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

Sustained Effectiveness and Safety of Therapeutic miR-10a/b in Alleviating Diabetes and Gastrointestinal Dysmotility without Inducing Cancer or Inflammation in Murine Liver and Colon

microRNAs (miRNAs) are key regulators of both physiological and pathophysiological mechanisms in diabetes and gastrointestinal (GI) dysmotility. Our previous studies have demonstrated the therapeutic potential of miR-10a-5p mimic and miR-10b-5p mimic (miR-10a/b mimics) in rescuing diabetes and GI dysmotility in murine models of diabetes. In this study, we elucidated the safety profile of a long-term treatment with miR-10a/b mimics in diabetic mice. Male C57BL/6 mice were fed a high-fat, high-sucrose diet (HFHSD) to induce diabetes and treated by five subcutaneous injections of miR-10a/b mimics for a 5 month period. We examined the long-term effects of the miRNA mimics on diabetes and GI dysmotility, including an assessment of potential risks for cancer and inflammation in the liver and colon using biomarkers. HFHSD-induced diabetic mice subcutaneously injected with miR-10a/b mimics on a monthly basis for 5 consecutive months exhibited a marked reduction in fasting blood glucose levels with restoration of insulin and significant weight loss, improved glucose and insulin intolerance, and restored GI transit time. In addition, the miR-10a/b mimic-treated diabetic mice showed no indication of risk for cancer development or inflammation induction in the liver, colon, and blood for 5 months post-injections. This longitudinal study demonstrates that miR-10a/b mimics, when subcutaneously administered in diabetic mice, effectively alleviate diabetes and GI dysmotility for 5 months with no discernible risk for cancer or inflammation in the liver and colon. The sustained efficacy and favorable safety profiles position miR-10a/b mimics as promising candidates in miRNA-based therapeutics for diabetes and GI dysmotility.

Integrated Bioinformatics Analysis Reveals Diagnostic Biomarkers and Immune Cell Infiltration Characteristics of Solar Lentigines

Background

Solar lentigines (SLs), serving as a prevalent characteristic of skin photoaging, present as cutaneous aberrant pigmentation. However, the underlying pathogenesis remains unclear and there is a dearth of reliable diagnostic biomarkers.

Objective

The aim of this study was to identify diagnostic biomarkers for SLs and reveal its immunological features.

Methods

In this study, gene expression profiling datasets (GSE192564 and GSE192565) of SLs were obtained from the GEO database. The GSE192564 was used as the training group for screening of differentially expressed genes (DEGs) and subsequent depth analysis. Gene set enrichment analysis (GSEA) was employed to explore the biological states associated with SLs. The weighted gene co-expression network analysis (WGCNA) was employed to identify the significant modules and hub genes. Then, the feature genes were further screened by the overlapping of hub genes and up-regulated differential genes. Subsequently, an artificial neural network was constructed for identifying SLs samples. The GSE192565 was used as the test group for validation of feature genes expression level and the model's classification performance. Furthermore, we conducted immune cell infiltration analysis to reveal the immune infiltration landscape of SLs.

Results

The 9 feature genes were identified as diagnostic biomarkers for SLs in this study. And an artificial neural network based on diagnostic biomarkers was successfully constructed for identification of SLs. GSEA highlighted potential role of immune system in pathogenesis of SLs. SLs samples had a higher proportion of several immune cells, including activated CD8 T cell, dendritic cell, myeloid-derived suppressor cell and so on. And diagnostic biomarkers exhibited a strong relationship with the infiltration of most immune cells.

Conclusion

Our study identified diagnostic biomarkers for SLs and explored its immunological features, enhancing the comprehension of its pathogenesis.

A concise review of the regulatory, diagnostic, and prognostic implications of HOXB-AS3 in tumors

Recent studies have reported that HOXB-AS3 (HOXB Cluster Antisense RNA 3) is an intriguing molecule with dual functionality as a long noncoding RNA (lncRNA) and putative coding peptide in tumorigenesis and progression. The significant expression alterations of HOXB-AS3 were detected in diverse cancer types and closely correlated with clinical stage and patient survival. Furthermore, HOXB-AS3 was involved in a spectrum of biological processes in solid tumors and hematological malignancies, such as stemness, lipid metabolism, migration, invasion, and tumor growth. This review comprehensively analyzes its clinical relevance for diagnosis and prognosis across human tumors and summarizes its functional role and regulatory mechanisms in different malignant tumors, including liver cancer, acute myeloid leukemia, ovarian cancer, lung cancer, endometrial carcinoma, colon cancer, and oral squamous cell carcinoma. Overall, HOXB-AS3 emerges as a promising biomarker and novel therapeutic target in multiple human tumors.

