HOXC6-mediated transcriptional activation of ENO2 promotes oral squamous cell carcinoma progression through the Warburg effect.

Oral squamous cell carcinoma (OSCC) requires an in-depth exploration of its molecular mechanisms. The Warburg effect, along with the oncogenes enolase 2 (ENO2) and homeobox C6 (HOXC6), plays a central role in cancer. However, the specific interaction between ENO2 and HOXC6 in driving the Warburg effect and OSCC progression remains poorly understood. Through differential gene expression analysis in head and neck squamous cell carcinomas using Gene Expression Profiling Interactive Analysis, we identified upregulated ENO2 in OSCC. Silencing ENO2 in OSCC cells revealed its involvement in migration, invasion, and aerobic glycolysis of OSCC cells. Further exploration of ENO2's regulatory network identified HOXC6 as a potential transcriptional regulator. Subsequently, HOXC6 was silenced in OSCC cells, and expressions of ENO2 were assessed to validate its relationship with ENO2. Chromatin Immunoprecipitation and luciferase assays were utilized to investigate the direct transcriptional activation of ENO2 by HOXC6. A rescue assay co-overexpressing ENO2 and silencing HOXC6 in OSCC cells affirmed HOXC6's role in ENO2-associated glycolysis. High ENO2 expression in OSCC was validated through quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry analyses, which correlated with poor patient survival. Functional assays demonstrated that ENO2 silencing inhibited glycolysis and attenuated the aggressiveness of OSCC cells. In vivo studies confirmed the oncogenic role of ENO2 in OSCC growth. Notably, HOXC6 exhibited a positive correlation with ENO2 expression in clinical samples. Mechanistically, HOXC6 was identified as a direct transcriptional activator of ENO2, orchestrating the Warburg effect in OSCC cells. This study reveals the intricate link between HOXC6-mediated ENO2 transcriptional activation and the Warburg effect in OSCC, offering a potential therapeutic target for treating OSCC patients.

METTL3 facilitates prostate cancer progression via inducing HOXC6 m6A modification and stabilizing its expression through IGF2BP2-dependent mechanisms.

HOXC6 (Homeobox C6) and methyltransferase-like 3 (METTL3) have been shown to be involved in the progression of prostate cancer (PCa). However, whether HOXC6 performs oncogenic effects in PCa via METTL3-mediated N6-methyladenosine (m6A) modification is not yet reported. The Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, scratch, sphere formation assays were applied for cell growth, invasion, migration and stemness analyses. Glycolysis was evaluated by measuring glucose consumption, lactate generation and ATP/ADP ratio. The N6-methyladenine (m6A) modification profile was determined by RNA immunoprecipitation (Me-RIP) assay. The proteins that interact with PGK1 (phosphoglycerate kinase 1) were confirmed by Co-immunoprecipitation assay. Tumor formation experiments in mice were conducted for in vivo assay. PCa tissues and cells showed highly expressed HOXC6 and METTL3. Functionally, the silencing of HOXC6 or METTL3 suppresses PCa cell proliferation, invasion, migration, stemness, and glycolysis. Moreover, METTL3-induced HOXC6 m6A modification to stabilize its expression. In addition, the m6A reader IGF2BP2 directly recognized and bound to HOXC6 mRNA, and maintained its stability, and was involved in the regulation of HOXC6 expression by METTL3. Furthermore, IGF2BP2 knockdown impaired PCa cell proliferation, invasion, migration, stemness, and glycolysis by regulating HOXC6. Besides that HOXC6 interacted with the glycoytic enzyme PGK1 in PCa cells. In vivo assays further showed that METTL3 silencing reduced the expression of HOXC6 and PGK1, and impeded PCa growth. METTL3 promoted PCa progression by maintaining HOXC6 expression in an m6A-IGF2BP2-dependent mechanism.

HOXC6: A promising biomarker linked to an immunoevasive microenvironment in colorectal cancer based on TCGA analysis and cohort validation.

