ERbeta impedes prostate cancer EMT by destabilizing HIF-1alpha and inhibiting VEGF-mediated snail nuclear localization: implications for Gleason grading

Histone demethylase PHF8 promotes prostate cancer metastasis via the E2F1-SNAI1 axis

Metastasis is the primary culprit behind cancer-related fatalities in multiple cancer types, including prostate cancer. Despite great advances, the precise mechanisms underlying prostate cancer metastasis are far from complete. By using a transgenic mouse prostate cancer model (TRAMP) with and without Phf8 knockout, we have identified a crucial role of PHF8 in prostate cancer metastasis. By complexing with E2F1, PHF8 transcriptionally upregulates SNAI1 in a demethylation-dependent manner. The upregulated SNAI1 subsequently enhances epithelial-to-mesenchymal transition (EMT) and metastasis. Given the role of the abnormally activated PHF8/E2F1-SNAI1 axis in prostate cancer metastasis and poor prognosis, the levels of PHF8 or the activity of this axis could serve as biomarkers for prostate cancer metastasis. Moreover, targeting this axis could become a potential therapeutic strategy for prostate cancer treatment. © 2024 The Pathological Society of Great Britain and Ireland.

Targeting the crosstalk between estrogen receptors and membrane growth factor receptors in breast cancer treatment: Advances and opportunities

Estrogens play a critical role in the initiation and progression of breast cancer. Estrogen receptor (ER)α, ERβ, and G protein-coupled estrogen receptor are the primary receptors for estrogen in breast cancer. These receptors are mainly activated by binding with estrogens. The crosstalk between ERs and membrane growth factor receptors creates additional pathways that amplify the effects of their ligands and promote tumor growth. This crosstalk may cause endocrine therapy resistance in ERα-positive breast cancer. Furthermore, this may explain the resistance to anti-human epidermal growth factor receptor-2 (HER2) treatment in ERα-/HER2-positive breast cancer and chemotherapy resistance in triple-negative breast cancer. Accordingly, it is necessary to understand the complex crosstalk between ERs and growth factor receptors. In this review, we delineate the crosstalk between ERs and membrane growth factor receptors in breast cancer. Moreover, this review highlights the current progress in clinical treatment and discusses how pharmaceuticals target the crosstalk. Lastly, we discuss the current challenges and propose potential solutions regarding the implications of targeting crosstalk via pharmacological inhibition. Overall, the present review provides a landscape of the crosstalk between ERs and membrane growth factor receptors in breast cancer, along with valuable insights for future studies and clinical treatments using a chemotherapy-sparing regimen to improve patient quality of life.

PrLZ regulates EMT and invasion in prostate cancer via the TGF-β1/p-smad2/miR-200 family/ZEB1 axis

BACKGROUND

Prostate leucine zipper (PrLZ) is a prostate-specific protein, and our previous study demonstrated that PrLZ enhances the malignant progression of prostate cancer (Pca). However, the roles of PrLZ in epithelial to mesenchymal transition (EMT) remain unknown.

METHODS

Quantitative real-time PCR (qRT-PCR), immunohistochemical (IHC) staining, hematoxylin-eosin (HE) staining, and western blotting were used to analyze the expression of protein and genes level in human PCa cell lines. Invasion assay was used to examine the effect of PrLZ, miR-200a, miR-200b, miR-200c, miR-141, miR-429, miR-205, and ZEB1 on PCa cell line invasion in vitro. Prostate cancer metastasis animal model was designed to assess the effect of PrLZ on PCa cell line invasion in vivo.

RESULTS

We proved that high PrLZ expression initiates EMT, which was shown by the downregulation of E-cadherin and upregulation of vimentin in PC-3/PrLZ and ARCaP-E/PrLZ cells. Mechanistic analysis revealed that PrLZ regulates EMT by activating TGF-β1/p-smad2 signaling and further inhibiting the expression of miR-200 family members, which negatively regulates ZEB1 expression and causes EMT in Pca. Moreover, using two of orthotopic mouse model and tail vein injection of human prostate cancer cells mouse model, we observed that PC-3/PrLZ cells led to the development of distant organ metastases in vivo.

CONCLUSIONS

Our results show the mechanism by which PrLZ regulates EMT and metastasis and suggest that PrLZ may be a potential therapeutic target for Pca metastasis.

Pharmacological inhibition of KDM1A/LSD1 enhances estrogen receptor beta-mediated tumor suppression in ovarian cancer

Ovarian cancer (OCa) is the most lethal gynecologic cancer. Emerging data indicates that estrogen receptor beta (ERβ) functions as a tumor suppressor in OCa. Lysine-specific histone demethylase 1A (KDM1A) is an epigenetic modifier that acts as a coregulator for steroid hormone receptors. However, it remain unknown if KDM1A interacts with ERβ and regulates its expression/functions in OCa. Analysis of TCGA data sets indicated KDM1A and ERβ expression showed an inverse relationship in OCa. Knockout (KO), knockdown (KD), or inhibition of KDM1A increased ERβ isoform 1 expression in established and patient-derived OCa cells. Further, KDM1A interacts with and functions as a corepressor of ERβ, and its inhibition enhances ERβ target gene expression via alterations of histone methylation marks at their promoters. Importantly, KDM1A-KO or -KD enhanced the efficacy of ERβ agonist LY500307, and the combination of KDM1A inhibitor (KDM1Ai) NCD38 with ERβ agonist synergistically reduced the cell viability, colony formation, and invasion of OCa cells. RNA-seq and DIA mass spectrometry analyses showed that KDM1A-KO resulted in enhanced ERβ signaling and that genes altered by KDM1A-KO and ERβ agonist were related to apoptosis, cell cycle, and EMT. Moreover, combination treatment significantly reduced the tumor growth in OCa orthotopic, syngeneic, and patient-derived xenograft models and proliferation in patient-derived explant models. Our results demonstrate that KDM1A regulates ERβ expression/functions, and its inhibition improves ERβ mediated tumor suppression. Overall, our findings suggest that KDM1Ai and ERβ agonist combination therapy is a promising strategy for OCa.

Travelling under pressure - hypoxia and shear stress in the metastatic journey

Cancer cell invasion, intravasation and survival in the bloodstream are early steps of the metastatic process, pivotal to enabling the spread of cancer to distant tissues. Circulating tumor cells (CTCs) represent a highly selected subpopulation of cancer cells that tamed these critical steps, and a better understanding of their biology and driving molecular principles may facilitate the development of novel tools to prevent metastasis. Here, we describe key research advances in this field, aiming at describing early metastasis-related processes such as collective invasion, shedding, and survival of CTCs in the bloodstream, paying particular attention to microenvironmental factors like hypoxia and mechanical stress, considered as important influencers of the metastatic journey.

Nuclear Estrogen Receptors in Prostate Cancer: From Genes to Function

Estrogens are almost ubiquitous steroid hormones that are essential for development, metabolism, and reproduction. They exert both genomic and non-genomic action through two nuclear receptors (ERα and ERβ), which are transcription factors with disregulated functions and/or expression in pathological processes. In the 1990s, the discovery of an additional membrane estrogen G-protein-coupled receptor augmented the complexity of this picture. Increasing evidence elucidating the specific molecular mechanisms of action and opposing effects of ERα and Erβ was reported in the context of prostate cancer treatment, where these issues are increasingly investigated. Although new approaches improved the efficacy of clinical therapies thanks to the development of new molecules targeting specifically estrogen receptors and used in combination with immunotherapy, more efforts are needed to overcome the main drawbacks, and resistance events will be a challenge in the coming years. This review summarizes the state-of-the-art on ERα and ERβ mechanisms of action in prostate cancer and promising future therapies.

WFDC3 inhibits tumor metastasis by promoting the ERβ-mediated transcriptional repression of TGFBR1 in colorectal cancer

Estrogen plays a protective role in colorectal cancer (CRC) and primarily functions through estrogen receptor β (ERβ). However, clinical strategies for CRC therapy associated with ERβ are still under investigation. Our discoveries identified WFDC3 as a tumor suppressor that facilitates estrogen-induced inhibition of metastasis through the ERβ/TGFBR1 signaling axis. WFDC3 interacts with ERβ and increases its protein stability by inhibiting its proteasome-dependent degradation. WFDC3 represses TGFBR1 expression through ERβ-mediated transcription. Blocking TGFβ signaling with galunisertib, a drug used in clinical trials that targets TGFBR1, impaired the migration of CRC cells induced by WFDC3 depletion. Moreover, there was clinical significance to WFDC3 in CRC, as CRC patients with high WFDC3 expression in tumor cells had favorable prognoses. Therefore, this work suggests that WFDC3 could be an indicator for therapies targeting the estrogen/ERβ pathway in CRC patients.

