Jak2V617F Reversible Activation Shows Its Essential Requirement in Myeloproliferative Neoplasms

Gain-of-function mutations activating JAK/STAT signaling are seen in the majority of patients with myeloproliferative neoplasms (MPN), most commonly JAK2V617F. Although clinically approved JAK inhibitors improve symptoms and outcomes in MPNs, remissions are rare, and mutant allele burden does not substantively change with chronic therapy. We hypothesized this is due to limitations of current JAK inhibitors to potently and specifically abrogate mutant JAK2 signaling. We therefore developed a conditionally inducible mouse model allowing for sequential activation, and then inactivation, of Jak2V617F from its endogenous locus using a combined Dre-rox/Cre-lox dual-recombinase system. Jak2V617F deletion abrogates MPN features, induces depletion of mutant-specific hematopoietic stem/progenitor cells, and extends overall survival to an extent not observed with pharmacologic JAK inhibition, including when cooccurring with somatic Tet2 loss. Our data suggest JAK2V617F represents the best therapeutic target in MPNs and demonstrate the therapeutic relevance of a dual-recombinase system to assess mutant-specific oncogenic dependencies in vivo.

SIGNIFICANCE

Current JAK inhibitors to treat myeloproliferative neoplasms are ineffective at eradicating mutant cells. We developed an endogenously expressed Jak2V617F dual-recombinase knock-in/knock-out model to investigate Jak2V617F oncogenic reversion in vivo. Jak2V617F deletion abrogates MPN features and depletes disease-sustaining MPN stem cells, suggesting improved Jak2V617F targeting offers the potential for greater therapeutic efficacy. See related commentary by Celik and Challen, p. 701. This article is featured in Selected Articles from This Issue, p. 695.

Mapping genotypes to chromatin accessibility profiles in single cells

In somatic tissue differentiation, chromatin accessibility changes govern priming and precursor commitment towards cellular fates1-3. Therefore, somatic mutations are likely to alter chromatin accessibility patterns, as they disrupt differentiation topologies leading to abnormal clonal outgrowth. However, defining the impact of somatic mutations on the epigenome in human samples is challenging due to admixed mutated and wild-type cells. Here, to chart how somatic mutations disrupt epigenetic landscapes in human clonal outgrowths, we developed genotyping of targeted loci with single-cell chromatin accessibility (GoT-ChA). This high-throughput platform links genotypes to chromatin accessibility at single-cell resolution across thousands of cells within a single assay. We applied GoT-ChA to CD34+ cells from patients with myeloproliferative neoplasms with JAK2V617F-mutated haematopoiesis. Differential accessibility analysis between wild-type and JAK2V617F-mutant progenitors revealed both cell-intrinsic and cell-state-specific shifts within mutant haematopoietic precursors, including cell-intrinsic pro-inflammatory signatures in haematopoietic stem cells, and a distinct profibrotic inflammatory chromatin landscape in megakaryocytic progenitors. Integration of mitochondrial genome profiling and cell-surface protein expression measurement allowed expansion of genotyping onto DOGMA-seq through imputation, enabling single-cell capture of genotypes, chromatin accessibility, RNA expression and cell-surface protein expression. Collectively, we show that the JAK2V617F mutation leads to epigenetic rewiring in a cell-intrinsic and cell type-specific manner, influencing inflammation states and differentiation trajectories. We envision that GoT-ChA will empower broad future investigations of the critical link between somatic mutations and epigenetic alterations across clonal populations in malignant and non-malignant contexts.

Investigating strontium isotope linkage between biominerals (uroliths), drinking water and environmental matrices

This study presents the mineralogy and strontium isotope ratio (87Sr/86Sr) of 21 pathological biominerals (bladder and kidney stones) collected from patients admitted between 2018 and 2020 at the Department of Urology of the San Pio Hospital (Benevento, southern Italy). Urinary stones belong to the calcium oxalate, purine or calcium phosphate mineralogy types. Their corresponding 87Sr/86Sr range from 0.707607 for an uricite sample to 0.709970 for a weddellite one, and seem to be partly discriminated based on the mineralogy. The comparison with the isotope characteristics of 38 representative Italian bottled and tap drinking waters show a general overlap in 87Sr/86Sr with the biominerals. However, on a smaller geographic area (Campania Region), we observe small 87Sr/86Sr differences between the biominerals and local waters. This may be explained by external Sr inputs for example from agriculture practices, inhaled aerosols (i.e., particulate matter), animal manure and sewage, non-regional foods. Nevertheless, biominerals of patients that stated to drink and eat local water/wines and foods every day exhibited a narrower 87Sr/86Sr range roughly matching the typical isotope ratios of local geological materials and waters, as well as those of archaeological biominerals from the same area. Finally, we conclude that the strontium isotope signature of urinary stones may reflect that of the environmental matrices surrounding patients, but future investigations are recommended to ultimately establish the potential for pathological biominerals as reliable biomonitoring proxies, taking into the account the contribution of the external sources of Sr.

