The development of long-lasting plasma membrane (PM) and basement membrane (BM) probes is in high demand to advance our understanding of membrane dynamics during differentiation and disease conditions. Herein, we report that the microheterogeneity of heparan sulfate (HS) on fluorescent neo-proteoglycans backbone offers a facile platform for designing membrane probes. Confocal live-cell imaging studies of cancer and normal cell lines with a panel of Cy5 fluorescently tagged neo-proteoglycans confirmed that highly sulfated HS ligands with an l-iduronic acid component (PG@ID-6) induce a prolonged and brighter expression on the PM compared to low-sulfated and uronic acid counterparts.
View Article and Find Full Text PDFHeparan sulfate (HS) is a non-immunogenic antigen, and developing antibodies against specific sulfated patterns in HS poses significant challenges. Herein, we employed an innovative immunization strategy that exploits the molecular mimicry of HS to generate antibodies against HS sequences. Mice were immunized with synthetic sulfated oligo-l-idose () that mimics optimum 67% of the conserved structure of HS ligands.
View Article and Find Full Text PDFThe human airway contains specialized rare epithelial cells whose roles in respiratory disease are not well understood. Ionocytes express the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR), while chemosensory tuft cells express asthma-associated alarmins. However, surprisingly, exceedingly few mature tuft cells have been identified in human lung cell atlases despite the ready identification of rare ionocytes and neuroendocrine cells.
View Article and Find Full Text PDFLong non-coding RNAs (lncRNAs) are transcripts without coding potential that are pervasively expressed from the genome and have been increasingly reported to play crucial roles in all aspects of cell biology. They have been also heavily implicated in cancer development and progression, with both oncogenic and tumor suppressor functions. In this work, we identified and characterized a novel lncRNA, TAZ-AS202, expressed from the TAZ genomic locus and exerting pro-oncogenic functions in non-small cell lung cancer.
View Article and Find Full Text PDFThe transposase-accessible chromatin using sequencing (ATAC-seq) offers a simplified approach to detect chromatin changes in cancer cells after genetic intervention and drug treatment. Here, we present an optimized ATAC-seq protocol to elucidate chromatin accessibility changes at the epigenetic level in head and neck squamous cell carcinoma cells. We describe steps for cell lysate preparation, transposition, and tagmentation, followed by library amplification and purification.
View Article and Find Full Text PDFStrategies to overcome irreversible cochlear hair cell (HC) damage and loss in mammals are of vital importance to hearing recovery in patients with permanent hearing loss. In mature mammalian cochlea, co-activation of and reprograms supporting cells (SC) and promotes HC regeneration. Understanding of the underlying mechanisms may aid the development of a clinically relevant approach to achieve HC regeneration in the nontransgenic mature cochlea.
View Article and Find Full Text PDFHead and neck squamous cell carcinoma (HNSCC) and its treatments are associated with substantial morbidity, often resulting in cosmetic deformity and loss of physiologic functions including speech and swallowing. Despite advancements in treatment, 5-year survival rates for mucosal malignancies remain below 70%. Effective prevention of HNSCC demands an understanding of the molecular pathways of carcinogenesis.
View Article and Find Full Text PDFWith the introduction of immunotherapy, significant improvement has been made in the treatment of head and neck squamous cell carcinoma (HNSCC). However, only a small subset of patients with HNSCC benefit from immunotherapy. The current biomarker, a programmed cell death protein ligand 1 (PD-L1) expression that is widely used in treatment decision making for advanced HNSCC, has only a moderate predictive value.
View Article and Find Full Text PDFAnalysis of The Cancer Genome Atlas and other published data of head and neck squamous cell carcinoma (HNSCC) reveals somatic alterations of the Hippo-YAP pathway in approximately 50% of HNSCC. Better strategies to target the YAP1 transcriptional complex are sought. Here, we show that FAT1, an upstream inhibitor of YAP1, is mutated either by missense or by truncating mutation in 29% of HNSCC.
View Article and Find Full Text PDFAdvances in the treatment of malignant pleural mesothelioma (MPM) have been disappointing, despite the apparent need for new therapeutic options for this rare and devastating cancer. Drug resistance is common and surgical intervention has brought benefits only to a subset of patients. MPM is a heterogenous disease with a surprisingly low mutation rate and recent sequencing efforts have confirmed alterations in a limited number of tumor suppressors that do not provide apparent insights into the molecular mechanisms that drive this malignancy.
View Article and Find Full Text PDFPurpose: While chemotherapy remains the standard treatment for triple-negative breast cancer (TNBC), identifying and managing chemoresistant tumors has proven elusive. We sought to discover hallmarks and therapeutically actionable features of refractory TNBC through molecular analysis of primary chemoresistant TNBC specimens.
Experimental Design: We performed transcriptional profiling of tumors from a phase II clinical trial of platinum chemotherapy for advanced TNBC (TBCRC-009), revealing a gene expression signature that identified chemorefractory tumors.
Mutations in histone modifying enzymes and histone variants were identified in multiple cancers in The Cancer Genome Atlas (TCGA) studies. However, very little progress and understanding has been made in identifying the contribution of epigenetic factors in head and neck squamous cell carcinoma (HNSCC). Here, we report the identification of RUVBL1 (TIP49a), a component of the TIP60 histone modifying complex as being amplified and overexpressed in HNSCC.
