Upcycling HOXB13: enhancing prostate cancer detection with a novel antibody†.

Prostate cancer is one of the most prevalent and, upon metastasis, deadliest cancers in men. Timely identification is essential for effective treatment. Furthermore, accurate determination of prostatic origin is crucial for personalized therapy once the cancer has spread. However, current prostate cancer screening methods are lacking. A recent article in The Journal of Pathology addresses this issue by utilizing an improved antibody to reevaluate HOXB13 as a lineage marker for prostate cancer. The study's findings support the concept that, despite decreased expression in advanced prostate cancer, HOXB13 remains highly suitable for determining prostatic origin due to its androgen receptor independence, high specificity, and sensitivity. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Characterization of HOXB13 expression patterns in localized and metastatic castration-resistant prostate cancer.

HOXB13 is a key lineage homeobox transcription factor that plays a critical role in the differentiation of the prostate gland. Several studies have suggested that HOXB13 alterations may be involved in prostate cancer development and progression. Despite its potential biological relevance, little is known about the expression of HOXB13 across the disease spectrum of prostate cancer. To this end, we validated a HOXB13 antibody using genetic controls and investigated HOXB13 protein expression in murine and human developing prostates, localized prostate cancers, and metastatic castration-resistant prostate cancers. We observed that HOXB13 expression increases during later stages of murine prostate development. All localized prostate cancers showed HOXB13 protein expression. Interestingly, lower HOXB13 expression levels were observed in higher-grade tumors, although no significant association between HOXB13 expression and recurrence or disease-specific survival was found. In advanced metastatic prostate cancers, HOXB13 expression was retained in the majority of tumors. While we observed lower levels of HOXB13 protein and mRNA levels in tumors with evidence of lineage plasticity, 84% of androgen receptor-negative castration-resistant prostate cancers and neuroendocrine prostate cancers (NEPCs) retained detectable levels of HOXB13. Notably, the reduced expression observed in NEPCs was associated with a gain of HOXB13 gene body CpG methylation. In comparison to the commonly used prostate lineage marker NKX3.1, HOXB13 showed greater sensitivity in detecting advanced metastatic prostate cancers. Additionally, in a cohort of 837 patients, 383 with prostatic and 454 with non-prostatic tumors, we found that HOXB13 immunohistochemistry had a 97% sensitivity and 99% specificity for prostatic origin. Taken together, our studies provide valuable insight into the expression pattern of HOXB13 during prostate development and cancer progression. Furthermore, our findings support the utility of HOXB13 as a diagnostic biomarker for prostate cancer, particularly to confirm the prostatic origin of advanced metastatic castration-resistant tumors. © 2023 The Pathological Society of Great Britain and Ireland.

Evaluation of homeobox protein B13 (HOXB13) gene G84E mutation in patients with prostate cancer.

OBJECTIVES: To comprehensively investigate the potential association between prostate cancer (PCa) and the G84E mutation within the Homeobox Protein B13 (HOXB13) gene among individuals of Turkish descent, our study aims to undertake a prospective examination. METHODS: We evaluated 300 patients (150 diagnosed with prostate cancer, 150 controls) who presented in our clinic. Data collected were prospectively examined. DNA isolation was performed using an isolation kit. The HOXB13-G84E mutation (rs138213197) was analyzed in the obtained samples. Data encoding and statistical analysis were performed. RESULTS: The pathological allele for the G84E mutation was T. According to the findings, no mutations were detected in the control group, while the G84E mutation was detected in 17 patients in the patient group, all of whom had the TC genotype. The analysis showed that having the CC genotype reduced the risk of prostate cancer by 0.47 times (OR=0.47, CI=0.415-0.532). Our results did not support a trend toward family history or earlier-onset disease in comparisons between carriers and non-carriers of HOXB13 G84E mutation. Individuals with a positive family history exhibited a higher frequency of the G84E mutation. CONCLUSIONS: We concluded that HOXB13 gene mutation is indeed linked to PCa in Turkish men. However, we did not find a relationship between the HOXB13 gene G84E mutation carrier status and either early-onset PCa or familial PCa in Turkish men.

