Long-term stability and immunogenicity of lipid nanoparticle COVID-19 mRNA vaccine is affected by particle size.

Messenger ribonucleic acid (mRNA) technology has been rapidly applied for the development of the COVID-19 vaccine. However, naked mRNA itself is inherently unstable. Lipid nanoparticles (LNPs) protect mRNAs from extracellular ribonucleases and facilitate mRNA trafficking. For mRNA vaccines, antigen-presenting cells utilize LNPs through uptake to elicit antigen-specific immunity. There are reports on the impact of various physical characteristics of LNPs, particularly those with sizes less than 200 nm, especially 50 to 150 nm, on the overall stability and protective efficacy of mRNA vaccines. To address this, a single change in the size of LNPs using the same mRNA stock solution was assessed for the physicochemical characterization of the resulting mRNA-LNPs vaccine, along with the evaluation of their protective efficacy. Particles of smaller sizes generally disperse more effectively in solutions, with minimized occurrence of particle precipitation and aggregation. Here, we demonstrate that the vaccine containing 80-100 nm mRNA-LNPs showed the best stability and protection at 4°C and -20°C. Furthermore, we can conclude that freezing the vaccine at -20°C is more appropriate for maintaining stability over the long term. This effort is poised to provide a scientific basis for improving the quality of ongoing mRNA vaccine endeavors and providing information on the development of novel products.

A preparation method for mRNA-LNPs with improved properties.

The properties of mRNA lipid nanoparticles (mRNA-LNPs), including size, empty particles, morphology, storage stability, and transfection potency, are critically dependent on the preparation methods. Here, a Two-step tangential-flow filtration (TFF) method was successfully employed to improve the properties of mRNA-LNPs during the preparation process. This method involves an additional ethanol removal step prior to the particle fusion process. Notably, this innovative approach has yielded mRNA-LNPs with larger particles, a reduced proportion of empty LNPs, optimized storage stability (at least 6 months at 2-8 °C), improved in vitro transfection efficiency, and minimized distribution in the heart and blood in vivo. In summary, this study represents the implementation of the innovative Two-step TFF method in the preparation of mRNA-LNPs. Our findings indicate substantial enhancements in the properties of our mRNA-LNPs, specifically with regard to the percentage of empty LNPs, stability, transfection efficiency, and in vivo distribution. These improvements have the potential to optimize their industrial applicability and expand their clinical use.

The role of cannabidiol in aging.

Aging is usually considered a key risk factor associated with multiple diseases, such as neurodegenerative diseases, cardiovascular diseases and cancer. Furthermore, the burden of age-related diseases has become a global challenge. It is of great significance to search for drugs to extend lifespan and healthspan. Cannabidiol (CBD), a natural nontoxic phytocannabinoid, has been regarded as a potential candidate drug for antiaging. An increasing number of studies have suggested that CBD could benefit healthy longevity. Herein, we summarized the effect of CBD on aging and analyzed the possible mechanism. All these conclusions may provide a perspective for further study of CBD on aging.

Short-Term Clinical Response and Changes in the Fecal Microbiota and Metabolite Levels in Patients with Crohn's Disease After Stem Cell Infusions.

Recent studies have shown a close relationship between the gut microbiota and Crohn's disease (CD). This study aimed to determine whether mesenchymal stem cell (MSC) treatment alters the gut microbiota and fecal metabolite pathways and to establish the relationship between the gut microbiota and fecal metabolites. Patients with refractory CD were enrolled and received 8 intravenous infusions of MSCs at a dose of 1.0 × 106 cells/kg. The MSC efficacy and safety were evaluated. Fecal samples were collected, and their microbiomes were analyzed by 16S rDNA sequencing. The fecal metabolites at baseline and after 4 and 8 MSC infusions were identified by liquid chromatography-mass spectrometry (LC--MS). A bioinformatics analysis was conducted using the sequencing data. No serious adverse effects were observed. The clinical symptoms and signs of patients with CD were substantially relieved after 8 MSC infusions, as revealed by changes in weight, the CD activity index (CDAI) score, C-reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR). Endoscopic improvement was observed in 2 patients. A comparison of the gut microbiome after 8 MSC treatments with that at baseline showed that the genus Cetobacterium was significantly enriched. Linoleic acid was depleted after 8 MSC treatments. A possible link between the altered Cetobacterium abundance and linoleic acid metabolite levels was observed in patients with CD who received MSCs. This study enabled an understanding of both the gut microbiota response and bacterial metabolites to obtain more information about host-gut microbiota metabolic interactions in the short-term response to MSC treatment.

