Aberrant activation of the CD45-Wnt signaling axis promotes stemness and therapy resistance in colorectal cancer cells

Single-cell data revealed the function of natural killer cells and macrophage cells in chemotherapy tolerance in acute myeloid leukemia

Background

Acute myeloid leukemia (AML) is highly prevalent and heterogeneous among adult acute leukemias. Current chemotherapeutic approaches for AML often face the challenge of drug resistance, and AML immune cells play an important role in the regulation of AML drug resistance. Thus, it is of key significance to explore the regulatory mechanisms of immune cells in AML to alleviate chemotherapy resistance in AML.

Methods

Based on AML single-cell transcriptomic data, this study revealed the differences in the expression of immune cell subpopulations and marker genes in AML patients in the complete remission group (CR) compared to AML patients in the non-complete remission group (non-CR) after chemotherapy. Functional enrichment by clusterprofiler revealed the regulatory functions of differentially expressed genes (DEGs) in AML. AUCell enrichment scores were used to assess the immunoregulatory functions of immune cells. Pseudotime analysis was used to construct immune cell differentiation trajectories. CellChat was used for cellular communication analysis to elucidate the interactions between immune cells. Survival analysis with the R package "survival" revealed the role of immune cell marker genes on AML prognosis. Finally, the wound healing and trans-well assay were performed.

Results

Single-cell clustering analysis revealed that NK/T cells and macrophage cells subpopulations were significantly higher in non-CR AML patients than in CR AML. AUCell enrichment analysis revealed that FCAR+ and FCGR3A+ macrophages were significantly more active in the non-CR group and correlated with processes regulating cellular energy metabolism and immune cell activity. Differentially expressed NK cell marker genes between CR and non-CR groups mainly included HBA1, S100A8, and S100A9, which were associated with cancer drug resistance regulation, these marker genes of (FCAR, FCGR3A, PREX1, S100A8 and S100A9) were upregulated in human chronic myeloid leukemia cells (HAP1) and silencing of S100A8 affected migration and invasion of HAP1 cells. In particular, the differentiation pathways of macrophages and NK cells in non-CR differed from those of patients in the CR group. Cellular communication analyses showed that ligand-receptor pairs between NK cells and macrophage cells mainly included HLA-E-KLRK1, HLA-E-KLRC1, HLA-E-CD94:NKG2A, CLEC2B-KLRB1. In addition, LGALS9-CD45, CCL3L1- CCR1, CCL3-CCR1 between these two immune cells mainly regulate secreted signaling to mediate AML progression. Marker genes in NK/T cells and macrophage cells were significantly associated with AML prognosis.

Conclusion

This study reveals the potential role of NK cells and macrophages in AML chemoresistance through the analysis of single-cell RNA sequencing data. This provides new ideas and insights into the key mechanisms of immune cells in AML treatment.

GTSE1-driven ZEB1 stabilization promotes pulmonary fibrosis through the epithelial-to-mesenchymal transition

G2 and S phase-expressed protein 1 (GTSE1) has been implicated in the development of pulmonary fibrosis (PF); however, its biological function, molecular mechanism, and potential clinical implications remain unknown. Here, we explored the genomic data of patients with idiopathic PF (IPF) and found that GTSE1 expression is elevated in their lung tissues, but rarely expressed in normal lung tissues. Thus, we explored the biological role and downstream events of GTSE1 using IPF patient tissues and PF mouse models. The comprehensive bioinformatics analyses suggested that the increase of GTSE1 in IPF is linked to the enhanced gene signature for the epithelial-to-mesenchymal transition (EMT), leading us to investigate the potential interaction between GTSE1 and EMT transcription factors. GTSE1 preferentially binds to the less stable form of zinc-finger E-box-binding homeobox 1 (ZEB1), the unphosphorylated form at Ser585, inhibiting ZEB1 degradation. Consistently, the ZEB1 protein level in IPF patient and PF mouse tissues correlates with the GTSE1 protein level and the amount of collagen accumulation, representing fibrosis severity. Collectively, our findings highlight the GTSE1-ZEB1 axis as a novel driver of the pathological EMT characteristic during PF development and progression, supporting further investigation into GTSE1-targeting approaches for PF treatment.

