Prognostic role of HOTAIR in colorectal cancer: A meta-analysis

BACKGROUND

Colorectal cancer is one of the most common malignant tumors. It is essential to find biomarkers for the early detection and evaluation of tumor prognosis. In recent years, studies have revealed that the expression of Hox transcription antisense RNA (HOTAIR) increases in various cancers, including colorectal cancer. However, due to the small sample size of each study, the persuasiveness is not strong.

AIM

To perform a meta-analysis to explore the relationship between the expression of HOTAIR and the prognosis of colorectal cancer.

METHODS

PubMed, MEDLINE, CNKI, CBM, and The Cochrane Library were searched for articles published before December 2020 on the relationship between HOTAIR expression and the prognosis of patients with colorectal cancer. Two reviewers independently evaluated the quality of the included articles and extracted the data. The risk ratio (HR) of overall survival (OS) and the odds ratio of lymph node metastasis (LNM) and distant metastasis (DM) were calculated to evaluate the association strength.

RESULTS

Seven articles that met the inclusion criteria were included. Six of them compared the correlation between HOTAIR expression level and OS, and the results suggested that there existed a significant correlation between them (OR = 2.36, 95%CI: 1.74-3.19, P < 0.05). The correlation between HOTAIR expression level and LNM was compared in five articles, with a statistically significant correlation observed (OR = 4.07, 95%CI: 1.38-12.0, P < 0.05). Four articles compared the correlation between HOTAIR expression level and DM, and there was a statistically significant correlation between them (OR = 4.32, 95%CI: 1.60-11.62, P < 0.05).

CONCLUSION

The high expression of HOTAIR in colorectal cancer is significantly correlated with decreased OS, LNM, and DM, which indicates that HOTAIR may be a new biomarker for evaluating the prognosis of colorectal cancer.

Cancer-associated fibroblast-derived CCL5 contributes to cisplatin resistance in A549 NSCLC cells partially through upregulation of lncRNA HOTAIR expression

Aberrant C-C motif chemokine ligand 5 (CCL5) is associated with disease progression, poor prognosis and chemotherapy resistance in human malignancy. The tumor microenvironment (TME) contributes to chemotherapy resistance. However, the role of cancer-associated fibroblasts (CAFs)-derived CCL5 is not well documented. Hence, the present study aimed to investigate the effects of CAFs on chemotherapy resistance in A549 non-small cell lung cancer (NSCLC) cells and the underlying mechanism. Primary CAFs isolated from patients with NSCLC were found to express and secrete elevated levels of CCL5, which attenuated cisplatin (DDP)-induced apoptosis, as indicated by flow cytometry analysis. In addition, CCL5 upregulated the expression levels of long non-coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) in the tumor cells, and silencing HOTAIR in tumor cells enhanced the cytotoxic effect of cisplatin, characterized by decreased cell viability and increased apoptotic rate. Mechanistically, HOTAIR was found to inactivate the caspase-3/BCL-2 signaling pathway in A549 NSCLC cells. Collectively, the current study demonstrated that CAFs in the TME may serve a crucial role in the higher expression levels of CCL5 in tumors and that CAF-derived CCL5 may promote cisplatin resistance via upregulating lncRNA HOTAIR expression.

Association between HOTAIR lncRNA Polymorphisms and Coronary Artery Disease Susceptibility

Coronary artery disease (CAD), one of the most frequent causes of mortality, is the most common type of cardiovascular disease. This condition is characterized by the accumulation of plaques in the coronary artery, leading to blockage of blood flow to the heart. The main symptom of CAD is chest pain caused by blockage of the coronary artery and shortness of breath. HOX transcript antisense RNA gene (HOTAIR) is a long non-coding RNA which is well-known as an oncogene involved in various cancers, such as lung, breast, colorectal, and gastric cancer. We selected six single nucleotide polymorphisms, rs4759314 A>G, rs1899663 G>T, rs920778 T>C, rs7958904 G>C, rs12826786 C>T, and rs874945 C>T, for genotype frequency analysis and assessed the frequency of HOTAIR gene polymorphisms in 442 CAD patients and 418 randomly selected control subjects. To analyze the differences between these two populations, we performed a Student's t-test, adjusted odds ratio (AOR), 95% confidence intervals (CIs), and ANOVA analysis. According to our baseline characteristic analysis, control subjects and CAD patients were significantly different in hypertension and diabetes mellitus. We also found that the rs4759314 A>G, rs1899663 G>T, and rs12826786 C>T genotypes were strongly associated with CAD susceptibility (AA vs. AG+GG: AOR = 0.608, 95% CI = 0.393-0.940, p = 0.025; GG vs. TT: AOR = 2.276, 95% CI = 1.125-4.607, p = 0.022; CC vs. CT+TT: AOR = 1.366, 95% CI = 1.027-1.818, p = 0.032, respectively). Our data also demonstrated that the genotype of HOTAIR polymorphisms, genotype combination, and haplotype analysis affect disease occurrence. Moreover, these polymorphisms are linked to clinical factors that contribute to disease susceptibility. In conclusion, results from our study suggest that HOTAIR polymorphisms may be useful novel biomarkers for diagnosing CAD.