View Article and Find Full Text PDFWomen harboring heterozygous germline mutations of have a 50 to 80% risk of developing breast cancer, yet the pathogenesis of these cancers is poorly understood. To reveal early steps in -associated carcinogenesis, we analyzed sorted cell populations from freshly-isolated, non-cancerous breast tissues of mutation carriers and matched controls. Single-cell whole-genome sequencing demonstrates that >25% of carrier ( ) luminal progenitor (LP) cells exhibit sub-chromosomal copy number variations, which are rarely observed in non-carriers.
View Article and Find Full Text PDFSWI/SNF chromatin remodeling enzymes are multisubunit complexes that contain one of two catalytic subunits, BRG1 or BRM and 9-11 additional subunits called BRG1 or BRM-associated factors (BAFs). BRG1 interacts with the microphthalmia-associated transcription factor (MITF) and is required for melanocyte development in vitro and in vivo. The subunits of SWI/SNF that mediate interactions between BRG1 and MITF have not been elucidated.
View Article and Find Full Text PDFWe show that the loss or gain of transcription factor programs that govern embryonic cell-fate specification is associated with a form of tumor plasticity characterized by the acquisition of alternative cell fates normally characteristic of adjacent organs. In human non-small cell lung cancers, downregulation of the lung lineage-specifying TF NKX2-1 is associated with tumors bearing features of various gut tissues. Loss of Nkx2-1 from murine alveolar, but not airway, epithelium results in conversion of lung cells to gastric-like cells.
View Article and Find Full Text PDFWe sought to uncover genetic drivers of hormone receptor-positive (HR) breast cancer, using a targeted next-generation sequencing approach for detecting expressed gene rearrangements without prior knowledge of the fusion partners. We identified intergenic fusions involving driver genes, including , and , in 14% (24/173) of unselected patients with advanced HR breast cancer. FISH confirmed the corresponding chromosomal rearrangements in both primary and metastatic tumors.
View Article and Find Full Text PDFLoss-of-function mutations in SWI/SNF chromatin-remodeling subunit genes are observed in many cancers, but an oncogenic role for SWI/SNF is not well established. Here, we reveal that ACTL6A, encoding an SWI/SNF subunit linked to stem cell and progenitor cell function, is frequently co-amplified and highly expressed together with the p53 family member p63 in head and neck squamous cell carcinoma (HNSCC). ACTL6A and p63 physically interact, cooperatively controlling a transcriptional program that promotes proliferation and suppresses differentiation, in part through activation of the Hippo-YAP pathway via regulators including WWC1.
View Article and Find Full Text PDFOur understanding of how stem cells are regulated to maintain appropriate tissue size and architecture is incomplete. We show that Yap (Yes-associated protein 1) is required for the actual maintenance of an adult mammalian stem cell. Without Yap, adult airway basal stem cells are lost through their unrestrained differentiation, resulting in the simplification of a pseudostratified epithelium into a columnar one.
View Article and Find Full Text PDFBrahma (BRM) and Brahma-related gene 1(BRG1) are catalytic subunits of SWItch/sucrose non-fermentable (SWI/SNF) chromatin remodeling complexes. BRM is epigenetically silenced in a wide-range of tumors. Mutations in the v-raf murine sarcoma viral oncogene homolog B1 (BRAF) gene occur frequently in melanoma and lead to constitutive activation of the mitogen-activated protein kinase (MAPK)/extracellular signal regulated kinase (ERK1/2) pathway.
View Article and Find Full Text PDFThe mammary epithelium is organized as a bilayer of luminal and basal/myoepithelial cells. During pregnancy, the luminal compartment expands for milk production, while basal cells are thought to provide structural and contractile support. Here, we reveal a pregnancy-specific role of basal epithelia as a central coordinator of lactogenesis.
View Article and Find Full Text PDFBackground: Metastatic melanoma is an aggressive malignancy that is resistant to therapy and has a poor prognosis. The progression of primary melanoma to metastatic disease is a multi-step process that requires dynamic regulation of gene expression through currently uncharacterized epigenetic mechanisms. Epigenetic regulation of gene expression often involves changes in chromatin structure that are catalyzed by chromatin remodeling enzymes.
View Article and Find Full Text PDFEmbryonic stem (ES) cells are pluripotent cells that can self renew or be induced to differentiate into multiple cell lineages, and thus have the potential to be utilized in regenerative medicine. Key pluripotency specific factors (Oct 4/Sox2/Nanog/Klf4) maintain the pluripotent state by activating expression of pluripotency specific genes and by inhibiting the expression of developmental regulators. Pluripotent ES cells are distinguished from differentiated cells by a specialized chromatin state that is required to epigenetically regulate the ES cell phenotype.
View Article and Find Full Text PDFPurpose: Genomic instability plays a major role in the genesis and progression of tumors, and in the evolution of tumor heterogeneity. To determine the role of genomic instability in the genesis and progression of oral cancer, we assessed the extent of genomic alterations in oral squamous cell carcinomas (OSCCs).
Experimental Design: We used the recently developed inter-(simple sequence repeat) PCR technique to quantitate genomic instability using matched tumor and normal OSCC samples (n = 25).