Inhibitory effect of endostar combined with radiotherapy on gastric cancer animal models

Impact of Drp1-regulated changes in T cell activity on the combined antitumor effects of PARPi and PD-1 inhibitors

This study aimed to investigate the influence of dynamin-related protein 1 (Drp1)-regulated T cells on the antitumor effects of poly (ADP-ribose) polymerase inhibitors (PARPi) combined with programmed cell death protein 1 (PD-1) inhibitors to identify potential targets for enhancing immunotherapy efficacy. We found that T cells with high expression of Drp1 promoted the inhibitory and killing effects of the PARPi and PD-1 inhibitor combination on lung cancer cells in vivo and in vitro. This synergistic mechanism involves Drp1-regulated promotion of activation, migration, and intratumor infiltration of effector T cells; inhibition of negative immunomodulatory cells in the tumor microenvironment; and suppression of PARPi-induced upregulation of PD-L1 expression in tumor cells. These findings suggest that Drp1 could serve as a new target for comprehensively improving the tumor microenvironment, enhancing immunotherapy efficacy, and reversing immunotherapy resistance.

Enhanced T cell immune activity mediated by Drp1 promotes the efficacy of PD-1 inhibitors in treating lung cancer

BACKGROUND

Dynamin-related protein 1 (Drp1)-mediated mitochondrial fission plays important roles in the activation, proliferation, and migration of T cells.

METHODS

We investigated the synergistic effect of Drp1-mediated T cell antitumor activities and programmed cell death protein 1 (PD-1) blockade for treating lung cancer through in vitro co-culture experiments and an in vivo nude mouse xenograft model.

RESULTS

High expression levels of Drp1 positively regulated T cell activation, enhanced T cell-induced suppression of lung cancer cells, promoted CD8+ T cell infiltration in the tumor and spleen, and significantly enhanced the antitumor immune response of the PD-1 inhibitor pembrolizumab. The mechanism of this synergistic antitumor effect involved the secretion of immune killing-related cytokines and the regulation of the PD-1-ERK/Drp1 pathway in T cells.

CONCLUSIONS

Our findings suggest that modifying Drp1 expression in T cells could serve as a potential therapeutic target for enhancing the antitumor immune response in future immunotherapies.

Multi-omics sequencing revealed endostar combined with cisplatin treated non small cell lung cancer via anti-angiogenesis

BACKGROUND

Endostar, an anti-angiogenic drug, has been approved for treating non-small cell lung cancer (NSCLC). At present, endostar combined with radiotherapy or chemotherapy has achieved ideal results in the treatment of some tumors, but there is a lack of application and study in NSCLC. This study investigated the therapeutic effect and potential mechanism of endostar combined with cisplatin (EC) in NSCLC.

METHODS

HE staining, TUNEL staining, immunofluorescence, colony formation ability, and cell migration ability were used to evaluate the anti-tumor activity of EC. The expressions of FMOD, VEGF, FGF-2, and PDGF-B were detected by western blotting and qPCR. The target of combination therapy was analyzed by m6A sequencing and RNA sequencing. METTL3 knockdown and overexpressed A549 cells were constructed and co-cultured with HUVECs to further evaluate the effect of METLL3 on combination therapy.

RESULTS

Combination therapy significantly reduced the colony formation and migration ability of NSCLC cells, induced cell apoptosis, and inhibited the tube formation ability of HUVECs. The results of m6A sequencing and RNA sequencing showed that the EC could down-regulate the expression level of FMOD in tumor tissues, which might be related to the reduction of its m6A methylation modification regulatory enzyme METTL3. Restricting FMOD expression could reduce the expression of FGF2, TGF-β1, VEGF and PDGF-B. Moreover, overexpression of METTLE almost abolished the anti-tumor effect of EC and promoted angiogenesis.

CONCLUSIONS

Endostar combined with cisplatin might exert anti-tumor effects by down-regulating the expression of METTL3 and FMOD.

Iodine-125 Seeds Inhibit Carcinogenesis of Hepatocellular Carcinoma Cells by Suppressing Epithelial-Mesenchymal Transition via TGF-β1/Smad Signaling

To investigate the radioactive iodine-125 (I-125) seed on migrating and invading of hepatocellular carcinoma (HCC) cells and its mechanism, the irradiation of PLC and Huh7 cells was carried out with I-125 seeds in vitro. Cell counting kit 8 assay was employed to measure cell viability. Cell migration was evaluated by using wound-healing assay. Cell invasion was detected by Transwell assay; RT-PCR and Western blot were used for the detection of the mRNA and proteins of TGF-β1 signaling pathway-related genes. The viability of PLC and Huh7 cells declined in a dose-dependent manner with increasing irradiation from 0 Gy, 2 Gy, 4 Gy, and 6 Gy, to 8 Gy, respectively. The IC50 of PLC and Huh7 cells were 6.20 Gy and 5.39 Gy, respectively, after 24 h of irradiation. Migration and invasion abilities of I-125 group cells were greatly weakened (P < 0.05) comparing with the control group. According to the outcomes of RT-PCR and WB, I-125 seed irradiation significantly inhibited the mRNA and protein expression of N-cadherin, vimentin, TGF-β1, p-Smad2/3, and Snail. But the mRNA and protein expressions of E-cadherin were enhanced. Rescue experiment demonstrates that TGF-β1 activator could reverse the inhibitory effects of I-125 on invasion and migration of cells. The results of in vivo experiments further verified that the I-125 seeds can inhibit the proliferation and TGF-β1 of xenographed PLC cells. In conclusion, I-125 seeds restrain the invasion and migration of HCC cells by suppressing epithelial to mesenchymal transition, which may associate with the inhibition of the TGF-β1 signaling.

