Immune checkpoint‐blocking antibodies have therapeutic activity against relapsed or progressive classic Hodgkin lymphoma (cHL), but Hodgkin Reed‐Sternberg cells can develop resistance to this therapy ...via multiple mechanisms. To improve the efficacy of immune checkpoint blockade, we need a more precise understanding of the immune escape mechanisms active in individual cHL patients, and this requires a detailed characterization of immune cell populations in the tumor microenvironment. These cell‐cell interactions can now be studied by multiplex immunohistochemistry coupled to digital image analysis. This method should allow the identification of actionable target molecules mediating resistance to immune checkpoint inhibitors in individual cHL patients, thereby favoring the implementation of personalized therapies.
The paper reviews the composition of the tumor microenvironment in Hodgkin lymphoma and discusses the mechanisms of immune evasion that may inform therapy. It also highlights the role of multiplex immunohistochemistry of the tumor to assess multiple immunomodulatory molecules expressed by the different cell types.
The HER2 splice variant characterized by the deletion of exon 16 and denominated as d16HER2, is associated with HER2-positive breast cancer (BC) aggressiveness, stemness, and trastuzumab ...susceptibility and is considered to be a "flag" of HER2 dependence. However, with the exception of quantitative real-time PCR analysis, easily reproducible assays are still lacking to clinically detect and quantify the d16HER2 expression. Further, no data on d16HER2 expression and its potential role are available in HER2-positive gastrointestinal malignancies. Here, we used a novel RNA in situ hybridization technique (BaseScope) to discriminate d16HER2 variant expression from the wild type isoform (WTHER2) and to assess their levels across different HER2-positive histological samples. Our results demonstrate the existence of outliers, with d16HER2 mRNA high scores restricted to HER2-positive gastric cancer (GC) and colorectal cancer (CRC) coupled with increased d16HER2 expression compared with BC. Consistent with previously reported data on BC, experiments performed in HER2-positive GC patient-derived xenografts suggest that increased d16HER2 expression is associated with a clinical benefit/response to single-agent trastuzumab. Therefore, d16HER2 may be considered as a "flag" of HER2 dependence in GC and can be clinically investigated as a marker of trastuzumab susceptibility in several other HER2-driven cancers, including CRC. As a clinical proof-of-concept, we indicate that high d16HER2 mRNA scores are exclusively found in patients with a long-term benefit from trastuzumab exceeding 12 months (clinical "outliers"), and that d16HER2 expression is also increased in circulating tumor-released exosomes obtained from baseline plasma samples of long-term responders.
Antiangiogenic agents and therapeutic strategies have entered the clinical oncology arena. The classical tumor size measurements defined to monitor efficacy of chemotherapy, however, might not be ...appropriate for these newer therapeutics. We previously found that circulating endothelial cells (CECs) were increased in number and more viable in cancer patients compared with control subjects. We investigated the correlation between CEC kinetics and clinical outcome in patients with advanced breast cancer receiving metronomic chemotherapy, a therapeutic strategy associated with antiangiogenic activity and anticancer efficacy. CEC number and viability were measured by flow cytometry in patients and in preclinical models. CECs were decreased in patients for whom no overall clinical benefit (defined as a clinical response or a stable disease) was observed compared with those who had a clinical benefit (P = .015). This difference was due to an increased fraction of apoptotic CECs in patients with a clinical benefit. Univariate and multivariate analyses indicated that CEC values greater than 11/μL were associated with a longer progression-free survival (P = .001) and an improved overall survival (P = .005). Preclinical models indicated that the source of apoptotic CECs was most likely the tumor vasculature. CEC kinetics and viability are very promising as predictors of clinical response in patients undergoing metronomic chemotherapy.
Recent randomized trials focused on gene expression-based determination of the cell of origin in diffuse large B-cell lymphoma could not show significant improvements by adding novel agents to ...standard chemoimmunotherapy. The aim of this study was the identification of a gene signature able to refine current prognostication algorithms and applicable to clinical practice. Here we used a targeted gene expression profiling panel combining the Lymph2Cx signature for cell of origin classification with additional targets including MYC, BCL-2 and NFKBIA, in 186 patients from 2 randomized trials (discovery cohort) (NCT00355199 and NCT00499018). Data were validated in 3 independent series (2 large public datasets and a real-life cohort). By integrating the cell of origin, MYC/BCL-2 double expressor status and NFKBIA expression, we defined a 3-gene signature combining MYC, BCL-2 and NFKBIA (MBN-signature), which outperformed the MYC/BCL-2 double expressor status in multivariate analysis, and allowed further risk stratification within the germinal center B-cell/unclassified subset. The high-risk (MBN Sig-high) subgroup identified the vast majority of double hit cases and a significant fraction of Activated B-Cell-derived diffuse large B-cell lymphomas. These results were validated in 3 independent series including a cohort from the REMoDL-B trial, where, in an exploratory ad hoc analysis, the addition of bortezomib in the MBN Sig-high subgroup provided a progression free survival advantage compared with standard chemoimmunotherapy. These data indicate that a simple 3-gene signature based on MYC, BCL-2 and NFKBIA could refine the prognostic stratification in diffuse large B-cell lymphoma, and might be the basis for future precision-therapy approaches.