HOXC6 plays an essential part of the carcinogenesis of solid tumors, but its functional relevance within the immune contexture in patients with colorectal cancer (CRC) is still uncertain. We intended to investigate the predictive value of HOXC6 expression for survival outcomes and its correlation with immune contexture in CRC patients by utilizing the Cancer Genome Atlas database (n = 619). Validation was performed in cohorts from Zhongshan Hospital (n = 200) and Shanghai Cancer Center (n = 300). Immunohistochemical (IHC) staining was utilized to compare the levels of immunocytes infiltrating the tumor between the groups with high and low expression of HOXC6. Elevated levels of HOXC6 expression in CRC tissues were linked to malignant progression and poor prognosis. HOXC6 as a risk factor for survival of CRC patients was confirmed. Receiver operating characteristic analysis confirmed its diagnostic value, and a reliable prognostic nomogram was constructed. KEGG analysis and GSEA showed that HOXC6 participated in immune regulation, and its expression was tightly linked to the abundance of infiltrating immunocytes. HOXC6 was upregulated in patients diagnosed with CRC within the two cohorts, and high HOXC6 levels were correlated with a worse prognosis. The high-HOXC6 expression group showed increased infiltration of Treg cells, CD68+ macrophages, CD66b+ neutrophils, and CD8+ T-cells and elevated levels of PD-L1 and PD-1, but decreased levels of granzyme B and perforin. These findings suggest that HOXC6 abundance in patients with CRC determines a poor prognosis, promotes an immunoevasive environment, and directs CD8+ T-cell dysfunction. HOXC6 is expected to become a prospective biomarker for the outcome of CRC.

HOXC6 drives a therapeutically targetable pancreatic cancer growth and metastasis pathway by regulating MSK1 and PPP2R2B.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, which lacks effective therapies. Here, we demonstrate that the transcription factor, homeobox C6 (HOXC6), is overexpressed in most PDACs, and its inhibition blocks PDAC tumor growth and metastasis. HOXC6 transcriptionally activates tumor-promoting kinase MSK1 and suppresses tumor-inhibitory protein PPP2R2B in PDAC. HOXC6-induced PPP2R2B suppression causes mammalian target of rapamycin (mTOR) pathway activation, which facilitates PDAC growth. Also, MSK1 upregulation by HOXC6 is necessary for PDAC growth because of its ability to suppress apoptosis via its substrate DDX17. Combinatorial pharmacological inhibition of MSK1 and mTOR potently suppressed PDAC tumor growth and metastasis in PDAC mouse models. PDAC cells with acquired resistance to MSK1/mTOR-inhibitors displayed activated insulin-like growth factor 1 receptor (IGF1R) signaling and were successfully eradicated by IGF1R inhibitor. Furthermore, MEK inhibitor trametinib enhanced the efficacy of dual MSK1 and mTOR inhibition. Collectively, these results identify therapeutic vulnerabilities of PDAC and an approach to overcome acquired drug resistance to prolong therapeutic benefit.

High expression of HOXC6 predicts a poor prognosis and induces proliferation and inflammation in multiple myeloma cells.

BACKGROUND: Multiple myeloma (MM) is a common blood system malignance accompanied by monoclonal plasma cell hyperplasia. Homeobox C6 (HOXC6) acts as an oncogene in various cancers, but its function on MM is elusive. OBJECTIVE: The role of HOXC6 on MM development was clarified in this study. METHODS: HOXC6 expression and its clinical significance were determined in the peripheral blood samples collected from forty MM patients and thirty healthy adult volunteers. The overall survival was evaluated by Kaplan-Meier analysis with the log-rank test. Cell viability, proliferation and apoptosis were measured by CCK-8, EdU assay and Flow cytometry in U266 and MM.1R cells. Tumor growth was estimated by a xenograft assay. The apoptosis of tumor tissues was evaluated using TUNEL staining. The protein level in tissues was tested by immunohistochemistry. RESULTS: The HOXC6 expression was elevated in MM and high HOXC6 level was associated with the poor overall survival of MM. Besides, the HOXC6 expression was associated with hemoglobin level and ISS stage. Furthermore, silencing HOXC6 suppressed cell proliferation, induced cell apoptosis, and restrained the secretion of inflammatory factors (TNF-α, IL-6, and IL-8) in MM cells through inactivating the NF-κB pathway. Moreover, silencing HOXC6 suppressed the tumor growth of MM, the inflammatory factors levels, and the activation of NF-κB pathway but enhanced apoptosis in vivo. CONCLUSION: HOXC6 was elevated in MM and associated with poor survival. Knockdown of HOXC6 suppressed proliferation, inflammation and tumorigenicity of MM cells via inactivating the NF-κB pathway. HOXC6 may be a meaningful target for MM therapy.

