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Cellular senescence and the senescence-associated secretory phenotype (SASP) are implicated in aging and age-related disease, and SASP-related inflammation is thought to contribute to tissue dysfunction in aging and diseased animals. However, whether and how SASP factors influence the regenerative capacity of tissues remains unclear. Here, using intestinal organoids as a model of tissue regeneration, we show that SASP factors released by senescent fibroblasts deregulate stem cell activity and differentiation and ultimately impair crypt formation. We identify the secreted N-terminal domain of Ptk7 as a key component of the SASP that activates non-canonical Wnt / Ca2+ signaling through FZD7 in intestinal stem cells (ISCs). Changes in cytosolic [Ca2+] elicited by Ptk7 promote nuclear translocation of YAP and induce expression of YAP/TEAD target genes, impairing symmetry breaking and stem cell differentiation. Our study discovers secreted Ptk7 as a factor released by senescent cells and provides insight into the mechanism by which cellular senescence contributes to tissue dysfunction in aging and disease. Cellular senescence and associated secretory phenotype (SASP) are thought to contribute to aging and tissue dysfunction, though it is unclear how SASP impacts regeneration. Here the authors show that SASP factors impair regeneration, and that Ptk7 is a key secreted protein mediating that dysregulation. [ABSTRACT FROM AUTHOR]

Efficient photon upconversion at low light intensities promises major advances in technologies spanning solar energy harvesting to deep-tissue biophotonics. Here, we discover the critical mechanisms that enable near-infrared dye antennas to significantly enhance performance in lanthanide-doped upconverting nanoparticle (UCNP) systems, and leverage these findings to design dye-UCNP hybrids with a 33,000-fold increase in brightness and a 100-fold increase in efficiency over bare UCNPs. We show that increasing the lanthanide content in the UCNPs shifts the primary energy donor from the dye singlet to its triplet, and the resultant triplet states then mediate energy transfer into the nanocrystals. Time-gated phosphorescence, density functional theory, singlet lifetimes and triplet-quenching experiments support these findings. This interplay between the excited-state populations in organic antennas and the composition of UCNPs presents new design rules that overcome the limitations of previous upconverting materials, enabling performances now relevant for photovoltaics, biophotonics and infrared detection. Lanthanide-doped upconverting nanoparticles exhibiting a 33,000 times increase in brightness and a 100 times increase in efficiency over bare upconverting nanoparticles are demonstrated. The findings are relevant in fields from solar energy to biophotonics. [ABSTRACT FROM AUTHOR]

Understanding how gene regulatory networks control the progressive restriction of cell fates is a long-standing challenge. Recent advances in measuring gene expression in single cells are providing new insights into lineage commitment. However, the regulatory events underlying these changes remain unclear. Here we investigate the dynamics of chromatin regulatory landscapes during embryogenesis at single-cell resolution. Using single-cell combinatorial indexing assay for transposase accessible chromatin with sequencing (sci-ATAC-seq), we profiled chromatin accessibility in over 20,000 single nuclei from fixed Drosophila melanogaster embryos spanning three landmark embryonic stages: 2-4 h after egg laying (predominantly stage 5 blastoderm nuclei), when each embryo comprises around 6,000 multipotent cells; 6-8 h after egg laying (predominantly stage 10-11), to capture a midpoint in embryonic development when major lineages in the mesoderm and ectoderm are specified; and 10-12 h after egg laying (predominantly stage 13), when each of the embryo's more than 20,000 cells are undergoing terminal differentiation. Our results show that there is spatial heterogeneity in the accessibility of the regulatory genome before gastrulation, a feature that aligns with future cell fate, and that nuclei can be temporally ordered along developmental trajectories. During mid-embryogenesis, tissue granularity emerges such that individual cell types can be inferred by their chromatin accessibility while maintaining a signature of their germ layer of origin. Analysis of the data reveals overlapping usage of regulatory elements between cells of the endoderm and non-myogenic mesoderm, suggesting a common developmental program that is reminiscent of the mesendoderm lineage in other species. We identify 30,075 distal regulatory elements that exhibit tissue-specific accessibility. We validated the germ-layer specificity of a subset of these predicted enhancers in transgenic embryos, achieving an accuracy of 90%. Overall, our results demonstrate the power of shotgun single-cell profiling of embryos to resolve dynamic changes in the chromatin landscape during development, and to uncover the cis-regulatory programs of metazoan germ layers and cell types. [ABSTRACT FROM AUTHOR]

