Tumor cells infected by Epstein–Barr virus (EBV) express latency proteins, among which LMP1 is able to increase the level of the anti‐apoptotic protein BCL‐2, today considered as an attractive target ...for therapeutic strategies. Our results suggest that agents targeting BCL‐2, used either alone or in combination with rituximab, represent a novel promising approach for post‐transplant EBV‐positive B lymphoproliferative disorder treatment.
Post‐transplant lymphoproliferative disorders (PTLD) and Burkitt's lymphoma (BL) are B‐cell malignancies strongly associated with Epstein–Barr virus (EBV) infection. In these lymphoproliferative disorders, EBV infection induces an increase in the expression of the anti‐apoptotic protein BCL‐2. Given its chemoprotective effect, BCL‐2 constitutes an attractive target for new therapeutic strategies for EBV‐positive B‐cell malignancies. Here, we show that ABT‐737, a small inhibitor of BCL‐2, BCL‐X(L), and BCL‐w, strongly induced apoptosis in vitro in EBV‐positive lymphoblastoid cell lines (which is a model for PTLD), whereas BL was less sensitive. ABT‐737 reduced tumor growth and increased the overall survival of mice in a xenograft model of PTLD but had no effect on BL xenograft mice. ABT‐737 combined with a low dose of cyclophosphamide, a major component of the conventional CHOP chemotherapy regimen for BL patients, reduced tumor growth during treatment but failed to improve the overall survival of BL xenograft mice. By contrast, the combination of ABT‐737 and rituximab, one of the main options for the treatment of PTLD, was highly efficient and induced approximately 70% remission in PTLD xenograft mice. These results suggest that the use of agents targeting BCL‐2, either alone or in combination with other conventional drugs, represents a novel promising approach for post‐transplant EBV‐positive B lymphoproliferative disorders.
IDH1 and IDH2 somatic mutations have been identified in solid tumors and blood malignancies. The development of inhibitors of mutant IDH1 and IDH2 in the past few years has prompted the development ...of a fast and sensitive assay to detect IDH1R132, IDH2R140 and IDH2R172 mutations to identify patients eligible for these targeted therapies. This study aimed to compare two new multiplexed PCR assays – an automated quantitative PCR (qPCR) on the PGX platform and a droplet digital PCR (ddPCR) with next‐generation sequencing (NGS) for IDH1/2 mutation detection. These assays were evaluated on 102 DNA extracted from patient peripheral blood, bone marrow and formalin‐fixed paraffin‐embedded tissue samples with mutation allelic frequency ranging from 0.6% to 45.6%. The ddPCR assay had better analytical performances than the PGX assay with 100% specificity, 100% sensitivity and a detection limit down to 0.5% on IDH1R132, IDH2R140 and IDH2R172 codons, and a high correlation with NGS results. Therefore, the new highly multiplexed ddPCR is a fast and cost‐effective assay that meets most clinical needs to identify and follow cancer patients in the era of anti‐IDH1/2‐targeted therapies.
This study presents the first evaluation of two new highly multiplexed PCR assays as compared with next‐generation sequencing (NGS): an automated qPCR on the PGX platform and an allele‐specific droplet digital PCR (ddPCR) assay, both designed to detect most IDH1 and IDH2 hotspot mutations. The ddPCR assay was the best assay in terms of sensitivity, specificity, robustness, cost and timeliness, regardless of patient sample processing. It is, therefore, an appealing alternative to NGS to screen patients eligible for IDH1/2 targeted therapies.
Exonucleasic domain POLE (edPOLE) mutations, which are responsible for a hypermutated tumor phenotype, occur in 1–2% of colorectal cancer (CRC) cases. These alterations represent an emerging ...biomarker for response to immune checkpoint blockade. This study aimed to assess the molecular characteristics of edPOLE‐mutated tumors to facilitate patient screening. Based on opensource data analysis, we compared the prevalence of edPOLE mutations in a control group of unselected CRC patients (n = 222) vs a group enriched for unusual BRAF/RAS mutations (n = 198). Tumor mutational burden (TMB) and immune infiltrate of tumors harboring edPOLE mutations were then analyzed. In total, 420 CRC patients were analyzed: 11 edPOLE‐mutated tumors were identified, most frequently in microsatellite (MMR)‐proficient young (< 70 years) male patients, with left‐sided tumors harboring noncodon 12 KRAS mutation. The prevalence of edPOLE‐mutated tumors in the control vs the experimental screening group was, respectively, 0.45% (n = 1) vs 5.0% (n = 10). Among the 11 edPOLE‐mutated cases, two had a low TMB, three were hypermutated, and six were ultramutated. EdPOLE‐mutated cases had a high CD8+ tumor‐infiltrating lymphocyte (TIL) infiltration. These clinicopathological and molecular criteria may help to identify edPOLE mutations associated with a high TMB in CRC, and improve the selection of patients who could benefit from immunotherapy.
