Ubiquitin D is correlated with colon cancer progression and predicts recurrence for stage II-III disease after curative surgery. Br J Cancer. 2010;103:961-969. [PMID: 20808312 DOI: 10.1038/sj.bjc.6605870]

The pivotal role of ZNF384: driving the malignant behavior of serous ovarian cancer cells via the LIN28B/UBD axis

Zinc finger protein 384 (ZNF384) is a highly conserved transcribed gene associated with the development of multiple tumors, however, its role and mechanism in serous ovarian cancer (SOC) are unknown. We first confirmed that ZNF384 was abnormally highly expressed in SOC tissues by bioinformatics analysis and immunohistochemistry. We further used lentivirus packaging and transfection techniques to construct ZNF384 overexpression or knockdown cell lines, and through a series of cell function experiments, gradually verified that ZNF384 promoted a series of malignant behaviors of SOC cell proliferation, migration, and invasion. By establishing a xenotransplantation model in nude mice, it was confirmed that ZNF384 promoted the progress of SOC in vivo. Mechanistically, Overexpression of ZNF384 enhanced the transcriptional activity of Lin-28 homolog B (LIN28B), which promoted the malignant behavior of SOC cells. In addition, LIN28B could regulate the expression of the downstream factor ubiquitin D (UBD) in SOC cells, further promoting the development of SOC. This study shows that ZNF384 aggravates the malignant behavior of SOC cells through the LIN28B/UBD axis, which may be used as a diagnostic biomarker for patients with SOC.

Prognostic significance of FAT10 expression in malignant tumors: a systematic review and meta-analysis

Aim: FAT10, a ubiquitin-like modifier protein, influences apoptosis, DNA damage response and tumor growth, with unclear effects on cancer prognosis.Methods: We reviewed FAT10 expression's impact on malignancy prognosis through a systematic review and meta-analysis, including studies up to September 2023 from PubMed, EMBASE and Web of Science.Results: From 18 studies involving 2513 patients, FAT10 overexpression significantly reduced overall and disease-free survival across various tumors, indicating correlations with advanced disease stage, poor differentiation, lymph node metastasis and larger tumor size.Conclusion: FAT10's overexpression suggests a negative prognostic value in cancer, meriting further investigation.PROSPERO Registration Number: CRD42023431287.

Dual roles of TRIM3 in colorectal cancer by retaining p53 in the cytoplasm to decrease its nuclear expression

Colorectal cancer is a very heterogeneous disease caused by the interaction of genetic and environmental factors. P53, as a frequent mutation gene, plays a critical role in the adenoma-carcinoma transition during the tumorous pathological process. Our team discovered TRIM3 as a tumor-associated gene in CRC by high-content screening techniques. TRIM3 demonstrated both tumor-suppressive and tumorigenic features in cell experiments dependent on the cell status of wild or mutant p53. TRIM3 could directly interact with the C terminus of p53 (residues 320 to 393), a common segment of wtp53 and mutp53. Moreover, TRIM3 could exert different neoplastic features by retaining p53 in the cytoplasm to decrease its nuclear expression in a wtp53 or mutp53-dependent pathway. Chemotherapy resistance develops in nearly all patients with advanced CRC and seriously limits the therapeutic efficacies of anticancer drugs. TRIM3 could reverse the chemotherapy resistance of oxaliplatin in mutp53 CRC cells by degradation of mutp53 in the nuclei to downregulate the multidrug resistance gene. Therefore, TRIM3 could be a potential therapeutic strategy to improve the survival of CRC patients with mutp53.

Ubiquitin D promotes the progression of rheumatoid arthritis via activation of the p38 MAPK pathway

Ubiquitin D (UBD), a member of the ubiquitin‑like modifier family, has been reported to be highly expressed in various types of cancer and its overexpression is positively associated with tumor progression. However, the role and mechanism of UBD in rheumatoid arthritis (RA) remain elusive. In the present study, the gene expression profiles of GSE55457 were downloaded from the Gene Expression Omnibus database to assess differentially expressed genes and perform functional enrichment analyses. UBD was overexpressed by lentivirus transfection. The protein level of UBD, p‑p38 and p38 in RA‑fibroblast‑like synoviocytes (FLSs) were examined by western blotting. Cell Counting Kit‑8 and flow cytometry assays were used to detect the functional changes of RA‑FLSs transfected with UBD and MAPK inhibitor SB202190. The concentrations of inflammatory factors (IL‑2, IL‑6, IL‑10 and TNF‑α) were evaluated using ELISA kits. The results revealed that UBD was overexpressed in RA tissues compared with in the healthy control tissues. Functionally, UBD significantly accelerated the viability and proliferation of RA‑FLSs, whereas it inhibited their apoptosis. Furthermore, UBD significantly promoted the secretion of inflammatory factors (IL‑2, IL‑6, IL‑10 and TNF‑α). Mechanistically, elevated UBD activated phospohorylated‑p38 in RA‑FLSs. By contrast, UBD overexpression and treatment with the p38 MAPK inhibitor SB202190 not only partially relieved the UBD‑dependent effects on cell viability and proliferation, but also reversed its inhibitory effects on cell apoptosis. Furthermore, SB202190 partially inhibited the effects of UBD overexpression on the enhanced secretion of inflammatory factors. The present study indicated that UBD may mediate the activation of p38 MAPK, thereby facilitating the proliferation of RA‑FLSs and ultimately promoting the progression of RA. Therefore, UBD may be considered a potential therapeutic target and a promising prognostic biomarker for RA.

Upregulated Ubiquitin D is a Favorable Prognostic Indicator for Rectal Cancer Patients Undergoing Preoperative Concurrent Chemoradiotherapy

PURPOSE

For locally advanced rectal cancer, neoadjuvant concurrent chemoradiotherapy (CCRT) allows tumor downstaging and makes curative radical proctectomy possible. However, we lack a genetic biomarker to predict cancer prognosis or treatment response. We investigated the association between ubiquitin D (UBD) expression and clinical outcomes in rectal cancer patients receiving CCRT.

PATIENTS AND METHODS

We analyzed the genes associated with the protein modification process (GO:0036211) and identified the UBD gene as the most relevant among the top 7 differentially expressed genes associated with CCRT resistance. We collected tissue specimens from 172 rectal cancer patients who had received CCRT followed by a curative proctectomy. We examine the relationship between UBD expression and patient characteristics, pathological findings, and patient survival, such as metastasis-free survival (MeFS) and disease-specific survival.

RESULTS

Upregulated UBD expression was associated with lower pre-CCRT tumor T stage (P = 0.009), lower post-CCRT tumor T stage (P < 0.001), lower post-CCRT nodal stage (P < 0.001), less vascular invasion (P = 0.015), and better tumor regression (P < 0.001). Using univariate analysis, we found that high UBD expression was correlated with better disease-free survival (DFS) (P < 0.0001), local recurrence-free survival (LRFS) (P < 0.0001) and MeFS (P < 0.0001). Moreover, multivariate analysis demonstrated that high UBD expression was associated with superior DFS (P < 0.001), LRFS (P = 0.01), and MeFS (P = 0.004).

CONCLUSION

UBD upregulation was linked to better clinical prognosis, favorable pathological features, and good treatment response in rectal cancer patients undergoing CCRT. These results suggest UBD is a biomarker for rectal cancer.

Relationship of Placental and Serum Lipoprotein-Associated Phospholipase A2 Levels with Hypertensive Disorders of Pregnancy

Background

A series of studies has shown that lipoprotein-associated phospholipase A2 (Lp-PLA2) is closely associated with abnormal lipid metabolism and vascular endothelial cell injury, but its role in hypertensive disorders of pregnancy (HDP) remains unclear. This study aims to determine the relationship between placental and serum LP-PLA2 levels and HDP, and to provide a feasible method for predicting HDP.

Methods

The placental and serum Lp-PLA2 levels of 63 patients with HDP (20, 25, and 18 cases with gestational hypertension, mild preeclampsia, and severe preeclampsia, respectively) and 20 women with normal pregnancies (control group) were measured via a combination of tissue microarray and immunohistochemistry, real-time quantitative RT-PCR and enzyme-linked immunosorbent assay (ELISA).

Results

1) The gene and protein expression levels of placental LP-PLA2: the HDP group had significantly higher levels than those of the control group (P < 0.05). The mild preeclampsia group had significantly higher levels than those of the control group (P < 0.05); the severe preeclampsia group had significantly higher levels than those of the mild preeclampsia group (P < 0.05). 2) Serum levels of Lp-PLA2: the HDP group had significantly higher levels than those of the control group (P < 0.05). The Lp-PLA2 levels increased gradually with the progression of the HDP; there were significant differences in the four groups using pair-wise comparisons (P < 0.05). 3) Serum levels of LP-PLA2 were positively correlated with placental LP-PLA2 levels in the HDP group (r = 0.435, P < 0.05).

Conclusion

Elevated Lp-PLA2 levels may be associated with the occurrence of HDP, and changes of Lp-PLA2 levels in the maternal blood may be regarded as a monitoring indicator for this disease.

