The novel indole compound SK228 induces apoptosis and FAK/Paxillin disruption in tumor cell lines and inhibits growth of tumor graft in the nude mouse

The activity of pyrazolo[4,3-e][1,2,4]triazine and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide derivatives in monolayer and spheroid breast cancer cell cultures

In the last decade, an increasing interest in compounds containing pyrazolo[4,3-e][1,2,4]triazine moiety is observed. Therefore, the aim of the research was to synthesise a novel sulphonyl pyrazolo[4,3-e][1,2,4]triazines (2a, 2b) and pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulphonamide derivatives (3a, 3b) to assess their anticancer activity. The MTT assay showed that 2a, 2b, 3a, 3b have stronger cytotoxic activity than cisplatin in both breast cancer cells (MCF-7 and MDA-MB-231) and exhibited weaker effect on normal breast cells (MCF-10A). The obtained results showed that the most active compound 3b increased apoptosis via caspase 9, caspase 8, and caspase 3/7. It is worth to note that compound 3b suppressed NF-κB expression and promoted p53, Bax, and ROS which play important role in activation of apoptosis. Moreover, our results confirmed that compound 3b triggers autophagy through increased formation of autophagosomes, expression of beclin-1 and mTOR inhibition. Thus, our study defines a possible mechanism underlying 3b-induced anti-cancer activity against breast cancer cell lines.

Design and Synthesis of Novel β-Carboline-Bisindole Hybrids as Potential Anticancer Agents

We are reporting a short and convenient pathway for the synthesis of novel β-carboline-bisindole hybrid compounds from relatively cheap and commercially available chemicals such as tryptamine, dialdehydes and indoles. These newly designed compounds can also be prepared in high yields with the tolerance of many functional groups under mild conditions. Notably, these β-carboline-bisindole hybrid compounds exhibited some promising applications as anticancer agents against the three common cancer cell lines MCF-7 (breast cancer), SK-LU-1 (lung cancer), and HepG2 (liver cancer). The two best compounds 5 b and 5 g inhibited the aforementioned cell lines with the same IC50 range of the reference Ellipticine at less than 2 μM. A molecular docking study to gain more information about the interactions between the synthesized molecules and the kinase domain of the EGFR was performed. Therefore, this finding can have significant impacts on the development of future research in medicinal chemistry and drug discovery.

Paxillin knockout in mouse granulosa cells increases fecundity†

Paxillin is an intracellular adaptor protein involved in focal adhesions, cell response to stress, steroid signaling, and apoptosis in reproductive tissues. To investigate the role of paxillin in granulosa cells, we created a granulosa-specific paxillin knockout mouse model using Cre recombinase driven by the Anti-Müllerian hormone receptor 2 gene promoter. Female granulosa-specific paxillin knockout mice demonstrated increased fertility in later reproductive age, resulting in higher number of offspring when bred continuously up to 26 weeks of age. This was not due to increased numbers of estrous cycles, ovulated oocytes per cycle, or pups per litter, but this was due to shorter time to pregnancy and increased number of litters in the granulosa-specific paxillin knockout mice. The number of ovarian follicles was not significantly affected by the knockout at 30 weeks of age. Granulosa-specific paxillin knockout mice had slightly altered estrous cycles but no difference in circulating reproductive hormone levels. Knockout of paxillin using clustered regularly interspaced short palindromic repeat-associated protein 9 (CRISPR-Cas9) in human granulosa-derived immortalized KGN cells did not affect cell proliferation or migration. However, in cultured primary mouse granulosa cells, paxillin knockout reduced cell death under basal culture conditions. We conclude that paxillin knockout in granulosa cells increases female fecundity in older reproductive age mice, possibly by reducing granulosa cell death. This study implicates paxillin and its signaling network as potential granulosa cell targets in the management of age-related subfertility.

The Role of Paxillin Aberrant Expression in Cancer and Its Potential as a Target for Cancer Therapy

Paxillin is a multi-domain adaptor protein. As an important member of focal adhesion (FA) and a participant in regulating cell movement, paxillin plays an important role in physiological processes such as nervous system development, embryonic development, and vascular development. However, increasing evidence suggests that paxillin is aberrantly expressed in many cancers. Many scholars have also recognized that the abnormal expression of paxillin is related to the prognosis, metastases, invasion, survival, angiogenesis, and other aspects of malignant tumors, suggesting that paxillin may be a potential cancer therapeutic target. Therefore, the study of how aberrant paxillin expression affects the process of tumorigenesis and metastasis will help to develop more efficacious antitumor drugs. Herein, we review the structure of paxillin and its function and expression in tumors, paying special attention to the multifaceted effects of paxillin on tumors, the mechanism of tumorigenesis and progression, and its potential role in tumor therapy. We also hope to provide a reference for the clinical prognosis and development of new tumor therapeutic targets.

