Despite therapeutic advances, multiple myeloma (MM) remains an incurable disease, predominantly because of the development of drug resistance. The activator protein-1 (AP-1) transcription factor ...family has been implicated in a multitude of physiologic processes and tumorigenesis; however, its role in MM is largely unknown. Here we demonstrate specific and rapid induction of the AP-1 family member JunB in MM cells when co-cultured with bone marrow stromal cells. Supporting a functional key role of JunB in MM pathogenesis, knockdown of JUNB significantly inhibited in vitro MM cell proliferation and survival. Consistently, induced silencing of JUNB markedly decreased tumor growth in a murine MM model of the microenvironment. Subsequent gene expression profiling revealed a role for genes associated with apoptosis, DNA replication and metabolism in driving the JunB-mediated phenotype in MM cells. Importantly, knockdown of JUNB restored the response to dexamethasone in dexamethasone-resistant MM cells. Moreover, 4-hydroxytamoxifen-induced activation of a JunB-ER fusion protein protected dexamethasone-sensitive MM cells against dexamethasone- and bortezomib-induced cytotoxicity. In summary, our results demonstrate for the first time a specific role for AP-1/JunB in MM cell proliferation, survival and drug resistance, thereby strongly supporting that this transcription factor is a promising new therapeutic target in MM.
Gene transfer into hematopoietic stem cells has been used successfully for correcting lymphoid but not myeloid immunodeficiencies. Here we report on two adults who received gene therapy after ...nonmyeloablative bone marrow conditioning for the treatment of X-linked chronic granulomatous disease (X-CGD), a primary immunodeficiency caused by a defect in the oxidative antimicrobial activity of phagocytes resulting from mutations in gp91(phox). We detected substantial gene transfer in both individuals' neutrophils that lead to a large number of functionally corrected phagocytes and notable clinical improvement. Large-scale retroviral integration site-distribution analysis showed activating insertions in MDS1-EVI1, PRDM16 or SETBP1 that had influenced regulation of long-term hematopoiesis by expanding gene-corrected myelopoiesis three- to four-fold in both individuals. Although insertional influences have probably reinforced the therapeutic efficacy in this trial, our results suggest that gene therapy in combination with bone marrow conditioning can be successfully used to treat inherited diseases affecting the myeloid compartment such as CGD.
Activating BRAF mutations, in particular V600E/K, drive many cancers and are considered mutually exclusive with mutant RAS, whereas inactivating BRAF mutations in the D(594)F(595)G(596) motif ...cooperate with RAS via paradoxical MEK/ERK activation. Due to the increasing use of comprehensive tumor genomic profiling, many non-V600 BRAF mutations are being detected whose functional consequences and therapeutic actionability are often unknown. We investigated an atypical BRAF mutation, F595L, which was identified along with mutant HRAS in histiocytic sarcoma and also occurs in epithelial cancers, melanoma and neuroblastoma, and determined its interaction with mutant RAS. Unlike other DFG motif mutants, BRAF(F595L) is a gain-of-function variant with intermediate activity that does not act paradoxically, but nevertheless cooperates with mutant RAS to promote oncogenic signaling, which is efficiently blocked by pan-RAF and MEK inhibitors. Mutation data from patients and cell lines show that BRAF(F595L), as well as other intermediate-activity BRAF mutations, frequently coincide with mutant RAS in various cancers. These data define a distinct class of activating BRAF mutations, extend the spectrum of patients with systemic histiocytoses and other malignancies who are candidates for therapeutic blockade of the RAF-MEK-ERK pathway and underscore the value of comprehensive genomic testing for uncovering the vulnerabilities of individual tumors.
Summary
Background
Eccrine porocarcinoma (EPC) is a rare skin cancer arising from the eccrine sweat glands. Due to the lack of effective therapies, metastasis is associated with a high mortality ...rate.
Objectives
To investigate the drivers of EPC progression.
Methods
We carried out genomic and transcriptomic profiling of metastatic EPC (mEPC), validation of the observed alterations in an EPC patient‐derived cell line, confirmation of relevant observations in a large patient cohort of 30 tumour tissues, and successful treatment of a patient with mEPC under the identified treatment regimens.
