Effects of 17β-estradiol and tamoxifen on gastric cancer cell proliferation and apoptosis and ER-α36 expression

Hormone replacement therapy and cancer mortality in women with 17 site-specific cancers: a cohort study using linked medical records

BACKGROUND

There is limited evidence on the safety of Hormone Replacement Therapy (HRT) in women with cancer. Therefore, we systematically examined HRT use and cancer-specific mortality in women with 17 site-specific cancers.

METHODS

Women newly diagnosed with 17 site-specific cancers from 1998 to 2019, were identified from general practitioner (GP) records, hospital diagnoses or cancer registries in Scotland, Wales and England. Breast cancer patients were excluded because HRT is contraindicated in breast cancer patients. The primary outcome was time to cancer-specific mortality. Time-dependent Cox regression models were used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (95% CIs) for cancer-specific mortality by systemic HRT use.

RESULTS

The combined cancer cohorts contained 182,589 women across 17 cancer sites. Overall 7% of patients used systemic HRT after their cancer diagnosis. There was no evidence that HRT users, compared with non-users, had higher cancer-specific mortality at any cancer site. In particular, no increase was observed in common cancers including lung (adjusted HR = 0.98 95% CI 0.90, 1.07), colorectal (adjusted HR = 0.79 95% CI 0.70, 0.90), and melanoma (adjusted HR = 0.77 95% CI 0.58, 1.02).

CONCLUSIONS

We observed no evidence of increased cancer-specific mortality in women with a range of cancers (excluding breast) receiving HRT.

Analysis of endoscopic and pathological features of 6961 cases of gastric cancer

Gastric cancer (GC) stage and tissue differentiation affect treatment efficacy and prognosis, highlighting the importance of understanding the risk factors that affect these parameters. Therefore, this study analyzed risk factors affecting the GC stage and differentiation and the relationships between the cancer site and the sex and age of the patient. We collected clinical data from 6961 patients with GC, including sex, age, endoscopic lesion location, and pathological differentiation. Patients were grouped based on GC stage (early or advanced), differentiation (well or poorly differentiated), and lesion site (upper stomach [cardia and fundus], middle stomach [gastric body], and lower stomach [gastric antrum]). Differences in sex, age, location, stage, and degree of differentiation were assessed based on these groupings. Univariate analysis revealed that the disease location and differentiation significantly differed based on the GC stage (P < 0.05), whereas sex, age, site, and stage significantly differed based on GC differentiation (P < 0.05). A multivariate analysis confirmed these factors as independent risk factors affecting GC. Moreover, lesion sites significantly differed between sexes (P < 0.05) and among age groups (P < 0.05). Although the effects of family history, lifestyle, and Helicobacter pylori infection status of the patients were not considered, this single-center retrospective study established independent risk factors for GC.Trial registration ChiCTR2200061989.

Identification of Hub Genes Associated With the Development of Stomach Adenocarcinoma by Integrated Bioinformatics Analysis

Objective

This study was conducted in order to gain a better understanding of the molecular mechanisms of stomach adenocarcinoma (STAD), which is necessary to predict the prognosis of STAD and develop novel gene therapy strategies.

Methods

In this study, the gene expression profile of GSE118916 in the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas Program (TCGA) was used to explore the differential co-expression genes of STAD and normal tissues.

Results

A total of 407 STAD samples were collected, consisting of 375 from stomach adenocarcinoma tissues and 32 from normal tissues, as well as RNA-seq count data for 19,600 genes. Forty-two differentially expressed genes were screened by weighted gene co-expression network analysis (WGCNA) and differentially expressed gene analysis. According to the functional annotation analysis of the clusterProfiler R package, these genes were analyzed for GO function enrichment, digestion (biological process), tube bottom material membrane (cell component), and oxidoreductase activity (molecular function). The KEGG pathway was enriched in gastric acid secretion and chemical carcinogenesis. In addition, Cytoscape's cytoHubba plug-in was used to identify seven hub genes (EWSR1, ESR1, CLTC, PCMT1, TP53, HUWE1, and HDAC1) in a protein-protein interaction (PPI) network consisting of 7 nodes and 11 edges. Compared with normal tissues, CLTC and TP53 genes were upregulated in stomach adenocarcinoma (P < 0.05). TP53 was expressed differently in stages II and IV, EWSR1 was expressed differently in stages II and III, and ESR1 was expressed differently in stages I-III. Among the seven hub genes, Kaplan-Meier analysis and TCGG showed that the expression levels of HDAC1 and CLTC were significantly correlated with OS in patients with stomach adenocarcinoma (P < 0.05). GEPIA2 analysis showed that ESR1 expression was closely correlated with OS and DFS in gastric adenocarcinoma (P < 0.05). Then, the expression of the genes and their correlations were revealed by the R2 Platform (http://r2.amc.nl). Finally, we collected 18 pairs of gastric mucosal tissues from normal people and cancer tissues from patients with stomach adenocarcinoma. The expression levels of the above seven hub genes and their relative protein expression were detected by RT-PCR and immunohistochemistry (IHC). The results showed that the gene and protein expression levels in stomach adenocarcinoma tissues were increased than those in the normal group.