Synthesis and Characterization of Novel Thiazolidinones and Thioxothiazolidinones Derived from Substituted Indole

Based on recent discoveries concerning the numerous biological properties of thiazolidinones and thiosemicarbazones, new N-substituted heterocyclic derivatives have been designed by combining the indole ring with thioxothiazolidinone, thiazolidinone or thiosemicarbazone. Thus, a series of new thioxothiazolidinone, thiazolidinone, or thiosemicarbazone derivatives bearing indole-based moiety have been designed, synthesized, and developed in good yields.

Exploring the Mechanism of the miRNA-145/Paxillin Axis in Cell Metabolism During VEGF-A-Induced Corneal Angiogenesis

Purpose

Paxillin (PXN) is a key component of focal adhesions and plays an important role in angiogenesis. The aim of the present study was to investigate the effect of PXN in vascular endothelial growth factor A (VEGF-A)–induced angiogenesis in human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were transfected with PXN overexpression and PXN interference vectors. Biochemical detection was used to detect adenosine triphosphate and lactic acid production. The morphology of mitochondria was observed under an electron microscope, and flow cytometry was conducted to measure mitochondrial membrane potential. Transwell experiments were used to detect the migration and tube formation ability of each group of cells. The expression of hexokinase (HK)1, HK2, glucose transporter 1 (GLUT1), phosphorylated phosphatidylinositol 3-kinase (PI3K), phosphorylated AKT, and phosphorylated mechanistic target of rapamycin (mTOR) was evaluated by western blot.

Results

PXN silencing reduced the levels of lactic acid and adenosine triphosphate, downregulated HK1, HK2, and GLUT1, suppressed PI3K/AKT/mTOR signaling activation, and inhibited VEGF-A–induced mitochondria injury in VEGF-A–induced HUVECs. We also determined that miR-145-5p decreased the VEGF-A–induced expression of PXN and inhibited the invasion and angiogenesis of HUVECs. Also, miR-145-5p inhibition blocked the protective effect of PXN interference on VEGF-A–induced HUVEC injury. Furthermore, PXN interference significantly decreased lactic acid and adenosine triphosphate levels, inhibited PI3K/AKT/mTOR activation, and decreased the levels of HK1, HK2, and GLUT1 in VEGF-A-treated mouse corneal.

Conclusions

The results indicate that PXN silencing inhibited the VEGF-A–induced invasion and angiogenesis of HUVECs via regulation of cell metabolism and mitochondrial damage, suggesting that PXN may be a potential target for antiangiogenic therapies.

Inflammatory Immune Cytokine TNF-α Modulates Ezrin Protein Activation via FAK/RhoA Signaling Pathway in PMVECs Hyperpermeability

Background: One of the important pathogenesis of acute respiratory distress syndrome (ARDS) is the dysfunction of pulmonary microvascular endothelial barrier induced by a hyperinflammatory immune response. However, the potential mechanisms of such an imbalance in pulmonary microvascular endothelial cells (PMVECs) are not yet understood. Purpose: Explore the molecular mechanism of endothelial barrier dysfunction induced by inflammatory immune cytokines in ARDS, and find a therapeutic target for this syndrome. Methods: Rat PMVECs were cultured to form a monolayer. Immunofluorescence, flow cytometry, and Western blotting were selected to detect the distribution and the expression level of phosphorylated Ezrin protein and Ezrin protein. Transendothelial electrical resistance (TER) and transendothelial fluxes of fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (BSA) were utilized to measure the permeability of the cell monolayer. Ezrin short hairpin RNA (shRNA) and Ezrin 567-site threonine mutant (Ezrin^T567A) were used to examine the role of Ezrin protein and phosphorylated Ezrin protein in endothelial response induced by tumor necrosis factor-alpha (TNF-α), respectively. The function of focal adhesion kinase (FAK) and Ras homolog gene family, member A (RhoA) signaling pathways were estimated by inhibitors and RhoA/FAK shRNA in TNF-α-stimulated rat PMVECs. The activation of FAK and RhoA was assessed by Western blotting or pull-down assay plus Western blotting. Results: The TER was decreased after TNF-α treatment, while the Ezrin protein phosphorylation was increased in a time- and dose-dependent manner. The phosphorylated Ezrin protein was localized primarily at the cell periphery, resulting in filamentous actin (F-actin) rearrangement, followed by a significant decrease in TER and increase in fluxes of FITC-BSA. Moreover, FAK and RhoA signaling pathways were required in the phosphorylation of Ezrin protein, and the former positively regulated the latter. Conclusion: The phosphorylated Ezrin protein was induced by TNF-α via the FAK/RhoA signaling pathway leading to endothelial hyperpermeability in PMVECs.

