Optimizing Vision Transformers for Histopathology: Pretraining and Normalization in Breast Cancer Classification.

This paper introduces a self-attention Vision Transformer model specifically developed for classifying breast cancer in histology images. We examine various training strategies and configurations, including pretraining, dimension resizing, data augmentation and color normalization strategies, patch overlap, and patch size configurations, in order to evaluate their impact on the effectiveness of the histology image classification. Additionally, we provide evidence for the increase in effectiveness gathered through geometric and color data augmentation techniques. We primarily utilize the BACH dataset to train and validate our methods and models, but we also test them on two additional datasets, BRACS and AIDPATH, to verify their generalization capabilities. Our model, developed from a transformer pretrained on ImageNet, achieves an accuracy rate of 0.91 on the BACH dataset, 0.74 on the BRACS dataset, and 0.92 on the AIDPATH dataset. Using a model based on the prostate small and prostate medium HistoEncoder models, we achieve accuracy rates of 0.89 and 0.86, respectively. Our results suggest that pretraining on large-scale general datasets like ImageNet is advantageous. We also show the potential benefits of using domain-specific pretraining datasets, such as extensive histopathological image collections as in HistoEncoder, though not yet with clear advantages.

Diaphragmatic morphological post-mortem findings in critically ill COVID-19 patients: an observational study.

Our study investigates the post-mortem findings of the diaphragm's muscular structural changes in mechanically ventilated COVID-19 patients. Diaphragm samples of the right side from 42 COVID-19 critically ill patients were analyzed and correlated with the type and length of mechanical ventilation (MV), ventilatory parameters, prone positioning, and use of sedative drugs. The mean number of fibers was 550±626. The cross-sectional area was 4120±3280 µm2, while the muscular fraction was 0.607±0.126. The overall population was clustered into two distinct populations (clusters 1 and 2). Cluster 1 showed a lower percentage of slow myosin fiber and higher fast fiber content than cluster 2, 68% versus 82%, p<0.00001, and 29.8% versus 18.8%, p=0.00045 respectively. The median duration of MV was 180 (41-346) hours. In cluster 1, a relationship between assisted ventilation and fast myosin fiber percentage (R2=-0.355, p=0.014) was found. In cluster 2, fast fiber content increased with increasing the length of the controlled MV (R2=0.446, p=0.006). A high grade of fibrosis was reported. Cluster 1 was characterized by fibers' atrophy and cluster 2 by hypertrophy, supposing different effects of ventilation on the diaphragm but without excluding a possible direct viral effect on diaphragmatic fibers.

Predictive and prognostic biomarkers in urological tumours.

Advancements in cutting-edge molecular profiling techniques, such as next-generation sequencing and bioinformatic analytic tools, have allowed researchers to examine tumour biology in detail and stratify patients based on factors linked with clinical outcome and response to therapy. This manuscript highlights the most relevant prognostic and predictive biomarkers in kidney, bladder, prostate and testicular cancers with recognised impact in clinical practice. In bladder and prostate cancer, new genetic acquisitions concerning the biology of tumours have modified the therapeutic scenario and led to the approval of target directed therapies, increasing the quality of patient care. Thus, it has become of paramount importance to choose adequate molecular tests, i.e., FGFR screening for urothelial cancer and BRCA1-2 alterations for prostate cancer, to guide the treatment plan for patients. While no tissue or blood-based biomarkers are currently used in routine clinical practice for renal cell carcinoma and testicular cancers, the field is quickly expanding. In kidney tumours, gene expression signatures might be the key to identify patients who will respond better to immunotherapy or anti-angiogenic drugs. In testicular germ cell tumours, the use of microRNA has outperformed conventional serum biomarkers in the diagnosis of primary tumours, prediction of chemoresistance, follow-up monitoring, and relapse prediction.

Nuts and bolts of salivary gland pathology in primary Sjögren's syndrome.

