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.

Effects of HOXC8 on the Proliferation and Differentiation of Porcine Preadipocytes

Transcription factor Homeobox C8 (HOXC8) is identified as a white adipose gene as revealed by expression profile analysis in fat tissues. However, the specific role of HOXC8 in fat accumulation remains to be identified. This study was designed to reveal the effects of HOXC8 on preadipocyte proliferation and differentiation. We first make clear that the expression of HOXC8 is associated with fat contents in muscles, highlighting a role of HOXC8 in fat accumulation. Next, it is demonstrated that HOXC8 promotes the proliferation and differentiation of preadipocytes through gain- and loss-of-function assays in primary cultured porcine preadipocytes. Then, mechanisms underlying the regulation of HOXC8 on preadipocyte proliferation and differentiation are identified with RNA sequencing, and a number of differentially expressed genes (DEGs) in response to HOXC8 knockdown are identified. The top GO (Gene Ontology) terms enriched by DEGs involved in proliferation and differentiation, respectively, are identical. IL-17 signaling pathway is the common one significantly enriched by DEGs involved in preadipocyte proliferation and differentiation, respectively, indicating its importance in mediating fat accumulation regulated by HOXC8. Additionally, we find that the inhibition of proliferation is one of the main processes during preadipocyte differentiation. The results will contribue to further revealing the mechanisms underlying fat accumulation regulated by HOXC8.

Homeobox Gene Expression Dysregulation as Potential Diagnostic and Prognostic Biomarkers in Bladder Cancer

Homeobox genes serve as master regulatory transcription factors that regulate gene expression during embryogenesis. A homeobox gene may have either tumor-promoting or tumor-suppressive properties depending on the specific organ or cell lineage where it is expressed. The dysregulation of homeobox genes has been reported in various human cancers, including bladder cancer. The dysregulated expression of homeobox genes has been associated with bladder cancer clinical outcomes. Although bladder cancer has high risk of tumor recurrence and progression, it is highly challenging for clinicians to accurately predict the risk of tumor recurrence and progression at the initial point of diagnosis. Cystoscopy is the routine surveillance method used to detect tumor recurrence. However, the procedure causes significant discomfort and pain that results in poor surveillance follow-up amongst patients. Therefore, the development of reliable non-invasive biomarkers for the early detection and monitoring of bladder cancer is crucial. This review provides a comprehensive overview of the diagnostic and prognostic potential of homeobox gene expression dysregulation in bladder cancer.

HOXC8 alleviates high glucose-triggered damage of trophoblast cells during gestational diabetes mellitus via activating TGFβ1-mediated Notch1 pathway

Gestational diabetes mellitus (GDM) is an increasingly frequent disease occurred during pregnancy. HOXC8 has been disclosed to take part in the regulation of cancers. Additionally, the HOXC8 expression was dramatically decreased in the placenta of pre-eclampsia patients, but its expression and function have not been investigated in GDM. In this work, it was demonstrated that the mRNA and protein expression of HOXC8 was lower in GDM placenta tissues and GDM cell model. In addition, HOXC8 facilitated trophoblast cell proliferation and weakened trophoblast cell mitochondrial apoptosis. HOXC8 enhanced trophoblast cell migration and angiogenesis. Moreover, HOXC8 activated the TGFβ1-mediated Notch1 signaling pathway. Results showed that the mRNA and protein expressions of TGFβ1 and Notch1 were both lower in the GDM group than that in the NP group. Besides, there were positive correlations among HOXC8, TGFβ1 and Notch1. Inhibition of TGFβ1 (SB202190 treatment) reversed the effects of HOXC8 on trophoblast cells through modulating cell proliferation, mitochondrial apoptosis, migration and angiogenesis. At last, through in vivo experiments, it was identified that HOXC8 relieved GDM symptoms in vivo. In conclusion, HOXC8 alleviated HG-stimulated damage of trophoblast cells during GDM through activating TGFβ1-mediated Notch1 pathway. This discovery may provide a novel and useful bio-target for GDM treatment.

