A Novel HOXA10-Associated 5-Gene-Based Prognostic Signature for Stratification of Short-term Survivors of Pancreatic Ductal Adenocarcinoma

PURPOSE

Despite the significant association of molecular subtypes with poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC), few efforts have been made to identify the underlying pathway(s) responsible for this prognosis. Identifying a clinically relevant prognosis-based gene signature may be the key to improving patient outcomes.

EXPERIMENTAL DESIGN

We analyzed the transcriptomic profiles of treatment-naïve surgically resected short-term survivor (STS) and long-term survivor (LTS) tumors (GSE62452) for expression and survival, followed by validation in several datasets. These results were corroborated by IHC analysis of PDAC-resected STS and LTS tumors. The mechanism of this differential survival was investigated using CIBERSORT and pathway analyses.

RESULTS

We identified a short-surviving prognostic subtype of PDAC with a high degree of significance (P = 0.018). One hundred thirty genes in this novel subtype were found to be regulated by a master regulator, homeobox gene HOXA10, and a 5-gene signature derived from these genes, including BANF1, EIF4G1, MRPS10, PDIA4, and TYMS, exhibited differential expression in STSs and a strong association with poor survival. This signature was further associated with the proportion of T cells and macrophages found in STSs and LTSs, demonstrating a potential role in PDAC immunosuppression. Pathway analyses corroborated these findings, revealing that this HOXA10-driven prognostic signature is associated with immune suppression and enhanced tumorigenesis.

CONCLUSIONS

Overall, these findings reveal the presence of a HOXA10-associated prognostic subtype that can be used to differentiate between STS and LTS patients of PDAC and inform on the molecular interactions that play a role in this poor prognosis.

HOXA10 expression is decreased in endometrium of women with adenomyosis

HOXA10 gene expression is decreased in the secretory phase endometrium of women with adenomyosis. Diminished expression of HOXA10 is a potential mechanism explaining decreased implantation observed in women with adenomyosis.

The role of the Hoxa10/HOXA10 gene in the etiology of endometriosis and its related infertility: a review

PURPOSE

endometriosis and its associated infertility have been the object of continuous research for over a century. To understand the molecular mechanisms underlying the disease, it has become necessary to determine the aspects of its etiology that are not explained by the retrograde menstruation theory. This could in turn elucidate how various clinical and surgical treatments might affect the evolution and remission of the disease.

METHODS

this review is focused on the most recent clinical and laboratory findings regarding the association of HOXA10 with endometriosis and infertility.

RESULT

the homebox (Hox/HOX) proteins are highly conserved transcription factors that determine segmental body identities in multiple species, including humans. Hoxa10/HOXA10 is directly involved in the embryogenesis of the uterus and embryo implantation via regulation of downstream genes. Cyclical endometrial expression of Hoxa10/HOXA10, with a peak of expression occurring during the window of implantation, is observed in the adult in response to estrogen and progesterone. Women with endometriosis do not demonstrate the expected mid-luteal rise of HOXA10 expression, which might partially explain the infertility observed in many of these patients. Recent studies also demonstrated HOXA10 expression in endometriotic foci outside the Müllerian tract.

CONCLUSIONS

multiple lines of evidence suggest that the actions of the homeobox A10 (Hoxa10/HOXA10) gene could account for some aspects of endometriosis.

Reduced expression of biomarkers associated with the implantation window in women with endometriosis

OBJECTIVE

To evaluate the expression of biomarkers of implantation, glycodelin A (GdA), osteopontin (OPN), lysophosphatidic acid receptor 3 (LPA3), and HOXA10, in eutopic endometrium of women with and without endometriosis.

DESIGN

Prospective observational study.

SETTING

Clinical research center.

PATIENT(S)

Twenty-four women with endometriosis and 23 healthy volunteers of similar age.

INTERVENTION(S)

Secretory phase endometrial biopsy.