MAVS signaling is required for preventing persistent chikungunya heart infection and chronic vascular tissue inflammation

Chikungunya virus (CHIKV) infection has been associated with severe cardiac manifestations, yet, how CHIKV infection leads to heart disease remains unknown. Here, we leveraged both mouse models and human primary cardiac cells to define the mechanisms of CHIKV heart infection. Using an immunocompetent mouse model of CHIKV infection as well as human primary cardiac cells, we demonstrate that CHIKV directly infects and actively replicates in cardiac fibroblasts. In immunocompetent mice, CHIKV is cleared from cardiac tissue without significant damage through the induction of a local type I interferon response from both infected and non-infected cardiac cells. Using mice deficient in major innate immunity signaling components, we found that signaling through the mitochondrial antiviral-signaling protein (MAVS) is required for viral clearance from the heart. In the absence of MAVS signaling, persistent infection leads to focal myocarditis and vasculitis of the large vessels attached to the base of the heart. Large vessel vasculitis was observed for up to 60 days post infection, suggesting CHIKV can lead to vascular inflammation and potential long-lasting cardiovascular complications. This study provides a model of CHIKV cardiac infection and mechanistic insight into CHIKV-induced heart disease, underscoring the importance of monitoring cardiac function in patients with CHIKV infections.

Establishment of patient-derived tumor organoids to functionally inform treatment decisions in metastatic colorectal cancer

BACKGROUND

Metastatic colorectal cancer (mCRC) patients tend to have modest benefits from molecularly driven therapeutics. Patient-derived tumor organoids (PDTOs) represent an unmatched model to elucidate tumor resistance to therapy, due to their high capacity to resemble tumor characteristics.

MATERIALS AND METHODS

We used viable tumor tissue from two cohorts of patients with mCRC, naïve or refractory to treatment, respectively, for generating PDTOs. The derived models were subjected to a 6-day drug screening assay (DSA) with a comprehensive pipeline of chemotherapy and targeted drugs against almost all the actionable mCRC molecular drivers. For the second cohort DSA data were matched with those from PDTO genotyping.

RESULTS

A total of 40 PDTOs included in the two cohorts were derived from mCRC primary tumors or metastases. The first cohort included 31 PDTOs derived from patients treated in front line. For this cohort, DSA results were matched with patient responses. Moreover, RAS/BRAF mutational status was matched with DSA cetuximab response. Ten out of 12 (83.3%) RAS wild-type PDTOs responded to cetuximab, while all the mutant PDTOs, 8 out of 8 (100%), were resistant. For the second cohort (chemorefractory patients), we used part of tumor tissue for genotyping. Four out of nine DSA/genotyping data resulted applicable in the clinic. Two RAS-mutant mCRC patients have been treated with FOLFOX-bevacizumab and mitomycin-capecitabine in third line, respectively, based on DSA results, obtaining disease control. One patient was treated with nivolumab-second mitochondrial-derived activator of caspases mimetic (phase I trial) due to high tumor mutational burden at genotyping, experiencing stable disease. In one case, the presence of BRCA2 mutation correlated with DSA sensitivity to olaparib; however, the patient could not receive the therapy.

CONCLUSIONS

Using CRC as a model, we have designed and validated a clinically applicable methodology to potentially inform clinical decisions with functional data. Undoubtedly, further larger analyses are needed to improve methodology success rates and propose suitable treatment strategies for mCRC patients.

