The role of HOX genes in head and neck squamous cell carcinoma

Global gene expression profile of proliferative verrucous leukoplakia and its underlying biological disease mechanisms

BACKGROUND

Proliferative verrucous leukoplakia (PVL) is a rare and enigmatic oral potentially malignant disorder which almost invariably results in oral squamous cell carcinoma (OSCC). The aims of this project were to use transcriptome profiling to characterise PVL gene expression patterns for biomarker identification and gain insight into the molecular aetiopathogenesis of PVL.

METHODS

Forty-three oral cavity mucosal biopsies from 32 patients with oral lesions clinically compatible with either PVL or non-PVL conventional oral leukoplakia (OLK) underwent transcriptome profiling by RNA sequencing. Data was analysed by hierarchical clustering, differential gene expression, functional enrichment and network analysis, sparse partial least squares discriminant analysis sPLS-DA, and immune cell phenotypic estimation.

RESULTS

We found 464 genes significantly differentially expressed at least 2-fold between PVL and non-PVL OLK (193 up and 271 down). HOX genes, including HOXA1 and HOXB7, keratin-associated proteins (KRTAPs) and olfactory receptor G proteins (OR) were significantly upregulated in PVL. Other upregulated genes in PVL included FOS, WNT16 and IFNA1. Pathway analysis showed that there was a significant downregulation of connective tissue signalling in PVL. Classifying multivariate models based upon 22 genes discriminated PVL from non-PVL OLK. Bioinformatic profiling showed that immune cell profiles in PVL and OLK were similar except that fibroblast markers were reduced in PVL.

CONCLUSION

These results demonstrate that PVL and conventional OLK are molecularly distinct with upregulation of many cancer-associated genes. They provide insight into the pathogenesis of PVL and show that biomarker based molecular diagnostics is feasible to discriminate and inform diagnosis and management.

Differentially Expressed Genes, miRNAs and Network Models: A Strategy to Shed Light on Molecular Interactions Driving HNSCC Tumorigenesis

Head and neck squamous cell carcinoma (HNSCC) is among the most common cancer worldwide, accounting for hundreds thousands deaths annually. Unfortunately, most patients are diagnosed in an advanced stage and only a percentage respond favorably to therapies. To help fill this gap, we hereby propose a retrospective in silico study to shed light on gene-miRNA interactions driving the development of HNSCC. Moreover, to identify topological biomarkers as a source for designing new drugs. To achieve this, gene and miRNA profiles from patients and controls are holistically reevaluated using protein-protein interaction (PPI) and bipartite miRNA-target networks. Cytoskeletal remodeling, extracellular matrix (ECM), immune system, proteolysis, and energy metabolism have emerged as major functional modules involved in the pathogenesis of HNSCC. Of note, the landscape of our findings depicts a concerted molecular action in activating genes promoting cell cycle and proliferation, and inactivating those suppressive. In this scenario, genes, including VEGFA, EMP1, PPL, KRAS, MET, TP53, MMPs and HOXs, and miRNAs, including mir-6728 and mir-99a, emerge as key players in the molecular interactions driving HNSCC tumorigenesis. Despite the heterogeneity characterizing these HNSCC subtypes, and the limitations of a study pointing to relationships that could be context dependent, the overlap with previously published studies is encouraging. Hence, it supports further investigation for key molecules, both those already and not correlated to HNSCC.