OTUB2 regulates KRT80 stability via deubiquitination and promotes tumour proliferation in gastric cancer

OTUB2 is a deubiquitinating enzyme that contributes to tumor progression. However, the expression of OTUB2 and its prognostic importance in gastric cancer remain unclear. The expression of OTUB2 and KRT80 in GC tissues was investigated using western blotting, qRT-PCR, multiple immunofluorescence staining, and immunohistochemistry. For survival studies, Kaplan-Meier analysis with the log-rank test was used. The role of OTUB2 during GC proliferation was investigated using in vivo and in vitro assays. OTUB2 was found to be overexpressed in GC tissues and to act as an oncogene, which was linked to patients' poor prognosis. Knockdown of OTUB2 inhibited the proliferative capacity of GC cells in vitro and in vivo, although the proliferative capacity was restored upon re-supplementation with KRT80. OTUB2 mechanically stabilized KRT80 by deubiquitinating and shielding it from proteasome-mediated degradation through Lys-48 and Lys-63. Furthermore, by activating the Akt signaling pathway, OTUB2 and KRT80 facilitated GC proliferation. In summary, OTUB2 regulates KRT80 stability via deubiquitination promoting proliferation in GC via activation of the Akt signaling pathway, implying that OTUB2 could be a novel prognostic marker.

Persistent Cryptosporidium parvum Infection Leads to the Development of the Tumor Microenvironment in an Experimental Mouse Model: Results of a Microarray Approach

Cryptosporidium spp. are enteric protozoa parasites that infect a variety of vertebrate hosts. These parasites are capable of inducing life-threatening gastrointestinal disease in immunocompromised individuals. With the rising epidemiological evidence of the occurrence of Cryptosporidium infections in humans with digestive cancer, the tumorigenic potential of the parasite has been speculated. In this regard, Cryptosporidium parvum has been reported to induce digestive adenocarcinoma in a rodent model of chronic cryptosporidiosis. However, the processes by which the parasite could induce this carcinogenesis are still unknown. Therefore, the transcriptomes of C. parvum infected ileo-cecal regions of mice developing tumors were analyzed in the current study. For the first time, downregulation of the expression of α-defensin, an anti-microbial target of the parasite in response to C. parvum infection was observed in the transformed tissues. This phenomenon has been speculated to be the result of resistance of C. parvum to the host defense through the upregulated expression of interferon γ-stimulated genes. The inflammatory response generated as result of attenuated expression of anti-microbial peptides highlights the role of immune evasion in the C. parvum-induced tumorigenesis. The study has also succeeded in the characterization of the tumor microenvironment (TME) which is characterized by the presence of cancer associated fibroblasts, myeloid-derived suppressor cells, tumor-associated macrophages and extracellular matrix components. Identification of immune suppressor cells and accumulation of pro-inflammatory mediators speculates that chronic inflammation induced by persistent C. parvum infection assists in development of an immunosuppressive tumor microenvironment.

Modulation of the Host Cell Transcriptome and Epigenome by Fusobacterium nucleatum

Fusobacterium nucleatum is a ubiquitous opportunistic pathogen with an emerging role as an oncomicrobe in colorectal cancer and other cancer settings. F. nucleatum can adhere to and invade host cells in a manner that varies across F. nucleatum strains and host cell phenotypes. Here, we performed pairwise cocultures between three F. nucleatum strains and two immortalized primary host cell types (human colonic epithelial [HCE] cells and human carotid artery endothelial [HCAE] cells) followed by transcriptome sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) to investigate transcriptional and epigenetic host cell responses. We observed that F. nucleatum-induced host cell transcriptional modulation involves strong upregulation of genes related to immune migration and inflammatory processes, such as TNF, CXCL8, CXCL1, and CCL20. Furthermore, we identified genes strongly upregulated in a cell line-specific manner. In HCE cells, overexpressed genes included UBD and DUOX2/DUOXA2, associated with p53 degradation-mediated proliferation and intestinal reactive oxygen species (ROS) production, respectively. In HCAE cells, overexpressed genes included EFNA1 and LIF, two genes commonly upregulated in colorectal cancer and associated with poor patient outcomes, and PTGS2 (COX2), a gene associated with the protective effect of aspirin in the colorectal cancer setting. Interestingly, we also observed downregulation of numerous histone modification genes upon F. nucleatum exposure. We used the ChIP-seq data to annotate chromatin states genome wide and found significant chromatin remodeling following F. nucleatum exposure in HCAE cells, with increased frequencies of active enhancer and low-signal/quiescent states. Thus, our results highlight increased inflammation and chemokine gene expression as conserved host cell responses to F. nucleatum exposure and extensive host cell epigenomic changes specific to host cell type. IMPORTANCE Fusobacterium nucleatum is a bacterium normally found in the healthy oral cavity but also has an emerging role in colorectal cancer and other cancer settings. The host-microbe interactions of F. nucleatum and its involvement in tumor initiation, progression, and treatment resistance are not fully understood. We explored host cell changes that occur in response to F. nucleatum. We identified key genes differentially expressed in response to various conditions of F. nucleatum exposure and determined that the conserved host cell response to F. nucleatum was dominated by increased inflammation and chemokine gene expression. Additionally, we found extensive host cell epigenomic changes as a novel aspect of host modulation associated with F. nucleatum exposure. These results extend our understanding of F. nucleatum as an emerging pathogen and highlight the importance of considering strain heterogeneity and host cell phenotypic variation when exploring pathogenic mechanisms of F. nucleatum.

Salivary proteomics in monitoring the therapeutic response of canine oral melanoma

Saliva biomarkers are suitable for monitoring the therapeutic response of canine oral melanoma (COM), because saliva directly contacts the tumor, and saliva collection is non-invasive, convenient and cost effective. The present study aimed to investigate novel biomarkers from the salivary proteome of COM treated with surgery and a chemotherapy drug, carboplatin, 1-6 times, using a liquid chromatography-tandem mass spectrometry approach. The expression of a potential salivary biomarker, ubiquitin D (UBD), was observed and verified by western blot analysis. A significantly increased ratio of free UBD (fUBD) to conjugated UBD (cUBD) was shown in the pre-surgery stage (PreS) in OM dogs with short-term survival (STS) (less than 12 months after surgery) compared with that with long-term survival (more than 12 months after surgery). In dogs with STS, the ratio was also shown to be augmented in PreS compared with that after surgery, followed by treatment with carboplatin twice, 4 and 5 times [After treatment (AT)2, AT4 and AT5]. In addition, the expression of fUBD was enhanced in PreS compared with that of AT2 in the STS group. In conclusion, this study revealed that a ratio of fUBD to cUBD in PreS was plausibly shown to be a potential prognostic biomarker for survival in dogs with OM.

Ubiquitin-Like Protein UBD Promotes Cell Proliferation in Colorectal Cancer by Facilitating p53 Degradation

Purpose

Ubiquitin D (UBD) is a member of the ubiquitin-like modifier (UBL) family and is highly expressed in a variety of cancers including colorectal cancer (CRC). However, the mechanisms of its regulatory roles in CRC are largely elusive. In this study, we revealed the effect of UBD on the proliferation of CRC.

Methods

The expression of UBD in clinical tissue samples of CRC and seven CRC cell lines was detected using qRT-PCR, immunohistochemistry (IHC) and Western blotting. CCK-8, colony formation, EdU and flow cytometry assays were used to detect the functional changes of CRC cells transfected with UBD stable expression plasmids in vitro. A xenograft model was constructed to assess the effect of UBD on the growth of CRC cells in vivo. The connection between UBD and p53 was analyzed using Western blotting, immunoprecipitation, proteasome inhibition assay and Cycloheximide (CHX) chase assay.

Results

UBD was overexpressed in CRC tumor tissues compared with nontumor tissues, and its overexpression was positively associated with the tumor size and TNM stage of CRC patients. Functionally, UBD significantly accelerated CRC cell viability and proliferation in vitro and promoted tumorigenesis in vivo. Mechanistically, UBD interacted with p53 in CRC cells, downregulated the expression of p53 by regulating its degradation, shortened the p53 half-life, thereby further affecting the decrease in p21 and the increase in Cyclin D1, Cyclin E, CDK2, CDK4 and CDK6. Moreover, in vivo experiments showed that UBD-induced tumor growth in nude mice was dependent on a decrease in p53.

Conclusions

Our study proved that UBD mediates the degradation of p53, thereby facilitating the growth of CRC cells and ultimately promoting the progression of CRC. Therefore, UBD may be a potential therapeutic target and a promising prognostic biomarker for CRC.

Elevated Expression of ASXL2 is Associated with Poor Prognosis in Colorectal Cancer by Enhancing Tumorigenesis and Inducing Cell Proliferation

Objective

Colorectal cancer is one of the most common malignant tumors worldwide. ASXL2 is an enhancer of the trithorax and polycomb genes, which have been proven to act in many tumor types. The role of ASXL2 in the occurrence and development of tumors has been extensively studied in recent years. However, the relationship between ASXL2 and the prognosis of CRC is still unclear.

Materials and Methods

In this study, quantitative real-time polymerase chain reaction (qRT-PCR), Western blot analysis and immunohistochemistry (IHC) were used to examine the expression of ASXL2 in CRC tissues. Cells were transfected with siRNAs or lentivirus to regulate the expression of ASXL2. The effects of ASXL2 on the proliferation of CRC cells were determined by CCK8 assay.

