Risk factors for mid- and long-term mortality in lung transplant recipients aged 70 years and older.

OBJECTIVES: With increased lung transplantation in those aged 70 and older, limited literature addresses risk factors affecting their survival. Our study aims to identify independent factors impacting mid- and long-term mortality in this elderly population. METHODS: This study analyzed lung transplant patients over 70 from May 2005 to December 2022 using United Network for Organ Sharing data. The 3- or 5-year cohort excluded multi-organ, secondary transplantation and loss to follow-up. Univariable Cox analysis was conducted to assess recipient, donor and transplant factors. Factors with a significance level of P < 0.2 were subsequently included in a multivariable Cox model to identify correlations with 3- and 5-year mortality in patients aged over 70. RESULTS: Multivariable analysis has identified key factors affecting 3- and 5-year mortality in elderly lung transplant patients over 70. Common notable factors include recipient total bilirubin, intensive care unit status at the time of transplantation, donor diabetes, Cytomegalovirus (CMV) mismatch and single lung transplantation. Additionally, Hispanic/Latino patients and ischaemia time of the transplant significantly impact the 3-year mortality, while recipient age, diabetes, nitric oxide use before transplantation and creatinine were identified as unique independent risk factors affecting the 5-year morality. CONCLUSIONS: The study identified several independent risk factors that impact the mid- and long-term survival of lung transplantation for individuals over 70 years. These findings can contribute to the optimization of lung transplant treatment strategies and perioperative management in elderly patients, thereby enhancing the survival rate of this age group.

Clinical phenotypes and prognoses of microscopic polyangiitis based on kidney biopsies.

BACKGROUND: To classify the different clinical phenotypes and compare the distinct prognoses of microscopic polyangiitis (MPA). METHODS: A retrospective analysis of 436 patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) from 2015 to 2022 was conducted in our center, of which 90 patients were diagnosed with MPA and underwent renal biopsy. RESULTS: Among the 90 MPA patients, 63% were female, and the median age at onset was 63 years (25th-75th percentile: 58-68). The median follow-up time was 26 months (25th-75th percentile: 10-53). We identified four subtypes: renal impairment type (cluster 1, 39%), pure type (cluster 2, 22%), systemic inflammation type (cluster 3, 26%), and rapid progress type (cluster 4, 13%). Cluster 1, characterized by renal dysfunction at onset (80%), demonstrated poor prognoses with only 26% achieved complete remission (CR), 11% dying, and 19% developing renal failure. In contrast, patients in cluster 2, exclusively female, most had only kidney involvement showed the best prognoses with 55% achieving CR and none experiencing death or renal failure within 10 years. Cluster 3 mostly consisted of males; high fever and C-reactive protein levels were the primary characteristics. These cases exhibited moderate prognoses with 53% achieving CR, 9% dying, and 4% developing renal failure. Finally, patients in cluster 4, which was characterized by rapidly progressive glomerulonephritis, had the worst prognoses, with none achieving CR, 8% dying, and 75% developing renal failure despite aggressive treatment. CONCLUSIONS: MPA is classified into four subtypes with distinct clinical manifestations and prognoses.

Association of Cytomegalovirus Infection With Anti-MDA5 Antibody-Positive Dermatomyositis: A Prospective Cohort Study.

Objectives: To investigate whether cytomegalovirus (CMV) infection plays a role in the pathogenesis and prognosis of idiopathic inflammatory myopathy (IIM), particularly in anti-MDA5 antibody-positive (anti-MDA5+) dermatomyositis (DM). Methods: A prospective cohort of 204 newly diagnosed IIM patients and 50 healthy individuals were enrolled in the study. CMV-IgM and CMV-IgG antibody concentrations and lymphocyte counts were analyzed. Differences in categorical data were compared using Fisher's exact test and the chi-square test. One-year survival rates were analyzed in MDA5+ DM patients with and without CMV infection. Results: In IIM patients, the median CMV-IgM level was significantly higher than in healthy controls (6 U/mL vs. 0 U/mL, p < 0.05) as was the median CMV-IgG level (114 U/mL vs. 105 U/mL, p < 0.05). The percentage of recent CMV infections in the MDA5+ DM group was much higher than it was in the MDA5- IIM group (19.1% vs. 7.0%, p = 0.009). MDA5+ DM patients with CMV DNA-emia had poorer 1 year survival than the CMV-DNA- group (33.3% vs. 86.3%, p = 0.010). CMV-IgM-positive (CMV-IgM+) MDA5+ DM patients had lower CD4+ T cell counts (245.7 cells/µL vs. 420.5 cells/µL, p < 0.05) and CD19+ B cell counts (97.3 cells/µL vs. 240.6 cells/µL, p < 0.05). Conclusion: The number of CMV infections was significantly higher in IIM patients, particularly in MDA5+ DM patients. Lower CD4+ T cells and CD19+ B cells were observed in CMV-IgM+ MDA5+ DM patients. CMV infection may have an important role in the pathogenesis and prognosis of MDA5+ DM by disrupting immunity.

