Dowregulation of OTX1 attenuates gastric cancer cell proliferation, migration and invasion

OTX Genes in Adult Tissues

OTX homeobox genes have been extensively studied for their role in development, especially in neuroectoderm formation. Recently, their expression has also been reported in adult physiological and pathological tissues, including retina, mammary and pituitary glands, sinonasal mucosa, in several types of cancer, and in response to inflammatory, ischemic, and hypoxic stimuli. Reactivation of OTX genes in adult tissues supports the notion of the evolutionary amplification of functions of genes by varying their temporal expression, with the selection of homeobox genes from the "toolbox" to drive or contribute to different processes at different stages of life. OTX involvement in pathologies points toward these genes as potential diagnostic and/or prognostic markers as well as possible therapeutic targets.

Orthodenticle Homeobox OTX1 Promotes Papillary Thyroid Carcinoma Progression and Is a Potential Prognostic Biomarker

Papillary thyroid carcinoma (PTC) is the most common type of thyroid neoplasms, characterized by evidence of follicular cell differentiation. Orthodenticle homeobox 1 (OTX1) is a transcription factor which has been implicated in numerous diseases, including malignancies. The objective of this research was to explore the function of OTX1 in PTC. Immunohistochemistry (IHC) was employed to determine the protein level of OTX1 in PTC specimens. Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, a xenograft model on nude mice was established to investigate in vivo effects of OTX1. Our results revealed that OTX1 was significantly upregulated within specific PTC tissues and was remarkably correlated with unfavorable clinical outcomes in PTC. Silencing OTX1 resulted in a significant inhibition in cell viability and suppressed cell proliferation. In addition, in vivo experiments demonstrated that OTX1 silencing resulted in a significant suppression of tumor growth in nude mice. Collectively, these results suggest that OTX1 may play crucial roles in promoting PTC progression.

MiR-195-5p suppresses gastric adenocarcinoma cell progression via targeting OTX1

Gastric adenocarcinoma (GAC) caused by malignant transformation of gastric adenocytes is a malignancy with high incidence. MiR-195-5p modulates a variety of cancers. One of its target genes, orthodenticle homeobox 1 (OTX1), is believed to be a key modulator of tumor progression. We aim to analyze the mechanism of miR-195-5p and OTX1 in GAC. MiR-195-5p and OTX1 mRNA levels in GAC cells were tested via qRT-PCR. OTX1 protein and EMT-related protein levels were examined through western blot. Several cell functional assays were designed to measure changes in cell malignant behaviors. Dual luciferase assay verified the targeting relation of miR-195-5p and OTX1. These experimental results showed significantly low miR-195-5p expression and significantly high OTX1 expression in GAC cells. Enforced miR-195-5p level repressed cell malignant progression and accelerated cell apoptosis in GAC. Increased OTX1 weakened the above-mentioned effect caused by overexpressing miR-195-5p. Thus, miR-195-5p restrained migration, proliferation, invasion and epithelial-mesenchymal transition process of GAC cells, and promoted cell apoptosis through regulating OTX1. A new insight is provided for searching for biomarkers or therapeutic targets of GAC.

Knockdown of circMYOF inhibits cell growth, metastasis, and glycolysis through miR-145-5p/OTX1 regulatory axis in laryngeal squamous cell carcinoma

New evidence suggests that abnormal expression of circular RNA (circRNA) is associated with the development of human cancers. This study aims to reveal circMYOF roles in the malignant phenotype of laryngeal squamous cell carcinoma (LSCC). The expression of circMYOF, microRNA (miR)-145-5p, and orthodenticle homeobox 1 (OTX1) was detected by quantitative real-time PCR. Cell proliferation, migration, invasion, and apoptosis were determined using colony formation assay and EdU assay, wound healing assay, transwell assay, and flow cytometry, respectively. Protein expression was examined by western blot analysis. Cell glycolysis was assessed by detecting glucose consumption and lactate production. Mice xenograft models were constructed to evaluate the regulation of circMYOF on LSCC tumorigenesis. The regulatory relationships among circMYOF, miR-145-5p, and OTX1 were identified using dual-luciferase reporter assay and RIP assay. Serum exosomes were isolated to confirm the existence of circMYOF in LSCC patients. CircMYOF was upregulated in LSCC tissues and cells, and its knockdown suppressed LSCC cell growth, metastasis, and glycolysis, as well as inhibited LSCC tumor growth. MiR-145-5p had decreased expression in LSCC, and it could be sponged by circMYOF. The inhibition effect of circMYOF lentivirus short hairpin RNA (sh-circMYOF) on LSCC progression was restored by the inhibitor of miR-145-5p (in-miR-145-5p). Also, OTX1 was targeted by miR-145-5p and was positively regulated by circMYOF. MiR-145-5p could repress LSCC progression, and OTX1 overexpression also eliminated this effect. In addition, we found that circMYOF was significantly overexpressed in the serum exosomes of LSCC patients. Our data revealed that circMYOF contributed to LSCC progression by promoting cell growth, metastasis, and glycolysis through miR-145-5p/OTX1 axis.

