GM-CSF-miRNA-Jak2/Stat3 Signaling Mediates Chemotherapy-Induced Cancer Cell Stemness in Gastric Cancer

CSF2 promotes chemoresistance in colorectal cancer by regulating Notch pathway

BACKGROUND

Increasing evidence suggests that resistance to 5-fluorouracil (5FU) and oxaliplatin (OXP) in colorectal cancer (CRC) is linked to poor prognosis. This study aimed to probe the effect of colony-stimulating factor 2 (CSF2) on the resistance of CRC to 5FU and OXP.

METHODS

The expression of CSF2 in CRC and the impact of abnormal CSF2 expression on the prognosis of CRC patients were analyzed using bioinformatics. The half-maximal inhibitory concentrations (IC50) of 5FU and OXP on CRC cells were determined using the CCK-8 assay. Apoptosis in CRC cells was assessed through flow cytometry. mRNA and protein levels were measured using qRT-PCR and western blot, respectively. Gene Set Enrichment Analysis (GSEA) was conduced to investigate the signaling pathways regulated by CSF2 in CRC. The Notch pathway activator Jagged-1 (JAG) was employed to verify whether CSF2 influences the resistance of CRC cells to 5-FU and OXP by modulating the Notch signaling pathway.

RESULTS

High expression of CSF2 is associated with poor prognosis in CRC patients. CSF2 is downregulated in CRC cells that resistance to 5-FU and OXP. Silencing CSF2 inhibits resistance to 5FU and OXP, reduces the survival of resistant CRC cells, and promotes apoptosis. CSF2 activates the Notch signaling pathway, which is highly expressed in CRC resistant cells; conversely, silencing CSF2 inhibits the activation of this pathway. Treatment with JAG reversed the effects of CSF2 silencing on resistance to 5FU and OXP in CRC cells.

CONCLUSION

The silencing of CSF2 inhibited the resistance of CRC cells to 5FU and OXP by regulating the Notch signaling pathway.

Impact of miRNAs involved in the STAT3 signaling pathway on esophageal cancer (Review)

Esophageal cancer (ESCA) is a common tumor noted in the digestive tract, which is highly malignant due to unclear early symptoms and poor last‑stage treatment effects; its mortality rate is relatively high. MicroRNA (miR) and signal transducer and activator of transcription 3 (STAT3) are key components of cellular signaling pathways; their interaction forms a complex and intricate information network that controls several types of biological behaviors in the cells. In the tumor cell, these signal transduction pathways are abnormally active, indicating that the STAT3 signaling pathway mediated by miRs is involved in the progression of various cancer types. The present review introduces the biological characteristics of miR and STAT3 and their relationship with ESCA. It summarizes the regulation of ESCA by the miR and STAT3 signaling pathways and analyzes the effects of these pathways on proliferation, apoptosis, invasion, metastasis and immune escape of cancer cells, as well as the impact on patient survival and prognosis. The purpose of the present review is to assess the miR/STAT3 signaling pathway in ESCA, improve the understanding of the pathogenesis of ESCA and facilitate the identification of therapeutic targets for ESCA.

Advanced progress in the genetic modification of the oncolytic HSV-1 virus

The use of replication-competent viruses for selective tumor oncolysis while sparing normal cells marks a significant advancement in cancer treatment. HSV-1 presents several advantages that position it as a leading candidate for oncolytic virotherapies. Its large genome can accommodate insertions over 30 kb or deletions of multiple virulence genes without compromising lytic replication in tumor cells. Additionally, anti-herpes drugs can inhibit its replication during accidental infections. Importantly, HSV-1 does not integrate into the host genome and cause mutations. The HSV-1 genome can be modified through genetic engineering in two main ways: first, by reducing infectivity and toxicity to normal cells via limited replication and assembly, altered protein-virus receptor binding, and minimized immune evasion; second, by enhancing anticancer activity through disruption of tumor cell metabolism, induction of autophagy, improved immune recognition, and modification of the tumor microenvironment. In this mini-review, we systematically examine genetic modification strategies for oncolytic HSV-1 while highlighting advancements from these modifications. Certain genetic alterations have shown efficacy in improving clinical outcomes for HSV-1-based therapies. These modifications include silencing specific genes and inserting exogenous genes into the HSV-1 genome. The insertion of exogenous genes has increasingly been used to develop new oncolytic HSV-1 variants. Finally, we discuss limitations associated with oncolytic virotherapy at the conclusion of this review. As more clinical trials explore newly engineered therapies, they are likely to yield breakthroughs and promote broader adoption for cancer treatment.