The role of ß-catenin in cardiac diseases.

The Wnt/ß-catenin signaling pathway is a classical Wnt pathway that regulates the stability and nuclear localization of ß-catenin and plays an important role in adult heart development and cardiac tissue homeostasis. In recent years, an increasing number of researchers have implicated the dysregulation of this signaling pathway in a variety of cardiac diseases, such as myocardial infarction, arrhythmias, arrhythmogenic cardiomyopathy, diabetic cardiomyopathies, and myocardial hypertrophy. The morbidity and mortality of cardiac diseases are increasing, which brings great challenges to clinical treatment and seriously affects patient health. Thus, understanding the biological roles of the Wnt/ß-catenin pathway in these diseases may be essential for cardiac disease treatment and diagnosis to improve patient quality of life. In this review, we summarize current research on the roles of ß-catenin in human cardiac diseases and potential inhibitors of Wnt/ß-catenin, which may provide new strategies for cardiac disease therapies.

Key genes associated with non-alcoholic fatty liver disease and hepatocellular carcinoma with metabolic risk factors.

Background: Hepatocellular carcinoma (HCC) has become the world's primary cause of cancer death. Obesity, hyperglycemia, and dyslipidemia are all illnesses that are part of the metabolic syndrome. In recent years, this risk factor has become increasingly recognized as a contributing factor to HCC. Around the world, non-alcoholic fatty liver disease (NAFLD) is on the rise, especially in western countries. In the past, the exact pathogenesis of NAFLD that progressed to metabolic risk factors (MFRs)-associated HCC has not been fully understood. Methods: Two groups of the GEO dataset (including normal/NAFLD and HCC with MFRs) were used to analyze differential expression. Differentially expressed genes of HCC were verified by overlapping in TCGA. In addition, functional enrichment analysis, modular analysis, Receiver Operating Characteristic (ROC) analysis, LASSO analysis, and Genes with key survival characteristics were analyzed. Results: We identified six hub genes (FABP5, SCD, CCL20, AGPAT9(GPAT3), PLIN1, and IL1RN) that may be closely related to NAFLD and HCC with MFRs. We constructed survival and prognosis gene markers based on FABP5, CCL20, AGPAT9(GPAT3), PLIN1, and IL1RN.This gene signature has shown good diagnostic accuracy in both NAFLD and HCC and in predicting HCC overall survival rates. Conclusion: As a result of the findings of this study, there is some guiding significance for the diagnosis and treatment of liver disease associated with NAFLD progression.

A glance at transient hyperammonemia of the newborn: Pathophysiology, diagnosis, and treatment: A review.

Hyperammonemia is the excessive accumulation of ammonia in the blood, and is usually defined as a plasma level above 100 µmol/L in neonates or above 50 µmol/L in term infants, children, and adolescents. Patients with hyperammonemia usually experience life-threatening neuropsychiatric symptoms, especially newborns. It is routinely caused by inherited metabolic diseases and also by acquired disorders, such as liver failure, portosystemic shunting, gastrointestinal hemorrhage, ureterosigmoidostomy, renal tubular acidosis, hypoxic ischemic encephalopathy, infections with urea-metabolizing organisms, and some drugs. Transient hyperammonemia of the newborn (THAN) is a special type of hyperammonemia acknowledged in the field of metabolic disease as an inwell-defined or well-understood entity, which can be diagnosed only after the exclusion of genetic and acquired causes of hyperammonemia. Although the prognosis for THAN is good, timely identification and treatment are essential. Currently, THAN is underdiagnosed and much less is mentioned for early diagnosis and vigorous treatment. Herein, we present common themes that emerge from the pathogenesis, diagnosis, and management of THAN, based on current evidence. When a newborn presents with sepsis, intracranial hemorrhage, or asphyxia that cannot explain coma and seizures, doctors should always keep this disease in mind.

