HOXA10 mRNA Research Articles

Aberrant Hoxa10 gene methylation as a mechanism for endosulfan-induced implantation failures in rats

DNA methylation is a well-established epigenetic mechanism controlling gene expression. Environmental chemicals, such as pesticides have been shown to alter DNA methylation. We have previously shown that the insecticide endosulfan impairs female fertility in rats by increasing the rate of preimplantation embryo losses. In this study, we evaluated whether early postnatal exposure to endosulfan affects long-term transcriptional regulation of Homeobox A10 (Hoxa10) gene, which is a key marker of endometrial receptivity. Female rats were neonatally exposed to 6 or 600 μg/kg/day (ENDO6 and ENDO600, respectively) of endosulfan and uterine samples collected on gestational day (GD) 5. Hoxa10 protein and mRNA levels were assessed by immunohistochemistry and quantitative real-time PCR (qRT-PCR), respectively. In silico analysis of enzyme-specific restriction sites and predicted transcription factors were performed to investigate the methylation status of the regulatory regions of Hoxa10 gene by methylation-sensitive restriction enzymes-PCR technique. The expression of the DNA methyltransferases (Dnmts) was also evaluated. ENDO600 showed a decreased uterine Hoxa10 expression at protein and transcript level, while ENDO6 decreased only the level of transcripts, during the receptive stage. In addition, endosulfan increased levels of Dnmt3a and Dnmt3b. Dysregulation of DNA methylation patterns of Hoxa10 regulatory regions was detected in ENDO6- and ENDO600-treated rats. All these results suggest that aberrant DNA methylation in Hoxa10 gene could be an underlining mechanism contributing to explain endosulfan-induced preimplantation losses.

Induction of Endometrial HOXA 10 Gene Expression by Vitamin D and its Possible Influence on Reproductive Outcome of PCOS Patients Undergoing Ovulation Induction Procedure.

Background and Objectives:Polycystic ovarian syndrome (PCOS) is one of the most common endocrinopathies in women frequently presenting with anovulatory infertility. Low successful pregnancy and live birth rates even after successful ovulation induction (OI) and in vitro fertilization (IVF) in these patients indicate that endometrial dysfunction may be another important factor contributing to infertility. Vitamin D acting through nuclear receptors induces the expression of various genes required for cell growth and differentiation and plays a crucial role in reproduction. Homeobox 10 (HOXA10) may be one of the potential targets for vitamin D action. HOXA10 gene product promotes the differentiation of endometrial cells, making the endometrium receptive for implantation. The present study was undertaken to determine the effect of circulating vitamin D levels on HOXA10 gene expression in endometrial tissues and its possible influence on the reproductive outcome of PCOS patients undergoing OI procedure.Materials and Methods:A prospective cohort study was conducted on 110 infertile PCOS patients. The patients were divided into two groups: Group 1: Vitamin D ³20 ng/ml, Group 2: Vitamin D <20 ng/ml. Endometrial samples were obtained from 22 patients using pipelle biopsy, used to determine HOXA10 mRNA (messenger ribonucleic acid) expression by quantitative RT-PCR (reverse transcription-polymerase chain reaction) and protein expression by Western blotting. OI was performed using Clomiphene citrate or Letrozole from the 3rd day of the cycle, and patients were followed up for a maximum of five cycles. Attainment of successful pregnancy was considered a positive outcome.Results:Both the groups were similar in mean age and other endocrine parameters. Serum vitamin D levels were significantly low (P < 0.001), and BMI (body mass index) was significantly high (P = 0.032) in group 2 compared to group 1. Endometrial HOXA10 mRNA (by quantitative rtPCR) and protein expression (by western blotting) were significantly low in group 2 compared to group 1. The clinical pregnancy rate was low in group 2 (28.6%) compared to group 1 (42.3%), but this difference was not significant (P = 0.22). On regression analysis adjusted for age and BMI, vitamin D was an independent predictor of successful pregnancy after OI (P = 0.09).Conclusion:Circulating vitamin D levels influence the endometrial HOXA10 gene expression, and this may be reflected on the reproductive outcome of infertile PCOS patients undergoing OI.

