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Non-structural carbohydrates (NSC) are an important “buffer” for maintaining plant physiological functions under drought conditions; however, our understanding of the dynamics of NSC at the organ level during sustained drought of varying intensities and re-watering remains poor. In this study, two-year-old Pinus yunnanensis seedlings were subjected to drought and re-watering trials. Plants were subjected to three drought intensities (light drought, moderate drought, and severe drought) as well as control conditions (suitable moisture) for 51 days, including 30 days of drought followed by 21 days of re-watering for drought-treated seedlings, to study the dynamics of NSC in the leaves, stems, coarse roots, and fine roots. Changes in the distribution of NSC concentrations in the organ of P. yunnanensis seedlings under drought stress varied; in the early drought stages, the drought resistance of P. yunnanensis seedlings was enhanced by increasing soluble sugar concentrations; in later stages of drought, the stored starch in organs, stems, and coarse roots was consumed. Drought inhibited the growth of P. yunnanensis seedlings, but the maximum limit of drought tolerance was not reached under the different drought treatments after 30 days. P. yunnanensis seedlings in all treatment groups resumed growth after re-watering, and the growth of seedlings was actually promoted during re-watering in the moderate drought treatment group, indicating that drought induced the compensatory growth of seedlings. The growth of P. yunnanensis seedlings during re-watering was inhibited in the severe drought treatment group, and NSC continued to be regulated in seedlings in this group. Given that P. yunnanensis seedlings maintain growth through the consumption of coarse root starch in the late stages of drought, seedlings with a larger root-to-shoot ratio should be selected for cultivation in actual production. Based on our findings, exposure to moderate drought stress can enhance the drought tolerance of P. yunnanensis seedlings and promote the compensatory growth of seedlings.

Summary: Aberrant activation of the forkhead protein FOXA1 is observed in advanced hormone-related cancers. However, the key mediators of high FOXA1 signaling remain elusive. We demonstrate that ectopic high FOXA1 (H-FOXA1) expression promotes estrogen receptor-positive (ER+) breast cancer (BC) metastasis in a xenograft mouse model. Mechanistically, H-FOXA1 reprograms ER-chromatin binding to elicit a core gene signature (CGS) enriched in ER+ endocrine-resistant (EndoR) cells. We identify Secretome14, a CGS subset encoding ER-dependent cancer secretory proteins, as a strong predictor for poor outcomes of ER+ BC. It is elevated in ER+ metastases vs. primary tumors, irrespective of ESR1 mutations. Genomic ER binding near Secretome14 genes is also increased in mutant ER-expressing or mitogen-treated ER+ BC cells and in ER+ metastatic vs. primary tumors, suggesting a convergent pathway including high growth factor receptor signaling in activating pro-metastatic secretome genes. Our findings uncover H-FOXA1-induced ER reprogramming that drives EndoR and metastasis partly via an H-FOXA1/ER-dependent secretome.

Abstract G Protein-Coupled Receptors (GPCRs) represent the largest superfamily of cell-surface proteins. However, the expression and function of majority of GPCRs remain unexplored in breast cancer (BC). We interrogated the expression and phosphorylation status of 398 non-sensory GPCRs using the landmark BC proteogenomics and phosphoproteomic dataset from The Cancer Genome Atlas. Neuropeptide Y Receptor Y1 (NPY1R) gene and protein expression were significantly higher in Luminal A tumors versus other BC subtypes. The trend of NPY1R gene, protein, and phosphosite (NPY1R-S368s) expression was decreasing in the order of Luminal A, Luminal B, Basal, and human epidermal growth factor receptor 2 (HER2) subtypes. NPY1R gene expression increased in response to estrogen and reduced with endocrine therapy in estrogen receptor-positive (ER+) BC cells and xenograft models. Conversely, NPY1R expression decreased in ER+ BC cells resistant to endocrine therapies (estrogen deprivation, tamoxifen, and fulvestrant) in vitro and in vivo. NPY treatment reduced estradiol-stimulated cell growth, which was reversed by NPY1R antagonist (BIBP-3226) in ER+ BC cells. Higher NPY1R gene expression predicted better relapse-free survival and overall survival in ER+ BC. Our study demonstrates that NPY1R mediates the inhibitory action of NPY on estradiol-stimulated growth of ER+ BC cells, and its expression serves as a biomarker to predict endocrine sensitivity and survival in ER+ BC patients.

In breast cancer, the 3D architecture of the genome can impact gene regulation. Here, the authors use tethered chromatin conformation profiling to investigate 3D chromatin structure in models of hormone-induced breast cancer and endocrine resistance, finding dynamic temporal reorganisation.

