Spatial transcriptomics reveals prognosis-associated cellular heterogeneity in the papillary thyroid carcinoma microenvironment.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common malignant endocrine tumour, and its incidence and prevalence are increasing considerably. Cellular heterogeneity in the tumour microenvironment is important for PTC prognosis. Spatial transcriptomics is a powerful technique for cellular heterogeneity study. METHODS: In conjunction with a clinical pathologist identification method, spatial transcriptomics was employed to characterise the spatial location and RNA profiles of PTC-associated cells within the tissue sections. The spatial RNA-clinical signature genes for each cell type were extracted and applied to outlining the distribution regions of specific cells on the entire section. The cellular heterogeneity of each cell type was further revealed by ContourPlot analysis, monocle analysis, trajectory analysis, ligand-receptor analysis and Gene Ontology enrichment analysis. RESULTS: The spatial distribution region of tumour cells, typical and atypical follicular cells (FCs and AFCs) and immune cells were accurately and comprehensively identified in all five PTC tissue sections. AFCs were identified as a transitional state between FCs and tumour cells, exhibiting a higher resemblance to the latter. Three tumour foci were shared among all patients out of the 13 observed. Notably, tumour foci No. 2 displayed elevated expression levels of genes associated with lower relapse-free survival in PTC patients. We discovered key ligand-receptor interactions, including LAMB3-ITGA2, FN1-ITGA3 and FN1-SDC4, involved in the transition of PTC cells from FCs to AFCs and eventually to tumour cells. High expression of these patterns correlated with reduced relapse-free survival. In the tumour immune microenvironment, reduced interaction between myeloid-derived TGFB1 and TGFBR1 in tumour focus No. 2 contributed to tumourigenesis and increased heterogeneity. The spatial RNA-clinical analysis method developed here revealed prognosis-associated cellular heterogeneity in the PTC microenvironment. CONCLUSIONS: The occurrence of tumour foci No. 2 and three enhanced ligand-receptor interactions in the AFC area/tumour foci reduced the relapse-free survival of PTC patients, potentially leading to improved prognostic strategies and targeted therapies for PTC patients.

Cortical responses correlate with speech performance in pre-lingually deaf cochlear implant children.

Introduction: Cochlear implantation is currently the most successful intervention for severe-to-profound sensorineural hearing loss, particularly in deaf infants and children. Nonetheless, there remains a significant degree of variability in the outcomes of CI post-implantation. The purpose of this study was to understand the cortical correlates of the variability in speech outcomes with a cochlear implant in pre-lingually deaf children using functional near-infrared spectroscopy (fNIRS), an emerging brain-imaging technique. Methods: In this experiment, cortical activities when processing visual speech and two levels of auditory speech, including auditory speech in quiet and in noise with signal-to-noise ratios of 10 dB, were examined in 38 CI recipients with pre-lingual deafness and 36 normally hearing children whose age and sex matched CI users. The HOPE corpus (a corpus of Mandarin sentences) was used to generate speech stimuli. The regions of interest (ROIs) for the fNIRS measurements were fronto-temporal-parietal networks involved in language processing, including bilateral superior temporal gyrus, left inferior frontal gyrus, and bilateral inferior parietal lobes. Results: The fNIRS results confirmed and extended findings previously reported in the neuroimaging literature. Firstly, cortical responses of superior temporal gyrus to both auditory and visual speech in CI users were directly correlated to auditory speech perception scores, with the strongest positive association between the levels of cross-modal reorganization and CI outcome. Secondly, compared to NH controls, CI users, particularly those with good speech perception, showed larger cortical activation in the left inferior frontal gyrus in response to all speech stimuli used in the experiment. Discussion: In conclusion, cross-modal activation to visual speech in the auditory cortex of pre-lingually deaf CI children may be at least one of the neural bases of highly variable CI performance due to its beneficial effects for speech understanding, thus supporting the prediction and assessment of CI outcomes in clinic. Additionally, cortical activation of the left inferior frontal gyrus may be a cortical marker for effortful listening.

MTOR suppresses autophagy-mediated production of IL25 in allergic airway inflammation.