The role of 25 hydroxycholecalciferol (VITD3) on insulinandndash; resistance in patients with polycystic ovary syndrome (PCOS)

Background: Polycystic ovary syndrome (PCOS) is the greatest frequent endocrine syndrome in females, giving with numerous likely mixtures of symptoms and signs and a variety of phenotypes, which might contain generative, endocrine, and metabolic modifications. PCOS is characterized by hypothalamic&ndash;pituitary&ndash; ovary axis dysfunction and anovulation ovulatory dysfunction can still occur with regular cycles and if anovulation needs to be confirmed serum progesterone levels can be measured but, unlike other causes of ovulatory disappointment that feature inadequate ovarian follicle development or repressed gonadotropin emission, PCOS typically includes androgen excess and subtle alterations in serum levels of gonadotropins and estrogens. Objective: demonstrate and compare therapeutic effect of vitamin D; supplementation on the metabolism and endocrine parameters of polycystic ovary syndrome patients with insulin- resistance. Subjective: The study was carried out on 86 patients, divided into 2 groups, group A treated by vitamin D supplement, while group B treated by placebo. Results: The fasting blood sugar was significant decreased in the two studied groups. HOMA IR shows a significant decrease in the two studied groups after treatment but in group A &ldquo;vitamin D supplement&rdquo; decrease by a highly significant degree than the placebo group. SHBG show a significant increase in both studied groups, after treatment there was a slight increase in group A more than group B in SHBG but this increase was insignificant. Vitamin D induces the transcription of HOXA10 through vitamin D receptors. Managenent with vitamin D rises mRNA and protein appearance of HOXA10. Vitamin D too has a straight influence on the rule of HOXA10, and this has implications for fertility. Conclusion: A significant effects of vitamin D supplementation on either metabolic or endocrine parameters in our study of PCOS women with insufficient baseline 25(OH)D concentrations.

Increased METTL3-mediated m6A methylation inhibits embryo implantation by repressing HOXA10 expression in recurrent implantation failure

BackgroundRecurrent implantation failure (RIF) is a major limitation of assisted reproductive technology, which is associated with impaired endometrial receptivity. Although N6-methyladenosine (m6A) has been demonstrated to be involved in various biological processes, its potential role in the endometrium of women with RIF has been poorly studied.MethodsGlobal m6A levels and major m6A methyltransferases/demethylases mRNA levels in mid-secretory endometrium from normal and RIF women were examined by colorimetric m6A quantification strategy and quantitative real-time PCR, respectively. The effects of METTL3-mediated m6A modification on embryo attachment were evaluated by an vitro model of a confluent monolayer of Ishikawa cells co-cultured with BeWo spheroids, and the expression levels of homeo box A10 (HOXA10, a well-characterized marker of endometrial receptivity) and its downstream targets were evaluated by quantitative real-time PCR and Western blotting in METTL3-overexpressing Ishikawa cells. The molecular mechanism for METTL3 regulating HOXA10 expression was determined by methylated RNA immunoprecipitation assay and transcription inhibition assay.ResultsGlobal m6A methylation and METTL3 expression were significantly increased in the endometrial tissues from women with RIF compared with the controls. Overexpression of METTL3 in Ishikawa cells significantly decreased the ration of BeWo spheroid attachment, and inhibited HOXA10 expression with downstream decreased β3-integrin and increased empty spiracles homeobox 2 expression. METTL3 catalyzed the m6A methylation of HOXA10 mRNA and contributed to its decay with shortened half-life. Enforced expression of HOXA10 in Ishikawa cells effectively rescued the impairment of METTL3 on the embryo attachment in vitro.ConclusionIncreased METTL3-mediated m6A modification represents an adverse impact on embryo implantation by inhibiting HOXA10 expression, contributing to the pathogenesis of RIF.

Molecular regulators of HOXA9 in acute myeloid leukemia.