KHSRP promotes cancer stem cell maintenance, tumorigenesis, and suppresses anti-tumor immunity in gastric cancer

Objectives

KH-type splicing regulatory protein (KHSRP) is an RNA-binding protein involved in several cellular processes, including nuclear splicing, mRNA localization, and cytoplasmic degradation. While KHSRP's role has been studied in other cancers, its specific involvement in gastric cancer remains poorly understood. This study aims to explore KHSRP expression in gastric cancer and its potential effects on tumor progression and immune response.

Methods

KHSRP expression in gastric cancer tissues and normal tissues was analyzed using data from The Cancer Genome Atlas (TCGA) database. The correlation between KHSRP expression, patient survival, and immune response was also assessed. Immunohistochemistry was performed to evaluate KHSRP expression in gastric cancer tissues. Gain- and loss-of-function experiments were conducted to assess KHSRP's effects on gastric cancer cell proliferation, stemness, and migration. Furthermore, the impact of KHSRP silencing on tumor volume and immune cell infiltration was evaluated in a C3H/He mouse xenograft model.

Results

KHSRP was found to be overexpressed in gastric cancer tissues compared to normal tissues, with a positive correlation to tumor stage and a negative correlation with patient prognosis. Functional assays revealed that KHSRP promotes gastric cancer cell proliferation, enhances cancer stem cell properties, and increases migratory capabilities in vitro. In vivo, KHSRP silencing led to a significant reduction in tumor volume and increased immune cell infiltration in the mouse xenograft model.

Conclusions

KHSRP acts as an oncogene in gastric cancer by promoting tumorigenesis and suppressing anti-tumor immune responses. Its overexpression is associated with poor prognosis, making KHSRP a potential prognostic marker and therapeutic target in gastric cancer.

Studying the non-coding RNA expression and its role in drug resistance mechanisms of gastric cancer

Gastric cancer is the fifth most common malignancy and the fifth primary cause of death from cancer all over the world. Because of diagnosis of gastric cancer at advanced, incurable stages and limited response to treatment, the disease has an adverse prognosis and a low survival rate. Chemotherapy consisting of medications such as platinum and 5-Fluorouracil can be effective for patients with advanced stomach cancer. Nevertheless, drug resistance eventually leads to unsuccessful therapy and adverse outcomes for gastric cancer patients. Most therapy failures in gastric cancer patients undergoing chemotherapy are caused by the development of drug resistance. Several studies have shown that noncoding RNAs (ncRNAs) play important roles in the resistance of gastric cancer to chemotherapy drugs. The development of stomach cancer is greatly impacted by a number of ncRNAs, including microRNAs (e.g., miR-21, miR-27a), circular RNAs (e.g., CircPVT1), and long noncoding RNAs (e.g., HOTAIR). Because of their regulatory characteristics in certain genes implicated in the chemoresistant phenotype of gastric cancer, much evidence has demonstrated their function in the emergence and persistence of drug resistance. In the future, ncRNA-based treatment could represent a novel approach to treating drug resistance. Despite numerous studies on anticancer drug resistance mechanisms, it is still unclear how these mechanisms are regulated. In this review, we investigated the evolving function and molecular mechanisms of ncRNAs related to drug resistance, their function in controlling drug resistance in gastric cancer, and their potential to create targeted therapeutics for reducing drug resistance in gastric cancer.

