HOXB5 Promotes the Proliferation and Invasion of Breast Cancer Cells

HOXB5 promotes the progression and metastasis of osteosarcoma cells by activating the JAK2/STAT3 signalling pathway

Objective

To investigate the involvement of the homeobox gene B5 (HOXB5) in the progression and metastasis of osteosarcoma.

Methods

The expression of HOXB5 in human osteosarcoma tissues and its correlation with clinical indicators were investigated using bioinformatics analysis and immunohistochemical labelling. Human osteosarcoma cells (HOS, MG63, U2OS, and Saos-2) and normal human osteoblasts (hFOB1.19) were cultivated. The expression of HOXB5 in these cells was detected using western blotting (WB) and RT‒PCR. Two cell lines exhibiting elevated HOXB5 expression were chosen and divided into three groups: the blank group (mock), control group (control) and transfection group (shHOXB5). The transfection group was infected with lentivirus expressing shRNAs targeting HOXB5. The transfection efficiency was detected by WB. Cell proliferation suppression was measured by CCK-8 and 5-ethynyl-2'-deoxyuridine (EdU) assays; the percentage of apoptotic cells was determined by flow cytometry; and cell migration and invasion were detected via the Transwell chamber test. WB was utilized to determine the protein expression of genes linked to metastasis (MMP2, MMP9), apoptosis (Bax, Bcl-2), and the JAK2/STAT3 pathway (JAK2, p-JAK2, STAT3, p-STAT3).

Results

In osteosarcoma tissues, HOXB5 expression was elevated and strongly correlated with distant metastasis. Silencing HOXB5 reduced the proliferation, migration and invasion of osteosarcoma cells; prevented the progression and metastasis of tumours in tumour-bearing nude mice; and reduced the activation of key proteins in the JAK2/STAT3 signalling pathway.

Conclusion

Through the JAK2/STAT3 signalling pathway, HOXB5 plays a crucial role in the malignant progression of osteosarcoma and is a promising target for osteosarcoma treatment.

Integrative analysis of the lncRNA-miRNA-mRNA interactions in smooth muscle cell phenotypic transitions

Objectives: We previously found that the pluripotency factor OCT4 is reactivated in smooth muscle cells (SMC) in human and mouse atherosclerotic plaques and plays an atheroprotective role. Loss of OCT4 in SMC in vitro was associated with decreases in SMC migration. However, molecular mechanisms responsible for atheroprotective SMC-OCT4-dependent effects remain unknown. Methods: Since studies in embryonic stem cells demonstrated that OCT4 regulates long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), making them candidates for OCT4 effect mediators, we applied an in vitro approach to investigate the interactions between OCT4-regulated lncRNAs, mRNAs, and miRNAs in SMC. We used OCT4 deficient mouse aortic SMC (MASMC) treated with the pro-atherogenic oxidized phospholipid POVPC, which, as we previously demonstrated, suppresses SMC contractile markers and induces SMC migration. Differential expression of lncRNAs, mRNAs, and miRNAs was obtained by lncRNA/mRNA expression array and small-RNA microarray. Long non-coding RNA to mRNA associations were predicted based on their genomic proximity and association with vascular diseases. Given a recently discovered crosstalk between miRNA and lncRNA, we also investigated the association of miRNAs with upregulated/downregulated lncRNA-mRNA pairs. Results: POVPC treatment in SMC resulted in upregulating genes related to the axon guidance and focal adhesion pathways. Knockdown of Oct4 resulted in differential regulation of pathways associated with phagocytosis. Importantly, these results were consistent with our data showing that OCT4 deficiency attenuated POVPC-induced SMC migration and led to increased phagocytosis. Next, we identified several up- or downregulated lncRNA associated with upregulation of the specific mRNA unique for the OCT4 deficient SMC, including upregulation of ENSMUST00000140952-Hoxb5/6 and ENSMUST00000155531-Zfp652 along with downregulation of ENSMUST00000173605-Parp9 and, ENSMUST00000137236-Zmym1. Finally, we found that many of the downregulated miRNAs were associated with cell migration, including miR-196a-1 and miR-10a, targets of upregulated ENSMUST00000140952, and miR-155 and miR-122, targets of upregulated ENSMUST00000155531. Oppositely, the upregulated miRNAs were anti-migratory and pro-phagocytic, such as miR-10a/b and miR-15a/b, targets of downregulated ENSMUST00000173605, and miR-146a/b and miR-15b targets of ENSMUST00000137236. Conclusion: Our integrative analyses of the lncRNA-miRNA-mRNA interactions in SMC indicated novel potential OCT4-dependent mechanisms that may play a role in SMC phenotypic transitions.

Upregulated Expression of ErbB1 in Diffuse Large B-Cell Lymphoma as a Predictor of Poor Overall Survival Outcome

We examined the transcript-level expression of ErbB family protein tyrosine kinases, including ERBB1, in primary malignant lymphoma cells from 498 adult patients with diffuse large B-cell lymphoma (DLBCL). ERBB1 expression in DLBCL cells was significantly higher than in normal B-lineage lymphoid cells. An upregulated expression of ERBB1 mRNA in DLBCL cells was correlated with an amplified expression of mRNAs for transcription factors that recognized ERBB1 gene promoter sites. Notably, amplified ERBB1 expression in DLBCL and its subtypes were associated with significantly worse overall survival (OS). Our results encourage the further evaluation of the prognostic significance of high-level ERBB1 mRNA expression and the clinical potential of ERBB1-targeting therapeutics as personalized medicines in high-risk DLBCL.

ERBB1/EGFR and JAK3 Tyrosine Kinases as Potential Therapeutic Targets in High-Risk Multiple Myeloma

Our main objective was to identify abundantly expressed tyrosine kinases in multiple myeloma (MM) as potential therapeutic targets. We first compared the transcriptomes of malignant plasma cells from newly diagnosed MM patients who were risk-categorized based on the patient-specific EMC-92/SKY-92 gene expression signature values vs. normal plasma cells from healthy volunteers using archived datasets from the HOVON65/GMMG-HD4 randomized Phase 3 study evaluating the clinical efficacy of bortezomib induction/maintenance versus classic cytotoxic drugs and thalidomide maintenance. In particular, ERBB1/EGFR was significantly overexpressed in MM cells in comparison to normal control plasma cells, and it was differentially overexpressed in MM cells from high-risk patients. Amplified expression of EGFR/ERBB1 mRNA in MM cells was positively correlated with increased expression levels of mRNAs for several DNA binding proteins and transcription factors with known upregulating activity on EGFR/ERBB1 gene expression. MM patients with the highest ERBB1/EGFR expression level had significantly shorter PFS and OS times than patients with the lowest ERBB1/EGFR expression level. High expression levels of EGFR/ERBB1 were associated with significantly increased hazard ratios for unfavorable PFS and OS outcomes in both univariate and multivariate Cox proportional hazards models. The impact of high EGFR/ERBB1 expression on the PFS and OS outcomes remained significant even after accounting for the prognostic effects of other covariates. These results regarding the prognostic effect of EGFR/ERBB1 expression were validated using the MMRF-CoMMpass RNAseq dataset generated in patients treated with more recently applied drug combinations included in contemporary induction regimens. Our findings provide new insights regarding the molecular mechanism and potential clinical significance of upregulated EGFR/ERBB1 expression in MM.

Hox proteins as regulators of extracellular matrix interactions during neural crest migration

Emerging during embryogenesis, the neural crest are a migratory, transient population of multipotent stem cell that differentiates into various cell types in vertebrates. Neural crest cells arise along the anterior-posterior extent of the neural tube, delaminate and migrate along routes to their final destinations. The factors that orchestrate how neural crest cells undergo delamination and their subsequent sustained migration is not fully understood. This review provides a primer about neural crest epithelial-to-mesenchymal transition (EMT), with a special emphasis on the role of the Extracellular matrix (ECM), cellular effector proteins of EMT, and subsequent migration. We also summarize published findings that link the expression of Hox transcription factors to EMT and ECM modification, thereby implicating Hox factors in regulation of EMT and ECM remodeling during neural crest cell ontogenesis.

