Molecularly matched targeted therapy: a promising approach for refractory metastatic melanoma.

BACKGROUND: Only a fraction of patients with metastatic melanoma derive durable benefit from approved treatments. The clinical impact of personalized medicine strategies for melanoma, apart from BRAF, NRAS, or CKIT targeting, has rarely been reported. MATERIALS AND METHODS: By means of the Group of Cutaneous Oncology of the French Society of Dermatology, we retrospectively included all patients with advanced melanoma aged 18 years and older for whom molecular testing identified one or more actionable molecular alterations and who accordingly received molecularly matched therapy. We excluded patients with only BRAF, NRAS, or CKIT alterations and patients who received molecularly matched therapy for less than 15 days. RESULTS: We included 26 patients with a median follow-up of 8 months (1-54), a median age of 63 years (24-89), and a sex ratio of 2.7. These patients had been heavily pretreated, and 64% had elevated LDH levels. The disease control rate was 38%, with 4 cases of partial response (overall response rate: 15%) and 6 of stable disease for at least 6 months. The median duration of treatment was 3.1 months (0.9-13.5). Among patients with disease control, the median duration of control was 6.6 months (2.6-13.5) and 3 cases were ongoing at the end of the study. Patients with controlled disease had GNA11, MAP2K1, FYCO1-RAF1, HRAS, ATM, CCND1, MDM2/CDK4, and CDKN2A/NRAS alterations. CONCLUSIONS: High-throughput sequencing followed by matched targeted therapy is a promising approach for patients with advanced melanoma refractory to approved treatments.

Cytidine deaminase status as a marker of response to azacytidine treatment in MDS and AML patients.

Azacitidine (Aza) is a mainstay of treatment for patients with acute myeloid leukaemia (AML) ineligible for induction chemotherapy and other high-risk myelodysplastic syndromes (MDS). Only half of patients respond, and almost all will eventually relapse. There are no predictive markers of response to Aza. Aza is detoxified in the liver by cytidine deaminase (CDA). Here, we investigated the association between CDA phenotype, toxicity and efficacy of Aza in real-world adult patients. Median overall survival (OS) was 15 months and 13 months in AML and high-risk MDS patients respectively. In addition, our data suggest that delaying Aza treatment was not associated with lack of efficacy and should not be considered a signal to switch to an alternative treatment. Half of the patients had deficient CDA activity (i.e. <2 UA/mg), with a lower proportion of deficient patients in MDS patients (34%) compared to AML patients (67%). In MDS patients, CDA deficiency correlated with longer landmark OS (14 vs. 8 months; p = 0.03), but not in AML patients. Taken together, our data suggest that CDA is an independent covariate and may therefore be a marker for predicting clinical outcome in MDS patients treated with Aza.

Molecular characterization of fast-growing melanomas.

BACKGROUND: The rate of growth of primary melanoma is a robust predictor of aggressiveness, but the mutational profile of fast-growing melanomas (FGMM) and the potential to stratify patients at high risk of death has not been comprehensively studied. OBJECTIVE: To investigate the epidemiologic, clinical, and mutational profile of primary cutaneous melanomas with a thickness ≥ 1 mm, stratified by rate of growth. METHODS: Observational prospective study. Deep-targeted sequencing of 40 melanoma driver genes on formalin fixed, paraffin-embedded primary melanoma samples. Comparison of FGMM (rate of growth > 0.5 mm/month) and nonFGMM (rate of growth ≤ 0.5 mm/month). RESULTS: Two hundred patients were enrolled, among wom 70 had FGMM. The relapse-free survival was lower in the FGMM group (P = .014). FGMM had a higher number of predicted deleterious mutations within the 40 genes than nonFGMM (P = .033). Ulceration (P = .032), thickness (P = .006), lower sun exposure (P = .049), and fibroblast growth factor receptor 2 (FGFR2) mutations (P = .037) were significantly associated with fast growth. LIMITATIONS: Single-center study, cohort size, potential memory bias, number of investigated genes. CONCLUSION: Fast growth is linked to specific tumor biology and environmental factors. Ulceration, thickness, and FGFR2 mutations are associated with fast growth. Screening for FGFR2 mutations might provide an additional tool to better identify FGMM, which are probably good candidates for adjuvant therapies.