Efficacy and safety of a selective URAT1 inhibitor SHR4640 in Chinese subjects with hyperuricaemia: a randomized controlled phase II study.

OBJECTIVE: To evaluate the efficacy and safety of SHR4640, a highly selective urate transporter 1 inhibitor, in Chinese subjects with hyperuricaemia. METHODS: This was a randomized double-blind dose-ranging phase II study. Subjects whose serum uric acid (sUA) levels were ≥480 µmol/l with gout, ≥480 µmol/l without gout but with comorbidities, or ≥540 µmol/l were enrolled. Subjects were randomly assigned (1:1:1:1:1) to receive once daily 2.5 mg, 5 mg, 10 mg of SHR4640, 50 mg of benzbromarone or placebo, respectively. The primary end point was the proportion of subjects who achieved target sUA level of ≤360 µmol/l at week 5. RESULTS: 99.5% of subjects (n = 197) were male and 95.9% of subjects had gout history. The proportions of subjects who achieved target sUA at week 5 were 32.5%, 72.5% and 61.5% in the 5 mg, 10 mg SHR4640 and benzbromarone groups, respectively, significantly higher than the placebo group (0%; P < 0.05 for 5 mg and 10 mg SHR4640 group). The sUA was reduced by 32.7%, 46.8% and 41.8% at week 5 with 5 mg, 10 mg SHR4640 and benzbromarone, respectively, vs placebo (5.9%; P < 0.001 for each comparison). The incidences of gout flares requiring intervention were similar among all groups. Occurrences of treatment-emergent adverse events (TEAEs) were comparable across all groups, and serious TEAEs were not reported. CONCLUSIONS: The present study indicated a superior sUA-lowering effect and well tolerated safety profile after 5-week treatment with once-daily 5 mg/10 mg of SHR4640 as compared with placebo in Chinese subjects with hyperuricaemia. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT03185793.

GeneExpressScore Signature: a robust prognostic and predictive classifier in gastric cancer.

Although several prognostic signatures have been developed for gastric cancer (GC), the utility of these tools is limited in clinical practice due to lack of validation with large and multiple independent cohorts, or lack of a statistical test to determine the robustness of the predictive models. Here, a prognostic signature was constructed using a least absolute shrinkage and selection operator (LASSO) Cox regression model and a training dataset with 300 GC patients. The signature was verified in three independent datasets with a total of 658 tumors across multiplatforms. A nomogram based on the signature was built to predict disease-free survival (DFS). Based on the LASSO model, we created a GeneExpressScore signature (GESGC ) classifier comprised of eight mRNA. With this classifier patients could be divided into two subgroups with distinctive prognoses [hazard ratio (HR) = 4.00, 95% confidence interval (CI) = 2.41-6.66, P < 0.0001]. The prognostic value was consistently validated in three independent datasets. Interestingly, the high-GESGC group was associated with invasion, microsatellite stable/epithelial-mesenchymal transition (MSS/EMT), and genomically stable (GS) subtypes. The predictive accuracy of GESGC also outperformed five previously published signatures. Finally, a well-performed nomogram integrating the GESGC and four clinicopathological factors was generated to predict 3- and 5-year DFS. In summary, we describe an eight-mRNA-based signature, GESGC , as a predictive model for disease progression in GC. The robustness of this signature was validated across patient series, populations, and multiplatform datasets.

RING-Finger Protein 6 Amplification Activates JAK/STAT3 Pathway by Modifying SHP-1 Ubiquitylation and Associates with Poor Outcome in Colorectal Cancer.

