PIN1P1 is activated by CREB1 and promotes gastric cancer progression via interacting with YBX1 and upregulating PIN1.

Long noncoding RNAs (lncRNAs) play critical roles in the carcinogenesis and progression of cancers. However, the role and mechanism of the pseudogene lncRNA PIN1P1 in gastric carcinoma remain unclear. The expression and effects of lncRNA PIN1P1 in gastric cancer were investigated. The transcriptional regulation of CREB1 on PIN1P1 was determined by ChIP and luciferase assays. The mechanistic model of PIN1P1 in gastric cancer was further explored by RNA pull-down, RIP and western blot analysis. PIN1P1 was overexpressed in gastric cancer tissues, and upregulated PIN1P1 predicted poor prognosis in patients. CREB1 was directly combined with the promoter region of PIN1P1 to promote the transcription of PIN1P1. CREB1-mediated enhanced proliferation, migration and invasion could be partially reversed by downregulation of PIN1P1. Overexpressed PIN1P1 promoted the proliferation, migration and invasion of gastric cancer cells, whereas decreased PIN1P1 showed the opposite effects. PIN1P1 directly interacted with YBX1 and promoted YBX1 protein expression, leading to upregulation of PIN1, in which E2F1 may be involved. Silencing of YBX1 during PIN1P1 overexpression could partially rescue PIN1 upregulation. PIN1, the parental gene of PIN1P1, was elevated in gastric cancer tissues, and its upregulation was correlated with poor patient outcomes. PIN1 facilitated gastric cancer cell proliferation, migration and invasion. To sum up, CREB1-activated PIN1P1 could promote gastric cancer progression through YBX1 and upregulating PIN1, suggesting that it is a potential target for gastric cancer.

HRCT1, negatively regulated by miR-124-3p, promotes tumor metastasis and the growth of gastric cancer by activating the ERBB2-MAPK pathway.

BACKGROUND: Gastric cancer is the fourth leading cause of cancer-related deaths worldwide. And patient outcomes are poor due to tumor relapse and metastasis. To develop new therapeutic strategies, it is of great importance to explore the mechanism underlying the progression of gastric cancer. METHODS: Primary gastric cancer samples with lymph node metastases (LNM) and without LNM were subjected to mRNA microarray assay. The differentially expressed genes were confirmed by RT-qPCR. HRCT1 protein expression was further detected using an immunohistochemistry (IHC) assay. In vitro and in vivo assays were performed to investigate the role of HRCT1 in tumor invasion, metastasis, and proliferation. The expressions of the downstream target genes of HRCT1 were detected by microarray, RT-qPCR and Western blot assays. Dual-luciferase reporter and Western blot assays were carried out to identify miRNAs target to HRCT1. RESULTS: HRCT1 was upregulated in gastric cancer, and high expression of HRCT1 was associated with poor overall survival (OS) and disease-free survival (DFS). Moreover, HRCT1protein expression was an independent predictor for poor OS and DFS. HRCT1 could promote gastric cancer cells' migration, invasion, and proliferation in vitro as well as tumor metastasis and growth in vivo. Notably, our data showed that HRCT1 promoted gastric cancer progression by activating the ERBB2-MAPK signaling pathway. At least partially, the expression of HRCT1 could be negatively regulated by miR-124-3p. CONCLUSIONS: The upregulated expression of HRCT1 predicts poor survival for patients with gastric cancer. HRCT1 promotes tumor progression by activating the ERBB2-MAPK pathway. HRCT1, negatively regulated by miR-124-3p, may be a potential therapeutic target for patients with gastric cancer.

Construction of coaxial liquid centrifugal platform for the extraction of active ingredients from natural products.

