2-Methoxyestradiol, a promising anticancer agent

Inhibition of STAT3 by 2-Methoxyestradiol suppresses M2 polarization and protumoral functions of macrophages in breast cancer

BACKGROUND

Breast cancer metastasis remains the leading cause of cancer-related deaths in women worldwide. Infiltration of tumor-associated macrophages (TAMs) in the tumor stroma is known to be correlated with reduced overall survival. The inhibitors of TAMs are sought after for reprogramming the tumor microenvironment. Signal transducer and activator of transcription 3 (STAT3) is well known to contribute in pro-tumoral properties of TAMs. 2-Methoxyestradiol (2ME2), a potent anticancer and antiangiogenic agent, has been in clinical trials for treatment of breast cancer. Here, we investigated the potential of 2ME2 in modulating the pro-tumoral effects of TAMs in breast cancer.

METHODS

THP-1-derived macrophages were polarized to macrophages with or without 2ME2. The effect of 2ME2 on macrophage surface markers and anti-inflammatory genes was determined by Western blotting, flow cytometry, immunofluorescence, qRT‒PCR. The concentration of cytokines secreted by cells was monitored by ELISA. The effect of M2 macrophages on malignant properties of breast cancer cells was determined using colony formation, wound healing, transwell, and gelatin zymography assays. An orthotopic model of breast cancer was used to determine the effect of 2ME2 on macrophage polarization and metastasis in vivo.

RESULTS

First, our study found that polarization of monocytes to alternatively activated M2 macrophages is associated with the reorganization of the microtubule cytoskeleton. At lower concentrations, 2ME2 treatment depolymerized microtubules and reduced the expression of CD206 and CD163, suggesting that it inhibits the polarization of macrophages to M2 phenotype. However, the M1 polarization was not significantly affected at these concentrations. Importantly, 2ME2 inhibited the expression of several anti-inflammatory cytokines and growth factors, including CCL18, TGF-β, IL-10, FNT, arginase, CXCL12, MMP9, and VEGF-A, and hindered the metastasis-promoting effects of M2 macrophages. Concurrently, 2ME2 treatment reduced the expression of CD163 in tumors and inhibited lung metastasis in the orthotopic breast cancer model. Mechanistically, 2ME2 treatment reduced the phosphorylation and nuclear translocation of STAT3, an effect which was abrogated by colivelin.

CONCLUSIONS

Our study presents novel findings on mechanism of 2ME2 from the perspective of its effects on the polarization of the TAMs via the STAT3 signaling in breast cancer. Altogether, the data supports further clinical investigation of 2ME2 and its derivatives as therapeutic agents to modulate the tumor microenvironment and immune response in breast carcinoma.

Exploration and biological evaluation of 20-vinyl pregnenes: A step forward toward selective modulators of the estrogen receptor α signaling for breast cancer treatment

A series of D-ring modified steroids bearing a vinyl ketone pendant were synthesized and evaluated for antiproliferative activity against breast cancer cell line and cytochromes P450. The lead compound, 21-vinyl 20-keto-pregnene (2f) (IC50 = 2.4 µM), was shown to be a promising candidate for future anticancer drug design, particularly against estrogen receptor α (ERα)-positive breast cancer. The lead compound was found to have a significant effect on the signaling pathways in parental and 4-hydroxytamoxifen-resistant cells. Compound 2f modulated the ERK, cyclin D1, and CDK4 pathways and blocked the expression of ERα, the main driver of breast cancer growth. Compound 2f significantly reduced 17β-estradiol-induced progesterone receptor expression. Accumulation of cleaved poly(ADP-ribose) polymerase in cells treated with compound 2f indicated induction of apoptosis. The selectivity analysis showed that lead compound 2f produces no significant effects on cytochromes P450, CYP19A1, CYP21A2, and CYP7B1.

Targeting an Old Foe for Cancer: A Molecular Dynamics Perspective to Unravel the Specific Binding Nature of 2-Methoxy Estradiol to Human β-Tubulin Isotypes

Microtubules, composed of α- and β-tubulin subunits are crucial for cell division with their dynamic tissue-specificity which is dictated by expression of isotypes. These isotypes differ in carboxy-terminal tails (CTTs), rich in negatively charged acidic residues in addition to the differences in the composition of active site residues. 2-Methoxy estradiol (2-ME) is the first antimicrotubule agent that showed less affinity toward hemopoietic-specific β1 isotype consequently preventing myelosuppression toxicity. The present study focuses on the MD-directed conformational analysis of 2-ME and estimation of its binding affinity in the colchicine binding pocket of various β-tubulin isotypes combined with the α-tubulin isotype, α1B. AlphaFold 2.0 was used to predict the 3D structure of phylogenetically divergent human β-tubulin isotypes in dimer form with α1B. The dimeric complexes were subjected to induced-fit docking with 2-ME. The statistical analysis of docking showed differences in the binding characteristics of 2-ME with different isotypes. The replicas of atom-based molecular dynamic simulations of the best conformation of 2-ME provided insights into the molecular-level details of its binding pattern across the isotypes. Furthermore, the MM/GBSA analyses revealed the specific binding energy profile of 2-ME in β-tubulin isotypes. It also highlighed, 2-ME exhibits the lowest binding affinity toward the β1 isotype as supported by experimental study. The present study may offer useful information for designing next-generation antimicrotubule agents that are more specific and less toxic.

Optical coherence tomography for multicellular tumor spheroid category recognition and drug screening classification via multi-spatial-superficial-parameter and machine learning

Optical coherence tomography (OCT) is an ideal imaging technique for noninvasive and longitudinal monitoring of multicellular tumor spheroids (MCTS). However, the internal structure features within MCTS from OCT images are still not fully utilized. In this study, we developed cross-statistical, cross-screening, and composite-hyperparameter feature processing methods in conjunction with 12 machine learning models to assess changes within the MCTS internal structure. Our results indicated that the effective features combined with supervised learning models successfully classify OVCAR-8 MCTS culturing with 5,000 and 50,000 cell numbers, MCTS with pancreatic tumor cells (Panc02-H7) culturing with the ratio of 0%, 33%, 50%, and 67% of fibroblasts, and OVCAR-4 MCTS treated by 2-methoxyestradiol, AZD1208, and R-ketorolac with concentrations of 1, 10, and 25 µM. This approach holds promise for obtaining multi-dimensional physiological and functional evaluations for using OCT and MCTS in anticancer studies.

2-Methoxyestradiol and Hydrogen Peroxide as Promising Biomarkers in Parkinson's Disease

Estrogens function in numerous physiological processes including controlling brain cell growth and differentiation. 2-Methoxestradiol (2-ME2), a 17β-estradiol (E2) metabolite, is known for its anticancer effects as observed both in vivo and in vitro. 2-ME2 affects all actively dividing cells, including neurons. The study aimed to determine whether 2-ME2 is a potentially cancer-protective or rather neurodegenerative agent in a specific tissue culture model as well as a clinical setup. In this study, 2-ME2 activity was determined in a Parkinson's disease (PD) in vitro model based on the neuroblastoma SH-SY5Y cell line. The obtained results suggest that 2-ME2 generates nitro-oxidative stress and controls heat shock proteins (HSP), resulting in DNA strand breakage and apoptosis. On the one hand, it may affect intensely dividing cells preventing cancer development; however, on the other hand, this kind of activity within the central nervous system may promote neurodegenerative diseases like PD. Thus, the translational value of 2-ME2's neurotoxic activity in a PD in vitro model was also investigated. LC-MS/MS technique was used to evaluate estrogens and their derivatives, namely, hydroxy and methoxyestrogens, in PD patients' blood, whereas the stopped-flow method was used to assess hydrogen peroxide (H2O2) levels. Methoxyestrogens and H2O2 levels were increased in patients' blood as compared to control subjects, but hydoxyestrogens were simultaneously decreased. From the above, we suggest that the determination of plasma levels of methoxyestrogens and H2O2 may be a novel PD biomarker. The presented research is the subject of the pending patent application "The use of hydrogen peroxide and 17β-estradiol and its metabolites as biomarkers in the diagnosis of neurodegenerative diseases," no. P.441360.

