COMMD10 inhibited DNA damage to promote the progression of gastric cancer.

PURPOSE: The copper metabolism MURR1 domain 10 (COMMD10) plays a role in a variety of tumors. Here, we investigated its role in gastric cancer (GC). METHODS: Online prediction tools, quantitative real-time PCR, western blotting and immunohistochemistry were used to evaluate the expression of COMMD10 in GC. The effect of COMMD10 knockdown was investigated in the GC cell lines and in in vivo xenograft tumor experiments. Western blotting and immunofluorescence were used to explore the relationships between COMMD10 and DNA damage. RESULTS: The expression of COMMD10 was upregulated in GC compared to that in para-cancerous tissue and correlated with a higher clinical TNM stage (P = 0.044) and tumor size (P = 0.0366). High COMMD10 expression predicted poor prognosis in GC. Knockdown of COMMD10 resulted in the suppression of cell proliferation, migration, and invasion, accompanied by cell cycle arrest and an elevation in apoptosis rate. Moreover, the protein expression of COMMD10 was decreased in cisplatin-induced DNA-damaged GC cells. Suppression of COMMD10 impeded DNA damage repair, intensified DNA damage, and activated ATM-p53 signaling pathway in GC. Conversely, restoration of COMMD10 levels suppressed DNA damage and activation of the ATM-p53 signaling cascade. Additionally, knockdown of COMMD10 significantly restrained the growth of GC xenograft tumors while inhibiting DNA repair, augmenting DNA damage, and activating the ATM-p53 signaling pathway in xenograft tumor tissue. CONCLUSION: COMMD10 is involved in DNA damage repair and maintains genomic stability in GC; knockdown of COMMD10 impedes the development of GC by exacerbating DNA damage, suggesting that COMMD10 may be new target for GC therapy.

Dark-field imaging and fluorescence dual-mode detection of microRNA-21 in living cells by core-satellite plasmonic nanoprobes.

The in situ precise quantification and simultaneous imaging of low abundance microRNAs (miRNAs) within living cells is critical for cancer diagnosis, yet it remains a significant challenge. Leveraging the excellent sensitivity and spatiotemporal resolution of dark-field microscopy (DFM) and fluorescence imaging, we have successfully devised a novel detection approach using dual-signal reporter probes (DSRPs). These probes allow for highly sensitive detection of miRNA-21 in living cells via toehold-mediated strand displacement cascades. The DSRPs were constructed by Au nanoparticles and Ag nanoclusters core-satellite nanostructures. After the recognition of miRNA-21, the strand displacement cascades were triggered, inducing the disassembly of the Au/Ag core-satellite nanostructure with apparent scattering intensity decrease and peak wavelength shifts. Additionally, the fluorescence of Ag clusters could be recovered and further enhanced when in close proximity to specific guanine-rich strands. The dual-signal response capability enables the accurate detection of miRNA-21 from 1 fM to 1 nM, with a limit of detection reached 0.75 fM. DFM and fluorescent imaging of living cells efficiently confirms the applicable detection of miRNA-21 in complex detection media. The biosensor based on DSRPs represents a promising nanoplatform for visual monitoring and imaging of biomolecules in living cells, even at the single particle level.

A Mitochondria-Targeted NIR-II Molecule Fluorophore for Precise Cancer Phototheranostics.

Subcellular organelle mitochondria are becoming a key player and a driver of cancer. Mitochondrial targeting phototheranostics has attracted increasing attention for precise cancer therapy. However, those phototheranostic systems still face great challenges, including complex and multiple components, light scattering, and insufficient therapeutic efficacy. Herein, a molecular fluorophore IR-TPP-1100 was tactfully designed by molecular engineering for mitochondria-targeted fluorescence imaging-guided phototherapy in the second near-infrared window (NIR-II). IR-TPP-1100 not only exhibited prominent photophysical properties and high photothermal conversion efficiency but also achieved excellent mitochondria-targeting ability. The mitochondria-targeting IR-TPP-1100 enabled NIR-II fluorescence and photoacoustic dual-modality imaging of mitochondria at the organism level. Moreover, it integrated photothermal and photodynamic therapy, obtaining remarkable tumor therapeutic efficacy by inducing mitochondrial apoptosis. These results indicate that IR-TPP-1100 has great potential for precise cancer therapy and provides a promising strategy for developing mitochondria-targeting NIR-II phototheranostic agents.