Background: Few data exist to elucidate whether patients with a suspicious axillary lymph node (ALN) at ultrasound but a negative fine-needle aspiration result (FNA group) can be managed as having ultrasound node-negative disease (AUN group). This study compared various ALN statuses between the AUN and FNA groups to guide further ALN management. Methods: Patients who had clinical T1-2N0 breast cancer treated with sentinel lymph node (SLN) biopsy were retrospectively analyzed. The ALN metastasis status, SLN status, and non-SLN metastasis rates in the entire population and the patients with one or two positive SLNs were compared between the AUN and FNA groups. Results: A total of 1007 patients (886 AUN and 121 FNA patients) were eligible for the final analysis: The incidence of ALN metastasis did not differ between the AUN group (16.5%) and the FNA group (21.5%) ( P = 0.170). In addition, three or more metastases were found in only 2.4% of the AUN patients and 3.3% of the FNA patients ( P = 0.405). The non-SLN metastasis rate was 22.6% (33/146) in the AUN group and 19.2% (5/26) in the FNA group ( P = 0.699). For the patients with one or two positive SLNs, the rate of non-SLN metastasis was similar between the AUN group (19.6%, 27/138) and the FNA group (12.5%, 3/24) ( P = 0.591). Conclusions: Patients with a suspicious ALN at ultrasound but a negative FNA result had ALN statuses similar to those of the ultrasound node-negative patients, indicating that these patients can be treated as having ultrasound node-negative disease. [ABSTRACT FROM AUTHOR]

Embryonic development is driven by tightly regulated patterns of gene expression, despite extensive genetic variation among individuals. Studies of expression quantitative trait loci (eQTL) indicate that genetic variation frequently alters gene expression in cell-culture models and differentiated tissues. However, the extent and types of genetic variation impacting embryonic gene expression, and their interactions with developmental programs, remain largely unknown. Here we assessed the effect of genetic variation on transcriptional (expression levels) and post-transcriptional (3′ RNA processing) regulation across multiple stages of metazoan development, using 80 inbred Drosophila wild isolates, identifying thousands of developmental-stage-specific and shared QTL. Given the small blocks of linkage disequilibrium in Drosophila, we obtain near base-pair resolution, resolving causal mutations in developmental enhancers, validated transcription-factor-binding sites and RNA motifs. This fine-grain mapping uncovered extensive allelic interactions within enhancers that have opposite effects, thereby buffering their impact on enhancer activity. QTL affecting 3′ RNA processing identify new functional motifs leading to transcript isoform diversity and changes in the lengths of 3′ untranslated regions. These results highlight how developmental stage influences the effects of genetic variation and uncover multiple mechanisms that regulate and buffer expression variation during embryogenesis. [ABSTRACT FROM AUTHOR]

Purpose: Current criteria for identification of synchronous non-small cell lung cancers (NSCLCs) may be confusing in patients with lymphatic metastases. This study was aimed at investigating the strategy using both the new histologic classification and driver-mutational testing to define multiple primary lung cancers. Methods: Prospectively collected data of surgical patients with synchronous NSCLCs were retrospectively analyzed. Cases were defined using the Martini-Melamed criteria, and validated by histologic subtyping based on the new classification and driver mutation of selected genes. Survival was estimated between patients with multiple primary and metastatic disease controlling by nodal (N) stage. Factors associated with prolonged survival were evaluated using the Cox proportional hazards mode. Results: A total of 131 patients followed for at least 12 months were included in this study. Controlling by N0 stage, patients who were diagnosed with multiple primary NSCLCs showed better relapse-free survival (RFS) than those with intrapulmonary metastases categorized either by the Martini-Melamed criteria or by histologic-mutational methods (both p < 0.0001). However, at N+ stage, patients stratified by Martini-Melamed criteria showed no difference in survival ( p = 0.517), while those defined by histologic-mutational methods maintained superior survival compared with the control group ( p = 0.042). On multivariate analysis, only N0 and diagnosis of independent lung lesions by histologic-mutational methods were significant predictors of better RFS ( p = 0.031 and 0.001, respectively) Conclusions: The histologic-mutational strategy may be an option for identification of synchronous NSCLC when traditional criteria were not applicable, especially in cases with positive lymphatics. N0 stage and the diagnosis of independent pulmonary tumors were associated with better RFS. [ABSTRACT FROM AUTHOR]

