CNS tumor with EP300::BCOR fusion: discussing its prevalence in adult population.

The Central Nervous System (CNS) tumor with BCOR internal tandem duplication (ITD) has recently been added as a novel embryonal histomolecular tumor type to the 2021 World Health Organization (WHO) Classification of CNS Tumors. In addition, other CNS tumors harboring a BCOR/BCORL1 fusion, which are defined by a distinct DNA-methylation profile, have been recently identified in the literature but clinical, radiological and histopathological data remain scarce. Herein, we present two adult cases of CNS tumors with EP300::BCOR fusion. These two cases presented radiological, histopathological, and immunohistochemical homologies with CNS tumors having BCOR ITD in children. To compare these tumors with different BCOR alterations, we performed a literature review with a meta-analysis. CNS tumors with EP300::BCOR fusion seem to be distinct from their BCOR ITD counterparts in terms of age, location, progression-free survival, tumor growth pattern, and immunopositivity for the BCOR protein. CNS tumors from the EP300::BCOR fusion methylation class in adults may be added to the future WHO classification.

Indocyanine green fluorescence patterns of hepatocellular carcinoma correlate with pathological and molecular features.

BACKGROUND: Intraoperative Indocyanine Green Dye (ICG) routinely used in hepatobiliary surgery identifies different fluorescent patterns of hepatocellular carcinoma (HCC), a highly heterogeneous cancer. We aimed to correlate these patterns with gene mutations and extensive pathological features beyond the well-known tumor differentiation. METHODS: Between February 2017 and December 2019, 21 HCC in 16 consecutive patients who underwent intraoperative ICG fluorescence imaging were included. Pathological review was performed by one pathologist blinded to fluorescence features. Random forest machine learning algorithm correlated pathological features of the tumor, peritumoral and non-tumoral liver, and gene mutations from a 28 gene-panel with rim and intra-lesion fluorescence. RESULTS: Three HCC had negative intra-lesion and rim-like emission, 7 HCC had homogeneous pattern and 11 heterogeneous patterns in whom 3 with rim-like emission. Rim emission was associated with peritumoral vascular changes, lower differentiation and lower serum AFP level. Homogeneous intra-lesion fluorescence was associated with lower necrosis rate, thinner capsule, absence of peritumoral liver changes, and higher serum AFP level. Heterogeneous HCC without rim harbored lesser TP53 and ARID1A mutations. CONCLUSION: Tumoral and peri-tumoral fluorescence classification of HCC yielded a possible intraoperative pathological and molecular characterization. These preliminary observations could lead to intraoperative refinement in surgical strategy.

De novo hepatocellular carcinoma in a non-cirrhotic allograft 27 years after liver transplantation: A case report.

Hepatocellular carcinoma recurrence after liver transplantation is a well-known complication but the development of de novo hepatocellular carcinoma in non-cirrhotic allograft with no previous history of hepatic malignancy either in the donor or the recipient is extremely rare. A 33-year-old man underwent deceased donor liver transplantation due to HBV-HDV cirrhosis in 1991. The donor was healthy, with negative viral serology. Pretransplant assessment and explant liver pathology revealed no tumor. He developed an 8 cm mediastinal thymus cancer in 2014, a chronic myeloid leukemia in 2015 and a 16 mm renal cell carcinoma in 2017. After 27 years, in 2018, his routine follow-up sonography showed incidentally a 37 mm hepatic nodule in segment VII which revealed after percutaneous liver guided biopsy a hepatocellular carcinoma. As no extra hepatic metastasis was noted, segmentectomy was done. The pathological report confirmed a moderately differentiated hepatocellular carcinoma nodule of 50 mm diameter with absence of microvascular invasion and the non-tumoral liver showed histological features of NASH (SAF score: S1A2F3, NAS score: A3F3 and LAFSc:5) with absence of HBsAg and HBcAg. This case emphasizes the importance of long-term close surveillance by imaging of the graft even in the absence of viral recurrence and graft cirrhosis.