ODP551 Halting ErbB-2 Isoforms Retrograde Transport to the Nucleus as a New Theragnostic Approach for Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) is clinically defined by the absence of estrogen and progesterone receptors and the lack of membrane overexpression or gene amplification of the receptor tyrosine kinase ErbB-2/HER2. Due to its heterogeneity, clinical biomarkers and targeted therapies for this disease remain elusive, and chemotherapy has been the standard of care for TNBC. ErbB-2 is classically located at the membrane of BC cells, where it triggers signaling cascades and promotes oncogenesis. We previously demonstrated that ErbB-2 is also localized in the nucleus (NErbB-2) of TNBC cells, from where it drives growth (1). We also discovered that TNBC expresses both wild-type ErbB-2 (WTErbB-2) and alternative ErbB-2 isoform c (ErbB-2c) (1). ErbB-2 migrates to the nucleus via retrograde transport. Here, we revealed that Retro-2, an inhibitor of retrograde transport that protects cells form the deleterious effects of toxins and viruses, evicts both WTErbB-2 and ErbB-2c from the nucleus of BC cells. Using BC models from several molecular subtypes, as well as normal breast cells, we demonstrated that Retro-2 specifically halts the proliferation of cells expressing NErbB-2. Moreover, Retro-2 decreased the expression of genes induced by NErbB-2 (i. e. cyclin D1 and Erk5) and promoted cell cycle arrest at G0/G1 phase and apoptosis. In addition to R2 growth inhibitory activity in vitro, we here also demonstrated that its optimized cyclic derivative Retro-2.1 (in particular the (S)-enantiomer) showed improved efficacy both to evict ErbB-2 isoforms from the nucleus and to inhibit proliferation in vitro. Importantly, Retro-2 eviction of both ErbB-2 isoforms from the nucleus resulted in a striking growth abrogation in multiple TNBC preclinical models, including xenografts and tumor explants). Our mechanistic studies demonstrated that Retro-2 induces a differential accumulation of WTErbB-2 at the early endosomes and plasma membrane, and of ErbB-2c at the Golgi, shedding light both on Retro-2 action on endogenous protein cargoes undergoing retrograde transport and on the biology of ErbB-2 splicing variants. Compelling evidence demonstrated that mRNAs 5' and 3' untranslated regions (UTRs) mediate post-transcriptional regulation of gene expression and determine protein levels and fate. While both T1 and T3 have different 5' but the same 3' UTRs sequences, our in silico studies showed that T1 and T3 RNA secondary structures vary in the region containing both their 5' and 3' UTRs. These findings suggest that T3 secondary structure impacts in its cell specific localization. Together, our present discoveries identify R2 as a precision oncology tool to target NErbB-2 retrograde transport. This novel theragnostic approach could greatly improve the outcome of TNBC patients. (1) Chervo MF et al, Oncogene 2020: 39: 6245-62.

Presentation: No date and time listed

May a comprehensive mineralogical study of a jackstone calculus and some other human bladder stones unveil health and environmental implications?

This paper represents the first result of an active collaboration between the University of Sannio and the San Pio Hospital (Benevento, Italy), started in the 2018, that aims to a detailed mineralogical investigation of urinary stones of patients from Campania region. Herein, selected human bladder stones have been deeply characterized for clinical purposes and environmental biomonitoring, focusing on the importance to evaluate the concentration and distribution of undesired trace elements by means of microscopic techniques in the place of conventional wet chemical analyses. A rare bladder stone with a sea-urchin appearance, known as jackstone calculus, were also investigated (along with bladder stones made of uric acid and brushite) by means a comprehensive analytical approach, including Synchrotron X-ray Diffraction and Simultaneous Thermal Analyses. Main clinical assumptions were inferred according to the morpho-constitutional classification of bladder stones and information about patient's medical history and lifestyle. In most of the analyzed uroliths, undesired trace elements such as copper, cadmium, lead, chromium, mercury and arsenic have been detected and generally attributable to environmental pollution or contaminated food. Simultaneous occurrence of selenium and mercury should denote a methylmercury detoxification process, probably leading to the formation of a very rare HgSe compound known as tiemannite.

Single-cell multi-omics of human clonal hematopoiesis reveals that DNMT3A R882 mutations perturb early progenitor states through selective hypomethylation

Somatic mutations in cancer genes have been detected in clonal expansions across healthy human tissue, including in clonal hematopoiesis. However, because mutated and wild-type cells are admixed, we have limited ability to link genotypes with phenotypes. To overcome this limitation, we leveraged multi-modality single-cell sequencing, capturing genotype, transcriptomes and methylomes in progenitors from individuals with DNMT3A R882 mutated clonal hematopoiesis. DNMT3A mutations result in myeloid over lymphoid bias, and an expansion of immature myeloid progenitors primed toward megakaryocytic-erythroid fate, with dysregulated expression of lineage and leukemia stem cell markers. Mutated DNMT3A leads to preferential hypomethylation of polycomb repressive complex 2 targets and a specific CpG flanking motif. Notably, the hypomethylation motif is enriched in binding motifs of key hematopoietic transcription factors, serving as a potential mechanistic link between DNMT3A mutations and aberrant transcriptional phenotypes. Thus, single-cell multi-omics paves the road to defining the downstream consequences of mutations that drive clonal mosaicism.

