Cancer stem cells in esophageal squamous cell cancer

MiR-15a-5p Knockdown up-Regulated ABCB1 Expression and Abated HNSCC Progression via the NF-κB Signaling Pathway

BACKGROUND

The high invasion and heterogeneity of head and neck squamous cell carcinoma (HNSCC) commonly leads to poor clinical outcomes. Identification of reliable biomarkers for HNSCC is imperative.

METHODS

The targeted gene with the highest mutation was screened out in cBioPortal database, and the interactive microRNAs (miRNAs) were identified by miRNA-mRNA co-expression analysis. CCK-8 and transwell assays were used to explore the proliferative, migrative, and invasive behaviors of HNSCC cells. The dual-luciferase reporter assay and cell transfection experiment were conducted. The role of miR-15a-5p was investigated in the in vivo xenograft mouse model.

RESULTS

ATP binding cassette transporter 1 (ABCB1) had the highest mutation frequency and multiple mutation types in HNSCC, and the decreased ABCB1 was significantly related to better prognosis of HNSCC patients. MiR-15a-5p was a regulator for ABCB1, which was up-regulated after miR-15a-5p inhibition in vitro. Furthermore, the miR-15a-5p knockdown significantly suppressed HNSCC cell proliferation, migration, and invasion in vitro, and reduced the HNSCC tumor growth and migration capabilities in vivo, possibly through NF-κB signaling pathway.

CONCLUSION

Collectively, miR-15a-5p knockdown increased the ABCB1 level and abated the HNSCC progression via the NF-κB signaling pathway. ABCB1 and miR-15a-5p were underlying predictors for HNSCC therapeutic biomarkers.

Aryl hydrocarbon receptor dynamics in esophageal squamous cell carcinoma: From immune modulation to therapeutic opportunities

Esophageal squamous cell carcinoma (ESCC) is a substantial global health burden. Immune escape mechanisms are important in ESCC progression, enabling cancer cells to escape the surveillance of the host immune system. One key player in this process is the Aryl Hydrocarbon Receptor (AhR), which influences multiple cellular processes, including proliferation, differentiation, metabolism, and immune regulation. Dysregulated AhR signaling participates in ESCC development by stimulating carcinogenesis, epithelial-mesenchymal transition, and immune escape. Targeting AhR signaling is a potential therapeutic approach for ESCC, with AhR ligands showing efficacy in preclinical studies. Additionally, modification of AhR ligands and combination therapies present new opportunities for therapeutic intervention. This review aims to address the knowledge gap related to the role of AhR signaling in ESCC pathogenesis and immune escape.

Umbrella Review on Cancer Stem Cell in Oral and Head and Neck Squamous Cell Carcinoma

Cancer stem cells (CSCs) are cells in a tumor which can begin to grow, develop, and induce resistance in the tumor. Recent studies have shown that as with mesenchymal stem cells, CSCs can also regenerate themselves and be involved in tumorigenesis. Recent advances in detection of biomarkers for identifying CSCs as well as development of new techniques for evaluating the tumorigenesis and carcinogenesis roles of CSCs have been considerable. In recent years, more systematic review papers have been published about CSCs and head and neck squamous cell carcinoma (HNSCC), highlighting the need to accumulate information and draw final conclusions from these studies. Methods: This research protocol for review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols (PRISMA-P) checklist. The protocol for this meta-analysis was registered on PROSPERO (International Prospective Register of Systematic Reviews) and the registration number is CRD42022301720. Results: We identified 8 review articles about CSCs in HNSCCs. Conclusions: This umbrella review provides a comprehensive summary of the body of published systematic reviews and reviews in CSCs and HNSCCs. There is strong evidence suggesting that targeting the cancer stem cells could lead to a more definitive response, since the cancer stem cells are the putative drivers of recurrence and metastatic spread in HNSCCs.