A Comprehensive Analysis of HOXB13 Expression in Hepatocellular Carcinoma.

Background and objectives: Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and is caused by multiple factors. To explore novel targets for HCC treatment, we comprehensively analyzed the expression of HomeoboxB13 (HOXB13) and its role in HCC. Materials and Methods: The clinical significance of HCC was investigated using open gene expression databases, such as TIMER, UALCAN, KM, OSlihc, and LinkedOmics, and immunohistochemistry analysis. We also analyzed cell invasion and migration in HCC cell lines transfected with HOXB13-siRNA and their association with MMP9, E2F1, and MEIS1. Results: HOXB13 expression was higher in fibrolamellar carcinoma than in other histological subtypes. Its expression was associated with lymph node metastasis, histological stage, and tumor grade. It was positively correlated with immune cell infiltration of B cells (R = 0.246), macrophages (R = 0.182), myeloid dendritic cells (R = 0.247), neutrophils (R = 0.117), and CD4+ T cells (R = 0.258) and negatively correlated with immune cell infiltration of CD8+ T cells (R = -0.107). A positive correlation was observed between HOXB13, MMP9 (R = 0.176), E2F1 (R = 0.241), and MEIS1 (R = 0.189) expression (p < 0.001). The expression level of HOXB13 was significantly downregulated in both HepG2 and PLC/PFR/5 cell lines transfected with HOXB13-siRNA compared to that in cells transfected with NC siRNA (p < 0.05). Additionally, HOXB13 significantly affected cell viability and wound healing. Conclusions: HOXB13 overexpression may lead to poor prognosis in patients with HCC. Additional in vivo studies are required to improve our understanding of the biological role and the exact mechanism of action of HOXB13 in HCC.

Clinicopathological Characteristics and Mutational Landscape of APC, HOXB13, and KRAS among Rwandan Patients with Colorectal Cancer.

Cancer research in Rwanda is estimated to be less than 1% of the total African cancer research output with limited research on colorectal cancer (CRC). Rwandan patients with CRC are young, with more females being affected than males, and most patients present with advanced disease. Considering the paucity of oncological genetic studies in this population, we investigated the mutational status of CRC tissues, focusing on the Adenomatous polyposis coli (APC), Kirsten rat sarcoma (KRAS), and Homeobox B13 (HOXB13) genes. Our aim was to determine whether there were any differences between Rwandan patients and other populations. To do so, we performed Sanger sequencing of the DNA extracted from formalin-fixed paraffin-embedded adenocarcinoma samples from 54 patients (mean age: 60 years). Most tumors were located in the rectum (83.3%), and 92.6% of the tumors were low-grade. Most patients (70.4%) reported never smoking, and 61.1% of patients had consumed alcohol. We identified 27 variants of APC, including 3 novel mutations (c.4310_4319delAAACACCTCC, c.4463_4470delinsA, and c.4506_4507delT). All three novel mutations are classified as deleterious by MutationTaster2021. We found four synonymous variants (c.330C>A, c.366C>T, c.513T>C, and c.735G>A) of HOXB13. For KRAS, we found six variants (Asp173, Gly13Asp, Gly12Ala, Gly12Asp, Gly12Val, and Gln61His), the last four of which are pathogenic. In conclusion, here we contribute new genetic variation data and provide clinicopathological information pertinent to CRC in Rwanda.

HOXB13 facilitates hepatocellular carcinoma progression by activating AKT/mTOR signaling pathway.

