HOXC6 Research Articles

Supt20 is required for development of the axial skeleton

Somitogenesis and subsequent axial skeletal development is regulated by the interaction of pathways that determine the periodicity of somite formation, rostrocaudal somite polarity and segment identity. Here we use a hypomorphic mutant mouse line to demonstrate that Supt20 (Suppressor of Ty20) is required for development of the axial skeleton. Supt20 hypomorphs display fusions of the ribs and vertebrae at lower thoracic levels along with anterior homeotic transformation of L1 to T14. These defects are preceded by reduction of the rostral somite and posterior shifts in Hox gene expression. While cycling of Notch target genes in the posterior presomitic mesoderm (PSM) appeared normal, expression of Lfng was reduced. In the anterior PSM, Mesp2 expression levels and cycling were unaffected; yet, expression of downstream targets such as Lfng, Ripply2, Mesp1 and Dll3 in the prospective rostral somite was reduced accompanied by expansion of caudal somite markers such as EphrinB2 and Hes7. Supt20 interacts with the Gcn5-containing SAGA histone acetylation complex. Gcn5 hypomorphic mutant embryos show similar defects in axial skeletal development preceded by posterior shift of Hoxc8 and Hoxc9 gene expression. We demonstrate that Gcn5 and Supt20 hypomorphs show similar defects in rostral-caudal somite patterning potentially suggesting shared mechanisms.

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.

Development of a real-time PCR system for the detection of the potential allergen fish in food

Fish is one of the most important triggers of food-allergic reactions. Regulation (EU) No 1169/2011 governs the labelling of allergenic ingredients including fish. A real-time PCR assay, using TaqMan® probes, was applied to detect fish in food. For generating primer and probes, the Hoxc13 gene was selected. Based on the alignment of available DNA sequences from this gene from different fish species in public nucleic acid database, specific oligonucleotides were generated. To cover all relevant species of the phylogenetic class fish, the CTfish-system consists of two forward primers, three reverse primers and one TaqMan® probe. The real-time PCR method is able to detect specifically fish species belonging to the subclass Teleostei. The sensitivity is in an animal food product 100 mg/kg and in a vegetable food matrix 10 mg/kg relating to the fresh weight. The calculated limit of detection (LOD95 %) of fish DNA in background DNA is 2.5 copies. The method developed is robust against small, deliberate changes in the reaction conditions. The CTfish-system can be used to sensitively and selectively identify the presence of fish DNA in food.

HOX genes: potential candidates for the progression of laryngeal squamous cell carcinoma.

Laryngeal squamous cell carcinoma (LSCC) is a very aggressive cancer, considered to be a subtype of the head and neck squamous cell carcinoma (HNSCC). Despite significant advances in the understanding and treatment of cancer, prognosis of patients with LSCC has not improved recently. In the present study, we sought to understand better the genetic mechanisms underlying LSCC development. Thirty-two tumor samples were collected from patients undergoing surgical resection of LSCC. The samples were submitted to whole-genome cDNA microarray analysis aiming to identify genetic targets in LSCC. We also employed bioinformatic approaches to expand our findings using the TCGA database and further performed functional assays, using human HNSCC cell lines, to evaluate viability, cell proliferation, and cell migration after silencing of selected genes. Eight members of the homeobox gene family (HOX) were identified to be overexpressed in LSCC samples when compared to normal larynx tissue. Quantitative RT-PCR analysis validated the overexpression of HOX gene family members in LSCC. Receiver operating characteristic (ROC) statistical method curve showed that the expression level of seven members of HOX gene family can distinguish tumor from nontumor tissue. Correlation analysis of clinical and gene expression data revealed that HOXC8 and HOXD11 genes were associated with the differentiation degree of tumors and regional lymph node metastases, respectively. Additionally, siRNA assays confirmed that HOXC8, HOXD10, and HOXD11 genes might be critical for cell colony proliferation and cell migration. According to our findings, several members of the HOX genes were overexpressed in LSCC samples and seem to be required in biological processes involved in tumor development. This suggests that HOX genes might play a critical role in the physiopathology of LSCC tumors.

Homeobox family Hoxc localization during murine palate formation.