OCT4's role and mechanism underlying oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), a common malignancy of the head and neck, ranks sixth worldwide in terms of cancers with the most negative impact, owing to tumor relapse rates, cervical lymphnode metastasis, and the lack of an efficacious systemic therapy. Its prognosis is poor, and its mortality rate is high. Octamer-binding transcription factor 4 (OCT4) is a member of the Pit-Oct-Unc (POU) family and is a key reprogramming factor that produces a marked effect in preserving the pluripotency and self-renewal state of embryonic stem cells (ESCs). According to recent studies, OCT4 participates in retaining the survival of OSCC cancer stem cells (CSCs), which has far-reaching implications for the occurrence, recurrence, metastasis, and prognosis of oral carcinogenesis. Therefore, we summarize the structure, subtypes, and function of OCT4 as well as its role in the occurrence, progression, and prognosis of OSCC.

lncRNA SSTR5-AS1 Predicts Poor Prognosis and Contributes to the Progression of Esophageal Cancer

Esophageal cancer (ESCA), as a common cancer worldwide, is a main cause of cancer-related mortality. Long noncoding RNAs (lncRNAs) have been shown in an increasing number of studies to be capable of playing an important regulatory function in human malignancies. Our study is aimed at delving into the prognostic value and potential function of lncRNA SSTR5-AS1 (SSTR5-AS1) in ESCA. The gene expression data of 182 ESCA samples from TCGA and 653 nontumor specimens from GTEx. The expressions of SSTR5-AS1 were analyzed. We investigated whether there was a correlation between the expression of SSTR5-AS1 and the clinical aspects of ESCA. In order to compare survival curves, the Kaplan-Meier method together with the log-rank test was utilized. The univariate and multivariate Cox regression models were used to analyze the data in order to determine the SSTR5-AS1 expression's significance as a prognostic factor in ESCA patients. In order to investigate the level of SSTR5-AS1 expression in ESCA cells, RT-PCR was utilized. CCK-8 trials served as a model for the loss-of-function tests. In this study, we found that the expressions of SSTR5-AS1 were increased in ESCA specimens compared with nontumor specimens. According to the ROC assays, high SSTR5-AS1 expression had an AUC value of 0.7812 (95% CI: 0.7406 to 0.8217) for ESCA. Patients who had a high level of SSTR5-AS1 expression had a lower overall survival rate than those who had a low level of SSTR5-AS1 expression. In addition, multivariate analysis suggested that SSTR5-AS1 was an independent predictor of overall survival for ESCA patients. Moreover, RT-PCR experiments indicated that SSTR5-AS1 expression was distinctly increased in three ESCA cells compared with HET1A cells. CCK-8 experiments indicated that silence of SSTR5-AS1 distinctly inhibited the proliferation of ESCA cells. Overall, ESCA patients with elevated SSTR5-AS1 had a worse chance of survival, suggesting it could be used as a prognostic and diagnostic biomarker for ESCA.

Drug Resistance in Cancers: A Free Pass for Bullying

The cancer burden continues to grow globally, and drug resistance remains a substantial challenge in cancer therapy. It is well established that cancerous cells with clonal dysplasia generate the same carcinogenic lesions. Tumor cells pass on genetic templates to subsequent generations in evolutionary terms and exhibit drug resistance simply by accumulating genetic alterations. However, recent evidence has implied that tumor cells accumulate genetic alterations by progressively adapting. As a result, intratumor heterogeneity (ITH) is generated due to genetically distinct subclonal populations of cells coexisting. The genetic adaptive mechanisms of action of ITH include activating "cellular plasticity", through which tumor cells create a tumor-supportive microenvironment in which they can proliferate and cause increased damage. These highly plastic cells are located in the tumor microenvironment (TME) and undergo extreme changes to resist therapeutic drugs. Accordingly, the underlying mechanisms involved in drug resistance have been re-evaluated. Herein, we will reveal new themes emerging from initial studies of drug resistance and outline the findings regarding drug resistance from the perspective of the TME; the themes include exosomes, metabolic reprogramming, protein glycosylation and autophagy, and the relates studies aim to provide new targets and strategies for reversing drug resistance in cancers.

Cancer stem-like cells contribute to paclitaxel resistance in esophageal squamous cell carcinoma

OBJECTIVE

To examine the role of esophageal squamous cell carcinoma (ESCC) stem cells in paclitaxel resistance through the molecular characterization of ESCC stem cells.

METHODS

A resistant cell line (RR-ECl09) of cells were established using intermittent induction and time increments of high-dose paclitaxel in a human esophageal squamous cell carcinoma line (EC109). The multidrug resistance of RR-ECl09 cells to anticancer agents was evaluated by MTT assay. The RR-EC109 and EC109 cells were used for sphere formation assays, clonogenicity assays, stem cell gene expression, and the expression of epithelial-mesenchymal transition markers.