INTRODUCTION AND OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the sixth most common malignancies worldwide and is accompanied by high mortality. Homeobox B13 (HOXB13) has been shown to be involved in the development of various cancers. This study aimed to investigate the role of HOXB13 in HCC progression. MATERIALS AND METHODS: The expression of HOXB13 in HCC tumor tissues was analyzed using qRT-PCR and immunohistochemical staining . After overexpression or downregulation of HOXB13 in HCC cell lines, cell proliferation was detected by CCK8 assay and Ki67 staining and cell invasion ability were tested by transwell assay. Western blot assay was applied to analyze the effect of HOXB13 on related signaling pathways. In addition, the role of HOXB13 on HCC in vivo was explored using a HCC mouse model. IF and WB were performed to detect cell proliferation, apoptosis and related protein expression in mice tumor tissues. RESULTS: The results showed that the expression of HOXB13 was significantly increased in HCC tissues compared with adjacent tissues and positively correlated with the tumor stage and survival of HCC patients. Overexpression of HOXB13 promoted the proliferation and invasion of HCC cells and up-regulated the protein expression of AKT, mTOR and MMP2. In contrast, the downregulation of HOXB13 resulted in the opposite results. In vivo experiments, HOXB13 significantly promoted tumor growth in mice bearing HCC by promoting cell proliferation and inhibiting cell apoptosis. CONCLUSIONS: This study suggested that HOXB13 can facilitate HCC progression by activation of the AKT/mTOR signaling pathway. HOXB13 may be a novel target for HCC therapy.

Comprehensive network analysis of dysregulated genes revealed MNX1-AS1/hsa-miR-4697-3p/HOXB13 axis in ovarian cancer chemotherapy response.

Poor chemotherapy response is the main obstacle of ovarian cancer (OC) treatment. Platinum-refractory and -resistant patients are associated with a worse outcome than platinum-sensitive and partially sensitive patients, but the comprehensive similarities and differences among them are not yet clear. In this study, we analyzed the data of patients with different chemotherapy response in The Cancer Genome Atlas. We found a minority of altered genes were overlapped in refractory and resistant groups, as did the enriched pathways and Gene Ontology terms. We noticed that the neural signaling and drug metabolism enzymes were more significantly enriched and the protein-protein interaction supported these results. The transcription analysis highlighted PDX1 as the common and central transcription factor in both refractory and resistant groups. The competing endogenous RNA (ceRNA) network shared no common ceRNA pairs, indicating a major difference in noncoding RNA post-transcriptional regulation. In the end, we validated the expression, regulation, binding, and effect on chemotherapy response for selected MNX1-AS1/hsa-miR-4697-3p/HOXB13 in OC cell lines. Our study offered a novel and comprehensive insight into chemotherapy response, and potential targets for improving chemotherapy response in OC.

Excessive activation of HOXB13/PIMREG axis promotes hepatocellular carcinoma progression and drug resistance.

The transcription factor HOXB13 is bound up with the occurrence, progression and drug fast of many kinds of cancer. Nevertheless, the specific molecular mechanism of HOXB13 in hepatocellular carcinoma (HCC) is still unknown. This provides an obstacle to the exploration of HCC treatments targeting HOXB13. This study found that HOXB13 was up-regulated in HCC tissues. HOXB13 enhanced the multiplication and metastasis of HCC cells. It enhanced HCC cell drug and anoikis resistance. The analysis of HCC RNA seq data indicated that the expression of HOXB13 and PIMREG were positively correlated. Luciferase report assay showed that HOXB13 could activate PIMREG promoter transcription. The results of RT-qPCR and western blot showed that HOXB13 regulated the transcription of PIMREG. Western blot proved that high expression of PIMREG participated in DNA damage repair and cell cycle regulation by up-regulating RAD51, BRCA1, CDC25A, CDC25B and CDC25C and down-regulating HIPK2. This led to a significant increase in DNA repair capacity, accelerated cell cycle progression, and insensitive to DNA damage. Down-regulation of PIMREG in Hep3B cells overexpressing HOXB13 attenuated the phenotype induced by HOXB13. Therefore, HOXB13 functioned through PIMREG instead of directly regulating the transcription of RAD51, BRCA1, CDC25A, CDC25B and CDC25C. The same results were obtained in vivo. It was concluded that HOXB13 affected the expression of cell cycle and DNA repair related factors by up-regulating the transcription of PIMREG, thereby promoting the progression of HCC and enhancing the resistance of HCC to chemotherapeutics.

Germline HOXB13 mutation p.G84E do not confer an increased bladder or kidney cancer risk in polish population.

