HOXC13 promotes proliferation of esophageal squamous cell carcinoma via repressing transcription of CASP3

Function and Therapeutic Potential of Non-Coding RNA in Ameloblastoma

Ameloblastoma (AB) is a common odontogenic tumor that develops in the mouth. Despite its benign nature, AB exhibits significant invasiveness leading to tumor metastasis and high postoperative recurrence rates. Studies have shown a relationship between the occurrence and development of various tumors and non-coding RNA (ncRNA). NcRNA, transcribed from the genomes of mammals and other complex organisms, are often products of alternative splicing and processing into smaller products. MicroRNA (miRNA), circular RNA (circRNA), and long non-coding RNA (lncRNA) are the main types of ncRNA. NcRNA play increasingly significant roles in the pathogenesis of human cancers, regulating their occurrence and progression as oncogenes or tumor suppressors. They are involved in tumor development and progression through alternative splicing of pre-mRNA, transcriptional regulation, mRNA stability, protein translation, and chromatin remodeling and modification. The importance of ncRNA in AB has received significant attention in recent years. However, the biological functions and mechanisms of ncRNA in AB remain largely unknown. In this review, we not only explore the functions and roles of ncRNA in AB, but also describe and envision their potential functional roles as biomarkers in AB diagnosis. In particular, we highlight the potential of miR-29a as a molecular marker for diagnosis and therapy. As promising novel therapeutic targets, the biological functions of ncRNA need further study, which is indispensable.

Identification of HOXC Gene Family as Prognostic and Immune-Related Biomarkers in Breast Cancer Through mRNA Transcriptional Profile and Experimental Validation

Breast cancer (BC) is the most common malignancy in women worldwide, and more effective biomarkers are urgently needed for the prevention and treatment of BC. Our study aimed to investigate the role of the HOXC gene family (HOXCs) and its relationship with the immune response in BC. The differential expression of HOXCs and its clinical prognostic significance in BC were explored using bioinformatics analysis, and the cBioPortal database was used to evaluate the genetic mutation profile of the HOXCs in BC. The results indicated that the expression levels of HOXC4, 10, 11, 12, and 13 were significantly increased in BC tissues compared with the normal tissues, and expressions of these genes were closely associated with BC stage, among them, high expression levels of HOXC10 and HOXC13 predicted poor outcome in BC patients. In addition, to elucidate the essential role of HOXCs in the tumor microenvironment and immunotherapeutic response of BC, the impact of HOXCs on the regulation of immune infiltration in BC was comprehensively assessed. The result showed that HOXC10 and HOXC13 expressions were significantly positively linked with the infiltration levels of CD8+T cell and M1 macrophage, while they were negatively related to Mast and Natural killer cells, suggesting the important influence of HOXCs on regulating tumor immunity in BC patients. Lastly, the RT-qPCR assay was employed to validate HOXCs expression in samples of BC patients. In conclusion, HOXCs may be a promising prognostic indicator and could regulate the immune infiltration in BC patients, thus being a promising targeted immunotherapy for BC.

HOXC6: A promising biomarker linked to an immunoevasive microenvironment in colorectal cancer based on TCGA analysis and cohort validation

HOXC6 plays an essential part of the carcinogenesis of solid tumors, but its functional relevance within the immune contexture in patients with colorectal cancer (CRC) is still uncertain. We intended to investigate the predictive value of HOXC6 expression for survival outcomes and its correlation with immune contexture in CRC patients by utilizing the Cancer Genome Atlas database (n = 619). Validation was performed in cohorts from Zhongshan Hospital (n = 200) and Shanghai Cancer Center (n = 300). Immunohistochemical (IHC) staining was utilized to compare the levels of immunocytes infiltrating the tumor between the groups with high and low expression of HOXC6. Elevated levels of HOXC6 expression in CRC tissues were linked to malignant progression and poor prognosis. HOXC6 as a risk factor for survival of CRC patients was confirmed. Receiver operating characteristic analysis confirmed its diagnostic value, and a reliable prognostic nomogram was constructed. KEGG analysis and GSEA showed that HOXC6 participated in immune regulation, and its expression was tightly linked to the abundance of infiltrating immunocytes. HOXC6 was upregulated in patients diagnosed with CRC within the two cohorts, and high HOXC6 levels were correlated with a worse prognosis. The high-HOXC6 expression group showed increased infiltration of Treg cells, CD68+ macrophages, CD66b+ neutrophils, and CD8+ T-cells and elevated levels of PD-L1 and PD-1, but decreased levels of granzyme B and perforin. These findings suggest that HOXC6 abundance in patients with CRC determines a poor prognosis, promotes an immunoevasive environment, and directs CD8+ T-cell dysfunction. HOXC6 is expected to become a prospective biomarker for the outcome of CRC.