PTPRC Inhibits Ferroptosis of Osteosarcoma Cells via Blocking TFEB/FTH1 Signaling

Protein tyrosine phosphatase receptor type C (PTPRC) is reported to function as an oncogenic role in various cancer. However, the studies on the roles of PTPRC in osteosarcoma (OS) are limited. This study aimed to explore the potentials of PTPRC in OS. mRNA levels were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Protein expression was detected by western blot. Lysosome biogenesis was determined using immunofluorescence. The binding sites of transcription factor EB (TFEB) on the promoter of ferritin heavy chain 1 (FTH1) were predicted by the online dataset JASPAR and confirmed by luciferase and chromatin immunoprecipitation (ChIP) assays. Cell death was determined using propidium iodide (PI) and TdT-mediated dUTP nick-end labeling (TUNEL) staining. The results showed that PTPRC was significantly overexpressed in OS tissues and cells. PTPRC knockdown promoted the phosphorylation and nuclear translocation of TFEB. Moreover, PTPRC knockdown markedly promoted lysosome biogenesis and the accumulation of ferrous ion (Fe2+), whereas decreased the release of glutathione (GSH). Besides, PTPRC knockdown significantly promoted autophagy and downregulated mRNA expression of FTH1 and ferritin light chain (FTL). Additionally, TFEB transcriptionally inactivated FTH1. PTPRC knockdown significantly promoted the ferroptosis of OS cells, which was markedly alleviated by TFEB shRNA. Taken together, PTPRC knockdown-mediated TFEB phosphorylation and translocation dramatically promoted lysosome biogenesis, ferritinophagy, as well as the ferroptosis of OS cells via regulating FTH1/FTL signaling. Therefore, PTPRC/TFEB/FTH1 signaling may be a potential target for OS.

Circulating tumor cells shielded with extracellular vesicle-derived CD45 evade T cell attack to enable metastasis

Circulating tumor cells (CTCs) are precursors of distant metastasis in a subset of cancer patients. A better understanding of CTCs heterogeneity and how these CTCs survive during hematogenous dissemination could lay the foundation for therapeutic prevention of cancer metastasis. It remains elusive how CTCs evade immune surveillance and elimination by immune cells. In this study, we unequivocally identified a subpopulation of CTCs shielded with extracellular vesicle (EVs)-derived CD45 (termed as CD45+ CTCs) that resisted T cell attack. A higher percentage of CD45+ CTCs was found to be closely correlated with higher incidence of metastasis and worse prognosis in cancer patients. Moreover, CD45+ tumor cells orchestrated an immunosuppressive milieu and CD45+ CTCs exhibited remarkably stronger metastatic potential than CD45- CTCs in vivo. Mechanistically, CD45 expressing on tumor surfaces was shown to form intercellular CD45-CD45 homophilic interactions with CD45 on T cells, thereby preventing CD45 exclusion from TCR-pMHC synapse and leading to diminished TCR signaling transduction and suppressed immune response. Together, these results pointed to an underappreciated capability of EVs-derived CD45-dressed CTCs in immune evasion and metastasis, providing a rationale for targeting EVs-derived CD45 internalization by CTCs to prevent cancer metastasis.