Extracellular Succinate: A Physiological Messenger and a Pathological Trigger

When tissues are under physiological stresses, such as vigorous exercise and cold exposure, skeletal muscle cells secrete succinate into the extracellular space for adaptation and survival. By contrast, environmental toxins and injurious agents induce cellular secretion of succinate to damage tissues, trigger inflammation, and induce tissue fibrosis. Extracellular succinate induces cellular changes and tissue adaptation or damage by ligating cell surface succinate receptor-1 (SUCNR-1) and activating downstream signaling pathways and transcriptional programs. Since SUCNR-1 mediates not only pathological processes but also physiological functions, targeting it for drug development is hampered by incomplete knowledge about the characteristics of its physiological vs. pathological actions. This review summarizes the current status of extracellular succinate in health and disease and discusses the underlying mechanisms and therapeutic implications.

A VEGFB-Based Peptidomimetic Inhibits VEGFR2-Mediated PI3K/Akt/mTOR and PLCγ/ERK Signaling and Elicits Apoptotic, Antiangiogenic, and Antitumor Activities

Vascular endothelial growth factor receptor 2 (VEGFR2) mediates VEGFA signaling mainly through the PI3K/AKT/mTOR and PLCγ/ERK1/2 pathways. Here we unveil a peptidomimetic (VGB3) based on the interaction between VEGFB and VEGFR1 that unexpectedly binds and neutralizes VEGFR2. Investigation of the cyclic and linear structures of VGB3 (named C-VGB3 and L-VGB3, respectively) using receptor binding and cell proliferation assays, molecular docking, and evaluation of antiangiogenic and antitumor activities in the 4T1 mouse mammary carcinoma tumor (MCT) model showed that loop formation is essential for peptide functionality. C-VGB3 inhibited proliferation and tubulogenesis of human umbilical vein endothelial cells (HUVECs), accounting for the abrogation of VEGFR2, p-VEGFR2 and, subsequently, PI3K/AKT/mTOR and PLCγ/ERK1/2 pathways. In 4T1 MCT cells, C-VGB3 inhibited cell proliferation, VEGFR2 expression and phosphorylation, the PI3K/AKT/mTOR pathway, FAK/Paxillin, and the epithelial-to-mesenchymal transition cascade. The apoptotic effects of C-VGB3 on HUVE and 4T1 MCT cells were inferred from annexin-PI and TUNEL staining and activation of P53, caspase-3, caspase-7, and PARP1, which mechanistically occurred through the intrinsic pathway mediated by Bcl2 family members, cytochrome c, Apaf-1 and caspase-9, and extrinsic pathway via death receptors and caspase-8. These data indicate that binding regions shared by VEGF family members may be important in developing novel pan-VEGFR inhibitors that are highly relevant in the pathogenesis of angiogenesis-related diseases.

Trends in estrogen and progesterone receptors in prostate cancer: a bibliometric analysis

Introduction

The bibliometric analysis aims to identify research trends in estrogen receptor (ERs) and progesterone receptor (PRs) in prostate cancer (PCa), and also discuss the hotspots and directions of this field.

Methods

835 publications were sourced from the Web of Science database (WOS) from 2003 to 2022. Citespace, VOSviewer, and Bibliometrix were used for the bibliometric analysis.

Results

The number of published publications increased in early years, but declined in the last 5 years. The United States was the leading country in citations, publications, and top institutions. Prostate and Karolinska Institutet were the most publications of journal and institution, respectively. Jan-Ake Gustafsson was the most influential author based on the number of citations/publications. The most cited paper was "Estrogen receptors and human disease" by Deroo BJ, published in the Journal of Clinical Investigation. The most frequently used keywords were PCa (n = 499), gene-expression (n = 291), androgen receptor (AR) (n = 263), and ER (n = 341), while ERb (n = 219) and ERa (n = 215) further emphasized the importance of ER.

Conclusions

This study provides useful guidance that ERa antagonists, ERb agonists, and the combination of estrogen with androgen deprivation therapy (ADT) will potentially serve as a new treatment strategy for PCa. Another interesting topic is relationships between PCa and the function and mechanism of action of PRs subtypes. The outcome will assist scholars in gaining a comprehensive understanding of the current status and trends in the field, and provide inspiration for future research.

Complex Extract of Polygonatum sibiricum and Nelumbinis semen Improves Menopause Symptoms via Regulation of Estrogen Receptor Beta in an Ovariectomized Rat Model

Menopause is a hormone-deficiency state that causes facial flushing, vaginal dryness, depression, anxiety, insomnia, obesity, osteoporosis, and cardiovascular disease as ovarian function decreases. Hormone-replacement therapy is mainly used to treat menopause; however, its long-term use is accompanied by side effects such as breast cancer and endometriosis. To identify the effect of a complex extract of Polygonatum sibiricum (PS) and Nelumbinis semen (NS) on improving menopause without side effects, an ovariectomized rat model was established to analyze several menopause symptoms. Compared to single extracts, the complex extract restored vaginal epithelial cell thickness and decreased serotonin concentration by increasing the estrogen receptors ERα (ESR1) and ERβ (ESR2), depending on the ratio. Although the complex extract exerted a lower weight-loss effect than the single extracts, improved blood-lipid metabolism was observed after increasing high-density lipoprotein cholesterol levels and decreasing low-density lipoprotein cholesterol and triglyceride levels, and ovariectomy-induced osteoporosis was alleviated by suppressing osteoclast production. Thus, by increasing only ERβ expression without regulating ERα expression in the uterus, the complex extract of PS and NS may be a natural treatment for improving menopause symptoms without side effects, such as endometriosis.

Molecular mechanisms of microRNA-301a during tumor progression and metastasis

Cancer is known as one of the leading causes of human deaths globally. Late diagnosis is considered as one of the main reasons for the high mortality rate among cancer patients. Therefore, the introduction of early diagnostic tumor markers can improve the efficiency of therapeutic modalities. MicroRNAs (miRNAs) have a key role in regulation of cell proliferation and apoptosis. MiRNAs deregulation has been frequently reported during tumor progressions. Since, miRNAs have a high stability in body fluids; they can be used as the reliable non-invasive tumor markers. Here, we discussed the role of miR-301a during tumor progressions. MiR-301a mainly functions as an oncogene via the modulation of transcription factors, autophagy, epithelial-mesenchymal transition (EMT), and signaling pathways. This review paves the way to suggest miR-301a as a non-invasive marker for the early tumor diagnosis. MiR-301a can also be suggested as an effective target in cancer therapy.

Signaling pathways in cancer metabolism: mechanisms and therapeutic targets

A wide spectrum of metabolites (mainly, the three major nutrients and their derivatives) can be sensed by specific sensors, then trigger a series of signal transduction pathways and affect the expression levels of genes in epigenetics, which is called metabolite sensing. Life body regulates metabolism, immunity, and inflammation by metabolite sensing, coordinating the pathophysiology of the host to achieve balance with the external environment. Metabolic reprogramming in cancers cause different phenotypic characteristics of cancer cell from normal cell, including cell proliferation, migration, invasion, angiogenesis, etc. Metabolic disorders in cancer cells further create a microenvironment including many kinds of oncometabolites that are conducive to the growth of cancer, thus forming a vicious circle. At the same time, exogenous metabolites can also affect the biological behavior of tumors. Here, we discuss the metabolite sensing mechanisms of the three major nutrients and their derivatives, as well as their abnormalities in the development of various cancers, and discuss the potential therapeutic targets based on metabolite-sensing signaling pathways to prevent the progression of cancer.

Therapeutic blocking of VEGF binding to neuropilin-2 diminishes PD-L1 expression to activate antitumor immunity in prostate cancer

Prostate cancers are largely unresponsive to immune checkpoint inhibitors (ICIs), and there is strong evidence that programmed death-ligand 1 (PD-L1) expression itself must be inhibited to activate antitumor immunity. Here, we report that neuropilin-2 (NRP2), which functions as a vascular endothelial growth factor (VEGF) receptor on tumor cells, is an attractive target to activate antitumor immunity in prostate cancer because VEGF-NRP2 signaling sustains PD-L1 expression. NRP2 depletion increased T cell activation in vitro. In a syngeneic model of prostate cancer that is resistant to ICI, inhibition of the binding of VEGF to NRP2 using a mouse-specific anti-NRP2 monoclonal antibody (mAb) resulted in necrosis and tumor regression compared with both an anti-PD-L1 mAb and control immunoglobulin G. This therapy also decreased tumor PD-L1 expression and increased immune cell infiltration. We observed that the NRP2, VEGFA, and VEGFC genes are amplified in metastatic castration-resistant and neuroendocrine prostate cancer. We also found that individuals with NRP2^High PD-L1^High metastatic tumors had lower androgen receptor expression and higher neuroendocrine prostate cancer scores than other individuals with prostate cancer. In organoids derived from patients with neuroendocrine prostate cancer, therapeutic inhibition of VEGF binding to NRP2 using a high-affinity humanized mAb suitable for clinical use also diminished PD-L1 expression and caused a substantial increase in immune-mediated tumor cell killing, consistent with the animal studies. These findings provide justification for the initiation of clinical trials using this function-blocking NRP2 mAb in prostate cancer, especially for patients with aggressive disease.

