OCIA domain containing 2 is highly expressed in adenocarcinoma mixed subtype with bronchioloalveolar carcinoma component and is associated with better prognosis

OCIAD2 promotes pancreatic cancer progression through the AKT signaling pathway

BACKGROUND

OCIAD2（Ovarian carcinoma immunoreactive antigen-like protein 2） is a protein reported in various cancers. However, the role of OCIAD2 has not been explored in pan-cancer datasets. The purpose of this research lies in analyzing the expression level and prognostic-related value of OCIAD2 in different human cancers, as well as revealing the underlying mechanism in specific cancer type (pancreatic adenocarcinoma, PAAD).

METHODS

The correlation between OCIAD2 expression level and clinical relevance in different human cancers was investigated from bioinformatical perspective (GTEx and TCGA). The OCIAD2 expression level and clinical significance in PAAD were explored in GEO datasets and tissue microarray. Functional experiments were used to determine the OCIAD2 cell functions in vitro and in vivo. GSEA, western blot and immunohistochemistry were used to uncover the potential mechanism.

RESULTS

OCIAD2 expression level was closely correlated with clinical relevance in many cancer types through pan-cancer analysis, and we found OCIAD2 was highly expressed in PAAD and associated with poorer prognosis. OCIAD2 acted as the promotor of Warburg effect and influenced PAAD cells proliferation, migration and apoptosis. Mechanistically, OCIAD2 upregulation may boost glycolysis in PAAD via activating the AKT signaling pathway in PAAD.

CONCLUSIONS

In PAAD, OCIAD2 promotes Warburg effect via AKT signaling pathway and targeting cancer cells metabolic reprogramming could be a potential treatment.

Development and evaluation of an adenosine-to-inosine RNA editing-based prognostic model for survival prediction of bladder cancer patients

Adenosine-to-inosine RNA editing (ATIRE) is a common form of ribonucleic acid (RNA) editing, which has highlighted the importance of ATIRE in tumors. However, its role in bladder cancer (BLCA) remains poorly understood. To study ATIRE impact on BLCA patient prognosis, we obtained ATIRE, gene expression, and clinical data from the Cancer Genome Atlas (TCGA) database for 251 patients, randomly dividing them into training and testing groups. Univariate proportional hazards model (COX) regression identified prognosis-associated ATIRE loci, while the least absolute shrinkage and selection operator (LASSO) selected final loci to construct prognostic models and generate ATIRE scores. We developed a nomogram to predict BLCA patients' overall survival (OS) and analyzed the effect of ATIRE editing levels on host gene expression. We also compared immune cell infiltration and drug treatment between patients with high and low ATIRE scores. The ATIRE prognostic prediction model was constructed using ten ATIRE loci that are closely associated with BLCA survival. Patients with high ATIRE scores showed significantly worse OS than those with low ATIRE scores. Furthermore, the nomogram, which incorporates the ATIRE score, can better predict the prognosis of patients. Multiple functional and pathway changes associated with immune responses, as well as significant differences in immune cell infiltration levels and response to drug therapy were observed between patients with high and low ATIRE scores. This study represented the first comprehensive analysis of the role of ATIRE events in BLCA patient prognosis and provided new insights into potential prognostic markers for BLCA research.

Aberrant OCIAD2 demethylation in lung adenocarcinoma is associated with outcome

Overexpression of OCIAD2 in lung adenocarcinoma has already been reported in several research articles, but the molecular mechanism involved remains unknown. Promoter CpG methylation is a representative form of epigenetic gene regulation, and a considerable number of tumor suppressor genes show hypermethylation in many cancers. In contrast, promoter CpG hypomethylation causes oncogene overexpression, resulting in carcinogenesis and malignant progression. In the present study, we investigated the CpG methylation and expression status of OCIAD2 using tumor tissues and adjacent normal tissues from seven cases of lung adenocarcinoma. We also examined the relationship between CpG methylation status and outcome in 58 patients with adenocarcinoma. Pyrosequencing showed that CpG sites in OCIAD2 promoter regions were more frequently demethylated in tumor tissues than in adjacent normal tissues, and reverse transcription-quantitative polymerase chain reaction revealed overexpression of OCIAD2 in lung adenocarcinoma. There was a correlation between OCIAD2 CpG demethylation and the level of mRNA expression, and statistical analysis showed that CpG hypomethylation of OCIAD2 was associated with poor outcomes. Our results suggest that overexpression of OCIAD2 might be caused mainly by CpG hypomethylation and that OCIAD2 methylation status might be a useful prognostic indicator in lung adenocarcinoma.