Lectin-Based Immunophenotyping and Whole Proteomic Profiling of CT-26 Colon Carcinoma Murine Model

A murine colorectal carcinoma (CRC) model was established. CT26 colon carcinoma cells were injected into BALB/c mice's spleen to study the primary tumor and the mechanisms of cell spread of colon cancer to the liver. The CRC was verified by the immunohistochemistry of Pan Cytokeratin and Vimentin expression. Immunophenotyping of leukocytes isolated from CRC-bearing BALB/c mice or healthy controls, such as CD19+ B cells, CD11+ myeloid cells, and CD3+ T cells, was carried out using fluorochrome-labeled lectins. The binding of six lectins to white blood cells, such as galectin-1 (Gal1), siglec-1 (Sig1), Sambucus nigra lectin (SNA), Aleuria aurantia lectin (AAL), Phytolacca americana lectin (PWM), and galectin-3 (Gal3), was assayed. Flow cytometric analysis of the splenocytes revealed the increased binding of SNA, and AAL to CD3 + T cells and CD11b myeloid cells; and increased siglec-1 and AAL binding to CD19 B cells of the tumor-bearing mice. The whole proteomic analysis of the established CRC-bearing liver and spleen versus healthy tissues identified differentially expressed proteins, characteristic of the primary or secondary CRC tissues. KEGG Gene Ontology bioinformatic analysis delineated the established murine CRC characteristic protein interaction networks, biological pathways, and cellular processes involved in CRC. Galectin-1 and S100A4 were identified as upregulated proteins in the primary and secondary CT26 tumor tissues, and these were previously reported to contribute to the poor prognosis of CRC patients. Modelling the development of liver colonization of CRC by the injection of CT26 cells into the spleen may facilitate the understanding of carcinogenesis in human CRC and contribute to the development of novel therapeutic strategies.

The Role of Tumor Stem Cells in Colorectal Cancer Drug Resistance

Background: Colorectal cancer is a major cause of mortality among the prevalent malignant tumors of the gastrointestinal tract. Although chemotherapy is a standard treatment for colorectal cancer, its efficacy is limited by chemoresistance. Recent studies have investigated targeting tumor stem cells as a potential new therapeutic approach for addressing chemoresistance in colorectal cancer. Colorectal cancer frequently relapses, with tumor stem cells often representing one of the leading causes of treatment failure. Purpose: Understanding drug resistance in colorectal cancer stem cells is crucial for improving treatment outcomes. By focusing on developing targeted therapies that specifically address drug resistance in colorectal cancer stem cells, there is potential to make significant advancements in the treatment of colorectal cancer.This approach may lead to more effective and lasting outcomes in patients battling colorectal cancer. Research Design: In this review, a comprehensive overview of recent research on colorectal cancer stem cell treatment resistance is presented.Results: Elucidating the key underlying mechanisms. This review also highlights the potential benefits of targeted therapies in overcoming colorectal cancer resistance to treatment. Conclusions: CCSCs are key players in drug resistance of CRC, indicating their potential as targets for effective therapy. Elucidating their role in this process could aid in discovering tailored treatment strategies.The significance of signaling pathways, TME, and miRNA in regulating drug resistance in CCSCs is been highlighted.

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.

Differential Gene Expression of Checkpoint Markers and Cancer Markers in Mouse Models of Spontaneous Chronic Colitis

The presence of checkpoint markers in cancer cells aids in immune escape. The identification of checkpoint markers and early cancer markers is of utmost importance to gain clarity regarding the relationship between colitis and progressive inflammation leading to cancer. Herein, the gene expression levels of checkpoint makers, cancer-related pathways, and cancer genes in colon tissues of mouse models of chronic colitis (Winnie and Winnie-Prolapse mice) using next-generation sequencing are determined. Winnie mice are a result of a Muc2 missense mutation. The identification of such genes and their subsequent expression and role at the protein level would enable novel markers for the early diagnosis of cancer in IBD patients. The differentially expressed genes in the colonic transcriptome were analysed based on the Kyoto Encyclopedia of Genes and Genomes pathway. The expression of several oncogenes is associated with the severity of IBD, with Winnie-Prolapse mice expressing a large number of key genes associated with development of cancer. This research presents a number of new targets to evaluate for the development of biomarkers and therapeutics.

