Chemical Modification Of Jasmonates And The Study Of Their Anticancer Effects On Human Cancer Cells

Objective:To design, synthesize and purify the jasmonic acid-TAT cell penetrating peptide conjugate.Methods:The cross-linker was synthesized based on Maleic anhydride. Carboxyl terminal of jasmonic acid was coupled to the cross-linker through the ester link. FITC-labeled TAT cell penetrating peptide was synthesized by manual solid phase peptide synthesis technique, and was linked to jasmonic acid-intermediate with sulfide bond through fixation reaction.Results:Identified by H NMR, jasmonic acid was successfully linked to intermediate. Identified by high performance liquid chromatography, the purity of newly synthesized TAT-FITC peptide and jasmonic acid-TAT penetrating peptide conjugate was more then 95%. Identified by mass spectrometry, the molecular ion peak of TAT-FITC peptide and jasmonic acid-TAT penetrating peptide conjugate was consistent with the expectations.Conclusion:Jasmonic acid-TAT penetrating peptide conjugate was successfully synthesized for further study of the anti-tumor activity. Objective:To study of the anticancer effects and the mechanism of jasmonic acid-TAT cell penetrating peptide conjugateon on human cancer cells.Methods:After administration of 0.5-2 mmol·L-1 jasmonates and jasmonic acid-TAT cell penetrating peptide conjugate for 6～24 hrs, the activity of EJ and PC-3 cells were studied by MTT colorimetry. Cell proliferation was assayed by colony formation assay. Cellular apoptosis was inspected by Hoechst 33258 fluorescent staining and was quantified by nnexinV-Phycoerythrin (PE) and 7-amino-actinomycin D (7-AAD) staining flow cytometry. The expression of XIAP mRNA was determined by realtime reverse transcription polymerase chain reaction. The level of XIAP, caspase-3 and caspase-9 protein was determined by western -blot. After administration of jasmonic acid-TAT cell penetrating peptide conjugate in subcutaneous tumor model of nude mice, tumor size and weight were measured, and apoptosis of tumor cells was detected by TUNEL staining.Results:Jasmonic acid-TAT cell penetrating peptide conjugate was as effective as TAT cell penetrating peptide peptide sequence in attaching onto surface of the cell membrane and sufficiently internalized in EJ and PC3 cells. Jasmonates inhibited the growth of EJ and PC-3 cells in a dose- and time-dependent manner, while the jasmonic acid-TAT cell penetrating peptide conjugate showed significant enhanced efficient. After administration of 0.05 mmol·L-1 of jasmonic acid-TAT cell penetrating peptide conjugate for 24 hrs, cell clone formation rate was significantly decreased and apoptotic cells were significantly increased. The expression of both XIAP mRNA and XIAP protein were down-regulated by administration of jasmonic acid-TAT cell penetrating peptide conjugate,while the XIAP gene transcription activity was not affected. Compared with the control group given PBS, jasmonic acid-TAT penetrating peptide conjugate inhibited tumor growth rate by 85.6% (P <0.05) and TUNEL staining showed positive nuclear staining of apoptotic cells increased significantly.Conclusion:The results indicated that jasmonic acid-TAT penetrating peptide conjugate inhibit the growth of cancer cells through suppressing cell proliferation, downregulating the expression XIAP might be one of its molecular mechanisms.