Conclusion

In summary, we believe that the identified hub genes were related to the occurrence of stomach adenocarcinoma, especially the expression of ESR1, HDAC1, and CLTC genes, which are related to the prognosis and overall survival of patients and may become the potential for the future diagnosis and treatment of STAD.

Hormone replacement therapy and cancer survival: a longitudinal cohort study: protocol paper

INTRODUCTION

Hormone replacement therapy (HRT) can help women experiencing menopausal symptoms, but usage has declined due to uncertainty around risks of cancer and some cardiovascular diseases (CVD). Moreover, improved cancer survival rates mean that more women who survive cancer go on to experience menopausal symptoms. Understanding these relationships is important so that women and their clinicians can make informed decisions around the risks and benefits of HRT. This study's primary aim is to determine the association between HRT use after cancer diagnosis and the risk of cancer-specific mortality. The secondary aims are to investigate the risks of HRT on subsequent cancer, all-cause mortality and CVD.

METHODS AND ANALYSIS

We will conduct a population-based longitudinal cohort study of 18-79 year-old women diagnosed with cancer between 1998 and 2020, using the QResearch database. The main exposure is HRT use, categorised based on compound, dose and route of administration, and modelled as a time-varying covariate. Analysis of HRT use precancer and postcancer diagnosis will be conducted separately. The primary outcome is cancer-specific mortality, which will be stratified by cancer site. Secondary outcomes include subsequent cancer diagnosis, CVD (including venous thrombo-embolism) and all-cause mortality. Adjustment will be made for key confounders such as age, body mass index, ethnicity, deprivation index, comorbidities, and cancer grade, stage and treatment. Statistical analysis will include descriptive statistics and Cox proportional hazards models to calculate HRs and 95% CIs.

ETHICS AND DISSEMINATION

Ethical approval for this project was obtained from the QResearch Scientific Committee (Ref: OX24, project title 'Use of hormone replacement therapy and survival from cancer'). This project has been, and will continue to be, supported by patient and public involvement panels. We intend to the submit the findings for peer-reviewed publication in an academic journal and disseminate them to the public through Cancer Research UK.

Hormone replacement therapy in women with cancer and risk of cancer-specific mortality and cardiovascular disease: a protocol for a cohort study from Scotland and Wales

BACKGROUND

Hormone replacement therapy (HRT) is widely used and has proven benefits for women with menopausal symptoms. An increasing number of women with cancer experience menopausal symptoms but the safety of HRT use in women with cancer is unclear. There are particular concerns that HRT could accelerate cancer progression in women with cancer, and also that HRT could increase the risk of cardiovascular disease in such women. Therefore, our primary aim is to determine whether HRT use alters the risk of cancer-specific mortality in women with a range of common cancers. Our secondary objectives are to investigate whether HRT alters the risk of second cancers, cardiovascular disease, venous thromboembolism and all-cause mortality.

METHODS

The study will utilise independent population-based data from Wales using the SAIL databank and Scotland based upon the national Prescribing Information System. The study will include women newly diagnosed with common cancers from 2000 to 2016, identified from cancer registries. Women with breast cancers will be excluded. HRT will be ascertained using electronic prescribing in Wales or dispensing records in Scotland. The primary outcome will be time to cancer-specific mortality from national mortality records. Time-dependent cox regression models will be used to calculate hazard ratios (HR) and 95% confidence intervals (95% CIs) for cancer specific death in HRT users compared with non-users after cancer diagnosis after adjusting for relevant confounders, stratified by cancer site. Analysis will be repeated investigating the impact of HRT use immediately before cancer diagnosis. Secondary analyses will be conducted on the risk of second cancers, cardiovascular disease, venous thromboembolism and all-cause mortality. Analyses will be conducted within each cohort and pooled across cohorts.

