CRISPR/Cas12a-Responsive Hydrogels for Conjugation-Free and Universal Indicator Release in Colorimetric Detection.

Recent advances have demonstrated the significant potential and advantages to repurpose existing point-of-care reactions/devices to realize portable detection of nonoriginal targets, e.g., pathogen genes. However, pursuing this aim usually requires protein indicator-nucleic acid conjugation via a covalent bond, which may bring drawbacks such as high cost, complicated procedure, and annoying component rebuilding. Herein, we developed a conjugation-free, effective, and universal detection platform called CRIs-gel (CRISPR/Cas12a-Responsive Indicators@RCA hydrogels). Various protein indicators are pre-encapsulated into the hydrogels made of effective and high-yield rolling circle amplification (RCA). Upon a targeting sequence binding with its antisense crRNA, CRISPR/Cas12a starts its trans-cleavage activity to crush the hydrogel, which may directly release the indicator for downstream readout. Two proteins, amylase (GA) and human chorionic gonadotropin (hCG), are successfully used as model indicators to trigger the downstream amylum-I2 color change and pregnancy test strip response. After coupling with upstream isothermal nucleic acid amplification, both portable readouts may detect as few as 2 copies/µL genetic sequences of influenza A virus (FluA), human papilloma virus (HPV), SARS-CoV-2, and influenza B virus (FluB). This conjugation-free CRIs-gel platform is thus simple, sensitive, and universal and can provide innovative insights for portable point-of-care testing (POCT) development.

Changes in Tumor Immune Microenvironment after Radiotherapy Resistance in Colorectal Cancer: A Narrative Review.

BACKGROUND: Colorectal cancer (CRC) is a common digestive tract malignancy with high incidence and mortality rates. Radiotherapy is the most common anti-tumor therapeutic regime and is frequently used for treating CRC, especially rectal cancer. However, radiotherapy can lead to tumor resistance to treatment. While previous research on radiotherapy resistance in CRC has mostly focused on the tumor itself, recent advances, especially the emergence of immunotherapy, have led to a greater emphasis on the immune microenvironment of the tumor. SUMMARY: This review has summarized the recent literature on the role of the tumor immune microenvironment in CRC resistance to radiotherapy and provided new ideas for future anti-tumor treatment strategies. KEY MESSAGES: The proportion of immunosuppressive cells is greater than the numbers of cells associated with immune activation, leading to an overall state of immunosuppression; both the tumor and immunosuppressive cells secrete increased amounts of immunosuppressive regulatory factors, reduce the recognition and presentation of tumor antigens, inhibit immune cell's anti-tumor effect, and offset the non-targeted anti-tumor effect of radiotherapy.

Case report and literature review: Giant retroperitoneal cystic lymphangioma.

Background: Cystic lymphangioma is a rare benign tumor of the lymphatic system, which is most commonly observed in the neck, head and armpit.Less than 5% of lymphangiomas occur in the abdominal cavity and even less in the retroperitoneum. Case description: A 65-year-old male patient was diagnosed with an "abdominal mass that had persisted for 1 year, accompanied by abdominal pain, abdominal distension and dyspnea for 7 days". After abdominal computerd tomography, a giant multilobed abdominal lymphangioma was suspected, which squeezed the intestinal canal and was closely related to the inferior vena cava. The patient underwent an exploratory laparotomy, during which, it was found that the tumor formed extensive adhesions to the transverse colon, small intestine and pelvic wall, and enveloped the abdominal aorta, superior mesenteric artery, inferior mesenteric artery and inferior vena cava to varying degrees. It was diffcult to remove the cyst completely. Postoperative pathology confirmed the diagnosis of retroperitoneal cystic lymphangioma. The patient recovered well after the operation, was eating normally by 5 days postoperatively,and was discharged 10 days postoperatively.The patient was followed up 1 month after postoperatively and no evidence of recurrence was observed. Conclusion: In this case, we report a patient with giant retroperitoneal cystic lymphangioma who underwent exploratory laparotomy combined with preoperative abdominal computerd tomography and acute abdominal pain, abdominal distension and dyspnea. Because of the large volume of the tumor and its close relationship with the superior mesenteric artery and other blood vessels, the surgeon used scissors to separate the tumor sharply and removed the whole tumor completely.

Dual-hairpin ligation amplification enabled ultra-sensitive and selective ATP detection for cancer monitor.