Human umbilical cord-derived mesenchymal stem cells ameliorate experimental colitis by normalizing the gut microbiota.

BACKGROUND: Crohn's disease (CD) is a chronic non-specific inflammatory bowel disease. Current CD therapeutics cannot fundamentally change the natural course of CD. Therefore, it is of great significance to find new treatment strategies for CD. Preclinical and clinical studies have shown that mesenchymal stromal cells (MSCs) are a promising therapeutic approach. However, the mechanism by which MSCs alleviate CD and how MSCs affect gut microbes are still unclear and need further elucidation. METHODS: We used 2,4,6-trinitrobenzenesulfonic acid (TNBS) to induce experimental colitis in mice and analysed the microbiota in faecal samples from the control group, the TNBS group and the TNBS + MSC group with faecal 16S rDNA sequencing. Subsequent analyses of alpha and beta diversity were all performed based on the rarified data. PICRUStII analysis was performed on the 16S rRNA gene sequences to infer the gut microbiome functions. RESULTS: MSC Treatment improved TNBS-induced colitis by increasing survival rates and relieving symptoms. A distinct bacterial signature was found in the TNBS group that differed from the TNBS + MSC group and controls. MSCs prevented gut microbiota dysbiosis, including increasing α-diversity and the amount of Bacteroidetes Firmicutes and Tenericutes at the phylum level and decreasing the amount of Proteobacteria at the phylum level. MSCs alleviated the increased activities of sulphur and riboflavin metabolism. Meanwhile some metabolic pathways such as biosynthesis of amino acids lysine biosynthesis sphingolipid metabolism and secondary bile acid biosynthesis were decreased in the TNBS group compared with the control group and the TNBS + MSC group CONCLUSIONS: Overall, our findings preliminarily confirmed that colitis in mice is closely related to microbial and metabolic dysbiosis. MSC treatment could modulate the dysregulated metabolism pathways in mice with colitis, restoring the abnormal microbiota function to that of the normal control group. This study provides insight into specific intestinal microbiota and metabolism pathways linked with MSC treatment, suggesting a new approach to the treatment of CD.

An Injectable Epigenetic Autophagic Modulatory Hydrogel for Boosting Umbilical Cord Blood NK Cell Therapy Prevents Postsurgical Relapse of Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) exhibits resistance to conventional treatments due to the presence of cancer stem cells (CSCs), causing postsurgical relapse and a dismal prognosis. Umbilical cord blood natural killer (UCB-NK) cell-based immunotherapy represents a promising strategy for cancer treatment. However, its therapeutic efficacy is greatly restrained by downregulation of the NK cell activation ligand MHC class I-related chain A/B (MICA/B) and autophagy-mediated degradation of NK cell-derived granzyme B (GZMB) in CSCs. Herein, it is demonstrated that suberoylanilide hydroxamic acid (SAHA) epigenetically downregulates let-7e-5p and miR-615-3p to increase MICA/B expression and that 3-methyl adenine (3MA) inhibits autophagy-mediated GZMB degradation, thereby sensitizing breast CSCs to UCB-NK cells. Then, an injectable hydrogel is designed to codeliver SAHA and 3MA to enhance UCB-NK cell infusion efficacy in TNBC. The hydrogel precursors can be smoothly injected into the tumor resection bed and form a stable gel in situ, allowing for a pH-sensitive sustained release of SAHA and 3MA. Moreover, UCB-NK cell infusion in combination with the hydrogel efficiently controls postsurgical relapse of TNBC. In addition, the hydrogel exhibits good hemostasis and wound-healing functions. Therefore, the work provides proof of concept that an injectable epigenetic autophagic modulatory hydrogel augments UCB-NK cell therapy to combat postsurgical relapse of TNBC.