Effect of 2-methoxyestradiol treatment on early- and late-stage breast cancer progression in a mouse model

The prevalence of breast cancer (BC) continues to increase and is the leading cause of cancer deaths in many countries. Numerous in vitro and in vivo studies have demonstrated that 2-methoxyestradiol (2-ME) has antiproliferative and antiangiogenic effects in BC, thereby inhibiting tumour growth and metastasis. We compared the effect of 2-ME in early- and late-stage BC using a transgenic mouse model-FVB/N-Tg(MMTV-PyVT)-of spontaneously development of aggressive mammary carcinoma with lung metastasis. Mice received 100 mg/kg 2-ME treatment immediately when palpable mammary tumours were identified (early-stage BC; Experimental group 1) and 28 days after palpable mammary tumours were detected (late-stage BC; Experimental group 2). 2-ME was administered via oral gavage three times a week for 28 days after initiation of treatment, whereas control mice received the vehicle containing 10% dimethyl sulfoxide and 90% sunflower oil for the same duration as the treatment group. Mammary tumours were measured weekly over the 28 days and at termination, blood, mammary and lung tissue were collected for analysis. Mice with a tumour volume threshold of 4000 mm3 were killed before the treatment regime was completed. 2-ME treatment of early-stage BC led to lower levels of mammary tumour necrosis, whereas tumour mass and volume were increased. Additionally, necrotic lesions and anti-inflammatory CD163-expressing cells were more frequent in pulmonary metastatic tumours in this group. In contrast, 2-ME treatment of late-stage BC inhibited tumour growth over the 28-day period and resulted in increased CD3+ cell number and tumour necrosis. Furthermore, 2-ME treatment slowed down pulmonary metastasis but did not increase survival of late-stage BC mice. Besides late-stage tumour necrosis, none of the other results were statistically significant. This study demonstrates that 2-ME treatment has an antitumour effect on late-stage BC, however, with no increase in survival rate, whereas the treatment failed to demonstrate any benefit in early-stage BC.

Estrogens and the risk of breast cancer: A narrative review of literature

In female mammals, the development and regulation of the reproductive system and non-reproductive system are significantly influenced by estrogens (oestrogens). In addition, lipid metabolism is another physiological role of estrogens. Estrogens act through different types of receptors to introduce signals to the target cell by affecting many estrogen response elements. Breast cancer is considered mostly a hormone-dependent disease. Approximately 70% of breast cancers express progesterone receptors and/or estrogen receptors, and they are a good marker for cancer prognosis. This review will discuss estrogen metabolism and the interaction of estrogen metabolites with breast cancer. The carcinogenic role of estrogen is discussed in light of both conventional and atypical cancers susceptible to hormones, such as prostate, endometrial, and lung cancer, as we examine how estrogen contributes to the formation and activation of breast cancer. In addition, this review will discuss other factors that can be associated with estrogen-driven breast cancer.

Systematic identification of anticancer drug targets reveals a nucleus-to-mitochondria ROS-sensing pathway

Multiple anticancer drugs have been proposed to cause cell death, in part, by increasing the steady-state levels of cellular reactive oxygen species (ROS). However, for most of these drugs, exactly how the resultant ROS function and are sensed is poorly understood. It remains unclear which proteins the ROS modify and their roles in drug sensitivity/resistance. To answer these questions, we examined 11 anticancer drugs with an integrated proteogenomic approach identifying not only many unique targets but also shared ones-including ribosomal components, suggesting common mechanisms by which drugs regulate translation. We focus on CHK1 that we find is a nuclear H2O2 sensor that launches a cellular program to dampen ROS. CHK1 phosphorylates the mitochondrial DNA-binding protein SSBP1 to prevent its mitochondrial localization, which in turn decreases nuclear H2O2. Our results reveal a druggable nucleus-to-mitochondria ROS-sensing pathway-required to resolve nuclear H2O2 accumulation and mediate resistance to platinum-based agents in ovarian cancers.

Effects of xenobiotics on CYP1 enzyme-mediated biotransformation and bioactivation of estradiol

Endogenous estradiol (E2) exerts diverse physiological and pharmacological activities, commonly used for hormone replacement therapy. However, prolonged and excessive exposure to E2 potentially increases estrogenic cancer risk. Reportedly, CYP1 enzyme-mediated biotransformation of E2 is largely concerned with its balance between detoxification and carcinogenic pathways. Among the three key CYP1 enzymes (CYP1A1, CYP1A2, and CYP1B1), CYP1A1 and CYP1A2 mainly catalyze the formation of nontoxic 2-hydroxyestradiol (2-OH-E2), while CYP1B1 specifically catalyzes the formation of genotoxic 4-hydroxyestradiol (4-OH-E2). 4-OH-E2 can be further metabolized to electrophilic quinone intermediates accompanied by the generation of reactive oxygen species (ROS), triggering DNA damage. Since abnormal alterations in CYP1 activities can greatly affect the bioactivation process of E2, regulatory effects of xenobiotics on CYP1s are essential for E2-associated cancer development. To date, thousands of natural and synthetic compounds have been found to show potential inhibition and/or induction actions on the three CYP1 members. Generally, these chemicals share similar planar polycyclic skeletons, the structural motifs and substituent groups of which are important for their inhibitory/inductive efficiency and selectivity toward CYP1 enzymes. This review comprehensively summarizes these known inhibitors and/or inductors of E2-metabolizing CYP1s based on chemical categories and discusses their structure-activity relationships, which would contribute to better understanding of the correlation between xenobiotic-regulated CYP1 activities and estrogenic cancer susceptibility.

Therapeutic significance of molecular hybrids for breast cancer research and treatment

Worldwide, breast cancer is still a leading cause of cancer death in women. Indeed, over the years, several anti-breast cancer drugs have been developed; however, the complex heterogeneous nature of breast cancer disease reduces the applicability of conventional targeted therapies with the upsurge in side effects and multi-drug resistance. Molecular hybrids generated by a combination of two or more active pharmacophores emerged as a promising approach in recent years for the design and synthesis of anti-breast cancer drugs. The hybrid anti-breast cancer molecules are well known for their several advantages compared to the parent moiety. These hybrid forms of anti-breast cancer molecules demonstrated remarkable effects in blocking different pathways contributing to the pathogenies of breast cancer and improved specificity. In addition, these hybrids are patient compliant with reduced side effects and multi-drug resistance. The literature revealed that molecular hybrids are applied to discover and develop novel hybrids for various complex diseases. This review article highlights the recent progress (∼2018-2022) in developing molecular hybrids, including linked, merged, and fused hybrids, as promising anti-breast cancer agents. Furthermore, their design principles, biological potential, and future perspective are discussed. The provided information will lead to the development of novel anti-breast cancer hybrids with excellent pharmacological profiles in the future.

Straightforward synthesis of steroidal selenocyanates through oxidative umpolung selenocyanation of steroids and their antitumor activity

Straightforward access to steroidal selenocyanates in a single assembly step from steroids remains a significant challenge. However, the development of novel method for the synthesis of steroidal selenocyanates and further investigation of their bioactivities have largely lagged behind. In this work, selenocyano groups were directly introduced into the 17- or 21-position of pregnenolone, the 2-position of estradiol, and the 16-position of estrone. A total of 16 estrogen selenocyanate derivatives with diverse structures were synthesized, and the tumor cell lines closely related to the expression level of estrogen were used to investigate the inhibitory activity of the target products on tumor cell proliferation in vitro. The results revealed that the 17-selenocyano-substituted pregnenolone selenocyanate derivatives 1b-3b exhibit obvious inhibitory activity against the tested tumor cell lines. Additionally, the 2-selenocyano-substituted estradiol derivatives and 16-selenocyano-substituted estrone derivatives exhibit selective inhibitory on HeLa cell lines. Among them, 2-selenocyano-3-methoxyestradiol-17-benzoate (7e) displayed an IC₅₀ value of 4.1 µM against HeLa cells and induced programmed apoptosis in HeLa cancer cells. Furthermore, compound 7e could significantly inhibit the growth of human cervical cancer xenografts in zebrafish in vivo. This approach provides new insights for future steroid antitumor drug design.