Abstract 344: Blockade of retrograde transport in triple negative breast cancer excludes ErbB-2 isoforms from the nucleus and abrogates tumor growth

Triple negative breast cancer (TNBC) is clinically defined by the absence of estrogen and progesterone receptors and the lack of membrane overexpression or gene amplification of the receptor tyrosine kinase ErbB-2/HER2. Due to its heterogeneity, clinical biomarkers and targeted therapies for this disease remain elusive, and chemotherapy has been the standard of care for early and metastatic TNBC. ErbB-2 is classically located at the membrane of BC cells, where it triggers signalling cascades and promotes oncogenesis. However, we have demonstrated that ErbB-2 is also localized in the nucleus (NErbB-2) of TNBC cells and primary tumors, from where it drives growth. We also discovered that TNBC expresses both wild-type ErbB-2 (WTErbB-2) and alternative ErbB-2 isoform c (ErbB-2c). ErbB-2 migrates to the nucleus via retrograde transport. The small molecule Retro-2 is a non-toxic inhibitor of the retrograde transport route that protects cells from the deleterious effects of toxins and viruses. Here, we revealed that Retro-2 evicts both WTErbB-2 and ErbB-2c from the nuclei. Using BC models from several molecular subtypes, we demonstrated that Retro-2 specifically halts the proliferation of cells expressing NErbB-2 in a dose-dependent manner, whilst did not inhibit cell proliferation in the ErbB-2-negative MCF10A normal breast cell line. Additionally, Retro-2 decreased the expression of genes induced by NErbB-2 (cyclin D1 and Erk5) and promoted cell cycle arrest at G0/G1 phase and apoptosis. Even more, in preclinical models (including xenografts and tumor explants), Retro-2 treatment resulted in the eviction of NErbB-2 and abrogation of tumor growth. Our mechanistic studies demonstrated that Retro-2 induces a differential accumulation of WTErbB-2 at the early endosomes and plasma membrane, and of ErbB-2c at the Golgi, further preventing its sorting to the endoplasmic reticulum. These findings shed light both on Retro-2 action on endogenous protein cargoes undergoing retrograde transport and on the biology of ErbB-2 splicing variants. Together, our present discoveries provide evidence for the rational repurposing of Retro-2 as a novel therapeutic agent for TNBC.

Citation Format: Santiago Madera, Franco Izzo, Maria F. Chervo, Agustina Dupont, Violeta A. Chiauzzi, Sofia Bruni, Ezequiel Petrillo, Diego Montero, Sharon Merin, Maria F. Mercogliano, Cecilia J. Proietti, Roxana Schillaci, Rosalia I. Cordo Russo, Patricia V. Elizalde. Blockade of retrograde transport in triple negative breast cancer excludes ErbB-2 isoforms from the nucleus and abrogates tumor growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 344.

Halting ErbB-2 isoforms retrograde transport to the nucleus as a new theragnostic approach for triple-negative breast cancer

Triple-negative breast cancer (TNBC) is clinically defined by the absence of estrogen and progesterone receptors and the lack of membrane overexpression or gene amplification of receptor tyrosine kinase ErbB-2/HER2. Due to TNBC heterogeneity, clinical biomarkers and targeted therapies for this disease remain elusive. We demonstrated that ErbB-2 is localized in the nucleus (NErbB-2) of TNBC cells and primary tumors, from where it drives growth. We also discovered that TNBC expresses both wild-type ErbB-2 (WTErbB-2) and alternative ErbB-2 isoform c (ErbB-2c). Here, we revealed that the inhibitors of the retrograde transport Retro-2 and its cyclic derivative Retro-2.1 evict both WTErbB-2 and ErbB-2c from the nucleus of BC cells and tumors. Using BC cells from several molecular subtypes, as well as normal breast cells, we demonstrated that Retro-2 specifically blocks proliferation of BC cells expressing NErbB-2. Importantly, Retro-2 eviction of both ErbB-2 isoforms from the nucleus resulted in a striking growth abrogation in multiple TNBC preclinical models, including tumor explants and xenografts. Our mechanistic studies in TNBC cells revealed that Retro-2 induces a differential accumulation of WTErbB-2 at the early endosomes and the plasma membrane, and of ErbB-2c at the Golgi, shedding new light both on Retro-2 action on endogenous protein cargoes undergoing retrograde transport, and on the biology of ErbB-2 splicing variants. In addition, we revealed that the presence of a functional signal peptide and a nuclear export signal (NES), both located at the N-terminus of WTErbB-2, and absent in ErbB-2c, accounts for the differential subcellular distribution of ErbB-2 isoforms upon Retro-2 treatment. Our present discoveries provide evidence for the rational repurposing of Retro-2 as a novel therapeutic agent for TNBC.