Screening of Hub Genes in Hepatocellular Carcinoma Based on Network Analysis and Machine Learning

Hepatocellular carcinoma (LIHC) is the fifth common cancer worldwide, and it requires effective diagnosis and treatment to prevent aggressive metastasis. The purpose of this study was to construct a machine learning-based diagnostic model for the diagnosis of liver cancer. Using weighted correlation network analysis (WGCNA), univariate analysis, and Lasso-Cox regression analysis, protein-protein interactions network analysis is used to construct gene networks from transcriptome data of hepatocellular carcinoma patients and find hub genes for machine learning. The five models, including gradient boosting, random forest, support vector machine, logistic regression, and integrated learning, were to identify a multigene prediction model of patients. Immunological assessment, TP53 gene mutation and promoter methylation level analysis, and KEGG pathway analysis were performed on these groups. Potential drug molecular targets for the corresponding hepatocellular carcinomas were obtained by molecular docking for analysis, resulting in the screening of 2 modules that may be relevant to the survival of hepatocellular carcinoma patients, and the construction of 5 diagnostic models and multiple interaction networks. The modes of action of drug-molecule interactions that may be effective against hepatocellular carcinoma core genes CCNA2, CCNB1, and CDK1 were investigated. This study is expected to provide research ideas for early diagnosis of hepatocellular carcinoma.

Identification of Candidate Gene Signatures and Regulatory Networks in Endometriosis and its Related Infertility by Integrated Analysis

Endometriosis is a common gynecological disease associated with infertility, and it represents an economic burden worldwide. However, the molecular mechanisms underlying endometriosis development have not yet been fully elucidated. Here, we aimed to identify reliable key genes and the related regulatory network that may be involved in endometriosis. Differentially expressed genes (DEGs) were identified through integrated analysis of four expression datasets of endometriosis from Gene Expression Omnibus. Gene functional analysis and protein-protein interaction network construction were performed to reveal the potential function of DEGs. Subsequently, candidate hub genes were defined and validated in GSE105764 dataset, and the associated regulatory networks were constructed. Additionally, GSE120103 dataset was applied to identify the differential expression between the infertile and fertile groups of patients with stage IV endometriosis. Finally, real-time quantitative polymerase chain reaction analysis was performed to identify the differential expression of hub genes in the collected clinical specimens. Robust rank aggregation integrated analysis determined 158 DEGs. Epithelial cell differentiation was the most significantly enriched biological process, and leukocyte transendothelial migration was the most significantly enriched pathway. Eight hub genes including CLDN3, CLDN5, CLDN7, CLDN11, HOXC8, HOXC6, HOXB6, and HOXB7 were identified, and most of these were validated as abnormally expressed genes in both the infertile group and patients with endometriosis. Transcriptional factors and microRNAs related to these genes were identified. Altogether, our integrated analysis identified critical gene signatures, involved pathways, and regulatory networks, which could provide clinically significant insights into the molecular mechanisms underlying endometriosis and its related infertility.

Identification of prognostic marker genes in head and neck squamous cell carcinoma: A study based on The Cancer Genome Atlas database and experimental validation

BACKGROUND

Early detection and prognostic prediction are crucial in improving the survival of patients with head and neck squamous cell carcinoma (HNSCC). Therefore, we provided potential molecular markers in this study for early diagnosis and prognosis of this cancer based on The Cancer Genome Atlas (TCGA) database analysis and experimental validations.

METHODS

Differentially expressed genes (DEGs) between HNSCC tumor and normal samples were identified by TCGA database-based analyses. Univariate and multivariate Cox regression analyses were applied, respectively, to identify survival-related DEGs and independent prognostic factors in HNSCC. Further, RT-qPCR was employed to verify expression of DEGs in cancer and adjacent tissues from HNSCC patients recruited in our hospital, in which we also clarified the correlation between candidate genes and clinicopathological characteristics and prognosis of HNSCC patients.

