Sequential gene expression analysis of myelodysplastic syndrome transformation identifies HOXB3 and HOXB7 as the novel targets for mesenchymal cells in disease

BACKGROUND

Myelodysplastic syndrome (MDS) is known to arise through the pathogenic bone marrow mesenchymal stem cells (MSC) by interacting with hematopoietic stem cells (HSC). However, due to the strong heterogeneity of MDS patients, it is difficult to find common targets in studies with limited sample sizes. This study aimed to describe sequential molecular changes and identify biomarkers in MSC of MDS transformation.

METHODS

Multidimensional data from three publicly available microarray and TCGA datasets were analyzed. MDS-MSC was further isolated and cultured in vitro to determine the potential diagnostic and prognostic value of the identified biomarkers.

RESULTS

We demonstrated that normal MSCs presented greater molecular homogeneity than MDS-MSC. Biological process (embryonic skeletal system morphogenesis and angiogenesis) and pathways (p53 and MAPK) were enriched according to the differential gene expression. Furthermore, we identified HOXB3 and HOXB7 as potential causative genes gradually upregulated during the normal-MDS-AML transition. Blocking the HOXB3 and HOXB7 in MSCs could enhance the cell proliferation and differentiation, inhibit cell apoptosis and restore the function that supports hematopoietic differentiation in HSCs.

CONCLUSION

Our comprehensive study of gene expression profiling has identified dysregulated genes and biological processes in MSCs during MDS. HOXB3 and HOXB7 are proposed as novel surrogate targets for therapeutic and diagnostic applications in MDS.

HOXB3 promotes trophoblast cell proliferation, invasion, and migration to alleviate preeclampsia via mediating the Notch/Wnt/β-catenin pathway

Preeclampsia (PE) harms a significant number of pregnant women and fetuses. However, because of its complex pathological mechanisms, there is no cure except for delivery. This study identified the impact and mechanisms of action of HOXB3 in PE. The behaviors of HTR-8/SVneo cells were analyzed using a cell counting kit-8, EdU, and transwell assays. The interaction between HOXB3 and Notch1 was assessed using a luciferase reporter and chromatin immunoprecipitation assays. Expression was measured by quantitative real-time polymerase chain reaction, western blotting, and immunofluorescence assays. Additionally, the function of HOXB3 was evaluated in an established rat model of PE. We found that HOXB3 was upregulated in PE. HOXB3 overexpression facilitated trophoblast cell proliferation, migration, and invasion. HOXB3 transcriptionally regulated Notch1 by binding to its promoter. Notch1 knockdown abrogated the functions of HOXB3 and the-catenin pathway in trophoblasts. Suppression of the Wnt/β-catenin pathway abrogated the effects of HOXB3. Additionally, HOXB3 alleviated the symptoms in PE rats. In conclusion, HOXB3 transcriptionally activated Notch1 expression and the-catenin pathway, promoting trophoblast cell proliferation, invasion, and migration, thereby alleviating PE progression. This study provides a novel approach for PE therapy.

High expression of HOXB3 predicts poor prognosis and correlates with tumor immunity in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD) is one of the most prevalent human cancers worldwide. The homeobox-B (HOXB) gene cluster has been reported to contribute to cancer development. Nevertheless, the expression status, clinical significance and biological role of HOXB genes in LUAD remain largely unclear.

METHODS AND RESULTS

This study comprehensively investigated the transcriptional levels and prognostic values of the HOXB genes in LUAD based on The Cancer Genome Atlas (TCGA) database. Flow cytometry, CCK-8, and Transwell assays were used for detecting apoptosis, proliferation, and migration, respectively. We discovered that eight members of the HOXB cluster genes (HOXB2, HOXB3, HOXB4, HOXB6, HOXB7, HOXB8, HOXB9, and HOXB13) were dysregulated in LUAD tumor tissues. Increased expression of HOXB3, HOXB6, HOXB7, HOXB8, or HOXB9 was independently associated with unsatisfactory overall survival (OS) in LUAD patients. In addition, a high level of HOXB3 also predicted poor patient relapse-free survival (RFS), suggesting that HOXB3 may play a vital role in the progression of LUAD compared to other members of the HOXB cluster. Additionally, further analysis by TIMER and TISIDB algorithms revealed that HOXB3 was positively correlated with a panel of immune checkpoint molecules (ICMs), tumor-infiltrating lymphocytes (TILs), and tumor immune regulators (TIRs). Gene enrichment analysis based on KEGG showed that HOXB3 was closely associated with multiple tumor-related biological processes and signaling pathways. Functionally, the in vitro experiments revealed that depletion of HOXB3 significantly alleviated the resistance of LUAD cells to apoptosis, and suppressed cell proliferation and migration.