Results
mEPC was characterized by a high tumour mutational burden (TMB) with an ultraviolet signature, widespread copy number alterations and gene expression changes that affected cancer‐relevant cellular processes such as cell cycle regulation and proliferation, including a pathogenic TP53 (tumour protein 53) mutation, a copy number deletion in the CDKN2A (cyclin dependent kinase inhibitor 2A) region and a CTNND1/PAK1 catenin delta 1/p21 (RAC1) activated kinase 1 gene fusion. The overexpression of EGFR (epidermal growth factor receptor), PAK1 and MAP2K1 (mitogen‐activated protein kinase kinase 1; also known as MEK1) genes translated into strong protein expression and respective pathway activation in the tumour tissue. Furthermore, a patient‐derived cell line was sensitive to EGFR and MEK inhibition, confirming the functional relevance of the pathway activation. Immunohistochemistry analyses in a large patient cohort showed the relevance of the observed changes to the pathogenesis of EPC. Our results indicate that mEPC should respond to immune or kinase inhibitor therapy. Indeed, the advanced disease of our index patient was controlled by EGFR‐directed therapy and immune checkpoint inhibition for more than 2 years.
Conclusions
Molecular profiling demonstrated high TMB and EGFR/MAPK pathway activation to be novel therapeutic targets in mEPC.
What is already known about this topic?
Eccrine porocarcinoma (EPC) is a rare skin cancer with a largely unknown aetiology and molecular makeup.
In cases not amendable by surgery, no effective treatment is available.
What does this study add?
Using comprehensive genomic and transcriptomic profiling, aberrations in cancer‐relevant signalling pathways were identified that could not only be validated functionally in a newly established patient‐derived culture model but could also be confirmed in a larger series of retrospective cases.
Importantly, these observations were translated into treatment regimens resulting in substantial clinical benefit in a patient with metastatic EPC.
What is the translational message?
Here, we provide an excellent example of how from‐bedside‐to‐bench and back can work.
We not only detected relevant genetic aberrations in EPC, but also confirmed their functional relevance and their transferability to additional cases, culminating in effective treatment of the patient.
We thus provide new therapeutic options for EPC and possibly other adnexal carcinomas with similar molecular makeup.
Plain language summary available online
Summary
Background
Epithelioid haemangioma (EH) arising from the skin is a benign vascular tumour with marked inflammatory cell infiltration, which exhibits a high tendency to persist and frequently ...recurs after resection. So far, the underlying pathogenesis is largely elusive.
Objectives
To identify genetic alterations by next‐generation sequencing and/or droplet digital polymerase chain reaction (ddPCR) in cutaneous EH.
Methods
DNA and RNA from an EH lesion of an index patient were subjected to whole‐genome and RNA sequencing. Multiplex PCR‐based panel sequencing of genomic DNA isolated from archival formalin‐fixed paraffin‐embedded tissue of 18 patients with cutaneous EH was performed. ddPCR was used to confirm mutations.
Results
We identified somatic mutations in genes of the mitogen‐activated protein kinase (MAPK) pathway (MAP2K1 and KRAS) in cutaneous EH biopsies. By ddPCR we could confirm the recurrent presence of activating, low‐frequency mutations affecting MAP2K1. In total, nine out of 18 patients analysed showed activating MAPK pathway mutations, which were mutually exclusive. Comparative analysis of tissue areas enriched for lymphatic infiltrate or aberrant endothelial cells, respectively, revealed an association of these mutations with the presence of endothelial cells.
Conclusions
Taken together, our data suggest that EH shows somatic mutations in genes of the MAPK pathway which might contribute to the formation of this benign tumour.
What is already known about this topic?
Epithelioid haemangioma (EH) arising from the skin is a benign vascular tumour of unknown aetiology.
Cutaneous EH often shows a marked inflammatory infiltrate indicating a reactive origin.
What does this study add?
Half of the samples from cutaneous EH in this study showed activating mutations in the mitogen‐activated protein kinase pathway (MAP2K1 and KRAS).
Mutations were mutually exclusive.
What is the translational message?
Somatic mutations seem to contribute to the formation of a significant proportion of cutaneous EH.
The molecular alterations found might be sensitive for targeted therapies.
Linked Comment: W. Tan and J.S. Nelson. Br J Dermatol 2022; 186:393–394.
Disease progression of hepatocellular cancer (HCC) in patients eligible for liver transplantation (LTx) occurs in up to 50% of patients, resulting in withdrawal from the LTx waiting list. ...Transarterial chemoembolization (TACE) is used as bridging therapy with highly variable response rates. The oral multikinase inhibitor sorafenib significantly increases overall survival and time-to-progression in patients with advanced hepatocellular cancer.
The HeiLivCa study is a double-blinded, controlled, prospective, randomized multi-centre phase III trial. Patients in study arm A will be treated with transarterial chemoembolization plus sorafenib 400 mg bid. Patients in study arm B will be treated with transarterial chemoembolization plus placebo. A total of 208 patients with histologically confirmed hepatocellular carcinoma or HCC diagnosed according to EASL criteria will be enrolled. An interim patients' analysis will be performed after 60 events. Evaluation of time-to-progression as primary endpoint (TTP) will be performed at 120 events. Secondary endpoints are number of patients reaching LTx, disease control rates, OS, progression free survival, quality of live, toxicity and safety.