RESULTS

TCGA data analyses yielded 59 DEGs. Cox analyses identified 13 candidate genes closely related to prognosis of HNSCC patients and established a five-gene signature comprising AC103702.2, LINC00941, RPL29, FOXL2, and CCL11. This five-gene signature could classify patients into high- and low-risk groups. The survival rate of the high-risk group was significantly lower than that of the low-risk group. Clinical tissue experiments further confirmed that AC103702.2, LINC00941, CCL11, and RPL29P19 genes were inversely associated with the prognosis of HNSCC patients, while CCL11 gene was positively associated. We also found that high-risk HNSCC patients presented a higher incidence of lymph node metastasis.

CONCLUSION

Five prognostic marker genes (AC103702.2, LINC00941, CCL11, RPL29P19, and FOXL2) as a gene cluster may serve as prognostic marker genes in HNSCC.

Identification of a two-gene prognostic model associated with cytolytic activity for colon cancer

Background

Increasing evidence has shown that cytolytic activity (CYT) is a new immunotherapy biomarker that characterises the antitumour immune activity of cytotoxic T cells and macrophages. In this study, we established a prognostic model associated with CYT.

Methods

A prognostic model based on CYT-related genes was developed. Furthermore, aberrant expression of genes of the model in colon cancer (CC) was identified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry (IHC) assays. Next, the correlation between the model and T-cell infiltration in the CC microenvironment was analysed. The Tumour Immune Dysfunction and Exclusion (TIDE) algorithm and subclass mapping were used to predict clinical responses to immune checkpoint inhibitors.

Results

In total, 280 of the 1418 genes were differentially expressed based on CYT. A prognostic model (including HOXC8 and MS4A2) was developed based on CYT-related genes. The model was validated using the testing set, the whole set and a Gene Expression Omnibus (GEO) cohort (GSE41258). Gene set enrichment analysis (GSEA) and other analyses showed that the levels of immune infiltration and antitumour immune activation in low-risk-score tumours were greater than those in high-risk-score tumours. CC patients with a low-risk-score showed more promise in the response to anti-immune checkpoint therapy.

Conclusions

Overall, our model may precisely predict the overall survival of CC and reflect the strength of antitumour immune activity in the CC microenvironment. Furthermore, the model may be a predictive factor for the response to immunotherapy.

An Integrated Genomic Approach Identifies HOXC8 as an Upstream Regulator in Ovarian Endometrioma

PURPOSE

To identify the upstream regulators (URs) involved in the onset and pathogenesis of ovarian endometrioma.

METHODS

Recently, a method called Significance-based Modules Integrating the Transcriptome and Epigenome (SMITE) that uses transcriptome data in combination with publicly available data for identifying URs of cellular processes has been developed. Here, we used SMITE with transcriptome data from ovarian endometrioma stromal cells (ovESCs) and eutopic endometrium stromal cells (euESCs) in combination with publicly available gene regulatory network data. To confirm the URs identified by SMITE, we developed a Boolean network simulation to see if correcting aberrant expressions of the identified genes could restore the entire gene expression profile of ovESCs to a profile similar to that of euESCs. We then established euESCs overexpressing the identified gene and characterized them by cell function assays and transcriptome analysis.

RESULTS

SMITE identified 12 potential URs in ovarian endometrioma that were confirmed by the Boolean simulation. One of the URs, HOXC8, was confirmed to be overexpressed in ovESCs. HOXC8 overexpression significantly enhanced cell proliferation, migration, adhesion, and fibrotic activities, and altered expression statuses of the genes involved in transforming growth factor (TGF)-β signaling. HOXC8 overexpression also increased the expression levels of phosphorylated SMAD2/SMAD3. The increased adhesion and fibrosis activities by HOXC8 were significantly inhibited by E-616452, a selective inhibitor of TGF-β receptor type I kinases.

MAIN CONCLUSIONS

Integrated genomic approaches identified HOXC8 as an UR in ovarian endometrioma. The pathological features of ovarian endometrioma including cell proliferation, adhesion, and fibrosis were induced by HOXC8 and its subsequent activation of TGF-β signaling.

Insight into epigenetics of human endometriosis organoids: DNA methylation analysis of HOX genes and their cofactors

OBJECTIVE

To evaluate and compare the methylation pattern of Human Homeobox (HOX) clusters (A-D) and HOX cofactors in normal, eutopic, and ectopic endometrial tissues with ectopic and eutopic endometriosis organoids as advanced preclinical research models.