Objective: The E3 ubiquitin ligase RNF6 (RING-finger protein 6) plays a crucial role in carcinogenesis. However, the copy number and expression of RNF6 were rarely reported in colorectal cancer. We aimed to explore the mechanical, biological, and clinical role of RNF6 in colorectal cancer initiation and progression.Design: The copy number and expression of RNF6 were analyzed from Tumorscape and The Cancer Genome Atlas (TCGA) datasets. Gene expressions were examined by real-time PCR, Western blot, and immunohistochemical staining. Gene expression profiling studies were performed to identify pivotal genes regulated by RNF6. Biological function of RNF6 on tumor growth and metastasis was detected in vivo and in vitro Role of RNF6 in modulating SHP-1 expression was examined by coimmunoprecipitation and confocal microscopy, respectively.Results: The copy number of RNF6 was significantly amplified in colorectal cancer, and the amplification was associated with RNF6 expression level. Amplification and overexpression of RNF6 positively correlated with patients with colorectal cancer with poor prognosis. The gene set enrichment analysis (GSEA) revealed cell proliferation, and invasion-related genes were enriched in RNF6 high-expressed colorectal cancer cells as well as in patients from TCGA dataset. Downregulation of RNF6 impaired the colorectal cancer cell proliferation and invasion in vitro and in vivo RNF6 may activate the JAK/STAT3 pathway and increase pSTAT3 levels by inducing the ubiquitination and degradation of SHP-1.Conclusions: Genomic amplification drives RNF6 overexpression in colorectal cancer. RNF6 may be a novel biomarker in colorectal carcinogenesis, and RNF6 may increase pSTAT3 level via promoting SHP-1 ubiquitylation and degradation. Targeting the RNF6/SHP-1/STAT3 axis provides a potential therapeutic option for RNF6-amplified tumors. Clin Cancer Res; 24(6); 1473-85. ©2017 AACR.

CD44v6 overexpression related to metastasis and poor prognosis of colorectal cancer: A meta-analysis.

CD44v6 has recently been reported as a biomarker for colorectal cancer. However, the clinical and prognostic significance of CD44v6 in colorectal cancer remains controversial. Therefore, we performed a meta-analysis to clarify this issue. A comprehensive literature search was performed using Medline, Embase and Web of Science, and the statistical analysis was conducted using Stata software. A total of twenty-one studies including 3918 colorectal cancer cases were included. The pooled analysis showed that CD44v6 overexpression in colorectal cancer was an independent prognostic marker correlating with lower 5-year overall survival rate (OR=0.78, 95%CI =0.67-0.91, p=0.001). CD44v6 overexpression was also associated with more lymph node invasion (OR=1.48, 95%CI= 1.02-2.15, p=0.04), and advanced Dukes stage (OR=2.47, 95%CI= 1.29-4.73, p=0.01). In addition, while excluding Zolbec's study, CD44v6 overexpression was associated with distance metastasis (OR=1.65, 95%CI =1.13-2.40, p=0.01). Taken together, this meta-analysis suggested that CD44v6 is an efficient prognostic factor in colorectal cancer.

Th22 cells control colon tumorigenesis through STAT3 and Polycomb Repression complex 2 signaling.

Th22 cells traffic to and retain in the colon cancer microenvironment, and target core stem cell genes and promote colon cancer stemness via STAT3 and H3K79me2 signaling pathway and contribute to colon carcinogenesis. However, whether Th22 cells affect colon cancer cell proliferation and apoptosis remains unknown. We studied the interaction between Th22 cells and colon cancer cells in the colon cancer microenvironment. Colon cancer proliferation was examined by flow cytometry analysis and H(3) thymidine incorporation. Cell cycle related genes were quantified by real-time PCR and Western blotting. We transfected colon cancer cells with lentiviral vector encoding specific gene shRNAs and used chromatin immunoprecipitation (ChIP) assay to determine the genetic signaling involved in interleukin (IL)-22-mediated colon cancer cell proliferation. We showed that Th22 cells released IL-22 and stimulated colon cancer proliferation. Mechanistically, IL-22 activated STAT3, and subsequently STAT3 bound to the promoter areas of the Polycomb Repression complex 2 (PRC2) components SUZ12 and EED, and stimulated the expression of PRC2. Consequently, the activated PRC2 catalyzed the promoters of the cell cycle check-point genes p16 and p21, and inhibited their expression through H3K27me3-mediated histone methylation, and ultimately caused colon cancer cell proliferation. Bioinformatics analysis revealed that the levels of IL-22 expression positively correlated with the levels of genes controlling cancer proliferation and cell cycling in colon cancer. In addition to controlling colon cancer stemness, Th22 cells support colon carcinogenesis via affecting colon cancer cell proliferation through a distinct histone modification.

