Long non-coding RNA SPRY4-IT1 as a promising indicator for three field lymph-node dissection of thoracic esophageal carcinoma

Biomarkers of lymph node metastasis in esophageal cancer

Esophageal cancer (EC) is among the most aggressive malignancies, ranking as the seventh most prevalent malignant tumor worldwide. Lymph node metastasis (LNM) indicates localized spread of cancer and often correlates with a poorer prognosis, emphasizing the necessity for neoadjuvant systemic therapy before surgery. However, accurate identification of LNM in EC presents challenges due to the lack of satisfactory diagnostic techniques. Imaging techniques, including ultrasound and computerized tomography scans, have low sensitivity and accuracy in assessing LNM. Additionally, the existing serological detection lacks precise biomarkers. The intricate and not fully understood molecular processes involved in LNM of EC contribute to current detective limitations. Recent research has shown potential in using various molecules, circulating tumor cells (CTCs), and changes in the microbiota to identify LNM in individuals with EC. Through summarizing potential biomarkers associated with LNM in EC and organizing the underlying mechanisms involved, this review aims to provide insights that facilitate biomarker development, enhance our understanding of the underlying mechanisms, and ultimately address the diagnostic challenges of LNM in clinical practice.

Long noncoding RNA SPRY4-IT1 acts as a miR-101-5p sponge to promote gastrointestinal stromal tumor progression by inhibiting ZEB1

OBJECTIVES

Research on long noncoding RNAs (lncRNAs) has been conducted in different areas of oncology. Currently, the biological significance of lncRNAs and their regulatory features in gastrointestinal stromal tumors (GIST) remain largely unknown. We have previously identified SPRY4-IT1 overexpression in GIST through lncRNA sequencing of GIST tissues. Coincidentally, SPRY4-IT1 is an intron of the SPRY4 gene, and SPRY4 is specifically highly expressed in GIST. Thus the aim of the present study was to investigate the role of lncRNA SPRY4-IT1 in GIST pathogenesis.

METHODS

Herein, we screened for SPRY4-IT1 and analyzed its possible phenotypes using Gene set enrichment analysis (GSEA). The phenotypes of GIST were verified using CCK-8, colony formation, and wound-healing assays. The ceRNA mechanism was determined by the location of lncRNA SPRY4-IT1, and its relationship to the Ago2 protein. The SPRY4-IT1/miR-101-5p/ZEB1 axis was predicted using online software and sequencing. Luciferase and pull-down assays were performed for verification. Pathway-associated and phenotype-associated proteins were detected by western blotting.

RESULTS

Sequencing analysis revealed 117 differentially expressed lncRNAs in GIST and normal gastric tissue samples. Accordingly, SPRY4-IT1 was screened out and its phenotype was predicted by GSEA. Mechanistically, SPRY4-IT1 was identified as a competing endogenous RNA (ceRNA) that downregulated miR-101-5p and upregulated ZEB1, which activated extracellular signal-regulated kinase (ERK) signaling to stimulate GIST proliferation, invasion, and epithelial-mesenchymal transition. Although this effect was regulated by a negative feedback loop through SPRY4, it was still controlled by SPRY4-IT1.

CONCLUSIONS

In GIST, we revealed a ceRNA mechanism by which SPRY4-IT1 modulates ZEB1 by sponging miR-101-5p, eventually driving tumor cell proliferation, migration, and epithelial-mesenchymal transition (EMT).

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

A Review on the Role of SPRY4-IT1 in the Carcinogenesis

Sprouty RTK signaling antagonist 4-intronic transcript 1 (SPRY4-IT1) is a long non-coding RNA (lncRNA) encoded by a gene located on 5q31.3. This lncRNA has a possible role in the regulation of cell growth, proliferation, and apoptosis. Moreover, since SPRY4-IT1 controls levels of lipin 2, it is also involved in the biosynthesis of lipids. During the process of biogenesis, SPRY4-IT1 is produced as a primary transcript which is then cleaved to generate a mature transcript which is localized in the cytoplasm. SPRY4-IT1 has oncogenic roles in diverse tissues. A possible route of participation of SPRY4-IT1 in the carcinogenesis is through sequestering miRNAs such as miR-101-3p, miR-6882-3p and miR-22-3p. The sponging effect of SPRY4-IT1 on miR-101 has been verified in colorectal cancer, osteosarcoma, cervical cancer, bladder cancer, gastric cancer and cholangiocarcinoma. SPRY4-IT1 has functional interactions with HIF-1α, NF-κB/p65, AMPK, ZEB1, MAPK and PI3K/Akt signaling. We explain the role of SPRY4-IT1 in the carcinogenesis according to evidence obtained from cell lines, xenograft models and clinical studies.