Epigenetic regulation of temozolomide resistance in human cancers with an emphasis on brain tumors: Function of non-coding RNAs

Brain tumors, which are highly malignant, pose a significant threat to health and often result in substantial rates of mortality and morbidity worldwide. The brain cancer therapy has been challenging due to obstacles such as the BBB, which hinders effective delivery of therapeutic agents. Additionally, the emergence of drug resistance further complicates the management of brain tumors. TMZ is utilized in brain cancer removal, but resistance is a drawback. ncRNAs are implicated in various diseases, and their involvement in the cancer is particularly noteworthy. The focus of the current manuscript is to explore the involvement of ncRNAs in controlling drug resistance, specifically in the context of resistance to the chemotherapy drug TMZ. The review emphasizes the function of ncRNAs, particularly miRNAs, in modulating the growth and invasion of brain tumors, which significantly influences their response to TMZ treatment. Through their interactions with various molecular pathways, miRNAs are modulators of TMZ response. Similarly, lncRNAs also associate with molecular pathways and miRNAs, affecting the efficacy of TMZ chemotherapy. Given their functional properties, lncRNAs can either induce or suppress TMZ resistance in brain tumors. Furthermore, circRNAs, which are cancer controllers, regulate miRNAs by acting as sponges, thereby impacting the response to TMZ chemotherapy. The review explores the correlation between ncRNAs and TMZ chemotherapy, shedding light on the underlying molecular pathways involved in this process.

CD44 expression is correlated with osteosarcoma cell progression and immune infiltration and affects the Wnt/β-catenin signaling pathway

CD44 is associated with a variety of human diseases and plays a potential role in tumorigenesis, however, the mechanism of its role in osteosarcoma remains unclear. We analyzed the expression of CD44 in the Cancer Genome Atlas (TCGA) and genotype-tissue expression pan-cancer data and found that it was highly expressed in most tumors, including sarcoma. The expression of CD44 in osteosarcoma cell lines was higher than that in human osteoblast cell line in the results of the Western blot and Immunohistochemical staining assay. The results of colony formation assay and CCK 8 showed that CD44 improved the proliferation capacity of osteosarcoma cells, transwell assay and wound healing assay showed that CD44 improved the migration capacity of osteosarcoma cells. Further studies revealed that CD44 exerts its influence on the biological behavior of osteosarcoma cells through the Wnt/β-catenin signaling pathway. Since CD44 may be involved in the immune response, we analyzed the correlation between CD44 expression and immune cell infiltration in TCGA database using the previous cluster analyzer R software package, TIMER2.0 database and, GEPIA2 database, and found its involvement in the immune infiltration of osteosarcoma. Therefore, we believe that CD44 could be a potential target for the treatment of osteosarcoma patients and may be a candidate biomarker for immune infiltration-related prognosis.

Dihydroartemisinin inhibited stem cell-like properties and enhanced oxaliplatin sensitivity of colorectal cancer via AKT/mTOR signaling

Colorectal cancer (CRC) is a common tumor with high morbidity and mortality. The use of oxaliplatin (L-OHP) as a first-line treatment for CRC is limited due to chemoresistance. Growing evidence have revealed that the existence of cancer stem-like cells (CSLCs) is one of the important reasons for drug resistance and recurrence of cancers. Dihydroartemisinin (DHA), a derivative of artemisinin, has showed anticancer effects on a variety of malignancies, in addition to its antimalarial effects. However, the effect and mechanism of DHA on CSLCs and chemosensitivity in CRC cells remains unclear. In this study, we found that DHA inhibited cell viability in HCT116 and SW620 cells. Moreover, DHA decreased cell clonogenicity, and improved L-OHP sensitivity. Furthermore, DHA treatment attenuated tumor sphere formation, and the expressions of stem cell surface marker (CD133 and CD44) and stemness-associated transcription factor (Nanog, c-Myc, and OCT4). Mechanistically, the present findings showed that DHA inhibited of AKT/mTOR signaling pathway. The activation of AKT/mTOR signaling reversed DHA-decreased cell viability, clonogenicity, L-OHP resistance, tumor sphere, and expressions of stemness-associated protein in CRC. The inhibitory effect of DHA on tumorigenicity of CRC cells has also been demonstrated in BALB/c nude mice. In conclusion, this study revealed that DHA inhibited CSLCs properties in CRC via AKT/mTOR signaling, suggesting that DHA may be used as a potential therapeutic agent for CRC.