Specification of fetal liver endothelial progenitors to functional zonated adult sinusoids requires c-Maf induction

The liver vascular network is patterned by sinusoidal and hepatocyte co-zonation. How intra-liver vessels acquire their hierarchical specialized functions is unknown. We study heterogeneity of hepatic vascular cells during mouse development through functional and single-cell RNA-sequencing. The acquisition of sinusoidal endothelial cell identity is initiated during early development and completed postnatally, originating from a pool of undifferentiated vascular progenitors at E12. The peri-natal induction of the transcription factor c-Maf is a critical switch for the sinusoidal identity determination. Endothelium-restricted deletion of c-Maf disrupts liver sinusoidal development, aberrantly expands postnatal liver hematopoiesis, promotes excessive postnatal sinusoidal proliferation, and aggravates liver pro-fibrotic sensitivity to chemical insult. Enforced c-Maf overexpression in generic human endothelial cells switches on a liver sinusoidal transcriptional program that maintains hepatocyte function. c-Maf represents an inducible intra-organotypic and niche-responsive molecular determinant of hepatic sinusoidal cell identity and lays the foundation for the strategies for vasculature-driven liver repair.

Radiological assessment of peritoneal carcinomatosis: a primer for resident

The imaging has critical responsibility in the assessment of peritoneal lesions along with estimating the overall extent. Valuing disease burden is crucial for selection of combining cytoreductive surgery (CRS) and intraperitoneal hyperthermic chemotherapy (HIPEC) treatment. An approach that combines the strength of several imaging tools and increases diagnostic accuracy, should be chosen, even if the preferred imaging tool in patients with suspected Peritoneal Carcinomatosis (PC) is CT. The outcomes of PC are mainly correlated to tumor spread, localization, and lesion size. Accurate assessment of these features is critical for prognosis and treatment planning. These data can be evaluated by Peritoneal Cancer Index (PCI), a quantitative index suggested by Harman and Sugarbaker. Additionally, precise predictive biomarkers should be established to predict PC in patients at risk. The radiomics analysis could predict PC throughout the evaluation of cancers heterogeneity.

Diagnostic performance of LI-RADS in adult patients with rare hepatic tumors

OBJECTIVE

The rare hepatic tumor can have a wide spectrum of radiologic features, representing a diagnostic challenge. Our purpose is to report the experience of a National Cancer Center, emphasizing the radiological features encountered and assessing the LR-M categories in the diagnostic performances for these lesions.

PATIENTS AND METHODS

We assessed 113 patients who underwent surgical resection or biopsy for rare liver lesions from May 2010 to December 2020. For these patients a computerized search of radiological records was performed to identify which had been studied with MRI and CT. For each lesion, the radiologists recorded the attenuation on CT studies and signal intensity (SI) in T1 weighted (W), in T2-W, DWI and in the related map of the apparent diffusion coefficient (ADC). We assessed the presence and the type of contrast enhancement (CE) during contrast study on CT and MRI and the enhancement was categorized according to LI-RADS 2018. We also assessed the presence of other features in LR-M categories (ancillary LR-M features) in order to classify different subgroups. The lesions were classified according to LR categories, and the gold standard was histological analysis.

RESULTS

The final study population included 95 patients (46 females and 49 males), with a mean age of 51 years (range 38-83 years). 83 patients had solid lesions, 12 patients had cystic lesions (simple or complex). According to histological analysis, we categorized 79 patients with malignant lesions and 16 patients with benign lesions. According to radiological features we assessed as malignant 82 patients (79 true malignant and 3 false malignant), as benign 13 patients (all true benign). Therefore, sensitivity, specificity, positive predictive value, negative predictive value and accuracy of radiological features to identify benign and malignant lesions were 100.0%, 81.3%, 96.3%, 100.0% and 96.8%, respectively. We found no significant difference in signal and contrast enhancement appearance among all LR-M categories (p-value =0.34 at Chi square test). However, among LR-M categories the presence of satellite nodules was a feature typical of cHCC-CC (p-value < 0.05 at Chi square test). The presence of intra lesion necrosis and haemorrhage was suggestive of sarcoma (p-value < 0.05 at Chi square test).