HOXC13 promotes cell proliferation, metastasis and glycolysis in breast cancer by regulating DNMT3A

Breast cancer (BC) is a life-threatening malignant tumor that affects females more commonly than males. The mechanisms underlying BC proliferation, metastasis and glycolysis require further investigation. Homeobox C13 (HOXC13) is highly expressed in BC; however, the specific mechanisms in BC are yet to be fully elucidated. Therefore, the aim of the present study was to investigate the role of HOXC13 in BC proliferation, migration, invasion and glycolysis. In the present study, the UALCAN database was used to predict the expression levels of HOXC13 in patients with BC. Western blot analysis and reverse transcription-quantitative PCR were used to determine the expression levels of HOXC13 in BC cell lines. Moreover, HOXC13 knockdown was induced using cell transfection, and the viability, proliferation and apoptosis of cells were detected using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine staining and flow cytometry. Migration, invasion and epithelial-mesenchymal transition (EMT) were measured using wound healing assay, Transwell assay and western blotting. In addition, XF96 extracellular flux analyzer and corresponding kits were used to detect glycolysis. The JASPAR database was used to predict promoter binding sites for the transcription factors HOXC13 and DNA methyltransferase 3α (DNMT3A). HOXC13 expression was silenced and DNMT3A was simultaneously overexpressed using cell transfection. The results of the present study revealed that HOXC13 expression was significantly elevated in BC tissues and cells. Following HOXC13 knockdown in BC cells, the viability, proliferation, glycolysis, migration, invasion and EMT were significantly decreased, and apoptosis was significantly increased. In addition, HOXC13 positively regulated the transcription of DNMT3A in BC cells, thus playing a regulatory role in the malignant progression of cells. In conclusion, HOXC13 promoted cell viability, proliferation, migration, invasion, EMT and glycolysis in BC by regulating DNMT3A.

A novel and robust pyroptosis-related prognostic signature predicts prognosis and response to immunotherapy in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly malignant gastrointestinal tumor, has a poor prognosis and high mortality rate. Pyroptosis could regulate tumor cell proliferation, invasion, and metastasis, thereby affecting the prognosis of cancer patients. However, the role of pyroptosis-related genes (PRGs) in ESCC remains unclear. This study selected 33 PRGs, and finally identified 29 PRGs that were differentially expressed between ESCC and normal esophageal tissues. The genetic mutation variation landscape of PRG in ESCC was also summarised. Based on consensus clustering for the 33 PRGs, all ESCC patients could be divided into two subtypes. Functional enrichment analysis revealed that these 33 PRGs were mainly involved in cytokine production, interleukin-1 production, and the NOD-like receptor signalling pathway. We created a prognostic PRG signature based on least absolute shrinkage and selection operator regression and Cox regression analysis with good survival prediction ability in both GEO and TCGA cohorts. Combined with the clinical characteristics, signature-based risk score was found to be an independent factor for predicting the OS of ESCC patients. A nomogram with enhanced precision for forecasting ESCC was established based on various independent prognostic elements. Significant correlation was observed between prognostic PRGs and immune-cell infiltration, tumor mutation burden, microsatellite instability, immune checkpoint, and drug sensitivity. Finally, we validated the expression of four PRGs in ESCC cell lines and tissues samples. In conclusion, the PRGs exerted significant effects on tumor immunity and prognosis of ESCC.

Ribosomal protein L8 regulates the expression and splicing pattern of genes associated with cancer-related pathways

Background/aim

Ribosomal proteins have been shown to perform unique extraribosomal functions in cell apoptosis and other biological processes. Ribosomal protein L8 (RPL8) not only has important nonribosomal regulatory functions but also participates in the oncogenesis and development of tumors. However, the specific biological functions and pathways involved in this process are still unknown.

Materials and methods

RPL8 was overexpressed (RPL8-OE) in HeLa cells. MTT assay and flow cytometry were used to detect cell proliferation and apoptosis, respectively. Transcriptome sequencing was performed to analyze the differentially expressed genes (DEGs) and regulated alternative splicing events (RASEs) by RPL8-OE, both of which were validated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay.

