Jianpi Jiedu Recipe inhibits colorectal cancer liver metastasis via regulating ITGBL1-rich extracellular vesicles mediated activation of cancer-associated fibroblasts

BACKGROUND

Extracellular vesicles (EVs) contribute greatly to the formation of pre-metastatic niche and tumor metastasis. Our previous study has revealed that tumor-derived ITGBL1 (integrin beta- like 1)-rich EVs activate fibroblasts through the NF-κB signaling to promote colorectal cancer (CRC) metastasis. Targeting ITGBL1-loaded EVs may be a new and effective therapy for treating CRC metastasis. Simultaneously, our preliminary clinical trial has demonstrated that Jianpi Jiedu Recipe (JPJDR) was an ideal alternative traditional Chinese medicine for the prevention and treatment of CRC metastasis. However, the underlying mechanism of JPJDR in the prevention of CRC metastasis is not clear. In this study, we will investigate the regulatory effect of JPJDR on ITGBL1 levels in CRC-derived EVs, and to detect how JPJDR regulate ITGBL1-rich EVs mediated activation of fibroblasts to inhibit CRC metastasis.

METHODS

EVs derived from CRC cells with/without JPJDR treatment were obtained by ultracentrifugation, following by characterization with electron microscopy, LM10 nanoparticle characterization system and western blot. The migration and growth of CRC cells were tested by transwell assay, wound healing assay and colony formation assay. The effect of JPJDR on the fibroblasts-activation associated inflammatory factors including IL-6, IL-8 and α-SMA was detected by real-time PCR. The levels of IL-6, IL-8 and α-SMA in the cell culture supernatant were detected by ELISA. The protein expressions of TNFAIP3, ITGBL1, p-NF-κB, IκBα and β-actin were detected by western blot. Liver metastasis model in mice was established by injecting MC38 single cell suspension into the spleen of mice to observe the effect of JPJDR on CRC liver metastasis. Immunohistochemistry were applied to detect the expression of ITGBL1 and TNFAIP3 in the liver metastatic tissues. Tissue immunofluorescence detection was performed to observe the regulatory effect of JPJDR on the ITGBL1-NF-κB signaling pathway. Cancer-associated fibroblasts (CAFs) in the liver metastatic tissues were sorted and characterized by platelet-derived growth factor receptor β (PDGFRβ) with flow cytometry, following by the detection of inflammatory factors including IL-6, IL-8 and α-SMA using real-time PCR.

RESULTS

JPJDR reduced the ITGBL1 levels in CRC cells-derived EVs. JPJDR inhibited the migration and growth of CRC cells via regulating ITGBL1-rich EVs mediated fibroblasts activity. Mechanically, JPJDR decreased fibroblasts activation by regulating ITGBL1-rich EVs mediated TNFAIP3-NF-κB signaling. Further in vivo experiments demonstrated that JPJDR reduced CRC liver metastasis by regulating ITGBL1-rich EVs secretion from CRC and blocked the fibroblasts activation by regulating ITGBL1-TNFAIP3- NF-κB signaling.

CONCLUSION

Our research demonstrated that JPJDR preventd CRC liver metastasis via down-regulating CRC-derived ITGBL1-loaded EVs mediated activation of CAFs, providing the experimental evidence for the clinical application of JPJDR in the prevention and treatment of CRC metastasis. More importantly, our study confirmed the great benefits of therapeutic targeting the EVs-mediated metastasis and warranted future clinical validation.

Involvement of miR-199a downregulation in the preventive effects of Jianpi Jiedu Recipe against experimental hepatocarcinoma in rats

AIM: To investigate the preventive effects of Jianpi Jiedu Recipe against diethylnitrosamine-induced hepatocarcinoma in rats and explore the involvement of miR-199a downregulation in this process.

METHODS: Male Wistar rats were randomly divided into three groups: normal control group (n = 25), model group (n = 40 ) and prevention group (n = 40). The normal control group was given normal saline [10 mL/(kg•d) ig] for 12 weeks, the model group was given diethylnitrosamine dissolved in drinking water (80 ppm) at a dose of 8 mg/(kg•d) for the same duration, and the prevention group was given both diethylnitrosamine at the same dose and Jianpi Jiedu Recipe [17.5 g/(kg•d), ig] for the same duration. Five rats in each group were executed at weeks 4, 8, 12 and 16, respectively, and the remaining rats were killed at week 20. Meanwhile, the mortality, incidence of ascites, and liver and spleen index were measured. Hematoxylin-eosin staining (HE) was used to examine hepatic pathological changes. The expression of miR-199a mRNA was detected by real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: At week 20, the mortality rate and the incidence rate of ascites were 0% and 0% in the normal control group, 42.5% and 87.5% in the model group, and 17.5% and 44.4% in the prevention group, respectively. The mortality rate and the incidence of ascites were significantly lower in the prevention group than in the model group (both P < 0.05). At week 16, the incidence of HCC was 100% in both the model group and prevention group and 0% in the normal control group, the incidence of grade III liver cancer was 100% (5/5) in the model group, and the incidences of grade I, II and III liver cancer were 40% (2/5), 40% (2/5 ) and 20% (1/5) in the prevention group, respectively. Compared with the model group, the liver and spleen index in the prevention group were significantly reduced at all time points (all P < 0.01). Real-time RT-PCR results showed that the expression of miR-199a was significantly upregulated in the model group. However, miR-199a expression was significantly downregulated in the prevention group at all time points except at week 16 (all P < 0.01).

CONCLUSION: Jianpi Jiedu Recipe has good preventive effects against hepatocarcinoma in rats perhaps partly by downregulating miR-199a expression.