Nitrogen-Containing Heterocycles as Anticancer Agents: An Overview

Background:

Cancer is spreading all over the world, and it is becoming the leading cause of major deaths. Today’s most difficult task for every researcher is to invent a new drug that can treat cancer with minimal side effects. Many factors, including pollution, modern lifestyle and food habits, exposure to oncogenic agents or radiations, enhanced industrialization, etc. can cause cancer. Treatment of cancer is done by various methods that include chemotherapy, radiotherapy, surgery and immunotherapy in combination or singly along with kinase inhibitors. Most of the anti-cancer drugs use the concept of kinase inhibition.

Objective:

The number of drugs being used in chemotherapy has heterocycles as their basic structure in spite of various side effects. Medicinal chemists are focusing on nitrogen-containing heterocyclic compounds like pyrrole, pyrrolidine, pyridine, imidazole, pyrimidines, pyrazole, indole, quinoline, oxadiazole, azole, benzimidazole, etc. as the key building blocks to develop active biological compounds. The aim of this study is to attempt to compile a dataset of nitrogen-containing heterocyclic anti-cancer drugs.

Methods:

We adopted a structural search on notorious journal publication websites and electronic databases such as Bentham Science, Science Direct, PubMed, Scopus, USFDA, etc. for the collection of peer-reviewed research and review articles for the present review. The quality papers were retrieved, studied, categorized into different sections, analyzed and used for article writing.

Conclusion:

As per FDA databases, nitrogen-based heterocycles in the drug design are almost 60% of unique small-molecule drugs. Some of the nitrogen-containing heterocyclic anti-cancer drugs are Axitinib, Bosutinib, Cediranib, Dasatanib (Sprycel®), Erlotinib (Tarceva®), Gefitinib (Iressa®), Imatinib (Gleevec®), Lapatinib (Tykerb ®), Linifanib, Sorafenib (Nexavar®), Sunitinib (Sutent®), Tivozanib, etc. In the present review, we shall focus on the overview of nitrogen-containing heterocyclic active compounds as anti-cancer agents.

Focal adhesion kinase: Insight into its roles and therapeutic potential in oesophageal cancer

Oesophageal cancer is associated with high morbidity and mortality rates because it is highly invasive and prone to recurrence and metastasis, with a five-year survival rate of <20%. Therefore, there is an urgent need for new methods aimed at improving therapeutic intervention. Several studies have shown that targeted therapy may be effective for the treatment of oesophageal cancer. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase with kinase activity and scaffolding function, could be overexpressed in a variety of solid tumours, including oesophageal cancer. FAK participates in survival, proliferation, progression, adhesion, invasion, migration, epithelial-to-mesenchymal transition, angiogenesis, DNA damage repair, and other biological processes through multiple signalling pathways in cancer cells. It plays an important role in the occurrence and development of tumours and has been linked to the prognosis of oesophageal cancer. FAK has been suggested as a potential therapeutic target in oesophageal cancer; thus, the combination of FAK inhibitors with chemotherapy, radiotherapy, and immunotherapy is expected to prolong the survival of patients. This paper presents a brief overview of the structure of FAK and its potential role in oesophageal cancer, providing a rationale for the future application of FAK inhibitors in the treatment of the disease.

Role of Indole Scaffolds as Pharmacophores in the Development of Anti-Lung Cancer Agents

Lung cancer is the leading cause of death in men and women worldwide, affecting millions of people. Between the two types of lung cancers, non-small cell lung cancer (NSCLC) is more common than small cell lung cancer (SCLC). Besides surgery and radiotherapy, chemotherapy is the most important method of treatment for lung cancer. Indole scaffold is considered one of the most privileged scaffolds in heterocyclic chemistry. Indole may serve as an effective probe for the development of new drug candidates against challenging diseases, including lung cancer. In this review, we will focus on discussing the existing indole based pharmacophores in the clinical and pre-clinical stages of development against lung cancer, along with the synthesis of some of the selected anti-lung cancer drugs. Moreover, the basic mechanism of action underlying indole based anti-lung cancer treatment, such as protein kinase inhibition, histone deacetylase inhibition, DNA topoisomerase inhibition, and tubulin inhibition will also be discussed.

