A small-molecule inhibitor of MDMX suppresses cervical cancer cells via the inhibition of E6-E6AP-p53 axis

Discovery and biological evaluation of hederagenin derivatives as non-substrate inhibitors of P-glycoprotein-mediated multidrug resistance

Multidrug Resistance (MDR) is an essential cause of failure of tumor chemotherapy, and P-glycoprotein (P-gp) overexpression is one of the major causes of MDR in tumor cells. Hederagenin (HRG) derivatives showed significant inhibitory effects in P-gp-mediated tumor MDR. Herein, we designed and synthesized 30 HRG derivatives and evaluated these compounds' tumor MDR reversal ability. For the first time, we identified a potential P-gp non-substrate inhibitor of the HRG derivatives 15, which binds to non-substrate active sites in transmembrane structural domains (TMDs) with high binding affinity. Subsequent assays confirmed that 15 exerted significant tumor MDR reversal activity by binding to P-gp and inhibiting P-gp function rather than affecting its expression. It could not be pumped out of the cell by P-gp. In addition, 15 inhibited Rhodamine123 efflux, rendered the KBV cells sensitive to paclitaxel (Ptx), blocked the cells in the G2/M phase, and induced apoptosis. Notably, 15 increased Ptx sensitivity in vivo, significantly inhibited the growth of KBV cell-derived xenograft tumors in nude mice, with a tumor suppression rate as high as 63.71 %.

Key roles of ubiquitination in regulating critical regulators of cancer stem cell functionality

The ubiquitin (Ub) system, a ubiquitous presence across eukaryotes, plays a crucial role in the precise orchestration of diverse cellular protein processes. From steering cellular signaling pathways and orchestrating cell cycle progression to guiding receptor trafficking and modulating immune responses, this process plays a crucial role in regulating various biological functions. The dysregulation of Ub-mediated signaling pathways in prevalent cancers ushers in a spectrum of clinical outcomes ranging from tumorigenesis and metastasis to recurrence and drug resistance. Ubiquitination, a linchpin process mediated by Ub, assumes a central mantle in molding cellular signaling dynamics. It navigates transitions in biological cues and ultimately shapes the destiny of proteins. Recent years have witnessed an upsurge in the momentum surrounding the development of protein-based therapeutics aimed at targeting the Ub system under the sway of cancer stem cells. The article provides a comprehensive overview of the ongoing in-depth discussions regarding the regulation of the Ub system and its impact on the development of cancer stem cells. Amidst the tapestry of insights, the article delves into the expansive roles of E3 Ub ligases, deubiquitinases, and transcription factors entwined with cancer stem cells. Furthermore, the spotlight turns to the interplay with pivotal signaling pathways the Notch, Hedgehog, Wnt/β-catenin, and Hippo-YAP signaling pathways all play crucial roles in the regulation of cancer stem cells followed by the specific modulation of Ub-proteasome.

Human papilloma virus (HPV) mediated cancers: an insightful update

Human papillomavirus (HPV), a DNA virus, is a well-documented causative agent of several cancers, including cervical, vulvar, vaginal, penile, anal, and head & neck cancers. Major factors contributing to HPV-related cancers include persistent infection and the oncogenic potential of particular HPV genotypes. High-risk HPV strains, particularly HPV-16 and HPV-18, are responsible for over 70% of cervical cancer cases worldwide, as well as a significant proportion of other genital and head and neck cancers. At the molecular level, the oncogenic activity of these viruses is driven by the overexpression of E6 and E7 oncoproteins. These oncoproteins dysregulate the cell cycle, inhibit apoptosis, and promote the accumulation of DNA damage, ultimately transforming normal cells into cancerous ones. This review aims to provide a comprehensive overview of the recent advances in HPV-related cancer biology and epidemiology. The review highlights the molecular pathways of HPV-driven carcinogenesis, focusing on the role of viral oncoproteins in altering host cell targets and disrupting cellular signalling pathways. The review explores the therapeutic potential of these viral proteins, and discusses current diagnostic and treatment strategies for HPV-associated cancers. Furthermore, the review highlights the critical role of HPV in the development of various malignancies, emphasizing the persistent challenges in combating these cancers despite advancements in vaccination and therapeutic strategies. We also emphasize recent breakthroughs in utilizing biomarkers to monitor cancer therapy responses, such as mRNAs, miRNAs, lncRNAs, proteins, and genetic markers. We hope this review will serve as a valuable resource for researchers working on HPV, providing insights that can guide future investigations into this complex virus, which continues to be a major contributor to global morbidity and mortality.

