Targeting the β2 -adrenergic receptor increases chemosensitivity in multiple myeloma by induction of apoptosis and modulating cancer cell metabolism

Effects of chronic stress on cancer development and the therapeutic prospects of adrenergic signaling regulation

Long-term chronic stress is an important factor in the poor prognosis of cancer patients. Chronic stress reduces the tissue infiltration of immune cells in the tumor microenvironment (TME) by continuously activating the adrenergic signaling, inhibits antitumor immune response and tumor cell apoptosis while also inducing epithelial-mesenchymal transition (EMT) and tumor angiogenesis, promoting tumor invasion and metastasis. This review first summarizes how adrenergic signaling activates intracellular signaling by binding different adrenergic receptor (AR) heterodimers. Then, we focused on reviewing adrenergic signaling to regulate multiple functions of immune cells, including cell differentiation, migration, and cytokine secretion. In addition, the article discusses the mechanisms by which adrenergic signaling exerts pro-tumorigenic effects by acting directly on the tumor itself. It also highlights the use of adrenergic receptor modulators in cancer therapy, with particular emphasis on their potential role in immunotherapy. Finally, the article reviews the beneficial effects of stress intervention measures on cancer treatment. We think that enhancing the body's antitumor response by adjusting adrenergic signaling can enhance the efficacy of cancer treatment.

G protein-coupled receptor-mediated autophagy in health and disease

G protein-coupled receptors (GPCRs) constitute the largest and most diverse superfamily of mammalian transmembrane proteins. These receptors are involved in a wide range of physiological functions and are targets for more than a third of available drugs in the market. Autophagy is a cellular process involved in degrading damaged proteins and organelles and in recycling cellular components. Deficiencies in autophagy are involved in a variety of pathological conditions. Both GPCRs and autophagy are essential in preserving homeostasis and cell survival. There is emerging evidence suggesting that GPCRs are direct regulators of autophagy. Additionally, autophagic machinery is involved in the regulation of GPCR signalling. The interplay between GPCR and autophagic signalling mechanisms significantly impacts on health and disease; however, there is still an incomplete understanding of the underlying mechanisms and therapeutic implications in different tissues and disease contexts. This review aims to discuss the interactions between GPCR and autophagy signalling. Studies on muscarinic receptors, beta-adrenoceptors, taste receptors, purinergic receptors and adhesion GPCRs are summarized, in relation to autophagy.

Repurposing beta-blockers for combinatory cancer treatment: effects on conventional and immune therapies

Beta-adrenergic receptor signaling regulates cellular processes associated with facilitating tumor cell proliferation and dampening anti-tumor immune response. These cellular processes may lead to compromised tumor control and cancer progression. Based on this ramification, Beta-blockers (BBs) have emerged as a potential treatment by inhibiting beta-adrenergic receptor signaling. This review aimed to investigate the relationship between the use of BBs and tumor progression and treatment response. Therefore, the authors explored several aspects: the potential synergistic relationship of BBs with chemotherapy and immunotherapy in enhancing the effectiveness of chemotherapeutic and immunotherapeutic treatments and their role in boosting endogenous immunity. Further, this review explores the distinctions between the major types of BBs: Non-selective Beta Blockers (NSBBs) and Selective Beta Blockers (SBBs), and their contributions to combinatory cancer treatment. In this review, we presented a perspective interpretation of research findings and future directions. Overall, this review discusses the potential and challenge that BBs present in improving the effectiveness and outcome of cancer treatment.

Trial watch: beta-blockers in cancer therapy

Compelling evidence supports the hypothesis that stress negatively impacts cancer development and prognosis. Irrespective of its physical, biological or psychological source, stress triggers a physiological response that is mediated by the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medullary axis. The resulting release of glucocorticoids and catecholamines into the systemic circulation leads to neuroendocrine and metabolic adaptations that can affect immune homeostasis and immunosurveillance, thus impairing the detection and eradication of malignant cells. Moreover, catecholamines directly act on β-adrenoreceptors present on tumor cells, thereby stimulating survival, proliferation, and migration of nascent neoplasms. Numerous preclinical studies have shown that blocking adrenergic receptors slows tumor growth, suggesting potential clinical benefits of using β-blockers in cancer therapy. Much of these positive effects of β-blockade are mediated by improved immunosurveillance. The present trial watch summarizes current knowledge from preclinical and clinical studies investigating the anticancer effects of β-blockers either as standalone agents or in combination with conventional antineoplastic treatments or immunotherapy.

Ginsenoside Rh4 inhibits the malignant progression of multiple myeloma and induces ferroptosis by regulating SIRT2

Multiple myeloma (MM) has a high mortality rate, and the exploration of therapeutic drugs for MM with low side effects is a hot topic at the moment. Ginsenoside Rh4 has been shown to inhibit tumour growth in many cancers. However, the role of ginsenoside Rh4 in MM and its reaction mechanism have not been reported so far. After the treatment with different concentrations of ginsenoside Rh4, the proliferation of NCI-H929 cells was detected by Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine staining. The cell apoptosis and cycle arrest were detected by flow cytometry and western blot. The thiobarbituric acid-reactive substances (TBARS) production was assessed with TBARS assay, whereas Fe²⁺ fluorescence assay was used for the measurement of Fe²⁺ level. The production of reactive oxygen species was evaluated with dichloro-dihydro-fluorescein diacetate staining, and western blot was applied for the estimation of ferroptosis-related proteins. The potential targets of ginsenoside Rh4 were predicted by molecular docking technology and verified by western blot. The transfection efficacy of overexpression-SIRT2 was examined with quantitative reverse transcription polymerase chain reaction and western blot. To figure out the detailed reaction mechanism between ginsenoside Rh4 and SIRT2 in MM, rescue experiments were conducted. We found that ginsenoside Rh4 inhibited cell proliferation, induced cell apoptosis, promoted cycle arrest and facilitated ferroptosis in MM. Moreover, ginsenoside Rh4 inhibited SIRT2 expression in MM cells. The overexpression of SIRT2 reversed the effects of ginsenoside Rh4 on cell proliferation, cell apoptosis, cycle arrest and ferroptosis in MM. Overall, ginsenoside Rh4 inhibited the malignant progression of MM and induced ferroptosis by regulating SIRT2.

Drug Repurposing in Oncology: A Systematic Review of Randomized Controlled Clinical Trials

Quality pharmacological treatment can improve survival in many types of cancer. Drug repurposing offers advantages in comparison with traditional drug development procedures, reducing time and risk. This systematic review identified the most recent randomized controlled clinical trials that focus on drug repurposing in oncology. We found that only a few clinical trials were placebo-controlled or standard-of-care-alone-controlled. Metformin has been studied for potential use in various types of cancer, including prostate, lung, and pancreatic cancer. Other studies assessed the possible use of the antiparasitic agent mebendazole in colorectal cancer and of propranolol in multiple myeloma or, when combined with etodolac, in breast cancer. We were able to identify trials that study the potential use of known antineoplastics in other non-oncological conditions, such as imatinib for severe coronavirus disease in 2019 or a study protocol aiming to assess the possible repurposing of leuprolide for Alzheimer's disease. Major limitations of these clinical trials were the small sample size, the high clinical heterogeneity of the participants regarding the stage of the neoplastic disease, and the lack of accounting for multimorbidity and other baseline clinical characteristics. Drug repurposing possibilities in oncology must be carefully examined with well-designed trials, considering factors that could influence prognosis.