As TACE is the most widely used primary treatment of HCC before LTx and sorafenib is the only proven effective systemic treatment for advanced HCC there is a strong rational to combine both treatment modalities. This study is designed to reveal potential superiority of the combined TACE plus sorafenib treatment over TACE alone and explore a new neo-adjuvant treatment concept in HCC before LTx.
Sinonasal carcinomas (SNCs) comprise various rare tumor types that are characterized by marked histologic diversity and largely unknown molecular profiles, yet share an overall poor prognosis owing ...to an aggressive clinical course and frequent late-stage diagnosis. The lack of effective systemic therapies for locally advanced or metastatic SNC poses a major challenge to therapeutic decision making for individual patients. We here aimed to identify actionable genetic alterations in a patient with metastatic SNC whose tumor, despite all diagnostic efforts, could not be assigned to any known SNC category and was refractory to multimodal therapy.
We used whole-exome and transcriptome sequencing to identify a KIT exon 11 mutation (c.1733_1735del, p.D579del) as potentially druggable target in this patient and carried out cancer hotspot panel sequencing to detect secondary resistance-conferring mutations in KIT. Furthermore, as a step towards clinical exploitation of the recently described signatures of mutational processes in cancer genomes, we established and applied a novel bioinformatics algorithm that enables supervised analysis of the mutational catalogs of individual tumors.
Molecularly guided treatment with imatinib in analogy to the management of gastrointestinal stromal tumor (GIST) resulted in a dramatic and durable response with remission of nearly all tumor manifestations, indicating a dominant driver function of mutant KIT in this tumor. KIT dependency was further validated by a secondary KIT exon 17 mutation (c.2459_2462delATTCinsG, p.D820_S821delinsG) that was detected upon tumor progression after 10 months of imatinib treatment and provided a rationale for salvage therapy with regorafenib, which has activity against KIT exon 11/17 mutant GIST.
These observations highlight the potential of unbiased genomic profiling for uncovering the vulnerabilities of individual malignancies, particularly in rare and unclassifiable tumors, and underscore that KIT exon 11 mutations represent tractable therapeutic targets across different histologies.
Xenograft models of chronic phase human chronic myeloid leukemia (CML) have been difficult to develop because of the persistence of normal hematopoietic stem cells in most chronic phase CML patients ...and the lack of methods to selectively isolate the rarer CML stem cells. To circumvent this problem, we first identified nine patients' samples in which the long-term culture-initiating cells were predominantly leukemic and then transplanted cells from these samples into sublethally irradiated NOD/SCID and NOD/SCID-beta2microglobulin-/- mice. This resulted in the consistent and durable (>5 months) repopulation of both host genotypes with similar numbers of BCR-ABL+/Ph+ cells. The regenerated leukemic cells included an initial, transient population derived from CD34+CD38+ cells as well as more sustained populations derived from CD34+CD38- progenitors, indicative of a hierarchy of transplantable leukemic cells. Analysis of the phenotypes produced revealed a reduced output of B-lineage cells, enhanced myelopoiesis with excessive production of erythroid and megakaropoietic cells and the generation of primitive (CD34+) leukemic cells displaying an autocrine IL-3 and G-CSF phenotype, all characteristics of primary CML cells. These findings demonstrate the validity of this xenograft model of chronic phase human CML, which should enable future investigation of disease pathogenesis and new approaches to therapy.
There is a lack of relevant prognostic and predictive factors in neurooncology besides mutation of
isocitrate dehydrogenase 1
, codeletion of 1p/19q and promoter hypermethylation of
O
6
...-methylguanine
-
DNA
-
methyltransferase
. More importantly, there is limited translation of these factors into clinical practice. The cancer genome atlas data and also clinical correlative analyses suggest a pivotal role for the epidermal growth factor receptor /protein kinase B/mammalian target of rapamycin (mTOR) pathway in both biology and the clinical course of gliomas. However, attempts to stratify gliomas by activating alterations in this pathway have failed thus far. The tumors of 40 patients with WHO grade II gliomas without immediate postoperative genotoxic treatment and known progression and survival status at a median follow-up of 12.2 years were analyzed for expression of the mTOR complex 2 downstream target N-myc downstream regulated gene (NDRG)1 using immunohistochemistry. Baseline characteristics for NDRG1 absent/low versus moderate/high patients were similar. Time to reintervention was significantly longer in the NDRG1 group (
P
= 0.026). NDRG1 may become a novel biomarker to guide the decision which WHO°II glioma patients may be followed without postsurgical intervention and which patients should receive genotoxic treatment early on. Validation of this hypothesis will be possible with the observational arm of the RTOG 9802 and the pretreatment step of the EORTC 22033/26032 trials.
PDF