Homeobox genes play important roles in craniofacial morphogenesis. However, the characteristics of the transcription factor Hoxc during palate formation remain unclear. We examined the immunolocalization patterns of Hoxc5, Hoxc4, and Hoxc6 in palatogenesis of cleft palate (Eh/Eh) mice. On the other hand, mutations in the FGF/FGFR pathway are exclusively associated with syndromic forms of cleft palate. We also examined the immunolocalization of Fgfr1 and Erk1/2 to clarify their relationships with Hoxc in palatogenesis. Some palatal epithelial cells showed Hoxc5 labeling, while almost no labeling of mesenchymal cells was observed in +/+ mice. As palate formation progressed in +/+ mice, Hoxc5, Hoxc4, and Hoxc6 were observed in medial epithelial seam cells. Hoxc5 and Hoxc6 were detected in the oral epithelium. The palatal mesenchyme also showed intense staining for Fgfr1 and Erk1/2 with progression of palate formation. In contrast, the palatal shelves of Eh/Eh mice exhibited impaired horizontal growth and failed to fuse, resulting in a cleft. Hoxc5 was observed in a few epithelial cells and diffusely in the mesenchyme of Eh/Eh palatal shelves. No or little labeling of Fgfr1 and Erk1/2 was detected in the cleft palate of Eh/Eh mice. These findings suggest that Hoxc genes are involved in palatogenesis. Furthermore, there may be the differences in the localization pattern between Hoxc5, Hoxc4, and Hoxc6. Additionally, Hoxc distribution in palatal cells during palate development may be correlated with FGF signaling. (228/250 words) © 2016 Japanese Teratology Society.

Expression and role of HOXC gene in tumor

As a member of homeobox gene family, HOXC is expressed in many organs and can regulate gene expression, cell differentiation and morphogenesis. Abnormality of its function is closely related to the prognosis of leukemia, breast cancer, renal cell carcinoma, prostate cancer and so on. Key words: Neoplasms; Genes, homeobox; HOXC

CTCF-mediated Chromatin Loop for the Posterior Hoxc Gene Expression in MEF Cells.

Modulation of chromatin structure has been proposed as a molecular mechanism underlying the spatiotemporal collinear expression of Hox genes during development. CCCTC-binding factor (CTCF)-mediated chromatin organization is now recognized as a crucial epigenetic mechanism for transcriptional regulation. Thus, we examined whether CTCF-mediated chromosomal conformation is involved in Hoxc gene expression by comparing wild-type mouse embryonic fibroblast (MEF) cells expressing anterior Hoxc genes with Akt1 null MEFs expressing anterior as well as posterior Hoxc genes. We found that CTCF binding between Hoxc11 and -c12 is important for CTCF-mediated chromosomal loop formation and concomitant posterior Hoxc gene expression. Hypomethylation at this site increased CTCF binding and recapitulated the chromosomal conformation and posterior Hoxc gene expression patterns observed in Akt1 null MEFs. From this work we found that CTCF at the C12|11 does not function as a barrier/boundary, instead let the posterior Hoxc genes switch their interaction from inactive centromeric to active telomeric genomic niche, and concomitant posterior Hoxc gene expression. Although it is not clear whether CTCF affects Hoxc gene expression solely through its looping activity, CTCF-mediated chromatin structural modulation could be an another tier of Hox gene regulation during development. © 2016 IUBMB Life, 68(6):436-444, 2016.

Abstract A39: Epigenetic upregulation of lncRNA HOTAIR expression in three-dimensional culture of triple-negative breast cancer cells

