β2-AR signaling controls trastuzumab resistance-dependent pathway

Neuroscience in peripheral cancers: tumors hijacking nerves and neuroimmune crosstalk

Cancer neuroscience is an emerging field that investigates the intricate relationship between the nervous system and cancer, gaining increasing recognition for its importance. The central nervous system governs the development of the nervous system and directly affects brain tumors, and the peripheral nervous system (PNS) shapes the tumor microenvironment (TME) of peripheral tumors. Both systems are crucial in cancer initiation and progression, with recent studies revealing a more intricate role of the PNS within the TME. Tumors not only invade nerves but also persuade them through remodeling to further promote malignancy, creating a bidirectional interaction between nerves and cancers. Notably, immune cells also contribute to this communication, forming a triangular relationship that influences protumor inflammation and the effectiveness of immunotherapy. This review delves into the intricate mechanisms connecting the PNS and tumors, focusing on how various immune cell types influence nerve‒tumor interactions, emphasizing the clinical relevance of nerve‒tumor and nerve‒immune dynamics. By deepening our understanding of the interplay between nerves, cancer, and immune cells, this review has the potential to reshape tumor biology insights, inspire innovative therapies, and improve clinical outcomes for cancer patients.

STAT3: Key targets of growth-promoting receptor positive breast cancer

Breast cancer has become the malignant tumor with the first incidence and the second mortality among female cancers. Most female breast cancers belong to luminal-type breast cancer and HER2-positive breast cancer. These breast cancer cells all have different driving genes, which constantly promote the proliferation and metastasis of breast cancer cells. Signal transducer and activator of transcription 3 (STAT3) is an important breast cancer-related gene, which can promote the progress of breast cancer. It has been proved in clinical and basic research that over-expressed and constitutively activated STAT3 is involved in the progress, proliferation, metastasis and chemotherapy resistance of breast cancer. STAT3 is an important key target in luminal-type breast cancer and HER2-positive cancer, which has an important impact on the curative effect of related treatments. In breast cancer, the activation of STAT3 will change the spatial position of STAT3 protein and cause different phenotypic changes of breast cancer cells. In the current basic research and clinical research, small molecule inhibitors activated by targeting STAT3 can effectively treat breast cancer, and enhance the efficacy level of related treatment methods for luminal-type and HER2-positive breast cancers.

Impact of Tumoral β2-Adrenergic Receptor Expression on Chemotherapeutic Response and Prognosis in Patients with Advanced Colorectal Cancer

BACKGROUND

The β2-adrenergic receptor (β2-AR) is a therapeutic target for circulatory agonists and exhibits oncogenic activity in several cancers. However, its role in advanced colorectal cancer (CRC) treated using chemotherapy remains unclear. We investigated the potential of β2-AR as a novel chemosensitivity marker and therapeutic target in inoperable CRC.

METHODS

β2-AR expression was evaluated immunohistochemically in 80 advanced or recurrent CRC cases for which untreated resected specimens were available before systemic chemotherapy implementation. We assessed the relationship among β2-AR protein expression, clinicopathological factors, therapeutic response, and prognosis. Furthermore, we evaluated the significance of β2-AR as an in vitro and in vivo therapeutic target using CRC cell lines and a CRC xenograft model treated with the β-blocker, propranolol, and other anticancer agents.

RESULTS

High tumoral β2-AR expression was associated with shorter progression-free survival and chemotherapeutic resistance in patients treated with oxaliplatin-based regimens and bevacizumab-based regimens. We found no synergistic effect between propranolol and oxaliplatin. However, combined administration of propranolol and bevacizumab induced significant tumor shrinkage in the CRC xenograft model.

CONCLUSIONS

β2-AR is a possible biomarker for chemosensitivity and prognosis in advanced CRC. Repositioning existing β-blockers could be beneficial for treating CRC resistant to existing treatment regimens.

