Autopsies performed on COVID-19 patients have provided critical information about SARS-CoV-2's tropism, mechanisms of tissue injury, and the spectrum of disease.
To provide an updated database of ...postmortem disease in COVID-19 patients, assess relationships among clinical and pathologic variables, evaluate the accuracy of death certification, and correlate disease variables to causes of death.
The 272 postmortem examinations reported in this paper were submitted by 14 pathologists from 9 medical or forensic institutions across the United States. The study spans the eras of the 3 principal COVID-19 strains and incorporates surveyed demographic, clinical, and postmortem data from decedents infected with SARS-CoV-2, including primary and contributing causes of death. It is the largest database of its kind to date.
Demographics of the decedents reported here correspond well to national statistics. Primary causes of death as determined by autopsy and official death certificates were significantly correlated. When specifically cited disease conditions found at autopsy were correlated with COVID-19 versus non-COVID-19 death, only lung findings characteristic of SARS-CoV-2 infection or the absence of lung findings were significantly associated.
Changes in hospitalization and disease likely stem from longer lifespans after COVID-19 diagnosis and alteration in treatment approaches. Although Omicron variants preferentially replicate in the upper airways, autopsied patients who died of COVID-19 in that time period showed the same lung damage as earlier decedents. Most importantly, findings suggest that there are still unelucidated risk factors for death from COVID-19 including possibly genetic susceptibility.
Aberrant type 2 responses underlie the pathologies in allergic diseases like asthma, yet, our understanding of the mechanisms that drive them remains limited. Recent evidence suggests that ...dysregulated innate immune factors can perpetuate asthma pathogenesis. In susceptible individuals, allergen exposure triggers the activation of complement, a major arm of innate immunity, leading to the aberrant generation of the C3a anaphylatoxin. C3 and C3a have been shown to be important for the development of Th2 responses, yet remarkably, the mechanisms by which C3a regulates type 2 immunity are relatively unknown. We demonstrate a central role for C3a in driving type 2 innate lymphoid cells (ILC2)-mediated inflammation in response to allergen and IL-33. Our data suggests that ILC2 recruitment is C3a-dependent. Further, we show that ILC2s directly respond to C3a, promoting type 2 responses by specifically: (1) inducing IL-13 and granulocyte-macrophage colony-stimulating factor, whereas inhibiting IL-10 production from ILC2; and (2) enhancing their antigen-presenting capability during ILC-T-cell cross-talk. In summary, we identify a novel mechanism by which C3a can mediate aberrant type 2 responses to aeroallergen exposure, which involves a yet unrecognized cross-talk between two major innate immune components-complement and group 2 innate lymphoid cells.
Microarray technology is a powerful tool for measuring RNA expression for thousands of genes at once. Various studies have been published comparing competing platforms with mixed results: some find ...agreement, others do not. As the number of researchers starting to use microarrays and the number of cross-platform meta-analysis studies rapidly increases, appropriate platform assessments become more important. Here we present results from a comparison study that offers important improvements over those previously described in the literature. In particular, we noticed that none of the previously published papers consider differences between labs. For this study, a consortium of ten laboratories from the Washington, DC-Baltimore, USA, area was formed to compare data obtained from three widely used platforms using identical RNA samples. We used appropriate statistical analysis to demonstrate that there are relatively large differences in data obtained in labs using the same platform, but that the results from the best-performing labs agree rather well.
ABSTRACT
Oncogenic Kras mutations are one of the most common alterations in non‐small cell lung cancer and are associated with poor response to treatment and reduced survival. Driver oncogenes, such ...as Kras are now appreciated for their ability to promote tumor growth via up‐regulation of anabolic pathways. Therefore, we wanted to identify metabolic vulnerabilities in Kras‐mutant lung cancer. Using the KrasLSL‐G12D lung cancer model, we show that mutant Kras drives a lipogenic gene‐expression program. Stable‐isotope analysis reveals that mutant Kras promotes de novo fatty acid synthesis in vitro and in vivo. The importance of fatty acid synthesis in Kras‐induced tumorigenesis was evident by decreased tumor formation in KrasLSL‐G12D mice after treatment with a fatty acid synthesis inhibitor. Importantly, with gain and loss of function models of mutant Kras, we demonstrate that mutant Kras potentiates the growth inhibitory effects of several fatty acid synthesis inhibitors. These studies highlight the potential to target mutant Kras tumors by taking advantage of the lipogenic phenotype induced by mutant Kras.—Singh, A., Ruiz, C., Bhalla, K., Haley, J. A., Li, Q. K., Acquaah‐Mensah, G., Montal, E., Sudini, K. R., Skoulidis, F., Wistuba, I. I., Papadimitrakopoulou, V., Heymach, J. V., Boros, L. G., Gabrielson, E., Carretero, J., Wong, K.‐K., Haley, J.D., Biswal, S., Girnun, G.D. De novo lipogenesis represents a therapeutic target in mutant Kras non‐small cell lung cancer. FASEB J. 32, 7018–7027 (2018). www.fasebj.org
