Mucin staining is of limited value in addition to basic immunohistochemical analyses in the diagnostics of non-small cell lung cancer

Protective effect of β-glucan on Poly(I:C)-induced acute lung injury/inflammation: Therapeutic implications of viral infections in the respiratory system

AIMS

Acute lung inflammation, particularly acute respiratory distress syndrome (ARDS), is caused by a variety of pathogens including bacteria and viruses. β-Glucans have been reported to possess both anti-inflammatory and immunomodulatory properties. The current study evaluated the therapeutic effect of β-glucans on polyinosinic:polycytidylic acid (Poly(I:C)) induced lung inflammation in both hamster and mice models.

MAIN METHODS

Poly(I:C)-induced ALI/inflammation models were developed in hamsters (2.5 mg/kg) and mice (2 mg/kg) by delivering the Poly(I:C) intratracheally, and followed with and without β-glucan administration. After treatment, lung mechanics were assessed and lung tissues were isolated and analyzed for mRNA/protein expression, and histopathological examinations.

KEY FINDINGS

Poly(I:C) administration, caused a significant elevation of inflammatory marker's expression in lung tissues and showed abnormal lung mechanics in mice and hamsters. Interestingly, treatment with β-glucan significantly (p < 0.001) reversed the Poly(I:C)-induced inflammatory events and inflammatory markers expression in both mRNA (IL-6, IL-1β, TNF-α, CCL2 and CCL7) and protein levels (TNF-α, CD68, myeloperoxidase, neutrophil elastase, MUC-5Ac and iNOS). Lung functional assays revealed that β-glucan treatment significantly improved lung mechanics. Histopathological analysis showed that β-glucan treatment significantly attenuated the Poly(I:C) induced inflammatory cell infiltration, injury and goblet cell population in lung tissues. Consistent with these findings, β-glucan treatment markedly reduced the number of neutrophils and macrophages in lung tissues. Our findings further demonstrated that β-glucan could reduce inflammation by suppressing the MAPK pathway.

SIGNIFICANCE

These results suggested that β-glucan may attenuate the pathogenic effects of Poly(I:C)-induced ALI/ARDS via modulating the MAPK pathway, indicating β-glucan as a possible therapeutic agent for the treatment of viral-pulmonary inflammation/injury.

The Role of Membrane-Tethered Mucins in Axial Epithelial Adhesion in Controlled Normal Stress Environments

The collective adhesive behavior of epithelial cell layers mediated by complex macromolecular fluid environments plays a vital role in many biological processes. Mucins, a family of highly glycosylated proteins, are known to lubricate cell-on-cell contacts in the shear direction. However, the role of mucins mediating axial epithelial adhesion in the direction perpendicular to the plane of the cell sheet has received less attention. This article subjects cell-on-cell layers of live ocular epithelia that express mucins on their apical surfaces to compression/decompression cycles and tensile loading using a customized instrument. In addition to providing compressive moduli of native cell-on-cell layers, it is found that the mucin layer between the epithelia acts as a soft cushion between the epithelial cell layers. Decompression experiments reveal mucin layers act as soft, nonlinear springs in the axial direction. The cell-on-cell layers withstand decompression before fracturing by a cohesive failure within the mucin layer. When mucin deficiency is induced via a protease treatment, it is found that the axial adhesion between the cell layers is increased. The findings which correlate changes in biological factors with changes in mechanical properties might be of interest to challenges in ophthalmology, vision care, and mucus research.

Diagnostic gastrointestinal markers in primary lung cancer and pulmonary metastases

Histopathological diagnosis of pulmonary tumors is essential for treatment decisions. The distinction between primary lung adenocarcinoma and pulmonary metastasis from the gastrointestinal (GI) tract may be difficult. Therefore, we compared the diagnostic value of several immunohistochemical markers in pulmonary tumors. Tissue microarrays from 629 resected primary lung cancers and 422 resected pulmonary epithelial metastases from various sites (whereof 275 colorectal cancer) were investigated for the immunohistochemical expression of CDH17, GPA33, MUC2, MUC6, SATB2, and SMAD4, for comparison with CDX2, CK20, CK7, and TTF-1. The most sensitive markers for GI origin were GPA33 (positive in 98%, 60%, and 100% of pulmonary metastases from colorectal cancer, pancreatic cancer, and other GI adenocarcinomas, respectively), CDX2 (99/40/100%), and CDH17 (99/0/100%). In comparison, SATB2 and CK20 showed higher specificity, with expression in 5% and 10% of mucinous primary lung adenocarcinomas and both in 0% of TTF-1-negative non-mucinous primary lung adenocarcinomas (25-50% and 5-16%, respectively, for GPA33/CDX2/CDH17). MUC2 was negative in all primary lung cancers, but positive only in less than half of pulmonary metastases from mucinous adenocarcinomas from other organs. Combining six GI markers did not perfectly separate primary lung cancers from pulmonary metastases including subgroups such as mucinous adenocarcinomas or CK7-positive GI tract metastases. This comprehensive comparison suggests that CDH17, GPA33, and SATB2 may be used as equivalent alternatives to CDX2 and CK20. However, no single or combination of markers can categorically distinguish primary lung cancers from metastatic GI tract cancer.