2-Difluoromethoxy-Substituted Estratriene Sulfamates: Synthesis, Antiproliferative SAR, Antitubulin Activity, and Steroid Sulfatase Inhibition

2-Difluoromethoxyestratriene derivatives were designed to improve potency and in vivo stability of the drug candidate 2-methoxyestradiol (2ME2). Compound evaluation in vitro against the proliferation of MCF-7 and MDA MB-231 breast cancer cells, as inhibitors of tubulin polymerisation and also steroid sulfatase (STS) both in cell lysates and in whole cells, showed promising activities. In antiproliferative assays 2-difluoromethoxyestradiol was less potent than 2ME2, but its sulfamates were often more potent than their corresponding non-fluorinated analogues. The fluorinated bis-sulfamate is a promising antiproliferative agent in MCF-7 cells (GI50 0.28 μM) vs the known 2-methoxyestradiol-3,17-O,O-bissulfamate (STX140, GI50 0.52 μM), confirming the utility of our approach. Compounds were also evaluated in the NCI 60-cell line panel and the fluorinated bis-sulfamate derivative displayed very good overall activities with a sub-micromolar average GI50 . It was a very potent STS inhibitor in whole JEG-3 cells (IC50 3.7 nM) similar to STX140 (4.2 nM) and additionally interferes with tubulin assembly in vitro and colchicine binding to tubulin. An X-ray study of 2-difluoromethoxy-3-benzyloxyestra-1,3,5(10)-trien-17-one examined conformational aspects of the fluorinated substituent. The known related derivative 2-difluoromethyl-3-sulfamoyloxyestrone was evaluated for STS inhibition in whole JEG-3 cells and showed an excellent IC50 of 55 pM.

A Halogen-Atom Transfer (XAT)-Based Approach to Indole Synthesis Using Aryl Diazonium Salts and Alkyl Iodides

Indoles are among the most important N-heterocycles in pharmaceuticals. Here, we present an alternative to the classic Fischer indole synthesis based on the radical coupling between aryl diazoniums and alkyl iodides. This iron-mediated strategy features a double role for the aryl diazoniums that sequentially activate the alkyl iodides through halogen-atom transfer and then serve as radical acceptors. The process operates under mild conditions and enables the preparation of densely functionalized indoles.

NeRD: a multichannel neural network to predict cellular response of drugs by integrating multidimensional data

BACKGROUND

Considering the heterogeneity of tumors, it is a key issue in precision medicine to predict the drug response of each individual. The accumulation of various types of drug informatics and multi-omics data facilitates the development of efficient models for drug response prediction. However, the selection of high-quality data sources and the design of suitable methods remain a challenge.

METHODS

In this paper, we design NeRD, a multidimensional data integration model based on the PRISM drug response database, to predict the cellular response of drugs. Four feature extractors, including drug structure extractor (DSE), molecular fingerprint extractor (MFE), miRNA expression extractor (mEE), and copy number extractor (CNE), are designed for different types and dimensions of data. A fully connected network is used to fuse all features and make predictions.

RESULTS

Experimental results demonstrate the effective integration of the global and local structural features of drugs, as well as the features of cell lines from different omics data. For all metrics tested on the PRISM database, NeRD surpassed previous approaches. We also verified that NeRD has strong reliability in the prediction results of new samples. Moreover, unlike other algorithms, when the amount of training data was reduced, NeRD maintained stable performance.

CONCLUSIONS

NeRD's feature fusion provides a new idea for drug response prediction, which is of great significance for precise cancer treatment.

Potential of cytochrome P450, a family of xenobiotic metabolizing enzymes, in cancer therapy

SIGNIFICANCE

Targeted cancer therapy with minimal off-target consequences has shown promise for some cancer types. Although cytochrome P450 (CYP) consists of 18 families, CYP1-4 families play key role in metabolizing xenobiotics and cancer drugs. This eventually affects the process of carcinogenesis, treatment outcome, and cancer drug resistance. Differential overexpression of CYPs in transformed cells, together with phenotypic alterations in tumors, presents a potential for therapeutic intervention.

RECENT ADVANCES

Recent advances in molecular tools and information technology have helped utilize CYPs as cancer targets. The precise expression in various tumors, X-ray crystal structures, improved understanding of the structure-activity relationship, and new approaches in the development of prodrugs have supported the ongoing efforts to develop CYPs-based drugs with a better therapeutic index.

CRITICAL ISSUES

Narrow therapeutic index, off-target effects, drug resistance, and tumor heterogeneity limit the benefits of CYP-based conventional cancer therapies. In this review, we address the CYP1-4 families as druggable targets in cancer. An emphasis is given to the CYP expression, function, and the possible mechanisms that drive expression and activity in normal and transformed tissues. The strategies that inhibit or activate CYPs for therapeutic benefits are also discussed.

FUTURE DIRECTIONS

Efforts are needed to develop more selective tools that will help comprehend molecular and metabolic alterations in tumor tissues with biological end-points in relation to CYPs. This will eventually translate to developing more specific CYP inhibitors/inducers.

2-Methoxyestradiol TPGS Micelles Attenuate Cyclosporine A-Induced Nephrotoxicity in Rats through Inhibition of TGF-β1 and p-ERK1/2 Axis

The immunosuppressant cyclosporine A (CSA) has been linked to serious renal toxic effects. Although 2-methoxyestradiol (2ME) possesses a wide range of pharmacological abilities, it suffers poor bioavailability after oral administration. The purpose of this study was to evaluate the potential of 2ME loaded D-ɑ-tocopheryl polyethylene glycol succinate (TPGS) micelles to prevent CSA-induced nephrotoxicity in rats. A 2ME-TPGS was prepared and showed particle size of 44.3 ± 3.5 nm with good entrapment efficiency and spherical structures. Male Wistar rats were divided into 5 groups, namely: Control, Vehicle, CSA, CSA + 2ME-Raw, and CSA + 2ME-Nano. CSA was injected daily at a SC dose of 20 mg/kg. Both 2ME-Raw and 2ME-Nano were given daily at oral doses of 5 mg/kg. Treatments continued for three successive weeks. 2ME-TPGS exerted significant protective effects against CSA nephrotoxicity. This was evidenced in ameliorating deterioration of renal functions, attenuation of pathological changes in kidney tissues, exerting significant anti-fibrotic, antioxidant, and anti-inflammatory effects together with significant anti-apoptotic effects. Western blot analyses showed both 2ME-Raw and 2ME-Nano significantly inhibited protein expression of TGF-β1 and phospho-ERK (p-ERK). It was observed that 2ME-TPGS, in almost all experiments, exerted superior protective effects as compared with 2ME-Raw. In conclusion, 2ME loaded in a TPGS nanocarrier possesses significant protective activities against CSA-induced kidney injury in rats. This is attributable to 2ME anti-fibrotic, antioxidant, anti-inflammatory, and anti-apoptotic activities which are mediated at least partly by inhibition of TGF-β1/p-ERK axis.