Comparison between Immunocytochemistry, FISH and NGS for ALK and ROS1 Rearrangement Detection in Cytological Samples.

The detection of ROS1 and ALK rearrangements is performed for advanced-stage non-small cell lung cancer. Several techniques can be used on cytological samples, such as immunocytochemistry (ICC), fluorescence in situ hybridization (FISH) and, more recently, next-generation sequencing (NGS), which is gradually becoming the gold standard. We performed a retrospective study to compare ALK and ROS1 rearrangement results from immunocytochemistry, FISH and NGS methods from 131 cytological samples. Compared to NGS, the sensitivity and specificity of ICC were 0.79 and 0.91, respectively, for ALK, and 1 and 0.87 for ROS1. Regarding FISH, the sensitivity and specificity were both at 1 for ALK and ROS1 probes. False-positive cases obtained by ICC were systematically corrected by FISH. When using ICC and FISH techniques, results are very close to NGS. The false-positive cases obtained by ICC are corrected by FISH, and the true-positive cases are confirmed. NGS has the potential to improve the detection of ALK and ROS1 rearrangements in cytological samples; however, the cost of this technique is still much higher than the sequential use of ICC and FISH.

[BRAF mutation evolution in melanoma: Myth or reality?] / Évolution du statut braf dans le melanome : mythe ou Réalité ?

Knowledge of the BRAF mutational status has become essential for melanoma therapeutic management. B-Raf inhibitors are associated with significant overall survival in patients with BRAFV600-mutated metastatic melanoma. Although the BRAF mutation appears to be an early and driver mutation, some authors hypothesized that its expression was not stable during melanoma progression, suggesting a molecular heterogeneity. This argument is often used to explain discrepancy in molecular status among patients with melanoma, discrepancies that we occasionally met during our practice. We retrospectively compared BRAF mutational status on matched melanoma samples (primary & metastatic lesions), thus 150 samples from 56 patients were analysed through immunohistochemistry anti-BRAF, PCR-HRM and Sanger sequencing, Next Generation Sequencing (NGS) and digital PCR. Seven cases presented an apparent tumor heterogeneity. The analysis of these discrepancies by a technique of increasing sensitivity made it possible to identify 1 false-negative result for the immunohistochemistry, 1 false-negative result for the NGS sequencing and 5 (3%) false-negative results by PCR-HRM SANGER. Our results are consistent with the most recent data, demonstrating the stability of the BRAF mutation during the course of melanoma. Immunohistochemistry shows excellent sensitivity for detecting the main BRAF mutation. In our study, the mutational heterogeneity was actually misleading, a result of imperfect sensitivity of some older molecular approaches.

Using Digital Droplet Polymerase Chain Reaction to Detect the Mosaic GNAS Mutations in Whole Blood DNA or Circulating Cell-Free DNA in Fibrous Dysplasia and McCune-Albright Syndrome.

The GNAS postzygotic mosaic activating mutations involved in fibrous dysplasia and McCune-Albright syndrome (MAS) are not detectable in leukocytes by Sanger sequencing. Digital droplet polymerase chain reaction detects GNAS mutations in 7 of 12 patients (58.3%) suspected to have fibrous dysplasia/MAS from whole blood DNA, and in 4 of 5 patients (80%) from circulating cell-free DNA.

Detection of EGFR, KRAS and BRAF mutations in metastatic cells from cerebrospinal fluid.