A Novel Multi-Omics Analysis Model for Diagnosis and Survival Prediction of Lower-Grade Glioma Patients

Background

Lower-grade gliomas (LGGs) are characterized by remarkable genetic heterogeneity and different clinical outcomes. Classification of LGGs is improved by the development of molecular stratification markers including IDH mutation and 1p/19q chromosomal integrity, which are used as a hallmark of survival and therapy sensitivity of LGG patients. However, the reproducibility and sensitivity of the current classification remain ambiguous. This study aimed to construct more accurate risk-stratification approaches.

Methods

According to bioinformatics, the sequencing profiles of methylation and transcription and imaging data derived from LGG patients were analyzed and developed predictable risk score and radiomics score. Moreover, the performance of predictable models was further validated.

Results

In this study, we determined a cluster of 6 genes that were correlated with IDH mutation/1p19q co-deletion status. Risk score model was calculated based on 6 genes and showed gratifying sensitivity and specificity for survival prediction and therapy response of LGG patients. Furthermore, a radiomics risk score model was established to noninvasively assist judgment of risk score in pre-surgery. Taken together, a predictable nomogram that combined transcriptional signatures and clinical characteristics was established and validated to be preferable to the histopathological classification. Our novel multi-omics nomograms showed a satisfying performance. To establish a user-friendly application, the nomogram was further developed into a web-based platform: https://drw576223193.shinyapps.io/Nomo/, which could be used as a supporting method in addition to the current histopathological-based classification of gliomas.

Conclusions

Our novel multi-omics nomograms showed the satisfying performance of LGG patients and assisted clinicians to draw up individualized clinical management.

Ovarian carcinoma immunoreactive antigen domain 2 controls mitochondrial apoptosis in lung adenocarcinoma

Ovarian carcinoma immunoreactive antigen domain 2 (OCIAD2) has been reported to show significantly higher expression in invasive lung adenocarcinoma than in lung adenocarcinoma in situ, and its abnormal expression is associated with poorer prognosis of the patients. However, the cellular function of OCIAD2 in this tumor remains poorly understood. In the present study, we first validated that OCIAD2 showed higher expression in human lung adenocarcinoma tissues or cell lines than in normal lung tissue or immortalized normal bronchial epithelial cells. OCIAD2 was localized predominantly at the mitochondrial membrane in lung adenocarcinoma cells. Interestingly, suppression of OCIAD2 led to loss of mitochondrial structure and a reduction in the number of mitochondria. Moreover, OCIAD2 suppression led to downregulation of cellular growth, proliferation, migration, and invasion, and upregulation of mitochondria‐related apoptosis. We also showed that OCIAD2 suppression induced a decrease in mitochondrial membrane potential and release of cytochrome c. Transcriptional profiling using RNA sequencing revealed a total of 137 genes whose expression was commonly altered after OCIAD2 knockdown in three lung adenocarcinoma cell lines (A549, HCC827, and PC9). Pathway enrichment analysis of those genes demonstrated significant enrichment in apoptotic signaling or endoplasmic reticulum (ER) stress pathways. Our data suggest that OCIAD2 inhibits the mitochondria‐initiated apoptosis and thus promotes the survival of lung cancer cells. Therefore, OCIAD2 may be an effective target for treatment of lung adenocarcinoma.

Significance of stratifin in early progression of lung adenocarcinoma and its potential therapeutic relevance

Lung cancer is the most common cause of global cancer-related mortality, and the main histological type is adenocarcinoma, accounting for 50% of non-small cell lung cancer. In 2015, the World Health Organization (WHO) histological classification defined the concepts of "adenocarcinoma in situ" (AIS) and "minimally invasive adenocarcinoma" (MIA), which are considered to be adenocarcinomas at a very early stage. Although AIS and MIA have a very favorable outcome, once they progress to early but invasive adenocarcinoma (eIA), they can sometimes have a fatal outcome. We previously compared the expression profiles of eIA and AIS, and identified stratifin (SFN; 14-3-3 sigma) as a protein showing significantly higher expression in eIA than in AIS. Expression of SFN is controlled epigenetically by DNA demethylation, and its overexpression is significantly correlated with poorer outcome. In vitro and in vivo analyses have shown that SFN facilitates early progression of adenocarcinoma by enhancing cell proliferation. This review summarizes genetic and epigenetic abnormalities that can occur in early-stage lung adenocarcinoma and introduces recent findings regarding the biological significance of SFN overexpression during the course of lung adenocarcinoma progression. Therapeutic strategies for targeting SFN are also discussed.