Dysregulation of the oncogenic transcription factor HOXA9 is a prominent feature for most aggressive acute myeloid leukemia cases and a strong indicator of poor prognosis in patients. Leukemia subtypes with hallmark overexpression of HOXA9 include those carrying MLL gene rearrangements, NPM1c mutations, and other genetic alternations. A growing body of evidence indicates that HOXA9 dysregulation is both sufficient and necessary for leukemic transformation. The HOXA9 mRNA and protein regulation includes multilayered controls by transcription factors (such as CDX2/4 and USF2/1), epigenetic factors (such as MLL-menin-LEDGF, DOT1L, ENL, HBO1, NPM1c-XPO1, and polycomb proteins), microRNAs (such as miR-126 and miR-196b), long noncoding RNAs (such as HOTTIP), three-dimensional chromatin interactions, and post-translational protein modifications. Recently, insights into the dynamic regulation of HOXA9 have led to an advanced understanding of the HOXA9 regulome and provided new cancer therapeutic opportunities, including developing inhibitors targeting DOT1L, menin, and ENL proteins. This review summarizes recent advances in understanding the molecular mechanisms controlling HOXA9 regulation and the pharmacological approaches that target HOXA9 regulators to treat HOXA9-driven acute myeloid leukemia.

CircRNA FUT10 regulates the regenerative potential of aged skeletal muscle stem cells by targeting HOXA9.

Skeletal muscle is capable of repairing itself after injury to maintain the stability of its own tissue, but this ability declines with aging. Circular RNAs (circRNAs) are involved in cell aging. However, there is little research into their role and underlying mechanisms, especially in skeletal muscle stem cells (SkMSCs). In this study, we assessed circRNA FUT10 expression in aged and adult SkMSCs. We observed that circRNA FUT10 was upregulated in aged SkMSCs compared with that in adult SkMSCs. Furthermore, we identified putative miR-365-3p binding sites on circRNA FUT10, suggesting that this circRNA sponges miR-365a-3p. We also found that HOXA9 is a downstream target of miR-365a-3p and confirmed that miR-365a-3p can bind to circRNA FUT10 and the 3′-untranslated region of HOXA9 mRNA. This finding indicated that miR-365a-3p might serve as a “bridge” between circRNA FUT10 and HOXA9. Finally, we found that the circRNA FUT10/miR365a-3p/HOXA9 axis is involved in SkMSC aging. Collectively, our results show that the circRNA FUT10/miR365a-3p/HOXA9 axis is a promising therapeutic target and are expected to facilitate the development of therapeutic strategies to improve the prognosis of degenerative muscle disease.

Endometrial HOXA10 mRNA Expression in PCOS Patients at High Risk for Ovarian Hyperstimulation Syndrome

Background: This study was designed to determine whether the risk of ovarian hyperstimulation syndrome (OHSS) contributes to the subfertility in PCOS. Endometrial HOXA-10 mRNA expression, a well-characterized gene essential to endometrial receptivity, was evaluated in PCOS patients whose embryos are planned to be frozen due to the risk of OHSSS. Methods: Twent-five women with PCOS in high risk group for OHSS and age and BMI matched 25 non-PCOS infertile patients were included the study. Five fertile women were accepted as positive control. Following egg collection each group of subject underwent total embryo freezing. After the egg collection, endometrial sampling was performed with a pipella cannula from each gruop of participant and fertile control. Expression levels of HOXA-10 mRNA were determined by RT-PCR. Gene expression results are presented as Ct (cycle threshold), ΔCt, and ΔΔCt. Reults: Average ΔCt value of HOXA-10 mRNA in PCOS, non-PCOS and fertile groups were found to 5.88, 6.77, and 7.79 respectively. Compared to endometrial HOXA-10 mRNA levels of fertile cases, the HOXA-10 mRNA levels of the patients in the PCOS group were found to be significantly lower (ΔCt 7.79 vs. ΔCt 5.88, p&lt;0.002). Similarly, endometrial HOXA-10 mRNA levels in the non-PCOS control group were significantly lower than the HOXA-10 mRNA levels in the fertile group (ΔCt 6.77 vs. ΔCt 7.79, p&lt;0.001). HOXA-10 mRNA levels in endometrial samples taken from patients in the PCOS group were found to be significantly lower than the HOXA-10 mRNA levels in non-PCOS control group. Conclusions: HOXA-10 mRNA levels were found to be lower in PCOS patients with high risk for OHSS compared to both fertile and infertile patients without PCOS. OHSS risk in PCOS decreases endometrial HOXA-10 mRNA expression.