RESULTS

The RR-EC109 cells were established over 7 months. RR-ECl09 cells had 67.258 fold resistance to paclitaxel. The percentage of sphere formation and clone proliferation ability of RR-EC109 cells was higher than that of EC109 cells (P < 0.05). The amount of side population cells in RR-EC109 cells was higher than that of EC109 cells (P < 0.05). RR-EC109 cells produced more mRNA for Bmi1, Nanog, Oct4, Sox2, ABCG2, Nestin, and Ki-67 than EC109 cells (P < 0.05). E-cadherin expression was lower in RR-EC109 cells than in EC109 cells, while N-cadherin, Snail, and Twist expressions were higher in RR-EC109 cells than in EC109 cells (P < 0.05).

CONCLUSIONS

Cancer stem cell (CSC)-like cells exist among paclitaxel-resistant cells in ESCC and may play a role in ESCC drug resistance.

EpCAM expression in esophageal cancer and its correlation with immunotherapy of solitomab

Background

Recurrence of esophageal cancer (EC) after chemotherapy may mainly be explained by the existence of chemotherapy-resistant cells, and an effective drug against chemotherapy-resistant cells is highly sought. The aim of this study was to investigate the cytotoxicity of bispecific antibody solitomab combined with γ δ T cells on Eca109 cell spheres.

Methods

We cultured Eca109 cell spheres in serum-free medium, and the morphological differences between wild-type Eca109 cells and Eca109 cell spheres were compared by microscope and flow cytometry. Different concentrations of nanoparticle albumin-bound paclitaxel (Nab-PTX) and cisplatin were used to treat the two groups of cells and compare their drug resistance. Flow cytometry was then used to detect the expression level of epithelial cell adhesion molecule (EpCAM) and the cytotoxicity of γ δ T cells combined with bispecific antibody solitomab on the two groups.

Results

Flow cytometry analysis showed that Eca109 cell spheres were smaller in size and had less cytoplasmic granules and CCK-8 assay showed that the viability of Eca109 cell spheres treated with different concentrations of Nab-PTX and cisplatin was significantly higher than that of wild-type Eca109 cells (P<0.05). Flow cytometry also showed that the expression level of EpCAM on Eca109 cell spheres was higher than that of wild-type Eca109 cells. Co-culture experiment showed that there was no significant difference in the cytotoxicity of γ δ T cells to wild-type Eca109 cells and Eca109 cell spheres without solitomab. However, after adding solitomab, the cytotoxicity of γ δ T cells to Eca109 cell spheres was significantly higher than that of wild-type Eca109 cells (P<0.05).

Conclusions

EC Eca109 cell spheres have strong stem cell characteristics such as multidrug resistance and may contain a high proportion of EC stem cells. Further, EC Eca109 cell spheres have a high expression level of EpCAM, and EpCAM may be one of the markers of EC stem cells. Therefore, EpCAM could be used as a potential molecular target of immunotherapy for EC, and solitomab may become an effective immunotherapeutic drug for chemotherapy-resistant EC cells.

Therapeutic Strategies Against Cancer Stem Cells in Esophageal Carcinomas

Cancer stem cells (CSCs) in esophageal cancer have a key role in tumor initiation, progression and therapy resistance. Novel therapeutic strategies to target CSCs are being tested, however, more in-depth research is necessary. Eradication of CSCs can result in successful therapeutic approaches against esophageal cancer. Recent evidence suggests that targeting signaling pathways, miRNA expression profiles and other properties of CSCs are important strategies for cancer therapy. Wnt/β-catenin, Notch, Hedgehog, Hippo and other pathways play crucial roles in proliferation, differentiation, and self-renewal of stem cells as well as of CSCs. All of these pathways have been implicated in the regulation of esophageal CSCs and are potential therapeutic targets. Interference with these pathways or their components using small molecules could have therapeutic benefits. Similarly, miRNAs are able to regulate gene expression in esophageal CSCs, so targeting self-renewal pathways with miRNA could be utilized to as a potential therapeutic option. Moreover, hypoxia plays critical roles in esophageal cancer metabolism, stem cell proliferation, maintaining aggressiveness and in regulating the metastatic potential of cancer cells, therefore, targeting hypoxia factors could also provide effective therapeutic modalities against esophageal CSCs. To conclude, additional study of CSCs in esophageal carcinoma could open promising therapeutic options in esophageal carcinomas by targeting hyper-activated signaling pathways, manipulating miRNA expression and hypoxia mechanisms in esophageal CSCs.