Progresses in microRNA Delivery Using Synthetic Nanovectors in Cancer Therapy

Oncogenesis and Tumor Inhibition by MicroRNAs and its Potential Therapeutic Applications: A Systematic Review

MicroRNAs appear as small molecule modifiers, which improve many new findings and mechanical illustrations for critically important biological phenomena and pathologic events. The best-characterized non-coding RNA family consists of about 2600 human microRNAs. Rich evidence has revealed their crucial importance in maintaining normal development, differentiation, growth control, aging, modulation of cell survival or apoptosis, as well as migration and metastasis as microRNAs dysregulation leads to cancer incidence and progression. By far, microRNAs have recently emerged as attractive targets for therapeutic intervention. The rationale for developing microRNA therapeutics is based on the premise that aberrantly expressed microRNAs play a significant role in the emergence of a variety of human diseases ranging from cardiovascular defects to cancer, and that repairing these microRNA deficiencies by either antagonizing or restoring microRNA function may yield a therapeutic benefit. Although microRNA antagonists are conceptually similar to other inhibitory therapies, improving the performance of microRNAs by microRNA replacement or inhibition that is a less well- described attitude. In this assay, we have condensed the last global knowledge and concepts regarding the involvement of microRNAs in cancer emergence, which has been achieved from the previous studies, consisting of the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response and the disruption of profile expression in human cancer. Here, we have reviewed the special characteristics of microRNA replacement and inhibition therapies and discussed explorations linked with the delivery of microRNA mimics in turmeric cells. Besides, the achievement of biomarkers based on microRNAs in clinics is considered as novel non-invasive biomarkers in diagnostic and prognostic assessments.

Hydrophobically modified carbon dots as a multifunctional platform for serum-resistant gene delivery and cell imaging

The development of novel multifunctional gene delivery systems with high efficiency is significant. Herein, due to the unique physical and optical properties of carbon dots (CDs), CDs prepared from polyethyleneimine (PEI) were modified with various hydrophobic chains and different degrees of substitution via an epoxide ring-opening reaction. The modification and substitution degree were confirmed using several analytical methods including ¹H NMR spectroscopy, FT-IR spectroscopy, TEM, and XPS. These CDs were utilized as multifunctional, safe and efficient non-viral gene vectors. The results showed that these materials possessed capability for dual-channel imaging, which enabled the intracellular tracking of the delivered DNA. Both the type and substitution degree of the hydrophobic chain have a large influence on their transfection efficiency. Among the prepared CDs, Ole1.5-CD gave the highest transfection efficiency, which was up to 200 times higher than that of PEI 25 kDa in the presence of serum in A549 cells. Meanwhile, these CD materials showed much less cytotoxicity and better serum tolerance than the traditional cationic polymeric gene vector. The cellular uptake assay further confirmed the good serum tolerance and structure-activity relationship of the CD materials. Thus, these CDs with good biocompatibility, self-imaging and high gene transfection efficiency may serve as a promising platform for both gene delivery and bio-imaging.

LncRNA NEAT1 Interacted With DNMT1 to Regulate Malignant Phenotype of Cancer Cell and Cytotoxic T Cell Infiltration via Epigenetic Inhibition of p53, cGAS, and STING in Lung Cancer

Purpose

Lung cancer is the main cause of cancer-related mortality worldwide. We report here the biological role of nuclear paraspeckle assembly transcript 1 (NEAT1) in the pathogenesis of lung cancer and the underlying mechanisms.

Methods

Reverse transcription–quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis were used to evaluate expression of mRNA and protein. RNA immunoprecipitation (RIP) assay, chromatin immunoprecipitation followed by qPCR analysis, and reporter assay were used to detect DNA/RNA and protein binding. Tumor-infiltrating lymphocytes were assessed with hematoxylin-eosin staining. Cytotoxic T cell infiltration was evaluated with flow cytometric analysis and immunohistochemistry (IHC) staining. The changes of cell viability and cell invasive and migratory ability were analyzed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), colony formation, and Transwell assays, respectively. Syngeneic tumor model was set up to evaluate antitumor effect.

Results

The results showed that NEAT1 was overexpressed in lung cancer tissues and cancer cell lines. This aberrant expression was closely related with tumor stage and lymph node metastasis. Tumor sample with high CD8⁺ showed lower NEAT1 expression. In vitro studies displayed that inhibition of NEAT1 with shRNA resulted in suppression of survival and migration/invasion of lung cancer cells. On the other side, NEAT1 was found to promote tumor growth via inhibiting cytotoxic T cell immunity in syngeneic models. Finally, NEAT1 was found to interact with DNMT1, which in turn inhibited P53 and cyclic GMP-AMP synthase stimulator of interferon genes (cGAS/STING) expression.

Conclusion

Our findings demonstrated that NEAT1 interacted with DNMT1 to regulate cytotoxic T cell infiltration in lung cancer via inhibition of cGAS/STING pathway. The results provided the novel mechanistic insight into the pathogenesis of lung cancer.

Pancreatic Ductal Adenocarcinoma: MicroRNAs Affecting Tumor Growth and Metastasis in Preclinical In Vivo Models

Patients with pancreatic ductal adenocarcinoma have a dismall prognosis because at the time of diagnosis, in the vast majority of patients the tumor has already disseminated to distant organs and the therapeutic benefit of approved agents such as gemcitabine is limited. Therefore, the identification and preclinical and clinical validation of therapeutic agents covering new targets is of paramount importance. In this review we have summarized microRNAs and corresponding targets which affect growth and metastasis of pancreatic tumors in preclinical mouse in vivo models. We identified four up-regulated and 16 down-regulated miRs in PDAC in comparison to corresponding normal tissues. Three sub-categories of miRs have emerged: miRs affecting tumor growth and miRs with an impact on both, tumor growth and metastasis or metastasis only. Finally, we discuss technical and therapeutic aspects of miR-related therapeutic agents for the treatment of pancreatic ductal adenocarcinoma.