Genomic landscape and gene expression profiles of feline oral squamous cell carcinoma

Feline oral squamous cell carcinoma (FOSCC) is a cancer of the squamous cell lining in the oral cavity and represents up to 80% of all oral cancers in cats, with a poor prognosis. We have used whole exome sequencing (WES) and RNA sequencing of the tumor to discover somatic mutations and gene expression changes that may be associated with FOSCC occurrence. FOSCC offers a potential comparative model to study human head and neck squamous cell carcinoma (HNSCC) due to its similar spontaneous formation, and morphological and histological features. In this first study using WES to identify somatic mutations in feline cancer, we have identified tumor-associated gene mutations in six cats with FOSCC and found some overlap with identified recurrently mutated genes observed in HNSCC. Four samples each had mutations in TP53, a common mutation in all cancers, but each was unique. Mutations in other cellular growth control genes were also found such as KAT2B and ARID1A. Enrichment analysis of FOSCC gene expression profiles suggests a molecular similarity to human OSCC as well, including alterations in epithelial to mesenchymal transition and IL6/JAK/STAT pathways. In this preliminary study, we present exome and transcriptome results that further our understanding of FOSCC.

Identification of HOXB9 to predict prognosis of endometrial cancer based on comprehensive bioinformatics analysis

BACKGROUND

The HOXB9 gene, which plays a key role in embryonic development, is also involved in the regulation of various human cancers. However, the potential relationship between HOXB9 and endometrial cancer (EC) has not yet been comprehensively analyzed and fully understood.

METHODS

We used multiple bioinformatics tools to explore the role of HOXB9 in EC.

RESULTS

The expression of HOXB9 was significantly upregulated in pan-cancer, including EC (P < 0.05). Quantitative real time polymerase chain reaction (qRT-PCR) experiment confirmed the high expression of HOXB9 in EC from clinical samples (P < 0.001). Double validated by Enrichr and Metascape, HOXB9 showed a strong correlation with HOX family, suggesting that HOX family may also involve in the development of EC (P < 0.05). Enrichment analysis revealed HOXB9 is mainly associated with cellular process, developmental process, P53 signaling pathway, etc. At the single-cell level, the clusters of cells ranked were glandular and luminal cells c-24, glandular and luminal cells c-9, endothelial cells c-15, compared with the other cells. At the genetic level, promoter methylation levels of HOXB9 were significantly higher in tumors than in normal tissues. Furthermore, variations of HOXB9 were closely associated with overall survival (OS) and recurrence free survival (RFS) in EC patients (P < 0.05). The agreement between univariate and multivariate Cox regression indicated that the results were more reliable. Stages III and IV, G2 and G3, tumor invasion ≥ 50%, mixed or serous histological type, age > 60 years, and high expression of HOXB9 were risk factors strongly associated with OS in EC patients (P < 0.05). Therefore, six factors were incorporated to construct a nomogram for survival prediction. Finally, we used the Kaplan-Meier (KM) curve, receiver operating characteristic (ROC) curve, and time-dependent ROC to assess predictive power of HOXB9. KM curve showed EC patients overexpressing HOXB9 had a worse OS. AUC of diagnostic ROC was 0.880. AUCs of time-dependent ROC were 0.602, 0.591, and 0.706 for 1-year, 5-year, and 10-year survival probabilities (P < 0.001).

CONCLUSIONS

Our study provids new insights into the diagnosis and prognosis of HOXB9 in EC and constructs a model that can accurately predict the prognosis of EC.

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.