MicroRNA-574-5p targeting HOXC6 expression inhibits the hepatocyte lipid uptake to alleviate non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is one of the main causes of liver disease that has reached its last stage. Over the past few years, evidence for miRNAs' centrality in NAFLD pathogenesis has accumulated. According to some studies, miR-574-5p plays a role in lipid metabolism. However, research on the relationship between miR-574-5p and NAFLD is lacking. For in vivo experiments, we induced the NAFLD mice model with a high-fat diet (HFD). AgomiR-574-5p was injected intravenously into HFD-fed mice for eight weeks, and qPCR was used to identify the expression of miR-574-5p in the serum. In in vitro experiments, The treatment of L-O2 cells with a miR-574-5p mimic resulted in a significant reduction in lipid deposition, suggesting that miR-574-5p can inhibit lipid accumulation and lipid formation induced by OA. The dual-luciferase reporter gene assay revealed that miR-574-5p targets the 3' UTR region of HOXC6 directly. We discovered that OA-induced lipid accumulation in hepatocytes might be mediated through the miR-574-5p-HOXC6 signaling axis. Additional research is required in order to determine the specific mechanism by which HOXC6 downstream pathways are involved in the miR-574-5p induced lipid uptake.

The performance and limitations of PCA3, TMPRSS2:ERG, HOXC6 and DLX1 urinary markers combined in the improvement of prostate cancer diagnostics.

BACKGROUND: Prostate cancer (PCa) is the second most commonly diagnosed cancer in men. To date, the role of the combined application of long non-coding RNAs (PCA3, DLX1, HOXC6, TMPRSS2:ERG) for obtaining the most accurate method of detection of PCa has not yet been comprehensively investigated. METHODS: In total 240 persons were included in the retrospective study. Among them were 150 patients with confirmed PCa, 30 patients with benign prostatic hyperplasia, 30 patients with active chronic prostatitis and 30 healthy volunteers. In all patients, the urine samples were collected prior to biopsy or treatment. Polymerase chain reaction with reverse transcription was performed to detect the expression level of PCA3, HOXC6, DLX1 and the presence of the TMPRSS2:ERG transcript. RESULTS: PCA3 was detected in urine samples in all cases. Using a PCA3 score of 56 allowed the differentiation between PCa and all other cases with a sensitivity of 61% and specificity of 96% (p < 0.001) while a PCA3 score threshold value of 50 resulted in a differentiation between clinically significant PCa (ISUP grades 2-5) and all other cases with a sensitivity of 93% and specificity of 93% (p < 0.001). The TMPRSS2:ERG expression in urine was detected exclusively in the group of patients with PCa and only in 16% of all cases. CONCLUSIONS: PCA3 score detected in urine demonstrated moderate sensitivity and good specificity in differentiation between PCa and non-PCa and high sensitivity and specificity in differentiation between clinically significant PCa and non-PCa.

Multitranscriptome analyses of keloid fibroblasts reveal the role of the HIF-1α/HOXC6/ERK axis in keloid development.

