MicroRNAs: Potential prognostic and theranostic biomarkers in chronic lymphocytic leukemia

Small noncoding ribonucleic acids called microRNAs coordinate numerous critical physiological and biological processes such as cell division, proliferation, and death. These regulatory molecules interfere with the function of many genes by binding the 3'-UTR region of target mRNAs to inhibit their translation or even degrade them. Given that a large proportion of miRNAs behave as either tumor suppressors or oncogenes, any genetic or epigenetic aberration changeing their structure and/or function could initiate tumor formation and development. An example of such cancers is chronic lymphocytic leukemia (CLL), the most prevalent adult leukemia in Western nations, which is caused by unregulated growth and buildup of defective cells in the peripheral blood and lymphoid organs. Genetic alterations at cellular and molecular levels play an important role in the occurrence and development of CLL. In this vein, it was noted that the development of this disease is noticeably affected by changes in the expression and function of miRNAs. Many studies on miRNAs have shown that these molecules are pivotal in the prognosis of different cancers, including CLL, and their epigenetic alterations (e.g., methylation) can predict disease progression and response to treatment. Furthermore, miRNAs are involved in the development of drug resistance in CLL, and targeting these molecules can be considered a new therapeutic approach for the treatment of this disease. MiRNA screening can offer important information on the etiology and development of CLL. Considering the importance of miRNAs in gene expression regulation, their application in the diagnosis, prognosis, and treatment of CLL is reviewed in this paper.

Elevated Bax/Bcl-2 Ratio: A Cytotoxic Mode of Action of Kermanian Propolis Against an Acute Lymphoblastic Leukemia Cell Line, NALM-6

Currently, alternative cancer remedies, especially herbal-derived medicines, have attracted great interest. Propolis, a honeybee-produced naturopathic formulation, is an available, affordable, and safe example of such remedies with different content according to its geographic location. Findings regarding the protective properties of this resinous substance across numerous pathological conditions are promising. Although the anti-tumor effects of propolis from different origins have been explored to some degree, yet there is no study on the effects of Kermanian propolis in the treatment of hematologic malignancies. Accordingly, the objective of the present experiment was to divulge the anti-tumor potential of this bioactive substance both as monotherapy and in combination with doxorubicin against an acute lymphoblastic leukemia cell line (NALM-6).The viability of cells treated with Kermanian propolis (5-500 μg/mL) and doxorubicin (5-100 μg/mL) was analyzed during 72 h. Based on the MTT results, the best incubation time, IC50 concentrations, and finally the cytotoxicity of the combination therapy were ascertained. Next, the apoptotic rate and expression of apoptosis-related genes (Bcl-2 and Bax) were assessed in mono and combination therapies using flow cytometry and real-time PCR assays, respectively. Kermanian propolis and doxorubicin have impressive tumor-suppressing activity in a dose-dependent manner (IC50 concentrations: 100 and 40 μg/mL respectively). The best incubation time was considered 48 h. For the combination approach, 50 and 10 μg/mL were determined as optimum concentrations of the compounds. The selected concentrations induced notable apoptosis in the studied cells through significant (P < 0.01) upregulation of Bax/Bcl-2 level. The present study clearly suggests that Kermanian propolis, as an adjunct treatment option, has a promising apoptosis-induced cell death potential in the NALM-6 cell line.

Predicting the possible effect of miR-203a-3p and miR-29a-3p on DNMT3B and GAS7 genes expression

Aberrant expression of genes involved in methylation, including DNA methyltransferase 3 Beta (DNMT3B), can cause hypermethylation of various tumor suppressor genes. In this regard, various molecular factors such as microRNAs can play a critical role in regulating these methyltransferase enzymes and eventually downstream genes such as growth arrest specific 7 (GAS7). Accordingly, in the present study we aimed to predict regulatory effect of miRNAs on DNMT3B and GAS7 genes expression in melanoma cell line. hsa-miR-203a-3p and hsa-miR-29a-3p were predicted and selected using bioinformatics software. The Real-time PCR technique was performed to investigate the regulatory effect of these molecules on the DNMT3B and GAS7 genes expression. Expression analysis of DNMT3B gene in A375 cell line showed that there was a significant increase compared to control (p value = 0.0015). Analysis of hsa-miR-203a-3p and hsa-miR-29a-3p indicated the insignificant decreased expression in melanoma cell line compared to control (p value < 0.05). Compared to control, the expression of GAS7 gene in melanoma cells showed a significant decrease (p value = 0.0323). Finally, our findings showed that the decreased expression of hsa-miR-203a-3p and hsa-miR-29a-3p can hypothesize that their aberrant expression caused DNMT3B dysfunction, possible methylation of the GAS7 gene, and ultimately decreased its expression. However, complementary studies are necessary to definite comment.