lncRNA HAR1B has potential to be a predictive marker for pazopanib therapy in patients with sarcoma

Bone and soft-tissue sarcomas are rare and are highly heterogeneous mesenchymal malignancies. It is therefore challenging to acquire the clinical data of patients with specific histological subtypes of sarcoma using large clinical trials, and there is a need to further establish the diagnosis and treatment of sarcomas. The results of the current study revealed that long non-coding RNA (lncRNA) highly accelerated region 1B (HAR1B) may serve as a predictive biomarker for pazopanib treatment in bone and soft-tissue sarcomas. Using multiplex reverse transcription-quantitative PCR and microarray analyses, the results demonstrated that HAR1B and HOX transcript antisense RNA (HOTAIR) were differentially expressed in pazopanib-sensitive cells and responders. It was further revealed that small interfering RNA-knockdown of HAR1B led to an increased resistance to pazopanib in sarcoma cell lines. Gene expression profiles associated with pazopanib sensitivity included cellular molecular pathways, such as genes involved in von-Willebrand factor-related signaling. The current study demonstrated that lncRNA HAR1B expression in sarcoma cell lines affected cellular sensitivity to pazopanib in patients with sarcoma.

The expression and clinical significance of three lncRNAs in patients with a missed abortion

Missed abortions are common complications that occur in early pregnancy, and impaired trophoblast functions have been indicated to be associated with their pathogenesis. The long noncoding RNAs (lncRNAs) Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1), HOX Transcript Antisense RNA (HOTAIR) and Maternally expressed gene 3 (MEG3) have been demonstrated to serve a crucial regulatory role in the mobility of trophoblast cells and embryo implantation. However, the expression profile and role of each of these three lncRNAs in patients with a missed abortion remain unclear. The expression of MALAT1, HOTAIR, and MEG3 in decidual and villous tissues from 26 patient exhibiting a missed abortion and 26 healthy controls was detected using reverse-transcription quantitative PCR. Serum TNF-α, IL-1β, IL-6 and IL-10 levels were measured using ELISA, and serum estradiol and progesterone levels were measured with electrochemiluminescence immunoassays. Additionally, the correlations between lncRNA expression and the levels of cytokines and hormones were further analyzed. MALAT1, HOTAIR and MEG3 expression was significantly higher in villous tissues of patients exhibiting a missed abortion compared with healthy controls. MALAT1 expression was higher in decidual tissues of patients exhibiting a missed abortion compared with healthy controls. Serum IL-10 levels were significantly lower in patients exhibiting a missed abortion compared with healthy controls. Serum estradiol and progesterone levels were significantly lower in the group of patients exhibiting a missed abortion compared with the control group. Furthermore, MALAT1 expression in villous tissue was inversely related to serum progesterone levels. The results of the current study suggest that MALAT1 may be associated with the pathogenesis of missed abortions.