INTRODUCTION: Airway epithelial cells are recognised as an essential controller for the initiation and perpetuation of asthmatic inflammation, yet the detailed mechanisms remain largely unknown. This study aims to investigate the roles and mechanisms of the mechanistic target of rapamycin (MTOR)-autophagy axis in airway epithelial injury in asthma. METHODS: We examined the MTOR-autophagy signalling in airway epithelium from asthmatic patients or allergic mice induced by ovalbumin or house dust mites, or in human bronchial epithelial (HBE) cells. Furthermore, mice with specific MTOR knockdown in airway epithelium and autophagy-related lc3b-/- mice were used for allergic models. RESULTS: MTOR activity was decreased, while autophagy was elevated, in airway epithelium from asthmatic patients or allergic mice, or in HBE cells treated with IL33 or IL13. These changes were associated with upstream tuberous sclerosis protein 2 signalling. Specific MTOR knockdown in mouse bronchial epithelium augmented, while LC3B deletion diminished allergen-induced airway inflammation and mucus hyperproduction. The worsened inflammation caused by MTOR deficiency was also ameliorated in lc3b-/- mice. Mechanistically, autophagy was induced later than the emergence of allergen-initiated inflammation, particularly IL33 expression. MTOR deficiency increased, while knocking out of LC3B abolished the production of IL25 and the eventual airway inflammation on allergen challenge. Blocking IL25 markedly attenuated the exacerbated airway inflammation in MTOR-deficiency mice. CONCLUSION: Collectively, these results demonstrate that allergen-initiated inflammation suppresses MTOR and induces autophagy in airway epithelial cells, which results in the production of certain proallergic cytokines such as IL25, further promoting the type 2 response and eventually perpetuating airway inflammation in asthma.

Tumor Suppressive Function of NQO1 in Cutaneous Squamous Cell Carcinoma (SCC) Cells.

Cutaneous squamous cell carcinoma (SCC) is a common cancer that significantly decreases the quality of life. It is known that external stimulus such as ultraviolet (UV) radiation induces cutaneous SCC via provoking oxidative stress. NAD(P)H dehydrogenase 1 (NQO1) is a ubiquitous flavoenzyme that functions as a guardian against oxidative stress. However, the effect of NQO1 on cutaneous SCC is not clearly elucidated. In this study, we investigated the effect of NQO1 on cutaneous SCC cells using the recombinant adenoviruses that can upregulate and/or downregulate NQO1 expression. Overexpression of NQO1 resulted in significant decrease of cell proliferation and colony forming activity of SCC lines (SCC12 and SCC13 cells). By contrast, knockdown of NQO1 increased the cell proliferation and colony forming activity. Accordingly, the levels of proliferation-related regulators, such as Cyclin D1, Cyclin E, PCNA, SOX2, and p63, were decreased by the overexpression of NQO1, while those were increased by knockdown of NQO1. In addition, NQO1 affected the invasion and migration of SCC cells in a very similar way, with the regulation of epithelial-mesenchymal transition- (EMT-) related molecules, including E-cadherin, N-cadherin, Vimentin, Snail, and Slug. Finally, the overexpression of NQO1 decreased the level of phosphorylated AKT, JNK, and p38 MAPK, while the knockdown of NQO1 increased the level of phosphorylated signaling molecules. Based on these data, NQO1 has tumor suppressive function in cutaneous SCC cells.

Antitumor Effect of Albendazole on Cutaneous Squamous Cell Carcinoma (SCC) Cells.

Drug repurposing and/or repositioning is an alternative method to develop new treatment for certain diseases. Albendazole was originally developed as an anthelmintic medication, and it has been used to treat a variety of parasitic infestations. In this study, we investigated the antitumor effect of albendazole and putative action mechanism. Results showed that albendazole dramatically decreased the cell viability of SCC cell lines (SCC12 and SCC13 cells). Albendazole increased apoptosis-related signals, including cleaved caspase-3 and PARP-1 in a dose-dependent fashion. The mechanistic study showed that albendazole induced endoplasmic reticulum (ER) stress, evidenced by increase of CHOP, ATF-4, caspase-4, and caspase-12. Pretreatment with ER stress inhibitor 4-PBA attenuated albendazole-induced apoptosis of SCC cells. In addition, albendazole decreased the colony-forming ability of SCC cells, together with inhibition of Wnt/ß-catenin signaling. These results indicate that albendazole shows an antitumor effect via regulation of ER stress and cancer stemness, suggesting that albendazole could be repositioned for cutaneous SCC treatment.