Comprehensive analysis of a homeobox family gene signature in clear cell renal cell carcinoma with regard to prognosis and immune significance

The homeobox (HOX) family genes have been linked to multiple types of tumors, while their effect on malignant behaviors of clear cell renal cell carcinoma (ccRCC) and clinical significance remains largely unknown. Here, we comprehensively analyzed the expression profiles and prognostic value of HOX genes in ccRCC using datasets from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. We developed a prognostic signature comprising eight HOX genes (HOXB1, HOXA7, HOXB5, HOXD8, HOXD9, HOXB9, HOXA9, and HOXA11) for overall survival prediction in ccRCC and it allowed patients to be subdivided into high- and low-risk groups. Kaplan-Meier survival analysis in all the internal and external cohorts revealed significant difference in clinical outcome of patients in different risk groups, indicating the satisfactory predictive power of the signature. Additionally, we constructed a prognostic nomogram by integrating signature-derived risk score and clinical factors such as gender, age, T and M status, which might be helpful for clinical decision-making and designing tailored management schedules. Immunological analysis revealed that the regulatory T cells (Tregs) infiltrated differently between the two subgroups in both TCGA and ICGC cohorts. ssGSEA method showed that the enrichment scores for mast cells were significantly lower in high-risk group compared with the low-risk group, which was consistent in both TCGA and ICGC cohorts. As for the related immune function, the enrichment scores of APC co-inhibition, para-inflammation, and type II IFN response were consistently lower in high-risk group in both cohorts. Of the eight HOX genes, the mRNA and protein levels of HOXD8 were downregulated in ccRCC than that in normal tissues, and decreased expression of HOXD8 was associated with increased tumor grade and stage, and lymph node metastasis. Survival analysis revealed that lower expression of HOXD8 predicted worse overall survival in ccRCC. In conclusion, our HOX gene-based signature was a favorable indicator to predict the prognosis of ccRCC cases and associated with immune cell infiltration. HOXD8 might be a tumor suppressor gene in ccRCC and a potential predictor of tumor progression.

HOXB5‑activated ANGPT2 promotes the proliferation, migration, invasion and angiogenic effect of esophageal cancer cells via activating ERK/AKT signaling pathway

Esophageal cancer, which is the eighth most common cancer worldwide, has a poor prognosis and high mortality rate. The present study was designed to investigate the proliferation, migration, invasion and angiogenic effect of the homeobox B5 (HOXB5)/angiopoietin-2 (ANGPT2) interplay in esophageal cancer. The relative expression of ANGPT2 and HOXB5 in esophageal cancer and the association between gene expression was evaluated using data from Gene Expression Profiling Interactive Analysis databases. Following transduction of short hairpin RNA-ANGPT2#1/2 plasmids, ANGPT2 was silenced. Viability, proliferation and invasion of esophageal cancer cells were assessed using CCK-8, 5-EdU, colony formation, wound healing and Transwell assays, respectively. Moreover, the transcriptional activity of ANGPT2 and angiogenesis were detected with luciferase reporter, chromatin immunoprecipitation (CH-IP) and tube formation assays. The results of the present study indicated that ANGPT2 was upregulated, both in esophageal cancer cell lines and tissue and there was an association between the ANGPT2 upregulation and the poor patient prognosis. In addition, ANGPT2 silencing suppressed esophageal cancer cell proliferation, migration, invasion and angiogenesis. The HOXB5 expression was also increased in esophageal cancer, and transcriptionally activated ANGPT2. Moreover, HOXB5 overexpression reversed the effects of ANGPT2 silencing in esophageal cancer cells. Furthermore, ANGPT2 silencing inactivated ERK/AKT signaling, whereas the HOXB5 overexpression blocked this effect. In conclusion, ANGPT2, which was transcriptionally activated by HOXB5, activated the ERK/AKT signaling pathway to promote proliferation, metastasis and angiogenesis of esophageal cancer cells.

Molecular implications of HOX genes targeting multiple signaling pathways in cancer

Homeobox (HOX) genes encode highly conserved homeotic transcription factors that play a crucial role in organogenesis and tissue homeostasis. Their deregulation impacts the function of several regulatory molecules contributing to tumor initiation and progression. A functional bridge exists between altered gene expression of individual HOX genes and tumorigenesis. This review focuses on how deregulation in the HOX-associated signaling pathways contributes to the metastatic progression in cancer. We discuss their functional significance, clinical implications and ascertain their role as a diagnostic and prognostic biomarker in the various cancer types. Besides, the mechanism of understanding the theoretical underpinning that affects HOX-mediated therapy resistance in cancers has been outlined. The knowledge gained shall pave the way for newer insights into the treatment of cancer.

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

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

Homeobox Genes in Cancers: From Carcinogenesis to Recent Therapeutic Intervention

The homeobox (HOX) genes encoding an evolutionarily highly conserved family of homeodomain-containing transcriptional factors are essential for embryogenesis and tumorigenesis. HOX genes are involved in cell identity determination during early embryonic development and postnatal processes. The deregulation of HOX genes is closely associated with numerous human malignancies, highlighting the indispensable involvement in mortal cancer development. Since most HOX genes behave as oncogenes or tumor suppressors in human cancer, a better comprehension of their upstream regulators and downstream targets contributes to elucidating the function of HOX genes in cancer development. In addition, targeting HOX genes may imply therapeutic potential. Recently, novel therapies such as monoclonal antibodies targeting tyrosine receptor kinases, small molecular chemical inhibitors, and small interfering RNA strategies, are difficult to implement for targeting transcriptional factors on account of the dual function and pleiotropic nature of HOX genes-related molecular networks. This paper summarizes the current state of knowledge on the roles of HOX genes in human cancer and emphasizes the emerging importance of HOX genes as potential therapeutic targets to overcome the limitations of present cancer therapy.

LncRNA DCST1-AS1 Promotes Endometrial Cancer Progression by Modulating the MiR-665/HOXB5 and MiR-873-5p/CADM1 Pathways

Dysregulation of long noncoding RNA (lncRNA) is implicated in the initiation and progression of various tumors, including endometrial cancer (EC). However, the mechanism of lncRNAs in EC tumorigenesis and progression remains largely unexplored. In this work, we identified a novel lncRNA DC-STAMP domain-containing 1-antisense 1 (DCST1-AS1), which is highly upregulated and correlated with poor survival in EC patients. Overexpression of DCST1-AS1 significantly enhanced EC cell proliferation, colony formation, migration, and invasion in vitro and promoted tumor growth of EC in vivo. Mechanistically, DCST1-AS1 mediated EC progression by inducing the expression of homeobox B5 (HOXB5) and cell adhesion molecule 1 (CADM1), via acting as a competing endogenous RNA for microRNA-665 (miR-665) and microRNA-873-5p (miR-873-5p), respectively. In addition, we found that the expression of miR-665 and miR-873-5p was significantly downregulated, while HOXB5 and CADM1 expression levels were increased in EC tissues. Taken together, our findings support the important role of DCST1-AS1 in EC progression, and DCST1-AS1 may be used as a prognostic biomarker as well as a potential therapeutic target for EC.

HOXB5 Overexpression Is Associated with Neuroendocrine Differentiation and Poor Prognosis in Prostate Cancer

Homeobox genes function as master regulatory transcription factors during embryogenesis. HOXB5 is known to play an important role in several cancers. However, the biological role of HOXB5 in prostate cancer (PCa) is not fully elucidated. This study aimed to analyze the expression and function of HOXB5 and involvement of HOXB5 in neuroendocrine differentiation in PCa. Immunohistochemistry showed that 56 (43.8%) of 128 cases of localized PCa were positive for HOXB5. HOXB5-positive cases were associated with poor prostate-specific antigen recurrence-free survival after prostatectomy. Among 74 cases of metastatic PCa, 43 (58.1%) were positive for HOXB5. HOXB5 expression was higher in metastatic PCa than that in localized PCa. HOXB5 knockdown suppressed cell growth and invasion, but HOXB5 overexpression increased cell growth and invasion in PCa cell lines. Furthermore, HOXB5 regulated RET expression. Gene set enrichment analysis revealed that Nelson androgen response gene set was enriched in low HOXB5 expression group. RB1 knockout increased HOXB5 expression. Of note, additional p53 knockdown further increased HOXB5 expression in RB1 knockout cells. In silico analysis showed that HOXB5 expression was increased in neuroendocrine PCa (NEPC). These results suggest that HOXB5 may be a promising prognostic marker after prostatectomy and is involved in progression to NEPC.

