SummaryBackgroundPublished findings on breast cancer risk associated with different types of menopausal hormone therapy (MHT) are inconsistent, with limited information on long-term effects. We bring together the epidemiological evidence, published and unpublished, on these associations, and review the relevant randomised evidence.MethodsPrincipal analyses used individual participant data from all eligible prospective studies that had sought information on the type and timing of MHT use; the main analyses are of individuals with complete information on this. Studies were identified by searching many formal and informal sources regularly from Jan 1, 1992, to Jan 1, 2018. Current users were included up to 5 years (mean 1·4 years) after last-reported MHT use. Logistic regression yielded adjusted risk ratios (RRs) comparing particular groups of MHT users versus never users.FindingsDuring prospective follow-up, 108 647 postmenopausal women developed breast cancer at mean age 65 years (SD 7); 55 575 (51%) had used MHT. Among women with complete information, mean MHT duration was 10 years (SD 6) in current users and 7 years (SD 6) in past users, and mean age was 50 years (SD 5) at menopause and 50 years (SD 6) at starting MHT. Every MHT type, except vaginal oestrogens, was associated with excess breast cancer risks, which increased steadily with duration of use and were greater for oestrogen-progestagen than oestrogen-only preparations. Among current users, these excess risks were definite even during years 1–4 (oestrogen-progestagen RR 1·60, 95% CI 1·52–1·69; oestrogen-only RR 1·17, 1·10–1·26), and were twice as great during years 5–14 (oestrogen-progestagen RR 2·08, 2·02–2·15; oestrogen-only RR 1·33, 1·28–1·37). The oestrogen-progestagen risks during years 5–14 were greater with daily than with less frequent progestagen use (RR 2·30, 2·21–2·40 vs 1·93, 1·84–2·01; heterogeneity p<0·0001). For a given preparation, the RRs during years 5–14 of current use were much greater for oestrogen-receptor-positive tumours than for oestrogen-receptor-negative tumours, were similar for women starting MHT at ages 40–44, 45–49, 50–54, and 55–59 years, and were attenuated by starting after age 60 years or by adiposity (with little risk from oestrogen-only MHT in women who were obese). After ceasing MHT, some excess risk persisted for more than 10 years; its magnitude depended on the duration of previous use, with little excess following less than 1 year of MHT use.InterpretationIf these associations are largely causal, then for women of average weight in developed countries, 5 years of MHT, starting at age 50 years, would increase breast cancer incidence at ages 50–69 years by about one in every 50 users of oestrogen plus daily progestagen preparations; one in every 70 users of oestrogen plus intermittent progestagen preparations; and one in every 200 users of oestrogen-only preparations. The corresponding excesses from 10 years of MHT would be about twice as great.FundingCancer Research UK and the Medical Research Council.
Direct sequencing of exons 3 to 35 and the exon-intron boundaries of the CACNA1H gene was conducted in 118 childhood absence epilepsy patients of Han ethnicity recruited from North China. Sixty-eight variations have been detected in the CACNA1H gene, and, among the variations identified, 12 were missense mutations and only found in 14 of the 118 patients in a heterozygous state, but not in any of 230 unrelated controls. The identified missense mutations occurred in the highly conserved residues of the T-type calcium channel gene. Our results suggest that CACNA1H might be an important susceptibility gene involved in the pathogenesis of childhood absence epilepsy.
Esophageal cancer (EC) is one of the most lethal cancers in the world, and its morbidity and mortality rates rank among the top ten in China. Currently, surgical resection, radiotherapy and chemotherapy are the primary clinical treatments for esophageal cancer. However, outcomes are still unsatisfactory due to the limited efficacy and severe adverse effects of conventional treatments. As a new type of approach, targeted therapies have been confirmed to play an important role in the treatment of esophageal cancer; these include cetuximab and bevacizumab, which target epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF), respectively. In addition, other drugs targeting surface antigens and signaling pathways or acting on immune checkpoints have been continuously developed. For example, trastuzumab, a monoclonal antibody targeting human epidermal growth factor receptor 2 (HER-2), has been approved by the Food and Drug Administration (FDA) as a first-line treatment of HER-2-positive cancer. Moreover, the PD-L1 inhibitor pembrolizumab has been approved as a highly efficient drug for patients with PD-L1-positive or advanced esophageal squamous cell carcinoma (ESCC). These novel drugs can be used alone or in combination with other treatment strategies to further improve the treatment efficacy and prognosis of cancer patients. Nevertheless, adverse events, optimal dosages and effective combinations still need further investigation. In this review, we expound an outline of the latest advances in targeted therapies of esophageal cancer and the mechanisms of relevant drugs, discuss their efficacy and safety, and provide a clinical rationale for precision medicine in esophageal cancer.