Abstract lncRNA HOX transcript antisense RNA (HOTAIR) represses gene expression via recruitment of the chromatin modifying complex polycomb repressive complex 2 (PRC2) and its overexpression mediates invasion and metastasis in breast cancer. In an apparent paradox we observed silencing of HOTAIR expression in MDA-MB231 cells, an invasive and metastatic triple-negative breast cancer cell line in two dimensional monolayer culture (2-D). This observation prompted us to question limitations of 2-D culture as a model system to investigate the role of HOTAIR in breast cancer. Thus we examined HOTAIR expression in reconstituted basement membrane matrix Matrigel-based three dimensional organotypic culture (rBM 3-D) because MDA-MB231 cells undergo stellate morphogenesis, a phenomenon that is characteristic of invasive cancer cells. In MDA-MB231 cells HOTAIR expression in rBM 3-D culture and the grafted tumors exhibited ~130-fold and ~60-fold over than that in 2-D culture, respectively. Induction of HOTAIR in rBM 3-D culture involved transcription from an uncharacterized promoter located in the 1st intron of the HOXC11 gene. However HOXC11 did not exhibit difference in its expression between 2-D and rBM 3-D cultures. Induction of HOTAIR in rBM 3-D culture was congruent to a wide spread increase in expression of the protein coding HOX genes. Moreover stellate morphogenesis was abrogated by the HOTAIR-specific siRNA and replaced by mass morphogenesis that is characteristic of non-invasive cells. To validate induction of HOTAIR as a response to extracellular matrix (ECM), we knocked down a major ECM receptor integrin α2 using lentiviral vectors expressing integrin α2-specific shRNA. As expected knockdown of integrin α2 resulted in a substantial decrease of HOTAIR expression. Because the HOX genes are tightly regulated by CpG methylation, we compared CpG methylation of the promoters of HOTAIR and HOXA9 in 2-D and rBM 3-D cultures. Indeed the promoters of HOTAIR and HOXA9 exhibited lower CpG methylation in rBM 3-D culture than that in 2-D culture. Moreover 5-Azacytidinewe up-regulated the expression of HOTAIR and HOXA9 in 2-D culture of MDA-mb231 cells. Moreover induction of HOTAIR was associated with increased binding of BRD4 to the HOTAIR promoter region located in the HOXC11 1st intron. The BRD4-specific siRNA substantially reduced the expression of HOTAIR in rBM 3-D culture. Taken together our findings suggest that ECM up-regulate the expression of HOTAIR via reduced CpG methylation and increased BRD4 binding in a human triple-negative breast cancer cell line. Note: This abstract was not presented at the conference. Citation Format: Miao Li, Xi Li, Bin Shan. Epigenetic upregulation of lncRNA HOTAIR expression in three-dimensional culture of triple-negative breast cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Noncoding RNAs and Cancer: Mechanisms to Medicines ; 2015 Dec 4-7; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2016;76(6 Suppl):Abstract nr A39.

Fat accumulation in differentiated brown adipocytes is linked with expression of Hox genes

Homeobox (Hox) genes are involved in body plan of embryo along the anterior–posterior axis. Presence of several Hox genes in white adipose tissue (WAT) and brown adipose tissue (BAT) is indicative of involvement of Hox genes in adipogenesis. We propose that differentiation inducing agents viz. isobutyl-methyl-xanthine (IBMX), indomethacin, dexamethasone (DEX), triiodothyronine (T3) and insulin may regulate differentiation in brown adipose tissue through Hox genes. In vitro culture of brown fat stromalvascular fraction (SVF) in presence or absence of differentiation inducing agents was used for establishing relationship between fat accumulation in differentiated adipocytes and expression of Hox genes. Relative expression of Pref1, UCP1 and Hox genes was determined in different stages of adipogenesis. Presence or absence of IBMX, indomethacin and DEX during differentiation of proliferated pre-adipocytes resulted in marked differences in expression of Hox genes and lipid accumulation. In presence of these inducing agents, lipid accumulation as well as expression of HoxA1, HoxA5, HoxC4 &HoxC8 markedly enhanced. Irrespective of presence or absence of T3, insulin down regulates HoxA10. T3 results in over expression of HoxA5, HoxC4 and HoxC8 genes, whereas insulin up regulates expression of only HoxC8. Findings suggest that accumulation of fat in differentiated adipocytes is linked with expression of Hox genes.

Deletions of 5′ HOXC genes are associated with lower extremity malformations, including clubfoot and vertical talus

BackgroundDeletions of the HOXC gene cluster result in variable phenotypes in mice, but have been rarely described in humans.ObjectiveTo report chromosome 12q13.13 microdeletions ranging from 13 to 175 kb and...

