Thiophene derivative-loaded nanoparticles mediate anticancer activity through the inhibition of kinases and microtubule assembly

A decade's overview of 2-aminothiophenes and their fused analogs as promising anticancer agents

Over the past decades, cancer has been a challenging domain for medicinal chemists as it is an international health concern. In association, small molecules such as 2-aminothiophenes and their derivatives showed significant antitumor activity through variable modes of action. Therefore, this article aims to review the advances regarding these core scaffolds over the past 10 years, where 2-aminothiophenes and their fused analogs are classified and discussed according to their biological activity and mode of action, in the interest of boosting new design pathways for medicinal chemists to develop targeted antitumor candidates.

Exploring chemical space, scaffold diversity, and activity landscape of spleen tyrosine kinase active inhibitors

This study aims to comprehensively characterize 576 inhibitors targeting Spleen Tyrosine Kinase (SYK), a non-receptor tyrosine kinase primarily found in haematopoietic cells, with significant relevance to B-cell receptor function. The objective is to gain insights into the structural requirements essential for potent activity, with implications for various therapeutic applications. Through chemoinformatic analyses, we focus on exploring the chemical space, scaffold diversity, and structure-activity relationships (SAR). By leveraging ECFP4 and MACCS fingerprints, we elucidate the relationship between chemical compounds and visualize the network using RDKit and NetworkX platforms. Additionally, compound clustering and visualization of the associated chemical space aid in understanding overall diversity. The outcomes include identifying consensus diversity patterns to assess global chemical space diversity. Furthermore, incorporating pairwise activity differences enhances the activity landscape visualization, revealing heterogeneous SAR patterns. The dataset analysed in this work has three activity cliff generators, CHEMBL3415598, CHEMBL4780257, and CHEMBL3265037, compounds with high affinity to SYK are very similar to compounds analogues with reasonable potency differences. Overall, this study provides a critical analysis of SYK inhibitors, uncovering potential scaffolds and chemical moieties crucial for their activity, thereby advancing the understanding of their therapeutic potential.

Ciprofloxacin Derivative-Loaded Nanoparticles Synergize with Paclitaxel Against Type II Human Endometrial Cancer

Combinations of chemotherapeutic agents comprise a clinically feasible approach to combat cancers that possess resistance to treatment. Type II endometrial cancer is typically associated with poor outcomes and the emergence of chemoresistance. To overcome this challenge, a combination therapy is developed comprising a novel ciprofloxacin derivative-loaded PEGylated polymeric nanoparticles (CIP2b-NPs) and paclitaxel (PTX) against human type-II endometrial cancer (Hec50co with loss of function p53). Cytotoxicity studies reveal strong synergy between CIP2b and PTX against Hec50co, and this is associated with a significant reduction in the IC50 of PTX and increased G2/M arrest. Upon formulation of CIP2b into PEGylated polymeric nanoparticles, tumor accumulation of CIP2b is significantly improved compared to its soluble counterpart; thus, enhancing the overall antitumor activity of CIP2b when co-administered with PTX. In addition, the co-delivery of CIP2b-NPs with paclitaxel results in a significant reduction in tumor progression. Histological examination of vital organs and blood chemistry was normal, confirming the absence of any apparent off-target toxicity. Thus, in a mouse model of human endometrial cancer, the combination of CIP2b-NPs and PTX exhibits superior therapeutic activity in targeting human type-II endometrial cancer.

A patent review of MAPK inhibitors (2018 - present)

INTRODUCTION

The mitogen-activated protein kinase (MAPK) family consist of p38 MAP kinases, c-Jun N-terminal kinases (JNKs) and extracellular signal-regulated kinases (ERKs). They are involved in a multitude of diseases, including inflammatory, autoimmune, neurodegenerative, and metabolic diseases as well as cancer. In recent years, further developments in the field of MAPK-inhibitors have been reported, including an isoform or downstream target selective inhibition of MAPKs as well as target protein degradation approaches.

AREAS COVERED

This review summarizes newly patented MAPK-inhibitors that were claimed between 2018 and early 2023. Presented are the patents as well as their corresponding publications, the storyline of development, and clinical trials involving these compounds. This article elaborates a total of 27 patents, which were identified using established search engines.

EXPERT OPINION

Although industrial research on MAPK-inhibitors has been ongoing for more than 20 years, novel clinical trials of MAPK-inhibitors as potential drug candidates are still being conducted in the period under review. Recently reported inhibitors show an excellent selectivity profile and are even achieving selectivity between closely related isoforms. This progression offers the possibility to eliminate unwanted side effects and may finally lead to the approval of the first MAPK-inhibitor.

