Effects of dimension reduction of hyperspectral images in skin gross pathology.

BACKGROUND: Hyperspectral imaging (HSI) is an emerging modality for the gross pathology of the skin. Spectral signatures of HSI could discriminate malignant from benign tissue. Because of inherent redundancies in HSI and in order to facilitate the use of deep-learning models, dimension reduction is a common preprocessing step. The effects of dimension reduction choice, training scope, and number of retained dimensions have not been evaluated on skin HSI for segmentation tasks. MATERIALS AND METHODS: An in-house dataset of HSI signatures from pigmented skin lesions was prepared and labeled with histology. Eleven different dimension reduction methods were used as preprocessing for tumor margin detection with support vector machines. Cluster-wise principal component analysis (ClusterPCA), a new variant of PCA, was proposed. The scope of application for dimension reduction was also investigated. RESULTS: The components produced by ClusterPCA show good agreement with the expected optical properties of skin chromophores. Random forest importance performed best during classification. However, all methods suffered from low sensitivity and generalization. CONCLUSION: Investigation of more complex reduction and segmentation schemes with emphasis on the nature of HSI and optical properties of the skin is necessary. Insights on dimension reduction for skin tissue could facilitate the development of HSI-based systems for cancer margin detection at gross level.

Distinct transcriptional programs of SOX2 in different types of small cell lung cancers.

SOX2 is recognized as an oncogene in human small cell lung cancer (SCLC), which is an aggressive neuroendocrine (NE) tumor. However, the role of SOX2 in SCLC is not completely understood, and strategies to selectively target SOX2 in SCLC cells remain elusive. Here, we show, using next-generation sequencing, that SOX2 expressed in the ASCL1-high SCLC (SCLC-A) subtype cell line is dependent on ASCL1, which is a lineage-specific transcriptional factor, and is involved in NE differentiation and tumorigenesis. ASCL1 recruits SOX2, which promotes INSM1 and WNT11 expression. Immunohistochemical studies revealed that SCLC tissue samples expressed SOX2, ASCL1, and INSM1 in 18 out of the 30 cases (60%). Contrary to the ASCL1-SOX2 signaling axis controlling SCLC biology in the SCLC-A subtype, SOX2 targets distinct genes such as those related to the Hippo pathway in the ASCL1-negative, YAP1-high SCLC (SCLC-Y) subtype. Although SOX2 knockdown experiments suppressed NE differentiation and cell proliferation in the SCLC-A subtype, they did not sufficiently impair the growth of the SCLC-Y subtype cell lines in vitro and ex vivo. The present results support the importance of the ASCL1-SOX2 axis as a main subtype of SCLC, and suggest the therapeutic potential of targeting the ASCL1-SOX2 axis.

Significance of achaete-scute complex homologue 1 (ASCL1) in pulmonary neuroendocrine carcinomas; RNA sequence analyses using small cell lung cancer cells and Ascl1-induced pulmonary neuroendocrine carcinoma cells.

ASCL1 is one of the master transcription factors of small cell lung carcinoma (SCLC). To investigate the significance of ASCL1 in pulmonary neuroendocrine carcinoma, we performed 2 comparative RNA-seq studies between H69 (ASCL1-positive, classical type SCLC) and H69AR (ASCL1-negative, variant type SCLC) and between ASCL1-transfected A549 adenocarcinoma cell lines (A549(ASCL1+) cell lines) and A549(control) cell lines. RNA-seq analyses revealed that 940 genes were significantly different between the H69 and H69AR cell lines, and 728 between the A549(ASCL1+) and A549(control) cell lines. In total, 120 common genes between these analyses were selected as candidate ASCL1-related genes, and included genes with various cellular functions, such as neural development, secretion, growth, and morphology. Their expression degrees in three classical and two variant SCLC cell lines, two A549(ASCL1+) and two A549(control) cell lines were subjected to quantitative PCR analyses. Since the candidate ASCL1-related genes were strongly expressed in the classical SCLC and A549(ASCL1+) cell lines and more weakly expressed in the variant SCLC and A549(control) cell lines, the ASCL1-related 7 molecules INSM1, ISL1, SYT4, KCTD16, SEZ6, MS4A8, and COBL were further selected. These molecules suggested diverse functions for A549(ASCL1+): INSM1 and ISL1 are transcription factors associated with neuroendocrine differentiation, while SYT4, KTCD16, and SEZ6 may be related to neurosecretory functions and MS4A8 and COBL to cell growth and morphology. An immunohistochemistry of these seven molecules was performed on lung carcinoma tissues and the xenotransplanted tumors of A549(ASCL1+), and they were preferentially and positively stained in ASCL1-postive tumor tissues.

