HCP5 Promotes Proliferation and Contributes to Cisplatin Resistance in Gastric Cancer Through miR-519d/HMGA1 Axis

Long Non-Coding RNAs in Drug Resistance of Gastric Cancer: Complex Mechanisms and Potential Clinical Applications

Gastric cancer (GC) ranks as the third most prevalent malignancy and a leading cause of cancer-related mortality worldwide. However, the majority of patients with GC are diagnosed at an advanced stage, highlighting the urgent need for effective perioperative and postoperative chemotherapy to prevent relapse and metastasis. The current treatment strategies have limited overall efficacy because of intrinsic or acquired drug resistance. Recent evidence suggests that dysregulated long non-coding RNAs (lncRNAs) play a significant role in mediating drug resistance in GC. Therefore, there is an imperative to explore novel molecular mechanisms underlying drug resistance in order to overcome this challenging issue. With advancements in deep transcriptome sequencing technology, lncRNAs-once considered transcriptional noise-have garnered widespread attention as potential regulators of carcinogenesis, including tumor cell proliferation, metastasis, and sensitivity to chemo- or radiotherapy through multiple regulatory mechanisms. In light of these findings, we aim to review the mechanisms by which lncRNAs contribute to drug therapy resistance in GC with the goal of providing new insights and breakthroughs toward overcoming this formidable obstacle.

HCP5 prevents ubiquitination-mediated UTP3 degradation to inhibit apoptosis by activating c-Myc transcriptional activity

Inducing cancer cell apoptosis through cytotoxic reagents is the main therapeutic strategy for diverse cancer types. However, several antiapoptotic factors impede curative cancer therapy by driving cancer cells to resist cytotoxic agent-induced apoptosis, thus leading to refractoriness and relapse. To define critical antiapoptotic factors that contribute to chemoresistance in esophageal squamous cell carcinoma (ESCC), we generated two pairs of parental and apoptosis-resistant cell models through cisplatin (DDP) induction and then performed whole-transcriptome sequencing. We identified the long noncoding RNA (lncRNA) histocompatibility leukocyte antigen complex P5 (HCP5) as the chief culprit for chemoresistance. Mechanistically, HCP5 interacts with UTP3 small subunit processome component (UTP3) and prevents UTP3 degradation from E3 ligase tripartite motif containing 29 (TRIM29)-mediated ubiquitination. UTP3 then recruits c-Myc to activate vesicle-associated membrane protein 3 (VAMP3) expression. Activated VAMP3 suppresses caspase-dependent apoptosis and eventually leads to chemoresistance. Accordingly, the expression level of the HCP5/UTP3/c-Myc/VAMP3 axis in chemoresistant patients is significantly higher than that in chemosensitive patients. Thus, our study demonstrated that the HCP5/UTP3/c-Myc/VAMP3 axis plays an important role in the inhibition of cancer cell apoptosis and that HCP5 may be a promising chemosensitivity target for cancer treatment.

Construction of miRNA-lncRNA-mRNA co-expression network affecting EMT-mediated cisplatin resistance in ovarian cancer

Platinum resistance is one of the major concerns in ovarian cancer treatment. Recent evidence shows the critical role of epithelial-mesenchymal transition (EMT) in this resistance. Epithelial-like ovarian cancer cells show decreased sensitivity to cisplatin after cisplatin treatment. Our study prospected the association between epithelial phenotype and response to cisplatin in ovarian cancer. Microarray dataset GSE47856 was acquired from the GEO database. After identifying differentially expressed genes (DEGs) between epithelial-like and mesenchymal-like cells, the module identification analysis was performed using weighted gene co-expression network analysis (WGCNA). The gene ontology (GO) and pathway analyses of the most considerable modules were performed. The protein-protein interaction network was also constructed. The hub genes were specified using Cytoscape plugins MCODE and cytoHubba, followed by the survival analysis and data validation. Finally, the co-expression of miRNA-lncRNA-TF with the hub genes was reconstructed. The co-expression network analysis suggests 20 modules relating to the Epithelial phenotype. The antiquewhite4, brown and darkmagenta modules are the most significant non-preserved modules in the Epithelial phenotype and contain the most differentially expressed genes. GO, and KEGG pathway enrichment analyses on these modules divulge that these genes were primarily enriched in the focal adhesion, DNA replication pathways and stress response processes. ROC curve and overall survival rate analysis show that the co-expression pattern of the brown module's hub genes could be a potential prognostic biomarker for ovarian cancer cisplatin resistance.