Reprogramming of Polycomb-Mediated Gene Silencing in Embryonic Stem Cells by the miR-290 Family and the Methyltransferase Ash1l

SummaryMembers of the miR-290 family are the most abundantly expressed microRNAs (miRNAs) in mouse embryonic stem cells (ESCs). They regulate aspects of differentiation, pluripotency, and proliferation of ESCs, but the molecular program that they control has not been fully delineated. In the absence of Dicer, ESCs fail to express mature miR-290 miRNAs and have selective aberrant overexpression of Hoxa, Hoxb, Hoxc, and Hoxd genes essential for body plan patterning during embryogenesis, but they do not undergo a full differentiation program. Introduction of mature miR-291 into DCR−/− ESCs restores Hox gene silencing. This was attributed to the unexpected regulation of Polycomb-mediated gene targeting by miR-291. We identified the methyltransferase Ash1l as a pivotal target of miR-291 mediating this effect. Collectively, our data shed light on the role of Dicer in ESC homeostasis by revealing a facet of molecular regulation by the miR-290 family.

The Hox cluster microRNA miR-615: a case study of intronic microRNA evolution.

BackgroundIntrons represent a potentially rich source of existing transcription for the evolution of novel microRNAs (miRNAs). Within the Hox gene clusters, a miRNA gene, miR-615, is located within the intron of the Hoxc5 gene. This miRNA has a restricted phylogenetic distribution, providing an opportunity to examine the origin and evolution of a new miRNA within the intron of a developmentally-important homeobox gene.ResultsAlignment and structural analyses show that the sequence is highly conserved across eutherian mammals and absent in non-mammalian tetrapods. Marsupials possess a similar sequence which we predict will not be efficiently processed as a miRNA. Our analyses suggest that transcription of HOXC5 in humans is accompanied by expression of miR-615 in all cases, but that the miRNA can also be transcribed independently of its host gene through the use of an intragenic promoter. We present scenarios for the evolution of miR-615 through intronic exaptation, and speculate on the acquisition of independent transcriptional regulation. Target prediction and transcriptomic analyses suggest that the dominant product of miR-615 is involved in the regulation of growth and a range of developmental processes.ConclusionsThe miR-615 gene evolved within the intron of Hoxc5 in the ancestor of placental mammals. Using miR-615 as a case study, we propose a model by which a functional miRNA can emerge within an intron gradually, by selection on secondary structure followed by evolution of an independent miRNA promoter. The location within a Hox gene intron is of particular interest as the miRNA is specific to placental mammals, is co-expressed with its host gene and may share complementary functions.Electronic supplementary materialThe online version of this article (doi:10.1186/s13227-015-0027-1) contains supplementary material, which is available to authorized users.

Analysis of gastric cancer tissues genome methylation by DNA methylation chip

To detect the methylation status of gastric cancer tissue genome by DNA methylation chip. Methylation status of 6 samples of gastric cancer tissues and their matched adjacent tissues was analyzed using methylated DNA immunoprecipitation(MeDIP) combined with NibleGen chip. Significantly different methylated genes in promoter region and CpG island between two tissues were searched. Functions of these significantly different methylated genes were analyzed by Gene Ontology and Pathway assays. In gene promoter regions, 113 significantly different methylated genes were identified in gastric cancer tissues, such as SHP1, FGF8 and CSF2RA, while 161 significantly different methylated genes were identified in their matched adjacent tissues, such as TNF, IGF2 and BMP7. In the CpG islands, 123 significantly different methylated genes were identified in gastric cancer tissues, such as WNT2B, JAK2 and TPT1, while 139 significantly different methylated genes were identified in their matched adjacent tissues, such as TNFRSF4, HOXC8 and NFYA. These genes located on different chromosomes. In gastric cancer tissues, the 1st and the 4th chromosomes had the most (both 11), the 18th and the 20th chromosomes had the least(both 1). In matched adjacent normal tissues, the 11th chromosome had the most (17), and no significantly different methylated gene was found on Y chromosome. These genes involved in many functions, such as protein phosphorylation, regulating cellular catabolism, ion transport, enzyme activity, transcriptional regulation, cell division, cell cycle regulation, and signal transduction. There are significant differences between gastric cancer tissues and their matched adjacent tissues in DNA methylation. DNA methylation genes locate on different chromosomes, and their number and distribution vary widely. These genes may be associated with many pathways in carcinogenesis.