One-Pot Approach for the Synthesis of Bis-indole-1,4-disubstituted-1,2,3-triazoles

A new strategy for the synthesis of bis-indoletriazoles was developed using a sequential one-pot four-step procedure via I₂ and H₂SO₄-SiO₂ catalyzed Friedel-Crafts reactions of indole with aldehyde followed by N-alkylation with propargyl bromide, azidation, and copper(I)-catalyzed azide alkyne cycloaddition (CuAAC). The reaction proceeded smoothly at room temperature in a short time, and a series of bis-indoletriazoles were obtained in good to excellent yields proving the generality of this one-pot methodology.

Breaking down Leukemia Walls: Heteronemin, a Sesterterpene Derivative, Induces Apoptosis in Leukemia Molt4 Cells through Oxidative Stress, Mitochondrial Dysfunction and Induction of Talin Expression

Heteronemin, the most abundant secondary metabolite in the sponge Hippospongia sp., exhibited potent cytotoxic activity against several cancer cell lines. It increased the percentage of apoptotic cells and reactive oxygen species (ROS) in Molt4 cells. The use of ROS scavenger, N-acetyl cysteine (NAC), suppressed both the production of ROS from mitochondria and cell apoptosis that were induced by heteronemin treatment. Heteronemin upregulated talin and phosphorylated talin expression in Molt4 cells but it only upregulated the expression of phosphorylated talin in HEK293 cells. However, pretreatment with NAC reversed these effects. Talin siRNA reversed the activation of pro-apoptotic cleaved caspases 3 and 9. On the other hand, the downstream proteins including FAK and NF-κB (p65) were not affected. In addition, we confirmed that heteronemin directly modulated phosphorylated talin expression through ROS generation resulting in cell apoptosis, but it did not affect talin/FAK complex. Furthermore, heteronemin interfered with actin microfilament and caused morphology changes. Taken together, these findings suggest that the cytotoxic effect of heteronemin is associated with oxidative stress and induction of phosphorylated talin expression. Our results suggest that heteronemin represents an interesting candidate which can be further developed as a drug lead against leukemia.

Nature-inspired design of tetraindoles: Optimization of the core structure and evaluation of structure-activity relationship

Building on the initial successful optimization of a novel series of tetraindoles, a second generation of the compounds with changes in the core phenyl ring was synthesized to improve anticancer properties. 17 new compounds with different rigidity, planarity, symmetry and degree of conjugation of their core structures to 5-hydroxyindole units were synthesized. All the compounds were fully characterized and tested against breast cancer cell line (MDA-MB-231). The results revealed that the core structure is required for activity and it should be aromatic, rigid, planar, symmetrical and conjugated for optimal activity. Compound 29, which has strong anticancer activity against various tumor-derived cell lines, including Mahlavu (hepatocellular), SK-HEP-1 (hepatic), HCT116 (colon), MIA PaCa-2 (pancreatic), H441 (lung papillary), A549 (lung), H460 (non-small cell lung) and CL1-5 (lung carcinoma) with IC50 values ranging from 0.19 to 3.50μM, was generated after series of successive optimizations. It was found to induce cell cycle arrest and apoptosis in vitro and inhibit tumor growth in the non-obese diabetic-severe combined immunodeficiency (NOD/SCID) mice bearing xenografted MIA PaCa-2 human pancreatic cancer.

Heterocyclic Anticancer Compounds: Recent Advances and the Paradigm Shift towards the Use of Nanomedicine's Tool Box

The majority of heterocycle compounds and typically common heterocycle fragments present in most pharmaceuticals currently marketed, alongside with their intrinsic versatility and unique physicochemical properties, have poised them as true cornerstones of medicinal chemistry. Apart from the already marketed drugs, there are many other being investigated for their promising activity against several malignancies. In particular, anticancer research has been capitalizing on the intrinsic versatility and dynamic core scaffold of these compounds. Nevertheless, as for any other promising anticancer drugs, heterocyclic compounds do not come without shortcomings. In this review, we provide for a concise overview of heterocyclic active compounds and families and their main applications in medicine. We shall focus on those suitable for cancer therapy while simultaneously addressing main biochemical modes of action, biological targets, structure-activity relationships as well as intrinsic limitation issues in the use of these compounds. Finally, considering the advent of nanotechnology for effective selective targeting of drugs, we shall discuss fundamental aspects and considerations on nanovectorization of such compounds that may improve pharmacokinetic/pharmacodynamic properties of heterocycles.

