Underexpression of circulating miR-145-5p and miR-133a-3p are associated with breast cancer and immunohistochemical markers

Circular RNA circ_KIAA1429 accelerates hepatocellular carcinoma progression via the miR-133a-3p/high mobility group AT-hook 2 (HMGA2) axis in an m6A-dependent manner

Hepatocellular carcinoma (HCC) is the most common primary liver cancer worldwide with high mortality rate, and the N6-methyladenosine (m6A) epigenetic modifications have been reported to be closely associated with the pathogenesis of HCC, but the detailed molecular mechanisms by which m6A regulates HCC progression have not been fully delineated. In this study, we evidenced that the m6A methyltransferase-like 3 (METTL3)-mediated m6A modification contributed to HCC aggressiveness through modulating a novel circ_KIAA1429/miR-133a-3p/HMGA2 axis. Specifically, circ_KIAA1429 was aberrantly overexpressed in HCC tissues and cells, and the expression levels of circ_KIAA1429 was positively regulated by METTL3 in HCC cells in a m6A-dependent manner. Then, functional experiments confirmed that deletion of both circ_KIAA1429 and METTL3 suppressed HCC cell proliferation, migration and cell mitosis in vitro and in vivo, and conversely, circ_KIAA1429 overexpression had opposite effects to accelerate HCC development. Furthermore, the downstream mechanisms by which circ_KIAA1429 regulated HCC progression were uncovered, and we validated that silencing of circ_KIAA1429 restrained the malignant phenotypes in HCC cells through modulating the miR-133a-3p/high mobility group AT-hook 2 (HMGA2) axis. To summarize, our study firstly investigated the involvement of a novel METTL3/m6A/circ_KIAA1429/miR-133a-3p/HMGA2 axis in regulating HCC development, which provided novel indicators for HCC diagnosis, therapy and prognosis.

MicroRNAs Derived from Extracellular Vesicles: Keys to Understanding SARS-CoV-2 Vaccination Response in Cancer Patients?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provoked a global pandemic identified as coronavirus disease (COVID-19), with millions of deaths worldwide. However, several important questions regarding its impact on public health remain unanswered, such as the impact of vaccination on vulnerable subpopulations such as cancer patients. Cytokine storm and a sustained inflammatory state are commonly associated with immune cell depletion, being manifested in most immunocompromised individuals. This strong immunosuppression can lead to a dysfunctional antiviral response to natural viral infection and compromised vaccination response. Extracellular vesicles (EVs) are membrane-bound vesicles released from cells that are involved in intercellular communication. EVs carry various molecules including microRNAs that play a crucial role in COVID-19 pathophysiology, influencing cellular responses. This review summarizes the state of the art concerning the role of EV-derived miRNAs in COVID-19 infection and their potential use as prognosis biomarkers for vaccination response in cancer patients.

Potential utility of miRNAs for liquid biopsy in breast cancer

Breast cancer (BC) remains the most prevalent malignancy due to its incidence rate, recurrence, and metastasis in women. Conventional strategies of cancer detection– mammography and tissue biopsy lack the capacity to detect the complete cancer genomic landscape. Besides, they often give false- positive or negative results. The presence of this and other disadvantages such as invasiveness, high-cost, and side effects necessitates developing new strategies to overcome the BC burden. Liquid biopsy (LB) has been brought to the fore owing to its early detection, screening, prognosis, simplicity of the technique, and efficient monitoring. Remarkably, microRNAs (miRNAs)– gene expression regulators seem to play a major role as biomarkers detected in the samples of LB. Particularly, miR-21 and miR-155 among other possible candidates seem to serve as favorable biomarkers in the diagnosis and prognosis of BC. Hence, this review will assess the potential utility of miRNAs as biomarkers and will highlight certain promising candidates for the LB approach in the diagnosis and management of BC that may optimize the patient outcome.