HMGA1 Has Predictive Value in Response to Chemotherapy in Gastric Cancer

Gastric cancer is a serious health problem worldwide. Although its incidence is decreasing, the five-year survival rate remains low. Thus, it is essential to identify new biomarkers that could promote better diagnosis and treatment of patients with gastric cancer. High-mobility group AT-hook 1 (HMGA1) is a non-histone, chromatin-binding protein that has been found overexpressed in several tumor types. It has been correlated with invasion, metastasis, and drug resistance, leading to worse patient survival. The aim of this work was to evaluate the clinical value of HMGA1 in gastric cancer. HMGA1 expression was analyzed by immunohistochemistry in a single hospital series (n = 323) of gastric adenocarcinoma cases (stages I to IV) with clinicopathological and treatment data. In this series, HMGA1 expression showed no significant relevance as a prognostic biomarker. Nevertheless, a significantly better overall survival was observed in cases with high levels of HMGA1 when they were treated with chemotherapy, compared to the nontreated ones, implying that they can benefit more from treatment than patients with low expression of HMGA1. We thereby show for the first time that HMGA1 expression has a substantial value as a biomarker of response to chemotherapy in gastric cancer.

LncRNA HCP5 as a potential therapeutic target and prognostic biomarker for various cancers: a meta‑analysis and bioinformatics analysis

BACKGROUND

Accumulating studies indicated that dysregulated long non-coding RNA human histocompatibility leukocyte antigen (HLA) Complex P5 (HCP5) may functions as an potential prognostic predictor in multiple cancers. This meta-analysis was performed to systematically collect studies and conduct an evidence-based evaluation of the prognostic role of HCP5 in malignancies.

METHODS

Four databases (PubMed, Web of Science, Embase and Cochrane library) were comprehensively retrieved from their initiation date to November 9, 2021. Hazard ratio (HR) or odds ratio (OR) with 95% confidence interval (CI) were used to assess the associations between the expression level of HCP5 and prognosis or clinical characteristics. Moreover, results were validated by Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and the National Genomics Data Center (NGDC). Subsequently, the molecular mechanism of HCP5 was predicted based on MEM and StarBase databases. The study protocol was registered at PROSPERO (ID: CRD42021274208).

RESULTS

9 studies, containing 641 patients, were included in this meta-analysis. Our results revealed that HCP5 overexpression was associated with poor overall survival (OS), tumor type, histological differentiation, and lymph node metastasis in most cancers, but was not associated with age, gender and tumor size; down-regulation of HCP5 was associated with worse OS, advanced tumor stage, positive distal metastasis and lymph node metastasis in skin cutaneous melanoma (SKCM). HCP5 was significantly up-regulated in four cancers and down-regulated in SKCM, which was validated by the GEPIA2 cohort. HCP5 expression in various types of cancer was also verified in NGDC. Further functional prediction revealed that HCP5 may participate in some cancer-related pathways.

CONCLUSION

There is a significantly association between dysregulation of HCP5 and both prognosis and clinicopathological features in various cancers. HCP5 may be functions as a novel potential prognostic biomarker and therapeutic target in multiple human cancers.

MicroRNA-519d-3p antagonizes osteosarcoma resistance against cisplatin by targeting PD-L1

Accumulating evidence indicates that a ligand of programmed cell death receptor-1 (PD-L1) participates in the progression and recurrence of multiple malignancies, including osteosarcoma. Nevertheless, the role of PD-L1 in chemoresistance development is not fully understood. In the current study, we aim to clarify the interaction of miR-519d-3p and PD-L1 in the development of cisplatin resistance. Immunohistochemistry, quantitative reverse-transcription polymerase reaction, and Western blot were used to evaluate PD-L1 expression. MTT and transwell migration assays were used to measure cell growth and motility, respectively. ENCORI, miRCode, and miRDB databases were recruited to predict candidate miRNAs targeting PD-L1. The binding sequences of miR-519d-3p and PD-L1 3' untranslated region were identified by dual-luciferase reporter and RNA immunoprecipitation assays. Flow cytometric analysis was conducted to measure the cycle distribution and cell apoptosis. Metastatic mouse models were generated with cisplatin-resistant sublines by intravenous injection. We found that PD-L1 expression was positively correlated to cisplatin resistance and metastasis, whereas miR-519d-3p expression was reduced in cisplatin-resistant specimens and was negatively correlated to cisplatin resistance and metastasis of osteosarcoma. We demonstrated that miR-519d-3p overexpression reversed cisplatin resistance, induced G1/S phase arrest and apoptosis. In addition, we proved that miR-519d-3p inhibited lung metastasis by establishing cisplatin-resistant MG63 metastatic xenograft models. The present findings suggest that miR-519d-3p/PD-L1 axis is a novel signaling pathway contributing to cisplatin resistance. Our study provides new clues for curing refractory osteosarcoma beyond immune checkpoint inhibitors.

