SOX11, CCND1, BCL1/IgH and IgH-VDJ: a battle of minimal residual disease markers in mantle cell lymphoma?

Abstract

Minimal residual disease (MRD) is defi ned as the persistence of residual tumor cells in patients during or after treatment, when the patient is in remission. Th e monitoring of MRD has been shown to be an excellent tool for optimization of patient care and therapy response. Formal proof of its benefi cial eff ects has been published for patients with diff erent types of leukemia [1], usually employing quantitative polymerase chain reaction (qPCR) methodology, which currently is the most sensitive approach for disease monitoring. In patients with non-Hodgkin lymphoma (NHL), however, the impact of MRD monitoring is less well defi ned.Mantle cell lymphoma (MCL) is a heterogeneous disease representing about 5 -10% of all cases of NHL [2]. Approximately 90% of patients with MCL are diagnosed by pathology, with overexpression of the cyclin D1 gene ( CCND1 ) caused by fusion of the BCL1 gene on chromosome 11 to the immunoglobulin heavy chain ( IgH ) locus on chromosome 14 [2,3]. In addition to t(11;14), clonal rearrangements of the IgH locus can be identifi ed in most MCLs [4]. Recently, overexpression of the intron-less SOX11 gene was reported as a diagnostic marker highly associated with MCL, with the added advantage of identifying CCND1-negative patients with MCL [5,6].Th e overexpression of SOX11 and CCND1 and the presence of t(11;14) and/or clonal rearrangements are all previously described as potent MRD markers for MCL [7 -10]. However, the literature is lacking direct comparisons of these four key biomarkers.We previously reported assays for sensitive and mRNA specifi c quantifi cation of the overexpression of SOX11 and CCND1 as well as the genomic fusion of BCL1/IgH [7,11]. Expanding the latter assay with patient-specifi c forward primers targeting IgH-VDJ we were, in addition, able to cover the clonal rearrangements of IgH@ .Given these prerequisites, we aimed to compare the four MRD markers for MCL in order to determine their relative values as MRD vehicles in MCL. A total of 213 samples from 78 patients were analyzed with a median number of 2 samples per patient (range 1 -12): 44 patients each contributed a diagnostic peripheral blood (PB) sample, 21 patients with relapse each contributed a PB sample, whereof seven of these patients also included a diagnostic sample in the diagnostic cohort of 44 patients, and 148 follow-up PB samples from 47 patients (20 of these patients had no diagnostic or relapse sample available) were examined for both SOX11 and CCND1 expression; a subgroup of these samples was additionally analyzed for BCL1/IgH and clonal IgH-VDJ allelic burden. Part of the patient material has been used in other studies [7,8,11]. Figure 1(A) shows a strong correlation ( r 2 value: 0.7867) between SOX11 and CCND1 expression in samples ranging from diagnosis to complete remission (CR) and relapse. This was in agreement with a previous study, performed by Meggendorfer et al. , targeting mRNA expression levels at diagnosis [12]. Also apparent in the present study is the low background expression of CCND1...

Mantle cell lymphoma in the era of precision medicine-diagnosis, biomarkers and therapeutic agents

“…A few studies suggest that the lack of IGVH somatic mutations correlates with a more aggressive clinical course and possibly with shorter survival of MCL patients [54]. More recently, BCL1/IgH, and IgH-VDJ along with SOX11 and Cyclin D1 have been discussed as biomarkers for MRD-guided management of patients with mature B cell malignancies including MCL [55]. …”

Minimal residual disease in non‐Hodgkin lymphoma – current applications and future directions

“…Conversely, MRD negativity at EOT has been shown to predict long disease‐free survival (Andersen et al , ; Liu et al , ). This has been observed with a number of different MRD techniques including IGH‐CCND1 , IGH VDJ , or SOX11 tracking (Andersen et al , ; Pott et al , ; Simonsen et al , ). In one study, patients in complete remission after R‐CHOP or hyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone, methotrexate and cytarabine) induction therapy were assessed for MRD status before ASCT.…”

“…We will refer henceforth to these methods as IgNGS approaches (TCR‐based MRD detection is outside the scope of this review). Alternatively, one can look for somatic mutations or other genetic abnormalities that are present in a given patient's tumour and that can be used to track ctDNA (Newman et al , ; Simonsen et al , ; Scherer et al , ). We will refer to these methods as mutNGS approaches.…”

“…Alternatively, using PCR targeting a single gene can track common mutations. As proof of concept, SOX11 , the gene encoding a transcription factor involved in cellular differentiation, has been shown to be upregulated in the majority of patients with MCL and displays similar kinetics to other MRD markers (Simonsen et al , ).…”

Sensitive quantification of the intronless SOX11 mRNA from lymph nodes biopsies in mantle cell lymphoma

“…mRNA was purified from PBMCs isolated using a Ficoll gradient centrifugation and from homogenized LN and tonsil tissues. SOX11 and CCND1 expression was quantified and calculated as reference gene normalized expression values (RGN), using the reference genes GUSB and B2M and defined as relative expression levels per 1000 reference gene transcripts as previously described ((2 (CqRGmean-CqSOX11 or CCND1) )*1000)[1,10,11]. Employing this assay, based on cDNA synthesis using oligo(dT) primer and a poly-T specific reverse PCR primer together with a locked nucleic acid (LNA)modified hydrolysis probe compensating for the low GC content, there was no risk of genomic DNA amplification[10], thereby excluding a critical methodological issue for the reliable quantification of low levels of transcripts from intronless genes.…”