A Functional Screening Identifies a New Organic Selenium Compound Targeting Cancer Stem Cells: Role of c-Myc Transcription Activity Inhibition in Liver Cancer

TTC36 promotes proliferation and drug resistance in hepatocellular carcinoma cells by inhibiting c-Myc degradation

High c-Myc protein accumulation contributes to the proliferation, invasion, and drug resistance in multiple cancer cells, but the underlying mechanism about c-Myc accumulation remains not to be elucidated. Here, we demonstrate that TTC36 promotes c-Myc protein accumulation in hepatocellular carcinoma cells, thereby driving the proliferation and sorafenib resistance in hepatocellular carcinoma cells. Ttc36 depletion disrupts the interaction between SET and PPP2R1A, consequently activating PP2A. Activated PP2A directly dephosphorylates p-c-MycS62 and activates GSK3β, relying on AKT, leading increased phosphorylation of p-c-MycT58, finally promotes FBXW7-mediated polyubiquitination and degradation of c-Myc. Inhibitors targeting GSK3β and PP2A effectively reverse the sorafenib resistance promoted by TTC36. These findings highlight the crucial role of TTC36 in c-Myc accumulation-caused proliferation and sorafenib resistance in HCC, providing a promising combination strategy for treating patients with c-Myc protein accumulation in advanced HCC.

DCAF13 influences breast cancer chemotherapy resistance through metabolic reprogramming by regulating c-Myc expression

Chemotherapy resistance remains a major obstacle in breast cancer treatment. This study identifies DCAF13, a substrate recognition receptor of the CRL4 ubiquitin ligase complex, as a critical regulator of chemotherapy resistance through c-Myc-driven metabolic reprogramming. We found that DCAF13 expression was significantly upregulated in chemotherapy-resistant breast cancer cell lines compared to their parental counterparts. Inhibition of DCAF13 enhanced chemotherapy sensitivity, whereas its overexpression suppressed drug sensitivity. Mechanistically, DCAF13 upregulated c-Myc expression, driving metabolic reprogramming, characterized by increased glycolysis and oxidative phosphorylation. This metabolic shift promoted cell proliferation and resistance to chemotherapy. Clinically, DCAF13 expression correlated with poor prognosis in breast cancer patients, particularly in advanced stages and triple-negative breast cancer (TNBC). Our findings highlight the DCAF13-c-Myc axis as a critical mediator of chemotherapy resistance, suggesting that targeting this pathway could provide novel therapeutic strategies to overcome drug resistance in breast cancer. Further clinical studies are needed to explore the potential of DCAF13 as a therapeutic target.

Pseudouridine synthase 1 promotes progression of hepatocellular carcinoma via mTOR and MYC signaling pathways

Pseudouridine synthases (PUSs) are associated with the development and progression of various cancers. However, the role of pseudouridine synthase 1 (PUS1) on HCC is unclear. The purpose of this study is to explore the biological role and mechanism of PUS1 in HCC growth and progression. We identified the expression of PUS1 in HCC. The biological roles and downstream cell signaling pathways of PUS1 were explored to clarify the molecular mechanism of PUS1 in the growth and development of HCC. The results showed that the expression of PUS1 was correlated with HCC progression, metastasis, and poor survival. In addition, the knockdown of PUS1 dramatically inhibited cell proliferation and colony formation and promoted cell apoptosis. GSEA analysis revealed that c-MYC, DNA repair, and mTORC1 pathways were significantly enriched in patients with high PUS1 expression. An intersection of the PUS1-dependent Ψ modification genes and c-MYC or mTORC1 pathway genes was performed. The expression of a part of these genes changed after PUS1 knockdown. Meanwhile, the expression of c-MYC and mTOR were down-regulated after PUS1 knockdown, but the inhibitory effect of PUS1 on cell growth capacity was not enhanced after inhibiting c-MYC or mTOR pathways. In conclusion, PUS1 regulates the occurrence and development of HCC through c-MYC and mTOR-related signaling pathways. It could be a novel molecule for clinical diagnosis, progression surveillance, prognosis assessment and therapeutic target of HCC.