Colon cancer transcriptome

Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.

Tumor Microenvironmental Cytokines Drive NSCLC Cell Aggressiveness and Drug-Resistance via YAP-Mediated Autophagy

Dynamic reciprocity between cellular components of the tumor microenvironment and tumor cells occurs primarily through the interaction of soluble signals, i.e., cytokines produced by stromal cells to support cancer initiation and progression by regulating cell survival, differentiation and immune cell functionality, as well as cell migration and death. In the present study, we focused on the analysis of the functional response of non-small cell lung cancer cell lines elicited by the treatment with some crucial stromal factors which, at least in part, mimic the stimulus exerted in vivo on tumor cells by microenvironmental components. Our molecular and functional results highlight the role played by the autophagic machinery in the cellular response in terms of the invasive capacity, stemness and drug resistance of two non-small lung cancer cell lines treated with stromal cytokines, also highlighting the emerging role of the YAP pathway in the mutual and dynamic crosstalk between tumor cells and tumor microenvironment elements. The results of this study provide new insights into the YAP-mediated autophagic mechanism elicited by microenvironmental cytokines on non-small cell lung cancer cell lines and may suggest new potential strategies for future cancer therapeutic interventions.

The profile of circulating extracellular vesicles depending on the age of the donor potentially drives the rejuvenation or senescence fate of hematopoietic stem cells

Blood donor age has become a major concern due to the age-associated variations in the content and concentration of circulating extracellular nano-sized vesicles (EVs), including exosomes. These EVs mirror the state of their parental cells and transfer it to the recipient cells via biological messengers such as microRNAs (miRNAs, miRs). Since the behavior of hematopoietic stem cells (HSCs) is potentially affected by the miRs of plasma-derived EVs, a better understanding of the content of EVs is important for the safety and efficacy perspectives in blood transfusion medicine. Herein, we investigated whether the plasma-derived EVs of young (18-25 years) and elderly human donors (45-60 years) can deliver "youth" or "aging" signals into human umbilical cord blood (hUCB)-derived HSCs in vitro. The results showed that EVs altered the growth functionality and differentiation of HSCs depending on the age of the donor from which they are derived. EVs of young donors could ameliorate the proliferation and self-renewal potential of HSCs whereas those of aged donors induced senescence-associated differentiation in the target cells, particularly toward the myeloid lineage. These findings were confirmed by flow cytometric analysis of surface markers and microarray profiling of genes related to stemness (e.g., SOX-1, Nanog) and differentiation (e.g., PU-1). The results displayed an up-regulation of miR-29 and miR-96 and a down-regulation of miR-146 in EVs derived from elderly donors. The higher expression of miR-29 and miR-96 contributed to the diminished expression of CDK-6 and CDKN1A (p21), promoting senescence fate via cell growth suppression, while the lower expression of miR-146 positively regulates TRAF-6 expression to accelerate biological aging. Our findings reveal that plasma-derived EVs from young donors can reverse the aging-associated changes in HSCs, while vice versa, the EVs from elderly donors rather promote the senescence process.

SEC22B inhibition attenuates colorectal cancer aggressiveness and autophagic flux under unfavorable environment

Autophagy has bidirectional functions in cancer by facilitating cell survival and death in a context-dependent manner. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a large family of proteins essential for numerous biological processes, including autophagy; nevertheless, their potential function in cancer malignancy remains unclear. Here, we explored the gene expression patterns of SNAREs in tissues of patients with colorectal cancer (CRC) and discovered that SEC22B expression, a vesicle SNARE, was higher in tumor tissues than in normal tissues, with a more significant increase in metastatic tissues. Interestingly, SEC22B knockdown dramatically decreased CRC cell survival and growth, especially under stressful conditions, such as hypoxia and serum starvation, and decreased the number of stress-induced autophagic vacuoles. Moreover, SEC22B knockdown successfully attenuated liver metastasis in a CRC cell xenograft mouse model, with histological signs of decreased autophagic flux and proliferation within cancer cells. Together, this study posits that SEC22B plays a crucial role in enhancing the aggressiveness of CRC cells, suggesting that SEC22B might be an attractive therapeutic target for CRC.