NR4A1 Regulates Tamoxifen Resistance by Suppressing ERK Signaling in ER-Positive Breast Cancer

Endocrine therapy is used to treat estrogen receptor (ER)-positive breast cancer. Tamoxifen is effective against this cancer subtype. Nonetheless, approximately 30% of patients treated with tamoxifen acquire resistance, resulting in therapeutic challenges. NR4A1 plays key roles in processes associated with carcinogenesis, apoptosis, DNA repair, proliferation, and inflammation. However, the role of NR4A1 in tamoxifen-resistant ER-positive breast cancer has not yet been elucidated. Here, we propose that NR4A1 is a promising target to overcome tamoxifen resistance. NR4A1 gene expression was downregulated in tamoxifen-resistant MCF7 (TamR) cells compared to that in MCF7 cells. Kaplan-Meier plots were used to identify high NR4A1 expression correlated with increased survival rates in patients with ER-positive breast cancer following tamoxifen treatment. Gain and loss of function experiments showed that NR4A1 restores sensitivity to tamoxifen by regulating cell proliferation, migration, invasion, and apoptosis. NR4A1 localized to the cytoplasm enhanced the expression of apoptotic factors. In silico and in vitro analyses revealed that NR4A1 enhanced responsiveness to tamoxifen by suppressing ERK signaling in ER-positive breast cancer, suggesting that the NR4A1/ERK signaling axis modulates tamoxifen resistance. These results indicate that NR4A1 could be a potential therapeutic target to overcome tamoxifen resistance in ER-positive breast cancer.

NR4A1 Regulates Tamoxifen Resistance by Suppressing ERK Signaling in ER-Positive Breast Cancer

Endocrine therapy is used to treat estrogen receptor (ER)-positive breast cancer. Tamoxifen is effective against this cancer subtype. Nonetheless, approximately 30% of patients treated with tamoxifen acquire resistance, resulting in therapeutic challenges. NR4A1 plays key roles in processes associated with carcinogenesis, apoptosis, DNA repair, proliferation, and inflammation. However, the role of NR4A1 in tamoxifen-resistant ER-positive breast cancer has not yet been elucidated. Here, we propose that NR4A1 is a promising target to overcome tamoxifen resistance. NR4A1 gene expression was downregulated in tamoxifen-resistant MCF7 (TamR) cells compared to that in MCF7 cells. Kaplan-Meier plots were used to identify high NR4A1 expression correlated with increased survival rates in patients with ER-positive breast cancer following tamoxifen treatment. Gain and loss of function experiments showed that NR4A1 restores sensitivity to tamoxifen by regulating cell proliferation, migration, invasion, and apoptosis. NR4A1 localized to the cytoplasm enhanced the expression of apoptotic factors. In silico and in vitro analyses revealed that NR4A1 enhanced responsiveness to tamoxifen by suppressing ERK signaling in ER-positive breast cancer, suggesting that the NR4A1/ERK signaling axis modulates tamoxifen resistance. These results indicate that NR4A1 could be a potential therapeutic target to overcome tamoxifen resistance in ER-positive breast cancer.

HOXB5 promotes proliferation, migration, and invasion of pancreatic cancer cell through the activation of the GSK3β/β-catenin pathway

Many homeobox (HOX) genes have been shown to be related to cancer progression. HOXB5, a member of the HOX genes, is overexpressed in retinoblastoma cancer and positively regulates the breast cancer cell proliferation as well as invasion. However, the role and underlying mechanism of HOXB5 in pancreatic cancer cells are still unclear. HOXB5 expression was measured in four pancreatic cancer cell lines, including PANC-1, ASPC-1, MIA-PaCa-2, and CFPAC-1. PANC-1 and ASPC-1 cells were selected for cell transfection experiments. Cell proliferation, migration, and invasion were measured by Cell Counting Kit-8 (CCK-8) assay, wound healing assay, and transwell assay. Expressions of epithelial-to-mesenchymal transition (EMT) markers were determined by western blotting. Immunofluorescence staining and cellular morphology were used to confirm the effect of HOXB5 dysregulation on pancreatic cancer cells. We found that HOXB5 was markedly expressed in pancreatic cancer cell lines. HOXB5 overexpression contributed to proliferation, migration, and invasion in ASPC-1 cells, whereas HOXB5 knockdown decreased proliferation, migration, and invasion of PANC-1 cells. Western blotting confirmed that overexpression of HOXB5 promoted the EMT process. Conversely, knockdown of HOXB5 alleviated EMT. Furthermore, knockdown of HOXB5 suppressed proliferation, migration, and invasion of pancreatic cancer cells via the Glycogen synthase kinase 3β (GSK3β)/β-catenin pathway. Our study demonstrates that HOXB5 is a tumor promoter in pancreatic cancer, and the GSK3β/β-catenin pathway is important in HOXB5-induced proliferation, migration, and invasion in pancreatic cancer cells.

Estrogen suppresses HOXB2 expression via ERα in breast cancer cells

The expression of HOXB2, a homeobox transcription factor, is altered in a variety of solid tumors. Using an in vivo screen to identify regulators of breast tumor growth in murine mammary fat pads, Boimel and co-workers recently identified HOXB2 as a tumor suppressor. However, the mechanistic underpinnings of its role in breast cancer is not understood. Given the emerging interaction of estrogen-regulated gene expression and altered HOX gene expression network in the pathophysiology of breast cancer, this study addressed the relationship between estrogen signaling and HOXB2 expression. Using a mouse model and human breast cancer cell lines, we show that estrogen suppresses HOXB2 expression. Suppression of HOXB2 by PPT, a known ERα agonist, in MCF-7 and T47D cells indicated the involvement of ERα, which was confirmed by siRNA-mediated ERα knockdown experiments. In-silico analysis of the upstream promoter region revealed the presence of three putative EREs. Chromatin immunoprecipitation experiments showed that upon estrogen binding, ERα engaged with EREs in the 5' upstream region of HOXB2 in MCF-7 and T47D cells. Future investigations should address the implications of estrogen-mediated suppression on the proposed tumor suppressor function of HOXB2.

The SRSF1/circATP5B/miR-185-5p/HOXB5 feedback loop regulates the proliferation of glioma stem cells via the IL6-mediated JAK2/STAT3 signaling pathway

Background

Glioma is the most common and malignant tumor of central nervous system. The tumor initiation, self-renewal, and multi-lineage differentiation abilities of glioma stem cells (GSCs) are responsible for glioma proliferation and recurrence. Although circular RNAs (circRNAs) play vital roles in the progression of glioma, the detailed mechanisms remain unknown.

Methods

qRT-PCR, western blotting, immunohistochemistry, and bioinformatic analysis were performed to detect the expression of circATP5B, miR-185-5p, HOXB5, and SRSF1. Patient-derived GSCs were established, and MTS, EDU, neurosphere formation, and limiting dilution assays were used to detect the proliferation of GSCs. RNA-binding protein immunoprecipitation, RNA pull-down, luciferase reporter assays, and chromatin immunoprecipitation assays were used to detect these molecules’ regulation mechanisms.

Results

We found circATP5B expression was significantly upregulated in GSCs and promoted the proliferation of GSCs. Mechanistically, circATP5B acted as miR-185-5p sponge to upregulate HOXB5 expression. HOXB5 was overexpressed in glioma and transcriptionally regulated IL6 expression and promoted the proliferation of GSCs via JAK2/STAT3 signaling. Moreover, RNA binding protein SRSF1 could bind to and promote circATP5B expression and regulate the proliferation of GSCs, while HOXB5 also transcriptionally regulated SRSF1 expression.

Conclusions

Our study identified the SRSF1/circATP5B/miR-185-5p/HOXB5 feedback loop in GSCs. This provides an effective biomarker for glioma diagnosis and prognostic evaluation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01931-9.

Penalized logistic regression based on L1/2 penalty for high-dimensional DNA methylation data

BACKGROUND:

DNA methylation is a molecular modification of DNA that is vital and occurs in gene expression. In cancer tissues, the 5’–C–phosphate–G–3’(CpG) rich regions are abnormally hypermethylated or hypomethylated. Therefore, it is useful to find out the diseased CpG sites by employing specific methods. CpG sites are highly correlated with each other within the same gene or the same CpG island.

OBJECTIVE:

Based on this group effect, we proposed an efficient and accurate method for selecting pathogenic CpG sites.

METHODS:

Our method aimed to combine a L1/2 regularized solver and a central node fully connected network to penalize group constrained logistic regression model. Consequently, both sparsity and group effect were brought in with respect to the correlated regression coefficients.