The sympathetic nervous system shapes the tumor microenvironment to impair chemotherapy response

The tumor microenvironment influences cancer progression and response to treatments, which ultimately impacts the survival of patients with cancer. The sympathetic nervous system (SNS) is a core component of solid tumors that arise in the body. In addition to influencing cancer progression, a role for the SNS in the effectiveness of cancer treatments is beginning to emerge. This review explores evidence that the SNS impairs chemotherapy efficacy. We review findings of studies that evaluated the impact of neural ablation on chemotherapy outcomes and discuss plausible mechanisms for the impact of neural signaling on chemotherapy efficacy. We then discuss implications for clinical practice, including opportunities to block neural signaling to improve response to chemotherapy.

Nerve-tumor crosstalk in tumor microenvironment: From tumor initiation and progression to clinical implications

The autonomic nerve system (ANS) innervates organs and tissues throughout the body and maintains functional balance among various systems. Further investigations have shown that excessive activation of ANS not only causes disruption of homeostasis, but also may promote tumor formation. In addition, the dynamic interaction between nerve and tumor cells in the tumor microenvironment also regulate tumor progression. On the one hand, nerves are passively invaded by tumor cells, that is, perineural invasion (PNI). On the other hand, compared with normal tissues, tumor tissues are subject to more abundant innervation, and nerves can influence tumor progression through regulating tumor proliferation, metastasis and drug resistance. A large number of studies have shown that nerve-tumor crosstalk, including PNI and innervation, is closely related to the prognosis of patients, and contributes to the formation of cancer pain, which significantly deteriorates the quality of life for patients. These findings suggest that nerve-tumor crosstalk represents a potential target for anti-tumor therapies and the management of cancer pain in the future. In this review, we systematically describe the mechanism by which nerve-tumor crosstalk regulates tumorigenesis and progression.

Harnessing adrenergic blockade in stress-promoted TNBC in vitro and solid tumor in vivo: disrupting HIF-1α and GSK-3β/β-catenin driven resistance to doxorubicin

Sympathetic activation triggered by chronic stress afflicting cancer survivors is an emerging modulator of tumorigenesis. Adrenergic blockade was previously associated with improving response to doxorubicin (DOX) in triple-negative breast cancer (TNBC), yet the precise underlying mechanisms remain obscure. The resilience of cancer stem cells (CSCs) during chemotherapy fosters resistance and relapse. Hypoxia-inducible factor-1α (HIF-1α) and β-catenin are intertwined transcriptional factors that enrich CSCs and evidence suggests that their expression could be modulated by systemic adrenergic signals. Herein, we aimed to explore the impact of adrenoreceptor blockade using carvedilol (CAR) on DOX and its potential to modulate CSCs overcoming chemoresistance. To achieve this aim, in vitro studies were conducted using adrenaline-preincubated MDA-MB-231 cells and in vivo studies using a chronic restraint stress-promoted solid tumor mouse model. Results revealed that adrenaline increased TNBC proliferation and induced a phenotypic switch reminiscent of CSCs, as evidenced by enhanced mammosphere formation. These results paralleled an increase in aldehyde dehydrogenase-1 (ALDH-1) and Nanog expression levels as well as HIF-1α and β-catenin upsurge. In vivo, larger tumor volumes were observed in mice under chronic stress compared to their unstressed counterparts. Adrenergic blockade using CAR, however, enhanced the impact DOX had on halting TNBC cell proliferation and tumor growth via enhanced apoptosis. CAR also curbed HIF-1α and β-catenin tumor levels subsequently suppressing ALDH-1 and SOX2. Our study unveils a central role for HIF-1α linking stress-induced sympathetic activation fueling CSC enrichment via the β-catenin pathway. It also highlights novel insights into CAR's capacity in reversing DOX chemoresistance in TNBC.

Unveiling the Molecular Mechanism of Trastuzumab Resistance in SKBR3 and BT474 Cell Lines for HER2 Positive Breast Cancer

