Preparation and characterization of starch/PBAT film containing hydroxypropyl-ß-cyclodextrin/ethyl lauroyl arginate/cinnamon essential oil microcapsules and its application in the preservation of strawberry.

Cinnamon essential oil (CEO) was emulsified by hydroxypropyl-ß-cyclodextrin/ ethyl lauroyl arginate (HPCD/LAE) complex to make nanoemulsions, which were then incorporated into maltodextrin (MD) to prepare HPCD/LAE/CEO/MD microcapsules by spray drying. The starch/polybutylene adipate terephthalate (starch/PBAT, SP) based extrusion-blowing films containing above microcapsules were developed and used as packaging materials for strawberry preservation. The morphology, encapsulation efficiency, thermal and antibacterial properties of microcapsules with different formulations were investigated. The effects of microcapsules on the physicochemical and antimicrobial properties of SP films were evaluated. When the formula was 4 % HPCD/LAE-3% CEO-10% MD (HL-3C-MD), the microcapsule had the smallest particle size (3.3 µm), the highest encapsulation efficiency (84.51 %) of CEO and the best antibacterial effect. The mechanical and antimicrobial properties of the SP film were enhanced while the water vapor transmittance and oxygen permeability decreased with the incorporation of HL-3C-MD microcapsules. The films effectively reduced the weight loss rate (49.03 %), decay rate (40.59 %) and the total number of colonies (2.474 log CFU/g) and molds (2.936 log CFU/g), thus extending the shelf life of strawberries. This study revealed that the developed SP films containing HPCD/LAE/CEO microcapsules had potential applications in degradable bioactive food packaging materials.

Immunotherapy-based novel nanoparticles in the treatment of gastrointestinal cancer: Trends and challenges.

Gastrointestinal cancer (GIC) is the most common cancer with a poor prognosis. Currently, surgery is the main treatment for GIC. However, the high rate of postoperative recurrence leads to a low five-year survival rate. In recent years, immunotherapy has received much attention. As the only immunotherapy drugs approved by the Food and Drug Administration (FDA), immune checkpoint blockade (ICB) drugs have great potential in cancer therapy. Nevertheless, the efficacy of ICB treatment is greatly limited by the low immunogenicity and immunosuppressive microenvironment of GIC. Therefore, the targets of immunotherapy have expanded from ICB to increasing tumor immunogenicity, increasing the recruitment and maturation of immune cells and reducing the proportion of inhibitory immune cells, such as M2-like macrophages, regulatory T cells and myeloid-derived suppressor cells. Moreover, with the development of nanotechnology, a variety of nanoparticles have been approved by the FDA for clinical therapy, so novel nanodrug delivery systems have become a research focus for anticancer therapy. In this review, we summarize recent advances in the application of immunotherapy-based nanoparticles in GICs, such as gastric cancer, hepatocellular carcinoma, colorectal cancer and pancreatic cancer, and described the existing challenges and future trends.

Identification and analysis of a CD8+ T cell-related prognostic signature for colorectal cancer based on bulk RNA sequencing and scRNA sequencing data: A STROBE-compliant retrospective study.

Colorectal cancer (CRC) is one of the most common malignancies worldwide, leading to a large number of cancer-related mortalities. Aberrant CD8+ T cell infiltration plays a critical role in tumor progression and patient prognosis. This study aimed to identify a prognostic model for CRC based on CD8+ T cell-related genes. The infiltration levels of immune cells in CRC tissues were accessed by the ESTIMATE algorithm. Weighted gene co-expression network analysis (WGCNA) analysis was used to select CD8+ T cell-related genes. Prognostic genes were identified using Cox regression analysis and Kaplan-Meier curves. The least absolute shrinkage and selection operator (LASSO) algorithm was used to construct prognostic models. Gene set enrichment analysis (GSEA) was performed to annotate enriched gene sets. Single-cell RNA (scRNA) sequencing analysis was used to examine gene expression in different cell types. We found that the downregulated infiltration level of CD8+ T cells was an independent prognostic factor for CRC and selected a cluster of differentially expressed genes correlated with CD8+ T cell infiltration (CD8TDEGs). Subsequently, we identified 18 prognostic CD8TDEGs, according to which patients were reclassified into two clusters with distinct overall survival. Seven prognostic CD8TDEGs were selected to calculate the constructed prognostic model's risk scores. Interestingly, although CRC tissues with higher risk scores had higher infiltration levels of CD8+ T cells, the level of immune checkpoint genes was also high. Moreover, the scRNA-sequencing analysis showed that the expression levels of CD8TDEGs in the prognostic model varied among different types of cells. This study constructed a novel prognostic model for CRC and provided a foundation for targeting CD8+ T cell infiltration to improve the survival of CRC patients.

