Adrenergic modulation of AMPK‑dependent autophagy by chronic stress enhances cell proliferation and survival in gastric cancer

Abstract

Epidemiological data show that chronic stress has adverse effects on the incidence and progression of cancer. As a critical target organ for stress hormones, the stomach is frequently subjected to stress-related injury. However, few reports regarding the association between stress and gastric cancer (GC) have been published. The present study aimed to investigate the effect of chronic stress on the growth and survival of GC, and the role of the autophagy process. A restraint-stress procedure over 21 days was used to establish a chronic stress mouse model. Subcutaneous xenografts and gastric orthotopic xenografts were established in BALB/c nude mice. Alzet osmotic minipumps containing either PBS or propranolol hydrochloride was inserted on the nape of the neck 7 days prior to the initiation of restraint stress. The presence of autophagosomes and autolysosomes were examined by electron microscopy. The stress hormone norepinephrine significantly enhanced the proliferation of GC cells. By inhibiting adrenoreceptor expression, it was demonstrated that β2-adrenergic receptor (ADRB2) was the specific β-adrenergic receptor subtype responsible for catecholamine release. In addition, it was demonstrated that the induction of autophagy was a novel consequence of β2-adrenergic activation in GC cells. This was demonstrated by the appearance of double-membrane vesicles, punctuate GFP-RFP-microtubule-associated protein 1 light chain 3 distribution in the cytoplasm and a corresponding increase in autophagic flux. Notably, norepinephrine-induced autophagy was shown to have a tumor-promoting role under conditions of chronic stress in vitro and in vivo . It was further demonstrated that, upon activation of cAMP-response element binding protein, chronic stress promoted autophagic flux through the adenosine 5′-monophosphate-activated protein kinase-unc-51 like autophagy activating kinase 1 (AMPK-ULK1) pathway. Tissue microarray analysis revealed a negative correlation between the expression of ADRB2 and autophagic marker p62/sequestosome-1 in GC tumor samples. Additionally, high protein levels of ADRB2 correlated positively with tumor, node, metastasis stage and poor prognosis in patients with GC. These results establish a novel pathway that chronic stress activates tumor-promoting autophagy to accelerate the progression of GC. The present study is the first, to the best of our knowledge, providing preclinical evidence that chronic stress serves a role in the progression of GC.

Chronic Stress Promotes Cancer Development

“…The relationship between chronic stress and cancers has aroused increasingly widespread interest and concern in the medical community. Many scholars have performed research on the relationships between stress and cancers such as prostate (8)(9)(10), breast (8)(9)(10)(11)(12), gastric (13,14), lung (15,16), and skin cancer (17,18), and have found evidence indicating that chronic stress can induce tumorigenesis and promote cancer development ( Table 1).…”

JP1 suppresses proliferation and metastasis of melanoma through MEK1/2 mediated NEDD4L-SP1-Integrin αvβ3 signaling

“…However, the instability of peptide drugs is still needed to be improved in drug development 35 . Some progress has been made in the use of subcutaneous slow-release pump and the study of oral polypeptide drugs, which are expected to be used in the clinical treatment of polypeptide drugs in the future 36 , 37 . In addition, the combination of peptide drugs and other drugs or therapies may become a feasible way for cancer therapy 38 , 39 .…”

Psychological Stress Up-Regulates CD147 Expression Through Beta-Arrestin1/ERK to Promote Proliferation and Invasiveness of Glioma Cells

“…regulate a variety of cellular functions (42). NE affects the invasion and migration ability of various tumor cells, such as ovarian cancer and gastric cancer cells, mainly through beta receptors (43,44).…”

“…The endogenous ligands adrenaline and norepinephrine activate a series of signaling cascades of key proteins such as PKA. In addition to PKA, phosphorylated beta ARs recruit beta-arrestins, which then activate different downstream molecules such as Src and ERK, and thus they regulate a variety of cellular functions ( 42 ). NE affects the invasion and migration ability of various tumor cells, such as ovarian cancer and gastric cancer cells, mainly through beta receptors ( 43 , 44 ).…”