INTRODUCTION: The role of HOXB13 in bladder and renal tumorigenesis is unclear. Our goal was to determine the prevalence of HOXB13 p.G84E mutation in bladder and kidney cancer patients from Poland. MATERIALS AND METHODS: 1418 patients with bladder cancer and 813 cases with kidney cancer and 4497 controls were genotyped for HOXB13 p.G84E. RESULTS: p.G84E mutation of HOXB13 gene was detected in three of 1418 (0.2%) bladder cancer cases and in six of 4497 controls (odds ratio [OR], 1.6; 95% CI 0.39-6.36; p = 0.8). Among 813 kidney cancer cases HOXB13 mutations was reported in three patients (0,4%) (odds ratio [OR], (OR = 2,8; 95% CI 0.69-11.11; p = 0.3). In cases with mutations in the HOXB13 gene, the family history of cancer was negative. CONCLUSION: HOXB13 mutation was not associated with bladder or kidney cancer. Mutation p.G84E in HOXB13 seem not to play a role in bladder and kidney cancer development in Polish patients.

Developmental estrogenization: Prostate gland reprogramming leads to increased disease risk with aging.

While estrogens are involved in normal prostate morphogenesis and function, inappropriate early-life estrogenic exposures, either in type, dose or timing, can reprogram the prostate gland and lead to increased disease risk with aging. This process is referred to as estrogen imprinting or developmental estrogenization of the prostate gland. The present review discusses published and new evidence for prostatic developmental estrogenization that includes extensive research in rodent models combined with epidemiology findings that together have helped to uncover the architectural and molecular underpinnings that promote this phenotype. Complex interactions between steroid receptors, developmental morphoregulatory factors, epigenetic machinery and stem-progenitor cell targets coalesce to hard wire structural, cellular and epigenomic reorganization of the tissue which retains a life-long memory of early-life estrogens, ultimately predisposing the gland to prostatitis, hyperplasia and carcinogenesis with aging.

FTO demethylates m6A modifications in HOXB13 mRNA and promotes endometrial cancer metastasis by activating the WNT signalling pathway.

Although many studies have confirmed the relationship between obesity and endometrial cancer (EC), the molecular mechanism between obesity and EC progression has not been elucidated. Overexpression of fat mass and the obesity associated protein FTO leads to weight gain, although recently it has been discovered that FTO can serve as a demethylase which erases N6-methyladenosine (m6A) modification and regulates the metabolization of mRNAs. In this study, we found high expression of FTO in metastatic EC and that this action promote both metastasis and invasion in vivo and in vitro. Mechanistically, FTO can catalyse demethylation modification in 3'UTR region of HOXB13 mRNA, thereby abolishing m6A modification recognition with the YTHDF2 protein. Decreasing HOXB13 mRNA decay and increasing HOXB13 protein expression was accompanied by WNT signalling pathway activation and the expression of downstream proteins, leading to tumour metastasis and invasion. We also found the WNT signalling pathway inhibitor ICG-001 can block HOXB13 gene-induced tumour metastasis, therefore ICG-001 may be a promising molecular intervention. This study provides insight into the relationship between obesity and the pathogenesis of endometrial cancer while highlighting future areas of research.

HOXB13 controls cell state through super-enhancers.

Expression of the homeodomain transcription factor HOXB13 has been demonstrated in several malignancies but its role in tumorigenesis remains elusive. We observed high levels of HOXB13 in poorly differentiated pediatric tumors including a highly aggressive childhood neoplasm - malignant rhabdoid tumor. In a xenograft model of rhabdoid tumor, knockout of HOXB13 diminished tumor growth while partial knockdown of HOXB13 promoted differentiation of tumor cells into bone. These results suggest that HOXB13 enhances rhabdoid malignancy by interfering with mesenchymal stem cell differentiation. Consistent with this hypothesis, overexpression of HOXB13 in mesenchymal progenitor cells inhibited adipogenic, myogenic, and osteogenic differentiation. Mechanistically, we demonstrated that HOXB13 binds to super-enhancer regions regulating genes involved in differentiation and tumorigenesis.

Diverse AR-V7 cistromes in castration-resistant prostate cancer are governed by HoxB13.

