MicroRNA Expression in Plasma of Esophageal Squamous Cell Carcinoma Patients

Inhibiting histone deacetylase 6 suppresses the proliferation of microvascular endothelial cells by epigenetically activating miR-375-3p, potentially contributing to bone loss during mechanical unloading

BACKGROUND

Mechanical unloading-induced bone loss threatens prolonged spaceflight and human health. Recent studies have confirmed that osteoporosis is associated with a significant reduction in bone microvessels, but the relationship between them and the underlying mechanism under mechanical unloading are still unclear.

METHODS

We established a 2D clinostat and hindlimb-unloaded (HLU) mouse model to simulate unloading in vitro and in vivo. Micro-CT scanning was performed to assess changes in the bone microstructure and mass of the tibia. The levels of CD31, Endomucin (EMCN) and histone deacetylase 6 (HDAC6) in tibial microvessels were detected by immunofluorescence (IF) staining. In addition, we established a coculture system of microvascular endothelial cells (MVECs) and osteoblasts, and qRT‒PCR or western blotting was used to detect RNA and protein expression; cell proliferation was detected by CCK‒8 and EdU assays. ChIP was used to detect whether HDAC6 binds to the miRNA promoter region.

RESULTS

Bone mass and bone microvessels were simultaneously significantly reduced in HLU mice. Furthermore, MVECs effectively promoted the proliferation and differentiation of osteoblasts under coculture conditions in vitro. Mechanistically, we found that the HDAC6 content was significantly reduced in the bone microvessels of HLU mice and that HDAC6 inhibited the expression of miR-375-3p by reducing histone acetylation in the miR-375 promoter region in MVECs. miR-375-3p was upregulated under unloading and it could inhibit MVEC proliferation by directly targeting low-density lipoprotein-related receptor 5 (LRP5) expression. In addition, silencing HDAC6 promoted the miR-375-3p/LRP5 pathway to suppress MVEC proliferation under mechanical unloading, and regulation of HDAC6/miR-375-3p axis in MVECs could affect osteoblast proliferation under coculture conditions.

CONCLUSION

Our study revealed that disuse-induced bone loss may be closely related to a reduction in the number of bone microvessels and that the modulation of MVEC function could improve bone loss induced by unloading. Mechanistically, the HDAC6/miR-375-3p/LRP5 pathway in MVECs might be a promising strategy for the clinical treatment of unloading-induced bone loss.

Clinical Implications of Circulating Tumor Cells in Patients with Esophageal Squamous Cell Carcinoma: Cancer-Draining Blood Versus Peripheral Blood

Circulating tumor cells (CTCs) in cancer-draining veins have diagnostic and prognostic value. However, studies on esophageal squamous cell carcinoma (ESCC) are limited. This study aimed to compare CTCs obtained from different sampling sites (peripheral vein vs. cancer-draining azygos vein) and to investigate their association with the clinicopathological characteristics of ESCC patients. Blood samples were collected preoperatively from both veins in 40 ESCC patients at Pusan National University Hospital from June 2020 to April 2022. CTCs were detected using a centrifugal microfluidic method with fluid-assisted separation. CTCs and TWIST (+) CTCs were detected more frequently in the azygos vein blood than in the peripheral vein blood; however, the difference was not statistically significant (85.0% [34/40] vs. 77.5% [31/40], p = 0.250 and 82.5% [33/40] vs. 75.0% [30/40], p = 0.586, respectively). CTC and TWIST (+) CTC counts were significantly higher in the azygos vein blood than in the peripheral vein blood (7 vs. 3, p < 0.001, and 6 vs. 2, p < 0.001, respectively). CTCs and TWIST (+) CTCs from peripheral and azygos veins showed no association with clinicopathological characteristics. Further large-scale studies are needed to clarify their role as predictive biomarkers for prognosis and chemotherapy responses in ESCC patients.

Human plasma can modulate micronucleus frequency in TK6 and OE33 cells in vitro

In this paper, we studied the potential genotoxic effects of human plasma from healthy volunteers, as well as patients with gastro-oesophageal reflux disease, Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC) using the oesophageal adenocarcinoma cell line (OE33) and the lymphoblastoid cell line (TK6). Both TK6 and OE33 cells were treated with plasma (10 % volume, replacing foetal bovine serum (FBS) or horse serum (HS)) at different time points of 4 h (for the micronucleus (Mn) assay and the invasion assay) and 24 h (for the cell cycle studies). Plasma-induced effects on DNA damage levels, cell viability and the cell cycle were studied by the micronucleus assay, cytokinesis block proliferation index (CBPI) and flow cytometry respectively. The expression of IL-8 in supernatants of TK6 cells and IFN-β in OE33 cells was also analysed by enzyme-linked immunosorbent assay (ELISA). Finally, we carried out an assessment of cellular invasion of OE33 cells following plasma treatment. The results of the micronucleus assay confirmed the genotoxicity of direct plasma treatment from some participants through the increase in DNA damage in TK6 cells. Conversely, some individual patient plasma samples reduced background levels of TK6 cell Mn frequency, in an anti-genotoxic fashion. In TK6 cells, (on average) plasma samples from patients with Barrett's oesophagus induced higher micronucleus levels than healthy volunteers (p= 0.0019). There was little difference in Mn induction when using plasma versus serum to treat the cells in vitro. Cell cycle results showed that direct plasma treatment had a marked impact on OE33 cells at 24 h (p=0.0182 for BO and p=0.0320 for OAC) by decreasing the proportion of cells in the S phase, while plasma exposure was less impactful on the cell cycle of TK6 cells. Invasion of OE33 cells was also seen to be non-significantly affected by plasma treatment of OE33 cells. The addition of N-acetyl cysteine NAC in a dose-dependent matter did not alter the formation of Mn in TK6 cells, suggesting that reactive oxygen species (ROS) are not the root cause of plasma's genotoxicity. The concentration of IL-8 in TK6 cells and IFN-β in OE33 cells was significantly higher in cells treated with OAC-derived plasma than in the untreated negative control. Collectively, our results demonstrate that plasma-specific effects are detectable which helps us better understand some important aspects of the biology of blood-based biomarkers under development.