Oncogenic and Receptor-Mediated Wnt Signaling Influence the Sensitivity of Colonic Cells to Butyrate

Deregulated Wnt signaling is responsible for most cases of colorectal cancer (CRC). Dietary fiber is protective against CRC and this activity is likely mediated by butyrate, a breakdown product of dietary fiber that hyperactivates Wnt signaling, repressing CRC proliferation and inducing apoptosis. Receptor-mediated Wnt signaling and oncogenic Wnt signaling, which is typically initiated by mutation in more downstream elements of the pathway, activate non-overlapping patterns of gene expression. Receptor-mediated signaling is associated with a poor prognosis for CRC while oncogenic signaling is associated with a relatively good prognosis. We have compared the expression of genes differentially expressed in receptor-mediated vs. oncogenic Wnt signaling to microarray data generated in our laboratory. Most importantly we evaluated these gene expression patterns comparing the early stage colon microadenoma line LT97 with the metastatic CRC cell line SW620. LT97 cells exhibit a gene expression pattern more strongly associated with that observed with oncogenic Wnt signaling, while SW620 cells exhibit a gene expression pattern moderately associated with that observed with receptor-mediated Wnt signaling. Given that SW620 cells are more advanced and malignant compared to LT97 cells, these findings are generally consistent with the better prognosis observed with tumors exhibiting a more oncogenic Wnt gene expression pattern. Importantly, LT97 cells are more sensitive to the effects of butyrate on proliferation and apoptosis that are CRC cells. We further examine these gene expression patterns in butyrate-resistant vs. butyrate-sensitive CRC cells. Based upon all of these observations, we hypothesize that colonic neoplastic cells exhibiting a more oncogenic as compared to receptor-mediated Wnt signaling gene expression pattern would be more sensitive to the effects of butyrate, and, hence, fiber, than are those cells exhibiting a more receptor-mediated Wnt signaling pattern of expression. Diet-derived butyrate may affect the differential patient outcomes resulting from the two types of Wnt signaling. We further posit that development of butyrate resistance and concomitant changes in Wnt signaling patterns, including associations with CBP and p300, disrupts the association between the two major types of Wnt signaling (receptor-mediated and oncogenic) and neoplastic progression/prognosis. Ideas about testing the hypothesis and therapeutic implications are briefly considered.

Advances of Wnt Signalling Pathway in Colorectal Cancer

Colorectal cancer (CRC) represents one of the most common cancers worldwide, with a high mortality rate despite the decreasing incidence and new diagnostic and therapeutic strategies. CRC arises from both epidemiologic and molecular backgrounds. In addition to hereditary factor and genetic mutations, the strongly varying incidence of CRC is closely linked to chronic inflammatory disorders of the intestine and terrible dietary habits. The Wnt signalling pathway is a complex regulatory network that is implicated in many CRC physiological processes, including cancer occurrence, development, prognosis, invasion, and metastasis. It is currently believed to include classical Wnt/β-catenin, Wnt/PCP, and Wnt/Ca²⁺. In this review, we summarise the recent mechanisms and potential regulators of the three branches of the Wnt signalling pathway in CRC.