Hydrogel Microneedle Patches Loaded with Stem Cell Mitochondria-Enriched Microvesicles Boost the Chronic Wound Healing

Rescuing or compensating mitochondrial function represents a promising therapeutic avenue for radiation-induced chronic wounds. Adult stem cell efficacies are primarily dependent on the paracrine secretion of mitochondria-containing extracellular vesicles (EVs). However, effective therapeutic strategies addressing the quantity of mitochondria and mitochondria-delivery system are lacking. Thus, in this study, we aimed to design an effective hydrogel microneedle patch (MNP) loaded with stem cell-derived mitochondria-rich EVs to gradually release and deliver mitochondria into the wound tissues and boost wound healing. We, first, used metformin to enhance mitochondrial biogenesis and thereby increasing the secretion of mitochondria-containing EVs (termed "Met-EVs") in adipose-derived stem cells. To verify the therapeutic effects of Met-EVs, we established an in vitro and an in vivo model of X-ray-induced mitochondrial dysfunction. The Met-EVs ameliorated the mitochondrial dysfunction by rescuing mitochondrial membrane potential, increasing adenosine 5'-triphosphate levels, and decreasing reactive oxygen species production by transferring active mitochondria. To sustain the release of EVs into damaged tissues, we constructed a Met-EVs@Decellularized Adipose Matrix (DAM)/Hyaluronic Acid Methacrylic Acid (HAMA)-MNP. Met-EVs@DAM/HAMA-MNP can load and gradually release Met-EVs and their contained mitochondria into wound tissues to alleviate mitochondrial dysfunction. Moreover, we found Met-EVs@DAM/HAMA-MNP can markedly promote macrophage polarization toward the M2 subtype with anti-inflammatory and regenerative functions, which can, in turn, enhance the healing process in mice with skin wounds combined radiation injuries. Collectively, we successfully fabricated a delivery system for EVs, Met-EVs@DAM/HAMA-MNP, to effectively deliver stem cell-derived mitochondria-rich EVs. The effectiveness of this system has been demonstrated, holding great potential for chronic wound treatments in clinic.

The correlation between cancer stem cells and epithelial-mesenchymal transition: molecular mechanisms and significance in cancer theragnosis

The connections between cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT) is critical in cancer initiation, progression, metastasis, and therapy resistance, making it a focal point in cancer theragnosis. This review provides a panorama of associations and regulation pathways between CSCs and EMT, highlighting their significance in cancer. The molecular mechanisms underlined EMT are thoroughly explored, including the involvement of key transcription factors and signaling pathways. In addition, the roles of CSCs and EMT in tumor biology and therapy resistance, is further examined in this review. The clinical implications of CSCs-EMT interplay are explored, including identifying mesenchymal-state CSC subpopulations using advanced research methods and developing targeted therapies such as inhibitors and combination treatments. Overall, understanding the reciprocal relationship between EMT and CSCs holds excellent potential for informing the development of personalized therapies and ultimately improving patient outcomes.

UTP11 promotes the growth of hepatocellular carcinoma by enhancing the mRNA stability of Oct4

BACKGROUND

Several publications suggest that UTP11 may be a promising gene engaged for involvement of hepatocellular carcinoma (HCC) pathology. However, there are extremely limited biological, mechanistic and clinical studies of UTP11 in HCC.

METHODS

To anayze the UTP11 mRNA expression in HCC and normal clinical samples and further investigate the correlation between UTP11 expression and pathology and clinical prognosis via the Cancer Tissue Gene Atlas (TCGA) database. The protein levels of UTP11 were checked using the Human Protein Atlas (HPA) database. GO-KEGG enrichment was performed from Cancer Cell Line Encyclopedia (CCLE) database and TCGA dataset. The levels of UTP11 were tested with qRT-PCR and western blotting assays. Cell viability, immunofluorescence and flow cytometry assays and animal models were used to explore the potential involvement of UTP11 in regulating HCC growth in vitro and in vivo. The correlation of UTP11 and tumor stemness scores and stemness-associated proteins from TCGA database. The mRNA stability was treated with Actinomycin D, followed by testing the mRNA expression using qRT-PCR assay.