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Breast cancer (BCa) molecular subtypes include luminal A, luminal B, normal-like, HER-2–enriched, and basal-like tumors, among which luminal B and basal-like cancers are highly aggressive. Biochemical pathways associated with patient survival or treatment response in these more aggressive subtypes are not well understood. With the limited availability of pathologically verified clinical specimens, cell line models are routinely used for pathway-centric studies. We measured the metabolome of luminal and basal-like BCa cell lines using mass spectrometry, linked metabolites to biochemical pathways using Gene Set Analysis, and developed a novel rank-based method to select pathways on the basis of their enrichment in patient-derived omics data sets and prognostic relevance. Key mediators of the pathway were then characterized for their role in disease progression. Pyrimidine metabolism was altered in luminal versus basal BCa, whereas the combined expression of its associated genes or expression of one key gene, ribonucleotide reductase subunit M2 (RRM2) alone, associated significantly with decreased survival across all BCa subtypes, as well as in luminal patients resistant to tamoxifen. Increased RRM2 expression in tamoxifen-resistant patients was verified using tissue microarrays, whereas the metabolic products of RRM2 were higher in tamoxifen-resistant cells and in xenograft tumors. Both genetic and pharmacological inhibition of this key enzyme in tamoxifen-resistant cells significantly decreased proliferation, reduced expression of cell cycle genes, and sensitized the cells to tamoxifen treatment. Our study suggests for evaluating RRM2-associated metabolites as noninvasive markers for tamoxifen resistance and its pharmacological inhibition as a novel approach to overcome tamoxifen resistance in BCa.

Traditionally, GRP78 has been regarded as an endoplasmic reticulum (ER) lumenal protein due to its carboxyl KDEL retention motif. Recently, a subfraction of GRP78 is found to localize to the surface of specific cell types, serving as co-receptors and regulating signaling. However, the physiological relevance of cell surface GRP78 (sGRP78) expression in cancer and its functional interactions at the cell surface are just emerging. In this report, we combined biochemical, imaging and mutational approaches to address these issues. For detection of sGRP78, we utilized a mouse monoclonal antibody highly potent and specific for GRP78 or epitope-tagged GRP78, coupled with imaging and biochemical techniques that allowed detection of sGRP78 but not intracellular GRP78. Our studies revealed that breast and prostate cancer cells resistant to hormonal therapy actively promote GRP78 to the cell surface, which can be further elevated by a variety of ER stress-inducing conditions. We showed that sGRP78 forms complex with PI3K, and overexpression of sGRP78 promotes PIP3 formation, indicative of PI3K activation. We further discovered that an insertion mutant of GRP78 at its N-terminus domain, while retaining stable expression and the ability to translocate to the cell surface as the wild-type protein, exhibited reduced complex formation with p85 and production of PIP3. Thus, our studies provide a mechanistic explanation for the regulation of the PI3K/AKT signaling by sGRP78. Our findings suggest that targeting sGRP78 may suppress therapeutic resistance in cancer cells and offer a novel strategy to suppress PI3K activity.

A highly efficient and practical 12-step synthesis method was developed to 34% yield of 3,4-isopropylidene proline I, from (+)-3-carene as starting material. The optimized sequence leading to proline I which was successfully applied on a mutligram scale confirmed the practical use of the method.

Forkhead box A1 (FOXA1) is a pioneer factor that facilitates chromatin binding and function of lineage-specific and oncogenic transcription factors. Hyperactive FOXA1 signaling due to gene amplification or overexpression has been reported in estrogen receptorpositive (ER+) endocrine-resistant metastatic breast cancer. However, the molecular mechanisms by which FOXA1 up-regulation promotes these processes and the key downstream targets of the FOXA1 oncogenic network remain elusive. Here, we demonstrate that FOXA1 overexpression in ER+ breast cancer cells drives genome-wide enhancer reprogramming to activate prometastatic transcriptional programs. Up-regulated FOXA1 employs superenhancers (SEs) to synchronize transcriptional reprogramming in endocrine-resistant breast cancer cells, reflecting an early embryonic development process. We identify the hypoxia-inducible transcription factor hypoxiainducible factor-2a (HIF-2α) as the top high FOXA1-induced SE target, mediating the impact of high FOXA1 in activating prometastatic gene sets and pathways associated with poor clinical outcome. Using clinical ER+/HER2- metastatic breast cancer datasets, we show that the aberrant FOXA1/HIF2α transcriptional axis is largely nonconcurrent with the ESR1 mutations, suggesting different mechanisms of endocrine resistance and treatment strategies. We further demonstrate the selective efficacy of an HIF-2a antagonist, currently in clinical trials for advanced kidney cancer and recurrent glioblastoma, in reducing the clonogenicity, migration, and invasion of endocrineresistant breast cancer cells expressing high FOXA1. Our study has uncovered high FOXA1-induced enhancer reprogramming and HIF- 2α-dependent transcriptional programs as vulnerable targets for treating endocrine-resistant and metastatic breast cancer. [ABSTRACT FROM AUTHOR]