Characterization of chitosan film with cinnamon essential oil emulsion co-stabilized by ethyl-Nα-lauroyl-l-arginate hydrochloride and hydroxypropyl-ß-cyclodextrin.

To improve the antimicrobial properties of chitosan films, cinnamon essential oil (CEO) nanoemulsion (1% and 3% v/v CEO) stabilized by ethyl-Nα-lauroyl-l-arginate hydrochloride (LAE) alone or co-stabilized by LAE and hydroxypropyl-ß-cyclodextrin (HPCD) were incorporated into chitosan matrix. The micromorphology, physical and antimicrobial properties of the composite films were compared. The dense structure of the CEO nanoemulsion co-stabilized by LAE and HPCD reduced the water vapor permeability and water content. The incorporation of the CEO nanoemulsion co-stabilized by LAE and HPCD, reduced the adverse effects of CEO on the mechanical properties and microstructure of the film, and even slightly increased the tensile strength. In addition, the antimicrobial properties of chitosan films were enhanced due to the encapsulation and emulsification effect of HPCD and LAE on CEO. This work indicated that the prepared chitosan based edible films had the potential to be used in the field of food packaging to improve food safety.

MicroRNA­592 promotes cell proliferation, migration and invasion in colorectal cancer by directly targeting SPARC.

Colorectal cancer (CRC), one of the most common cancer types, causes a large number of cancer­related mortalities annually worldwide. Dysregulated microRNAs (miRNAs/miR) are closely associated with the malignant progression of CRC. Therefore, the present study aimed to investigate the expression and regulatory role of miR­592 in CRC. It was found that miR­592 expression was significantly elevated in CRC tissues and cell lines, and was associated with the prognosis of patients. Cellular phenotype assays demonstrated that miR­592 could promote CRC cell proliferation, migration and invasion. Bioinformatics analysis demonstrated that miR­592 mainly participated in the positive regulation of transcription, as well as the regulation of cell motility. Moreover, miR­592 targets were enriched in several signaling pathways, such as the 'mTOR' and 'FoxO' signaling pathways. In addition, secreted protein acidic and rich in cysteine (SPARC) was identified as a target of miR­592 in CRC. The present results suggested that miR­592 acts as an oncogene in CRC, in part, by directly inhibiting SPARC expression. Collectively, the present study provides a novel potential therapeutic strategy for CRC.

A novel Diels-Alder adduct of mulberry leaves exerts anticancer effect through autophagy-mediated cell death.

Guangsangon E (GSE) is a novel Diels-Alder adduct isolated from leaves of Morus alba L, a traditional Chinese medicine widely applied in respiratory diseases. It is reported that GSE has cytotoxic effect on cancer cells. In our research, we investigated its anticancer effect on respiratory cancer and revealed that GSE induces autophagy and apoptosis in lung and nasopharyngeal cancer cells. We first observed that GSE inhibits cell proliferation and induces apoptosis in A549 and CNE1 cells. Meanwhile, the upregulation of autophagosome marker LC3 and increased formation of GFP-LC3 puncta demonstrates the induction of autophagy in GSE-treated cells. Moreover, GSE increases the autophagy flux by enhancing lysosomal activity and the fusion of autophagosomes and lysosomes. Next, we investigated that endoplasmic reticulum (ER) stress is involved in autophagy induction by GSE. GSE activates the ER stress through reactive oxygen species (ROS) accumulation, which can be blocked by ROS scavenger NAC. Finally, inhibition of autophagy attenuates GSE-caused cell death, termed as "autophagy-mediated cell death." Taken together, we revealed the molecular mechanism of GSE against respiratory cancer, which demonstrates great potential of GSE in the treatment of representative cancer.