RESULTS:

Extensive simulation studies were used to compare our proposed approach with existing mainstream regularization in respect of classification accuracy and stability. The simulation results show that a greater predictive accuracy was attained in comparison to previous methods. Furthermore, our method was applied to over 20000 CpG sites and verified using the ovarian cancer data generated from Illumina Infinium HumanMethylation 27K Beadchip. In the result of the real dataset, not only the indicators of predictive accuracy are higher than the previous methods, but also more CpG sites containing genes are confirmed pathogenic. Additionally, the total number of CpG sites chosen is less than other methods and the results show higher accuracy rates in comparison to other methods in simulation and DNA methylation data.

CONCLUSION:

The proposed method offers an advanced tool to researchers in DNA methylation and can be a powerful tool for recognizing pathogenic CpG sites.

Homeobox B5 promotes metastasis and poor prognosis in Hepatocellular Carcinoma, via FGFR4 and CXCL1 upregulation

Background: Since metastasis remains the main reason for HCC-associated death, a better understanding of molecular mechanism underlying HCC metastasis is urgently needed. Here, we elucidated the role of Homeobox B5 (HOXB5), a member of the HOX transcriptional factor family, in promoting HCC metastasis.

Method: The expression of HOXB5 and its functional targets fibroblast growth factor receptor 4 (FGFR4) and C-X-C motif chemokine ligand 1 (CXCL1) were detected by immunohistochemistry. Luciferase reporter and chromatin immunoprecipitation assays were performed to measure the transcriptional regulation of target genes by HOXB5. The effects of FGFR4 and CXCL1 on HOXB5-mediated metastasis were analyzed by an orthotopic metastasis model.

Results: Elevated expression of HOXB5 had a positive correlation with poor tumour differentiation, higher TNM stage, and indicated unfavorable prognosis. Overexpression of HOXB5 promoted HCC metastasis through transactivating FGFR4 and CXCL1 expression, whereas knockdown of FGFR4 and CXCL1 decreased HOXB5-enhanced HCC metastasis. Moreover, HOXB5 overexpression in HCC cells promoted myeloid derived suppressor cells (MDSCs) infiltration through CXCL1/CXCR2 axis. Either depletion of MDSCs by anti-Gr1 or blocking CXCL1-CXCR2 axis by CXCR2 inhibitor impaired HOXB5-mediated HCC metastasis. In addition, fibroblast growth factor 19 (FGF19) contributed to the HOXB5 upregulation through PI3K/AKT/HIF1α pathway. Overexpression of FGF15 (an analog of FGF19 in mouse) promoted HCC metastasis, whereas knockdown of HOXB5 significantly inhibited FGF15-enhanced HCC metastasis in immunocompetent mice. HOXB5 expression was positively associated with CXCL1 expression and intratumoral MDSCs accumulation in human HCC tissues. Patients who co-expressed HOXB5/CXCL1 or HOXB5/CD11b exhibited the worst prognosis. Furthermore, the combination of FGFR4 inhibitor BLU-554 and CXCR2 inhibitor SB265610 dramatically decreased HOXB5-mediated HCC metastasis.

Conclusion: HOXB5 was a potential prognostic biomarker in HCC patients and targeting this loop may provide a promising treatment strategy for the inhibition of HOXB5-mediated HCC metastasis.

Multiple roles of HOX proteins in Metastasis: Let me count the ways

Knowledge of the role of HOX proteins in cancer has been steadily accumulating in the last 25 years. They are encoded by 39 HOX genes arranged in 4 distinct clusters, and have unique and redundant function in all types of cancers. Many HOX genes behave as oncogenic transcriptional factors regulating multiple pathways that are critical to malignant progression in a variety of tumors. Some HOX proteins have dual roles that are tumor-site specific, displaying both oncogenic and tumor suppressor function. The focus of this review is on how HOX proteins contribute to growth or suppression of metastasis. The review will cover HOX protein function in the critical aspects of epithelial-mesenchymal transition, in cancer stem cell sustenance and in therapy resistance, manifested as distant metastasis. The emerging role of adiposity in both initiation and progression of metastasis is described. Defining the role of HOX genes in the metastatic process has identified candidates for targeted cancer therapies that may combat the metastatic process. We will discuss potential therapeutic opportunities, particularly in pathways influenced by HOX proteins.

CXCL12-mediated HOXB5 overexpression facilitates Colorectal Cancer metastasis through transactivating CXCR4 and ITGB3

Background: Metastasis is the major reason for the high mortality of colorectal cancer (CRC). However, the molecular mechanism underlying CRC metastasis remains unclear. Here, we report a novel role of homeobox B5 (HOXB5), a member of the HOX family, in promoting CRC metastasis. Method: The expression of HOXB5 and its target genes were examined by immunohistochemistry in human CRC. Chromatin immunoprecipitation and luciferase reporter assays were performed to measure the transcriptional regulation of target genes by HOXB5. The metastatic capacities of CRC cells were evaluated by in vivo lung and liver metastatic models. Results: The elevated expression of HOXB5 was positively correlated with distant metastasis, higher AJCC stage, and poor prognosis in CRC patients. HOXB5 expression was an independent and significant risk factor for the recurrence and survival in CRC patients. Overexpression of HOXB5 promoted CRC metastasis by transactivating metastatic related genes, C-X-C motif chemokine receptor 4 (CXCR4) and integrin subunit beta 3 (ITGB3). C-X-C motif chemokine ligand 12 (CXCL12), which is the ligand of CXCR4, upregulated HOXB5 expression through the extracellular regulated protein kinase (ERK)/ETS proto-oncogene 1, transcription factor (ETS1) pathway. The knockdown of HOXB5 decreased CXCL12-enhanced CRC metastasis. Furthermore, AMD3100, a specific CXCR4 inhibitor, significantly suppressed HOXB5-mediated CRC metastasis. HOXB5 expression was positively correlated with CXCR4 and ITGB3 expression in human CRC tissues, and patients with positive co-expression of HOXB5/CXCR4, or HOXB5/ITGB3 exhibited the worst prognosis. Conclusion: Our study implicates HOXB5 as a prognostic biomarker in CRC, and defines a CXCL12-HOXB5-CXCR4 positive feedback loop that plays an important role in promoting CRC metastasis.

Roles of the HOX Proteins in Cancer Invasion and Metastasis

Invasion and metastasis correspond to the foremost cause of cancer-related death, and the molecular networks behind these two processes are extremely complex and dependent on the intra- and extracellular conditions along with the prime of the premetastatic niche. Currently, several studies suggest an association between the levels of HOX genes expression and cancer cell invasion and metastasis, which favour the formation of novel tumour masses. The deregulation of HOX genes by HMGA2/TET1 signalling and the regulatory effect of noncoding RNAs generated by the HOX loci can also promote invasion and metastasis, interfering with the expression of HOX genes or other genes relevant to these processes. In this review, we present five molecular mechanisms of HOX deregulation by which the HOX clusters products may affect invasion and metastatic processes in solid tumours.

Putative molecular determinants mediating sensitivity or resistance towards carnosic acid tumor cell responses

BACKGROUND

Carnosic acid (CA) is one of the main constituents in rosemary extract. It possesses valuable pharmacological properties, including anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer activities. Numerous in vitro and in vivo studies investigated the anticancer profile of CA and emphasized its potentiality for cancer treatment. Nevertheless, the role of multidrug-resistance (MDR) related mechanisms for CA's anticancer effect is not yet known.

PURPOSE

We investigated the cytotoxicity of CA against known mechanisms of anticancer drug resistance (P-gp, ABCB5, BCRP, EGFR and p53) and determined novel putative molecular factors associated with cellular response towards CA.

STUDY DESIGN

Cytotoxicity assays, bioinformatic analysis, flow cytometry and western blotting were performed to identify the mode of action of CA towards cancer cells.

METHODS

The cytotoxicity to CA was assessed using the resazurin assays in cell lines expressing the mentioned resistance mechanisms. A pharmacogenomic characterization of the NCI 60 cell line panel was applied via COMPARE, hierarchical cluster and network analyses. Flow cytometry was used to detect cellular mode of death and ROS generation. Changes in proteins-related to apoptosis were determined by Western blotting.