A Bio-Inspired Spiking Neural Network with Few-Shot Class-Incremental Learning for Gas Recognition.

The sensitivity and selectivity profiles of gas sensors are always changed by sensor drifting, sensor aging, and the surroundings (e.g., temperature and humidity changes), which lead to a serious decline in gas recognition accuracy or even invalidation. To address this issue, the practical solution is to retrain the network to maintain performance, leveraging its rapid, incremental online learning capacity. In this paper, we develop a bio-inspired spiking neural network (SNN) to recognize nine types of flammable and toxic gases, which supports few-shot class-incremental learning, and can be retrained quickly with a new gas at a low accuracy cost. Compared with gas recognition approaches such as support vector machine (SVM), k-nearest neighbor (KNN), principal component analysis (PCA) +SVM, PCA+KNN, and artificial neural network (ANN), our network achieves the highest accuracy of 98.75% in five-fold cross-validation for identifying nine types of gases, each with five different concentrations. In particular, the proposed network has a 5.09% higher accuracy than that of other gas recognition algorithms, which validates its robustness and effectiveness for real-life fire scenarios.

Activation of Aldehyde Dehydrogenase 2 Ameliorates Glucolipotoxicity of Pancreatic Beta Cells.

Chronic hyperglycemia and hyperlipidemia hamper beta cell function, leading to glucolipotoxicity. Mitochondrial aldehyde dehydrogenase 2 (ALDH2) detoxifies reactive aldehydes, such as methylglyoxal (MG) and 4-hydroxynonenal (4-HNE), derived from glucose and lipids, respectively. We aimed to investigate whether ALDH2 activators ameliorated beta cell dysfunction and apoptosis induced by glucolipotoxicity, and its potential mechanisms of action. Glucose-stimulated insulin secretion (GSIS) in MIN6 cells and insulin secretion from isolated islets in perifusion experiments were measured. The intracellular ATP concentrations and oxygen consumption rates of MIN6 cells were assessed. Furthermore, the cell viability, apoptosis, and mitochondrial and intracellular reactive oxygen species (ROS) levels were determined. Additionally, the pro-apoptotic, apoptotic, and anti-apoptotic signaling pathways were investigated. We found that Alda-1 enhanced GSIS by improving the mitochondrial function of pancreatic beta cells. Alda-1 rescued MIN6 cells from MG- and 4-HNE-induced beta cell death, apoptosis, mitochondrial dysfunction, and ROS production. However, the above effects of Alda-1 were abolished in Aldh2 knockdown MIN6 cells. In conclusion, we reported that the activator of ALDH2 not only enhanced GSIS, but also ameliorated the glucolipotoxicity of beta cells by reducing both the mitochondrial and intracellular ROS levels, thereby improving mitochondrial function, restoring beta cell function, and protecting beta cells from apoptosis and death.

Association of polymorphisms in endothelial dysfunction-related genes with susceptibility to essential hypertension in elderly Han population in Liaoning province, China.

Hypertension is a complex disease which is mainly influenced by genetic factors. Recently, genome-wide association study (GWAS) found three novel endothelial dysfunction-related sites: Vascular endothelial growth factor A (VEGFA) rs9472135, Faciogenital dysplasia 5 (FGD5) rs11128722, Zinc Finger C3HC-type Containing 1 (ZC3HC1) rs11556924. Endothelial dysfunction is one of the early events in pathophysiology of essential hypertension. To investigate the association of endothelial dysfunction-related genes with essential hypertension, we conducted a case-control study of 431 patients with hypertension and 345 controls. The polymorphisms were detected using Taqman Probe. The alleles and genotypes of ZC3HC1 rs11556924 and VEGFA rs9472135 were not statistically different between the two groups, while the allele of FGD5 rs11128722 was different [P = 0.045, OR = 1.265, 95% CI = (1.009-1.586)], especially in the male [P = 0.035, OR = 1.496, 95% CI = (1.037-2.158)]. Analyzing the different of genotype distribution of 3 SNPs in the two groups under different genetic models, the genotypes of FGD5 rs11128722 showed difference in male under dominant model [P = 0.049, OR = 1.610, 95% CI = (1.018-2.544)]. The polymorphism of FGD5 rs11128722 had a significant difference in Body Mass Index (BMI) among different genotypes; In the additive genetic model, BMI of GA genotype was higher than that of GG (P = 0.038); GA + AA was higher than GG in the dominant genetic model (P = 0.011). In our study, we found that the polymorphisms of VEGFA rs9472135 and ZC3HC1 rs11556924 may not significantly associated with the risk of essential hypertension, and FGD5 rs11128722 may increase the risk of it, especially in elderly men.

