BACKGROUND: Profiling studies in small-cell lung cancer (SCLC) have mainly focused on primary tumors, omitting the potential molecular changes that might occur during lymphatic metastasis formation. Here, we assessed the molecular discordance between primary SCLCs and corresponding lymph node (LN) metastases in the light of subtype distribution and expression of clinically relevant proteins. METHODS: Comparative profiling of 32 surgically resected primary SCLCs and their LN metastases was achieved by RNA expression analysis and immunohistochemistry (IHC). In addition to subtype markers (ASCL1, NEUROD1, POU2F3, and YAP1), the expression of nine cancer-specific proteins was evaluated. RESULTS: The selected clinically relevant molecules showed no significant differences in their RNA expression profile when assessing the primary tumors and their corresponding LN metastases. Nevertheless, IHC analyses revealed significantly higher DLL3 expression in the primary tumors than in the LN metastases (P = 0.008). In contrast, NEUROD1 expression was significantly lower in the primary tumors (versus LN metastases, P < 0.001). No statistically significant difference was found by IHC analysis in the case of other clinically relevant proteins. Concerning SCLC molecular subtypes, a change in subtype distribution was detected in 21 cases. Phenotype switching from neuroendocrine (NE) subtypes toward non-NE lesions and from non-NE landscape toward NE subtypes were both detected. CONCLUSIONS: Although the molecular landscape of SCLC LN metastases largely resembles that of the tumor of origin, key differences exist in terms of DLL3 and NEUROD1 expression, and in subtype distribution. These diagnostic pitfalls should be considered when establishing the tumors' molecular profile for future clinical trials solely based on LN biopsies.
- MeSH
- Immunohistochemistry MeSH
- Middle Aged MeSH
- Humans MeSH
- Lymphatic Metastasis * pathology MeSH
- Small Cell Lung Carcinoma * surgery pathology genetics MeSH
- Biomarkers, Tumor genetics MeSH
- Lung Neoplasms * pathology surgery genetics MeSH
- Aged MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
BACKGROUND: Head and neck paragangliomas (HNPGLs) are typically slow-growing, hormonally inactive tumors of parasympathetic paraganglia. Inactivation of prolyl-hydroxylase domain-containing 2 protein causing indirect gain-of-function of hypoxia-inducible factor-2α (HIF-2α), encoded by EPAS1, was recently shown to cause carotid body hyperplasia. We previously described a syndrome with multiple sympathetic paragangliomas caused by direct gain-of-function variants in EPAS1 (Pacak-Zhuang syndrome, PZS) and developed a corresponding mouse model. METHODS: We evaluated a cohort of patients with PZS (n = 9) for HNPGL by positron emission tomography, magnetic resonance imaging, and computed tomography and measured carotid body size compared to literature reference values. Resected tumors were evaluated by histologic sectioning and staining. We evaluated the corresponding mouse model at multiple developmental stages (P8 and adult) for lesions of the head and neck by high resolution ex vivo imaging and performed immunohistochemical staining on histologic sections of the identified lesions. RESULTS: hree patients had imaging consistent with HNPGL, one of which warranted resection and was confirmed on histology. Three additional patients had carotid body enlargement (Z-score > 2.0), and 3 had carotid artery malformations. We found that 9 of 10 adult variant mice had carotid body tumors and 6 of 8 had a paraganglioma on the cranio-caval vein, the murine homologue of the superior vena cava; these were also found in 4 of 5 variant mice at post-natal day 8. These tumors and the one resected from a patient were positive for tyrosine hydroxylase, synaptophysin, and chromogranin A. Brown fat in a resected patient tumor carried the EPAS1 pathogenic variant. CONCLUSIONS: These findings (1) suggest HNPGL as a feature of PZS and (2) show that these pathogenic variants are sufficient to cause the development of these tumors, which we believe represents a continuous spectrum of disease starting from hyperplasia.