RESULTS

Cell lines expressing ABC transporters (P-gp, BCRP or ABCB5), mutant EGFR or p53 were not cross-resistant to CA compared to their parental counterparts. By pharmacogenomic approaches, we identified genes that belong to different functional groups (e.g. signal transduction, regulation of cytoskeleton and developmental regulatory system). These genes were predicted as molecular determinants that mediate CA tumor cellular responses. The top affected biofunctions included cellular development, cellular proliferation and cellular death and survival. The effect of CA-mediated apoptosis in leukemia cells, which were recognized as the most sensitive tumor type, was confirmed via flow cytometry and western blot analysis.

CONCLUSION

CA may provide a novel treatment option to target refractory tumors and to effectively cooperate with established chemotherapy. Using pharmacogenomic approaches and network pharmacology, the relationship between cancer complexity and multi-target potentials of CA was analyzed and many putative molecular determinants were identified. They could serve as novel targets for CA and further studies are needed to translate the possible implications to clinical cancer treatment.

HOXB5 promotes the progression of breast cancer through wnt/beta-catenin pathway

OBJECTIVE

The present study was designed to explore the function of HOXB5 in breast cancer and related signaling pathway.

METHODS

Breast cancer tissues and non-cancerous tissues were collected from 82 cases who were pathologically diagnosed with breast cancer. The mRNA level of HOXB5 was detected via quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was adopted to analyze the association of HOXB5 with clinical features. The viability, migration and invasion of breast cancer cells were detected through MTT and Transwell assays, respectively. Protein analysis was performed adopting western blot analysis.

RESULTS

HOXB5 expression was increased in breast cancer tissues and cells, and showed positive correlation with tumor size (P = 0.028), TNM stage (P = 0.048), and lymph node metastasis (P = 0.002). Losing HOXB5 expression suppressed clone formation, proliferation, migration and invasion of breast cancer cells. The knockdown of HOXB5 significantly inactivated wnt/β-catenin pathway. Furthermore, wnt/β-catenin pathway had the potential to neutralize the oncogenic function of HOXB5 in breast cancer.

CONCLUSION

HOXB5 may be involved in the invasive progression of breast cancer. The function of HOXB5 in breast cancer was mediated by wnt/β-catenin pathway.

Context-dependent HOX transcription factor function in health and disease

During animal development, HOX transcription factors determine the fate of developing tissues to generate diverse organs and appendages. The power of these proteins is striking: mis-expressing a HOX protein causes homeotic transformation of one body part into another. During development, HOX proteins interpret their cellular context through protein interactions, alternative splicing, and post-translational modifications to regulate cell proliferation, cell death, cell migration, cell differentiation, and angiogenesis. Although mutation and/or mis-expression of HOX proteins during development can be lethal, changes in HOX proteins that do not pattern vital organs can result in survivable malformations. In adults, mutation and/or mis-expression of HOX proteins disrupts their gene regulatory networks, deregulating cell behaviors and leading to arthritis and cancer. On the molecular level, HOX proteins are composed of DNA binding homeodomain, and large regions of unstructured, or intrinsically disordered, protein sequence. The primary roles of HOX proteins in arthritis and cancer suggest that mutations associated with these diseases in both the structured and disordered regions of HOX proteins can have substantial functional effects. These insights lead to new questions critical for understanding and manipulating HOX function in physiological and pathological conditions.

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.

Identification of Potential Biomarkers Associated with Basal Cell Carcinoma

Purpose

This work is aimed at identifying several molecular markers correlated with the diagnosis and development of basal cell carcinoma (BCC).

Methods

The available microarray datasets for BCC were obtained from the Gene Expression Omnibus (GEO) database, and differentially expressed genes (DEGs) were identified between BCC and healthy controls. Afterward, the functional enrichment analysis and protein-protein interaction (PPI) network analysis of these screened DEGs were performed. An external validation for the DEG expression level was also carried out, and receiver operating characteristic curve analysis was used to evaluate the diagnostic values of DEGs.

Result

In total, five microarray datasets for BCC were downloaded and 804 DEGs (414 upregulated and 390 downregulated genes) were identified. Functional enrichment analysis showed that these genes including CYFIP2, HOXB5, EGFR, FOXN3, PTPN3, CDC20, MARCKSL1, FAS, and PTCH1 were closely correlated with the cell process and PTCH1 played central roles in the BCC signaling pathway. Moreover, EGFR was a hub gene in the PPI network. The expression changes of six genes (CYFIP2, HOXB5, FOXN3, PTPN3, MARCKSL1, and FAS) were validated by an external GSE74858 dataset analysis. Finally, ROC analysis revealed that CYFIP2, HOXB5, PTPN3, MARCKSL1, PTCH1, and CDC20 could distinguish BCC and healthy individuals.

Conclusion

Nine gene signatures (CYFIP2, HOXB5, EGFR, FOXN3, PTPN3, CDC20, MARCKSL1, FAS, and PTCH1) may serve as promising targets for BCC detection and development.

Homeobox B5 suppression attenuates proliferation and elevates apoptosis in hepatoma cell lines through ERK/MDM2 signalling

Homeobox B5 (HOXB5), a member of the HOX gene family, is an important gene in tumourigenesis. However, its role in hepatocellular carcinoma (HCC) cell proliferation and apoptosis remains unclear. In this study, we investigated the role and regulation mechanism of HOXB5 in HCC cell lines Hep3B and LM6. The data indicated high expression of HOXB5 in HCC tissues and cell lines. In HCC cells, inhibition of HOXB5 by transfection with HOXB5 siRNA significantly constrained cell viability, and Bcl-2 levels, and it increased cell apoptosis, cytochrome c levels, BAX levels, and caspase-3 activity. On the contrary, HOXB5 overexpression increased proliferation and Bcl-2 levels but inhibited BAX levels and caspase-3 activity in these cells. HOXB5 downregulation attenuated activation of extracellular signal-regulated kinase (ERK) and expression of the murine double minute 2 (MDM2) oncogene. Incubation with the ERK activator, phorbol 12-myristate 13-acetate (40 μmol/L), for 12 hours reversed the effects of HOXB5 inhibition on MDM2 expression, cell proliferation, and apoptosis in HCC cells. Overall, this study demonstrated that HOXB5 inhibition regulated MDM2 expression by controlling ERK activation and that it modulated proliferation and apoptosis in HCC cells.

HOX genes function in Breast Cancer development

Breast cancer develops in the mammary glands during mammalian adulthood and is considered the second most common type of human carcinoma and the most incident and mortal in the female population. In contrast to other human structures, the female mammary glands continue to develop after birth, undergoing various modifications during pregnancy, lactation and involution under the regulation of hormones and transcription factors, including those encoded by the HOX clusters (A, B, C, and D). Interestingly, HOX gene deregulation is often associated to breast cancer development. Within the HOXB cluster, 8 out of the 10 genes present altered expression levels in breast cancer with an impact in its aggressiveness and resistance to hormone therapy, which highlights the importance of HOXB genes as potential therapeutic targets used to overcome the limitations of tamoxifen-resistant cancer treatments. Here, we review the current state of knowledge on the role of HOX genes in breast cancer, specially focus on HOXB, discussing the causes and consequences of HOXB gene deregulation and their relevance as prognostic factors and therapeutic targets.

HOXB5 promotes malignant progression in pancreatic cancer via the miR-6732 pathway

Background: Homeobox B5 (HOXB5) is associated with the poor prognosis of various cancer types. However, the specific mechanism by which HOXB5 promotes the malignant progression of pancreatic cancer (PC) remains to be determined.Methods: The Cancer Genome Atlas database indicated HOXB5 expression level correlated to PC prognosis. The biological functions of HOXB5 was confirmed by colony formation, migration, and invasion assays. The effects of HOXB5 on the expression of cancer stem cell and epithelial-mesenchymal transition markers were evaluated. The downstream target of HOXB5 was miR-6723, which was detected by transcriptional assay. A xenograft tumor model was established in nude mice for the assessment of the role of HOXB5 in tumor growth and metastasis.Results: PC tissues had higher HOXB5 expression levels than noncancerous tissues, and high HOXB5 expression was significantly associated with poor PC prognosis. HOXB5 knockdown suppressed clone formation and the proliferation, invasion, and migration of PC cells in vitro. Conversely, these activities were enhanced by HOXB5 overexpression. The HOXB5 that bound two synergy motifs regulated miR-6723 expression and contributed to PC malignant progression. The role of HOXB5 in promoting tumor growth and metastasis was verified in vivo. Further investigation revealed that Twist1 and Zeb1 expression levels were increased by HOXB5.Conclusions: HOXB5 overexpression was significantly correlated with poor PC prognosis. HOXB5 accelerated the malignant progression of PC by up-regulating miR-6723, which afforded PC cells stem-like properties and facilitated the epithelial-mesenchymal transition of PC cells.