The programmed death-1 (PD-1) molecule is mainly expressed on functionally 'exhausted' CD8 T cells, dampening the host antitumor immune response. We evaluated the ratio between effective and regulatory T cells (Tregs) and PD-1 expression as a prognostic factor for operable breast cancer patients. A series of 218 newly diagnosed invasive breast cancer patients who had undergone primary surgery at Ruijin Hospital were identified. The influence of CD8 cytotoxic T lymphocytes, FOXP3 (Treg cell marker), and PD-1 immune cell counts on prognosis was analyzed utilizing immunohistochemistry. Both PD-1 immune cells and FOXP3 Tregs counts were significantly associated with unfavorable prognostic factors. In bivariate, but not multivariate analysis, high tumor infiltrating PD-1 cell counts correlated with significantly shorter patient survival. Our results suggest a prognostic value of the PD-1 immune cell population in such breast cancer patients. Targeting the PD-1 pathway may be a feasible approach to treating patients with breast cancer. [ABSTRACT FROM AUTHOR]

Cancer is a systemic disease encompassing multiple components of both tumor cells themselves and host stromal cells. It is now clear that stromal cells in the tumor microenvironment play an important role in cancer development. Molecular events through which reactive stromal cells affect cancer cells can be defined so that biomarkers and therapeutic targets can be identified. Cancer-associated fibroblasts (CAFs) make up the bulk of cancer stroma and affect the tumor microenvironment such that they promote cancer initiation, angiogenesis, invasion, and metastasis. In breast cancer, CAFs not only promote tumor progression but also induce therapeutic resistance. Accordingly, targeting CAFs provides a novel way to control tumors with therapeutic resistance. This review summarizes the current understandings of tumor stroma in breast cancer with a particular emphasis on the role of CAFs and the therapeutic implications of CAFs. In addition, the effects of other stromal components such as endothelial cells, macrophages, and adipocytes in breast cancer are also discussed. Finally, we describe the biologic markers to categorize patients into a specific and confirmed subtype for personalized treatment. [ABSTRACT FROM AUTHOR]

Aim:Gefitinib is effective in only approximately 20% of patients with non-small-cell lung cancer (NSCLC), and the underlying mechanism remains unclear. FoxM1 is upregulated in NSCLC and associated with a poor prognosis in NSCLC patients. In this study, we examined the possible role of FoxM1 in gefitinib resistance and the related mechanisms.Methods:Gefitinib resistant human lung adenocarcinoma cell line SPC-A-1 and gefitinib-sensitive human lung mucoepidermoid carcinoma cell line NCI-H292 were used. mRNA and protein expression of FoxM1 and other factors were tested with quantitative RT PCR and Western blot analysis. RNA interference was performed to suppress FoxM1 expression in SPC-A-1 cells, and lentiviral infection was used to overexpress FoxM1 in H292 cells. MTT assay and flow cytometry were used to examine the proliferation and apoptosis of the cells.Results:Treatment of SPC-A-1 cells with gefitinib (1 and 10 μmol/L) upregulated the expression of FoxM1 in time- and concentration-dependent manners, while gefitinib (1 μmol/L) downregulated in H292 cells. In SPC-A-1 cells treated with gefitinib (1 μmol/L), the expression of several downstream targets of FoxM1, including survivin, cyclin B1, SKP2, PLK1, Aurora B kinase and CDC25B, were significantly upregulated. Overexpression of FoxM1 increased the resistance in H292 cells, while attenuated FoxM1 expression restored the sensitivity to gefitinib in SPC-A-1 cells by inhibiting proliferation and inducing apoptosis.Conclusion:The results suggest that FoxM1 plays an important role in the resistance of NSCLC cells to gefitinib in vitro. FoxM1 could be used as a therapeutic target to overcome the resistance to gefitinib. [ABSTRACT FROM AUTHOR]

The authors reflect on the study "Expression of FAK and PTEN in bronchioloalveolar carcinoma and lung adenocarcinoma," which failed to distinguish mucinous (M) and nonmucinous (NM), subtypes of bronchioloalveolar carcinoma (BAC). The authors note that epidermal growth factor receptor (EGFR) drives more NM-BAC while mutations of K-ras causes M-BAC. The authors cite the importance of identifying the phosphate and tensin homolog (PTEN) and focal adhesion molecule (FAK) in 77 BAC cases of the study.