Non-endoscopic Screening for Esophageal Squamous Cell Carcinoma: Recent Advances

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common tumors in the gastrointestinal tract, and China has a high incidence area with a high burden on the disease. As early symptoms of ESCC are not obvious, the mortality rate is high, and it is often diagnosed in the intermediate and advanced stages. However, early screening and treatment may reduce morbidity and mortality.

METHODS

Screening methods are divided into endoscopic and non-endoscopic screening.

RESULTS

Endoscopic screening cannot be widely used because of its invasive nature and high cost. Currently, non-endoscopic screening consists primarily of tumor biomarkers and cytology, and tumor biomarkers including autoantibodies, circulating tumor cells, circulating tumor DNA, exosomes and serum metabolomics are more likely to be effective. But the efficiency of early diagnosis of esophageal cancer is low and the accuracy of screening needs to be improved. The aim of this study is to summarize advances in non-endoscopic esophageal cancer screening and strategies to provide a scientific basis and research idea for esophageal cancer prevention and control.

CONCLUSIONS

Non-endoscopic screening is better than endoscopic screening. And the application of tumor biomarkers is much better than other non-endoscopic screening methods.

Identification of combinatorial miRNA panels derived from extracellular vesicles as biomarkers for esophageal squamous cell carcinoma

MicroRNAs (miRNAs) are relatively stable in blood, emerging as one of the most promising biomarkers in tumor liquid biopsy. Both total and extracellular vesicles (EVs) encapsulated miRNA have been studied for prognostic potential in a variety of cancers. Here, we systematically compared and verified the total and vesicle-derived miRNA expression profiles from plasma samples in healthy controls and patients with esophageal squamous cell carcinoma (ESCC). In the present study, four miRNA species miR-636, miR-7641, miR-28-3p, and miR-1246 that were differentially expressed in ESCC patients were chosen for further study. We first elucidated their essential function in ESCC progression and further explored their preliminary mechanism by identifying target proteins and involving signal pathways. Subsequently, the prognostic miRNA panels including miR-636, miR-7641, miR-1246, and miR-28-3p for ESCC diagnosis were constructed and validated using different cohort. Our results showed that the panel including the above four miRNAs derived from plasma EVs was most effective in distinguishing tumor patients from normal subjects, while integrated plasma EVs-derived miR-1246, miR-28-3p and total plasma miRNAs miR-636, miR-7641 showed the best capability in predicting lymph node metastasis. In summary, our studies revealed that plasma EVs-derived miRNAs could be emerged as promising biomarkers for ESCC diagnosis.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

Biomarkers for Early Detection, Prognosis, and Therapeutics of Esophageal Cancers

Esophageal cancer (EC) is the deadliest cancer worldwide, with a 92% annual mortality rate per incidence. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two major types of ECs, with EAC having one of the worst prognoses in oncology. Limited screening techniques and a lack of molecular analysis of diseased tissues have led to late-stage presentation and very low survival durations. The five-year survival rate of EC is less than 20%. Thus, early diagnosis of EC may prolong survival and improve clinical outcomes. Cellular and molecular biomarkers are used for diagnosis. At present, esophageal biopsy during upper endoscopy and histopathological analysis is the standard screening modality for both ESCC and EAC. However, this is an invasive method that fails to yield a molecular profile of the diseased compartment. To decrease the invasiveness of the procedures for diagnosis, researchers are proposing non-invasive biomarkers for early diagnosis and point-of-care screening options. Liquid biopsy involves the collection of body fluids (blood, urine, and saliva) non-invasively or with minimal invasiveness. In this review, we have critically discussed various biomarkers and specimen retrieval techniques for ESCC and EAC.

MicroRNAs in esophageal squamous cell carcinoma: Application in prognosis, diagnosis, and drug delivery

MicroRNAs (miRNAs) play a vital role in various cell biology processes, including cancer formation. These small non-coding RNAs could function as diagnostic and prognostic markers. They may involve esophageal squamous cell carcinoma (ESCC) and distinctive miRNA expression profiles; they are also known as therapeutic targets in human diseases. Therefore, in this study, the function of miRNAs was reviewed regarding the prognosis and diagnosis of ESCC. The changes in miRNAs before and after cancer therapy and the effects of miRNAs on chemo-susceptibility patterns were also investigated. MiRNA delivery systems in ESCC were also highlighted, providing a perspective on how these systems can improve miRNA efficiency.