LncRNA GClnc1 Promotes Gastric Carcinogenesis and May Act as a Modular Scaffold of WDR5 and KAT2A Complexes to Specify the Histone Modification Pattern.

UNLABELLED: Long noncoding RNAs (lncRNA) play a role in carcinogenesis. However, the function of lncRNAs in human gastric cancer remains largely unknown. In this study, we identified a novel lncRNA, GClnc1, which was upregulated and associated with tumorigenesis, tumor size, metastasis, and poor prognosis in gastric cancer. GClnc1 affected gastric cancer cell proliferation, invasiveness, and metastasis in multiple gastric cancer models. Mechanistically, GClnc1 bound WDR5 (a key component of histone methyltransferase complex) and KAT2A histone acetyltransferase, acted as a modular scaffold of WDR5 and KAT2A complexes, coordinated their localization, specified the histone modification pattern on the target genes, including SOD2, and consequently altered gastric cancer cell biology. Thus, GClnc1 is mechanistically, functionally, and clinically oncogenic in gastric cancer. Targeting GClnc1 and its pathway may be meaningful for treating patients with gastric cancer. SIGNIFICANCE: This report documents a novel lncRNA, GClnc1, which may act as a scaffold to recruit the WDR5 and KAT2A complex and modify the transcription of target genes. This study reveals that GClnc1 is an oncogenic lncRNA in human gastric cancer. Cancer Discov; 6(7); 784-801. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 681.

Biological and pathological activities of interleukin-22.

Interleukin (IL)-22, a member of the IL-10 family, is a cytokine secreted by several types of immune cells including IL-22(+)CD4(+) T cells (Th22) and IL-22 expressing innate leukocytes (ILC22). Recent studies have demonstrated that IL-22 is a key component in mucosal barrier defense, tissue repair, epithelial cell survival, and proliferation. Furthermore, accumulating evidence has defined both protective and pathogenic properties of IL-22 in a number of conditions including autoimmune disease, infection, and malignancy. In this review, we summarize the expression and signaling pathway and functional characteristics of the IL-22 and IL-22 receptor axis in physiological and pathological scenarios and discuss the potential to target IL-22 signaling to treat human diseases.

MiR-198 represses tumor growth and metastasis in colorectal cancer by targeting fucosyl transferase 8.

In this study we investigated the biological role and mechanism of miR-198 in colorectal carcinoma (CRC). MiR-198 expression was shown to exhibit a strongly negative correlation with lymph node invasion, distant metastasis and patient survival in examinations of colorectal cancer tissues and paired normal colorectal mucosa tissues. fucosyl transferase 8 (FUT8) was identified as a potential target of miR-198 in bioinformatics analysis and luciferase reporter assays. Overexpression of miR-198 in CRC cell lines decreased FUT8 levels as shown by immunofluorescence analysis, and inhibited cell proliferation, migration, and invasion. These anti-tumor phenotypes were rescued by reconstitution of FUT8 expression. Furthermore, miR-198 was shown to target the 3'UTR of FUT8 directly to downregulate FUT8 expression at both mRNA and protein levels in qRT-PCR and Western blot analyses, respectively. In vivo, restoration of miR-198 significantly inhibited xenograft growth and invasion of CRC tumors in nude mice. Therefore, it could be concluded that miR-198 suppresses the proliferation and invasion of CRC by directly targeting FUT8.

IL-22(+)CD4(+) T cells promote colorectal cancer stemness via STAT3 transcription factor activation and induction of the methyltransferase DOT1L.