The constitutively active androgen receptor (AR) splice variant 7 (AR-V7) plays an important role in the progression of castration-resistant prostate cancer (CRPC). Although biomarker studies established the role of AR-V7 in resistance to AR-targeting therapies, how AR-V7 mediates genomic functions in CRPC remains largely unknown. Using a ChIP-exo approach, we show AR-V7 binds to distinct genomic regions and recognizes a full-length androgen-responsive element in CRPC cells and patient tissues. Remarkably, we find dramatic differences in AR-V7 cistromes across diverse CRPC cells and patient tissues, regulating different target gene sets involved in CRPC progression. Surprisingly, we discover that HoxB13 is universally required for and colocalizes with AR-V7 binding to open chromatin across CRPC genomes. HoxB13 pioneers AR-V7 binding through direct physical interaction, and collaborates with AR-V7 to up-regulate target oncogenes. Transcriptional coregulation by HoxB13 and AR-V7 was further supported by their coexpression in tumors and circulating tumor cells from CRPC patients. Importantly, HoxB13 silencing significantly decreases CRPC growth through inhibition of AR-V7 oncogenic function. These results identify HoxB13 as a pivotal upstream regulator of AR-V7-driven transcriptomes that are often cell context-dependent in CRPC, suggesting that HoxB13 may serve as a therapeutic target for AR-V7-driven prostate tumors.

Mutations in ATM, NBN and BRCA2 predispose to aggressive prostate cancer in Poland.

In designing national strategies for genetic testing, it is important to define the full spectrum of pathogenic mutations in prostate cancer (PCa) susceptibility genes. To investigate the frequency of mutations in PCa susceptibility genes in Polish familial PCa cases and to estimate gene-related PCa risks and probability of aggressive disease, we analyzed the coding regions of 14 genes by exome sequencing in 390 men with familial prostate cancer and 308 cancer-free controls. We compared the mutation frequencies between PCa cases and controls. We also compared clinical characteristics of prostate cancers between mutation carriers and noncarriers. Of the 390 PCa cases, 76 men (19.5%) carried a mutation in BRCA1, BRCA2, NBN, ATM, CHEK2, HOXB13, MSH2 or MSH6 genes. No mutations were found in BRIP1, PTEN, TP53, MLH1, PMS2 and SPOP. Significant associations with familial PCa risk were observed for CHEK2, NBN, ATM, and HOXB13. High-grade (Gleason 8-10) tumors were seen in 56% of BRCA2, NBN or ATM carriers, compared to 21% of patients who tested negative for mutations in these genes (OR = 4.7, 95% CI 2.0-10.7, P = .0003). In summary, approximately 20% of familial prostate cancer cases in Poland can be attributed to mutations in eight susceptibility genes. Carriers of mutations in BRCA2, NBN and ATM develop aggressive disease and may benefit from intensified screening and/or chemotherapy.

Mutation HOXB13 c.853delT in Martinican prostate cancer patients.

BACKGROUND: In Martinique, prostate cancer (Pca) incidence rates are nowadays among the highest worldwide with a high incidence of early-onset and familial forms. Despite the demonstration of a strong familial component, identification of the genetic basis for hereditary Pca is challenging. The HOXB13 germline variant G84E (rs138213197) was described in men of European descent with Pca risk. METHODS: To investigate the potential involvement of HOXB13 mutations in Martinique, we performed sequencing of the HOXB13 coding regions of 46 index cases with early-onset Pca (before the age of 51). Additional breast cancers and controls were performed. All cancer cases analyzed in this study have been observed in the context of genetic counseling. RESULTS: We identified a rare heterozygous germline variant c.853delT (p.Ter285Lysfs) rs77179853, reported only among patients of African ancestry with a minor allele frequency of 3.2%. This variant is a stop loss reported only among patients of African ancestry with a frequency of 0.2%. CONCLUSION: In conclusion, we think that this study provides supplementary arguments that HOXB13 variants are involved in Pca.

LncRNA SNHG14 regulates the DDP-resistance of non-small cell lung cancer cell through miR-133a/HOXB13 pathway.

