Microsatellite instability (MSI) is present in 15–20% of primary colorectal cancers. MSI status is assessed to detect Lynch syndrome, guide adjuvant chemotherapy, determine prognosis, and use as a ...companion test for checkpoint blockade inhibitors. Traditionally, MSI status is determined by immunohistochemistry or molecular methods. The Idylla™ MSI Assay is a fully automated molecular method (including automated result interpretation), using seven novel MSI biomarkers (
ACVR2A
,
BTBD7
,
DIDO1
,
MRE11
,
RYR3
,
SEC31A
,
SULF2
) and not requiring matched normal tissue. In this real-world global study, 44 clinical centers performed Idylla™ testing on a total of 1301 archived colorectal cancer formalin-fixed, paraffin-embedded (FFPE) tissue sections and compared Idylla™ results against available results from routine diagnostic testing in those sites. MSI mutations detected with the Idylla™ MSI Assay were equally distributed over the seven biomarkers, and 84.48% of the MSI-high samples had ≥ 5 mutated biomarkers, while 98.25% of the microsatellite-stable samples had zero mutated biomarkers. The concordance level between the Idylla™ MSI Assay and immunohistochemistry was 96.39% (988/1025); 17/37 discordant samples were found to be concordant when a third method was used. Compared with routine molecular methods, the concordance level was 98.01% (789/805); third-method analysis found concordance for 8/16 discordant samples. The failure rate of the Idylla™ MSI Assay (0.23%; 3/1301) was lower than that of referenced immunohistochemistry (4.37%; 47/1075) or molecular assays (0.86%; 7/812). In conclusion, lower failure rates and high concordance levels were found between the Idylla™ MSI Assay and routine tests.
Summary
Diffuse large B‐cell lymphoma (DLBCL), the most common type of malignant lymphoma, accounts for 30% of adult non‐Hodgkin lymphomas. Epstein–Barr virus (EBV) ‐positive DLBCL of the elderly is ...a newly recognized subtype that accounts for 8–10% of DLBCLs in Asian countries, but is less common in Western populations. Five DLBCL‐derived cell lines were employed to characterize patterns of EBV latent gene expression, as well as response to cytokines and chemotaxis. Interleukin‐4 and interleukin‐21 modified LMP1, EBNA1 and EBNA2 expression depending on cell phenotype and type of EBV latent programme (type I, II or III). These cytokines also affected CXCR4‐ or CCR7‐mediated chemotaxis in two of the cell lines, Farage (type III) and Val (type II). Further, we investigated the effect of EBV by using dominant‐negative EBV nuclear antigen 1(dnEBNA1) to eliminate EBV genomes. This resulted in decreased chemotaxis. By employing an alternative way to eliminate EBV genomes, Roscovitine, we show an increase of apoptosis in the EBV‐positive lines. These results show that EBV plays an important role in EBV‐positive DLBCL lines with regard to survival and chemotactic response. Our findings provide evidence for the impact of microenvironment on EBV‐carrying DLBCL cells and might have therapeutic implications.
Epstein–Barr virus (EBV) plays an important role in EBV‐positive diffuse large B‐cell lymphoma lines with regard to survival and chemotactic response.
Epstein-Barr virus (EBV) is associated with a variety of human tumors. Although the EBV-infected normal B cells in vitro and the EBV-carrying B cell lymphomas in immunodeficient patients express the ...full set of latent proteins (type III latency), the majority of EBV-associated malignancies express the restricted type I (EBNA-1 only) or type II (EBNA-1 and LMPs) viral program. The mechanisms responsible for these different latent viral gene expression patterns are only partially known. IL-21 is a potent B cell activator and plasma cell differentiation-inducer cytokine produced by CD4⁺ T cells. We studied its effect on EBV-carrying B cells. In type I Burkitt lymphoma (BL) cell lines and in the conditional lymphoblastoid cell line (LCL) ER/EB2-5, IL-21 potently activated STAT3 and induced the expression of LMP-1, but not EBNA-2. The IL-21-treated type I Jijoye M13 BL line ceased to proliferate, and this was paralleled by the induction of IRF4 and the down-regulation of BCL6 expression. In the type III LCLs and BL lines, IL-21 repressed the C-promoter-derived and LMP-2A mRNAs, whereas it up-regulated the expression of LMP-1 mRNAs. The IL-21-treated type III cells underwent plasma cell differentiation with the induction of Blimp-1, and high levels of Ig and Oct-2. IL-21 might be involved in the EBNA-2-independent expression of LMP-1 in EBV-carrying type II cells. In light of the fact that IL-21 is already in clinical trials for the treatment of multiple malignancies, the in vivo modulation of EBV gene expression by IL-21 might have therapeutic benefits for the EBV-carrying malignancies.