A Novel Benzofuran Derivative Moracin N Induces Autophagy and Apoptosis Through ROS Generation in Lung Cancer.

INTRODUCTION: The leaves of Morus alba L is a traditional Chinese medicine widely applied in lung diseases. Moracin N (MAN), a secondary metabolite extracted form the leaves of Morus alba L, is a potent anticancer agent. But its molecular mechanism remains unveiled. OBJECTIVE: In this study, we aimed to examine the effect of MAN on human lung cancer and reveal the underlying molecular mechanism. METHODS: MTT assay was conducted to measure cell viability. Annexin V-FITC/PI staining was used to detect cell apoptosis. Confocal microscope was performed to determine the formation of autophagosomes and autolysosomes. Flow cytometry was performed to quantify cell death. Western blotting was used to determine the related-signaling pathway. RESULTS: In the present study, we demonstrated for the first time that MAN inhibitd cell proliferation and induced cell apoptosis in human non-small-cell lung carcinoma (NSCLC) cells. We found that MAN treatment dysregulated mitochondrial function and led to mitochondrial apoptosis in A549 and PC9 cells. Meanwhile, MAN enhanced autophagy flux by the increase of autophagosome formation, the fusion of autophagsomes and lysosomes and lysosomal function. Moreover, mTOR signaling pathway, a classical pathway regualting autophagy, was inhibited by MAN in a time- and dose-dependent mannner, resulting in autophagy induction. Interestingly, autophagy inhibition by CQ or Atg5 knockdown attenuated cell apoptosis by MAN, indicating that autophagy serves as cell death. Furthermore, autophagy-mediated cell death by MAN can be blocked by reactive oxygen species (ROS) scavenger NAC, indicating that ROS accumulation is the inducing factor of apoptosis and autophagy. In summary, we revealed the molecular mechanism of MAN against lung cancer through apoptosis and autophagy, suggesting that MAN might be a novel therapeutic agent for NSCLC treatment.

Effects of zein stabilized clove essential oil Pickering emulsion on the structure and properties of chitosan-based edible films.

Clove essential oil (CLO) Pickering emulsions were prepared with zein colloid particles as stabilizer, and the effects of CLO Pickering emulsion incorporation on the structure, mechanical, barrier and antimicrobial properties of chitosan-based edible films were explored. CLO Pickering emulsions with 3% w/v zein and 50% v/v CLO had smaller particle size and more even distribution. Incorporation of CLO Pickering emulsion in the films decreased the water vapor permeability and tensile strength, but the elongation at break firstly increased then decreased with the maximum value of 19.2% when the content of emulsion was 0.4%. Scanning electron microscopy revealed the formation of microstructure-sized holes in the films by the addition of CLO Pickering emulsion. The emulsified oil droplets were uniformly distributed, due to the good compatibility between oil phase and chitosan matrix. The antimicrobial properties of the films were strengthened by CLO Pickering emulsion incorporation and mainly depended on its concentration.

Characterization of chitosan based polyelectrolyte films incorporated with OSA-modified gum arabic-stabilized cinnamon essential oil emulsions.

