Complex roles of cAMP-PKA-CREB signaling in cancer

Hydrophilic molecularly imprinted polymers functionalized magnetic carbon nanotubes for selective extraction of cyclic adenosine monophosphate from winter jujube

In this work, a green strategy was developed to prepare molecularly imprinted polymers functionalized magnetic carbon nanotubes in aqueous phase under mild conditions for cyclic adenosine monophosphate. Thanks to water solubility of chitosan, a natural polysaccharide which is rich in amino and hydroxyl groups, provided the feasibility to synthesize the green molecularly imprinted polymers for water soluble template in aqueous media. Coupled with high-performance liquid chromatography, the method exhibited a short equilibrium time (6 min), high adsorption capacity (22.42 μg/mg), high magnetic susceptibility, and good selectivity to template molecule with the imprinting factor of 2.94. A good linearity in the range of 0.020-3.0 mg/mL for target was obtained with a correlation coefficient of 0.9998. The limit of detection (signal-to-noise ratio = 3) and limit of quantitation (signal-to-noise ratio = 10) of the magnetic solid phase extraction method for cyclic adenosine monophosphate were 5 and 15 ng/mg, respectively. And the practical application of chitosan-based molecularly imprinted polymers as adsorbent to isolate and determine cyclic adenosine monophosphate in real natural samples (winter jujube) was demonstrated.

SEPHS1 promotes SMAD2/3/4 expression and hepatocellular carcinoma cells invasion

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the common cancers that are very aggressive. The secreted cytokine transforming growth factor-β (TGF-β) promotes cancer metastasis by multiple mechanisms such as epithelial-mesenchymal transition and immune evasion. The canonical TGF-β signaling is largely mediated by smooth muscle actin/mothers against decapentaplegic (SMAD) proteins. The current study aims to explore the regulation of TGF-β/SMAD signaling by selenophosphate synthetase 1 (SEPHS1).

METHODS

Immunohistochemistry was used to detect the expression of SEPHS1 in HCC and adjacent liver tissues. Western blotting and quantitative reverse-transcription PCR were used to detect the protein and mRNA levels in HCC cell lines. Cell migration and invasion were determined by transwell assay. Bioinformatic analysis was conducted to determine SEPHS1 expression in HCC and its correlation with the survival of HCC patients.

RESULTS

Here we report that SEPHS1 is a positive regulator of SMAD proteins. SEPHS1 expression is up-regulated in HCC compared with adjacent liver tissues. SEPHS1 knockdown leads to decreased expression of SMAD2/3/4 and mesenchymal markers including snail, slug and N-cadherin in HCC cells. Furthermore, SEPHS1 knockdown results in a decrease in HCC cells migration and invasion, and suppresses the stimulation of HCC cells migration and invasion by TGF-β. Overexpression of SEPHS1 in HCC cells promotes cell invasion, which can be abrogated by SMAD3 knockdown. Lastly, higher expression of SEPHS1 is correlated with poor prognosis in HCC patients, as manifested by decreased overall survival and disease-free survival.

CONCLUSIONS

SEPHS1 is a positive regulator of TGF-β/SMAD signaling that is up-regulated in HCC. Increased SEPHS1 expression may indicate poor prognosis for patients with HCC.

[A Review of Chronic Stress and the Initiation and Evolution of Cancer]

Chronic stress activates the typical neuroendocrine system, hypothalamus pituitary adrenal axis and sympathetic nervous system, and leads to a sustained non-specific adaptive response. It has been proved that chronic stress can promote tumor initiation and induce tumor evolution, especially in immune function and remodeling of tumor microenvironment. However, due to the complex mechanism of chronic stress and the great difference in individual tolerance, the research evidence of chronic stress in tumor genesis and progression is still unclear. Therefore, in this paper, we review the research on the relationship between chronic stress and tumor initiation and evolution, focusing on the molecular mechanism of chronic stress promoting tumor occurrence and development, inhibiting immune response and remodeling tumor immune microenvironment, and exploring the stress management program of healthy people and cancer patients, so as to provide clues for exploring new strategies of cancer prevention and treatment. In our opinion, targeting the cAMP/PKA/CREB signaling pathway to reverse tumor treatment strategy, the relationship between the tumor and stress, inflammation, immunity, the suppressor activity of β receptor antagonist and its mechanism as well as associated with different treatment options, still need to be further explored. A healthy lifestyle, positive life attitudes and professional stress management guidance are essential for the prevention and treatment of cancer.