HOXB5 acts as an oncogenic driver in head and neck squamous cell carcinoma via EGFR/Akt/Wnt/β-catenin signaling axis

INTRODUCTION

Identification of therapeutic targets in head and neck squamous cell carcinoma (HNSCC) is essential because most of the patients with advanced HNSCC have a poor prognosis. Homeobox genes constitute a large cluster of transcription factors with important regulatory roles in mammalian embryonic development and cell differentiation. The oncogenic role of homeobox B5 (HOXB5) in HNSCC has not been investigated.

MATERIALS AND METHODS

We used The Cancer Genome Atlas (TCGA) data to evaluate the correlations between HOXB5 expression and various HNSCC clinicopathological factors. We knocked down HOXB5 expression in HNSCC cell lines and explored the in vitro and in vivo effects on cell proliferation and motility, and HOXB5 signaling.

RESULTS

The Cancer Genome Atlas (TCGA) data shows that HOXB5 is overexpressed in HNSCC compared to normal tissues and significantly associates with tumor stage (P = 0.003), lymph node metastasis (P = 0.031), disease stage (P = 0.002), and angiolymphatic invasion (P = 0.004). Our results also show that HOXB5 expression is up-regulated in HNSCC cell lines, and HOXB5 knockdown significantly reduced cell proliferation and tumor growth in vitro and in vivo. Inhibition of HOXB5 decreases cell migration and invasion via suppression of epithelial-to-mesenchymal transition (EMT)-associated proteins expression. Moreover, HOXB5 directly binds to the promoter region of EGFR and consequently regulates the activity of the Akt/Wnt/β-catenin signaling axis.

CONCLUSION

HOXB5 may be a novel therapeutic target as an oncogenic driver by regulating EGFR transcription in HNSCC.

Overexpression of HOXC6 promotes cell proliferation and migration via MAPK signaling and predicts a poor prognosis in glioblastoma

Background

Homeobox (HOX) genes encode transcription factors that are critical to morphogenesis and cell differentiation. Although the dysregulation of several HOX genes in glioblastoma (GBM) has been reported, little is known about HOXC6 expression in GBM. Therefore, in this study, we investigated the expression levels of the HOXC6 in GBM and explored the regulatory mechanism underlying the role of HOXC6 in GBM progression.

Methods

The ONCOMINE and Oncolnc databases were used to predict the expression level of HOXC6 mRNA and its prognostic value in GBM. The expressions of HOXC6 mRNA in GBM tissues and adjacent brain tissues were detected using qRT-PCR and Western blot. Immunohistochemistry was performed to verify the HOXC6 protein expression in 107 GBM tissues. Kaplan–Meier and Cox analyses were performed to validate the correlation between HOXC6 expression and GBM prognosis. Lentivirus-mediated HOXC6 mRNA overexpression and interference system were established and transfected into U251 and U87 cell lines. CCK-8, colony formation, wound healing and transwell assay were utilized to evaluate the effects of HOXC6 on proliferation and migration of human GBM cells.

Results

High expression of HOXC6 was observed in GBM tissues and GBM cells lines, and it correlated with a decreased overall survival and disease-free survival. Overexpression of HOXC6 promoted the GBM cell proliferation and migration, whereas depletion of HOXC6 reduced GBM cell proliferation and migration. Mechanistic study showed that upregulation of HOXC6 significantly increased the phosphorylation of Jun amino-terminal kinase, ERK and P38, as well as the expression of mitogen-activated protein kinase (MAPK) signaling–related genes, including c-myc, c-jun and p53. Inversely, silencing HOXC6 showed the opposite results.

Conclusion

HOXC6 promoted proliferation and migration of GBM cells via the activation of MAPK pathway.

Dysregulation of DNA methylation patterns may identify patients with breast cancer resistant to endocrine therapy: A predictive classifier based on differentially methylated regions

Endocrine therapy (ET) is one of a number of targeted therapies for estrogen receptor-positive breast cancer (BRCA); however, resistance to ET has become the primary issue affecting treatment outcome. In the present study, a predictive classifier was created using a DNA methylation dataset to identify patients susceptible to endocrine resistance. DNA methylation and RNA sequencing data, and the clinicopathological features of BRCA, were obtained from The Cancer Genome Atlas. Stringent criteria were set to select and classify patients into two groups, namely those resistant to ET (n=11) and sensitive to ET (n=21) groups. Bump hunting analysis revealed that 502 out of 135,418 genomic regions were differentially methylated between these two groups; these regions were differentially methylated regions (DMRs). The majority of the CpG sites contained in the DMRs mapped to the promoter region. Functional enrichment analyses indicated that a total of 562 specific genes encompassing these DMRs were primarily associated with 'biological progress of organ morphogenesis and development' and 'cell-cell adhesion' gene ontologies. Logistic regression and Pearson's correlation analysis were conducted to construct a predictive classifier for distinguishing patients resistant or sensitive to ET. The highest areas under the curve and relatively low Akaike information criterion values were associated with a total of 60 DMRs; a risk score retained from this classifier was revealed to be an unfavorable predictor of survival in two additional independent datasets. Furthermore, the majority of genes (55/63) exhibited a statistically significant association between DNA methylation and mRNA expression (P<0.05). The association between the mRNA expression of a number of genes (namely calcium release activated channel regulator 2A, Schlafen family member 12, chromosome 3 open reading frame 18, zinc finger protein 880, dual oxidase 1, major histocompatibility complex, class II, DP β1, C-terminal binding protein 1, ALG13 UDP-N-acetylglucosaminyltransferase subunit and RAS protein activator like 2) and the prognosis of patients with estrogen receptor-positive BRCA and ET resistance was determined using Kaplan-Meier Plotter. In summary, the predictive classifier proposed in the present study may aid the identification of patients sensitive or resistant to ET, and numerous genes maybe potential therapeutic targets to delay the development of resistance to ET.

MicroRNA-625 inhibits the progression of non‑small cell lung cancer by directly targeting HOXB5 and deactivating the Wnt/β-catenin pathway

Numerous microRNAs (miRs) are dysregulated in non‑small cell lung cancer (NSCLC), serving pivotal roles in its formation and progression. miR‑625 is dysregulated in several types of human cancer, but its involvement in the formation and development of NSCLC remains poorly understood. In the present study, we aimed to investigate miR‑625 expression in NSCLC and its role in regulating NSCLC cell behavior. miR‑625 expression in NSCLC tissues and cell lines was detected using reverse transcription‑quantitative polymerase chain reaction. The effects of miR‑625 overexpression on NSCLC cell proliferation, apoptosis, migration and invasion in vitro were assessed using an MTT assay, flow cytometry, and cell migration and invasion assays, respectively. The effects of miR‑625 upregulation on NSCLC growth were evaluated in an in vivo xenograft model. The molecular mechanisms underlying the tumor‑suppressing roles of miR‑625 in NSCLC were explored in detail. miR‑625 expression was determined to be downregulated in NSCLC tissues and cell lines. This decreased expression was associated with advanced clinical features and poor overall survival of patients with NSCLC. Exogenous miR‑625 expression suppressed NSCLC cell proliferation, migration and invasion, and induced apoptosis in vitro. miR‑625 upregulation hindered NSCLC tumor growth in vivo. Homeobox B5 (HOXB5) was proposed to be the direct target gene of miR‑625 in NSCLC cells. The tumor‑suppressing effects of HOXB5 silencing were similar to those of miR‑625 overexpression in NSCLC cells. In rescue experiments, HOXB5 overexpression partially reversed the inhibitory effects of miR‑625 in NSCLC cells. miR‑625 upregulation directly targeted HOXB5 to deactivate the Wnt/β‑catenin signaling pathway in NSCLC cells in vitro and in vivo. miR‑625 was determined to be associated with HOXB5 suppression and Wnt/β‑catenin pathway deactivation, which in turn inhibited the aggressive behavior of NSCLC cells in vitro and in vivo.