Octenyl succinic anhydride (OSA) modified gum arabic (GA) was synthesized and used as an emulsifier to stabilize cinnamon essential oil (CEO) emulsions. The structure and properties of chitosan based polyelectrolyte films incorporated with above OSA-GA stabilized CEO emulsions were investigated. Results showed that OSA modification introduced the hydrophobic groups, which greatly influenced the emulsification capability of GA. The antimicrobial activities of CEO emulsions were significantly enhanced by the synergistic effect of GA modification and ultrasonic treatment. When the proportions of CEO emulsion increased, the improved water barrier properties but deteriorated tensile properties of films were observed. The retention of CEO during storage was prolonged to 20 days and the release of CEO in food simulant was effectively inhibited as emulsion ratios increased to 20%, indicating the effectiveness of the system for CEO delivery. As a result, the antimicrobial activities of films significantly enhanced with the innovative incorporation of OSA-GA stabilized CEO emulsions.

Structure, physical and antioxidant properties of chitosan-gum arabic edible films incorporated with cinnamon essential oil.

Active films based on chitosan (CS) and gum arabic (GA) incorporated with cinnamon essential oil (CEO) have been developed, and the effect of CS/GA ratios on the film structure, physical and antioxidant properties were investigated. Possible interactions among CS, GA and CEO was evaluated using rheological studies, Fourier transform infrared Spectroscopy (FT-IR) and X-ray diffraction (XRD). These results showed that there existed electrostatic interactions between CS and GA, which led to the formation of entangled structure. The addition of GA enhanced the water barrier properties of films, while it became less resistant to breakage and stretching. Confocal laser scanning microscopy (CLSM) results confirmed the higher CEO retention in films. Greatly enhanced antioxidant effectiveness were observed when the ratio of CS/GA changed from 1:0 to 1:2. However, when the ratio reached 1:4, the antioxidant capacity quickly decreased, which could be attributed to the negative influence of maximal interactions between CS and GA, leading to the loss of CEOs.

Evaluations of physicochemical and biological properties of pullulan-based films incorporated with cinnamon essential oil and Tween 80.

The effects of cinnamon essential oil (CEO) and Tween 80 addition on the structural, physical, antioxidant and antimicrobial properties of the pullulan-based edible films were investigated in this study. The results demonstrated that the incorporation of CEO in pullulan-based composite films decreased their tensile strength, transparency, water content and water vapor permeability, but considerably increased the antioxidant and antimicrobial properties. The films with 12% CEO exhibited the strongest antioxidant and antimicrobial capacities. With regard to the influences of Tween 80 on the films, SEM micrographs indicated that the submicroscopic micelle formed in the films by the addition of Tween 80. Tween 80 improved the stability of the composite films and reduced the loss of CEO, but weakened the physical properties including transparency and water barrier properties.

Development and preparation of active starch films carrying tea polyphenol.

Starch films incorporated with tea polyphenol (TP) were developed to produce active food packaging. The effect of the incorporation of TP with different content on the structure, physicochemical properties, antioxidant activity and antimicrobial activity of the starch films was systematically evaluated. Results showed that TP was well dispersed in the starch matrix, which induced a slight influence on the surface and barrier properties of the films. TP addition led to an important improvement in antioxidant capability, as well as inhibition efficiency against the microorganisms of S. aureus and E. coli. However, a decrease in mechanical properties of films was observed. Moreover, a new automatic counting method which combined the computer vision and machine learning algorithm was developed to identify and count the colonies, and the method performed much faster without subjective uncertainty.

Laponite crosslinked starch/polyvinyl alcohol hydrogels by freezing/thawing process and studying their cadmium ion absorption.

In this study, Laponite RD (LRD) cross-linked hydrogels consisting of starch, polyvinyl alcohol (PVA) were prepared by freezing/thawing process and the influence of LRD content on structure and properties of hydrogels was investigated. FTIR showed a new structure of hydrogen bonding might result from cross-linking reactions between LRD and polymers. X-ray diffraction (XRD) analysis showed that high degree of exfoliation of LRD clay layers had occurred during the preparation of hydrogels. The synergistic effect of physical cross-linking by freeze/thaw cycles and by LRD led to more porous, uniform and stable network, which was shown in SEM images. The melting temperature decreased and thermal stability got improved with the increase of LRD content. Reswelling ratios of hydrogels had the highest value when LRD content was 10%. Additionally, cadmium ion absorption capacity of the hydrogel was studied and the results showed that increasing the concentration of LRD increased absorption ratio and amount of Cd2+ ion in the solution. In a word, LRD could be used as a physical crosslinker and reinforced agent for starch-PVA based hydrogels and the formed hydrogels could be used as novel type and high capacity absorbent materials in heavy metal removing processes.