Site-Specific Hypermethylation of SST 1stExon as a Biomarker for Predicting the Risk of Gastrointestinal Tract Cancers

Background

DNA methylation is an important epigenetic modification in tumorigenesis, and similar epigenetic regulation mechanisms have been found in the gastrointestinal tract (GIT) cancers. Somatostatin (SST) has been confirmed to be expressed throughout the GIT. This study aimed to simultaneously explore the relationships between the SST methylation and the risks of three GIT cancers (esophageal cancer (EC), gastric cancer (GC), and colorectal cancer (CRC)) and to evaluate its diagnostic value.

Methods

Differentially methylated regions (DMRs) of the SST gene, including TSS200, 1stExon, and the gene body, were identified in GIT cancers by The Cancer Genome Atlas (TCGA) database analysis. Further analyses were conducted in tissue samples of EC (n = 50), GC (n = 99), and CRC (n = 80). The SST methylation was detected by bisulfite-sequencing PCR (BSP), and the SST expression was detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR).

Results

In GIT cancers, DMR-related CpG islands were mainly located in the 1stExon. The methylation status of the SST 1stExon in the tumor tissues was significantly higher than that in the adjacent noncancerous tissues, and the methylation rates of the specific CpG sites were correlated with clinical phenotypes. The average methylation rate (AMR) of the SST 1stExon was negatively correlated with the SST gene expression in GC and CRC (both P < 0.001). For the diagnosis of GIT cancers, the combined detection of methylation at CpG sites +18 and +129 showed the highest area under the curve (AUC 0.698), with a sensitivity of 59.3% and a specificity of 72.8%.

Conclusions

The site-specific hypermethylation of the SST 1stExon increases the risk of GIT cancers and might be a potential predictive marker for pan-GIT cancers.

Dynamic transcriptome and chromatin architecture in granulosa cells during chicken folliculogenesis

Folliculogenesis is a complex biological process involving a central oocyte and its surrounding somatic cells. Three-dimensional chromatin architecture is an important transcription regulator; however, little is known about its dynamics and role in transcriptional regulation of granulosa cells during chicken folliculogenesis. We investigate the transcriptomic dynamics of chicken granulosa cells over ten follicular stages and assess the chromatin architecture dynamics and how it influences gene expression in granulosa cells at three key stages: the prehierarchical small white follicles, the first largest preovulatory follicles, and the postovulatory follicles. Our results demonstrate the consistency between the global reprogramming of chromatin architecture and the transcriptomic divergence during folliculogenesis, providing ample evidence for compartmentalization rearrangement, variable organization of topologically associating domains, and rewiring of the long-range interaction between promoter and enhancers. These results provide key insights into avian reproductive biology and provide a foundational dataset for the future in-depth functional characterization of granulosa cells.

The domestic chicken Gallus gallus domesticus is a classic model for the study of folliculogenesis. Here the authors integrate multi-omics analyses characterizing the dynamic transcriptome and chromatin architecture in granulosa cells during chicken folliculogenesis.

miR-223-5p Suppresses OTX1 to Mediate Malignant Progression of Lung Squamous Cell Carcinoma Cells

BACKGROUND

Lung squamous cell carcinoma (LUSC) features high morbidity and mortality as a worldwide malignant tumor. This study mainly explored a miR-223-5p-dependent mechanism that affected proliferation, invasion, and migration of LUSC cells.

METHODS

Expression data of mature miRNAs and sequencing data of total RNA of LUSC were downloaded from TCGA database. Differentially expressed mRNAs were obtained. Function of miR-223-5p in LUSC cells was detected by assays like qRT-PCR, MTT, wound healing assay, Western blot, and Transwell assay. Western blot was performed to analyze the relationship between OTX1 and JAK/STAT signaling pathways. Dual-luciferase assay detected the relationship between miR-223-5p and OTX1. The way how miR-223-5p regulated LUSC cell biological functions via OTX1 was further explored.