BACKGROUND: Recently, long non-coding RNAs (lncRNAs) have been reported to be involved in regulating chemo-resistance of NSCLC, however, the role of lncRNA SNHG14 in the DDP-resistance of NSCLC remains unexplored. METHODS: Relative expression of SNHG14, HOXB13 and miR-133a in DDP-resistant A549 (A549/DDP) cell and its parental cell A549 were measured using qRT-PCR. Cell proliferation viability of indicated A549/DDP cell was estimated via CCK-8 and colony formation experiments. Cell cycle and apoptosis were analyzed through flow cytometry. Expression of apoptosis-related protein and HOXB13 were detected via western blot. The interaction among SNHG14, HOXB13 and miR-133a was predicted by bioinformatics and validated by dual-luciferase reporter assay. RESULTS: LncRNA SNHG14 and HOXB13 were upregulated while miR-133a was downregulated in A549/DDP cell line compared to A549 cell line. SNHG14 knockdown or miR-133a overexpression was demonstrated to increase the DDP-sensitivity of A549/DDP cells. SNHG14 was revealed to compete with HOXB13 for miR-133a binding in A549/DDP cells. Inhibition of miR-133a in A549 cells could reverse the promotive effects of SNHG14 knockdown on DDP-sensitivity, as well as the inhibitory effects on HOXB13 expression. HOXB13 overexpression was revealed to abolish the enhanced effects of miR-133a on the sensitivity of A549/DDP cell to DDP. CONCLUSION: Our findings demonstrated that SNHG14 was involved in the development of DDP-resistance of A549/DDP cells through miR-133a/HOXB13 axis, which may present a path to novel therapeutic stratagems for DDP resistance of NSCLC.

HOXB13 promotes proliferation, migration, and invasion of glioblastoma through transcriptional upregulation of lncRNA HOXC-AS3.

HOXB13 exerts a close relation in several human cancers. This study explored the role of HOXB13 in glioblastoma (GBM), a brain tissue with the highest aggressive rate and mortality in adults. Through microarray and immunohistochemistry analyses, HOXB13 was highly expressed in GBM tissues. Furthermore, we showed that high-level expression of HOXB13 in GBM was associated with worse survival, suggesting that HOXB13 could be a prognostic marker for patients with GBM. GBM cells U87 and U251 overexpressing HOXB13 showed enhanced proliferation, migration, and invasion relative to the control cells, while knockdown of HOXB13 led to decreased cell proliferation, migration, and invasion abilities. In addition, dual-luciferase report assay, chromatin immunoprecipitation assay, and quantitative real-time polymerase chain reaction data showed that HOXB13 directly bound to HOXC-AS3 promoter. HOXC-AS3 was involved in HOXB13-induced proliferation, migration, and invasion of GBM cells. In summary, this study revealed the prognostic potential of HOXB13 in GBM. We believed that HOXB13/HOXC-AS3 signaling axis can be served as therapeutic targets for this highly aggressive cancer.

HOXB13 interaction with MEIS1 modifies proliferation and gene expression in prostate cancer.

BACKGROUND: The recurrent p.Gly84Glu germline mutation (G84E) in HOXB13 is consistently associated with prostate cancer (PCa), although the mechanisms underlying such linkage remain elusive. The majority of the PCa-associated HOXB13 mutations identified are localized to two conserved domains in HOXB13 that have been shown to mediate the interaction with MEIS cofactors belonging to the TALE family of homeodomain transcription factors. In this study, we sought to interrogate the biochemical and functional interactions between HOXB13 and MEIS in prostatic cells with a goal of defining how the HOXB13-MEIS complex impacts PCa pathobiology and define the extent to which the oncogenic activity of G84E is related to its effect on HOXB13-MEIS interaction/function. METHODS: HOXB13 and MEIS paralog expression in prostate epithelial cells and PCa cell lines was characterized by qPCR and immunoblot analyses. HOXB13 and MEIS1 co-expression in human prostate tissue was confirmed by IHC, followed by co-IP mapping of HOXB13-MEIS1 interactions. Proliferation of the PCa cell line LAPC4 following shRNA-mediated knockdown of each gene or both genes was assessed using DNA- and metabolic-based assays. Transcriptional targets of HOXB13 and MEIS1 were identified by gene expression profiling and qPCR. Finally, protein stability of HOXB13 in the context of MEIS1 was determined using pulse-chase assays. RESULTS: HOXB13 and MEIS1 are co-expressed and interact in prostate cells. Both of the putative MEIS interacting domains (MID) within HOXB13 were shown to be capable of mediating the interaction between HOXB13 and MEIS1 independently and such interactions were not influenced by the G84E mutation. The inhibitory effect of either HOXB13 or MEIS1 knockdown on cellular proliferation was augmented by knockdown of both genes, and MEIS1 knockdown abolished HOXB13-driven regulation of BCHE and TNFSF10 mRNA expression. Notably, we demonstrated that MEIS1 stabilized the HOXB13 protein in LAPC4 cells. CONCLUSIONS: Our study provides evidence for functional HOXB13-MEIS1 interactions in PCa. MEIS1 may contribute to the cancer-promoting actions of HOXB13 in cellular proliferation and gene regulation by prolonging HOXB13 half-life. Our data demonstrates that G84E is not a loss-of-function mutation that interferes with HOXB13 stability or ability to interact with MEIS1.

