Downregulation of MST4 Underlies a Novel Inhibitory Role of MicroRNA Let-7a in the Progression of Retinoblastoma

Targeting pediatric solid tumors in the new era of RNA therapeutics

Despite substantial progress in pediatric cancer treatment, poor prognosis remained for patients with recurrent or metastatic disease, given the limitations of approved targeted treatments and immunotherapies. RNA therapeutics offer significant potential for addressing a broad spectrum of diseases, including cancer. Advances in manufacturing and delivery systems are paving the way for the rapid development of therapeutic RNAs for clinical applications. This review summarizes therapeutic RNA classifications and the mechanisms of action, highlighting their potential in manipulating major cancer-related pathways and biological effects. We also focus on the pre-clinical investigation of RNA molecules with efficient delivery systems for their therapeutic potential targeting pediatric solid tumors.

Deciphering potential vascularization factors of on-chip co-cultured hiPSC-derived cerebral organoids

The lack of functional vascular system in stem cell-derived cerebral organoids (COs) limits their utility in modeling developmental processes and disease pathologies. Unlike other organs, brain vascularization is poorly understood, which makes it particularly difficult to mimic in vitro. Although several attempts have been made to vascularize COs, complete vascularization leading to functional capillary network development has only been achieved via transplantation into a mouse brain. Understanding the cues governing neurovascular communication is therefore imperative for establishing an efficient in vitro system for vascularized cerebral organoids that can emulate human brain development. Here, we used a multidisciplinary approach combining microfluidics, organoids, and transcriptomics to identify molecular changes in angiogenic programs that impede the successful in vitro vascularization of human induced pluripotent stem cell (iPSC)-derived COs. First, we established a microfluidic cerebral organoid (CO)-vascular bed (VB) co-culture system and conducted transcriptome analysis on the outermost cell layer of COs cultured on the preformed VB. Results revealed coordinated regulation of multiple pro-angiogenic factors and their downstream targets. The VEGF-HIF1A-AKT network was identified as a central pathway involved in the angiogenic response of cerebral organoids to the preformed VB. Among the 324 regulated genes associated with angiogenesis, six transcripts represented significantly regulated growth factors with the capacity to influence angiogenic activity during co-culture. Subsequent on-chip experiments demonstrated the angiogenic and vasculogenic potential of cysteine-rich angiogenic inducer 61 (CYR61) and hepatoma-derived growth factor (HDGF) as potential enhancers of organoid vascularization. Our study provides the first global analysis of cerebral organoid response to three-dimensional microvasculature for in vitro vascularization.

Tandem mass tag (TMT) quantitative protein analysis-based proteomics and parallel reaction monitoring (PRM) validation revealed that MST4 accelerates osteosarcoma proliferation by increasing MRC2 activity

Osteosarcoma is one of the most common orthopedic malignancies and is characterized by rapid disease progression and a poor prognosis. Currently, research on methods to inhibit osteosarcoma proliferation is still limited. In this study, we found that MST4 levels were significantly increased in osteosarcoma cell lines and tumor tissues compared to normal controls and demonstrated that MST4 is an influential factor in promoting osteosarcoma proliferation both in vivo and in vitro. Proteomic analysis was performed on osteosarcoma cells in the MST4 overexpression and vector expression groups, and 545 significantly differentially expressed proteins were identified and quantified. The candidate differentially expressed protein MRC2 was then identified using parallel reaction monitoring validation. Subsequently, MRC2 expression was silenced with small interfering RNA (siRNA), and we were surprised to find that this alteration affected the cell cycle of MST4-overexpressing osteosarcoma cells, promoted apoptosis and impaired the positive regulation of osteosarcoma growth by MST4. In conclusion, this study identified a novel approach for suppressing osteosarcoma proliferation. Reduction of MRC2 activity inhibits osteosarcoma proliferation in patients with high MST4 expression by altering the cell cycle, which may be valuable for treating osteosarcoma and improving patient prognosis.

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.

LINC00488 Induces Tumorigenicity in Retinoblastoma by Regulating microRNA-30a-5p/EPHB2 Axis

OBJECTIVE

LINC00488 confers oncogenic activity in the progression of some tumors. Hence, the target of the study was about to specify LINC00488-mediated network in retinoblastoma (RB).

METHODS

LINC00488 expression was tested in RB clinical tissues. siRNA targeting LINC00488 or miR-30a-5p mimic was introduced into RB cell line (Y79) to observe cellular biological functions. The relationship between LINC00488, miR-30a-5p and EPHB2 was verified. Afterward, the role of miR-30a-5p involved in RB through targeted regulation of EPHB2 was probed in vitro and in vivo.

RESULTS

LINC00488 was induced in RB tissue and cells. LINC00488 knockdown or miR-30a-5p upregulation depressed the malignant activities of Y79 cells. LINC00488 could sponge miR-30a-5p that targeted EPHB2. EPHB2, and EPHB2 overexpression counteracted miR-30a-5p restoration-induced inhibition of Y79 cell development in vitro and in vivo.

CONCLUSION

LINC00488 induces tumorigenicity in RB by binding to miR-30a-5p to target EPHB2, which may offer a new clue of RB treatment from an lncRNA-miRNA-mRNA network.

Regulation of epigenetic homeostasis in uveal melanoma and retinoblastoma

Uveal melanoma (UM) and retinoblastoma (RB), which cause blindness and even death, are the most frequently observed primary intraocular malignancies in adults and children, respectively. Epigenetic studies have shown that changes in the epigenome contribute to the rapid progression of both UM and RB following classic genetic changes. The loss of epigenetic homeostasis plays an important role in oncogenesis by disrupting the normal patterns of gene expression. The targetable nature of epigenetic modifications provides a unique opportunity to optimize treatment paradigms and establish new therapeutic options for both UM and RB with these aberrant epigenetic modifications. We aimed to review the research findings regarding relevant epigenetic changes in UM and RB. Herein, we 1) summarize the literature, with an emphasis on epigenetic alterations, including DNA methylation, histone modifications, RNA modifications, noncoding RNAs and an abnormal chromosomal architecture; 2) elaborate on the regulatory role of epigenetic modifications in biological processes during tumorigenesis; and 3) propose promising therapeutic candidates for epigenetic targets and update the list of epigenetic drugs for the treatment of UM and RB. In summary, we endeavour to depict the epigenetic landscape of primary intraocular malignancy tumorigenesis and provide potential epigenetic targets in the treatment of these tumours.