Results

RPL8-OE inhibited cell proliferation and promoted cell apoptosis. RPL8 regulated the differential expression of many oncogenic genes and the occurrence of RASEs. Many DEGs and RASE genes (RASGs) were enriched in tumorigenesis and tumor progression-related pathways, including angiogenesis, inflammation, and regulation of cell proliferation. RPL8 could regulate the RASGs enriched in the negative regulation of apoptosis, consistent with its proapoptosis function. Furthermore, RPL8 may influence cancer-related DEGs by modulating the alternative splicing of transcription factors.

Conclusion

RPL8 might affect the phenotypes of cancer cells by altering the transcriptome profiles, including gene expression and splicing, which provides novel insights into the biological functions of RPL8 in tumor development.

Variants Identified in the HOXC13 and HOXD13 Genes Suggest Association with Cervical Cancer in a Cohort of Mexican Women

HOX genes have been associated with carcinogenesis. However, the molecular mechanism by which tumors are generated remains unclear. The HOXC13 and HOXD13 genes are of interest for their involvement in the development of genitourinary structures. The aim of this first study in the Mexican population was to search for and analyze variants in the coding region of the HOXC13 and HOXD13 genes in women with cervical cancer. Samples from Mexican women with cervical cancer and healthy women were sequenced (50/50). Allelic and genotypic frequencies were compared between groups. The functional impact of the proteins was determined with two bioinformatics servers (SIFT and PolyPhen-2), and the oncogenic potential of the identified nonsynonymous variants was determined using the CGI server. We identified five unreported gene variants: c.895C>A p.(Leu299Ile) and c.777C>T p.(Arg259Arg) in the HOXC13 gene and c.128T>A p.(Phe43Tyr), c.204G>A p.(Ala68Ala), and c.267G>A p.(Ser89Ser) in the HOXD13 gene. In this study, we suggest that the non-synonymous variants c.895C>A p.(Leu299Ile) and c.128T>A p.(Phe43Tyr) could represent a risk factor for the development of the disease, although additional studies in larger patient populations and in different ethnic groups are needed in order to support the results observed.

The Role and Interactions of Programmed Cell Death 4 and its Regulation by microRNA in Transformed Cells of the Gastrointestinal Tract

Data from GLOBOCAN 2020 estimates that there were 19.3 million new cases of cancer and 10.0 million cancer-related deaths in 2020 and that this is predicted to increase by 47% in 2040. The combined burden of cancers of the gastrointestinal (GI) tract, including oesophageal-, gastric- and colorectal cancers, resulted in 22.6% of the cancer-related deaths in 2020 and 18.7% of new diagnosed cases. Understanding the aetiology of GI tract cancers should have a major impact on future therapies and lessen this substantial burden of disease. Many cancers of the GI tract have suppression of the tumour suppressor Programmed Cell Death 4 (PDCD4) and this has been linked to the expression of microRNAs which bind to the untranslated region of PDCD4 mRNA and either inhibit translation or target the mRNA for degradation. This review highlights the properties of PDCD4 and documents the evidence for the regulation of PDCD4 expression by microRNAs in cancers of the GI tract.

Downstream of the HOX genes: explaining conflicting tumour suppressor and oncogenic functions in cancer

The HOX genes are a highly conserved group of transcription factors that have key roles in early development, but which are also highly expressed in most cancers. Many studies have found strong associative relationships between the expression of individual HOX genes in tumours and clinical parameters including survival. For the majority of HOX genes, high tumour expression levels seem to be associated with a worse outcome for patients, and in some cases this has been shown to result from the activation of pro-oncogenic genes and pathways. However, there are also many studies that indicate a tumour suppressor role for some HOX genes, sometimes with conclusions that contradict earlier work. In this review, we have attempted to clarify the role of HOX genes in cancer by focusing on their downstream targets as identified in studies that provide experimental evidence for their activation or repression. On this basis, the majority of HOX genes would appear to have a pro-oncogenic function, with the notable exception of HOXD10, which acts exclusively as a tumour suppressor. HOX proteins regulate a wide range of target genes involved in metastasis, cell death, proliferation, and angiogenesis, and activate key cell signalling pathways. Furthermore, for some functionally related targets, this regulation is achieved by a relatively small subgroup of HOX genes.