Primary Sjögren's syndrome (pSS) is a chronic, systemic, inflammatory autoimmune disease characterised by lymphocyte proliferation and progressive damage to exocrine glands. Salivary gland histopathology based on salivary gland biopsy is relevant for the diagnosis of pSS and therefore broadly applied in clinical practice. Tissue can be obtained from labial salivary glands (LSG) biopsy or from major salivary glands (MSG) biopsy, namely the parotid; in this latter scenario, the procedure can be either an open surgical biopsy or a US guided core needle biopsy.In this review we will: i) present the histopathological findings that may be encountered by pathologists on biopsies from pSS patients; ii) discuss the advantages and disadvantages of the surgical and/or imaging guided procedures to obtain tissues from LSG or MSG; iii) describe the histopathological features of lymphoma of MSG in pSS patients.

Secretagogue effect of PDE4 inhibitor apremilast on human salivary gland organoids obtained from primary Sjögren's syndrome patients.

OBJECTIVES: The aim of the study was to culture vital salivary gland organoids obtained through labial or parotid biopsy of primary Sjögren's syndrome (pSS) patients in order to evaluate their morphological and functional features in basal condition and after stimulation with Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) activator forskolin and phosphodiesterase 4 (PDE4) inhibitor apremilast, their in vitro regenerative capacity and the immune-histological resemblance with original tissue. METHODS: Salivary gland tissues from five pSS patients were processed to obtain vital organoids; swelling assay and cell proliferation tests were performed after forskolin and apremilast application. Immunochemistry evaluation on original salivary gland tissue and corresponding organoids was performed, and secretomics analysis was conducted to assess their functional status. REULTS: After application of forskolin and apremilast, we observed organoid swelling after 30 minutes, compatible with a positive functional status and enhancement of saliva production. In 3 cases, apremilast induced organoid proliferation. All cases were positive for cytokeratin 14 (CK14) and most for cytokeratin 5 (CK5). All the cases were positive for amylase; its secretion, and thus functional status of organoids, was confirmed by its high concentration in the culture medium. A focal ductal differentiation was found in some cases, highlighted by epithelial membrane antigen (EMA) positivity. The more differentiated EMA positive areas were negative for the staminal marker CK14, showing a sort of "complementary staining". CONCLUSIONS: Our data highlighted that differentiated cells and vital functional organoids that recapitulate the development of original salivary glands can be obtained from pSS epithelium. For the first time, the direct stimulating effect of PDE4 inhibitor apremilast on pSS human salivary gland organoids is reported, opening new perspectives on targeting oral dryness with drugs that combine secretagogue and immunomodulatory effects.

Machine learning to improve interpretability of clinical, radiological and panel-based genomic data of glioma grade 4 patients undergoing surgical resection.

BACKGROUND: Glioma grade 4 (GG4) tumors, including astrocytoma IDH-mutant grade 4 and the astrocytoma IDH wt are the most common and aggressive primary tumors of the central nervous system. Surgery followed by Stupp protocol still remains the first-line treatment in GG4 tumors. Although Stupp combination can prolong survival, prognosis of treated adult patients with GG4 still remains unfavorable. The introduction of innovative multi-parametric prognostic models may allow refinement of prognosis of these patients. Here, Machine Learning (ML) was applied to investigate the contribution in predicting overall survival (OS) of different available data (e.g. clinical data, radiological data, or panel-based sequencing data such as presence of somatic mutations and amplification) in a mono-institutional GG4 cohort. METHODS: By next-generation sequencing, using a panel of 523 genes, we performed analysis of copy number variations and of types and distribution of nonsynonymous mutations in 102 cases including 39 carmustine wafer (CW) treated cases. We also calculated tumor mutational burden (TMB). ML was applied using eXtreme Gradient Boosting for survival (XGBoost-Surv) to integrate clinical and radiological information with genomic data. RESULTS: By ML modeling (concordance (c)- index = 0.682 for the best model), the role of predicting OS of radiological parameters including extent of resection, preoperative volume and residual volume was confirmed. An association between CW application and longer OS was also showed. Regarding gene mutations, a role in predicting OS was defined for mutations of BRAF and of other genes involved in the PI3K-AKT-mTOR signaling pathway. Moreover, an association between high TMB and shorter OS was suggested. Consistently, when a cutoff of 1.7 mutations/megabase was applied, cases with higher TMB showed significantly shorter OS than cases with lower TMB. CONCLUSIONS: The contribution of tumor volumetric data, somatic gene mutations and TBM in predicting OS of GG4 patients was defined by ML modeling.

