Design, synthesis and biological evaluation of novel modified dual-target shikonin derivatives for colorectal cancer treatment

Comprehensive analysis of the antibacterial activity of 5,8-dihydroxy-1,4-naphthoquinone derivatives against methicillin-resistant Staphylococcus aureus

Given the increasing concern regarding antibacterial resistance, the antimicrobial properties of naphthoquinones have recently attracted significant attention. While 1,4-naphthoquinone and its derivatives have been extensively studied, the antibacterial properties of 5,8-dihydroxy-1,4-naphthoquinone derivatives remain relatively unexplored. This study presents a comprehensive in vitro and in vivo analysis of the antibacterial activity of 35 naturally sourced and chemically synthesized derivatives of 5,8-dihydroxy-1,4-naphthoquinone. Kirby-Bauer antibiotic testing identified three compounds with activity against methicillin-resistant Staphylococcus aureus (MRSA), with one compound (PNP-02) demonstrating activity comparable to vancomycin in minimum inhibitory concentration, minimum bactericidal concentration (MBC), and time-kill assays. Microscopic and biochemical analyses revealed that PNP-02 adversely affects the cell wall and cell membrane of MRSA. Mechanistic investigations, including proteomic sequencing analyses, Western blotting, and RT-qPCR assays, indicated that PNP-02 compromises cell membrane integrity by inhibiting arginine biosynthesis and pyrimidine metabolism pathways, thereby increasing membrane permeability and inducing bacterial death. In an in vivo mouse model of skin wound healing, PNP-02 exhibited antibacterial efficacy similar to vancomycin. The compound demonstrated low toxicity to cultured human cells and in hemolysis assays and remained stable during serum incubation. These findings suggest that PNP-02 possesses promising bioactivity against MRSA and represents a potential novel antibacterial agent.

Novel Phenoxyacetic Acid (4-Aminophenoacetic Acid) Shikonin Ester Kills KRAS Mutant Colon Cancer Cells via Targeting the Akt Allosteric Site

The PI3K-Akt axis is abnormally activated in KRAS-mutated colorectal cancer and is considered to be a potential therapeutic target. A novel series of phenoxyacetic acid (4-aminophenoacetic acid) shikonin esters was designed by computer-aided drug design (CADD) and synthesized as Akt allosteric inhibitors. Most compounds exhibited greater anti-proliferative activity compared to the positive control MK2206, while also demonstrating lower cytotoxicity against normal cells than shikonin. One of the promising candidates, L8, was selected for further biological evaluation. Docking studies indicated that L8 effectively bound to the allosteric site of Akt through hydrophobic and hydrogen interactions. Enzyme activity and kinetics assessments revealed that L8 bound to Akt with a Kd of 2.07 × 10-6 M and inhibited its activity. Further intracellular assays, including western blotting, enzyme activity assay, flow cytometry, etc., verified that L8 mediated the death of two KRAS-mutant colon cancer cell lines HCT116 (KRASG13D) and HCT-8 (KRASG12A) cells by inactivating Akt, causing tumor cell apoptosis, cell cycle arrest, and interfering with tumor cell invasion and metabolism. A 3D-QSAR model was constructed to understand the relationship between the structure of the shikonin derivatives and their anti-proliferative activity. The in silico ADMET and toxicity prediction studies revealed a few undesired pharmacokinetic attributes of our compounds.

CTHRC1: a key player in colorectal cancer progression and immune evasion

The multifunctional secreted protein, collagen triple helix repeat containing 1 (CTHRC1), has recently emerged as a significant focus within oncology research. CTHRC1 expression in tumors is governed by a complex interplay of regulatory signals, including methylation, glycosylation, and notably, non-coding RNAs, which constitute its predominant regulatory mechanism. Colorectal cancer (CRC), a highly prevalent epithelial malignancy, sees CTHRC1 influencing tumor progression and metastasis through its modulation of several downstream signaling cascades, such as Wnt/PCP, TGF-β/Smad, and MEK/ERK pathways. Furthermore, CTHRC1 contributes to immune evasion in CRC via diverse mechanisms. It is intricately associated with macrophage phenotypic switching within the tumor microenvironment (TME), favoring M2 macrophage polarization and facilitating the infiltration of T cells and neutrophils. CTHRC1 is also instrumental in immune escape by driving the remodeling of the extracellular matrix through interactions with cancer-associated fibroblasts. Additionally, CTHRC1's roles extend to the regulation of hypoxia-related pathways, metabolism of glycolysis and fatty acids, and involvement in tumor angiogenesis, all of which support tumor immune evasion. Considering its multifaceted activities, CTHRC1 emerges as a promising therapeutic target in CRC, with the potential to enhance the outcomes of existing radiotherapeutic and immunotherapeutic regimens. This review endeavors to delineate the mechanistic and therapeutic landscapes of CTHRC1 in CRC. Through a comprehensive discussion of CTHRC1's diverse functions, we aim to provide insights that could pave the way for innovative approaches in cancer therapy.