[Effect of lncRNA HOTAIR on the radiosensitivity of HCCLM3 cells]

Objective: To investigate the effect of down-regulating long non-coding RNA (lncRNA) and HOX transcript antisense RNA (HOTAIR) targeting miR-761 on the radiosensitivity of HCCLM3. Methods: The expression of HOTAIR in liver cancer cells HuH-7, SNU-449, HCCLM3 and normal liver cells L-02 were measured by real-time quantitative PCR. HCCLM3 cells were divided into control, Sh-NC (transfected shRNA negative control), Sh-HOTAIR (transfected HOTAIR shRNA), RAD+Sh-NC (transfected shRNA negative control and irradiated with 8Gy dose), and RAD+Sh-HOTAIR (HOTAIR shRNA was transfected and irradiated with 8Gy dose) group. Apoptosis was detected by flow cytometry, Bcl-2 Associated X Protein (Bx-2), cleaved cysteine-containing Cleaved cysteinyl aspartate specific proteinase 3 (C-Caspase-3) protein expression. Sh-NC, Sh-HOTAIR cells were irradiated with 0, 2, 4, 6, 8 Gy, and plate-clone experiments were used to determine radiosensitivity. Bioinformatics software predicted that miR-761 might be a target gene of HOTAIR, and the luciferase reporter system identified the targeting relationship. The miR-761 inhibitor, HOTAIR shRNA and inhibitor negative control, and HOTAIR shRNA were co-transfected into HCCLM3 cells, respectively. Cell apoptosis and Bax and C-cysteine-containing aspartate proteins were also measured using the above method, as well as the hydrolase-3 protein expression and cell survival fraction. Results: The expression levels of HOTAIR in liver cancer cells HuH-7, SNU-449, and HCCLM3 were higher than those in normal liver cells L-02 (1.85±0.12, 2.27±0.23, 2.68±0.15 vs 1.00±0.09, P<0.05). Compared with Sh-NC, the apoptosis rate of Sh-HOTAIR, RAD+Sh-NC cells and Bax, C-Caspase-3 protein levels are higher [Apoptotic rate: (13.47±1.32)%, (12.84±1.19)% vs (2.98±0.27)%; Bax protein: 0.74±0.08, 0.72±0.06 vs 0.42±0.06; C-Caspase-3 protein: 0.56±0.06, 0.54±0.08 vs 0.25±0.04, all P<0.05]. Compared with Sh-HOTAIR and RAD+Sh-NC, RAD+Sh-HOTAIR cell apoptosis rate and Bax, C-Caspase-3 protein levels are higher [apoptosis rate:(22.57±2.36)% vs (13.47±1.32)%, (12.84±1.19)%, Bax protein: 0.99±0.11 vs 0.74±0.08, 0.72±0.06, C-Caspase-3 protein: 1.03±0.12 vs 0.56±0.06, 0.54±0.08,all P<0.05]. Compared with Sh-NC, Sh-HOTAIR cells had lower survival scores and higher radiosensitivity (P<0.05). HOTAIR targets negative regulation of miR-761 expression. Compared with cells co-transfected with inhibitor negative control and HOTAIR shRNA, cells co-transfected with miR-761 inhibitor and HOTAIR shRNA had lower apoptosis rate after radiation treatment [(10.24±1.32)% vs (21.84±2.01))%], Bax (0.50±0.06 vs 1.01±0.10) and C-Caspase-3 protein (0.56±0.07 vs 1.05±0.14) had lower expression and higher cell survival scores (all P<0.05). Conclusion: Down-regulating lncRNA HOTAIR targets miR-761 to increase the radiosensitivity of HCCLM3.

A single nucleotide polymorphism within HOX Transcript Antisense RNA (HOTAIR) is associated with risk of psoriasis

Recent studies have shown participation of long non-coding RNAs (lncRNAs) in the pathogenesis of psoriasis. Several mechanisms might be involved in the dysregulation of expression of lncRNAs in patients with psoriasis, among them is the presence of single nucleotide polymorphisms (SNPs) which modulate expression or function of these transcripts. In the present work, we genotyped three SNPs (rs12826786, rs1899663 and rs4759314) of the HOX Transcript Antisense RNA (HOTAIR) in 286 patients with psoriasis and 300 control subjects. The rs12826786 was associated with risk of psoriasis in dominant model (TC + TT vs. CC: OR (95% CI) = 1.59 (0.1.14-2.22), adjusted p-value = .02). In the allelic model, T allele of this SNP significantly increased the risk of psoriasis compared with the C allele (OR (95% CI) = 1.35 (1.06-1.71), adjusted p-value = .04). Other SNPs were not associated with risk of psoriasis in any inheritance model. No significant difference was found in haplotype frequencies between cases and controls. The current work shows association between a genomic variant within HOTAIR and risk of psoriasis. The clinical significance of this finding should be assessed in future studies.

