Active compounds of Caodoukou () inhibit the migration, invasion and metastasis of human pancreatic cancer cells by targeting phosphoinosmde-3-kinase/ protein kinase B/mammalian target of rapamycin pathway

OBJECTIVE

To detect the effects of active compounds of Caodoukou () (ACAK) on the proliferation, migration and invasion of pancreatic cancer, and explain the possible molecular mechanism of ACAK interacting with these processes.

METHODS

Cell counting kit-8 method, cell scratch repair experiment, Transwell migration and invasion experiment, immunohistochemistry, western blot assay and real-time polymerase chain reaction experiment were used to evaluate the effect of ACAK on the proliferation, migration and invasion of pancreatic cancer cells. The levels of active molecules involved in the phosphoinosmde-3-kinase (PI3K)/Akt/the mammalian target of rapamycin (mTOR) signal transduction were detected by Western blot assay. In addition, the function of ACAK was evaluated by xenotransplantation tumor model in nude mice.

RESULTS

The inhibitory effect of ACAK on the proliferation of pancreatic cancer cells showed certain time-dose dependence. The results of scratch repair test, Transwell test, Western blotting and real time polymerase chain reaction assay showed that ACAK could inhibit the migration and invasion of pancreatic cancer cells . In addition, the regulatory effect of ACAK on epithelial-mesenchymal transition (EMT) is partly attributed to PI3K/Akt/mTOR signaling pathway. The experimental results showed that ACAK regulated the development of pancreatic cancer.

CONCLUSIONS

ACAK can partly inhibit the activity of EMT and matrix metallopeptidases by down-regulating the downstream proteins of PI3K/Akt/mTOR signal pathway, thus inhibiting the ability of migration and invasion of pancreatic cancer.

STUDIES IN METABOLIC SPECTRA IV

Cheng, Lorraine (Radiobiochemistry Department, Chas. Pfizer & Co., Inc., Maywood, N. J.) and J. F. Snell . Studies in metabolic spectra. IV. Effects of tetracyclines, some of their derivatives, and chloramphenicol on accumulation of glutamic acid in Escherichia coli . J. Bacteriol. 83: 711–719. 1962.— Escherichia coli strain 21 was incubated in the Warburg apparatus at 37 C with sodium acetate-2-C 14 and 0.1 μmole/ml of various test compounds. Up to 1 hr, de novo C 14 -glutamic acid (synthesized from the C 14 -acetate precursor) accumulation in the fermentation broth was found to be a common phenomenon for the control cells and cells treated with oxytetracycline, chlortetracycline, tetracycline, and chloramphenicol. Subsequently, C 14 -glutamic acid continued to accumulate in the broth of the inhibited cells, but began to disappear from the broth of the control cells. During the first half hour, the rate of accumulation was most rapid in the presence of oxytetracycline. At 3 hr the total de nova C 14 -glutamic acid was found to be the same whether cells were treated with oxytetracycline or not. However, the distribution of this glutamic acid was different. In the oxytetracycline-treated cells, more than 87% of the total de nova C 14 -glutamic acid was in the broth, and only 13% was incorporated into the cell residue. In the control cells, no C 14 -glutamic acid was found in the broth, although 67% was in the cell residue. The possibility that the tetracyclines and chloramphenicol have different modes of action, and that oxytetracycline inhibits the incorporation of d -glutamic acid into the cell wall and membrane material in E. coli 21, was discussed.