- MeSH
- Adult MeSH
- Hyperplasia MeSH
- Carotid Body * pathology diagnostic imaging MeSH
- Middle Aged MeSH
- Humans MeSH
- Magnetic Resonance Imaging * MeSH
- Young Adult MeSH
- Disease Models, Animal MeSH
- Mice MeSH
- Head and Neck Neoplasms * genetics pathology diagnostic imaging MeSH
- Paraganglioma * genetics diagnostic imaging pathology MeSH
- Tomography, X-Ray Computed MeSH
- Positron-Emission Tomography MeSH
- Basic Helix-Loop-Helix Transcription Factors * genetics analysis MeSH
- Animals MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Juvenile hormone (JH) signaling is realized at the gene regulatory level by receptors of the bHLH-PAS transcription factor family. The sesquiterpenoid hormones and their synthetic mimics are agonist ligands of a unique JH receptor (JHR) protein, methoprene-tolerant (MET). Upon binding an agonist to its PAS-B cavity, MET dissociates from a cytoplasmic chaperone complex including HSP83 and concomitantly switches to a bHLH-PAS partner taiman, forming a nuclear, transcriptionally active JHR heterodimer. This course of events resembles the vertebrate aryl hydrocarbon receptor (AHR), activated by a plethora of endogenous and synthetic compounds. Like in AHR, the pliable PAS-B cavity of MET adjusts to diverse ligands and binds them through similar mechanisms. Despite recent progress, we only begin to discern agonist-induced conformational shifts within the PAS-B domain, with the ultimate goal of understanding how these localized changes stimulate the assembly of the active JHR complex and, thus, fully grasp the mechanism of JHR signaling.
- MeSH
- Juvenile Hormones * metabolism MeSH
- Signal Transduction MeSH
- Basic Helix-Loop-Helix Transcription Factors metabolism genetics chemistry MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
The presence of key hypoxia regulators, namely, hypoxia-inducible factor (HIF)-1α or HIF-2α, in tumors is associated with poor patient prognosis. Hypoxia massively activates several genes, including the one encoding the BCRP transporter that proffers multidrug resistance to cancer cells through the xenobiotic efflux and is a determinant of the side population (SP) associated with cancer stem-like phenotypes. As natural medicine comes to the fore, it is instinctive to look for natural agents possessing powerful features against cancer resistance. Hypericin, a pleiotropic agent found in Hypericum plants, is a good example as it is a BCRP substrate and potential inhibitor, and an SP and HIF modulator. Here, we showed that hypericin efficiently accumulated in hypoxic cancer cells, degraded HIF-1/2α, and decreased BCRP efflux together with hypoxia, thus diminishing the SP population. On the contrary, this seemingly favorable result was accompanied by the stimulated migration of this minor population that preserved the SP phenotype. Because hypoxia unexpectedly decreased the BCRP level and SP fraction, we compared the SP and non-SP proteomes and their changes under hypoxia in the A549 cell line. We identified differences among protein groups connected to the epithelial-mesenchymal transition, although major changes were related to hypoxia, as the upregulation of many proteins, including serpin E1, PLOD2 and LOXL2, that ultimately contribute to the initiation of the metastatic cascade was detected. Altogether, this study helps in clarifying the innate and hypoxia-triggered resistance of cancer cells and highlights the ambivalent role of natural agents in the biology of these cells.