HER2-positive breast cancer is one of the most prevalent forms of cancer among women worldwide. Generally, the molecular characteristics of this breast cancer include activation of human epidermal growth factor receptor-2 (HER2) and hormone receptor activation. HER2-positive is associated with a higher death rate, which led to the development of a monoclonal antibody called trastuzumab, specifically targeting HER2. The success rate of HER2-positive breast cancer treatment has been increased; however, drug resistance remains a challenge. This fact motivated us to explore the underlying molecular mechanisms of trastuzumab resistance. For this purpose, a two-fold approach was taken by considering well-known breast cancer cell lines SKBR3 and BT474. In the first fold, trastuzumab treatment doses were optimized separately for both cell lines. This was done based on the proliferation rate of cells in response to a wide variety of medication dosages. Thereafter, each cell line was cultivated with a steady dosage of herceptin for several months. During this period, six time points were selected for further in vitro analysis, ranging from the untreated cell line at the beginning to a fully resistant cell line at the end of the experiment. In the second fold, nucleic acids were extracted for further high throughput-based microarray experiments of gene and microRNA expression. Such expression data were further analyzed in order to infer the molecular mechanisms involved in the underlying development of trastuzumab resistance. In the list of differentially expressed genes and miRNAs, multiple genes (e.g., BIRC5, E2F1, TFRC, and USP1) and miRNAs (e.g., hsa miR 574 3p, hsa miR 4530, and hsa miR 197 3p) responsible for trastuzumab resistance were found. Downstream analysis showed that TFRC, E2F1, and USP1 were also targeted by hsa-miR-8485. Moreover, it indicated that miR-4701-5p was highly expressed as compared to TFRC in the SKBR3 cell line. These results unveil key genes and miRNAs as molecular regulators for trastuzumab resistance.

MicroRNA-21's role in PTEN suppression and PI3K/AKT activation: Implications for cancer biology

MicroRNA-21 (miR-21) was recognized as a key figure in the intricate web of tumor biology, with a prominent role in regulating the PTEN tumor suppressor gene and the PI3K/AKT cascade. This review elucidates the multifaceted interactions between miR-21, PTEN, and the PI3K/AKT signaling, shedding light on their profound implications in cancer initiation, progression, and therapeutic strategies. The core of this review delves into the mechanical intricacies of miR-21-mediated PTEN suppression and its consequent impact on PI3K/AKT pathway activation. It explores how miR-21, as an oncogenic miRNA, targets PTEN directly or indirectly, resulting in uncontrolled activation of PI3K/AKT, fostering cancerous cell survival, proliferation, and evasion of apoptosis. Furthermore, the abstract emphasizes the clinical relevance of these molecular interactions, discussing their implications in various cancer types, prognostic significance, and potential as therapeutic targets. The review provides insights into ongoing research efforts to develop miR-21 inhibitors and strategies to restore PTEN function, offering new avenues for cancer treatment. This article illuminates the critical function of miR-21 in PTEN suppression and PI3K/AKT activation, offering profound insights into its implications for cancer biology and the potential for targeted interventions.

β2-Adrenoceptor Activation Favor Acquisition of Tumorigenic Properties in Non-Tumorigenic MCF-10A Breast Epithelial Cells

Noradrenaline and adrenaline, and their cognate receptors, are currently accepted to participate in cancer progression. They may also participate in cancer initiation, although their role in this phase is much less explored. The aim of this work was to study the influence of adrenergic stimulation in several processes related to breast cancer carcinogenesis, using several adrenergic agonists in the MCF-10A non-tumorigenic breast cells. Activation of the β-adrenoceptors promoted an epithelial phenotype in MCF-10A cells, revealed by an increased expression of the epithelial marker E-cadherin and a decrease in the mesenchymal markers, N-cadherin and vimentin. MCF-10A cell motility and migration were also impaired after the β-adrenoceptors activation. Concomitant with this effect, β-adrenoceptors decrease cell protrusions (lamellipodia and filopodia) while increasing cell adhesion. Activation of the β-adrenoceptors also decreases MCF-10A cell proliferation. When the MCF-10A cells were cultured under low attachment conditions, activation the of β- (likely β2) or of α2-adrenoceptors had protective effects against cell death, suggesting a pro-survival role of these adrenoceptors. Overall, our results showed that, in breast cells, adrenoceptor activation (mainly through β-adrenoceptors) may be a risk factor in breast cancer by inducing some cancer hallmarks, providing a mechanistic explanation for the increase in breast cancer incidences that may be associated with conditions that cause massive adrenergic stimulation, such as stress.