Irigenin sensitizes TRAIL-induced apoptosis via enhancing pro-apoptotic molecules in gastric cancer cells.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) holds promising value for cancer therapy due to its capacity to induce apoptosis in cancer cells. Nevertheless, TRAIL therapy is greatly hampered by its resistance. Irigenin (Iri), isoflavonoids, can be isolated from the rhizome of Belamcanda chinensis, and has been shown anti-cancer properties. In this study, we explored if Iri could enhance TRAIL-regulated apoptosis in TRAIL resistant gastric cancer cells. Iri significantly potentiated TRAIL-triggered cytotoxicity. Iri alone and TRAIL alone showed no effective role in apoptosis induction, whereas combined treatment with Iri and TRAIL markedly induced apoptosis in cancer cells, as evidenced by the up-regulation of cleaved Caspase-8/-9/-3 and PARP. Additionally, the sensitization to TRAIL was along with the enhancement of pro-apoptotic proteins, including FAS-associated protein with death domain (FADD), death receptor 5 (DR5) and Bax. And suppressing FADD, DR5 and Bax by si RNA significantly reduced the apoptosis and enhanced the cell viability induced by the co-application of Iri and TRAIL. Moreover, the sensitization to TRAIL was accompanied by the decrease of Cellular-FLICE inhibitory protein (c-FLIP), Bcl-2 and Survivin. Additionally, Iri could sensitize TRAIL to produce reactive oxygen species (ROS). Pre-treatment of N-acetyl-cysteine (NAC), ROS scavenger, attenuated Iri plus TRAIL-induced apoptosis and improved cell viability. Finally, combination of Iri and TRAIL inhibited tumor growth in the xenograft model. Collectively, our present study gave new insights into the effects of Iri on potentiating TRAIL-sensitivity, and suggested that Iri could be a potential candidate for sensitizer of TRAIL-resistant cancer cell treatment.

MicroRNA-615-5p targets insulin-like growth factor 2 and exerts tumor-suppressing functions in human esophageal squamous cell carcinoma.

To investigate the expression pattern, clinical significance and functional roles of microRNA (miR)-615-5p in human esophageal squamous cell carcinoma (ESCC), , quantitative real-time PCR was performed to detect expression levels of miR­615­5p in ESCC tissues and cell lines. Associations between miR­615­5p expression and various clinicopathological features of ESCC patients were also statistically evaluated. The candidate targets of miR­615­5p were identified by integrating bioinformatics miRNA target prediction, western blot analysis and luciferase reporter assay. Moreover, the functions of miR­615­5p in ESCC cell migration and invasion were determined using the transfection of miRNA mimics, or co-transfected with miRNA mimics and the expression vector of its target gene. As a result, miR­615­5p expression in ESCC tissues and cells were markedly lower than those in non-cancerous esophageal mucosa and human normal esophageal cells, respectively (both P<0.001). miR­615­5p downregulation was significantly associated with advanced tumor-node-metastasis stage, positive lymph node metastasis and moderate-poor differentiation. Functionally, the re-expression of miR­615­5p suppressed the invasion and migration of ESCC cells in vitro. Interestingly, insulin-like growth factor 2 (IGF2) was identified as a direct target gene of miR­615­5p, and the inhibitory effects of miR­615­5p in ESCC cell motility were reversed by the restoration of IGF2 expression. In conclusion, miR­615­5p downregulation may be an underlying molecular mechanism of development and progression of ESCC, and may function as a potential therapeutic target of this malignancy. Also, we illustrate that the miR­615­5p/IGF2 axis may bring important contributions to cell motility of human ESCC.

