Cyclooxygenase-2 mediates gefitinib resistance in non-small cell lung cancer through the EGFR/PI3K/AKT axis

Hederagenin suppresses glioma cell biological activities via Nur77 in vitro study

The aim of this research was to discuss Hederagenin's antitumor effects on glioma by in vitro study. U251 and U87 cell lines were used as research target in our research. In the first step, the different Hed concentrations were treated to U251 and U87 cell lines, and the second step is Nur77 transfection in U251 and U87 with Hed treatment; measuring cell proliferation by MTT and EdU staining; evaluating cell invasion and migration abilities by transwell assay and relative gene and protein expressions by RT-qPCR and WB assay. Compared with NC group, U251 and U87 cell proliferation were significantly depressed with cell apoptosis significantly increasing, and cell invasion and migration abilities were significantly inhibited in Hed-treated groups (p < .05, respectively); however, with Nur77 transfection, the Hed's antitumor effects disappeared. Meanwhile, with Hed supplement, Nur77, PI3K, and AKT gene expressions were significantly downregulated (p < .05, respectively) in Hed-treated groups; and Nur77, p-PI3K, and p-AKT protein expressions were significantly decreased (p < .05, respectively) in Hed-treated groups. Hed had antitumor effects on glioma cell biological activities via Nur77/PI3K/AKT pathway in vitro study.

Integrating Network Pharmacology and Experimental Validation to Elucidate the Mechanism of Yiqi Yangyin Decoction in Suppressing Non-Small-Cell Lung Cancer

Yiqi Yangyin Decoction (YYD) is a classic traditional Chinese medicine (TCM) formulation to treat lung cancer in clinic. Nevertheless, the active ingredients, key targets, and molecular mechanisms for YYD are still poorly understood. This study is focused on elucidating the pharmacological mechanism of YYD in non-small-cell lung cancer (NSCLC) by using a combined network pharmacology approach and biological experiment validation. Online bioinformatics tools showed that 40 bioactive compounds and 229 putative targets of YYD were associated with anti-NSCLC activity. Protein-Protein Interaction (PPI) network demonstrated AKT1, SRC, JUN, TP53, and EGFR as the top five key targets for YYD against NSCLC. Through enrichment analysis, YYD was found to affect cell proliferation and apoptosis in NSCLC possibly by PI3K-AKT signaling. Molecular docking confirmed a strong binding between the main compounds (quercetin or luteolin) and EGFR. As demonstrated by CCK-8, EdU, and colony formation assays, we found a significant inhibition of YYD on cell proliferation. Moreover, YYD treatment induced cell cycle arrest by affecting p53, p21, and cyclin D1 expression. YYD administration enhanced apoptosis by changing the expression of cleaved caspase-3, Bax, and Bcl-2. Mechanistically, YYD resulted in a significant inactivation of EGFR-PI3K-AKT signaling. Furthermore, EGFR activator significantly reversed YYD-mediated proliferation inhibition and apoptosis. YYD also showed an inhibitory effect on tumor growth in mice. Together, YYD might target the EGFR-PI3K-AKT pathway to repress NSCLC progression.

Exploring the Biological Mechanism of Mammalian Phosphatidylinositol-3-Kinase/Protein Kinase B/Target of Rapamycin (PI3K/Akt/mTOR) Signaling in the Treatment of Triple-Negative Breast Cancer (TNBC)

We aimed to study the biological effect of PI3K/Akt/mTOR signal pathway on the treatment of TNBC, along with the efficiency of PI3K inhibitor BKM120, mTOR inhibitor PF-4708671 and dual inhibitor GDC-0980 on treating breast cancer in terms of proliferation and apoptosis utilizing MDA-MB-213 cell line, as well as on the expression of S6K1. The expressions of PI3K, mTOR and Akt in TNBC and paired adjacent tissues were detected by PCR. After treatment with BKM120, PF-4708671 and GDC-0980 for 24, 48, 72 and 96 hours, CCK-8 method was employed to assess the proliferation and apoptosis curves of the MDA-MB-231 cell line, the expression of S6K1 was detected by Western Blot. Expressions of PI3K, mTOR and Akt in TNBC tissues were significantly increased than those in normal specimens (P = 0.000); Compared with control group, cell proliferation treated with three inhibitors was significantly impeded, of which the inhibitory effect of PF-5708671 was slightly stronger than BKM120, while the strongest inhibitory effect was observed for GDC-0980 treatment. After 48 hours treatment, the expression intensity of p-mTOR, p-PI3K and S6K1 in MDA-MB-213 cells treated with BKM120, PF-4708671 and GDC-0980 was decreased, of which the suppression of p-mTOR, p-PI3K and S6K1 by GDC-0980 was stronger than other groups. The inclined expression of PI3K, mTOR and Akt was observed in TNBC tissues. The antagonists targeting the PI3K/Akt/mTOR signaling could inhibit the proliferation of triple-negative breast cancer cell line, of which the dual inhibitor exerted the strongest inhibition effect, and could decreased the expression of S6K1 and activity. The antagonists targeting the PI3K/Akt/mTOR signal transduction showed a promising prospect in the treatment of TNBC.