Mir20a/106a-WTX axis regulates RhoGDIa/CDC42 signaling and colon cancer progression.

Wilms tumor gene on the X chromosome (WTX) is a putative tumor suppressor gene in Wilms tumor, but its expression and functions in other tumors are unclear. Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in women and the second leading cause in men in the United States. We demonstrated that WTX frequently lost in CRC which was highly correlated with cell proliferation, tumor invasion and metastasis. Mechanistically, WTX loss disrupts the interaction between RhoGDIα and CDC42 by losing of the binding with RhoGDIα and triggers the activation of CDC42 and its downstream cascades, which promotes CRC development and liver metastasis. The aberrant upregulation of miR-20a/miR-106a were identified as the reason of WTX loss in CRC both in vivo and in vitro. These study defined the mechanism how miR-20a/miR-106a-mediated WTX loss regulates CRC progression and metastasis, and provided a potential therapeutic target for preventing CRC progression.

Inhibition of Poly(I:C)-Induced Inflammation by Salvianolic Acid A in Skin Keratinocytes.

BACKGROUND: Skin keratinocytes participate actively in inducing immune responses when external pathogens are introduced, thereby contributing to elimination of pathogens. However, in condition where the excessive inflammation is occurred, chronic skin disease such as psoriasis can be provoked. OBJECTIVE: We tried to screen the putative therapeutics for inflammatory skin disease, and found that salvianolic acid A (SAA) has an inhibitory effect on keratinocyte inflammatory reaction. The aim of this study is to demonstrate the effects of SAA in poly(I:C)-induced inflammatory reaction in skin keratinocytes. METHODS: We pre-treated keratinocytes with SAA then stimulated with poly(I:C). Inflammatory reaction of keratinocytes was verified using real-time polymerase chain reaction, enzyme-linked immunosorbent assay and Western blot. RESULTS: When skin keratinocytes were pre-treated with SAA, it significantly inhibited poly (I:C)-induced expression of inflammatory cytokines including interleukin (IL)-1ß, IL-6, IL-8, tumor necrosis factor-α, and CCL20. SAA inhibited poly(I:C)-induced activation of nuclear factor-κB signaling. And SAA also inhibited inflammasome activation, evidenced by decrease of IL-1ß secretion. Finally, SAA markedly inhibited poly(I:C)-induced NLRP3 expression. CONCLUSION: These results demonstrate that SAA has an inhibitory effect on poly(I:C)-induced inflammatory reaction of keratinocytes, suggesting that SAA can be developed for the treatment of inflammatory skin diseases such as psoriasis.

Three new labdane-type diterpenoids from Callicarpa macrophylla Vahl.

Three new labdane-type diterpenoids, callicapene M3-M5 (1-3) were isolated from the Callicarpa macrophylla Vahl. Their structures were identified by spectroscopic method. The isolated compounds were evaluated for inhibitory activity on NO production in LPS-activated RAW 264.7 macrophage cells by using MTT assays. Compounds 1-3 showed potent inhibitory activity, with IC50 value of 48.15, 46.31 and 38.72 µM respectively.

The General Expression Analysis of WTX Gene in Normal and Cancer Tissues.

WTX (Wilms' tumor suppressor X chromosome) is a novel putative tumor suppressor gene in Wilms' tumor of kidney, its expression and function in other human cancers had not been explored. This study detected the expression of WTX in 459 cases of 15 organs of cancers and adjacent normal tissues by using immunohistochemical staining (IHC), and validated them by in situ hybridization (ISH) and quantitative real-time reverse transcription PCR (qRT-PCR). IHC and ISH data showed that WTX protein was generally expressed in normal tissues, but reduced expression in corresponding cancers. This study demonstrated that WTX downregulation is a common phenomenon in human cancers, WTX might be a general tumor-suppressor gene and biological marker of multiple cancer tissues. Apart from kidney, stomach is another target tissue of WTX gene. The germline and somatic mutations of WTX were screened in 12 gastric cancer patients and identified in one cases (8.3%). Mutation in the WTX gene might be one of the reasons of WTX loss in gastric cancer patients.

[Effect of shRNA-mediated CDC42 knockdown on morphology of colorectal cancer cells in vitro].