Baseline Predictors of the Long-Term Insufficient Biochemical Response in Patients with Autoimmune Hepatitis: A Single Center Experience.

The treatment response criteria in autoimmune hepatitis (AIH) have been recently updated. This study aimed to assess treatment responses in 39 (16 males) patients with AIH confirmed by histology. Prednisone added to azathioprine or mycophenolate was the most frequent first-line treatment. Serum alanine aminotransferase (ALT) levels were periodically checked for a median of 45 months. Eight (20.5%) patients presented 4 weeks non-response (NR). Baseline lower multiples of ALT above the upper normal limit (UNL) (p = 0.005), Ishak liver fibrosis score > 3 (p = 0.029), and less frequent confluent necrosis > 2 (p < 0.001) were independent predictors of NR. 24 (61.5%) patients achieved complete biochemical response (CBR) at six months. Ishak liver fibrosis score ≤ 3 (p < 0.001), lobular eosinophilic infiltrate (p < 0.001), and ≥50% decrease in serum ALT levels at week 4 (p < 0.001) were independent predictors of CBR. In addition, the GLUCRE score, derived from the multiplication of serum creatinine (mg/dL) and glucose (mg/dL) levels, were identified. A baseline GLUCRE value > 100 strongly predicted CBR failure (p = 0.003) at a follow-up greater than 12 months. In conclusion, the absence of cirrhosis and a ≥50% UNL decrease in serum ALT levels were independent predictors for CBR. A baseline GLUCRE score may help identify patients maintaining longer CBR.

The protean role of Val804Met RET mutation in thyroid neoplasms: An example of a "MEN2C" syndrome?

BACKGROUND: Val804Met RET is one of the most common genetic alterations in Multiple Endocrine Neoplasia 2 and is considered to confer only a moderate risk for familial medullary thyroid carcinoma (MTC). The associated phenotype can however be much more complex in some cases. METHODS: A clinical, genetic, and pathological analysis was conducted on a family cluster of thyroid neoplasms associated with Val804Met RET mutation. RESULTS: All the kindreds who are carriers of the mutated RET received total thyroidectomy + /- VI level dissection. The proband presented with a pT1bN0 MTC, her 29-yo brother showed a concomitant papillary thyroid carcinoma (PTC) and MTC, their father had a pT1a PTC plus a follicular adenoma, while the uncle of the proband showed C-cell hyperplasia. None had clinical or biochemical evidence of parathyroid disorders or pheochromocytoma. CONCLUSIONS: In the presence of Val804Met RET several types of thyroid premalignant and malignant should be screened for, and without limiting to MTC.

Usefulness of ultrasound guided core needle biopsy of the parotid gland for the diagnosis of primary Sjögren's syndrome.

OBJECTIVES: The diagnosis and classification of primary Sjögren's syndrome (pSS) relies on labial biopsy, whereas the role of open parotid biopsy is mainly reserved to evaluate the lymphoproliferative complications. Recently ultrasound-guided core needle biopsy (US-guided CNB) appeared as a novel and safe technique useful in lymphoma assessment, however, its potential role in the diagnosis of pSS has never been assessed.The main aim of this study was to evaluate the diagnostic value of US-guided CNB of the parotid glands in patients affected by pSS. METHODS: Patients affected by pSS who underwent US-guided CNB for a suspected glandular lymphoma were included. Adequacy of the samples and histopathological features related to pSS were analysed. RESULTS: US-guided CNB was performed on 29 parotid glands. The biopsied samples were adequate for diagnosis in 28/29 (96.5%) cases. Fifteen patients showed pathologic features of parotid lymphoma. Among the remaining patients, 9/13 presented focus score≥1; LELs were present in 8/13 patients, and GCs in 11/13. In 8 cases the histological features were coherent with MESA/LESA. Acinar atrophy, fibrosis and duct dilatation were also evaluated. CONCLUSIONS: This preliminary study suggests the possible usefulness of US-guided CNB for the diagnosis of pSS by enabling the collection of adequate salivary gland tissue to assess the FS, GCs, LELs, and other histopathologic features also useful in the management of pSS patients.