MDACT: A New Principle of Adjunctive Cancer Treatment Using Combinations of Multiple Repurposed Drugs, with an Example Regimen

In part one of this two-part paper, we present eight principles that we believe must be considered for more effective treatment of the currently incurable cancers. These are addressed by multidrug adjunctive cancer treatment (MDACT), which uses multiple repurposed non-oncology drugs, not primarily to kill malignant cells, but rather to reduce the malignant cells' growth drives. Previous multidrug regimens have used MDACT principles, e.g., the CUSP9v3 glioblastoma treatment. MDACT is an amalgam of (1) the principle that to be effective in stopping a chain of events leading to an undesired outcome, one must break more than one link; (2) the principle of Palmer et al. of achieving fractional cancer cell killing via multiple drugs with independent mechanisms of action; (3) the principle of shaping versus decisive operations, both being required for successful cancer treatment; (4) an idea adapted from Chow et al., of using multiple cytotoxic medicines at low doses; (5) the idea behind CUSP9v3, using many non-oncology CNS-penetrant drugs from general medical practice, repurposed to block tumor survival paths; (6) the concept from chess that every move creates weaknesses and strengths; (7) the principle of mass-by adding force to a given effort, the chances of achieving the goal increase; and (8) the principle of blocking parallel signaling pathways. Part two gives an example MDACT regimen, gMDACT, which uses six repurposed drugs-celecoxib, dapsone, disulfiram, itraconazole, pyrimethamine, and telmisartan-to interfere with growth-driving elements common to cholangiocarcinoma, colon adenocarcinoma, glioblastoma, and non-small-cell lung cancer. gMDACT is another example of-not a replacement for-previous multidrug regimens already in clinical use, such as CUSP9v3. MDACT regimens are designed as adjuvants to be used with cytotoxic drugs.

Hybrid Pharmacophore- and Structure-Based Virtual Screening Pipeline to Identify Novel EGFR Inhibitors That Suppress Non-Small Cell Lung Cancer Cell Growth

Dysregulated epidermal growth factor receptor (EGFR) expression is frequently observed in non-small cell lung cancer (NSCLC) growth and metastasis. Despite recent successes in the development of tyrosine kinase inhibitors (TKIs), inevitable resistance to TKIs has led to urgent calls for novel EGFR inhibitors. Herein, we report a rational workflow used to identify novel EGFR-TKIs by combining hybrid ligand- and structure-based pharmacophore models. Three types of models were developed in this workflow, including 3D QSAR-, common feature-, and structure-based EGFR-TK domain-containing pharmacophores. A National Cancer Institute (NCI) compound dataset was adopted for multiple-stage pharmacophore-based virtual screening (PBVS) of various pharmacophore models. The six top-scoring compounds were identified through the PBVS pipeline coupled with molecular docking. Among these compounds, NSC609077 exerted a significant inhibitory effect on EGFR activity in gefitinib-resistant H1975 cells, as determined by an enzyme-linked immunosorbent assay (ELISA). Further investigations showed that NSC609077 inhibited the anchorage-dependent growth and migration of lung cancer cells. Furthermore, NSC609077 exerted a suppressive effect on the EGFR/PI3K/AKT pathway in H1975 cells. In conclusion, these findings suggest that hybrid virtual screening may accelerate the development of targeted drugs for lung cancer treatment.