Abnormal concentration of ATP is related to many diseases such as Parkinson's disease, hypoglycaemia, inflammation and cancer. However, most of the reported strategies exhibit moderate sensitivity with ∼nM level detection limit and few of them can distinguish ATP from its analogues, such as GTP, CTP, UTP and adenosine. Herein, we report an ultra-sensitive and selective ATP detection strategy that combines dual hairpin ligation-induced isothermal amplification (DHLA) with ATP-dependent enzymatic reaction. A good linear relationship between Cq value and ATP concentration in the range from 16 fM to 160 nM is acquired. Meanwhile, the strategy can distinguish ATP from its analogues with high selectivity. Furthermore, our proposed strategy has been successfully utilized to detect ATP from colon cell line and cell culture media with great potential applications in cell metabolism and cancer diagnosis.

Downregulation of CCKBR Expression Inhibits the Proliferation of Gastric Cancer Cells, Revealing a Potential Target for Immunotoxin Therapy.

BACKGROUND: Increased CCKBR expression density or frequency has been reported in many neoplasms. OBJECTIVE: We aimed to investigate whether CCKBR drives the growth of gastric cancer (GC) and its potential as a therapeutic target of immunotoxins. METHODS: A lentiviral interference system was used to generate CCKBR-knockdown gastric cancer cells. Cell Counting Kit-8 and clonogenic assays were used to evaluate cell proliferation. Woundhealing and cell invasion assays were performed to evaluate cell mobility. Cell cycle was analyzed by flow cytometry. Tumor growth in vivo was investigated using a heterologous tumor transplantation model in nude mice. In addition, we generated the immunotoxin FQ17P and evaluated the combining capacity and tumor cytotoxicity of FQ17P in vitro. RESULTS: Stable downregulation of CCKBR expression resulted in reduced proliferation, migration and invasion of BGC-823 and SGC-7901 cells. The impact of CCKBR on gastric cancer cells was further verified through CCKBR overexpression studies. Downregulation of CCKBR expression also inhibited the growth of gastric tumors in vivo. Furthermore, FQ17P killed CCKBR-overexpressing GC cells by specifically binding to CCKBR on the tumor cell surface. CONCLUSION: The CCKBR protein drives the growth, migration, and invasion of gastric cancer cells, and it might be a promising target for immunotoxin therapy based on its aberrant expression, functional binding interactions with gastrin, and subsequent internalization.

Establishment of Dual Hairpin Ligation-Induced Isothermal Amplification for Universal, Accurate, and Flexible Nucleic Acid Detection.

Isothermal amplifications have found their potentials in applications of portable nucleic acid diagnostics. However, there are still several certain deficiencies existing in the current amplification methods, including high false-positive signals, limited range of targets, difficult primer design, and so forth. Here, we report an effective solution via the development of dual hairpin ligation-induced isothermal amplification (DHLA) consisting of (1) the formation of a dual hairpin probe (DHP) based on sequence specific hybridization and ligation and (2) exponential isothermal amplification of DHP in the presence of polymerase and primers. Taking both microRNA and virus RNA as model targets, DHLA is proven to be accurate, flexible, and applicable to most deoxyribonucleic acid and ribonucleic acid targets ranging from ∼20 to hundreds of nt. The detection limit is down to the ∼aM level without a false-positive signal. More importantly, the whole detection can be directly applied to a new target via a slight change in the DHP sequence, without redesigning the primer set. This unique property not only simplifies the process for new reaction development but also enables flexible multiprobe strategies to achieve antidegradation analysis.

Intratumorally CpG immunotherapy with carbon nanotubes inhibits local tumor growth and liver metastasis by suppressing the epithelial-mesenchymal transition of colon cancer cells.