BackgroundCombination therapies that aim to improve the clinical efficacy to immune checkpoint inhibitors have led to the need for non-invasive and early pharmacodynamic biomarkers. Positron emission ...tomography (PET) is a promising non-invasive approach to monitoring target dynamics, and programmed death-ligand 1 (PD-L1) expression is a central component in cancer immunotherapy strategies. 18FDK222, a peptide-based PD-L1 imaging agent, was investigated in this study using humanized mouse models to explore the relationship between PD-L1 expression and therapy-induced changes in cancer.MethodsCell lines and xenografts derived from three non-small cell lung cancers (NSCLCs) and three urothelial carcinomas (UCs) were used to validate the specificity of 18FDK222 for PD-L1. PET was used to quantify anti-programmed cell death protein-1 (PD-1) therapy-induced changes in PD-L1 expression in tumors with and without microsatellite instability (MSI) in humanized mice. Furthermore, 18FDK222-PET was used to validate PD-L1 pharmacodynamics in the context of monotherapy and combination immunotherapy in humanized mice bearing A375 melanoma xenografts. PET measures of PD-L1 expression were used to establish a relationship between pathological and immunological changes. Lastly, spatial distribution analysis of 18FDK222-PET was developed to assess the effects of different immunotherapy regimens on tumor heterogeneity.Results18FDK222-PET and biodistribution studies in mice with NSCLC and UC xenografts revealed high but variable tumor uptake at 60 min that correlated with PD-L1 expression. In MSI tumors treated with anti-PD-1, 18FDK222 uptake was higher than in control tumors. Moreover, 18FDK222 uptake was higher in A375 tumors treated with combination therapy compared with monotherapy, and negatively correlated with final tumor volumes. In addition, a higher number of PD-L1+ cells and higher CD8+-to-CD4+ cell ratio was observed with combination therapy compared with monotherapy, and positively correlated with PET. Furthermore, spatial distribution analysis showed higher 18FDK222 uptake towards the core of the tumors in combination therapy, indicating a more robust and distinct pattern of immune cell infiltration.Conclusion18FDK222-PET has potential as a non-invasive tool for monitoring the effects of immunotherapy on tumors. It was able to detect variable PD-L1 expression in tumors of different cancer types and quantify therapy-induced changes in tumors. Moreover, 18FDK222-PET was able to differentiate the impact of different therapies on tumors.
Cathepsin D (Cat D) is well known for its roles in metastasis, angiogenesis, proliferation, and carcinogenesis in cancer. Despite Cat D being a promising target in cancer cells, effects and ...underlying mechanism of its inhibition remain unclear. Here, we investigated the plausibility of using Cat D inhibition as an adjuvant or sensitizer for enhancing anticancer drug-induced apoptosis. Inhibition of Cat D markedly enhanced anticancer drug-induced apoptosis in human carcinoma cell lines and xenograft models. The inhibition destabilized Bcl-xL through upregulation of the expression of RNF183, an E3 ligase of Bcl-xL, via NF-κB activation. Furthermore, Cat D inhibition increased the proteasome activity, which is another important factor in the degradation of proteins. Cat D inhibition resulted in p62-dependent activation of Nrf2, which increased the expression of proteasome subunits (PSMA5 and PSMB5), and thereby, the proteasome activity. Overall, Cat D inhibition sensitized cancer cells to anticancer drugs through the destabilization of Bcl-xL. Furthermore, human renal clear carcinoma (RCC) tissues revealed a positive correlation between Cat D and Bcl-xL expression, whereas RNF183 and Bcl-xL expression indicated inverse correlation. Our results suggest that inhibition of Cat D is promising as an adjuvant or sensitizer for enhancing anticancer drug-induced apoptosis in cancer cells.
Summary Personalized treatment of lung cancer requires an accurate subclassification of non-small cell lung carcinoma (NSCLC) into adenocarcinoma (ADC), squamous cell carcinoma (SqCC) and other ...subtypes. In poorly differentiated tumors especially on small fine needle aspirate (FNA) specimens the subclassification could be difficult in certain cases. Our previous study using resected tumor tissue has shown that the combination of commonly used individual markers (TTF-1, P40 and Napsin A) into a novel triple marker has high sensitivity and specificity in subclassification of NSCLC, and also the advantage of using minimal tumor tissue. In this study, we further evaluated the utility of this novel triple marker using FNA cases. We included primary NSCLC, consisting of 37 SqCCs (primary = 35 and metastasis = 2) and 50 ADCs (primary = 29 and metastasis = 21), 12 metastatic ADCs of non-pulmonary primary, and 10 small cell lung carcinomas (SCLCs). The IHC patterns were semi-quantitatively scored. In lung SqCCs and ADCs, the sensitivity and specificity of the triple marker were 100% and 97.1%, and 86.0% and 100%, respectively. The triple marker showed no immunoreactivity in 12 metastatic non-pulmonary ADCs. In 10 SCLCs, TTF-1 had focal positivity in 40% cases. The limitations of the triple marker include staining of alveolar macrophages (by TTF-1 and Napsin A), basal layer of bronchial epithelial cells (by P40), and non-specific cytoplasmic staining of TTF-1. Our study not only supports our previous finding using resected tumor specimens, but also provides evidence that the triple marker can be used for cytological material, and preserving tumor tissue for molecular testing.