BACKGROUND: In lung adenocarcinoma, molecular profiling of actionable genes has become essential to set up targeted therapies. However, the feasibility and the relevance of molecular profiling from the cerebrospinal fluid (CSF) in the context of meningeal metastasis have been poorly assessed. METHODS: We selected patients with stage IV lung adenocarcinoma harbouring metastatic cells in the CSF after cytological analysis. Seven samples from six patients were eligible for molecular testing of epidermal growth factor receptor (EGFR), V-Ki-ras2 Kirsten rat sarcoma viral oncogene homologue (KRAS), v-Raf murine sarcoma viral oncogene homologue B1 (BRAF) and human epidermal growth factor receptor 2 (HER2) mutations using quantitative polymerase chain reaction (PCR) high-resolution melting curve analysis and Sanger sequencing after DNA extraction from the cell pellets of the CSF. RESULTS: Five patients showed mutations in one or two actionable genes, two harboured an EGFR mutation (exons 19 and 21), one only a KRAS mutation, one both EGFR and KRAS mutations and one a BRAF mutation. In all cases, the results of mutation testing provided new major information for patient management, leading to therapeutic adaptation. CSF molecular analysis identified mutations not detected in other neoplastic sites for two patients. In one case, the EGFR p.Thr790Met was identified. CSF was also the only sample available for genetic testing for almost all patients at the time of disease progression. CONCLUSIONS: When cancer cells are present in the CSF, the molecular profiling from the cell pellets is relevant, as it can detect supplemental or different mutations compared to a previous analysis of the primitive tumour or plasma cell-free DNA and allows the adaptation of the treatment strategy.

Routine molecular profiling of patients with advanced non-small-cell lung cancer: results of a 1-year nationwide programme of the French Cooperative Thoracic Intergroup (IFCT).

BACKGROUND: The molecular profiling of patients with advanced non-small-cell lung cancer (NSCLC) for known oncogenic drivers is recommended during routine care. Nationally, however, the feasibility and effects on outcomes of this policy are unknown. We aimed to assess the characteristics, molecular profiles, and clinical outcomes of patients who were screened during a 1-year period by a nationwide programme funded by the French National Cancer Institute. METHODS: This study included patients with advanced NSCLC, who were routinely screened for EGFR mutations, ALK rearrangements, as well as HER2 (ERBB2), KRAS, BRAF, and PIK3CA mutations by 28 certified regional genetics centres in France. Patients were assessed consecutively during a 1-year period from April, 2012, to April, 2013. We measured the frequency of molecular alterations in the six routinely screened genes, the turnaround time in obtaining molecular results, and patients' clinical outcomes. This study is registered with ClinicalTrials.gov, number NCT01700582. FINDINGS: 18,679 molecular analyses of 17,664 patients with NSCLC were done (of patients with known data, median age was 64·5 years [range 18-98], 65% were men, 81% were smokers or former smokers, and 76% had adenocarcinoma). The median interval between the initiation of analysis and provision of the written report was 11 days (IQR 7-16). A genetic alteration was recorded in about 50% of the analyses; EGFR mutations were reported in 1947 (11%) of 17,706 analyses for which data were available, HER2 mutations in 98 (1%) of 11,723, KRAS mutations in 4894 (29%) of 17,001, BRAF mutations in 262 (2%) of 13,906, and PIK3CA mutations in 252 (2%) of 10,678; ALK rearrangements were reported in 388 (5%) of 8134 analyses. The median duration of follow-up at the time of analysis was 24·9 months (95% CI 24·8-25·0). The presence of a genetic alteration affected first-line treatment for 4176 (51%) of 8147 patients and was associated with a significant improvement in the proportion of patients achieving an overall response in first-line treatment (37% [95% CI 34·7-38·2] for presence of a genetic alteration vs 33% [29·5-35·6] for absence of a genetic alteration; p=0·03) and in second-line treatment (17% [15·0-18·8] vs 9% [6·7-11·9]; p<0·0001). Presence of a genetic alteration was also associated with improved first-line progression-free survival (10·0 months [95% CI 9·2-10·7] vs 7·1 months [6·1-7·9]; p<0·0001) and overall survival (16·5 months [15·0-18·3] vs 11·8 months [10·1-13·5]; p<0·0001) compared with absence of a genetic alteration. INTERPRETATION: Routine nationwide molecular profiling of patients with advanced NSCLC is feasible. The frequency of genetic alterations, acceptable turnaround times in obtaining analysis results, and the clinical advantage provided by detection of a genetic alteration suggest that this policy provides a clinical benefit. FUNDING: French National Cancer Institute (INCa).