Identification of novel COX-2 / CYP19A1 axis involved in the mesothelioma pathogenesis opens new therapeutic opportunities

BACKGROUND

Based on previous studies highlighting that the induction of cyclooxygenase-2 (COX-2) and high prostaglandin E2 (PGE2) levels contribute to the pathogenesis of malignant pleural mesothelioma (MPM), and that aromatase (CYP19A1), an enzyme that plays a key role in estrogen biosynthesis, along with estradiol (E2) were expressed in MPM, this study aimed to investigate the possible interplay between COX-2 and CYP19A1 in the pathogenesis of mesothelioma, as well as the underlying mechanism.

METHODS

The interaction between COX-2 and CYP19A1 was first investigated on different MPM lines upon PGE2, and COX-2 inhibitor (rofecoxib) treatment by western blot, RT-PCR. The key regulatory pathways involved in the COX-2 and CYP19A1 axis were further studied in MPM cells, after rofecoxib and exemestane (CYP19A1 inhibitor) treatment in monotherapy and in combination, by cell cycle distribution, western blot, and combination index analysis. To explore the role of COX-2/CYP19A1 axis in 3D preclinical models of MPM cells, we analyzed the effect of combination of COX-2 and CYP19A1 inhibitors in mesosphere formation. Immunohistochemical analysis of MPM mesosphere and specimens was utilized to evaluate the involvement of COX-2 on the CYP19A1 activity and the relationship between E2 and COX-2.

RESULTS

PGE2 or rofecoxib treatment caused in MPM cells an increased or decreased, respectively, CYP19A1 expression at mRNA and protein levels. The effect of rofecoxib and exemestane combination in MPM cell proliferation was synergistic. Activation of caspase-3 and cleavage of PARP confirmed an apoptotic death for MPM cell lines. Increased expression levels of p53, p21, and p27, downregulation of cyclin D1 and inhibition of Akt activation (pAKT) were also found. The antagonistic effect of rofecoxib and exemestane combination found only in one cell line, was reverted by pretreatment with MK2206, a pAKT inhibitor, indicating pAKT as an actionable mediator in the COX-2-CYP19A1 axis. Reduction of size and sphere-forming efficiency in MPM spheres after treatment with both inhibitor and a decrease in COX-2 and E2 staining was found. Moreover, immunohistochemical analysis of 46 MPM samples showed a significant positive correlation between COX-2 and E2.

CONCLUSIONS

Collectively, the results highlighted a novel COX-2/CYP19A1 axis in the pathogenesis of MPM that can be pharmacologically targeted, consequently opening up new therapeutic options.

The Emerging Role of COX-2, 15-LOX and PPARγ in Metabolic Diseases and Cancer: An Introduction to Novel Multi-target Directed Ligands (MTDLs)

Emerging evidence supports an intertwining framework for the involvement of different inflammatory pathways in a common pathological background for a number of disorders. Of importance are pathways involving arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 15-lipoxygenase (15-LOX). Both enzyme activities and their products are implicated in a range of pathophysiological processes encompassing metabolic impairment leading to adipose inflammation and the subsequent vascular and neurological disorders, in addition to various pro- and antitumorigenic effects. A further layer of complexity is encountered by the disparate, and often reciprocal, modulatory effect COX-2 and 15-LOX activities and metabolites exert on each other or on other cellular targets, the most prominent of which is peroxisome proliferator-activated receptor gamma (PPARγ). Thus, effective therapeutic intervention with such multifaceted disorders requires the simultaneous modulation of more than one target. Here, we describe the role of COX-2, 15-LOX, and PPARγ in cancer and complications of metabolic disorders, highlight the value of designing multi-target directed ligands (MTDLs) modifying their activity, and summarizing the available literature regarding the rationale and feasibility of design and synthesis of these ligands together with their known biological effects. We speculate on the potential impact of MTDLs in these disorders as well as emphasize the need for structured future effort to translate these early results facilitating the adoption of these, and similar, molecules in clinical research.

Dihydroartemisinin as a Sensitizing Agent in Cancer Therapies

Cancer is one of the major threats to human health. Although humans have struggled with cancer for decades, the efficacy of treatments for most tumors is still very limited. Dihydroartemisinin (DHA) is a derivative of artemisinin, a first-line antimalarial drug originally developed in China. Beyond the anti-malarial effect, DHA has also been reported to show anti-inflammatory, anti-parasitosis, and immune-modulating properties in vitro and in vivo. Furthermore, an increasing number of studies report that DHA possesses anticancer activities on a wide range of cancer types both in vitro and in vivo, as well as enhances the efficacy of chemotherapy, targeted therapy, and even radiotherapy. However, the mechanisms of DHA on different tumors differ in various ways. In this review, we intend to summarize how DHA sensitizes cancer cells to anti-cancer therapies, highlight its molecular mechanisms and pharmacological effects in vitro and in vivo as well as in current clinical trials, and discuss potential issues concerning DHA. Hopefully, more attention will be paid to DHA as a sensitizer for cancer therapy in the future.