Background: A keloid is a disease of excessive fibrosis that is characterized by the aberrant proliferation of fibroblasts. However, the molecular mechanisms of fibroblasts during the development of keloids remain unclear. This study aims to identify new molecular targets that promote the proliferation and migration of keloid fibroblasts, providing new ideas for the prevention and treatment of keloids. Methods: We utilized bioinformatics tools to analyze data from keloid fibroblasts (KFs) available in the Gene Expression Omnibus (GEO) database to identify the key genes involved in keloid development. Homeobox C6 (HOXC6) emerged as a hub gene in KFs from the GEO database was verified in keloid tissue samples and KFs using reverse transcription-quantitative polymerase chain reaction, western blot (WB) and immunohistochemistry. Subsequently, the effects of downregulated HOXC6 expression on the cellular behaviors of KFs were examined by performing Cell Counting Kit-8, flow cytometry, transwell migration and WB assays. Meanwhile, we performed transcriptome sequencing and gene set enrichment analysis (GSEA) to further explore HOXC6-related mechanisms and validated the signaling pathways by performing a series of experiments. Results: HOXC6 was the top-ranking hub gene of KFs in microarray datasets from GEO and was upregulated in keloid tissue samples and KFs. Downregulation of HOXC6 inhibited proliferation, migration and extracellular matrix (ECM) accumulation and promoted KF apoptosis. GSEA predicted that the hypoxia signaling pathway was associated with HOXC6 in KFs. Transcriptome sequencing suggested that the extracellular regulated protein kinase (ERK) pathway was one of the downstream pathways of HOXC6 in KFs. Our experiments confirmed that hypoxia-inducible factor-1α (HIF-1α) upregulates HOXC6, contributing to KFs proliferation, migration, apoptosis inhibition and collagen accumulation through the ERK signaling pathway. Conclusions: Our findings first revealed that HOXC6 acts as an oncogenic driver in the molecular mechanisms of fibroblasts in keloids. The HIF-1α/HOXC6/ERK axis promotes proliferation, migration and ECM production by KFs, contributing to the progression of keloids. Taken together, HOXC6 may serve as a promising novel therapeutic target and new focus for research designed to understand the pathogenesis of keloids.

HOXC6 impacts epithelial-mesenchymal transition and the immune microenvironment through gene transcription in gliomas.

BACKGROUND: Gliomas are the most common primary malignant tumours of the central nervous system (CNS). To improve the prognosis of glioma, it is necessary to identify molecular markers that may be useful for glioma therapy. HOXC6, an important transcription factor, is involved in multiple cancers. However, the role of HOXC6 in gliomas is not clear. METHODS: Bioinformatic and IHC analyses of collected samples (n = 299) were performed to detect HOXC6 expression and the correlation between HOXC6 expression and clinicopathological features of gliomas. We collected clinical information from 177 to 299 patient samples and estimated the prognostic value of HOXC6. Moreover, cell proliferation assays were performed. We performed Gene Ontology (GO) analysis and gene set enrichment analysis (GSEA) based on ChIP-seq and public datasets to explore the biological characteristics of HOXC6 in gliomas. RNA-seq was conducted to verify the relationship between HOXC6 expression levels and epithelial-mesenchymal transition (EMT) biomarkers. Furthermore, the tumour purity, stromal and immune scores were evaluated. The relationship between HOXC6 expression and infiltrating immune cell populations and immune checkpoint proteins was also researched. RESULTS: HOXC6 was overexpressed and related to the clinicopathological features of gliomas. In addition, knockdown of HOXC6 inhibited the proliferation of glioma cells. Furthermore, increased HOXC6 expression was associated with clinical progression. The biological role of HOXC6 in gliomas was primarily associated with EMT and the immune microenvironment in gliomas. High HOXC6 expression was related to high infiltration by immune cells, a low tumour purity score, a high stromal score, a high immune score and the expression of a variety of immune checkpoint genes, including PD-L1, B7-H3 and CLTA-4. CONCLUSIONS: These results indicated that HOXC6 might be a key factor in promoting tumorigenesis and glioma progression by regulating the EMT signalling pathway and might represent a novel immune therapeutic target in gliomas.

LINC01857 promotes the proliferation, migration, and invasion of gastric cancer cells via regulating miR-4731-5p/HOXC6.

The great importance of long non-coding RNAs (lncRNAs) in tumorigenesis has been acknowledged gradually. LINC01857 is previously reported to be highly expressed in gastric cancer (GC), while the regulatory mechanism of LINC01857 in GC is largely unknown. In this study, we detected high expression of LINC01857 from the GC microarray GSE109476. Additionally, LINC01857 expression is remarkably upregulated in GC cell lines (AGS, MKN-45, HGC-27, and SGC-7901) compared with the normal gastric mucosal cell line GES-1. Functionally, LINC01857 knockdown suppressed the proliferation, migration, invasion, and epithelial-mesenchymal transformation (EMT) of GC cells, while LINC01857 overexpression promoted the proliferation, migration, invasion, and EMT of GC cells. Furthermore, our data demonstrate that LINC01857 targeted miR-4731-5p and subsequently increased the expression of HOXC6 in GC. Rescue experiments showed that miR-4731-5p inhibition and HOXC6 overexpression could reverse the biological behavior of GC cells induced by LINC01857 knockdown. In conclusion, we demonstrated that LINC01857 sponged miR-4731-5p to promote the expression of HOXC6 and eventually acts as an oncogene in GC.