HOXC6/8/10/13 predict poor prognosis and associate with immune infiltrations in glioblastoma

BACKGROUND

Glioblastoma (GBM), characterized by deregulated cell proliferation and immune cells infiltration, is a common and lethal tumor of the central nervous system. Recently, the infiltration of immune cells has attracted attention as a potential novel GBM immunotherapy option. Homeobox C cluster (HOXC) is an evolutionarily conserved family of transcriptional factors that are involved in embryogenesis and tumorigenesis. Nevertheless, the correlations of HOXCs with the prognosis and immune infiltration of GBM remain blurred.

METHODS

The RNA-seq data with corresponding clinical characteristics were downloaded from TCGA and GTEx databases. The correlations between HOXCs and clinical characteristics were calculated using univariable and multivariate Cox regression. R language with ggplot2, survminer, survival, GSVA, and pROC packages were employed to analyze the data and present the plots. MethSurv, UALCAN and cBioPortal were employed to evaluate the DNA methylation and mutation status of HOXCs in GBM. We also verified the expression and prognosis of HOXCs by qPCR and immunohistochemistry in a cohort of 36 patients.

RESULTS

We identified that HOXC6/8/10/13 were crucial biomarkers for diagnosis and prognostic judgement in GBM. Gene set variation analysis revealed that levels of expression of HOXCs were associated with the infiltration of various immune cells. The qPCR and immunohistochemistry data validated the prognostic values of HOXC6/8/10/13 in GBM. Finally, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that HOXCs might be involved in DNA-binding transcription activator activity and the apelin signaling pathway.

CONCLUSION

This research highlights that HOXC6/8/10/13 are involved in the immune infiltrates, also provide potential clinical utility as therapeutic targets in GBM.

Naked (N) mutant mice carry a nonsense mutation in the homeobox of Hoxc13

Loss of function mutations in HOXC13 have been associated with Ectodermal Dysplasia-9, Hair/Nail Type (ECTD9) in consanguineous families, characterized by sparse to complete absence of hair and nail dystrophy. Here we characterize the spontaneous mouse mutation Naked (N) as a terminal truncation in the Hoxc13 (homeobox C13) gene. Similar to previous reports for homozygous Hoxc13 knock-out (KO) mice, homozygous N/N mice exhibit generalized alopecia with abnormal nails and a short lifespan. However, in contrast to Hoxc13 heterozygous KO mice, N/+ mice show generalized or partial alopecia, associated with loss of hair fibres, along with normal lifespan and fertility. Our data point to a lack of nonsense-mediated Hoxc13 transcript decay and the presence of the truncated mutant protein in N/N and N/+ hair follicles, thus suggesting a dominant-negative mutation. To our knowledge, this is the first report of a semi-dominant and potentially dominant-negative mutation affecting Hoxc13/HOXC13. Furthermore, recreating the N mutant allele in mice using CRISPR/Cas9-mediated genome editing resulted in the same spectrum of deficiencies as those associated with the spontaneous Naked mutation, thus confirming that N is indeed a Hoxc13 mutant allele. Considering the low viability of the Hoxc13 KO mice, the Naked mutation provides an attractive new model for studying ECTD9 disease mechanisms.

HOXC13 promotes cervical cancer proliferation, invasion and Warburg effect through β-catenin/c-Myc signaling pathway

Cervical cancer (CC) is one of the most common malignancy and is the second leading cause of death in gynecologic malignancies worldwide. The homeobox transcription factor homeobox C13 (HOXC13) has been demonstrated to play crucial roles in various cancers. However, its function in CC remains to be addressed. In the present study, upregulation of HOXC13 expression in human CC tissues was found in The Cancer Genome Atlas (TCGA) dataset and clinical samples and was associated with tumor size, FIGO stage and lymph node metastasis. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assays suggested that the expression of HOXC13 was up-regulated in CC cells. Cell Counting Kit (CCK)-8, colony formation and cell cycle analysis assays indicated that HOXC13 promoted the proliferation and cycle progression of CC cells in vitro. Of note, knockdown of HOXC13 hinders tumor growth of xenograft tumor mice in vivo. Moreover, transwell and glycolysis measurement assays demonstrated that HOXC13 enhanced the migration, invasion and glycolysis of CC cells in vitro. Further mechanism analysis suggested that HOXC13 participated in CC progression through regulation of the β-catenin/c-Myc signaling pathway. Collectively, HOXC13 facilitated cell proliferation, migration, invasion and glycolysis through modulating β-catenin/c-Myc signaling pathway in CC, indicating that HOXC13 may provide a promising therapeutic target for the therapy of CC.