CYP2S1 and CYP2W1 expression is associated with patient survival in breast cancer

The cytochrome P450 family of enzymes metabolise a wide range of compounds and play important roles in breast cancer pathogenesis due to their involvement in estrogen metabolism and the production of carcinogenic metabolites during this process. The orphan CYPs, CYP2S1, and CYP2W1 are reportedly upregulated in breast cancer. However, their expression and association with clinicopathological and survival parameters have not been previously assessed in a large cohort of breast cancers. Protein expression of CYP2S1 and CYP2W1 was assessed in early-stage invasive breast cancers (n = 1,426) using immunohistochemistry and correlated with various clinicopathological parameters and survival. mRNA expression of CYP2S1 and CYP2W1 was also assessed in the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohort. Low nuclear and cytoplasmic CYP2S1 was significantly associated with high-grade tumours (p ≤ 0.009), intermediate Nottingham prognostic index (NPI) group (p ≤ 0.025), high mitotic frequency (p ≤ 0.002), human epidermal growth factor receptor 2 (HER2)-negative disease (p ≤ 0.011), and ductal carcinoma (p ≤ 0.022). Cytoplasmic CYP2S1 was additionally associated with patients ≥50 years (p < 0.001), estrogen receptor (ER)-positive tumours (p = 0.011), and high nuclear pleomorphism (p = 0.003). Low cytoplasmic CYP2W1 was significantly associated with patients ≥50 years (p = 0.002), HER2-negative disease (p = 0.003), intermediate NPI (p = 0.013), and mitosis (p = 0.009). Low cytoplasmic CYP2S1 was significantly associated with adverse breast cancer specific survival (p = 0.034), which remained so in multivariate analysis (hazard ratio [HR]: 0.639; 95% confidence interval [CI]: 0.483-0.846; p = 0.002). Low nuclear CYP2W1 was significantly associated with adverse breast cancer specific survival (p = 0.012), with significance also maintained in multivariate analysis (HR: 0.677; 95% CI: 0.510-0.898; p = 0.007). No associations with survival were observed in the METABRIC cohort. CYP2S1 and CYP2W1 are associated with patient survival in breast cancer and may be important prognostic biomarkers.

Optimized 2-methoxyestradiol invasomes fortified with apamin: a promising approach for suppression of A549 lung cancer cells

Certain anticancer agents selectively target the nucleus of cancer cells. One such drug is 2-methoxyestradiol (2ME), which is used for treating lung cancer. To improve the therapeutic effectiveness of these agents, many new methods have been devised. 2ME was entrapped into the core of hydrophobic invasomes (INVA) covered with Phospholipon 90G and apamin (APA). The Box–Behnken statistical design was implemented to enhance the composition. Using Design-Expert software (Stat-Ease Inc., Minneapolis, MN), the INVA component quantities were optimized to obtain spherical particles with the smallest size, that is, a diameter of 167.8 nm. 2ME-INVA-APA significantly inhibited A549 cells and exhibited IC₅₀ of 1.15 ± 0.04 µg/mL, which is lower than raw 2ME (IC₅₀ 5.6 ± 0.2 µg/mL). Post 2ME-INVA-APA administration, a significant rise in cell death and necrosis was seen among the A549 cells compared to those treated with plain formula or 2ME alone. This effect was indicated by increased Bax expression and reduced Bcl-2 expression, as well as mitochondrial membrane potential loss. Moreover, the cell cycle analysis showed that 2ME-INVA-APA arrests the G2-M phase of the A549 cells. Additionally, it was observed that the micellar formulation of the drug increased the cell count in pre-G1, thereby exhibiting phenomenal apoptotic potential. Furthermore, it up-regulates caspase-9 and p53 and downregulates TNF-α and NF-κβ. Collectively, these findings showed that our optimized 2ME-INVA-APA could easily seep through the cell membrane and induce apoptosis in relatively low doses.

2-Methoxyestradiol Inhibits Radiation-Induced Skin Injuries

Radiation-induced skin injury (RISI) is a main side effect of radiotherapy for cancer patients, with vascular damage being a common pathogenesis of acute and chronic RISI. Despite the severity of RISI, there are few treatments for it that are in clinical use. 2-Methoxyestradiol (2-ME) has been reported to regulate the radiation-induced vascular endothelial-to-mesenchymal transition. Thus, we investigated 2-ME as a potent anti-cancer and hypoxia-inducible factor 1 alpha (HIF-1α) inhibitor drug that prevents RISI by targeting HIF-1α. 2-ME treatment prior to and post irradiation inhibited RISI on the skin of C57/BL6 mice. 2-ME also reduced radiation-induced inflammation, skin thickness, and vascular fibrosis. In particular, post-treatment with 2-ME after irradiation repaired the damaged vessels on the irradiated dermal skin, inhibiting endothelial HIF-1α expression. In addition to the increase in vascular density, post-treatment with 2-ME showed fibrotic changes in residual vessels with SMA⁺CD31⁺ on the irradiated skin. Furthermore, 2-ME significantly inhibited fibrotic changes and accumulated DNA damage in irradiated human dermal microvascular endothelial cells. Therefore, we suggest that 2-ME may be a potent therapeutic agent for RISI.

AHR agonistic effects of 6-PN contribute to potential beneficial effects of Hops extract

Hops (Humulus lupulus) is used as an alternative to hormone replacement therapy due to the phytoestrogen, 8-prenylnaringenin (8-PN). To examine the potential risks/benefits of hops extract and its compounds (8-PN and 6-prenylnaringenin, 6-PN), we aimed to evaluate the estrogen receptor α (ERα) and aryl hydrocarbon receptor (AHR) signaling pathways in human endometrial cancer cells. Hops extract, 8-PN and 6-PN showed estrogenic activity. Hops extract and 6-PN activated both ERα and AHR pathways. 6-PN increased the expression of the tumor suppressor gene (AHRR), and that of genes involved in the estrogen metabolism (CYP1A1, CYP1B1). Although 6-PN might activate the detoxification and genotoxic pathways of estrogen metabolism, hops extract as a whole only modulated the genotoxic pathway by an up-regulation of CYP1B1 mRNA expression. These data demonstrate the relevant role of 6-PN contained in the hops extract as potential modulator of estrogen metabolism due to its ERα and AHR agonist activity.

Microtubule Targeting Agents in Disease: Classic Drugs, Novel Roles

Microtubule-targeting agents (MTAs) represent one of the most successful first-line therapies prescribed for cancer treatment. They interfere with microtubule (MT) dynamics by either stabilizing or destabilizing MTs, and in culture, they are believed to kill cells via apoptosis after eliciting mitotic arrest, among other mechanisms. This classical view of MTA therapies persisted for many years. However, the limited success of drugs specifically targeting mitotic proteins, and the slow growing rate of most human tumors forces a reevaluation of the mechanism of action of MTAs. Studies from the last decade suggest that the killing efficiency of MTAs arises from a combination of interphase and mitotic effects. Moreover, MTs have also been implicated in other therapeutically relevant activities, such as decreasing angiogenesis, blocking cell migration, reducing metastasis, and activating innate immunity to promote proinflammatory responses. Two key problems associated with MTA therapy are acquired drug resistance and systemic toxicity. Accordingly, novel and effective MTAs are being designed with an eye toward reducing toxicity without compromising efficacy or promoting resistance. Here, we will review the mechanism of action of MTAs, the signaling pathways they affect, their impact on cancer and other illnesses, and the promising new therapeutic applications of these classic drugs.

Targeting the redox imbalance in mitochondria: A novel mode for cancer therapy

Changes in reactive oxygen species (ROS) levels affect many aspects of cell behavior. During carcinogenesis, moderate ROS production modifies gene expression to alter cell function, elevating metabolic activity and ROS. To avoid extreme ROS-activated death, cancer cells increase antioxidative capacity, regulating sustained ROS levels that promote growth. Anticancer therapies are exploring inducing supranormal, cytotoxic oxidative stress levels either inhibiting antioxidative capacity or promoting excess ROS to selectively destroy cancer cells, triggering mechanisms such as apoptosis, autophagy, necrosis, or ferroptosis. This review exemplifies pro-oxidants (natural/synthetic/repurposed drugs) and their clinical significance as cancer therapies providing revolutionary approaches.

Secosteroidal hydrazides: Promising scaffolds for anti-breast cancer agents

A convenient and selective approach to 13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazides and their N'-(het)arylmethylene derivatives was disclosed and these novel types of secosteroids were screened for cytotoxicity against hormone-dependent human breast cancer cell line MCF-7. A number of 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(het)arylmethylene]hydrazides show significant cytotoxic effect comparable or superior to that for reference drug cisplatin. Compound 3l exhibits the highest activity with the IC₅₀ value of about 2 μM and is 2.8 times more active than cisplatin. Hit 13,17-secoestra-1,3,5(10)-trien-17-oic acid [N'-(het)arylmethylene]hydrazides 3d, 3l and 3q are characterized by high cytotoxicity and good selectivity towards MCF-7 breast cancer cells. The synthesized secosteroids may be considered as new promising antitumor agents.