DESIGN

A chromatin immunoprecipitation (ChIP) array containing 84 genes was used to analyze methylation levels of HOX clusters (A-D) and HOX cofactors in normal, eutopic, and ectopic endometrial biopsy specimens as well as ectopic and eutopic endometriosis organoids.

SETTING

Reproductive biomedicine and cell science research centers.

PATIENT(S)

Nine healthy women without endometriosis (control) and 16 women diagnosed with endometriosis.

INTERVENTION(S)

Ectopic endometrial lesions were obtained using a laparoscopic procedure, and eutopic and control endometrium biopsy specimens were obtained using pipelle sampling.

MAIN OUTCOME MEASURE(S)

Methylation levels of HOX clusters (A-D) and HOX cofactors in eutopic and ectopic endometrial biopsy specimens, as well as eutopic and ectopic endometriosis organoids and normal endometrium.

RESULT(S)

Most HOX clusters (A-D) and HOX cofactors showed methylation alterations in ectopic/eutopic endometrial tissues and ectopic/eutopic endometriosis organoids compared with normal endometrium. These methylation alterations had the same pattern in ectopic/eutopic tissue biopsy specimens and ectopic/eutopic endometriosis organoids in most genes. A contrariwise methylation pattern was observed in 28 of 84 genes in the ectopic/eutopic tissue biopsy specimens and ectopic/eutopic endometriosis organoids.

CONCLUSION(S)

Because a conserved pattern of methylation alterations in endometriosis tissues and organoids was observed for most of the investigated genes (56 of 84), it can be concluded that endometriosis organoids maintain epigenetic changes. Therefore, our study suggests endometriosis organoids as a novel preclinical model to determine the epigenetic mechanisms that underlie endometriosis.

Downregulation of circNRIP1 Suppresses the Paclitaxel Resistance of Ovarian Cancer via Regulating the miR-211-5p/HOXC8 Axis

Background

Circular RNA (circRNA) has an essential regulatory role in the chemotherapy resistance of cancers. Nevertheless, the role of circRNA nuclear receptor-interacting protein 1 (circNRIP1) in the paclitaxel (PTX) resistance of ovarian cancer (OC) remains unclear.

Material and Methods

The circNRIP1, miR-211-5p and homeobox C8 (HOXC8) expression levels were assessed using qRT-PCR. The PTX resistance of cells was measured by 3-(4, 5-dimethylthiazolyl-2-yl)-2-5 diphenyl tetrazolium bromide (MTT) assay. Furthermore, cell proliferation, apoptosis, migration and invasion were detected by colony formation assay, flow cytometry and transwell assay, respectively. Moreover, the protein levels of proliferation, apoptosis, metastasis-related markers and HOXC8 were determined by Western blot (WB) analysis. Tumor xenograft models were constructed to explore the influence of circNRIP1 on OC tumor growth. The interaction between miR-211-5p and circNRIP1 or HOXC8 was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay.

Results

CircNRIP1 was highly expressed in PTX-resistant OC tissues and cells. Silencing of circNRIP1 repressed the PTX resistance of OC cells in vitro and OC tumor in vivo. Furthermore, circNRIP1 sponged miR-211-5p, and miR-211-5p inhibitor could reverse the inhibitory effect of circNRIP1 knockdown on the PTX resistance of OC cells. In addition, miR-211-5p targeted HOXC8, and HOXC8 overexpression could reverse the suppression effect of miR-211-5p on the PTX resistance of OC cells. Additionally, the expression of HOXC8 was regulated by circNRIP1 and miR-211-5p.

Conclusion

CircNRIP1 silencing could inhibit the PTX resistance of OC via regulating the miR-211-5p/HOXC8 axis, showing that circNRIP1 might be a potential target for OC resistance treatment.

