Detection of DNA methylated microRNAs in hepatocellular carcinoma. Gene. 2019;702:153-157. [PMID: 30922710 DOI: 10.1016/j.gene.2019.02.080]

The art of managing hepatitis C virus in special population groups: a paradigm shift

The first direct-acting antiviral (DAA) medications were approved for the treatment of chronic hepatitis C virus (HCV) in 2011. Later, the appearance of novel DAAs had revolutionized the landscape of HCV treatment whose early treatment options were limited to interferon (IFN) either alone or in combinations. This review discusses the paradigm shift in legibility for treating different groups of patients with HCV after the introduction of DAAs, along with the consequent changes in treatment guidelines. IFN-based therapy was the firstly used for treating chronic HCV. Unfortunately, it exhibited many pitfalls, such as low efficacy in some patients and unsuitability for usage in lots of patients with some specific conditions, which could be comorbidities such as autoimmune thyroiditis, or liver related as in decompensated cirrhosis. Furthermore, IFN failed to treat all the extrahepatic manifestations of HCV. Nowadays, the breakthroughs brought by DAAs have benefited the patients and enabled the treatment of those who could not be treated or did not usually respond well to IFN. DAAs achieve a high success rate of HCV eradication in addition to avoiding unfavorable harms and, sometimes, adverse effects related to the previously used PEGylated IFN regimens.

MicroRNA: A signature for cancer progression

MicroRNAs (miRNAs) are a group of small non-coding RNAs that post-transcriptionally control expression of genes by targeting mRNAs. miRNA alterations partake in the establishment and progression of different types of human cancer. Consequently, expression profiling of miRNA in human cancers has correlations with cancer detection, staging, progression, and response to therapies. Particularly, amplification, deletion, abnormal pattern of epigenetic factors and the transcriptional factors that mediate regulation of primary miRNA frequently change the landscape of miRNA expression in cancer. Indeed, changes in the quantity and quality of miRNAs are associated with the initiation of cancer, its progression and metastasis. Additionally, miRNA profiling has been used to categorize genes that can affect oncogenic pathways in cancer. Here, we discuss several circulating miRNA signatures, their expression profiles in different types of cancer and their impacts on cellular processes.

Demethylation of miR-34a upregulates expression of membrane palmitoylated proteins and promotes the apoptosis of liver cancer cells

BACKGROUND

Liver cancer is a common cancer and the main cause of cancer-related deaths worldwide. Liver cancer is the sixth most common cancer in the world. Although miR-34a and palmitoyl membrane palmitoylated protein (MPP2) are reportedly involved in various cell processes, their precise roles in liver cancer are still unclear.

AIM

To investigate the expression of micro RNA 34a (miR-34a), methylation of the miR-34a promoter and the expression of MPP2 in liver cancer cells and their related mechanisms.

METHODS

Together, 78 cases of liver cancer tissues and 78 cases of adjacent tissues were collected. The methylation degree of miR-34a promoter in liver cancer/ paracancerous tissue and liver cancer cells/normal liver cells, and the expression levels of miR-34a and MPP2 in the above samples were detected. Demethylation of liver cancer cells or transfection of liver cancer cells with miR-34a mimetic was performed. The MPP2 overexpression vector was used to transfect liver cancer cells, and the changes in proliferation, invasion, apoptosis, migration, and other biological functions of liver cancer cells after the above interventions were observed. Double luciferase reporter genes were used to detect the targeting relationship between miR-34a and MPP2.

RESULTS

Clinical samples showed that the expression levels of miR-34a and MPP2 in liver cancer tissues were lower than those in the normal tissues. The methylation degree of miR-34a promoter region in liver cancer cells was higher than that in normal liver cells. After miR-34a demethylation/mimetic transfection/MPP2 overexpression, the apoptosis of liver cancer cells was increased; the proliferation, invasion and migration capabilities were decreased; the expression levels of caspase 3, caspase 9, E-cadherin, and B-cell lymphoma 2 (Bcl-2)-associated X protein were increased; and the expression levels of Bcl-2, N-cadherin, and β-catenin were decreased. Double luciferase reporter genes confirmed that MPP2 is targeted by miR-34a. Rescue experiments showed that small interfering MPP2 could counteract the promoting effect of miR-34a demethylation on apoptosis and the inhibitory effect on cell proliferation, invasion, and migration.

CONCLUSION

miR-34a demethylation upregulates the expression level of MPP2 in liver cancer cells and promotes the apoptosis of liver cancer cells. miR-34a demethylation is a potential method for liver cancer treatment.

The Prospect and Challenges to the Flow of Liquid Biopsy in Africa

Liquid biopsy technologies have the potential to transform cancer patient management as it offers non-invasive diagnosis and real-time monitoring of disease progression and treatment responses. The use of liquid biopsy for non-invasive cancer diagnosis can have pivotal importance for the African continent where access to medical infrastructures is limited, as it eliminates the need for surgical biopsies. To apply liquid biopsy technologies in the African setting, the influence of environmental and population genetic factors must be known. In this review, we discuss the use of circulating tumor cells, cell-free nucleic acids, extracellular vesicles, protein, and other biomolecules in liquid biopsy technology for cancer management with special focus on African studies. We discussed the prospect, barriers, and other aspects that pose challenges to the use of liquid biopsy in the African continent.