Cytoskeleton Reorganization in EndMT-The Role in Cancer and Fibrotic Diseases

Chronic inflammation promotes endothelial plasticity, leading to the development of several diseases, including fibrosis and cancer in numerous organs. The basis of those processes is a phenomenon called the endothelial–mesenchymal transition (EndMT), which results in the delamination of tightly connected endothelial cells that acquire a mesenchymal phenotype. EndMT-derived cells, known as the myofibroblasts or cancer-associated fibroblasts (CAFs), are characterized by the loss of cell–cell junctions, loss of endothelial markers, and gain in mesenchymal ones. As a result, the endothelium ceases its primary ability to maintain patent and functional capillaries and induce new blood vessels. At the same time, it acquires the migration and invasion potential typical of mesenchymal cells. The observed modulation of cell shape, increasedcell movement, and invasion abilities are connected with cytoskeleton reorganization. This paper focuses on the review of current knowledge about the molecular pathways involved in the modulation of each cytoskeleton element (microfilaments, microtubule, and intermediate filaments) during EndMT and their role as the potential targets for cancer and fibrosis treatment.

2-Methoxy-estradiol Loaded Alpha Lipoic Acid Nanoparticles Augment Cytotoxicity in MCF-7 Breast Cancer Cells

The therapeutic effectiveness of anticancer drugs with a selective target for the nucleus of cancer cells may be improved by experimental approaches. In this regard, the formulation of anticancer drugs is considered one of the best ways to improve their effectiveness in targeting cancerous tissues. To enhance the anticancer activity of 2-methoxy-estradiol (2 ME) for breast cancer, 2-methoxyestradiol loaded alpha lipoic acid nanoparticles have been formulated. The prepared formula was observed to be spherical with a nanometer-scale and low PDI size (.234). The entrapment efficiency of the 2ME-ALA NPs was 87.32 ± 2.21% with > 85% release of 2 ME within 24 h. There was a 1.2-fold increase in apoptosis and a 3.46-fold increase in necrosis of the MCF-7 cells when incubated with 2ME-ALA NPs when compared to control cells. This increased apoptosis was also associated with increased ROS and increased p53 expression in 2ME-ALA NPs treated cells compared to the raw-2 ME group. Evaluation of cell-cycle data showed a substantial arrest of the G2-M phase of the MCF-7 cells when incubated with 2ME-ALA NPs. At the same time, a dramatically increased number of pre-G1 cells showed the increased apoptotic potential of the 2 ME when administered via the proposed formulation. In the end, the differential upregulation of caspase-3, p53, and ROS in MCF-7 cells established the superiority of the 2ME-ALA-Ms approach in targeting breast cancer. In summary, these results demonstrate that 2ME-ALA NPs are an efficient delivery tool for controlling the growth of breast cancer cells.

Sex Differences, Estrogen Metabolism and Signaling in the Development of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a complex and devastating disease with a poor long-term prognosis. While women are at increased risk for developing PAH, they exhibit superior right heart function and higher survival rates than men. Susceptibility to disease risk in PAH has been attributed, in part, to estrogen signaling. In contrast to potential pathological influences of estrogen in patients, studies of animal models reveal estrogen demonstrates protective effects in PAH. Consistent with this latter observation, an ovariectomy in female rats appears to aggravate the condition. This discrepancy between observations from patients and animal models is often called the "estrogen paradox." Further, the tissue-specific interactions between estrogen, its metabolites and receptors in PAH and right heart function remain complex; nonetheless, these relationships are essential to characterize to better understand PAH pathophysiology and to potentially develop novel therapeutic and curative targets. In this review, we explore estrogen-mediated mechanisms that may further explain this paradox by summarizing published literature related to: (1) the synthesis and catabolism of estrogen; (2) activity and functions of the various estrogen receptors; (3) the multiple modalities of estrogen signaling in cells; and (4) the role of estrogen and its diverse metabolites on the susceptibility to, and progression of, PAH as well as their impact on right heart function.

Endogenous estrogens-breast cancer and chemoprevention

Breast cancer is the most common female malignancy and the second leading cause of cancer related deaths. It is estimated that about 40% of all cancer in women is hormonally mediated. Both estrogens and androgens play critical roles in the initiation and development of breast cancer. Estrogens influence normal physiological growth, proliferation, and differentiation of breast tissues, as well as the development and progression of breast malignancy. Breast cancer is caused by numerous endo- and exogenous risk factors. The paper presents estrogen metabolism, in particular 17β-estradiol and related hormones. The mechanisms of estrogen carcinogenesis include the participation of estrogen receptors, the genotoxic effect of the estrogen metabolites, and epigenetic processes that are also presented. The role of reactive oxygen species in breast cancer has been described. It called attention to a role of numerous signaling pathways in neoplastic transformation. Chemoprotective agents, besides other phytoestrogens, classical antioxidants, synthetic compounds, and their mechanisms of action have been shown.

Urinary oestrogen steroidome as an indicator of the risk of localised prostate cancer progression

BACKGROUND

Prostate cancer (PCa) is the most common cancer in North American men. Beyond the established contribution of androgens to disease progression, growing evidence suggest that oestrogen-related pathways might also be of clinical importance. The aim of this study was to explore the association of urinary oestrogen levels with clinical outcomes.

METHODS

Urine samples from the prospective multi-institutional PROCURE cohort were collected before RP for discovery (n = 259) and validation (n = 253). Urinary total oestrogens (unconjugated + conjugated), including oestrone and oestradiol, their bioactive and inactive catechol and methyl derivatives (n = 15), were measured using mass spectrometry (MS).

RESULTS

The median follow-up time for the discovery and replication cohorts was 7.6 and 6.5 years, respectively. Highly significant correlations between urinary oestrogens were observed; however, correlations with circulating oestrogens were modest. Our findings indicate that higher levels of urinary oestriol and 16-ketoestradiol were associated with lower risk of BCR. In contrast, higher levels of 2-methoxyestrone were associated with an increased risk of development of metastasis/deaths.

CONCLUSIONS

Our data suggest that urinary levels of oestriol and 16-ketoestradiol metabolites are associated with a more favourable outcome, whereas those of 2-methoxyestrone are associated with an elevated risk of metastasis after RP. Further studies are required to better understand the impact of oestrogens on disease biology and as easily accessible urine-based risk-stratification markers.

Sex-Steroid Signaling in Lung Diseases and Inflammation

Sex/gender difference exists in the physiology of multiple organs. Recent epidemiological reports suggest the influence of sex-steroids in modulating a wide variety of disease conditions. Sex-based discrepancies have been reported in pulmonary physiology and various chronic inflammatory responses associated with lung diseases like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and rare lung diseases. Notably, emerging clinical evidence suggests that several respiratory diseases affect women to a greater degree, with increased severity and prevalence than men. Although sex-specific differences in various lung diseases are evident, such differences are inherent to sex-steroids, which are major biological variables in men and women who play a central role to control these differences. The focus of this chapter is to comprehend the sex-steroid biology in inflammatory lung diseases and to understand the mechanistic role of sex-steroids signaling in regulating these diseases. Exploring the roles of sex-steroid signaling in the regulation of lung diseases and inflammation is crucial for the development of novel and effective therapy. Overall, we will illustrate the importance of differential sex-steroid signaling in lung diseases and their possible clinical implications for the development of complementary and alternative medicine to treat lung diseases.

Discovery of breast cancer risk genes and establishment of a prediction model based on estrogen metabolism regulation

Background

Multiple common variants identified by genome-wide association studies have shown limited evidence of the risk of breast cancer in Chinese individuals. In this study, we aimed to uncover the relationship between estrogen levels and the genetic polymorphism of estrogen metabolism-related enzymes in breast cancer (BC) and establish a risk prediction model composed of estrogen-metabolizing enzyme genes and GWAS-identified breast cancer-related genes based on a polygenic risk score.