- MeSH
- ATP Binding Cassette Transporter, Subfamily G, Member 2 genetics metabolism MeSH
- Hypoxia-Inducible Factor 1, alpha Subunit metabolism MeSH
- Cell Hypoxia MeSH
- Hypoxia MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Neoplasm Proteins genetics metabolism MeSH
- Neoplasms * metabolism MeSH
- Gene Expression Regulation, Neoplastic MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics metabolism MeSH
- Side-Population Cells * pathology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The tissue distribution and prognostic relevance of subtype-specific proteins (ASCL1, NEUROD1, POU2F3, YAP1) present an evolving area of research in small-cell lung cancer (SCLC). The expression of subtype-specific transcription factors and P53 and RB1 proteins were measured by immunohistochemistry (IHC) in 386 surgically resected SCLC samples. Correlations between subtype-specific proteins and in vitro efficacy of various therapeutic agents were investigated by proteomics and cell viability assays in 26 human SCLC cell lines. Besides SCLC-A (ASCL1-dominant), SCLC-AN (combined ASCL1/NEUROD1), SCLC-N (NEUROD1-dominant), and SCLC-P (POU2F3-dominant), IHC and cluster analyses identified a quadruple-negative SCLC subtype (SCLC-QN). No unique YAP1-subtype was found. The highest overall survival rates were associated with non-neuroendocrine subtypes (SCLC-P and SCLC-QN) and the lowest with neuroendocrine subtypes (SCLC-A, SCLC-N, SCLC-AN). In univariate analyses, high ASCL1 expression was associated with poor prognosis and high POU2F3 expression with good prognosis. Notably, high ASCL1 expression influenced survival outcomes independently of other variables in a multivariate model. High POU2F3 and YAP1 protein abundances correlated with sensitivity and resistance to standard-of-care chemotherapeutics, respectively. Specific correlation patterns were also found between the efficacy of targeted agents and subtype-specific protein abundances. In conclusion, we investigated the clinicopathological relevance of SCLC molecular subtypes in a large cohort of surgically resected specimens. Differential IHC expression of ASCL1, NEUROD1, and POU2F3 defines SCLC subtypes. No YAP1-subtype can be distinguished by IHC. High POU2F3 expression is associated with improved survival in a univariate analysis, whereas elevated ASCL1 expression is an independent negative prognosticator. Proteomic and cell viability assays of human SCLC cell lines revealed distinct vulnerability profiles defined by transcription regulators. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
- MeSH
- Humans MeSH
- Small Cell Lung Carcinoma * genetics metabolism surgery MeSH
- Cell Line, Tumor MeSH
- Lung Neoplasms * genetics metabolism surgery MeSH
- Prognosis MeSH
- Proteomics MeSH
- Gene Expression Regulation, Neoplastic MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics metabolism MeSH
- Transcription Factors genetics metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Research Support, Non-U.S. Gov't MeSH
Diabetes is a metabolic disease that involves the death or dysfunction of the insulin-secreting β cells in the pancreas. Consequently, most diabetes research is aimed at understanding the molecular and cellular bases of pancreatic development, islet formation, β-cell survival, and insulin secretion. Complex interactions of signaling pathways and transcription factor networks regulate the specification, growth, and differentiation of cell types in the developing pancreas. Many of the same regulators continue to modulate gene expression and cell fate of the adult pancreas. The transcription factor NEUROD1 is essential for the maturation of β cells and the expansion of the pancreatic islet cell mass. Mutations of the Neurod1 gene cause diabetes in humans and mice. However, the different aspects of the requirement of NEUROD1 for pancreas development are not fully understood. In this study, we investigated the role of NEUROD1 during the primary and secondary transitions of mouse pancreas development. We determined that the elimination of Neurod1 impairs the expression of key transcription factors for α- and β-cell differentiation, β-cell proliferation, insulin production, and islets of Langerhans formation. These findings demonstrate that the Neurod1 deletion altered the properties of α and β endocrine cells, resulting in severe neonatal diabetes, and thus, NEUROD1 is required for proper activation of the transcriptional network and differentiation of functional α and β cells.
