Estrogen receptor (ER)α-positive tumors are commonly treated with ERα antagonists or inhibitors of estrogen synthesis, but most tumors develop resistance, and we need to better understand the pathways that underlie the proliferative and tumorigenic role of this estrogen-activated transcription factor. We here present the first single-molecule sequencing of the estradiol-induced ERα transcriptome in the luminal A-type human breast cancer cell lines MCF7 and T47D. Sequencing libraries were prepared from the polyadenylated RNA fraction after 8 hours of estrogen or vehicle treatment. Single-molecule sequencing was carried out in biological and technical replicates and differentially expressed genes were defined and analyzed for enriched processes. Correlation analysis with clinical expression and survival were performed, and follow-up experiments carried out using time series, chromatin immunoprecipitation and quantitative real-time PCR. We uncovered that ERα in addition to regulating approximately 2000 protein-coding genes, also regulated up to 1000 long noncoding RNAs (lncRNAs). Most of these were up-regulated, and 178 lncRNAs were regulated in both cell lines. We demonstrate that Long Intergenic Non-protein Coding RNA 1016 (LINC01016) and LINC00160 are direct transcriptional targets of ERα, correlate with ERα expression in clinical samples, and show prognostic significance in relation to breast cancer survival. We show that silencing of LINC00160 results in reduced proliferation, demonstrating that lncRNA expression have functional consequences. Our findings suggest that ERα regulation of lncRNAs is clinically relevant and that their functions and potential use as biomarkers for endocrine response are important to explore.

Colon cancer is a common cause of cancer death in the Western world. Accumulating evidence supports a protective role of estrogen via estrogen receptor beta (ERβ) but the mechanism of action is not known. Here, we elucidate a molecular mechanism whereby ERβ represses the oncogenic prospero homebox 1 (PROX1) through the upregulation of miR-205. We show that PROX1 is a potential target of miR-205 and that in clinical specimens from The Cancer Genome Atlas data, ERβ and miR-205 are decreased in colorectal cancer tissue compared to non-tumorous colon, while PROX1 levels are increased. Through mechanistic studies in multiple colorectal cancer cell lines, we show that ERβ upregulates miR-205, and that miR-205 targets and represses PROX1 through direct interaction with its 3′UTR. Through the generation of intestine-specific ERβ knockout mice, we establish that this pathway is correspondingly regulated in normal intestinal epithelial cells in vivo. Functionally, we demonstrate that miR-205 decreases cell proliferation and decreases migratory and invasive potential of colon cancer cells, leading to a reduction of micrometastasis in vivo. In conclusion, ERβ in both normal and cancerous colon epithelial cells upregulates miRNA-205, which subsequently reduces PROX1 through direct interaction with its 3′UTR. This results in reduced proliferative and metastatic potential of the cells. Our study proposes a novel pathway that may be exploited using ERβ-selective agonists and/or miR-205-replacement therapy in order to improve preventive and therapeutic approaches against colon cancer.

Triple-negative breast cancer (TNBC) is an aggressive, highly recurrent breast cancer subtype, affecting approximately one-fifth of all breast cancer patients. Subpopulations of treatment-resistant cancer stem cells within the tumors are considered to contribute to disease recurrence. A potential druggable target for such cells is the maternal embryonic leucine-zipper kinase (MELK). MELK expression is upregulated in mammary stem cells and in undifferentiated cancers, where it correlates with poor prognosis and potentially mediates treatment resistance. Several MELK inhibitors have been developed, of which one, OTSSP167, is currently in clinical trials. In order to better understand how MELK and its inhibition influence TNBC, we verified its anti-proliferative and apoptotic effects in claudin-low TNBC cell lines MDA-MB-231 and SUM-159 using MTS assays and/or trypan blue viability assays together with analysis of PARP cleavage. Then, using microarrays, we explored which genes were affected by OTSSP167. We demonstrate that different sets of genes are regulated in MDA-MB-231 and SUM-159, but in both cell lines genes involved in cell cycle, mitosis and protein metabolism and folding were regulated. We identified p53 (TP53) as a potential upstream regulator of the regulated genes. Using western blot we found that OTSSP167 downregulates mutant p53 in all tested TNBC cell lines (MDA-MB-231, SUM-159, and BT-549), but upregulates wild-type p53 in the luminal A subtype MCF-7 cell line. We propose that OTSSP167 might have context-dependent or off-target effects, but that one consistent mechanism of action could involve the destabilization of mutant p53.