Undetectable RAS-Mutant Clones in Plasma: Possible Implication for Anti-EGFR Therapy and Prognosis in Patients With RAS-Mutant Metastatic Colorectal Cancer.

PURPOSE: Combining cetuximab with chemotherapy provides clinical benefit to 60% of the patients with RAS wild-type (RAS-wt) metastatic colorectal cancer (mCRC). This pilot study investigated the efficacy of cetuximab-based chemotherapy in a sample of patients (40%) with RAS mutation (RAS-mt) in their primary tumor whose circulating tumor DNA (ctDNA) was RAS-wt. MATERIALS AND METHODS: The occurrence of Kirsten rat sarcoma viral oncogene homolog (KRAS), neuroblastoma rat sarcoma viral oncogene homolog (NRAS), V-raf murine sarcoma viral oncogene homolog B1 (BRAF), and PI3KCA mutations was determined in ctDNA by using a new ultrasensitive analysis based on mass spectrometry detection. All consenting patients with confirmed RAS-mt mCRC had disease progression on previous chemotherapy that contained no anti-epidermal growth factor receptor (EGFR). The patients with RAS-wt ctDNA received cetuximab + fluorouracil, leucovorin, and irinotecan (FOLFIRI), whereas those with RAS-mt ctDNA were treated with the oncologist's choice of therapy. RESULTS: Of 16 registered patients, 11 were male and five female. They were age 48 to 81 years, and they had unresectable metastatic adenocarcinoma from the colon (n = 11) or rectum (n = 5), with a median of two metastatic sites. They had received a median number of three previous chemotherapy protocols. Plasma genotyping identified RAS-mt in seven patients (44%) and RAS-wt in nine patients (56%). In the patients with wt ctDNA, objective tumor response rate was 50.0%, including one complete response and four partial responses after a median number of 6 courses of cetuximab + FOLFIRI (range, 1 to 16 courses). Two of the nine patients had stable disease, and two had progressive disease. No grade 3 to 4 toxicities were encountered. One-year survival rates were 60.0% for the patients with RAS-wt ctDNA and 17.9% for those with RAS-mt ctDNA. Median overall survival times were not reached and 4.7 months, respectively. CONCLUSION: Patients with RAS-mt mCRC whose plasma biopsies contained RAS-wt could benefit from cetuximab-based therapy, a hypothesis to be tested in a prospective randomized trial.

Effects in Cancer Cells of the Recombinant l-Methionine Gamma-Lyase from Brevibacterium aurantiacum. Encapsulation in Human Erythrocytes for Sustained l-Methionine Elimination.

Methionine deprivation induces growth arrest and death of cancer cells. To eliminate l-methionine we produced, purified, and characterized the recombinant pyridoxal 5'-phosphate (PLP)-dependent l-methionine γ-lyase (MGL)- BL929 from the cheese-ripening Brevibacterium aurantiacum Transformation of an Escherichia coli strain with the gene BL929 from B. aurantiacum optimized for E. coli expression led to production of the MGL-BL929. Elimination of l-methionine and cytotoxicity in vitro were assessed, and methylation-sensitive epigenetics was explored for changes resulting from exposure of cancer cells to the enzyme. A bioreactor was built by encapsulation of the protein in human erythrocytes to achieve sustained elimination of l-methionine in extracellular fluids. Catalysis was limited to α,γ-elimination of l-methionine and l-homocysteine. The enzyme had no activity on other sulfur-containing amino acids. Enzyme activity decreased in presence of serum albumin or plasma resulting from reduction of PLP availability. Elimination of l-methionine induced cytotoxicity on a vast panel of human cancer cell lines and spared normal cells. Exposure of colorectal carcinoma cells to the MGL-BL929 reduced methyl-CpG levels of hypermethylated gene promoters including that of CDKN2A, whose mRNA expression was increased, together with a decrease in global histone H3 dimethyl lysine 9. The MGL-erythrocyte bioreactor durably preserves enzyme activity in vitro and strongly eliminates l-methionine from medium.