CONCLUSIONS

High diagnostic accuracy was obtained by LI-RADS classification between malignant and benign lesion. The presence of ancillary features could help the radiologist towards a correct diagnosis.

Non-thyroidal illness syndrome and SARS-CoV-2-associated multisystem inflammatory syndrome in children

PURPOSE

COVID-19 disease may result in a severe multisystem inflammatory syndrome in children (MIS-C), which in turn may alter thyroid function (TF). We assessed TF in MIS-C, evaluating its impact on disease severity.

METHODS

We retrospectively considered children admitted with MIS-C to a single pediatric hospital in Milan (November 2019-January 2021). Non-thyroidal illness syndrome (NTIS) was defined as any abnormality in TF tests (FT3, FT4, TSH) in the presence of critical illness and absence of a pre-existing hormonal abnormality. We devised a disease severity score by combining severity scores for each organ involved. Glucose and lipid profiles were also considered. A principal component analysis (PCA) was performed, to characterize the mutual association patterns between TF and disease severity.

RESULTS

Of 26 (19 M/7F) patients, median age 10.7 (IQR 5.8-13.3) years, 23 (88.4%) presented with NTIS. A low FT3 level was noted in 15/23 (65.3%), while the other subjects had varying combinations of hormone abnormalities (8/23, 34.7%). Mutually correlated variables related to organ damage and inflammation were represented in the first dimension (PC1) of the PCA. FT3, FT4 and total cholesterol were positively correlated and characterized the second axis (PC2). The third axis (PC3) was characterized by the association of triglycerides, TyG index and HDL cholesterol. TF appeared to be related to lipemic and peripheral insulin resistance profiles. A possible association between catabolic components and severity score was also noted.

CONCLUSIONS

A low FT3 level is common among MIS-C. TF may be useful to define the impact of MIS-C on children's health and help delineate long term follow-up management and prognosis.

Epigenetic encoding, heritability and plasticity of glioma transcriptional cell states

Single-cell RNA sequencing has revealed extensive transcriptional cell state diversity in cancer, often observed independently of genetic heterogeneity, raising the central question of how malignant cell states are encoded epigenetically. To address this, here we performed multiomics single-cell profiling-integrating DNA methylation, transcriptome and genotype within the same cells-of diffuse gliomas, tumors characterized by defined transcriptional cell state diversity. Direct comparison of the epigenetic profiles of distinct cell states revealed key switches for state transitions recapitulating neurodevelopmental trajectories and highlighted dysregulated epigenetic mechanisms underlying gliomagenesis. We further developed a quantitative framework to directly measure cell state heritability and transition dynamics based on high-resolution lineage trees in human samples. We demonstrated heritability of malignant cell states, with key differences in hierarchal and plastic cell state architectures in IDH-mutant glioma versus IDH-wild-type glioblastoma, respectively. This work provides a framework anchoring transcriptional cancer cell states in their epigenetic encoding, inheritance and transition dynamics.

Liver resection and ablation for squamous cell carcinoma liver metastases

Background

Limited evidence exists to guide the management of patients with liver metastases from squamous cell carcinoma (SCC). The aim of this retrospective multicentre cohort study was to describe patterns of disease recurrence after liver resection/ablation for SCC liver metastases and factors associated with recurrence-free survival (RFS) and overall survival (OS).

Method

Members of the European–African Hepato-Pancreato-Biliary Association were invited to include all consecutive patients undergoing liver resection/ablation for SCC liver metastases between 2002 and 2019. Patient, tumour and perioperative characteristics were analysed with regard to RFS and OS.

Results

Among the 102 patients included from 24 European centres, 56 patients had anal cancer, and 46 patients had SCC from other origin. RFS in patients with anal cancer and non-anal cancer was 16 and 9 months, respectively (P = 0.134). A positive resection margin significantly influenced RFS for both anal cancer and non-anal cancer liver metastases (hazard ratio 6.82, 95 per cent c.i. 2.40 to 19.35, for the entire cohort). Median survival duration and 5-year OS rate among patients with anal cancer and non-anal cancer were 50 months and 45 per cent and 21 months and 25 per cent, respectively. For the entire cohort, only non-radical resection was associated with worse overall survival (hazard ratio 3.21, 95 per cent c.i. 1.24 to 8.30).