Contributions of HOX genes to cancer hallmarks: Enrichment pathway analysis and review

Homeobox genes function as master regulatory transcription factors during development, and their expression is often altered in cancer. The HOX gene family was initially studied intensively to understand how the expression of each gene was involved in forming axial patterns and shaping the body plan during embryogenesis. More recent investigations have discovered that HOX genes can also play an important role in cancer. The literature has shown that the expression of HOX genes may be increased or decreased in different tumors and that these alterations may differ depending on the specific HOX gene involved and the type of cancer being investigated. New studies are also emerging, showing the critical role of some members of the HOX gene family in tumor progression and variation in clinical response. However, there has been limited systematic evaluation of the various contributions of each member of the HOX gene family in the pathways that drive the common phenotypic changes (or "hallmarks") and that underlie the transformation of normal cells to cancer cells. In this review, we investigate the context of the engagement of HOX gene targets and their downstream pathways in the acquisition of competence of tumor cells to undergo malignant transformation and tumor progression. We also summarize published findings on the involvement of HOX genes in carcinogenesis and use bioinformatics methods to examine how their downstream targets and pathways are involved in each hallmark of the cancer phenotype.

The Role of ARF Family Proteins and Their Regulators and Effectors in Cancer Progression: A Therapeutic Perspective

The Adenosine diphosphate-Ribosylation Factor (ARF) family belongs to the RAS superfamily of small GTPases and is involved in a wide variety of physiological processes, such as cell proliferation, motility and differentiation by regulating membrane traffic and associating with the cytoskeleton. Like other members of the RAS superfamily, ARF family proteins are activated by Guanine nucleotide Exchange Factors (GEFs) and inactivated by GTPase-Activating Proteins (GAPs). When active, they bind effectors, which mediate downstream functions. Several studies have reported that cancer cells are able to subvert membrane traffic regulators to enhance migration and invasion. Indeed, members of the ARF family, including ARF-Like (ARL) proteins have been implicated in tumorigenesis and progression of several types of cancer. Here, we review the role of ARF family members, their GEFs/GAPs and effectors in tumorigenesis and cancer progression, highlighting the ones that can have a pro-oncogenic behavior or function as tumor suppressors. Moreover, we propose possible mechanisms and approaches to target these proteins, toward the development of novel therapeutic strategies to impair tumor progression.

LncRNA SNHG1 Regulates the Progression of Esophageal Squamous Cell Cancer by the miR-204/HOXC8 Axis

Objective

Long noncoding RNA small nucleolar RNA host gene 1 (SNHG1) has been reported to be aberrantly expressed and plays an important role in human cancers, including esophageal squamous cell cancer. However, the regulatory mechanism underlying SNHG1 in the progression of esophageal squamous cell cancer is poorly defined.

Materials and Methods

Fifty-three esophageal squamous cell cancer patients were recruited and overall survival was analyzed. EC9706 and KYSE150 cells were cultured for study in vitro. The expression levels of SNHG1, microRNA (miR)-204 and homeobox c8 (HOXC8) were detected by quantitative real-time polymerase chain reaction and Western blot. Cell cycle distribution, apoptosis, migration and invasion were determined by flow cytometry and transwell assays, respectively. The target interaction among SNHG1, miR-204 and HOXC8 was validated by luciferase reporter assay and RNA immunoprecipitation. Xenograft model was established to investigate the role of SNHG1 in vivo.

Results

High expression of SNHG1 was exhibited in esophageal squamous cell cancer and indicated poor outcomes of patients. SNHG1 silence led to cell cycle arrest at G0-G1 phase, inhibition of migration and invasion and increase of apoptosis. miR-204 was validated to sponge by SNHG1 and target HOXC8 in esophageal squamous cell cancer cells. miR-204 knockdown or HOXC8 restoration reversed the inhibitive role of SNHG1 silence in the progression of esophageal squamous cell cancer cells. Furthermore, inhibiting SNHG1 decreased xenograft tumor growth by regulating miR-204 and HOXC8.

Conclusion

SNHG1 knockdown suppresses migration and invasion but induces apoptosis of esophageal squamous cell cancer cells by increasing miR-204 and decreasing HOXC8.

