hsa_circ_0000264 promotes tumor progression via the hsa-let-7b-5p/HMGA2 axis in head and neck squamous cell carcinoma

miRNome Profiling Analysis Reveals Novel Hepatocellular Carcinoma Diagnostic, Prognostic and Treatment-Related Candidate Biomarkers: Post hoc Analysis of SORAMIC Trial

INTRODUCTION

Early diagnosis of hepatocellular carcinoma (HCC) as well as evaluation of prognosis and prediction of treatment efficacy remains challenging due to the missing specific non-invasive biomarkers. The aim of this study was to identify disease-specific microRNA (miRNA) patterns for diagnosis, prediction of prognosis, and treatment response in patients with HCC.

METHODS

The study population included 42 HCC patients from SORAMIC clinical trial: 22 patients received sorafenib monotherapy, 20 patients underwent 90Y radioembolization in combination with sorafenib. 20 individuals were included in the control group. HCC patients underwent collection of plasma samples before and 7-9 weeks after the beginning of the treatment. Isolation of circulating miRNAs, preparation of small RNA sequencing libraries and next-generation sequencing were performed. Association analysis for novel diagnostic, prognostic, and treatment-related candidate biomarkers was performed.

RESULTS

A total of 42 differentially expressed (16 up-regulated and 26 down-regulated) miRNAs were identified comparing baseline and control group plasma samples. hsa-miR-215-5p and hsa-miR-192-5p were down-regulated, while hsa-miR-483-5p and hsa-miR-23b-3p were up-regulated comparing baseline and 7-9 weeks post-sorafenib monotherapy samples. hsa-miR-215-5p was the sole down-regulated miRNA in the same combination therapy comparison. hsa-miR-183-5p, hsa-miR-28-3p, and hsa-miR-1246 were found to be significantly up-regulated comparing non-responders versus responders to sorafenib. High hsa-miR-215-5p expression was significantly associated with worse HCC patients' prognosis.

CONCLUSIONS

Systematic miRNA profiling of highly characterized samples from SORAMIC study revealed a subset of potential miRNA biomarkers for HCC diagnosis and prognosis of sorafenib-treated patients' survival.

Revealing splenectomy-driven microRNA hsa-7b-5p's role in pancreatic cancer progression

Splenectomy often accompanies distal pancreatectomy for pancreatic cancer. However, debates persist on splenic function loss impact. Prior studies in mice revealed splenectomy promotes pancreatic cancer growth by altering CD4/Foxp3 and CD8/Foxp3 ratios. The effect on other immune cells remains unclear. Clinical observations indicate splenectomy induces immunosuppression, heightening recurrence and metastasis risk. Here, we established an orthotopic pancreatic cancer model with splenectomy and observed a significant increase in tumor burden. Flow cytometry revealed elevated MDSCs, CD8+PD-1high+ T cells, and reduced CD4+ T cells, CD8+ T cells, and natural killer cells in tumors. Bulk sequencing identified increased MicroRNA (miRNA) hsa-7b-5p post-splenectomy, correlating with staging and immunosuppression. Similar results were obtained in vivo by constructing a KPC-miRNA hsa-7b-5p-sh cell line. These findings suggest that splenectomy enhances the expression of miRNA hsa-7b-5p, inhibits the tumor immune microenvironment, and promotes pancreatic cancer growth.

The circRNA hsa-circ-0013561 regulates head and neck squamous cell carcinoma development via the miR-7-5p/PDK3 axis

BACKGROUND

Circular RNAs (circRNAs) belong to a class of covalently closed single stranded RNAs that have been implicated in cancer progression. Former investigations showed that hsa-circ-0013561 is abnormally expressed in head and neck squamous cell carcinoma (HNSCC). Nevertheless, the role of hsa-circ-0013561 during the progress of HNSCC still unclear.

METHODS

Present study applied FISH and qRT-PCR to examine hsa-circ-0013561 expression in HNSCC cells and tissue samples. Dual-luciferase reporter assay was employed to identify downstream targets of hsa-circ-0013561. Transwell migration, 5-ethynyl-2'-deoxyuridine incorporation, CCK8 and colony formation assays were utilized to test cell migration and proliferation. A mouse tumor xenograft model was utilized to determine the hsa-circ-0013561 roles in HNSCC progression and metastasis in vivo.

RESULTS

We found that hsa-circ-0013561 was upregulated in HNSCC tissue samples. hsa-circ-0013561 downregulation inhibited HNSCC cell proliferation and migration to promote apoptosis and G1 cell cycle arrest. The dual-luciferase reporter assay revealed that miR-7-5p and PDK3 are hsa-circ-0013561 downstream targets. PDK3 overexpression or miR-7-5p suppression reversed the hsa-circ-0013561-induced silencing effects on HNSCC cell proliferation and migration. PDK3 overexpression reversed miR-7-5p-induced effects on HNSCC cell proliferation and migration.

CONCLUSION

The findings suggest that hsa-circ-0013561 downregulation inhibits HNSCC metastasis and progression through PDK3 expression and miR-7-5p binding modulation.