Ascl1-induced Wnt11 regulates neuroendocrine differentiation, cell proliferation, and E-cadherin expression in small-cell lung cancer and Wnt11 regulates small-cell lung cancer biology.

The involvement of Wnt signaling in human lung cancer remains unclear. This study investigated the role of Wnt11 in neuroendocrine (NE) differentiation, cell proliferation, and epithelial-to-mesenchymal transition (EMT) in human small-cell lung cancer (SCLC). Immunohistochemical staining of resected specimens showed that Wnt11 was expressed at higher levels in SCLCs than in non-SCLCs; 58.8% of SCLC, 5.2% of adenocarcinoma (ADC), and 23.5% of squamous cell carcinoma tissues stained positive for Wnt11. A positive relationship was observed between Achaete-scute complex homolog 1 (Ascl1) and Wnt11 expression in SCLC cell lines, and this was supported by transcriptome data from SCLC tissue. The expression of Wnt11 and some NE markers increased after the transfection of ASCL1 into the A549 ADC cell line. Knockdown of Ascl1 downregulated Wnt11 expression in SCLC cell lines. Ascl1 regulated Wnt11 expression via lysine H3K27 acetylation at the enhancer region of the WNT11 gene. Wnt11 controlled NE differentiation, cell proliferation, and E-cadherin expression under the regulation of Ascl1 in SCLC cell lines. The phosphorylation of AKT and p38 mitogen-activated protein kinase markedly increased after transfection of WNT11 into the SBC3 SCLC cell line, which suggests that Wnt11 promotes cell proliferation in SCLC cell lines. Ascl1 plays an important role in regulating the Wnt signaling pathway and is one of the driver molecules of Wnt11 in human SCLC. Ascl1 and Wnt11 may employ a cooperative mechanism to control the biology of SCLC. The present results indicate the therapeutic potential of targeting the Ascl1-Wnt11 signaling axis and support the clinical utility of Wnt11 as a biological marker in SCLC.

Encapsulating Peritoneal Sclerosis in Systemic Lupus Erythematosus, Rheumatoid Arthritis, and Systemic Sclerosis.

We encountered a 57-year-old Japanese woman with encapsulating peritoneal sclerosis (EPS) in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis. The patient was admitted to our hospital because of ascites retention. Administration of tocilizumab, an anti-interleukin-6 receptor antibody, for her RA reduced the refractory ascites remarkably; however, she developed sudden acute gastrointestinal bleeding and died a year later. On autopsy, sclerotic thickening of the peritoneum showed diffuse infiltration of podoplanin-positive fibroblast-like cells, and a diagnosis of EPS was made. EPS rarely occurs in SLE, and tocilizumab may be a new treatment candidate for EPS.

Biallelic BCL6 rearrangements by dual t(3;14)(q27;q32) and t(3;22)(q27;q11) translocations in diffuse large B-cell lymphoma.