Methods

Unrelated BC patients and healthy subjects were recruited for analysis of estrogen levels and single nucleotide polymorphisms (SNPs) in genes encoding estrogen metabolism-related enzymes. The polygenic risk score (PRS) was used to explore the combined effect of multiple genes, which was calculated using a Bayesian approach. An independent sample t-test was used to evaluate the differences between PRS scores of BC and healthy subjects. The discriminatory accuracy of the models was compared using the area under the receiver operating characteristic (ROC) curve.

Results

The estrogen homeostasis profile was disturbed in BC patients, with parent estrogens (E1, E2) and carcinogenic catechol estrogens (2/4-OHE1, 2-OHE2, 4-OHE2) significantly accumulating in the serum of BC patients. We then established a PRS model to evaluate the role of SNPs in multiple genes. PRS model 1 (M1) was established from SNPs in 6 GWAS-identified high risk genes. On the basis of M1, we added SNPs from 7 estrogen metabolism enzyme genes to establish PRS model 2 (M2). The independent sample t-test results showed that there was no difference between BC and healthy subjects in M1 (P = 0.17); however, there was a significant difference between BC and healthy subjects in M2 (P = 4.9*10^− 5). The ROC curve results showed that the accuracy of M2 (AUC = 62.18%) in breast cancer risk identification was better than that of M1 (AUC = 54.56%).

Conclusion

Estrogen and related metabolic enzyme gene polymorphisms are closely related to BC. The model constructed by adding estrogen metabolic enzyme gene SNPs has a good predictive ability for breast cancer risk, and the accuracy is greatly improved compared with that of the PRS model that only includes GWAS-identified gene SNPs.

Characterization of Signalling Pathways That Link Apoptosis and Autophagy to Cell Death Induced by Estrone Analogues Which Reversibly Depolymerize Microtubules

The search for novel anti-cancer compounds which can circumvent chemotherapeutic drug resistance and limit systemic toxicity remains a priority. 2-Ethyl-3-O-sulphamoyl-estra-1,3,5(10)15-tetraene-3-ol-17one (ESE-15-one) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16) are sulphamoylated 2-methoxyestradiol (2-ME) analogues designed by our research team. Although their cytotoxicity has been demonstrated in vitro, the temporal and mechanistic responses of the initiated intracellular events are yet to be determined. In order to do so, assays investigating the compounds' effects on microtubules, cell cycle progression, signalling cascades, autophagy and apoptosis were conducted using HeLa cervical- and MDA-MB-231 metastatic breast cancer cells. Both compounds reversibly disrupted microtubule dynamics as an early event by binding to the microtubule colchicine site, which blocked progression through the cell cycle at the G₁/S- and G₂/M transitions. This was supported by increased pRB and p27^Kip1 phosphorylation. Induction of apoptosis with time-dependent signalling involving the p-JNK, Erk1/2 and Akt/mTOR pathways and loss of mitochondrial membrane potential was demonstrated. Inhibition of autophagy attenuated the apoptotic response. In conclusion, the 2-ME analogues induced a time-dependent cross-talk between cell cycle checkpoints, apoptotic signalling and autophagic processes, with an increased reactive oxygen species formation and perturbated microtubule functioning appearing to connect the processes. Subtle differences in the responses were observed between the two compounds and the different cell lines.

Biological roles of cytochrome P450 1A1, 1A2, and 1B1 enzymes

Human cytochrome P450 enzymes (CYPs) play a critical role in various biological processes and human diseases. CYP1 family members, including CYP1A1, CYP1A2, and CYP1B1, are induced by aryl hydrocarbon receptors (AhRs). The binding of ligands such as polycyclic aromatic hydrocarbons activates the AhRs, which are involved in the metabolism (including oxidation) of various endogenous or exogenous substrates. The ligands that induce CYP1 expression are reported to be carcinogenic xenobiotics. Hence, CYP1 enzymes are correlated with the pathogenesis of cancers. Various endogenous substrates are involved in the metabolism of steroid hormones, eicosanoids, and other biological molecules that mediate the pathogenesis of several human diseases. Additionally, CYP1s metabolize and activate/inactivate therapeutic drugs, especially, anti-cancer agents. As the metabolism of drugs determines their therapeutic efficacy, CYP1s can determine the susceptibility of patients to some drugs. Thus, understanding the role of CYP1s in diseases and establishing novel and efficient therapeutic strategies based on CYP1s have piqued the interest of the scientific community.

Serine-70 phosphorylated Bcl-2 prevents oxidative stress-induced DNA damage by modulating the mitochondrial redox metabolism

Bcl-2 phosphorylation at serine-70 (S70pBcl2) confers resistance against drug-induced apoptosis. Nevertheless, its specific mechanism in driving drug-resistance remains unclear. We present evidence that S70pBcl2 promotes cancer cell survival by acting as a redox sensor and modulator to prevent oxidative stress-induced DNA damage and execution. Increased S70pBcl2 levels are inversely correlated with DNA damage in chronic lymphocytic leukemia (CLL) and lymphoma patient-derived primary cells as well as in reactive oxygen species (ROS)- or chemotherapeutic drug-treated cell lines. Bioinformatic analyses suggest that S70pBcl2 is associated with lower median overall survival in lymphoma patients. Empirically, sustained expression of the redox-sensitive S70pBcl2 prevents oxidative stress-induced DNA damage and cell death by suppressing mitochondrial ROS production. Using cell lines and lymphoma primary cells, we further demonstrate that S70pBcl2 reduces the interaction of Bcl-2 with the mitochondrial complex-IV subunit-5A, thereby reducing mitochondrial complex-IV activity, respiration and ROS production. Notably, targeting S70pBcl2 with the phosphatase activator, FTY720, is accompanied by an enhanced drug-induced DNA damage and cell death in CLL primary cells. Collectively, we provide a novel facet of the anti-apoptotic Bcl-2 by demonstrating that its phosphorylation at serine-70 functions as a redox sensor to prevent drug-induced oxidative stress-mediated DNA damage and execution with potential therapeutic implications.

Free Radicals as a Double-Edged Sword: The Cancer Preventive and Therapeutic Roles of Curcumin

Free radicals, generally composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS), are generated in the body by various endogenous and exogenous systems. The overproduction of free radicals is known to cause several chronic diseases including cancer. However, increased production of free radicals by chemotherapeutic drugs is also associated with apoptosis in cancer cells, indicating the dual nature of free radicals. Among various natural compounds, curcumin manifests as an antioxidant in normal cells that helps in the prevention of carcinogenesis. It also acts as a prooxidant in cancer cells and is associated with inducing apoptosis. Curcumin quenches free radicals, induces antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), and upregulates antioxidative protein markers-Nrf2 and HO-1 that lead to the suppression of cellular oxidative stress. In cancer cells, curcumin aggressively increases ROS that results in DNA damage and subsequently cancer cell death. It also sensitizes drug-resistant cancer cells and increases the anticancer effects of chemotherapeutic drugs. Thus, curcumin shows beneficial effects in prevention, treatment and chemosensitization of cancer cells. In this review, we will discuss the dual role of free radicals as well as the chemopreventive and chemotherapeutic effects of curcumin and its analogues against cancer.

Pharmacologic Inhibition of HIF-1α Attenuates Radiation-Induced Pulmonary Fibrosis in a Preclinical Image Guided Radiation Therapy

PURPOSE

Radiation-induced pulmonary fibrosis (RIPF) is a long-term side effect of thoracic radiation therapy. Hypoxia-induced vascular endothelial mesenchymal transition (EndMT) can occur during the development of RIPF. Here, we examined the direct contribution of endothelial HIF-1α (EC-HIF1α) on RIPF.

METHODS AND MATERIALS

An inducible Cre-lox-mediated endothelial Hif1a deletion mouse line was used to evaluate the potential of HIF-1α inhibition to suppress RIPF. To evaluate the effects of a pharmacologic HIF-1α inhibitor on RIPF after image guided radiation therapy (IGRT) for spontaneous lung adenocarcinoma, we generated conditional tdTomato; K-Ras^G12D; and p53 ^flox/flox mice to facilitate tracking of tumor cells expressing tdTomato.

