Decreased expression of the long non-coding RNA HOXD-AS2 promotes gastric cancer progression by targeting HOXD8 and activating PI3K/Akt signaling pathway

The diagnostic potential of miR-196a-1 in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a common malignancy worldwide. MicroRNAs (miRNAs) are important epigenetic alterations that notably impact various physiological and pathological processes by acting as negative regulators of gene expression. Furthermore, they have a vital function in different types of cancers, including CRC. In this research, we evaluated, for the very first time, the expression levels of miR-196a-1 in the tissue and plasma of patients with CRC and also homeobox D8 (HOXD8) as the target gene.

MATERIALS AND METHODS

This study included a collection of 220 plasma and tissue samples from 55 patients diagnosed with CRC, as well as 55 healthy individuals matched by age and sex. Total RNA was extracted from plasma and tissue samples, and then polyadenylation and cDNA synthesis were performed. The expression levels of miR-196a-1 and HOXD8 as target gene was evaluated by quantitative RT-PCR (qRT-PCR) assay. We compared the diagnostic value of plasma miR-196a-1 with that of the circulating tumor markers CA19-9 and CEA using a Receiver Operating Characteristics (ROC) analysis. The association of miR-196a-1 with clinicopathological characteristics was assessed in tissue and plasma samples from patients with CRC.

RESULTS

Our data demonstrated that the expression levels of miR-196a-1 in the tissue and plasma samples of CRC patients were 11.426- and 11.655-fold higher, respectively than those in adjacent normal tissue and plasma samples from normal subjects (p < 0.001). Through ROC curve analysis, it was identified that the sensitivity and specificity of miR-196a-1 for tissue samples, with an AUC of 0.925, were 89% and 98%, respectively. In addition, the sensitivity and specificity for plasma samples with an AUC of 0.801 were 70% and 98%, respectively. These findings reveal that miR-196a-1 is a useful biomarker for discriminating cases from controls. Furthermore, the expression of HOXD8 was not significantly altered in tumor tissue samples compared to adjacent normal tissues (P > 0.05).

CONCLUSIONS

These results show that miR-196a-1 has an oncogenic impact and plays a significant role in CRC development. The results also indicate that miR-196a-1 could serve as a novel noninvasive biomarker for the detection of CRC.

A Positive Feedback Loop of lncRNA HOXD-AS2 and SMYD3 Facilitates Hepatocellular Carcinoma Progression via the MEK/ERK Pathway

Purpose

HOX cluster-embedded long noncoding RNAs (HOX-lncRNAs) have been shown to be tightly related to hepatocellular carcinoma (HCC). However, the potential biological roles and underlying molecular mechanism of HOX-lncRNAs in HCC largely remains to be elucidated.

Methods

The expression signature of eighteen HOX-lncRNAs in HCC cell lines were measured by qRT-PCR. HOXD-AS2 expression and its clinical significance in HCC was investigated by bioinformatics analysis utilizing the TCGA data. Subcellular localization of HOXD-AS2 in HCC cells was observed by RNA-FISH. Loss‑of‑function experiments in vitro and in vivo were conducted to probe the roles of HOXD-AS2 in HCC. Potential HOXD-AS2-controlled genes and signaling pathways were revealed by RNA-seq. Rescue experiments were performed to validate that SMYD3 mediates HOXD-AS2 promoting HCC progression. The positive feedback loop of HOXD-AS2 and SMYD3 was identified by luciferase reporter assay and ChIP-qPCR.

Results

HOXD-AS2 was dramatically elevated in HCC, and its up-regulation exhibited a positive association with aggressive clinical features (T stage, pathologic stage, histologic grade, AFP level, and vascular invasion) and unfavorable prognosis of HCC patients. HOXD-AS2 was distributed both in the nucleus and the cytoplasm of HCC cells. Knockdown of HOXD-AS2 restrained the proliferation, migration, invasion of HCC cells in vitro, as well as tumor growth in subcutaneous mouse model. Transcriptome analysis demonstrated that SMYD3 expression and activity of MEK/ERK pathway were impaired by silencing HOXD-AS2 in HCC cells. Rescue experiments revealed that SMYD3 as downstream target mediated oncogenic functions of HOXD-AS2 in HCC cells through altering the expression of cyclin B1, cyclin E1, MMP2 as well as the activity of MEK/ERK pathway. Additionally, HOXD-AS2 was uncovered to be positively regulated at transcriptional level by its downstream gene of SMYD3.

Conclusion

HOXD-AS2, a novel oncogenic HOX-lncRNA, facilitates HCC progression by forming a positive feedback loop with SMYD3 and activating the MEK/ERK pathway.