Discovery of amino acid-conjugated dimethylcardamonin analogues as potent anti-cervical cancer agents on SiHa cells targeting p53 signalling pathway

DMC (1) is a phytochemical found in the seeds of Syzygium nervosum, exhibiting anticancer activity in various cells through multiple pathways. Herein, the bioactivity of DMC (1) was enhanced by chemical modification through esterification, attaching fatty acid and amino acid moieties to yield 27 semi-synthetic derivatives. These compounds were evaluated for their in vitro cytotoxicity against three main types of cervical cancer cells, including SiHa, HeLa, and C-33A. As a result, the amino acid DMC derivative, 4´-(L-tyrosinyloxy)-DMC (7j), exhibited potent cytotoxicity against SiHa cells, which was approximately two-fold greater than that of 1. Further investigation into the mechanism of action of 7j was conducted, revealing its ability to induce cell cycle arrest and apoptosis. Gene expression analysis showed the downregulation of CDK2 and upregulation of the BAX/BCL2 ratio. Atomistic insight was studied on HPV 16 E6 via molecular dynamics simulation, revealing key interactions between tyrosinyl portion and C51 residue.

MDM4 inhibits ferroptosis in p53 mutant colon cancer via regulating TRIM21/GPX4 expression

MDM4 is one of the major regulators of p53. The biological effect of MDM4 on tumor is controversial, its role and molecular mechanism in colon cancer progression and prognosis are still unclear. In this study, we identify that MDM4 is significantly overexpressed in human colon cancer and high MDM4 expression was associated with poor prognosis of colon cancer with mutant p53. MDM4 inhibits the ubiquitination of the ferroptosis marker protein GPX4 at K167 and K191 by upregulating the protein expression level of the E3 ubiquitin ligase TRIM21, which promotes the polyubiquitination of GPX4 transfer from K48- to K63- linked ubiquitination. Thereby, MDM4 enhances the stability of GPX4 protein, inhibiting ferroptosis, increasing the resistance of colon cancer patients to chemotherapy, and promoting colon cancer progression. These findings elucidate the ferroptosis inhibition effect of MDM4 via regulating TRIM21/GPX4 on p53-mutated colon cancer and provide a potential therapeutic strategy for colon cancer therapy.

Cellular, Structural Basis, and Recent Progress for Targeting Murine Double Minute X (MDMX) in Tumors

Murine double minute X (MDMX) is an oncoprotein that mainly has a negative regulatory effect on the tumor suppressor p53 to induce tumorigenesis. As MDMX is highly expressed in various types of tumor cells, targeting and inhibiting MDMX are becoming a promising strategy for treating cancers. However, the high degree of structural homology between MDMX and its homologous protein murine double minute 2 (MDM2) is a great challenge for the development of MDMX-targeted therapies. This review introduces the structure, distribution, and regulation of the MDMX, summarizes the structural features and structure-activity relationships (SARs) of MDMX ligands, and focuses on the differences between MDMX and MDM2 in these aspects. Our purpose of this work is to propose potential strategies to achieve the specific targeting of MDMX.

Small molecule NMD and MDM2 inhibitors synergistically trigger apoptosis in HeLa cells

The nonsense-mediated mRNA decay (NMD) pathway and the p53 pathway, linked to tumorgenesis, are also promising targets for cancer treatment. NMD plays an important role in RNA quality control, while the p53 pathway is involved in cancer suppression. However, their individual and combined effects on cervical cancer are poorly understood. In this study, we evaluated the impacts of NMD inhibitor, Mouse double minute 2 homolog (MDM2) inhibitor, and their combination on cell apoptosis, cell cycle, and p53 target genes in human papillomavirus-18-positive HeLa cells. Our findings revealed that XR-2 failed to activate p53 or induce apoptosis in HeLa cells, whereas SMG1 (serine/threonine-protein kinase 1) inhibitor repressed cell proliferation at high concentrations. Notably, the combination of these 2 agents significantly inhibited cell proliferation, arrested the cell cycle, and triggered cell apoptosis. Mechanistically, MDM2 inhibitor and NMD inhibitor likely exert a synergistically through the truncated E6 protein. These results underscore the potential of employing a combination of MDM2 inhibitor and NMD inhibitor as a promising candidate for the clinical treatment of human papillomavirus-infected tumors.