EGFR tyrosine kinase inhibitors versus chemotherapy in EGFR wild-type pre-treated advanced nonsmall cell lung cancer in daily practice.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are approved for second-line treatment of EGFR wild-type (EGFR-wt) nonsmall cell lung cancer (NSCLC). However, results from randomised trials performed to compare EGFR-TKIs with chemotherapy in this population did not show any survival benefit. In the era of immunotherapy, many drugs are approved for second-line treatment of EGFR-wt NSCLC and there is a need to reassess the role of EGFR-TKIs in this setting.The Biomarkers France study is a large nationwide cohort of NSCLC patients tested for EGFR mutations. We used this database to collect clinical, biological, treatment and outcome data on EGFR-wt patients who received second-line treatment with either EGFR-TKIs or chemotherapy.Among 1278 patients, 868 received chemotherapy and 410 received an EGFR-TKI. Median overall survival and progression-free survival were longer with chemotherapy than with an EGFR-TKI. Overall survival was 8.38 versus 4.99 months, respectively (hazard ratio 0.70, 95% CI 0.59-0.83; p<0.0001) and progression-free survival was 4.30 versus 2.83 months, respectively (hazard ratio 0.66, 95% CI 0.57-0.77; p<0.0001).This study is helpful to guide a multiline treatment strategy for EGFR-wt NSCLC patients. Immunotherapy is approved for second-line treatment. For third-line treatment, chemotherapy results in longer overall survival and progression-free survival, and should be preferred to EGFR-TKIs.

OTX015 (MK-8628), a novel BET inhibitor, displays in vitro and in vivo antitumor effects alone and in combination with conventional therapies in glioblastoma models.

Bromodomain and extraterminal (BET) bromodomain (BRD) proteins are epigenetic readers that bind to acetylated lysine residues on chromatin, acting as co-activators or co-repressors of gene expression. BRD2 and BRD4, members of the BET family, are significantly increased in glioblastoma multiforme (GBM), the most common primary adult brain cancer. OTX015 (MK-8628), a novel BRD2/3/4 inhibitor, is under evaluation in dose-finding studies in solid tumors, including GBM. We investigated the pharmacologic characteristics of OTX015 as a single agent and combined with targeted therapy or conventional chemotherapies in glioblastoma cell lines. OTX015 displayed higher antiproliferative effects compared to its analog JQ1, with GI50 values of approximately 0.2 µM. In addition, C-MYC and CDKN1A mRNA levels increased transiently after 4 h-exposure to OTX015, while BRD2, SESN3, HEXIM-1, HIST2H2BE, and HIST1H2BK were rapidly upregulated and sustained after 24 h. Studies in three additional GBM cell lines supported the antiproliferative effects of OTX015. In U87MG cells, OTX015 showed synergistic to additive activity when administered concomitant to or before SN38, temozolomide or everolimus. Single agent oral OTX015 significantly increased survival in mice bearing orthotopic or heterotopic U87MG xenografts. OTX015 combined simultaneously with temozolomide improved mice survival over either single agent. The passage of OTX015 across the blood-brain barrier was demonstrated with OTX015 tumor levels 7 to 15-fold higher than in normal tissues, along with preferential binding of OTX015 to tumor tissue. The significant antitumor effects seen with OTX015 in GBM xenograft models highlight its therapeutic potential in GBM patients, alone or combined with conventional chemotherapies.

EGFR and KRAS Mutations Predict the Incidence and Outcome of Brain Metastases in Non-Small Cell Lung Cancer.