Agreement Between Mucicarmine-Stained Bronchial Brushing and Bronchial Biopsy in Subtyping Non-small Cell Lung Carcinoma

Background Bronchial brushing and biopsy are used for the diagnosis of lung carcinoma as most of these tumors are unresectable. Recently, the subclassification of non-small cell lung carcinoma (NSCLC) into adenocarcinoma (ADC) and squamous cell carcinoma (SCC) has become mandatory due to the emergence of targeted therapies. Due to the inherent limitations of small samples, subcategorization of a tumor is not always possible. Immunohistochemical and mucin stains are being used for this purpose, especially for tumors with poorly differentiated features. In our study, we utilized mucicarmine mucin stain to refine the differentiation of SCC and ADC on bronchial brushing and determine its agreement with bronchial biopsy. This study aimed to measure the degree of agreement between mucicarmine-stained bronchial brushing and bronchial biopsy for subtyping NSCLC into SCC and ADC. Methodology This descriptive, cross-sectional study was conducted in the pathology department of Allama Iqbal Medical College. Samples were collected by the pulmonology department of Jinnah Hospital Lahore. The study was conducted for 10 months from June 2020 to April 2021. A total of 60 cases diagnosed as NSCLC, aged between 35 and 80 years, were included in this study. After cytohistological evaluation of bronchial brushing and bronchial biopsy specimens, the agreement was deduced using kappa statistics. Results The strength of agreement between mucicarmine-stained bronchial brushing and bronchial biopsy for subtyping NSCLC into SCC and ADC was found to be substantial. Conclusions As significant agreement exists between the two modalities, mucicarmine-stained bronchial brushing can be used for a reliable and rapid categorization of NSCLC.

Clinicopathological features of cytokeratin 5-positive pulmonary adenocarcinoma

Cytokeratin 5 (CK5) is a marker for pulmonary squamous cell carcinoma; however, CK5 is sometimes present in pulmonary adenocarcinoma (ADC), and there is insufficient information regarding the clinicopathological features of CK5-positive ADC. We aimed to explore the clinicopathological characteristics of CK5-positive ADC using immunohistochemistry. We prepared the following two cohorts: a resected cohort containing 220 resected tumours for primarily studying the detailed morphological characteristics, and a tissue microarray (TMA) cohort containing 337 samples for investigating the associations of CK5 expression with other protein expressions, genetic and prognostic findings. CK5-positive ADC was defined to have ≥ 10% tumour cells and presence of CK5-positive tumour cells in the resected and TMA cohorts, respectively. CK5-positive ADCs were identified in 91 (16.3%) patients in the combined cohort. CK5-positive ADCs had male predominance (P = 0.012), smoking history (P = 0.001), higher stage (P < 0.001), histological high-grade components (P < 0.001), vascular invasion (P < 0.001), mucinous differentiation (P < 0.001), spread through airspaces (P < 0.001), EGFR wild-type (P < 0.001), KRAS mutations (P < 0.001), ALK rearrangement (P < 0.001) and ROS1 rearrangement (P = 0.002). In the resected cohort, more than half the CK5-positive ADCs (19 cases, 65.5%) showed mucinous differentiation; the remaining cases harboured high-grade components. In the TMA cohort, CK5-positive ADCs correlated with TTF-1 negativity (P = 0.002) and MUC5B, MUC5AC and HNF4alpha positivity (P < 0.001, 0.048, < 0.001). Further, CK5-positive ADCs had significantly lower disease-free and overall survival rates than CK5-negative ADCs (P < 0.001 for each). Additionally, multivariate analysis revealed that CK5 expression was an independent poor prognostic factor. CK5-positive ADCs showed aggressive clinical behaviour, with high-grade morphology and mucinous differentiation.