Assessment of Oxaliplatin-Loaded Iodine Nanoparticles for Chemoradiotherapy of Human Colorectal Cancer (HT-29) Cells

Colorectal cancer is highly prevalent worldwide and has significant morbidity and mortality in humans. High-atomic-number nanoparticles such as iodine can act as X-rays absorbers to increase the local dose. The synthesis and fabrication of oxaliplatin-loaded iodine nanoparticles, their characterization, cell toxicity, radiosensitivity, cell apoptosis, and cell cycle assay in human colorectal cancer (HT-29) cells are investigated. Results show that the synthesis of a new iodine nanoparticle, polymerized triiodobenzene coated with chitosan and combined with oxaliplatin as a chemotherapeutic drug, performed well in vitro in an intracellular radiosensitizer as chemoradiotherapy agent in HT-29 cell lines. Findings also show that the INPs alone have no impact on cell cycle development and apoptosis. In contrast, oxaliplatin-loaded INPs along with 2 and 6 MV radiation doses produced more apoptosis. The interaction of INPs with mega-voltage photon energies is the cause of a major radiosensitization enhancement in comparison to radiation alone. Furthermore, results show that INPs may work as radiosensitization nanoprobe agents in the treatment of HT-29 cells due to their effect on increasing radiation dose absorption. Overall, iodine nanoparticles may be used in the treatment of colorectal cancers in clinical studies.

SHMT2 Induces Stemness and Progression of Head and Neck Cancer

Various enzymes in the one-carbon metabolic pathway are closely related to the development of tumors, and they can all be potential targets for cancer therapy. Serine hydroxymethyltransferase2 (SHMT2), a key metabolic enzyme, is very important for the proliferation and growth of cancer cells. However, the function and mechanism of SHMT2 in head and neck cancer (HNC) are not clear. An analysis of The Cancer Genome Atlas (TCGA) data showed that the expression of SHMT2 was higher in tumor tissue than in normal tissue, and its expression was significantly associated with male sex, aggressive histological grade, lymph node metastasis, distant metastasis, advanced TNM stage, and lymphovascular invasion in HNC. SHMT2 knockdown in FADU and SNU1041 cell lines significantly inhibited cell proliferation, colony formation, migration, and invasion. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses using TCGA data revealed that SHMT2 was closely related to cancer stem cell regulation and maintenance. Furthermore, we found that silencing SHMT2 inhibited the expression of stemness markers and tumor spheroid formation compared with a control group. On the contrary, stemness markers were significantly increased after SHMT2 overexpression in HEP-2 cells. Interestingly, we found that knocking down SHMT2 reduced the expression of genes related to the Notch and Wnt pathways. Finally, silencing SHMT2 significantly reduced tumor growth and decreased stemness markers in a xenograft model. Taken together, our study suggests that targeting SHMT2 may play an important role in inhibiting HNC progression.

The Small-Molecule Wnt Inhibitor ICG-001 Efficiently Inhibits Colorectal Cancer Stemness and Metastasis by Suppressing MEIS1 Expression

Recurrence and metastasis remain major obstacles in colorectal cancer (CRC) treatment. Recent studies suggest that a small subpopulation of cells with a self-renewal ability, called cancer stem-like cells (CSCs), promotes recurrence and metastasis in CRC. Unfortunately, no CSC inhibitor has been demonstrated to be more effective than existing chemotherapeutic drugs, resulting in a significant unmet need for effective CRC therapies. In this study, transcriptomic profiling of metastatic tumors from CRC patients revealed significant upregulation in the Wnt pathway and stemness genes. Thus, we examined the therapeutic effect of the small-molecule Wnt inhibitor ICG-001 on cancer stemness and metastasis. The ICG-001 treatment efficiently attenuated self-renewal activity and metastatic potential. Mechanistically, myeloid ecotropic viral insertion site 1 (MEIS1) was identified as a target gene of ICG-001 that is transcriptionally regulated by Wnt signaling. A series of functional analyses revealed that MEIS1 enhanced the CSC behavior and metastatic potential of the CRC cells. Collectively, our findings suggest that ICG-001 efficiently inhibits CRC stemness and metastasis by suppressing MEIS1 expression. These results provide a basis for the further clinical investigation of ICG-001 as a targeted therapy for CSCs, opening a new avenue for the development of novel Wnt inhibitors for the treatment of CRC metastasis.