BACKGROUND: Lung cancer is the leading cause of brain metastases (BM). The identification of driver oncogenes and matched targeted therapies has improved outcome in non-small cell lung cancer (NSCLC) patients; however, a better understanding of BM molecular biology is needed to further drive the process in this field. METHODS: In this observational study, stage IV NSCLC patients tested for EGFR and KRAS mutations were selected, and BM incidence, recurrence and patients' outcome were assessed. RESULTS: A total of 144 patients (142 Caucasian and two Asian) were selected, including 11.27% with EGFR-mutant and 33.10% with KRAS-mutant tumors, and 57.04% patients had developed BM. BM incidence was more frequent in patients with EGFR mutation according to multivariate analyses (MVA) (Odds ratio OR = 8.745 [1.743-43.881], p = 0.008). Among patients with treated BM, recurrence after local treatment was less frequent in patients with KRAS mutation (OR = 0.234 [0.078-0.699], p = 0.009). Among patients with untreated BM, overall survival (OS) was shorter for patients with KRAS mutation according to univariate analysis (OR = 7.130 [1.240-41.012], p = 0.028), but not MVA. CONCLUSIONS: EGFR and KRAS mutations have a predictive role on BM incidence, recurrence and outcome in Caucasian NSCLC patients. These results may impact the routine management of disease in these patients. Further studies are required to assess the influence of other biomarkers on NSCLC BM.

Lethal toxicity after administration of azacytidine: implication of the cytidine deaminase-deficiency syndrome.

Azacytidine, an antimetabolite with an original epigenetic mechanism of action, increases survival in patients diagnosed with high-risk myelodysplasic syndromes or acute myeloid leukemia with less than 30% medullar blasts. Azacytidine is a pyrimidine derivative that undergoes metabolic detoxification driven by cytidine deaminase (CDA), a liver enzyme whose gene is prone to genetic polymorphism, leading to erratic activity among patients. Clinical reports have shown that patients with the poor metabolizer (PM) phenotype are likely to experience early severe or lethal toxicities when treated with nucleosidic analogs such as gemcitabine or cytarabine. No clinical data have been available thus far on the relationships between CDA PM status and toxicities in azacytidine-treated patients. Here, we measured CDA activity in a case of severe toxicities with fatal outcome in a patient undergoing standard azacytidine treatment. Results showed that the patient was PM (i.e. residual activity reduced by 63%), thus suggesting that an impaired detoxification step could have given rise to the lethal toxicities observed. This case report calls for further prospective studies investigating the exact role that CDA status plays in the clinical outcome of patients treated with azacytidine.

MALDI imaging and in-source decay for top-down characterization of glioblastoma.

Glioblastoma multiforme is one of the most common intracranial tumors encountered in adults. This tumor of very poor prognosis is associated with a median survival rate of approximately 14 months. One of the major issues to better understand the biology of these tumors and to optimize the therapy is to obtain the molecular structure of glioblastoma. MALDI molecular imaging enables location of molecules in tissues without labeling. However, molecular identification in situ is not an easy task. In this paper, we used MALDI imaging coupled to in-source decay to characterize markers of this pathology. We provided MALDI molecular images up to 30 µm spatial resolution of mouse brain tissue sections. MALDI images showed the heterogeneity of the glioblastoma. In the various zones and at various development stages of the tumor, using our top-down strategy, we identified several proteins. These proteins play key roles in tumorigenesis. Particular attention was given to the necrotic area with characterization of hemorrhage, one of the most important poor prognosis factors in glioblastoma.

Recipient/donor contradictory genotypes with impact on drug pharmacogenetics after liver transplant: a deadly gift?

A 5-year-old girl who had undergone liver transplantation was scheduled for treatment with high-dose cytarabine for a Burkitt lymphoma. Because of impaired transplantation, a study of cytidine deaminase (CDA), the liver enzyme responsible for cytarabine detoxification, was conducted before initiating treatment to evaluate the risk for toxicity in this patient. The CDA genotype and phenotype were both studied and showed none of the polymorphisms usually associated with impaired CDA, but surprisingly functional deficiency was observed. Despite a subsequent 30% reduction in cytarabine dosing, life-threatening toxicities appeared quickly and treatment was discontinued. Further genetic investigations performed on liver biopsy showed that the donor was actually homozygous for CDA*2, a genotype associated with severe CDA deficiency. On the basis of the liver genotype, treatment was resumed with further dose reduction, which led to a better tolerance. This case report highlights the limits of searching germline polymorphisms in patients with liver transplant when the story plays in the liver.

The landscape of cancer-associated transcript fusions in adult brain tumors: a longitudinal assessment in 140 patients with cerebral gliomas and brain metastases.