Homeobox A5 and A9 expression and beta-thalassemia

ABSTRACT Background and aim: The pathogenesis of β-thalassemia has been attributed to ineffective erythropoiesis. The function of Hox genes in normal haematopoiesis has been widely studied using gene expression analysis. The aim of this study is to evaluate the expression of HoxA9, and HoxA5 genes in beta-thalassemia. Materials and methods: Children with thalassemia major, thalassemia intermediate, and age and sex-matched healthy controls (n = 50/group) were enrolled. Detection of HoxA5 and HoxA9 mRNA expression was performed by real-time polymerase chain reaction (RT-PCR). Results: Expression of HoxA9 increased in a direct linear trend (median 0.5 in controls, 2.4 in intermediate disease, 4.1 in major disease, p = 0.001) and generally correlated with the red cell count, haematocrit, ferritin and levels of beta-globin. In those with thalassemia major, the relative change of HoxA9 was linked to transfusion history, the white blood cell count, ferritin, and beta-globin (all r > 0.5, p < 0.001). Levels of HoxA9 were superior to HoxA5 in differentiating controls from thalassemia intermedia, whilst both differentiated major from the intermediate disease. Conclusion: This study highlights the importance of HoxA genes in early identification of patients, at high risk of developing complications, as it allows specific measures to delay the progression of the disease. HoxA gene expression is a promising diagnostic and prognostic marker in patients with β-thalassemia.

Hypoxia and its possible relationship with endometrial receptivity in adenomyosis: a preliminary study

BackgroundAdenomyosis (AM) is an important cause of female infertility. However, the underlying mechanism remains unclear. This report describes a preliminary study of hypoxia and its possible association with endometrial receptivity in AM.MethodsThe study was divided into in vitro and in vivo experiments. In vitro, expression levels of the endometrial receptivity markers HOXA10 and HOXA11 in the implantation period were examined using real-time PCR and western blotting. Endometrial expression of hypoxia-inducible factor (HIF)-1α, HIF-2α, and HIF-3α was determined using immunohistochemistry. In vivo, using an AM mouse model established by oral administration of tamoxifen, we inhibited expression of HIF-2α using an HIF-2α antagonist (PT2399; 30 mg/kg body weight, twice daily by oral gavage for 2 days) and then examined expression levels of Hoxa10 and Hoxa11 using real-time PCR and western blotting.ResultsEndometrial mRNA and protein expression levels of HOXA10 and HOXA11 were significantly lower in patients with AM than in control patients. Expression of HIF-2α was significantly higher in the AM group than in the control group, whereas that of HIF-1α and HIF-3α was equivalent in both groups. In vivo analysis showed that administration of the HIF-2α antagonist resulted in increased expression of Hoxa10 and Hoxa11 at both the mRNA and protein levels in AM model mice.ConclusionsHIF-2α overexpression may be one reason for decreased endometrial receptivity in AM. The current findings provide insight into HIF-2α-mediated AM-related infertility and suggest that PT2399 has potential as a treatment for AM.Trial registrationThis trial was retrospectively registered.

Homeobox A5 and C10 genes modulate adaptation of brown adipose tissue during exercise training in juvenile rats.