Prognostic value of combined and individual expression of microRNA-1290 and its target gene nuclear factor I/X in human esophageal squamous cell carcinoma.

BACKGROUND: microRNA (miR)-1290 was previously indicated to promote esophageal squamous cell carcinoma (ESCC) progression via regulating its target gene nuclear factor I/X (NFIX). OBJECTIVE: To investigate clinical significance of miR-1290 and NFIX in ESCC. METHODS: Quantitative real-time PCR was performed to detect miR-1290 and NFIX mRNA expression in ESCC tissues. Associations of miR-1290 and/or NFIX mRNA expression with various clinicopathological features and prognosis in ESCC patients were statistically evaluated. RESULTS: Compared to noncancerous esophageal mucosa, miR-1290 expression was upregulated, while NFIX mRNA expression was downregulated in ESCC tissues. There was a significantly negative correlation between miR-1290 and NFIX expression in ESCC tissues (r=-0.427, P= 0.01). Interestingly, miR-1290-high and/or NFIX-low expression were all significantly associated with positive lymph node metastasis and advanced tumor-node-metastasis stage of ESCC patients (all P< 0.05). Moreover, miR-1290 upregulation and NFIX downregulation both correlated short overall and disease-free survivals of ESCC patients. Importantly, the prognostic value of combined miR-1290 and NFIX expression was more significant than those considered alone. CONCLUSIONS: Our data suggest that the dysregulation of miR-1290-NFIX axis may play crucial roles in esophageal carcinogenesis and progression. We also confirmed miR-1290 and its target gene NFIX as independent prognostic factors for ESCC patients.

Combining TRAIL and liquiritin exerts synergistic effects against human gastric cancer cells and xenograft in nude mice through potentiating apoptosis and ROS generation.

Gastric cancer is one of the most factors, leading to cancer-related death worldwide. However, the therapies to prevent gastric cancer are still limited and the emergence of drug resistance leads to development of new anti-cancer drugs and combinational chemotherapy regimens. Our study was aimed to explore the anti-gastric cancer effects of liquiritin (LIQ), a major constituent of Glycyrrhiza Radix, which possesses a variety of pharmacological activities. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) preferentially inhibited tumor cells over other normal cells, when used in alone or in combination. The results indicated that LIQ, when applied in single, was moderately effective to suppress proliferation, and migration, as well as to induce apoptosis and reactive oxygen species (ROS) generation of human gastric cancer cell lines, AGS and SNU-216, which are TRAIL-resistant. Significantly, when used in combination, the two drugs functioned synergistically to impede the progression and growth of human gastric cancer cells in vitro and gastric cancer cell xenograft nude mice in vivo. Both intrinsic and extrinsic apoptosis were induced by the two in combination via activating Caspases. And c-Jun N-terminal kinase (JNK) activity was dramatically induced by TRAIL/LIQ. Importantly, TRAIL/LIQ-triggered apoptosis and JNK were dependent on ROS production. The data indicated that application of TRAIL/LIQ in combination had a potential value for clinical use to synergistically prevent human gastric cancer development.

MicroRNA-30d inhibits the migration and invasion of human esophageal squamous cell carcinoma cells via the post­transcriptional regulation of enhancer of zeste homolog 2.