CONCLUSION

Our study suggests that HOXB3 may play an oncogenic role in LUAD and correlate with tumor immunity.

Long non-coding RNA LINC00514 promotes the proliferation and invasion through the miR-708-5p/HOXB3 axis in cervical squamous cell carcinoma

Long non-coding RNA (lncRNA) LINC00514 is a cancer-related lncRNA that has been proven to be implicated in the progression of several cancers. However, the biological function of LINC00514 in cervical squamous cell carcinoma (CSCC) remains unclear. Thus, we aimed to identify the LINC00514 expression profile in CSCC and determine its exact mechanism. Our results showed that the expression of LINC00514 was up-regulated in human CSCC tissues and cell lines. Knockdown of LINC00514 significantly inhibited the proliferation and invasion of CSCC cells, as well as suppressed tumorigenesis of CSCC in vivo. In addition, LINC00514 was found to work as a miRNA sponge for miR-708-5p and suppressed the expression of miR-708-5p in CSCC cells. Homeobox B3 (HOXB3) was found to be a target gene of miR-708-5p. Rescue assays demonstrated that miR-708-5p inhibitor attenuated the effects of LINC00514 knockdown on cell proliferation and invasion in CSCC cells. In addition, overexpression of HOXB3 reversed the inhibitory effects of miR-708-5p mimics on cell proliferation and invasion. Taken together, our findings for the first time elucidated that lncRNA LINC00514 promotes the proliferation and invasion through the miR-708-5p/HOXB3 axis in CSCC. Thus, LINC00514/miR-708-5p/HOXB3 axis might be a promising therapeutic target for the treatment of CSCC.

Evaluating the Expression of Candidate Homeobox Genes and Their Role in Local-Site Inflammation in Mucosal Tissue Obtained from Children with Non-Syndromic Cleft Lip and Palate

Craniofacial development including palatogenesis is a complex process which requires an orchestrated and spatiotemporal expression of various genes and factors for proper embryogenesis and organogenesis. One such group of genes essential for craniofacial development is the homeobox genes, transcriptional factors that are commonly associated with congenital abnormalities. Amongst these genes, DLX4, HOXB3, and MSX2 have been recently shown to be involved in the etiology of non-syndromic cleft lip and palate. Hence, we investigated the gene and protein expression of these genes in normal and cleft affected mucosal tissue obtained from 22 children, along with analyzing their role in promoting local-site inflammation using NF-κB. Additionally, we investigated the role of PTX3, which plays a critical role in tissue remodeling and wound repair. We found a residual gene and protein expression of DLX4 in cleft mucosa, although no differences in gene expression levels of HOXB3 and MSX2 were noted. However, a significant increase in protein expression for these genes was noted in the cleft mucosa (p < 0.05), indicating increased cellular proliferation. This was coupled with a significant increase in NF-κB protein expression in cleft mucosa (p < 0.05), highlighting the role of these genes in promotion of pro-inflammatory environment. Finally, no differences in gene expression of PTX3 were noted.

Loss of HOXB3 correlates with the development of hormone receptor negative breast cancer

Background

The homeobox gene family, encoding a specific nuclear protein, is essential for embryonic development, differentiation, and homeostasis. The role of the HOXB3 protein varies in different tumors. This study aims to explore the role of the HOXB3 gene in breast cancer.

Method

Differentially expressed genes were screened by analyzing metastatic breast cancer gene chip data from TCGA and GEO databases. The function of the selected HOXB3 gene was also analyzed in different databases and through molecular biology methods, such as qRT-PCR, western blot and IF to verify bioinformatics findings.

Results

Both bioinformatics analyses and western blot showed that HOXB3 was lost in breast cancer compared to normal breast tissue. Survival analysis also showed that lower expression of HOXB3 was associated with poor prognosis. Bioinformatics analyses further showed that HOXB3 was positively correlated with hormone receptors. Metascape for GO analysis of GEO data provided possible mechanisms that HOXB3 could positively regulate cell adhesion, inhibit cell proliferation and activate immune response in breast cancer; moreover, GSEA included several cancer-associated pathways.

Conclusion

In summary, HOXB3 expression was decreased in breast cancer, and it was associated with poor prognosis. It might become a new biomarker to predict prognosis of breast cancer.