Colon cancer liver metastasis accounts for the major cause of death of colon cancer patients. Previous study reported a carbon nanotubes (CNT)-conjugated CpG complex (CNT-CpG), which displayed a significant antitumor effect in gliomas. However, whether CNT-CpG could limit colon tumor growth and suppress the colon cancer liver metastasis has not been evaluated. In this study, we report CNT enhances CpG uptake in mouse colon cancer cells. Results demonstrated only CpG with CNT conjugation showed significant activation of NF-κB signal. Moreover, intratumorally delivery of CNT-CpG successfully suppressed local xenograft tumor growth and liver metastasis. CNT-CpG treatments cured 75% of mice and inhibited local tumor growth, significantly prolonged survival outcomes and limited liver metastatic tumor nodules from colon cancer cells. Using human colon cancer cell line, HCT116, we observed significantly inhibitory effects of CNT-CpG on cell growth, invasion and migration. Importantly, CNT-CpG treatment blocked the epithelial to mesenchymal transition (EMT). We compared the mRNA levels of EMT markers of colon cancer cells without or with CNT-CpG treatment from in-vitro and in-vivo models. Consistent results demonstrated expression of epithelial marker, E-cadherin was upregulated by CNT-CpG. In contrast, three mesenchymal markers, snail, fibronectin and vimentin were significantly suppressed by CNT-CpG treatment compared with control or free CpG. In summary, our data suggest CNT-CpG is an effective therapeutic approach against local colon tumor and their liver metastasis. This study presents the CNT-CpG complex as a promising therapeutic target for developing novel therapies against both local colon tumors and liver metastatic tumors.

Helicobacter pylori CagA Protein Attenuates 5-Fu Sensitivity of Gastric Cancer Cells Through Upregulating Cellular Glucose Metabolism.

INTRODUCTION: Gastric cancer (GC) is one of the most malignancies leading to human mortality due to its development, progress, metastasis and poor prognosis, despite the development of remarkable chemotherapy and surgery. The 5-fluorouracil (5-Fu) is an effective anti-gastric cancer agent. However, a fraction of GC patients acquire 5-Fu chemoresistance. METHODS: In this study, the CagA protein was detected from CagA-positive gastric cancer patients by qRT-PCR and immunohistochemistry. The 5-Fu resistant gastric cancer cell line was generated from MKN45-CagA cells which was transfected with CagA overexpression vector. Cellular glucose metabolism was determined by measurements of glucose uptake, lactate product and glycolysis enzymes. RESULTS: We report that the Helicobacter pylori (H. pylori)-secreted Cytotoxin-associated gene A (CagA) oncoprotein is positively correlated with 5-Fu resistance of gastric cancer. From totally 72 CagA-positive gastric cancer patients, CagA high-expressed patients showed more resistance to 5-Fu than CagA low-expressed patients. Moreover, statistical analysis revealed that CagA mRNA and protein expressions were significantly upregulated in 5-Fu resistant gastric cancer patients. We observed that CagA protein is upregulated in 5-Fu resistant gastric cancer cells compared with sensitive cells. Interestingly, cellular glucose metabolism was upregulated; the glucose uptake and lactate production were significantly higher in 5-Fu resistant gastric cancer cells. The Akt phosphorylation and expressions of glycolysis key enzymes, Hexokinase 2 and LDHA, were significantly upregulated in 5-Fu resistant gastric cancer cells. On the other way, inhibition of glycolysis or Akt pathway effectively overcame 5-Fu resistance from both in vitro and in vivo models. Finally, we report that the combination of Akt or glycolysis inhibitor with 5-Fu could synergistically enhance the cytotoxicity of 5-Fu to CagA-overexpressed gastric cancer cells. DISCUSSION: In summary, our study demonstrated a CagA-Akt-glycolysis-5-Fu resistance axis, contributing to the development of new therapeutic agents against chemoresistant human gastric cancer.

Cholecystokinin type 2 receptor in colorectal cancer: diagnostic and therapeutic target.

INTRODUCTION: Cholecystokinin type 2 receptor (CCK2R), which mediates the action of gastrin and cholecystokinin (CCK), has been demonstrated to promote the proliferation of colorectal cancer (CRC). A number of studies showed that CCK2R overexpressed in gastric cancer and pancreatic cancer but few in CRC. The correlation between CCK2R expression and clinicopathological characteristics is also not clear. METHODS: This study investigated CCK2R expression in a wide range of cell lines and clinical CRC samples, and explored expression pattern and prognostic value of CCK2R in relation to clinicopathological parameters. The location and expression levels of CCK2R were measured by immunocytochemical (ICC), qRT-PCR and Western blot. The druggability and antineoplastic effects of CCK2R as a therapeutic target were investigated using an anti-CCK2R targeting recombinant toxin named rCCK8PE38 by CCK-8 assay. RESULTS: Compared with paracarcinoma tissues, tumor samples showed overexpression of CCK2R (p = 0.028) including both CRC tissue and plasma samples, with plasma detection showing a significant indication for CCK2R evaluation. Aberrant expression correlated significantly with histological type (p = 0.032) and p53 status (p < 0.01), and patients with CCK2R overexpression had significantly lower disease-free survival. Application of rCCK8PE38 demonstrated the specificity and druggability of CCK2R as a therapeutic target, providing a strategy for clinical case screening of drugs targeting CCK2R. CONCLUSION: This study highlighted the aberrant expression and clinical correlation of CCK2R and reveals its diagnostic, prognostic and treatment value in CRC. We hypothesize that CCK2R serve as a target for the diagnosis and treatment of this cancer.