What is the central question of this study? Exercise can stimulate brown adipose tissue (BAT) with subsequent increase in uncoupling protein 1 expression and mitochondrial biogenesis. In that case, do BAT-specific Hox genes modify BAT functioning and cause uncoupling protein expression changes due to exercise? What is the main finding and its importance? Exercise enhanced brown adipocyte markers, with significant upregulation of HoxA5 and downregulation of HoxC10 mRNA expression in rat BAT. HoxA5 and HoxC10 are thus likely to play distinct roles in exercise-induced changes in BAT markers during the early postnatal period. These findings provide new insight into the mechanisms underlying exercise-induced changes in BAT function. Brown adipose tissue (BAT) recruitment is involved in increased energy expenditure associated with cold exposure and exercise training. We explored whether exercise training induced changes in expression levels of brown adipocyte-selective factors and Homeobox (Hox) genes during the post-weaning growth period of male Wistar rats. Relative to total body weight, BAT weights alone were lower in exercise-trained (EX) rats compared to sedentary control (SED) rats. mRNA expression of HoxA5 was higher and that of HoxC10 was lower in EX rats than in SED rats, accompanied by both higher citrate synthase activity and protein expression levels for uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor (PPAR) α, and PPARγ-coactivator (PGC)-1α. HoxA5 knockdown with siRNA reduced the expression of PR-domain containing 16 (Prdm16), cell death-inducing DNA fragmentation factor-α-like effector A (Cidea) gene, type 2 deiodinase mRNA, and PRDM16 protein. Comparatively, HoxC10 knockdown with siRNA enhanced mRNA expression of Prdm16, Pparα and Pgc1α and protein expression of UCP1, PPARα and PGC1α in brown adipocytes. The stimulation of brown adipocytes with isoproterenol, a β-adrenoceptor agonist, caused a phenomenon similar to the effect of exercise training on the genes tested: upregulation of HoxA5 mRNA, downregulation of HoxC10 mRNA, and increased protein expression for UCP1 and PGC1α. Collectively, HoxA5 and HoxC10 may have unique functions that contribute to modulating the expression of BAT-selective markers in BAT of juvenile rats during exercise training. The study findings regarding activation and recruitment of BAT during exercise training have implications for anti-obesity management.

Gene- and Species-Specific Hox mRNA Translation by Ribosome Expansion Segments

Ribosomes have been suggested to directly control gene regulation, but regulatory roles for ribosomal RNA (rRNA) remain largely unexplored. Expansion segments (ESs) consist of multitudes of tentacle-like rRNA structures extending from the core ribosome in eukaryotes. ESs are remarkably variable in sequence and size across eukaryotic evolution with largely unknown functions. In characterizing ribosome binding to a regulatory element within a Homeobox (Hox) 5' UTR, we identify a modular stem-loop within this element that binds to a single ES, ES9S. Engineering chimeric, "humanized" yeast ribosomes for ES9S reveals that an evolutionary change in the sequence of ES9S endows species-specific binding of Hoxa9 mRNA to the ribosome. Genome editing to site-specifically disrupt the Hoxa9-ES9S interaction demonstrates the functional importance for such selective mRNA-rRNA binding in translation control. Together, these studies unravel unexpected gene regulation directly mediated by rRNA and how ribosome evolution drives translation of critical developmental regulators.

High expression of HOXA5 is associated with poor prognosis in acute myeloid leukemia

Background: HOXA5 is considered as an oncogene in many tumors. This study in- vestigated the HOXA5 expression in Chinese acute myeloid leukemia (AML) patients and evaluated the predictive significance of HOXA5 with a single-center retrospective study. Methods: We investigated the expression pattern and prognostic value of HOXA5 in patients with AML through by using a series of databases and various datasets, including the ONCOMINE, TCGA, and STRING datasets. The bone marrow samples of 53 newly diagnosed AML patients (non-M3 subtype) and 19 benign individuals were collected in our center. HOXA5 mRNA expression levels were detected by real-time qPCR, HOXA5 protein expression levels were detected by Western Blot. Clinical data was obtained from inpatient medical records. Results: Two microarrays in Oncomine showed that the expression level of HOXA5 was significantly upregulated in AML. Our data revealed that AML patients had higher HOXA5 mRNA and protein expression levels than the controls (P < 0.001). The blast percentage in bone marrow of HOXA5 high-expression group was higher that of HOXA5 low-expression group (P < 0.05). Higher expression level of HOXA5 revealed a worse OS in AML (P < 0.05). Conclusion: Our findings suggested that HOXA5 might have the potential ability to act as a diagnostic biomarker and potential therapeutic target for AML.