Identification of HOX signatures contributing to oral cancer phenotype

The role of evolutionarily conserved homeobox-containing HOX genes as transcriptional regulators in the developmental specification of organisms is well known. The contribution of HOX genes involvement in oral cancer phenotype has yet to be fully ascertained. TCGA-HNSC HTSeq-counts and clinical data were retrieved from the GDC portal for oral cavity neoplasms. GEO datasets (GSE72627, GSE30784, GSE37991) were accessed and analyzed using GEO2R. Differential HOX gene expression was profiled using the DESeq2 R package with a log2 fold change cut-off (- 1 and + 1) and Benjamini-Hochberg p-adjusted value at ≤ 0.01. Gene set over-representation analysis and semantic analysis associated with the disease ontology was performed using the ClusterProfiler R package, and pathway over-representation analysis was performed using IMPaLa. HOX protein interaction network was constructed using the Pathfind R package. HOX phenotype associations were performed using Mammalian Phenotype Ontology, Human Phenotype Ontology, PhenGenI associations, Jensen tissues, and OMIM entries. Drug connectivity mapping was carried out with Dr. Insight R package. HOXA2 was upregulated in oral dysplasia but silenced during tumor progression. Loss of HOXB2 expression was consistent in the potentially malignant oral lesions as well as in the primary tumor. HOXA7, HOXA10, HOXB7, HOXC6, HOXC10, HOXD10, and HOXD11 were consistently upregulated from premalignancy to malignancy and were notably associated with risk factors. Overrepresentation analysis suggested HOXA10 was involved in the transcriptional misregulation contributing to the oral cancer phenotype. HOX genes subnetwork analysis showed crucial interactions with cell cycle regulators, growth responsive elements, and proto-oncogenes. Phenotype associations specific to the oral region involving HOX genes provide intrinsic cues to tumor development. The 5' HOX genes were aberrantly upregulated during oral carcinogenesis reflecting their posterior prevalence.

HOX and PBX gene dysregulation as a therapeutic target in glioblastoma multiforme

BACKGROUND

Glioblastoma multiforme (GBM) is the most common high-grade malignant brain tumour in adults and arises from the glial cells in the brain. The prognosis of treated GBM remains very poor with 5-year survival rates of 5%, a figure which has not improved over the last few decades. Currently, there is a modest 14-month overall median survival in patients undergoing maximum safe resection plus adjuvant chemoradiotherapy. HOX gene dysregulation is now a widely recognised feature of many malignancies.

METHODS

In this study we have focused on HOX gene dysregulation in GBM as a potential therapeutic target in a disease with high unmet need.

RESULTS

We show significant dysregulation of these developmentally crucial genes and specifically that HOX genes A9, A10, C4 and D9 are strong candidates for biomarkers and treatment targets for GBM and GBM cancer stem cells. We evaluated a next generation therapeutic peptide, HTL-001, capable of targeting HOX gene over-expression in GBM by disrupting the interaction between HOX proteins and their co-factor, PBX. HTL-001 induced both caspase-dependent and -independent apoptosis in GBM cell lines.

CONCLUSION

In vivo biodistribution studies confirmed that the peptide was able to cross the blood brain barrier. Systemic delivery of HTL-001 resulted in improved control of subcutaneous murine and human xenograft tumours and improved survival in a murine orthotopic model.

HOXC11 Expression Is Associated with the Progression of Colon Adenocarcinoma and Is a Prognostic Biomarker

This study aimed to evaluate the role of HOXC11 in progression and prognosis in colon adenocarcinoma (COAD) patients. The COAD patient data were downloaded from "The Cancer Genome Atlas (TCGA)" database. The Wilcoxon rank-sum test or Kruskal-Wallis test was used to analyze the correlation between HOXC11 expression and clinicopathologic characteristics. The significance of difference in overall survival between different groups was determined by log-rank test. The HOXC11 expression was verified from mRNA and protein level by conducting real-time quantitative PCR, Western blot, and immunohistochemistry analysis. Significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were screened after gene set enrichment analysis. As a result, high HOXC11 expression was closely related to the occurrence of COAD based on the data in TCGA, which was then successfully validated in cell lines and clinical tissues. Enhanced HOXC11 expression was significantly associated with tumor-node-metastasis (TNM) and M stage. Prognosis of highly expressed HOXC11 COAD patients was significantly worse than those with low HOXC11 expression. GRAFT_VERSUS_HOST_DISEASE and other signaling pathways were significantly activated in high HOXC11 expression COAD patients. In conclusion, high expression of HOXC11 was closely associated with the progression of COAD, and HOXC11 was a promising prognostic biomarker in COAD patients.