Understanding the HPV associated cancers: A comprehensive review

Human papillomavirus (HPV), a common cause of sexually transmitted diseases, may cause warts and lead to various types of cancers, which makes it important to understand the risk factors associated with it. HPV is the leading risk factor and plays a crucial role in the progression of cervical cancer. Viral oncoproteins E6 and E7 play a pivotal role in this process. Beyond cervical cancer, HPV-associated cancers of the mouth and throat are also increasing. HPV can also contribute to other malignancies like penile, vulvar, and vaginal cancers. Emerging evidence links HPV to these cancers. Research on the oncogenic effect of HPV is still ongoing and explorations of screening techniques, vaccination, immunotherapy and targeted therapeutics are all in progress. The present review offers valuable insight into the current understanding of the role of HPV in cancer and its potential implications for treatment and prevention in the future.

Novel 9-Methylanthracene Derivatives as p53 Activators for the Treatment of Glioblastoma Multiforme

Glioblastoma multiforme, a highly aggressive and lethal brain tumor, is a substantial clinical challenge and a focus of increasing concern globally. Hematological toxicity and drug resistance of first-line drugs underscore the necessity for new anti-glioma drug development. Here, 43 anthracenyl skeleton compounds as p53 activator XI-011 analogs were designed, synthesized, and evaluated for their cytotoxic effects. Five compounds (13d, 13e, 14a, 14b, and 14n) exhibited good anti-glioma activity against U87 cells, with IC50 values lower than 2 μM. Notably, 13e showed the best anti-glioma activity, with an IC50 value up to 0.53 μM, providing a promising lead compound for new anti-glioma drug development. Mechanistic analyses showed that 13e suppressed the MDM4 protein expression, upregulated the p53 protein level, and induced cell cycle arrest at G2/M phase and apoptosis based on Western blot and flow cytometry assays.

PCC0208057 as a small molecule inhibitor of TRPC6 in the treatment of prostate cancer

Prostate cancer (PCa) is a common malignant tumor, whose morbidity and mortality keep the top three in the male-related tumors in developed countries. Abnormal ion channels, such as transient receptor potential canonical 6 (TRPC6), are reported to be involved in the carcinogenesis and progress of prostate cancer and have become potential drug targets against prostate cancer. Here, we report a novel small molecule inhibitor of TRPC6, designated as PCC0208057, which can suppress the proliferation and migration of prostate cancer cells in vitro, and inhibit the formation of Human umbilical vein endothelial cells cell lumen. PCC0208057 can effectively inhibit the growth of xenograft tumor in vivo. Molecular mechanism studies revealed that PCC0208057 could directly bind and inhibit the activity of TRPC6, which then induces the prostate cancer cells arrested in G2/M phase via enhancing the phosphorylation of Nuclear Factor of Activated T Cells (NFAT) and Cdc2. Taken together, our study describes for the first time that PCC0208057, a novel TRPC6 inhibitor, might be a promising lead compound for treatment of prostate cancer.

Targeting G-rich sequence to regulate the transcription of murine double minute (MDM) genes in triple-negative breast cancers

Murine double minute 2 (MDM2) and homologous protein murine double minute X (MDMX) are p53 negative regulators that perform significant driving effects in tumorigenesis, and targeting these oncoproteins has became an efficient strategy in treating cancers. However, the definite antitumor activity and significance ordering of each protein in MDM family is still unclear due to the similar structure and complicated regulation. Herein, we identified two G-rich sequences (G1 and G5) located in the promoter that could assemble the G-quadruplex to respectively inhibit and promote the transcription of the MDM2 and MDMX. Based on this target, we designed and synthesized a novel G-quadruplex ligand A3f and achieved the differentiated regulation of MDM protein. In triple-negative breast cancer (TNBC) cells, A3f could induce MDM2-dependent proliferation arrest and exhibit additive therapeutic effect with MDMX inhibitors. Overall, this study provided a novel strategy to regulate the transcription of MDM genes by targeting certain G-rich sequences, and discovered an active antitumor molecule for use in TNBC treatment.

