ABSTRACT
With a deepened understanding of the pathophysiology and pathogenesis of thoracic malignancies, the treatment has been transited from traditional treatment on the basis of surgery, radiotherapy, and chemotherapy to individualized and precise targeted therapy and immunotherapy. As an antitumor immunotherapy, chimeric antigen receptor gene-modified T (CAR-T) cells have been approved by the FDA for the treatment of hematological malignancies in five CAR-T products. They have also achieved good therapeutic effects in solid tumors. However, significant challenges remain in the clinical application of CAR-T cell immunotherapy in thoracic malignancies. In this review, the latest research progress of CAR-T cell immunotherapy in the treatment of thoracic malignancies were summarized, including the basic characteristics of CAR-T cells, the popular target antigens, and the existing problems and challenges, to provide new ideas and strategies for clinical immunotherapy of thoracic malignancies.
ABSTRACT
Objective:To explore the influence of bromodomain-containing protein 4 (BRD4) inhibitor on wild-type Kras differentiated thyroid carcinoma (DTC) and its mechanism.Methods:The DTC cell line Kras WT TPC-1 was selected and the mutant Kras G12D TPC-1 cells were constructed. CCK-8 assay was used to detect the effect of BRD4 inhibitor JQ-1 on the proliferation activity of Kras WT TPC-1 cells. Kras WT TPC-1 cells were treated with 0.2 μmol/L JQ-1 (JQ-1 group), and a negative control group (NC group) was set. Transwell invasion assay and flow cytometry were used to detect the effect of JQ-1 on the invasion and apoptosis of Kras WT TPC-1 cells. The effect of JQ-1 on the expressions of BRD4, miR-106b-5p and P21, and the effect of P21 inhibitor UC2288 on the expressions of P21 and BRD4 were detected. Kras WT TPC-1 cells were divided into JQ-1+ NC-OE group, JQ-1+ p21-OE group (overexpression of p21) and JQ-1+ p21-OE+ miR-106b-5p mimic group (overexpression of p21 and miR-106b-5 at the same time), and the proliferation, invasion and apoptosis of cells in each group were detected. TPC-1 cells were divided into Kras WT group, Kras WT+ JQ-1 group, Kras G12D group and Kras G12D+ JQ-1 group, and the cell proliferation, invasion and apoptosis of each group were detected. Results:JQ-1 inhibited the proliferation activity of Kras WT TPC-1 cells in a dose-dependent and time-dependent manner. In the NC group and JQ-1 group, the numbers of cell invasion were 124.67±9.61 and 82.67±8.02, and the apoptosis rates were (5.91±0.34)% and (10.33±1.10)%, respectively, with statistically significant differences ( t=5.812, P=0.004; t=6.653, P=0.003). JQ-1 significantly inhibited the expressions of BRD4 and miR-106b-5p, and promoted the expression of P21 in Kras WT TPC-1 cells. UC2288 significantly inhibited P21 expression, but had no significant effect on BRD4 expression. In the JQ-1+ NC-OE group, JQ-1+ p21-OE group and JQ-1+ p21-OE+ miR-106b-5p mimic group, the proliferation activities at 24 h of Kras WT TPC-1 cells was 0.46±0.03, 0.35±0.04 and 0.44±0.03 ( F=8.720, P=0.017), and the proliferation activity of JQ-1+ p21-OE group was significantly lower than that of the JQ-1+ NC-OE group ( P<0.05). The numbers of cell invasion in the three groups were 83.00±9.17, 56.67±6.03 and 79.67±10.07 ( F=8.347, P=0.018), and the number of cell invasion in the JQ-1+ p21-OE group was significantly lower than that in the JQ-1+ NC-OE group ( P=0.009). The apoptosis rates of the three groups were (10.00±0.49)%, (15.39±1.14)% and (10.32±0.80)% ( F=37.764, P<0.001), and the apoptosis rate of the JQ-1+ p21-OE group was significantly higher than that in the JQ-1+ NC-OE group ( P<0.001). There were no significant differences in cell proliferation activity, invasion number and apoptosis rate between JQ-1+ p21-OE+ miR-106b-5p mimic group and JQ-1+ NC-OE group (all P>0.05). In Kras WT group, Kras WT+ JQ-1 group, Kras G12D group and Kras G12D+ JQ-1 group, the cell proliferation activities at 24 h were 0.50±0.05, 0.39±0.04, 0.68±0.08 and 0.64±0.05 ( F=17.776, P<0.001). Compared with the Kras WT group, cell proliferation activity in the Kras WT+ JQ-1 group was significantly decreased, while that in the Kras G12D group was significantly increased (both P<0.05). The numbers of cell invasion in the four groups were 129.33±11.50, 86.00±9.54, 161.67±13.01 and 146.33±13.20 ( F=22.598, P<0.001). Compared with the Kras WT group, the number of cell invasion in the Kras WT+ JQ-1 group was significantly decreased ( P=0.002), and that in the Kras G12D group was significantly increased ( P=0.010). The apoptosis rates in the four groups were (6.17±0.50)%, (10.42±0.73)%, (3.43±0.47)% and (3.41±0.32)% ( F=119.170, P<0.001). Compared with the Kras WT group, the apoptosis rate in the Kras WT+ JQ-1 group was significantly increased ( P<0.001), and that in the Kras G12D group was significantly decreased ( P<0.001). There were no significant differences in cell proliferation activity, invasion number and apoptosis rate between Kras G12D+ JQ-1 group and Kras G12D group (all P>0.05). Conclusion:BRD4 inhibitor can specifically inhibit the development of wild-type Kras DTC via regulating the molecular axis of BRD4/miR-106b-5p/P21, but has no significant effect on the proliferation, invasion and apoptosis of mutant Kras DTC tumor cells.