MiR-135b-5p promotes viability, proliferation, migration and invasion of gastric cancer cells by targeting Krüppel-like factor 4 (KLF4).

INTRODUCTION: The expression of MiR-135b-5p was up-regulated while Krüppel-like factor 4 (KLF4) expression was extremely low in human gastric carcinoma (GC) tissues. This study aimed to explore the role of miR-135b-5p in GC cells and its influence on various cell capacity and viability by targeting KLF4. MATERIAL AND METHODS: The dual-luciferase reporter assay was first performed and the target relationship between miR-135b-5p and KLF4 was confirmed. Then three GC cell lines and the human normal gastric epithelial cell line (GES1) were analyzed for the expression level of miR-135b-5p and KLF4 mRNA by RT-qPCR. The BGC-823 GC cell line was chosen for subsequent assays. RESULTS: The expression of miR-135b-5p and KLF4 was manipulated via transfection. The changes of proliferation, invasion, migration, viability, cycle and apoptosis of GC cells were evaluated by MTS, colony formation assay, transwell assay, wound healing assay and flow cytometry assay, respectively. Overexpression of MiR-135b-5p enhanced viability, proliferation, invasion and migration of GC cells, increased cell viability and reduced cell apoptosis. Replenishing of KLF4 functioned oppositely. CONCLUSIONS: The inhibitory effects of ectopic KLF4 could be attenuated by co-transfection of miR-135b-5p. Collective data suggested that miR-135b-5p has a tumor-promoting role in GC cells via downregulating KLF4. Hence, inhibition of miR-135b-5p could be valuable for treatment of gastric cancer.

Runx3 expression in rectal cancer cells and its effect on cell invasion and proliferation.

Effect of Runx3 gene on the cell proliferation and invasion of rectal cancer was investigated to explore potential new targets for targeted treatment of rectal cancer. The Runx3 overexpression group (OE group), blank plasmid control group, negative control and blank group of the rectal cancer HRC-9698 cell strain were set. The overexpressed Runx3 plasmid was transfected in OE group; the empty plasmid was transfected in blank plasmid control group; only liposome Lipofectamine was added to negative control group; only 1640 medium was used in blank group. RT-qPCR was used for detection of the mRNA expression of Runx3 in different groups; CCK-8 kit for detection of cell proliferation in different groups; Transwell chamber test for detection of cell strain invasion in different groups. The mRNA expression of Runx3 gene in OE group was the highest, significantly higher than that in blank plasmid control group, negative control and blank group (P<0.01). The OD values of overexpressed Runx3 at 96 h after transfection in OE group was significantly lower than each control group (P<0.01). At the same time-point, pairwise comparison in each group found that OE group was significantly lower than blank plasmid control, negative control and blank groups (all P<0.01). In the invasion experiment, the number of invasion cells in OE, blank plasmid control, negative control and blank groups were 38.63±9.33, 107.87±5.66, 110.93±4.33 and 112.86±6.66, respectively. OE group was significantly lower than each control group (P<0.01). Overexpression of Runx3 gene in vitro inhibits the cell proliferation of rectal cancer and blocks the cell invasion and metastasis. This study provides a new idea and a new molecular therapeutic target for molecular targeted therapy of rectal cancer.

Dysregulation of NCAPG, KNL1, miR-148a-3p, miR-193b-3p, and miR-1179 may contribute to the progression of gastric cancer.