The Effects of Differentially-Expressed Homeobox Family Genes on the Prognosis and HOXC6 on Immune Microenvironment Orchestration in Colorectal Cancer.

Background: The homeobox (HOX) gene family encodes highly conserved transcription factors, that play important roles in the morphogenesis and embryonic development of vertebrates. Mammals have four similar HOX gene clusters, HOXA, HOXB, HOXC, and HOXD, which are located on chromosomes 7, 17,12 and 2 and consist of 38 genes. Some of these genes were found to be significantly related to a variety of tumors; however, it remains unknown whether abnormal expression of the HOX gene family affects prognosis and the tumor microenvironment (TME) reshaping in colorectal cancer (CRC). Therefore, we conducted this systematic exploration to provide additional information for the above questions. Methods: RNA sequencing data from The Cancer Genome Atlas (TCGA) and mRNA expression data from Gene Expression Omnibus (GEO) combined with online tumor analysis databases (UALCAN, TIMER, PrognoScan) were utilized to explore the relationship among abnormal expression of HOX family genes, prognosis and the tumor immune microenvironment in CRC. Results: 1. Differential expression and prognosis analysis: 24 genes were significantly differentially expressed in CRC compared to adjacent normal tissues, and seven upregulated genes were significantly associated with poor survival. Among these seven genes, univariate and multivariate Cox regression analysis revealed that only high expression of HOXC6 significantly contributed to poor prognosis; 2. The influence of overexpressed HOXC6 on the pathway and TME: High HOXC6 expression was significantly related to the cytokine pathway and expression of T cell attraction chemokines, the infiltration ratio of immune cells, expression of immune checkpoint markers, tumor mutation burden (TMB) scores and microsatellite instability-high (MSI-H) scores; 3. Stratified analysis based on stages: In stage IV, HOXC6 overexpression had no significant impact on TMB, MSI-H, infiltration ratio of immune cells and response prediction of immune checkpoint blockers (ICBs), which contributed to significantly poor overall survival (OS). Conclusion: Seven differentially expressed HOX family genes had significantly worse prognoses. Among them, overexpressed HOXC6 contributed the most to poor OS. High expression of HOXC6 was significantly associated with high immunogenicity in nonmetastatic CRC. Further research on HOXC6 is therefore worthwhile to provide potential alternatives in CRC immunotherapy.

Downregulation of HOXC6 by miR-27a ameliorates gefitinib resistance in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a major type of lung cancer. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), represented by gefitinib (Gef), are targeted drugs used for the treatment of NSCLC. However, NSCLC patients often develop resistance to tyrosine kinase inhibitors, which limits their efficacy. Homeobox gene HOXC6 is dysregulated in many cancers and contributes to chemoresistance in cancer cells. However, the role and mechanism of HOXC6 in the development of Gef resistance in NSCLC remains unclear. In the present study, we found that HOXC6 was highly expressed in Gef-resistant NSCLC cells. Further experiments showed that silencing of HOXC6 ameliorated Gef resistance in PC9/G cells whereas overexpression of HOXC6 promoted Gef resistance in PC9 cells. HOXC6 influenced Gef sensitivity in NSCLC cells by regulating cell proliferation, colony formation, cell apoptosis, cell cycle, cell mobility and other related signaling molecules or pathways. HOXC6 was also found to be a direct target of miR-27a. As expected, overexpression of miR-27a ameliorated Gef resistance by inhibiting HOXC6 expression in vitro and in vivo. Clinical analysis revealed that high HOXC6 levels and low miR-27a levels were significantly correlated with more malignant clinical features and poorer survival of NSCLC patients. In summary, the present study demonstrates that HOXC6 may be a potential therapeutic target for overcoming Gef resistance in NSCLC patients. A combination of Gef and miR-27a agomirs may be an effective intervention for Gef-resistant NSCLC.

HOXC6-Mediated miR-188-5p Expression Induces Cell Migration through the Inhibition of the Tumor Suppressor FOXN2.