RESULTS

UTP11 was highly expressed in HCC samples compared to normal tissues from TCGA database. Similarly, UTP11 protein expression levels were obviously elevated in HCC tissue samples from HPA database. Furthermore, UTP11 levels were correlated with poor prognosis in HCC patient samples in TCGA dataset. In addition, the UTP11 mRNA levels was notably enhanced in different HCC cell lines than in normal liver cells and knocking down UTP11 was obviously reduced the viability and cell death of HCC cells. UTP11 knockdown suppressed the tumor growth of HCC in vivo experiment and extended the mice survival time. GO-KEEG analysis from CCLE and TCGA database suggested that UTP11 might involve in RNA splicing and the stability of mRNA. Further, UTP11 was positively correlated with tumor stemness scores and stemness-associated proteins from TCGA database. Knockdown of UTP11 was reduced the expression of stem cell-related genes and regulated the mRNA stability of Oct4.

CONCLUSIONS

UTP11 is potentially a diagnostic molecule and a therapeutic candidate for treatment of HCC.

Regulation and signaling pathways in cancer stem cells: implications for targeted therapy for cancer

Cancer stem cells (CSCs), initially identified in leukemia in 1994, constitute a distinct subset of tumor cells characterized by surface markers such as CD133, CD44, and ALDH. Their behavior is regulated through a complex interplay of networks, including transcriptional, post-transcriptional, epigenetic, tumor microenvironment (TME), and epithelial-mesenchymal transition (EMT) factors. Numerous signaling pathways were found to be involved in the regulatory network of CSCs. The maintenance of CSC characteristics plays a pivotal role in driving CSC-associated tumor metastasis and conferring resistance to therapy. Consequently, CSCs have emerged as promising targets in cancer treatment. To date, researchers have developed several anticancer agents tailored to specifically target CSCs, with some of these treatment strategies currently undergoing preclinical or clinical trials. In this review, we outline the origin and biological characteristics of CSCs, explore the regulatory networks governing CSCs, discuss the signaling pathways implicated in these networks, and investigate the influential factors contributing to therapy resistance in CSCs. Finally, we offer insights into preclinical and clinical agents designed to eliminate CSCs.

First Generation of Antioxidant Precursors for Bioisosteric Se-NSAIDs: Design, Synthesis, and In Vitro and In Vivo Anticancer Evaluation

The introduction of selenium (Se) into organic scaffolds has been demonstrated to be a promising framework in the field of medicinal chemistry. A novel design of nonsteroidal anti-inflammatory drug (NSAID) derivatives based on a bioisosteric replacement via the incorporation of Se as diacyl diselenide is reported. The antioxidant activity was assessed using the DPPH radical scavenging assay. The new Se-NSAID derivatives bearing this unique combination showed antioxidant activity in a time- and dose-dependent manner, and also displayed different antiproliferative profiles in a panel of eight cancer cell lines as determined by the MTT assay. Ibuprofen derivative 5 was not only the most antioxidant agent, but also selectively induced toxicity in all the cancer cell lines tested (IC50 < 10 µM) while sparing nonmalignant cells, and induced apoptosis partially without enhancing the caspase 3/7 activity. Furthermore, NSAID derivative 5 significantly suppressed tumor growth in a subcutaneous colon cancer xenograft mouse model (10 mg/kg, TGI = 72%, and T/C = 38%) without exhibiting any apparent toxicity. To our knowledge, this work constitutes the first report on in vitro and in vivo anticancer activity of an unprecedented Se-NSAID hybrid derivative and its rational use for developing precursors for bioisosteric selenocompounds with appealing therapeutic applications.