TALE transcription factors: Cofactors no more

Exd/PBX, Hth/MEIS and PREP proteins belong to the TALE (three-amino-acid loop extension) superclass of transcription factors (TFs) with an atypical homedomain (HD). Originally discovered as "cofactors" to HOX proteins, revisiting their traditional role in light of genome-wide experiments reveals a strong and reproducible pattern of HOX and TALE co-occupancy across diverse embryonic tissues. While confirming that TALE increases HOX specificity and selectivity in vivo, this wider outlook also reveals novel aspects of HOX:TALE collaboration, namely that HOX TFs generally require pre-bound TALE factors to access their functional binding sites in vivo. In contrast to the restricted expression domains of HOX TFs, TALE factors are largely ubiquitous, and PBX and PREP are expressed at the earliest developmental stages. PBX and MEIS control development of many organs and tissues and their dysregulation is associated with congenital disease and cancer. Accordingly, many instances of TALE cooperation with non HOX TFs have been documented in various systems. The model that emerges from these studies is that TALE TFs create a permissive chromatin platform that is selected by tissue-restricted TFs for binding. In turn, HOX and other tissue-restricted TFs selectively convert a ubiquitous pool of low affinity TALE binding events into high confidence, tissue-restricted binding events associated with transcriptional activation. As a result, TALE:TF complexes are associated with active chromatin and domain/lineage-specific gene activity. TALE ubiquitous expression and broad genomic occupancy, as well as the increasing examples of TALE tissue-specific partners, reveal a universal and obligatory role for TALE in the control of tissue and lineage-specific transcriptional programs, beyond their initial discovery as HOX co-factors.

G-quadruplex is critical to epigenetic activation of the lncRNA HOTAIR in cancer cells

The cancer-promoting lncRNA HOTAIR has multiple isoforms. Which isoform of HOTAIR accounts for its expression and functions in cancer is unknown. Unlike HOTAIR's canonical intergenic isoform NR_003716 (HOTAIR-C), the novel isoform NR_047517 (HOTAIR-N) forms an overlapping antisense transcription locus with HOXC11. We identified HOTAIR-N as the dominant isoform that regulates the gene expression programs and networks for cell proliferation, survival, and death in cancer cells. The CpG island in the HOTAIR-N promoter was marked with epigenetic markers for active transcription. We identified a G-quadruplex (G4) motif rich region in the HOTAIR-N CpG island. Our findings indicate that G4s in HOTAIR-N CpG island is critical for expression of HOTAIR-N in cancer cells. Disruption of G4 may represent a novel therapeutic approach for cancer. The transcriptomes regulated by HOTAIR-N and Bloom in cancer cells as provided herein are important resources for the exploration of lncRNA, DNA helicases, and G4 in cancer.

Gastrodin Induces Ferroptosis of Glioma Cells via Upregulation of Homeobox D10

Gastrodin, the primary bioactive compound found in Gastrodia elata, has been shown to exhibit neuroprotective properties in a range of neurological disorders. However, the precise mechanisms through which gastrodin influences glioma cells remain unclear, and there is a scarcity of data regarding its specific effects. To ascertain the viability of glioma cell lines LN229, U251, and T98, the CCK-8 assay, a colony formation assay, and a 3D culture model were employed, utilizing varying concentrations of gastrodin (0, 5, 10, and 20 μM). Gastrodin exhibited a notable inhibitory effect on the growth of glioma cells, as evidenced by its ability to suppress colony formation and spheroid formation. Additionally, gastrodin induced ferroptosis in glioma cells, as it can increase the levels of reactive oxygen species (ROS) and peroxidized lipids, and reduced the levels of glutathione. Using a subcutaneous tumor model, gastrodin was found to significantly inhibit the growth of the T98 glioma cell line in vivo. Using high-throughput sequencing, PPI analysis, and RT-qPCR, we successfully identified Homeobox D10 (HOXD10) as the principal target of gastrodin. Gastrodin administration significantly enhanced the expression of HOXD10 in glioma cells. Furthermore, treatment with gastrodin facilitated the transcription of ACSL4 via HOXD10. Notably, the inhibition of HOXD10 expression impeded ferroptosis in the cells, which was subsequently restored upon rescue with gastrodin treatment. Overall, our findings suggest that gastrodin acts as an anti-cancer agent by inducing ferroptosis and inhibiting cell proliferation in HOXD10/ACSL4-dependent pathways. As a prospective treatment for gliomas, gastrodin will hopefully be effective.