Knockdown of lncRNA HOXD-AS2 Improves the Prognosis of Glioma Patients by Inhibiting the Proliferation and Migration of Glioma Cells

Objective

Increasing studies reported that long noncoding RNAs are involved in regulating glioma progression. However, the specific roles and mechanisms of lncRNAs in glioma remain unclear. Here, we sought to explore the functions of HOXD-AS2 in glioma progression.

Methods

Gene expressions of lncRNAs in 5 normal brain tissue specimens and 5 glioblastoma tissue specimens were detected by gene expression profile chip technology. Bioinformatic analysis was performed to see whether differential expression of lncRNAs played any significant role in glioma occurrence and progression. The relationship between HOXD-AS2 level and clinical prognosis of the patients was analyzed. HOXD-AS2 was specifically interfered with by siRNA technology to observe its effects on U251 cell growth, proliferation, apoptosis, and invasion.

Results

The expression level of HOXD-AS2 gene in glioma was significantly higher than that in the normal brain tissue, which was related to the tumor grade. The level of HOXD-AS2 gene in patients with high-grade glioma was higher than that in patients with low-grade glioma. High expression of HOXD-AS2 gene was a risk factor for poor prognosis of glioma patients. Knocking down the expression of HOXD-AS2 in glioma cell line U251 arrested the cell cycle and reduced the cell proliferation. Furthermore, it could significantly reduce the migration ability of the cells but had no significant effect on the invasion.

Conclusion

HOXD-AS2 is an oncogenic lncRNA associated with the poor prognosis of glioma. Knockdown of HOXD-AS2 may reduce the growth of glioma, which may provide a new avenue for treatment.

Significance of HOXD transcription factors family in progression, migration and angiogenesis of cancer

The transcription factors (TFs) of the HOX family play significant roles during early embryonic development and cellular processes. They also play a key role in tumorigenesis as tumor oncogenes or suppressors. Furthermore, TFs of the HOXD geFIne cluster affect proliferation, migration, and invasion of tumors. Consequently, dysregulated activity of HOXD TFs has been linked to clinicopathological characteristics of cancer. HOXD TFs are regulated by non-coding RNAs and methylation of DNA on promoter and enhancer regions. In addition, HOXD genes modulate the biological function of cancer cells via the MEK and AKT signaling pathways, thus, making HOXD TFs, a suitable molecular marker for cancer prognosis and therapy. In this review, we summarized the roles of HOXD TFs in different cancers and highlighted its potential as a diagnostic and therapeutic target.

Regulatory Roles of Noncoding RNAs in the Progression of Gastrointestinal Cancers and Health Disparities

Annually, more than a million individuals are diagnosed with gastrointestinal (GI) cancers worldwide. With the advancements in radio- and chemotherapy and surgery, the survival rates for GI cancer patients have improved in recent years. However, the prognosis for advanced-stage GI cancers remains poor. Site-specific GI cancers share a few common risk factors; however, they are largely distinct in their etiologies and descriptive epidemiologic profiles. A large number of mutations or copy number changes associated with carcinogenesis are commonly found in noncoding DNA regions, which transcribe several noncoding RNAs (ncRNAs) that are implicated to regulate cancer initiation, metastasis, and drug resistance. In this review, we summarize the regulatory functions of ncRNAs in GI cancer development, progression, chemoresistance, and health disparities. We also highlight the potential roles of ncRNAs as therapeutic targets and biomarkers, mainly focusing on their ethnicity-/race-specific prognostic value, and discuss the prospects of genome-wide association studies (GWAS) to investigate the contribution of ncRNAs in GI tumorigenesis.

Regulatory RNAs, microRNA, long-non coding RNA and circular RNA roles in colorectal cancer stem cells

The properties of cancer stem cells (CSCs), such as self-renewal, drug resistance, and metastasis, have been indicated to be responsible for the poor prognosis of patients with colon cancers. The epigenetic regulatory network plays a crucial role in CSC properties. Regulatory non-coding RNA (ncRNA), including microRNAs, long noncoding RNAs, and circular RNAs, have an important influence on cell physiopathology. They modulate cells by regulating gene expression in different ways. This review discusses the basic characteristics and the physiological functions of colorectal cancer (CRC) stem cells. Elucidation of these ncRNAs will help us understand the pathological mechanism of CRC progression, and they could become a new target for cancer treatment.