3q27 chromosomal translocation involving the BCL6 gene is one of the most frequent forms of cytogenetic abnormality observed in B-cell lymphoma. We report a case with diffuse large B-cell lymphoma (DLBCL) presenting dual 3q27 translocations. The patient was a 71-year-old man who presented with swelling of multiple abdominal lymph nodes (LNs) and obstructive jaundice. LN biopsy exhibited dense proliferation of atypical large cells expressing CD20, MUM1/IRF4, BCL2, BCL6, and MYC, but not CD10. He was diagnosed with non-GCB/ABC type DLBCL and showed an initially good response to R-CHOP chemotherapy, but relapsed soon after the completion of therapy. Chromosomal analysis of the biopsied LN exhibited multiple abnormalities including t(3;14)(q27;q32) and t(3;22)(q27;q11). Fluorescence in situ hybridization (FISH) using BCL6 break-apart probes confirmed chromosomal breaks occurring on both BCL6 alleles. Molecular analysis revealed two independent rearrangements of BCL6, either with the IGH or the IGL gene. 3q27 breakpoints were located 1.2kb apart from each other within the first intron of BCL6, while the IGH and IGL breaks occurred at the 5' of IGHG2 and within IGLV3-1, respectively. The results suggest that biallelic BCL6 rearrangements might be a rare but recurrent genetic event in B-cell lymphoma.

Hyperspectral imaging for tumor segmentation on pigmented skin lesions.

Significance: Malignant skin tumors, which include melanoma and nonmelanoma skin cancers, are the most prevalent type of malignant tumor. Gross pathology of pigmented skin lesions (PSL) remains manual, time-consuming, and heavily dependent on the expertise of the medical personnel. Hyperspectral imaging (HSI) can assist in the detection of tumors and evaluate the status of tumor margins by their spectral signatures. Aim: Tumor segmentation of medical HSI data is a research field. The goal of this study is to propose a framework for HSI-based tumor segmentation of PSL. Approach: An HSI dataset of 28 PSL was prepared. Two frameworks for data preprocessing and tumor segmentation were proposed. Models based on machine learning and deep learning were used at the core of each framework. Results: Cross-validation performance showed that pixel-wise processing achieves higher segmentation performance, in terms of the Jaccard coefficient. Simultaneous use of spatio-spectral features produced more comprehensive tumor masks. A three-dimensional Xception-based network achieved performance similar to state-of-the-art networks while allowing for more detailed detection of the tumor border. Conclusions: Good performance was achieved for melanocytic lesions, but margins were difficult to detect in some cases of basal cell carcinoma. The frameworks proposed in this study could be further improved for robustness against different pathologies and detailed delineation of tissue margins to facilitate computer-assisted diagnosis during gross pathology.

Pulmonary Neuroendocrine Cells and Small Cell Lung Carcinoma: Immunohistochemical Study Focusing on Mechanisms of Neuroendocrine Differentiation.

Neuroendocrine (NE) differentiation has been histochemically detected in normal and cancer tissues and cells. Immunohistochemical analyses have provided a more detailed understanding of NE biology and pathology. Pulmonary NE cells are a rare lung epithelial type, and small cell carcinoma of the lung (SCLC) is a high-grade NE tumor. Pulmonary NE and SCLC cells share common mechanisms for NE differentiation. Neural or NE cell lineage-specific transcription factors, such as achaete-scute homologue 1 (Ascl1) and insulinoma-associated protein 1 (INSM1), are crucial for the development of pulmonary NE cells, and NE differentiation is influenced by the balance between Ascl1 and the suppressive neural transcription factor, hairy-enhancer of split 1, a representative target molecule of the Notch signaling pathway. In this review, we discuss the importance of Ascl1 and INSM1 in identifying pulmonary NE and SCLC cells and introduce Ascl1-related molecules detected by comparative RNA-sequence analyses. The molecular classification of SCLC based on the expression of lineage-specific transcription or co-transcription factors, including ASCL1, NEUROD1, POU2F3, and YAP1, was recently proposed. We attempted to characterize these 4 SCLC subtypes using integrated immunohistochemical studies, which will provide insights into the molecular characteristics of these subtypes and clarify the inter- and intratumor heterogeneities of SCLC.