The nerve cells in gastrointestinal cancers: from molecular mechanisms to clinical intervention

Gastrointestinal (GI) cancer is a formidable malignancy with significant morbidity and mortality rates. Recent studies have shed light on the complex interplay between the nervous system and the GI system, influencing various aspects of GI tumorigenesis, such as the malignance of cancer cells, the conformation of tumor microenvironment (TME), and the resistance to chemotherapies. The discussion in this review first focused on exploring the intricate details of the biological function of the nervous system in the development of the GI tract and the progression of tumors within it. Meanwhile, the cancer cell-originated feedback regulation on the nervous system is revealed to play a crucial role in the growth and development of nerve cells within tumor tissues. This interaction is vital for understanding the complex relationship between the nervous system and GI oncogenesis. Additionally, the study identified various components within the TME that possess a significant influence on the occurrence and progression of GI cancer, including microbiota, immune cells, and fibroblasts. Moreover, we highlighted the transformation relationship between non-neuronal cells and neuronal cells during GI cancer progression, inspiring the development of strategies for nervous system-guided anti-tumor drugs. By further elucidating the deep mechanism of various neuroregulatory signals and neuronal intervention, we underlined the potential of these targeted drugs translating into effective therapies for GI cancer treatment. In summary, this review provides an overview of the mechanisms of neuromodulation and explores potential therapeutic opportunities, providing insights into the understanding and management of GI cancers.

Pyrotinib-based therapeutic approaches for HER2-positive breast cancer: the time is now

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) is a highly aggressive subtype associated with poor prognosis. The advent of HER2-targeted drugs, including monoclonal antibodies, tyrosine-kinase inhibitors (TKIs) and antibody-drug conjugates, has yielded improved prognosis for patients. Compared with widely used monoclonal antibodies, small-molecule TKIs have unique advantages including oral administration and favorable penetration of blood-brain barrier for brain metastatic BC, and reduced cardiotoxicity. Pyrotinib is an irreversible TKI of the pan-ErbB receptor, and has recently been shown to be clinically effective for the treatment of HER2-positive BC in metastatic and neoadjuvant settings. This review highlights the development on the application of pyrotinib-based therapeutic approaches in the clinical settings of HER2-positive BC.

β2-AR inhibition enhances EGFR antibody efficacy hampering the oxidative stress response machinery

The β2-Adrenergic receptor (β2-ARs) is a cell membrane-spanning G protein-coupled receptors (GPCRs) physiologically involved in stress-related response. In many cancers, the β2-ARs signaling drives the tumor development and transformation, also promoting the resistance to the treatments. In HNSCC cell lines, the β2-AR selective inhibition synergistically amplifies the cytotoxic effect of the MEK 1/2 by affecting the p38/NF-kB oncogenic pathway and contemporary reducing the NRF-2 mediated antioxidant cell response. In this study, we aimed to validate the anti-tumor effect of β2-AR blockade and the synergism with MEK/ERK and EGFR pathway inhibition in a pre-clinical orthotopic mouse model of HNSCC. Interestingly, we found a strong β2-ARs expression in the tumors that were significantly reduced after prolonged treatment with β2-Ars inhibitor (ICI) and EGFR mAb Cetuximab (CTX) in combination. The β2-ARs down-regulation correlated in mice with a significant tumor growth delay, together with the MAPK signaling switch-off caused by the blockade of the MEK/ERK phosphorylation. We also demonstrated that the administration of ICI and CTX in combination unbalanced the cell ROS homeostasis by blocking the NRF-2 nuclear translocation with the relative down-regulation of the antioxidant enzyme expression. Our findings highlighted for the first time, in a pre-clinical in vivo model, the efficacy of the β2-ARs inhibition in the treatment of the HNSCC, remarkably in combination with CTX, which is the standard of care for unresectable HNSCC.

