Circ_0000527 Drives Retinoblastoma Progression by Regulating miR-1236-3p/SMAD2 Pathway

MiR-1236: Key controller of tumor development and progression: Focus on the biological functions and molecular mechanisms

Combating with the cancer, as one of the leading causes of morbidity and mortality worldwide, scientific community extensively evidenced microRNA 1236 (miR-1236) roles in the pathogenesis of malignant tumors. It has been mentioned that miR-1236 target genes and signal pathways that are key controller of tumor development and progression. Consistently, increasing evidence reports that miR-1236 participates in cancer cell growth, migration, invasion, apoptosis, and drug resistance, as well as tumor diagnosis, and prognosis. MiR-1236 is also implicated in epithelial-mesenchymal transition (EMT), which is a significant indicator of the metastatic process. Moreover, miR-1236 itself is regulated by several newly discovered long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). Current review aimed to summarize and discuss different dimensions of miR-1236 involvement in the fundamental cellular and molecular mechanisms of tumor progressions. We believe that miR-1236 may serve as a non-invasive diagnostic marker and potential therapeutic target for cancer.

The functional role of circular RNAs in the pathogenesis of retinoblastoma: a new potential biomarker and therapeutic target?

Retinoblastoma (RB) is a common cancer in infants and children. It is a curable disease; however, a delayed diagnosis or treatment makes the treatment difficult. Genetic mutations have a central role in the pathogenesis of RB. Genetic materials such as RNAs (coding and non-coding RNAs) are also involved in the progression of the tumor. Circular RNA (circRNA) is the most recently identified RNA and is involved in regulating gene expression mainly through "microRNA sponges". The dysregulation of circRNAs has been observed in several diseases and tumors. Also, various studies have shown that circRNAs expression is changed in RB tissues. Due to their role in the pathogenesis of the disease, circRNAs might be helpful as a diagnostic or prognostic biomarker in patients with RB. In addition, circRNAs could be a suitable therapeutic target to treat RB in a targeted therapy approach.

Role of non-coding RNAs and exosomal non-coding RNAs in retinoblastoma progression

Retinoblastoma (RB) is a rare aggressive intraocular malignancy of childhood that has the potential to affect vision, and can even be fatal in some children. While the tumor can be controlled efficiently at early stages, metastatic tumors lead to high mortality. Non-coding RNAs (ncRNAs) are implicated in a number of physiological cellular process, including differentiation, proliferation, migration, and invasion, The deregulation of ncRNAs is correlated with several diseases, particularly cancer. ncRNAs are categorized into two main groups based on their length, i.e. short and long ncRNAs. Moreover, ncRNA deregulation has been demonstrated to play a role in the pathogenesis and development of RB. Several ncRNAs, such as miR-491-3p, miR-613,and SUSD2 have been found to act as tumor suppressor genes in RB, but other ncRNAs, such as circ-E2F3, NEAT1, and TUG1 act as tumor promoter genes. Understanding the regulatory mechanisms of ncRNAs can provide new opportunities for RB therapy. In the present review, we discuss the functional roles of the most important ncRNAs in RB, their interaction with the genes responsible for RB initiation and progression, and possible future clinical applications as diagnostic and prognostic tools or as therapeutic targets.

Role of circular RNAs in retinoblastoma

Retinoblastoma (RB), the most common malignant retinal tumor among children under 3 years old, is lethal if left untreated. Early diagnosis, together with timely and effective treatment, is important to improve retinoblastoma-related outcomes. Circular RNAs (circRNAs), a new class of non-coding RNAs with the capacity to regulate cellular activities, have great potential in retinoblastoma diagnosis and treatment. Recent studies have identified circular RNAs that regulate multiple cellular processes involved in retinoblastoma, including cell viability, proliferation, apoptosis, autophagy, migration, and invasion. Six circular RNAs (circ-FAM158A, circ-DHDDS, circ-E2F3, circ-TRHDE, circ-E2F5, and circ-RNF20) promote disease progression and metastasis in retinoblastoma and function as oncogenic factors. Other circular RNAs, such as circ-TET1, circ-SHPRH, circ-MKLN1, and circ-CUL2, play tumor suppressive roles in retinoblastoma. At present, the studies on the regulatory mechanism of circular RNAs in retinoblastoma are not very clear. The purpose of this review is to summarize recent studies on the functional roles and molecular mechanisms of circular RNAs in retinoblastoma and highlight novel strategies for retinoblastoma diagnosis, prognosis, and treatment.

Effect of NLRP3 repression on NLRP3 inflammasome activation in human corneal epithelial cells with black carbon exposure

PURPOSE

To investigate the inhibitory effects of NLRP3 siRNA on NLRP3 inflammasome activation in human corneal epithelial cells (HCECs) with fresh black carbon (FBC) particles and ozone-oxidized BC (OBC) particles treatment.

METHODS

HCECs were transfected with NLRP3 siRNA or control siRNA for 48 h, followed by 200 μg/ml FBC or OBC suspension for an additional 72 h. Untreated controls were cells with no siRNA transfection or BC treatment. RT-qPCR and Western blot were used to measure mRNA and protein levels of components of the NLRP3 inflammasome (NLRP3, ASC, and Caspase-1) and downstream cytokine (IL-1β), respectively.

RESULTS

Compared with untreated control cells, mRNA levels of NLRP3, ASC, Caspase-1, and IL-1β were significantly higher (p < 0.05) in control siRNA transfected cells with BC treatments. Compared with the control siRNA transfected cells, NLRP3 siRNA transfection reduced the expression of NLRP3 and ASC, whereas it had a limited effect on the expression of Caspase-1 and IL-1β with FBC or OBC exposures. Under FBC treatment, the reductions of NLRP3 and Caspase-1 mRNA levels were 53.5% (p < 0.001) and 34.2% (p < 0. 01), respectively, and NLRP3 and ASC protein levels were lowered by 58.2% (p < 0.001) and 45.4% (p < 0.001), respectively. Under OBC treatment, the reductions of NLRP3 and Caspase-1 mRNA levels were 39.8% (p < 0.001) and 25.6% (p < 0.05), respectively, and NLRP3 and ASC protein levels were lowered by 44.8% (p < 0.001) and 41.7% (p < 0.001), respectively. Moreover, mRNA levels of ASC and IL-1β, the protein levels of Caspase-1 and IL-1β showed a tendency to decrease in NLRP3 siRNA transfected cells, it was statistically insignificant (p > 0.05).

CONCLUSIONS

NLRP3 siRNA transfection could partially reverse the increased mRNA levels of NLRP3 and Caspase-1, the protein levels of NLRP3 and ASC in HCECs with BC treatment, whereas the reductions of protein levels of Caspase-1 and IL-1β were not significant, indicating that NLRP3 siRNA has a limited inhibitory effect on the activation of NLRP3 inflammasome triggered by BC.