Structure of the p53 degradation complex from HPV16

Human papillomavirus (HPV) is a significant contributor to the global cancer burden, and its carcinogenic activity is facilitated in part by the HPV early protein 6 (E6), which interacts with the E3-ligase E6AP, also known as UBE3A, to promote degradation of the tumor suppressor, p53. In this study, we present a single-particle cryoEM structure of the full-length E6AP protein in complex with HPV16 E6 (16E6) and p53, determined at a resolution of ~3.3 Å. Our structure reveals extensive protein-protein interactions between 16E6 and E6AP, explaining their picomolar binding affinity. These findings shed light on the molecular basis of the ternary complex, which has been pursued as a potential therapeutic target for HPV-driven cervical, anal, and oropharyngeal cancers over the last two decades. Understanding the structural and mechanistic underpinnings of this complex is crucial for developing effective therapies to combat HPV-induced cancers. Our findings may help to explain why previous attempts to disrupt this complex have failed to generate therapeutic modalities and suggest that current strategies should be reevaluated.

Discovery of N-alkyl-N-benzyl thiazoles as novel TRPC antagonists for the treatment of glioblastoma multiforme

Glioblastoma multiforme represents a substantial clinical challenge. Transient receptor potential channel (TRPC) antagonists might provide new therapeutic options for this aggressive cancer. In this study, a series of N-alkyl-N-benzoyl and N-alkyl-N-benzyl thiazoles were designed and prepared using a scaffold-hopping strategy and evaluated as TRPC6 antagonists. This resulted in the discovery of 15g, a potent TRPC antagonist that exhibited suitable inhibitory micromolar activities against TRPC3, TRPC4, TRPC5, TPRC6, and TRPC7 and displayed noteworthy anti-glioblastoma efficacy in vitro against U87 cell lines. In addition, 15g featured an acceptable pharmacokinetic profile and exhibited better in vivo potency (25 mg/kg/d) than the frontline therapeutic agent temozolomide (50 mg/kg/d) in xenograft models. Taken together, the TRPC antagonist 15g represents a promising lead compound for developing new anti-glioblastoma agents.

MDM4 was associated with poor prognosis and tumor-immune infiltration of cancers

MDM4 is one of the MDM protein family and is generally recognized as the key negative regulator of p53. As a cancer-promoting factor, it plays a non-negligible role in tumorigenesis and development. In this article, we analyzed the expression levels of MDM4 in pan-cancer through multiple databases. We also investigated the correlations between MDM4 expression and prognostic value, immune features, genetic mutation, and tumor-related pathways. We found that MDM4 overexpression is often accompanied by adverse clinical features, poor prognosis, oncogenic mutations, tumor-immune infiltration and aberrant activation of oncogenic signaling pathways. We also conducted transcriptomic sequencing to investigate the effect of MDM4 on transcript levels in colon cancer and performed qPCR to verify this. Finally, we carried out some in vitro experiments including colony formation assay, chemoresistance and senescence-associated β-galactosidase activity assay to study the anti-tumor treatment effect of small molecule MDM4 inhibitor, NSC146109. Our research confirmed that MDM4 is a prognostic biomarker and potential therapeutic target for a variety of malignancies.

A novel scaffold long-acting selective estrogen receptor antagonist and degrader with superior preclinical profile against ER+ breast cancer

Breast cancer is one of the most common malignant tumors in women worldwide, with the majority of cases showing expression of estrogen receptors (ERs). Although drugs targeting ER have significantly improved survival rates in ER-positive patients, drug resistance remains an unmet clinical need. Fulvestrant, which overcomes selective estrogen receptor modulator (SERM) and AI (aromatase inhibitor) resistance, is currently the only long-acting selective estrogen receptor degrader (SERD) approved for both first and second-line settings. However, it fails to achieve satisfactory efficacy due to its poor solubility. Therefore, we designed and synthesized a series of novel scaffold (THC) derivatives, identifying their activities as ER antagonists and degraders. G-5b, the optimal compound, exhibited binding, antagonistic, degradation or anti-proliferative activities comparable to fulvestrant in ER+ wild type and mutants breast cancer cells. Notably, G-5b showed considerably improved stability and solubility. Research into the underlying mechanism indicated that G-5b engaged the proteasome pathway to degrade ER, subsequently inhibiting the ER signaling pathway and leading to the induction of apoptosis and cell cycle arrest events. Furthermore, G-5b displayed superior in vivo pharmacokinetics and pharmacodynamics properties, coupled with a favorable safety profile in the MCF-7 tamoxifen-resistant (MCF-7/TR) tumor xenograft model. Collectively, G-5b has emerged as a highly promising lead compound, offering potent antagonistic and degradation activities, positioning it as a novel long-acting SERD worthy of further refinement and optimization.

