Theanine combined with cisplatin inhibits the proliferation and metastasis of TNBC cells through Akt signaling pathway

Background: Theanine, was natural compounds, has been employed in antibacterial, antineoplastic, promotion of hair growth, therapy of poliosis, and removing pattogenic heat from the blood and toxic material from the body for centuries. However, few reports focused on the treatment by theanine combined with chemotherapy in triple negative breast cancer. Methods: Our study aimed to evaluate and compare the molecular and cellular effects of theanine in combination with cisplatin in triple negative breast cancer lines MDA-MB-231. The 50% inhibitory concentration and cell viability were determined by the cell counting kit-8 assay. Meanwhile, wound healing and transwell assays were used to evaluate the effect of theanine combination with cisplatin on triple negative breast cancer (TNBC) cell metastasis. Moreover, the label-free proteomic method was available to explore the molecular mechanism of theanine combination with cisplatin on TNBC cells. What's more, reverse transcription-polymerase chain reaction and western blotting were carried out to evaluate the related protein and mRNA alteration in the Akt signaling pathway. Results: With theanine added, the inhibitory effect of cisplatin on cell proliferation and metastasis was significantly improved. Meanwhile, with the increase of theanine concentration, the anti-tumor effect of the combination group was also significantly improved. Afterward, label-free proteomics analysis showed that theanine combined with cisplatin could significantly activate the Akt signaling pathway, thus improving the anti-tumor effect of cisplatin. Finally, reverse transcription-polymerase chain reaction and western blotting experiment showed that the combination of cisplatin with theanine induced the greatest down-regulation of phosphorylated Akt expression. Conclusion: All in all, combining theanine with appears to be a promising strategy for the effective treatment of TNBC in the prospective application which merits further clinical investigation.