Background: Oncogenic fusions of neurotrophic receptor tyrosine kinase NTRK1, NTRK2, or NTRK3 genes have been found in different types of solid tumors. The treatment of patients with TRK fusion cancer with a first-generation TRK inhibitor (such as larotrectinib or entrectinib) is associated with high response rates (>75%), regardless of tumor histology and presence of metastases. Due to the efficacy of TRK inhibitor therapy of larotrectinib and entrectinib, it is clinically important to identify patients accurately and efficiently with TRK fusion cancer. In this retrospective study, we provide unique data on the incidence of oncogenic NTRK gene fusions in patients with brain metastases (BM) and gliomas. Methods: 140 samples fixed and paraffin-embedded tissue (FFPE) of adult patients (59 of gliomas [17 of WHO grade II, 20 of WHO grade III and 22 glioblastomas] and 81 of brain metastasis (BM) of different primary tumors) are analyzed. Identification of NTRK gene fusions is performed using next-generation sequencing (NGS) technology using Focus RNA assay kit (Thermo Fisher Scientific). Results: We identified an ETV6 (5)::NTRK3 (15) fusion event using targeted next-generation sequencing (NGS) in one of 59 glioma patient with oligodendroglioma-grade II, IDH-mutated and 1p19q co-deleted at incidence of 1.69%. Five additional patients harboring TMPRSS (2)::ERG (4) were identified in pancreatic carcinoma brain metastasis (BM), prostatic carcinoma BM, endometrium BM and oligodendroglioma (grade II), IDH-mutated and 1p19q co-deleted. A FGFR3 (17)::TACC3 (11) fusion was identified in one carcinoma breast BM. Aberrant splicing to produce EGFR exons 2-7 skipping mRNA, and MET exon 14 skipping mRNA were identified in glioblastoma and pancreas carcinoma BM, respectively. Conclusions: This study provides data on the incidence of NTRK gene fusions in brain tumors, which could strongly support the relevance of innovative clinical trials with specific targeted therapies (larotrectinib, entrectinib) in this population of patients. FGFR3 (17)::TACC3 (11) rearrangement was detected in breast carcinoma BM with the possibility of using some specific targeted therapies and TMPRSS (2)::ERG (4) rearrangements occur in a subset of patients with, prostatic carcinoma BM, endometrium BM, and oligodendroglioma (grade II), IDH-mutated and 1p19q co-deleted, where there are yet no approved ERG-directed therapies.

Cytological Samples: An Asset for the Diagnosis and Therapeutic Management of Patients with Lung Cancer.

BACKGROUND: Lung cancer has become the leading cause of cancer death for men and women. Most patients are diagnosed at an advanced stage when surgery is no longer a therapeutic option. At this stage, cytological samples are often the less invasive source for diagnosis and the determination of predictive markers. We assessed the ability of cytological samples to perform diagnosis, and to establish molecular profile and PD-L1 expression, which are essential for the therapeutic management of patients. METHODS: We included 259 cytological samples with suspected tumor cells and assessed the ability to confirm the type of malignancy by immunocytochemistry. We summarized results of molecular testing by next generation sequencing (NGS) and PD-L1 expression from these samples. Finally, we analyzed the impact of these results in the patient management. RESULTS: Among the 259 cytological samples, 189 concerned lung cancers. Of these, immunocytochemistry confirmed the diagnosis in 95%. Molecular testing by NGS was obtained in 93% of lung adenocarcinomas and non-small cell lung cancer. PD-L1 results were obtained in 75% of patients tested. The results obtained with cytological samples led to a therapeutic decision in 87% of patients. CONCLUSION: Cytological samples are obtained by minimally invasive procedures and can provide enough material for the diagnosis and therapeutic management in lung cancer patients.

Determination of 5-azacitidine in human plasma by LC-MS/MS: application to pharmacokinetics pilot study in MDS/AML patients.