Results

This study demonstrated that ASXL2 was significantly more highly expressed in CRC specimens than in normal adjacent tissues. The upregulation of ASXL2 was related to advanced clinical stage. Patients who exhibited high expression levels of ASXL2 had poorer overall survival, whereas those with low expression of ASXL2 survived longer. Multivariate Cox regression analysis revealed that ASXL2 expression could be considered an independent prognostic factor for CRC. Inhibition or overexpression of ASXL2 markedly influenced the proliferation of CRC cells.

Conclusion

These results showed that ASXL2 could induce cell proliferation, which was associated with poor prognosis of CRC patients, suggesting that ASXL2 might be a new therapeutic target for CRC.

The Role of FAT10 in Alcoholic Hepatitis Pathogenesis

FAT10 expression is highly up-regulated by pro-inflammatory cytokines IFNγ and TNFα in all cell types and tissues. Increased FAT10 expression may induce increasing mitotic non-disjunction and chromosome instability, leading to tumorigenesis. In this review, we summarized others’ and our work on FAT10 expression in liver biopsy samples from patients with alcoholic hepatitis (AH). FAT10 is essential to maintain the function of liver cell protein quality control and Mallory–Denk body (MDB) formation. FAT10 overexpression in AH leads to balloon degeneration and MDB aggregation formation, all of which is prevented in fat10-/- mice. FAT10 causes the proteins’ accumulation, overexpression, and forming MDBs through modulating 26s proteasome’s proteases. The pathway that increases FAT10 expression includes TNFα/IFNγ and the interferon sequence response element (ISRE), followed by NFκB and STAT3, which were all up-regulated in AH. FAT10 was only reported in human and mouse specimens but plays critical role for the development of alcoholic hepatitis. Flavanone derivatives of milk thistle inhibit TNFα/IFNγ, NFκB, and STAT3, then inhibit the expression of FAT10. NFκB is the key nodal hub of the IFNα/TNFα-response genes. Studies on Silibinin and other milk thistle derivatives to treat AH confirms that overexpressed FAT10 is the major key molecule in these networks.

Monoamine Oxidase B Expression Correlates with a Poor Prognosis in Colorectal Cancer Patients and Is Significantly Associated with Epithelial-to-Mesenchymal Transition-Related Gene Signatures

Monoamine oxidases (MAOs) including MAOA and MAOB are enzymes located on the outer membranes of mitochondria, which are responsible for catalyzing monoamine oxidation. Recently, increased level of MAOs were shown in several cancer types. However, possible roles of MAOs have not yet been elucidated in the progression and prognosis of colorectal carcinoma (CRC). We therefore analyzed the importance of MAOs in CRC by an in silico analysis and tissue microarrays. Several independent cohorts indicated that high expression of MAOB, but not MAOA, was correlated with a worse disease stage and poorer survival. In total, 203 colorectal adenocarcinoma cases underwent immunohistochemical staining of MAOs, and associations with clinicopathological parameters and patient outcomes were evaluated. We found that MAOB is highly expressed in CRC tissues compared to normal colorectal tissues, and its expression was significantly correlated with a higher recurrence rate and a poor prognosis. Moreover, according to the univariate and multivariate analyses, we found that MAOB could be an independent prognostic factor for overall survival and disease-free survival, and its prognostic value was better than T and N stage. Furthermore, significant positive and negative correlations of MAOB with mesenchymal-type and epithelial-type gene expressions were observed in CRC tissues. According to the highlighted characteristics of MAOB in CRC, MAOB can be used as a novel indicator to predict the progression and prognosis of CRC patients.

Different roles of FAT10, FOXO1, and ADRA2A in hepatocellular carcinoma tumorigenesis in patients with alcoholic steatohepatitis (ASH) vs non-alcoholic steatohepatitis (NASH)

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer related deaths worldwide. Among others, non-alcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) are the two major risk factors as both of them may develop cirrhosis and hepatocellular carcinoma (HCC) if left untreated. However, patients with NASH progress to HCC at a rate around 0.5% annually, while 3-10% ASH patients may progress to HCC annually. The present study is to demonstrate the molecular differences in oncogenesis pathway between NASH and ASH. By using immunofluorescence study and quantitating the fluorescence intensity morphometrically in liver biopsied specimens from NASH and ASH patients, the protein expression of candidate molecules within hepatocytes cytoplasm are studied, including two HCC-related molecules FAT10 and FOXO1, and one GPCR pathway related molecule ADRA2A. Compared with the control group patients, the expression levels of all the molecules were upregulated in the ASH group of patients (p < 0.001 in all molecules), while FAT10 and ADRA2A were upregulated, FOXO1 did not change in the NASH group of patients. The most important finding is that compared with the ASH group of patients, the expression levels of all three molecules were significantly lower than in the NASH group of patients (p < 0.001 in all molecules). These results confirmed our previous finding that there are significant differences of molecules change in ASH compared to NASH. Thus, we conclude that there are significantly different molecules and pathways involved during the pathogenesis of HCC development in ASH compared to NASH which could help explain why the tumorigenic rate is different in ASH and NASH.

Cartilage oligomeric matrix protein is a prognostic factor and biomarker of colon cancer and promotes cell proliferation by activating the Akt pathway

PURPOSE

Recent studies have determined that cartilage oligomeric matrix protein (COMP) plays a vital role in carcinogenesis. We sought to clarify the role of COMP in colon cancer.

METHODS

We investigated gene expression data from The Cancer Genome Atlas (TCGA) dataset. Tissue microarrays (TMA) containing paired samples from 253 patients with colon cancer were subjected to immunostaining. COMP levels in serum of colon cancer patients and healthy donors were measured with ELISA. We established COMP-knockout cells using the CRISPR/Cas9 system and COMP-overexpressing cells using lentiviral vectors to detect the effects of COMP on colon cancer cells using Cell Counting Kit-8 (CCK8), colony formation, apoptosis detection kit, and tumorigenesis assays in nude mice.

RESULTS

The analysis of TCGA dataset and the results of the TMA suggested that COMP expression levels were significantly higher in cancer tissues than in adjacent normal tissues. Moreover, high COMP expression was correlated with the poor outcome of colon cancer patients. COMP levels in the sera of preoperative patients with colon cancer were much higher than those in healthy donors and were significantly reduced after colectomy. Colon cancer cells without COMP were defective with respect to the ability to proliferate, colony formation, the ability to resist 5-Fluorouracil-induced apoptosis and the growth of xenograft tumors in mice. Contrasting results were observed in COMP overexpressed cells. COMP promoted colon cancer cell proliferation partially through the activation of PI3K/ Akt/ mTOR/ p70S6K pathway.

CONCLUSIONS

COMP may be a novel prognostic indicator and biomarker and also a potential therapeutic target for colon cancer.

Identification of genes associated with matrix metalloproteinases in invasive lung adenocarcinoma

The aim of the present study was to identify genes with similar function to that of matrix metalloproteinases (MMPs) in invasive lung adenocarcinoma (AC) and to screen the transcription factors that regulate MMPs. The gene expression dataset GSE2514, including 20 invasive lung AC samples and 19 adjacent normal lung samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were screened using the limma package in R. Genes with similar function to MMPs were identified by K-means clustering. Their correlations with MMPs were validated using Pearson correlation analysis. The expression of MMPs in lung cancer and normal tissues was evaluated by western blot analysis. Protein-protein interaction (PPI) network and transcriptional regulatory network analyses were performed with Retrieval of Interacting Genes and Database for Annotation, Visualization and Integrated Discovery, respectively. As a result, 269 DEGs were identified between invasive lung AC samples and normal lung samples, including 78 upregulated and 191 downregulated genes. Four MMPs (MMP1, MMP7, MMP9 and MMP12), which were upregulated in lung AC, were clustered into one group with other genes, including NAD(P)H quinone oxidoreductase 1, claudin 3 (CLDN3), S100 calcium-binding protein P, serine protease inhibitor Kazal type 1, collagen type XI α 1 chain, periostin and desmoplakin (DSP), following cluster analysis. Pearson correlation analysis further confirmed correlations between MMP9-CLDN3, MMP9-DSP and MMP12-DSP. PPI network analysis also indicated multiple interactions between MMPs-associated genes. Furthermore, MMPs were commonly regulated by CCAAT/enhancer binding protein α transcription factor. These findings may provide further insight into the mechanisms of MMPs in invasive lung AC.

