Objective

2

To explore the possible mechanism of

Changweiqing

（肠胃清） in the treatment of colorectal cancer.

Methods

2

HCT 116 cancer cells were used to prepare intestinal cancer cells with silenced polypyrimidine region binding protein 3 （PTBP3） gene and stably transfected cells with overexpressed PTBP3 gene. Stably transfected cells with silenced PTBP3， stably transfected cells with overexpressed PTBP3 and untransfected cancer cells were injected into the armpit of 72 nude mice to construct three different subcutaneous transplanted tumor models of colorectal cancer cells， including the silenced model， the overexpressed model and the control model， with 24 mice per model. Mice of each transplanted tumor modelwere randomly divided into

Changweiqing

（CWQ） group， oxaliplatin （OXA） group and normal saline （NS） group， with 8 mice in each group. The CWQ groups were given intragastric administration of 35.9625 g/kg of

Changweiqing

oral liquid and were intraperitoneally injected with 0.2ml of normal saline； the NS groups were given 0.5ml of normal saline by gavage， and intraperitoneal injection of 0.2ml of normal saline； the OXA groups were intraperitoneally injected with 5 mg/kg （0.2 ml） of oxaliplatin and given 0.5ml of normal saline by gavage. Each group was given intragastric administration once a day and intraperitoneal injection three times a week. After 31 days， the weight of subcutaneous tumors in each group was measured， and the tumor inhibition rate of the groups in each model were measured. Immunohistochemistry and other methods were used to detect the expression level of cell proliferation cell nuclear antigen Ki67 and apoptosis index. Real-time PCR and Western Blot were used to detect mRNA and protein expressions of PTBP3， signal transducer and activator of transcription 3 （STAT3） splicing isoform α （STAT3α）， STAT3 splicing isoform β （STAT3β）， B-cell lymphoma/leukemia-2 （Bcl-2） splicing isoform α （Bcl-2α）， and Bcl-2 splicing isoform β （Bcl-2β） in subcutaneous tumor cells in each group.

Results

2

For all three transplanted tumor models， the weight of the subcutaneous tumors and Ki67 expression level of subcutaneous tumor tissue in all CWQ groups and OXA groups were lower than those of the corresponding NS groups， while the apoptosis level were higher （

P

＜0.05 or

P

＜0.01）. The mRNA and protein expressions of PTBP3， STAT3α， and Bcl-2α in the subcutaneous tumor tissues of the silenced model CWQ group and the overexpressed model CWQ group were lower than those of the corresponding NS groups， while the mRNA and protein expression levels of STAT3β and Bcl-2β were higher （

P

＜0.05 or

P

＜0.01）. All there groups of silenced model had lower subcutaneous tumor weight， Ki67 expression level， and mRNA and protein expression levels of PTBP3， STAT3α， and Bcl-2α in subcutaneous tumor tissue， as well as higher apoptosis level and mRNA and protein expression levels of STAT3β and Bcl-2β than those in all groups of control model； all groups of overexpressed model had higher subcutaneous tumor weight， Ki67 expression level， and mRNA and protein expression levels of PTBP3， STAT3α， and Bcl-2α ， while lower apoptosis level and mRNA and protein expression levels of STAT3β and Bcl-2β than those in all control model groups （

P

＜0.05 or

P

＜0.01）. In the control model， compared with the NS group， The tumor inhibition rate of all OXA groups was higher than that of corresponding CWQ groups， respectively. Compared to that of each control model group， the tumor inhibition rate was positive value of each silenced model group， and negative value of each overexpressed model group.

Conclusion

2

PTBP3 can promote the proliferation and inhibit apoptosis of intestinal cancer cells， upregulate the expression of STAT3α and Bcl-2α， and downregulate the expression of STAT3β and Bcl-2β in intestinal cancer cells. The meachnism of action of

Changweiqing

in the treatment of colorectal cancer maybe related to the inhibition of PTBP3， and regulation of the expression of STAT3α， STAT3β， Bcl-2α， and Bcl-2β.