Estrogen Receptor β4 Regulates Chemotherapy Resistance and Induces Cancer Stem Cells in Triple Negative Breast Cancer

Triple Negative Breast Cancer (TNBC) has the worst prognosis among all breast cancers, and survival in patients with recurrence is rarely beyond 12 months due to acquired resistance to chemotherapy, which is the standard of care for these patients. Our hypothesis is that Estrogen Receptor β1 (ERβ1) increases response to chemotherapy but is opposed by ERβ4, which it preferentially dimerizes with. The role of ERβ1 and ERβ4 in influencing chemotherapy sensitivity has never been studied before. CRISPR/CAS9 was used to truncate ERβ1 Ligand Binding Domain (LBD) and knock down the exon unique to ERβ4. We show that the truncated ERβ1 LBD in a variety of mutant p53 TNBC cell lines, where ERβ1 ligand dependent function was inactivated, had increased resistance to Paclitaxel, whereas the ERβ4 knockdown cell line was sensitized to Paclitaxel. We further show that ERβ1 LBD truncation, as well as treatment with ERβ1 antagonist 2-phenyl-3-(4-hydroxyphenyl)-5,7-bis(trifluoromethyl)-pyrazolo[1,5-a] pyrimidine (PHTPP), leads to increase in the drug efflux transporters. Hypoxia Inducible Factors (HIFs) activate factors involved in pluripotency and regulate the stem cell phenotype, both in normal and cancer cells. Here we show that the ERβ1 and ERβ4 regulate these stem cell markers like SOX2, OCT4, and Nanog in an opposing manner; and we further show that this regulation is mediated by HIFs. We show the increase of cancer cell stemness due to ERβ1 LBD truncation is attenuated when HIF1/2α is knocked down by siRNA. Finally, we show an increase in the breast cancer stem cell population due to ERβ1 antagonist using both ALDEFLUOR^TM and SOX2/OCT4 response element (SORE6) reporters in SUM159 and MDA-MB-231 cell lines. Since most TNBC cancers are ERβ4 positive, while only a small proportion of TNBC patients are ERβ1 positive, we believe that simultaneous activation of ERβ1 with agonists and inactivation of ERβ4, in combination with paclitaxel, can be more efficacious and yield better outcome for chemotherapy resistant TNBC patients.

The Role of ERα and ERβ in Castration-Resistant Prostate Cancer and Current Therapeutic Approaches

Castration-resistant prostate cancer, or CRPC, is an aggressive stage of prostate cancer (PCa) in which PCa cells invade nearby or other parts of the body. When a patient with PCa goes through androgen deprivation therapy (ADT) and the cancer comes back or worsens, this is called CRPC. Instead of androgen-dependent signalling, recent studies show the involvement of the estrogen pathway through the regulation of estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) in CRPC development. Reduced levels of testosterone due to ADT lead to low ERβ functionality in inhibiting the proliferation of PCa cells. Additionally, ERα, which possesses androgen independence, continues to promote the proliferation of PCa cells. The functions of ERα and ERβ in controlling PCa progression have been studied, but further research is needed to elucidate their roles in promoting CRPC. Finding new ways to treat the disease and stop it from becoming worse will require a clear understanding of the molecular processes that can lead to CRPC. The current review summarizes the underlying processes involving ERα and ERβ in developing CRPC, including castration-resistant mechanisms after ADT and available medication modification in mitigating CRPC progression, with the goal of directing future research and treatment.

Lactate promotes endothelial-to-mesenchymal transition via Snail1 lactylation after myocardial infarction

High levels of lactate are positively associated with the prognosis and mortality in patients with heart attack. Endothelial-to-mesenchymal transition (EndoMT) plays an important role in cardiac fibrosis. Here, we report that lactate exerts a previously unknown function that increases cardiac fibrosis and exacerbates cardiac dysfunction by promoting EndoMT following myocardial infarction (MI). Treatment of endothelial cells with lactate disrupts endothelial cell function and induces mesenchymal-like function following hypoxia by activating the TGF-β/Smad2 pathway. Mechanistically, lactate induces an association between CBP/p300 and Snail1, leading to lactylation of Snail1, a TGF-β transcription factor, through lactate transporter monocarboxylate transporter (MCT)-dependent signaling. Inhibiting Snail1 diminishes lactate-induced EndoMT and TGF-β/Smad2 activation after hypoxia/MI. The MCT inhibitor CHC mitigates lactate-induced EndoMT and Snail1 lactylation. Silence of MCT1 compromises lactate-promoted cardiac dysfunction and EndoMT after MI. We conclude that lactate acts as an important molecule that up-regulates cardiac EndoMT after MI via induction of Snail1 lactylation.

Mechanisms of Prostate Cancer Cells Survival and Their Therapeutic Targeting

Prostate cancer (PCa) is today the second most common cancer in the world, with almost 400,000 deaths annually. Multiple factors are involved in the etiology of PCa, such as older age, genetic mutations, ethnicity, diet, or inflammation. Modern treatment of PCa involves radical surgical treatment or radiation therapy in the stages when the tumor is limited to the prostate. When metastases develop, the standard procedure is androgen deprivation therapy, which aims to reduce the level of circulating testosterone, which is achieved by surgical or medical castration. However, when the level of testosterone decreases to the castration level, the tumor cells adapt to the new conditions through different mechanisms, which enable their unhindered growth and survival, despite the therapy. New knowledge about the biology of the so-called of castration-resistant PCa and the way it adapts to therapy will enable the development of new drugs, whose goal is to prolong the survival of patients with this stage of the disease, which will be discussed in this review.

Prognostic value of estrogen receptors in patients who underwent prostatectomy for non‑metastatic prostate cancer

Estrogen receptors in prostate cancer (PCa) are a subject of debate. The aim of the present study was to investigate whether estrogen receptor-α (ERα) and estrogen receptor-β (ERβ) impact the biochemical recurrence (BCR) of non-metastatic PCa after surgery. Following the application of the exclusion criteria, data from 108 patients who underwent laparoscopic radical prostatectomy between January 2011 and December 2019 were retrospectively evaluated. A total of 36 patients with BCR constituted the BCR group. The control group was formed using the Propensity Score Matching (PSM) method with a 1:2 ratio, including parameters with well-studied effects on BCR. The median follow-up time was 74.3 (range, 30-127.5) months in the BCR group and 66.6 (range, 31.5-130) months in the control group. Pathology specimens from the two groups were immunohistochemically stained with ERα and ERβ antibodies. Logistic regression analysis and survival analysis were performed. No differences in clinicopathological characteristics were detected between the two groups. The patients with ERα(-)/ERβ(+) staining results had a significantly fewer BCRs than other patients (P=0.024). In the logistic regression analysis, patients with ERα(-)/ERβ(+) PCa also had a significantly lower risk of recurrence (P=0.048). In the survival analysis, the 5-year BCR-free survival rate of patients with ERα(-)/ERβ(+) PCa was higher than that of other patients (85.7 vs. 66.1%; P=0.031). Excluding the effects of well-studied risk factors for recurrence by the PSM method, the present study showed that ERα and ERβ have prognostic value for non-metastatic PCa. The 5-year BCR-free survival rate is significantly higher in patients whose PCa tissue has ERα(-)/ERβ(+) staining results.

An Overview of Epithelial-to-Mesenchymal Transition and Mesenchymal-to-Epithelial Transition in Canine Tumors: How Far Have We Come?

Historically, pre-clinical and clinical studies in human medicine have provided new insights, pushing forward the contemporary knowledge. The new results represented a motivation for investigators in specific fields of veterinary medicine, who addressed the same research topics from different perspectives in studies based on experimental and spontaneous animal disease models. The study of different pheno-genotypic contexts contributes to the confirmation of translational models of pathologic mechanisms. This review provides an overview of EMT and MET processes in both human and canine species. While human medicine rapidly advances, having a large amount of information available, veterinary medicine is not at the same level. This situation should provide motivation for the veterinary medicine research field, to apply the knowledge on humans to research in pets. By merging the knowledge of these two disciplines, better and faster results can be achieved, thus improving human and canine health.

Hypoxia-Inducible Factor-1: A Novel Therapeutic Target for the Management of Cancer, Drug Resistance, and Cancer-Related Pain

Hypoxia-inducible factor-1 (HIF-1) is a key transcription factor that regulates the transcription of many genes that are responsible for the adaptation and survival of tumor cells in hypoxic environments. Over the past few decades, tremendous efforts have been made to comprehensively understand the role of HIF-1 in tumor progression. Based on the pivotal roles of HIF-1 in tumor biology, many HIF-1 inhibitors interrupting expression, stabilization, DNA binding properties, or transcriptional activity have been identified as potential therapeutic agents for various cancers, yet none of these inhibitors have yet been successfully translated into clinically available cancer treatments. In this review, we briefly introduce the regulation of the HIF-1 pathway and summarize its roles in tumor cell proliferation, angiogenesis, and metastasis. In addition, we explore the implications of HIF-1 in the development of drug resistance and cancer-related pain: the most commonly encountered obstacles during conventional anticancer therapies. Finally, the current status of HIF-1 inhibitors in clinical trials and their perspectives are highlighted, along with their modes of action. This review provides new insights into novel anticancer drug development targeting HIF-1. HIF-1 inhibitors may be promising combinational therapeutic interventions to improve the efficacy of current cancer treatments and reduce drug resistance and cancer-related pain.