MAIN OUTCOME MEASURE(S)

Expression of immunohistochemical staining intensity and localization of GdA, OPN, LPA3, and HOXA10 in eutopic endometrium.

RESULT(S)

Endometrial GdA expression was significantly reduced in patients after cycle day 22. The endometrium from women with endometriosis also showed decreased expression of OPN in the late secretory phase and LPA3 and HOXA10 expression in the midsecretory and late secretory phases.

CONCLUSION(S)

The decreased expression of these four biomarkers of implantation may indicate impaired endometrial receptivity in patients with endometriosis, providing one explanation for the subfertility observed even in women with few pelvic implants. Because many of these markers are P dependent, these findings suggest the possibility of reduced endometrial P action in this population.

Calpain5 expression is decreased in endometriosis and regulated by HOXA10 in human endometrial cells

Calpains have been implicated in the regulation of apoptosis. Here, we identified Calpain5 as a target of HOXA10 transcriptional regulation in endometrial cells as well as its aberrant regulation in endometriosis. Histologically confirmed biopsies of endometriosis were obtained from 20 women. Eutopic endometrium was collected by endometrial biopsy from 30 controls and from the 20 subjects with endometriosis. First trimester decidual samples were obtained from five subjects at the time of pregnancy termination. Immunohistochemistry was used to identify Calpain5 expression. Calpain5 was expressed in endometrial stromal and glandular cells throughout the menstrual cycle and in decidua. Calpain5 protein expression was decreased in both stromal and glandular cells from women with endometriosis compared with that of fertile controls. Human endometrial stromal and epithelial cell lines were transfected with pcDNA/HOXA10, HOXA10 siRNA or respective controls. Quantitative real-time RT-PCR was performed to determine expression of HOXA10 and Calpain5 in each group. Transfection of HESC cells with an HOXA10 expression construct led to increased Calpain5 expression, whereas transfection with siRNA resulted in decreased expression. In conclusion, Calpain5 expression is regulated by HOXA10. Calpain5 expression was decreased in endometriosis likely as a result of decreased HOXA10 expression. Decreased apoptosis in endometrial cells may promote the development of endometriosis through a pathway involving HOXA10, Calpain5 and caspase.

Myeloid ecotropic viral integration site 1 (MEIS) 1 involvement in embryonic implantation

BACKGROUND

The HOXA10 homeobox gene controls embryonic uterine development and adult endometrial receptivity. The three-amino-acid loop extension (TALE) family homeobox genes like myeloid ecotropic viral integration site 1 (MEIS) provide enhanced target gene activation and specificity in HOX-regulated cellular processes by acting as HOX cofactors.

METHODS AND RESULTS

Analysis of an Affymetrix data set in the public domain showed high expression of MEIS1 in human endometrium. MEIS1 expression was confirmed during the human menstrual cycle by RT-PCR and in situ hybridization and was increased during the secretory compared with proliferative phase of the cycle (P = 0.0001), the time of implantation. To assess the importance of maternal Meis1 expression in a mouse model, the uteri of Day 2 pregnant mice were injected with Meis1 over-expression or small interfering RNA (siRNA) constructs. Blocking Meis1 expression by siRNA before implantation significantly reduced average implantation rates (P = 0.00001). Increased or decreased Meis1 expression significantly increased or decreased the expression of integrin beta3, a transcriptional target of HOXA10 and an important factor in early embryo-endometrium interactions (P = 0.006). Manipulating Meis1 expression before implantation also dramatically affected the number of pinopodes, uterine endometrial epithelial projections that develop at the time of endometrial receptivity.

CONCLUSIONS

The results suggest that in mouse, meis1 contributes to regulating endometrial development during the menstrual cycle and establishing the conditions necessary for implantation.

