Relationship of the Levels of microRNA Gene Methylation with the Level of Their Expression and Pathomorphological Characteristics of Breast Cancer

The Role of Methylation of a Group of microRNA Genes in the Pathogenesis of Metastatic Renal Cell Carcinoma

The role of methylation of 9 miRNA genes in the pathogenesis of metastatic clear cell renal cell carcinoma was determined by quantitative methylation-specific PCR (MS-PCR). For 5 genes (MIR125B-1, MIR137, MIR193A, MIR34B/C, and MIR375), a significant correlation of high methylation level with late (III-IV) stages, large size (T3+T4) of the tumor, and metastasis to lymph nodes and/or distant organs was revealed. For another group of genes (MIR125B-1, MIR1258, MIR193A, MIR34B/C, and MIR375), a statistically significant correlation of high methylation level with loss of differentiation in the tumor (G3-G4) was found, and the opposite pattern was found for MIR203A. A total of 7 microRNA genes (MIR125B-1, MIR1258, MIR137, MIR193A, MIR203A, MIR34B/C, and MIR375) were identified, the methylation of which is associated with the progression of metastatic clear cell renal cell carcinoma. For 6 of them (except MIR34B/C) these data were obtained for the first time. Thus, new factors of the development and progression of clear cell renal cell carcinoma were identified as potential biomarkers for the early diagnosis and prognosis of metastatic clear cell renal cell carcinoma.

DNA methylation biomarkers accurately detect esophageal cancer prior and post neoadjuvant chemoradiation

BACKGROUND

Esophageal cancer (ECa) is associated with high mortality, mostly due to late diagnosis, precluding curativeintent surgery. Hence, neoadjuvant chemoradiation (ChRT) is recommended in most patients regardless of histological subtype. A proportion of these patients, however, achieve complete disease remission and might be spared of radical surgery. The lack of reliable, minimally invasive biomarkers able to detect post-ChRT disease persistence is, nonetheless, a major drawback. We have previously shown that miRNA promotor methylation enables accurate cancer detection in tissues and liquid biopsies but has been seldom explored in ECa patients.

AIMS

Herein, we sought to unveil and validate novel candidate biomarkers able to detect ECa prior and post ChRT.

MATERIALS AND METHODS

Promoter methylation of miR129-2, miR124-3 and ZNF569 was assessed, using quantitative methylation-specific PCR (qMSP), in tissue samples from normal esophagus, treatment-naïve and post-ChRT ECa, as well as in liquid biopsies from ECa patients.

RESULTS

All genes disclosed significantly different promoter methylation levels between ECa and normal esophagus, accurately detecting post-ChRT disease, especially for adenocarcinoma. Remarkably, miR129-2_me /ZNF569_me methylation panel identified ECa in liquid samples with 53% sensitivity and 87% specificity.

DISCUSSION

MiR129-2_me , miR124-3_me and ZNF569_me accurately discriminate ECa, either pre- or post-ChRT, from normal tissue, enabling ECa detection. Furthermore, circulalting methylation-based biomarkers are promising minimally invasive tools to detect post-ChRT residual ECa.

CONCLUSION

Overall, our results encourage the use of miRNA methylation biomarkers as accurate ECa detection tools as a novel approach for ChRT response monitoring.

miR-127-5p Targets JAM3 to Regulate Ferroptosis, Proliferation, and Metastasis in Malignant Meningioma Cells

Objective

Meningiomas are one of the most common primary tumors of the central nervous system. Most of them are benign and can be cured by surgery, while a few meningiomas are malignant. Ferroptosis gene characteristics might be associated with drug therapy and survival in patients with clinically aggressive, unresectable meningiomas. This study explored the mechanism of differentially expressed miRNAs and ferroptosis in meningioma to provide a new reference to treat meningioma.

Methods

Bioinformatics analysis of differential miRNA profiles and functions in patients with meningioma was performed. The contents of lactate dehydrogenase (LDH), malondialdehyde (MDA), and Fe²⁺ were determined. Reactive oxygen species (ROS) values, as well as cell cycle changes, were analyzed by flow cytometry. The targets of miR-127-5p and JAM3 were detected by dual luciferase assays. Cell counting kit-8 (CCK8) and Transwell assays were used to analyze cell activity. Ki67 expression was analyzed by immunohistochemistry. Expression levels of miR-127-5p and JAM3 were analyzed by RT-qPCR. GPX4 expression was quantified by western blotting.

Results

miR-127-5p was expressed at low levels in IOMM-Lee cells, while JAM3 was highly expressed in IOMM-Lee cells. A dual luciferase assay demonstrated that miR-127-5p could target JAM3. Upregulation of miR-127-5p in IOMM-Lee cells resulted in cell cycle arrest and inhibition of cell activity. Upregulation of miR-127-5p increased LDH, MDA, and ROS levels and Fe²⁺ content and inhibited the expression of GPX4 protein. Upregulation of JAM3 reversed the results of miR-127-5p upregulation.

Conclusion

miR-127-5p regulated meningioma formation and ferroptosis through JAM3, providing insights for the development of new treatments for meningioma.