Chronological occurrence of PI3KCA mutations in breast cancer liver metastases after repeat partial liver resection.

BACKGROUND: Liver metastases of breast cancer are frequent and can recur even after "complete/R0" resection in combination with systemic and hormonal treatments. The aim of this study was to analyze throughout repeat hepatectomies for liver metastases the evolution of PI3KCA gene mutational status. METHODS: All liver metastases nodules (n = 70) from 19 women who underwent at least 2 liver resections were reexamined. DNA extraction from archived tumoral tissue was performed and the major 'hot spot' mutations in the helical and catalytic domains of PI3KCA have been analyzed using Massarray platform (Agena Bioscience) based on allelic discrimination PCR amplification followed by sensitive mass spectrometry detection. RESULTS: The two major somatic hot spot PI3KCA mutations were found in 27 (38.6%) nodules corresponding to 8 of the 19 patients (42%). The frequency of women whose breast cancer liver metastases (BCLM) carries PI3KCA mutations increased from the first to the third hepatectomy. Tumors carrying PI3KCA mutations are significantly larger and more frequently observed when resections were R0 compared to patients with no PI3KCA mutation. CONCLUSION: PI3KCA mutations are frequently observed in BCLM and persist along with the recurrence. Their identification in circulating tumor cells should become a useful biomarker in the routine practice of breast cancer management to prevent tumor recurrence and overcome the problems of intra- and inter-tumoral heterogeneity of the current biomarkers.

CSRP3 mediates polyphenols-induced cardioprotection in hypertension.

Berries contain bioactive polyphenols, whose capacity to prevent cardiovascular diseases has been established recently in animal models as well in human clinical trials. However, cellular processes and molecular targets of berries polyphenols remain to be identified. The capacity of a polyphenol-enriched diet (i.e., blueberries, blackberries, raspberries, strawberry tree fruits and Portuguese crowberries berries mixture) to promote animal survival and protect cardiovascular function from salt-induced hypertension was evaluated in a chronic salt-sensitive Dahl rat model. The daily consumption of berries improved survival of Dahl/salt-sensitive rats submitted to high-salt diet and normalized their body weight, renal function and blood pressure. In addition, a prophylactic effect was observed at the level of cardiac hypertrophy and dysfunction, tissue cohesion and cardiomyocyte hypertrophy. Berries also protected the aorta from fibrosis and modulated the expression of aquaporin-1, a channel involved in endothelial water and nitric oxide permeability. Left ventricle proteomics analysis led to the identification of berries and salt metabolites targets, including cystein and glycin-rich protein 3 (CSRP3), a protein involved in myocyte cytoarchitecture. In neonatal rat ventricular cardiomyocytes, CSRP3 was validated as a target of a berries-derived polyphenol metabolite, 4-methylcatechol sulfate, at micromolar concentrations, mimicking physiological conditions of human plasma circulation. Accordingly, siRNA silencing of CSRP3 and 4-methylcatechol sulfate pretreatment reversed cardiomyocyte hypertrophy and CSRP3 overexpression induced by phenylephrine. Our systemic study clearly supports the modulation of CSRP3 by a polyphenol-rich berries diet as an efficient cardioprotective strategy in hypertension-induced heart failure.

Impact of country of birth on genetic testing of metastatic lung adenocarcinomas in France: African women exhibit a mutational spectrum more similar to Asians than to Caucasians.