PURPOSE: Azacitidine (Vidaza®, AZA) is a mainstay for treating acute myeloid leukemia (AML) in patients unfit for standard induction and other myelodysplastic syndromes (MDS). However, only half of the patients usually respond to this drug and almost all patients will eventually relapse. Predictive markers for response to AZA are yet to be identified. AZA is metabolized in the liver by a single enzyme, cytidine deaminase (CDA). CDA is a ubiquitous enzyme coded by a highly polymorphic gene, with subsequent great variability in resulting activities in the liver. The quantitative determination of AZA in plasma is challenging due the required sensitivity and because of the instability in the biological matrix upon sampling, possibly resulting in erratic values. METHODS: We have developed and validated following EMA standards a simple, rapid, and cost-effective liquid chromatography-tandem mass spectrometry method for the determination of azacitidine in human plasma. RESULTS: After a simple and rapid precipitation step, analytes were successfully separated and quantitated over a 5-500 ng/mL range. The performance and reliability of this method were tested as part of an investigational study in MDS/AML patients treated with standard azacitidine (75 mg/m2 for 7 days a week every 28 days). CONCLUSION: Overall, this new method meets the requirements of current bioanalytical guidelines and could be used to monitor drug levels in MDS/AML patients.

Extreme Gradient Boosting Tuned with Metaheuristic Algorithms for Predicting Myeloid NGS Onco-Somatic Variant Pathogenicity.

The advent of next-generation sequencing (NGS) technologies has revolutionized the field of bioinformatics and genomics, particularly in the area of onco-somatic genetics. NGS has provided a wealth of information about the genetic changes that underlie cancer and has considerably improved our ability to diagnose and treat cancer. However, the large amount of data generated by NGS makes it difficult to interpret the variants. To address this, machine learning algorithms such as Extreme Gradient Boosting (XGBoost) have become increasingly important tools in the analysis of NGS data. In this paper, we present a machine learning tool that uses XGBoost to predict the pathogenicity of a mutation in the myeloid panel. We optimized the performance of XGBoost using metaheuristic algorithms and compared our predictions with the decisions of biologists and other prediction tools. The myeloid panel is a critical component in the diagnosis and treatment of myeloid neoplasms, and the sequencing of this panel allows for the identification of specific genetic mutations, enabling more accurate diagnoses and tailored treatment plans. We used datasets collected from our myeloid panel NGS analysis to train the XGBoost algorithm. It represents a data collection of 15,977 mutations variants composed of a collection of 13,221 Single Nucleotide Variants (SNVs), 73 Multiple Nucleoid Variants (MNVs), and 2683 insertion deletions (INDELs). The optimal XGBoost hyperparameters were found with Differential Evolution (DE), with an accuracy of 99.35%, precision of 98.70%, specificity of 98.71%, and sensitivity of 1.

Soluble CD146 displays angiogenic properties and promotes neovascularization in experimental hind-limb ischemia.

CD146, an endothelial molecule involved in permeability and monocyte transmigration, has recently been reported to promote vessel growth. As CD146 is also detectable as a soluble form (sCD146), we hypothesized that sCD146 could stimulate angiogenesis. Experiments of Matrigel plugs in vivo showed that sCD146 displayed chemotactic activity on endogenous endothelial cells, and exogenously injected late endothelial progenitor cells (EPCs). Recruited endothelial cells participated in formation of vascular-like structures. In vitro, sCD146 enhanced angiogenic properties of EPCs, with an increased cell migration, proliferation, and capacity to establish capillary-like structures. Effects were additive with those of vascular endothelial growth factor (VEGF), and sCD146 enhanced VEGFR2 expression and VEGF secretion. Consistent with a proangiogenic role, gene expression profiling of sCD146-stimulated EPCs revealed an up-regulation of endothelial nitric oxide synthase, urokinase plasminogen activator, matrix metalloproteinase 2, and VEGFR2. Silencing membrane-bound CD146 inhibited responses. The potential therapeutic interest of sCD146 was tested in a model of hind limb ischemia. Local injections of sCD146 significantly reduced auto-amputation, tissue necrosis, fibrosis, inflammation, and increased blood flow. Together, these findings establish that sCD146 displays chemotactic and angiogenic properties and promotes efficient neovascularization in vivo. Recombinant human sCD146 might thus support novel strategies for therapeutic angiogenesis in ischemic diseases.