The ongoing coronavirus disease 2019 (COVID-19) pandemic has caused >20 million infections and >750,000 deaths. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, has been found closely related to the bat coronavirus strain RaTG13 (Bat-CoV RaTG13) and a recently identified pangolin coronavirus (Pangolin-CoV-2020). Here we first investigated the ability of SARS-CoV-2 and three related coronaviruses to utilize animal orthologs of angiotensin-converting enzyme 2 (ACE2) for cell entry. We found that ACE2 orthologs of a wide range of domestic and wild mammals, including camels, cattle, horses, goats, sheep, cats, rabbits and pangolins, were able to support cell entry of SARS-CoV-2, suggesting that these species might be able to harbor and spread this virus. In addition, the pangolin and bat coronaviruses, Pangolin-CoV-2020 and Bat-CoV RaTG13, were also found able to utilize human ACE2 and a number of animal-ACE2 orthologs for cell entry, indicating risks of spillover of these viruses into humans in the future. We then developed potently anti-coronavirus ACE2-Ig proteins that are broadly effective against the four distinct coronaviruses. In particular, through truncating ACE2 at its residue 740 but not 615, introducing a D30E mutation, and adopting an antibody-like tetrameric-ACE2 configuration, we generated an ACE2-Ig variant that neutralizes SARS-CoV-2 at picomolar range. These data demonstrate that the improved ACE2-Ig variants developed in this study could potentially be developed to protect from SARS-CoV-2 and some other SARS-like viruses that might spillover into humans in the future. IMPORTANCE The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the currently uncontrolled coronavirus disease 2019 (COVID-19) pandemic. It is important to study the host range of SARS-CoV-2 because some domestic species might harbor the virus and transmit it back to humans. In addition, insight into the ability of SARS-CoV-2 and SARS-like viruses to utilize animal orthologs of the SARS-CoV-2 receptor ACE2 might provide structural insight into improving ACE2-based viral entry inhibitors. In this study, we found that ACE2 orthologs of a wide range of domestic and wild animals can support cell entry of SARS-CoV-2 and three related coronaviruses, providing insights into identifying animal hosts of these viruses. We also developed recombinant ACE2-Ig proteins that are able to potently block these viral infections, providing a promising approach to developing antiviral proteins broadly effective against these distinct coronaviruses.
BackgroundTriple-negative breast cancer (TNBC) is highly invasive and aggressive and lacks specific molecular targets to improve the prognosis. MiR-25-3p promotes proliferation of many tumors and its role and underlying mechanisms in TNBC remain to be well elucidated.MethodsDifferential expression of miR-25-3p in TNBC was measured with quantitative real-time PCR (qRT-PCR) in both TNBC tissues and cell lines and was validated in the Cancer Genome Atlas (TCGA) database. The effects of miR-25-3p on proliferation, apoptosis capacity of TNBC were evaluated using Cell counting kit-8 (CCK-8), colony formation assay and Annexin V-FITC/PI analyses. The tumor growth in vivo was observed in xenograft model. Luciferase reporter assay, qPCR and western blot were performed to validate a potential target of miR-25-3p in TNBC. Involvement of the AKT and MAPK pathways was investigated by western blot.ResultsMiR-25-3p was found to be upregulated in TNBC in tissues and cell lines. MiR-25-3p promoted TNBC cell proliferation in vitro and tumor growth in xenograft model, while suppression of miR-25-3p induced cell apoptosis. The luciferase reporter assay confirmed that B-cell translocation gene 2 (BTG2) might be a direct target of miR-25-3p, and its expression was negatively regulated by miR-25-3p. Moreover, inhibition of BTG2 expression accounted for the role of miR-25-3p in TNBC. Furthermore, BTG2 suppression might indirectly activate the AKT and ERK-MAPK signaling pathways to mediate the downstream effects of miR-25-3p.ConclusionsThis study demonstrates that miR-25-3p promotes proliferation by targeting tumor suppressor BTG2 and may identify new diagnostic and therapeutic targets in TNBC.Electronic supplementary materialThe online version of this article (10.1186/s12943-017-0754-0) contains supplementary material, which is available to authorized users.