RESULTS

It was noted that miR-223-5p expression in LUSC tissue and cells was significantly reduced. Overexpression of miR-223-5p negatively regulated the proliferation, invasion, and migration of LUSC cells. The downstream target gene OTX1 was detected to be notably elevated in LUSC cells. A negative correlation between OTX1 and miR-223-5p was also found. As analyzed by GSEA, OTX1 was significantly enriched in the JAK/STAT signaling pathway and activated the pathway. Dual-luciferase assay demonstrated that OTX1 was a direct molecular target of miR-223-5p in LUSC cells. Rescue experiment verified that miR-223-5p regulated the malignant phenotypes of LUSC cells by pairing with OTX1.

CONCLUSION

This study indicated that miR-223-5p was lowly expressed in LUSC cells. The impact of miR-223-5p on cell proliferation, invasion, and migration was realized by targeting OTX1. It is likely that miR-223-5p can be a novel target for LUSC treatment, which provides new ideas for future LUSC treatment.

MiR-4269 suppresses the tumorigenesis and development of pancreatic cancer by targeting ZEB1/OTX1 pathway

As one of the most prevalent malignant tumors, pancreatic cancer (PC) is a leading fatal cancer worldwide. Surging evidence has unraveled that miRNAs are involved in the occurrence and progression of multiple cancers, including PC. The tumor suppressor effects of miR-4269 have been certified in gastric carcinoma. However, the potential function of miR-4269 remains largely unclear, which drives us to identify the role of miR-4269 in PC development. In the present study, we determined the expression pattern of miR-4269 in PC cells and normal cells. Results of RT-qPCR analysis illuminated that miR-4269 expression level in PC cells was lower than that in normal cells. Functional assays demonstrated that up-regulation of miR-4269 obviously inhibited the proliferation, migration and invasion of PC cells. In order to elucidate the mechanism governing miR-4269 in PC, we carried out bioinformatics analysis and further experimental investigations. Our results validated that ZEB1 was a direct target of miR-4269. Additionally, ZEB1 activated the transcription of OXT1. More importantly, miR-4269 attenuated the expression level of OXT1 via targeting ZEB1. Ultimately, our findings confirmed that miR-4269 served as a cancer suppressor in PC through regulation of ZEB1/OTX1 pathway, which suggested that miR-4269 might represent a promising target for the clinical treatment of PC.

A Novel DNA Methylation Signature as an Independent Prognostic Factor in Muscle-Invasive Bladder Cancer

Background

Muscle-invasive bladder cancer (MIBC) accounts for approximately 20% of all urothelial bladder carcinomas (UBC) at time of diagnosis, and up to 30% of patients with non-muscle invasive UBC will progress to MIBC over time. An increasing body of evidence has revealed a strong correlation between aberrant DNA methylation and tumorigenesis in MIBC.

Results

Using The Cancer Genome Atlas (TCGA) molecular data for 413 patients, we described a DNA methylation-based signature as a prognostic factor for overall survival (OS) in MIBC patients. By using a least absolute shrinkage and selection operator (LASSO) model, differentially methylated regions were first identified using multiple criteria followed by survival and LASSO analyses to identify DNA methylation probes related to OS and build a classifier to stratify patients with MIBC. The prognostic value of the classifier, referred to as risk score (RS), was validated in a held-out testing set from the TCGA MIBC cohort. Finally, receiver operating characteristic (ROC) analysis was used to compare the prognostic accuracy of the models built with RS alone, RS plus clinicopathologic features, and clinicopathologic features alone. We found that our seven-probe classifier-based RS stratifies patients into high- and low-risk groups for overall survival (OS) in the testing set (n = 137) (AUC at 3 years, 0.65; AUC at 5 years, 0.65). In addition, RS significantly improved the prognostic model when it was combined with clinical information including age, smoking status, Tumor (T) stage, and Lymph node metastasis (N) stage.

Conclusions

The DNA methylation-based RS can be a useful tool to predict the accuracy of preoperative and/or post-cystectomy models of OS in MIBC patients.

miR-3196 acts as a Tumor Suppressor and Predicts Survival Outcomes in Patients With Gastric Cancer

BACKGROUND

Gastric cancer is one of the most common malignancies worldwide with high mortality. Therefore, identifying cancer-related biomarkers for predicting prognosis and progression of gastric cancer is essential. This study aimed to investigate the clinical value and functional role of microRNA-3196 in gastric cancer.