Long non-coding RNA CCDC183-AS1 regulates gastric cancer AGS cell proliferation, migration, and invasion by targeting miR-1301-3p

BACKGROUND

The long noncoding RNA (lncRNA) CCDC183-AS1 is up-regulated in hepatocellular carcinoma and promotes the progression of hepatocellular carcinoma. However, the effect of CCDC183-AS1 on gastric cancer and its molecular mechanism are unknown. Starbase prediction shows that CCDC183-AS1 may target miR-1301-3p. We hypothesized that CCDC183-AS1 can target and regulate miR-1301-3p to affect the proliferation, migration, and invasion of gastric cancer cells, thereby affecting the development of gastric cancer.

AIM

To investigate the effect of CCDC183-AS1 on the proliferation, migration, and invasion of gastric cancer AGS cells and the underlying molecular mechanism.

METHODS

Thirty gastric cancer tissues and matched adjacent normal tissues were collected at our hospital. RT-qPCR was used to detect the expression of CCDC183-AS1 and miR-1301-3p in the collected tissues. MTT assay was used to detect cell proliferation in AGS cells, and transwell assay was used to detect cell migration and invasion. Western blot was used to detect the protein expression of CyclinD1, MMP-2, MMP-9, and p21. Small interfering RNA targeting CCDC183-AS1 (si-CCDC183-AS1) and miR-1301-3p were transfected into AGS cells, respectively, and the changes in cell proliferation, migration, and invasion were detected using the above methods. StarBase prediction showed that the sequence of lncRNA CCDC183-AS1 contains nucleotide sequences complementary to miR-1301-3p, and the targeting relationship was confirmed by dual luciferase report assay.

RESULTS

Compared with adjacent normal tissues, the expression levels of CCDC183-AS1 and miR-1301-3p in gastric cancer tissues were significantly increased and decreased, respectively (P < 0.05). Inhibition of CCDC183-AS1 or overexpression of miR-1301-3p reduced the proliferation, migration, and invasion of AGS cells, decreased the expression levels of CyclinD1, MMP-2, and MMP-9, and increased the expression level of p21 (P < 0.05). CCDC183-AS1 targeted the expression of miR-1301-3p. Down-regulation of miR-1301-3p reversed the effect of inhibition of CCDC183-AS1 expression on the proliferation, migration, and invasion of AGS cells.

CONCLUSION

Inhibition of CCDC183-AS1 regulates the proliferation, migration, and invasion of gastric cancer AGS cells via targeted up-regulation of miR-1301-3p expression.

Long Non-coding RNA ASNR Targeting miR-519e-5p Promotes Gastric Cancer Development by Regulating FGFR2

Gastric cancer (GC), as a common gastrointestinal tumor, is an important cause of death from cancer all around the world. Long non-coding RNAs (lncRNAs), a novel class of transcripts, have attracted great attention of researchers. However, the mechanisms of the clinical significance of most lncRNAs in human cancer are mainly undocumented. This research desires to explore the clinical significance, biological function, and mechanism of Lnc_ASNR (apoptosis suppressing-non-coding RNA) in GC. Cell proliferation, cell cycle, cell migration, and invasion abilities were respectively determined by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT), flow cytometry, wound healing, and Transwell assay (Sigma-Aldrich, St. Louis, MO, United States). The association of Lnc_ASNR, miR-519e-5p, and fibroblast growth factor receptor 2 (FGFR2) was evaluated via luciferase reporter experiments. The tumor xenograft assay was conducted to confirm the results of cell experiments. High expressed Lnc_ASNR was detected in both GC cells and tissues using qRT-PCR. Downregulated Lnc_ASNR could reduce proliferation, migration, and invasion in GC cells, while upregulated Lnc_ASNR could promote the cell proliferation, migration, and invasion. Moreover, the effect of Lnc_ASNR on migration and invasion ability is closely related to epithelial-mesenchymal transition (EMT). The bioinformatics analysis, luciferase assay, and Western blot demonstrated that Lnc_ASNR inhibited miR-519e-5p expression but increased FGFR2 expression. Lnc_ASNR and FGFR2 were both targeted to miR-519e-5p, and they were negatively correlated with the expression of miR-519e-5p. All investigations indicated that Lnc_ASNR functioned as a ceRNA targeting miR-519e-5p and facilitated GC development by regulating the pathway of miR-519e-5p/FGFR2.