Cancer Stem Cells in Hepatocellular Carcinoma: Intrinsic and Extrinsic Molecular Mechanisms in Stemness Regulation

Hepatocellular carcinoma (HCC) remains the most predominant type of liver cancer with an extremely poor prognosis due to its late diagnosis and high recurrence rate. One of the culprits for HCC recurrence and metastasis is the existence of cancer stem cells (CSCs), which are a small subset of cancer cells possessing robust stem cell properties within tumors. CSCs play crucial roles in tumor heterogeneity constitution, tumorigenesis, tumor relapse, metastasis, and resistance to anti-cancer therapies. Elucidation of how these CSCs maintain their stemness features is essential for the development of CSCs-based therapy. In this review, we summarize the present knowledge of intrinsic molecules and signaling pathways involved in hepatic CSCs, especially the CSC surface markers and associated signaling in regulating the stemness characteristics and the heterogeneous subpopulations within the CSC pool. In addition, we recapitulate the effects of crucial extrinsic cellular components in the tumor microenvironment, including stromal cells and immune cells, on the modulation of hepatic CSCs. Finally, we synopsize the currently valuable CSCs-targeted therapy strategies based on intervention in these intrinsic and extrinsic molecular mechanisms, in the hope of shedding light on better clinical management of HCC patients.

Genistein Restricts the Epithelial Mesenchymal Transformation (EMT) and Stemness of Hepatocellular Carcinoma via Upregulating miR-1275 to Inhibit the EIF5A2/PI3K/Akt Pathway

Simple Summary

Genistein is a natural phytoestrogen with various antitumor effects. Our study focused on exploring the mechanisms of microRNAs and genistein to inhibit the epithelial mesenchymal transformation (EMT) and stemness of hepatocellular carcinoma (HCC). We found that miR-1275 was more highly expressed in HCC cells treated with genistein compared with the control. Then, we performed series functional experiments to explore the relationship between genistein and miR-1275 in HCC. The inhibition of genistein on HCC cells was enhanced by the increase in treatment time and dose, and miR-1275 can be raised by genistein. The overall survival and recurrence-free survival of HCC patients with low expressed miR-1275 were lower than those of those with high expression levels. The experimental results exhibited that genistein and miR-1275 can both significantly suppress the proliferation, migration, invasion, metastasis, EMT and stemness of HCC. Moreover, the inhibition can be further enhanced with the co-existence of miR-1275 mimic and genistein. Finally, we demonstrated that miR-1275 can inhibit the EMT and stemness of HCC via inhibiting the EIF5A2/PI3K/Akt pathway. Our findings proved that genistein can inhibit the EIF5A2/PI3K/Akt pathway by upregulating miR-1275 so as to attenuate the EMT and stemness of HCC cells to restrict their progression and metastasis.

Abstract

Purpose: Genistein is a natural phytoestrogen with various antitumor effects. In recent years, some microRNAs (miRNA) in cancer cells have been reported to be regulated by genistein. Our study focused on exploring the mechanisms of miRNA upregulation to inhibit the epithelial mesenchymal transformation (EMT) and stemness of hepatocellular carcinoma (HCC). Patients and Methods: MiR-1275 was discovered by the transcriptome sequencing of miRNA expression profiles in HepG2 cells treated with genistein or DMSO as a control. Then, we performed series functional experiments in vitro and vivo to explore the relationship between genistein and miR-1275 in HCC. The target gene (Eukaryotic initiation factor 5A2, EIF5A2) of miR-1275 was predicted by databases and finally determined by a dual luciferase reporter assay. The downstream signaling pathway of EIF5A2 was assessed by bioinformatics analysis and Western blot. Results: the inhibition of genistein on the viability of HCC cells was enhanced by the increase in treatment time and dose, but it had no obvious inhibitory effect on normal hepatocytes (QSG-7701). Through qRT-PCR and transcriptome sequencing, we discovered that miR-1275 was lowly expressed in HCC, and it can be raised by genistein. The overall survival (OS) and recurrence-free survival (RFS) of HCC patients with lowly expressed miR-1275 were lower than those of those with high expression levels. In vitro and vivo experiments exhibited that genistein and the overexpression of miR-1275 can both significantly suppress the proliferation, migration, invasion, metastasis, EMT and stemness of HCC. Moreover, the inhibition can be further enhanced when miR-1275 mimic and genistein exist together. Finally, we demonstrated that miR-1275 can inhibit the epithelial mesenchymal transformation (EMT) and stemness of HCC via inhibiting the EIF5A2/PI3K/Akt pathway. Conclusion: Our findings proved that genistein can inhibit the EIF5A2/PI3K/Akt pathway by upregulating miR-1275 so as to attenuate the EMT and stemness of HCC cells to restrict their progression and metastasis.