Genistein (Gen) has been reported as a protective factor against breast cancer. However, the molecular mechanism by which Gen elicits its effects on triple-negative breast cancer cells has not been fully elucidated. In our study, the breast cancer cell line MDA-MB-231 was selected to determine the action of Gen on triple-negative breast cancer cells. MTT assay, flow cytometric analysis, siRNA transfection, western blotting and nuclear factor-κB (NF-κB) activation-nuclear translocation assay were used to address the role of NF-κB activity and the Notch-1 signaling pathway on the effects of Gen. Our study revealed that Gen elicited a dramatic effect on cell growth inhibition, in a dose-dependent and time-dependent manner. Treatment of MDA-MB-231 cells with 0, 5, 10 or 20 µM Gen induced apoptosis of 6.78, 18.98, 30.45 and 60.64%, respectively. Exposure of MDA-MB-231 cells to Gen also resulted in G2/M phase accumulation of cells corresponding to 4.93, 12.54, 18.93 and 30.95%, respectively. Furthermore, our data demonstrated for the first time that Gen inhibited the growth of MDA-MB-231 triple-negative breast cancer cells by inhibiting NF-κB activity via the Nocth-1 signaling pathway in a dose-dependent manner. We also found that Gen downregulated the expression of cyclin B1, Bcl-2 and Bcl-xL, possibly mediated by NF-κB activation via the Notch-1 signaling pathway. In conclusion, our results suggest that inhibition of NF-κB activity via the Notch-1 pathway may be a novel mechanism by which Gen suppresses the growth of triple-negative breast cancer cells. Further preclinical and clinical studies are warranted to further investigate the application of Gen for the treatment of triple-negative breast cancer.
Autopolyploidy is widespread in higher plants and important for agricultural yield and quality. However, the effects of genome duplication on the chromatin organization and transcriptional regulation are largely unknown in plants. Using High-throughput Chromosome Conformation Capture (Hi-C), we showed that autotetraploid Arabidopsis presented more inter-chromosomal interactions and fewer short-range chromatin interactions compared with its diploid progenitor. In addition, genome duplication contributed to the switching of some loose and compact structure domains with altered H3K4me3 and H3K27me3 histone modification status. 539 genes were identified with altered transcriptions and chromatin interactions in autotetraploid Arabidopsis. Especially, we found that genome duplication changed chromatin looping and H3K27me3 histone modification in Flowering Locus C. We propose that genome doubling modulates the transcription genome-wide by changed chromatin interactions and at the specific locus by altered chromatin loops and histone modifications.
Targeting hepatic stellate cells (HSCs) has been challenging due to the lack of specific receptors or motifs on the cells. The aim of the present study was to develop a HSC-specific system for improving drug delivery to HSCs. The affinity of a cyclic peptide containing Arg-Gly-Asp (cRGD) to collagen type VI receptor on HSCs was examined in both in vitro and in vivo experiments. Sterically stable liposomes (SSLs) were modified with this peptide to yield a new carrier, cRGD-SSL. The targeting efficiency of this carrier in delivering interferon (IFN)-␣1b was investigated in a rat model of liver fibrosis induced by bile duct ligation (BDL). When incubating HSCs or hepatocytes with cyclic RGD peptide, the peptide was bound preferentially to activated HSCs. Biodistribution study showed that the accumulation of cRGD peptide-labeled liposomes in HSCs isolated from BDL rats was 10-fold more than unlabeled SSLs. BDL rats receiving injections of IFN-␣1b entrapped in cRGD-SSL exhibited significantly reduced extent of liver fibrosis compared with BDL control rats or BDL rats treated with IFN-␣1b entrapped in SSLs. Thus, cRGD-SSL is an efficient drug carrier, which selectively targets activated HSCs and improves drug therapy for liver fibrosis to a significant extent. This liposomal formulation represents a new means of targeting drug carrier for the treatment of liver fibrosis, and it may have potential clinical applications.
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