In the classical natural product extraction and separation process, it is tedious and requires large amounts of reagents and time. In this study, an efficient coaxial liquid centrifugal oil-water-oil triple-liquid-phase system with a simple structure and convenient operation was successfully constructed and used to extract flavonoids from Platycladi Cacumen. The results showed that the coaxial liquid centrifugal platform constructed in this study had good stability and 6 ml was the minimum volume of the middle phase for 1000 rpm to stabilize the system. Besides, it was easy to repeat the operation: the relative standard deviations of the extraction yields of flavonoids and sugar in six parallel operations were all less than 10%. Moreover, it was only one-tenth of the time required for this method as traditional liquid-liquid extraction while reducing the use of volatile organic reagents. Finally, the new method was more selective than the traditional method for the extraction of flavonoids. Therefore, this study provides a possibility for the coaxial liquid centrifugal platform to be used in multi-liquid phase systems to achieve the simultaneous extraction of different parts of natural products by different liquid phases. It is expected to provide a reliable reference for further expansion of small-scale experimental operations to industrial production.

LncRNA-HNF1A-AS1 functions as a competing endogenous RNA to activate PI3K/AKT signalling pathway by sponging miR-30b-3p in gastric cancer.

BACKGROUND: Accumulating evidence demonstrated that long noncoding RNAs (lncRNAs) played important regulatory roles in many cancer types. However, the role of lncRNAs in gastric cancer (GC) progression remains unclear. METHODS: RT-qPCR assay was performed to detect the expression of HNF1A-AS1 in gastric cancer tissues and the non-tumourous gastric mucosa. Overexpression and RNA interference approaches were used to investigate the effects of HNF1A-AS1 on GC cells. Insight into competitive endogenous RNA (ceRNA) mechanisms was gained via bioinformatics analysis, luciferase assays and an RNA-binding protein immunoprecipitation (RIP) assay, RNA-FISH co-localisation analysis combined with microRNA (miRNA)-pulldown assay. RESULTS: This study displayed that revealed expression of HNF1A-AS1 was associated with positive lymph node metastasis in GC. Moreover, HNF1A-AS1 significantly promoted gastric cancer invasion, metastasis, angiogenesis and lymphangiogenesis in vitro and in vivo. In addition, HNF1A-AS1 was demonstrated to function as a ceRNA for miR-30b-3p. HNF1A-AS1 abolished the function of the miRNA-30b-3p and resulted in the derepression of its target, PIK3CD, which is a core oncogene involved in the progression of GC. CONCLUSION: This study demonstrated that HNF1A-AS1 worked as a ceRNA and promoted PI3K/AKT signalling pathway-mediated GC metastasis by sponging miR-30b-3p, offering novel insights of the metastasis mechanism in GC.

Chronic ghrelin administration suppresses IKK/NF-κB/BACE1 mediated Aß production in primary neurons and improves cognitive function via upregulation of PP1 in STZ-diabetic rats.

Diabetic rats display cognition impairments accompanied by activation of NF-κB signalling and increased Aß expression. Ghrelin has been suggested to improve cognition in diabetic rats. In this study, we investigated the role of ghrelin on cognition and NF-κB mediated Aß production in diabetic rats. A diabetic rat model was established with streptozotocin (STZ) injection, and diabetic rats were intracerebroventricularly administered with ghrelin or (D-lys3)-GHRP-6 (DG). Our results showed that diabetic rats had cognition impairment in the Morris water maze test, accompanied by the higher expression of Aß in the hippocampus. Western blot analysis showed that diabetic rats exhibited significantly decreased levels of GHSR-1a and protein phosphatase 1 (PP1) in the hippocampus and increased activation of the IKK/NF-κB/BACE1 pathway. Chronic ghrelin administration upregulated hippocampal PP1 expression, suppressed IKK/NF-κB/BACE1 mediated Aß production, and improved cognition in STZ-induced diabetic rats. These effects were reversed by DG. Then, primary rat hippocampal neurons were isolated and treated with high glucose, followed by Ghrelin and DG, PP1 or IKK. Similar to the in vivo results, high glucose suppressed the expression levels of GHSR-1a and PP1, activated the IKK/NF-κB/BACE1 pathway, increased Aß production. Ghrelin suppressed IKK/NF-κB/BACE1 induced Aß production. This improvement was reversed by DG and a PP1 antagonist and was enhanced by the IKK antagonist. Our findings indicated that chronic ghrelin administration can suppress IKK/NF-κB/BACE1 mediated Aß production in primary neurons with high glucose treatment and improve the cognition via PP1 upregulation in diabetic rats.