A comprehensive study of oxidative stress-related effects on the prognosis and drug therapy of cervical cancer

BACKGROUND

Cervical cancer (CC) is a serious global disease with poor prognoses and a significant recurrence rate in patients with advanced disease. Oxidative stress (OS) greatly influences many types of human cancers, making it crucial to understand the functional mechanisms of OS-related genes in CC.

METHODS

The transcriptome and clinical data of three normal samples and 306 patients with CC were obtained from The Cancer Genome Atlas dataset. The GSE44001 dataset was acquired from the Gene Expression Omnibus database. OS-related subtypes in the cohort with CC were identified using unsupervised hierarchical clustering, univariate Cox analysis, gene set enrichment analysis (GSEA), and least absolute shrinkage and selection operator regression analysis. Additionally, molecular pathways that differ across subtypes were determined and OS-related genes linked to the prognosis of patients of CC were determined. Finally, a clinical prognostic gene signature was developed and validated. The relative infiltration level of immune cell subpopulations in different risk groups and subtypes was evaluated using the cell-type identification by estimating relative subsets of RNA transcripts (CIBERPORT) algorithm and single-sample GSEA (ssGSEA) techniques.

RESULTS

The present study established two distinct OS subtypes (OS clusters A and B). Analysis using ssGSEA and CIBERSPORT revealed that OS cluster B exhibited a significant level of immune infiltration. A clinical prognostic gene signature was established using OS-related characteristic genes identified by examining the differentially expressed genes across both subtypes. Furthermore, patients with CC were grouped into high- and low-risk groups, with the low-risk group showing higher survival rates. Additionally, these individuals exhibited significant advantages in terms of survival and immunotherapy. Receiver operating characteristic curve analysis demonstrated the higher predictive value of the clinical prognostic gene signature. The outcomes of the validation group depicted congruence with those recorded in the training group.

CONCLUSIONS

A new model was constructed based on eight OS-related characteristic genes to aid the prediction of the survival rates of individuals with CC. The present study contributes to the existing literature on the mechanisms of OS genes in CC and offers a fresh perspective for future advancements in immunotherapy for such individuals.

Design, Synthesis, and In vitro Anti-cervical Cancer Activity of a Novel MDM2-p53 Inhibitor Based on a Chalcone Scaffold

OBJECTIVE

Several novel fluorinated chalcone derivatives were synthesized, and their in vitro anticervical cancer activity and mechanism of action were investigated using the parent nucleus of licorice chalcone as the lead compound backbone and MDM2-p53 as the target.

METHODS

In this study, 16 novel chalcone derivatives (3a-3r) were designed and synthesized by molecular docking technology based on the licorice chalcone parent nucleus as the lead compound scaffold and the cancer apoptosis regulatory target MDM2-p53. The structures of these compounds were confirmed by 1H-NMR, 13C-NMR, and HR-ESI-MS. The inhibitory effects of the compounds on the proliferation of three human cervical cancer cell lines (SiHa, HeLa, and C-33A) and two normal cell lines (H8 and HaCaT) were determined by MTT assay, and the initialstructure-activity relationship was analyzed. Transwell and flow cytometry were used to evaluate the effects of target compounds on the inhibition of cancer cell migration and invasion, apoptosis induction, and cell cycle arrest. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB) were used to detect the effects of candidate compounds on mRNA, p53, and Murine double minute 2 (MDM2) protein expression. The binding characteristics of the target compounds to the MDM2 protein target in the p53-MDM2 pathway were evaluated by molecular docking technology.

RESULTS

The target compounds had considerable inhibitory activity on the proliferation of three cervical cancer cell lines. Among them, compound 3k (E)-3-(4-(dimethylamino)phenyl)-2-methyl-1-(3-(trifluoromethyl)phenyl) prop-2-en-1-one) showed the highest activity against HeLa cells (IC50=1.08 μmol/L), which was better than that of the lead compound Licochalcone B, and 3k showed lower toxicity to both normal cells. Compound 3k strongly inhibited the migration and invasion of HeLa cells and induced apoptosis and cell cycle arrest at the G0/G1 phase. Furthermore, compound 3k upregulated the expression of p53 and BAX and downregulated the expression of MDM2, MDMX, and BCL2. Moreover, molecular docking results showed that compound 3k could effectively bind to the MDM2 protein (binding energy: -9.0 kcal/mol). These results suggest that the compounds may activate the p53 signaling pathway by inhibiting MDM2 protein, which prevents cancer cell proliferation, migration, and invasion and induces apoptosis and cell cycle arrest in cancer cells.