Interleukin-18 diagnostically distinguishes and pathogenically promotes human and murine macrophage activation syndrome

Hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening hyperferritinemic systemic inflammatory disorders. Although profound cytotoxic impairment causes familial HLH (fHLH), the mechanisms driving non-fHLH and MAS are largely unknown. MAS occurs in patients with suspected rheumatic disease, but the mechanistic basis for its distinction is unclear. Recently, a syndrome of recurrent MAS with infantile enterocolitis caused by NLRC4 inflammasome hyperactivity highlighted the potential importance of interleukin-18 (IL-18). We tested this association in hyperferritinemic and autoinflammatory patients and found a dramatic correlation of MAS risk with chronic (sometimes lifelong) elevation of mature IL-18, particularly with IL-18 unbound by IL-18 binding protein, or free IL-18. In a mouse engineered to carry a disease-causing germ line NLRC4^T337S mutation, we observed inflammasome-dependent, chronic IL-18 elevation. Surprisingly, this NLRC4^T337S-induced systemic IL-18 elevation derived entirely from intestinal epithelia. NLRC4^T337S intestines were histologically normal but showed increased epithelial turnover and upregulation of interferon-γ-induced genes. Assessing cellular and tissue expression, classical inflammasome components such as Il1b, Nlrp3, and Mefv predominated in neutrophils, whereas Nlrc4 and Il18 were distinctly epithelial. Demonstrating the importance of free IL-18, Il18 transgenic mice exhibited free IL-18 elevation and more severe experimental MAS. NLRC4^T337S mice, whose free IL-18 levels were normal, did not. Thus, we describe a unique connection between MAS risk and chronic IL-18, identify epithelial inflammasome hyperactivity as a potential source, and demonstrate the pathogenicity of free IL-18. These data suggest an IL-18-driven pathway, complementary to the cytotoxic impairment of fHLH, with potential as a distinguishing biomarker and therapeutic target in MAS.

High-level expression of P21-Cdc/Rac-activated kinase 7 is closely related to metastatic potential and poor prognosis of colon carcinoma

P21 protein (Cdc42/Rac)-activated kinase 7 (PAK7) can promote neurite outgrowth, induce microtubule stabilization, and activate cell survival signaling pathways. PAK7 expression was found to increase with colon carcinoma progression, but the prognostic value, clinical significance, and underlying mechanisms have not been explored. In my study, the expression of PAK7 was up-related at both the transcriptional and the translational levels in colon tumors compared to that in adjacent normal colon tissue. Patients with PAK7-positive tumors had a lower rate of overall survival (OS) and metastasis-free survival (MFS) (log-rank test, P < 0.001). A Cox proportional hazards model showed that PAK7 expression was an independent prognostic factor for OS (hazard ration [HR], 2.08; 95% confidence interval [CI], 1.16-3.73; P = 0.004) and MFS (HR, 2.88; 95% CI, 1.53-5.42; P < 0.001) in patients with colon cancer. Patients with tumors that were over-expressing PAK7 experienced metastasis, and died within a significantly shorter time after surgery (P < 0.001). Knockdown of PAK7 by a specific short hairpin RNA (shRNA) significantly suppressed the progression of epithelial to mesechymal transition (EMT), migration, and invasion of colon cancer cells in vitro and tumor growth in vivo. However, overexpression of PAK7 significantly promoted these processes. These findings indicate that aberrant PAK7 expression is associated with the occurrence of metastasis and poor clinical outcomes of human colon cancer by promoting the EMT, and the assessment of PAK7 expression might be helpful in predicting metastasis and prognostication for patients with colon cancer.

MicroRNA‑24‑1‑5p promotes malignant melanoma cell autophagy and apoptosis via regulating ubiquitin D

The present study aimed to investigate the key roles and possible regulatory mechanism of microRNA (miR)‑24‑1‑5p in regulating the autophagy, and apoptosis of malignant melanoma cells. The expression levels of miR‑24‑1‑5p in malignant melanoma tissues were determined. Human melanoma A375 cells were transfected with miR‑24‑1‑5p mimic and control. The effects of miR‑24‑1‑5p overexpression on regulating the expressions of autophagy‑related proteins [microtubule‑associated protein 1A/1B‑light chain 3 (LC3)‑II, LC3‑I and Beclin‑1] and apoptosis‑related proteins [apoptosis regulator Bcl‑2 (Bcl‑2) and (BCL2 like 1) Bcl‑xL] were investigated. The percentage of apoptotic cells in different transfected cells was detected. In addition, luciferase reporter assays were performed to confirm whether ubiquitin D (UBD) was a target of miR‑24‑1‑5p. The effects of UBD silencing on autophagy and apoptosis were also investigated. The expression levels of janus kinase (JNK), phosphorylated (P)‑JNK, Jun proto‑oncogene AP‑1 transcription factor subunit (c‑Jun) and p‑c‑Jun were determined following the overexpression of miR‑24‑1‑5p, and UBD. In comparison with adjacent normal tissues, miR‑24‑1‑5p was significantly downregulated in malignant melanoma tissues. Overexpression of miR‑24‑1‑5p significantly increased the levels of LC3‑II/I ratio and Beclin‑1 expression, and decreased the expression levels of Bcl‑2 and Bcl‑xL. Flow cytometry also showed that miR‑24‑1‑5p overexpression promoted cell apoptosis. Moreover, UBD was confirmed as a direct target of miR‑24‑1‑5p. Silencing of UBD promoted melanoma cell autophagy and apoptosis via regulating the expression levels of related proteins. Besides, the levels of the p‑JNK/JNK and p‑c‑Jun/Jun ratios were significantly increased following miR‑24‑1‑5p overexpression, which were reversed following co‑overexpression of miR‑24‑1‑5p, and UBD. Overexpression of miR‑24‑1‑5p may target UBD, and subsequently promote the autophagy and apoptosis of malignant melanoma cells through activation of the JNK signaling pathway.

Comprehensive analysis of differentially expressed profiles of lncRNAs and construction of miR-133b mediated ceRNA network in colorectal cancer

Background

Growing evidence suggests that long non-coding RNAs (lncRNAs) play a key role in tumorigenesis. However, the mechanism remains largely unknown.

Results

Thousands of significantly dysregulated lncRNAs and mRNAs were identified by microarray. Furthermore, a miR-133b-meditated lncRNA-mRNA ceRNA network was revealed, a subset of which was validated in 14 paired CRC patient tumor/non-tumor samples. Gene set enrichment analysis (GSEA) results demonstrated that lncRNAs ENST00000520055 and ENST00000535511 shared KEGG pathways with miR-133b target genes.

Materials and Methods

We used microarrays to survey the lncRNA and mRNA expression profiles of colorectal cancer and para-cancer tissues. Gene Ontology (GO) and KEGG pathway enrichment analyses were performed to explore the functions of the significantly dysregulated genes. An innovate method was employed that combined analyses of two microarray data sets to construct a miR-133b-mediated lncRNA-mRNA competing endogenous RNAs (ceRNA) network. Quantitative RT-PCR analysis was used to validate part of this network. GSEA was used to predict the potential functions of these lncRNAs.

Conclusions

This study identifies and validates a new method to investigate the miR-133b-mediated lncRNA-mRNA ceRNA network and lays the foundation for future investigation into the role of lncRNAs in colorectal cancer.

Three-dimensional culture system identifies a new mode of cetuximab resistance and disease-relevant genes in colorectal cancer

We previously reported that single cells from a human colorectal cancer (CRC) cell line (HCA-7) formed either hollow single-layered polarized cysts or solid spiky masses when plated in 3D in type-I collagen. To begin in-depth analyses into whether clonal cysts and spiky masses possessed divergent properties, individual colonies of each morphology were isolated and expanded. The lines thus derived faithfully retained their parental cystic and spiky morphologies and were termed CC (cystic) and SC (spiky), respectively. Although both CC and SC expressed EGF receptor (EGFR), the EGFR-neutralizing monoclonal antibody, cetuximab, strongly inhibited growth of CC, whereas SC was resistant to growth inhibition, and this was coupled to increased tyrosine phosphorylation of MET and RON. Addition of the dual MET/RON tyrosine kinase inhibitor, crizotinib, restored cetuximab sensitivity in SC. To further characterize these two lines, we performed comprehensive genomic and transcriptomic analysis of CC and SC in 3D. One of the most up-regulated genes in CC was the tumor suppressor 15-PGDH/HPGD, and the most up-regulated gene in SC was versican (VCAN) in 3D and xenografts. Analysis of a CRC tissue microarray showed that epithelial, but not stromal, VCAN staining strongly correlated with reduced survival, and combined epithelial VCAN and absent HPGD staining portended a poorer prognosis. Thus, with this 3D system, we have identified a mode of cetuximab resistance and a potential prognostic marker in CRC. As such, this represents a potentially powerful system to identify additional therapeutic strategies and disease-relevant genes in CRC and possibly other solid tumors.

The destruction complex of beta-catenin in colorectal carcinoma and colonic adenoma

OBJECTIVE

To evaluate the destruction complex of beta-catenin by the expression of the proteins beta-catetenin, adenomatous polyposis coli, GSK3β, axin and ubiquitin in colorectal carcinoma and colonic adenoma.

METHODS

Tissue samples from 64 patients with colorectal carcinoma and 53 patients with colonic adenoma were analyzed. Tissue microarray blocks and slides were prepared and subjected to immunohistochemistry with polyclonal antibodies in carcinoma, adjacent non-neoplastic mucosa, and adenoma tissues. The immunoreactivity was evaluated by the percentage of positive stained cells and by the intensity assessed through of the stained grade of proteins in the cytoplasm and nucleus of cells. In the statistical analysis, the Spearman correlation coefficient, Student's t, χ2, Mann-Whitney, and McNemar tests, and univariate logistic regression analysis were used.

