Tumor-associated macrophages regulate gastric cancer cell invasion and metastasis through TGFβ2/NF-κB/Kindlin-2 axis

Objective: Recent studies have shown that tumor-associated macrophages(TAMs) play an important role in cancer invasion and metastasis. Our previous studies have reported that TAMs promote the invasion and metastasis of gastric cancer(GC) cells through the Kindlin-2 pathway. However, the mechanism needs to be clarified.Methods: THP-1 monocytes were induced by PMA/interleukin(IL)-4/IL-13 to establish an efficient TAM model in vitro and M2 macrophages were isolated via flow cytometry. A dual luciferase reporter system and chromatin immunoprecipitation(Ch IP) assay were used to investigate the mechanism of transforming growth factor β2(TGFβ2) regulating Kindlin-2 expression. Immunohistochemistry was used to study the relationships among TAM infiltration in human GC tissues, Kindlin-2 protein expression, clinicopathological parameters and prognosis in human GC tissues. A nude mouse oncogenesis model was used to verify the invasion and metastasis mechanisms in vivo.Results: We found that Kindlin-2 expression was upregulated at both m RNA and protein levels in GC cells cocultured with TAMs, associated with higher invasion rate. Kindlin-2 knockdown reduced the invasion rate of GC cells under coculture condition. TGFβ2 secreted by TAMs regulated the expression of Kindlin-2 through the transcription factor NF-кB. TAMs thus participated in the progression of GC through the TGFβ2/NF-κB/Kindlin-2 axis. Kindlin-2 expression and TAM infiltration were significantly positively correlated with TNM stage, and patients with high Kindlin-2 expression had significantly poorer overall survival than patients with low Kindlin-2 expression. Furthermore, Kindlin-2 promoted the invasion of GC cells in vivo.Conclusions: This study elucidates the mechanism of TAMs participating in GC cell invasion and metastasis through the TGFβ2/NF-κB/Kindlin-2 axis, providing a possibility for new treatment options and approaches.

Establishment of organoid models based on a nested array chip for fast and reproducible drug testing in colorectal cancer therapy

The conventional microwell-based platform for construction of organoid models exhibits limitations in precision oncology applications because of low-speed growth and high variability. Here, we established organoid models on a nested array chip for fast and reproducible drug testing using 50% matrigel. First, we constructed mouse small intestinal and colonic organoid models. Compared with the conventional microwell-based platform, the mouse organoids on the chip showed accelerated growth and improved reproducibility due to the nested design of the chip. The design of the chip provides miniaturized and uniform shaping of the matrigel that allows the organoid to grow in a concentrated and controlled manner. Next, a patient-derived organoid(PDO) model from colorectal cancer tissues was successfully generated and characterized on the chip. Finally, the PDO models on the chip, from three patients, were implemented for high-throughput drug screening using nine treatment regimens. The drug sensitivity testing on the PDO models showed good quality control with a coefficient of variation under 10% and a Z’ factor of more than 0.7. More importantly, the drug responses on the chip recapitulate the heterogeneous response of individual patients, as well as showing a potential correlation with clinical outcomes. Therefore,the organoid model coupled with the nested array chip platform provides a fast and reproducible means for predicting drug responses to accelerate precise oncology.