PTEN) and levels of microRNAs. We also discuss the crosstalk of BCR with other signalling pathways (NF-κB, adhesion through integrins, migration and chemokine signalling) to emphasise that the 'BCR inhibitors' target multiple pathways interconnected with BCR, which might explain some of their clinical activity.
- MeSH
- B-lymfocyty účinky léků metabolismus patologie MeSH
- chronická lymfatická leukemie farmakoterapie genetika metabolismus patologie MeSH
- difúzní velkobuněčný B-lymfom farmakoterapie genetika metabolismus patologie MeSH
- folikulární lymfom farmakoterapie genetika metabolismus patologie MeSH
- inhibitory proteinkinas terapeutické užití MeSH
- interakce mezi receptory a ligandy * MeSH
- lidé MeSH
- protinádorové látky terapeutické užití MeSH
- receptory antigenů B-buněk antagonisté a inhibitory genetika metabolismus MeSH
- regulace genové exprese u leukemie * MeSH
- signální transdukce genetika MeSH
- tyrosinkinasy antagonisté a inhibitory genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