RESULTS

We found that vascular endothelial-specific HIF-1α deletion shortly before radiation therapy inhibited the progression of RIPF along with reduced EndMT, whereas prolonged deletion of endothelial HIF-1α before irradiation did not. Moreover, we revealed that postirradiation treatment with the novel HIF-1α inhibitor, 2-methoxyestradiol (2-ME) could efficiently inhibit RIPF and EndMT. In addition, IGRT using primary mouse models of non-small cell lung cancer showed that combined treatment of 2-ME with ablative high-dose radiation therapy efficiently inhibited RIPF and the growth of both multifocal and single tumors, concomitantly reducing radiation-induced EndMT of normal as well as tumor regions.

CONCLUSION

These results suggest that a negative regulator of HIF-1α-mediated EndMT, such as 2-ME, may serve as a promising inhibitor of RIPF in radiation therapy.

Metabolomic Biomarkers for Detection, Prognosis and Identifying Recurrence in Endometrial Cancer

Metabolic reprogramming is increasingly recognised as one of the defining hallmarks of tumorigenesis. There is compelling evidence to suggest that endometrial cancer develops and progresses in the context of profound metabolic dysfunction. Whilst the incidence of endometrial cancer continues to rise in parallel with the global epidemic of obesity, there are, as yet, no validated biomarkers that can aid risk prediction, early detection, prognostic evaluation or surveillance. Advances in high-throughput technologies have, in recent times, shown promise for biomarker discovery based on genomic, transcriptomic, proteomic and metabolomic platforms. Metabolomics, the large-scale study of metabolites, deals with the downstream products of the other omics technologies and thus best reflects the human phenotype. This review aims to provide a summary and critical synthesis of the existing literature with the ultimate goal of identifying the most promising metabolite biomarkers that can augment current endometrial cancer diagnostic, prognostic and recurrence surveillance strategies. Identified metabolites and their biochemical pathways are discussed in the context of what we know about endometrial carcinogenesis and their potential clinical utility is evaluated. Finally, we underscore the challenges inherent in metabolomic biomarker discovery and validation and provide fresh perspectives and directions for future endometrial cancer biomarker research.

2-Methoxyestradiol inhibits high fat diet-induced obesity in rats through modulation of adipose tissue macrophage infiltration and immunophenotype

Recently, experimental studies demonstrated that 2-methoxyestradiol (2ME2) ameliorates high fat diet (HFD)-induced obesity and restores insulin sensitivity. However, the mechanisms underlying these effects are unveiled yet. The current study was undertaken to test the hypothesis that 2ME2 exerts its effects by modulating adipose tissue macrophages (ATMs) accumulation, polarization and immunophenotypes. The experiment was carried out in males Wistar rats (n = 28) for 13 consecutive weeks. In HFD-fed group; body weight, glucose intolerance, serum insulin, HOMA-IR, lipid profile and adipose tissue (AT) weight were significantly higher compared to normal standard diet (NSD)- fed rats. However, treatment of HFD-fed rats with 2ME2 (200 μg/kg/day; i.p. from the beginning of the 9th week) resulted in significant enhancements in all these parameters as compared to HFD-fed rats. Treatment with 2ME2 was associated with a significant reduction in macrophage infiltration in the AT, shifting macrophage polarization towards M2 phenotype as indicated by significant decrease in the expression of pro-inflammatory M1 macrophages markers (IL-6, IL-1β, CD11c and iNOS) and concurrent significant increase in the M2 anti-inflammatory macrophage markers (Arginase 1 and IL-10). 2ME2 ameliorates HFD-induced obesity and glucose intolerance through inhibition of ATM infiltration in AT and shifting macrophage polarization from pro-inflammatory M1 to M2 anti-inflammatory phenotypes.

Heterocyclic steroids: Efficient routes for annulation of pentacyclic steroidal pyrimidines

Steroids are components of cell membranes, signaling molecules and are a type of secondary metabolites as a result of their high impact of biological significance. The present review described the literature reports of pentacyclic steroidal pyrimidines as a type of heterocyclic steroids. The main sections included the synthesis of the investigated steroids fused at rings-A or B or D of steroid skeleton, synthesis of binary or linked-type pyrimidines, pyrimidine oxides, macromolecules and mono- or di- or tri-peptides linked-steroidal pyrimidines. Besides, the present research highlighted the biological significance of steroidal pyrimidines, in which the compounds revealed potent anticancer, antioxidant, antibacterial, and anti-Alzheimer agents. In addition, some hetero-steroids were screened for binding DNA assay and gene expression analysis. It was settled that the incorporation of pyrimidine scaffold into steroid basic skeleton is crucial for better biological results.

Design, Synthesis, and Evaluation of Novel 2-Methoxyestradiol Derivatives as Apoptotic Inducers Through an Intrinsic Apoptosis Pathway

In order to discover novel derivatives in the anti-tumor field, reported anti-tumor pharmacophores (uridine, uracil, and thymine) were combined with 2-methoxyestradiol, which has been characterized as having excellent biological properties in terms of anti-tumor activity. Thus, 20 hybrids were synthesized through etherification at the 17β-OH or 3-phenolic hydroxyl group of 2-methoxyestradiol, and evaluated for their biological activities against the human breast adenocarcinoma MCF-7 cell lines, human breast cancer MDA-MB-231 cell lines, and the normal human liver L-O2 cell lines. As a result, all the uridine derivatives and single-access derivatives of uracil/thymine possessed good anti-proliferative activity against tested tumor cells (half maximal inhibitory concentration values from 3.89 to 19.32 µM), while only one dual-access derivative (21b) of thymine possessed good anti-proliferative activity (half maximal inhibitory concentration ≈ 25 µM). Among them, the uridine derivative 11 and the single-access derivative of uracil 12a possessed good anti-proliferative selectivity against tested tumor cells. Furthermore, basic mechanism studies revealed that hybrids 11 and 12a could induce apoptosis in MCF-7 cells through mitochondrial pathway. These hybrids induced morphological changes in MCF-7 cells, causing mitochondrial depolarization. These two hybrids also had the following effects: arrest of the cell cycle at the G2 phase; up regulation of Apaf-1, Bax, and cytochrome c; down regulation of Bcl-2 and Bcl-xL for both mRNA and protein; and increase of the expression for caspase-8 and -9. Finally, apoptotic effector caspase-3 was increased, which eventually caused nuclear apoptosis at least through an intrinsic pathway in the mitochondria. Additionally, hybrids 11 and 12a could specifically bind to estradiol receptor alpha in a dose-dependent manner.

Understanding of ROS-Inducing Strategy in Anticancer Therapy

Redox homeostasis is essential for the maintenance of diverse cellular processes. Cancer cells have higher levels of reactive oxygen species (ROS) than normal cells as a result of hypermetabolism, but the redox balance is maintained in cancer cells due to their marked antioxidant capacity. Recently, anticancer therapies that induce oxidative stress by increasing ROS and/or inhibiting antioxidant processes have received significant attention. The acceleration of accumulative ROS disrupts redox homeostasis and causes severe damage in cancer cells. In this review, we describe ROS-inducing cancer therapy and the anticancer mechanism employed by prooxidative agents. To understand the comprehensive biological response to certain prooxidative anticancer drugs such as 2-methoxyestradiol, buthionine sulfoximine, cisplatin, doxorubicin, imexon, and motexafin gadolinium, we propose and visualize the drug-gene, drug-cell process, and drug-disease interactions involved in oxidative stress induction and antioxidant process inhibition as well as specific side effects of these drugs using pathway analysis with a big data-based text-mining approach. Our review will be helpful to improve the therapeutic effects of anticancer drugs by providing information about biological changes that occur in response to prooxidants. For future directions, there is still a need for pharmacogenomic studies on prooxidative agents as well as the molecular mechanisms underlying the effects of the prooxidants and/or antioxidant-inhibitor agents for effective anticancer therapy through selective killing of cancer cells.

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.

