Mortal Obligate RNA Transcript Inhibits Cancer Cell Invasion and Migration in Lung Adenocarcinoma by Downregulating miRNA-223

Promoter of lncRNA MORT is aberrantly methylated in colorectal cancer

Aberrant DNA methylation plays essential roles in the colorectal cancer (CRC) carcinogenesis and has been demonstrated as a promising marker for cancer early detection. In this project, methylation status of the MORT promoter was studied in CRC and their marginal tissues using qMSP assay. Furthermore, we investigated the molecular function of MORT in CRC progression using computational analysis. The results showed a high methylation level of MORT promoter in CRC tissues. By in silico analysis, we found that MORT downregulation could promote the proliferation of CRC cells via sponging of has-miR-574-5p and has-miR-31-5p, and alteration of their targets expression pattern such as MYOCD and FOXP2. In conclusion, based on our results, promoter hypermethylation of MORT might be considered as a potential biomarker for CRC detection.

In situ detection of exosomal RNAs for cancer diagnosis

Exosomes are considered as biomarkers reflecting the physiological state of the human body. Studies have revealed that the expression levels of specific exosomal RNAs are closely associated with certain cancers. Thus, detection of exosomal RNA offers a new avenue for liquid biopsy of cancers. Many exosomal RNA detection methods based on various principles have been developed, and most of the methods detect the extracted RNAs after lysing exosomes. Besides complex and time-consuming extraction steps, a major drawback of this approach is the degradation of the extracted RNAs in the absence of plasma membrane and cytosol. In addition, there is considerable loss of RNAs during their extraction. In situ detection of exosomal RNAs can avoid these drawbacks, thus allowing higher diagnostic reliability. In this paper, in situ detection of exosomal RNAs was systematically reviewed from the perspectives of detection methods, transport methods of the probe systems, probe structures, signal amplification strategies, and involved functional materials. Furthermore, the limitations and possible improvements of the current in situ detection methods for exosomal RNAs towards the clinical diagnostic application are discussed. This review aims to provide a valuable reference for the development of in situ exosomal RNA detection strategies for non-invasive diagnosis of cancers. STATEMENT OF SIGNIFICANCE: Certain RNAs have been identified as valuable biomarkers for some cancers, and sensitive detection of cancer-related RNAs is expected to achieve better diagnostic efficacy. Currently, the detection of exosomal RNAs is receiving increasing attention due to their high stability and significant concentration differences between patients and healthy individuals. In situ detection of exosomal RNAs has greater diagnostic reliability due to the avoidance of RNA degradation and loss. However, this mode is still limited by some factors such as detection methods, transport methods of the probe systems, probe structures, signal amplification strategies, etc. This review focuses on the progress of in situ detection of exosomal RNAs and aims to promote the development of this field.

miRNA-223 expression in patient-derived eutopic and ectopic endometrial stromal cells and its effect on epithelial-to-mesenchymal transition in endometriosis

OBJECTIVE

This study was designed to evaluate the expression of microRNA-223 (miRNA-223) in patient-derived eutopic and ectopic endometrial stromal cells (SCs). Given the fact that miRNA-223 was previously shown to be upregulated in these cells and that this upregulation has been linked to epithelial-to-mesenchymal transition (EMT) during endometriosis, this study aimed to further explore the expression of miRNA-223, its effect in endometriosis, and the mechanisms underlying its effects.

METHODS

Endometrial tissue was collected from 26 patients with endometriosis and 14 patients with hysteromyoma (control group). Primary endometrial SCs were isolated and cultured from several endometrial samples and miRNA-223 expression was evaluated using qRT-PCR. Cells were then transfected with a miRNA-223 overexpression lentiviral vector (sh-miR-223 cells) or an empty control (sh-NC cells) and then used to monitor the effects of miRNA-223 on the expression of several EMT-associated proteins, including N-cadherin, vimentin, and Slug, using western blot. Cellular migration, invasion, and proliferation were then evaluated using a wound healing, Transwell, and CCK-8 assay, respectively. Flow cytometry was used to detect apoptosis.