Homeobox gene amplification and methylation in oral squamous cell carcinoma

OBJECTIVES

Investigate the DNA copy number and the methylation profile of the homeobox genes HOXA5, HOXA7, HOXA9, HOXB5, HOXB13, HOXC12, HOXC13, HOXD10, HOXD11, IRX4 and ZHX1, and correlate them with clinicopathological parameters and overall survival.

MATERIAL AND METHODS

DNA from OSCC samples and surgical margins were submitted to DNA amplification by qPCR and to DNA methylation analysis using a DNA Methylation PCR Array System.

RESULTS

HOXA5, HOXB5 and HOXD10 were amplified in surgical margins while HOXA9, HOXB13 and IRX4 were amplified in OSCC. HOXD10 demonstrated hypermethylation in half of the tumor while ZHX1 did not show hypermethylation. No correlation of DNA copy number or methylation with clinicopathological parameters or survival was observed.

CONCLUSION

HOXA9, HOXB13 and IRX4 genes appears to be regulated by amplification and HOXD10 by methylation in OSCC. Further studies are needed to determine the role of these events in OSCC development.

In silico analysis of HOX-associated transcription factors as potential regulators of oral cancer

OBJECTIVE

The objective of this study was identification of the transcription factor binding sites (TFBS) in the promoter of HOX genes and elucidation of the comprehensive interaction of transcription factors (TFs)/genes with HOX.

METHODOLOGY

Promoter sequences of HOXA3, HOXA5, HOXA9, HOXA10, HOXA13, HOXB5, HOXC10, HOXC12, and HOXD10 were analyzed to predict the TFBS and their targets using TRANSFAC, TRRUST, and Harmonizome. Functional analysis of the processed data sets was carried out using DAVID and GATHER gene annotation tools. A network of regulatory interactions was constructed using NetworkAnalyst and a comprehensive illustration of the TF-gene network was constructed with HOX as a central hub using the Encyclopedia of DNA Elements chromatin immunoprecipitation sequencing data. Further, the enriched network was constructed to elucidate the roles of these genes in the various pathways.

RESULTS

Binding sites for E2F1, HNF3α, SP3, and KLF6 were common to promoter regions of all of the HOX genes. The functional annotation and pathway analysis elucidated the regulatory activity of a distinct set of TF-genes in interaction with HOX. A P value ≤.05 and false discovery rate ≤0.01 were considered statistically significant.

CONCLUSION

We have confirmed that the predicted TFBSs in the HOX gene promoters function in transcriptional regulation by modulating target gene activity. TF-gene interactions are crucial to understanding oral carcinogenesis.

miRNA for the assessment of lymph node metastasis in patients with oral squamous cell carcinoma: Systematic review and metanalysis

BACKGROUND

miRNA is one of the advanced epigenetic molecular markers correlating with lymph node metastasis in patients with Oral squamous cell carcinoma (OSCC). Numerous published papers are showing correlation of miRNA with metastasis. There is a need to analyze and validate such correlation.

METHOD

English language literature in major databases from the last 20 years was searched using controlled vocabulary and keywords. Strict inclusion and exclusion criteria were followed for selection of studies. The quality assessment was done as per the QUADAS tool 2 by three independent reviewers. The metanalysis was performed by using random effect model. Standardized mean difference (SMD) was considered as the effect measure. Statistical software used was STATA version 13.1.

RESULTS

With all inclusion and exclusion criteria, eight studies could qualify for metanalysis. The pooled estimate is found to be 0.13 (-0.35, 0.62), P = .585, which is statistically not significant. This indicates that there is a no significant difference in the fold change between metastasis and no metastasis groups. P-value of chi-square statistic for heterogeneity is <.001 (significant), and I-squared statistic is 87.2%, which indicates that heterogeneity is present to a considerable extent. Egger's test shows there is no publication bias involved (P = .819).