Homeobox C6 (HOXC6) is a transcription factor that plays a role in the malignant progression of various cancers. However, the roles of HOXC6 and its regulatory mechanism remain unclear. In this study, we used microRNA (miRNA) regulatory networks to identify key regulatory interactions responsible for HOXC6-mediated cancer progression. In microarray profiling of miRNAs, the levels of miRNAs such as hsa-miR-188-5p, hsa-miR-8063, and hsa-miR-8064 were significantly increased in HOXC6-overexpressing cells. Higher positive expression rates of HOXC6 and miR-188-5p were observed in malignant cancer. We also found that HOXC6 significantly upregulated miR-188-5p expression. The underlying function of HOXC6-mediated miR-188-5p expression was predicted through TargetScan and the MiRNA Database. Overexpression of mir-188-5p inhibited the expression of forkhead box N2 (FOXN2), a tumor suppressor gene. Furthermore, in the luciferase assay, miR-188-5p bound to the 3'-UTR of FOXN2 and was mainly responsible for the dysregulation of FOXN2 expression. Silencing FOXN2 induced cell migration, and the effect of FOXN2 silencing was enhanced when the HOXC6/miR-188-5p axis was induced. These results suggest that HOXC6/miR-188-5p may induce malignant progression in cancer by inhibiting the activation of the FOXN2 signaling pathway.

Cloning and expression of Hoxc6 gene from Pampus argenteus and its relationship with pelvic fin absence.

Hoxc6 gene can be described as having roles in axial patterning in early embryogenesis, and in at least some species, having a contribution to limb positioning. In this study, we cloned and characterised Pampus argenteus Hoxc6. The highly conserved HOXC6 protein sequence contains a homeodomain and a low-complexity region. Expression of Hoxc6 mRNA was measured at different developmental stages and in different tissues by real-time PCR (p < 0.05), and was high during eye capsule and brain differentiation stages, but low in 7 and 13-day-old larvae. Hoxc6 mRNA was more abundant in fin tissue than brain and eye tissues. Western blotting showed that HOXC6 protein levels were high at embryonic stages, but decreased significantly in 7, 13, 16 and 19-day-old larvae, and levels were essentially consistent with those of mRNA measured by real-time PCR in different tissues. In situ hybridisation showed that the Hoxc6 transcript was strongly expressed in the whole brain and anterior part of the body axis in 1-day-old larvae, but in the hindbrain, pectoral fin, mandible and hypothetical pelvic fin region in 7, 13, 16 and 19-day-old organisms. These results clarify the expression and localisation characteristics of Hoxc6 gene in P. argenteus, and provide a theoretical basis for the molecular mechanism of pelvic fin loss in silver pomfret.

Metformin Derivative HL156A Reverses Multidrug Resistance by Inhibiting HOXC6/ERK1/2 Signaling in Multidrug-Resistant Human Cancer Cells.

Multidrug resistance is a significant clinical crisis in cancer treatment and has been linked to the cellular expression of multidrug efflux transporters. The aim of this study was to examine the effects and mechanisms of the metformin derivative HL156A on human multidrug resistance (MDR) cancer cells. Here, HL156A significantly suppressed cell growth and colony formation through G2/M phase cell cycle arrest in MDR cancer cells. HL156A also reduced the wound closure rate and cell migration and induced caspase-3-dependent apoptosis. We found that HL156A inhibited the expression of MDR1 by inhibiting the HOXC6-mediated ERK1/2 signaling pathway and increased the sensitivity to paclitaxel or doxorubicin in MDR cells. Furthermore, HL156A significantly inhibited angiogenesis in a chicken chorioallantoic membrane (CAM) assay. These results suggest the potential of the metformin derivative HL156A as a candidate therapeutic modality for the treatment of human multidrug-resistant cancers.

Abnormal expression of homeobox c6 in the atherosclerotic aorta and its effect on proliferation and migration of rat vascular smooth muscle cells.