Nervous regulation: beta-2-adrenergic signaling in immune homeostasis, cancer immunotherapy, and autoimmune diseases

Beta-2-adrenergic receptor (β2-AR) mediates neural signaling from the sympathetic nervous system (SNS) to the immune system to modulate immunogenic and immunosuppressive responses for maintaining immune homeostasis. β2-AR regulates various cellular activities on the innate and adaptive immune cells through differential signaling to modulate activation, proliferation, differentiation, and cytokine production. This signaling pathway has been found to be critical for regulating anti-tumor immune responses and autoimmune responses. Recently, β2-AR has also been implicated in the mobilization of immune cells in peripheral blood and ex-vivo expansion of cytotoxic T cells from donor blood that has clinical implications for improving cancer immunotherapy. This review attempts to provide a comprehensive overview of the established and emerging roles of β2-AR signaling in immune homeostasis, cancer immunotherapy, and autoimmune diseases.

Survival outcomes of beta-blocker usage in HER2-positive advanced breast cancer patients: a retrospective cohort study

Background

Clinical trials investigating the effects of beta-blockers (BBs) on cancer are underway. Evidence from preclinical research suggests that BBs could serve as anticancer agents and immune boosters. There is conflicting evidence regarding the effect of BB use on clinical outcomes in patients with breast cancer.

Objectives

The study aimed to determine whether BB use is associated with progression-free survival (PFS) and overall survival (OS) in patients receiving anti-human epidermal growth factor receptor 2 (HER2) treatment for advanced breast cancer.

Design

Retrospective hospital-based study.

Methods

The participants enrolled were breast cancer patients with advanced HER2-positive status who initiated trastuzumab monotherapy or concomitant therapy with trastuzumab and any dose of BB. The patients were enrolled between January 2012 and May 2021 and divided into three groups based on whether they received a BB or not in the therapeutic regimen: BB-/trastuzumab+, BB+ (non-selective)/trastuzumab+, and BB+ (selective)/trastuzumab+. PFS and OS were the primary and secondary endpoints, respectively.

Results

The estimated median PFS in the BB-/trastuzumab+, BB+ (non-selective)/trastuzumab+, and BB+ (selective)/trastuzumab+ groups was 51.93, 21.50, and 20.77 months, respectively. The corresponding OS was 56.70, 29.10, and 27.17 months. The intergroup differences in these durations were significant. Both PFS [adjusted hazard ratio (HR): 2.21, 95% confidence interval (CI): 1.56-3.12; p < 0.001]) and OS (adjusted HR: 2.46, 95% CI: 1.69-3.57; p < 0.001) were worse when BBs were used.

Conclusion

Our study provides important evidence that BB use potentially has a negative effect on patients with HER2-positive advanced breast cancer. Nevertheless, despite the study's results, cardiovascular disease (CVD) should be appropriately treated in patients with HER2-positive advanced breast cancer. Other types of drugs can be used to treat CVD, but BB use should be avoided. Large real-world database and prospective studies should be conducted to validate the results of this study.

Norepinephrine/β2-Adrenergic Receptor Pathway Promotes the Cell Proliferation and Nerve Growth Factor Production in Triple-Negative Breast Cancer

PURPOSE

Invasive ductal carcinoma (IDC) accounts for 90% of triple-negative breast cancer (TNBC). IDC is mainly derived from the breast ductal epithelium which is innervated by the 4th to 6th thoracic sympathetic nerves. However, little is known about the contribution of the interactions between sympathetic nerves and breast cancer cells to the malignant progression of TNBC.

METHODS

The expression levels of the β₂-adrenergic receptor (β₂-AR, encoded by ADRB2 gene), nerve growth factor (NGF), and tropomyosin receptor kinase A (TrkA) were determined using immunohistochemistry (IHC). NGF expression levels in the serum were compared by enzyme-linked immunosorbent assay (ELISA). Cell proliferation was assessed using the Cell Counting Kit-8 assay. The β₂-AR, NGF, p-ERK, and p-CERB expression levels were determined using western blotting. TNBC cells and neuronal cells of the dorsal root ganglion (DRG) in 2-day-old Sprague Dawley rats were co-cultured. Using norepinephrine (NE), NGF, and β₂-AR, NGF/TrkA blocker pretreatments, the axon growth of each group of DRG neuron cells was detected by immunofluorescence analysis.