DISCUSSION

Our study will provide evidence to inform guidance given to women diagnosed with cancer on the safety of HRT use and/or guide modifications to clinical practice.

Tamoxifen Downregulates the Expression of Notch1 and DLL1 Genes in MKN-45 Gastric Cancer Cells

PURPOSE

Gastric cancer is one of the most prevalent cancers worldwide and the second most common cause for cancer associated mortality. Anti-tumor effects of tamoxifen in breast cancer are well-established. However, no study has so far investigated the effects of tamoxifen on gene expression of Notch1 and DLL1 in gastric cancer cell line. The present study was conducted to explore the effects of tamoxifen, as a repurposed drug, on gene expression of Notch1 and DLL1 in MKN-45, a gastric cancer cell line.

METHODS

MKN-45 cells were cultured in DMEM/F12 medium containing 10% FBS. Cytotoxic effects of tamoxifen on these cells at various concentrations were evaluated by trypan blue exclusion assay. For gene expression analysis, the cells were first incubated with 100 μM tamoxifen followed by total RNA extraction from treated and control cells. Then, cDNA was synthesized. Quantitative real-time PCR using specific primers for Notch1 and DLL1 was performed to assess the effect of tamoxifen on the transcript of them.

RESULTS

Treatment with tamoxifen decreased viability of MKN-45 cells in a dose-dependent manner. CC₅₀ was estimated to be around 200 μM. Also, tamoxifen at the dose of 100 μM could significantly downregulate mRNA levels of both Notch1 and DLL1 genes as compared with untreated cells by 24% and 92%, respectively.

CONCLUSION

Based on these results, tamoxifen interferes with Notch signaling pathway through downregulating the expression of Notch1 and DLL1 genes and this could be regarded as a mechanism for its anti-cancer effects in this malignant disease.

Does tamoxifen have a therapeutic role outside of breast cancer? A systematic review of the evidence

INTRODUCTION

Tamoxifen is a widely used hormonal based therapy for breast cancer in the adjuvant and metastatic setting, prolonging overall and recurrence-free survival. There has been increasing interest in the potential for novel "off-target" effects of tamoxifen and its metabolite N-desmethyltamoxifen across a number of cancer types. We aim to review the current literature regarding the potential use of tamoxifen in other primary malignancies.

METHOD

A qualitative systematic review was performed according to the PRISMA guidelines using pre-set search criteria across the PubMed, Cochrane and Scopus databases from 1985 to 2019. Additional results were generated from included papers references.

RESULTS

A total of 324 papers were identified, of which 47 were included; a further 29 articles were obtained from additional referencing to give a total of 76 articles. Clinical trials have demonstrated benefits with the use of tamoxifen in isolation and combination, specifically in patients with advanced non-resectable malignancy, however results are not consistent across the literature. In vivo data consistently suggests that off target effects of tamoxifen are mediated through the ceramide pathway or through inhibition of protein kinase C (PKC).

CONCLUSIONS

With increased focus upon the potential of repurposing drugs, tamoxifen may be a candidate for repurposing in the wider cancer setting. There is evidence to suggest that the ceramide or PKC pathway could act as a therapeutic target for tamoxifen or alternative chemotherapeutics and merits further investigation.

Reprogramming of Mesothelial-Mesenchymal Transition in Chronic Peritoneal Diseases by Estrogen Receptor Modulation and TGF-β1 Inhibition

