Chaihu Longgu Muli Decoction attenuates chronic stress-induced endothelial dysfunction and potentiates chemotherapy in breast cancer by inhibiting cAMP/PKA/CREB1 mediated glycolysis.

Ethnopharmacological relevance: Clinical evidence indicates that breast cancer frequently coexist with depressive disorders, with research demonstrating a strong correlation between chronic stress-induced depression and the promotion of breast cancer growth and metastasis. Chaihu Longgu Muli Decoction (CLM), a traditional herbal formulation, has been commonly employed as an antidepressant in clinical. Nevertheless, the potential inhibitory effects of CLM on chronic stress-induced breast cancer progression remain to be elucidated.

Aim of study: To investigate the effect and underlying mechanisms of CLM in the treatment of chronic stress-induce breast cancer progression.

Materials and methods: Using a syngeneic 4T1 breast cancer model combined with the chronic unpredictable mild stress (CUMS) paradigm, we evaluated the efficacy of CLM on CUMS-induced depressive-like behaviors and tumor progression. Scanning electron microscopy (SEM) and immunofluorescence staining were employed to assess morphological and molecular alterations in tumor vasculature. LC-MS identified the blood-absorbed components of CLM, and network pharmacology was employed to predict the signal pathways involved in CLM's suppression of CUMS-induced endothelial dysfunction. In vitro, epinephrine (Epi)-induced angiogenesis model were using human umbilical vein endothelial cells (HUVECs) was established to examine the effects of CLM on endothelial dysfunction. Finally, MMTV-PyMT transgenic mouse model of spontaneous breast cancer with comorbid depression was utilized to validate whether CLM enhances chemosensitivity by promoting tumor vascular normalization.

Results: In the 4T1-derived tumor model, CUMS enhanced tumor growth, upregulated the proliferation marker Ki67, and increased serum Epi levels. SEM and immunofluorescence staining revealed that CUMS promoted angiogenesis and endothelial dysfunction. CLM treatment significantly ameliorated CUMS-induced depressive-like behaviors and suppressed tumor growth. Notably, CLM restored CUMS-impaired endothelial function. LC-MS and network pharmacology analysis identified that CLM-mediated tumor vascular normalization was associated with cAMP signaling pathways. In vitro, CLM inhibited Epi-induced endothelial cell migration, invasion, and tube formation while upregulating tight junction proteins (VE-cad and ZO-1). Mechanistically, CLM suppressed cAMP/PKA/CREB1 activation and inhibits glycolysis. In MMTV-PyMT mice, CUMS accelerated tumor progression and vascular dysfunction, impairing the efficacy of Dox chemotherapy. Conversely, CLM promoted tumor vascular normalization, enhanced intratumoral Dox delivery, and effectively attenuates CUMS-driven breast cancer growth and metastasis.

Conclusion: Chronic stress attenuates chemotherapeutic drug delivery by inducing endothelial dysfunction in breast cancer. CLM promotes tumor vascular normalization, reverses chronic stress-induced vascular dysfunction, and potentiates chemotherapy by inhibiting cAMP/PKA/CREB1 mediated glycolysis in breast cancer.