CONCLUSION

This study provides a new effective and low-toxicity drug candidate from licochalcone derivatives for treating cervical cancer.

Modulation of the ubiquitin-proteasome system by phytochemicals: Therapeutic implications in malignancies with an emphasis on brain tumors

Regarding the multimechanistic nature of cancers, current chemo- or radiotherapies often fail to eradicate disease pathology, and frequent relapses or resistance to therapies occur. Brain malignancies, particularly glioblastomas, are difficult-to-treat cancers due to their highly malignant and multidimensional biology. Unfortunately, patients suffering from malignant tumors often experience poor prognoses and short survival periods. Thus far, significant efforts have been conducted to discover novel and more effective modalities. To that end, modulation of the ubiquitin-proteasome system (UPS) has attracted tremendous interest since it affects the homeostasis of proteins critically engaged in various cell functions, for example, cell metabolism, survival, proliferation, and differentiation. With their safe and multimodal actions, phytochemicals are among the promising therapeutic tools capable of turning the operation of various UPS elements. The present review, along with an updated outline of the role of UPS dysregulation in multiple cancers, provided a detailed discussion on the impact of phytochemicals on the UPS function in malignancies, especially brain tumors.

Implications of viral infections and oncogenesis in uterine cervical carcinoma etiology and pathogenesis

Background

Uterine Cervical Carcinoma (UCC) is the most prevalent gynecological malignancy globally, with a rising incidence in recent years. Accumulating evidence indicates that specific viral infections, including human papillomavirus (HPV), Epstein-Barr virus (EBV), Hepatitis B and C viruses (HBV and HCV), and human herpesvirus (HHV), may contribute to UCC development and progression. Understanding the complex interplay between viral infections and UCC risk is crucial for developing novel preventative and therapeutic interventions.

Methods

This comprehensive review investigates the association between viral infections and UCC risk by examining the roles of various viral pathogens in UCC etiology and pathogenesis, and possible molecular mechanisms. Additionally, we evaluate current diagnostic methods and potential therapeutic strategies targeting viral infections for UCC prevention or treatment.

Results

The prevention of UCC has been significantly advanced by the emergence of self-sampling for HPV testing as a crucial tool, allowing for early detection and intervention. However, an essential challenge in UCC prevention lies in understanding how HPV and other viral coinfections, including EBV, HBV, HCV, HHV, HIV, or their concurrent presence, may potentially contribute to UCC development. The molecular mechanisms implicated in the association between viral infections and cervical cancer development include: (1) interference of viral oncogenes with cellular regulatory proteins, resulting in uncontrolled cell proliferation and malignant transformation; (2) inactivation of tumor suppressor genes by viral proteins; (3) evasion of host immune responses by viruses; (4) induction of a persistent inflammatory response, contributing to a tumor-promoting microenvironment; (5) epigenetic modifications that lead to aberrant gene expression; (6) stimulation of angiogenesis by viruses; and (7) activation of telomerase by viral proteins, leading to cellular immortalization. Additionally, viral coinfections can also enhance oncogenic potential through synergistic interactions between viral oncoproteins, employ immune evasion strategies, contribute to chronic inflammation, modulate host cellular signaling pathways, and induce epigenetic alterations, ultimately leading to cervical carcinogenesis.

Conclusion

Recognizing the implications of viral oncogenes in UCC etiology and pathogenesis is vital for addressing the escalating burden of UCC. Developing innovative preventative and therapeutic interventions requires a thorough understanding of the intricate relationship between viral infections and UCC risk.

Identification of a novel heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) ligand that disrupts HnRNPA2B1/nucleic acid interactions to inhibit the MDMX-p53 axis in gastric cancer

Gastric carcinoma is a highly malignant tumor that still lacks effective molecular targets. Heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1) is an essential oncogenic driver overexpressed in various cancers. The potential role of hnRNPA2B1 in oncotherapy has not been revealed because of the absence of active chemical molecules. In this study, we identified the pseudourea derivative XI-011 as a novel hnRNPA2B1 ligand using chemical proteomics. An interaction study indicated that XI-011 could bind the nucleotide-binding domain to disrupt the recruitment of hnRNPA2B1 to the promoter and untranslated region of the murine double minute X (MDMX) gene, thereby inhibiting its transcription. In addition, chemical targeting of hnRNPA2B1 recovered inactivated p53 and enhanced the therapeutic efficacy of apatinib in vivo. This work presented a novel strategy to restore p53 activity for the treatment of gastric cancers via chemically targeting hnRNPA2B1.

Drugging p53 in cancer: one protein, many targets

Mutations in the TP53 tumour suppressor gene are very frequent in cancer, and attempts to restore the functionality of p53 in tumours as a therapeutic strategy began decades ago. However, very few of these drug development programmes have reached late-stage clinical trials, and no p53-based therapeutics have been approved in the USA or Europe so far. This is probably because, as a nuclear transcription factor, p53 does not possess typical drug target features and has therefore long been considered undruggable. Nevertheless, several promising approaches towards p53-based therapy have emerged in recent years, including improved versions of earlier strategies and novel approaches to make undruggable targets druggable. Small molecules that can either protect p53 from its negative regulators or restore the functionality of mutant p53 proteins are gaining interest, and drugs tailored to specific types of p53 mutants are emerging. In parallel, there is renewed interest in gene therapy strategies and p53-based immunotherapy approaches. However, major concerns still remain to be addressed. This Review re-evaluates the efforts made towards targeting p53-dysfunctional cancers, and discusses the challenges encountered during clinical development.

Anti-Colorectal Cancer Effects of a Novel Camptothecin Derivative PCC0208037 In Vitro and In Vivo

Colorectal cancer is one of the most common malignancies, and the topoisomerase inhibitor irinotecan (CPT-11)-based chemotherapeutic regimen is currently the first-line treatment with impressive therapeutic efficacy. However, irinotecan has several clinically significant side effects, including diarrhea, which limit its clinical utility and efficacy in many patients. In an effort to discover better and improved pharmacotherapy against colorectal cancer, we synthesized a novel topoisomerase inhibitor, PCC0208037, examined its anti-tumor efficacy and related molecular mechanisms, and characterized its toxicity and pharmacokinetic profiles. PCC0208037 suppressed colorectal cancer cell (CRC) proliferation and increased cell cycle arrest, which may be related to its effects on up-regulating DNA damage response (DDR)-related molecules and apoptosis-related proteins. PCC0208037 demonstrated robust anti-tumor activity in vivo in a colorectal cancer cell xenograft model, which was comparable to or slightly better than CPT-11. In a preliminary toxicology study, PCC0208037 demonstrated much weaker tissue damage to colorectal tissue than CPT-11, and its impacts on food intake and body weight loss were more transient and recovered faster than CPT-11 in mice. This could be partially explained by the pharmacokinetic findings, which showed that PCC0208037 and its active metabolite, SN-38, were more accumulated in tumor tissue than in the intestine, as compared to CPT-11. Taken together, these results described a novel Topo I inhibitor with a comparative advantage over the standard treatment of colorectal cancer CPT-11 and could be a promising candidate compound for the treatment of colorectal cancer that warrants further investigation.

The E3 Ligases in Cervical Cancer and Endometrial Cancer

Endometrial (EC) and cervical (CC) cancers are the most prevalent malignancies of the female reproductive system. There is a global trend towards increasing incidence and mortality, with a decreasing age trend. E3 ligases label substrates with ubiquitin to regulate their activity and stability and are involved in various cellular functions. Studies have confirmed abnormal expression or mutations of E3 ligases in EC and CC, indicating their vital roles in the occurrence and progression of EC and CC. This paper provides an overview of the E3 ligases implicated in EC and CC and discusses their underlying mechanism. In addition, this review provides research advances in the target of ubiquitination processes in EC and CC.

Regulated cell death (RCD) in cancer: key pathways and targeted therapies

Regulated cell death (RCD), also well-known as programmed cell death (PCD), refers to the form of cell death that can be regulated by a variety of biomacromolecules, which is distinctive from accidental cell death (ACD). Accumulating evidence has revealed that RCD subroutines are the key features of tumorigenesis, which may ultimately lead to the establishment of different potential therapeutic strategies. Hitherto, targeting the subroutines of RCD with pharmacological small-molecule compounds has been emerging as a promising therapeutic avenue, which has rapidly progressed in many types of human cancers. Thus, in this review, we focus on summarizing not only the key apoptotic and autophagy-dependent cell death signaling pathways, but the crucial pathways of other RCD subroutines, including necroptosis, pyroptosis, ferroptosis, parthanatos, entosis, NETosis and lysosome-dependent cell death (LCD) in cancer. Moreover, we further discuss the current situation of several small-molecule compounds targeting the different RCD subroutines to improve cancer treatment, such as single-target, dual or multiple-target small-molecule compounds, drug combinations, and some new emerging therapeutic strategies that would together shed new light on future directions to attack cancer cell vulnerabilities with small-molecule drugs targeting RCD for therapeutic purposes.