Association study of long non-coding RNA HOTAIR rs920778 polymorphism with the risk of cancer in an elderly Japanese population

The HOTAIR gene encodes a long noncoding RNA (lncRNA), which functions in development and tumorigenesis. A single nucleotide polymorphism (SNP) rs920778 in the HOTAIR gene, has been recurrently studied for susceptibility to many cancers including oesophageal cancer, gastric cancer, lung cancer, and hepatocellular carcinoma. Most of these studies were conducted in Chinese populations, and a few in Turkish, Iranian, and Portuguese populations. They mostly give rise to controversial results. It still remains largely unknown whether the cancer risk is conferred in a Japanese population. Here, we established an association study on the representative SNP rs920778, to examine its contribution to the presence of cancer in consecutive autopsy cases in the JG-SNP database. A total of 1373 subjects (mean age 80) including 827 cancer positive and 546 cancer negative subjects were analyzed. As a result, the occurrence of overall cancer was not associated with the rs920778 polymorphism (p > 0.05). For each cancer type, we did not find association except for lung cancer (p = 0.04) which was more likely a by-chance association after multiple testing. Our findings imply that rs920778 polymorphism does not affect total cancer presence and the effect on specific cancer types is also weak in the Japanese population.

Drug-induced modifications and modulations of microRNAs and long non-coding RNAs for future therapy against Glioblastoma Multiforme

Non-coding RNAs are known to participate in cancer initiation, progression, and metastasis by regulating the status of chromatin epigenetics and gene expression. Although these non-coding RNAs do not possess defined protein-coding potential, they are involved in the expression and stability of messenger RNA (mRNA). The length of microRNAs (miRs) ranges between 20 and 22 nt, whereas, long non-coding RNAs (lncRNAs) length ranges between 200 nt to 1 Kb. In the case of circular RNAs (circRNAs), the size varies depending upon the length of the exon from where they were derived. Epigenetic regulations of miR and lncRNA genes will influence the gene expression by modulating histone acetylation and methylation patterns. Especially, lncRNAs will act as a scaffold for various epigenetic proteins, such as EZH2 and LSD1, and influence the chromatin epigenetic state at various genomic loci involved at silencing. Thus investigations on the expression of lncRNAs and designing drugs to modulate the expression of these genes will have a profound impact on future therapeutics against cancers such as Glioblastoma Multiforme (GBM) and also against various other diseases. With the recent advancements in genome-wide transcriptomic studies, scientists are focused on the non-coding RNAs and their regulations on various cellular processes involved in GBM and on other types of cancer as well as trying to understand possible epigenetic modulations that help in generating promising therapeutics for the future generations. In this review, the involvement of epigenetic proteins, enzymes that change chromatin architecture and epigenetic landscape and new roles of lncRNAs that are involved in GBM progression are elaborately discussed.

Down-regulation of long non-coding RNA HOTAIR inhibits invasion and migration of oesophageal cancer cells via up-regulation of microRNA-204

Oesophageal cancer is a progressive tumour with high mortality. However, therapies aimed at treating oesophageal cancer remain relatively limited. Accumulating studies have highlighted long non‐coding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR), microRNA‐204 (miR‐204) and homeobox C8 (HOXC8) in the progression of oesophageal cancer. Herein, we tried to demonstrate the function of HOTAIR, miR‐204 and HOXC8 in oesophageal cancer and their relationship. Differentially expressed genes involved in oesophageal cancer were identified. The endogenous expression of HOTAIR and miR‐204 in oesophageal cancer cell lines was altered to elucidate their effects and to identify the interaction among HOTAIR, miR‐204 and HOXC8. We also explored the underlying regulatory mechanisms of HOTAIR and miR‐204 with siRNA against HOTAIR, miR‐204 mimic or miR‐204 inhibitor. Cell proliferation, migration, invasion and apoptosis were subsequently detected. Xenograft in nude mice was induced to evaluate tumourigenicity. miR‐204 was down‐regulated, while HOTAIR and HOXC8 were up‐regulated in the oesophageal cancer tissues. HOTAIR could competitively bind to miR‐204 and miR‐204 could further target HOXC8. The oesophageal cancer cells treated with si‐HOTAIR or miR‐204 mimic exhibited decreased expression levels of HOXC8, Vimentin and MMP‐9, but increased E‐cadherin level. Silenced HOTAIR or elevated miR‐204 inhibited proliferation, migration and invasion, along with stimulated apoptosis of oesophageal cancer cells. In summary, our results show that lncRNA HOTAIR could specifically bind to miR‐204 as a competing endogenous RNA and regulate miR‐204 and HOXC8. Hence, down‐regulation of HOTAIR could inhibit progression of oesophageal cancer, indicating a novel target for oesophageal cancer treatment.