Injectable adhesive hemostatic gel with tumor acidity neutralizer and neutrophil extracellular traps lyase for enhancing adoptive NK cell therapy prevents post-resection recurrence of hepatocellular carcinoma.

Post-resection recurrence remains an intractable problem in hepatocellular carcinoma (HCC) management. Natural killer (NK) cell infusion is considered as a promising cancer therapy, but acidic tumor microenvironment (TME) and neutrophil extracellular traps (NETs) greatly counteract its efficacy. Recently, polymer hydrogels have aroused much interest in tumor combination therapy, since they load and controllably release therapeutic agents with high bioavailability and low systemic toxicity. Therefore, a biocompatible hydrogel with tumor acidity neutralizer and NETs lyase may show promise for enhancing NK infusion to prevent post-resection HCC recurrence. Herein, a dual pH-responsive hydrogel with tumor acidity neutralizer (mesoporous bioactive glass nanoparticles) and NETs lyase (Deoxyribonuclease I, DNase I) is developed and used in combination with NK cell infusion for preventing post-resection HCC recurrence. The hydrogel can be injected to surgical margin and form an adhesive gel with a rapid hemostasis. Besides, it neutralizes tumor acidity to reduce tumor infiltration of immunosuppressive cells, and releases DNase I in a pH-responsive manner to degrade NETs. Moreover, this combination therapy significantly enhances NK cell infusion to combat post-surgical HCC recurrence without systemic toxicity. This study provides proof of concept that combination of NK cell adoptive therapy and hydrogel-based delivery system can successfully prevent post-resection HCC recurrence.

CCR2-overexpressing mesenchymal stem cells targeting damaged liver enhance recovery of acute liver failure.

BACKGROUND: Mesenchymal stem cell (MSC) transplantation is emerging as a promising cell therapeutic strategy in acute liver failure (ALF) clinical research. The potency of MSCs to migrate and engraft into targeted lesions could largely determine their clinical efficacy, in which chemokine/receptor axes play a crucial role. Unfortunately, the downregulation of chemokine receptors expression after in vitro expansion results in a poor homing capacity of MSCs. METHODS: By evaluating the chemokine expression profile in the liver of ALF patients and ALF mice, we found that CCL2 expression was highly upregulated in damaged livers, while the corresponding receptor, CCR2, was lacking in cultured MSCs. Thus, we genetically modified MSCs to overexpress CCR2 and investigated the targeted homing capacity and treatment efficacy of MSCCCR2 compared to those of the MSCvector control. RESULTS: In vivo and ex vivo near-infrared fluorescence imaging showed that MSCCCR2 rapidly migrated and localized to injured livers in remarkably greater numbers following systemic infusion, and these cells were retained in liver lesions for a longer time than MSCvector. Furthermore, MSCCCR2 exhibited significantly enhanced efficacy in the treatment of ALF in mice, which was indicated by a dramatically improved survival rate, the alleviation of liver injury with reduced inflammatory infiltration and hepatic apoptosis, and the promotion of liver regeneration. CONCLUSIONS: Altogether, these results indicate that CCR2 overexpression enhances the targeted migration of MSCs to damaged livers, improves their treatment effect, and may provide a novel strategy for improving the efficacy of cell therapy for ALF.

Investigating the Multitarget Pharmacological Mechanism of Ursolic Acid Acting on Colon Cancer: A Network Pharmacology Approach.