OBJECTIVE: To test the effect of CDC42 (a member of Rho family of small GTPases) knockdown mediated by a CDC42 short-hairpin RNA (shRNA) on the morphology of colorectal cancer SW480 cells in vitro. METHODS: Four CDC42 siRNA fragments targeting CDC42 were designed and the most efficient siRNA for CDC42 knockdown was selected to construct the shRNA vector for transfection of colorectal cancer SW480 cells. The interference efficiency in the stably transfected cells (sw480.shCDC) was detected using real-time PCR and Western blotting, and the morphological changes of the transfected cells were observed. RESULTS: Western blotting result showed that siCDC42-3 was the most efficient fragment for CDC42 knockdown, which caused CDC42 knockdown by over 50%. DNA sequencing confirmed successful construction of the CDC42 shRNA vector. Transfection of the cells with the vector significantly reduced CDC42 expressions at both the mRNA and protein levels. The transfected cells exhibited reduced filopodia and cell size with smooth cell margins. CONCLUSION: shRNA-mediated CDC42 knockdown can reduce the cytoskeleton dynamics of colorectal cancer cells to lower their invasiveness. This shRNA construct facilitates further study of the role of CDC42 in the tumorigenesis and progression of colorectal cancer.

[Transurethral transumbilical laparoendoscopic single-site surgery for radical prostatectomy].

OBJECTIVE: To investigate the feasibility and advantages of transurethral transumbilical laparoendoscopic single-site surgery (TU-LESS) for radical prostatectomy. METHODS: Five patients with prostate cancer underwent TU-LESS for radical prostatectomy, with a four-channel single-port device inserted into a 2. 5 cm periumbilical incision and another placed through the urethra, followed by analysis of the perioperative data. RESULTS: All the operations were successfully accomplished, with neither conversion to open surgery nor additional channel. The mean operation time, intraoperative blood loss, and postoperative hospital stay were 168 min, 120 ml, and 15 d, respectively. No severe perioperative complications were observed. TNM stage classification manifested T2cN0M0 in 2 cases and T2bN0M0 in the other 3. Postoperative pathology showed no negative surgical margins in any of the cases. CONCLUSION: TU-LESS is safe and feasible for radical prostatectomy and can reduce the complication of low urinary tract surgery by single-site laparoendoscopy.

Prenatal Training Improves New Mothers' Understanding of Jaundice.

BACKGROUND: Mothers' knowledge of neonatal jaundice (NNJ) is grossly deficient or inaccurate, which may adversely affect the actions of mothers in the recognition of NNJ and cause a delay in seeking medical attention. MATERIAL AND METHODS: A total of 1036 primiparas were separated randomly into the intervention group and the control group, with 518 primiparas in each group. RESULTS: All (100%) mothers in the intervention group understood that NNJ is a yellow discoloration of the skin and sclera; 94.19% of them considered that NNJ is a common problem in newborns; 82.80% and 95.27% replied that jaundice appearing within the first 36 hours and lasting more than 2 weeks usually indicates pathological NNJ; 96.34%, 80.86%, and 90.32% realized that premature newborns, low birth weight, and perinatal asphyxia, respectively, are more likely to be accompanied by NNJ; 97.41%, 78.71%, and 64.95% knew that maternal-fetal blood group incompatibility, infection, and glucose-6-phosphate dehydrogenase deficiency, respectively, are the common inducements to NNJ; 94.84% could associate NNJ with brain damage; 92.26%, 93.12%, and 74.62% agreed that phototherapy, strengthen feeding, and exchange blood transfusion, respectively, can greatly relieve NNJ. However, some respondents in the control group responded in other ways, such as stopping breastfeeding (9.19%), placing newborns in sunlight (10.24%) and traditional Chinese medicine (10.24%), which was significantly higher than that of the intervention group. There was also a significant delay for respondents in the control group in consulting a pediatrician, and 6.30% of them did not seek medical help until after the interview. CONCLUSIONS: Prenatal training could significantly improve new mothers' understanding of NNJ.

[Relationship between the expressions of indoleamine 2, 3-dioxygenase in hepatocellular carcinoma and clinicopathological parameters].