Analysis of Copy-Number Variations and Feline Mammary Carcinoma Survival

Feline mammary carcinomas (FMCs) are highly malignant. As the disease-free survival (DFS) and overall survival (OS) are short, prognostication is crucial. Copy-number variations (CNVs) analysis by next-generation sequencing serves to identify critical cancer-related genomic regions. Thirty-three female cats with FMCs were followed during two years after surgery. Tumours represented tubulopapillary and solid carcinomas encompassing six molecular subtypes. Regardless of the histopathological diagnosis, molecular subtypes showed important differences in survival. Luminal A tumours exhibited the highest DFS (p = 0.002) and cancer-specific OS (p = 0.001), and the lowest amount of CNVs (p = 0.0001). In contrast, basal-like triple-negative FMCs had the worst outcome (DFS, p < 0.0001; and OS, p < 0.00001) and were the most aberrant (p = 0.05). In the multivariate analysis, copy-number losses (CNLs) in chromosome B1 (1-23 Mb) harbouring several tumour-repressors (e.g. CSMD1, MTUS1, MSR1, DBC2, and TUSC3) negatively influenced DFS. Whereas, copy-number gains (CNGs) in B4 (1-29 Mb) and F2 (64-82.3 Mb) comprising epithelial to mesenchymal transition genes and metastasis-promoting transcription factors (e.g. GATA3, VIM, ZEB1, and MYC) negatively influenced DFS and cancer-specific OS. These data evidence an association between specific CNVs in chromosomes B1, B4 and F2, and poor prognosis in FMCs.

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.

HOX Genes in High Grade Ovarian Cancer

HOX genes are highly conserved members of the homeobox superfamily that have a crucial role in determining cellular identity. High grade ovarian cancer is the most lethal gynaecological malignancy. Our understanding of the role of HOX genes in the oncogenesis of ovarian cancer is evolving, and here we review their dysregulated expression patterns, their function in cell survival and invasion, their potential uses as biomarkers, and ways in which HOX genes are being targeted with new and existing drugs.

Homeobox C8 is a transcriptional repressor of E-cadherin gene expression in non-small cell lung cancer

Loss of E-cadherin expression is a hallmark of epithelial-mesenchymal transition (EMT) in tumor progression. Because previous findings suggested that homeobox C8 (HOXC8) promotes EMT in non-small-cell lung cancer (NSCLC), we investigated whether E-cadherin is a target of HOXC8 protein. In this study, we report that HOXC8 binds to the E-cadherin promoter and acts as a transcriptional repressor to regulate E-cadherin transcription in NSCLC. We further show that loss of E-cadherin leads to an increase in anchorage-independent growth and migration of NSCLC cells, and the inhibitory effects mediated by HOXC8 knockdown can be largely rescued by reduction of E-cadherin expression, suggesting that the HOXC8-E-cadherin pathway is involved in lung cancer progression. Moreover, analysis of E-cadherin and HOXC8 expression indicates that expression of HOXC8 is strongly correlated with loss of E-cadherin expression, and high HOXC8 / low E-cadherin expression is significantly correlated with poor survival for lung cancer patients. Taken together, these data indicate that E-cadherin is a target gene of HOXC8 and that the loss of E-cadherin promotes the growth and migration of NSCLC.

HOXC8: a predictive glioma biomarker that induces epithelia-mesenchymal transition

BACKGROUND

The transcription factor Homeobox C8 (HOXC8) is overexpressed and regulates many important genes involved in the proliferation and invasion of many malignant tumors. However, the function of HOXC8 in gliomas remains unclear.

METHOD

Based on the Chinese Glioma Genome Atlas (CGGA) set, HOXC8 expression is negatively correlated with overall survival (OS). Small interfering RNA (si-HOXC8) was used to downregulate the mRNA and protein expression levels of HOXC8 to assess glioma cell proliferation, migration and invasion.

RESULTS

Patients with higher HOXC8 levels showed poorer prognosis. DAVID analysis results indicated that HOXC8 was related to cell cycle, cell adhesion and immune response. In U251 and LN229 glioma cells treated with small interfering RNA for HOXC8 (si-HOXC8) for gene knockdown, significantly lower cell capacity of growth, migration and invasion was observed. Moreover, HOXC8 knockdown could reduce the protein expression of classical epithelial mesenchymal transition (EMT) related markers.

