[Association between serum levels of S100A8/S100A9 and clinical features of colorectal cancer patients].

OBJECTIVE: To analyze the association between serum levels of S100A8/S100A9 and clinicopathological features of colorectal cancer patients.
 METHODS: A total of 82 patients with CRC and 14 healthy controls were enrolled for this study. The levels of S100A8 and S100A9 in serum were detected by ELISA assay. The association between S100A8/S100A9 and clinicopathological features was analyzed by student-t test and one-way ANOVA. Receiver Operating Characteristic curve was used to analyze diagnostic efficiency of serum S100A8 and S100A9 for colon rectal cancer. Logistic regression model was also established to analyze the possible risk factors for elevation of S100A8/S100A9.
 RESULTS: The levels of S100A8 and S100A9 were (1 403.3±593.7) and (2 890.3±994.9) pg/mL in patients with colon cancer, and (712.8±265.3) and (1 492.7±564.6) pg/mL in controls, respectively, with significant difference between the two groups (P<0.01). The similar results were found in rectal cancer patients, with a level of S100A8 and S100A9 at (1 417.7±666.5) and (3 026.7±887.6) pg/mL, respectively. Diagnostic sensitivity and specificity of S100A8 and S100A9 are better than traditional biomarkers. The levels of S100A9 in serum of CRC patients were correlated with clinical stages and distant metastasis. Serum levels of S100A9 in patients of stage III [(3 111.9±178.5) pg/mL] and stage IV [(3 831.4±278.5) pg/mL] were significantly (P<0.01) higher than that in stage I [(2 276.1±167.4) pg/mL], whereas there was significant change in S100A8 levels. Logistic regression showed the possible risk factors for the elevation of S100A9, including depth of invasion, lymphatic metastasis and degree of differentiation (P<0.05).
 CONCLUSION: Serum level of S100A8 and S100A9 in CRC patients were significantly increased and serum level of S100A9 was positively correlated with the malignant features of CRC.

[Exendin-4 promotes paracrine action of adipose-derived stem cells through PI3K/Akt signaling pathways].

OBJECTIVE: To investigate the mechanism by which exendin-4 promotes paracrine secretion of cytokines by adipose-derived stem cells (ADSCs). METHODS: In vitro cultured SD rat ADSCs (fourth passage) with or without exendin-4 treatment underwent flow cytometry to characterize the surface markers. MTT assay was performed to assess the proliferation of the cells exposed to different concentrations (0-20 nm/L) of exendin-4, and the paracrine secretion of cytokines (bFGF, VEGF, HGF, and IGF-1) by the ADSCs was evaluated by qPCR. The changes in the expressions of p-Akt in the cells were analyzed by Western blotting and qPCR in response to exendin-4 (10 nm/L) with or without exposure to PI3K/Akt inhibitor LY-294002 (50 nm/L); bFGF, VEGF, HGF, and IGF-1 production in the cells were detected using ELISA kits. RESULTS: Treatment with exendin-4 for 12 h did not affect the surface marker profile of the ADSCs but promoted the cell proliferation (P<0.05). Exendin-4 significantly increased the mRNA expressions of VEGF, bFGF, HGF, and IGF-1 in a concentration-dependent manner, and 10 nm/L was the optimum concentration (P<0.05). Exendin-4 treatment resulted in significantly increased p-Akt expressions in the ADSCs, and PI3K/Akt inhibitor not only reversed such effects of exendin-4 on p-Akt but also diminished the exendin-4- mediated up-regulation of the paracrine cytokines. CONCLUSION: Exendin-4 can concentration-dependently promote the proliferative and paracrine capacities of ADSCs partially through the PI3K/Akt signaling pathway without affecting the surface marker profile of the cells.