RESULTS

In colorectal carcinoma, the expressions of beta-catenin and adenomatous polyposis coli proteins were significantly higher than in colonic adenomas (p<0.001 and p<0.0001, respectively). The immunoreactivity of GSK3β, axin 1 and ubiquitin proteins was significantly higher (p=0.03, p=0.039 and p=0.03, respectively) in colorectal carcinoma than in the colonic adenoma and adjacent non-neoplastic mucosa. The immunohistochemistry staining of these proteins did not show significant differences with the clinical and pathological characteristics of colorectal cancer and colonic adenoma.

CONCLUSIONS

These results suggest that, in adenomas, the lower expression of the beta-catenin, axin 1 and GSK3β proteins indicated that the destruction complex of beta-catenin was maintained, while in colorectal carcinoma, the increased expression of beta-catenin, GSK3β, axin 1, and ubiquitin proteins indicated that the destruction complex of beta-catenin was disrupted.

OBJETIVO

Avaliar o complexo de destruição da betacatenina no carcinoma colorretal e no adenoma do colo pela expressão das proteínas betacatenina, adenomatous polyposis coli, GSK3β, axina e ubiquitina.

MÉTODOS

Amostras de tecidos de 64 doentes com carcinoma colorretal e de 53 pacientes com adenoma do colo foram analisadas. Blocos de tecidos foram submetidos ao estudo imuno-histoquímico com anticorpos policlonais nos tecidos do carcinoma, mucosa não neoplásica adjacente e adenoma. A imunorreatividade foi avaliada pela porcentagem de positividade de células coradas e pela intensidade do grau de coloração das proteínas no citoplasma e no núcleo das células. Na análise estatística, foram utilizados o coeficiente de correlação de Spearman, os testes t de Student, χ2, Mann-Whitney e de McNemar, e a análise de regressão logística univariada.

RESULTADOS

No carcinoma colorretal, as expressões da betacatenina e da adenomatous polyposis coli foram significativamente maiores do que em adenomas do colo (p<0,001 e p<0,0001, respectivamente). A imunorreatividade das proteínas GSK3β, axina 1 e ubiquitina foi significativamente maior (p=0,03, p=0,039 e p=0,03, respectivamente) no carcinoma colorretal do que no adenoma e na mucosa não neoplásica adjacente. A coloração imuno-histoquímica dessas proteínas não apresentou diferenças significantes em relação às características clinicopatológicas do câncer colorretal e do adenoma.

CONCLUSÕES

Em adenomas, as menores expressões de betacatenina, axina 1 e GSK3β indicaram que o complexo de destruição da betacatenina estava conservado, enquanto que, no carcinoma colorretal, o aumento das expressões da betacatenina, GSK3β, 1 axina, e ubiquitina indicaram que o complexo de destruição de betacatenina estava alterado.

miR-4775 promotes colorectal cancer invasion and metastasis via the Smad7/TGFβ-mediated epithelial to mesenchymal transition

Background

Despite advancements in the diagnosis and treatment of colorectal cancer (CRC), many patients die because of tumor metastasis or recurrence. Therefore, identifying new prognostic markers and elucidating the mechanisms of CRC metastasis and recurrence will help to improve the prognosis of the disease. As dysregulation of microRNAs is strongly related to cancer progression, the aim of this study was to identify the role of miR-4775 in the prognosis of CRC patients and the underling mechanisms involved in CRC progression.

Methods

qPCR and in situ hybridization were used to evaluate the expression of miR-4775 in 544 pairs of paraffin-embedded normal and CRC tissues. Kaplan–Meier analysis with the log-rank test was used for survival analyses. Immunohistochemical staining was applied to investigate the expression of miR-4775-regulated Smad7/TGFβ pathway-associated markers. In vitro and in vivo invasion and metastasis assays were used to explore the function of miR-4775 in the progression of CRC.

Results

miR-4775 was identified as a high-risk factor for CRC metastasis and recurrence, with high levels predicting poor survival among the 544 studied CRC patients. Furthermore, high miR-4775 expression promoted the invasion of CRC cells as well as metastasis and the epithelial to mesenchymal transition (EMT) via Smad7-mediated activation of TGFβ signaling both in vitro and in vivo. Downregulating miR-4775 or overexpressing Smad7 reversed the tumor-promoting roles of miR-4775/Smad7/TGFβ in vitro and in vivo.

Conclusion

miR-4775 promotes CRC metastasis and recurrence in a Smad7/TGFβ signaling-dependent manner, providing a new therapeutic target for inhibiting the metastasis or recurrence of the disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-017-0585-z) contains supplementary material, which is available to authorized users.

Relationship of Liver X Receptors α and Endoglin Levels in Serum and Placenta with Preeclampsia

Background

Liver X receptor alpha (LXRα) and endoglin have been postulated to play roles in trophoblast invasion and lipid metabolic disturbances. However, the relationship between LXRα and endoglin levels in serum and placenta of patients with preeclampsia remains poorly understood. The objective of this study was to identify correlations between LXRα, endoglin and preeclampsia and provide new feasible methods of clinical prediction and treatment for preeclampsia.

Methods

We enrolled 45 patients with preeclampsia (24 with moderate preeclampsia and 21 with severe preeclampsia) and 15 normal pregnant women (control group) who were admitted to the Department of Obstetrics of the General Hospital of Beijing Command between October 2012 and July 2013 in this study. Serum and placental LXRα and endoglin levels were analyzed by enzyme-linked immunosorbent assay, real-time quantitative PCR, tissue microarray and immunohistochemistry.

Results

Serum and placental LXRα and endoglin levels were significantly higher in patients with preeclampsia than those in control group (P<0.05, each). Moreover, patients with severe preeclampsia displayed significantly higher LXRα and endoglin levels than those with moderate preeclampsia (P<0.05, each). The LXRα sensitivity, specificity and positive and negative predictive values were 66.00%, 80.00%, 89.19% and 48.48%, respectively, while those of endoglin levels were 62.00%, 85.00%, 91.18% and 47.22%, respectively. LXRα and endoglin levels in serum and placenta from patients with preeclampsia were positively correlated (serum: r = 0.486, P<0.01; placenta: r = 0.569, P<0.01).

Conclusions

Elevated LXRα and endoglin levels may be associated with preeclampsia pathogenesis and development and could be used as potential predictors for this disorder.

FERMT1 mediates epithelial-mesenchymal transition to promote colon cancer metastasis via modulation of β-catenin transcriptional activity

We previously demonstrated that fermitin family member 1 (FERMT1) was significantly overexpressed in colon cancer (CC) and associated with poor metastasis-free survival. This study aimed to investigate the precise role of FERMT1 in CC metastasis and the mechanism by which FERMT1 is involved in the epithelial-mesenchymal transition (EMT). Correlations between FERMT1 and EMT markers (E-cadherin, Slug, N-cadherin and β-catenin) were examined via immunohistochemistry in a cohort of CC tissues and adjacent normal colon mucosae. A series of in vitro and in vivo assays were performed to elucidate the function of FERMT1 in CC metastasis and underlying mechanisms. The upregulated expression of FERMT1 in CC tissues correlated positively with that of Slug, N-cadherin and β-catenin, but correlated inversely with E-cadherin expression. Altered FERMT1 expression led to marked changes in the proliferation, migration, invasion and EMT markers of CC cells both in vitro and in vivo. Investigations of underlying mechanisms found that FERMT1 interacted directly with β-catenin and activated the Wnt/β-catenin signaling pathway by decreasing the phosphorylation level of β-catenin, enhancing β-catenin nuclear translocation and increasing the transcriptional activity of β-catenin/TCF/LEF. Activation of the Wnt/β-catenin pathway by CHIR99021 reversed the effect of FERMT1 knockdown, whereas inhibition of the Wnt/β-catenin pathway by XAV939 impaired the effect of FERMT1 overexpression on EMT and cell motility. In conclusion, findings of this study suggest that FERMT1 activates the β-catenin transcriptional activity to promote EMT in CC metastasis.

SERPINA4 is a novel independent prognostic indicator and a potential therapeutic target for colorectal cancer

Serpina family A member 4 (SERPINA4), also known as kallistatin, exerts important effects in inhibiting tumor growth and angiogenesis in many malignancies. However, the precise role of SERPINA4 in CRC has not been fully elucidated. The present study aimed to investigate the expression of SERPINA4 and its clinical significance in CRC. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analyses showed that the mRNA and protein expression of SERPINA4 in colorectal cancer (CRC) specimens was significantly decreased than that in adjacent normal mucosa. Immunohistochemistry (IHC) was conducted to characterize the expression pattern of SERPINA4 by using a tissue microarray (TMA) containing 327 archived paraffin-embedded CRC specimens. Statistical analyses revealed that decreased SERPINA4 expression was significantly associated with invasion depth, nodal involvement, distant metastasis, American Joint Committee on Cancer (AJCC) stage, and tumor differentiation. SERPINA4 was also an independent prognostic indicator of disease-free survival and overall survival in patients with CRC. Furthermore, the impact of altered SERPINA4 expression on CRC cells was analyzed with a series of in vitro and in vivo assays. The results demonstrated that SERPINA4 significantly inhibits malignant tumor progression and serves as a novel prognostic indicator and a potential therapeutic target for CRC.