Circular RNA ITCH suppressed prostate cancer progression by increasing HOXB13 expression via spongy miR-17-5p.

BACKGROUND: Circular RNA Itchy E3 ubiquitin protein ligase (Circ-ITCH) is significantly down-regulated in various kinds of tumors, however, the mechanisms of action and functions of circITCH gene in prostate cancer (PC) are still under investigation. The mail goal of this research was to study the functional role of Circ-ITCH gene in prostate cancer and to illuminate the function role of circ-ITCH gene in prostate cancer by targeting miR-17-5p/HOXB13. METHODS: RT-qPCR was applied to measure the expression level of circ-ITCH and miR-17-5p in PC cell lines and tissues. CCK-8, colony formation, Brdu incorporation labeling and flow cytometry assays were applied to detect the effects of circ-ITCH and miR-17-5p on proliferation and cell apoptosis. Target gene prediction and screening, luciferase reporter gene assays were utilized to assess downstream target genes of miR-17-5p and Circ-ITCH. The protein and expression of HOXB13 gene were measured by Western blotting and RT-qPCR. RESULTS: CircITCH was significantly reduced in PC cell lines and tissues. Low circITCH expression level was highly related with preoperative PSA, tumor stage and Gleason score. Overexpression of circITCH can inhibit the malignant phenotype of prostate cancer. There was a high negative relationship between the expression level of microRNA-17-5p and circITCH in PC tissues, however, there existed a positive relationship between the expression of HOXB13 and circITCH. CircITCH acted as a sponge of miR-17-5p to increase HOXB13 gene expression. In addition, miR-17-5p overexpression or HOXB13 silencing can reduce the carcinogenic effects of circICCH in prostate cancer. CONCLUSION: CircITCH promoted prostate cancer progression by regulating the HOXB13/miR-17-5p axis, and circITCH have a potential usage as therapeutic target for PC tumors.

G84E germline mutation in HOXB13 gene is associated with increased prostate cancer risk in Polish men.

We tested the association between HOXB13 G84E (rs138213197) germline mutation and PC risk in Polish men. DNA from 103 consecutive, newly diagnosed patients hospitalised because of PC and DNA from 103 men: volunteers, healthy at the time of the study. The G84E mutation was genotyped using Sanger sequencing. The HOXB13 G84E germline mutation was detected in 2.9% of PC men (3/103) and not detected in any healthy man. Two mutation carriers originated from two of 25 families fulfilling hereditary prostate cancer criteria (HPC) and one mutation carrier from one family among 78 families without HPC (PC frequency: 8% vs. 1.3%, OR = 6.70, p = 0.13). In two of three mutation carriers, disease was detected above 60 years of age. There was a trend for a lower probability of 5-year survival in patients with G84E than in patients without it (66.7% vs. 94.0%, p = 0.08). The HOXB13 G84E germline mutation is associated with increased prostate cancer risk in Polish men, with hereditary form of the disease, and probably with older age at PC onset (> 60 years of age) and shorter survival. However, it is not associated with PSA level, or PC stage or grade at the time of diagnosis.