Clinical, laboratory and immunohistochemical characterization of in situ pulmonary arterial thrombosis in fatal COVID-19.

BACKGROUND: COVID-19 patients carry an increased rate of thrombosis. It is controversial to which extent thrombi in the pulmonary arterial tree really contribute to disease severity with hypoxemia secondary to microvascular/lung parenchymal damage with viral alveolitis considered to play the main role in critical disease. OBJECTIVES: The primary objective was to compare post-mortem lung disease from fatal COVID-19 pneumonia in patients with macroscopically evident pulmonary arterial tree thrombosis and patients without, by characterizing the immunohistochemical nature of thrombi, and by comparing clinical and laboratory features of these patients with other COVID-19 patients who died but without evidence of pulmonary arterial thrombosis (controls). PATIENTS AND METHODS: 13 COVID-19 pneumonia cases (mean age ± standard deviation: 74 ± 6.5 years) with macroscopically visible pulmonary arterial thrombosis were compared to 14 controls. Hematoxylin and Eosin stained slides were reviewed choosing those with visible pulmonary thrombi which were further characterized by immunohistochemistry, in particular for the inflammatory infiltrates. Ante mortem serum markers relevant to pulmonary embolism were evaluated in both groups. RESULTS: Twenty arterial thrombi (5 cases with multiple thrombi) were selected for study and were composed by white blood cells (WBC) [median, IQR range: 10 % (5-12.25)], mainly neutrophils [58 % (35.2-64.5)]. Cases with thrombosis showed significantly higher levels of platelet count [median, IQR range: 195000/mmc (157750-274,500) vs 143,500 (113000-175,250), p = 0.011], LDH [854 U/L (731-1315) vs 539 (391.5-660), p = 0.003] at admission, and D-dimer at ICU transfer [25,072 FEU (6951-50,531) vs 1024 (620-5501), p = 0.003]. CONCLUSIONS: Immunothrombotically driven arterial thrombi in COVID-19 patients are associated with D-Dimer and LDH elevations, thus linking inflammation, coagulopathy and organ damage in fatal COVID-19.

Identification of a Prognostic Microenvironment-Related Gene Signature in Glioblastoma Patients Treated with Carmustine Wafers.

Despite the state-of-the-art treatment, patients diagnosed with glioblastoma (GBM) have a median overall survival (OS) of 14 months. The insertion of carmustine wafers (CWs) into the resection cavity as adjuvant treatment represents a promising option, although its use has been limited due to contrasting clinical results. Our retrospective evaluation of CW efficacy showed a significant improvement in terms of OS in a subgroup of patients. Given the crucial role of the tumor microenvironment (TME) in GBM progression and response to therapy, we hypothesized that the TME of patients who benefited from CW could have different properties compared to that of patients who did not show any advantage. Using an in vitro model of the glioma microenvironment, represented by glioma-associated-stem cells (GASC), we performed a transcriptomic analysis of GASC isolated from tumors of patients responsive and not responsive to CW to identify differentially expressed genes. We found different transcriptomic profiles, and we identified four genes, specifically down-regulated in GASC isolated from long-term survivors, correlated with clinical data deposited in the TCGA-GBM dataset. Our results highlight that studying the in vitro properties of patient-specific glioma microenvironments can help to identify molecular determinants potentially prognostic for patients treated with CW.

Trop-2 induces ADAM10-mediated cleavage of E-cadherin and drives EMT-less metastasis in colon cancer.