BACKGROUND: Emerging evidence indicate that miRNAs play an important role on gastric cancer (GC) progression via regulating several downstream targets, but it is still partially uncovered. This study aimed to explore the molecular mechanisms of GC by comprehensive analysis of mRNAs and miRNA expression profiles. METHODS: The mRNA and miRNA expression profiles of GSE79973 and GSE67354 downloaded from Gene Expression Omnibus were used to analyze the differentially expressed genes (DEGs) and DE-miRNAs among GC tissues and normal tissues. Then, targets genes of DE-miRNAs were predicted and the DE-miRNA-DEG regulatory network was constructed. Next, function enrichment analysis of the overlapped genes between the predicted DE-miRNAs targets and DEGs was performed and a protein-protein interactions network of overlapped genes was constructed. Finally, RT-PCR analysis was performed to detect the expression levels of several key DEGs and DE-miRNAs. RESULTS: A set of 703 upregulated and 600 downregulated DEGs, as well as 8 upregulated DE-miRNAs and 27 downregulated DE-miRNAs were identified in GC tissue. hsa-miR-193b-3p and hsa-miR-148a-3p, which targeted most DEGs, were highlighted in the DE-miRNA-DEG regulatory network, as well as hsa-miR-1179, which targeted KNL1, was newly predicted to be associated with GC. In addition, NCAPG, which is targeted by miR-193b-3p, and KNL1, which is targeted by hsa-miR-1179, had higher degrees in the PPI network. RT-qPCR results showed that hsa-miR-148a-3p, hsa-miR-193b-3p, and hsa-miR-1179 were downregulated, and NCAPG and KNL1 were upregulated in GC tissues; this is consistent with our bioinformatics-predicted results. CONCLUSIONS: The downregulation of miR-193b-3p might contribute to GC cell proliferation by mediating the upregulation of NCAPG; as additionally, the downregulation of miR-193b-3p might contribute to the mitotic nuclear division of GC cells by mediating the upregulation of KNL1.

Baicalein Inhibits Proliferation Activity of Human Colorectal Cancer Cells HCT116 Through Downregulation of Ezrin.

BACKGROUND/AIMS: The present study was aimed at examining Ezrin expression in human colorectal cancer (CRC) tissues and elucidating the influence of baicalein on the proliferation of HCT116 cells. METHODS: The expression of Ezrin was determined by qRT-PCR and immunohistochemistry. HCT116 cells were divided into four groups－ baicalein groups with various concentrations, pcDNA3.1-Ezrin group, si-Ezrin group and dual inhibitory group (baicalein + si-Ezrin). CCK-8 assay and flow cytometry (FCM) were employed to assess cell proliferation and to detect the distribution of cell cycle respectively. The expression levels of Ezrin protein and cell cycle-associated proteins were detected by using western blot. The proliferation ability of CRC cells was also evaluated in vivo. RESULTS: Ezrin expression in CRC tissues was observably higher than that in adjacent colorectal tissues. With drug concentration and action time of baicalein increasing, the cell propagation capacity of HCT116 cells was decreased and the cell cycle progression was arrested. Ezrin expression was inhibited by the administration of baicalein in a dose-dependent way. The levels of CyclinD1 and CDK4 were also significantly decreased, but the expression of P53 pathway proteins P53 and P21 was markedly upregulated. CONCLUSION: Baicalein repressed proliferation of human colorectal cancer cells HCT116 and blocked cell cycle through downregulating Ezrin and upregulating P53 pathway-related proteins.

Impact of protamine I on colon cancer proliferation, invasion, migration, diagnosis and prognosis.

This paper investigates protamine I (PRM1) expression and its effects on proliferation, invasion and migration of colon cancer cells as well as its function in clinical diagnosis and prognosis. Gene chips were used to screen differentially expressed genes. PRM1 expression was detected by Western blotting and quantitative real time-polymerase chain reaction (qRT-PCR). Hematoxylin and eosin (HE) staining and immunohistochemistry were utilized to compare the expression of PRM1 from multiple differentiation levels of colon cancer tissues. Cell viability, cell apoptosis and cell cycle were tested using the MTT assay and flow cytometry. Cell invasion and migration capability were tested using the Transwell assay and wound healing. In vivo effects of PRM1 on colon cancer were explored using a xenograft model. PRM1 expression in serum was detected by enzyme-linked immunosorbent assay (ELISA). The expression level of PRM1 was significantly higher in colon cancer tissues and the staining degree of PRM1 in poorly-differentiated was stronger. pcDNA3.1-PRM1 decreased cell apoptosis while it increased the proliferation, cell invasion and migration. The si-PRM1 group displayed an opposite tendency. The serum PRM1 level was significantly higher and could serve as a diagnostic biomarker for colon cancer.