Interleukin-6 and rs1800796 locus single nucleotide polymorphisms in response to hypoxia/reoxygenation in hepatocytes

Ischemia-reperfusion injury due to hypoxia/reoxygenation (H/R) is one of the main causes of liver damage during liver surgery. Donor interleukin-6 (IL-6) rs1800796 single nucleotide polymorphisms (SNPs) affect the metabolism of tacrolimus following liver transplantation-related hepatic H/R. This study investigated the response of IL-6 and its promoter polymorphisms to hepatic H/R in liver parenchymal cells. The association between IL-6 rs1800796 SNPs and IL‑6 expression was measured in 84 disease-free liver tissues using tissue microarrays and immunohistochemistry. Subsequently, LO2G, LO2C and NC-LO2 cells were successfully constructed via stable lentivirus-mediated transfection. The effects of IL-6 and its SNPs on the biological function of LO2 cells were examined using a cell model of H/R. Our results revealed that IL-6 was mainly expressed in hepatocytes. The intermediate IL-6 expression rate in genotype CC carriers was higher than that in genotype CG/GG carriers (P=0.006), which was subsequently verified at the IL-6 mRNA level (P=0.002). The concentrations of alanine aminotransferase in the LO2G cells were significantly higher than those in the LO2C cells following H/R for 6 h and H/R for 24 h (P<0.05). The viability of the LO2C cells was higher than that of the LO2G cells (P<0.05). Furthermore, the expression of IL-6 and its downstream molecules was significantly increased in the LO2C cells compared with the LO2G cells (P<0.05). Therefore, the sequence variants of rs1800796 SNPs (G→C) exhibit an increased IL-6 transcription efficiency in liver parenchymal cells. In addition, the increased expression of IL-6 protects the hepatocytes following hepatic H/R injury.

Karyopherin alpha 2 is a novel prognostic marker and a potential therapeutic target for colon cancer

Background

Karyopherin alpha 2 (KPNA2), a member of the karyopherin family, plays a vital role in carcinogenesis. Yet its role in colon cancer is poorly characterized. We sought to clarify the clinical significance of its dysregulated expression in human colon tumor specimens.

Methods

We evaluated KPNA2 mRNA and protein expression by real-time polymerase chain reaction and Western blotting in 40 primary colon cancer tissues and paired adjacent normal colon mucosa specimens. KPNA2 protein expression in colon tissue microarray of tumor and normal tissue specimens and lymph node metastasis specimens obtained from 195 colon cancer patients were analyzed immunohistochemically. The effect of KPNA2 knockdown on carcinogenesis potential of human colon cancer cells was determined using Cell Counting Kit-8 (CCK8), colony formation, cell migration, and tumorigenesis in nude mice.

Results

KPNA2 was expressed at higher levels in colon tumors and lymph node metastasis specimens than in normal tissues. Patients with KPNA2-positive tumors were significantly correlated with the American Joint Committee on Cancer (AJCC) stage (p = 0.01), T-classification (p = 0.018), regional lymph node metastasis (p = 0.025), distant metastasis (p = 0.014), and differentiated degree (p = 0.001). KPNA2 was shown to be an independent prognostic indicator of disease-free survival (HR 1.681; 95 % CI: 1.170–2.416; p = 0.005) and overall survival (HR 2.770; 95 % CI: 1.314–5.837; p = 0.007) for patients with colon cancer. Knockdown of KPNA2 expression inhibited colon cancer cell proliferation, colony formation, and migration.

Conclusion

KPNA2 might play an important role in colorectal carcinogenesis and functions as a novel prognostic indicator and a potential therapeutic target for colorectal cancer.

Structure of UBE2Z Enzyme Provides Functional Insight into Specificity in the FAT10 Protein Conjugation Machinery

FAT10 conjugation, a post-translational modification analogous to ubiquitination, specifically requires UBA6 and UBE2Z as its activating (E1) and conjugating (E2) enzymes. Interestingly, these enzymes can also function in ubiquitination. We have determined the crystal structure of UBE2Z and report how the different domains of this E2 enzyme are organized. We further combine our structural data with mutational analyses to understand how specificity is achieved in the FAT10 conjugation pathway. We show that specificity toward UBA6 and UBE2Z lies within the C-terminal CYCI tetrapeptide in FAT10. We also demonstrate that this motif slows down transfer rates for FAT10 from UBA6 onto UBE2Z.

Structural maintenance of chromosomes 4 is a predictor of survival and a novel therapeutic target in colorectal cancer

BACKGROUND

Structural maintenance of chromosomes 4 (SMC-4) is a chromosomal ATPase which plays an important role in regulate chromosome assembly and segregation. However, the role of SMC-4 in the incidence of malignancies, especially colorectal cancer is still poorly understood.

MATERIALS AND METHODS

We here used quantitative PCR and Western blot analysis to examine SMC-4 mRNA and protein levels in primary colorectal cancer and paired normal colonic mucosa. SMC-4 clinicopathological significance was assessed by immunohistochemical staining in a tissue microarray (TMA) in which 118 cases of primary colorectal cancer were paired with noncancerous tissue. The biological function of SMC-4 knockdown was measured by CCK8 and plate colony formation assays. Fluorescence detection has been used to detect cell cycling and apoptosis.

RESULTS

SMC-4 expression was significantly higher in colorectal cancer and associated with T stage, N stage, AJCC stage and differentiation. Knockdown of SMC-4 expression significantly suppressed the proliferation of cancer cells and degraded its malignant degree.

CONCLUSIONS

Our clinical and experimental data suggest that SMC-4 may contribute to the progression of colorectal carcinogenesis. Our study provides a new therapeutic target for colorectal cancer treatment.

Developmental pluripotency-associated 4: a novel predictor for prognosis and a potential therapeutic target for colon cancer

Backgrounds

Developmental pluripotency-associated 4 (Dppa4) gene plays an important role in self-renewal and pluripotency sustainability in embryonic stem cells. It is re-expressed in several malignant tumors and is identified as a new pluripotency-related oncogene. The present study investigates the expression and clinical significance of Dppa4 in colon cancer.

Methods

Real-time polymerase chain reaction and Western blotting were used to evaluate Dppa4 mRNA and protein expression in 39 pairs of fresh-frozzen colon cancer samples, which were compared with adjacent normal mucosa. The Dppa4 protein was evaluated by immunohistochemical techniques using colon tissue microarrays (TMA). The sample included 185 cancer specimens and corresponding normal colorectal mucosa. The effect of Dppa4 knockdown on colorectal cancer cell proliferation was investigated using Cell Counting Kit-8 (CCK8) assays and colony-formation assays.

Results

Both the mRNA and protein level expression of Dppa4 gene was found to be upregulated in colon cancer tissues. Furthermore, the upregulated expression of Dppa4 was significantly correlated with the results of American Joint Committee on Cancer (AJCC) stage (P = 0.01), invasion depth (P = 0.028), nodal involvement (P = 0.012), distant metastasis (P = 0.003), and differentiation (P = 0.002). Dppa4 was also shown to be an independent prognostic indicator of disease-free survival (HR 6.118, 95 % CI 3.004–12.462) and overall survival (HR 6.348, 95 % CI 2.875–14.014) for patients with colon cancer. Knockdown of Dppa4 expression inhibited the proliferation of colorectal cancer cell lines through G1/S transition regulation.

Conclusion

The results indicate that Dppa4 might play an important role in colon cancer progression and function as a novel prognostic indicator and a potential therapeutic target.

Reporting in studies of protein biomarkers of prognosis in colorectal cancer in relation to the REMARK guidelines

PURPOSE

The REMARK guidelines give authors comprehensive and specific advice on the complete and transparent reporting of studies of prognostic tumor markers. The aim of this study was to use the REMARK guidelines to evaluate the quality of reporting in a sample of studies assessing tissue-based protein markers for survival after resection of colorectal cancer.

EXPERIMENTAL DESIGN

Eighty pertinent articles were scored according to their conformity to 26 items derived from the REMARK criteria.

RESULTS

Overall, on a scale of adequacy of reporting that potentially ranged from 26 to 78, the median for these studies was 60 (interquartile range 54-64) and several criteria were adequately covered in a large proportion of studies. However, others were either not dealt with or inadequately covered, including description of the study design (35%), definition of survival endpoints (48%), adjuvant therapy (54%), follow-up procedures and time (59%), neoadjuvant therapy (63%), inclusion/exclusion criteria (73%), multivariable modeling methods and results (74%), and discussion of study limitations (85%).

CONCLUSIONS AND CLINICAL RELEVANCE

Inadequacies in presentation militate against comparability among protein marker studies and undermine the generalizability of their findings. The quality of reporting could be improved if journal editors were to require authors to ensure that their work satisfied the REMARK criteria.