Hepatocellular carcinoma cells loss lenvatinib efficacy in vitro through autophagy and hypoxia response-derived neuropilin-1 degradation

Despite pharmacological advances such as lenvatinib approval, therapeutic failure of hepatocellular carcinoma (HCC) remains a big challenge due to the complexity of its underlying molecular mechanisms. Neuropilin-1 (NRP1) is a co-receptor involved in several cellular processes associated to chemoresistance development. Since both the double-edged process of autophagy and hypoxia-derived response play crucial roles in the loss of therapeutic effectiveness, herein we investigated the interplay among NRP1, autophagy and hypoxia in development of lenvatinib resistance in HCC cell lines. We first analyzed NRP1 expression levels in human HCC samples from public databases, found significantly increased NRP1 expression in human HCC samples as well as its correlation with advanced tumor and metastasis stages. Among 3 HCC cell lines (HepG2, Huh-7 and Hep3B), Hep3B and Huh-7 cells showed significantly increased NRP1 expression levels and cell migration ability together with higher susceptibility to lenvatinib. We demonstrated that NRP1 gene silencing significantly enhanced the anticancer effects of lenvatinib on Hep3B and Huh-7 cells. Furthermore, lenvatinib suppressed NRP1 expression through promoting autophagy in Hep3B and Huh-7 cells; co-treatment with bafilomycin A1 attenuated the antitumor effects of lenvatinib, and NRP1 silencing prevented this loss of in vitro effectiveness of lenvatinib even in the presence of bafilomycin A1. In addition, exposure to a hypoxic microenvironment significantly decreased NRP1 expression through autophagy in Hep3B and Huh-7 cells. Under hypoxia, HIF-1α directly modulated NRP1 expression; HIF-1α silencing not only enhanced the anticancer effects of combined lenvatinib and hypoxia, but also prevented the loss of effectiveness caused by bafilomycin A1, highlighting the potential role of HIF-1α-derived hypoxia response in the adaptive cellular response to lenvatinib and promoting resistance acquisition by autophagy modulation. Overall, NRP1 may constitute a potential therapeutic target to prevent lenvatinib failure derived from a hypoxia-associated modulation of autophagy in advanced HCC.

Cancer-derived extracellular succinate: a driver of cancer metastasis

Succinate is a tricarboxylic acid (TCA) cycle intermediate normally confined to the mitochondrial matrix. It is a substrate of succinate dehydrogenase (SDH). Mutation of SDH subunits (SDHD and SDHB) in hereditary tumors such as paraganglioma or reduction of SDHB expression in cancer results in matrix succinate accumulation which is transported to cytoplasma and secreted into the extracellular milieu. Excessive cytosolic succinate is known to stabilize hypoxia inducible factor-1α (HIF-1α) by inhibiting prolyl hydroxylase. Recent reports indicate that cancer-secreted succinate enhances cancer cell migration and promotes cancer metastasis by activating succinate receptor-1 (SUCNR-1)-mediated signaling and transcription pathways. Cancer-derived extracellular succinate enhances cancer cell and macrophage migration through SUCNR-1 → PI-3 K → HIF-1α pathway. Extracellular succinate induces tumor angiogenesis through SUCNR-1-mediated ERK1/2 and STAT3 activation resulting in upregulation of vascular endothelial growth factor (VEGF) expression. Succinate increases SUCNR-1 expression in cancer cells which is considered as a target for developing new anti-metastasis drugs. Furthermore, serum succinate which is elevated in cancer patients may be a theranostic biomarker for selecting patients for SUCNR-1 antagonist therapy.

Silencing of OGDHL promotes liver cancer metastasis by enhancing hypoxia inducible factor 1 α protein stability

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases associated with a high rate of mortality. Frequent intrahepatic spread, extrahepatic metastasis, and tumor invasiveness are the main factors responsible for the poor prognosis of patients with HCC. Hypoxia-inducible factor 1 (HIF-1) has been verified to play a critical role in the metastasis of HCC. HIFs are also known to be modulated by small molecular metabolites, thus highlighting the need to understand the complexity of their cellular regulation in tumor metastasis. In this study, lower expression levels of oxoglutarate dehydrogenase-like (OGDHL) were strongly correlated with aggressive clinicopathologic characteristics, such as metastasis and invasion in three independent cohorts featuring a total of 281 postoperative HCC patients. The aberrant expression of OGDHL reduced cell invasiveness and migration in vitro and HCC metastasis in vivo, whereas the silencing of OGDHL promoted these processes in HCC cells. The pro-metastatic role of OGDHL downregulation is most likely attributed to its upregulation of HIF-1α transactivation activity and the protein stabilization by promoting the accumulation of L-2-HG to prevent the activity of HIF-1α prolyl hydroxylases, which subsequently causes an epithelial-mesenchymal transition process in HCC cells. These results demonstrate that OGDHL is a dominant factor that modulates the metastasis of HCC.

ComABAN: refining molecular representation with the graph attention mechanism to accelerate drug discovery

An unsolved challenge in developing molecular representation is determining an optimal method to characterize the molecular structure. Comprehension of intramolecular interactions is paramount toward achieving this goal. In this study, ComABAN, a new graph-attention-based approach, is proposed to improve the accuracy of molecular representation by simultaneously considering atom-atom, bond-bond and atom-bond interactions. In addition, we benchmark models extensively on 8 public and 680 proprietary industrial datasets spanning a wide variety of chemical end points. The results show that ComABAN has higher prediction accuracy compared with the classical machine learning method and the deep learning-based methods. Furthermore, the trained neural network was used to predict a library of 1.5 million molecules and picked out compounds with a classification result of grade I. Subsequently, these predicted molecules were scored and ranked using cascade docking, molecular dynamics simulations to generate five potential candidates. All five molecules showed high similarity to nanomolar bioactive inhibitors suppressing the expression of HIF-1α, and we synthesized three compounds (Y-1, Y-3, Y-4) and tested their inhibitory ability in vitro. Our results indicate that ComABAN is an effective tool for accelerating drug discovery.

AMPK's double-faced role in advanced stages of prostate cancer

Prostate cancer (PCa) is the second leading cause of cancer deaths in men. Unfortunately, a very limited number of drugs are available for the relapsed and advanced stages of PCa, adding only a few months to survival; therefore, it is vital to develop new drugs. 5´ AMP-activated protein kinase (AMPK) is a master regulator of cell metabolism. It plays a significant role in the metabolism of PCa; hence, it can serve well as a treatment option for the advanced stages of PCa. However, whether this pathway contributes to cancer cell survival or death remains unknown. The present study reviews the possible pathways by which AMPK plays role in the advanced stages of PCa, drug resistance, and metastasis: (1) AMPK has a contradictory role in promoting glycolysis and the Warburg effect which are correlated with cancer stem cells (CSCs) survival and advanced PCa. It exerts its effect by interacting with hypoxia-induced factor 1 (HIF1) α, pyruvate kinase 2 (PKM2), glucose transporter (GLUT) 1 and pyruvate dehydrogenase complex (PDHC), which are key regulators of glycolysis; however, whether it promotes or discourage glycolysis is not conclusive. It can also exert an anti-CSC effect by negative regulation of NANOG and epithelial-mesenchymal transition (EMT) transcription factors, which are the major drivers of CSC maintenance; (2) the regulatory effect of AMPK on autophagy is also noticeable. Androgen receptors' expression increases AMPK activation through Calcium/calmodulin-dependent protein kinase 2 (CaMKK2) and induces autophagy. In addition, AMPK itself increases autophagy by downregulating the mammalian target of rapamycin complex (mTORC). However, whether increased autophagy inhibits or promotes cell death and drug resistance is contradictory. This study reveals that there are numerous pathways other than cell metabolism by which AMPK exerts its effects in the advanced stages of PCa, making it a priceless treatment target. Finally, we mention some drugs developed to treat the advanced stages of PCa by acting on AMPK.