Homeobox c6 (Hoxc6) affects the proliferation, migration, and infiltration of malignant tumor cells; however, the effect of Hoxc6 on atherosclerosis (AS) as well as the proliferation and migration of vascular smooth muscle cells (VSMCs), which play a role in promoting AS, has not yet been well clarified. In the present study, we tested the hypothesis that Hoxc6 affects the proliferation and migration of rat VSMCs, and hence is involved in AS. The results showed that the expression of Hoxc6 mRNA and protein was higher in normal rat aortic wall than in the myocardium. Subsequently, a rat model of AS was established by high-fat feeding for 2 months. The expression of Hoxc6 mRNA and protein was increased significantly in AS lesions, while the expression of p53 protein was decreased and that of proliferating cell nuclear antigen (PCNA) was increased. Moreover, not only the proliferation and mobility of cells in normal culture were decreased, but also the proliferation was stimulated by oxidized low-density lipoprotein, which was decreased after downregulation of Hoxc6 expression in VSMCs in rat. Consecutively, the expression of PCNA protein was decreased, while that of p53 was increased. These results indicated that Hoxc6 is probably involved in AS via p53 and PCNA by affecting the proliferation and migration of VSMCs.

LncRNA BBOX1-AS1 upregulates HOXC6 expression through miR-361-3p and HuR to drive cervical cancer progression.

OBJECTIVES: Over the past years, growing attention has been paid to deciphering the pivotal role of long non-coding RNAs (lncRNAs) in regulating the occurrence and development of human malignancies, cervical cancer (CC) included. Nonetheless, the regulatory role of lncRNA BBOX1 antisense RNA 1 (BBOX1-AS1) has not been explored as yet. MATERIAL AND METHODS: The expression of BBOX1-AS1 was detected by reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR). Cell Counting Kit-8 (CCK-8), colony formation, TUNEL, Western blot, transwell and immunofluorescence assays testified the critical role of BBOX1-AS1 in CC. The relationship between RNAs (BBOX1-AS1, miR-361-3p, HOXC6 and HuR) was analysed by luciferase reporter, RNA Immunoprecipitation (RIP) and RNA pull-down assays. RESULTS: BBOX1 antisense RNA 1 antisense RNA 1 was revealed to be highly expressed in CC. Decreased expression of BBOX1-AS1 had suppressive effects on CC cell growth and migration. Molecular mechanism assays verified that BBOX1-AS1 had negative interaction with miR-361-3p in CC. Additionally, homeobox C6 (HOXC6) was validated to be a downstream target of miR-361-3p in CC. Furthermore, ELAV-like RNA-binding protein 1, also known as HuR, was uncovered to be capable of regulating the mRNA stability of HOXC6 in CC. More importantly, rescue assays delineated that knockdown of HuR after overexpressing miR-361-3p could reverse BBOX1-AS1 upregulation-mediated effect on CC progression. Similarly, the function induced by BBOX1-AS1 upregulation on CC progression could be countervailed by HOXC6 depletion. CONCLUSIONS: BBOX1 antisense RNA 1 facilitates CC progression by upregulating HOXC6 expression via miR-361-3p and HuR.

hsa_circ_001653 Implicates in the Development of Pancreatic Ductal Adenocarcinoma by Regulating MicroRNA-377-Mediated HOXC6 Axis.

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive pancreatic cancer with poor survival rate. Circular RNAs (circRNAs) signatures have been identified in some human cancers, but there are little data concerning their presence in PDAC. We investigated the role of hsa_circ_001653, a newly identified circRNA, in the development of PDAC. hsa-circ-001653 expression was measured in 83 paired normal and tumor tissues surgically resected from PDAC patients. Phenotypic changes of PDAC cells were evaluated by assays for cell viability, cell cycle, invasion, and apoptosis. Tube-like structure formation of human umbilical vein endothelial cells (HUVECs) was examined in the presence of PDAC cells. Cross-talk between hsa_circ_001653 and microRNA-377 (miR-377)/human homeobox C6 (HOXC6) was assessed using dual-luciferase reporter assay, Ago2 immunoprecipitation, and northern blot analysis. Nude mice were inoculated with human PDAC cells for in vivo analysis. hsa_circ_001653 was an upregulated circRNA in PDAC. Silencing of hsa_circ_001653 in PDAC cells via RNA interference inhibited cell viability, cell-cycle progression, in vitro angiogenesis, and invasive properties, showing a pro-apoptotic effect. hsa_circ_001653 was found to bind to miR-377, which in turn repressed HOXC6 expression. Inhibition of miR-377 by its specific inhibitor restored cell viability, cell-cycle progression, in vitro angiogenesis, and invasive properties in PDAC cells lacking endogenous hsa_circ_001653. When nude mice were inoculated with human PDAC cells, inhibition of hsa_circ_001653 had a therapeutic effect. Collectively, the present study provides an enhanced understanding of hsa_circ_001653 as a therapeutic target for PDAC.