- MeSH
- Insulin-Secreting Cells cytology metabolism MeSH
- Cell Differentiation MeSH
- Cell Lineage MeSH
- Diabetes Mellitus genetics MeSH
- Insulin metabolism MeSH
- Islets of Langerhans cytology metabolism ultrastructure MeSH
- Mice, Inbred C57BL MeSH
- Mice, Transgenic MeSH
- Animals, Newborn MeSH
- Pancreas cytology embryology MeSH
- Cell Proliferation MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics metabolism MeSH
- Gene Expression Regulation, Developmental MeSH
- Animals MeSH
- Check Tag
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
We review the molecular basis of several transcription factors (Eya1, Sox2), including the three related genes coding basic helix-loop-helix (bHLH; see abbreviations) proteins (Neurog1, Neurod1, Atoh1) during the development of spiral ganglia, cochlear nuclei, and cochlear hair cells. Neuronal development requires Neurog1, followed by its downstream target Neurod1, to cross-regulate Atoh1 expression. In contrast, hair cells and cochlear nuclei critically depend on Atoh1 and require Neurod1 expression for interactions with Atoh1. Upregulation of Atoh1 following Neurod1 loss changes some vestibular neurons' fate into "hair cells", highlighting the significant interplay between the bHLH genes. Further work showed that replacing Atoh1 by Neurog1 rescues some hair cells from complete absence observed in Atoh1 null mutants, suggesting that bHLH genes can partially replace one another. The inhibition of Atoh1 by Neurod1 is essential for proper neuronal cell fate, and in the absence of Neurod1, Atoh1 is upregulated, resulting in the formation of "intraganglionic" HCs. Additional genes, such as Eya1/Six1, Sox2, Pax2, Gata3, Fgfr2b, Foxg1, and Lmx1a/b, play a role in the auditory system. Finally, both Lmx1a and Lmx1b genes are essential for the cochlear organ of Corti, spiral ganglion neuron, and cochlear nuclei formation. We integrate the mammalian auditory system development to provide comprehensive insights beyond the limited perception driven by singular investigations of cochlear neurons, cochlear hair cells, and cochlear nuclei. A detailed analysis of gene expression is needed to understand better how upstream regulators facilitate gene interactions and mammalian auditory system development.
- MeSH
- Cochlea cytology metabolism MeSH
- Humans MeSH
- Neurogenesis genetics physiology MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics metabolism MeSH
- Transcription Factors genetics metabolism MeSH
- Hair Cells, Auditory metabolism MeSH
- Gene Expression Regulation, Developmental MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Most genes associated with neurodevelopmental disorders (NDDs) were identified with an excess of de novo mutations (DNMs) but the significance in case-control mutation burden analysis is unestablished. Here, we sequence 63 genes in 16,294 NDD cases and an additional 62 genes in 6,211 NDD cases. By combining these with published data, we assess a total of 125 genes in over 16,000 NDD cases and compare the mutation burden to nonpsychiatric controls from ExAC. We identify 48 genes (25 newly reported) showing significant burden of ultra-rare (MAF < 0.01%) gene-disruptive mutations (FDR 5%), six of which reach family-wise error rate (FWER) significance (p < 1.25E-06). Among these 125 targeted genes, we also reevaluate DNM excess in 17,426 NDD trios with 6,499 new autism trios. We identify 90 genes enriched for DNMs (FDR 5%; e.g., GABRG2 and UIMC1); of which, 61 reach FWER significance (p < 3.64E-07; e.g., CASZ1). In addition to doubling the number of patients for many NDD risk genes, we present phenotype-genotype correlations for seven risk genes (CTCF, HNRNPU, KCNQ3, ZBTB18, TCF12, SPEN, and LEO1) based on this large-scale targeted sequencing effort.
- MeSH
- CCCTC-Binding Factor genetics MeSH
- DNA-Binding Proteins genetics MeSH
- KCNQ3 Potassium Channel genetics MeSH
- Genetic Predisposition to Disease * MeSH
- Genetic Association Studies MeSH
- Heterogeneous-Nuclear Ribonucleoprotein U genetics MeSH
- Cohort Studies MeSH
- Humans MeSH
- Mutation MeSH
- DNA Mutational Analysis MeSH
- Neurodevelopmental Disorders genetics MeSH
- RNA-Binding Proteins genetics MeSH
- Repressor Proteins genetics MeSH
- Case-Control Studies MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics MeSH
- Transcription Factors genetics MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
The plant-specific receptor-like cytoplasmic kinases (RLCKs) form a large, poorly characterized family. Members of the RLCK VI_A class of dicots have a unique characteristic: their activity is regulated by Rho-of-plants (ROP) GTPases. The biological function of one of these kinases was investigated using a T-DNA insertion mutant and RNA interference. Loss of RLCK VI_A2 function resulted in restricted cell expansion and seedling growth. Although these phenotypes could be rescued by exogenous gibberellin, the mutant did not exhibit lower levels of active gibberellins nor decreased gibberellin sensitivity. Transcriptome analysis confirmed that gibberellin is not the direct target of the kinase; its absence rather affected the metabolism and signalling of other hormones such as auxin. It is hypothesized that gibberellins and the RLCK VI_A2 kinase act in parallel to regulate cell expansion and plant growth. Gene expression studies also indicated that the kinase might have an overlapping role with the transcription factor circuit (PIF4-BZR1-ARF6) controlling skotomorphogenesis-related hypocotyl/cotyledon elongation. Furthermore, the transcriptomic changes revealed that the loss of RLCK VI_A2 function alters cellular processes that are associated with cell membranes, take place at the cell periphery or in the apoplast, and are related to cellular transport and/or cell wall reorganisation.