In chronic peritoneal diseases, mesothelial-mesenchymal transition is determined by cues from the extracellular environment rather than just the cellular genome. The transformation of peritoneal mesothelial cells and other host cells into myofibroblasts is mediated by cell membrane receptors, Transforming Growth Factor β1 (TGF-β1), Src and Hypoxia-inducible factor (HIF). This article provides a narrative review of the reprogramming of mesothelial mesenchymal transition in chronic peritoneal diseases, drawing on the similarities in pathophysiology between encapsulating peritoneal sclerosis and peritoneal metastasis, with a particular focus on TGF-β1 signaling and estrogen receptor modulators. Estrogen receptors act at the cell membrane/cytosol as tyrosine kinases that can phosphorylate Src, in a similar way to other receptor tyrosine kinases; or can activate the estrogen response element via nuclear translocation. Tamoxifen can modulate estrogen membrane receptors, and has been shown to be a potent inhibitor of mesothelial-mesenchymal transition (MMT), peritoneal mesothelial cell migration, stromal fibrosis, and neoangiogenesis in the treatment of encapsulating peritoneal sclerosis, with a known side effect and safety profile. The ability of tamoxifen to inhibit the transduction pathways of TGF-β1 and HIF and achieve a quiescent peritoneal stroma makes it a potential candidate for use in cancer treatments. This is relevant to tumors that spread to the peritoneum, particularly those with mesenchymal phenotypes, such as colorectal CMS4 and MSS/EMT gastric cancers, and pancreatic cancer with its desmoplastic stroma. Morphological changes observed during mesothelial mesenchymal transition can be treated with estrogen receptor modulation and TGF-β1 inhibition, which may enable the regression of encapsulating peritoneal sclerosis and peritoneal metastasis.

Black tea and D. candidum extracts play estrogenic activity via estrogen receptor α-dependent signaling pathway

In recent years, phytoestrogens have been shown as useful selective estrogen receptor modulators. The estrogen-like effects of black tea (BT) and D. candidum (DC), as well as the combination of the two herbs, have remained largely elusive. This study aims to investigate the phytoestrogenic effect of BT and DC extract, and the possible mechanism. The effects on T47D (ER+ cell line) proliferation were evaluated by using MTT assay. The S phase proportion of ER+ cells was determined by using flow cytometry. The estrogen antagonist ICI 182,780 was applied to block the ER function. The activation of ER-mediated PI3K/AKT and ERK signal pathways were observed by using western blot. Expression of ERα and PGR, as well as PS2 and Cyclin D1 were detected by using western blot and real-time quantitative PCR. Firstly, our results found that BT and DC extracts promoted cell proliferation in ER-positive cells, and this effect was ER-dependent. Besides, BT and DC extracts increased the S-phase cell number. Next, PI3K, AKT and ERK pathways below ER were activated by phytoestrogen treatment, and this activation was blocked by the ER antagonist. Moreover, prolonged BT and DC treatments increased the expression of ESR1 and PGR. Consistently, the mRNA levels of not only ESR1 and PGR but also estrogen-dependent effectors ps2 and cyclin D1, were increased by phytoestrogens and blocked by ICI 182,780. Taken Together, BT and DC extracts have phytoestrogenic effects, and this may provide new ideas and experimental basis for the development and application of phytoestrogens.

Tamoxifen inhibits fibroblast proliferation and prevents epidural fibrosis by regulating the AKT pathway in rats

Many factors contribute to epidural fibrosis after lumbar laminectomy, particularly the excessive proliferation of fibroblasts. Many studies have shown that tamoxifen (TAM) inhibits fibroblast proliferation and reduces fibrosis, but the detailed effect and mechanism of TAM on preventing epidural fibrosis are unknown. To investigate the effect of TAM on fibroblast proliferation and epidural fibrosis, fibroblasts were cultured and treated with different concentrations of TAM. Cell Counting Kit-8(CCK-8) detection, cell cycle analysis and western blot analysis were used to detect the roles of TAM in regulating fibroblast proliferation. Lumbar laminectomies were performed in rats, and various concentrations of TAM were administered by gavage. Histological and immunohistochemical analyses were used to evaluate the effects of TAM on preventing epidural fibrosis. CCK-8 detection showed that TAM could inhibit fibroblast viability; western blot analysis showed that TAM could decrease the expression of proliferative proteins p-AKT and cyclinD1 and increase the expression of antiproliferative proteins P21 and P27. Histological analysis showed that TAM could reduce epidural fibrosis. Immunohistochemical analysis showed that the p-ATK expression in epidural scar tissue was decreased after TAM treatment. The present study demonstrated that TAM could inhibit fibroblast proliferation and prevent epidural fibrosis, potentially through the regulation of the AKT pathway.