Improved cadmium resistance and removal capacity in Pichia kudriavzevii A16 by sucrose preincubation.

Removal of heavy metals from food material by growing micro-organisms is limited by the toxicity to cells. In this study, different preincubation treatments were investigated to analyze their effects on cadmium resistance and removal ability of Pichia kudriavzevii A16 and Saccharomyces cerevisiae CICC1211. Sucrose preincubation improved the cadmium resistance of both yeast cells and increased the cadmium-removal rate of P. kudriavzevii A16. An evident decrease of intracellular and cell-surface cadmium accumulation was observed after sucrose preincubation, which may be the primary reason responsible for the improved cadmium resistance. Flow cytometry assay showed that sucrose significantly reduced the production of reactive oxygen species (ROS) and cell death rate of both yeasts under cadmium compared with those normally cultured cells. Under cadmium stress, the content of both protein carbonyls and malonyldialdehyde were also reduced by the addition of sucrose, the results were in accordance with the tendency of ROS, exhibiting a defending function of sucrose. Osmotic regulators as proline and trehalose were increased by sucrose preincubation in P. kudriavzevii A16 in the presence of cadmium. The results suggested that sucrose preincubation could be applied to improve cadmium resistance and removal rate of yeasts.

Protocadherin 7 inhibits cell migration and invasion through E-cadherin in gastric cancer.

The protocadherin 7 is a member of the protocadherin family that expressed aberrantly in many types of human cancers. However, its expression, function, and underlying mechanisms are little known in gastric cancer. In this study, we detected protocadherin 7 expression in gastric cancer tissues and non-tumorous gastric mucosa tissues by real-time quantitative polymerase chain reaction and immunohistochemistry. The association of protocadherin 7 expression with the clinicopathological characteristics and the prognosis was subsequently analyzed. MTS ((3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)) and transwell assays were performed to assess the effect of protocadherin 7 on proliferation, migration, and invasion in gastric cancer cell lines. Moreover, real-time quantitative polymerase chain reaction and western blot were used to detect the expression of epithelial-mesenchymal transition markers. Protocadherin 7 expression was decreased gradiently from normal tissue to gastric cancer, especially in gastric cancer tissue with lymph node metastasis. Low expression of protocadherin 7 was significantly associated with Lauren's classification ( p = 0.0005), lymph node metastases ( p = 0.0002), and tumor node metastasis stage ( p = 0.0221), as well as poor prognosis ( p < 0.05). Furthermore, down-regulation of protocadherin 7 in gastric cancer cell lines significantly increased their migration and invasion abilities (both p < 0.05), while it had no influence on the gastric cancer cell proliferation ( p > 0.05). Additionally, our results demonstrated that E-cadherin expression was down-regulated in gastric cancer cells with protocadherin 7 depletion. Our data indicated that protocadherin 7 may play important roles in the invasion and metastasis of gastric cancer, and protocadherin 7 could suppress cell migration and invasion through E-cadherin inhibition. Protocadherin 7 can serve as a novel biomarker for diagnostic and prognosis in patients with gastric cancer.

Functionalization of Microporous Lanthanide-Based Metal-Organic Frameworks by Dicarboxylate Ligands with Methyl-Substituted Thieno[2,3-b]thiophene Groups: Sensing Activities and Magnetic Properties.