CONCLUSION

The metanalysis showed no significant difference in the fold change of miRNA expression between metastasis and non-metastasis OSCC patients. Future studies can be directed to eliminate the heterogeneity among the studies noted in this analysis to confirm the role of miRNA for assessment of regional metastasis with special focus on tongue squamous cell carcinoma.

miR-7 Reduces High Glucose Induced-damage Via HoxB3 and PI3K/AKT/mTOR Signaling Pathways in Retinal Pigment Epithelial Cells

BACKGROUND

Diabetic retinopathy (DR) is a common complication of diabetes. This study investigated the effect of miR-7 in the regulation of cell proliferation via the HoxB3 gene and PI3K/AKT/mTOR signaling pathways in DR.

METHODS

Human retinal pigment epithelial cell line (ARPE-19) cultured in normal medium (Control) and high glucose medium (25mM glucose, HG) was transfected with mimics NC (HG+ mimics NC), miR-7 mimics (HG+miR-7 mimics), inhibitor NC (HG+ inhibitor NC), and miR-inhibitor (HG+miR-7 inhibitor). The cells were assayed for viability, apoptosis, and expression of genes.

RESULTS

HG reduced cell viability and increased apoptosis. However, miR-7 mimics reduced the apoptosis. PCR results showed that miR-7 was significantly upregulated after transfection with miR-7 mimics. The expression of Hoxb3, mTOR, p-PI3K, and p- AKT was significantly downregulated at mRNA and protein levels after miR-7 mimics transfection, while no difference was observed for PI3K and AKT expression.

CONCLUSION

Our findings demonstrate that miR-7 regulates the growth of retinal epithelial cells through various pathways and is a potential therapeutic target for the prevention and treatment of diabetic retinopathy.

HOX genes as transcriptional and epigenetic regulators during tumorigenesis and their value as therapeutic targets

Several HOX genes are aberrantly expressed in a wide range of cancers interfering with their development and resistance to treatment. This seems to be often caused by alterations in the methylation profiles of their promoters. The role of HOX gene products in cancer is highly 'tissue specific', relying ultimately on their ability to regulate oncogenes or tumor-suppressor genes, directly as transcriptional regulators or indirectly interfering with the levels of epigenetic regulators. Nowadays, different strategies have been tested the use of HOX genes as therapeutic targets for cancer diagnosis and treatment. Here, we trace the history of the research concerning the involvement of HOX genes in cancer, their connection with epigenetic regulation and their potential use as therapeutic targets.

Kinase Regulation of HOX Transcription Factors

The HOX genes are a group of homeodomain-containing transcription factors that play important regulatory roles in early development, including the establishment of cell and tissue identity. HOX expression is generally reduced in adult cells but is frequently re-established as an early event in tumour formation and supports an oncogenic phenotype. HOX transcription factors are also involved in cell cycle regulation and DNA repair, along with normal adult physiological process including stem cell renewal. There have been extensive studies on the mechanism by which HOX proteins regulate transcription, with particular emphasis on their interaction with cofactors such as Pre-B-cell Leukaemia Homeobox (PBX) and Myeloid Ecotropic Viral Integration Site 1 (MEIS). However, significantly less is known of how the activity of HOX proteins is regulated. There is growing evidence that phosphorylation may play an important role in this context, and in this review, we draw together a number of important studies published over the last 20 years, and discuss the relevance of phosphorylation in the regulation and function of HOX proteins in development, evolution, cell cycle regulation, and cancer.