Deoxyshikonin triggers apoptosis in cervical cancer cells through p38 MAPK-mediated caspase activation

Deoxyshikonin (DSK) is a biological component derived from Lithospermum erythrorhizon. Although DSK possesses potential anticancer activities, whether DSK exerts anticancer effects on cervical cancer cells is incompletely explored. This study was aimed to investigate the anticancer activity of DSK against cervical cancer cells and its molecular mechanisms. Cell viability was evaluated by MTT assay. Level of phosphorylation and protein was determined using Western blot. Involvement of signaling kinases was assessed by specific inhibitors. Our results revealed that DSK reduced viability of human cervical cell in a dose-dependent fashion. Meanwhile, DSK significantly elicited apoptosis of HeLa and SiHa cells. Apoptosis microarray was used to elucidate the involved pathways, and the results showed that DSK dose-dependently diminished cellular inhibitor of apoptosis protein 1 (cIAP1), cIAP2, and XIAP, and induced cleavage of poly(ADP-ribose) polymerase (PARP) and caspase-8/9/3. Furthermore, we observed that DSK significantly triggered activation of ERK, JNK, and p38 MAPK (p38), and only inhibition of p38 diminished the DSK-mediated pro-caspases cleavage. Taken together, our results demonstrate that DSK has anti-cervical cancer effects via the apoptotic cascade elicited by downregulation of IAPs and p38-mediated caspase activation. This suggests that DSK could act as an adjuvant to facilitate cervical cancer management.

Unlocking the potential of 1,4-naphthoquinones: A comprehensive review of their anticancer properties

Cancer encompasses a group of pathologies with common characteristics, high incidence, and prevalence in all countries. Although there are treatments available for this disease, they are not always effective or safe, often failing to achieve the desired results. This is why it is necessary to continue the search for new therapies. One of the strategies for obtaining new antitumor drugs is the use of 1,4-naphthoquinone as a scaffold in synthetic or natural products with antitumor activity. This review focuses on compiling studies related to the antitumor activity of 1,4-naphthoquinone and its natural and synthetic derivatives over the last 10 years. The work describes the main natural naphthoquinones with antitumor activity and classifies the synthetic naphthoquinones based on the structural modifications made to the scaffold. Additionally, the formation of metal complexes using naphthoquinones as a ligand is considered. After a thorough review, 197 synthetic compounds with potent biological activity against cancer have been classified according to their chemical structures and their mechanisms of action have been described.

Atractylenolide II Suppresses Glycolysis and Induces Apoptosis by Blocking the PADI3-ERK Signaling Pathway in Endometrial Cancer Cells

Atractylenolide II (AT-II), the major bioactive compound of Atractylodes macrocephala, exhibits anti-cancer activity against many types of tumors, but the roles and the potential mechanisms in endometrial cancer remain unclear. In the present study, AT-II treatment was found to significantly suppress RL95-2 and AN3CA cell proliferation and glycolysis, and induced their apoptosis by inactivating the ERK signaling pathway, accompanied by the changing expression of the glycolytic key enzymes and apoptotic-related proteins. Peptidyl arginine deiminase 3 (PADI3), as the candidate target gene of AT-II, was highly expressed in the endometrial cancer tissues and associated with a poor prognosis according to bioinformatics analysis. PADI3 knockdown inhibited proliferation and glycolysis in endometrial cancer cells and induced cell apoptosis. Furthermore, AT-II negatively regulated the expression of PADI3, and PADI3 overexpression reversed the effects of AT-II on endometrial cancer cells. Our findings suggested that the anti-cancer function of AT-II is associated with the suppression of glycolysis and induction of apoptosis by blocking the PADI3-ERK signaling pathway. Thus, AT-II represents a novel therapeutic target for endometrial cancer and targeting AT-II may serve as a potential strategy for the clinical therapy of endometrial cancer.

Glycometabolic reprogramming in cementoblasts: A vital target for enhancing cell mineralization

Cementum, a constituent part of periodontal tissues, has important adaptive and reparative functions. It serves to attach the tooth to alveolar bone and acts as a barrier delimit epithelial growth and bacteria evasion. A dynamic and highly responsive cementum is essential for maintaining occlusal relationships and the integrity of the root surface. It is a thin layer of mineralized tissue mainly produced by cementoblasts. Cementoblasts are osteoblast-like cells essential for the restoration of periodontal tissues. In recent years, glucose metabolism has been found to be critical in bone remodeling and osteoblast differentiation. However, the glucose metabolism of cementoblasts remains incompletely understood. First, immunohistochemistry staining and in vivo tracing with 18 F-fluorodeoxyglucose (18 F-FDG) revealed significantly higher glucose metabolism in cementum formation. To test the bioenergetic pathways of cementoblast differentiation, we compared the bioenergetic profiles of mineralized and unmineralized cementoblasts. As a result, we observed a significant increase in the consumption of glucose and production of lactate, coupled with the higher expression of glycolysis-related genes. However, the expression of oxidative phosphorylation-related genes was downregulated. The verified results were consistent with the RNA sequencing results. Likewise, targeted energy metabolomics shows that the levels of glycolytic metabolites were significantly higher in the mineralized cementoblasts. Seahorse assays identified an increase in glycolytic flux and reduced oxygen consumption during cementoblast mineralization. Apart from that, we also found that lactate dehydrogenase A (LDHA), a key glycolysis enzyme, positively regulates the mineralization of cementoblasts. In summary, cementoblasts mainly utilized glycolysis rather than oxidative phosphorylation during the mineralization process.