From a methyl-substituted thieno[2,3-b]thiophene dicarboxylate, three types of three-dimensional (3-D) microporous lanthanide-based metal-organic frameworks, {[Ln(DMTDC)1.5(H2O)2]·DEF}n (type I, Ln = Eu 1, Tb 2), {[Ln(DMTDC)1.5(H2O)2]·0.5DMF·0.5H2O}n (type II, Ln = Gd 3, Dy 4, Er 5), and {[Ln4(DMTDC)6(DMF)2]·0.5DMF·1.5H2O}n (type III, Ln = Er 6) (H2DMTDC = 3,4-dimethylthieno[2,3-b]thiophene-2,5-dicarboxylic acid, DEF = N,N'-diethylformamide, DMF = N,N'-dimethylformamide), have been solventhermally synthesized. Types I and II are isostructural, which exhibit 1-D triangular channels constructed by double-stranded rod-shaped {Ln(CO2)2}n chains. Type III demonstrates an intriguing framework with triple-stranded rod-shaped {Ln(CO2)3}n chains arranged along the (1,1,0) and (1,-1,0) axes and possesses two kinds of triangular channels along two axes, respectively. Immobilization of the Lewis basic sites of thiophene groups induced gas adsorption and sensing properties into these microporous frameworks. Complexes 5(Er) and 6(Er) display moderate adsorption properties toward N2 and CO2, and the Qst of CO2 are as high as 36.3 and 34.8 kJ mol(-1), respectively. Complexes 1(Eu) and 2(Tb) exhibit sensing properties toward nitrobenzene, acetone, and the Cu(2+) ion in both DMF and aqueous solution. Complex 3(Gd) shows a significant magnetocaloric effect with ΔSm = 24.3 J·kg(-1)·K(-1) at 3.0 K and 7 T. Complex 4(Dy) exhibits slow magnetic relaxation with the energy barrier Δ/kB of 48.29 K.

Diagnostic value of miRNA-96-5p/3p in dysplastic nodules and well-differentiated small hepatocellular carcinoma.

AIM: Hepatocarcinogenesis is a multistep process from cirrhosis through low-grade dysplastic nodule, high-grade dysplastic nodule to hepatocellular carcinoma. Differential diagnosis between high-grade dysplastic nodules and early hepatocellular carcinomas is particularly difficult. The present study aims to identify a novel biological marker for differential diagnosis of the two lesions. METHODS: The expression level of an miRNA pair, miRNA-96-5p and 3p, was assessed by reverse transcription polymerase chain reaction in hepatic tissues. RESULTS: We showed that mature miRNA-96-5p and passenger strand miRNA-96-3p were differentially expressed in multistep hepatocarcinogenesis. miRNA-96-5p was significantly upregulated from cirrhosis, dysplastic nodules to hepatocellular carcinoma. However, significance of determination of miRNA-96-5p expression level for differential diagnosis between high-grade dysplastic nodule and hepatocellular carcinoma is limited. In contrast, the expression of miRNA-96-3p was detectable in cirrhosis and dysplastic nodules. Also, it was completely undetectable in the majority of hepatocellular carcinomas (30/34, 88.2%). The sensitivity and specificity of miRNA-96-3p negative expression for differential diagnosis of hepatocellular carcinomas from high-grade dysplastic nodules were 88.2% and 84.2%, respectively. In addition, a more specific diagnosis could be carried out by combining miRNA-96-3p with glypican 3, with the specificity of 100%. CONCLUSION: These findings demonstrated that miRNA-96-3p is a helpful diagnostic biomarker in differential diagnosis between high-grade dysplastic nodules and well-differentiated small hepatocellular carcinomas, especially in combination with glypican 3.

ZEB1 expression is correlated with tumor metastasis and reduced prognosis of breast carcinoma in Asian patients.

Tumor metastasis is one of the key events leading to tumor relapse and poor prognosis. Nowadays, increasing evidences demonstrated that ZEB1 was implicated in human carcinogenesis. However, involvement of ZEB1 deregulation in tumorigenesis in Asian patients with breast carcinoma remains elusive. The present study included 102 Asian patients with breast carcinoma treated by surgery from January of 2005 to December of 2006, and the expression of ZEB1 was evaluated by immunohistochemistry. To further assess the prognostic value of ZEB1, Kaplan-Meier curves were constructed. In this study, elevated levels of ZEB1 expression was found in carcinomas with higher aggressive potential. We also correlated expression of ZEB1 with lymph node metastasis (P = 0.021), advanced clinical stage (P = 0.012) in all cases, and high tumor grade (P = 0.047) in invasive ductal carcinoma. Furthermore, our data suggested an elevated level of Ki-67 expression in cases with positive expression of ZEB1. Clinically, reduced overall survival and disease-free survival were observed in cases with positive ZEB1 expression than that in negative cases. Our results correlated ZEB1 with aggressive potentials of breast carcinoma and revealed a possibility for ZEB1 as a prognostic marker in breast carcinoma.