Little is known about how the immune system impacts human colorectal cancer invasiveness and stemness. Here we detected interleukin-22 (IL-22) in patient colorectal cancer tissues that was produced predominantly by CD4(+) T cells. In a mouse model, migration of these cells into the colon cancer microenvironment required the chemokine receptor CCR6 and its ligand CCL20. IL-22 acted on cancer cells to promote activation of the transcription factor STAT3 and expression of the histone 3 lysine 79 (H3K79) methytransferase DOT1L. The DOT1L complex induced the core stem cell genes NANOG, SOX2, and Pou5F1, resulting in increased cancer stemness and tumorigenic potential. Furthermore, high DOT1L expression and H3K79me2 in colorectal cancer tissues was a predictor of poor patient survival. Thus, IL-22(+) cells promote colon cancer stemness via regulation of stemness genes that negatively affects patient outcome. Efforts to target this network might be a strategy in treating colorectal cancer patients.

miR-194 as a predictor for adenoma recurrence in patients with advanced colorectal adenoma after polypectomy.

microRNAs (miRNA) are promising predictors in colorectal cancer (CRC). We investigated whether miRNAs could predict adenoma recurrence in patients with advanced colorectal adenoma (ACRA) after polypectomy. miRNA expression profiling was performed by miRNA microarray to identify recurrence-related miRNAs. Candidate miRNAs extracted from formalin-fixed paraffin-embedded blocks of patients with ACRA were measured using real-time PCR. Logistic regression analysis was conducted to investigate whether validated miRNA expression profiles were independent from other known adenoma recurrence risk factors. The prognostic values of six miRNAs and three independent risk factors were assessed by the area under the receiver operating characteristic (ROC) curve analysis. The expressions of six candidate miRNAs were significantly decreased from levels in normal colorectal tissue compared with ARCA with adenoma recurrence (RACRA) in this retrospective cohort. However, only miRNA (miR)-194 emerged as a practical predictor. The sensitivity and specificity of miR-194 as a predictor were 71.0% and 78.0%, respectively, at a cutoff value of 0.1311 in the retrospective cohort. Sensitivity and specificity were 76.1% and 77.2%, respectively, in the prospective cohort using the same cutoff value. Low expression levels of miR-194, adenoma size ≥2 cm, and ≥3 adenomas were independent risk factors for adenoma recurrence. Moreover, low expression of miR-194 was a better predictor of adenoma recurrence than the adenoma size and numbers according to ROC curve analysis. miR-194 may be an independent predictor for adenoma recurrence in patients with ACRA after polypectomy.

A positive feedback loop between STAT3 and cyclooxygenase-2 gene may contribute to Helicobacter pylori-associated human gastric tumorigenesis.

Persistent infection with Helicobacter pylori (H. pylori) contributes to gastric diseases including chronic gastritis and gastric cancer. However, the pathogenesis of this carcinogenic bacterium has not been completely elucidated. Here, we report that H. pylori rapidly triggers STAT3 signaling and induces STAT3-dependent COX-2 expression both in vitro and in vivo. STAT3 upregulates COX-2 by binding to and increasing the activity of COX-2 promoter. COX-2 in turn regulates IL-6/STAT3 signaling under basal conditions and during H. pylori infection. These findings suggest that a positive feedback loop between STAT3 and COX-2 exists in the basal condition and H. pylori infectious condition. Immunohistochemical staining revealed that H. pylori-positive gastritis tissues exhibited markedly higher levels of pSTAT3(Tyr705) than H. pylori-negative ones. High pSTAT3(Tyr705) levels are correlated with intestinal metaplasia and dysplasia, suggesting pSTAT3(Tyr705) may be useful in the early detection of gastric tumorigenesis. Additionally, a strong positive correlation between STAT3/pSTAT3(Tyr705) levels and COX-2 expression was identified in gastritis and gastric cancer tissues. Together, these findings provide new evidence for a positive feedback loop between STAT3 signaling and COX-2 in H. pylori pathogenesis and may lead to new approaches for early detection and effective therapy of gastric cancer

Identification of potential target genes of butyrate in dimethylhydrazine-induced colorectal cancer in mice.