Abstract 1993: Global correlation analysis of HOXC6 expression in ovarian cancer

Abstract Introduction: HOXC6 is a member of the HOX gene family known to be dysregulated in many cancers. We previously reported gene and protein down-regulation of HOXC6 in ovarian cancer tissue and serum of high-grade serous carcinoma patients. This study evaluates the relationship of the HOXC6 gene expression with other genes from transcriptional microarray analysis of 92 ovarian tissues. Methods: Transcriptional microarray data from ovarian tissue was analyzed from 67 whole tissue samples and 25 micro-dissected samples. The 25 samples consisted of 9 malignant tumor tissues, 9 normal epithelia (NE) tissues and 7 Benign Tumor tissues. Genes with significant direct or reverse correlations to HOXC6 were initially identified from the 67-sample set (FDR < 0.05). Correlated genes identified in the 67-sample set were then reanalyzed to reconfirm their significance against the HOXC6 in 25-sample set (FDR < 0.05). To verify validity of correlations in cancer, expression values of genes in this second group were compared between NE and malignant samples using ANOVA (FDR < 0.05). This analysis pipeline identified 116 genes, which were characterized by STRING-DB 9.1 for protein-protein interactions and GO enrichment analysis. 65 of the 116 genes with a fold change (FC) magnitude > 2.0 were used in unsupervised hierarchical clustering against both NE and malignant samples. Results: The absolute values of correlation coefficients (|r|) in 116 significant genes ranged from 0.43-0.81; 33 had (|r|) > 0.70, and 65 had |FC| > 2.0. Of note because of their known association to ovarian cancer, this analysis revealed PBX3, MAL2, TPD52, ZEB2, PTTG1, KLK7, and KLK8. GO enrichment analysis identified developmental process (36 genes), cell differentiation (34), anatomical structure development (36), and regulation of signaling (27) consistent with HOXC6 known functions (FDR < 0.05). Protein-protein interaction networks revealed SMAD3 to be the central node with the largest cluster of connectivity linked to other HOXC6 correlated genes including PAX8, ZEB2 and UCHL5. Unsupervised hierarchical clustering analysis clearly distinguished between NE obtained from non-tumorous and NE obtained from tumorous tissues. Discussion: Overall this analysis demonstrates a strong correlation between HOXC6 expression in ovarian tissue and multiple developmental genes. The hierarchical clustering results may indicate that effects of the reported genes are not limited to the tumor tissue and can be traced back to normal epithelial cells. Therefore, future study of large sample sets of micro-dissected malignant and nearby normal epithelia – to identify underlying developmental pathways in ovarian cancer – will increase understanding of growth mechanisms of ovarian tumors and their interaction with normal cells in the microenvironment. Our previous work along with these new findings could potentially be used for future study of identifying ovarian cancer specific biomarkers. Citation Format: Pourya Naderi Yeganeh, Zahra Bahrani-Mostafavi, Christine Richardson, David L. Tait, M. Taghi Mostafavi. Global correlation analysis of HOXC6 expression in ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1993. doi:10.1158/1538-7445.AM2015-1993