ABSTRACT. Mutations in the EDA gene are responsible for X-linked hypohidrotic ectodermal dysplasia, the most common form of ectodermal dysplasia. Males show a severe form of this disease, while females often manifest mild to moderate symptoms. We identified a missense mutation (c.463C>T) in the EDA gene in a Jordanian family, using direct DNA sequencing. This mutation leads to an amino acid change of arginine to cysteine in the extracellular domain of ectodysplasin-A, a protein encoded by the EDA gene. The phenotype of a severely affected 11-year-old boy with this mutation included heat intolerance, sparse hair (hypotrichosis), absence of 17 teeth (oligodontia), speech problems, and damaged eccrine glands, resulting in reduced sweating (anhidrosis). Both the mother (40 years old) and the sister (10 years old) were carriers with mild to moderate symptoms of this disease, while the father was healthy. This detailed description of the phenotype caused by this missense mutation could be useful for prenatal diagnosis.

Adipokines are important for regulation body metabolism and immune response. Many studies have shown that variants in adipokines genes play a role in age-associated diseases. In this study, we investigated the contribution of rs266729 (-11377G/C), rs2241766 (+45T/G), and rs1501299 (+276 G/T) SNPs of adiponectin gene (ADIPQO) and rs7799039 (-2548C/A) SNP of leptin (LEP) gene to human longevity phenotype in Jordanian population. Polymorphisms were genotyped in 110 randomly selected elderly subjects (>85 years old) with mean age of 90.2 years, and 120 young control subjects (range from 20 to 50 years) with mean age of 32.0 years. No significant differences were detected in the genotype and allele frequencies of examined gene variants between the two groups (p > 0.05). However, when gender was considered, genotypes and alleles frequencies of rs1501299 SNP in ADIPOQ gene and rs7799039 in LEP gene were significantly associated with longevity in men (p < 0.02) but not in women (p > 0.05). Thus, ADIPOQ and LEP genes polymorphisms might play a gender-specific role in the pathway to men's longevity.

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High-grade serous ovarian cancer (HGSOC) is characterized by chromosomal instability, DNA damage, oxidative stress, and high metabolic demand that exacerbate misfolded, unfolded, and damaged protein burden resulting in increased proteotoxicity. However, the underlying mechanisms that maintain protein homeostasis to promote HGSOC growth remain poorly understood. This study reports that the neuronal deubiquitinating enzyme, ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), is overexpressed in HGSOC and maintains protein homeostasis. UCHL1 expression was markedly increased in HGSOC patient tumors and serous tubal intraepithelial carcinoma (HGSOC precursor lesions). High UCHL1 levels correlated with higher tumor grade and poor patient survival. UCHL1 inhibition reduced HGSOC cell proliferation and invasion, as well as significantly decreased the in vivo metastatic growth of ovarian cancer xenografts. Transcriptional profiling of UCHL1-silenced HGSOC cells revealed downregulation of genes implicated with proteasome activity along with upregulation of endoplasmic reticulum stress-induced genes. Reduced expression of proteasome subunit alpha 7 (PSMA7) and acylaminoacyl peptide hydrolase (APEH), upon silencing of UCHL1, resulted in a significant decrease in proteasome activity, impaired protein degradation, and abrogated HGSOC growth. Furthermore, the accumulation of polyubiquitinated proteins in the UCHL1silenced cells led to attenuation of mTORC1 activity and protein synthesis, and induction of terminal unfolded protein response. Collectively, these results indicate that UCHL1 promotes HGSOC growth by mediating protein homeostasis through the PSMA7-APEH-proteasome axis.Implications: This study identifies the novel links in the proteostasis network to target protein homeostasis in HGSOC and recognizes the potential of inhibiting UCHL1 and APEH to sensitize cancer cells to proteotoxic stress in solid tumors.

Despite advances in cancer therapeutics, pancreatic cancer remains difficult to treat and often develops resistance to chemotherapies. We have evaluated a bioavailable genistein analogue, AXP107‐11 which has completed phase Ib clinical trial, as an approach to sensitize tumor cells to chemotherapy. Using organotypic cultures of 14 patient‐derived xenografts (PDX) of pancreatic ductal adenocarcinoma, we found that addition of AXP107‐11 indeed sensitized 57% of cases to gemcitabine treatment. Results were validated using PDX models in vivo. Further, RNA‐Seq from responsive and unresponsive tumors proposed a 41‐gene treatment‐predictive signature. Functional and molecular assays were performed in cell lines and demonstrated that the effect was synergistic. Transcriptome analysis indicated activation of G‐protein‐coupled estrogen receptor (GPER1) as the main underlying mechanism of action, which was corroborated using GPER1‐selective agonists and antagonists. GPER1 expression in pancreatic tumors was indicative of survival, and our study proposes that activation of GPER1 may constitute a new avenue for pancreatic cancer therapeutics.