HOXC-AS2 mediates the proliferation, apoptosis, and migration of non-small cell lung cancer by combining with HOXC13 gene

Non-small cell lung cancer (NSCLC) is the highest incidence and mortality of malignant tumors worldwide and has become a global public health problem. Long non-coding RNAs (LncRNAs) are expected to participate in the progression of NSCLC. This study aims to explore the effects and underlying mechanisms of LncRNA HOXC-AS2 on NSCLC cell proliferation, apoptosis, and migration. The Cell Counting Kit-8 (CCK-8) and clone formation assay were used to measure the A549 and HCC827 cell proliferation. The cell apoptosis and migration was respectively analyzed by flow cytometry and transwell assay. RNA immunoprecipitation (RIP) was used to detect the interaction between HOXC-AS2 and HOXC13. The expression of β-catenin, α-SMA, MMP-1, MMP-2 expression, E-cadherin, and Ki-67 expression were determined by Western blot or immunohistochemistry (IHC) assay. We found that HOXC-AS2 was significantly up-regulated in NSCLC tissues. Knockdown of HOXC-AS2 expression resulted in significant decreases in NSCLC cell proliferation, migration, and epithelial-mesenchymal transition (EMT) process marker proteins, simultaneously activated A549 and HCC827 cell apoptosis. RIP assay suggested that HOXC13 was a functional target for HOXC-AS2. And HOXC-AS2 and HOXC13 could positively regulate each other. Compared with the normal tissues, the mRNA level of HOXC13 was increased in NSCLC tissues. HOXC13 silencing counteracted increases of A549 and HCC827 cell proliferation and migration, as well as a decrease of cell apoptosis induced by HOXC-AS2 overexpression. Moreover, HOXC-AS2 silencing reduced tumor growth rate and Ki-67 expression in vivo. Taken together, HOXC-AS2 knockdown inhibited NSCLC cell proliferation and migration, as well as stimulated NSCLC cell apoptosis through regulation of HOXC13 expression.

The microRNA-424/503 cluster: A master regulator of tumorigenesis and tumor progression with paradoxical roles in cancer

MicroRNAs (miRNAs) are a group of non-coding RNAs that play a crucial role in post-transcriptional gene regulation and act as indispensable mediators in several critical biological processes, including tumorigenesis, tissue homeostasis, and regeneration. MiR-424 and miR-503 are intragenic miRNAs that are clustered on human chromosome Xq26.3. Previous studies have reported that both miRNAs are dysregulated and play crucial but paradoxical roles in tumor initiation and progression, involving different target genes and molecular pathways. Moreover, these two miRNAs are concomitantly expressed in several cancer cells, indicating a coordinating function as a cluster. In this review, the roles and regulatory mechanisms of miR-424, miR-503, and miR-424/503 cluster are summarized in different types of cancers.

MNX1 Promotes Malignant Progression of Cervical Cancer via Repressing the Transcription of p21cip1

Motor neuron and pancreas homeobox 1 (MNX1) is a development-related genes and has been found to be highly expressed in several cancers. However, its biological function in cervical cancer remains largely unexplored. QRT-PCR, western blot, and IHC showed that MNX1 was abnormally overexpressed in cervical cancer tissues and cell lines. The high expression level of MNX1 correlated with poorer clinicopathologic characteristics in cervical cancer patients. Evaluated by RTCA (Real Time Cellular Analysis) proliferation assay, colony formation assay, EdU assay, transwell assay, and matrigel assay, we found that knockdown of MNX1 inhibited proliferation, migration and invasion of cervical cancer in vitro, while overexpression of MNX1 promoted malignant phenotype of cervical cancer. And subcutaneous xenograft model confirmed the malignant phenotype of MNX1 in vivo. Furthermore, flow cytometry, chromatin immunoprecipitation, and luciferase reporter assay indicated that MNX1 accelerated cell cycle transition by transcriptionally downregulating cyclin-dependent kinases p21^cip1. In summary, our study revealed that MNX1 exerted an oncogenic role in cervical cancer via repressing the transcription of p21^cip1 and thus accelerating cell cycle progression. Our results suggested that MNX1 was a potential diagnostic marker and therapeutic target for cervical cancer patients.