Recombinant human endostatin combined with radiotherapy promotes cardiomyocyte apoptosis in rats via TGFβ1/Smads/CTGF signaling pathway

PURPOSE

The aim of the present study was to investigate the efficacy of recombinant human endostatin (ES) (rh-ES) combined with radiation on rat cardiomyocyte apoptosis and the regulatory mechanism of transforming growth factor beta1 (TGF-β1)/Sma and Mad-related protein 3 (Smad3)/connective tissue growth factor (CTGF) signaling.

METHOD

The primary cardiomyocytes were isolated from neonatal Sprague-Dawley rats for culture in vitro and divided into blank control group (without treatment), 10 Gy radiation + siTGF-β1 siRNA (gene silencing) group, ES + siTGF-β1 siRNA group, and 10 Gy radiation + ES + siTGF-β1 siRNA group. Methyl thiazolyl tetrazolium assay was used to calculate the half-maximal inhibitory concentration (IC50) of rh-ES on cardiomyocytes. Adenoviral vector was constructed for virus packaging to silence TGF-β1 expression in cardiomyocytes. Quantitative real-time polymerase chain reaction and Western blot were carried out to analyze TGF-β1, Smad2, Smad3 and CTGF expression at both gene and protein levels. Flow cytometry and electron microscope were used to examine cell apoptosis.

RESULTS

ES had a dose-dependent inhibitory effect on the proliferation of primary rat cardiomyocytes. ES combined with radiotherapy significantly inhibited cardiomyocyte proliferation and promoted cell apoptosis (P < 0.01). The gene and protein expression of TGF-β1, Smad2, Smad3 and CTGF were significantly up-regulated in primary cardiomyocytes transfected with TGF-β1 gene (P < 0.05).

CONCLUSION

The combination therapy with rh-ES and radiation can promote cardiomyocyte apoptosis and aggravate myocardial cell damage via TGF-β1/Smad3/CTGF signaling pathway.

Assessment of the value of adjuvant radiotherapy for treatment of gastric adenocarcinoma based on pattern of post-surgical progression

PURPOSE

To assess the value of adjuvant radiotherapy for treatment of gastric adenocarcinoma and to investigate subgroups of patients suitable for adjuvant radiotherapy.

METHODS AND MATERIALS

Data from 785 patients with gastric adenocarcinoma who had undergone D1/D2 radical resection and adjuvant chemotherapy were collected, the site of first progression was determined, and the relationship between the rate of local recurrence and clinicopathologic features was analyzed.

RESULTS

By the end of the follow-up period, progression was observed in 405 patients. Local recurrence was observed as the first progression in 161 cases. The local recurrence rate was significantly lower than the non-local progression rate (20.5% vs 31.5%, p=0.007). Multivariate Cox regression analysis showed a significant relationship among degree of differentiation, T stage, N stage, and rate of local recurrence.

CONCLUSIONS

Not all patients with gastric carcinoma required adjuvant radiotherapy. However, patients with poorly differentiated cancer cells, advanced T stage (T3/T4), and positive lymph nodes, which included patients in the T4N1-2M0 subgroup, were recommended for adjuvant radiotherapy.

Down-Regulation of Hypoxia-Inducible Factor-1α and Downstream Glucose Transporter Protein-1 Gene by β-elemene Enhancing the Radiosensitivity of Lung Adenocarcinoma Transplanted Tumor

Purpose

To study the effect of β-elemene on the radiosensitivity of A549 cell xenograft tumor and potential mechanisms by which β-elemene regulates the expression of hypoxia-inducible factor-1α (HIF-1α) and glucose transporter protein-1 (GLUT-1).

Methods

Using an A549 cell transplantation tumor model with male nude mice, we studied the effect of β-elemene on the radiosensitivity of non-small cell lung cancer (NSCLC). The expression of HIF-1α and GLUT-1 was detected by real-time PCR, Western blotting and immunohistochemistry. The relationship between the radiosensitivity of β-elemene and the expression of HIF-1α and GLUT-1 was analyzed.

Results

β-elemene and radiotherapy intervened in the growth of transplanted tumors in varying degrees. The enhancement factor (EF=2.44>1) was calculated; β-elemene at 45 mg/kg had the most significant enhanced effect on radiosensitivity. When β-elemene was used in combination with radiation, the expression of HIF-1α and GLUT-1 was significantly decreased, and there was a positive correlation between the two genes.

Conclusion

β-elemene exhibits a radiosensitizing effect on A549 cell xenograft tumor. The underlying molecular mechanism is probably associated with the down-regulation of HIF-1α and GLUT-1 expression, suggesting that β-elemene may directly or indirectly inhibit the expression of HIF-1α and GLUT-1. There is a positive significant correlation between expression of HIF-1α and GLUT-1. HIF-1α and downstream GLUT-1 could be used as a new target for the radiosensitization of NSCLC.