Induction, growth, drug resistance, and metastasis: A comprehensive summary of the relationship between STAT3 and gastric cancer

Gastric cancer is a prevalent and highly lethal malignancy that poses substantial challenges to healthcare systems globally. Owing to its often asymptomatic nature in early stages, diagnosis frequently occurs at advanced stages when surgical intervention is no longer a viable option, forcing most patients to rely on nonsurgical treatments such as chemotherapy, targeted therapies, and emerging immunotherapies. Unfortunately, the therapeutic response rates for these treatments are suboptimal, and even among responders, the eventual development of drug resistance remains a significant clinical hurdle. Signal transducer and activator of transcription 3 (STAT3) is a widely expressed cellular protein that plays crucial roles in regulating cellular processes such as growth, metabolism, and immune function. Aberrant activation of the STAT3 pathway has been implicated in the initiation, progression, and therapeutic resistance of several cancers, with gastric cancer being particularly affected. Dysregulated STAT3 signaling not only drives tumorigenesis but also facilitates the development of resistance to chemotherapy and targeted therapies, as well as promotes metastatic dissemination. In this study, we explored the critical role of the STAT3 signaling cascade in the pathogenesis of gastric cancer, its contribution to drug resistance, and its involvement in the metastatic process. Furthermore, we assess recent advances in the development of STAT3 inhibitors and their potential application as therapeutic agents in the treatment of gastric cancer. This work provides a comprehensive overview of the current understanding of STAT3 in gastric cancer and offers a foundation for future research aimed at improving therapeutic outcomes in this challenging disease.

Feature Engineering-Assisted Drug Repurposing on Disease-Drug Transcriptome Profiles in Gastric Cancer

Gastric cancer is one of the most common and deadly types of cancer in the world. To develop new biomarkers and drugs to diagnose and treat this cancer, it is necessary to identify the differences between the transcriptome profiles of gastric cancer and healthy individuals, identify critical genes associated with these differences, and make potential drug predictions based on these genes. In this study, using two gene expression datasets related to gastric cancer (GSE19826 and GSE79973), 200 genes that were ready for machine learning were selected, and their expression levels were analyzed. The best 100 genes for the model were chosen with the permutation feature importance method, and central genes, such as SCARB1, ETV3, SPATA17, FAM167A-AS1, and MTBP, which were shown to be associated with gastric cancer, were identified. Then, using the drug repurposing method with the Connectivity Map CLUE Query tools, potential drugs such as Forskolin, Gestrinone, Cediranib, Apicidine, and Everolimus, which showed a highly negative correlation with the expression levels of the selected genes, were identified. This study provides a method to develop new approaches to diagnosing and treating gastric cancer by comparing the transcriptome profiles of patients gastric cancer and performing a feature engineering-assisted drug repurposing analysis based on cancer data.

Tumor microenvironment of cancer stem cells: Perspectives on cancer stem cell targeting

There are few tumor cell subpopulations with stem cell characteristics in tumor tissue, defined as cancer stem cells (CSCs) or cancer stem-like cells (CSLCs), which can reconstruct neoplasms with malignant biological behaviors such as invasiveness via self-renewal and unlimited generation. The microenvironment that CSCs depend on consists of various cellular components and corresponding medium components. Among these factors existing at a variety of levels and forms, cytokine networks and numerous signal pathways play an important role in signaling transduction. These factors promote or maintain cancer cell stemness, and participate in cancer recurrence, metastasis, and resistance. This review aims to summarize the recent molecular data concerning the multilayered relationship between CSCs and CSC-favorable microenvironments. We also discuss the therapeutic implications of targeting this synergistic interplay, hoping to give an insight into targeting cancer cell stemness for tumor therapy and prognosis.

The Interplay Between Helicobacter pylori and Suppressors of Cytokine Signaling (SOCS) Molecules in the Development of Gastric Cancer and Induction of Immune Response

Helicobacter pylori (H. pylori) colonizes the stomach and leads to the secretion of a vast range of cytokines by infiltrated leukocytes directing immune/inflammatory response against the bacterium. To regulate immune/inflammatory responses, suppressors of cytokine signaling (SOCS) proteins bind to multiple signaling components located downstream of cytokine receptors, such as Janus kinase (JAK), signal transducers and activators of transcription (STAT). Dysfunctional SOCS proteins in immune cells may facilitate the immune evasion of H. pylori, allowing the bacteria to induce chronic inflammation. Dysregulation of SOCS expression and function can contribute to the sustained H. pylori-mediated gastric inflammation which can lead to gastric cancer (GC) development. Among SOCS molecules, dysregulated expression of SOCS1, SOCS2, SOCS3, and SOCS6 were indicated in H. pylori-infected individuals as well as in GC tissues and cells. H. pylori-induced SOCS1, SOCS2, SOCS3, and SOCS6 dysregulation can contribute to the GC development. The expression of SOCS molecules can be influenced by various factors, such as epigenetic DNA methylation, noncoding RNAs, and gene polymorphisms. Modulation of the expression of SOCS molecules in gastric epithelial cells and immune cells can be considered to control gastric carcinogenesis as well as regulate antitumor immune responses, respectively. This review aimed to explain the interplay between H. pylori and SOCS molecules in GC development and immune response induction as well as to provide insights regarding potential therapeutic strategies modulating SOCS molecules.