Antioxidative Stress: Inhibiting Reactive Oxygen Species Production as a Cause of Radioresistance and Chemoresistance

Radiotherapy and chemotherapy are the most effective nonsurgical treatments for cancer treatment. They usually induce regulated cell death by increasing the level of reactive oxygen species (ROS) in tumour cells. However, as intracellular ROS concentration increases, many antioxidant pathways are concurrently upregulated by cancer cells to inhibit ROS production, ultimately leading to drug resistance. Understanding the mechanism of antioxidant stress in tumour cells provides a new research direction for overcoming therapeutic resistance. In this review, we address (1) how radiotherapy and chemotherapy kill tumour cells by increasing the level of ROS, (2) the mechanism by which ROS activate antioxidant pathways and the subsequent cellular mitigation of ROS in radiotherapy and chemotherapy treatments, and (3) the potential research direction for targeted treatment to overcome therapeutic resistance.

LPIN1 downregulation enhances anticancer activity of the novel HDAC/PI3K dual inhibitor FK-A11

Phosphatidylinositol-3 kinase (PI3K) inhibitor and histone deacetylase (HDAC) inhibitor have been developed as potential anticancer drugs. However, the cytotoxicity of PI3K inhibitor or HDAC inhibitor alone is relatively weak. We recently developed a novel HDAC/PI3K dual inhibitor FK-A11 and confirmed its enhanced cytotoxicity when compared to that of PI3K inhibitor or HDAC inhibitor alone on several cancer cell lines. However, the in vivo antitumor activity of FK-A11 was insufficient. We conducted high-throughput RNA interfering screening and identified gene LPIN1 which enhances the cytotoxicity of FK-A11. Downregulation of LPIN1 enhanced simultaneous inhibition of HDAC and PI3K by FK-A11 and enhanced the cytotoxicity of FK-A11. Propranolol, a beta-adrenoreceptor which is also a LPIN1 inhibitor, enhanced the in vitro and in vivo cytotoxicity and antitumor effect of FK-A11. These findings should help in the development of FK-A11 as a novel HDAC/PI3K dual inhibitor.

Pulmonary Micro-Ecological Changes and Potential Microbial Markers in Lung Cancer Patients

The relationship between the microbiome and disease has been investigated for many years. As a highly malignant tumor, biomarkers for lung cancer are diverse. However, precision of these biomarkers has not yet been achieved. It has been confirmed that lung microecology changes in lung cancer patients compared with healthy individuals. Furthermore, the abundance of some bacterial species shows obvious changes, suggesting their potential use as a microbial marker for the detection of lung cancer. In addition, recent studies have confirmed that inflammation, immune response, virulence factors, and metabolism may be potential mechanisms linking the microbiome with carcinogenesis. In this review, microbiome studies of lung cancer, potential mechanisms, potential microbial markers, and the influence of the microbiome on the diagnosis and treatment of lung cancer are summarized, providing theoretical strategies for the diagnosis and treatment of lung cancer.

C-Myc Signaling Pathway in Treatment and Prevention of Brain Tumors

Brain tumors are responsible for high morbidity and mortality worldwide. Several factors such as the presence of blood-brain barrier (BBB), sensitive location in the brain, and unique biological features challenge the treatment of brain tumors. The conventional drugs are no longer effective in the treatment of brain tumors, and scientists are trying to find novel therapeutics for brain tumors. In this way, identification of molecular pathways can facilitate finding an effective treatment. c-Myc is an oncogene signaling pathway capable of regulation of biological processes such as apoptotic cell death, proliferation, survival, differentiation, and so on. These pleiotropic effects of c-Myc have resulted in much fascination with its role in different cancers, particularly brain tumors. In the present review, we aim to demonstrate the upstream and down-stream mediators of c-Myc in brain tumors such as glioma, glioblastoma, astrocytoma, and medulloblastoma. The capacity of c-Myc as a prognostic factor in brain tumors will be investigated. Our goal is to define an axis in which the c-Myc signaling pathway plays a crucial role and to provide direction for therapeutic targeting in these signaling networks in brain tumors.