OBJECTIVE: To explore the mechanisms of ursolic acid for treating colon cancer based on network pharmacology. METHOD: In this study, the potential targets of ursolic acid against colon cancer were predicted and screened through the TCMSP, SYMMAP, Drug Bank, UNI-PROT, and DISGENET databases. The protein interaction (PPI) network was constructed based on the STRING database, and graphs were drawn with the help of Cytoscape software. GO and KEGG enrichment analyses were performed on the targets by using the DAVID database for biological information annotation. RESULTS: Ursolic acid has 113 targets in the treatment of colon cancer. The core targets included interleukin-6 (IL-6), mitogen-activated protein kinase 3 (MAPK3), vascular endothelial growth factor receptor (VEGFA), prostaglandin endoperoxide synthase 2 (PTGS2), caspase-3 (CASP3), mitogen-activated protein kinase 8 (MAPK8), tumor necrosis factor (TNF), cyclin D1 (CCND1), JUN, signal transducer and transcriptional activator 3 (STAT3), and other targets. The first 10 pathways related to colon cancer were screened out. The main signaling pathways included the TNF signaling pathway and the AGE-RAGE signaling pathway in diabetic complications and human colon cancer infections. CONCLUSION: This study revealed that ursolic acid played a multitarget and multichannel antitumor role by inhibiting the proliferation of tumor cells, inducing apoptosis, and enhancing antiangiogenesis.

CD13: A Key Player in Multidrug Resistance in Cancer Chemotherapy.

Cancer is one of the most serious diseases that are harmful to human health. Systemic chemotherapy is an optimal therapeutic strategy for the treatment of cancer, but great difficulty has been encountered in its administration in the form of multidrug resistance (MDR). As an enzyme on the outer cell surface, CD13 is documented to be involved in the MDR development of tumor cells. In this review, we will focus on the role of CD13 in MDR generation based on the current evidence.

Dysbiosis of the Gut Microbiome is associated with Tumor Biomarkers in Lung Cancer.

Lung cancer is a malignancy with high morbidity and mortality worldwide. More evidences indicated that gut microbiome plays an important role in the carcinogenesis and progression of cancers by metabolism, inflammation and immune response. However, the study about the characterizations of gut microbiome in lung cancer is limited. In this study, the fecal samples were collected from 16 healthy individuals and 30 lung cancer patients who were divided into 3 groups based on different tumor biomarkers (cytokeratin 19 fragment, neuron specific enolase and carcinoembryonic antigen, respectively) and were analyzed using 16S rRNA gene amplicon sequencing. Each lung cancer group has characterized gut microbial community and presents an elimination, low-density, and loss of bacterial diversity microbial ecosystem compared to that of the healthy control. The microbiome structures in family and genera levels are more complex and significantly varied from each group presenting more different and special pathogen microbiome such as Enterobacteriaceae, Streptococcus, Prevotella, etc and fewer probiotic genera including Blautia, Coprococcus, Bifidobacterium and Lachnospiraceae. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and COG annotation demonstrated decreased abundance of some dominant metabolism-related pathways in the lung cancer. This study explores for the first time the features of gut microbiome in lung cancer patients and may provide new insight into the pathogenesis of lung cancer system, with the implication that gut microbiota may serve as a microbial marker and contribute to the derived metabolites, development and differentiation in lung cancer system.

NDNF inhibits the migration and invasion of human renal cancer cells through epithelial-mesenchymal transition.

Neuron-derived neurotrophic factor (NDNF) is a glycosylated, disulfide-bonded secretory protein that contains a fibronectin type III domain. NDNF has been identified as a neurotrophic factor; however, its role in carcinogenesis has not yet been identified. To investigate the expression and role of NDNF in carcinogenesis, the expression of NDNF in human Renal cell carcinoma (RCC) cell lines and tissues was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Cell proliferation was investigated using CCK-8 and colony formation assays, and the cell invasion and immigration capacity was evaluated using the transwell assay. The results demonstrated that NDNF expression was downregulated in RCC cell lines and RCC tissues. Restoring NDNF expression significantly inhibited the proliferation, migration and invasion of RCC cells. The study also demonstrated that the inhibitory effect of NDNF on invasive ability was mediated by suppressing the epithelial-mesenchymal transition (EMT) in RCC cells. NDNF may therefore be considered an important regulator of EMT in RCC progression and may represent a novel promising target for antimetastatic therapy.

