AIM: To investigate the expression of objective gene and the immunosuppressive effect of naked DNA vaccine pγ1.Ig H.SPTT targeting tissue factor by intrasplenic inoculation on colorectal cancer ( CRC) .METH-ODS:A special naked DNA vaccine which carried the SPTT peptides and immunoglobulin H chain gene ( named pγ1.Ig H.SPTT DNA plasmid ) was constructed by molecular biological techniques .After a single injection of this plasmid into the spleen, the concentrations of transgene product SPTT-Ig H in the peripheral blood at different time points were detected by ELISA, and the plasmid transfection efficiency and characteristics were analysis by PCR and Southern blotting .The immu-nologic effect of the plasmid on the CRC was observed in the mice .RESULTS:The strongest expression of SPTT-Ig H was observed during the 4th week after a single injection of the plasmid , which began to decline at the 12th week and disap-peared at the 16th week.The concentration of SPTT-Ig H in the peripheral blood at the 2nd week after transfection of plas-mid was 7.2 μg/L, then increased gradually , and reached a peak of 13.11μg/L at the 8th week.The plasmid-transcrip-tional gene was only expressed in the spleen , and was not detected in the lymph nodes , bone marrow, liver, kidney, and other organisms.Transfection of pγ1.Ig H.SPTT into the spleen had inhibitory effects on colorectal cancer as compared with control group .CONCLUSION:Naked DNA vaccine pγ1.Ig H.SPTT stimulates the immune response for protecting the body against colorectal cancer , which is a safe and effective method for CRC immunotherapy .

OBJECTIVETo compare fecal microbiota and metabolites between colorectal cancer (CRC) patients and healthy population.

METHODSFeces from fifteen CRC patients and twelve normal people were analyzed by using pyrosequencing and gas chromatography mass spectrometry(GC/MS).

RESULTSThere were no significant differences in the overall microbial community structure associated with the disease state, but 18 bacterial genera were underrepresented or overrepresented in the CRC samples. GC-MS profiling revealed higher concentrations for 9 kinds of amino acids and metabolites of short-chain fatty acids, lower concentrations for 3 kinds of unsaturated fatty acids and 2 kinds of glycerin and ursodeoxycholic acid in stool samples from CRC patients. Correlative analysis between the combined datasets revealed some potential relationships between stool metabolites and certain bacterial species.

CONCLUSIONSThere are significant differences in fecal metabolites and the relative abundance of certain types of bacteria between CRC patients and healthy people, which can provide insight into microbial functions occurring in a cancer environment and will help direct future mechanism studies.