Exposure to cigarette smoke (CS) is the primary factor associated with the development of chronic obstructive pulmonary disease (COPD). CS increases the level of oxidants in the lungs, resulting in a ...depletion of antioxidants, which promotes oxidative stress and the destruction of alveolar tissue. In response to CS, pulmonary epithelial cells counteract increased levels of oxidants by activating Nrf2-dependent pathways to augment the expression of detoxification and antioxidant enzymes, thereby protecting the lung from injury. We hypothesize that increasing the pathways activated by Nrf2 will afford protection against CS-induced lung damage. To this end we have developed a novel mouse model in which the cytosolic inhibitor of Nrf2, Keap1, is genetically deleted in Clara cells, which predominate in the upper airways in mice. Deletion of Keap1 in Clara cells resulted in increased expression of Nrf2-dependent genes, such as Nqo1 and Gclm, as determined by microarray analysis and quantitative PCR. Deletion of Keap1 in airway epithelium decreased Keap1 protein levels and significantly increased the total level of glutathione in the lungs. Increased Nrf2 activation protected Clara cells against oxidative stress ex vivo and attenuated oxidative stress and CS-induced inflammation in vivo. Expression of KEAP1 was also decreased in human epithelial cells through siRNA transfection, which increased the expression of Nrf2-dependent genes and attenuated oxidative stress. In conclusion, activating Nrf2 pathways in tissue-specific Keap1 knockout mice represents an important genetic approach against oxidant-induced lung damage.
Biallelic inactivation of cancer susceptibility gene BRCA1 leads to breast and ovarian carcinogenesis. Paradoxically, BRCA1 deficiency in mice results in early embryonic lethality, and similarly, ...lack of BRCA1 in human cells is thought to result in cellular lethality in view of BRCA1's essential function. To survive homozygous BRCA1 inactivation during tumorigenesis, precancerous cells must accumulate additional genetic alterations, such as p53 mutations, but this requirement for an extra genetic "hit" contradicts the two-hit theory for the accelerated carcinogenesis associated with familial cancer syndromes. Here, we show that heterozygous BRCA1 inactivation results in genomic instability in nontumorigenic human breast epithelial cells in vitro and in vivo. Using somatic cell gene targeting, we demonstrated that a heterozygous BRCA1 185delAG mutation confers impaired homology-mediated DNA repair and hypersensitivity to genotoxic stress. Heterozygous mutant BRCA1 cell clones also showed a higher degree of gene copy number loss and loss of heterozygosity in SNP array analyses. In BRCA1 heterozygous clones and nontumorigenic breast epithelial tissues from BRCA mutation carriers, FISH revealed elevated genomic instability when compared with their respective controls. Thus, BRCA1 haploinsufficiency may accelerate hereditary breast carcinogenesis by facilitating additional genetic alterations.
AMP-activated Protein Kinase (AMPK) activity retards growth of many types of cancers. Investigating effects of AMPK activation on breast cancer cell signaling and survival, we found that breast ...cancer cell lines with amplification and over-expression of HER2 or EGFR are 2- to 5-fold more sensitive to cytotoxic effects of AICAR, a canonical pharmacological activator of AMPK, than breast cancer cell lines lacking HER2 or EGFR overexpression. Paralleling effects on cell survival, AICAR leads to dose- and time-dependent inhibition of HER2 and EGFR in HER2-amplified breast cancer cells, with activation of AMPK and suppression of HER2/ EGFR activity preceding commitment to cell death. Transfection of constitutively active AMPKα also leads to decreased HER2 and EGFR phosphorylation, reduced downstream signaling associated with these receptor tyrosine kinases (RTKs), and reduced breast cancer cell growth, confirming effects of AMPK activity on HER2/ EGFR. Ensuing co-immunoprecipitation experiments demonstrated an interaction of HER2 with AMPK and an in vitro phosphorylation assay found that HER2 and EGFR contain sequences that are potential substrates for AMPK. Our results lead us to postulate that AMPK regulates HER2 and EGFR activity in HER2-amplified breast cancer cells and thus activation of AMPK might provide therapeutic benefit in such cancers.
PDF
