Long noncoding RNA HOXD-AS1 in various cancers: a meta-analysis and TCGA data review

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.

Identification of Immune-Related Prognostic mRNA and lncRNA in Patients with Hepatocellular Carcinoma

Background

As the most common hepatic malignancy, hepatocellular carcinoma (HCC) has a high incidence; therefore, in this paper, the immune-related genes were sought as biomarkers in liver cancer.

Methods

In this study, a differential expression analysis of lncRNA and mRNA in The Cancer Genome Atlas (TCGA) dataset between the HCC group and the normal control group was performed. Enrichment analysis was used to screen immune-related differentially expressed genes. Cox regression analysis and survival analysis were used to determine prognostic genes of HCC, whose expression was detected by molecular experiments. Finally, important immune cells were identified by immune cell infiltration and detected by flow cytometry.

Results

Compared with the normal group, 1613 differentially expressed mRNAs (DEmRs) and 1237 differentially expressed lncRNAs (DElncRs) were found in HCC. Among them, 143 immune-related DEmRs and 39 immune-related DElncRs were screened out. These genes were mainly related to MAPK cascade, PI3K-AKT signaling pathway, and TGF-beta. Through Cox regression analysis and survival analysis, MMP9, SPP1, HAGLR, LINC02202, and RP11-598F7.3 were finally determined as the potential diagnostic biomarkers for HCC. The gene expression was verified by RT-qPCR and western blot. In addition, CD4 + memory resting T cells and CD8 + T cells were identified as protective factors for overall survival of HCC, and they were found highly expressed in HCC through flow cytometry.

Conclusion

The study explored the dysregulation mechanism and potential biomarkers of immune-related genes and further identified the influence of immune cells on the prognosis of HCC, providing a theoretical basis for the prognosis prediction and immunotherapy in HCC patients.

PCAT6 may be a new prognostic biomarker in various cancers: a meta-analysis and bioinformatics analysis

Background

LncRNA prostate cancer-associated transcript 6 (PCAT6) has been reported to be dysregulated in several cancers and is associated with tumor progression. Here, we have performed a meta-analysis to assess the general prognostic role of PCAT6 in malignancies.

Methods

Four public databases (Embase, Pubmed, Web of Science, Cochrane Library) were used to identify eligible studies, then data was extracted and associations between prognostic indicators and clinical characteristics were combined to estimate hazard ratio (HR) or odds ratio (OR) with a 95% confidence interval (CI). Publication bias was measured using the Begg's test, and the stability of the combined results was measured using sensitivity analysis. Subsequently, results were validated using Gene Expression Profiling Interactive Analysis (GEPIA) and the National Genomics Data Center (NGDC).

Results

Ten studies were considered eligible for inclusion. In total, 937 patients and eight types of cancer were included. Our results revealed that overexpression of PCAT6 was significantly associated with a shorter OS (HR = 1.82; 95% CI, [1.40, 2.38]; P < 0.0001) and progression-free survival (PFS) (HR = 1.66; 95% CI, [1.22, 2.25]; P < 0.0001) in cancer patients, and that PCAT6 overexpression was significantly associated with individual tumor clinicopathological parameters, including TNM stage (OR = 0.29; 95% CI, [0.09, 0.94]; P = 0.04), gender (OR = 1.84; 95% CI, [1.31, 2.59]; P = 0.0005), and whether the tumor was metastatic (OR = 5.02; 95% CI, [1.36, 18.57]; P = 0.02). However, PCAT6 overexpression was not correlated with patient age and tumor differentiation. PCAT6 expression was significantly up-regulated in four types of cancer, which was validated using the GEPIA cohort. Combining OS and disease-free survival (DFS) of these four types of cancer revealed a shorter OS and DFS in patients with PCAT6 overexpression. PCAT6 expression in various types of cancer was also validated in NGDC. A total of eight cancers were analyzed and PCAT6 was highly expressed in all eight cancers. Further functional predictions suggest that PCAT6 is correlated with tumor prognosis, and that PCAT6 may be useful as a new tumor-specific marker.

Conclusions

LncRNA PCAT6 is highly expressed in multiple cancer types and its upregulation was significantly associated with patient prognosis and poorer clinical features, thereby suggesting that PCAT6 may be a novel prognostic factor in multiple cancer types.

Long Noncoding RNA HOXD-AS1 Promotes the Proliferation, Migration, and Invasion of Colorectal Cancer via the miR-526b-3p/CCND1 Axis

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies in the world. It has been reported that the abnormal expression of long noncoding RNA HOXD-AS1 promotes the development of CRC, while the mechanism is still unclear. The aim of this study is to investigate the effects of HOXD-AS1 on proliferation, migration, and invasion in CRC and explore the underlying mechanism.

METHODS

Quantitative real-time polymerase chain reaction was used to detect the expression levels of HOXD-AS1, miR-526b-3p, and cyclin D1 (CCND1) in CRC tissues and cells. Dual-luciferase reporter assay was applied to examine the interaction between miR-526b-3p and HOXD-AS1 or CCND1. In addition, cell proliferation ability was assessed by Cell Counting Kit-8 assay. Cell migration and invasion abilities were determined using transwell assay. Furthermore, Western blot assay was conducted to measure the protein expression of CCND1.

RESULTS

HOXD-AS1 was highly expressed in CRC, and high expression of HOXD-AS1 was related to the poor prognosis of patients with CRC. MiR-526b-3p could be targeted by HOXD-AS1. Function experiment results revealed that miR-526b-3p inhibitor could reverse the suppressive effect of HOXD-AS1 knockdown on the proliferation, migration, and invasion of CRC cells. Moreover, CCND1 was a target of miR-526b-3p, and its overexpression could reverse the inhibitory effect of miR-526b-3p overexpression on the proliferation, migration, and invasion of CRC cells. In addition, CCND1 overexpression reversed the suppressive effect of HOXD-AS1 knockdown on the proliferation, migration, and invasion of CRC.

CONCLUSIONS

HOXD-AS1 upregulated the expression of CCND1 to promote the proliferation, migration, and invasion of CRC through targeting miR-526b-3p. This provided a new theoretical basis for clinical anticancer research of CRC.

Long noncoding RNA LINC00511 induced by SP1 accelerates the glioma progression through targeting miR-124-3p/CCND2 axis

Mounting evidence suggests the vital roles of long noncoding RNA (lncRNAs) in the glioma. However, the role of LINC00511 in gliomagenesis is still uncovered. Here, in this study, we aim to investigate the effects of LINC00511 on the glioma cancer phenotype and its deepgoing mechanism. Results indicated that LINC00511 was up-regulated in glioma tissues and cell lines, moreover its overexpression positively correlated with the poor prognosis and advanced pathological stages. For the upstream regulation, LINC00511 was epigenetically up-regulated by transcription factor specificity protein 1 (SP1). Gain and loss of functional experiments demonstrated that LINC00511 promoted the proliferation and invasion of glioma cells in vitro. The knockdown of LINC00511 repressed the tumour growth in vivo. Mechanistically, LINC00511 positively regulated the CCND2 expression via competitively sponging with miR-124-3p. Overall, our finding illuminates that LINC00511 is induced by SP1 and accelerates the glioma progression through targeting miR-124-3p/CCND2 axis, constructing the SP1/LINC00511/miR-124-3p/CCND2 axis.