RESULTS

There was a significant decrease in the expression of miRNA-223 in both eutopic and ectopic endometrial SCs (p < 0.05) whereas upregulation of miRNA-223 inhibited the expression of EMT-related molecules and reduced cell migration, invasion, and proliferation. High levels of miRNA-223 also promoted apoptosis.

CONCLUSION

miRNA-223 expression decreased in endometrial SCs from endometriosis patients, which may facilitate the differential regulation of EMT during endometriosis.

CLINICAL TRIAL REGISTRATION NUMBER

SWYX2020-211.

TRAT1 overexpression delays cancer progression and is associated with immune infiltration in lung adenocarcinoma

The roles and mechanisms of T-cell receptor (TCR)-associated transmembrane adaptor 1 (TRAT1) in lung adenocarcinoma (LAC) have not yet been reported in the relevant literature. Therefore, this study aimed to understand the roles and mechanisms of TRAT1 in LAC using bioinformatics and in vitro experiments. TRAT1 expression levels in LAC samples were analysed using various databases. TRAT1 co-expressed genes were acquired by the correlation analysis of LAC tissues. The functional mechanisms and protein network of TRAT1 co-expressed genes were analysed using bioinformatics analysis. The expression of TRAT1 was activated in LAC cells, and the roles of TRAT1 overexpression in the growth and migration of cancer cells was investigated using flow cytometry, Cell Counting Kit-8 (CCK-8), and migration and invasion assays. The relationship between TRAT1 overexpression, the immune microenvironment, and RNA modification was evaluated using correlation analysis. TRAT1 expression levels were significantly abnormal at multiple mutation sites and were related to the prognosis of LAC. TRAT1 co-expressed genes were involved in cell proliferation, adhesion, and differentiation, and TRAT1 overexpression significantly inhibited cell viability, migration, and invasion and promoted apoptosis of A549 and H1299 cells, which might be related to the TCR, B cell receptor (BCR), MAPK, and other pathways. TRAT1 expression levels were significantly correlated with the ESTIMATE, immune, and stromal scores in the LAC microenvironment. Additionally, TRAT1 expression levels were significantly correlated with the populations of B cells, CD8 T cells, cytotoxic cells, and other immune cells. TRAT1 overexpression was significantly correlated with the expression of immune cell markers (such as PDCD1, CD2, CD3E) and genes involved in RNA modification (such as ALKBH1, ALKBH3, ALKBH5). In conclusions, TRAT1 overexpression inhibited the growth and migration of LAC cells, thereby delaying cancer progression, and was correlated with the LAC microenvironment and RNA modifications.

HDAC10 Inhibits Cervical Cancer Progression through Downregulating the HDAC10-microRNA-223-EPB41L3 Axis

Background

Although the tumorigenesis of cervical cancer (CC) has been widely investigated and recognized, the study of the systematic impact of histone deacetylase 10 (HDAC10), microRNA, and downstream molecular mechanisms in CC is still limited. Herein, cervical cancer, precancer lesions, and normal cervical tissues were collected to test the expression level of HDAC10, miR-223, and EPB41L3. The mechanism of HDAC10, miR-223, and EPB41L3 was interpreted in cervical cancer cells after HDAC10, miR-223, or EPB41L3 expression was altered.

Results

HDAC10 was poorly expressed in cervical cancer and precancer lesions, while miR-223 was highly expressed in cervical cancer. HDAC10 bound to miR-223, and miR-223 targeted EPB41L3. HDAC10 depressed the invasion property and tumorigenesis of cervical cancer via downregulating miR-223 and subsequently targeting EPB41L3.

Conclusion

The study clarifies that HDAC10 inhibits cervical cancer by downregulating miR-223 and subsequently targeting EPB41L3 expression, which might provide a new insight for management upon cervical cancer and precancer lesions.

LncRNA MORT (ZNF667-AS1) in Cancer-Is There a Possible Role in Gynecological Malignancies?