The estrogen receptor (ER) drives the growth of most luminal breast cancers and is the primary target of endocrine therapy. Although ER blockade with drugs such as tamoxifen is very effective, a major clinical limitation is the development of endocrine resistance especially in the setting of metastatic disease. Preclinical and clinical observations suggest that even following the development of endocrine resistance, ER signaling continues to exert a pivotal role in tumor progression in the majority of cases. Through the analysis of the ER cistrome in tamoxifen-resistant breast cancer cells, we have uncovered a role for an RUNX2-ER complex that stimulates the transcription of a set of genes, including most notably the stem cell factor SOX9, that promote proliferation and ametastatic phenotype. We show that up-regulation of SOX9 is sufficient to cause relative endocrine resistance. The gain of SOX9 as an ER-regulated gene associated with tamoxifen resistance was validated in a unique set of clinical samples supporting the need for the development of improved ER antagonists. [ABSTRACT FROM AUTHOR]

Forkhead box protein A1 (FOXA1) is a pioneer factor of estrogen receptor α (ER)-chromatin binding and function, yet its aberration in endocrine-resistant (Endo-R) breast cancer is unknown. Here, we report preclinical evidence for a role of FOXA1 in Endo-R breast cancer as well as evidence for its clinical significance. FOXA1 is gene-amplified and/or overexpressed in Endo-R derivatives of several breast cancer cell line models. Induced FOXA1 triggers oncogenic gene signatures and proteomic profiles highly associated with endocrine resistance. Integrated omics data reveal IL8 as one of the most perturbed genes regulated by FOXA1 and ER transcriptional reprogramming in Endo-R cells. IL-8 knockdown inhibits tamoxifen-resistant cell growth and invasion and partially attenuates the effect of overexpressed FOXA1. Our study highlights a role of FOXA1 via IL-8 signaling as a potential therapeutic target in FOXA1-overexpressing ER-positive tumors. [ABSTRACT FROM AUTHOR]

Introduction Activation of the phosphatidylinositol 3-kinase (PI3K) pathway in estrogen receptor α (ER)- positive breast cancer is associated with reduced ER expression and activity, luminal B subtype, and poor outcome. Phosphatase and tensin homolog (PTEN), a negative regulator of this pathway, is typically lost in ER-negative breast cancer. We set out to clarify the role of reduced PTEN levels in endocrine resistance, and to explore the combination of newly developed PI3K downstream kinase inhibitors to overcome this resistance. Methods Altered cellular signaling, gene expression, and endocrine sensitivity were determined in inducible PTEN-knockdown ER-positive/human epidermal growth factor receptor 2 (HER2)- negative breast cancer cell and/or xenograft models. Single or two-agent combinations of kinase inhibitors were examined to improve endocrine therapy. Results Moderate PTEN reduction was sufficient to enhance PI3K signaling, generate a gene signature associated with the luminal B subtype of breast cancer, and cause endocrine resistance in vitro and in vivo. The mammalian target of rapamycin (mTOR), protein kinase B (AKT), or mitogen-activated protein kinase kinase (MEK) inhibitors, alone or in combination, improved endocrine therapy, but the efficacy varied by PTEN levels, type of endocrine therapy, and the specific inhibitor(s). A single agent AKT inhibitor combined with fulvestrant conferred superior efficacy in overcoming resistance, inducing apoptosis and tumor regression. Conclusions Moderate reduction in PTEN, without complete loss, can activate the PI3K pathway to cause endocrine resistance in ER-positive breast cancer, which can be overcome by combining endocrine therapy with inhibitors of the PI3K pathway. Our data suggests that the ER degrader fulvestrant, to block both ligand-dependent and -independent ER signaling, combined with an AKT inhibitor is an effective strategy to test in patients. [ABSTRACT FROM AUTHOR]