RESULTS

The sympathetic adrenergic neurotransmitter NE activated the ERK signaling pathway in TNBC cells. NE/β₂-AR signaling promotes NGF secretion. NGF further facilitates the malignant progression of TNBC by increasing sympathetic neurogenesis. In the co-culture assay, the sympathetic adrenergic NE/β₂-AR signal pathway also enhanced NGF secretion. NGF binds TrkA in DRG neurons and promotes axonal growth.

CONCLUSION

These results suggest that NE/β₂-AR pathway promotes cell proliferation and NGF production in triple-negative breast cancer.

Impact of Beta Blockers on Breast Cancer Incidence and Prognosis

Several studies have investigated the link between beta blockers (BB) and breast cancer outcomes but have reported mixed results. Our aim was to investigate the relationship between BB and breast cancer outcomes. Literatures investigating the relationship between BB and breast cancer outcomes were searched through PubMed and Embase. A total 43 articles were included by meta-analysis. We found BB increased breast cancer risk (n = 22, RR: 1.169, 95% CI: 1.063-1.285). We also found BB were associated with a lower overall survival (OS, n = 19, RR: 1.125, 95% CI: 1.078-1.173) and a higher recurrence risk (n = 8, RR: 1.130, 95% CI: 1.040-1.227) for breast cancer. Interestingly, subgroup analyses found only selective BB increased breast cancer risk (n = 5, RR: 1.766, 95% CI: 1.148-2.718) and recurrence risk (n = 2, RR: 1.168 -, 95% CI: 1.026-1.328) while only nonselective BB were associated with a lower OS (n = 4, RR: 1.135, 95% CI: 1.073-1.202) for breast cancer. Moreover, we found BB were associated with a significantly lower OS (n = 3, RR: 2.751, 95% CI: 1.213-6.238) and higher recurrence (n = 2, RR: 1.284, 95% CI: 1.102-1.497) only in luminal breast cancer while with a higher PFS (n = 2, RR: 0.585, 95% CI: 0.343-0.997) in Her2+ breast cancer. No significant differences in terms of CSM (n = 19, RR: 1.009, 95% CI: 0.947-1.077), PFS (n = 4, RR: 0.932, 95% CI: 0.616-1.305), and DFS (n = 2, RR: 0.776, 95% CI: 0.512-1.176) were observed. Our results provide evidence of the relationship between BB and breast cancer incidence and prognosis.

Sympathetic β2-adrenergic receptor blockade overcomes docetaxel resistance in prostate cancer

PURPOSE

Due to the limited effective therapies, resistance to docetaxel is ordinarily fatal and remains a critical clinical challenge.β2-adrenergic receptor(β2-AR)can promote the metastasis and invasion of prostate cancer, but the role in chemotherapy-resistant prostate cancer remains unclear.

METHODS

By downloading the GEO database in NCBI, the expression of β2-AR in different prostate tissues was analyzed. We constructed docetaxel-resistant prostate cancer cell lines by the method of dose-escalation. LC3B-labeled stable cells and shAtg5 knockdown stable cells were constructed by lentivirus infection. The molecular mechanism of β2-AR affecting docetaxel sensitivity through apoptosis and autophage were investigated by flow cytometry, mitochondrial membrane potential and western blot. Then we detected the interaction between autophagy and apoptotic by performing immunoprecipitation assay.

RESULTS

We show that restraining the activity of β₂-AR sensitized the cell response and reduced the resistance to docetaxel. The mechanism involves the regulation of β₂-AR in the cellular response to docetaxel through apoptosis and autophagy via caspase signaling and Atg5/AMPK/mTOR pathway as well as the effect of β₂-AR on the crosstalk between apoptosis and autophagy via p38 MAPK and JNK/c-Jun/FOXO3a signaling pathways.

CONCLUSION

Our data demonstrate that β₂-AR inhibitor-induced autophagy and apoptosis contribute to the effectiveness responses to docetaxel in castration-resistant prostate cancer, and in combination with pharmacological agents of β₂-AR and autophagy inhibitors may provide a potential therapeutic strategy to enhance the limited capacity of docetaxel to control castration-resistant prostate cancer.