Loss of KCNJ15 expression promotes malignant phenotypes and correlates with poor prognosis in renal carcinoma.

BACKGROUND: KCNJ15 belongs to the inwardly rectifying potassium channel (KIR) family. Although members of the KIR family have been proven to play important roles in a variety of developmental processes, the molecular role and clinical effects of KCNJ15 in cancers remain unclear. PURPOSE: The aim of this study was to identify the expression, biological functions and molecular mechanisms of KCNJ15 in renal cell carcinoma (RCC). METHODS: KCNJ15 mRNA expression was evaluated in kidney cancer tissue, paired adjacent normal tissue, and cell lines with qRT-PCR. KCNJ15 protein expression was investigated via western blotting and immunohistochemistry. In addition, the clinical and prognostic significance of KCNJ15 in RCC were assessed using Kaplan-Meier analysis and Cox proportional hazards analysis. In vitro, the effects of KCNJ15 on kidney cancer cells were evaluated by means of a cell counting kit-8, transwell assay along with flow cytometry, respectively. Moreover, the potential mechanism of KCNJ15 was demonstrated by Western blot. RESULTS: Here, we first found that KCNJ15 was significantly downregulated in RCC, and this low expression was an independent prognostic factor for clear cell RCC (ccRCC). Moreover, KCNJ15 was associated with advanced TNM stage (n=150, p=0.014) and histological grade (n=150, p=0.045). Furthermore, KCNJ15 overexpression significantly inhibited RCC cell proliferation, migration, and colony formation, arrested the cell cycle and induced apoptosis of RCC cells in vitro. The inhibitory effect of KCNJ15 overexpression may be regulated by its effects on the epithelial mesenchymal transition (EMT) process and matrix metalloproteinase (MMP)-7 and p21 expression. CONCLUSION: These findings indicate that KCNJ15 may be a tumor suppressor in RCC and a possible target for RCC therapy.

Prognostic value of spleen tyrosine kinase in human solid tumors.

BACKGROUND: Spleen tyrosine kinase (SYK) was reported to be dysregulated in solid tumors and played an important role in cancer progression. However, the clinical and prognostic values of SYK in solid tumors remain unclear. This meta-analysis investigated the association between SYK expression and clinical outcomes in the patients with solid tumors. METHODS: A comprehensive literature search was conducted by screening the online electronic databases of PubMed, Embase, and the China National Knowledge Infrastructure. The hazard ratio (HR) with its corresponding 95% CI was used to explore the prognostic value of SYK. RESULTS: We analyzed a total of 1,075 patients from 10 studies, which met the criteria for this meta-analysis. Our pooled results demonstrated that a low expression of SYK did not correlate significantly with shorter overall survival (OS; HR=0.64, 95% CI: 0.34-1.21, P=0.169) or poorer disease-free survival (HR=0.51, 95% CI: 0.13-2.02, P=0.338). However, in a subgroup analysis based on tumor type and test method, under-expression of SYK was positively associated with worse OS in the groups of breast cancer (BC; HR=0.51, 95% CI: 0.32-0.80, P=0.003), hepatocellular carcinoma (HCC; HR=0.44, 95% CI: 0.29-0.69, P<0.001), methylation (HR=0.39, 95% CI: 0.30-0.51, P<0.001), and quantitative reverse transcription polymerase chain reaction (HR=0.24, 95% CI: 0.09-0.65, P=0.005). CONCLUSION: This meta-analysis demonstrated that under-expression of SYK may serve as a predictive biomarker for poor prognosis in BC and HCC patients. In other solid tumors, the clinical usefulness should be confirmed by large-scale studies.

Investigation of correlation between mutational status in key EGFR signaling genes and prognosis of stage II colorectal cancer.