Knockdown of lncRNA-HOTAIR downregulates the drug-resistance of breast cancer cells to doxorubicin via the PI3K/AKT/mTOR signaling pathway

The resistance to chemotherapeutic drugs is a critical feature of breast cancer recurrence and metastasis. Long non-coding RNAs (LncRNAs) serve key roles in tumor drug resistance. LncRNA-HOX transcript antisense RNA (HOTAIR) has been reported to be overexpressed in certain types of cancer and may be closely associated with tumor resistance. The current study aimed to investigate the role of lncRNA-HOTAIR in the regulation of breast cancer resistance to doxorubicin (DOX). A breast cancer cell line (MCF-7) and DOX-resistant breast cancer cell line (DOXR-MCF-7) were utilized in the current study. DOXR-MCF-7 cells were transfected with lncRNA-HOTAIR small interfering RNA (siRNA) and control siRNA. Subsequently, MTT and colony formation assays were performed to assess cell proliferation. Cell apoptosis was also evaluated via flow cytometry. In addition, western blotting and reverse transcription-quantitative polymerase chain reaction were performed to detect the expression of caspase-3, B-cell lymphoma 2, Bcl-2-associated X protein, phosphoinositide 3-kinase (PI3K), protein kinase B (AKT) and mechanistic target of rapamycin (mTOR), and the phosphorylation of PI3K, AKT, and mTOR. The data indicated that lncRNA-HOTAIR silencing decreased cell proliferation and increased apoptosis in MCF-7 and DOXR MCF-7 cells. Furthermore, lncRNA-HOTAIR silencing significantly decreased the phosphorylation of PI3K, AKT and mTOR, indicating that the knockdown of lncRNA-HOTAIR effectively attenuates the resistance of breast cancer cells to DOX by inhibiting the PI3K/AKT/mTOR pathway. In summary, the present study indicated that the knockdown of lncRNA-HOTAIR weakened the resistance of breast cancer cells to DOX via PI3K/AKT/mTOR signaling, suggesting that lncRNA-HOTAIR may be a novel intervention target to reverse DOX-resistance in breast cancer.

Down-Regulated LncRNA-HOTAIR Suppressed Colorectal Cancer Cell Proliferation, Invasion, and Migration by Mediating p21

BACKGROUND AND AIM

HOX transcript antisense intergenic RNA (HOTAIR) is a relatively well-understood RNA, which plays a central role in the pathogenesis of various tumors. The aim of the present study was to investigate the effect by which HOTAIR acts to influence the biological processes of colorectal cancer (CRC) through p21.

METHODS

Reverse transcription quantitative polymerase chain reaction and Western blot methods were employed to provide verification regarding the changes in HOTAIR, PCNA, Ki67, p21, cyclin E, and CDK2 among the CRC tissues and cells. The correlation between the clinicopathological characteristics of patients and expression of HOTAIR and p21 was subsequently evaluated, followed by an analysis into the effects of HOTAIR on the biological processes of M5 cells.

RESULTS

HOTAIR was found to be expressed at high levels, while p21 was determined to be at a low level among both the CRC tissues and the CRC cell lines. The expressions of HOTAIR and p21 were determined to be related to lymph node metastasis, tumor node metastasis, Dukes staging, distant metastases, histological types, and the degree of differentiation. Cells transfected with HOTAIR siRNA displayed inhibited rates of proliferation, invasion, and migration, as well as decreased cyclin E and CDK2, while apoptosis and p21 were increased.

CONCLUSION

The principal findings demonstrated that down-regulation of HOTAIR elicits an inhibitory effect on proliferation, invasion, and migration, while promoting the apoptosis of CRC cells through the up-regulation of p21. We believe that HOTAIR could represent a novel target for the treatment of CRC.

