Objective To study the in vitro anti-tumor activity of dendritic cells (DCs) loading with antigen produced by radiofrequency ablation of tumor lysate in situ combined with cytokine-induced killer cells (CIK).Methods CIK ceils derived from BALB/C mouse spleen and DCs derived from bone marrow were prepared,and experimental model of murine colon carcinoma were established for radiofrequency ablation.The supernatant of tumor tissue in situ lysis after repeated freezing and thawing were tested by lowry protein quantitative statutory,amounting to a final concentration of 5 μg/ml,then load to the first 5 days of culture DCs (Ag-DC),2 days later,co-cultured with CIK cells after the first seven days of culture 48 h (Ag-DC-CIK).Flow cytometry was used to analyze costimulatory molecules on the surface of the cells,and CCK-8 assay to detect in vitro cytotoxic activity.Results The DCs loading with antigen resulted in an increase in the proportion of CD86 + CD11 c +,MHC Ⅱ + CD11 c + and MHC Ⅱ + CD80 + cells.The main effector cells of CIK cells were CD3 + NK1.1 + cells.The percentage of CD3 + NK1.1 + cells was 1.45％ on the first day of the culture ; while when they had been cultured for 7 days,the percentage CD3 + NK1.1 + significantly increased to 36.9％.The cytotoxicity of Ag-DC-CIK cells toward C26 cells was much more efficient than that of DC-CIK,CIK cells.The cytotoxic activity of the former was significantly lower than the latter and the same target ratio.When the ratios of effector cells to target cells were 5 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (74.9 ± 3.5) ％,; while the DC-CIK was (71.2 ± 2.1) ％ and the CIK cells was (68.7 ± 2.9) ％.The difference was statistically significant(F =7.007,P =0.007).When the ratios of effector cells to target cells were 10 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (82.3 ± 4.5) ％,while the DC-CIK cells was (77.1 ± 5.1) ％,and the CIK cells was (72.7 ± 2.8) ％.The difference was statistically significant (F =7.727,P =0.005).When the ratios of effector cells to target cells were 20 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (83.2 ± 1.9) ％,while the DC-CIK cells was (77.2 ± 4.2) ％,and the CIK cells was (73.0 ± 2.6) ％.The difference was statistically significant (F =16.594,P =0.000).Conclusion DCs loading with antigen produced by radiofrequency ablation of tumor in situ pyrolysis products can improve in vitro cytotoxic activity combined with CIK cells,which can provide a new comprehensive cancer treatment strategy.

Objective:To investigate the risk factors and prognostic indicators of radioactive iodide refractory (RAIR) in differentiated thyroid cancer (DTC) with distant metastasis (DM).Methods:From January 2007 to November 2023, 140 DM-DTC patients who received 131I therapy in JiangYuan Hospital Affiliated to Jiangsu Institute of Nuclear Medicine were retrospectively conducted. According to the effect of 131I treatment, 84 cases in the RAIR group and 56 cases in the radioactive iodide efficient (RAIE) group were finally included. The general clinical data, B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E and telomerase reverse transcriptase promoter (TERTp) mutations were compared between the two groups by independent-sample t test, Mann-Whitney U test and χ2 test. Multiple logistic regression was used to analyze the influencing factors of RAIR. Results:There were significant differences between the RAIR group and the RAIE group in age, age≥55 years, tumor maximum diameter, cumulative dose of radioactive iodide, type of metastasis and preoperative thyroglobulin (pre-Tg) ( χ2 values: 7.78 and 9.03, t values: 2.44-2.74, z=-3.92, all P<0.05). The TERTp mutation rate in RAIR group was 39.39%(26/66), which was significantly higher than that in RAIE group (2.17%(1/46); χ2=20.97, P<0.001). The BRAF V600E mutation rate was 41.79%(28/67) in the RAIR group and 40.00%(20/50) in the RAIE group, with no significant difference ( χ2=0.04, P=0.846). Logistic regression analysis found that high pre-Tg level and TERTp mutation were independent risk factors for RAIR occurrence. Conclusion:TERTp mutation and high pre-Tg level are independent risk factors for RAIR occurrence, and they may be potential indicators for predicting RAIR.