Dysregulation of NCAPG, KNL1, miR-148a-3p, miR-193b-3p, and miR-1179 may contribute to the progression of gastric cancer

BACKGROUND: Emerging evidence indicate that miRNAs play an important role on gastric cancer (GC) progression via regulating several downstream targets, but it is still partially uncovered. This study aimed to explore the molecular mechanisms of GC by comprehensive analysis of mRNAs and miRNA expression profiles. METHODS: The mRNA and miRNA expression profiles of GSE79973 and GSE67354 downloaded from Gene Expression Omnibus were used to analyze the differentially expressed genes (DEGs) and DE-miRNAs among GC tissues and normal tissues. Then, targets genes of DE-miRNAs were predicted and the DE-miRNA-DEG regulatory network was constructed. Next, function enrichment analysis of the overlapped genes between the predicted DE-miRNAs targets and DEGs was performed and a protein-protein interactions network of overlapped genes was constructed. Finally, RT-PCR analysis was performed to detect the expression levels of several key DEGs and DE-miRNAs. RESULTS: A set of 703 upregulated and 600 downregulated DEGs, as well as 8 upregulated DE-miRNAs and 27 downregulated DE-miRNAs were identified in GC tissue. hsa-miR-193b-3p and hsa-miR-148a-3p, which targeted most DEGs, were highlighted in the DE-miRNA-DEG regulatory network, as well as hsa-miR-1179, which targeted KNL1, was newly predicted to be associated with GC. In addition, NCAPG, which is targeted by miR-193b-3p, and KNL1, which is targeted by hsa-miR-1179, had higher degrees in the PPI network. RT-qPCR results showed that hsa-miR-148a-3p, hsa-miR-193b-3p, and hsa-miR-1179 were downregulated, and NCAPG and KNL1 were upregulated in GC tissues; this is consistent with our bioinformatics-predicted results. CONCLUSIONS: The downregulation of miR-193b-3p might contribute to GC cell proliferation by mediating the upregulation of NCAPG; as additionally, the downregulation of miR-193b-3p might contribute to the mitotic nuclear division of GC cells by mediating the upregulation of KNL1.

Colorectal cancer cells are resistant to anti-EGFR monoclonal antibody through adapted autophagy.

The epidermal growth factor receptor (EGFR) signaling plays a key role in the initiation, progression, growth and metastases of colorectal carcinoma (CRC). Monoclonal antibody against EGFR (aEGFR; Cetuximab) has been used in treating CRC but some CRCs appeared to be resistant to aEGFR therapy, with undetermined mechanisms. Here, we studied the effects of aEGFR on CRC cells in vitro. We found that aEGFR dose-dependently activated Beclin-1 in 2 CRC cell lines, HT29 and SW480. Inhibition of autophagy significantly increased the aEGFR-induced CRC cell death in an CCK-8 assay. Moreover, microRNA (miR)-216b levels were significantly downregulated in aEGFR-treated CRC cells. Bioinformatics study showed that miR-216b targeted the 3'-UTR of Beclin-1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. Together, these data suggest that aEGFR may decrease miR-216b levels in CRC cells, which subsequently upregulates Beclin-1 to increase CRC cell autophagy to antagonize aEGFR-induced cell death. Strategies that increase miR-216b levels or inhibit cell autophagy may improve the outcome of aEGFR treatment in CRC therapy.

Correlation between microRNA-421 expression level and prognosis of gastric cancer.

The expression of microRNA-421 (miR-421) is significantly elevated in gastric carcinoma cells, thus may play an important role in tumor occurrence. This study thus aimed to further illustrate the correlation between miR-421 expression level and the progression and prognosis of gastric carcinoma. A total of 96 gastric carcinoma tissue samples were quantified for miR-421 expression level using quantitative PCR (qPCR) method. Kaplan-Meier survival curve was further deployed to analyze the postoperative survival of all patients. No significant correlation existed between miR-421 level and general information of patients such as age, sex, tumor size, location, invasion depth, TNM stage, differentiation stage and metastasis. However, miR-421 was significantly up-regulated in those tumors with lymph node metastasis (P<0.05), while those tumors with no lymph node metastasis had normal miR-421 level as those in control group (P>0.05). These results suggested the correlation between miR-421 up-regulation and lymph node metastasis. Those patients with high miR-421 expression had significantly shorter survival time compared to normal miR-421 patients (median: 37.34 months vs. 54.23 months, P<0.01), suggesting the correlation between miR-421 expression and prognosis of gastric cancer. MiR-421 level is correlated with lymph node metastasis and prognosis of gastric carcinoma, and is worth for further investigations.