Mucin 17 inhibits the progression of human gastric cancer by limiting inflammatory responses through a MYH9-p53-RhoA regulatory feedback loop

BACKGROUND

Mucins are key components of the mucosal barrier in the stomach that protects epithelia from carcinogenic effects of chronic inflammation. Analysis of The Cancer Genome Atlas database indicated that mucin-17 (MUC17) was more highly expressed in gastric cancer (GC) specimens, with favourable prognosis for patients. To explore the underlying mechanisms, we investigated the potential role of MUC17 in controlling chronic gastric inflammation.

METHODS

We initially quantified the expression of MUC17 and inflammatory factor, as well as the association of MUC17 with survive in GC using immunohistochemistry. To establish how the inflammatory factors affect MUC17 expression, we explored luciferase reporter, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift (EMSA) assays. The role and mechanism that MUC17 plays in inflammation-induced cell proliferation was examined in AGS cells with reduced MUC17 expression and MKN45 cells overexpressing a truncated MUC17.

RESULTS

We found MUC17 was induced by inflammatory cytokines in GC cells via CDX1upregulation. MUC17 thus inactivated NFκB to inhibit GC cell proliferation in response to pro-inflammatory cytokines. We also revealed that the function of MUC17 was dependent on its conserved epidermal growth factor domain and on downstream sequences to enable its interaction with myosin-9, resulting in a sustained regulatory feedback loop between myosin-9, p53, and RhoA, and then activation of p38 to negatively regulate the NFκB pathway in GC cells. This mechanism was also confirmed in vivo.

CONCLUSIONS

Our study demonstrates MUC17 as a GC suppressor protein which has the therapeutic potential for human GC.

A double helical motif in OCIAD2 is essential for its localization, interactions and STAT3 activation

The Ovarian Carcinoma Immunoreactive Antigen domain (OCIAD) - containing proteins OCIAD1/Asrij and OCIAD2, are implicated in several cancers and neurodegenerative diseases. While Asrij has a conserved role in facilitating STAT3 activation for JAK/STAT signaling, the expression and function of OCIAD2 in non-cancerous contexts remains unknown. Here, we report that ociad2 neighbors ociad1/asrij in most vertebrate genomes, and the two genes likely arose by tandem gene duplication, probably somewhere between the Ordovician and Silurian eras. We show that ociad2 expression is higher in the mouse kidney, liver and brain relative to other tissues. OCIAD2 localizes to early endosomes and mitochondria, and interacts with Asrij and STAT3. Knockdown and overexpression studies showed that OCIAD2 is essential for STAT3 activation and cell migration, which could contribute to its role in tumor metastasis. Structure prediction programs, protein disruption studies, biochemical and functional assays revealed a double helical motif in the OCIA domain that is necessary and sufficient for its localization, interactions and STAT3 activation. Given the importance of JAK/STAT signaling in development and disease, our studies shed light on the evolution and conserved function of the OCIA domain in regulating this pathway and will be critical for understanding this clinically important protein family.

OCIAD2 suppressed tumor growth and invasion via AKT pathway in Hepatocelluar carcinoma

Hepatocellular carcinoma (HCC) is an aggressive tumor and the third leading cause of cancer-related death worldwide. Ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) has been found frequently methylated in various cancers, including HCC. The aim of the present study was to investigate the role of OCIAD2 in HCC progression. We analyzed liver hepatocellular carcinoma patients' data from the Cancer Genome Atlas (TCGA), including data extracted from 371 HCC tissues and 50 adjacent normal liver tissues. The RNA sequencing and DNA methylation data revealed that OCIAD2 were significantly hypermethylated and its expression level in the tumor tissues was much lower than that in the corresponding adjacent normal tissues. The methylation level in the promoter was negatively correlated with the expression level of OCAID2. Treatment of HCC cell lines with the DNA methylation inhibitor 5-aza-2'-deoxycitydine (5-Aza) induced a significant increase in the OCIAD2 mRNA and protein. Knocking-down OCIAD2 led to an increased colony formation, migration and invasion dramatically, accompanying with an enhanced expression of MMP9 and activation of AKT and FAK. Inhibition of AKT signaling restored OCIAD2-mediated changes in HCC cell clonogenic growth, migration and invasion. Survival analysis of HCC patient's data indicated patients with a higher expression ratio of OCIAD2/MMP9 had a shorter overall survival than those with a lower expression ratio of OCIAD2/MMP9. Overall, our data indicate that reduced expression of OCIAD2 by DNA hypermethylation plays an important role in HCC tumor growth and invasion. Hypermethylation of OCIAD2 may contribute to HCC treatment development.