BACKGROUND: Limited data are available on the prevalence of oncogenic driver mutations in Caucasian populations, and especially in Europeans. AIM: To evaluate the targetable mutational spectra in unselected patients with lung adenocarcinoma in routine clinical practice from several French hospitals, using the same molecular platform. PATIENTS AND METHODS: Samples from 2,219 consecutive patients with histologically-proven advanced lung adenocarcinoma were centrally analysed at a referenced and certified diagnostic platform in order to test for activating and resistance mutations in EGFR, KRAS, BRAF, ERBB2 and PI3KCA. Demographic and clinical features were retrieved from the medical charts. Multivariate binary logistic regression was used to determine the independent predictive factors for the occurrence of specific mutations, in the whole study population or in selected subgroups. FINDINGS: The overall respective incidence of EGFR, KRAS, BRAF, ERBB2 and PI3KCA mutations was 10.5%, 0.9%, 25%, 1.5%, 2.1% and 1.4%, in our study sample including 87.4% white Caucasians, 10.8% Africans and 1.8% Asians; 60.6% men, 30.7% never smoker (median age: 68.3 years). Ethnicity was an independent predictor for EGFR, KRAS and ERBB2 gene abnormalities. In all cases, a significantly higher prevalence of targetable EGFR and ERBB2, and a lower prevalence of resistance KRAS mutations were observed in African women as compared to African men or Caucasians. CONCLUSIONS: In real life conditions of routine genetic testing, we have identified subsets of patients with specific targetable activating somatic mutations according to ethnicity, who could preferentially benefit from anti-EGFR and anti-ERBB2 targeted therapies.

Ischemic Postconditioning of the Liver Graft in Adult Liver Transplantation.

BACKGROUND: Ischemia-reperfusion (I/R) injury is the main cause of graft failure in liver transplantation (LT). Ischemic postconditioning (IPo) has shown to be beneficial against I/R injury. Our objective was to compare the results of LT with or without IPo. METHODS: One hundred patients undergoing LT alternatively received IPo or not. At the time of arterial reperfusion, IPo consisted of three 1-minute arterial occlusions, interspersed with 1-minute reperfusion pauses. The primary endpoint was postoperative aspartate aminotransferase (AST) peak value; early graft dysfunction and histological I/R injury were secondary endpoints. RESULTS: Median postoperative AST peak values was similar in both groups (426 vs 463 IU/L, P = 0.21); no difference was found in other postoperative liver function tests. In the IPo group, fewer grafts presented severe histological I/R injury (12% vs 28%; P = 0.029). Ischemic postconditioning did not induce changes in cellular apoptosis but triggered autophagy in periportal areas. Independent predictors of severe I/R injury were IPo (odds ratio, 0.20; P = 0.008) and arterial warm ischemia duration (odds ratio, 1.05; P = 0.008). Early graft dysfunction rate was similar in both groups (20% versus 26%, P = 0.47) and was associated with severe histological I/R injury and longer cold ischemia. Morbidity, mortality, and 1-year graft and patient survival were similar in both groups. CONCLUSIONS: Ischemic postconditioning did not influence postoperative AST peak values or other liver function tests. However, our results showed a better tolerance to I/R injury on histological findings of grafts receiving IPo. Future studies are necessary to optimize the IPo protocol in LT, to clarify its clinical impact, and to deepen the molecular understanding.

Mitochondrial roles and cytoprotection in chronic liver injury.

The liver is one of the richest organs in terms of number and density of mitochondria. Most chronic liver diseases are associated with the accumulation of damaged mitochondria. Hepatic mitochondria have unique features compared to other organs' mitochondria, since they are the hub that integrates hepatic metabolism of carbohydrates, lipids and proteins. Mitochondria are also essential in hepatocyte survival as mediator of apoptosis and necrosis. Hepatocytes have developed different mechanisms to keep mitochondrial integrity or to prevent the effects of mitochondrial lesions, in particular regulating organelle biogenesis and degradation. In this paper, we will focus on the role of mitochondria in liver physiology, such as hepatic metabolism, reactive oxygen species homeostasis and cell survival. We will also focus on chronic liver pathologies, especially those linked to alcohol, virus, drugs or metabolic syndrome and we will discuss how mitochondria could provide a promising therapeutic target in these contexts.

Conjugation of doxorubicin to cell penetrating peptides sensitizes human breast MDA-MB 231 cancer cells to endogenous TRAIL-induced apoptosis.