Meta-analysis of genotype and phenotype studies to confirm the predictive role of the RNF213 p.R4810K variant for moyamoya disease.

BACKGROUND AND PURPOSE: The aim of this meta-analysis study was to assess the predictive effects of RNF213 p.R4810K on phenotype in moyamoya disease (MMD). METHODS: Electronic databases (e.g., Pubmed and EMBASE) were searched, and relevant articles published up to August 2020 were retrieved. Review Manager 5.3 and Stata 12.0 were used for all statistical analyses. Pooled odds ratios, with 95% confidence intervals, and three comparison models were evaluated to analyze the association between RNF213 pR4810K variant and clinical characteristics of MMD patients using a fixed-effects model. RESULTS: A total of 2798 patients with MMD were selected and the effects of the heterozygous or homozygous RNF213 p.R4810K variant on 18 clinical features were identified. There were more patients aged <15 years in the GA and AA groups (AA vs GA: p = 0.009; AA vs GG: p = 0.003; GA vs GG: p = 0.001). Among homozygous patients, the majority experienced MMD onset before the age of 4 years (AA vs. GA: p < 0.00001; AA vs GG: p < 0.00001). The frequency of infarctions and transient ischemic attack was significantly higher in homozygotes and heterozygotes，respectively. However, the frequency of intracerebral/intraventricular hemorrhage was lower in patients with the GA than the GG genotype. More MMD patients with AA and GA genotypes had a family history of the disease (p = 0.003, p < 0.00001, respectively). Posterior cerebral artery involvement was more common in patients with the GA genotype (p < 0.00001). CONCLUSION: The homozygous or heterozygous RNF213 variant may be an efficient biomarker with which to classify different clinical phenotypes of MMD.

Effects of TNF-α-308G/A Polymorphism on the Risk of Diabetic Nephropathy and Diabetic Retinopathy: An Updated Meta-Analysis.

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are the major factors of morbidity and mortality in the patients with diabetes mellitus (DM). Growing studies have investigated the relationship between the TNF-α-308G/A polymorphism and the susceptibility to DN and DR, without achieving consensus. Thus, we conducted this meta-analysis to reach more comprehensive conclusions for these issues. Eligible studies were retrieved through electronic databases such as PubMed, Embase, Web of Science and China National Knowledge Infrastructure. Summary of odds ratios (OR) and 95% confidence intervals (CIs) were generated to evaluate the intensity of the associations. Statistical analyses were performed by STATA 11.0 and RevMan 5.2. There are fourteen eligible publications involving nineteen studies in this meta-analysis. TNF-α-308G/A polymorphism was significantly related to increasing risk of DN under recessive model (OR=1.37, 95% CI=1.03-1.83) and homozygous model (OR=1.54, 95% CI=1.15-2.06). Moreover, the similar results were also obtained in Asian groups for DN (recessive: OR=1.69, 95% CI=1.18-2.42; homozygous: OR=1.99, 95% CI=1.38-2.86; respectively), and significant association was also detected between TNF-α-308G/A and DN susceptibility in type 2 DM in recessive model (OR=1.39, 95% CI=1.02-1.89). No significant association was observed between TNF-α-308G/A and DR susceptibility in total analyses and subgroup analyses by ethnicity and type of DM. TNF-α-308G/A polymorphism may enhance the susceptibility to diabetic nephropathy, especially in Asian population and in T2DM patients, but not diabetic retinopathy.

MicroRNA­500a­5p inhibits colorectal cancer cell invasion and epithelial­mesenchymal transition.