Conclusion

Liver resection/ablation of liver metastases from SCC can result in long-term survival. Survival was superior in treated patients with liver metastases from anal versus non-anal cancer. A negative resection margin is paramount for acceptable outcome.

Current status on response to treatment in locally advanced rectal cancer: what the radiologist should know

The assessment of tumor response, after neoadjuvant radiochemotherapy (nCRT), allows stratifying the patient in order to consider the proper therapeutical management. Histopathology analysis of the surgical specimen is considered the gold standard to assess tumour response and the definition of a complete cancer response is related to the clinical and endoscopic features, by direct evaluation of the rectal wall. However, imaging studies, especially Magnetic Resonance Imaging (MRI) have provided additional parameters, as the evaluation of nodal or mesorectal status. MRI provides a radiological tumour regression grade (mrTRG) that is correlated with the pathologic tumor regression grade (pTRG). Functional MRI parameters have additional impending in early prediction of the efficacy of therapy and can be valuable in drug development processes. Some of functional methodologies are already part of clinical practice: diffusion-weighted MRI (DW-MRI) and perfusion imaging (dynamic contrast enhanced MRI [DCE-MRI]). Other technologies, such as radiomics with MRI are still in the experimental phase. An adequate radiological report describing the restaging of rectal cancer after nCRT should be a "structured report" to improve communication in a multidisciplinary team.

Acute Myeloid Leukemia iPSCs Reveal a Role for RUNX1 in the Maintenance of Human Leukemia Stem Cells

Leukemia stem cells (LSCs) are believed to have more distinct vulnerabilities than the bulk acute myeloid leukemia (AML) cells, but their rarity and the lack of universal markers for their prospective isolation hamper their study. We report that genetically clonal induced pluripotent stem cells (iPSCs) derived from an AML patient and characterized by exceptionally high engraftment potential give rise, upon hematopoietic differentiation, to a phenotypic hierarchy. Through fate-tracking experiments, xenotransplantation, and single-cell transcriptomics, we identify a cell fraction (iLSC) that can be isolated prospectively by means of adherent in vitro growth that resides on the apex of this hierarchy and fulfills the hallmark features of LSCs. Through integrative genomic studies of the iLSC transcriptome and chromatin landscape, we derive an LSC gene signature that predicts patient survival and uncovers a dependency of LSCs, across AML genotypes, on the RUNX1 transcription factor. These findings can empower efforts to therapeutically target AML LSCs.

Halting Retrograde Transport Excludes ErbB-2 From the Nucleus Abrogating Tumor Growth in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) refers to a subtype of tumors with poor prognosis, devoid of hormone receptors and of membrane overexpression or gene amplification of ErbB-2. Due to its molecular heterogeneity, TNBC represents a major clinical challenge. In this regard, clinical biomarkers and targeted therapies remain elusive, and chemotherapy has been the standard of care for early and metastatic TNBC. ErbB-2, a member of the ErbB family of tyrosine kinase receptors, is a major player in the BC scenario. While it is a cell membrane-bound receptor, it migrates to the nucleus (NErbB-2) where it acts as a transcription factor or coactivator. We recently found that both the canonical (wild-type, WT) ErbB-2 and the alternative isoform c are located in the nucleus of TNBC, a scenario with an aggressive oncogenic potential. The route of intracellular transport from the plasma membrane to the trans Golgi network (TGN) and the endoplasmic reticulum (ER) is termed retrograde trafficking, and constitutes the pathway by which ErbB-2 migrates to the nucleus. The retrograde transport route is also hijacked by toxins and viruses to access the ER and exert their deleterious effects. Retro-2, a small molecule inhibitor, was shown to protect cells from toxin and virus effects by blocking their retrograde trafficking. Given the high levels of NErbB-2 in TNBC cells, we explored whether treatment with Retro-2 modulates localization of ErbB-2 and proliferation in TNBC.