CMYC-initiated HNF1A-AS1 overexpression maintains the stemness of gastric cancer cells.

Cancer stem cells (CSCs) are believed to be responsible for cancer metastasis and recurrence due to their self-renewal ability and resistance to treatment. However, the mechanisms that regulate the stemness of CSCs remain poorly understood. Recently, evidence has emerged suggesting that long non-coding RNAs (lncRNAs) play a crucial role in regulating cancer cell function in different types of malignancies, including gastric cancer (GC). However, the specific means by which lncRNAs regulate the function of gastric cancer stem cells (GCSCs) are yet to be fully understood. In this study, we investigated a lncRNA known as HNF1A-AS1, which is highly expressed in GCSC s and serves as a critical regulator of GCSC stemness and tumorigenesis. Our experiments, both in vitro and in vivo, demonstrated that HNF1A-AS1 maintained the stemness of GC cells. Further analysis revealed that HNF1A-AS1, transcriptionally activated by CMYC, functioned as a competing endogenous RNA by binding to miR-150-5p to upregulate ß-catenin expression. This in turn facilitated the entry of ß-catenin into the nucleus to activate the Wnt/ß-catenin pathway and promote CMYC expression, thereby forming a positive feedback loop that sustained the stemness of GCSCs. We also found that blocking the Wnt/ß-catenin pathway effectively inhibited the function of HNF1A-AS1, ultimately resulting in the inhibition of GCSC stemness. Taken together, our results demonstrated that HNF1A-AS1 is a regulator of the stemness of GCSCs and could serve as a potential marker for targeted GC therapy.

ETS-1-activated LINC01016 over-expression promotes tumor progression via suppression of RFFL-mediated DHX9 ubiquitination degradation in breast cancers.

Long non-coding RNAs (lncRNAs) are key regulators during the development of breast cancer (BC) and thus may be viable treatment targets. In this study, we found that the expression of the long intergenic non-coding RNA 01016 (LINC01016) was significantly higher in BC tissue samples with positive lymph node metastasis. LINC01016, which is activated by the transcription factor ETS-1, contributes to the overt promotion of cell proliferation activity, enhanced cell migratory ability, S phase cell cycle arrest, and decreased apoptosis rate. By RNA pull-down assays and mass spectrometry analyses, we determined that LINC01016 competitively bound and stabilized DHX9 protein by preventing the E3 ubiquitin ligase RFFL from binding to DHX9, thereby inhibiting DHX9 proteasomal degradation. This ultimately led to an increase in intracellular DHX9 expression and activated PI3K/AKT signaling, with p-AKT, Bcl-2, and MMP-9 involvement. This is the first study to reveal that the LINC01016/DHX9/PI3K/AKT axis plays a critical role in the progression of BC, and thus, LINC01016 may serve as a potential therapeutic target for patients with BC.

CAP2 promotes gastric cancer metastasis by mediating the interaction between tumor cells and tumor-associated macrophages.