MiR-196a promoted cell migration, invasion and the epithelial-mesenchymal transition by targeting HOXA5 in osteosarcoma.

Osteosarcoma (OS), aggressive neoplasms of the bone, is the most common primary bone cancer in children. MiR-196a usually low expressed in several tumors and its functions in osteosarcoma still unclear. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the expression of miR-196a and the HOXA5. Cell metastasis and epithelial-mesenchymal transition (EMT) abilities were assessed using Transwell and western blot. The dual luciferase reporter assay was carried out to verify whether miR-196a directly targeted the 3'-untranslated region (UTR) of HOXA5 mRNA. MiR-196a was overexpressed and HOXA5 was low expressed in osteosarcoma versus the non-tumor tissues and normal cell lines. Upregulation of miR-196a or downregulation of HOXA5 was associated with worse outcome of osteosarcoma patients. MiR-196a enhanced cell migration, invasion and EMT by regulating the expression of HOXA5 through directly targeting the 3'-UTR of its mRNA in osteosarcoma. HOXA5 partially reversed roles of miR-196a on metastasis and EMT in osteosarcoma. MiR-196a promoted cell metastasis and EMT by targeting the 3'-UTR of HOXA5 mRNA in osteosarcoma. The newly identified miR-196a/HOXA5 axis provides novel insight into the pathogenesis of osteosarcoma.

Using multiple-steps bioinformatic analysis to predict the potential microRNA targets by cardiogenic HoxA11.

In this study, our major aim is to using multiple-steps bioinformatic analysis to predict cardiogenic genes with targeting mRNA profiling for predicting cardiogenic HoxA11 gene. We first analyzed the microarray data with bioinformatic measurement, including combining with panel module 1 (mouse embryonic stem cells), panel module 2 (mouse induced pluripotent stem cells), and panel module 3 (gene list form literature of heart development). A literature-based comparison of the two microarrays and a software-based (Targetscan program, www.targetscan.org) comparative analysis of the two datasets. Furthermore, we select the common central pathways and potential candidate genes involved in the cardiomyocyte-lineaged differentiation and development. Schematic presentation of a putative miR181a target site in Hox-A11 3'UTR. The bioinformatic result showed that potential interacted cardiogenic targets of Tbx5, Tbx20, Mal2c, Nkx2.5, cTNT, Cx43, MHC, and MCK in different treatment groups of pluripotent stem cells by using a literature-based comparison of the two microarrays and a software-based gene-lineage system. Our findings support that mir181a is an up-stream regulating microRNA to target the 3'UTR of HoxA11 mRNA during the process of cardiomyocyte differentiation.

CircRNA CDR1as/miR-641/HOXA9 pathway regulated stemness contributes to cisplatin resistance in non-small cell lung cancer (NSCLC)

BackgroundCisplatin (DDP) is the first-line chemotherapeutic drug for non-small cell lung cancer (NSCLC), and long-term DDP stimulation increased resistance of NSCLC cells to this drug by enriching cancer stem cells (CSCs), which contributed to recurrence and worse prognosis of NSCLC, but the molecular mechanisms are still not fully delineated.MethodsReal-Time qPCR and Western Blot analysis were conducted to examine gene expressions at mRNA and protein levels, respectively. Dual-luciferase reporter gene system was used to validate the targeting sites among circRNA CDR1as, miR-641 and HOXA9 mRNA. Cell growth was evaluated by CCK-8 assay, trypan blue staining assay and colony formation assay. The Annexin V-FITC/PI double staining method was employed to measure cell apoptosis ratio. Spheroid formation and flow cytometer assay was used to evaluate cell stemness. Xenograft mice models were established to measure tumorgenicity in vivo, and Ki67 expressions in mice tumor tissues were examined by immunohistochemistry (IHC).ResultsHere we identified a novel circRNA CDR1as/miR-641/Homeobox protein Hox-A9 (HOXA9) pathway regulated stemness and DDP chemoresistance in NSCLC. Mechanistically, circRNA CDR1as and HOXA9 were high-expressed, while miR-641 was low-expressed in DDP-resistant NSCLC cells, instead of their corresponding parental DDP-sensitive NSCLC cells. Additionally, we validated that circRNA CDR1as positively regulated HOXA9 in NSCLC cells by serving as an RNA sponge for miR-641, and knock-down of circRNA CDR1as increased the sensitivity of DDP-resistant NSCLC cells, which were reversed by downregulating miR-641 and upregulating HOXA9. Consistently, overexpression of circRNA CDR1as increased drug resistance of DDP-sensitive NSCLC cells by regulating miR-641/HOXA9 axis. In addition, the expression levels of stemness signatures (SOX2, OCT4 and Nanog) were higher in DDP-resistant NSCLC cells, which also tended to form spheres and enrich CD44+CD166+ population compared to their parental DDP-sensitive NSCLC cells, suggesting that CSCs were enriched in DDP-resistant NSCLC cells. Notably, knock-down of circRNA CDR1as inhibited stemness of DDP-resistant NSCLC cells by inhibiting HOXA9 through upregulating miR-641.ConclusionsTaken together, this study identified that circRNA CDR1as regulated stemness and DDP chemoresistance in NSCLC cells by targeting miR-641/HOXA9 axis.