The development of malignant tumors is a series of complex processes, the majority of which have not been elucidated. The aim of the present study was to investigate the microRNAs (miRNAs/miR) that affect the migration and invasion abilities of CRC cells. Our previous reports have revealed that miR­500a­5p suppressed CRC cell growth and malignant transformation. The present study demonstrated that overexpression of miR­500a­5p reduced the expression of vimentin, while increasing the expression of E­cadherin. Inhibition of miR­500a­5p resulted in spindle­like morphological changes and reorganization of F­actin in CRC cells. Furthermore, miR­500a­5p attenuated the transforming growth factor­ß signaling pathway in EMT. Additionally, emodin inhibited the miR­500a­5p inhibitor and suppressed the EMT process. In animal models of metastasis using nude mice, EMT and LoVo cell metastasis was modulated by miR­500a­5p. Therefore, the findings of the present study demonstrated that miR­500a­5p is associated with a positive therapeutic outcome in terms of invasion/migration of CRC cells and mesenchymal­like cell changes.

HOXD9 promote epithelial-mesenchymal transition and metastasis in colorectal carcinoma.

BACKGROUND: HOXD9, a Hox family member, is involved in cancer growth and metastasis. But, its regulation mechanism at the molecular level particularly in colorectal cancer (CRC), is mostly unknown. METHODS: The HOXD9 protein expression levels were analyzed using immunofluorescence, immunohistochemistry (IHC) assays, and western blot. The in vivo and in vitro roles of HOXD9 in CRC were determined using colony formation and EdU incorporation, CCK-8, wound scratch and transwell invasion assay, and animal models. RESULTS: Expression of HOXD9 was higher in CRC than in matched healthy tissues. High expression of HOXD9 has significantly associated with the American Joint Committee on Cancer (AJCC) stages, tumor differentiation, lymph node metastasis, and other serious invasions, and it had a poor prognosis. In vitro, HOXD9 encouraged proliferation, movement and EMT processes in cells of CRC. Also, TGF-ß1 promoted the expression of HOXD9 and this effect was dependent on the dose and downregulation of HOXD9 repressed TGF-ß1 -induced EMT. In vivo, HOXD9 promoted the invasive and metastasis of CRC cells via orthotopic implantation. CONCLUSIONS: The ectopic expression of HOXD9 promoted the invasion metastasis in cells of the colorectal tumor by induction of EMT in vitro and vivo.

Predictive role of heterozygous p.R4810K of RNF213 in the phenotype of Chinese moyamoya disease.

OBJECTIVE: Precise genetic analyses were conducted with ring finger protein 213 (RNF213) in relation to a particular clinical phenotype in Chinese patients with moyamoya disease (MMD) to determine whether heterozygosity is responsible for the early-onset and severe form of this disease. METHODS: A case-control study for RNF213 p.R4810K involving 1,385 Chinese patients with MMD and 2,903 normal control participants was performed. Correlation analyses between genotype and phenotype or different clinical features were also statistically explored. RESULTS: An obvious trend was observed: the carrying rate of RNF213 p.R4810K gradually decreased when moving from coastal cities in northeast, north, and east China to southern cities or inland areas. Higher frequencies of p.R4810K were observed in patients with MMD compared with control participants (odds ratio, 48.1; 95% confidence interval, 29.1-79.6; p = 1.6 × 10-141). In addition, the onset age of all patients with the GA and AA genotypes were lower than with the GG genotype, and the median onset age was 40.0, 36.0, and 11.5 years with GG, GA, and AA, respectively, thereby confirming that those with GA or AA could acquire MMD during early life stages. Patients with MMD with the GA genotype were more susceptible to posterior cerebral artery (PCA) involvement compared to those with the GG genotype (38.4% vs 23.3%, p = 8.3 × 10-7). CONCLUSIONS: Strong evidence suggests that the carrying rate of RNF213 p.R4810K is closely related MMD risk in China and has given rise to an earlier onset age and more severe PCA involvement.

Association of MTHFR gene polymorphisms with pancreatic cancer: meta-analysis of 17 case-control studies.