Design of a Hyper-Spectral Imaging System for Gross Pathology of Pigmented Skin Lesions.

Pigmented skin lesions (PSL) are prevalent in Asian populations and their gross pathology remains a manual, tedious task. Hyper-spectral imaging (HSI) is a non-invasive non-ionizing acquisition technique, allowing malignant tissue to be identified by its spectral signature. We set up a hyper-spectral imaging (HSI) system targeting cancer margin detection of PSL. Because classification among PSL is achieved via comparison of spectral signatures, appropriate calibration is necessary to ensure sufficient data quality. We propose a strategy for system building, calibration and pre-processing, under the requirements of fast acquisition and wide field of view. Preliminary results show that the HSI-based system is able to effectively resolve reflectance signatures of ex-vivo tissue.Clinical Relevance-The imaging system proposed in this study can recover reflectance spectra from PSL during gross pathology, providing a wide imaging area.

Telepathology Support System with Gross Specimen Image Using High Resolution 4K Multispectral Camera.

This study reports on the development of a high-resolution 4K multispectral camera designed to enhance telepathology support systems for remote gross-pathological diagnosis. We experimentally examine and evaluate the camera's effectiveness in three subjects: the reconstruction of precise color images, the emphasis of cancerous tissue areas, and pre-fixed image reproduction from fixed images. The evaluation results of the first and second subjects showed that the camera and supporting methods could be effectively used in gross pathology diagnosis. The images obtained in the third subject received positive evaluations from some pathologists, but others expressed reservations as to its utility.

Endoscopic Features and Diagnostic Procedures of Eosinophilic Gastroenteritis.

No specific endoscopic features for eosinophilic gastroenteritis (EGE) have been reported previously. This study therefore evaluated the endoscopic findings of six patients with EGE. The diagnosis was confirmed based on gastrointestinal symptoms, pathological findings on biopsy, and the absence of other diseases. The site of the lesion was identified based on eosinophilic infiltration with ≥20 cells per high-power field during a pathological specimen analysis. Flattening of the small intestinal villi was observed in four patients; we speculate that this may be a specific feature in the diagnosis of EGE.

MCAF mediates MBD1-dependent transcriptional repression.

DNA methylation is involved in a variety of genome functions, including gene control and chromatin dynamics. MBD1 is a transcriptional regulator through the cooperation of a methyl-CpG binding domain, cysteine-rich CXXC domains, and a transcriptional repression domain. A yeast two-hybrid screen was performed to investigate the role of MBD1 in methylation-based transcriptional repression. We report a mediator, MBD1-containing chromatin-associated factor (MCAF), that interacts with the transcriptional repression domain of MBD1. MCAF harbors two conserved domains that allow it to interact with MBD1 and enhancer-like transactivator Sp1. MCAF possesses a coactivator-like activity, and it seems to facilitate Sp1-mediated transcription. In contrast, the MBD1-MCAF complex blocks transcription through affecting Sp1 on methylated promoter regions. These data provide a mechanistic basis for direct inhibition of gene expression via methylation-dependent and histone deacetylation-resistant processes.

Activation of Sp1-mediated transcription by Rta of Epstein-Barr virus via an interaction with MCAF1.