Gene- and Species-Specific Translation by Ribosome Expansion Segments

Ribosomes have been suggested to directly control gene regulation, however regulatory roles for ribosomal RNA (rRNA) remain largely unexplored. Expansion segments (ESs) consist of a multitude of tentacle-like rRNA structures that extend from the core ribosome in eukaryotes. ESs are remarkably variable in sequence and size across eukaryotic evolution with a largely unknown function. In characterizing ribosome binding to a regulatory element within a Homeobox (Hox) 5’ UTR, we unexpectedly identify a modular stem-loop within this element that binds to a single ES, ES9S. Engineering chimeric, “humanized” yeast ribosomes for ES9S reveals that an evolutionary change in the sequence of ES9S endows species-specific binding of Hoxa9 mRNA to the ribosome. Genome editing to site-specifically disrupt the Hoxa9-ES9S interaction in neural stem cells demonstrates the functional importance for such selective mRNA-rRNA binding in translation control. Together, these studies unravel unexpected gene regulation directly mediated by rRNA.

Copper and lead exposures disturb reproductive features of primary endometrial stromal and epithelial cells

This study investigates if Cu and Pb act as endocrine disruptors affecting endometrial cells. Primary EnSCs and EnECs were exposed to Cu (0, 50, 100 and 200 μM) or Pb (0, 30, 100 and 500 μM) and assessed for viability, decidualization, apoptosis and proliferation on EnSCs, and wound healing and adhesion capabilities on EnECs. Cu exposure decreased significantly cell viability in a dose-dependent manner. Cu and Pb negatively affected in vitro decidualization, showing a significant decrease in PRL secretion. HOXA10 and ERα mRNA levels significantly decreased in decidualized cells (dEnSCs) exposed to Cu. Cu and Pb decreased adhesion and regeneration capability in EnEC. This study reveals that Cu and Pb could negatively affect endometrial functionality, compromising the decidualization process and disrupting endometrial regeneration and embryo adhesion. Therefore, special care should be taken considering heavy metals exposure if pregnancy is being pursued.

Laparoscopic Ovarian Drilling Improves Endometrial Homeobox Gene Expression in PCOS.

The study was designed to investigate whether laparoscopic ovarian drilling (LOD) of ovaries alters the expression levels of HOXA-10 and HOXA-11 mRNA in the endometrium of infertile women with clomiphene-resistant PCOS. Expression of HOXA-10 and HOXA-11 mRNA in the endometrium obtained before and after LOD during the midsecretory phase was measured. Expression of each gene was evaluated using real-time reverse transcriptase polymerase chain reaction (RT-PCR). Expression levels of HOXA-10 and HOXA-11 mRNA were lower in endometrium of patients with PCOS before LOD compared with fertile controls. But the differences failed to show statistical significance. Compared with fertile subjects, LOD of PCOS ovaries up-regulated endometrial HOXA-10 and HOXA-11 mRNA expression. Fold changes of HOXA-10 and HOXA-11 mRNA after LOD were found to be 4.46 and 4.19, respectively. Fold change increase in HOXA-10 and HOXA-11 mRNA was found to be statistically significant (P < .01, P < .02). There is a receptivity defect in the endometrium of women with PCOS that affects fertility regardless of other causes of infertility. LOD increases endometrial HOXA-10 and HOXA-11 mRNA expressions and improves receptivity in patients with clomiphene-resistant PCOS.