We found that Retro-2 treatment decreased the levels of both WT ErbB-2 and isoform c in the nucleus of TNBC cells demonstrating that Retro-2 effects are not limited to a particular ErbB-2 isoform. Indeed, immunofluorescence assays revealed accumulation of ErbB-2 in the Golgi after Retro-2 treatment further preventing its sorting to the ER. We previously demonstrated that growth factors induce ErbB-2 migration into the nucleus in ErbB-2-positive BC cells. Consistently, we observed that Retro-2 prevents growth factor-induced NErbB-2 in ErbB-2-positive BC cells. Retro-2 treatment resulted in a dose-dependent decrease in cell proliferation in a panel of TNBC cells, whilst did not inhibit cell proliferation in the ErbB-2-negative MCF10A normal breast cell line. Moreover, disruption of retrograde transport by Retro-2 decreased the expression of cell cycle related NErbB-2 target genes (i.e. Erk5 and cyclin D1) therefore inducing cell cycle arrest at the G0/G1 phase. Most importantly, Retro-2 excluded ErbB-2 from the nucleus and abrogated tumor growth in preclinical models of TNBC.

Collectively, our findings reveal Retro-2, a non-toxic inhibitor of the retrograde transport route, as a candidate novel therapeutic agent for TNBC based on its ability to evict ErbB-2 from the nucleus and to abrogate TNBC growth.

Beyond the vascular profile: conventional DWI, IVIM and kurtosis in the assessment of hepatocellular carcinoma

OBJECTIVE

To describe the role of the Diffusion Weighted Imaging (DWI) in the assessment of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Several electronic databases were evaluated in the present review. The search included articles published from January 2010 to May 2019. The references of all articles were also evaluated. All titles and abstracts were assessed, and only the studies of DWI in patients with HCC were retained.

RESULTS

HCC is the most common primitive hepatic cancer. The non-invasive radiological criteria for HCC diagnosis are based on the presence of the specific vascular profile characterized by contrast uptake during arterial phase, defined as arterial hyperenhancement, followed by washout in the venous/portal phase. However, arterial hyperenhancement and wash out appearance have a sensitivity rate of 50-60% in lesion smaller than 2 cm. Therefore, other functional parameters have been introduced in the detection and characterization of HCC nodules. DWI has been applied to liver imaging as an excellent tool for detection and characterization of focal liver lesions, increasing clinical confidence and decreasing false positives. The assessment of DW images can be done qualitatively and quantitatively, through the apparent diffusion coefficient (ADC) map. Intravoxel incoherent motion (IVIM) is a more sophisticated analysis, a biexponential model, to better defining the relationship between signal attenuation and increasing b value that separately reproduces tissue diffusivity and tissue perfusion. Traditionally DWI approach to analyze data is founded on the hypothesis that water molecules diffuse within a voxel following a single direction with a Gaussian behavior without any restriction. However, according to the presence of microstructures, water molecules within biologic tissues exhibits a non-Gaussian phenomena proposed by Jensen in 2005 called Diffusion Kurtosis Imaging (DKI). This approach assesses the kurtosis coefficient (K) that shows the deviance of diffusion from a Gaussian approach, and the diffusion coefficient (D) with the correction of non-Gaussian bias. DKI is an advanced DWI model that quantifies non-Gaussian behavior of diffusion and provides both a corrected ADC, as well as the excess kurtosis of tissue, a measure of the extent to which tissue diffusion deviates from a Gaussian pattern. It is believed that the DKI model is more sensitive to tissue microstructural complexity than standard DW.

CONCLUSIONS

DWI should be an integral part of study protocol for HCC patients, considering the great advantages due to DWI and DWI-based approaches in detection and characterization of HCC.

Electrochemotherapy of cholangiocellular carcinoma at hepatic hilum: a case report

OBJECTIVE

Cholangiocarcinoma (CCA) is the second most common primary hepatic malignancy after hepatocellular carcinoma. The current standard palliative treatment, chemotherapy regimen with gemcitabine and cisplatin, prolongs overall survival only of a few months. Established locoregional therapies are not a curative option or an alternative to surgery in the treatment of CCA. We report a case of a patient affected by a cholangiocellular carcinoma at hepatic hilum treated by Electrochemotherapy (ECT) at our oncologic center.

CASE PRESENTATION

A 71 years old male affected by a CCA at hepatic hilum was treated with ECT according to ESOPE guidelines. No complications occurred during ECT procedure. The patient was discharged after 10 days. The functional MR evaluation at 2 and at 4 months post-treatment showed a significant response without significant post-treatment adverse events. The Computed tomography (CT) assessment after 18 months did not show progression of disease.

CONCLUSIONS

ECT is safe and its use could be suggested as a palliative treatment of advanced neoplastic lesions in which radical surgical treatment is not possible.