HOXC13-AS accelerates cell proliferation and migration in oral squamous cell carcinoma via miR-378g/HOXC13 axis

Oral squamous cell carcinoma (OSCC) is an aggressive cancer type in head and neck. A number of long non-coding RNAs (lncRNAs) are discovered to serve regulatory roles in OSCC. HOXC13 antisense RNA (HOXC13-AS) has been proved to behave as a tumor-facilitator in nasopharyngeal carcinoma, but its regulatory role in OSCC has never been investigated. In this study, GEPIA indicated that HOXC13-AS and its neighbor gene HOXC13 were upregulated in HNSC samples, and we consistently unveiled their upregulation in OSCC tissues and cell lines. Silencing HOXC13-AS abrogated OSCC cell proliferation, migration, and epithelial-to-mesenchymal transition (EMT). Moreover, HOXC13 overexpression rescued the influences of HOXC13-AS silence on OSCC cellular processes and in vivo tumor growth. Mechanistically, HOXC13-AS upregulated HOXC13 expression in OSCC through sequestering miR-378g, which was proved to exert suppressive functions in the malignant behaviors of OSCC cells. Further, HOXC13 was revealed to be positively correlated with HOXC13-AS and negatively with miR-378g in expression in OSCC samples. In sum, our findings suggested that HOXC13-AS functioned as a ceRNA to accelerate the malignant behaviors of OSCC cells via miR-378g/HOXC13 axis, shedding a new light on the lncRNA-targeted treatment for OSCC.

HOXC10 is significantly overexpressed in colorectal cancer

Colorectal cancer (CRC) is one of the most common types of cancer in world and has a high rate of mortality. The majority of cases of CRC are sporadic; however, factors such as age, a family history of inflammatory diseases, diet, lifestyle and genetics increase the risk. HOX genes and lncRNAs are two classes of genes, and alterations in the expression levels of these genes are significantly associated with numerous different types of cancer. In the present study, the expression levels of HOXC10, HOXC-AS3, HOTAIR, HOXC13 and HOXC13-AS in tumor tissues were compared with normal healthy tissues in patients with CRC. Paired tumor and normal tissues were collected from 39 patients with CRC, and reverse transcription-quantitative PCR was used the expression of HOXC-AS3, HOXC13 and HOXC10 in the tumor tissues compared with the respective normal tissues. Expression of these genes were increased in the tumor tissues compared with normal tissues; however, the difference was only significant for HOXC10. Additionally, there was a strong and significant correlation between the expression of HOTAIR and HOXC13, a moderate and significant correlation between the expression of HOTAIR and HOXC13-AS, and between HOXC13 and HOXC13-AS genes. The expression of HOXC10 was significantly higher in tumor tissues compared with the normal tissues; whereas the upregulation of HOXC-AS3 and HOXC13 were not significant. Only the correlation between the expression of HOTAIR and HOXC13 was strong and significant. As HOXC10 expression was significantly upregulated in the tumor tissues relative to normal tissues, it may serve as a biomarker for the diagnosis of CRC and as a potential therapeutic target.

A Novel lncRNA ENST00000512916 Facilitates Cell Proliferation, Migration and Cell Cycle Progression in Ameloblastoma

Objective

Our purpose was to identify up-regulated long noncoding RNA ENST00000512916 in ameloblastoma (AB) and explore its role in the progression of AB.

Methods

We analyzed lncRNA microarray expression profile between six paired AB and normal oral mucosa (NOM) tissues. An up-regulated lncRNA, ENST00000512916 was identified and validated by real-time qPCR. Cell proliferation, migration and cell cycle were detected by CCK-8 assay, transwell chamber and flow cytometry, respectively. Western blotting analysis was used to measure the expression of cell-cycle-related proteins including CyclinD1 and Cyclin-dependent kinase (CDK) 2/4/6. In addition, Xenograft tumor model was constructed to investigate tumor growth.

Results

Real-time qPCR confirmed that lncRNA ENST00000512916 was up-regulated in AB tissues. ENST00000512916 knockdown significantly inhibited cell proliferation, migration and the expression of CDK2/4/6 in AM-1 cells. Moreover, ENST00000512916 knockdown suppressed tumor growth in vivo. We also found that ENST00000512916 overexpression significantly promoted the expression of HOXC13 in AM-1 cells. Overexpression of ENST00000512916 promoted cell cycle progression in AM-1 cells, which was reversed by HOXC13 knockdown.

Conclusion

Our findings reveal that lncRNA ENST00000512916 promotes cell proliferation, migration and cell cycle progression of AB.