We recently reported that activation of Trop-2 through its cleavage at R87-T88 by ADAM10 underlies Trop-2-driven progression of colon cancer. However, the mechanism of action and pathological impact of Trop-2 in metastatic diffusion remain unexplored. Through searches for molecular determinants of cancer metastasis, we identified TROP2 as unique in its up-regulation across independent colon cancer metastasis models. Overexpression of wild-type Trop-2 in KM12SM human colon cancer cells increased liver metastasis rates in vivo in immunosuppressed mice. Metastatic growth was further enhanced by a tail-less, activated ΔcytoTrop-2 mutant, indicating the Trop-2 tail as a pivotal inhibitory signaling element. In primary tumors and metastases, transcriptome analysis showed no down-regulation of CDH1 by transcription factors for epithelial-to-mesenchymal transition, thus suggesting that the pro-metastatic activity of Trop-2 is through alternative mechanisms. Trop-2 can tightly interact with ADAM10. Here, Trop-2 bound E-cadherin and stimulated ADAM10-mediated proteolytic cleavage of E-cadherin intracellular domain. This induced detachment of E-cadherin from ß-actin, and loss of cell-cell adhesion, acquisition of invasive capability, and membrane-driven activation of ß-catenin signaling, which were further enhanced by the ΔcytoTrop-2 mutant. This Trop-2/E-cadherin/ß-catenin program led to anti-apoptotic signaling, increased cell migration, and enhanced cancer-cell survival. In patients with colon cancer, activation of this Trop-2-centered program led to significantly reduced relapse-free and overall survival, indicating a major impact on progression to metastatic disease. Recently, the anti-Trop-2 mAb Sacituzumab govitecan-hziy was shown to be active against metastatic breast cancer. Our findings define the key relevance of Trop-2 as a target in metastatic colon cancer.

Integrated multi-omics analyses on patient-derived CRC organoids highlight altered molecular pathways in colorectal cancer progression involving PTEN.

BACKGROUND: Colorectal cancer (CRC) represents the fourth leading cause of cancer-related deaths. The heterogeneity of CRC identity limits the usage of cell lines to study this type of tumor because of the limited representation of multiple features of the original malignancy. Patient-derived colon organoids (PDCOs) are a promising 3D-cell model to study tumor identity for personalized medicine, although this approach still lacks detailed characterization regarding molecular stability during culturing conditions. Correlation analysis that considers genomic, transcriptomic, and proteomic data, as well as thawing, timing, and culturing conditions, is missing. METHODS: Through integrated multi-omics strategies, we characterized PDCOs under different growing and timing conditions, to define their ability to recapitulate the original tumor. RESULTS: Whole Exome Sequencing allowed detecting temporal acquisition of somatic variants, in a patient-specific manner, having deleterious effects on driver genes CRC-associated. Moreover, the targeted NGS approach confirmed that organoids faithfully recapitulated patients' tumor tissue. Using RNA-seq experiments, we identified 5125 differentially expressed transcripts in tumor versus normal organoids at different time points, in which the PTEN pathway resulted of particular interest, as also confirmed by further phospho-proteomics analysis. Interestingly, we identified the PTEN c.806_817dup (NM_000314) mutation, which has never been reported previously and is predicted to be deleterious according to the American College of Medical Genetics and Genomics (ACMG) classification. CONCLUSION: The crosstalk of genomic, transcriptomic and phosphoproteomic data allowed to observe that PDCOs recapitulate, at the molecular level, the tumor of origin, accumulating mutations over time that potentially mimic the evolution of the patient's tumor, underlining relevant potentialities of this 3D model.

Association between indocyanine green clearance test and ischemic type biliary lesions within one year after orthotopic liver transplantation.