Therapeutic Targeting of Ovarian Cancer Stem Cells Using Estrogen Receptor Beta Agonist

Ovarian cancer (OCa) is the deadliest gynecologic cancer. Emerging studies suggest ovarian cancer stem cells (OCSCs) contribute to chemotherapy resistance and tumor relapse. Recent studies demonstrated estrogen receptor beta (ERβ) exerts tumor suppressor functions in OCa. However, the status of ERβ expression in OCSCs and the therapeutic utility of the ERβ agonist LY500307 for targeting OCSCs remain unknown. OCSCs were enriched from ES2, OV90, SKOV3, OVSAHO, and A2780 cells using ALDEFLUOR kit. RT-qPCR results showed ERβ, particularly ERβ isoform 1, is highly expressed in OCSCs and that ERβ agonist LY500307 significantly reduced the viability of OCSCs. Treatment of OCSCs with LY500307 significantly reduced sphere formation, self-renewal, and invasion, while also promoting apoptosis and G2/M cell cycle arrest. Mechanistic studies using RNA-seq analysis demonstrated that LY500307 treatment resulted in modulation of pathways related to cell cycle and apoptosis. Western blot and RT-qPCR assays demonstrated the upregulation of apoptosis and cell cycle arrest genes such as FDXR, p21/CDKN1A, cleaved PARP, and caspase 3, and the downregulation of stemness markers SOX2, Oct4, and Nanog. Importantly, treatment of LY500307 significantly attenuated the tumor-initiating capacity of OCSCs in orthotopic OCa murine xenograft models. Our results demonstrate that ERβ agonist LY500307 is highly efficacious in reducing the stemness and promoting apoptosis of OCSCs and shows significant promise as a novel therapeutic agent in treating OCa.

Long Noncoding RNA and Circular RNA: Two Rising Stars in Regulating Epithelial-Mesenchymal Transition of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with especially poor prognosis. However, the molecular mechanisms of pancreatic oncogenesis and malignant progression are not fully elucidated. Epithelial-mesenchymal transition (EMT) process is important to drive pancreatic carcinogenesis. Recently, long noncoding RNAs (lncRNAs) and circular RNAs(circRNAs) have been characterized to participate in EMT in PDAC, which can affect the migration and invasion of tumor cells by playing important roles in epigenetic processes, transcription, and post-transcriptional regulation. LncRNAs can act as competing endogenous RNAs (ceRNA) to sequester target microRNAs(miRNAs), bind to the genes which localize physically nearby, and directly interact with EMT-related proteins. Currently known circRNAs mostly regulate the EMT process in PDAC also by acting as a miRNA sponge, directly affecting the protein degradation process. Therefore, exploring the functions of lncRNAs and circRNAs in EMT during pancreatic cancer might help pancreatic cancer treatments.

Saikosaponin d Alleviates Liver Fibrosis by Negatively Regulating the ROS/NLRP3 Inflammasome Through Activating the ERβ Pathway

Background and aims: Saikosaponin d (SSd) has a steroidal structure and significant anti-inflammatory effects. The purpose of this study was to explore the mechanism underlying SSd’s inhibitory effects on liver fibrosis.

Methods: Wild-type and estrogen receptor knockout (ERKO) mice were treated with CCl₄ to establish liver fibrosis mouse models. The effects of SSd on hepatic fibrogenesis were studied in these mouse models. Hepatic stellate cells (HSCs) were activated by H₂O₂ to investigate the potential molecular mechanisms. The establishment of the models and the degrees of inflammation and liver tissue fibrosis were evaluated by detecting changes in serum liver enzymes and liver histopathology. The expression of α-SMA and TGF-β1 was determined by immunohistochemistry. The expression and significance of NLRP3 inflammasome proteins were explored by RT-PCR and Western blotting analyses. The mitochondrial ROS-related indexes were evaluated by MitoSOX Red.

Results: In wild-type and ERKO mice treated with CCl₄, the fluorescence expression of mitochondrial ROS was up-regulated, while the mitochondrial membrane potential and ATP content were decreased, suggesting that the mitochondria were damaged. In addition, the expression of NLRP3 inflammatory bodies and fibrosis markers (α-SMA, TGF-β, TIMP-1, MMP-2, and Vimentin) in liver tissue increased. Furthermore, the above indexes showed the same expression trend in activated HSCs. In addition, the peripheral serum ALT and AST levels increased in CCl₄-induced liver injury model mice. And HE staining showed a large number of inflammatory cell infiltration in the liver of model mice. Picric acid-Sirius staining and Masson staining showed that there was significant collagen fibrous tissue deposition in mice liver sections. IHC and WB detection confirmed that the expression of α-SMA and TGF-β1 increased. Liver fibrosis scores were also elevated. Then, after SSd intervention, the expression of ROS in wild-type mice and αERKO mice decreased, mitochondrial membrane potential recovered, ATP level increased, NLRP3 inflammasome and fibrosis indexes decreased, liver enzyme levels decreased, and liver pathology showed liver inflammation. The damage and collagen deposition were significantly relieved, the expression of α-SMA and TGF-β1 was decreased, and the fibrosis score was also decreased. More importantly, the effect of SSd in alleviating liver injury and liver fibrosis had no effect on βERKO mice.

Conclusion: SSd alleviated liver fibrosis by negatively regulating the ROS/NLRP3 inflammasome through activating the ERβ pathway. By establishing liver fibrosis models using wild-type and ERKO mice, we demonstrated that SSd could alleviate liver fibrosis by inhibiting the ROS/NLRP3 inflammasome axis through activating the ERβ pathway.

A Novel Estrogen Receptor β Agonist Diminishes Ovarian Cancer Stem Cells via Suppressing the Epithelial-to-Mesenchymal Transition

Epithelial ovarian cancer is the most lethal malignancy of the female reproductive tract. A healthy ovary expresses both Estrogen Receptor α (ERα) and β (ERβ). Given that ERα is generally considered to promote cell survival and proliferation, thereby, enhancing tumor growth, while ERβ shows a protective effect against the development and progression of tumors, the activation of ERβ by its agonists could be therapeutically beneficial for ovarian cancer. Here, we demonstrate that the activation of ERβ using a newly developed ERβ agonist, OSU-ERb-12, can impede ovarian cancer cell expansion and tumor growth in an ERα-independent manner. More interestingly, we found that OSU-ERb-12 also reduces the cancer stem cell (CSC) population in ovarian cancer by compromising non-CSC-to-CSC conversion. Mechanistically, we revealed that OSU-ERb-12 decreased the expression of Snail, a master regulator of the epithelial-to-mesenchymal transition (EMT), which is associated with de novo CSC generation. Given that ERα can mediate EMT and facilitate maintenance of the CSC subpopulation and that OSU-ERb-12 can block the transactivity of ERα, we conclude that OSU-ERb-12 reduces the CSC subpopulation by inhibiting EMT in an ERα-dependent manner. Taken together, our data indicate that the ERβ agonist OSU-ERb-12 could be used to hinder tumor progression and limit the CSC subpopulation with the potential to prevent tumor relapse and metastasis in patients with ovarian cancer.

Multifaceted Interplay between Hormones, Growth Factors and Hypoxia in the Tumor Microenvironment

Hormones and growth factors (GFs) are signaling molecules implicated in the regulation of a variety of cellular processes. They play important roles in both healthy and tumor cells, where they function by binding to specific receptors on target cells and activating downstream signaling cascades. The stages of tumor progression are influenced by hormones and GF signaling. Hypoxia, a hallmark of cancer progression, contributes to tumor plasticity and heterogeneity. Most solid tumors contain a hypoxic core due to rapid cellular proliferation that outgrows the blood supply. In these circumstances, hypoxia-inducible factors (HIFs) play a central role in the adaptation of tumor cells to their new environment, dramatically reshaping their transcriptional profile. HIF signaling is modulated by a variety of factors including hormones and GFs, which activate signaling pathways that enhance tumor growth and metastatic potential and impair responses to therapy. In this review, we summarize the role of hormones and GFs during cancer onset and progression with a particular focus on hypoxia and the interplay with HIF proteins. We also discuss how hypoxia influences the efficacy of cancer immunotherapy, considering that a hypoxic environment may act as a determinant of the immune-excluded phenotype and a major hindrance to the success of adoptive cell therapies.

Exosomal LBH inhibits epithelial-mesenchymal transition and angiogenesis in nasopharyngeal carcinoma via downregulating VEGFA signaling

The limb-bud and heart (LBH) gene was reported to suppress nasopharyngeal carcinoma (NPC) progression in our previous study. Distant metastasis predominantly accounts for the unsatisfactory prognosis of NPC treatment, in which epithelial-mesenchymal transition (EMT) and tumor angiogenesis are of great significance. The roles of exosomes in mediating NPC progression have been highlighted in recent researches, and attempts have been made to explore the clinical application of NPC exosomes. Here we investigated the function of the LBH gene in NPC exosomes, and its potential mechanism. NPC xenografts were constructed, showing that vascular endothelial growth factor A (VEGFA) expression and neovascularity were attenuated by LBH overexpression, together with diminished EMT progression. NPC-derived exosomes were isolated, identified and applied for in vitro/in vivo experiments, and the exosomal distribution of LBH was elevated in exosomes derived from LBH-upregulated cells. Ectopic LBH, αB-crystallin (CRYAB) and VEGFA expression was induced by lentiviral infection or plasmid transfection to explore their functions in modulating EMT and angiogenesis in NPC. The addition of LBH+ NPC exosomes during a Matrigel plug assay in mice suppressed in vivo angiogenesis, and the treatment of human umbilical vein endothelial cells (HUVECs) with LBH+ NPC exosomes inhibited cellular proliferation, migration and tube formation. The interactions among LBH, CRYAB and VEGFA were confirmed by colocalization and fluorescence resonance energy transfer (FRET) assays, and extracellular VEGFA secretion from both HUVECs and NPC cells under the treatment with LBH+ NPC exosomes was diminished according to ELISA results. We concluded that exosomal LBH inhibits EMT progression and angiogenesis in the NPC microenvironment, and that its effects are partially implemented by modulation of VEGFA expression, secretion and related signaling. Thus, LBH could serve as a promising therapeutic target in VEGFA-focused NPC treatment.