Homeobox-D 1 and FTO form a transcriptional-epigenetic feedback loop to promote head and neck cancer proliferation

Transcription factors (TFs) and N6-methyladenosine (m6A) modifiers are involved in tumor progression through transcriptional regulation and posttranscriptional regulation of genes, respectively. However, the crosstalk and role of these two types of gene expression regulators in head and neck squamous cell carcinoma (HNSC) remains poorly understood. In this study, we demonstrate that the TF homeobox-D1 (HOXD1) and the m6A demethylase fat mass and obesity-associated protein (FTO) form a positive feedback loop to promote cell proliferation and survival in HNSC. Clinically, HOXD1 expression is dysregulated in multiple cancer types and is associated with worse prognosis in patients with HNSC, stomach adenocarcinoma, uterine corpus endometrial carcinoma, and pheochromocytoma and paraganglioma. Mechanistically, FTO is overexpressed in HNSC tumor samples and positively regulates HOXD1 expression in an m6A-dependent manner. Functionally, deficiency of HOXD1 relieved the resistance of HNSC cells to apoptosis and arrested tumor cells at the G0/G1 phase, thereby inhibiting cell growth, whereas overexpression of HOXD1 caused the opposite effect. Furthermore, HOXD1 activates the transcription of the oncogenic factor FTO by directly targeting its promoter. Downregulation of FTO mimicked the biological effect of HOXD1 knockdown on HNSC. Importantly, overexpression of HOXD1 significantly rescued the proliferation inhibition and apoptosis promotion of HNSC cells induced by deficiency of FTO. Together, our findings reveal HOXD1 as a novel prognostic predictor and a potential target for HNSC, providing mechanistic insights into the role of the HOXD1-FTO circuit in this cancer.

Prolonging somatic cell proliferation through constitutive hox gene expression in C. elegans

hox genes encode a conserved family of homeodomain transcription factors that are essential to determine the identity of body segments during embryogenesis and maintain adult somatic stem cells competent to regenerate organs. In contrast to higher organisms, somatic cells in C. elegans irreversibly exit the cell cycle after completing their cell lineage and the adult soma cannot regenerate. Here, we show that hox gene expression levels in C. elegans determine the temporal competence of somatic cells to proliferate. Down-regulation of the central hox gene lin-39 in dividing vulval cells results in their premature cell cycle exit, whereas constitutive lin-39 expression causes precocious Pn.p cell and sex myoblast divisions and prolongs the proliferative phase of the vulval cells past their normal point of arrest. Furthermore, ectopic expression of hox genes in the quiescent anchor cell re-activates the cell cycle and induces proliferation until young adulthood. Thus, constitutive expression of a single hox transcription factor is sufficient to prolong somatic cell proliferation beyond the restriction imposed by the cell lineage. The down-regulation of hox gene expression in most somatic cells at the end of larval development may be one cause for the absence of cell proliferation in adult C. elegans.

Role of homeobox d10 gene targeted signaling pathways in cancers

Homeobox D10 (HOXD10) is a transcription factor from the homeobox gene family that controls cell differentiation and morphogenesis throughout development.Due to their functional interaction, changes in HOXD10 gene expression might induce tumors. This narrative review focuses on how and why the dysregulation in the signaling pathways linked with HOXD10 contributes to the metastatic development of cancer. Organ development and tissue homeostasis need highly conserved homeotic transcription factors from homeobox (HOX) genes. Their dysregulation disrupts regulatory molecule action, causing tumors. The HOXD10 gene is upregulated in breast, gastric, hepatocellular, colorectal, bladder, cholangiocellular carcinoma and prostate cancer. Tumor signaling pathways are affected by HOXD10 gene expression changes. This study examines HOXD10-associated signaling pathway dysregulation, which may alter metastatic cancer signaling. In addition, the theoretical foundations that alter HOXD10-mediated therapeutic resistance in malignancies has been presented. New cancer therapy methods will be simpler to develop with the newly discovered knowledge. This review showed that HOXD10 may be a tumor suppressor gene and a new cancer treatment target signaling pathway.

HOXA3 accelerates wound healing in diabetic and aged non-diabetic mammals

Chronic wounds are characterized by a persistent, hyper-inflammatory environment that prevents progression to regenerative wound closure. Such chronic wounds are especially common in diabetic patients, often requiring distal limb amputation, but occur in non-diabetic, elderly patients as well. Induced expression of HoxA3, a member of the Homeobox family of body patterning and master regulatory transcription factors, has been shown to accelerate wound closure in diabetic mice when applied topically as a plasmid encased in a hydrogel. We now provide independent replication of those foundational in vivo diabetic wound closure studies, observing 16% faster healing (3.3 mm wounds vs 3.9 mm wounds at Day 9 post original injury of 6 mm diameter) under treatment with observable microscopic benefits. We then expand upon these findings with minimal dose threshold estimation of 1 μg HoxA3 plasmid delivered topically at a weekly interval. Furthermore, we observed similarities in natural wound healing rates between aged non-diabetic mice and young diabetic mice, which provided motivation to test topical HoxA3 plasmid in aged non-diabetic mice. We observed that HoxA3 treatment achieved complete wound closure (0 mm diameter) at 2 weeks whereas untreated wounds were only 50% closed (3 mm wound diameter). We did not observe any gross adverse effects macroscopically or via histology in these short studies. Whether as a plasmid or future alternative modality, topical HoxA3 is an attractive translational candidate for chronic wounds.