BACKGROUND: Ischemic type biliary lesions (ITBLs), a particular subset of non-anastomotic biliary strictures (NAS), are characterized by intra and extrahepatic strictures that occur in the absence of either hepatic artery thrombosis or stenosis. When they occur within the first year after liver transplantation their development is mostly related to ischemia-reperfusion injury (IRI). The indocyanine green plasma disappearance rate (ICG-PDR) might be able to predict the probability of IRI-induced graft damage after liver transplantation. OBJECTIVE: Our aim was to evaluate the association between ICG-PDR and the occurrence of ITBLs. Secondly, we searched for evidence of IRI in patients presenting ITBLs. METHODS: This retrospective single-center observational study assessed a cohort of 60 liver transplant patients. Each patient underwent ICG-PDR on the 1st postoperative day. ITBLs were identified by means of either cholangiography or magnetic resonance imaging evidence of a deformity and narrowing of the biliary tree in the absence of hepatic artery thrombosis/stenosis. RESULTS: ITBLs were discovered in 10 patients out of 60 liver recipients (16.67%) within one year after transplantation. A low ICG-PDR value was found to be a significant predictive factor for ITBL development, with an OR of 0.87 and a 95% CI of 0.77-0.97. Liver biopsies were performed in 56 patients presenting unexplained abnormal liver function test results. A statistically significant association was found between the development of ITBLs and anatomopathological evidence of IRI. LIMITATIONS: Retrospective, single-center study. CONCLUSIONS: The findings from this study show a relationship between low ICG-PDR values on first post-operative-day and the occurrence of ITBLs within 1 year after transplantation.

miRNA expression profiles in liver grafts of HCV and HIV/HCV-infected recipients, 6 months after liver transplantation.

In hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infected patients, HIV enhances HCV replication and liver damage. Several microRNAs (miRNAs), active in pro-fibrotic and inflammatory pathways, have been implicated in the pathogenesis of this phenomenon. However, these miRNAs have been tested only in explanted cirrhotic livers, when the liver damage has become chronic and irreversible. No data are available on the early phase of viral infection, such as early after liver transplantation (LT). In the present study, the expression of miR-101, miR-122, miR-155, miR-192, miR-200c, miR-338, and miR-532 was determined by quantitative real-time polymerase chain reaction in liver biopsies of HCV (n = 19) and HCV/HIV-infected (n = 20) LT recipients, as well as in a control group (n = 18) of noninfected patients, transplanted for alcoholic cirrhosis. The timing of liver biopsy was 6 months post-LT. None of the patients was treated with direct-acting anti-HCV drugs. All co-infected recipients had suppressed HIV viral load. Grading and staging were assessed according to the Ishak Classification. HCV and HIV viral load were measured in the sera. miR-101 (p = .03), miR-122 (p = .012), and miR-192 (p = .038) were significantly downregulated in HCV/HIV co-infected and HCV mono-infected recipients when compared with noninfected recipients, and such downregulation was more pronounced in co-infected ones. Moreover, in co-infected recipients but not in mono-infected ones, miR-101 inversely correlated with the peripheral HCV-RNA levels (r = .41, p = .04) and miR-122 inversely correlated with peripheral HCV-RNA levels (r = .49, p = .03) and with the histological grading (r = .51, p = .02).  In conclusion, as early as 6 months after LT, the presence of HIV-HCV co-infection enhanced a significant downregulation of certain miRNAs that showed a direct correlation with HCV viral load and liver inflammation.

Ultrasound-guided core needle biopsy compared with open biopsy: a new diagnostic approach to salivary gland enlargement in Sjögren's syndrome?