METHODS

The relative expression levels of microRNA-3196 in gastric cancer tissues and adjacent normal tissues were detected by quantitative reverse transcription-polymerase chain reaction. In this study, quantitative reverse transcription-polymerase chain reaction, cell proliferation assay, and Transwell migration and invasion assays were performed to explore microRNA-3196 expression level and its effects on cell proliferation, migration, and invasion in gastric cancer cells. The Kaplan-Meier method and multivariate Cox regression analyses were used to explore the prognostic significance of microRNA-3196 in gastric cancer. Dual-luciferase report assay was performed to validate the potential target gene regulated by microRNA-3196 in gastric cancer.

RESULTS

The expression of microRNA-3196 was downregulated in gastric cancer tissues and cell lines. Downregulation of microRNA-3196 was associated with lymph node metastasis and Tumor Node Metastasis (TNM) stage. The Kaplan-Meier curve analysis indicated that patients with low expression of microRNA-3196 had a poor prognosis, and the Cox regression analysis results showed microRNA-3196 expression was an independent prognostic factor of gastric cancer. Moreover, overexpression of microRNA-3196 inhibited cell proliferation, migration, and invasion, while knockdown of microRNA-3196 promoted these cellular behaviors in AGS and MKN45 cells. OTX1 may be a potential target gene regulated by microRNA-3196 in gastric cancer.

CONCLUSIONS

These results suggested that microRNA-3196 might not only a tumor suppressor in gastric cancer cells by modulating OTX1 but also might be an independent prognostic biomarker and therapeutic target of gastric cancer.

OTX1 exerts an oncogenic role and is negatively regulated by miR129-5p in laryngeal squamous cell carcinoma

Background

Orthodenticle homeobox 1 (OTX1) is a transcription factor that plays an important role in various human cancers. However, the function of OTX1 in laryngeal squamous cell carcinoma (LSCC) is largely unknown. We aimed to explore the roles of OTX1 in LSCC and its possible molecular mechanism.

Methods

The expression levels of OTX1 were assessed in LSCC cell lines and tissue samples. We further examined the effect of OTX1 on LSCC progression. The upstream regulator of OTX1 was identified using a computer algorithm and confirmed experimentally.

Results

OTX1 was highly expressed in 70.7% (70/99) of LSCC tissue samples. The OTX1 expression in LSCC was significantly correlated with lymph node metastasis. High OTX1 expression in patients with LSCC was correlated with poor prognosis. Knockdown of OTX1 inhibited proliferation, colony formation, migration and invasion in LSCC cells. Knockdown of OTX1 inhibited tumor growth in a xenograft mouse model. Mechanistically, OTX1 might act as a direct target of miR-129-5p. OTX1 enhanced tumorigenicity and tumor growth both in vitro and in vivo.

Conclusions

Our findings support that OTX1 is an oncogene in LSCC tumorigenesis and progression. Furthermore, OTX1 is a direct target of miR-129-5p in LSCC cells. Taken together, OTX1 is a promising diagnostic and therapeutic marker for LSCC.

A Genetic Screen for Human Genes Suppressing FUS Induced Toxicity in Yeast

FUS is a nucleic acid binding protein that, when mutated, cause a subset of familial amyotrophic lateral sclerosis (ALS). Expression of FUS in yeast recapitulates several pathological features of the disease-causing mutant proteins, including nuclear to cytoplasmic translocation, formation of cytoplasmic inclusions, and cytotoxicity. Genetic screens using the yeast model of FUS have identified yeast genes and their corresponding human homologs suppressing FUS induced toxicity in yeast, neurons and animal models. To expand the search for human suppressor genes of FUS induced toxicity, we carried out a genome-scale genetic screen using a newly constructed library containing 13570 human genes cloned in an inducible yeast-expression vector. Through multiple rounds of verification, we found 37 human genes that, when overexpressed, suppress FUS induced toxicity in yeast. Human genes with DNA or RNA binding functions are overrepresented among the identified suppressor genes, supporting that perturbations of RNA metabolism is a key underlying mechanism of FUS toxicity.