Exonucleasic domain POLE (edPOLE) mutations, which occur in 1–2% of colorectal cancer, represent an emerging biomarker for response to immunotherapy. This study aimed to assess the molecular characteristics of edPOLE‐mutated tumors. Results show that the prevalence of edPOLE‐mutated tumors is higher in microsatellite‐proficient young Male patients harboring non‐codon 12 KRAS mutations. EdPOLE‐mutated cases had a high CD8+ lymphocyte infiltration.
Aims
The differential diagnosis of small hepatocellular nodules in cirrhosis between dysplastic nodules and hepatocellular carcinoma (HCC) remains challenging on biopsy. As TERT promoter (pTERT) ...mutations may indicate the nodules already engaged in the malignant process, the aim of this study was to identify histological criteria associated with pTERT mutations by detecting these mutations by ddPCR in small formalin‐fixed paraffin‐embedded (FFPE) hepatocellular nodules arising in cirrhosis.
Methods and results
We built a bicentric cohort data set of 339 hepatocellular nodules < 2 cm from cirrhotic samples, divided into a test cohort of 299 resected samples and a validation cohort of 40 biopsies. Pathological review, based on the evaluation of 14 histological criteria, classified all nodules. pTERT mutations were identified by ddPCR in FFPE samples. Among the 339 nodules, ddPCR revealed pTERT mutations in 105 cases (31%), including 90 and 15 cases in the test and validation cohorts, respectively. On multivariate analysis, three histological criteria were associated with pTERT mutations in the test cohort: increased cell density (P = 0.003), stromal invasion (P = 0.036) and plate‐thickening anomalies (P < 0.001). With the combination of at least two of these major criteria, the AUC for predicting pTERT mutations was 0.84 in the test cohort (sensitivity: 86%, specificity: 83%) and 0.81 in the validation cohort (sensitivity: 87%, specificity: 76%).
Conclusions
We identified three histological criteria as surrogate markers of pTERT mutations that may be used in routine biopsy to more clearly classify small hepatocellular nodules arising in cirrhosis.
In this study, we identified three histological criteria as surrogate markers of pTERT mutations that may be used in routine biopsy to better classify small hepatocellular nodules arising in cirrhosis.
The overexpression of antiapoptotic members (BCL-2, BCL-xL, MCL-1, etc.) of the BCL-2 family contributes to tumor development and resistance to chemotherapy or radiotherapy. Synthetic inhibitors ...targeting these proteins have been developed, and some hematological malignancies are now widely treated with a BCL-2 inhibitor (venetoclax). However, acquired resistance to venetoclax or chemotherapy drugs due to an upregulation of MCL-1 has been observed, rendering MCL-1 an attractive new target for treatment. Six MCL-1 inhibitors (S64315, AZD-5991, AMG-176, AMG-397, ABBV-467 and PRT1419) have been evaluated in clinical trials since 2016, but some were affected by safety issues and none are currently used clinically. There is, therefore, still a need for alternative molecules. We previously described two drimane derivatives as the first covalent BH3 mimetics targeting MCL-1. Here, we described the characterization and biological efficacy of one of these compounds (NA1—115—7), isolated from Zygogynum pancheri, a plant belonging to the Winteraceae family. NA1—115—7 specifically induced the apoptosis of MCL-1-dependent tumor cells, with two hours of treatment sufficient to trigger cell death. The treatment of lymphoma cells with NA1—115—7 stabilized MCL-1, disrupted its interactions with BAK, and rapidly induced apoptosis through a BAK- and BAX-mediated process. Importantly, a similar treatment with NA1—115—7 was not toxic to erythrocytes, peripheral blood mononuclear cells, platelets, or cardiomyocytes. These results highlight the potential of natural products for use as specific BH3 mimetics non-toxic to normal cells, and they suggest that NA1—115—7 may be a promising tool for use in cancer treatment.