Knockdown of long non-coding RNA HOTAIR sensitizes hepatocellular carcinoma cell to cisplatin by suppressing the STAT3/ABCB1 signaling pathway

Long non-coding RNA HOX transcript antisense RNA (HOTAIR) has been demonstrated to exhibit oncogenic activity in several types of cancer, including hepatocellular carcinoma (HCC). However, the association between HOTAIR and HCC multidrug resistance remains uncertain. The present study aimed to investigate the role of HOTAIR in HCC chemoresistance; it was found that knockdown of HOTAIR expression in HCC Huh7 cells resulted in decreased cell proliferation and increased chemosensitivity to cisplatin. Furthermore, expression levels of ATP binding cassette subfamily B member 1 (ABCB1) mRNA and protein were decreased in Huh7 cells upon HOTAIR-knockdown. In addition, HOTAIR-knockdown reduced the levels of phosphorylated signal transducer and activator of transcription 3 (STAT3), and inhibition of STAT3 phosphorylation reduced HOTAIR-mediated ABCB1 expression. Together, these findings indicated that knockdown of HOTAIR in Huh7 cells decreased STAT3 activity and ABCB1 expression, and increased chemosensitivity to cisplatin. Thus HOTAIR could serve as a novel potential therapeutic target to reverse multidrug resistance in HCC.

Propofol promotes apoptosis and suppresses the HOTAIR-mediated mTOR/p70S6K signaling pathway in melanoma cells

Propofol is an intravenous anesthetic, which is widely used in clinical anesthesia induction and maintenance and is critical in the sedation of patients. However, the functions and mechanisms of propofol on apoptosis of melanoma cells remain unclear. The present study investigated whether propofol promotes cell apoptosis and suppresses the HOX transcript antisense RNA (HOTAIR)-mediated mechanistic target of rapamycin (mTOR) pathway in melanoma cells. B16F10 cells were cultured with different concentrations (0-10 µM) of propofol for 24 or 48 h. Proliferation and apoptosis of B16F10 cells were detected using MTT assay and flow cytometry. The pcDNA 3.1(-)-HOTAIR and pcDNA 3.1(-)-control plasmids were transfected into B16F10 cells using Lipofectamine 2000. In the present study, treatment with propofol significantly reduced viability, and induced apoptosis and caspase-3 activity in melanoma cells. Propofol treatment significantly inhibited HOTAIR expression and the expression of phosphorylated (p)-mTOR and p- p70S6K protein in melanoma cells. Overexpression of HOTAIR significantly increased viability of melanoma cells, and increased HOTAIR, p-mTOR and p-p70S6K protein expression in melanoma cells. These results indicated that propofol promotes apoptosis and suppresses the HOTAIR-mediated mTOR signaling pathway in melanoma cells.

Long non-coding RNA HOX transcript antisense RNA promotes expression of 14-3-3σ in non-small cell lung cancer

Evidence suggests that both 14-3-3σ and long non-coding RNA HOX transcript antisense RNA (HOTAIR) are involved in the tumorigenesis and progression of lung cancer. In the present study, the potential association between 14-3-3σ and HOTAIR in non-small cell lung cancer (NSCLC) was investigated. In tissue samples collected from 54 patients with NSCLC, expression of HOTAIR and 14-3-3σ was analyzed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). After stable ectopic expression of HOTAIR and stable HOTAIR knockdown in PC9 cancer cells, the effect of HOTAIR on levels of mRNA and protein 14-3-3σ expression levels were detected using RT-qPCR and western blotting, respectively. Expression of HOTAIR and 14-3-3σ in NSCLC tissues was significantly higher than in adjacent non-cancerous lung tissue (P<0.05). Correlation analysis also identified a correlation between levels of HOTAIR and 14-3-3σ expression in NSCLC tissues (r=0.725, P=0.0005). In addition, overexpression and knockdown of HOTAIR in the human NSCLC cell line PC9 led to the upregulation and downregulation of 14-3-3σ, respectively, at both the mRNA and protein levels (all P<0.05). To the best of our knowledge, the present study provides the first in vivo and in vitro evidence to suggest that HOTAIR promotes the expression of 14-3-3σ in NSCLC. The potential association between HOTAIR and 14-3-3σ indicates that both biomolecules may be viable targets in anticancer therapy.