Tumor microenvironment and redox dual stimuli-responsive polymeric nanoparticles for the effective cisplatin-based cancer chemotherapy

The serious side effects of cisplatin hindered its clinical application and the nanotechnology might be the potential strategy to address the limitation. However, rapid clearance in the blood circulation and ineffective controlled drug release from nanocarriers hamper the therapeutic efficacy of the nano-delivery system. We constructed a tumor microenvironment and redox dual stimuli-responsive nano-delivery system PEG-c-(BPEI-SS-Pt) by cross-linking the disulfide-containing polymeric conjugate BPEI-SS-Pt with the dialdehyde group-modified PEG₂₀₀₀via Schiff base. After optimized the cross-linking time, 72 h was selected to get the nano-delivery system.¹H NMR and drug release assays showed that under the acidic tumor microenvironment (pH 6.5-6.8), the Schiff base can be broken and detached the PEG cross-linked outer shells, displaying the capability to release the drugs with a sequential pH- and redox-responsive manner. Moreover, PEG-c-(BPEI-SS-Pt) showed more effective anti-tumor therapeutic efficacyin vivowith no significant side effects when compared with the drug of cisplatin used in the clinic. This strategy highlights a promising platform with the dual stimuli-responsive profile to achieve better therapeutic efficacy and minor side effects for platinum-based chemotherapy.

Cationic nanoparticles enhance T cell tumor infiltration and antitumor immune responses to a melanoma vaccine

In clinical settings, cancer vaccines as monotherapies have displayed limited success compared to other cancer immunotherapeutic treatments. Nanoscale formulations have the ability to increase the efficacy of cancer vaccines by combatting the immunosuppressive nature of the tumor microenvironment. Here, we have synthesized a previously unexplored cationic polymeric nanoparticle formulation using polyamidoamine dendrimers and poly(d,l-lactic-co-glycolic acid) that demonstrate adjuvant properties in vivo. Tumor-challenged mice vaccinated with an adenovirus-based cancer vaccine [encoding tumor-associated antigen (TAA)] and subsequently treated with this nanoparticulate formulation showed significant increases in TAA-specific T cells in the peripheral blood, reduced tumor burden, protection against tumor rechallenge, and a significant increase in median survival. An investigation into cell-based pathways suggests that administration of the nanoformulation at the site of the developing tumor may have created an inflammatory environment that attracted activated TAA-specific CD8⁺ T cells to the vicinity of the tumor, thus enhancing the efficacy of the vaccine.

Paclitaxel anticancer activity is enhanced by the MEK 1/2 inhibitor PD98059 in vitro and by PD98059-loaded nanoparticles in BRAFV600E melanoma-bearing mice

Melanoma, the most malignant form of skin cancer, shows resistance to traditional anticancer drugs including paclitaxel (PTX). Furthermore, over 50% of melanoma cases express the BRAF^V600E mutation which activates the MAPK pathway increasing cell proliferation and survival. In the current study, we investigated the capacity of the combination therapy of PTX and the MAPK inhibitor, PD98059, to enhance the cytotoxicity of PTX against melanoma and therefore improve treatment outcomes. Synergistic in vitro cytotoxicity was observed when soluble PTX and PD98059 were used to treat the A375 melanoma cell line as evidenced by a significant reduction in the cell viability and IC₅₀ value for PTX. Then, in further studies, TPGS-emulsified PD98059-loaded PLGA nanoparticles (NPs) were prepared, characterized in vitro and assessed for therapeutic efficacy when used in combination with soluble PTX. The average particle size (180 nm d.), zeta potential (-34.8 mV), polydispersity index (0.081), encapsulation efficiency (20%), particle yield (90.8%), and drug loading (6.633 µg/mg) of the prepared NPs were evaluated. Also, cellular uptake and in vitro cytotoxicity studies were performed with these PD98059-loaded NPs and compared to soluble PD98059. The PD98059-loaded NPs were superior to soluble PD98059 in terms of both cellular uptake and in vitro cytotoxicity in A375 cells. In in vivo studies, using A375 challenged mice, we report improved survival in mice treated with soluble PTX and PD98059-loaded NPs. Our findings suggest the potential for using this combinatorial therapy in the management of patients with metastatic melanoma harboring the BRAF mutation as a means to improve survival outcomes.