OBJECTIVE: To explore the expressions of indoleamine 2, 3-dioxygenase (IDO) in hepatocellular carcinoma and analyze its relationship with clinicopathological parameters. METHODS: Quantitative real-time polymerase chain reaction (PCR), fluorogenic quantitative PCR, immunohistochemical and immunofluorescence were used to detect the expression of indoleamine 2, 3-dioxygenase in hepatocellular carcinoma. RESULTS: The IDO mRNA expression in cancerous tissues increased markedly than that in the corresponding non-cancerous tissues (2(-ΔΔCT) = 1.71, P = 0.001) . The immunohistochemical and immunofluorescence results showed that IDO protein was expressed in cytoplasm of hepatocellular carcinoma and tumor-surrounding tissues. But there was no expression in normal liver tissues from benign hepatic lesions and corresponding non-cancerous tissues. An over-expression of IDO protein was detected in 43 patients (48.3%) , a low expression in 25 (28.1%) and no expression in 21 (23.6%). Relationship between IDO expression and clinicopathological parameters: an over-expression of IDO in HCC was associated with recurrence, survival time, metastasis and TNM stage (P < 0.05), but not associated with patient's cirrhosis, AFP level, histological differentiation type, Barcelona clinic liver cancer stage, gender, age, HbsAg positivity, number of tumors and tumor size (P > 0.05). CONCLUSION: An over-expression of IDO in HCC patients may affect patient prognosis.

Tiam1 transgenic mice display increased tumor invasive and metastatic potential of colorectal cancer after 1,2-dimethylhydrazine treatment.

BACKGROUND: T lymphoma invasion and metastasis 1 (Tiam1) is a potential modifier of tumor development and progression. Our previous study in vitro and in nude mice suggested a promotion role of Tiam1 on invasion and metastasis of colorectal cancer (CRC). In the present study, we generated Tiam1/C1199-CopGFP transgenic mice to investigate the tumorigenetic, invasive and metastatic alterations in the colon and rectum of wild-type and Tiam1 transgenic mice under 1,2-dimethylhydrazine (DMH) treatment. METHODS: Transgenic mice were produced by the method of pronuclear microinlectlon. Whole-body fluorescence imaging (Lighttools, Edmonton, Alberta, Canada), PCR, and immunohistochemical techniques (IHC) were applied sequentially to identify the transgenic mice. The carcinogen DMH (20 mg/kg) was used to induce colorectal tumors though intraperitoneal (i.p.) injections once a week for 24 weeks from the age of 4 weeks on Tiam1 transgenic or non-transgenic mice. RESULTS: We successfully generated Tiam1/C1199-CopGFP transgenic mice and induced primary tumors in the intestine of both wild type and Tiam1 transgenic mice by DMH treatment. In addition, Tiam1 transgenic mice developed larger and more aggressive neoplasm than wild-type mice. Moreover, immunohistochemical staining revealed that upregulation of Tiam1 was correlated with increased expression of ß-Catenin and Vimentin, and downregulation of E-Cadherin in these mice. CONCLUSIONS: Our study has provided in vivo evidence supporting that Tiam1 promotes invasion and metastasis of CRC, most probably through activation of Wnt/ß-catenin signaling pathway, in a Tiam1 transgenic mouse model.

[Exposure degree of important non-target arthropods to Cry2Aa in Bt rice fields].

Based on the principle of "risk = hazard x exposure", the selected representative nontarget organisms in the assessment of the potential effects of insect-resistant genetically modified (GM) crops on non-target arthropods in laboratory are generally the arthropod species highly exposed to the insecticidal proteins expressed by the GM crops in farmland ecosystem. In order to understand the exposure degree of the important arthropod species to Cry proteins in Bt rice fields, and to select the appropriate non-target arthropods in the risk assessment of insect-resistant GM crops, the enzyme-linked immunosorbent assay (ELISA) was conducted to measure the Cry2Aa protein concentration in the arthropods collected from the cry2Aa rice fields at different rice growth stages. The results showed that there was a significant difference in the Cry2Aa content protein concentration in different arthropod species. Some species did not contain Cry2Aa protein, while some species contained larger amounts of Cry2Aa protein. Relative to the arthropods colleted after rice anthesis, the arthropods colleted in rice anthesis contained relative higher concentrations of Cry2Aa protein, especially for the predacious arthropods. No Cry proteins were detected in parasitic arthropods. This study provided references for the laboratory assessment of the effects of GM rice on nontarget arthropods.

Simultaneous removal of organic matter and nitrogen by a heterotrophic nitrifying-aerobic denitrifying bacterial strain in a membrane bioreactor.