CONCLUSION

HOXC8 may play an important role in glioma proliferation, migration and invasion. These findings indicated that HOXC8 may constitute a novel target for glioma treatment.

HOXC8 promotes proliferation and migration through transcriptional up-regulation of TGFβ1 in non-small cell lung cancer

Homeobox (HOX) genes encode a family of transcription factors, which play crucial roles in numerous processes, and their dysregulation is involved in the carcinogenesis of many human cancers. In the present study, we investigated the roles of HOXC8 in non-small cell lung cancer (NSCLC). We showed that HOXC8 was upregulated in clinical NSCLC specimens compared to normal lung tissues, and the high expression of HOXC8 correlated with tumor node metastasis (TNM) stage, tumor status, lymph nodal status and poor relapse-free survival for lung cancer patients. Functionally, HOXC8 expression significantly promoted the proliferation, anchorage-independent growth and migration of NSCLC, and HOXC8 functioned as a transcription activator to induce the expression of TGFβ1, leading to an increase in the proliferation, anchorage-independent growth and migration of NSCLC. Furthermore, we demonstrated that HOXC8 expression was associated with chemoresistance and anti-apoptosis in NSCLC, suggesting that HOXC8 is a promising therapeutic target for chemosensitization of NSCLC to cisplatin. Altogether, our study defined a critical role of HOXC8 in promoting transcription of TGFβ1 and NSCLC tumorigenesis.

Dysregulated expression of homeobox family genes may influence survival outcomes of patients with epithelial ovarian cancer: analysis of data from The Cancer Genome Atlas

Homeobox (HOX) family genes encode key transcription factors for embryogenesis and may be correlated with carcinogenesis. The aim of this study was to elucidate whether aberrant expression of HOX genes influences outcomes in epithelial ovarian cancer (EOC). Gene expression data and clinicopathologic information from 630 patients with EOC were downloaded from The Cancer Genome Atlas database. We explored correlations between expression levels of HOX gene family members and clinicopathological variables. Higher expression of HOXA1, A4, A5, A7, A10, A11, B13, C13, D1, and D3 was associated with advanced FIGO stage. Suboptimal residual disease after debulking surgery was significantly correlated with higher expression of HOXB9, B13, and C13. Additionally, patients with high expression of HOXC6 and C11 were significantly more likely to have poor performance status. Overall survival was significantly shorter in patients with high, rather than low, expression of two HOX genes (HOXA10 and B3), and significantly longer in patients with high rather than low HOXC5 expression. Dysregulated expression of the HOXA10, B3, and C5 was significantly correlated with overall survival in EOC patients. HOX gene expression levels are potentially useful as a prognostic indicator in EOC, and HOX genes may represent a novel and promising target for anticancer therapeutics.

Effect of rs11614913 Polymorphism on Mature miR196a2 Expression and its Target Gene HOXC8 Expression in Human Glioma

miRNA polymorphisms are recently identified as a risk factor for various cancers, and it is associated with change in the expression of target genes in vitro. rs11614913 polymorphism in miR196a2 was associated with risk of glioma in Chinese population. In this study, we have evaluated the role of rs11614913 polymorphism and glioma risk in Indian population in 180 cases and controls. Seventy-two glioma tissue-blood pairs were also assessed for mutation in this SNP. Further, the effect of this polymorphism on mature miR196a2 expression and HOXC8 gene expression was analysed in 33 glioma tissue samples with different genotypes. Allelic discrimination assay was performed for genotyping and quantitative real time PCR for the expression of miR196a2 and HOXC8 gene. We could not find any association between rs11614913 polymorphism and glioma risk in Indian population. The rs11614913 genotyping of glioma tissue and blood pair revealed presence of mutations showing changes from C to T allele in majority of samples. The expression of the mature miR196a2 was significantly high in glioma samples, but there was no difference in expression with genotype. HOXC8 gene expression was not significantly different in glioma tissue when compared to non-glioma and interestingly there was a significant difference in expression with different genotypes, especially TT genotype was showing over expression when compared to other genotypes. Our study suggests that the rs11614913 polymorphism does not affect the mature miRNA expression, but shows its effect through target gene HOXC8 expression in glioma.