OBJECTIVE: Persistent (≥2 months) major salivary gland enlargement in primary SS (pSS) patients is a well-known sign of possible involvement by B cell lymphoma. The study aimed to evaluate the diagnostic accuracy and safety of US-guided core needle biopsy (CNB) of major salivary glands compared with open surgical biopsy. METHODS: Prospective pSS patients (cases) with clinically persistent salivary gland enlargement underwent US-guided CNB and were compared with retrospective pSS patients (controls) submitted to open surgical biopsy. The features analysed were pre-biopsy clinical and laboratory findings, adequacy of the material for histology and diagnostic-rendered and biopsy-related complications (reported by the patient with a questionnaire and clinically verified). RESULTS: Thirteen cases underwent US-guided CNB: in nine, biopsy was performed on the parotid gland and in four it was performed on the submandibular gland. Sufficient material was obtained for pathological diagnosis in all samples. The final diagnoses were 5 (38.5%) B cell lymphoma, 1 (7.7%) lymphoepithelial sialadenitis, 4 (30.7%) other sialadenitis (granulomatous consistent with sarcoidosis, IgG4-related disease, chronic sclerosing, diffuse chronic) and 3/13 (23.1%) miscellaneous lesions. Thirteen controls underwent open surgical biopsy of the parotid. In one, inadequate material was obtained, while in 12 (92.3%) the pathologic diagnoses were 4 (33.3%) B cell lymphoma, 2 (16.7%) lymphoepithelial sialadenitis, 4 (33.3%) uncertain lymphoproliferative lesions and 2 (16.7%) miscellaneous lesions. Six cases (46.1%) reported six transient complications and 12/13 (92.3%) controls had 2 persistent and 14 transient complications. CONCLUSION: US-guided CNB represents a novel, clinically relevant and safe approach for the management of pSS patients with parotid or submandibular persistent enlargement.

The miRNA Content of Exosomes Released from the Glioma Microenvironment Can Affect Malignant Progression.

Low-grade gliomas (LGG) are infiltrative primary brain tumors that in 70% of the cases undergo anaplastic transformation, deeply affecting prognosis. However, the timing of progression is heterogeneous. Recently, the tumor microenvironment (TME) has gained much attention either as prognostic factor or therapeutic target. Through the release of extracellular vesicles, the TME contributes to tumor progression by transferring bioactive molecules such as microRNA. The aim of the study was to take advantage of glioma-associated stem cells (GASC), an in vitro model of the glioma microenvironment endowed with a prognostic significance, and their released exosomes, to investigate the possible role of exosome miRNAs in favoring the anaplastic transformation of LGG. Therefore, by deep sequencing, we analyzed and compared the miRNA profile of GASC and exosomes obtained from LGG patients characterized by different prognosis. Results showed that exosomes presented a different signature, when compared to their cellular counterpart and that, although sharing several miRNAs, exosomes of patients with a bad prognosis, selectively expressed some miRNAs possibly responsible for the more aggressive phenotype. These findings get insights into the value of TME and exosomes as potential biomarkers for precision medicine approaches aimed at improving LGG prognostic stratification and therapeutic strategies.

Mitochondrial apurinic/apyrimidinic endonuclease 1 enhances mtDNA repair contributing to cell proliferation and mitochondrial integrity in early stages of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the leading cause of primary liver cancers. Surveillance of individuals at specific risk of developing HCC, early diagnostic markers, and new therapeutic approaches are essential to obtain a reduction in disease-related mortality. Apurinic/apyrimidinic endonuclease 1 (APE1) expression levels and its cytoplasmic localization have been reported to correlate with a lower degree of differentiation and shorter survival rate. The aim of this study is to fully investigate, for the first time, the role of the mitochondrial form of APE1 in HCC. METHODS: As a study model, we analyzed samples from a cohort of patients diagnosed with HCC who underwent surgical resection. Mitochondrial APE1 content, expression levels of the mitochondrial import protein Mia40, and mtDNA damage of tumor tissue and distal non-tumor liver of each patient were analyzed. In parallel, we generated a stable HeLa clone for inducible silencing of endogenous APE1 and re-expression of the recombinant shRNA resistant mitochondrially targeted APE1 form (MTS-APE1). We evaluated mtDNA damage, cell growth, and mitochondrial respiration. RESULTS: APE1's cytoplasmic positivity in Grades 1 and 2 HCC patients showed a significantly higher expression of mitochondrial APE1, which accounted for lower levels of mtDNA damage observed in the tumor tissue with respect to the distal area. In the contrast, the cytoplasmic positivity in Grade 3 was not associated with APE1's mitochondrial accumulation even when accounting for the higher number of mtDNA lesions measured. Loss of APE1 expression negatively affected mitochondrial respiration, cell viability, and proliferation as well as levels of mtDNA damage. Remarkably, the phenotype was efficiently rescued in MTS-APE1 clone, where APE1 is present only within the mitochondrial matrix. CONCLUSIONS: Our study confirms the prominent role of the mitochondrial form of APE1 in the early stages of HCC development and the relevance of the non-nuclear fraction of APE1 in the disease progression. We have also confirmed overexpression of Mia40 and the role of the MIA pathway in the APE1 import process. Based on our data, inhibition of the APE1 transport by blocking the MIA pathway could represent a new therapeutic approach for reducing mitochondrial metabolism by preventing the efficient repair of mtDNA.