Gynecological cancers (GCs) are currently among the major threats to female health. Moreover, there are different histologic subtypes of these cancers, which are defined as ‘rare’ due to an annual incidence of <6 per 100,000 women. The majority of these tend to be associated with a poor prognosis. Long non-coding RNAs (lncRNAs) play a critical role in the normal development of organisms as well as in tumorigenesis. LncRNAs can be classified into tumor suppressor genes or oncogenes, depending on their function within the cellular context and the signaling pathways in which they are involved. These regulatory RNAs are potential therapeutic targets for cancer due to their tissue and tumor specificity. However, there still needs to be a deeper understanding of the mechanisms by which lncRNAs are involved in the regulation of numerous biological functions in humans, both in normal health and disease. The lncRNA Mortal Obligate RNA Transcript (MORT; alias ZNF667-AS1) has been identified as a tumor-related lncRNA. ZNF667-AS1 gene, located in the human chromosome region 19q13.43, has been shown to be silenced by DNA hypermethylation in several cancers. In this review, we report on the biological functions of ZNF667-AS1 from recent studies and describe the regulatory functions of ZNF667-AS1 in human disease, including cancer. Furthermore, we discuss the emerging insights into the potential role of ZNF667-AS1 as a biomarker and novel therapeutic target in cancer, including GCs (ovarian, cervical, and endometrial cancers).

Histone deacetylase 10 exerts antitumor effects on cervical cancer via a novel microRNA-223/TXNIP/Wnt/β-catenin pathway

Dysfunction of histone deacetylase 10 (HDAC10) has been suggested in the carcinogenesis of cervical cancer (CC). However, its association with microRNAs (miRNAs) in CC remains exclusive. Hence, this study aims to probe the role of HDAC10 in regulating CC cell proliferation, migration, and invasion and its correlation with the screened-out miRNA target. Microarray analysis and RT-qPCR revealed that HDAC10 expressed poorly in CC cells relative to human immortalized endocervical cells (End1/E6E7). Moreover, HDAC10 downregulation predicted poor survival for patients with CC. Overexpression of HDAC10 reduced CC cell biological activities in vitro and tumor growth and lung metastases in vivo. miR-223, upregulated in CC, was regulated by HDAC10 through histone acetylation, while miR-223 inhibited the effects of HDAC10 overexpression in CC. miR-223 targeted the 3'-UTR of thioredoxin interacting protein (TXNIP) and suppressed its expression, leading to increased CC development in vitro and in vivo. TXNIP overexpression impaired Wnt/β-catenin pathway activity in CC cells.

The therapeutic potential of attenuated diphtheria toxin delivered by an adenovirus vector with survivin promoter on human lung cancer cells

Adenoviral vectors are superior to plasmid vectors in their gene transport efficiency. The A subunit of the diphtheria toxin (DTA) gene is a popular suicide gene in cancer gene therapy. However, DTA is seldom used in adenoviral therapy due to its great toxicity. The toxicity of DTA is so great that even a single molecule of DTA is enough to kill one cell. To avoid this highly toxic effect on normal cells, DTA should be controlled by tumor-specific promoters. The survivin promoter is a widely used tumor-specific promoter. But genes driven by the survivin promoter show a low level of basal gene expression in non-cancer cells. DTA driven by the survivin promoter in adenoviral vectors may be highly toxic not only to cancer cells but also to normal cells. Therefore, DTA should be attenuated when it is used in adenoviral vectors driven by the survivin promoter. In this study, we compared the three kinds of recombinant adenoviruses that carry DTA or its attenuated forms (DTA176 and DTA197) in the treatment of human lung cancer. The results showed that in comparison with both DTA and DTA176, DTA197 is more suitable for adenoviral cancer therapy controlled by the survivin promoter. In addition, Adsur-DTA197 (DTA197 delivered by an adenoviral vector with the survivin promoter) sensitized human lung cancer cells to cisplatin both in vitro and in vivo. These results indicated that Adsur-DTA197 may be a potential chemosensitizer in cancer therapy.