Bioinformatics analysis of the expression of HOXC13 and its role in the prognosis of breast cancer

The homeobox (HOX) genes, a class of transcription factors, are known to promote embryonic development and induce tumor formation. To date, the HOXA and HOXB gene families have been reported to be associated with breast cancer. However, the expression and exact role of homeobox C13 (HOXC13) in breast cancer has not yet been investigated. In the present study, the HOXC13 expression in human breast cancer was evaluated using the Oncomine database and Cancer Cell Line Encyclopedia (CCLE). Next, the Gene expression-based Outcome for Breast cancer online database, cBioportal, University of California Santa Cruz Xena browser and bc-GenExMinerv were used to explore the specific expression of HOXC13 in breast cancer. The methylation and mutation status of HOXC13 in breast cancer was then validated using the CCLE and cBioportal databases. Finally, the co-expression of HOX transcript antisense RNA (HOTAIR) and HOXC13 in breast cancer were analyzed and their impact on clinical prognosis determined. It was found that the expression of HOXC13 was high in breast cancer compared with other types of cancer, such as gastric cancer and colon cancer. Following co-expression analysis, a significant positive association was identified between HOTAIR and HOXC13. An association between HOTAIR and HOXC13, and lymph node and distant metastasis recurrence was also revealed during the development of breast cancer. Of note, survival analysis showed that high expression of HOTAIR and HOXC13 predicted poor prognosis. These findings revealed that HOXC13 plays an important role in the progression of breast cancer. However, the specific mechanism needs to be confirmed by subsequent experiments.

Integrative analysis of the lncRNA-associated ceRNA network reveals lncRNAs as potential prognostic biomarkers in human muscle-invasive bladder cancer

Background

Long noncoding RNAs (lncRNAs) play important roles in competing endogenous RNA (ceRNA) networks involved in the development and progression of various cancers, including muscle-invasive bladder cancer (MIBC).

Purpose

This study aims to construct the lncRNA-associated ceRNA network and identify lncRNA signatures correlated with the clinical features of MIBC tissue samples from The Cancer Genome Atlas (TGCA) database.

Methods

The differential expression profiles of MIBC associated lncRNAs, miRNAs and mRNAs were obtained from TCGA. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to determine the principal functions of significantly dysregulated mRNAs. The dysregulated lncRNA-associated ceRNA network of MIBC was constructed based on the bioinformatics data, and the correlations between lncRNA expression and clinical features were analyzed using a weighted gene coexpression network analysis (WGCNA). Six cancer specific lncRNAs from the ceRNA network were randomly selected to detect their expression in 32 paired MIBC tissue samples and 5 bladder cancer cell lines using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

The ceRNA network was constructed with 30 lncRNAs, 13 miRNAs and 32 mRNAs. Seventeen lncRNAs in the ceRNA network correlated with certain clinical features, and only 1 lncRNA (MIR137HG) correlated with the overall survival (OS) of patients with MIBC (log-rank test P<0.05). GO and KEGG analyses revealed roles for the potential mRNA targets of MIR137HG in epithelial cell differentiation and the peroxisome proliferator-activated receptor (PPAR) and tumor necrosis factor (TNF) signaling pathways. The expression data from TCGA were highly consistent with the verification results of the MIBC tissue samples and bladder cancer cell lines.

Conclusion

These findings improve our understanding of the regulatory mechanism of the lncRNA-miRNA-mRNA ceRNA network and reveal potential lncRNAs as prognostic biomarkers of MIBC.

Paralogous HOX13 Genes in Human Cancers

Hox genes (HOX in humans), an evolutionary preserved gene family, are key determinants of embryonic development and cell memory gene program. Hox genes are organized in four clusters on four chromosomal loci aligned in 13 paralogous groups based on sequence homology (Hox gene network). During development Hox genes are transcribed, according to the rule of “spatio-temporal collinearity”, with early regulators of anterior body regions located at the 3’ end of each Hox cluster and the later regulators of posterior body regions placed at the distal 5’ end. The onset of 3’ Hox gene activation is determined by Wingless-type MMTV integration site family (Wnt) signaling, whereas 5’ Hox activation is due to paralogous group 13 genes, which act as posterior-inhibitors of more anterior Hox proteins (posterior prevalence). Deregulation of HOX genes is associated with developmental abnormalities and different human diseases. Paralogous HOX13 genes (HOX A13, HOX B13, HOX C13 and HOX D13) also play a relevant role in tumor development and progression. In this review, we will discuss the role of paralogous HOX13 genes regarding their regulatory mechanisms during carcinogenesis and tumor progression and their use as biomarkers for cancer diagnosis and treatment.