BACKGROUND: Pancreatic cancer (PC) is a seriously malignant tumor with a low 5-year survival rate. The relationship between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and PC has been reported by several studies. However, the results were controversial. Thus, we conducted a meta-analysis to summarize available data on MTHFR gene and PC. METHODS: We searched PubMed, Embase, Web of Science, Wanfang, CNKI databases prior to July 2019. Data were analyzed by RevMan 5.3 and STATA 12.0 software. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the association. Subgroup analysis, sensitivity analysis and assessment of publication bias were performed in this study. RESULTS: Ten articles with 17 reports (10 for C677T, 7 for A1298C) were eligible for inclusion in the meta-analysis (1864 cases and 3165 controls for C677T, and 1488 cases and 1946 controls for A1298C). Our meta-analysis detected that C677T was associated with PC for three genetic models (allele model: OR = 1.24, 95% CI: 1.00-1.53, P = 0.047; recessive model: OR = 1.39, 95% CI: 1.04-1.86, P = 0.027; homozygous model: OR = 1.60, 95% CI: 1.04-2.45, P = 0.034). In the stratified analyses according to ethnicity, source of controls and genotyping method, significant association was observed in genotyping method subgroup. For the A1298C polymorphism, no significant association was observed either in overall analysis or in subgroup analysis under all genetic models. CONCLUSIONS: MTHFR gene C677T rather than A1298C polymorphism may be associated with PC. Larger sample size studies should be performed to find the association between MTHFR gene and PC.

Association of single nucleotide polymorphisms of MTHFR, TCN2, RNF213 with susceptibility to hypertension and blood pressure.

Methylenetetrahydrofolate reductase gene (MTHFR), transcobalaminII (TCN2) and ring finger protein 213 (RNF213) are related to homocysteine (Hcy) level and are of great significance for hypertension. We aimed to evaluate the associations of MTHFR (rs1801133, rs1801131, rs9651118), TCN2 (rs117353193) and RNF213 (rs9916351) with hypertension and blood pressure (BP). A total of 953 patients with hypertension and 1103 controls were enrolled. Genotyping was performed by Taqman. Logistic regression analysis indicated that A allele of TCN2 rs117353193 under the dominant model had a significantly protective effect (P=0.045) after adjustment, which showed that AA+GA genotype has a lower risk than GG. Additionally, the average diastolic BP (DBP) (P=0.044) and mean arterial pressure (MAP) (P=0.035) levels were significantly different between genotypes of RNF213 rs9916351. Further pairwise comparison showed that the average systolic BP (SBP) level of the TT genotype carriers were significantly higher than in CC (P=0.024), and the average DBP and MAP levels of the TT genotype carriers were higher than in CT (P=0.044, P=0.012, respectively) and CC (P=0.048, P=0.010, respectively). In the recessive model, the average SBP (P=0.043), DBP (P=0.018) and MAP (P=0.017) levels with the TT genotype carriers were significantly higher than in CT+CC. Multiple linear regression analysis suggested that RNF213 rs9916351 in the recessive model had significant effects on SBP (P=0.025), DBP (P=0.017) and MAP (P=0.010) as a risk factor. However, no associations were observed between MTHFR and hypertension. TCN2 rs117353193 might serve as a protective factor in hypertension, and RNF213 rs9916351 might be a risk factor that is linked to increase BP level in Northeast Chinese population.

HOXD9 promotes the growth, invasion and metastasis of gastric cancer cells by transcriptional activation of RUFY3.

BACKGROUND: The transcription factor HOXD9 is one of the members of the HOX family, which plays an important role in neoplastic processes. However, the role of HOXD9 in the growth and metastasis of gastric cancer (GC) remains to be elucidated. METHODS: In vitro functional role of HOXD9 and RURY3 in GC cells was determined using the TMA-based immunohistochemistry, western blot, EdU incorporation, gelatin zymography, luciferase, chromatin Immunoprecipitation (ChIP) and cell invasion assays. In vivo tumor growth and metastasis were conducted in nude mice. RESULTS: HOXD9 is overexpressed in GC cells and tissues. The high expression of HOXD9 was correlated with poor survival in GC patients. Functionally, HOXD9 expression significantly promoted the proliferation, invasion and migration of GC cells. Mechanically, HOXD9 directly associated with the RUFY3 promoter to increase the transcriptional activity of RUFY3. Inhibition of RUFY3 attenuated the proliferation, migration and invasiveness of HOXD9-overexpressing GC cells in vitro and in vivo. Moreover, both HOXD9 and RUFY3 were highly expressed in cancer cells but not in normal gastric tissues, with their expressions being positively correlated. CONCLUSIONS: The evidence presented here suggests that the HOXD9-RUFY3 axis promotes the development and progression of human GC.

Ubiquitin-specific protease 3 promotes cell migration and invasion by interacting with and deubiquitinating SUZ12 in gastric cancer.