Homeobox D10, a tumor suppressor, inhibits the proliferation and migration of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most common types of esophageal cancer, which is the sixth leading cause of cancer death globally. Homeobox D10 (HOXD10) is a member of the homeobox (HOX) gene family and has been reported to act as a tumor suppressor. However, the potential role of HOXD10 in ESCC has not been reported. Thus, the aim of this study was to examine the expression and function of HOXD10 in ESCC. The expressions of HOXD10 in human ESCC tissues and cell lines were detected by quantitative reverse transcription polymerase chain reaction and Western blot. The HOXD10 overexpressing cell lines were established, then CCK-8 and Transwell assays were performed to examine cell proliferation, migration, and invasion, respectively. The expression of EMT-related proteins and signaling pathway-related proteins were detected by Western blot. Our results showed that HOXD10 is lowly expressed in ESCC tissues as well as in ESCC cell lines. Ectopic overexpression of HOXD10 inhibited cell proliferation, migration, and invasion of ESCC cells (P < 0.05). HOXD10 overexpression repressed the epithelial-mesenchymal transition (EMT) process in ESCC cells. Besides, HOXD10 overexpression suppressed the activation of PI3K/AKT/mTOR signaling pathway. PI3K/Akt agonist, insulin-like growth factor-1, reversed the inhibitory effects of HOXD10 on cell proliferation and migration in ESCC cells. Additional in vivo study proved that ectopic expression of HOXD10 caused an obvious inhibitory effect on the tumor growth. These findings indicated that overexpression of HOXD10 suppressed the proliferation, migration, and invasion via regulating the PI3K/AKT/mTOR signaling pathway in ESCC cells. Thus, targeting HOXD10 may be considered as a therapeutic strategy for ESCC treatment.

Targeting HOX-PBX interactions causes death in oral potentially malignant and squamous carcinoma cells but not normal oral keratinocytes

BACKGROUND

High HOX gene expression has been described in many cancers, including oral squamous cell carcinoma and the functional roles of these genes are gradually being understood. The pattern of overexpression suggests that inhibition may be useful therapeutically. Inhibition of HOX protein binding to PBX cofactors by the use of synthetic peptides, such as HXR9, results in apoptosis in multiple cancers.

METHODS

Activity of the HOX-PBX inhibiting peptide HXR9 was tested in immortalised normal oral (NOK), potentially-malignant (PMOL) and squamous cell carcinoma (OSCC) cells, compared to the inactive peptide CXR9. Cytotoxicity was assessed by LDH assay. Expression of PBX1/2 and c-Fos was assessed by qPCR and western blotting. Apoptosis was assessed by Annexin-V assay.

RESULTS

PMOL and OSCC cells expressed PBX1/2. HOX-PBX inhibition by HXR9 caused death of PMOL and OSCC cells, but not NOKs. HXR9 treatment resulted in apoptosis and increased expression of c-Fos in some cells, whereas CXR9 did not. A correlation was observed between HOX expression and resistance to HXR9.

CONCLUSION

Inhibition of HOX-PBX interactions causes selective apoptosis of OSCC/PMOL, indicating selective toxicity that may be useful clinically.

Targeting HOX/PBX dimers in cancer

The HOX and PBX gene families encode transcription factors that have key roles in establishing the identity of cells and tissues in early development. Over the last 20 years it has become apparent that they are also dysregulated in a wide range of solid and haematological malignancies and have a predominantly pro-oncogenic function. A key mode of transcriptional regulation by HOX and PBX proteins is through their interaction as a heterodimer or larger complex that enhances their binding affinity and specificity for DNA, and there is growing evidence that this interaction is a potential therapeutic target in malignancies that include prostate, breast, renal, ovarian and lung cancer, melanoma, myeloma, and acute myeloid leukaemia. This review summarizes the roles of HOX and PBX genes in cancer and assesses the therapeutic potential of HOX/PBX dimer inhibition, including the availability of biomarkers for its application in precision medicine.