The mechanism by which butyrate prevents colorectal cancer (CRC) is unclear. The objective of this study was to identify potential target genes of butyrate in 1,2-dimethylhydrazine (DMH)-induced CRC in mice. Nontumor colorectal tissues of mice from DMH + butyrate, DMH, and control groups were hybridized on Agilent Mouse Whole Genome 44K Oligo Microarrays. Selected genes were validated by qRT-PCR. Data was further analyzed by KEGG, gene ontology (GO), and pathway studio software. The tumor incidence in the DMH + butyrate and DMH groups was 30% and 90%, respectively (P < 0.05). There were 355 genes downregulated due to DMH treatment while upregulated by butyrate, and 475 genes upregulated by DMH while downregulated by butyrate. The results revealed that most of the tumor-related signaling pathways (e.g., MAPK pathway, Wnt pathway, insulin pathway, and VEGF pathway) were downregulated by butyrate. The GO terms related to cell differentiation, cell cycle, cell proliferation, cell death, cell adhesion, and cell migration were significantly affected. The chemopreventive effects of butyrate were confirmed in the DMH-induced CRC mice model. And mechanisms encompassing multiple pathways and GO terms are involved in the regulation of gene expression.

Decreased dietary fiber intake and structural alteration of gut microbiota in patients with advanced colorectal adenoma.

BACKGROUND: Accumulating evidence indicates that diet is one of the most important environmental factors involved in the progression from advanced colorectal adenoma (A-CRA) to colorectal cancer. OBJECTIVE: We evaluated the possible effects of dietary fiber on the fecal microbiota of patients with A-CRA. DESIGN: Patients with a diagnosis of A-CRA by pathological examination were enrolled in the A-CRA group. Patients with no obvious abnormalities or histopathological changes were enrolled in the healthy control (HC) group. Dietary fiber intake was assessed in all patients. Short-chain fatty acids (SCFAs) in feces were detected by gas chromatography. The fecal microbiota community was analyzed by 454 pyrosequencing based on 16S ribosomal RNA. RESULTS: Lower dietary fiber patterns and consistently lower SCFA production were observed in the A-CRA group (n = 344). Principal component analysis showed distinct differences in the fecal microbiota communities of the 2 groups. Clostridium, Roseburia, and Eubacterium spp. were significantly less prevalent in the A-CRA group (n = 47) than in the HC group (n = 47), whereas Enterococcus and Streptococcus spp. were more prevalent in the A-CRA group (n = 47) (all P < 0.05). Butyrate and butyrate-producing bacteria were more prevalent in a subgroup of HC subjects with a high fiber intake than in those in both the low-fiber HC subgroup and the high-fiber A-CRA subgroup (all P < 0.05). CONCLUSION: A high-fiber dietary pattern and subsequent consistent production of SCFAs and healthy gut microbiota are associated with a reduced risk of A-CRA. This trial was registered at www.chictr.org as ChiCTR-TRC-00000123.

Role of STAT3 and vitamin D receptor in EZH2-mediated invasion of human colorectal cancer.

The polycomb group protein enhancer of zeste homologue 2 (EZH2), which has histone methyltransferase (HMT) activity, is overexpressed in malignant tumours. However, the role of EZH2 in colorectal cancer (CRC) invasion is little known. Here we investigated the clinical significance, biological effects, and mechanisms of EZH2 signalling. Knockdown of EZH2 significantly reduced cell invasion and secretion of matrix metalloproteinases 2/9 (MMP2/9) in in vitro studies. Knockdown of EZH2 dramatically increased overall survival and decreased metastasis of lung in in vivo studies. Conversely, overexpression of EZH2 significantly increased lung metastasis and shortened overall survival when compared with control tumours. EZH2-induced CRC cell invasion may depend on down-regulation of vitamin D receptor (VDR), which is considered to be a marker of CRC invasion. EZH2 regulates the histone trimethylation of lysine 27 (H3K27me3) in the VDR promoter. Moreover, we found that STAT3 directly binds to the EZH2 promoter and regulates VDR down-regulation in CRC cells. Significant inverse correlations were observed between the expression of EZH2 and pSTAT3 and that of VDR in CRC tissues compared with normal tissue in patients. We show the role of EZH2 in CRC metastasis and identify VDR as a target gene of EZH2. EZH2 expression may be directly regulated by STAT3, and STAT3 may play an important role in EZH2-mediated VDR down-regulation in CRC. This pathway may provide potential targets in aggressive CRC.

Bidirectional regulation between WDR83 and its natural antisense transcript DHPS in gastric cancer.