Up-regulation of HOXB cluster genes are epigenetically regulated in tamoxifen-resistant MCF7 breast cancer cells

Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

Down-regulation of HOXB5 inhibits TGF-β-induced migration and invasion in hepatocellular carcinoma cells via inactivation of the PI3K/Akt pathway

HOXB5, a member of the HOX gene family, is a developmental gene which encodes homeoproteins and is known to be a crucial player in development of enteric nervous systems. Recently, HOXB5 was reported to be associated with cancer progression. However, the specific effect of HOXB5 in hepatocellular carcinoma (HCC) remains unclear. In this study, we demonstrated the important role of HOXB5 in HCC. We showed that HOXB5 was up-regulated in HCC tissues and cell lines. Furthermore, down-regulation of HOXB5 inhibited TGF-β-induced HCC cell migration and invasion in vitro and suppressed tumor metastasis in vivo. We also found that the PI3K/Akt pathway partly accounted for the mechanisms underlying the inhibitory effect of HOXB5 down-regulation on TGF-β-induced HCC progression. Taken together, these findings demonstrated that down-regulation of HOXB5 inhibits TGF-β-induced migration and invasion in HCC cells via inactivation of the PI3K/Akt pathway. Thus, HOXB5 may be a novel therapeutic target for HCC treatment.

Downregulation of HOXA13 sensitizes human esophageal squamous cell carcinoma to chemotherapy

BACKGROUND

Chemoresistance often develops in esophageal squamous cell carcinoma (ESCC), leading to poor prognosis. HOX genes play a crucial role in embryonic development and cell differentiation. Studies have recently linked HOX with chemoresistance, thus we explored whether HOXA13 is involved in ESCC chemoresistance.

METHODS

One hundred thirty-one ESCC patients who received neoadjuvant chemotherapy were enrolled. HOXA13 expression was examined by immunohistochemistry. RNA interference was used to knock down the HOXA13 expression in KYSE70 and transfected HOXA13 plasmid to overexpress HOXA13 in KYSE510 cells. We examined half-maximal inhibitory concentration of cisplatin, apoptosis, and epithelial-to-mesenchymal transition (EMT) in ESCC cell lines with different HOXA13 expression levels by cell counting kit-8, flow cytometry, and transwell analysis.

RESULTS

The median survival of patients with high HOXA13 expression was significantly shorter than those with low expression (P = 0.027). HOXA13 was associated with worse tumor regression grade (P = 0.009). Low HOXA13 expressed cells decreased the half-maximal inhibitory concentration of cisplatin (P < 0.05), increased cisplatin-induced apoptosis (P < 0.05), and decreased EMT (P < 0.05) compared with high HOXA13 expressed cells. In low HOXA13 expressed cells, cleaved caspase-3 and cleaved PARP expression induced by cisplatin increased, while expression of E-cadherin and Snail protein, markers of EMT, was upregulated and downregulated, respectively. EMT decreased in low HOXA13 expressed cells.

CONCLUSION

High HOXA13 expression was associated with inferior tumor regression grade and poor overall survival in ESCC patients treated with neoadjuvant chemotherapy. HOXA13 increased cisplatin-resistance and promoted EMT in ESCC cells.

HOXB5 promotes retinoblastoma cell migration and invasion via ERK1/2 pathway-mediated MMPs production

Homeobox genes (HOX genes) have been implicated in many tumors. As a member of HOX genes, HOXB5 is overexpressed in bladder cancer and contributes to the proliferation and invasion of breast cancer cells. However, functions of HOXB5 in retinoblastoma remain elusive. In this study, we found that HOXB5 expression is upregulated in retinoblastoma cell lines and tissues. Overexpression of HOXB5 promoted retinoblastoma cell migration and invasion, but knockdown of HOXB5 suppressed the migration and invasion. Moreover, HOXB5 induced the activation of ERK1/2 and upregulated the production of MMP-3 and MMP-13. In addition, ERK1/2 pathway was required for HOXB5-mediated retinoblastoma cell migration and invasion. Taken together, our study suggests that HOXB5 promotes the migration and invasion of retinoblastoma cells by inducing the activation of ERK1/2 and increasing the production of MMP-3 and MMP-13. Therefore, HOXB5 may represent an effective target for treatment of retinoblastoma.

The untold stories of the speech gene, the FOXP2 cancer gene

FOXP2 encodes a transcription factor involved in speech and language acquisition. Growing evidence now suggests that dysregulated FOXP2 activity may also be instrumental in human oncogenesis, along the lines of other cardinal developmental transcription factors such as DLX5 and DLX6 [1-4]. Several FOXP familymembers are directly involved during cancer initiation, maintenance and progression in the adult [5-8]. This may comprise either a pro-oncogenic activity or a deficient tumor-suppressor role, depending upon cell types and associated signaling pathways. While FOXP2 is expressed in numerous cell types, its expression has been found to be down-regulated in breast cancer [9], hepatocellular carcinoma [8] and gastric cancer biopsies [10]. Conversely, overexpressed FOXP2 has been reported in multiple myelomas, MGUS (Monoclonal Gammopathy of Undetermined Significance), several subtypes of lymphomas [5,11], as well as in neuroblastomas [12] and ERG fusion-negative prostate cancers [13]. According to functional evidences reported in breast cancer [9] and survey of recent transcriptomic and proteomic analyses of different tumor biopsies, we postulate that FOXP2 dysregulation may play a main role throughout cancer initiation and progression. In some cancer conditions, FOXP2 levels are now considered as a critical diagnostic marker of neoplastic cells, and in many situations, they even bear strong prognostic value [5]. Whether FOXP2 may further become a therapeutic target is an actively explored lead. Knowledge reviewed here may help improve our understanding of FOXP2 roles during oncogenesis and provide cues for diagnostic, prognostic and therapeutic analyses.

Depletion of CTCF in Breast Cancer Cells Selectively Induces Cancer Cell Death via p53

CCCTC-binding factor (CTCF), a ubiquitous 11-zinc finger multifunctional protein, has distinct molecular functions, such as transcriptional activation, repression, and chromatin barrier activity, in a locus-specific manner. Elevated CTCF levels in breast cancer cells are known to contribute to tumorigenesis; however, the underlying mechanism remains elusive. We investigated the effect of CTCF expression on breast cancer cell survival and elucidated its mechanism. CTCF depletion in MCF-7 cells led to a decreased cell growth and proliferation, surpassing the growth of normal cells under co-culture system of MCF-7-GFP and MCF10A. Here we propose that the phenotypes observed in CTCF-depleted MCF-7 cancer cells, such as reduced cell proliferation, increased apoptosis, and cell cycle arrest, are closely linked with the activation of p53. The consensus CTCF-binding site, located approximately 800 bp upstream of the first exon of TP53, was marked by H3K27me3, but not by the active mark H3K4me3, although CTCF is expressed. Knockdown of CTCF conversely led to the recruitment of H3K4me3 instead of H3K27me3, accompanying with the higher enrichment of PolII in the proximal promoter region of TP53. With the activation of p53, increased p21 and Bax expressions were observed in CTCF knockdown MCF-7 cells. Elucidating functional roles of CTCF and regulation mechanisms may help to guide CTCF and/or its related molecules as a therapeutic target to prevent cancer cell growth.

Knockdown of Homeobox B5 (HOXB5) Inhibits Cell Proliferation, Migration, and Invasion in Non-Small Cell Lung Cancer Cells Through Inactivation of the Wnt/β-Catenin Pathway

Homeobox B5 (HOXB5), a member of the HOX gene family, has been shown to play an important role in tumor progression. However, the expression and functional role of HOXB5 in human non-small cell lung cancer (NSCLC) have not been defined. Thus, the purpose of this study was to elucidate the expression and functional role of HOXB5 in human NSCLC. Our results showed that HOXB5 expression was elevated in human NSCLC tissues and cell lines. The in vitro experiments demonstrated that knockdown of HOXB5 inhibited proliferation, migration, and invasion and prevented the EMT phenotype in NSCLC cells. In vivo experiments indicated that knockdown of HOXB5 attenuated the growth of NSCLC xenografts in vivo. Furthermore, knockdown of HOXB5 suppressed the protein expression levels of β-catenin and its downstream targets c-Myc and cyclin D1 in A549 cells. Taken together, for the first time we have shown that knockdown of HOXB5 significantly inhibited NSCLC cell proliferation, invasion, metastasis, and EMT, partly through the Wnt/β-catenin signaling pathway. These findings suggest that HOXB5 may be a novel therapeutic target for the treatment of NSCLC.