miR-3941: A novel microRNA that controls IGBP1 expression and is associated with malignant progression of lung adenocarcinoma

Immunoglobulin (CD79a) binding protein 1 (IGBP1) is universally overexpressed in lung adenocarcinoma and exerts an anti‐apoptotic effect by binding to PP2Ac. However, the molecular mechanism of IGBP1 overexpression is still unclear. In the present study, we used a microRNA (miRNA) array and TargetScan Human software to detect IGBP1‐related miRNAs that regulate IGBP1 expression. The miRNA array analysis revealed more than 100 miRNAs that are dysregulated in early invasive adenocarcinoma. On the other hand, in silico analysis using TargetScan Human revealed 79 miRNAs that are associated with IGBP1 protein expression. Among the miRNAs selected by miRNA array analysis, six (miR‐34b, miR‐138, miR‐374a, miR‐374b, miR‐1909, miR‐3941) were also included among those selected by TargetScan analysis. Real‐time reverse transcription PCR (real‐time RT‐PCR) showed that the six microRNAs were downregulated in invasive adenocarcinoma (IGBP1+) relative to adjacent normal lung tissue (IGBP1−). Among these microRNAs, only miR‐34b and miR‐3941 depressed luciferase activity by targeting 3′UTR‐IGBP1 in the luciferase vector. We transfected miR‐34b and miR‐3941 into lung adenocarcinoma cell lines (A549, PC‐9), and both of them suppressed IGBP1 expression and cell proliferation. Moreover, the transfected miR‐34b and miR‐3941 induced apoptosis of a lung adenocarcinoma cell line, similarly to the effect of siIGBP1 RNA. As well as miR‐34b, we found that miR‐3941 targeted IGBP1 specifically and was able to exclusively downregulate IGBP1 expression. These findings indicate that suppression of miR‐3941 has an important role in the progression of lung adenocarcinoma at an early stage.

Clinical prognostic value of DNA methylation in hepatoblastoma: Four novel tumor suppressor candidates

Hepatoblastoma (HB) is very rare but the most common malignant neoplasm of the liver occurring in children. Despite improvements in therapy, outcomes for patients with advanced HB that is refractory to standard preoperative chemotherapy remain unsatisfactory. To improve the survival rate among this group, identification of novel prognostic markers and therapeutic targets is needed. We have previously reported that altered DNA methylation patterns are of biological and clinical importance in HB. In the present study, using genome‐wide methylation analysis and bisulfite pyrosequencing with specimens from HB tumors, we detected nine methylated genes. We then focused on four of those genes, GPR180,MST1R,OCIAD2, and PARP6, because they likely encode tumor suppressors and their increase of methylation was associated with a poor prognosis. The methylation status of the four genes was also associated with age at diagnosis, and significant association with the presence of metastatic tumors was seen in three of the four genes. Multivariate analysis revealed that the presence of metastatic tumors and increase of methylation of GPR180 were independent prognostic factors affecting event‐free survival. These findings indicate that the four novel tumor suppressor candidates are potentially useful molecular markers predictive of a poor outcome in HB patients, which may serve as the basis for improved therapeutic strategies when clinical trials are carried out.