BACKGROUND: The deubiquitinating enzyme ubiquitin-specific protease 3 (USP3) plays a crucial role in numerous biological processes. The aberrant expression of USP3 may have an important role in tumor development. However, the mechanism by which USP3 promotes gastric cancer (GC) metastasis remains largely unknown. METHODS: Effects of USP3 on the progression of GC in vivo and in vitro and the potential underlying mechanisms have been investigated utilizing proteomics, RT-PCR, western blotting, immunohistochemistry, immunofluorescence, cell invasion and migration assays and xenograft tumor models. RESULTS: USP3 expression was upregulated in GC compared with matched normal tissues and was predictive of poor survival. USP3 also promoted migration and epithelial-to-mesenchymal transition (EMT) in GC cells. Moreover, TGF-ß1 induced USP3 expression, and USP3 knockdown inhibited TGF-ß1-induced EMT. Furthermore, we utilized Isobaric Tag for Relative and Absolute Quantitation (iTRAQ) to identify differentially expressed proteins in USP3-overexpressing cells compared with control cells. Importantly, we found that SUZ12 is indispensable for USP3-mediated oncogenic activity in GC. We observed that USP3 interacted with and stabilized SUZ12 via deubiquitination. SUZ12 knockdown inhibited USP3-induced migration and invasion, as well as EMT in GC cells. Examination of clinical samples confirmed that USP3 expression was positively correlated with SUZ12 protein expression and that the levels of USP3 or SUZ12 protein were negatively correlated with the levels of E-cadherin protein. CONCLUSIONS: These findings identify USP3 as a critical regulator. The USP3-SUZ12 axis might promote tumor progression and could be a potential therapeutic candidate for human GC.

Riboflavin photo-cross-linking method for improving elastin stability and reducing calcification in bioprosthetic heart valves.

BACKGROUND: Glutaraldehyde cross-linked bioprosthetic heart valves might fail due to progressive degradation and calcification. METHODS: In this study, we developed a new BHVs preparation strategy named as "HPA/TRA/FMN" that utilized 3,4-hydroxyphenylpropionic acid (HPA)/tyramine (TRA) conjugated pericardium and riboflavin 5'-monophosphate (FMN) initiated photo-cross-linking method. HPA/TRA-pericardium conjugation would provide extra phenol groups for FMN initiated photo-cross-linking. RESULTS: The feeding ratio of riboflavin 5'-monophosphate was optimized. The collagenase and elastase enzymatic degradation in vitro, biomechanics, calcification, elastin stability in vivo, and macrophage marker CD68 were characterized. We demonstrated that riboflavin photo-cross-linked pericardiums had great collagen and elastin stability, improved mechanical properties, better resistance for calcification, and less CD68 positive macrophages in rat subdermal implantation study. CONCLUSIONS: This new riboflavin photo-cross-linking strategy would be a promising method to make BHVs which have better elastin stability, less calcification, and reduced inflammatory response.

Coexpression of FOXK1 and vimentin promotes EMT, migration, and invasion in gastric cancer cells.

In human gastric cancer (GC), the upregulation of FOXK1 and vimentin is frequently observed in cancer cells and correlates with increased malignancy. We report that FOXK1 synergizes with vimentin to promote GC invasion and metastasis via the induction of epithelial-mesenchymal transition (EMT). We showed that higher expression levels of FOXK1 were significantly associated with GC development. FOXK1 can physically interact with and stabilize vimentin. Moreover, a positive correlation between the expression of FOXK1 and vimentin was found in GC cells. Higher expression levels of these two proteins were significantly associated with differentiation, lymph node metastasis, AJCC stage, and poorer prognosis. Furthermore, the coexpression of FOXK1 and vimentin enhances cell metastasis through the induction of EMT in GC cells. However, the siRNA-mediated repression of vimentin in FOXK1-overexpressing cells reversed the EMT-like phenotype and reduced GC cell migration and invasion in vitro and in vivo. Altogether, our findings suggest that the vimentin-FOXK1 axis provides new insights into the molecular mechanisms underlying EMT regulation during GC progression and metastasis.

The FOXK1-CCDC43 Axis Promotes the Invasion and Metastasis of Colorectal Cancer Cells.