Combination therapy with pazopanib and tivantinib modulates VEGF and c-MET levels in refractory advanced solid tumors

The vascular endothelial growth factor (VEGF)/VEGFR and hepatocyte growth factor (HGF)/c-MET signaling pathways act synergistically to promote angiogenesis. Studies indicate VEGF inhibition leads to increased levels of phosphorylated c-MET, bypassing VEGF-mediated angiogenesis and leading to chemoresistance. We conducted a phase 1 clinical trial with 32 patients with refractory solid tumors to evaluate the safety, pharmacokinetics, and pharmacodynamics of combinations of VEGF-targeting pazopanib and the putative c-MET inhibitor ARQ197 (tivantinib) at 5 dose levels (DLs). Patients either took pazopanib and tivantinib from treatment initiation (escalation phase) or pazopanib alone for 7 days, with paired tumor sampling, prior to starting combination treatment (expansion phase). Hypertension was the most common adverse event. No more than 1 dose limiting toxicity (DLT) occurred at any DL, so the maximum tolerated dose (MTD) was not determined; DL5 (800 mg pazopanib daily and 360 mg tivantinib BID) was used during the expansion phase. Twenty of 31 evaluable patients achieved stable disease lasting up to 22 cycles. Circulating VEGF, VEGFR2, HGF, and c-MET levels were assessed, and only VEGF levels increased. Tumor c-MET levels (total and phosphorylated) were determined in paired biopsies before and after 7 days of pazopanib treatment. Total intact c-MET decreased in 6 of 7 biopsy pairs, in contrast to previously reported c-MET elevation in response to VEGF inhibition. These results are discussed in the context of our previously reported analysis of epithelial-mesenchymal transition in these tumors.

Estrogen Receptor ß in Cancer: To ß(e) or not to ß(e)?

Estrogen receptors (ERs) are known to play an important role in the proper development of estrogen-sensitive organs, as well as in the development and progression of various types of cancer. ERα, the first ER to be discovered, has been the focus of most cancer research, especially in the context of breast cancer. However, ERβ expression also plays a significant role in cancer pathophysiology, notably its seemingly protective nature and loss of expression with oncogenesis and progression. Although ERβ exhibits antitumor activity in breast, ovarian, and prostate cancer, its expression is associated with disease progression and worse prognosis in lung cancer. The function of ERβ is complicated by the presence of multiple isoforms and single nucleotide polymorphisms, in addition to tissue-specific functions. This mini-review explores current literature on ERβ and its mechanism of action and clinical implications in breast, ovarian, prostate, and lung cancer.

Hsa_circ_0004296 inhibits metastasis of prostate cancer by interacting with EIF4A3 to prevent nuclear export of ETS1 mRNA

Background

Circular RNAs (circRNAs) have been shown to play vital biological functions in various tumors, including prostate cancer (PCa). However, the roles of circRNAs in the metastasis of PCa remain unclear. In the present study, differentially expressed circRNAs associated with PCa metastasis were screened using high-throughput RNA sequencing, from which hsa_circ_0004296 was identified.

Methods

Quantitative real-time PCR (qRT-PCR) was used to detect the expression of circ_0004296 in PCa tissues and adjacent normal tissues as well as in blood and urine. Gain and loss of function experiments were performed to investigate the function of circ_0004296 in PCa. Bioinformatics analyses, RNA pull-down assay, and mass spectrometry were conducted to identify RNA-binding proteins. RNA immunoprecipitation and RNA and protein nuclear-cytoplasmic fractionation were performed to investigate the underlying mechanism. A xenograft mouse model was used to analyze the effect of circ_0004296 on PCa growth and metastasis in vivo.

Results

The expression of circ_0004296 was decreased in PCa tissues, blood, and urine, which was negatively associated with metastasis. Furthermore, gain and loss of function experiments in vitro and in vivo showed that circ_0004296 inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition of PCa cells. Mechanistically, circ_0004296 regulated host gene ETS1 expression at the post-transcriptional level. EIF4A3 was identified and confirmed as the downstream binding protein of circ_0004296. EIF4A3 expression was significantly upregulated in PCa tissues and associated with PCa metastasis. Silencing EIF4A3 suppressed PCa cell proliferation, migration, invasion, and EMT.

Conclusions

Circ_0004296 overexpression efficiently inhibited ETS1 mRNA nuclear export by promoting EIF4A3 retention in the nucleus, leading to the downregulation of ETS1 expression and suppression of PCa metastasis; thus, circ_0004296 might be a potential biomarker and therapeutic target for patients with PCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02138-8.

Identification and validation of a hypoxia-related prognostic signature in clear cell renal cell carcinoma patients

Increasing evidence has shown that hypoxia is closely related to the development, progression, and prognosis of clear cell renal cell carcinoma (ccRCC). Nevertheless, reliable prognostic signatures based on hypoxia have not been well-established. This study aimed to establish a hypoxia-related prognostic signature and construct an optimized nomogram for patients with ccRCC.We accessed hallmark gene sets of hypoxia, including 200 genes, and an original RNA seq dataset of ccRCC cases with integrated clinical information obtained by mining the Cancer Genome Atlas database and the International Cancer Genome Consortium (ICGC) database. Univariate Cox regression analysis and multivariate Cox proportional hazards regression were performed to identify prognostic hub genes and further established prognostic model as well as visualized the nomogram. External validation of the optimized nomogram was performed in independent cohorts from the ICGC database.ANKZF1, ETS1, PLAUR, SERPINE1, FBP1, and PFKP were selected as prognostic hypoxia-related hub genes, and the prognostic model effectively distinguishes high-risk and low-risk patients with ccRCC. The results of receiver operating characteristic curve, risk plots, survival analysis, and independent analysis suggested that RiskScore was a useful tool and independent predictive factor. A novel prognosis nomogram optimized via RiskScore showed its promising performance in both the Cancer Genome Atlas-ccRCC cohort and an ICGC-ccRCC cohort.Our study reveals that the differential expressions of hypoxia-related genes are associated with the overall survival of patients with ccRCC. The prognostic model we established showed a good predictive and discerning ability in ccRCC patients. The novel nomogram optimized via RiskScore exhibited a promising predictive ability. It may be able to serve as a visualized tool for guiding clinical decisions and selecting effective individualized treatments.

4.1N-Mediated Interactions and Functions in Nerve System and Cancer

Scaffolding protein 4.1N is a neuron-enriched 4.1 homologue. 4.1N contains three conserved domains, including the N-terminal 4.1-ezrin-radixin-moesin (FERM) domain, internal spectrin–actin–binding (SAB) domain, and C-terminal domain (CTD). Interspersed between the three domains are nonconserved domains, including U1, U2, and U3. The role of 4.1N was first reported in the nerve system. Then, extensive studies reported the role of 4.1N in cancers and other diseases. 4.1N performs numerous vital functions in signaling transduction by interacting, locating, supporting, and coordinating different partners and is involved in the molecular pathogenesis of various diseases. In this review, recent studies on the interactions between 4.1N and its contactors (including the α7AChr, IP3R1, GluR1/4, GluK1/2/3, mGluR8, KCC2, D2/3Rs, CASK, NuMA, PIKE, IP6K2, CAM 1/3, βII spectrin, flotillin-1, pp1, and 14-3-3) and the 4.1N-related biological functions in the nerve system and cancers are specifically and comprehensively discussed. This review provides critical detailed mechanistic insights into the role of 4.1N in disease relationships.