Tackling the Cytotoxic Effect of a Marine Polycyclic Quinone-Type Metabolite: Halenaquinone Induces Molt 4 Cells Apoptosis via Oxidative Stress Combined with the Inhibition of HDAC and Topoisomerase Activities

A marine polycyclic quinone-type metabolite, halenaquinone (HQ), was found to inhibit the proliferation of Molt 4, K562, MDA-MB-231 and DLD-1 cancer cell lines, with IC₅₀ of 0.48, 0.18, 8.0 and 6.76 μg/mL, respectively. It exhibited the most potent activity against leukemia Molt 4 cells. Accumulating evidence showed that HQ may act as a potent protein kinase inhibitor in cancer therapy. To fully understand the mechanism of HQ, we further explored the precise molecular targets in leukemia Molt 4 cells. We found that the use of HQ increased apoptosis by 26.23%–70.27% and caused disruption of mitochondrial membrane potential (MMP) by 17.15%–53.25% in a dose-dependent manner, as demonstrated by Annexin-V/PI and JC-1 staining assays, respectively. Moreover, our findings indicated that the pretreatment of Molt 4 cells with N-acetyl-l-cysteine (NAC), a reactive oxygen species (ROS) scavenger, diminished MMP disruption and apoptosis induced by HQ, suggesting that ROS overproduction plays a crucial rule in the cytotoxic activity of HQ. The results of a cell-free system assay indicated that HQ could act as an HDAC and topoisomerase catalytic inhibitor through the inhibition of pan-HDAC and topoisomerase IIα expression, respectively. On the protein level, the expression of the anti-apoptotic proteins p-Akt, NFκB, HDAC and Bcl-2, as well as hexokinase II was inhibited by the use of HQ. On the other hand, the expression of the pro-apoptotic protein Bax, PARP cleavage, caspase activation and cytochrome c release were increased after HQ treatment. Taken together, our results suggested that the antileukemic effect of HQ is ROS-mediated mitochondrial apoptosis combined with the inhibitory effect on HDAC and topoisomerase activities.

The tetraindole SK228 reverses the epithelial-to-mesenchymal transition of breast cancer cells by up-regulating members of the miR-200 family

The results of recent studies have shown that metastasis, the most common malignancy and primary cause of mortality promoted by breast cancer in women, is associated with the epithelial-to-mesenchymal transition (EMT). The results of the current study show that SK228, a novel indole containing substance, exhibits anti-cancer activity. In addition, the effects of SK228 on the regulation of EMT in breast cancer cells as well as the underlying mechanism have been explored. SK228 was observed to induce a fibroblastoid to epithelial-like change in the appearance of various breast cancer cell lines and to suppress the migration and invasion of these cancer cells in vitro. Moreover, expression of E-cadherin was found to increase following SK228 treatment whereas ZEB1 expression was repressed. Expression of other major EMT inducers, including ZEB2, Slug and Twist1, is also repressed by SK228 as a consequence of up-regulation of members of the miR-200 family, especially miR-200c. The results of animal studies demonstrate that SK228 treatment leads to effective suppression of breast cancer growth and metastasis in vivo. The observations made in this investigation show that SK228 reverses the EMT process in breast cancer cells via an effect on the miR-200c/ZEB1/E-cadherin signalling pathway. In addition, the results of a detailed analysis of the in vivo anti-cancer activities of SK228, carried out using a breast cancer xenograft animal model, show that this substance is a potential chemotherapeutic agent for the treatment of breast cancer.

Paxillin controls endothelial cell migration and tumor angiogenesis by altering neuropilin 2 expression

Although a number of growth factors and receptors are known to control tumor angiogenesis, relatively little is known about the mechanism by which these factors influence the directional endothelial cell migration required for cancer microvessel formation. Recently, it has been shown that the focal adhesion protein paxillin is required for directional migration of fibroblasts in vitro. Here, we show that paxillin knockdown enhances endothelial cell migration in vitro and stimulates angiogenesis during normal development and in response to tumor angiogenic factors in vivo. Paxillin produces these effects by decreasing expression of neuropilin 2 (NRP2). Moreover, soluble factors secreted by tumors that stimulate vascular ingrowth, including vascular endothelial growth factor (VEGF), also decrease endothelial cell expression of paxillin and NRP2, and overexpression of NRP2 reverses these effects. These results suggest that the VEGF-paxillin-NRP2 pathway could represent a new therapeutic target for cancer and other angiogenesis-related diseases.