The present study was carried out to investigate the expression pattern, clinical significance and biological functions of microRNA-30d (miR-30d) in esophageal carcinogenesis. Quantitative real-time PCR was performed to detect the expression levels of miR-30d in esophageal squamous cell carcinoma (ESCC) tissues and cell lines. Then, associations between miR-30d expression and various clinicopathological features of patients with ESCC were statistically evaluated. In addition, the effects of miR-30d on the migration and invasion of two human ESCC cell lines transfected with miRNA or co-transfected with miRNA mimics and the expression vector of its target gene were determined. The results revealed that the expression levels of miR-30d were markedly decreased in ESCC tissues and cell lines, comparing with the corresponding normal controls. Notably, reduced expression of miR-30d occurred more frequently in ESCC patients with positive lymph node metastasis, moderate-poor differentiation and advanced tumor-node-metastasis stage than those with negative features. Functionally, enforced expression of miR-30d was found to inhibit cell invasion and migration of the ESCC cell lines. Luciferase reporter assay identified enhancer of zeste homolog 2 (EZH2) as a direct target gene of miR-30d. The expression level of EZH2 mRNA was negatively correlated with the expression of miR-30d in the ESCC tissues. Moreover, the inhibitory effect of miR-30d on ESCC cell motility was reversed by EZH2 overexpression. Collectively, these findings provide convincing evidence that decreased expression of miR-30d may be implicated in esophageal carcinogenesis and progression. We also confirmed miR-30d as a tumor-suppressor which may inhibit cancer cell motility by targeting EZH2, a potential therapeutic target for ESCC.

Effect of Bcl-xL gene expression silenced by RNA interference on invasion of human colorectal cancer cells.

PURPOSE: To investigate the effect and possible mechanisms of Bcl-xL gene on the invasive capacity of human colon cancer cells. METHODS: HT29 human colorectal carcinoma cell line was transfected by small interfering RNA (siRNA) of Bcl-xL gene. Quantitative real-time (RT)-PCR and Western blot were used to detect the transfection, and soft agar colony culture experiments and Boyden chamber model test were used for cancer cell proliferation and invasion, respectively. Western blot was used to detect the protein changes of urokinase-type plasminogen activator (uPA) in cancer cells. RESULTS: Compared with the control group, the number of soft agar colonies and the number of penetrating membrane cells significantly reduced in the siRNA transfection group, and had dose-dependent characteristics; the uPA protein decreased significantly in the siRNA transfected cells. CONCLUSION: Bcl-xL gene may play an important role in the invasion of colon cancer cells, and the mechanism may be related to regulation of uPA expression.

Activation of P21-activated protein kinase 2 is an independent prognostic predictor for patients with gastric cancer.

OBJECTIVE: p21-activated kinase (PAK) 2, as a member of the PAK family kinases, is involved in a number of hallmark processes including cell proliferation, survival, mitosis, apoptosis, motility and angiogenesis. However, the clinical significance of the activation of PAK2 in human gastric cancer has not been fully elucidated. The aim of this study was to investigate whether PAK2 expression and its phosphorylation status are correlated with tumor progression and prognosis in gastric cancer. METHODS: Expression patterns and subcellular localizations of PAK2 and Ser20-phosphorylated PAK2 (pSer20PAK2) in 82 gastric cancer patients were detected by immunohistochemistry. RESULTS: Both PAK2 and pSer20PAK2 immunostainings were localized in the cytoplasm of tumor cells of gastric cancer tissues. Compared with the normal gastric mucosa, the expression levels of PAK2 and pSer20PAK2 proteins were both significantly increased (both P < 0.001). Additionally, the patients displaying the over-expression of PAK2 and pSer20PAK2 proteins were dramatically associated with unfavorable clinicopathologic variables including higher tumor depth (P = 0.022 and 0.036, respectively), greater extent of lymph node metastasis ((P = 0.022 and 0.036, respectively), positive distant metastasis (P = 0.025 and 0.038, respectively) and advanced tumor stage (P = 0.018 and 0.031, respectively). Moreover, the patients overexpressing PAK2 and pSer20PAK2 proteins have poor overall survival rates relative to those without overexpression of these proteins. Furthermore, cox multi-factor analysis showed that PAK2 (p = 0.012) and pSer20PAK2 (p = 0.010) were independent prognosis factors for human gastric cancer. CONCLUSION: Our data suggest for the first time that PAK2 activation may be associated with advanced tumor progression and poor prognosis of gastric cancer. VIRTUAL SLIDES: The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1236344107120406.