The aim of this work was to assess the effect of age groups of earthworms on the quality of vermicomposts. For this, Eisenia foetida grouped into hatchlings, juveniles and adults were used for vermicomposting of food wastes spiked with vermicomposted materials. Compared to control treatment (without earthworms), vermicomposting treatment caused the significant reductions of TOC and C/N, while increases of pH and inorganic ions after 60 days. Vermicomposts by E. foetida showed the lowest TOC content and microbial activity and population in hatchlings, the largest increase of nitrogen in adults and the maximum enrichment of inorganic ions in juveniles, respectively. PCR-DGGE analysis revealed vermicomposts displayed the analogous microbial community structures. Overall results indicated that age-specific E. foetida did significantly affect the biochemical properties of their vermicomposts, but they could not effect on the microbial community profiles of the vermicomposts. [ABSTRACT FROM AUTHOR]

The discovery of RNAi has revolutionized loss-of-function genetic studies in mammalian systems. However, significant challenges still remain to fully exploit RNAi for mammalian genetics. For instance, genetic screens and in vivo studies could be broadly improved by methods that allow inducible and uniform gene expression control. To achieve this, we built the lentiviral pINDUCER series of expression vehicles for inducible RNAi in vivo. Using a multicistronic design, pINDUCER vehicles enable tracking of viral transduction and shRNA or cDNA induction in a broad spectrum of mammalian cell types in vivo. They achieve this uniform temporal, dose-dependent, and reversible control of gene expression across heterogenous cell populations via fluorescence-based quantification of reverse tet-transactivator expression. This feature allows isolation of cell populations that exhibit a potent, inducible target knockdown in vitro and in vivo that can be used in human xenotransplantation models to examine cancer drug targets. [ABSTRACT FROM AUTHOR]

In unstressed cells, the tumor suppressor p53 is maintained at low levels by ubiquitin-mediated proteolysis mainly through Mdm2. In response to DNA damage, p53 is stabilized and becomes activated to turn on transcriptional programs that are essential for cell cycle arrest and apoptosis. Activation of p53 leads to accumulation of Mdm2 protein, a direct transcriptional target of p53. It is not understood how p53 is protected from degradation when Mdm2 is upregulated. Here we report that p53 stabilization in the late phase after ionizing radiation correlates with active ubiquitination. We found that an E3 ubiquitin ligase RFWD3 (RNF201/FLJ10520) forms a complex with Mdm2 and p53 to synergistically ubiquitinate p53 and is required to stabilize p53 in the late response to DNA damage. This process is regulated by the DNA damage checkpoint, because RFWD3 is phosphorylated by ATM/ATR kinases and the phosphorylation mutant fails to stimulate p53 ubiquitination. In vitro experiments suggest that RFWD3 is a p53 E3 ubiquitin ligase and that RFWD3-Mdm2 complex restricts the polyubiquitination of p53 by Mdm2. Our study identifies RFWD3 as a positive regulator of p53 stability when the G1 cell cycle checkpoint is activated and provides an explanation for how p53 is protected from degradation in the presence of high levels of Mdm2. [ABSTRACT FROM AUTHOR]

Purpose. To investigate the sensitivity, specificity, and spatial distribution of the product of p28 gene (p28GANK protein) in human hepatocellular carcinoma (HCC) and nonhepatocellular carcinomas in relation to immunostaining with Cytokeratin 18 (CK18), α-fetoprotein (AFP), and Hepatocyte paraffin 1 (HepPar1). Method. In this retrospective study, formalin-fixed paraffin-embedded tissues from 24 HCCs, five intrahepatic cholangiocarcinomas (ICC), five combined hepatocellular cholangiocarcinomas (C-HCC-CC) and mine metastatic hepatic carcinomas (MHC) were immunostained for p28GANK as well as CK18, AFP and HepPar1. Only cases with more intensified staining in carcinoma contrast to the adjacent liver tissues were accepted as positive. Result. In HCC, p28GANK was expressed restrictively in hepatocytes of both para-lesion and carcinoma liver tissues, while absent in the bile duct epithelial cells, Kupffer cells, and other interstitial cells. The positive staining of p28GANK was noted in 16 (66.7%) specimens of HCC and three (60.0%) specimens of C-HCC-CC, and no specific lesion staining was found in all tested specimens of ICC and MHC. Sensitivity and specificity for hepatocyte-originated carcinoma were, respectively, 65.5% and 100% for p28GANK, 79.3% and 85.2% for CK18, 20.7% and 100% for AFP, 79.3% and 92.0% for HepPar1. Conclusion. The hepatocytic staining for p28GANK is clearly useful in differentiating hepatocyte-originated carcinoma from non-HCC. p28GANK may be used as an ancillary marker for the diagnosis of HCC. [ABSTRACT FROM AUTHOR]