The clinical relevance of circulating tumor cell clusters (CTC-clusters) in breast cancer (BC) has been mostly studied using the CellSearch®, a marker-dependent method detecting only ...epithelial-enriched clusters. However, due to epithelial-to-mesenchymal transition, resorting to marker-independent approaches can improve CTC-cluster detection. Blood samples collected from healthy donors and spiked-in with tumor mammospheres, or from BC patients, were processed for CTC-cluster detection with 3 technologies: CellSearch®, CellSieve™ filters, and ScreenCell® filters. In spiked-in samples, the 3 technologies showed similar recovery capability, whereas, in 19 clinical samples processed in parallel with CellSearch® and CellSieve™ filters, filtration allowed us to detect more CTC-clusters than CellSearch® (median number = 7 versus 1, p = 0.0038). Next, samples from 37 early BC (EBC) and 23 metastatic BC (MBC) patients were processed using ScreenCell® filters for attaining both unbiased enrichment and marker-independent identification (based on cytomorphological criteria). At baseline, CTC-clusters were detected in 70% of EBC cases and in 20% of MBC patients (median number = 2, range 0–20, versus 0, range 0–15, p = 0.0015). Marker-independent approaches for CTC-cluster assessment improve detection and show that CTC-clusters are more frequent in EBC than in MBC patients, a novel finding suggesting that dissemination of CTC-clusters is an early event in BC natural history.
The natural history of ductal carcinoma in situ (DCIS) is highly variable and difficult to predict. Biomarkers are needed to stratify patients with DCIS for adjuvant therapy. We investigated the ...prognostic and predictive relevance of cell cycle progression (CCP) score in women with DCIS. We measured the expression of 23 genes involved in CCP with quantitative RT-PCR on RNA extracted from formalin-fixed paraffin-embedded tumor samples, and assessed the correlation of a predefined score with histopathologic features and recurrence. The signature was analyzed in a cohort of 909 consecutive DCIS with full histopathological features treated in a single institution. The main outcome measure was ipsilateral breast event (IBE) as first event observed, be it in situ or invasive. Median follow-up time was 8.7 years (IQR 6.5-10.5 years). There were 150 ipsilateral IBEs, 84 (56%) of which were invasive. In the first 5 years of follow-up, the score provided statistically different findings (p = 0.009), with IBE rates of 14.7% (95% CI, 10.4-19.7) for the highest quartile of CCP score (Q4) and 8.7% (95% CI, 6.7-11.0) for the lowest quartiles (Q1-3). The prognostic value for IBEs approached significance also in women treated with mastectomy (adjusted hazard ratio HR Q4 vs. Q1-3 = 2.60; 95% CI: 0.96-7.08; P = 0.06). Radiotherapy provided a greater benefit in women with higher CCP score. In addition, Q4 predicted a different risk after tamoxifen depending on menopausal status, with a beneficial trend on IBEs in postmenopausal women (HR 0.30; 95% CI, 0.07-1.39), and an opposite trend in premenopausal women (HR 1.68; 95% CI, 0.38-7.44) (P-interaction = 0.03). The results of this study provide for the first time the evidence that CCP score is a prognostic marker, which, after additional validation, could have an important role in personalizing the management of DCIS.
Background Improvement of efficacy of immune checkpoint blockade (ICB) remains a major clinical goal. Association of ICB with immunomodulatory epigenetic drugs is an option. However, epigenetic ...inhibitors show a heterogeneous landscape of activities. Analysis of transcriptional programs induced in neoplastic cells by distinct classes of epigenetic drugs may foster identification of the most promising agents. Methods Melanoma cell lines, characterized for mutational and differentiation profile, were treated with inhibitors of DNA methyltransferases (guadecitabine), histone deacetylases (givinostat), BET proteins (JQ1 and OTX-015), and enhancer of zeste homolog 2 (GSK126). Modulatory effects of epigenetic drugs were evaluated at the gene and protein levels. Master molecules explaining changes in gene expression were identified by Upstream Regulator (UR) analysis. Gene set enrichment and IPA were used respectively to test modulation of guadecitabine-specific gene and UR signatures in baseline and on-treatment tumor biopsies from melanoma patients in the Phase Ib NIBIT-M4 Guadecitabine + Ipilimumab Trial. Prognostic significance of drug-specific immune-related genes was tested with Timer 2.0 in TCGA tumor datasets. Results Epigenetic drugs induced different profiles of gene expression in melanoma cell lines. Immune-related genes were frequently upregulated by guadecitabine, irrespective of the mutational and differentiation profiles of the melanoma cell lines, to a lesser extent by givinostat, but mostly downregulated by JQ1 and OTX-015. GSK126 was the least active drug. Quantitative western blot analysis confirmed drug-specific modulatory profiles. Most of the guadecitabine-specific signature genes were upregulated in on-treatment NIBIT-M4 tumor biopsies, but not in on-treatment lesions of patients treated only with ipilimumab. A guadecitabine-specific UR signature, containing activated molecules of the TLR, NF-kB, and IFN innate immunity pathways, was induced in drug-treated melanoma, mesothelioma and hepatocarcinoma cell lines and in a human melanoma xenograft model. Activation of guadecitabine-specific UR signature molecules in on-treatment tumor biopsies discriminated responding from non-responding NIBIT-M4 patients. Sixty-five % of the immune-related genes upregulated by guadecitabine were prognostically significant and conferred a reduced risk in the TCGA cutaneous melanoma dataset. Conclusions The DNMT inhibitor guadecitabine emerged as the most promising immunomodulatory agent among those tested, supporting the rationale for usage of this class of epigenetic drugs in combinatorial immunotherapy approaches. Keywords: Melanoma, Epigenetic drugs, Immune-related signatures, Guadecitabine, Innate immunity
Background
Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer (TC). Several genomic and transcriptomic studies explored the molecular landscape of follicular cell-derived ...TCs, and
BRAF
V600E,
RAS
mutations, and gene fusions are well-established drivers.