Production and Stabilization of Specific Upregulated Long Noncoding RNA HOXD-AS2 in Glioblastomas Are Mediated by TFE3 and miR-661, Respectively

Differential expression of long noncoding RNAs (lncRNA) plays a key role in the development of gliomas. Because gliomas are the most common primary central nervous system tumor and glioblastomas have poor prognosis, it is urgent to develop new diagnostic methods. We have previously reported that lncRNA HOXD-AS2, which is specifically up-regulated in gliomas, can activate cell cycle and promote the development of gliomas. It is expected to be a new marker for molecular diagnosis of gliomas, but little is known about HOXD-AS2. Here, we demonstrate that TFE3 and miR-661 maintain the high expression level of HOXD-AS2 by regulating its production and degradation. We found that TFE3 acted as a transcription factor binding to the HOXD-AS2 promoter region and raised H3K27ac to activate HOXD-AS2. As the cytoplasmic-located lncRNA, HOXD-AS2 could be degraded by miR-661. This process was inhibited in gliomas due to the low expression of miR-661. Our study explains why HOXD-AS2 was specifically up-regulated in gliomas, helps to understand the molecular characteristics of gliomas, and provids insights for the search for specific markers in gliomas.

Influence of steep Trendelenburg position on postoperative complications: a systematic review and meta-analysis

Intraoperative physiologic changes related to the steep Trendelenburg position have been investigated with the widespread adoption of robot-assisted pelvic surgery (RAPS). However, the impact of the steep Trendelenburg position on postoperative complications remains unclear. We conducted a meta-analysis to compare RAPS to laparoscopic/open pelvic surgery with regards to the rates of venous thromboembolism (VTE), cardiac, and cerebrovascular complications. Meta-regression was performed to evaluate the influence of confounding risk factors. Ten randomized controlled trials (RCTs) and 47 non-randomized controlled studies (NRSs), with a total of 380,125 patients, were included. Although RAPS was associated with a decreased risk of VTE and cardiac complications compared to laparoscopic/open pelvic surgery in NRSs [risk ratio (RR), 0.59; 95% CI 0.51–0.72, p < 0.001 and RR 0.93; 95% CI 0.58–1.50, p = 0.78, respectively], these differences were not confirmed in RCTs (RR 0.92; 95% CI 0.52–1.62, p = 0.77 and RR 0.93; 95% CI 0.58–1.50, p = 0.78, respectively). In subgroup analyses of laparoscopic surgery, there was no significant difference in the risk of VTE and cardiac complications in both RCTs and NRSs. In the meta-regression, none of the risk factors were found to be associated with heterogeneity. Furthermore, no significant difference was observed in cerebrovascular complications between RAPS and laparoscopic/open pelvic surgery. Our meta-analysis suggests that the steep Trendelenburg position does not seem to affect postoperative complications and, therefore, can be considered safe with regard to the risk of VTE, cardiac, and cerebrovascular complications. However, proper individualized preventive measures should still be implemented during all surgeries including RAPS to warrant patient safety.

HOXD8 inhibits the proliferation and migration of triple-negative breast cancer cells and induces apoptosis in them through regulation of AKT/mTOR pathway

HOXD8 (Homeobox D8) functions as an apoptotic inducer to suppress tumor progression. However, the role of HOXD8 in triple-negative breast cancer (TNBC) has not been fully understood. Firstly, HOXD8 was found to be reduced in TNBC tissues based on the TCGA samples through Ualcan (http://ualcan.path.uab.edu/analysis.html) prediction. Moreover, data from qRT-PCR and western blot confirmed the lower expression of HOXD8 in the TNBC tissues or cells than that in paracancerous tissues or human mammary epithelial cell line (MCF10A), respectively. Secondly, pcDNA-mediated over-expression of HOXD8 were conducted in TNBC cells, and the gain-of functional assays showed that over-expression of HOXD8 promoted TNBC cell progression with repressed cell apoptosis and induced proliferation, migration and invasion. Moreover, xenografted mouse model was constructed by injection of tumor cell line with stable over-expression of HOXD8 to assess the in vivo tumor growth, and the results revealed that over-expression of HOXD8 inhibited tumor growth. Lastly, our results showed that AKT and mTOR phosphorylation were repressed by HOXD8 over-expression in TNBC cells. In conclusion, HOXD8 functioned as an apoptotic inducer to suppress TNBC cell growth and progression by inhibition of AKT/mTOR pathway.

There and Back Again: Hox Clusters Use Both DNA Strands

Bilaterian animals operate the clusters of Hox genes through a rich repertoire of diverse mechanisms. In this review, we will summarize and analyze the accumulated data concerning long non-coding RNAs (lncRNAs) that are transcribed from sense (coding) DNA strands of Hox clusters. It was shown that antisense regulatory RNAs control the work of Hox genes in cis and trans, participate in the establishment and maintenance of the epigenetic code of Hox loci, and can even serve as a source of regulatory peptides that switch cellular energetic metabolism. Moreover, these molecules can be considered as a force that consolidates the cluster into a single whole. We will discuss the examples of antisense transcription of Hox genes in well-studied systems (cell cultures, morphogenesis of vertebrates) and bear upon some interesting examples of antisense Hox RNAs in non-model Protostomia.