Updates in pathology and molecular diagnostics to inform the evolving landscape of thoracic surgery and oncology

The pathologic assessment of lung cancers provides essential guidance to the surgeon and oncologist who are considering the best treatment strategies for patients with both early and advanced-stage disease. The management of patients with lung cancer is predicated first and foremost on access to an accurate diagnosis, even when the sample size is limited, as is often the case with use of modern, minimally invasive sampling techniques. Once the diagnosis and disease stage are established, predictive biomarker testing may be essential, particularly for those patients with nonsmall cell lung carcinoma (NSCLC) being considered for immunotherapy or genomic biomarker-driven targeted therapy. This review will discuss the best practices for the diagnosis of NSCLC using morphology and immunohistochemistry, thus providing the surgeon with needed information to understand and critically evaluate pathology reports. Controversial and evolving topics including tumor spread through airspaces, evaluation of multiple tumors, and staging based on invasive tumor size will be addressed. Clinical genomic profiling in NSCLC is driven by published guidelines and reflects evidence based on clinical trials and regulatory approvals. In this fast-moving space, surgeons should be aware of the critical immunohistochemical and genomic biomarkers that drive systemic therapy decisions and anticipate when such testing will be required, both to ensure adequate sampling and to advise the pathologist when tumor material will be required for biomarker analysis. The basic approaches to and sample requirements for molecular biomarker testing will be addressed. As biomarker testing moves exclusively from advanced-stage patients into earlier stage disease, the surgeon should be aware of the relevant markers and work with the pathologist and oncologist to ensure that this information is available to facilitate timely access to therapies not just in the advanced setting, but in consideration of neoadjuvant and adjuvant care.

Damage to Olfactory Organs of Adult Zebrafish Induced by Diesel Particulate Matter

Particulate matter (PM) is an environmental hazard that is associated with various human health risks. The olfactory system is directly exposed to PM; therefore, the influence of PM exposure on olfactory function must be investigated. In this study, we propose a zebrafish olfactory model to evaluate the effects of exposure to diesel particulate matter (DPM), which was labeled Korean diesel particulate matter (KDP20). KDP20 comprises heavy metals and polycyclic aromatic hydrocarbons (PAHs). KDP20 exposed olfactory organs exhibited reduced cilia and damaged epithelium. Olfactory dysfunction was confirmed using an odor-mediated behavior test. Furthermore, the olfactory damage was analyzed using Alcian blue and anti-calretinin staining. KDP20 exposed olfactory organs exhibited histological damages, such as increased goblet cells, decreased cell density, and calretinin level. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that PAHs exposure related genes (AHR2 and CYP1A) were upregulated. Reactive oxidation stress (ROS) (CAT) and inflammation (IL-1B) related genes were upregulated. Furthermore, olfactory sensory neuron (OSN) related genes (OMP and S100) were downregulated. In conclusion, KDP20 exposure induced dysfunction of the olfactory system. Additionally, the zebrafish olfactory system exhibited a regenerative capacity with recovery conditions. Thus, this model may be used in future investigating PM-related diseases.

Porphyromonas gingivalis gingipains potentially affect MUC5AC gene expression and protein levels in respiratory epithelial cells

Porphyromonas gingivalis (Pg) is a periodontopathic pathogen that may affect MUC5AC‐related mucus hypersecretion along airway epithelial cells. Here, we attempted to establish whether Pg virulence factors (lipopolysaccharide, FimA fimbriae, gingipains) affect MUC5AC in immortalized and primary bronchial cells. We report that MUC5AC gene expression and protein levels are affected by Pg culture supernatant, but not by lipopolysaccharide or FimA fimbriae. Cells treated with either Pg single (Kgp or Rgp) or double (Kgp/Rgp) mutants had altered levels of MUC5AC gene expression and protein levels, and MUC5AC staining of double mutant‐treated mouse lung cells showed that MUC5AC protein levels were unaffected. Taken together, we propose that Pg gingipains may be the primary virulence factor that influences both MUC5AC gene expression and protein levels.

Periodic acid-Schiff and alcian blue immunohistochemistry to detect mucin in mucinous breast carcinoma

BACKGROUND Detection of mucins has been shown to correlate with several clinicopathological characteristics in patients. Currently, periodic acid-Schiff (PAS) and alcian blue staining methods are the histochemistry staining techniques that are frequently used to detect mucin. This study was aimed to evaluate PAS and alcian blue staining in differentiating mucin characteristics between invasive carcinoma of no special type (ICNST) with mucinous degeneration and mucinous carcinoma. METHODS This cross-sectional study of 33 cases included biopsies of mucinous breast carcinoma and ICNST with mucin degeneration that were histologically verified using hematoxylin and eosin (H&E) staining. The PAS and alcian blue staining were conducted in the Laboratory of Histochemistry, Department of Anatomical Pathology, Cipto Mangunkusumo Hospital. Data were recorded using SPSS software, version 21 (IBM Corp, USA). RESULTS There were 17 cases of ICNST with mucinous degeneration and 16 cases of mucinous carcinoma with age varied from 27 to 75 years. PAS had sensitivity of 87.5% and specificity of 41.2%. Alcian blue had sensitivity of 43.8% and specificity of 82.4%. CONCLUSIONS PAS staining method is better than the alcian blue staining method in distinguishing between ICNST with mucinous degeneration and mucinous carcinoma. In the limited setting laboratory, PAS staining alone can be considered to detect mucin.