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•NA1—115—7 induced apoptosis of MCL-1-dependent tumor cells through BAK and BAX activation.•Two hours of treatment with NA1—115—7 was sufficient to trigger death of tumor cells.•Normal blood cells and cardiomyocytes are not killed by NA1—115—7.•NA1—115—7 is the first covalent MCL-1 inhibitor able to function as a "suicide" molecule.•NA1—115—7 could be a highly promising tool for the treatment of cancer.
Thirty analogues of natural meiogynin A, a pan-Bcl-2 inhibitor, were prepared in order to elaborate cytotoxic compounds on specific cancer cells overexpressing one or more proteins of the Bcl-2 ...family. The interaction of all the new analogues with Bcl-xL, Mcl-1 and Bcl-2 proteins was first evaluated by fluorescence polarization assay (FPA) and showed that modulation of the lateral chain has a dramatic impact as subtle changes significantly modify the activity on the target proteins. The acetoxymethyl prodrugs of the two most active compounds were then elaborated to determine their cytotoxicity on B cell lines. A strong cytotoxic effect on BL2, RS4;11 and H929 cells was observed with a triazole prodrug that induces apoptosis.
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During the last few years, determination of microstatellite instability (MSI) status has become a routine part of clinical practice, essentially to detect Lynch syndrome. Recently, MSI testing has ...increased with the development of immunotherapy and has expanded to a large panel of solid tumours. The aim of our work was to evaluate a fully automated system developed by Biocartis, the Idylla MSI Test, which performs an MSI analysis within 150 min.
A comparison between pentaplex PCR, immunohistochemistry and Idylla MSI Test was performed in 53 colorectal carcinoma samples, 7 small intestine adenocarcinomas, 15 duodenal and pancreatic adenocarcinomas, 16 gastric tumours, 15 endometrial adenocarcinomas, 5 ovarian carcinomas and 4 cases of urinary tract tumours using extracted DNA. Limit-of-detection (LOD) experiment was also done using a commercial DNA known to harbour MSI phenotype.
The overall sensitivity was 94% and the overall specificity was 100%. Two invalid and three false-negative results were observed. Our experiments showed that the amount of DNA loaded into the cartridge was decisive and should be superior to 25 ng. LOD comprised between 4% and 8%.
Overall, we have demonstrated that the Idylla MSI Test is a rapid and valid option to detect MSI phenotype which can be used in a large panel of solid tumours.
Histological transformation into squamous cell carcinoma (SCC) is a rare mechanism of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. Its pathophysiology remains ...unclear and its management is particularly challenging. We report on tumor progression with SCC histological transformation associated with the T790M mutation in a patient with stage IV bronchial adenocarcinoma with an L858R mutation of the EGFR gene and treated with gefitinib. We will discuss the importance of liquid and tumor biopsy in the diagnostic management of resistance mechanisms as well as therapeutic management options.
Post‐transplant lymphoproliferative disorders (PTLD) and Burkitt's lymphoma (BL) are B‐cell malignancies strongly associated with Epstein–Barr virus (EBV) infection. In these lymphoproliferative ...disorders, EBV infection induces an increase in the expression of the anti‐apoptotic protein BCL‐2. Given its chemoprotective effect, BCL‐2 constitutes an attractive target for new therapeutic strategies for EBV‐positive B‐cell malignancies. Here, we show that ABT‐737, a small inhibitor of BCL‐2, BCL‐X(L), and BCL‐w, strongly induced apoptosis in vitro in EBV‐positive lymphoblastoid cell lines (which is a model for PTLD), whereas BL was less sensitive. ABT‐737 reduced tumor growth and increased the overall survival of mice in a xenograft model of PTLD but had no effect on BL xenograft mice. ABT‐737 combined with a low dose of cyclophosphamide, a major component of the conventional CHOP chemotherapy regimen for BL patients, reduced tumor growth during treatment but failed to improve the overall survival of BL xenograft mice. By contrast, the combination of ABT‐737 and rituximab, one of the main options for the treatment of PTLD, was highly efficient and induced approximately 70% remission in PTLD xenograft mice. These results suggest that the use of agents targeting BCL‐2, either alone or in combination with other conventional drugs, represents a novel promising approach for post‐transplant EBV‐positive B lymphoproliferative disorders.
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