An inverse interaction between HOXA11 and HOXA11-AS is associated with cisplatin resistance in lung adenocarcinoma

ABSTRACTHOXA11, which is a member of the homeobox (HOX) gene family, and its natural antisense transcript (NAT) HOXA11-AS have been reported to be closely related to the development of lung cancer. We aimed to investigate their specific roles in cisplatin (DDP) resistance in lung adenocarcinoma (LUAD). First, we found that HOXA11 is hypermethylated and significantly downregulated in a DDP-resistant A549 cell line (A549/DDP) and LUAD tissues, while the HOXA11-AS expression level is elevated. Although HOXA11 and HOXA11-AS mRNA overlap in the 5ʹ-untranslated region (5ʹ UTR) and share two CpG islands, DNA methylation only regulates the expression of HOXA11. Then, we found that HOXA11 and HOXA11-AS have an inverse interaction by transfecting their siRNAs and overexpression vectors into A549 and A549/DDP cells. A dual-luciferase reporter assay further confirmed that the overlapping 5ʹUTR is essential for the bidirectional regulation between HOXA11 and HOXA11-AS. Functional analysis showed that knockdown of HOXA11 expression in A549 cells induced DDP resistance and activated Akt/β-catenin signaling, while overexpression of HOXA11 in A549/DDP cells increased DDP sensitivity and inhibited Akt/β-catenin signaling. Moreover, HOXA11-AS knockdown in A549 cells increased DDP sensitivity and inhibited Akt/β-catenin signaling, while the overexpression of HOXA11-AS in A549/DDP cells induced DDP resistance and activated Akt/β-catenin signaling. In conclusion, our study demonstrates that the inverse interaction between HOXA11 and HOXA11-AS promotes DDP resistance in LUAD.

HOXA10 expression profiling in prostate cancer.

HOX genes encode transcription factors that play key roles in modulating normal tissue morphogenesis, differentiation and homeostasis. Disruption of normal HOX gene expression occurs frequently in human cancers and is associated with both tumor promoting and suppressing activities. Among these is, HOXA10, a pleiotropic gene that is critical for normal prostate development. In this study we characterized HOXA10 expression in human and mouse PCa to gain insights into its clinical significance. A meta-analysis of HOXA10 mRNA expression was carried out across several publicly available data sets. Expression of HOXA10 protein expression was assessed by immunohistochemistry (IHC) using human radical prostatectomy (RP) cases. We correlated HOXA10 expression to clinicopathological features and investigated its relationship to biochemical recurrence (BCR) after RP by the Kaplan-Meier method. HOXA10 mRNA and IHC protein expression was also examined in a mouse model of Pten-null PCa. A meta-analysis of HOXA10 gene expression indicated dysregulated expression of HOXA10 in human PCa. IHC profiling of HOXA10 revealed inverse correlations between HOXA10 expression and Gleason pattern, Gleason score, and pathological stage (P < 0.01). Patients with low expression profiles of HOXA10 were associated with a higher risk of BCR, (OR, 3.54; 95%CI, 1.21-16.14; P = 0.049) whereas patients with high HOXA10 expression experienced longer times to BCR (P = 0.045). However, HOXA10 was not an independent predictor of BCR (OR, 1.52; 95%CI, 0.42-5.54; P = 0.52). Evaluation of expression patterns of HOXA10 in mouse prostate tumors mimicked that of humans. Our findings show that HOXA10 expression is inversely associated with tumor differentiation and high HOXA10 expression is associated with improved BCR-free survival. This study provides human and mouse evidence to suggest tumor suppressive roles for HOXA10 in the context of prostate cancer.