HOXB-AS1 accelerates the tumorigenesis of glioblastoma via modulation of HOBX2 and HOBX3 at transcriptional and posttranscriptional levels

Glioblastoma (GBM) is the most universal and invasive brain tumor among adults. Increasing studies have reported that long noncoding RNAs play vital roles in regulating downstream molecules at the transcriptional or posttranscriptional level in tumor progression. The purpose of the current research was to inquire the modulation mechanism by which homeobox B cluster antisense RNA 1 (HOXB-AS1) functioned in GBM. Our study first discovered the lifted expression of HOXB-AS1 and its nearby genes HOXB2 and HOXB3 in GBM and the positive relationship between HOXB-AS1 and HOXB2 or HOXB3. Loss-of-function assays and in vivo study detected that silencing of HOXB-AS1, HOXB2, or HOXB3 restrained the proliferation and induced the apoptosis in GBM. In addition, mechanism experiments demonstrated that HOXB-AS1 recruited interleukin enhancer-binding factor 3 (ILF3) to regulate HOXB2 and HOXB3 expression at the transcriptional level, and HOXB-AS1 sponged miR-186-5p to modulate HOXB2 and HOXB3 expression at posttranscriptional level. Finally, the regulatory mechanism of HOXB-AS1 in GBM was certified through rescue experiments. Our results indicated that HOXB-AS1 boost the HOXB2 or HOXB3 expression at the transcriptional and posttranscriptional levels. We detected the HOXB-AS1-ILF3-HOXB2/HOXB3 axis and HOXB-AS1-miR-186-5p-HOXB2/HOXB3 axis driving the GBM progression, which might generate more effective diagnostic biomarkers and therapeutic targets for patients with GBM.

LncRNA-UCA1 modulates progression of colon cancer through regulating the miR-28-5p/HOXB3 axis

Emerging evidence has shown that the long noncoding RNA urothelial carcinoma-associated 1 (UCA1) plays a tumor-promoting role in colorectal cancer, while miR-28-5p shows tumor-inhibitory activity in several tumor types. However, the mechanisms both of these in colon cancer progression are still unknown. In this work, the detailed roles and mechanisms of UCA1 and its target genes in colon cancer were studied. The results showed that UCA1 was upregulated in colon cancer tissues when compared with the adjacent nonhumorous tissues, as well as in the various colon cancer cell lines, but the expression of miR-28-5p showed an opposite trend. Furthermore, a high UCA1 level in colon cancer tissues is positively associated with the tumor size and advanced tumor stages. Functional assays revealed that both UCA1 knockdown and miR-28-5p overexpression could inhibit colon cancer cell growth and migration. Further mechanistic studies indicated that UCA1 knockdown played tumor suppressive roles in SW480 and HT116 cells through binding with miR-28-5p. We also, for the first time, identified HOXB3 as the target gene of miR-28-5p and that HOXB3 overexpression could mediate the functions of UCA1 in cell proliferation and migration of colon cancer cells. In conclusion, our data provided evidence for the regulatory network of UCA1/miR-28-5p/HOXB3 in colon cancer, suggesting that UCA1, miR-28-5p, and HOXB3 are the potential targets for colon cancer therapy.

A novel miR-375-HOXB3-CDCA3/DNMT3B regulatory circuitry contributes to leukemogenesis in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is a heterogeneous group of hematopoietic malignancies due to sophisticated genetic mutations and epigenetic dysregulation. MicroRNAs (miRNAs), a class of small non-coding RNAs, are important regulators of gene expression in all biological processes, including leukemogenesis. Recently, miR-375 has been reported to be a suppressive miRNA in multiple types of cancers, but its underlying anti-leukemia activity in AML is largely unknown.

METHODS

Quantitative reverse transcriptase PCR (qRT-PCR) was used to measure the expression of miR-375 and HOXB3 in leukemic cells and normal controls. Targets of miR-375 were confirmed by western blot and luciferase assay. Phenotypic effects of miR-375 overexpression and HOXB3 knockdown were assessed using viability (trypan blue exclusion assay), colony formation/replating, as well as tumor xenograft assays in vivo.

RESULTS

The expression of miR-375 was substantially decreased in leukemic cell lines and primary AML blasts compared with normal controls, because DNA hypermethylation of precursor-miR-375 (pre-miR-375) promoter was discovered in leukemic cells but not in normal controls. Lower expression of miR-375 predicted poor outcome in AML patients. Furthermore, forced expression of miR-375 not only decreased proliferation and colony formation in leukemic cells but also reduced xenograft tumor size and prolonged the survival time in a leukemia xenograft mouse model. Mechanistically, overexpression of miR-375 reduced HOXB3 expression and repressed the activity of a luciferase reporter through binding 3'-untranslated regions (3'-UTR) of HOXB3 mRNA. Overexpression of HOXB3 partially blocked miR-375-induced arrest of proliferation and reduction of colony number, suggesting that HOXB3 plays an important role in miR-375-induced anti-leukemia activity. Knockdown of HOXB3 by short hairpin RNAs reduced the expression of cell division cycle associated 3 (CDCA3), which decreased cell proliferation. Furthermore, HOXB3 induced DNA methyltransferase 3B (DNMT3B) expression to bind in the pre-miR-375 promoter and enhanced DNA hypermethylation of pre-miR-375, leading to the lower expression of miR-375.