- MeSH
- Arabidopsis drug effects enzymology genetics growth & development MeSH
- DNA, Bacterial genetics metabolism MeSH
- DNA-Binding Proteins genetics metabolism MeSH
- Plants, Genetically Modified MeSH
- Gibberellins metabolism pharmacology MeSH
- Hypocotyl drug effects enzymology genetics growth & development MeSH
- Mutagenesis, Insertional MeSH
- Cotyledon drug effects enzymology genetics growth & development MeSH
- Indoleacetic Acids metabolism pharmacology MeSH
- Protein Serine-Threonine Kinases genetics metabolism MeSH
- Arabidopsis Proteins genetics metabolism MeSH
- Gene Expression Regulation, Plant * MeSH
- Plant Growth Regulators pharmacology MeSH
- Seedlings drug effects enzymology genetics growth & development MeSH
- Gene Expression Profiling MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics metabolism MeSH
- Transcription Factors genetics metabolism MeSH
- Transcriptome MeSH
- Gene Expression Regulation, Developmental MeSH
- Publication type
- Journal Article MeSH
Ear development requires the transcription factors ATOH1 for hair cell differentiation and NEUROD1 for sensory neuron development. In addition, NEUROD1 negatively regulates Atoh1 gene expression. As we previously showed that deletion of the Neurod1 gene in the cochlea results in axon guidance defects and excessive peripheral innervation of the sensory epithelium, we hypothesized that some of the innervation defects may be a result of abnormalities in NEUROD1 and ATOH1 interactions. To characterize the interdependency of ATOH1 and NEUROD1 in inner ear development, we generated a new Atoh1/Neurod1 double null conditional deletion mutant. Through careful comparison of the effects of single Atoh1 or Neurod1 gene deletion with combined double Atoh1 and Neurod1 deletion, we demonstrate that NEUROD1-ATOH1 interactions are not important for the Neurod1 null innervation phenotype. We report that neurons lacking Neurod1 can innervate the flat epithelium without any sensory hair cells or supporting cells left after Atoh1 deletion, indicating that neurons with Neurod1 deletion do not require the presence of hair cells for axon growth. Moreover, transcriptome analysis identified genes encoding axon guidance and neurite growth molecules that are dysregulated in the Neurod1 deletion mutant. Taken together, we demonstrate that much of the projections of NEUROD1-deprived inner ear sensory neurons are regulated cell-autonomously.
- MeSH
- Apoptosis genetics MeSH
- Axons metabolism MeSH
- Models, Biological MeSH
- Cell Differentiation genetics MeSH
- Organ of Corti pathology MeSH
- Gene Deletion MeSH
- Epithelium metabolism MeSH
- Spiral Ganglion metabolism MeSH
- Mutation genetics MeSH
- Mice, Knockout MeSH
- Nerve Fibers metabolism MeSH
- Nerve Tissue Proteins genetics metabolism MeSH
- Gene Expression Regulation MeSH
- Gene Expression Profiling MeSH
- Basic Helix-Loop-Helix Transcription Factors genetics metabolism MeSH
- SOXB1 Transcription Factors metabolism MeSH
- Hair Cells, Auditory metabolism pathology ultrastructure MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH