Cancer Therapy Resistance Research Articles

CXCR4 promotes tumor stemness maintenance and CDK4/6 inhibitors resistance in ER-positive breast cancer

BackgroundCDK4/6 inhibitors have significantly improved the survival of patients with HR-positive/HER2-negative breast cancer, becoming a first-line treatment option. However, the development of resistance to these inhibitors is inevitable. To address this challenge, novel strategies are required to overcome resistance, necessitating a deeper understanding of its mechanisms. Recent research has identified several dysregulated genes in CDK4/6 inhibitors-resistant breast cancer, but the underlying mechanism is complex due to tumor heterogeneity and warrants further investigation.MethodsRNA sequencing and KEGG pathway analysis was carried out to identify the mainly dysregulated genes in CDK4/6 inhibitors-resistant breast cancer cells. The effects of CXCR4 knockdown and overexpression via siRNAs and plasmids transfection were examined by mammosphere formation, RT-qPCR, flow cytometry, MTT and colony formation assays. The regulation mechanisms were analyzed by RT-qPCR, western blotting and immunofluorescence experiments. Mouse xenografts were used to analyze the role of CXCR4 in regulation palbociclib sensitivity in vivo. Additionally, we collected the clinical samples and performed immunohistochemistry to analyze the clinical significance of CXCR4.ResultsIn our study, we focused on cancer stem cells, a critical contributor to cancer metastasis and therapy resistance, and detected an upregulation of stemness in our established palbociclib-resistant ER-positive breast cancer cells. Additionally, our research pinpointed CXCR4 as a pivotal gene responsible for maintaining cancer stemness and promoting palbociclib resistance. Mechanistically, CXCR4 activates the WNT5A/β-catenin signaling pathway by enhancing the expression of WNT5A and β-catenin, facilitating the nuclear translocation of β-catenin protein. Targeting CXCR4 using siRNAs or small molecular inhibitors effectively reduces cancer stemness and reverses palbociclib resistance both in vitro and in vivo. Clinical sample analysis further underscores the overactivation of the CXCR4/WNT5A/β-catenin axis in palbociclib-resistant breast cancer, suggesting CXCR4 as a potential biomarker for predicting resistance to CDK4/6 inhibitors.ConclusionsCollectively, our study demonstrates that CXCR4 overexpression plays a vital role in maintaining breast cancer stemness and promoting resistance to CDK4/6 inhibitors through the activation of the WNT5A/β-catenin pathway. Targeting CXCR4 may offer a promising therapeutic approach for advanced CDK4/6 inhibitor-resistant ER-positive breast cancer.

Targeting Metabolic Vulnerabilities to Combat Drug Resistance in Cancer Therapy

Drug resistance remains a significant barrier to effective cancer therapy. Cancer cells evade treatment by reprogramming their metabolism, switching from glycolysis to oxidative phosphorylation (OXPHOS), and relying on alternative carbon sources such as glutamine. These adaptations not only enable tumor survival but also contribute to immune evasion through mechanisms such as reactive oxygen species (ROS) generation and the upregulation of immune checkpoint molecules like PD-L1. This review explores the potential of targeting metabolic weaknesses in drug-resistant cancers to enhance therapeutic efficacy. Key metabolic pathways involved in resistance, including glycolysis, glutamine metabolism, and the kynurenine pathway, are discussed. The combination of metabolic inhibitors with immune checkpoint inhibitors (ICIs), particularly anti-PD-1/PD-L1 therapies, represents a promising approach to overcoming both metabolic and immune evasion mechanisms. Clinical trials combining metabolic and immune therapies have shown early promise, but further research is needed to optimize treatment combinations and identify biomarkers for patient selection. In conclusion, targeting cancer metabolism in combination with immune checkpoint blockade offers a novel approach to overcoming drug resistance, providing a potential pathway to improved outcomes in cancer therapy. Future directions include personalized treatments based on tumor metabolic profiles and expanding research to other tumor types.

Advances and challenges in molecular understanding, early detection, and targeted treatment of liver cancer.

In this review, we explore the application of next-generation sequencing in liver cancer research, highlighting its potential in modern oncology. Liver cancer, particularly hepatocellular carcinoma, is driven by a complex interplay of genetic, epigenetic, and environmental factors. Key genetic alterations, such as mutations in TERT, TP53, and CTNNB1, alongside epigenetic modifications such as DNA methylation and histone remodeling, disrupt regulatory pathways and promote tumorigenesis. Environmental factors, including viral infections, alcohol consumption, and metabolic disorders such as nonalcoholic fatty liver disease, enhance hepatocarcinogenesis. The tumor microenvironment plays a pivotal role in liver cancer progression and therapy resistance, with immune cell infiltration, fibrosis, and angiogenesis supporting cancer cell survival. Advances in immune checkpoint inhibitors and chimeric antigen receptor T-cell therapies have shown potential, but the unique immunosuppressive milieu in liver cancer presents challenges. Dysregulation in pathways such as Wnt/β-catenin underscores the need for targeted therapeutic strategies. Next-generation sequencing is accelerating the identification of genetic and epigenetic alterations, enabling more precise diagnosis and personalized treatment plans. A deeper understanding of these molecular mechanisms is essential for advancing early detection and developing effective therapies against liver cancer.

Interaction of GPER-1 with the endocrine signaling axis in breast cancer

G Protein-Coupled Estrogen Receptor 1 (GPER-1) is a membrane estrogen receptor that has emerged as a key player in breast cancer development and progression. In addition to its direct influence on estrogen signaling, a crucial interaction between GPER-1 and the hypothalamic-pituitary-gonadal (HPG) axis has been evidenced. The novel and complex relationship between GPER-1 and HPG implies a hormonal regulation with important homeostatic effects on general organ development and reproductive tissues, but also on the pathophysiology of cancer, especially breast cancer. Recent research points to a great versatility of GPER-1, interacting with classical estrogen receptors and with signaling pathways related to inflammation. Importantly, through its activation by environmental and synthetic estrogens, GPER-1 is associated with hormone therapy resistance in breast cancer. These findings open new perspectives in the understanding of breast tumor development and raise the possibility of future applications in the design of more personalized and effective therapeutic approaches.

Extracellular Vesicles as Mediators and Potential Targets in Combating Cancer Drug Resistance

Extracellular vesicles (EVs) are key mediators in the communication between cancer cells and their microenvironment, significantly influencing drug resistance. This review provides a comprehensive analysis of the roles of EVs in promoting drug resistance through mechanisms such as drug efflux, apoptosis resistance, autophagy imbalance, and tumor microenvironment modulation. Despite extensive research, details of EVs biogenesis, cargo selection, and specific pathways in EVs-mediated drug resistance are not fully understood. This review critically examines recent advancements, highlighting key studies that elucidate the molecular mechanisms of EVs functions. Additionally, innovative therapeutic strategies targeting EVs are explored, including inhibiting EVs biogenesis, engineering EVs for drug delivery, and identifying resistance-inhibiting molecules within EVs. By integrating insights from primary research and proposing new directions for future studies, this review aims to advance the understanding of EVs in cancer biology and foster effective interventions to mitigate drug resistance in cancer therapy.

The Slovenian translational platform GlioBank for brain tumour research: identification of molecular signatures of glioblastoma progression

Abstract Background Glioblastoma (GB) is one of the most lethal solid tumours in humans, with an average patient life expectancy of 15 months and 5-year survival rate of 5–10%. GB is still uncurable due to tumour heterogeneity and invasive nature as well as therapy-resistant cancer cells. Centralised biobanks with clinical data and corresponding biological material of GB patients facilitate the development of new treatment approaches and the search for clinically relevant biomarkers, with the goal of improving outcomes for GB patients. The aim of this study was firstly to establish a Sloveniantranslation platform, GlioBank, and secondly to demonstrate its utility through the identification of molecular signatures associated with GB progression and patient survival. Methods GlioBank contains tissue samples and corresponding tumour models as well as clinical data from patients diagnosed with glioma, with a focus on GB. Primary GB cells, glioblastoma stem cells (GSCs) and organoids have been established from fresh tumour biopsies. We performed expression analyses of genes associated with GB progression and bioinformatics analyses of available clinical and research data obtained from a subset of 91 GB patients. qPCR was performed to determine the expression of genes associated with therapy- resistance and cancer cell invasion, including markers of different GB subtypes, GSCs, epithelial-to-mesenchymal transition, and immunomodulation/chemokine signalling in tumour tissues and corresponding cellular models. Results GlioBank contains biological material and research, and clinical data collected in the SciNote electronic laboratory notebook. To date, more than 240 glioma tissue samples have been collected and stored in GlioBank, most of which are GB tissues (205) and were further processed to establish primary GB cells (n=64), GSCs (n=14), and GB organoids (n=17). Corresponding blood plasma (n=103) and peripheral blood mononuclear cells (n=101) are also stored. GB tumours were classified into four different subtypes that differed regarding patient survival; the mixed subtype exhibited the longest patient survival. High DAB2, S100A4, and STAT3 expression was associated with poor overall patient survival, and DAB2 was found to be an independent prognostic marker for GB survival. We analysed the molecular signatures between different tumour regions (core vs. rim). STMN4, ERBB3, and ACSBG1 were upregulated in the tumour rim, suggesting that these genes are associated with the invasive nature of GB. Conclusions GlioBank is a centralised biobank that has been built by a multidisciplinary network with the aim to facilitate disease-oriented basic and clinical research. The advantages of GlioBank include the molecular characterization of GB based on targeted gene expression, the availability of diverse cellular models (e.g. GB cells and organoids), and a large number of patient-matched tumour core and rim samples, all with accompanying molecular and clinical data. We report here for the first time an association between DAB2 expression and low overall survival in GB patients, indicative of a prognostic value of DAB2.

CD36 enrichment in HER2-positive mesenchymal stem cells drives therapy refractoriness in breast cancer

BackgroundGrowing evidence shows that the reprogramming of fatty acid (FA) metabolism plays a key role in HER2-positive (HER2 +) breast cancer (BC) aggressiveness, therapy resistance and cancer stemness. In particular, HER2 + BC has been defined as a "lipogenic disease" due to the functional and bi-directional crosstalk occurring between HER2-mediated oncogenic signaling and FA biosynthesis via FA synthase activity. In this context, the functional role exerted by the reprogramming of CD36-mediated FA uptake in HER2 + BC poor prognosis and therapy resistance remains unclear. In this study, we aimed to elucidate whether enhanced CD36 in mesenchymal HER2 + cancer stem cells (CSCs) is directly involved in anti-HER2 treatment refractoriness in HER2 + BC and to design future metabolism-based approaches targeting both FA reprogramming and the “root” of cancer.MethodsMolecular, biological and functional characterization of CD36-mediated FA uptake was investigated in HER2 + BC patients, cell lines, epithelial and mesenchymal CSCs. Cell proliferation was analyzed by SRB assay upon treatment with lapatinib, CD36 inhibitor, or Wnt antagonist/agonist. Engineered cell models were generated via lentivirus infection and transient silencing. CSC-like properties and tumorigenesis of HER2 + BC cells with or without CD36 depletion were examined by mammosphere forming efficiency assay, flow cytometry, cell sorting, ALDH activity assay and xenograft mouse model. FA uptake was examined by flow cytometry with FA BODIPY FL C16. Intratumor expression of CSC subsets was evaluated via multiplex immunostaining and immunolocalization analysis.ResultsMolecular data demonstrated that CD36 is significantly upmodulated on treatment in therapy resistant HER2 + BC patients and its expression levels in BC cells is correlated with FA uptake. We provided evidence of a consistent enrichment of CD36 in HER2 + epithelial-mesenchymal transition (EMT)-like CSCs from all tested resistant cell models that mechanistically occurs via Wnt signaling pathway activation. Consistently, both in vitro and in vivo dual blockade of CD36 and HER2 increased the anti-CSC efficacy of anti-HER2 drugs favoring the transition of the therapy resistant mesenchymal CSCs into therapy-sensitive mesenchymal-epithelial transition (MET)-like epithelial state. In addition, expression of CD36 in intratumor HER2 + mesenchymal CSCs is significantly associated with resistance to trastuzumab in HER2 + BC patients.ConclusionsThese results support the metabolo-oncogenic nature of CD36-mediated FA uptake in HER2 + therapy-refractory BC. Our study provides evidence that targeting CD36 might be an effective metabolic therapeutic strategy in the treatment of this malignancy.

Reevaluating Anti-Inflammatory Therapy: Targeting Senescence to Balance Anti-Cancer Efficacy and Vascular Disease.

Modulating immune function is a critical strategy in cancer and atherosclerosis treatments. For cancer, boosting or maintaining the immune system is crucial to prevent tumor growth. However, in vascular disease, mitigating immune responses can decrease inflammation and slow atherosclerosis progression. Anti-inflammatory therapy, therefore, presents a unique dilemma for cancer survivors: while it may decrease cardiovascular risk, it might also promote cancer growth and metastasis by suppressing the immune response. Senescence presents a potentially targetable solution to this challenge; senescence increases the risk of both cancer therapy resistance and vascular disease. Exercise, notably, shows promise in delaying this premature senescence, potentially improving cancer outcomes and lowering vascular disease risk post-treatment. This review focuses on the long-term impact of cancer therapies on vascular health. We underscore the importance of modulating senescence to balance cancer treatment's effectiveness and its vascular impact, and we emphasize investigating the role of exercise-mediated suppression of senescence in improving cancer survivorship.

DUSP12 promotes cell cycle progression and protects cells from cell death by regulating ZPR9.

Protein phosphatases are critical for regulating cell signaling, cell cycle, and cell fate decisions, and their dysregulation leads to an array of human diseases like cancer. The dual specificity phosphatases (DUSPs) have emerged as important factors driving tumorigenesis and cancer therapy resistance. DUSP12 is a poorly characterized atypical DUSP widely conserved throughout evolution. Although no direct substrate has been firmly established, DUSP12 that has been implicated in protecting cells from stress, regulating ribosomal biogenesis, and modulating cellular DNA content. In this study, we used affinity- and proximity-based biochemical purification approaches coupled to mass spectrometry to identify the zinc finger protein ZPR9 as a novel DUSP12 interactor, which was validated by in-cell and in-vitro IP assays. Interestingly, ZPR9 binds to the unique zinc-binding domain of DUSP12, which previous reports indicated was important for many of DUSP12's functions within the cell. Prior studies had implicated ZPR9 as a modulator of apoptosis, but it remained unclear if and how ZPR9 participated in the cell cycle and, more so, how it promoted cell death. Using mass spectrometry analyses, we found that overexpression of DUSP12 promoted de-phosphorylation of ZPR9 at Ser143. Overexpression of ZPR9, but not Ser143 phosphomimetic and phosphorylation-deficient mutants, led to an increase in pre-metaphase mitotic defects while knockdown of DUSP12 also showed mitotic defects in metaphase. Furthermore, knockdown of DUSP12 promoted, while knockdown of ZPR9 suppressed, stress-induced apoptosis. Our results support a model where DUSP12 protects cells from stress-induced apoptosis by promoting de-phosphorylation of ZPR9.

ZNFX1 functions as a master regulator of epigenetically induced pathogen mimicry and inflammasome signaling in cancer.

DNA methyltransferase and poly (ADP-ribose) polymerase inhibitors (DNMTis, PARPis) induce a stimulator of interferon genes (STING)-dependent pathogen mimicry response (PMR) in ovarian and other cancers. Here, we showed that combining DNMTis and PARPis upregulates expression of the nucleic-acid sensor NFX1-type zinc finger-containing 1 protein (ZNFX1). ZNFX1 mediated induction of PMR in mitochondria, serving as a gateway for STING-dependent interferon/inflammasome signaling. Loss of ZNFX1 in ovarian cancer cells promoted proliferation and spheroid formation in vitro and tumor growth in vivo. In patient ovarian cancer databases, expression of ZNFX1 was elevated in advanced stage disease, and ZNFX1 expression alone significantly correlated with an increase in overall survival in a phase 3 trial for therapy-resistant ovarian cancer patients receiving bevacizumab in combination with chemotherapy. RNA-sequencing revealed an association between inflammasome signaling through ZNFX1 and abnormal vasculogenesis. Together, this study identified that ZNFX1 as a tumor suppressor that controls PMR signaling through mitochondria and may serve as a biomarker to facilitate personalized therapy in ovarian cancer patients.

Hybrid prodrug nanoassembly for hypoxia-triggered immunogenic chemotherapy and immune modulation.

Tumor hypoxia is a critical driver of cancer progression, metastasis, and therapy resistance, posing significant challenges in effective cancer treatment. Hypoxia-activable prodrugs offer a promising strategy to target tumors in low-oxygen conditions, but their efficacy is often hindered by intrinsic properties and extrinsic cues. In this study, we developed a dual-prodrug nanoassembly system (CPPA) composed of a hypoxia-triggerable camptothecin (CPT)-based dimeric prodrug (CP) and a lipid-conjugated STAT3 antisense oligonucleotide (ASO) prodrug (PA), aiming to enhance tumor-targeted chemotherapy and overcome the immune evasion within the tumor microenvironment. The CPPA self-assemble into stable nanomicelle capable of co-delivering both agents directly to the tumor site, where the hypoxia-triggered release of CPT induces immunogenic cell death (ICD) while STAT3 inhibition enhances immune response. In murine breast cancer models, CPPA demonstrated superior therapeutic efficacy by improving tumor cell killing, promoting immune cell infiltration, and modulating the immunosuppressive tumor microenvironment. This combination therapy not only reversed drug resistance but also prevented the formation of the pre-metastatic niche, significantly inhibiting tumor progression and metastasis. These findings highlight the potential of CPPA as an effective strategy for enhancing cancer immunotherapy, offering a promising approach to address the complex challenges of tumor hypoxia, immune evasion, and resistance to chemotherapy.

Optimizing autophagy modulation for enhanced TRAIL-mediated therapy: Unveiling the superiority of late-stage inhibition over early-stage inhibition to overcome therapy resistance in cancer.

Autophagy is a vital mechanism that eliminates large cytoplasmic components via lysosomal degradation to maintain cellular homeostasis. The role of autophagy in cancer treatment has been studied extensively. Autophagy primarily prevents tumour initiation by maintaining genomic stability and preventing cellular inflammation. However, autophagy also supports cancer cell survival and growth by providing essential nutrients for therapeutic resistance. Thus, autophagy has emerged as a promising strategy for overcoming resistance and enhancing anti-cancer therapy. Inhibiting autophagy significantly improves the sensitivity of lung, colorectal, breast, liver and prostate cancer cells to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). This review investigates the intricate interplay between autophagy modulation and TRAIL-based therapy, specifically focussing on comparing the efficacy of late-stage autophagy inhibition versus early-stage inhibition in overcoming cancer resistance. We expose the distinctive advantages of late-stage autophagy inhibition by exploring the mechanisms underlying autophagy's impact on TRAIL sensitivity. Current preclinical and clinical investigations are inspected, showing the potential of targeting late-stage autophagy for sensitizing resistant cancer cells to TRAIL-induced apoptosis. This review emphasizes the significance of optimizing autophagy modulation to enhance TRAIL-mediated therapy and overcome the challenge of treatment resistance in cancer. We offer insights and recommendations for guiding the development of potential therapeutic strategies aimed at overcoming the challenges posed by treatment-resistant cancers.

Activation of sphingosine-1-phosphate receptor 2 (S1PR2) upregulates dihydropyrimidine dehydrogenase (DPD) expression in colon cancer cells.

Dihydropyrimidine dehydrogenase (DPD) is a major determinant of cancer 5-fluorouracyl (5-FU) resistance via its direct degradation. However, the mechanisms of tumoral DPD upregulation have not been fully understood. This study aimed to explore the role of S1PR2 in the regulation of tumoral DPD expression, identifying S1PR2 as the potential target for reversing 5-FU resistance. Western blot was used to analyze S1PR2 expression in cultured cancer cells and human colorectal cancer (CRC) tissues. 5-FU resistance was estimated in mouse xenografts of HT-29sh-S1PR2 and SW480S1PR2 cells. HPLC-UV was used to measure 5-FU levels in the xenografts. Chromatin immunoprecipitation (ChIP) was used to analyze the binding of YAP1/TEAD1 to the TWIST1 promoter. A luciferase reporter was used to analyze the binding of TWIST1 to the DPYD promoter. S1PR2 was highly expressed in cancer cell lines and human CRC tissues. Activation of S1PR2 upregulated DPD expression, leading to 5-FU resistance. Mechanistically, activated S1PR2 upregulated nuclear TWIST1 by activating the Hippo/TEAD1-TWIST1 pathway. Nuclear TWIST1 interacted with the JMJD3-RNA Pol II complex, resulting in the interaction of TWIST1 with the DPYD promoter, thus increasing H3K27me3-enriched DPYD transcription. These findings were confirmed in xenografted human colon cancer cells in nude mice. Transfection with an S1PR2 expression vector led to the upregulation of DPD, blunting the sensitivity of SW480S1PR2 cells to 5-FU by 45.14 %. Conversely, knockdown of S1PR2 resulted in a decrease of DPD, thus increasing the sensitivity of HT-29sh-S1PR2 cells to 5-FU by 62.12 %. Molecular analysis of these xenografts confirmed the role of S1PR2 in upregulating DPD expression by activating the Hippo/TEAD1-JMJD3 pathway. Activation of S1PR2 upregulated DPD expression by activating the Hippo/TWIST1-JMJD3 pathway. S1PR2 is therefore a potential target for novel inhibitors that may reverse 5-FU resistance in cancer therapy.

Pyrimidine-based dual-target inhibitors targeting epidermal growth factor receptor for overcoming drug resistance in cancer therapy(2006-present).

The epidermal growth factor receptor (EGFR) is a pivotal member of the epidermal growth factor receptor family, exerting crucial regulatory influence on cellular physiological processes, particularly in relation to cell growth, proliferation, and differentiation. In recent years, numerous EGFR inhibitors have been introduced to the market; unfortunately, the effectiveness of single-target EGFR inhibitors has been compromised due to the development of drug resistance caused by EGFR mutations. Despite attempts by some researchers to address this issue through combination therapy with two or more drugs, instances of dose-limiting toxicities have been observed. Consequently, EGFR dual-target inhibitors have emerged as a burgeoning field in cancer treatment, offering a novel therapeutic option for solid tumors with the added benefits of reduced risk of resistance, lower dosage requirements, diminished toxicity profiles, and enhanced efficacy. At present, a series of EGFR dual-target inhibitors with diverse structures have been developed successively. In this study, we initially investigated the pyrimidine-based EGFR dual-target inhibitors that have been reported in the past two decades and categorized them into aminopyrimidine derivatives and heterocyclic pyrimidine derivatives with increased molecular complexity. Subsequently, we comprehensively summarized the biological activity and structure-activity relationship of this class of inhibitors in the context of cancer therapy, while also exploring potential opportunities and challenges associated with their application in this field. The present study provides a partial framework to guide future endeavors in drug development.

Identification of the atypical antipsychotic Asenapine as a direct survivin inhibitor with anticancer properties and sensitizing effects to conventional therapies.

Therapy resistance in human cancers is a major limitation in Clinical Oncology. In this regard, overexpression of anti-apoptotic proteins, such as survivin, has been described in several tumors, contributing to this clinical issue. Survivin has a dual role in key cellular functions, inducing cell cycle progression and inhibiting apoptosis; thus, survivin is an attractive target for cancer therapy. Therefore, we focused on identifying and validating a novel specific, directly binding survivin inhibitor for cancer treatment and tumor sensitization to conventional proapoptotic therapies. In this work, we conducted a structure-based high-throughput virtual screening at the survivin homodimerization domain. Asenapine Maleate (AM), an approved drug for central nervous system diseases, was identified as a direct binder of the survivin homodimerization domain and it significantly affected cell viability of lung, colon, and brain cancer cell lines. Direct interaction of AM to survivin protein was corroborated by surface plasmon resonance and a specific survivin protein decrease was observed in cancer cells, compared to other inhibitors of apoptosis proteins. Therapeutic in vivo studies showed an impairment of tumor growth in AM-treated mice. Finally, a synergistic anticancer effect was detected in vitro when combined with different conventional chemotherapies, and in vivo studies showed higher antitumor effects when combined with cisplatin. Altogether, our results identify AM as a specific direct binding inhibitor of survivin, showing anticancer properties in vitro and in vivo and sensitizing effects when combined with cisplatin, opening the possibility of repositioning this approved drug for cancer treatment.

Syntheses of differentially fluorinated triazole-based 1-deoxysphingosine analogues en route to SphK inhibitors.

This study focuses on the stereoselective syntheses of 1-deoxysphingosine analogues as potential inhibitors of sphingosine kinase (SphK), particularly targeting its isoforms SphK1 and SphK2, which are implicated in cancer progression and therapy resistance. The research builds on previous work by designing a series of analogues featuring systematic structural modifications like the incorporation of a triazole ring, varying degrees of fluorination, and different head groups (e.g., guanidino, N-methylamino, and N,N-dimethylamino). These modifications aimed to enhance polar and hydrophobic interactions especially with SphK2. The synthesized compounds were evaluated for their inhibitory activity, revealing that certain derivatives, particularly those with guanidino groups and heptafluoropropyl fragments at the lipidic tail, exhibited significant potency and selectivity towards SphK2. Docking studies supported these findings by showing favorable binding interactions within the SphK2 active site, which were less pronounced in SphK1, correlating with the observed selectivity. This work contributes to the development of novel 1-deoxysphingosine analogues targeting SphK inhibition, as well as to the knowledge of the differential topology of the active sites in SphK1 and SphK2.

ArfGAP with the SH3 Domain, Ankyrin Repeat and PH Domain 1 Inversely Regulates Programmed Death-Ligand 1 Through Negative Feedback of Phosphorylated Epithelial Growth Factor Receptor and Activation of Nuclear Factor-Kappa B in Non-Small Cell Lung Cancer.

Signaling pathways centered on the G-protein ADP-ribosylation factor 6 (Arf6) and its downstream effector ArfGAP with the SH3 Domain, Ankyrin Repeat and PH Domain 1 (AMAP1) drive cancer invasion, metastasis, and therapy resistance. The Arf6-AMAP1 pathway has been reported to promote receptor recycling leading to programmed cell death-ligand 1 (PD-L1) overexpression in pancreatic ductal carcinoma. Moreover, AMAP1 regulates of nuclear factor-kappa B (NF-κB), which is an important molecule in inflammation and immune activation, including tumor immune interaction through PD-L1 regulation. In this study, we investigated the function of AMAP1 on PD-L1 expression using lung cancer cells. We used two non-small cell lung cancer cell lines. Protein expression was evaluated by Western blotting. AMAP1 and NF-kB expression were reduced by conventional siRNA methods, and osimertinib was used as an epithelial growth factor receptor (EGFR) inhibitor. Multiple analysis of receptor tyrosine kinases (RTKs) was conducted using a semi-comprehensive RTKs assay. We found that AMAP1 inversely regulated PD-L1 expression. Based on these results, we examined the activation levels of RTKs associated with both AMAP1 and PD-L1. Following a semi-comprehensive phosphorylated RTK assay, we observed the upregulation of phosphorylated EGFR (pEGFR) led by the downregulation of AMAP1. The inhibition of pEGFR by osimertinib downregulates PD-L1 expression. We investigated the relationships between AMAP1, NF-κB, and PD-L1 expression. AMAP1 knockdown upregulated the expression of both NF-κB and PD-L1. Subsequently, NF-κB knockdown downregulated PD-L1 levels, while double knockdown of AMAP1 and NF-κB, restored PD-L1 expression. AMAP1 may inversely regulate PD-L1 through negative feedback of pEGFR and activation of NF-κB in NSCLC cell lines.

Pan-cancer association of a mitochondrial function score with genomic alterations and clinical outcome

Mitochondria are pivotal in cellular energy metabolism and have garnered significant attention for their roles in cancer progression and therapy resistance. Despite this, the functional diversity of mitochondria across various cancer types remains inadequately characterized. This study seeks to fill this knowledge gap by introducing and validating MitoScore—a novel metric designed to quantitatively assess mitochondrial function across a wide array of cancers. Our investigation evaluates the capacity of MitoScore not only to distinguish between tumor and adjacent normal tissues but also to serve as a predictive marker for clinical outcomes. We analyzed gene expression data from 24 cancer types and corresponding normal tissues using the TCGA database. MitoScore was calculated by summing the normalized expression levels of six mitochondrial genes known to be consistently altered across multiple cancers. Differential gene expression was assessed using DESeq2, with a focus on identifying significant changes in mitochondrial function. MitoScore’s associations with tumor proliferation, hypoxia, aneuploidy, and clinical outcomes were evaluated using Spearman’s correlation, linear regression, and Kaplan–Meier survival analyses. MitoScore was significantly higher in tumor tissues compared to normal tissues across most cancer types (p < 0.001). It positively correlated with tumor proliferation rates (r = 0.46), hypoxia scores (r = 0.61), and aneuploidy (r = 0.44), indicating its potential as a marker of aggressive tumor behavior. High MitoScore was also associated with poorer prognosis in several cancer types, suggesting its utility as a predictive biomarker for clinical outcomes. This study introduces MitoScore, a metric for mitochondrial activity often elevated in tumors and linked to poor prognosis. It correlates positively with hypoxia and negatively with stromal and immune infiltration, highlighting mitochondria’s role in the tumor microenvironment. MitoScore’s association with genomic instability, such as aneuploidy, suggests mitochondrial dysfunction contributes to cancer progression. Despite challenges in mitochondrial-targeted therapies, MitoScore may identify tumors responsive to such treatments, warranting further research for clinical application.

Implications and mechanisms of O-GlcNAcylation in cancer therapy resistance

O-linked-N-acetylglucosaminylation (O-GlcNAcylation), one of the protein post-translational modifications, is the process of adding O-linked-β-D-N-acetylglucosaminylation (O-GlcNAc) to serine and threonine residues of proteins. O-GlcNAcylation regulates various fundamental cell biological processes, including gene transcription, signal transduction, and cellular metabolism. The role of dysregulated O-GlcNAcylation in tumorigenesis has been recognized, but its role in cancer therapy tolerance has not been elucidated. Therefore, this paper provides the latest evidence on the role of O-GlcNAcylation in cancer therapy responsiveness to understand the impact of O-GlcNAcylation on cancer therapy outcomes, as well as analyzing several possible mechanisms by which O-GlcNAcylation dysregulation affects cancer therapy efficacy, and discusses the possibility of O-GlcNAcylation as a cancer therapy sensitizer.

The advancement of structure, bioactivity, mechanism, and synthesis of bufotalin.

Toad venom, a family of toxic yet pharmacologically valuable biotoxins, has long been utilized in traditional medicine and holds significant promise in modern drug development. Bufotalin, a prominent bufotoxin, has demonstrated potent cytotoxic properties through mechanisms such as apoptosis induction, cell cycle arrest, endoplasmic reticulum stress activation, and inhibition of metastasis by modulating key pathways including Akt, p53, and STAT3/EMT signaling-these multi-target mechanisms position bufotalin as a promising agent to combat multidrug resistance in cancer therapy. Additionally, advances in bufotalin synthesis, including chemical and biocatalytic methods, have streamlined production, with strategies such as C14-α-hydroxylation and novel coupling techniques enhancing yield and reducing environmental impact. This review consolidates recent progress on bufotalin's structure, activity, cytotoxic mechanisms, and synthetic methodologies, offering a foundation for further development as an innovative chemotherapy agent.