Heterogeneity Matters: Different Regions of Glioblastoma Are Characterized by Distinctive Tumor-Supporting Pathways.

The glioblastoma microenvironment plays a substantial role in glioma biology. However, few studies have investigated its spatial heterogeneity. Exploiting 5-ALA Fluorescence Guided Surgery (FGS), we were able to distinguish between the tumor core (ALA+), infiltrating area (ALA-PALE) and healthy tissue (ALA-) of the glioblastoma, based on the level of accumulated fluorescence. The aim of this study was to investigate the properties of the microenvironments associated with these regions. For this purpose, we isolated glioma-associated stem cells (GASC), resident in the glioma microenvironment, from ALA+, ALA-PALE and ALA- samples and compared them in terms of growth kinetic, phenotype and for the expression of 84 genes associated with cancer inflammation and immunity. Differentially expressed genes were correlated with transcriptomic datasets from TCGA/GTEX. Our results show that GASC derived from the three distinct regions, despite a similar phenotype, were characterized by different transcriptomic profiles. Moreover, we identified a GASC-based genetic signature predictive of overall survival and disease-free survival. This signature, highly expressed in ALA+ GASC, was also well represented in ALA PALE GASC. 5-ALA FGS allowed to underline the heterogeneity of the glioma microenvironments. Deepening knowledge of these differences can contribute to develop new adjuvant therapies targeting the crosstalk between tumor and its supporting microenvironment.

Lesions of uncertain malignant potential of the breast (B3) on vacuum-assisted biopsy for microcalcifications: Predictors of malignancy.

PURPOSE: To investigate clinical, radiologic and pathologic features of B3 lesions diagnosed on VABB targeting microcalcifications, for identifying predictors of malignancy. METHOD: This retrospective multi-centre study included consecutive VABBs performed over a 10-year period on suspicious microcalcifications not associated with other radiological signs diagnosed as B3 on histology from VABB, with outcomes ascertained by surgical excision. Clinical, demographic, radiological and histological (B3 subcategory) data were collected. For statistical analysis (univariate and binary logistic regression), the primary outcome variable was the upgrade rate to malignancy after surgery. Predictors of upgrade to malignancy were identified from clinical, demographic, radiological and pathological variables (including B3 subcategory). RESULTS: Amongst 447 VABBs, there were 57(12.7 %) upgrades to malignancy at surgical histology (36 DCIS and 21 invasive cancer). At univariate analysis, variables significantly associated with increased risk of upgrade to malignancy were age>55 years (p = 0.01), lesion size>10 mm (p < 0.0001), BI-RADS 4b-c and 5 (p = 0.0001), and fine pleomorphic morphology (p = 0.002) of microcalcifications. Binary logistic regression confirmed as significant independent risk factors age, lesion size and BI-RADS category (p = 0.02, 0.02 and 0.0006 respectively). Amongst subcategories of B3 lesions, lobular neoplasia was significantly(p = 0.04) associated with upgrade, confirmed as an independent risk factor [p = 0.03, OR = 2.3(1.1-4.7)]. Flat epithelial atypia was significantly(p = 0.004) associated with reduced odds of upgrade, but binary logistic regression showed only borderline association [p = 0.052, OR = 0.4(0.2-1.01)]. CONCLUSIONS: Across B3 lesions diagnosed on histology from VABB of suspicious microcalcifications, older age, size>10 mm, BI-RADS category≥ 4b on imaging, and lobular neoplasia were risk factors for upgrade to malignancy. This information can be used to discuss patients' tailored management options.