PITX2 enhances progression of lung adenocarcinoma by transcriptionally regulating WNT3A and activating Wnt/β-catenin signaling pathway

Background

The homeodomain transcription factor, PITX2 is associated with tumorigenesis of multiple cancers. In this research, we aimed to study the expression, function and mechanism of PITX2 in lung adenocarcinoma (LUAD).

Methods

The TCGA dataset was used to analyze the expression and clinical significance of PITX2 in LUAD. The expression of PITX2 in tumor samples and LUAD cell lines was examined by quantitative real-time PCR (qRT-PCR) and western blotting. Small interfering RNAs (siRNAs) were constructed to knockdown PITX2 and to determine the physiological function of PITX2 in vitro. Xenograft model was used to confirm the role of PITX2 in vivo.

Results

PITX2 was overexpressed in LUAD and patients with high level of PITX2 had a worse overall survival and an advanced clinical stage. Knockdown of PITX2 inhibited cell proliferation, migration and invasion of LUAD cells. Further study revealed that the oncogenic role of PITX2 was dependent on activating Wnt/β-catenin signaling pathway, especially by transcriptionally regulating the Wnt gene family member, WNT3A. Lastly, we identified miR-140-5p as a negative mediator of PITX2 by binding its 3′UTR and ectopic expression of miR-140-5p inhibited progression of LUAD cells via suppressing the expression of PITX2.

Conclusions

Up-regulation of PITX2 acts as an oncogene in LUAD by activating Wnt/β-catenin signaling pathway, suggesting that PITX2 may serve as a novel diagnostic and prognostic biomarker in LUAD.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0800-7) contains supplementary material, which is available to authorized users.

Candidate genes involved in metastasis of colon cancer identified by integrated analysis

Colon cancer is one of the most malignant cancers worldwide. Nearly 20% of all colon cancer patients are diagnosed at stage IV (metastasis). However, further study of colon cancer is difficult due to a lack of understanding of its pathogenesis. In this study, we acquired high–throughput sequence data from TCGA datasets and performed integrated bioinformatic analysis including differential gene expression analysis, gene ontology and KEGG pathways analysis, protein–protein analysis, survival analysis, and multivariate Cox proportional hazards regression analysis in order to identify a panel of key candidate genes involved in the metastasis of colon cancer. We then constructed a prognostic signature based on the expression of REG1B, TGM6, NTF4, PNMA5, and HOXC13 which could provide significant prognostic value for colon cancer.

H19X-encoded miR-424(322)/-503 cluster: emerging roles in cell differentiation, proliferation, plasticity and metabolism

miR-424(322)/-503 are mammal-specific members of the extended miR-15/107 microRNA family. They form a co-expression network with the imprinted lncRNA H19 in tetrapods. miR-424(322)/-503 regulate fundamental cellular processes including cell cycle, epithelial-to-mesenchymal transition, hypoxia and other stress response. They control tissue differentiation (cardiomyocyte, skeletal muscle, monocyte) and remodeling (mammary gland involution), and paradoxically participate in tumor initiation and progression. Expression of miR-424(322)/-503 is governed by unique mechanisms involving sex hormones. Here, we summarize current literature and provide a primer for future endeavors.

HOXC13 promotes proliferation of esophageal squamous cell carcinoma via repressing transcription of CASP3

Esophageal squamous cell carcinoma (ESCC), the dominant subtype of esophageal cancer, is one of the most common digestive tumors worldwide. In this study, we confirmed that HOXC13, a member of the homeobox HOXC gene family, was significantly upregulated in ESCC and its overexpression was associated with poorer clinical characteristics and worse prognosis. Moreover, knockdown of HOXC13 inhibited proliferation and induced apoptosis of ESCC through upregulating CASP3. ChIP analysis revealed that HOXC13 repressed transcription of CASP3 through directly targeting the promotor region of CASP3. We also found that miR‐503 downregulated HOXC13, by directly targeting its 3′UTR, and inhibited proliferation of ESCC. In conclusion, our study demonstrates that HOXC13, which is directly targeted by miR‐503, promotes proliferation and inhibits apoptosis of ESCC through repressing transcription of CASP3.