Natural antisense transcripts (NATs) exist ubiquitously in mammalian genomes and play roles in the regulation of gene expression. However, both the existence of bidirectional antisense RNA regulation and the possibility of protein-coding genes that function as antisense RNAs remain speculative. Here, we found that the protein-coding gene, deoxyhypusine synthase (DHPS), as the NAT of WDR83, concordantly regulated the expression of WDR83 mRNA and protein. Conversely, WDR83 also regulated DHPS by antisense pairing in a concordant manner. WDR83 and DHPS were capable of forming an RNA duplex at overlapping 3' untranslated regions and this duplex increased their mutual stability, which was required for the bidirectional regulation. As a pair of protein-coding cis-sense/antisense transcripts, WDR83 and DHPS were upregulated simultaneously and correlated positively in gastric cancer (GC), driving GC pathophysiology by promoting cell proliferation. Furthermore, the positive relationship between WDR83 and DHPS was also observed in other cancers. The bidirectional regulatory relationship between WDR83 and DHPS not only enriches our understanding of antisense regulation, but also provides a more complete understanding of their functions in tumor development.

STAT5 isoforms regulate colorectal cancer cell apoptosis via reduction of mitochondrial membrane potential and generation of reactive oxygen species.

Although the two isoforms of signal transducer and activator of transcription 5 (STAT5) protein, STAT5a and STAT5b, have 94% sequence identity, they are encoded by different genes. Previous studies have been unable to define clearly the roles of the STAT5 genes in colorectal cancer (CRC). To investigate the role of STAT5 isoforms in CRC oncogenesis, immunohistochemical staining was performed. Colorectal adenocarcinomas showed higher expression of STAT5a/5b than normal colonic mucosa (P < 0.05), and STAT5b expression was significantly higher than that of STAT5a in colorectal adenocarcinoma tissue (P < 0.05). Furthermore, STAT5b expression was significantly associated with TNM stage. To delineate the roles of STAT5a/5b in CRC carcinogenesis, we studied CRC cells depleted of each isoform by treating the cells with small interfering RNA. Both STAT5a and STAT5b were found to be involved in cell growth, cell cycle progression, and apoptosis of CRC cells, and exerted their effects via the regulation of downstream targets of the STAT genes. However, STAT5b influenced CRC cell apoptosis more than STAT5a (P < 0.05), reducing mitochondrial membrane potential and generating reactive oxygen species. In conclusion, both isoforms of STAT5 are involved in the growth and cell cycle progression of CRC cells, STAT5b could play a more important role than STAT5a in the clinicopathological characteristics of CRC and CRC cell apoptosis.

Roles of STAT3 and ZEB1 proteins in E-cadherin down-regulation and human colorectal cancer epithelial-mesenchymal transition.

The progression of colorectal carcinoma (CRC) to invasive and metastatic disease may involve localized occurrences of epithelial-mesenchymal transition (EMT). However, mechanisms of the EMT process in CRC progression are not fully understood. We previously showed that knockdown of signal transducer and activator of transcription 3 (STAT3) up-regulated E-cadherin (a key component in EMT progression) in CRC. In this study, we examined the roles of STAT3 in CRC EMT and ZEB1, an EMT inducer, in STAT3-induced down-regulation of E-cadherin. Knockdown of STAT3 significantly increased E-cadherin and decreased N-cadherin and vimentin expressions in highly invasive LoVo CRC cells. Meanwhile, overexpression of STAT3 significantly reduced E-cadherin and enhanced N-cadherin and vimentin expressions in weakly invasive SW1116 CRC cells. Activation of STAT3 significantly increased CRC cell invasiveness and resistance to apoptosis. Knockdown of STAT3 dramatically enhanced chemosensitivity of CRC cells to fluorouracil. STAT3 regulated ZEB1 expression in CRC cells, and the STAT3-induced decrease in E-cadherin and cell invasion depended on activation of ZEB1 in CRC cells. Additionally, pSTAT3(Tyr-705) and ZEB1 expressions were significantly correlated with TNM (tumor, lymph node, and metastasis stages) (p < 0.01). In conclusion, STAT3 may directly mediate EMT progression and regulate ZEB1 expression in CRC. ZEB1 may participate in STAT3-induced cell invasion and E-cadherin down-regulation in CRC cells. The expressions of pSTAT3(Tyr-705) and ZEB1 may be positively associated with CRC metastasis. Our data may provide potential targets to prevent and/or treat CRC invasion and metastasis.