Rta is a transcription factor encoded by BRLF1 of the Epstein-Barr virus (EBV). This factor is expressed during the immediate-early stage of the lytic cycle to activate the genes required for EBV lytic development. Although transcription activation by Rta is frequently associated with the binding of Rta to the Rta-response element (RRE) in promoters, Rta sometimes activates promoters without an RRE. Here we show that Rta interacts with an Sp1-interacting protein, MBD1-containing chromatin-associated factor 1 (MCAF1). This interaction is critical to the formation of an Sp1-MCAF1-Rta complex at Sp1 sites. Therefore, following lytic induction and the expression of Rta, Rta increases Sp1-mediated transcription. The genes that are thus activated include p16, p21, SNRPN and BRLF1. However, the binding of Rta to RRE prevents the interaction between Rta and MCAF1; therefore, transcription activation by RRE depends only on Rta, and not on MCAF1 or Sp1. Furthermore, this study finds that MCAF1 promotes the expression of Rta and Zta from EBV, indicating that MCAF1 participates EBV lytic activation. Our study documents the critical role of Rta in regulating the transcription of the genes that are mediated by Sp1.

Mesh penetrating the cecum and bladder following inguinal hernia surgery: a case report.

BACKGROUND: Tension-free repair using mesh is a common inguinal hernia surgical procedure. However, various complications such as mesh-related infection and recurrence may develop as a result. Moreover, although rare, there are also reports of intestinal obstruction caused by adhesion of the mesh to the intestinal wall and cases of mesh migration into various organs. Here, we report our experience with a patient in whom mesh extraction was performed due to migration of mesh into the intestinal tract following inguinal hernia surgery and formation of a fistula with the bladder. CASE PRESENTATION: Our patient was a 63-year-old Japanese man who had a history of operative treatment for right inguinal hernia during early childhood. Because a relapse subsequently occurred, he was diagnosed as having recurrent right inguinal hernia at the age of 56 years for which operative treatment (the Kugel method) was performed. He presented to our hospital 6 years later with the chief complaint of lower abdominal pain. Computed tomography findings revealed a mass shadow in contact with his bladder and cecal walls, and enteric bacteria were detected in his urine. Furthermore, because lower gastrointestinal endoscopic findings confirmed mesh in the cecum, we performed operative treatment. The mesh had migrated into the cecum and a fistula with his bladder had formed. We removed the mesh through ileocecal resection and partial cystectomy. CONCLUSIONS: It appeared that a peritoneal defect occurred when the mesh was placed, allowing the mesh to migrate into our patient's intestinal tract. Because contact between the mesh and the cecum resulted in inflammation, a fistula formed in his bladder. It is important to completely close the peritoneum when placing the mesh.

Feature analysis of cell nuclear chromatin distribution in support of cervical cytology.

Cytology, a method of estimating cancer or cellular atypia from microscopic images of scraped specimens, is used according to the pathologist's experience to diagnose cases based on the degree of structural changes and atypia. Several methods of cell feature quantification, including nuclear size, nuclear shape, cytoplasm size, and chromatin texture, have been studied. We focus on chromatin distribution in the cell nucleus and propose new feature values that indicate the chromatin complexity, spreading, and bias, including convex hull ratio on multiple binary images, intensity distribution from the gravity center, and tangential component intensity and texture biases. The characteristics and cellular classification accuracies of the proposed features were verified through experiments using cervical smear samples, for which clear nuclear morphologic diagnostic criteria are available. In this experiment, we also used a stepwise support vector machine to create a machine learning model and a cross-validation algorithm with which to derive identification accuracy. Our results demonstrate the effectiveness of our proposed feature values.

Small cell lung cancer, an epithelial to mesenchymal transition (EMT)-like cancer: significance of inactive Notch signaling and expression of achaete-scute complex homologue 1.