MiR-195 inhibits the ubiquitination and degradation of YY1 by Smurf2, and induces EMT and cell permeability of retinal pigment epithelial cells

The dysregulated microRNAs (miRNAs) are involved in diabetic retinopathy progression. Epithelial mesenchymal transition (EMT) and cell permeability are important events in diabetic retinopathy. However, the function and mechanism of miR-195 in EMT and cell permeability in diabetic retinopathy remain largely unclear. Diabetic retinopathy models were established using streptozotocin (STZ)-induced diabetic mice and high glucose (HG)-stimulated ARPE-19 cells. Retina injury was investigated by hematoxylin-eosin (HE) staining. EMT and cell permeability were analyzed by western blotting, immunofluorescence, wound healing, and FITC-dextran assays. MiR-195 expression was detected via qRT-PCR. YY1, VEGFA, Snail1, and Smurf2 levels were detected via western blotting. The interaction relationship was analyzed via ChIP, Co-IP, or dual-luciferase reporter assay. The retina injury, EMT, and cell permeability were induced in STZ-induced diabetic mice. HG induced EMT and cell permeability in ARPE-19 cells. MiR-195, YY1, VEGFA, and Snail1 levels were enhanced, but Smurf2 abundance was reduced in STZ-induced diabetic mice and HG-stimulated ARPE-19 cells. VEGFA knockdown decreased Snail1 expression and attenuated HG-induced EMT and cell permeability. YY1 silence reduced VEGFA and Snail1 expression, and mitigated HG-induced EMT and cell permeability. YY1 could bind with VEGFA and Snail1, and it was degraded via Smurf2-mediated ubiquitination. MiR-195 knockdown upregulated Smurf2 to decrease YY1 expression and inhibited HG-induced EMT and cell permeability. MiR-195 targeted Smurf2, increased expression of YY1, VEGFA, and Snail1, and promoted HG-induced EMT and cell permeability. MiR-195 promotes EMT and cell permeability of HG-stimulated ARPE-19 cells by increasing VEGFA/Snail1 via inhibiting the Smurf2-mediated ubiquitination of YY1.

miR-593-3p Promotes Proliferation and Invasion in Prostate Cancer Cells by Targeting ADIPOR1

Background

Accumulating evidence has indicated that dysregulation of microRNAs (miRNAs) contributes to the tumorigenesis of prostate cancer (PCa). Nevertheless, the role of miR-593-3p in the development of PCa remains unclear. The objective of this study was to investigate the role and mechanisms of miR-593-3p in PCa cells.

Methods

RT-PCR was used to detect the expression levels of miR-593-3p. CCK-8, colony formation, spheroid formation and transwell assays were performed to examine the proliferation, migration and invasion of C4-2, DU145 and RWPE-1 cells. And then, transcriptome sequencing, dual-luciferase reporter assay and Western blot were taken to identify the target gene and downstream mechanisms of miR-593-3p.

Results

Here, we found that miR-593-3p promoted PCa cell proliferation, colony formation, spheroid formation, migration and invasion. Further mechanistic studies revealed that miR-593-3p possessed binding sites of ADIPOR1 3ʹ-UTR and played an important role in 5ʹ-AMP-activated protein kinase (AMPK) signaling pathway and epithelial–mesenchymal transition (EMT) process. In addition, the transfection of si-ADIPOR1 also enhanced the PCa cell proliferation and invasion.

Conclusion

Our study provides an empirical investigation of miR-593-3p, which exerts oncogenic function through targeting ADIPOR1 in PCa cells.

Fabrication of PNIPAm-based thermoresponsive hydrogel microwell arrays for tumor spheroid formation

Complex three-dimensional (3D) cell cultures are being increasingly implemented in biomedical research as they provide important insights into complex cancer biology, and cell-cell and cell-matrix interactions in the tumor microenvironment. However, most methods used today for 3D cell culture are limited by high cost, the need for specialized skills, low throughput and the use of unnatural culture environments. We report the development of a unique biomimetic hydrogel microwell array platform for the generation and stress-free isolation of cancer spheroids. The poly N-isopropylacrylamide-based hydrogel microwell array (PHMA) has thermoresponsive properties allowing for the attachment and growth of cell aggregates/ spheroids at 37 °C, and their easy isolation at room temperature (RT). The reversible phase transition of the microwell arrays at 35 °C was confirmed visually and by differential scanning calorimetry. Swelling/ shrinking studies and EVOS imaging established that the microwell arrays are hydrophilic and swollen at temperatures <35 °C, while they shrink and are hydrophobic at temperatures >35 °C. Spheroid development within the PHMA was optimized for seeding density, incubation time and cell viability. Spheroids of A549, HeLa and MG-63 cancer cell lines, and human lung fibroblast (HLF) cell line generated within the PHMAs had relatively spherical morphology with hypoxic cores. Finally, using MG-63 cell spheroids as representative models, a proof-of-concept drug response study using doxorubicin hydrochloride was conducted. Overall, we demonstrate that the PHMAs are an innovative alternative to currently used 3D cell culture techniques, for the high-throughput generation of cell spheroids for disease modeling and drug screening applications.

Androgens in prostate cancer: A tale that never ends

Androgens play an essential role in prostate cancer. Clinical treatments that target steroidogenesis and the androgen receptor (AR) successfully postpone disease progression. Abiraterone and enzalutamide, the next-generation androgen receptor pathway inhibitors (ARPI), emphasize the function of the androgen-AR axis even in castration-resistant prostate cancer (CRPC). However, with the increased incidence in neuroendocrine prostate cancer (NEPC) showing resistance to ARPI, the importance of androgen-AR axis in further disease management remains elusive. Herein we review the steroidogenic pathways associated with different disease stages and discuss the potential targets for disease management after manifesting resistance to abiraterone and enzalutamide.

Estrogen receptor β and treatment with a phytoestrogen are associated with inhibition of nuclear translocation of EGFR in the prostate

Knockout of ERβ in the mouse leads to nuclear expression of epidermal growth factor receptor (EGFR) in the prostate. To examine whether ERβ plays a similar role in the human prostate, we used four cohorts of men: 1) a Swedish cohort of normal prostates and PCa (prostate cancer) of different Gleason grades; 2) men with benign prostatic hyperplasia (BPH) treated with the 5α-reductase inhibitor, finasteride, and finasteride together with the ERβ agonists, soy isoflavones; 3) men with PCa above Gleason grade 4 (GG4), treated with ADT (androgen deprivation therapy) and abiraterone (AA), the blocker of androgen synthesis for different durations; and 4) men with GG4 PCa on ADT or ADT with the AR (androgen receptor) blocker, enzalutamide, for 4 mo to 6 mo. In men with BPH, finasteride treatment induced EGFR nuclear expression, but, when finasteride was combined with isoflavones, EGFR remained on the cell membrane. In GG4 patients, blocking of AR for 4 mo to 6 mo resulted in loss of ERβ and PTEN expression and increase in patients with nuclear EGFR from 10 to 40%. In the men with GG4 PCa, blocking of adrenal synthesis of testosterone for 2 mo to 7 mo had the beneficial effect of increasing ERβ expression, but, on treatment longer than 8 mo, ERβ was lost and EGFR moved to the nucleus. Since nuclear EGFR is a predictor of poor outcome in PCa, addition of ERβ agonists together with abiraterone should be considered as a treatment that might sustain expression of ERβ and offer some benefit to patients.

SKA3 promotes lung adenocarcinoma metastasis through the EGFR-PI3K-Akt axis

The processes that lead to lung adenocarcinoma (LUAD) metastasis are poorly characterized. Spindle and kinetochore associated complex subunit 3 (SKA3) plays a key role in cervical cancer development, but its contribution to LUAD is unknown. Here, we found that SKA3 is overexpressed in LUAD and its expression correlates with lymph node metastasis and poor prognosis. SKA3 silencing experiments identified SKA3 as an oncogene that promotes the metastasis of LUAD cell lines and tissues. SKA3 was found to induce the expression of matrix metalloproteinase (MMP)-2, -7, and -9, which activate PI3K–AKT. SKA3 was also found to bind and activate EGFR to activate PI3K–AKT. In summary, we identify a role for SKA3 in LUAD metastasis through its ability to bind EFGR and activate PI3K–AKT signaling.

Hypoxia and the phenomenon of immune exclusion

Over the last few years, cancer immunotherapy experienced tremendous developments and it is nowadays considered a promising strategy against many types of cancer. However, the exclusion of lymphocytes from the tumor nest is a common phenomenon that limits the efficiency of immunotherapy in solid tumors. Despite several mechanisms proposed during the years to explain the immune excluded phenotype, at present, there is no integrated understanding about the role played by different models of immune exclusion in human cancers. Hypoxia is a hallmark of most solid tumors and, being a multifaceted and complex condition, shapes in a unique way the tumor microenvironment, affecting gene transcription and chromatin remodeling. In this review, we speculate about an upstream role for hypoxia as a common biological determinant of immune exclusion in solid tumors. We also discuss the current state of ex vivo and in vivo imaging of hypoxic determinants in relation to T cell distribution that could mechanisms of immune exclusion and discover functional-morphological tumor features that could support clinical monitoring.

[A Review of High-altitude Hypoxia Adaptation and Hypoxic Solid Tumor]

Historically, the Cambrian explosion was a major life evolution event caused by changes of natural environmental oxygen concentration. The use of oxygen was part of the basic survival instinct of higher life, which evolved a complex regulation system in response to variant levels of oxygen concentration. Hypoxia is one of the typical environmental characteristics in plateau areas. After long-term natural selection in hypoxic conditions, numerous species living in plateau areas have evolved unique mechanisms adapted to hypoxia. Recent studies have found that there are some similarities in adaptation to hypoxia between the animals in highland and different types of human solid tumor cells. Herein, we will summarize recent findings about the hypoxia adaptation evolution in high-altitude animals and the characteristics of hypoxic solid tumors, especially the reactive oxygen species responses in hypoxic solid tumors. We believe that deciphering the underlying molecular mechanisms involved in hypoxia adaptation in highland will facilitate the identification of new genes or biomarkers critical for research on hypoxic solid tumors in the future.