Nanomicelles co-loaded with doxorubicin and salvianolic acid A for breast cancer chemotherapy

Background

Multi-drug delivery system based on polymer carrier is emerging for alleviating dose-limiting toxicities of first-line cytotoxic anticancer drugs, such as doxorubicin (DOX) for breast cancer chemotherapy. By co-loading the premium natural antioxidant salvianolic acid A (SAA) through colloidal self-assembly of amphiphilic copolymer, we herein developed CPMSD, a complex polymeric micellar system to overcome cardiotoxicity associated with DOX.

Results

Optimal formulation was obtained by DOE study and CPMSD micelles were well constructed by using mPEG-PCL for entrapment at a drug–carrier mass ratio of 1:5 and DOX–SAA mass ratio of 1:4. Molecular dynamics simulation revealed the ratiometrical co-encapsulation of SAA into the hydrophobic cavity but DOX to ball-shaped surface of micelles due to hydrophilicity. Characterization study manifested favorable biopharmaceutical properties, such as small and uniform particle size, fairly high drug loading capacity, as well as good colloidal stability and controlled drug release. CPMSD maintained anticancer efficacy of DOX and the action mechanism, which did not be affected by co-administering SAA. More to the point, it was of great benefit to systemic safety and cardioprotective effect against oxidative stress injuries associated with DOX in tumor-bearing mice.

Conclusions

All the findings substantiated that CPMSD would be a promising multifunctional nanosystem of DOX for breast cancer chemotherapy.

Synthesis and Biological Evaluation of Novel Synthetic Indolone Derivatives as Anti-Tumor Agents Targeting p53-MDM2 and p53-MDMX

A series of novel indolone derivatives were synthesized and evaluated for their binding affinities toward MDM2 and MDMX. Some compounds showed potent MDM2 and moderate MDMX activities. Among them, compound A13 exhibited the most potent affinity toward MDM2 and MDMX, with a K_i of 0.031 and 7.24 μM, respectively. A13 was also the most potent agent against HCT116, MCF7, and A549, with IC₅₀ values of 6.17, 11.21, and 12.49 μM, respectively. Western blot analysis confirmed that A13 upregulated the expression of MDM2, MDMX, and p53 by Western blot analysis. These results indicate that A13 is a potent dual p53-MDM2 and p53-MDMX inhibitor and deserves further investigation.

Molecular Research on Oral Diseases and Related Biomaterials: A Journey from Oral Cell Models to Advanced Regenerative Perspectives

Oral diseases such as gingivitis, periodontitis, and oral cancer affect millions of people worldwide. Much research has been conducted to understand the pathogenetic mechanisms of these diseases and translate this knowledge into therapeutics. This review aims to take the reader on a journey from the initial molecular discoveries to complex regenerative issues in oral medicine. For this, a semi-systematic literature search was carried out in Medline and Web of Science databases to retrieve the primary literature describing oral cell models and biomaterial applications in oral regenerative medicine. First, an in vitro cell model of gingival keratinocytes is discussed, which illustrates patho- and physiologic principles in the context of oral epithelial homeostasis and carcinogenesis and represents a cellular tool to understand biomaterial-based approaches for periodontal tissue regeneration. Consequently, a layered gradient nonwoven (LGN) is described, which demonstrates that the key features of biomaterials serve as candidates for oral tissue regeneration. LGN supports proper tissue formation and obeys the important principles for molecular mechanotransduction. Furthermore, current biomaterial-based tissue regeneration trends, including polymer modifications, cell-based treatments, antimicrobial peptides and optogenetics, are introduced to represent the full spectrum of current approaches to oral disease mitigation and prevention. Altogether, this review is a foray through established and new concepts in oral regenerative medicine and illustrates the process of knowledge translation from basic molecular and cell biological research to future clinical applications.