MicroRNA-4516 suppresses pancreatic cancer development via negatively regulating orthodenticle homeobox 1

Pancreatic cancer remains one of the most lethal human cancers without efficient therapeutic strategy. MicoRNAs (miRNAs) are a group of small non-coding RNAs involved in multiple biological processes including tumor development and progression. In this study, we investigated the expression and function of miR-4516 in pancreatic cancer. MiR-4516 was low-expressed in pancreatic cancer tissues and cell lines. Overexpression of miR-4516 inhibited pancreatic cancer cell proliferation, migration and invasion, while promoted cell apoptosis in vitro. Further, overexpression of miR-4516 suppressed xenograft pancreatic tumor growth in vivo. Bioinformatics analysis was performed and miR-4516 was predicted to negatively regulate orthodenticle homeobox 1 (OTX1) expression by binding to its 3'-UTR. Consistently, OTX1 was highly expressed in pancreatic cancer tissues and cell lines. Knockdown of OTX1 expression suppressed pancreatic cancer cell migration and invasion, with down-regulated MMP2 and MMP9 expression. Moreover, we demonstrated that miR-4516 regulated pancreatic cancer cell growth, migration, invasion and apoptosis via targeting OTX1. Overexpression of OTX1 could partially abrogate the inhibitory effect of miR-4516. Taken together, we conclude that miR-4516 could function as a tumor suppressor via targeting OTX1. These findings suggest that miR-4516/OTX1 axis might be a novel therapeutic target for miRNA-based therapy for pancreatic cancer patients.

Tspan8-Tumor Extracellular Vesicle-Induced Endothelial Cell and Fibroblast Remodeling Relies on the Target Cell-Selective Response

Tumor cell-derived extracellular vesicles (TEX) expressing tetraspanin Tspan8-alpha4/beta1 support angiogenesis. Tspan8-alpha6/beta4 facilitates lung premetastatic niche establishment. TEX-promoted target reprogramming is still being disputed, we explored rat endothelial cell (EC) and lung fibroblast (Fb) mRNA and miRNA profile changes after coculture with TEX. TEX were derived from non-metastatic BSp73AS (AS) or metastatic BSp73ASML (ASML) rat tumor lines transfected with Tspan8 (AS-Tspan8) or Tspan8-shRNA (ASML-Tspan8kd). mRNA was analyzed by deep sequencing and miRNA by array analysis of EC and Fb before and after coculture with TEX. EC and Fb responded more vigorously to AS-Tspan8- than AS-TEX. Though EC and Fb responses differed, both cell lines predominantly responded to membrane receptor activation with upregulation and activation of signaling molecules and transcription factors. Minor TEX-initiated changes in the miRNA profile relied, at least partly, on long noncoding RNA (lncRNA) that also affected chromosome organization and mRNA processing. These analyses uncovered three important points. TEX activate target cell autonomous programs. Responses are initiated by TEX targeting units and are target cell-specific. The strong TEX-promoted lncRNA impact reflects lncRNA shuttling and location-dependent distinct activities. These informations urge for an in depth exploration on the mode of TEX-initiated target cell-specific remodeling including, as a major factor, lncRNA.

The lncRNA FEZF1-AS1 Promotes the Progression of Colorectal Cancer Through Regulating OTX1 and Targeting miR-30a-5p

Long noncoding RNAs (lncRNAs) participate in and regulate the biological process of colorectal cancer (CRC) progression. Our previous research identified differentially expressed lncRNAs in 10 CRC tissues and 10 matched nontumor tissues by next-generation sequencing (NGS). In this study, we identified an lncRNA, FEZF1 antisense RNA 1 (FEZF1-AS1), and further explored its function and mechanism in CRC. We verified that FEZF1-AS1 is highly expressed in CRC tissues and cell lines. Through functional experiments, we found that reduced levels of FEZF1-AS1 significantly suppressed CRC cell migration, invasion, and proliferation and inhibited tumor growth in vivo. Mechanistically, we discovered that reduced levels of the lncRNA FEZF1-AS1 inhibited the activation of epithelial-mesenchymal transition (EMT); the overexpression of orthodenticle homeobox 1 (OTX1) partially rescued the FEZF1-AS1-induced inhibition of protein expression. It indicated that FEZF1-AS1 may play a role in the occurrence and development of CRC by regulating the FEZF1-AS1/OTX1/EMT pathway. Furthermore, it was reported that FEZF1-AS1 is located in both the nucleus and cytoplasm of HCT116 cells. Dual-luciferase reporter assays verified that FEZF1-AS1 directly binds miR-30a-5p and negatively regulated each other. Further, we showed that 5'-nucleotidase ecto (NT5E) is a direct target of miR-30a-5p, and the inhibition of miR-30a-5p expression partially rescued the inhibitory effect of FEZF1-AS1 on NT5E. Our results indicated that the mechanism by which FEZF1-AS1 positively regulates the expression of NT5E is through sponging miR-30a-5p. Our study demonstrated that lncRNA FEZF1-AS1 is involved in the development of CRC and may serve as a diagnostic and therapeutic target for CRC patients.