Role of the long non-coding RNA HOTAIR in hepatocellular carcinoma

A number of recent studies have focused on the association between long non-coding RNAs (lncRNAs) and cancer. HOX transcript antisense RNA (HOTAIR), an lncRNA that functions as a transcriptional modulator, has been implicated in various fundamental biological activities. HOTAIR mediates the trimethylation of histone H3 at lysine 27 and the demethylation of histone H3 dimethyl Lys4 by recruiting the polycomb repressive complex 2 and the lysine-specific demethylase 1/co-repressor of RE1-silencing transcription factor (coREST)/REST complex to the target gene promoters, which leads to gene silencing. Overexpression of HOTAIR in hepatocellular carcinoma (HCC) is strongly associated with an unfavorable prognosis for patients with HCC. HOTAIR promotes the carcinogenic activity of HCC cells through the suppression of RNA binding motif protein 38, triggering the epithelial-mesenchymal transition, and by interacting with microRNAs that act as tumor suppressors. In the present review, the role of the lncRNA HOTAIR in HCC is examined. The potential use of HOTAIR as a biomarker to achieve more accurate prognostic predictions and as an effective therapeutic target for HCC is then discussed.

HOTAIR is a promising novel biomarker in patients with thyroid cancer

Thyroid cancer (TC) is the most common endocrine malignancy. Lack of effective early diagnostic tools is one of the clinical obstacles for TC treatment. Thus, enhanced comprehension of the molecular changes in TC tumorigenesis is urgently needed to develop novel strategies for the diagnosis and treatment of TC. Long non-coding RNAs (lncRNAs) manage fundamental biochemical and cellular processes in tumorigenesis and development. One of the best-described lncRNAs, HOX transcript antisense RNA (HOTAIR), functions as a regulatory molecule in a wide variety of biological processes, and represses gene expression through recruitment of the chromatin modifying complex. However, the function of HOTAIR in TC remains unclear. In the current study, the expression of HOTAIR is elevated in TC and correlates with metastasis and poor prognosis. Furthermore, the expression of HOTAIR is significantly upregulated in human thyroid carcinoma cells compared with normal human thyroid cells. Furthermore, knockdown of HOTAIR significantly inhibited cell growth and invasion in TPC-1 and SW579 human thyroid carcinoma. In summary, HOTAIR is a promising novel biomarker in patients with TC.

Effects of irradiation on radioresistance, HOTAIR and epithelial-mesenchymal transition/cancer stem cell marker expression in esophageal squamous cell carcinoma

Radiotherapy is a common therapeutic strategy used to treat esophageal squamous cell carcinoma (ESCC). However, tumor cells often develop radioresistance, thereby reducing treatment efficacy. Here, we aimed to identify the mechanisms through which ESCC cells develop radioresistance and identify associated biomarkers. Eca109 cells were exposed to repeated radiation at 2 Gy/fraction for a total dose of 60 Gy (Eca109R60/2Gy cells). MTT and colony formation assays were performed to measure cell proliferation and compare the radiation biology parameters of Eca109 and Eca109R60/2Gy cells. Cell cycle distributions and apoptosis were assessed by flow cytometry. Reverse transcription-quantitative polymerase chain reaction and western blotting were employed to analyze the expression of HOX transcript antisense RNA (HOTAIR), in addition to biomarkers of the epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs). Eca109R60/2Gy cells exhibited increased cell proliferation and clone formation, with significantly higher radiobiological parameters compared with the parental Eca109 cells. The Eca109R60/2Gy cells also exhibited significantly decreased accumulation in G₂ phase and increased accumulation in S phase. Additionally, the apoptosis rate was significantly lower in Eca109R60/2Gy cells than in parental Eca109 cells. Finally, HOTAIR expression levels and SNAI1 and β-catenin mRNA and protein expression levels were significantly higher, whereas E-cadherin levels were significantly lower in Eca109R60/2Gy cells than in Eca109 cells. Therefore, our findings demonstrated that radioresistance was affected by the expression of HOTAIR and biomarkers of the EMT and CSCs.

