Chronic Lymphocytic Leukemia (CLL): evaluation of AKT protein kinase and microRNA gene expression related to disease pathogenesis

Abstract The present study evaluated 56 patients diagnosed with Chronic Lymphocytic Leukemia (CLL) and a control group of 44 clinically healthy subjects with no previous history of leukemia. Genetic expressions of AKT and microRNAs were evaluated by quantitative PCR (qPCR). A significant increase in AKT gene expression in patients when compared to controls was observed (p = 0.017). When the patients were stratified according to Binet subgroups, a significant difference was observed between the subgroups, with this protein kinase appearing more expressed in the B+C subgroup (p = 0.013). Regarding miRNA expression, miR-let-7b and miR-26a were reduced in CLL patients, when compared to controls. However, no significant differences were observed in these microRNA expressions between the Binet subgroups (A versus B+C). By contrast, miR-21 to miR-27a oncogenes showed no expression difference between CLL patients and controls. AKT protein kinase is involved in the signaling cascade that occurs with BCR receptor activation, leading to increased lymphocyte survival and protection against the induction of cell death in CLL. Thus, increased AKT protein kinase expression and the reduction of miR-let-7b and miR-26a, both tumor suppressors, may explain increased lymphocyte survival in CLL patients and may be promising markers for the prognostic evaluation of this disease.

NLRP3 inflammasome signaling as an early molecular response is negatively controlled by miR-186 in CFA-induced prosopalgia mice

The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most frequently studied in the central nervous system and has been linked to neuropathic pain. In this study, a post-translational mechanism of microRNA (miR)-186 via regulating the expression of NLRP3 in the complete Freund's adjuvant (CFA)-treated mice was investigated. The injection of CFA was used to induce trigeminal neuropathic pain in mice. miRs microarray chip assay was performed in trigeminal ganglions (TGs). CFA treatment significantly increased the mRNA expression of NLRP3, interleukin (IL)-1β, and IL-18 in TGs compared to the control group. Moreover, 26 miRs were differentially expressed in TGs from trigeminal neuropathic pain mice, and the expression of miR-186 showed the lowest level of all the miRs. Further examination revealed that NLRP3 was a candidate target gene of miR-186. We delivered miR-186 mimics to CFA-treated mice. The head withdrawal thresholds of the CFA-treated mice were significantly increased by miR-186 mimics injection compared with CFA single treatment. The mRNA and protein expression of NLRP3, IL-1β, and IL-18 in TGs from trigeminal neuropathic pain mice were significantly inhibited by miR-186 mimics treatment compared to the CFA group. miR-186 was able to suppress the neuropathic pain via regulating the NLRP3 inflammasome signaling.

Simultaneously expressed miR-424 and miR-381 synergistically suppress the proliferation and survival of renal cancer cells---Cdc2 activity is up-regulated by targeting WEE1

OBJECTIVES: MiRNAs are intrinsic RNAs that interfere with protein translation. Few studies on the synergistic effects of miRNAs have been reported. Both miR-424 and miR-381 have been individually reported to be involved in carcinogenesis. They share a common putative target, WEE1, which is described as an inhibitor of G2/M progression. Here, we studied the synergistic effects of miR-424 and miR-381 on renal cancer cells. METHODS: The viability of 786-O cells was analyzed after transfection with either a combination of miR-424 and miR-381 or each miRNA alone. We investigated cell cycle progression and apoptosis with flow cytometry. To confirm apoptosis and the abrogation of G2/M arrest, we determined the level of pHH3, which is an indicator of mitosis, and caspase-3/7 activity. The expression levels of WEE1, Cdc25, γH2AX, and Cdc2 were manipulated to investigate the roles of these proteins in the miRNA-induced anti-tumor effects. To verify that WEE1 was a direct target of both miR-424 and miR-381, we performed a dual luciferase reporter assay. RESULTS: We showed that the combination of these miRNAs synergistically inhibited proliferation, abrogated G2/M arrest, and induced apoptosis. This combination led to Cdc2 activation through WEE1 inhibition. This regulation was more effective when cells were treated with both miRNAs than with either miRNA alone, indicating synergy between these miRNAs. WEE1 was verified to be a direct target of each miRNA according to the luciferase reporter assay. CONCLUSIONS: These data clearly demonstrate that these two miRNAs might synergistically act as novel modulators of tumorigenesis by down-regulating WEE1 expression in renal cell cancer cells. .

MicroRNA 100: a context dependent miRNA in prostate cancer

OBJECTIVE: MicroRNAs are noncoding RNA molecules involved in the development and progression of tumors. We have found that miRNA-100 is underexpressed in metastatic prostate cancer compared to localized disease. Conversely higher levels of miR-100 are related to biochemical recurrence after surgery. This suggests that miR-100 may be a context-dependent miRNA, acting as oncogene or tumor suppressor miRNA. Our aim is to demonstrate the role of miR-100 in the control of predicted target genes in prostate cancer cell lines. METHODS: Cell lines DU145 and PC3 were transfected with miR-100, antimiR-100 and after 24 h and 48 h of exposure, qRT-PCR and western blot were performed for mTOR, FGFR3, THAP2, SMARCA5 and BAZ2A. RESULTS: There was reduction in mTOR (p = 0.025), THAP2 (p = 0.038), SMARCA5 (p = 0.001) and BAZ2A (p = 0.006) mRNA expression in DU145 cells after exposure to miR-100. In PC3 cells, mTOR expression was decreased by miR-100 (p = 0.01). There was a reduction in the expression levels of proteins encoded by studied genes, ranging from 34% to 69%. CONCLUSIONS: We demonstrate that miR-100 is a context-dependent miRNA controlling BAZ2, mTOR, FGFR3, SMARCA5 and THAP2 that might be involved in PC progression. The elucidation of the roles of miRNAs in tumors is important because they can be used as therapeutic targets in the future. .