Previous work from our laboratory has shown that coupling doxorubicin (Dox) to cell penetrating peptides (Dox-CPPs) is a good strategy to overcome Dox resistance in MDA-MB 231 breast cancer cells. We also reported that, in contrast to unconjugated Dox-induced cell death, the increase in apoptotic response does not involve the mitochondrial apoptotic pathway. In this study, we demonstrate that both Dox and Dox-CPPs can increase the density of the TRAIL receptors DR4 and DR5 at the plasma membrane and moderately sensitize MDA-MB 231 cells to exogeneously added recombinant TRAIL, as has already been shown for other chemotherapeutic drugs. Moreover, we show that Dox-CPPs, used alone, induce the clustering of TRAIL receptors into ceramide-enriched membrane lipid rafts, a property not shared by unconjugated Dox and that this process is due to the generation of ceramide during Dox-CPPs treatment. In addition, MDA-MB 231 cells were found to express TRAIL and we show that the increased apoptotic rate induced by Dox-CPPs is due to the sensitization of MDA-MB 231 cells to endogenous TRAIL. The capacity of Dox-CPPs to sensitize cancer cells to physiologic amounts of TRAIL suggests that, in addition to their efficiency in combination chemotherapy, these compounds might increase the response of tumor cells to cytotoxic lymphocyte-mediated killing via TRAIL.

Rho-ROCK-dependent ezrin-radixin-moesin phosphorylation regulates Fas-mediated apoptosis in Jurkat cells.

Upon engagement by its ligand, the Fas receptor (CD95/APO-1) is oligomerized in a manner dependent on F-actin. It has been shown that ezrin, a member of the ERM (ezrin-radixin-moesin) protein family can link Fas to the actin cytoskeleton. We show herein that in Jurkat cells, not only ezrin but also moesin can associate with Fas. The same observation was made in activated human peripheral blood T cells. Fas/ezrin or moesin (E/M) association increases in Jurkat cells following Fas triggering and occurs concomitantly with the formation of SDS- and 2-ME-stable high molecular mass Fas aggregates. Ezrin and moesin have to be present together for the formation of Fas aggregates since down-regulation of either ezrin or moesin expression with small interfering RNAs completely inhibits Fas aggregate formation. Although FADD (Fas-associated death domain protein) and caspase-8 associate with Fas in the absence of E/M, subsequent events such as caspase-8 activation and sensitivity to apoptosis are decreased. During the course of Fas stimulation, ezrin and moesin become phosphorylated, respectively, on T567 and on T558. This phosphorylation is mediated by the kinase ROCK (Rho-associated coiled coil-containing protein kinase) I subsequently to Rho activation. Indeed, inhibition of either Rho or ROCK prevents ezrin and moesin phosphorylation, abrogates the formation of Fas aggregates, and interferes with caspase-8 activation. Thus, phosphorylation of E/M by ROCK is involved in the early steps of apoptotic signaling following Fas triggering and regulates apoptosis induction.

Resistance of tumor cells to cytolytic T lymphocytes involves Rho-GTPases and focal adhesion kinase activation.

Tumor cells evade adaptive immunity by a variety of mechanisms, including selection of variants that are resistant to specific cytotoxic T lymphocyte (CTL) pressure. Recently, we have reported that the reorganization of the actin cytoskeleton can be used by tumor cells as a strategy to promote their resistance to CTL-mediated lysis. In this study, we further examined the functional features of a CTL-resistant tumor variant and investigated the relationship between cytoskeleton alteration, the acquisition of tumor resistance to CTL-induced cell death, Rho-GTPases, and focal adhesion kinase (FAK) pathways. Our data indicate that although the resistant cells do not display an increased migratory potential, an alteration of adhesion to the extracellular matrix was observed. When Rho-GTPases were activated in cells by the bacterial CNF1 (cytotoxic necrotizing factor 1), striking changes in the cell morphology, including actin cytoskeleton, focal adhesions, and membrane extensions, were observed. More importantly, such activation also resulted in a significant attenuation of resistance to CTL-induced cell death. Furthermore, we demonstrate that FAK signaling pathways were constitutively defective in the resistant cells. Silencing of FAK in the sensitive target cells resulted in the inhibition of immune synapse formation with specific CTLs and their subsequent lysis. Expression of the FAK mutant (Y397F) resulted in an inhibition of IGR-Heu cell adhesion and of their susceptibility to specific lysis. These results suggest that FAK activation plays a role in the control of tumor cell susceptibility to CTL-mediated lysis.