The metastasis of cancer cells is the main cause of death in patients with gastric cancer (GC). Mounting evidence has demonstrated the vital importance of tumor-associated macrophages in promoting tumor invasion and metastasis; however, the interaction between tumor cells and macrophages in GC is largely unknown. In this study, we demonstrated that cyclase-associated protein 2 (CAP2) was upregulated in GC, especially in cases with lymph node metastasis, and was correlated with a poorer prognosis. The transcription factor JUN directly bound to the promoter region of CAP2 and activated CAP2 transcription. The N-terminal domain of CAP2 bound to the WD5 to WD7 domains of receptor for activated C kinase 1 (RACK1) and induced M2 macrophage polarization by activating the SRC/focal adhesion kinase (FAK)/ERK signaling pathway, which resulted in IL-4 and IL-10 secretion. Polarized M2 macrophages induced premetastatic niche formation and promoted GC metastasis by secreting TGFB1, which created a TGFB1/JUN/CAP2 positive-feedback loop to activate CAP2 expression continuously. Furthermore, we identified salvianolic acid B as an inhibitor of CAP2, which effectively inhibited GC cell invasion capabilities by suppressing the SRC/FAK/ERK signaling pathway. Our data suggest that CAP2, a key molecule mediating the interaction between GC cells and tumor-associated macrophages, may be a promising therapeutic target for suppressing tumor metastasis in GC.

A signal on-off fluorescence sensor based on the self-assembly DNA tetrahedron for simultaneous detection of ochratoxin A and aflatoxin B1.

Highly rigid and versatile functionality of DNA tetrahedron nanostructures is often used in biosensing systems as a potential detection technique. In this work, a signal on-off fluorescence sensor based on the self-assembly DNA tetrahedron was developed for the rapid simultaneous detection of ochratoxin A (OTA) and aflatoxin B1 (AFB1). The fluorophore labeled DNA tetrahedron as probe was successfully synthesized via a simple denaturing annealing, the distance between fluorophore and quencher was regulated according to the change of hairpin structure on the tetrahedron. The fluorescence intensity of Cy3 decreased significantly in the presence of OTA, while the fluorescence intensity of Cy5 kept almost unchanged. And the fluorescence intensity of Cy5 decreased significantly in the presence of AFB1, while the fluorescence intensity of Cy3 kept almost unchanged. In the present of OTA and AFB1, the fluorescence intensity of Cy3 and Cy5 showed decreased significantly simultaneously, indicating the fluorescence sensor can be applied to simultaneous detect OTA and AFB1. Hence, the quantitative analysis of OTA and AFB1 was performed indirectly by the fluorescence intensity changes. The limits of detection (LOD) are as low as 0.005 ng/mL for OTA and 0.01 ng/mL for AFB1. In addition, the novel DNA tetrahedron-based fluorescence sensor possessed a universal applicability, which could be well applied in corn and wine.

Low Glucose-Induced Overexpression of HOXC-AS3 Promotes Metabolic Reprogramming of Breast Cancer.

Breast cancer is the most common malignancy in women worldwide. However, the mechanisms underlying breast cancer energy metabolism and progression remain obscure. Cancer cells rapidly adapt to microenvironments with fluctuating nutrient levels. Here, we characterized a long noncoding RNA (lncRNA), HOXC-AS3, which is activated upon glucose deprivation to trigger a nutrient-stress response and a switch in glucose metabolism. Upregulation of HOXC-AS3 in breast cancer was identified by in published microarray and RNA-sequencing datasets, and then confirmed by qRT-PCR in fresh breast cancer tissues. Glucose deprivation induced HOXC-AS3 overexpression in a dose- and time-dependent manner in breast cancer cells. Gain- and loss-of-function experiments in vitro and in vivo showed that HOXC-AS3 triggers energy metabolism reprogramming. ChIRP-mass spectrometry and unique molecular identifier RNA immunoprecipitation and high-throughput sequencing (UMI RIP-seq) identified binding motifs of HOXC-AS3 with SIRT6. HOXC-AS3 selectively antagonized SIRT6-mediated H3K9ac deacetylation of glycolysis-related genes. Moreover, HOXC-AS3 binding to SIRT6 prevented contact inhibition of HIF1α, leading to reprogramming of metabolic pathways. In addition, HOXC-AS3, SP1, and miR-1224-5p formed a positive feedback loop to maintain cancer-promoting signals. Furthermore, administration of anti-HOXC-AS3-motif-RNAs effectively blocked the function of HOXC-AS3, ultimately suppressing breast cancer progression. These results reveal a critical role for HOXC-AS3 in regulating the metabolic reprogramming of breast cancer cells under metabolic stress. Use of an anti-HOXC-AS3-motif RNA mixture may be a promising strategy to suppress breast cancer progression. SIGNIFICANCE: HOXC-AS3 is a low glucose-activated long noncoding RNA that triggers metabolic reprogramming in breast cancer cells to adapt to nutrient stress, identifying HOXC-AS3 as a potential therapeutic target for breast cancer treatment.