Ubiquitin D is an independent prognostic marker for survival in stage IIB-IIC colon cancer patients treated with 5-fluoruracil-based adjuvant chemotherapy

BACKGROUND

Postoperative 5-fluoruracil (5-FU)-based adjuvant chemotherapy is recommended for stage II colon cancer patients with high conventional risk factors; however, some of these patients still experience tumor recurrence. Identifying novel biomarkers to distinguish the risk of tumor recurrence after surgery is vital for improving their prognoses. We previously showed that ubiquitin D (UBD) can predict the prognosis of colon cancer; however, there are limited data on whether UBD is an independent prognostic factor for stage II patients treated with 5-FU-based adjuvant chemotherapy.

METHODS

Quantitative real-time PCR and Western blot analyses were used to examine UBD expression in randomly selected stage II patients' tumor tissues. UBD expression and p65 distribution were assessed using immunohistochemistry in paraffin-embedded specimens from the 101 tumor recurrence patients and 178 nonrelapse patients who received postoperative 5-FU-based adjuvant chemotherapy.

RESULTS

UBD expression, both at transcriptional and posttranscriptional levels, was higher in relapse tumors (P < 0.001). Immunohistochemistry staining of UBD and p65 showed significant differences between the two groups (P < 0.001). Patients with tumor tissues that UBD-positive expression alone or in combination with p65 nuclei translocation recurred early had a significantly shorter survival time (P < 0.001), especially in stage IIB-IIC patients. UBD-positive expression accompanied with p65 nuclei translocation was a significant independent predictive high risk factor for overall survival (HR 8.76; 95% CI, 5.35-14.27; P = 0.004) and disease-free survival (HR 5.70; 95% CI, 1.43-11.55; P = 0.016).

CONCLUSION

UBD may help to identify recurrent risk in stage IIB-IIC colon cancer patients and further predict which patients benefit from postoperative 5-FU-based adjuvant chemotherapy.

Risk of recurrence in patients with colon cancer stage II and III: a systematic review and meta-analysis of recent literature

BACKGROUND

Adjuvant chemotherapy is established routine therapy for colon cancer (CC) patients with radically resected stage III and 'high-risk' stage II disease. The decision on recommending adjuvant chemotherapy, however, is based on data from older patient cohorts not reflecting improvements in pre-operative staging, surgery, and pathological examination. The aim is to review the current risk of recurrence in stage II and III patients and second, to estimate the relative importance of routinely assessed clinico-pathological variables.

METHODS

The PubMed/MEDLINE and the Cochrane databases were systematically searched for randomized controlled studies and observational studies published after 1 January 2005 with patients included after January 1995 on prognosis in surgically treated stage II and III CC patients.

RESULTS

Of 2596 studies identified, 37 met the inclusion criteria and 25 provided data for meta-analysis. The total patient sample size in the 25 studies reporting either disease-free (DFS) or recurrence-free survival was 15 559 in stage II and 18 425 in stage III. Five-year DFS for stage II patients operated without subsequent adjuvant chemotherapy was 81.4% [95% confidence interval (CI) 75.4-87.4; in studies with good/very good quality of reporting 82.7%, (95% CI 80.8-84.6)]. For stage II patients treated with adjuvant chemotherapy, the five-year DFS was 79.3% (95% CI 75.6-83.1). For stage III patients without chemotherapy, five-year DFS was 49.0% (95% CI 23.2-74.8) and for those treated with adjuvant chemotherapy, 63.6% (95% CI 59.3-67.9). The prognostic impact of commonly investigated clinico-pathological parameters, (pT-stage, pN-stage, differentiation, number of lymph nodes studied, MMR-status, and emergency surgery) were confirmed.

CONCLUSIONS

In this meta-analysis, studies with good quality of reporting show a five-year DFS of 82.7% for stage II CC without adjuvant chemotherapy, whereas the five-year DFS is 63.8% for stage III CC with adjuvant chemotherapy. Due to insufficient reporting on treatment quality the presented DFS is likely an under-estimation of what is achieved at high-quality centers today.

Disruption of FAT10-MAD2 binding inhibits tumor progression

FAT10 (HLA-F-adjacent transcript 10) is a ubiquitin-like modifier that is commonly overexpressed in various tumors. It was found to play a role in mitotic regulation through its interaction with mitotic arrest-deficient 2 (MAD2). Overexpression of FAT10 promotes tumor growth and malignancy. Here, we identified the MAD2-binding interface of FAT10 to be located on its first ubiquitin-like domain whose NMR structure thus was determined. We further proceeded to demonstrate that disruption of the FAT10-MAD2 interaction through mutation of specific MAD2-binding residues did not interfere with the interaction of FAT10 with its other known interacting partners. Significantly, ablation of the FAT10-MAD2 interaction dramatically limited the promalignant capacity of FAT10, including promoting tumor growth in vivo and inducing aneuploidy, proliferation, migration, invasion, and resistance to apoptosis in vitro. Our results strongly suggest that the interaction of FAT10 with MAD2 is a key mechanism underlying the promalignant property of FAT10 and offer prospects for the development of anticancer strategies.

Disruption of FAT10-MAD2 binding inhibits tumor progression

FAT10 (HLA-F-adjacent transcript 10) is a ubiquitin-like modifier that is commonly overexpressed in various tumors. It was found to play a role in mitotic regulation through its interaction with mitotic arrest-deficient 2 (MAD2). Overexpression of FAT10 promotes tumor growth and malignancy. Here, we identified the MAD2-binding interface of FAT10 to be located on its first ubiquitin-like domain whose NMR structure thus was determined. We further proceeded to demonstrate that disruption of the FAT10-MAD2 interaction through mutation of specific MAD2-binding residues did not interfere with the interaction of FAT10 with its other known interacting partners. Significantly, ablation of the FAT10-MAD2 interaction dramatically limited the promalignant capacity of FAT10, including promoting tumor growth in vivo and inducing aneuploidy, proliferation, migration, invasion, and resistance to apoptosis in vitro. Our results strongly suggest that the interaction of FAT10 with MAD2 is a key mechanism underlying the promalignant property of FAT10 and offer prospects for the development of anticancer strategies.

Increased expression of prothymosin-α, independently or combined with TP53, correlates with poor prognosis in colorectal cancer

Human prothymosin-α (PTMA) plays an important role in tumorigenesis, and its overexpression triggers a TP53 response. In this study, we identified that PTMA expression was up-regulated at both the transcriptional and translational level in tumor tissue compared to that in adjacent normal tissue. PTMA overexpression was significantly associated with the depth of tumor invasion, lymph node metastasis (LNM), distant metastasis, advanced AJCC stage, and tumor differentiation. There was also a significant association between PTMA over-expression and mutant TP53 expression (r=0.515, P < 0.001). Survival analysis revealed that the disease-free survival (DFS) and overall survival (OS) rates were significantly lower among patients with PTMA- and TP53-positive tumors. Hence, PTMA might play an important role in the progression of CRC, and the assessment of both PTMA and mutant TP53 expression can help predict colon cancer prognosis.

FAT10, an ubiquitin-like protein, confers malignant properties in non-tumorigenic and tumorigenic cells

FAT10 (HLA-F-adjacent transcript 10) is an ubiquitin-like modifier, which has been implicated in immune response and cancer development. In particular, the hypothesis of FAT10 as a mediator of tumorigenesis stems from its ability to associate with a spindle checkpoint protein Mad2 during mitosis and cause aneuploidy, a hallmark of cancer cells. Furthermore, FAT10 is overexpressed in several carcinomas types, including that of liver and colon. Nevertheless, direct evidence linking FAT10 to cell malignant transformation and progression is lacking. Here, we demonstrate that high FAT10 expression enhanced the proliferative, invasive, migratory and adhesive functions of the transformed cell line, HCT116. These observations were consistently demonstrated in an immortalized, non-tumorigenic liver cell line NeHepLxHT. Importantly, FAT10 can induce malignant transformation as evidenced from the anchorage-independent growth as well as in vivo tumor-forming abilities of FAT10-overexpressing NeHepLxHT cells, whereas in rapidly proliferating HCT116, increased FAT10 further augmented tumor growth. FAT10 was found to activate nuclear factor-κB (NFκB), which in turn upregulated the chemokine receptors CXCR4 and CXCR7. Importantly, small interfering RNA depletion of CXCR7 and CXCR4 attenuated cell invasion of FAT10-overexpressing cells, indicating that the CXCR4/7 is crucial for the FAT10-dependent malignant phenotypes. Taken together, our data reveal novel functions of FAT10 in malignant transformation and progression, via the NFκB-CXCR4/7 pathway.