HMGA2 promotes cancer metastasis by regulating epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is a complex physiological process that transforms polarized epithelial cells into moving mesenchymal cells. Dysfunction of EMT promotes the invasion and metastasis of cancer. The architectural transcription factor high mobility group AT-hook 2 (HMGA2) is highly overexpressed in various types of cancer (e.g., colorectal cancer, liver cancer, breast cancer, uterine leiomyomas) and significantly correlated with poor survival rates. Evidence indicated that HMGA2 overexpression markedly decreased the expression of epithelial marker E-cadherin (CDH1) and increased that of vimentin (VIM), Snail, N-cadherin (CDH2), and zinc finger E-box binding homeobox 1 (ZEB1) by targeting the transforming growth factor beta/SMAD (TGFβ/SMAD), mitogen-activated protein kinase (MAPK), and WNT/beta-catenin (WNT/β-catenin) signaling pathways. Furthermore, a new class of non-coding RNAs (miRNAs, circular RNAs, and long non-coding RNAs) plays an essential role in the process of HMGA2-induced metastasis and invasion of cancer by accelerating the EMT process. In this review, we discuss alterations in the expression of HMGA2 in various types of cancer. Furthermore, we highlight the role of HMGA2-induced EMT in promoting tumor growth, migration, and invasion. More importantly, we discuss extensively the mechanism through which HMGA2 regulates the EMT process and invasion in most cancers, including signaling pathways and the interacting RNA signaling axis. Thus, the elucidation of molecular mechanisms that underlie the effects of HMGA2 on cancer invasion and patient survival by mediating EMT may offer new therapeutic methods for preventing cancer progression.

Let-7b-5p inhibits breast cancer cell growth and metastasis via repression of hexokinase 2-mediated aerobic glycolysis

Hexokinase 2 (HK2), a critical rate-limiting enzyme in the glycolytic pathway catalyzing hexose phosphorylation, is overexpressed in multiple human cancers and associated with poor clinicopathological features. Drugs targeting aerobic glycolysis regulators, including HK2, are in development. However, the physiological significance of HK2 inhibitors and mechanisms of HK2 inhibition in cancer cells remain largely unclear. Herein, we show that microRNA-let-7b-5p (let-7b-5p) represses HK2 expression by targeting its 3'-untranslated region. By suppressing HK2-mediated aerobic glycolysis, let-7b-5p restrains breast tumor growth and metastasis both in vitro and in vivo. In patients with breast cancer, let-7b-5p expression is significantly downregulated and is negatively correlated with HK2 expression. Our findings indicate that the let-7b-5p/HK2 axis plays a key role in aerobic glycolysis as well as breast tumor proliferation and metastasis, and targeting this axis is a potential therapeutic strategy for breast cancer.

Association of genetic variants of CircCHST15 with oral squamous cell carcinoma in the Chinese Han population

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most common cancer in the oral cavity. The relationship between the genetic susceptibility of circCHST15 and OSCC remains unclear.

METHODS

Genetic variants of circCHST15 were screened using a genotyping analysis from 1044 patients with OSCC and 3199 healthy participants. The circCHST15 expression was detected in 32 pairs of OSCC tissues. The circular RNA quantitative trait locus analysis and the reporter gene assay were performed for verification.

RESULTS

The circCHST15 expression was upregulated in OSCC (Wilcoxon p < 1e-3). The genotyping analysis screened out 61 loci in circCHST15 associated with the risk of OSCC. After adjustment and annotation, rs28707473 (A > C, odds ratio = 1.21, 95% CI: 1.076-1.361, p = 1.453e-3) was selected. This genetic variation could elevate the circCHST15 expression level possibly by altering the structure of circular RNAs and affecting transcription factor binding.

CONCLUSIONS

The results of this study suggested that genetic variants of circCHST15 may contribute to OSCC susceptibility.

HMGA2 regulation by miRNAs in cancer: affecting cancer hallmarks and therapy response

High mobility group A 2 (HMGA2) is a protein that modulates the structure of chromatin in the nucleus. Importantly, aberrant expression of HMGA2 occurs during carcinogenesis, and this protein is an upstream mediator of cancer hallmarks including evasion of apoptosis, proliferation, invasion, metastasis, and therapy resistance. HMGA2 targets critical signaling pathways such as Wnt/β-catenin and mTOR in cancer cells. Therefore, suppression of HMGA2 function notably decreases cancer progression and improves outcome in patients. As HMGA2 is mainly oncogenic, targeting expression by non-coding RNAs (ncRNAs) is crucial to take into consideration since it affects HMGA2 function. MicroRNAs (miRNAs) belong to ncRNAs and are master regulators of vital cell processes, which affect all aspects of cancer hallmarks. Long ncRNAs (lncRNAs) and circular RNAs (circRNAs), other members of ncRNAs, are upstream mediators of miRNAs. The current review intends to discuss the importance of the miRNA/HMGA2 axis in modulation of various types of cancer, and mentions lncRNAs and circRNAs, which regulate this axis as upstream mediators. Finally, we discuss the effect of miRNAs and HMGA2 interactions on the response of cancer cells to therapy. Regarding the critical role of HMGA2 in regulation of critical signaling pathways in cancer cells, and considering the confirmed interaction between HMGA2 and one of the master regulators of cancer, miRNAs, targeting miRNA/HMGA2 axis in cancer therapy is promising and this could be the subject of future clinical trial experiments.