A heterotrophic nitrifying-aerobic denitrifying bacterial strain, Bacillus methylotrophicus L7, was inoculated solely into a submerged membrane bioreactor (MBR) for continuous treatment of artificial sewage. The running conditions were also optimized for improvement of the treatment efficiency. The results indicated that inoculation of this single strain in a single reactor under constant aerobic conditions resulted in simultaneous removal of organic matter and nitrogen, in striking contrast to traditional aerobic nitrification-anaerobic denitrification treatment system and the sequencing batch reactor (SBR) systems. The optimal running conditions for the MBR were dissolved oxygen (DO) 4.5 mg/L, pH 7.5, loading ammonia <100 mg/L, and C/N ratio 3.5. Under these conditions, the removal percentages of chemical oxygen demand (COD), NH4(+)-N, and TN as high as 96%, 77.5% and 53%, respectively, were achieved without nitrite accumulation.

Clinical and pathological characteristics of giant cell angioblastoma: a case report.

Giant cell angioblastoma (GCAB) is an extremely rare soft tissue tumor of early childhood and only five cases have been described to date. As such the clinical, pathological, and prognostic features are poorly defined. We prensent here a new case of GCAB in bone of a child aged 4-years old. The lesion was composed of dense and loose cell regions. The dense regions were characterized by nodular, linear, and plexiform aggregates of oval- to spindle-shaped tumor cells around small vascular channels and interspersed with large mononuclear cells and multinucleate giant cells. The loose cell areas were characterized by distributed fibroblasts and abundant myxoid matrix, which diminished with patient age. Infiltrative growth was observed in some areas. Oval-to-spindle cells showed positivity for Vimentin, CD31 and CD34 staining, and partial positivity for smooth muscle actin. Mononuclear cells and multinucleate giant cells showed Vimentin and CD68 positivity. Seventeen months after thorough curettage of the lesion, a local recurrence was found. Based upon the clinical, histological and immunohistochemical findings, infiltrate condition, and prognosis, we classified GCAB into two subtypes. Type I does not infiltrate surrounding tissues and has good prognosis. Type II infiltrates the surrounding tissues, relapses earlier, and has worse prognosis. This report augments the limited GCAB literature to promote our understanding and guide therapy of this rare disease. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6699811297488137.

The establishment of supramolecular immunobead real-time PCR and the identification of Cox-2 as a metastasis-related marker in colorectal carcinoma.

Cyclooxygenase-2 (Cox-2) is an inducible enzyme that converts arachidonic acid to prostaglandins, and it is hypothesized to induce carcinogenesis and metastasis in colorectal cancer. Our previous data also indicated that a higher expression level of Cox-2 was correlated with colorectal cancer metastasis. The Cox-2 protein was detected in the glandular cavity of colorectal cancer and the surrounding interstitial tissues. The usefulness of the Cox-2 gene as a gene therapy target and diagnostic marker remains unknown. In this study, a method using immuno-PCR and real-time PCR followed by supramolecular immunobead real-time PCR was established and used to detect the expression of Cox-2 in serum samples of nude mice with colorectal carcinoma. In addition, we established a Cox-2 gene stable knockdown colorectal cell line (SW480-EGFP-Cox-2 shRNA) using lentiviral vector-mediated RNA interference (RNAi) technology and established an imageable colorectal cancer metastasis mouse model. We found that the proliferation, invasion and tumorigenesis of SW480-EGFP-Cox-2 shRNA cells were attenuated compared with SW480 cells. In vivo experiments also demonstrated that angiogenesis in the Cox-2 knockdown colorectal cancer cells was decreased. The whole body optical imaging revealed that the SW480-EGFP-Cox-2 shRNA cells had an abrogated ability to develop metastases in the lymph nodes, lungs or liver in vivo. The improved immunobead PCR assay detected significantly lower Cox-2 protein levels in the serum samples of the SW480-EGFP-Cox-2 shRNA group compared with those of the SW480-EGFP-Cox-2-Ctrl shRNA group. In conclusion, our results indicated that the knockdown of Cox-2 expression suppressed the proliferation and invasion of colorectal cancer cells both in vitro and in vivo. This study also demonstrated that silencing Cox-2 in vivo reduced the metastastic potential of colorectal cancer. Thus, Cox-2 is a promising marker for the diagnosis of colorectal metastasis and a potential therapeutic target for colorectal cancer.