Small cell lung cancer (SCLC) is one of the most malignant neoplasms in common human cancers. The tumor is composed of small immature-looking cells with a round or fusiform shape, which possesses weak adhesion features among them, suggesting that SCLC shows the morphological characteristics of epithelial to mesenchymal transition (EMT). SCLC is characterized by high metastatic and recurrent rates, sensitivity to the initial chemotherapy, and easy acquirement of chemoresistance afterwards. These characters may be related to the EMT phenotype of SCLC. Notch signaling is an important signaling pathway, and could have roles in regulating neuroendocrine differentiation, proliferation, cell adhesion, EMT, and chemoresistance. Notch1 is usually absent in SCLC in vivo, but could appear after chemotherapy. Notch1 can enhance cell adhesion by induction of E-cadherin in SCLC, which indicates mesenchymal to epithelial transition. On the other hand, achaete-scute complex homologue 1 (ASCL1), negatively regulated by Notch signaling, is a lineage-specific gene of SCLC, and functions to promote neuroendocrine differentiation as well as EMT. ASCL1-transfected adenocarcinoma cell lines induced neuroendocrine phenotypes and lost epithelial cell features. SCLC is characterized by neuroendocrine differentiation and EMT-like features, which could be produced by inactive Notch signaling and ASCL1 expression. In addition, chemical and radiation treatments can activate Notch signaling, which suppress neuroendocrine differentiation and induces chemoradioresistance, accompanied by secession from EMT. Thus, the status of Notch signaling and ASCL1 expression may determine the cell behaviors of SCLC partly through modifying EMT phenotypes.

Proposal of criteria for dyserythropoiesis in the diagnosis of myelodysplastic syndromes.

The percentage manifesting dysplasia in bone marrow needed to qualify as significant is ≥10 % in each lineage. However, detailed analyses of this threshold have not been reported. Here, we analyzed dyserythropoiesis (dysE) in 109 myelodysplastic syndromes (MDS) patients with 21 immune thrombocytopenia (ITP)/12 hemolytic anemia (HA) patients as a control. In present study, mild megaloblastic erythroblasts were specifically named 'red cell with abnormal chromatin clumping (RCACC)'. RCACC ≥10 % in erythroblasts was observed in 29 % of ITP patients and 58 % of HA patients. The numbers of MDS patients with RCACC in erythroblasts <10, 10-19 and ≥20 % were 1, 3, and 105, respectively. We analyzed dysE criteria according to the WHO classification (original WHO dysE). Most of our MDS patients (98 %) had original WHO dysE ≥20 %. The ITP patients with original WHO dysE ≥10 % was 48 %, and there were no ITP patients had original WHO dysE ≥20 %. Sixty-seven percent of HA patients had original WHO dysE ≥10 %, and three patients (25 %) had original WHO dysE ≥20 %. Raising the threshold of the original WHO dysE from 10 to 20 or 30 % may provide more suitable criteria. If RCACC is not included in dysE criteria, we think that '10 %' is a suitable threshold for the determination of dyserythropoiesis.

Epigenetic system: a pathway to malignancies and a therapeutic target.

Cancer cells possess both genetic and epigenetic alterations that dysregulate essential cellular processes, leading to disordered cell proliferation and differentiation. Oncogenes and tumor suppressor genes have been found to be activated and inactivated, respectively, in malignant cells. Epigenetic regulation of the genome is mediated by interactions between DNA methylation, chromatin, and modifications of histones and various transcriptional regulators. Recent studies have shown that some components of the epigenetic system as well as epigenetically mutated genes are diagnostic and therapeutic targets in cancer. We discuss the molecular basis of the epigenetic mechanism in association with the development of cancer.

Primary central nervous system cytotoxic T-cell lymphoma mimicking demyelinating disease.

A 40-year-old man visited to our hospital due to progressive right hemiparesis. Magnetic resonance imaging demonstrated a heterogeneous contrast-enhanced lesion in the left basal ganglia with compression of the ventricles. A brain biopsy did not demonstrate central nervous system (CNS) lymphoma, although acute demyelination was observed. Despite the administration of steroids, the lesion increased in size, and the patient died three months after admission. An autopsy disclosed perivascular and parenchymal infiltration of lymphoma cells. An immunohistochemical analysis showed that the lesion was a cytotoxic T-cell lymphoma. This case indicates that the development of primary CNS lymphoma of this immunophenotype may be preceded by demyelination with subsequent rapid progression, thus requiring a careful evaluation and meticulous diagnosis.