The mitotic checkpoint regulator RAE1 induces aggressive breast cancer cell phenotypes by mediating epithelial-mesenchymal transition

The gene RAE1 encodes ribonucleic acid export 1 (RAE1), which is involved in mRNA export and is known to serve as a mitotic checkpoint regulator. In addition, RAE1 haplo-insufficiency leads to chromosome missegregation and early aging-associated phenotypes. In humans, a positive correlation has been found between RAE1 copy number abnormalities and gene amplification in breast cancer cells. However, the precise functional role of RAE1 in breast cancer remains to be determined. An in silico analysis of data retrieved from GENT and cBio-Portal identified RAE1 upregulation in breast cancer tissues relative to normal breast cells. Functional studies of various cell lines showed that RAE1 induced invasive and migratory abilities by regulating epithelial-mesenchymal transition signals. A tissue microarray was constructed to demonstrate the interrelationship between clinicopathological features and RAE1 expression. Immunohistochemistry revealed a positive correlation between RAE1 expression and a high histologic grade. Furthermore, RAE1 overexpression was associated with considerably poorer disease-free survival and distant metastasis-free survival, especially in patients with oestrogen receptor-positive tumours. In summary, RAE1 may be a prognostic marker and therapeutic intervention target in malignant breast cancers.

Fascin Induces Epithelial-Mesenchymal Transition of Cholangiocarcinoma Cells by Regulating Wnt/β-Catenin Signaling

Background

Our preliminary study suggested that the expression of Fascin was increased in cholangiocarcinoma, which indicating poor prognosis The present study aimed to explore the roles and mechanisms of Fascin during the progression of cholangiocarcinoma.

Material/Methods

We evaluated the knockdown effect of endogenous Fascin expression by Short hairpin RNA (shRNA) in QBC939 cells. Cell proliferation was confirmed by MTS assay. Migration and invasion assay was used to examine the cell invasive ability. Tumorigenesis abilities in vivo were analyzed with a xenograft tumor model. Western blot analysis was used to test epithelial-mesenchymal transition (EMT) biomarkers and critical proteins in the Wnt/β-catenin signaling pathway.

Results

shRNA-mediated gene knockdown of Fascin significantly inhibited cell proliferation, invasion, and EMT, and shRNA-Fascin markedly inhibited the xenograft tumor volume. Silencing of Fascin up-regulated phosphorylation of β-catenin and decreased its nuclear localization. Additionally, knockdown of Fascin led to the upregulation of β-catenin and E-cadherin expression in plasma membrane fraction of QBC939 cells.

Conclusions

Our data indicate a key role of Fascin in cell proliferation, migration, and invasion in cholangiocarcinoma. Fascin promotes EMT of cholangiocarcinoma cells, in part through regulating Wnt/β-catenin signaling.

MicroRNA-1275 suppresses cell growth, and retards G1/S transition in human nasopharyngeal carcinoma by down-regulation of HOXB5

Through analysis of a reported microarray-based high-throughput examination, we found that miR-1275 was significantly down-regulated in nasopharyngeal carcinoma (NPC). While its role and mechanism participated in NPC progression are still little known. Here, we explored the effect of miR-1275 on the progression of NPC. Results demonstrated that miR-1275 was markedly down-regulated in NPC tissues and cell lines. MiR-1275 markedly repressed cell growth as confirmed by CCK8 and colony formation assay, via inhibition of HOXB5 in NPC cell lines. Moreover, miR-1275 suppressed G1/S transition via inhibition of HOXB5. Further, oncogene HOXB5 was evidenced to be a potential target of miR-1275, and its expression was conversely correlated with miR-1275 expression in NPC. Collectively, our study indicated that miR-1275, a tumor suppressor, played a critical effect on NPC progression via inhibition of cell growth, and suppression of G1/S transition by targeting oncogenic HOXB5.

HOXC9 Induces Phenotypic Switching between Proliferation and Invasion in Breast Cancer Cells

HOX genes encode a family of transcriptional regulators that are involved in pattern formation and organogenesis during embryo development. In addition, these genes play important roles in adult tissues and some of the dysregulated HOX genes are associated with cancer development and metastasis. Like many other HOX genes, HOXC9 is aberrantly expressed in certain breast cancer cell lines and tissues; however, its specific functions in breast cancer progression were not investigated. In the present study, we demonstrated that HOXC9 overexpression in breast cancer cell lines such as MDA-MB-231 and MCF7 increased the invasiveness but reduced the proliferation of cells, resembling a phenotype switch from a proliferative to an invasive state. Furthermore, the reciprocal result was detected in MCF7 and BT474 cells when the expression level of HOXC9 was reduced with siRNA. The clinical impact of HOXC9 in breast cancer was interpreted from the survival analysis data, in which high HOXC9 expression led to considerably poorer disease-free survival and distant metastasis-free survival, especially in lymph node-positive patients. Together, the prognostic relevance of HOXC9 and the HOXC9-derived phenotypic switch between proliferative and invasive states in the breast cancer cell lines suggest that HOXC9 could be a prognostic marker in breast cancer patients with lymph node metastasis and a target for therapeutic intervention in malignant breast cancer.

A Stable Thoracic Hox Code and Epimorphosis Characterize Posterior Regeneration in Capitella teleta

Regeneration, the ability to replace lost tissues and body parts following traumatic injury, occurs widely throughout the animal tree of life. Regeneration occurs either by remodeling of pre-existing tissues, through addition of new cells by cell division, or a combination of both. We describe a staging system for posterior regeneration in the annelid, Capitella teleta, and use the C. teleta Hox gene code as markers of regional identity for regenerating tissue along the anterior-posterior axis. Following amputation of different posterior regions of the animal, a blastema forms and by two days, proliferating cells are detected by EdU incorporation, demonstrating that epimorphosis occurs during posterior regeneration of C. teleta. Neurites rapidly extend into the blastema, and gradually become organized into discrete nerves before new ganglia appear approximately seven days after amputation. In situ hybridization shows that seven of the ten Hox genes examined are expressed in the blastema, suggesting roles in patterning the newly forming tissue, although neither spatial nor temporal co-linearity was detected. We hypothesized that following amputation, Hox gene expression in pre-existing segments would be re-organized to scale, and the remaining fragment would express the complete suite of Hox genes. Surprisingly, most Hox genes display stable expression patterns in the ganglia of pre-existing tissue following amputation at multiple axial positions, indicating general stability of segmental identity. However, the three Hox genes, CapI-lox4, CapI-lox2 and CapI-Post2, each shift its anterior expression boundary by one segment, and each shift includes a subset of cells in the ganglia. This expression shift depends upon the axial position of the amputation. In C. teleta, thoracic segments exhibit stable positional identity with limited morphallaxis, in contrast with the extensive body remodeling that occurs during regeneration of some other annelids, planarians and acoel flatworms.

Homeobox C9 suppresses Beclin1-mediated autophagy in glioblastoma by directly inhibiting the transcription of death-associated protein kinase 1

BACKGROUND

The transcription factor homeobox C9 (HOXC9) plays a crucial role in developmental regulatory systems, where it determines the specific positional identities of cells along the anteroposterior axis. The expression of HOXC9 has been found to be dysregulated in some cancers such as lung cancer, breast cancer, and neuroblastoma. Here, we report for the first time that HOXC9 is a novel autophagy regulator and reveal its oncogenic role in cell survival and its usefulness as a prognostic marker in glioblastoma patients.

METHODS

Kaplan-Meier analysis was performed to evaluate the possible prognostic value of HOXC9 in glioblastoma. Growth curve assays, subcutaneous, and orthotopic implantations were used to analyze cell viability and tumor formation, respectively. Luciferase and chromatin immunoprecipitation assays were employed to explore the mechanisms involved in the association between HOXC9 and its downstream effector, death-associated protein kinase 1 (DAPK1).

RESULTS

High expression of HOXC9 was found to be an indicator of a poor prognosis in glioblastoma. HOXC9 knockdown resulted in a significant reduction of cell viability, migration, invasion, and tumorigenicity and a marked increase in autophagy. During the autophagy process, HOXC9 inhibited DAPK1 transcription by directly binding to its promoter. The downregulation of HOXC9 releases its transcriptional inhibition of DAPK1, resulting in the activation of the DAPK1-Beclin1 pathway, which induces autophagy in glioblastoma cells.

CONCLUSIONS

Collectively, our data indicate that HOXC9 is an oncogene in glioblastoma. We have revealed its role in the control of autophagy, and we suggest that HOXC9 is a novel and promising therapeutic target.