Cytoskeleton and apoptosis.

Apoptosis is a genetically programmed and physiological mode of cell death that leads to the removal of unwanted or abnormal cells. Cysteine-proteases called caspases are responsible for the apoptotic execution phase which is characterized by specific biochemical events as well as morphological changes. These changes, which lead to the orderly dismantling of the apoptotic cell, include cell contraction, dynamic membrane blebbing, chromatin condensation, nuclear disintegration, cell fragmentation followed by phagocytosis of the dying cell. They involve major modifications of the cytoskeleton which are largely mediated by cleavage of several of its components by caspases. For example, dynamic membrane blebbing is due to the increased contractility of the acto-myosin system following myosin light chain (MLC) phosphorylation. MLC phosphorylation is a consequence of the cleavage of a Rho GTPase effector, the kinase ROCK I, by caspase-3. This cleavage induces a constitutive kinase activity by removal of an inhibitory domain. Chromatin condensation is facilitated by the processing of lamins by caspases. Collapse of the cytokeratin network is mediated by cleavage of keratin 18. On another hand, the actin cytoskeleton rearrangement needed in the phagocyte for engulfment of the dying cell is due to the activation of the small GTPase Rac, a GTPase of the Rho family that induces actin polymerisation and formation of lamellipodia. In addition to mediating the morphological modifications of the apoptotic cell, several proteins of the cytoskeleton such as actin and keratins are also involved in the regulation of apoptotic signaling.

Direct cleavage of ROCK II by granzyme B induces target cell membrane blebbing in a caspase-independent manner.

Caspase activation in target cells is a major function of granzyme B (grB) during cytotoxic lymphocyte granule-induced apoptosis. grB-mediated cell death can occur in the absence of active caspases, and the molecular targets responsible for this additional pathway remain poorly defined. Apoptotic plasma membrane blebbing is caspase independent during granule exocytosis-mediated cell death, whereas in other instances, this event is a consequence of the cleavage by caspases of the Rho effector, Rho-associated coiled coil-containing protein kinase (ROCK) I. We show here that grB directly cleaves ROCK II, a ROCK family member encoded by a separate gene and closely related to ROCK I, and this causes constitutive kinase activity and bleb formation. For the first time, two proteins of the same family are found to be specifically cleaved by either a caspase or grB, thus defining two independent pathways with similar phenotypic consequences in the cells. During granule-induced cell death, ROCK II cleavage by grB would overcome, for this apoptotic feature, the consequences of deficient caspase activation that may occur in virus-infected or malignant target cells.

N-WASP activation by a beta1-integrin-dependent mechanism supports PI3K-independent chemotaxis stimulated by urokinase-type plasminogen activator.

Urokinase-type plasminogen activator (uPA)-uPA receptor (uPAR) and epidermal growth factor (EGF)-EGF receptor (EGFR) expression is highly correlated with breast cancer metastasis. Phosphoinositide 3-kinase (PI3K), small Rho GTPases, such as Cdc42 and Rac1, and neuronal Wiskott Aldrich syndrome protein (N-WASP) are key effectors that regulate dynamic changes in the actin cytoskeleton and cell migration. uPA- and EGF-stimulated chemotaxis, cytoskeletal rearrangements and activation of Cdc42, Rac1 and N-WASP were studied in the highly metastatic human breast cancer cell line MDA MB 231. These studies reveal that divergent signalling occurs downstream of PI3K. The activity of PI3K was not necessary for uPA-induced chemotactic responses, but those induced by EGF were entirely dependent upon PI3K. Furthermore, PI3K-independent chemotactic signalling by uPA was shown to involve disruption of an interaction between beta(1)-integrins and N-WASP and translocation of N-WASP to the actin cytoskeleton.