Sorbitol dehydrogenase overexpression and other aspects of dysregulated protein expression in human precancerous colorectal neoplasms: a quantitative proteomics study

Colorectal adenomas are cancer precursor lesions of the large bowel. A multitude of genomic and epigenomic changes have been documented in these preinvasive lesions, but their impact on the protein effectors of biological function has not been comprehensively explored. Using shotgun quantitative MS, we exhaustively investigated the proteome of 30 colorectal adenomas and paired samples of normal mucosa. Total protein extracts were prepared from these tissues (prospectively collected during colonoscopy) and from normal (HCEC) and cancerous (SW480, SW620, Caco2, HT29, CX1) colon epithelial cell lines. Peptides were labeled with isobaric tags (iTRAQ 8-plex), separated via OFFGEL electrophoresis, and analyzed by means of LC-MS/MS. Nonredundant protein families (4325 in tissues, 2017 in cell lines) were identified and quantified. Principal component analysis of the results clearly distinguished adenomas from normal mucosal samples and cancer cell lines from HCEC cells. Two hundred and twelve proteins displayed significant adenoma-related expression changes (q-value < 0.02, mean fold change versus normal mucosa ±1.4), which correlated (r = 0.74) with similar changes previously identified by our group at the transcriptome level. Fifty-one (∼25%) proteins displayed directionally similar expression changes in colorectal cancer cells (versus HCEC cells) and were therefore attributed to the epithelial component of adenomas. Although benign, adenomas already exhibited cancer-associated proteomic changes: 69 (91%) of the 76 protein up-regulations identified in these lesions have already been reported in cancers. One of the most striking changes involved sorbitol dehydrogenase, a key enzyme in the polyol pathway. Validation studies revealed dramatically increased sorbitol dehydrogenase concentrations and activity in adenomas and cancer cell lines, along with important changes in the expression of other enzymes in the same (AKR1B1) and related (KHK) pathways. Dysregulated polyol metabolism might represent a novel facet of metabolome remodeling associated with tumorigenesis.

Increased expression of OCIA domain containing 2 during stepwise progression of ovarian mucinous tumor

Ovarian cancer immunoreactive antigen domain containing 2 (OCIAD2) has been reported to show cancer-specific expression in early invasive lung adenocarcinoma. OCIAD2 shows high homology with OCIAD1, which was originally immunoscreened from ascites of a patient with ovarian cancer and found to be a tumor-specific protein. Therefore, like OCIAD1, OCIAD2 is expected to show high immunoreactivity in ovarian tumors. In this study, we examined the expression pattern of OCIAD2 in 117 ovarian mucinous tumors, and confirmed that it was more highly expressed in borderline tumor and carcinoma (51/74 cases, 69%) than in adenoma (6/43 cases, 14%). The immunoreactivity of OCIAD2 in borderline tumor and carcinoma was more specific than that of OCIAD1 (adenoma, 21/43 cases, 49%), and more sensitive than that of CEA (borderline tumor and carcinoma, 35/74 cases, 47%). Like OCIAD1, OCIAD2 is a cancer-related protein and its expression level increases during the course of malignant progression and is thought to be a very useful marker for evaluating the malignancy of ovarian mucinous tumors.

Cancer biomarker discovery: the entropic hallmark

Background

It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods.

Methodology/Principal Findings

Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer.

Conclusions/Significance

We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.

Loss of full length CtBP1 expression enhances the invasive potential of human melanoma

BACKGROUND

The C-terminal binding protein 1 (CtBP1) is a known co-repressor of gene transcription. We recently revealed that CtBP1 expression is lost in melanoma cells and melanoma inhibitory activity (MIA) expression is subsequently increased. The present study was performed to evaluate a more general role of CtBP1 in human melanoma and identify further CtBP1-regulated target genes.

METHODS

Sequence analysis and expression profile of CtBP1 in melanoma cell lines were done by PCR. Boyden Chamber assays and co-immunoprecipitation were performed to investigate the functional role of CtBP1. Gene expression analysis and micro array data were used to define target genes.

RESULTS

Interestingly, we detected an alternative splice product of CtBP1 with unknown function whose expression is induced at reduction of full length CtBP1. Overexpression of full length CtBP1 in melanoma cells had no effect on cell proliferation but did influence cell migration and invasiveness. To understand the effect of CtBP1 we identified putative LEF/TCF target genes found to be strongly expressed in melanoma using DNA microarray analysis. We focused on fourteen genes not previously associated with melanoma. Detailed analysis revealed that most of these were known to be involved in tumor metastasis. Eleven genes had expression profiles associated with melanoma cell invasiveness.

CONCLUSION

In summary, this study revealed that reduction of CtBP1 expression is correlated with migratory, invasive potential of melanoma cells.