HoxC6 Functions as an Oncogene and Isoform HoxC6-2 May Play the Primary Role in Gastric Carcinogenesis.

PURPOSE: Based on previous researches of HoxC6, this study aims to investigate the expression levels of isoforms HoxC6-1 and HoxC6-2 and to explore their roles in gastric carcinogenesis as well as the possible molecular mechanism. METHODS: We investigated expression levels of HoxC6, HoxC6-1, and HoxC6-2 in gastric cancer tissues, coupled with relevant data in TCGA dataset. In vitro, HoxC6, HoxC6-1, and HoxC6-2 knockdown by small interference RNA was carried for evaluating the changes of malignant biological behaviors of gastric cancer cells, such as proliferation, migration, invasion, apoptosis, and cell cycle alternation. Metastasis-related nucleotide lncRNA HOTAIR was selected by bioinformatics, and verification was carried out by in vitro researches. RESULTS: Data suggested HoxC6-1 and HoxC6-2 were considerably over-expressed with different folds in gastric cancerous tissues. Decreased expression of HoxC6-2 was detected in well-differentiated type of gastric cancer. In vitro, the conclusion that HoxC6 functions as a tumor oncogene illuminated by previous studies was verified again. Additionally, down-regulating of HoxC6-2 significantly inhibited SGC-7901 and BGC-823 cells from proliferation, migration, invasion, apoptosis, while quite slight results or none statistically significant results were observed when HoxC6-1 was knockdown. Besides, over-expression of HOTAIR, which is relevant with HoxC6 during gastric carcinogenesis, was detected in gastric cancerous tissues. Restored expression of HoxC6 partially reversed the decreased migration caused by down-regulating HOTAIR in gastric cancer cells. CONCLUSION: HoxC6 acts as an oncogene in gastric carcinogenesis and might be a promising therapeutic target. Isoform HoxC6-2 plays a primary carcinogenic role in gastric carcinogenesis. HOTAIR, over-expressed in gastric cancer, might regulate HoxC6 on the protein level in promoting migration of gastric cells.

Clinically significant Prostate Cancer diagnosed using a urinary molecular biomarker-based risk score: two case reports.

BACKGROUND: Identifying men for a repeat prostate biopsy is a conundrum to urologists. Risk calculators (RCs) such as the European Randomized Study of Screening for Prostate Cancer (ERSPC) RCs have been developed to predict the outcome of prostate biopsies and have been shown to improve diagnostic accuracy compared to PSA alone. However, it was recently shown that the outcome for high-grade prostate cancer (PCa) upon biopsy tended to be underestimated in men with previous negative biopsies using ERSPC RC model 4. For these men, an individualized approach combining the clinical information with the outcome of biomarker-related urine tests may help to make a more informed decision. CASE PRESENTATION: Two men, aged 66 and 69 respectively when presented in the clinic, show the typical dilemma of urologist and patient for electing repeat prostate biopsy. Both men had normal DRE findings, did not have a family history of PCa, presented with serum PSA values between 3 and 10 ng/ml and the first biopsies were negative for disease. The ERSPC RC4 did not indicate a biopsy in these men. The urinary molecular biomarker-based test for HOXC6 and DLX1, combining biomarker-expression profiling with clinical risk factors, resulted in SelectMDx Risk scores for these men that were higher than the cut-off of the test. Based on this outcome, mpMRI was performed with an outcome of PI-RADS ≥4 in both men. Histopathological evaluation of TRUS-guided biopsies confirmed high-grade PCa. CONCLUSIONS: The urinary molecular biomarker-based risk score played a pivotal role in the diagnosis of clinically significant PCa whereas ERSPC RC4 outcome would not have indicated further diagnostic follow-up in these two cases. The timely diagnosis was shown to be crucial for the curative treatment by radical retropubic prostatectomy and the potential life-years gained for these two vital males.