Gene expression profiling reveals putative HOXA10 downstream targets in the periimplantation mouse uterus

HOXA10 encodes a transcription factor required for endometrial receptivity and embryo implantation. The objective of this study was to identify and to characterize those molecular markers regulated by HOXA10 expression. The authors have identified putative HOXA10 target genes identified by microarray analysis employing a murine model of transient HOXA10 expression during the anticipated implantation window. Microarray analysis identified 40 statistically significant genes regulated by HOXA10 overexpression of which 31 genes were downregulated greater than 2-fold over control and 9 genes were upregulated. Cellular ontogenies of differentially expressed genes include cell adhesion molecules, signal transduction factors, and metabolic regulators. Semiquantitative real-time reverse transcriptase polymerase chain reaction confirmed regulation of selected candidate genes. Examples included clusterin (Clu), phoshoglycerate 3-dehydrogenase (3-Pgdh), and tumor-associated calcium signal transducer 2 (Tacstd2). Elucidation of these pathways will allow further characterization of the molecular mechanisms governing endometrial development, which also may function to enhance uterine receptivity.

GnRH antagonists may affect endometrial receptivity

OBJECTIVE

HOXA10 is an essential regulator of endometrial receptivity. To determine the effect of GnRH antagonists on endometrial receptivity, we assessed endometrial HOXA10 expression in GnRH antagonist, GnRH agonist, and natural cycles.

DESIGN

Prospective case-control study.

SETTING

University academic medical center.

PATIENT(S)

Nineteen subjects were included: 12 subjects underwent controlled ovarian hyperstimulation with recombinant FSH and used either a GnRH antagonist or a GnRH agonist; seven control subjects underwent natural cycles.

INTERVENTION(S)

Pipelle endometrial biopsies were obtained 11 days after hCG administration or spontaneous LH surge in untreated cycles, respectively. Immunohistochemistry was used to assess HOXA10 protein expression in endometrial glands and stroma.

MAIN OUTCOME MEASURE(S)

Endometrial HOXA10 protein expression.

RESULT(S)

HOXA10 expression was significantly decreased in endometrial stromal cells in GnRH antagonist-treated cycles compared with GnRH agonist-treated cycles or natural cycle control subjects. There was no significant difference in glandular cell HOXA10 expression among the three groups.

CONCLUSION(S)

Use of GnRH antagonists may be associated with impaired HOXA10 expression in endometrial stromal cells and thus may affect endometrial receptivity.

Altered HOX and WNT7A expression in human lung cancer

HOX genes encode transcription factors that control patterning and cell fates. Alterations in HOX expression have been clearly implicated in leukemia, but their role in most other malignant diseases remains unknown. By using degenerate reverse transcription-PCR and subsequent real-time quantitative assays, we examined HOX expression in lung cancer cell lines, direct tumor-control pairs, and bronchial epithelial cultures. As in leukemia, genes of the HOX9 paralogous group and HOXA10 were frequently overexpressed. For HOXB9, we confirmed that elevated RNA was associated with protein overexpression. In some cases, marked HOX overexpression was associated with elevated FGF10 and FGF17. During development, the WNT pathway affects cell fate, polarity, and proliferation, and WNT7a has been implicated in the maintenance of HOX expression. In contrast to normal lung and mortal short-term bronchial epithelial cultures, WNT7a was frequently reduced or absent in lung cancers. In immortalized bronchial epithelial cells, WNT7a was lost concomitantly with HOXA1, and a statistically significant correlation between the expression of both genes was observed in lung cancer cell lines. Furthermore, we identified a homozygous deletion of beta-catenin in the mesothelioma, NCI-H28, associated with reduced WNT7a and the lowest overall cell line expression of HOXA1, HOXA7, HOXA9, and HOXA10, whereas HOXB9 levels were unaffected. Of note, both WNT7a and beta-catenin are encoded on chromosome 3p, which undergoes frequent loss of heterozygosity in these tumors. Our results suggest that alterations in regulatory circuits involving HOX, WNT, and possibly fibroblast growth factor pathways occur frequently in lung cancer.