EBV-positive nasopharyngeal carcinoma and Hodgkin, T, and natural killer (NK) lymphomas express EBNA-1 and the latent membrane proteins (LMP1-2; type II latency). In contrast to type III ...EBV-transformed lymphoblastoid cell lines, in these cells the LMPs are expressed in the absence of EBNA-2. We have previously reported that exposure to CD40 ligand and IL-4 could induce LMP-1 in an in vitro EBV-infected Hodgkin lymphoma-derived cell line, which expressed only EBNA-1. We show now that both human and EBV-encoded IL-10 can induce LMP-1 in the absence of EBNA-2 in the Daudi, P3HR1, and other BL cell lines. Interestingly, induction of LMP-1 was not accompanied by the downregulation of BCL-6. IL-10 could also induce LMP-1 in the conditional lymphoblastoid cell line ER/EB2-5 where EBNA-2 was downregulated in the absence of estrogen. Moreover, IL-10 could induce the expression of LMP-1 in tonsillar B cells infected with the nontransforming, EBNA-2-deficient EBV strain P3HR1 and enhance LMP-1 expression in 2 EBV-positive NK lymphoma lines. The demonstration that IL-10 can induce the expression of LMP-1 in an EBNA-2-independent manner shows that the major transforming EBV gene LMP-1 can be induced by extracellular signals in lymphoid cells, and IL-10 might contribute to the establishment of type II EBV latency.
Microscopy analysis of tumour samples is commonly performed on fixed, thinly sectioned and protein-labelled tissues. However, these examinations do not reveal the intricate three-dimensional ...structures of tumours, nor enable the detection of aberrant transcripts. Here, we report a method, which we name DIIFCO (for diagnosing in situ immunofluorescence-labelled cleared oncosamples), for the multimodal volumetric imaging of RNAs and proteins in intact tumour volumes and organoids. We used DIIFCO to spatially profile the expression of diverse coding RNAs and non-coding RNAs at the single-cell resolution in a variety of cancer tissues. Quantitative single-cell analysis revealed spatial niches of cancer stem-like cells, and showed that the niches were present at a higher density in triple-negative breast cancer tissue. The improved molecular phenotyping and histopathological diagnosis of cancers may lead to new insights into the biology of tumours of patients.
Initiation and progression in conventional adenomas is triggered by deregulation of WNT/β-catenin signaling. In the absence of WNT signal (off-state), β-catenin prevents phosphorylation of GSK3β, ...leading to aberrant nuclear accumulation in human tumors. It has been postulated that mutations in the β-catenin gene are always associated with a morphologically-neoplastic course. While investigating the nuclear expression of β-catenin in 170 colorectal biopsies, we observed a non-previously reported phenomenon, namely the presence of β-catenin cytoplasmic helices in 29% (n=7) of 24 sessile serrated adenoma/polyps (SSA/P), in 24% (n=13) of 54 adenomas, in 8% (n=3) of 38 specimens with IBD, but in none (0/54) with normal mucosa. The earliest β-catenin helices were found at the bottom of SSA/P glands (the domain of stem cells in the colorectal mucosa). It is submitted that β-catenin helices might highlight a non-previously described cytoplasmic phenomenon evolving during the serrated-carcinoma pathway in SSA/P, and during the adenoma-carcinoma pathway in conventional adenomas.
Primary effusion lymphoma (PEL) is a rare KSHV/HHV8-associated high-grade non-Hodgkin's lymphoma (NHL) of B-cell origin, characterized by serous effusions in body cavities. Most patients are ...HIV-infected men with severe immunosuppression and other HHV8-associated diseases such as Kaposi's sarcoma (KS). The prognosis for those infected is poor, with a median survival of less than 6 months in most cohorts. Sustained complete remission is rare. High-dose chemotherapy regimens are used to improve remission rate and survival. The aim of the present study was to compare the drug sensitivity pattern of the available primary effusion (body cavity based) lymphoma-derived cell lines in order to find additional, potentially effective drugs that are not included in current chemotherapy treatment protocols.
We have analyzed 11 cell lines against 27 frequently used cytostatic drugs in short term (3 days) survival assays using automated high throughput confocal microscopy.
All cell lines showed a distinct, individual drug sensitivity pattern. Considering the in vitro used and clinically achieved drug concentration, Vinorelbine, Paclitaxel, Epirubicin and Daunorubicin were the most effective drugs.
We suggest that inclusion of the above drugs into PEL chemotherapy protocols may be justified. The heterogeneity in the drug response pattern however indicated that assay-guided individualized therapy might be required to optimize therapeutic response.
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