MicroRNA-196a-5p is a potential prognostic marker of delayed lymph node metastasis in early-stage tongue squamous cell carcinoma

MicroRNAs (miRs) are expected to serve as prognostic tools for cancer. However, many miRs have been reported as prognostic markers of recurrence or metastasis in oral squamous cell carcinoma patients. We aimed to determine the prognostic markers in early-stage tongue squamous cell carcinoma (TSCC). Based on previous studies, we hypothesized that miR-10a, 10b, 196a-5p, 196a-3p, and 196b were prognostic markers and we retrospectively performed miR expression analyses using formalin-fixed paraffin-embedded sections of surgical specimens. Total RNA was isolated from cancer tissues and adjacent normal tissue as control, and samples were collected by laser-capture microdissection. After cDNA synthesis, reverse transcription-quantitative polymerase chain reaction was performed. Statistical analyses for patient clinicopathological characteristics, recurrence/metastasis, and survival rates were performed to discern their relationships with miR expression levels, and the 2^−ΔΔCq method was used. miR-196a-5p levels were significantly upregulated in early-stage TSCC, particularly in the lymph node metastasis (LNM) group. The LNM-free survival rate in the low miR-196a-5p ΔΔCq value regulation group was found to be lower than that in the high ΔΔCq value regulation group (P=0.0079). Receiver operating characteristic analysis of ΔΔCq values revealed that miR-196a-5p had a P-value=0.0025, area under the curve=0.740, and a cut-off value=−0.875 for distinguishing LNM. To our knowledge, this is the first study to examine LNM-related miRs in early-stage TSCC as well as miRs and ‘delayed LNM’ in head and neck cancer. miR-196a-5p upregulation may predict delayed LNM. Our data serve as a foundation for future studies to evaluate miR levels and facilitate the prediction of delayed LNM during early-stage TSCC, which prevent metastasis when combined with close follow-up and aggressive adjuvant therapy or elective neck dissection. Moreover, our data will serve as a foundation for future studies to evaluate whether miR-196a-5p can serve as a therapeutic marker for preventing metastasis.

Impact of homeobox genes in gastrointestinal cancer

Homeobox genes, including HOX and non-HOX genes, have been identified to be expressed aberrantly in solid tumors. In gastrointestinal (GI) cancers, most studies have focused on the function of non-HOX genes including caudal-related homeobox transcription factor 1 (CDX1) and CDX2. CDX2 is a crucial factor in the development of pre-cancerous lesions such as Barrett’s esophagus or intestinal metaplasia in the stomach, and its tumor suppressive role has been investigated in colorectal cancers. Recently, several HOX genes were reported to have specific roles in GI cancers; for example, HOXA13 in esophageal squamous cell cancer and HOXB7 in stomach and colorectal cancers. HOXD10 is upregulated in colorectal cancer while it is silenced epigenetically in gastric cancer. Thus, it is essential to examine the differential expression pattern of various homeobox genes in specific tumor types or cell lineages, and understand their underlying mechanisms. In this review, we summarize the available research on homeobox genes and present their potential value for the prediction of prognosis in GI cancers.

HOXB7 as a promising molecular marker for metastasis in cancers: a meta-analysis

Numerous studies on carcinoma have revealed that the expression level of HOXB7 in cancerous tissues was significantly higher than that in noncancerous tissues. Elevated expression of HOXB7 is associated with the susceptibility to lymph node metastasis and distant metastasis in various tumors. In this study, a meta-analysis was performed to involve majority of relevant articles and explore the association of HOXB7 expression level with metastasis in cancer patients. Literature retrieval was conducted by searching in a number of electronic databases (up to December 1, 2015). The meta-analysis was conducted with RevMan 5.3 software and Stata SE12.0. A total of 1,532 patients with carcinoma from 14 studies were included in analysis. The results of meta-analysis demonstrated that lymph node metastasis was observed more frequently in the patients group with high expression level of HOXB7 than in the patients group with low expression level of HOXB7 (odds ratio =2.17, 95% CI: 1.74–2.71, P<0.00001, fixed-effects model). In addition, a similar result was observed in the association between HOXB7 expression and distant metastasis; the odds ratio was 1.77 (95% CI: 1.09–2.88, P=0.02, fixed-effects model). This meta-analysis demonstrated that the overexpression of HOXB7 was significantly associated with metastasis in cancer patients, which may be served as a common molecular marker for indicating cancer metastasis.