CONCLUSIONS

Collectively, we have identified a miR-375-HOXB3-CDCA3/DNMT3B regulatory circuitry which contributes to leukemogenesis and suggests a therapeutic strategy of restoring miR-375 expression in AML.

miR-10b Inhibits Apoptosis and Promotes Proliferation and Invasion of Endometrial Cancer Cells via Targeting HOXB3

MicroRNAs are small RNA that are tightly interrelated with the initiation, development, and metastasis of cancers. Studies have shown that miR-10b is increased in various cancers. However, the underlying mechanisms of miR-10b in the occurrence and metastasis of endometrial cancer are poorly understood. To investigate its roles and correlations with Homeobox box 3 (HOXB3) in endometrial cancer, cancer tissues and adjacent normal endometrium tissues from 20 patients with endometrial cancer were studied. miR-10b expression was significantly up-regulated (p < 0.01) in endometrial cancer tissue, whereas HOXB3 was lowly expressed. The silence of miR-10b resulted in significantly enhanced cell apoptosis, and remarkably reduced cell proliferation, migration, and invasion (p < 0.05). Moreover, the protein levels of HOXB3 were increased in KLE cells with silenced miR-10b, and dual-luciferase reporter assay suggested that miR-10b could directly target HOXB3. Furthermore, overexpression of HOXB3 promoted cell apoptosis but inhibited cell proliferation, migration, and invasion (p < 0.01). To conclude, miR-10b might control cell apoptosis, proliferation, migration, and invasion in endometrial cancer via regulation of HOXB3 expression.

Deregulation of MicroRNA-375 inhibits cancer proliferation migration and chemosensitivity in pancreatic cancer through the association of HOXB3

BACKGROUND

The expression pattern and regulatory effect of microRNA-375 (miR-375) in human pancreatic cancer was explored.

METHODS

Gene expression of miR-375 was compared between pancreatic tumors and non-tumorous pancreatic tissues, as well as pancreatic cancer cell lines and normal epithelial cells. MiR-375 was downregulated in pancreatic cancer cell lines, Capan-1 and PANC-1 cells, to assess possible tumor suppressive effects on cancer proliferation, migration, cisplatin chemosensitivity and in vivo growth of tumor explant. The regulation of miR-375 on its target gene, homeobox B3 (HOXB3) gene, was assessed though luciferase activity assay and qRT-PCR. HOXB3 was also downregulated in Capan-1 and PANC-1 cells to assess its functional correlation with miR-375 on cancer regulation.

RESULTS

MiR-375 was upregulated in pancreatic tumors and pancreatic cancer cell lines. MiR-375 downregulation had tumor suppressive effects in Capan-1 and PANC-1 cells by reducing cancer proliferation & migration, increasing cisplatin sensitivity and inhibiting in vivo tumor explant growth. HOXB3 was directly bound by miR-375, and was negatively regulated by miR-375 in pancreatic cancer cells. Subsequent HOXB3 downregulation reversed the suppression of miR-375 downregulation on cancer proliferation, migration and cisplatin chemosensitivity in pancreatic cancer.

CONCLUSION

MiR-375 is an oncogene in pancreatic cancer. Deregulation of miR-375 is inhibitory to the development of pancreatic cancer, and reversely regulated by HOXB3.

The role of HOXB2 and HOXB3 in acute myeloid leukemia

Acute myeloid leukemia (AML) is a heterogeneous aggressive disease and the most common form of adult leukemia. Mutations in the type III receptor tyrosine kinase FLT3 are found in more than 30% of AML patients. Drugs against FLT3 have been developed for the treatment of AML, but they lack specificity, show poor response and lead to the development of a resistant phenotype upon treatment. Therefore, a deeper understanding of FLT3 signaling will facilitate identification of additional pharmacological targets in FLT3-driven AML. In this report, we identify HOXB2 and HOXB3 as novel regulators of oncogenic FLT3-ITD-driven AML. We show that HOXB2 and HOXB3 expression is upregulated in a group of AML patients carrying FLT3-ITD. Overexpression of HOXB2 or HOXB3 in mouse pro-B cells resulted in decreased FLT3-ITD-dependent cell proliferation as well as colony formation and increased apoptosis. Expression of HOXB2 or HOXB3 resulted in a significant decrease in FLT3-ITD-induced AKT, ERK, p38 and STAT5 phosphorylation. Our data suggest that HOXB2 and HOXB3 act as tumor suppressors in FLT3-ITD driven AML.