Aberrant promoter hypermethylation inhibits RGMA expression and contributes to tumor progression in breast cancer.

Breast cancer (BC) is the most common cancer in women worldwide, and the exploration of aberrantly expressed genes might clarify tumorigenesis and help uncover new therapeutic strategies for BC. Although RGMA was recently recognized as a tumor suppressor gene, its detailed biological function and regulation in BC remain unclear. Herein, we found that RGMA was downregulated in BC tissues compared with non-tumorous breast tissues, particularly in metastatic BC samples, and that patients with low RGMA expression manifested a poorer prognosis. Furthermore, DNMT1 and DNMT3A were found to be recruited to the RGMA promoter and induced aberrant hypermethylation, resulting in downregulation of RGMA expression in BC. In contrast, RGMA overexpression suppressed BC cell proliferation and colony-formation capabilities and increased BC cell apoptosis. Furthermore, RGMA knockdown accelerated BC cell proliferation and suppressed cellular apoptosis in vitro and in vivo. Reversal of RGMA promoter methylation with 5-Aza-CdR restored RGMA expression and blocked tumor growth. Overall, DNMT1- and DNMT3A-mediated RGMA promoter hypermethylation led to downregulation of RGMA expression, and low RGMA expression contributed to BC growth via activation of the FAK/Src/PI3K/AKT-signaling pathway. Our data thus suggested that RGMA might be a promising therapeutic target in BC.

lncRNA THAP7-AS1, transcriptionally activated by SP1 and post-transcriptionally stabilized by METTL3-mediated m6A modification, exerts oncogenic properties by improving CUL4B entry into the nucleus.

Long noncoding RNAs (lncRNAs) are dysregulated in different cancer types, and thus have emerged as important regulators of the initiation and progression of human cancers. However, the biological functions and the underlying mechanisms responsible for their functions in gastric cancer (GC) remain poorly understood. Here, by lncRNA microarray, we identified 1414 differentially expressed lncRNAs, among which THAP7-AS1 was significantly upregulated in GC tissues compared with non-tumorous gastric tissues. High expression of THAP7-AS1 was correlated with positive lymph node metastasis and poorer prognosis. SP1, a transcription factor, could bind directly to the THAP7-AS1 promoter region and activate its transcription. Moreover, the m6A modification of THAP7-AS1 by METTL3 enhanced its expression depending on the "reader" protein IGF2BP1-dependent pathway. THAP7-AS1 promoted GC cell progression. Mechanistically, THAP7-AS1 interacted with the 1-50 Amino Acid Region (nuclear localization signal) of CUL4B through its 1-442 nt Sequence, and it promoted interaction between nuclear localization signal (NLS) and importin α1, and improved the CUL4B protein entry into the nucleus, repressing miR-22-3p and miR-320a expression by CUL4B-catalyzed H2AK119ub1 and the EZH2-mediated H3K27me3, subsequently activating PI3K/AKT signaling pathway to promote GC progression. Moreover, LV-sh-THAP7-AS1 treatment could suppress GC growth, invasion and metastasis, indicating that THAP7-AS1 may act as a promising molecular target for GC therapies. Taken together, our results show that THAP7-AS1, transcriptionally activated by SP1 and then modified by METTL3-mediated m6A, exerts oncogenic functions, by promoting interaction between NLS and importin α1 and then improving the CUL4B protein entry into the nucleus to repress the transcription of miR-22-3p and miR-320a.

