microRNA-144 inhibits cell proliferation and invasion by directly targeting TIGAR in esophageal carcinoma

miR-378a-5p exerts tumor-suppressive effects on esophageal squamous cell carcinoma after neoadjuvant immunotherapy by downregulating APOC1/CEP55

Genetic assessment of tumors following neoadjuvant immunotherapy helps identifying targets that mediate anti-tumor immunity. In this study, we explored dysregulated RNAs in esophageal squamous cell carcinoma samples after neoadjuvant immunotherapy using deep sequencing and high-throughput screening. We identified 584 differentially expressed messenger RNAs (mRNAs), 67 differentially expressed microRNAs (miRNAs), and 1,047 differentially expressed long non-coding RNAs (lncRNAs) using differential expression analysis. Competing endogenous RNAs closely related to esophageal squamous cell carcinoma were selected via a combined Pearson's correlation test and weighted correlation network analysis. After validation using survival analysis and dry-lab and wet-lab-based studies, we identified the I-miR-378-5p-APOC1/CEP55 as a critical pathway for esophageal squamous cell carcinoma progression after neoadjuvant immunotherapy. Tumor immune infiltration analysis showed that APOC1 and CEP55 expression is associated with immune regulatory pathways and the function of multiple infiltrating immune cells. We investigated the mechanism of esophageal squamous carcinoma progression after neoadjuvant immunotherapy from the perspective of the mRNA-miRNA-lncRNA network. Furthermore, we identified accurate novel therapeutic targets and prognostic biomarkers, introduced novel perspectives to immunotherapy studies, and laid the foundation for the clinical treatment of patients with esophageal squamous carcinoma.

The Crosstalk Between Autophagy and MicroRNAs in Esophageal Carcinoma:

Esophageal cancer (EC) is considered one of the most prevalent and aggressive malignancies worldwide, with a variety of molecular alterations thought to contribute to its incidence, development, progression, and invasion. However, the exact underlying mechanism has not been elucidated. Autophagy is a highly conserved degradative and recycling process that can function with a dual role in either the progression or the treatment of EC. Since microRNAs (miRNAs) are described as upstream regulators capable of controlling both oncogenic pathways and autophagic flux, the present study has aimed to review the crosstalk between autophagy and miRNAs and the potential perspective of these mechanisms in EC prevention and treatment.

MicroRNAs and Corresponding Targets in Esophageal Cancer as Shown In Vitro and In Vivo in Preclinical Models

Squamous cell carcinoma of the esophagus is associated with a dismal prognosis. Therefore, identification of new targets and implementation of new treatment modalities are issues of paramount importance. Based on a survey of the literature, we identified microRNAs conferring antitumoral activity in preclinical in vivo experiments. In the category of miRs targeting secreted factors and transmembrane receptors, four miRs were up-regulated and 10 were down-regulated compared with five out of nine in the category transcription factors, and six miRs were down-regulated in the category enzymes, including metabolic enzymes. The down-regulated miRs have targets which can be inhibited by small molecules or antibody-related entities, or re-expressed by reconstitution therapy. Up-regulated miRs have targets which can be reconstituted with small molecules or inhibited with antagomirs.

MicroRNA-144 Suppresses Prostate Cancer Growth and Metastasis by Targeting EZH2

Background:

Prostate cancer is a common malignant tumor with a high incidence. MicroRNAs (miRNAs) have been shown to be important post-transcriptional regulators during tumorigenesis. This study aimed to explore the effect of miR-144 on PCa proliferation and apoptosis.

Material and Methods:

The expression of miR-144 and EZH2 were examined in clinical PCa tissues. PCa cell line LNCAP and DU-145 was employed and transfected with miR-144 mimics or inhibitors. The correlation between miR-144 and EZH2 was verified by luciferase reporter assay. Cell viability, apoptosis and migratory capacity were detected by CCK-8, flow cytometry assay and wound healing assay. The protein level of EZH2, E-Cadherin, N-Cadherin and vimentin were analyzed by western blotting.

Results:

miR-144 was found to be negatively correlated to the expression of EZH2 in PCa tissues. Further studies identified EZH2 as a direct target of miR-144. Moreover, overexpression of miR-144 downregulated expression of EZH2, reduced cell viability and promoted cell apoptosis, while knockdown of miR-144 led to an inverse result. miR-144 also suppressed epithelial-mesenchymal transition level of PCa cells.

Conclusion:

Our study indicated that miR-144 negatively regulate the expression of EZH2 in clinical specimens and in vitro. miR-144 can inhibit cell proliferation and induce cell apoptosis in PCa cells. Therefore, miR-144 has the potential to be used as a biomarker for predicting the progression of PCa.

siRNA-Inhibition of TIGAR Hypersensitizes Human Papillomavirus-Transformed Cells to Apoptosis Induced by Chemotherapy Drugs that Cause Oxidative Stress

The high-risk subtype Human Papillomaviruses (hrHPVs), including HPV16, HPV18, HPV31, HPV33, and HPV45, infect and oncogenically transform epithelial cells and cause squamous cell carcinomas and adenocarcinomas associated with the development of cervical cancer and subsets of vulvar, vaginal, penile, and anogenital cancers, as well as head-and-neck oropharyngeal carcinomas which often have poor clinical prognoses. Many cancers have been shown to contain elevated levels of the TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR)-a glycolytic enzyme and antioxidant effector which frequently correlates with an aggressive tumor phenotype and serves as a determinant of therapy-resistance. We therefore tested whether siRNA-inhibition of TIGAR protein expression could sensitize HPV18-transformed HeLa cells to genotoxic chemotherapy agents (i.e., cisplatin, etoposide, doxorubicin, and 4-hydroxycyclophosphamide) that induce oxidative stress and DNA-damage. Here we demonstrate that the siRNA-knockdown of TIGAR hypersensitized HeLa cells to low, otherwise sub-inhibitory concentrations of these drugs and markedly induced cellular apoptosis, as compared to a scrambled RNA (scrRNA) oligonucleotide negative control or a non-transformed immortalized human fibroblast cell-line, HFL1. Importantly, these findings suggest that therapeutically inhibiting TIGAR could hypersensitize hrHPV+ cervical tumor cells to low-dosage concentrations of chemotherapy drugs that induce oxidative DNA-damage, which could potentially lead to more favorable clinical outcomes by reducing the adverse side-effects of these anticancer medications and making them more tolerable for patients. Our studies have further shown that siRNA-inhibition of TIGAR sensitizes HPV18+ HeLa cells to apoptosis induced by 4-hydroxycyclophosphamide-a DNA-alkylating agent these cells were reported to have resistance to, alluding to another possible benefit of targeting TIGAR in combinatorial treatment strategies against virus-induced cancers.

MicroRNA-144: A novel biological marker and potential therapeutic target in human solid cancers

MicroRNAs (miRNAs) are a class of small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. It has been reported that microRNA-144 (miR-144) is highly conserved and can combine complementarily with the 3'-UTRs of target gene mRNAs to inhibit mRNA translation or promote targeted mRNA degradation. MiR-144 is abnormally expressed and has been identified as a tumor suppressor in many types of solid tumors. Increasing evidence supports a crucial role for miR-144 in modulating physiopathologic processes, such as proliferation, apoptosis, invasion, migration and angiogenesis in different tumor cells. Apart from these functions, miR-144 can also affect drug sensitivity, cancer treatment and patient prognosis. In this review, we summarize the biological functions of miR-144, its direct targets and the important signal pathways through which it acts in relation to various tumors. We also discuss the role of miR-144 in tumor biology and its clinical significance in detail and offer novel insights into molecular targeting therapy for human cancers.