DICER1
mutations were described in specific sets of TC patients but represent a rare event in adult TC patients.
Methods
Here, we report the molecular characterization of 30 retrospective follicular cell-derived thyroid tumors, comprising PTCs (90%) and poorly differentiated TCs (10%), collected at our Institute. We performed DNA whole-exome sequencing using patient-matched control for somatic mutation calling, and targeted RNA-seq for gene fusion detection. Transcriptional profiles established in the same cohort by microarray were investigated using three signaling-related gene signatures derived from The Cancer Genome Atlas (TCGA).
Results
The occurrence of
BRAF
V600E (44%),
RAS
mutations (13%), and gene fusions (13%) was confirmed in our cohort. In addition, in two patients lacking known drivers, mutations of the
DICER1
gene (p.D1709N and p.D1810V) were identified.
DICER1
mutations occur in two adult patients with follicular-pattern lesions, and in one of them a second concurrent
DICER1
mutation (p.R459*) is also observed. Additional putative drivers include
ROS1
gene (p.P2130A mutation), identified in a patient with a rare solid-trabecular subtype of PTC. Transcriptomics indicates that
DICER1
tumors are RAS-like, whereas the
ROS1
-mutated tumor displays a borderline RAS-/BRAF-like subtype. We also provide an overview of
DICER1
and
ROS1
mutations in thyroid lesions by investigating the COSMIC database.
Conclusion
Even though small, our series recapitulates the genetic background of PTC. Furthermore, we identified
DICER1
mutations, one of which is previously unreported in thyroid lesions. For these less common alterations and for patients with unknown drivers, we provide signaling information applying TCGA-derived classification.
Thyroid carcinoma (TC) comprises several histotypes with different aggressiveness, from well (papillary carcinoma, PTC) to less differentiated forms (poorly differentiated and anaplastic thyroid ...carcinoma, PDTC and ATC, respectively). Previous reports have suggested a functional role for cancer-associated fibroblasts (CAFs) or senescent TC cells in the progression of PTC. In this study, we investigated the presence of CAFs and senescent cells in proprietary human TCs including PTC, PDTC, and ATC. Screening for the driving lesions
and
mutations, and gene fusions was also performed to correlate results with tumor genotype. In samples with unidentified drivers, transcriptomic profiles were used to establish a BRAF- or RAS-like molecular subtype based on a gene signature derived from The Cancer Genome Atlas. By using immunohistochemistry, we found co-occurrence of stromal CAFs and senescent TC cells at the tumor invasive front, where deposition of collagen (COL1A1) and expression of lysyl oxidase (LOX) enzyme were also detected, in association with features of local invasion. Concurrent high expression of CAFs and of the senescent TC cells markers,
and
was confirmed in different TC histotypes in proprietary and public gene sets derived from Gene Expression Omnibus (GEO) repository, and especially in
mutated or BRAF-like tumors. In this study, we show that CAFs and senescent TC cells co-occur in various histotypes of BRAF-driven thyroid tumors and localize at the tumor invasive front.
Transcription factor (TF)-induced reprogramming of somatic cells into induced pluripotent stem cells (iPSC) is associated with genome-wide changes in chromatin modifications. Polycomb-mediated ...histone H3 lysine-27 trimethylation (H3K27me3) has been proposed as a defining mark that distinguishes the somatic from the iPSC epigenome. Here, we dissected the functional role of H3K27me3 in TF-induced reprogramming through the inactivation of the H3K27 methylase EZH2 at the onset of reprogramming. Our results demonstrate that surprisingly the establishment of functional iPSC proceeds despite global loss of H3K27me3. iPSC lacking EZH2 efficiently silenced the somatic transcriptome and differentiated into tissues derived from the three germ layers. Remarkably, the genome-wide analysis of H3K27me3 in Ezh2 mutant iPSC cells revealed the retention of this mark on a highly selected group of Polycomb targets enriched for developmental regulators controlling the expression of lineage specific genes. Erasure of H3K27me3 from these targets led to a striking impairment in TF-induced reprogramming. These results indicate that PRC2-mediated H3K27 trimethylation is required on a highly selective core of Polycomb targets whose repression enables TF-dependent cell reprogramming.
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