E2F1-initiated transcription of PRSS22 promotes breast cancer metastasis by cleaving ANXA1 and activating FPR2/ERK signaling pathway.

Breast cancer (BC) is the most common malignant tumor in women worldwide. Metastasis is the main cause of BC-related death. The specific mechanism underlying BC metastasis remains obscure. Recently, PRSS22 was discovered to be involved in tumor development, however, its detailed biological function and regulatory mechanism in BC are unclear. Here, we characterized that PRSS22 expression is upregulated in BC tissues compared with non-tumorous breast tissues. Dual luciferase assays, bioinformatics analyses and chromatin immunoprecipitation (ChIP) assays indicated that transcription factor E2F1 directly binds to the PRSS22 promoter region and activates its transcription. Functionally, upregulation of PRSS22 promoted invasion and metastasis of BC cells in vitro and in vivo, whereas knockdown of PRSS22 inhibited its function. Mechanistically, the combination of PRSS22 and ANXA1 protein in BC cells was first screened by protein mass spectrometry analysis, and then confirmed by co-immunoprecipitation (Co-IP) and western blot assays. Co-overexpression of PRSS22 and ANXA1 could promote BC cell migration and invasion. We further demonstrated that PRSS22 promotes the cleavage of ANXA1 and in turn generates an N-terminal peptide, which initiates the FPR2/ERK signaling axis to increase BC aggressiveness.

Long noncoding RNA lnc-LEMGC combines with DNA-PKcs to suppress gastric cancer metastasis.

Long non-coding RNAs (lncRNAs) play important roles in cancer development and progression; however, their contributions to gastric cancer metastasis remain largely unknown. By lncRNA microarray screening, our study showed that 453 lncRNAs are dysregulated in gastric cancer tissues with or without lymph node metastasis, of which lnc-LEMGC ranks as one of the most significantly downregulated lncRNAs. Lnc-LEMGC inhibited cell migration and invasion both in vitro and in vivo, by combining with protein DNA-PKcs. Importantly, nucleotides 1300-1800 of lnc-LEMGC prevented DNA-PKcs phosphorylation of serine 2056 and partially abrogated the effects of downstream effectors, ErbB1, SRC and protein tyrosine kinase 2 (FAK), in the epidermal growth factor receptor (EGFR) pathway. The results of this study extend our knowledge of lncRNA's molecular mechanisms, in which lnc-LEMGC functions by directly suppressing the phosphorylation of its combined protein DNA-PKcs and inactivating the DNA-PKcs downstream EGFR signaling.

ELK1-induced up-regulation of KIF26B promotes cell cycle progression in breast cancer.

KIF26B is a member of the kinesin superfamily that is up-regulated in various tumors, including breast cancer (BC), which can promote tumor progression. This study aimed to investigate the potential function of KIF26B in BC, and the underlying mechanisms, focusing mainly on cell proliferation. KIF26B expression was examined in BC tissue samples obtained from 99 patients. Then, we performed MTS, EdU and flow cytometry assays to detect cell proliferation, and western blotting to measure the expression of cell cycle-related proteins in MDA-MB-231 and MDA-MB-468 cells following KIF26B knockdown. Promoter analysis was used to study the upstream regulatory mechanism of KIF26B. KIF26B was upregulated in BC tissues. High expression of KIF26B was associated with clinicopathological parameters, such as positive lymph node metastasis, higher tumor grade, and higher proliferative index in BC. Furthermore, knockdown of KIF26B expression inhibited MDA-MB-231 and MDA-MB-468 cell proliferation, arresting cells in the G1 phase of the cell cycle in vitro. Similarly, KIF26B silencing decreased the expression levels of Wnt, ß-catenin, and cell cycle-related proteins such as c-Myc, cyclin D1, and cyclin-dependent kinase 4, while increasing the expression of p27. Moreover, ELK1 could bind to the core promoter region of KIF26B and activate its transcription. KIF26B acts as an oncogene in BC by regulating multiple proteins involved in the cell cycle. ELK1 activates KIF26B transcription.