F9 EC 세포에서 레티노산에 의해 유도되는 Hoxc 유전자의 발현에 히스톤 메틸화가 미치는 영향

Department of Anatomy, Embryology Laboratory, Brain Korea 21 Pl us project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, KoreaReceived December 1, 2014/Revised March 11, 2015/Accepted March 12, 2015Hox genes encode a highly conserved family of homeodomain-containing transcription factors control-ling vertebrate pattern formation along the anteroposterior body axis during embryogenesis. Retinoic acid (RA) is a key morphogen in embryogenesis and a critical regulator of both adult and embryonic cellular activity. Specifically, RA regulates Hox gene expression in mouse- or human-derived embry-onic carcinoma (EC) cells. Histone modification has been reported to play a pivotal role in the process of RA-induced gene expression and cell differentiation. As histone modification is thought to play an essential role in RA-induced Hox gene expression, we examined RA-induced initiation of collinear ex-pression of Hox genes and the corresponding histone modifications in F9 murine embryonic ter-atocarcinoma (EC) cells. Hox expression patterns and histone modifications were analyzed by semi- quantitative RT-PCR, RNA-sequencing, and chromatin immuno-precipitation (ChIP)-PCR analyses. The Hoxc4 gene (D0) was initiated earlier than the Hoxc5 to –c10 genes (D3) upon RA treatment (day 0 [D0], day 1 [D1], and day 3 [D3]). The Hox nonexpressing D0 sample had a strong repressive marker, H3K27me3, than the D1 and D3 samples. In the D1 and D3 samples, reduced enrichment of the H3K27me3 marker was observed in the whole cluster. The active H3K4me3 marker was closely asso-ciated with the collinear expression of Hoxc genes. Thus, the Hoxc4 gene (D1) and all Hoxc genes (D3) expressed H3K4me3 upon transcription activation. In conclusion, these data indicated that removing H3K27me3 and acquiring H3K4me3 regulated RA-induced Hoxc gene collinearity in F9 cells. Keywords :

Transcriptomic profiling comparison of YAP over-expression and conditional knockout mouse tooth germs.

To identify the downstream target genes of YAP, we used RNA-Seq technology to compare the transcriptomic profilings of Yap conditional knockout (Yap CKO) and YAP over-expression mouse tooth germs. Our results showed that some Hox, Wnt and Laminin family genes had concurrent changes with YAP transcripts, indicating that the expression of these genes may be regulated by YAP. Here, we provide the detailed experimental procedure for the transcriptomic profiling results (NCBI GEO accession number GSE65524). The associated study on the regulation of Hoxa1 and Hoxc13 genes by YAP was published in Molecular Cellular Biology in 2015 [Liu et al., 2015].

Prognostic role of HOTAIR in four estrogen-dependent malignant tumors: a meta-analysis

BackgroundHOX transcript antisense intergenic RNA (HOTAIR), a long non-coding RNA transcribed from the antisense strand of the HOXC gene locus, has been shown to be overexpressed in various carcinomas and is thought to be an indicator of poor prognosis. Recently, HOTAIR was found to be an estrogen-responsive gene. We therefore conducted a meta-analysis to systematically summarize and clarify the association between HOTAIR expression and prognosis in the four main estrogen-dependent tumors.MethodsA systematic search of studies that examined the association and prognostic impact of HOTAIR in four of the main estrogen-dependent tumors was conducted in PubMed and Embase. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated to pool the effect size.ResultsA total of 1,200 patients from eight eligible studies were included. The current study found an association between HOTAIR expression and overall survival (OS) in four estrogen-dependent tumor types (HR, 1.99; 95% CI: 1.02–3.90; PHeterogeneity=0.001). Subgroup analyses indicated that high HOTAIR expression appeared to be a potential prognostic biomarker in non-breast cancer patients (HR, 2.72; 95% CI: 1.65–4.48). There was also an increased risk in Asian populations (HR, 2.55; 95% CI: 1.62–4.00) compared with Caucasian populations (HR, 1.19; 95% CI: 0.16–8.83) and in patients without preoperative treatment (HR, 2.55; 95% CI: 1.62–4.00) compared with patients with preoperative treatment (HR, 1.19; 95% CI: 0.16–8.83). In addition, the HRs of patients with high HOTAIR expression for metastasis-free survival (MFS), relapse-free survival (RFS), and disease-free survival (DFS) were 2.30 (P=0.120), 1.39 (P=0.000), and 2.53 (P=0.714), respectively, but there were insufficient data to fully confirm these associations.ConclusionHOTAIR may be a predictor of poor prognosis in four of the main estrogen-dependent tumors, especially in cervical, ovarian, and endometrial cancer patients without preoperative treatment in Asian populations. It is important to note that the prognostic value of HOTAIR in MFS, RFS, and DFS should be interpreted with caution due to the limited sample size and sample heterogeneity. Well-designed and larger-scale studies are needed to validate our findings.