Functional Roles of CD133: More than Stemness Associated Factor Regulated by the Microenvironment

CD133 protein has been one of the most used surface markers to select and identify cancer cells with stem-like features. However, its expression is not restricted to tumoral cells; it is also expressed in differentiated cells and stem/progenitor cells in various normal tissues. CD133 participates in several cellular processes, in part orchestrating signal transduction of essential pathways that frequently are dysregulated in cancer, such as PI3K/Akt signaling and the Wnt/β-catenin pathway. CD133 expression correlates with enhanced cell self-renewal, migration, invasion, and survival under stress conditions in cancer. Aside from the intrinsic cell mechanisms that regulate CD133 expression in each cellular type, extrinsic factors from the surrounding niche can also impact CD33 levels. The enhanced CD133 expression in cells can confer adaptive advantages by amplifying the activation of a specific signaling pathway in a context-dependent manner. In this review, we do not only describe the CD133 physiological functions known so far, but importantly, we analyze how the microenvironment changes impact the regulation of CD133 functions emphasizing its value as a marker of cell adaptability beyond a cancer-stem cell marker.

CSF2 upregulates CXCL3 expression in adipocytes to promote metastasis of breast cancer via the FAK signaling pathway

Recent studies have demonstrated that cancer-associated adipocytes (CAAs) in the tumor microenvironment are involved in the malignant progression of breast cancer. However, the underlying mechanism of CAA formation and its effects on the development of breast cancer are still unknown. Here, we show that CSF2 is highly expressed in both CAAs and breast cancer cells. CSF2 promotes inflammatory phenotypic changes of adipocytes through the Stat3 signaling pathway, leading to the secretion of multiple cytokines and proteases, particularly C-X-C motif chemokine ligand 3 (CXCL3). Adipocyte-derived CXCL3 binds to its specific receptor CXCR2 on breast cancer cells and activates the FAK pathway, enhancing the mesenchymal phenotype, migration, and invasion of breast cancer cells. In addition, a combination treatment targeting CSF2 and CXCR2 shows a synergistic inhibitory effect on adipocyte-induced lung metastasis of mouse 4T1 cells in vivo. These findings elucidate a novel mechanism of breast cancer metastasis and provide a potential therapeutic strategy for breast cancer metastasis.

Epigenetic programing of cancer stemness by transcription factors-non-coding RNAs interactions

Cancer 'stemness' is fundamental to cancer existence. It defines the ability of cancer cells to indefinitely perpetuate as well as differentiate. Cancer stem cell populations within a growing tumor also help evade the inhibitory effects of chemo- as well as radiation-therapies, in addition to playing an important role in cancer metastases. NF-κB and STAT-3 are representative transcription factors (TFs) that have long been associated with cancer stemness, thus presenting as attractive targets for cancer therapy. The growing interest in non-coding RNAs (ncRNAs) in the recent years has provided further insight into the mechanisms by which TFs influence cancer stem cell characteristics. There is evidence for a direct regulation of TFs by ncRNAs, such as, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) as well as circular RNAs (circRNAs), and vice versa. Additionally, the TF-ncRNAs regulations are often indirect, involving ncRNA-target genes or the sponging of other ncRNA species by individual ncRNAs. The information is rapidly evolving and this review provides a comprehensive review of TF-ncRNAs interactions with implications on cancer stemness and in response to therapies. Such knowledge will help uncover the many levels of tight regulations that control cancer stemness, providing novel opportunities and targets for therapy in the process.