[Study of long non-coding RNA HOTAIR expression in middle ear cholesteatoma]

Objective:To discuss the different expression of some long-chain noncoding RNA between middle ear cholesteatoma epithelial tissue and normal external ear canal skin.Method:Real-time quantitative PCR was used to detect the expression of 6 kinds of lncRNA: HOTAIR, ANCR, TINCR, PRINS, BANCR, PICSAR in 25 cases of cholesteatoma epithelial tissues and 15 cases of normal external auditory canal skin tissue samples, respectively. And compared the expression level of lncRNA in patients with different degree of bone destruction.Result:Expression level of HOTAIR was significantly increased in cholesteatoma epithelial tissues compared with the normal external auditory canal skin tissues,and the difference is statistically significant (P< 0.01). While there was no statistically significant difference expression of the rest of the five kinds of lncRNA between middle ear cholesteatoma epithelial tissues and normal external ear canal skin (P> 0.05). And there was no statistically significant difference expression of HOTAIR in patients with different degree of bone destruction (P> 0.05).Conclusion:Expression level of HOTAIR was up-regulated in middle ear cholesteatoma epithelial tissue compared with the normal external auditory canal skin tissues, and the expression level of HOTAIR has no obvious correlation with degree of bone destruction in patients with cholesteatoma.

Long non-coding RNA HOTAIR is a marker for hepatocellular carcinoma progression and tumor recurrence

The present study aimed to investigate the expression level of HOX transcript antisense RNA (HOTAIR) in hepatocellular carcinoma (HCC) and its association with various clinicopathological characteristics, and to further explore the molecular mechanisms of HOTAIR function in HCC. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression level of HOTAIR in 60 paired fresh HCC samples and adjacent normal liver tissue samples. The association between HOTAIR expression and clinicopathological parameters was analyzed. Lentivirus-mediated HOTAIR-specific small hairpin RNA vectors were transfected into HepG2 cells. Cell proliferation and invasion in vitro were examined by MTT and Transwell assays, respectively. A xenograft model was used to analyze the tumorigenesis of liver cancer cells in vivo. In addition, semi-quantitative RT-PCR was used to detect the expression level of Wnt/β-catenin signaling molecules under the condition of HOTAIR inhibition. The results revealed that the expression level of HOTAIR in HCC tissues was higher than that in adjacent non-cancerous tissues. HOTAIR expression was significantly associated with poor tumor differentiation (P=0.002), metastasis (P=0.002) and early recurrence (P=0.001). In vitro, the inhibition of HOTAIR in liver cancer cells resulted in the suppression of cell proliferation and invasion. HOTAIR depletion significantly inhibited the rate of growth of liver cancer cells in vivo. Furthermore, the expression levels of Wnt and β-catenin were downregulated when HOTAIR expression was suppressed. In conclusion, HOTAIR is important in the progression and recurrence of HCC, partly through the regulation of the Wnt/β-catenin signaling pathway. Targeting HOTAIR may be a novel therapeutic strategy for HCC.

Long non-coding RNAs: a new frontier in the study of human diseases

With the development of whole genome and transcriptome sequencing technologies, long noncoding RNAs (lncRNAs) have received increased attention. Multiple studies indicate that lncRNAs act not only as the intermediary between DNA and protein but also as important protagonists of cellular functions. LncRNAs can regulate gene expression in many ways, including chromosome remodeling, transcription and post-transcriptional processing. Moreover, the dysregulation of lncRNAs has increasingly been linked to many human diseases, especially in cancers. Here, we reviewed the rapidly advancing field of lncRNAs and described the relationship between the dysregulation of lncRNAs and human diseases, highlighting the specific roles of lncRNAs in human diseases.

Long non-coding RNAs: a new frontier in the study of human diseases

With the development of whole genome and transcriptome sequencing technologies, long noncoding RNAs (lncRNAs) have received increased attention. Multiple studies indicate that lncRNAs act not only as the intermediary between DNA and protein but also as important protagonists of cellular functions. LncRNAs can regulate gene expression in many ways, including chromosome remodeling, transcription and post-transcriptional processing. Moreover, the dysregulation of lncRNAs has increasingly been linked to many human diseases, especially in cancers. Here, we reviewed the rapidly advancing field of lncRNAs and described the relationship between the dysregulation of lncRNAs and human diseases, highlighting the specific roles of lncRNAs in human diseases.