Targeting c-kit inhibits gefitinib resistant NSCLC cell growth and invasion through attenuations of stemness, EMT and acquired resistance

EGFR tyrosine kinase inhibitors (TKIs) are the first-line drugs for NSCLC. But, the acquired resistance limited their efficacy, so that the patients deteriorate eventually. Therefore, it is necessary to clarify the mechanism of the acquired resistance and overcome it for effective NSCLC therapy. In this experimental study, a stable gefitinib resistant lung adenocarcinoma cell line (PC9/GR) infected with shRNA-c-kit-homo-1386 were established; c-kit siRNA and c-kit inhibitors were used to block c-kit signaling; the acquired resistance of PC9/GR cells and the effects of c-kit siRNA and c-kit inhibitors on the growth and invasion of PC9/GR cells were investigated with CCK-8 assay, colony formation and cell invasion assays in vitro; the tumor growth inhibition effects of c-kit inhibitors on PC9/GR cell generated tumors were tested in vivo; the mechanisms involved in the acquired resistance reverse, growth and invasion inhibition effects of c-kit siRNA and c-kit inhibitors on PC9/GR cells were evaluated with qRT-PCR, Western blot and immunohistochemistry staining. The proliferation, colony formation, and invasion of PC9/GR cells were decreased by c-kit siRNA and inhibitors in vitro significantly; c-kit inhibitors suppressed the tumor growth of PC9/GR cell generated tumors in vivo. In the stable shRNA-c-kit transfected PC9/GR cells, the protein expressions of c-kit signaling and stemness phenotype related proteins, including ALDH1A1, Oct4, Sox2 and ABCG2 were decreased, and EMT phenotype related protein expressions including vimentin, N-cadherin, and Slug, were downregulated and with upregulation of E-cadherin; c-kit inhibitors reduced stemness phenotype related protein expressions, downregulated EMT phenotype related protein expressions including vimentin, N-cadherin, and Slug, with upregulation of E-cadherin, and the stemness related protein expressions of c-kit, ALDH1A1, ABCG2 and EMT-related proteins of vimentin and slug were decreased in the imatinib treated tumor tissues. The findings of this study indicated that c-kit signaling mediated the acquired gefitinib resistance, cell growth, invasion, stemness and EMT phenotype of PC9/GR cells. Targeting c-kit signaling with c-kit siRNA and small molecule c-kit inhibitors might overcome the acquired gefitinib resistance, and inhibit PC9/GR cell growth in vitro and in vivo.

Trifolium Flavonoids Overcome Gefitinib Resistance of Non-Small-Cell Lung Cancer Cell by Suppressing ERK and STAT3 Signaling Pathways

Gefitinib is a tyrosine kinase inhibitor of EGFR (epidermal growth factor receptor) and represents the first-line treatment for EGFR mutation patients with NSCLC (non-small-cell lung cancer) therapeutics. However, NSCLC patients are inclined to develop acquired gefitinib drug resistance through nowadays, unarticulated mechanisms of chemoresistance. Here, we investigated the role of TF (Trifolium flavonoids) on sensitizing gefitinib resistance in NSCLC cells and revealed its potential mechanism of action. We demonstrated that TF exerted significantly potential chemosensitivity in gefitinib resistant NSCLC cells. MTT assay and cytological methods were used to analyze cell viability and apoptosis in NSCLC cell line PC-9R. Both TF and gefitinib suppressed PC-9R cell growth in a dose-dependent manner. Subtoxic concentrations of TF did significantly augment gefitinib-induced apoptosis in PC-9R cell line. The TF promoted chemosensitivity was major mediated by the PARP and caspases activation. Meanwhile, the TF promoted chemosensitivity also decreased the expression of Bcl-2 and Mcl-1. Finally, TF significantly reduced the phosphorylation levels of STAT3 and ERK. Altogether, the results of the present study indicated the potential mechanisms of chemosensitivity of TF in gefitinib-induced apoptosis of NSCLC by downregulating ERK and STAT3 signaling pathways and Bcl2 and Mcl-1 expression and a promising application of TF in therapy of NSCLC with gefitinib resistant.