Isolation and Characterization of Phenylpropanoid and Lignan Compounds from Peperomia pellucida [L.] Kunth with Estrogenic Activities

Extracts of Peperomia pellucida [L.] Kunth have previously been demonstrated to have in vivo estrogenic-like effects, thereby functioning as an anti-osteoporotic agent. However, the compounds responsible for these effects have not yet been determined. Therefore, the aim of this study is to isolate and elucidate potential compounds with estrogenic activity. The structures of the isolated compounds were identified using 1D 1H and 13C-NMR and confirmed by 2D FT-NMR. The estrogenic activity was evaluated using the E-SCREEN assay, and a molecular docking study was performed to predict the binding affinity of the isolated compounds to estrogen receptors. In this experiment, we successfully isolated three phenylpropanoids and two lignan derivatives, namely, 6-allyl-5-methoxy-1,3-benzodioxol-4-ol (1), pachypostaudin B (2), pellucidin A (3), dillapiole (4), and apiol (5). Among these compounds, the isolation of 1 and 2 from P. pellucida is reported for the first time in this study. Activity assays clearly showed that the ethyl acetate extract and its fractions, subfractions, and isolated compounds exerted estrogenic activity. Methanol fraction of the ethyl acetate extract produced the highest estrogenic activity, while 1 and 2 had partial agonist activity. Some compounds (derivates of dillapiole and pellucidin A) also had, in addition, anti-estrogenic activity. In the docking study, the estrogenic activities of 1-5 appeared to be mediated by a classical ligand-dependent mechanism as suggested by the binding interaction between the compounds and estrogen receptors; binding occurred on Arg 394 and His 524 of the alpha receptor and Arg 346 and His 475 of the beta receptor. In summary, we reveal that P. pellucida is a promising anti-osteoporotic agent due to its estrogenic activity, and the compounds responsible for this activity were found to be lignan and phenylpropanoid derivatives. The presence of other compounds in either the extract or fraction may contribute to a synergistic effect, as suggested by the higher estrogenic activity of the methanol fraction. Hence, we suggest further research on the osteoporotic activity and safety of the identified compounds, especially regarding their effects on estrogen-responsive organs.

Molecular tracing of prostate cancer lethality

Prostate cancer is diagnosed mostly in men over the age of 50 years, and has favorable 5-year survival rates due to early cancer detection and availability of curative surgical management. However, progression to metastasis and emergence of therapeutic resistance are responsible for the majority of prostate cancer mortalities. Recent advancement in sequencing technologies and computational capabilities have improved the ability to organize and analyze large data, thus enabling the identification of novel biomarkers for survival, metastatic progression and patient prognosis. Large-scale sequencing studies have also uncovered genetic and epigenetic signatures associated with prostate cancer molecular subtypes, supporting the development of personalized targeted-therapies. However, the current state of mainstream prostate cancer management does not take full advantage of the personalized diagnostic and treatment modalities available. This review focuses on interrogating biomarkers of prostate cancer progression, including gene signatures that correspond to the acquisition of tumor lethality and those of predictive and prognostic value in progression to advanced disease, and suggest how we can use our knowledge of biomarkers and molecular subtypes to improve patient treatment and survival outcomes.

NT5DC2 knockdown inhibits colorectal carcinoma progression by repressing metastasis, angiogenesis and tumor-associated macrophage recruitment: A mechanism involving VEGF signaling

Colorectal cancer (CRC) is one of the most commonly diagnosed tumors among human worldwide. Angiogenesis and tumor-associated macrophage (TAM) recruitment are closely associated with CRC development. Nevertheless, the mechanisms revealing CRC progression are still not fully understood. 5'-Nucleotidase domain containing 2 (NT5DC2), a member of the NT5DC family, modulates various cellular events to mediate tumor growth, and thus serves as a disgnostic biomarker. Here, we explored the potential of NT5DC2 on tumor progression in CRC. We first found that NT5DC2 expression was significantly up-regulated in CRC tissues and cell lines. CRC patients with higher NT5DC2 expression showed poor overall survival. Furthermore, CRC cell lines stably transfected with shNT5DC2 lentivirus plasmids exhibited markedly reduced cell proliferation, migration and invasion compared with the negative control group. Hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGF-A) expression levels were remarkably reduced in CRC cells with NT5DC2 deletion, along with evidently reduced tube formation in the HUVECs cultured in the collected conditional medium. The expression levels of CC chemokine ligand 2 (CCL2) and its receptor CCR2 were found to be greatly down-regulated in CRC cells transfected with shNT5DC2. Moreover, NT5DC2 knockdown markedly suppressed the activation of protein kinase-B/nuclear transcription factor κB (AKT/NF-κB) signaling in CRC cells. Furthermore, we found that NT5DC2 deletion obviously reduced the TAM recruitments through suppressing CCL2/CCR2 and AKT/NF-κB signaling pathways. Intriguingly, our in vitro experiments demonstrated that VEGF reduction was necessary for shNT5DC2-inhibited cell proliferation, migration, invasion, angiogenesis and TAM recruitment. In vivo studies also confirmed that NT5DC2 knockdown effectively reduced the tumor growth and VEGF expression in a xonegraft mouse model with CRC. Lung metastasis of CRC cells was also hindered by NT5DC2 deletion in vivo. Collectively, our results indicated a previously unrecognized NT5DC2/VEGF/CCL2 axis involved in CRC development and metastasis.

Cediranib, an inhibitor of vascular endothelial growth factor receptor kinases, inhibits proliferation and invasion of prostate adenocarcinoma cells

Prostate Cancer is the second cause of cancer-related death in men and development of metastatic castration-resistant prostate cancer (mCRPC) is the major reason for its high mortality rate. Despite various treatments, all patients succumb to resistant disease, suggesting that there is a pressing need for novel and more efficacious treatments. Members of the vascular endothelial growth factor (VEGF) family play key roles in the tumorigenesis of mCRPC, indicating that VEGF-targeted therapies may have potential anti-tumor efficacy in this malignancy. However, due to compensatory activation of other family members, clinical trials with single-targeted VEGF inhibitors were discouraging. Here, we determined the anti-neoplastic activity of Cediranib, a pan-VEGF receptor inhibitor, in the mCRPC cell lines. Anti-growth effects of Cediranib were studied by MTT and BrdU cell proliferation assays and crystal violet staining. Annexin V/PI, radiation therapy and cell motility assays were carried out to examine the effects of Cediranib on apoptosis, radio-sensitivity and cell motility. Quantitative reverse transcription-PCR (qRT-PCR) and Western blot analyses were conducted to determine the molecular mechanisms underlying the anti-tumor activity of Cediranib. Cediranib decreased cell viability and induced apoptosis via inhibition of the anti-apoptotic proteins. Combination with Cediranib synergistically increased Docetaxel sensitivity and potentiated the effects of radiation therapy. Furthermore, Cediranib impaired cell motility via decrease in the expression of the epithelial-to-mesenchymal transition markers. These findings suggest that Cediranib may have anti-tumor activity in mCRPC cells and warrant further investigation on the therapeutic activity of this pan-VEGF receptor inhibitor in mCRPC.

Antitumor effects of aconitine in A2780 cells via estrogen receptor β‑mediated apoptosis, DNA damage and migration

Ovarian cancer (OVCA) is the deadliest type of malignant gynecological disease, and previous studies have demonstrated that estrogen receptor β (ERβ) serves important roles in this disease. Aconitine, a toxin produced by the Aconitum plant, displays potent effects against cancers. The aim of the study was to investigate the pharmacological activities and mechanisms of aconitum on OVCA. In the present study, the activity of aconitine in the human OVCA A2780 cell line was investigated. The results revealed that aconitine suppressed cell viability, colony formation and motility. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling, mitochondria membrane potential and comet assays showed that aconitine induced mitochondria apoptosis and DNA damage in A2780 cells. Investigation of the mechanism revealed that a high expression of ERβ and prolyl hydroxylase 2 was detected after aconitine treatment, and aconitine significantly suppressed the expression of vascular endothelial growth factor and hypoxia-inducible factor 1α to activate ERβ signaling. Moreover, the expression levels of p53, Bax, apoptotic peptidase activating factor 1, cytochrome C, cleaved caspase-3/9 and cleaved poly (ADP-ribose) polymerase were upregulated, and the expression levels of Bcl-2, Bcl-xl and phosphorylated ATM serine/threonine kinase were downregulated by aconitine. Interestingly, aconitine also markedly downregulated the expression of matrix metalloproteinase 2 (MMP2) and MMP9, which are associated with tumor invasion. In addition, a molecular docking assay revealed that aconitine exerted strong affinity towards ERβ mainly through hydrogen bonding and hydrophobic effects. Collectively, these results suggested that aconitine suppressed OVCA cell growth by adjusting ERβ-mediated apoptosis, DNA damage and migration, which should be considered a potential option for the future treatment of OVCA.