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@#[Abstract] Objective: To explore the anti-tumor activity of MUC16-targeted chimeric antigen receptor modified NK-92 (CARNK-92) cells against ovarian cancer. Methods: The expression of MUC16 in surgically resected tumor tissues of 15 patients with ovarian cancer treated in the Department of Obstetrics and Gynecology of Qingyang Hospital of Traditional Chinese Medicine and 4 ovarian tumor cell lines was detected by Immunohistochemistry and Flow cytometry. MUC CAR sequence was synthesized by gene synthesis, and its lentivirus expression vector were constructed. CARNK-92 cells targeting MUC16 (MUC-BBz) were obtained by lentivirus infection. The expression of CD107a in MUC-BBz was detected by Flow cytometry. The activation of MUC-BBz cells and its cytotoxicity against SKOV3 target cells were characterized by the release of LDH assay. The xenograft nude mouse model of SKOV3 cells was established to verify the in vivo anti-tumor activity of MUC-BBz cells. Results: MUC16 was highly expressed in ovarian cancer tissues and human ovarian cancer cells. MUC-BBz was successfully constructed by infecting NK-92 cells with lentivirus, with a positive rate of (42.79±2.58)%. MUC-BBz could be specifically activated by MUC16 over-expressing tumor cells. After co-incubation of effector cells and target cells, the expression of CD107a on MUC-BBz was upregulated significantly (P<0.01), and the ability of MUC-BBz secreting cytokines IFN-γ and perforin also increased (all P<0.01). The LDH test indicated that with the increase of effector-target ratio, the cytotoxicity of MUC-BBz against 4 ovarian cancer cells (hey, COC1, SKOV3 and A2780) also significantly enhanced. The results of transplanted tumor model showed that transfusion of MUC-BBz could significantly inhibit the growth of SKOV3 xenograft in mice (P<0.01). Conclusion: The CARNK-92 cells can significantly inhibit the growth of ovarian cancer cells in vitro and in vivo, which provides an important basis for further evaluation of its clinical application.
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@#[Abstract] Objective: To investigate the effect of IL-27 in combination with IL-15 on the anti-tumor effects of NK92 cells and the possible molecular and signaling mechanisms. Methods: NK92 cells with high IL-15 expression (IL-15-NK92 cells) were cultured in different mass concentrations of IL-27 (0, 10, 20, 30 and 60 ng/ml) for 24 h. The effects of IL-27 on IL-15 secretion, migration and proliferation of IL-15-NK92 cells were detected by ELISA, Transwell and CCK-8 assay, respectively. Flow cytometry was used to detect the expression levels of IL-15-NK92 cell surface receptors NKG2D, NKp30 and NKp46, as well as the secretion levels of perforin and granzyme B. LDH method was used to detect the cytotoxic effect of IL-15-NK92 cells on hematologic tumor cells and solid tumor cells, and WB was used to detect the expressions and phosphorylation level of STATs pathway-related proteins. Results: IL-27 at the concentration of 30 ng/ml promoted IL-15-NK92 cells secreting IL-15 (P<0.01), significantly enhanced the cell migration (P<0.05) but inhibited the proliferation of IL-15-NK92 cells (P<0.05). 30 ng/ml IL-27 could significantly promote the expressions of NKG2D, NKp30 and NKp46 on surface of IL-15-NK 92 cells, as well as elevate the secretion of perforin (all P<0.05), but didn’t affect the secretion of granzyme B (P>0.05); moreover, it also significantly enhanced the cytotoxicity of IL-15-NK92 cells against hematologic malignancies and solid tumor cells (P<0.05 or P<0.01), and up-regulated the phosphorylation levels of STAT1, STAT3 and STAT5 (all P<0.01). Conclusion: IL-27 can enhance the cytotoxicity of IL-15-NK92 cells against hematologic tumor cells and solid tumor cells, which might be related with its upregulation of phosphorylation level of STAT1, STAT3 and STAT5 in JAK-STAT pathway and multiple activating receptors in IL-15-NK92 cells.
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@#[Abstract] Objective: To construct and verify the anti-tumor activity of chimeric antigen receptor (CAR) modified NK-92 cells (CAR-NK-92 cells) targeting prostate stem cell antigen (PSCA) in cervical cancer. Methods: Lentiviral vector expressing CAR targeting PSCA was constructed, and PSCA CAR-NK-92 cells were obtained by lentivirus transfection. The expression of PSCA in human cervical cancer cells was determined by Flow cytometry and Western blotting. The killing effect of PSCA CAR-NK-92 cells against cervical cancer cells was verified by co-incubation of effector and target cells in vitro, and the tumor inhibitory ability of PSCA CAR-NK-92 cells was verified with the nude mice xenograft model in vivo. Results: PSCA CAR-NK-92 cells were successfully constructed. PSCA was highly expressed in human cervical cancer Hela and MS751 cells (all P<0.01). In vitro co-incubation results showed that PSCA CAR-NK-92 cells could lyse PSCA+ cervical cancer transplanted tumor in a dose-dependent manner. In vivo anti-tumor data showed that PSCA CAR-NK-92 cells significantly inhibited the growth of cervical cancer cells compared with NK-92 cells transfected with vehicle vectors (P<0.01). In addition, PSCA CAR-NK-92 cells could effectively infiltrate tumor tissues and promote the secretion of anti-tumor cytokines TNF-α and IFN-γ (all P<0.01). Conclusion: The CAR-NK-92 targeting PSCA shows good anti-tumor effect on PSCA+ tumor cells both in vitro and in vivo, and has potential to be a therapeutic strategy for cervical cancer.
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@#[Abstract] Objective: To construct CD33-CAR modified NK92 cells based on CD33-scFv sequence, and to explore its killing effect on CD33+ AML (acute myeloid leukemia) cells. Methods: DNA fragment encoding CD33-CAR was synthesized by gene synthesis and molecular cloning technology and then cloned into lentiviral vector. Lentivirus were packaged and used to transfect NK92 cells. The transfection efficiency was detected by flow cytometry, and puromycin was used to screen NK92 cells stably expressing CD33-CAR (CD33-CAR-NK92). Killing effect of CD33-CAR-NK92 cells on AML cells in vitro was examined with calcein-AM release assays. IFN-γ secretions of NK92 cells and CD33-CAR-NK92 cells were measured by ELISA. Results: The pCDH-CD33-CAR lentiviral vector was successfully constructed. After lentiviral transfection, about 18.7% of NK92 cells express CD33-CAR (referred as CD33-CARNK92 cells). The percentage of CD33-CAR+ NK92 cells was about 86.3% after puromycin selection. In contrast to unmodified NK92 cells, significantly higher cytotoxic effect against CD33+ MOLM-13 cells was found in CD33-CAR-NK92 cells (P<0.01); however, there was no significant difference in cytotoxicity against CD33- JURKAT cells between NK92 cells and CD33-CAR-NK92 cells (P> 0.05). After co-culture at an effect-target ratio of 2∶1 for 6 hours, the level of IFN-γ secreted by the CD33-CAR modified NK92 cells was significantly higher than that of the unmodified ([190.97±11.52] vs [88.41±2.75]pg/ml, P<0.01). Conclusion: The CD33-CARNK92 cells could specifically recognize CD33 antigen and kill CD33+ AML cells in comparison with the unmodified NK92 cells, which provides experimental basis for clinical transformation of CD33-CAR-NK92 cells in treatingAML.