Transcriptional Dynamics of Homeobox C11 Gene in Water Buffalo Bubalus bubalis

The Hox complex contains 39 genes clustered into four groups involved in cell differentiation and development. We cloned full-length sequence of Hoxc11 gene from water buffalo Bubalus bubalis, assessed its copy number, localized the same onto the chromosome 5, and studied its evolutionary conservation across the species. Northern hybridization of Hoxc11 showed a 2.2 kb band in the tissues analyzed. Real-Time PCR showed highest expression of Hoxc11 gene in lung followed by spleen, spermatozoa, and testis. Six interacting partners of this gene showed higher expression in spleen, lung, testis, and spermatozoa. During the early stages of development, Hoxc11 and its interacting partners both showed lower expression, which then became prominent during the age of 1-3 years, regressed drastically thereafter, and remained so until the animal's life time (∼ 20 years). The high expression of Hoxc11 and its interacting partners in spermatozoa and testis during the onset of puberty suggests its likely role in the differentiation of gonads and subsequent reproductive activities. Additional work on Hoxc11 especially, in the context of respiratory, immunological, and in/fertility in other species, including humans would be useful for establishing its broader biological significance towards the enrichment of functional and comparative genomics.

Preliminary screening of differentially expressed genes involved in methyl-CpG-binding protein 2 gene-mediated proliferation in human osteosarcoma cells.

Methyl-CpG-binding protein 2 (MeCP2) is essential in human brain development and has been linked to several cancer types and neuro-developmental disorders. This study aims to screen the MeCP2 related differentially expressed genes and discover the therapeutic targets for osteosarcoma. CCK8 assay was used to detect the proliferation and SaOS2 and U2OS cells. Apoptosis of cells was detected by flow cytometry analysis that monitored Annexin V-APC/7-DD binding and 7-ADD uptake simultaneously. Denaturing formaldehyde agarose gel electrophoresis was employed to examine the quality of total RNA 18S and 28S units. Gene chip technique was utilized to discover the differentially expressed genes correlated with MeCP2 gene. Differential gene screening criteria were used to screen the changed genes. The gene up-regulation or down-regulation more than 1.5 times was regarded as significant differential expression genes. The CCK8 results indicated that the cell proliferation of MeCP2 silencing cells (LV-MeCP2-RNAi) was significantly decreased compared to non-silenced cells (LV-MeCP2-RNAi-CN) (P < 0.05). MeCP2 silencing could also induce significant apoptosis compared to non-silenced cells (P < 0.05); 107 expression changed genes were screened from a total of 49,395 transcripts. Among the total 107 transcripts, 34 transcripts were up-regulated and 73 transcripts were down-regulated. There were five significant differentially expressed genes, including IGFBP4, HOXC8, LMO4, MDK, and CTGF, which correlated with the MeCP2 gene. The methylation frequency of CpG in IGFBP4 gene could achieve 55%. In conclusion, the differentially expressed IGFBP4, HOXC8, LMO4, MDK, and CTGF genes may be involved in MeCP2 gene-mediated proliferation and apoptosis in osteosarcoma cells.

HOX genes and their role in the development of human cancers.

In this review, we summarize published findings on the involvement of HOX genes in oncogenesis. HOX genes are developmental genes--they code for proteins that function as critical master regulatory transcription factors during embryogenesis. Many reports have shown that the protein products of HOX genes also play key roles in the development of cancers. Based on our review of the literature, we found that the expression of HOX genes is not only up- or downregulated in most solid tumors but also that the expression of specific HOX genes in cancers tends to differ based on tissue type and tumor site. It was also observed that HOXC family gene expression is upregulated in most solid tumor types, including colon, lung, and prostate cancer. The two HOX genes that were reported to be most commonly altered in solid tumors were HOXA9 and HOXB13. HOXA were often reported to have altered expression in breast and ovarian cancers, HOXB genes in colon cancers, HOXC genes in prostate and lung cancers, and HOXD genes in colon and breast cancers. It was found that HOX genes are also regulated at the nuclear-cytoplasmic transport level in carcinomas. Tumors arising from tissue having similar embryonic origin (endodermal), including colon, prostate, and lung, showed relatively similar HOXA and HOXB family gene expression patterns compared to breast tumors arising from mammary tissue, which originates from the ectoderm. The differential expression of HOX genes in various solid tumors thus provides an opportunity to advance our understanding of cancer development and to develop new therapeutic agents.