Electropermeabilization of metastatic chondrosarcoma cells from primary cell culture

Primary cell cultures are challenging, but reliable model reflecting tumor response in vitro. The study was designed to examine if the increased electropermeabilization can overcame initial drug insensitivity in chondrosarcoma cells from lung metastasis. We established a primary cell culture and evaluated the cytotoxic impact of four drugs-cisplatin (CDDP), camptothecin, 2-methoxyestradiol, and leucovorin calcium (LeuCa). After determination of parameters allowing for electropermeabilization, we performed electrochemotherapy in vitro with the least toxic drugs-CDDP and LeuCa. Although combining CDDP and leucovorin together increased their toxicity and supported apoptosis, application of pulsed electric fields (PEFs) brought no advantage for their efficacy. The study emphasizes the need for introduction of primary cell cultures into studies on pulse electric fields as model frequently less sensitive to PEF-based treatments than continuous cell lines.

Discovery of chalcone-modified estradiol analogs as antitumour agents that Inhibit tumour angiogenesis and epithelial to mesenchymal transition

Angiogenesis plays an essential role in tumourigenesis and tumour progression, and anti-angiogenesis therapies have shown promising antitumour effects in solid tumours. 2-Methoxyestradiol (2ME2), an endogenous metabolite of estradiol, has been regarded as a potential antitumour agent mainly targeting angiogenesis. Here we synthesized a novel series of chalcones based on 2-methoxyestradiol and evaluated their potential activities against tumours. Compound 11e was demonstrated to have potent antiangiogenic activity. Further studies showed that 11e suppressed tumour growth in human breast cancer (MCF-7) xenograft models without obvious side effects. Evaluation of the mechanism revealed that 11e targeted the epithelial to mesenchymal transition (EMT) process in MCF-7 cells and inhibited HUVEC migration and then contributed to hindrance of angiogenesis. Thus, 11e may be a promising antitumour agent with excellent efficacy and low toxicity.

2-Methoxyestradiol attenuates liver fibrosis in mice: implications for M2 macrophages

Liver fibrosis is a major health problem worldwide due to its serious complications including cirrhosis and liver cancer. 2-Methoxyestradiol (2-ME) is an end metabolite of estradiol with anti-proliferative, antioxidant, and anti-inflammatory activities. However, the protective role of 2-ME in liver fibrosis has not been fully investigated. The aim of this study was to determine the protective effect of 2-ME in carbon tetrachloride (CCl₄)-induced liver fibrosis in mice. Animals were injected intraperitoneally with CCl₄ twice weekly for 6 weeks. 2-ME 50 mg/kg or 100 mg/kg was administrated intraperitoneally every day over the same period. Our data showed that 2-ME reduced the extent of liver toxicity and fibrosis due to CCl₄ exposure. It restored the elevated serum liver enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) levels and ameliorated oxidative status. In addition, 2-ME significantly reduced collagen deposition and alpha-smooth muscle actin (α-SMA) protein expressions. Furthermore, 2-ME markedly lowered macrophage infiltration and macrophage alternative activation marker chitinase-like molecules (CHI3L3/YM1). The results of this study indicate an important protective activity of 2-ME in liver fibrosis and highlight the role of macrophage recruitment and alternative activation as a possible target.

Synthesis of Artemisinin-Estrogen Hybrids Highly Active against HCMV, P. falciparum, and Cervical and Breast Cancer

Artemisinin-estrogen hybrids were for the first time both synthesized and investigated for their in vitro biological activity against malaria parasites (Plasmodium falciparum 3D7), human cytomegalovirus (HCMV), and a panel of human malignant cells of gynecological origin containing breast (MCF7, MDA-MB-231, MDA-MB-361, T47D) and cervical tumor cell lines (HeLa, SiHa, C33A). In terms of antimalarial efficacy, hybrid 8 (EC50 = 3.8 nM) was about two times more active than its parent compound artesunic acid (7) (EC50 = 8.9 nM) as well as the standard drug chloroquine (EC50 = 9.8 nM) and was, therefore, comparable to the clinically used dihydroartemisinin (6) (EC50 = 2.4 nM). Furthermore, hybrids 9-12 showed a strong antiviral effect with EC50 values in the submicromolar range (0.22-0.38 μM) and thus possess profoundly stronger anti-HCMV activity (approximately factor 25) than the parent compound artesunic acid (7) (EC50 = 5.41 μM). These compounds also exerted a higher in vitro anti-HCMV efficacy than ganciclovir used as the standard of current antiviral treatment. In addition, hybrids 8-12 elicited substantially more pronounced growth inhibiting action on all cancer cell lines than their parent compounds and the reference drug cisplatin. The most potent agent, hybrid 12, exhibited submicromolar EC50 values (0.15-0.93 μM) against breast cancer and C33A cell lines.

Synthesis, molecular modeling and biological evaluation of potent analogs of 2-methoxyestradiol

The endogenous steroid 2-methoxyestradiol (1) has attracted a great interest as a lead compound towards the development of new anti-cancer drugs. Herein, the synthesis, molecular modeling, anti-proliferative and anti-angiogenic effects of ten 2-ethyl and four 2-methoxy analogs of estradiol are reported. The ethyl group was introduced to the steroid A-ring using a novel Friedel-Crafts alkylation protocol. Several analogs displayed potent anti-proliferative activity with IC₅₀-values in the submicromolar range towards the CEM human leukemia cancer cell line. As such, all of these compounds proved to be more active than the lead compound 2-methoxyestradiol (1) in these cells. The six most cytostatic analogs were also tested as anti-angiogenic agents using an in vitro tube formation assay. The IC₅₀-values were determined to be in the range of 0.1 μM ± 0.03 and 1.1 μM ± 0.2. These six compounds were also modest inhibitors against tubulin polymerization with the most potent inhibitor was 14b (IC₅₀ = 2.1 ± 0.1 μM). Binding studies using N,N'-ethylene-bis(iodoacetamide) revealed that neither14a or 14b binds to the colchicine binding site in the tubulin protein, in contrast to 2-methoxyestradiol (1). These observations were supported by molecular modeling studies. Results from a MDA-MB-231 cell cycle assay showed that both 10e and 14b gave accumulation in the G2/M phase resulting in induction of apoptosis. The results presented herein shows that the novel analogs reported exhibit their anticancer effects via several modes of action.

The in vitro effects of a novel estradiol analog on cell proliferation and morphology in human epithelial cervical carcinoma

Background

The majority of novel chemotherapeutics target the cell cycle, aiming to effect arrest and cause apoptosis. One such agent, 2-methoxyestradiol (2ME), has been shown to possess anticancer properties against numerous cancer types, both in vitro and in vivo. Despite its promise, 2ME has exhibited limitations, including low oral bioavailability and rapid hepatic enzymatic inactivation in vivo. A novel sulphamoylated estrogen analog, 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16), was in silico-designed in our laboratory to overcome these issues. It was then synthesized by a pharmaceutical company and used in an in vitro antiproliferative effect study on a human cervical carcinoma (HeLa) cell line.

Results

Cell proliferation data obtained from the crystal violet assay and real-time cell analysis demonstrated that 0.2 μM of ESE-16 had a significant inhibitory effect on the HeLa cells 24 h post-exposure. Immunofluorescence showed that ESE-16 is a microtubule disruptor that causes cells to undergo a mitotic block. Qualitative morphological studies using polarization-optical transmitted light differential interference contrast (PlasDIC) and light microscopy revealed a decrease in cell density and an increase in the number of cells arrested in metaphase. After ESE-16 exposure, hallmarks of apoptosis were also observed, including membrane blebbing, chromatin condensation and the presence of apoptotic bodies. Flow cytometry provided quantitative results from cell cycle progression analysis, indicating cells undergoing apoptosis and cells in the G₂/M phase of the cell cycle, confirming cell cycle arrest in metaphase after ESE-16 treatment. Quantification of the ESE-16-mediated upregulation of cyclin B in HeLa cells and spectrophotometric and flow cytometric confirmation of cell death via apoptosis further confirmed the substance's impact.

Conclusion

ESE-16 exerts its antiproliferative effects through microtubule disruption, which induces a mitotic block culminating in apoptosis. This research provided information on ESE-16 as a potential antitumor agent and on cellular targets that could aid in the design of prospective microtubule-disrupting compounds. Further in vitro and in vivo investigations of this novel compound are needed.