AIM: To investigate the relationship between mutations of key genes in the EGFR signaling pathway and the prognosis of stage II colorectal cancer patients without chemotherapy. MATERIALS & METHODS: The incidence of KRAS, NRAS, BRAF, PIK3CA mutations and deficient DNA mismatch repair were assessed in 160 stage II colorectal cancer patients who had been treated by radical operation without adjuvant chemotherapy. RESULTS: Mutations in KRAS, BRAF or PIK3CA were associated with poor prognosis, while the deficient DNA mismatch repair status was not associated with the prognosis. Combining these three markers, the sensitivity of the predicted value for poor progression-free survival and overall survival reached 0.645 (p = 0.002) and 0.709 (p = 0.001), respectively. CONCLUSION: Knowing the mutation status of KRAS, BRAF or PIK3CA in stage II colorectal cancer can significantly improve the accuracy of prognoses.

Overexpression of MSK1 is associated with tumor aggressiveness and poor prognosis in colorectal cancer.

BACKGROUND/AIMS: Mitogen- and stress-activated protein kinase 1 (MSK1) has recently been implicated in cell proliferation and neoplastic transformation. However, the involvement of MSK1 in colorectal cancer (CRC) has not been addressed. This study aimed to evaluate the expression and potential functions of MSK1 in CRC. METHODS: The MSK1 expression was investigated by immunohistochemistry, western blot and reverse transcription-polymerase chain reaction. The associations between clinicopathological characteristics and MSK1 expression were assessed. Kaplan-Meier analysis and Cox regression models were carried out. CRC cells with MSK1 knockdown or overexpression were generated. A range of experiments were performed to demonstrate MSK1's role in CRC. RESULTS: MSK1 was overexpressed in 148 out of 329 CRC patients. CRC patients with high MSK1 expression had shorter overall survival than those with low MSK1 (P=0.033), especially among patients with stage III tumors (P=0.005). Knockdown of MSK1 in CRC cells suppressed cell proliferation, anchorage-independent growth, migration and invasion, and promoted 5-fluorouracil chemosensitivity and intracellular NADP+/NADPH ratio. However, overexpression of MSK1 had the opposite effects. CONCLUSIONS: Overexpression of MSK1 is associated with poor prognosis in CRC and is connected to tumor aggressiveness. MSK1 is a potential target for new therapies and a candidate of biomarker for prognosis.

Alternative splicing of spleen tyrosine kinase differentially regulates colorectal cancer progression.

Spleen tyrosine kinase (SYK) has been reported as a potential tumor suppressor in colorectal cancer (CRC). However, the role of alternative splicing of SYK in carcinogenesis remains unclear. In the present study, SYK isoforms were overexpressed in the human CRC HCT 116 cell line using lentiviral expression vectors to investigate the biological functions of full length SYK [SYK(L)] and short form SYK [SYK(S)] in CRC. Real-time cellular analysis and the 5-ethynyl-2-deoxyuridine assay were used to detect the effects of SYK(L) and SYK(S) on cell proliferation. Cell cycle progression and migration were assessed via flow cytometry and Transwell assays, respectively. The results revealed that the recombinant lentivirus with SYK(L) overexpression significantly suppressed the proliferation and metastasis of CRC cells, while SYK(S) overexpression did not. In addition, MTS assays demonstrated that SYK(L) and SYK(S) increased the cellular sensitivity to 5-fluorouracil (5-FU), suggesting that SYK(L) and 5-FU produce a significant synergistic effect on CRC cell proliferation, while SYK(S) has an effect on modulating CRC 5-FU sensitivity. Furthermore, quantitative polymerase chain reaction results revealed that SYK(L) was downregulated in 69% of 26 pairs of CRC and adjacent non-cancerous tissues, whereas SYK(S) exhibited no significant differences between tumor and normal tissues. Overall, the present data provides evidence that SYK(L) is a tumor suppressor in CRC, and both SYK(L) and SYK(S) may serve as important predictors in the chemotherapeutic treatment of CRC.