BACKGROUND/AIMS: The CCDC43 gene is conserved in human, rhesus monkey, mouse and zebrafish. Bioinformatics studies have demonstrated the abnormal expression of CCDC43 gene in colorectal cancer (CRC). However, the role and molecular mechanism of CCDC43 in CRC remain unknown. METHODS: The functional role of CCDC43 and FOXK1 in epithelial-mesenchymal transition (EMT) was determined using immunohistochemistry, flow cytometry, western blot, EdU incorporation, luciferase, chromatin Immunoprecipitation (ChIP) and cell invasion assays. RESULTS: The CCDC43 gene was overexpressed in human CRC. High expression of CCDC43 protein was associated with tumor progression and poor prognosis in patients with CRC. Moreover, the induction of EMT by CCDC43 occurred through TGF-ß signaling. Furthermore, a positive correlation between the expression patterns of CCDC43 and FOXK1 was observed in CRC cells. Promoter assays demonstrated that FOXK1 directly bound and activated the human CCDC43 gene promoter. In addition, CCDC43 was necessary for FOXK1- mediated EMT and metastasis in vitro and vivo. Taken together, this work identified that CCDC43 promoted EMT and was a direct transcriptional target of FOXK1 in CRC cells. CONCLUSION: FOXK1-CCDC43 axis might be helpful to develop the drugs for the treatment of CRC.

Unexpected link between insect innexins and apoptosis of HeLa cells.

Little is known about how mammalian cells respond to the expression of innexins (Inxs), which are known to mediate cell-to-cell communication that causes apoptosis in the cells of the insect Spodoptera litura. The mammalian expression system, p3xFLAG tag protein, containing the CMV promoter, allowed us to construct two C-terminally elongated innexins (Cte-Inxs), SpliInx2 (Inx2-FLAG), and SpliInx3 (Inx3-FLAG), which were predicted to have the same secondary topological structures as the native SpliInx2 and SpliInx3. Here, we found that only the mRNAs of the two Cte-Inxs were expressed under the control of the CMV promoter in HeLa cells. Unexpectedly, mRNA expression of the two Cte-Inxs enhanced apoptosis of HeLa cells. The two Cte-Inx mRNAs were associated with a significant decrease in Akt phosphorylation in HeLa cells undergoing apoptosis. Furthermore, Inx3-FLAG mRNA expression in nonapoptotic HCT116 cells was also associated with a significant decrease in the levels of phosphorylated Akt. Intriguingly, expression of the mRNAs of the two Cte-Inxs did not activate caspase 3, but it markedly reduced Bid levels in HeLa cells undergoing apoptosis. These results suggest that mRNA expression of the two Cte-Inxs may activate a Bid-dependent apoptotic pathway in HeLa cells. Our study demonstrates that invertebrate gap junction mRNAs can function in vertebrate cancer cells as tumor suppressors.

Snail/FOXK1/Cyr61 Signaling Axis Regulates the Epithelial-Mesenchymal Transition and Metastasis in Colorectal Cancer.

BACKGROUND/AIMS: Metastasis is the primary cause of colorectal cancer (CRC)-related death. However, the molecular mechanisms underlying metastasis in CRC remain unclear. METHODS: We evaluated mRNA and protein expression levels by quantitative real-time reverse transcription PCR, western blotting, immunofluorescence, tissue microarrays, and immunohistochemistry assays. We also assessed the migration and invasion abilities of CRC cells in vitro by wound healing assays, invasion and migration assays, western blot analysis, and immunofluorescence. Tumor metastasis was evaluated in nude mice in vivo. RESULTS: A positive correlation was observed between the expression patterns of Forkhead box k1 (FOXK1) and Snail in CRC. Luciferase reporter and chromatin immunoprecipitation assays demonstrated that Snail directly bound to and activated the human FOXK1 gene promoter. Moreover, the Snail-FOXK1 axis promote epithelial mesenchymal transition (EMT)-mediated CRC cell invasion and metastasis. FOXK1 and Snail expression levels were correlated with tumor progression and served as significant predictors of overall survival in patients with CRC. Furthermore, overexpression of FOXK1 induced the EMT by upregulating the expression of cysteine-rich angiogenic inducer 61 (Cyr61). Luciferase assays showed that Cyr61 was a direct transcriptional target of FOXK1. Down regulation of Cyr61 decreased FOXK1-enhanced "CRC cell" migration, invasion, and metastasis. Additionally, FOXK1 expression was positively correlated with Cyr61 expression and was associated with poor prognosis. CONCLUSIONS: The Snail/FOXK1/Cyr61 signaling axis regulates the EMT and metastasis of CRC.