Up-regulation of tripartite motif-containing 29 promotes cancer cell proliferation and predicts poor survival in colorectal cancer

Tripartite motif-containing 29 (TRIM29), also known as ataxia-telangiectasia group D, is structurally a member of the tripartite motif family of proteins, which characterized by the conserved RING finger, B-box, and coiled-coil domains. TRIM29 functions as an oncogene or a tumor suppressor depending on the tumor types. In this study, we aim to evaluate whether TRIM29 affects the tumorigenesis and progression of colorectal cancer. The expression of TRIM29 was investigated using real-time PCR in 40 pairs of colorectal cancer tissues and immunohistochemistry on a tissue microarray containing 203 cases of primary colorectal cancer paired with non-cancerous tissues. Down-regulation of TRIM29 was achieved by transient transfection in RKO cell lines, and the effects of TRIM29 on tumor proliferation were evaluated by MTT and plate colony formation assays. Results indicated that TRIM29 expression was much higher in colorectal cancer tissues and significantly associated with the depth of tumor invasion, lymph node metastasis, distant metastasis, histological differentiation, vascular invasion, ki-67 index, and advanced tumor stage. Patients with TRIM29-positive tumors had a higher recurrence rate and poorer survival than patients with TRIM29-negative tumors. In multivariate analyses, the TRIM29 expression was an independent factor for determining colorectal cancer prognosis after surgery. Moreover, down-regulation of TRIM29 inhibited tumor cell proliferation in vitro. In conclusion, TRIM29 plays an important role in promoting colorectal cancer progression. Our findings suggest that TRIM29 may serve as a novel biomarker for tumor recurrence and survival for colorectal cancer patients.

Screening for differentially expressed genes between left- and right-sided colon carcinoma by microarray analysis

Left-sided colon carcinoma (LSCC) and right-sided colon carcinoma (RSCC) differ in their genetic susceptibilities to neoplastic transformation. The present study identified 11 genes that were differentially expressed in LSCC and RSCC by expression profiling with microarray analysis. Compared with RSCC, the human genes for L-lactate dehydrogenase B chain (LDHB), cyclin-dependent kinase 4 inhibitor D (CDKN2D), phosphatidylinositol-4-phosphate-3-kinase C2 domain-containing subunit α (PI3KC2α), protocadherin fat 1 (FAT; a human protein that closely resembles the Drosophila tumor suppressor, fat) and dual specificity protein phosphatase 2 (DUSP2) were upregulated in LSCC. By contrast, genes for ubiquitin D (UBD), casein kinase-1 binding protein (CK1BP), synaptotagmin-13 (SYT1), zinc finger protein 560 (ZNF560), pleckstrin homology domain-containing family B member 2 (PLEKHB2) and IgGFc-binding protein (FCGBP) were downregulated in LSCC compared with RSCC. A quantitative polymerase chain reaction (qPCR) analysis revealed that the mRNA levels of UBD and CK1BP in LSCC were significantly lower compared with those in RSCC (P=0.033 and P= 0.005, respectively), whereas the mRNA levels of LDHB and CDKN2D in LSCC were significantly higher compared with those in RSCC (P=0.008 and P=0.017, respectively). Western blot and immunohistochemical analyses demonstrated that the expression of CDKN2D in LSCC was significantly higher compared with that in RSCC, while the expression of UBD in LSCC was significantly lower compared with that in RSCC. The present study provides important insights into the understanding of the molecular genetic basis for the different biological behaviors observed between LSCC and RSCC. These insights may therefore serve as a basis for the identification of novel colon cancer markers and therapeutic targets.

Overexpression of RBBP6, alone or combined with mutant TP53, is predictive of poor prognosis in colon cancer

Retinoblastoma binding protein 6 (RBBP6) plays an important role in chaperone-mediated ubiquitination and interacts with TP53 in carcinogenesis. However, the clinicopathologic significance of RBBP6 expression in colon cancer is unknown; in particular, the prognostic value of RBBP6 combined with TP53 expression has not been explored. Therefore, quantitative real-time PCR and western blot analyses were performed to detect RBBP6 expression in colon cancer tissues. RBBP6 and TP53 expression were assessed by immunohistochemistry in a tissue microarray format, in which the primary colon cancer tissue was paired with noncancerous tissue. Tissue specimens were obtained from 203 patients. We found that RBBP6 was overexpressed in colon tumorous tissues and was significantly associated with clinical stage, depth of tumor invasion, lymph node metastasis (LNM), distant metastasis, and histologic grade. Further studies revealed that a corresponding correlation between RBBP6 overexpression and mutant TP53 was evident in colon cancer (r = 0.450; P<0.001). RBBP6 expression was an independent prognostic factor for overall survival (OS) and disease free survival (DFS). Interestingly, patients with tumors that had both RBBP6 overexpression and mutant TP53 protein accumulation relapsed and died within a significantly short period after surgery (P<0.001). Multivariate analysis showed that patients with LNM and patients with both RBBP6- and TP53-positive tumors had extremely poor OS (HR 6.75; 95% CI 2.63–17.35; P<0.001) and DFS (HR 8.08; 95% CI 2.80–23.30; P<0.001). These clinical findings indicate that the assessment of both RBBP6 and mutant TP53 expression will be helpful in predicting colon cancer prognosis.

Cullin 4B is a novel prognostic marker that correlates with colon cancer progression and pathogenesis

Cullin 4B (CUL4B), a scaffold protein of the Cullin4B-RING E3 ligase complex, functions in proteolysis. The present study aims to investigate its expression pattern and evaluate whether CUL4B expression was associated with histopathological and prognosis in the patients with colon cancer. Real-time PCR and western blot were used to identify CUL4B expression in tumor tissue and the paired adjacent normal mucosa from patients with colon cancer. Immunohistochemistry on a tissue microarray containing 203 cases of colon cancer was performed to analyze the association between CUL4B expression and clinicopathological features. Results indicated that CUL4B mRNA and protein levels in tumor tissues were both higher than that in normal mucosae (P < 0.001). Immunohistochemical study displayed that high CUL4B expression was significantly associated with the depth of tumor invasion, lymph node metastasis, distant metastasis, histological differentiation, vascular invasion, and advanced tumor stage. Patients with CUL4B-positive tumors had a higher recurrence rate and poorer survival than patients with CUL4B-negative tumors. In multivariate analyses, CUL4B expression was an independent factor for determining colon cancer prognosis after surgery. In conclusion, CUL4B might promote the progression of colon cancer and can be served as a novel independent prognostic marker for the prediction of recurrence in colon cancer.

Genome-wide transcription responses to synchrotron microbeam radiotherapy

The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

Analyzing proteasomal subunit expression reveals Rpt4 as a prognostic marker in stage II colorectal cancer

Colorectal cancer is a leading cause of cancer-related deaths worldwide. Early diagnosis and treatment of colorectal cancer is the key to improving survival rates and as such a need exists to identify patients who may benefit from adjuvant chemotherapy. The dysregulation of the ubiquitin-proteasome system (UPS) has been implicated in oncogenesis and cancer cell survival, and proteasome inhibitors are in clinical use for a number of malignancies including multiple myeloma. In our study, we examined the protein expression of several key components of the UPS in colorectal cancer using immunohistochemistry to determine expression levels of ubiquitinylated proteins and the proteasomal subunits, 20S core and Rpt4 in a cohort of 228 patients with colon cancer. Multivariate Cox analysis revealed that neither the intensity of either ubiquitinylated proteins or the 20S core was predictive in either Stage II or III colon cancer for disease free survival or overall survival. In contrast, in Stage II patients increased Rpt4 staining was significantly associated with disease free survival (Cox proportional hazard ratio 0.605; p = 0.0217). Our data suggest that Rpt4 is an independent prognostic variable for Stage II colorectal cancer and may aid in the decision of which patients undergo adjuvant chemotherapy.

High-throughput arrays identify distinct genetic profiles associated with lymph node involvement in rectal cancer

BACKGROUND

Preoperative clinical diagnosis of lymph node involvement guides treatment decisions for rectal cancer. Unfortunately, clinical staging still suffers from a lack of accuracy.

OBJECTIVE

The aim of this study was to evaluate objective genetic differences in primary rectal cancers with and without associated lymph node metastasis.

DESIGN

cDNA microarrays were generated from fresh-frozen tumors. Normalized data underwent global unsupervised hierarchical clustering analysis, and discriminating genes were mapped. Top discriminating genes were compared between stage II and III rectal cancers by use of an empirical Bayes 2 group t test with the Statistical Analysis of Microarrays and the Reproducibility-Optimized Test Statistic software separately to guide data reduction and deal with the difficulties of simultaneous statistical inference. Ingenuity Pathways Analysis software was used to analyze discriminating genes in terms of function and biological processes.

PATIENTS

Fifty-five patients with stage II and 22 patients with stage III rectal adenocarcinomas not treated with chemoradiation were included.

RESULTS

Two major unsupervised clusters emerged representing stage II and III cancers. In 1 cluster, 11 of 12 patients (92%) had stage III cancer; in the other cluster, 54 of 65 patients (83%) had stage II (p < 0.001). Five significantly differentially expressed genes characterized the stage III cluster: interleukin-8, 3-hydroxy-3-methylglutaryl coenzyme A synthase, carbonic anhydrase, ubiquitin, and cystatin (all p < 0.05). Of the 12 patients with differential expression of the 5 marker genes, only one had stage II cancer. Fifty-four of 55 stage II patients clustered with alternative expression patterns of the predictor genes. Differentially expressed genes are related to cancer-associated processes, pathways, and networks.

LIMITATIONS

The identified gene signatures have not yet been validated in independent patient populations.

CONCLUSIONS

Distinct gene expression signatures from primary rectal adenocarcinomas can help differentiate the presence or absence of lymph node metastases. These data are informative, and validation of this gene signature may provide a novel approach for more appropriate individualized treatment selection.