MUC1 induces the accumulation of Foxp3+ Treg cells in the tumor microenvironment to promote the growth and metastasis of cholangiocarcinoma through the EGFR/PI3K/Akt signaling pathway

Tumor microenvironment (TME) plays an important role in the progression of cholangiocarcinoma. This study aims to explore whether Mucin 1 (MUC1) regulates Foxp3⁺ Treg cells in the TME of cholangiocarcinoma through the epidermal growth factor receptor (EGFR)/phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway. High-throughput sequencing dataset in the GEO database combined with GeneCards and Phenolyzer databases was used to obtain key genes in cholangiocarcinoma, followed by downstream pathway prediction. The relationship among MUC1, EGFR, and PI3K/Akt signaling pathway was explored. CD4⁺ T cells extracted from peripheral blood were induced to differentiate into Treg cells, followed by co-culture with cholangiocarcinoma cells. A mouse model was constructed to detect the role of MUC1 in the accumulation of Foxp3⁺ Treg cells, malignant phenotypes of cholangiocarcinoma, and tumorigenesis in vivo. MUC1, highly expressed in cholangiocarcinoma, might be involved in cholangiocarcinoma development. MUC1 interacted with the EGFR to activate the EGFR/PI3K/Akt signaling pathway. MUC1 overexpression could activate the EGFR/PI3K/Akt signaling pathway, which promoted the accumulation of Foxp3⁺ Treg cells in the TME and the malignant phenotypes of cholangiocarcinoma cells both in vitro and in vivo and enhanced tumorigenesis in vivo. MUC1 may interact with EGFR to activate the EGFR/PI3K/Akt signaling pathway, which induces the accumulation of Foxp3⁺ Treg cells, enhancing the malignant phenotypes of cholangiocarcinoma cells and tumorigenesis in vivo and ultimately augmenting cholangiocarcinoma growth and metastasis.

Breast cancer and neurotransmitters: emerging insights on mechanisms and therapeutic directions

Exploring the relationship between various neurotransmitters and breast cancer cell growth has revealed their likely centrality to improving breast cancer treatment. Neurotransmitters play a key role in breast cancer biology through their effects on the cell cycle, epithelial mesenchymal transition, angiogenesis, inflammation, the tumor microenvironment and other pathways. Neurotransmitters and their receptors are vital to the initiation, progression and drug resistance of cancer and progress in our biological understanding may point the way to lower-cost and lower-risk antitumor therapeutic strategies. This review discusses multiple neurotransmitters in the context of breast cancer. It also discusses risk factors, repurposing of pharmaceuticals impacting neurotransmitter pathways, and the opportunity for better integrated models that encompass exercise, the intestinal microbiome, and other non-pharmacologic considerations. Neurotransmitters' role in breast cancer should no longer be ignored; it may appear to complicate the molecular picture but the ubiquity of neurotransmitters and their wide-ranging impacts provide an organizing framework upon which further understanding and progress against breast cancer can be based.

Chronic stress in solid tumor development: from mechanisms to interventions

Chronic stress results in disturbances of body hormones through the neuroendocrine system. Cancer patients often experience recurrent anxiety and restlessness during disease progression and treatment, which aggravates disease progression and hinders treatment effects. Recent studies have shown that chronic stress-regulated neuroendocrine systems secret hormones to activate many signaling pathways related to tumor development in tumor cells. The activated neuroendocrine system acts not only on tumor cells but also modulates the survival and metabolic changes of surrounding non-cancerous cells. Current clinical evidences also suggest that chronic stress affects the outcome of cancer treatment. However, in clinic, there is lack of effective treatment for chronic stress in cancer patients. In this review, we discuss the main mechanisms by which chronic stress regulates the tumor microenvironment, including functional regulation of tumor cells by stress hormones (stem cell-like properties, metastasis, angiogenesis, DNA damage accumulation, and apoptotic resistance), metabolic reprogramming and immune escape, and peritumor neuromodulation. Based on the current clinical treatment framework for cancer and chronic stress, we also summarize pharmacological and non-pharmacological therapeutic approaches to provide some directions for cancer therapy.

Activation of β-Adrenoceptors Promotes Lipid Droplet Accumulation in MCF-7 Breast Cancer Cells via cAMP/PKA/EPAC Pathways

Physiologically, β-adrenoceptors are major regulators of lipid metabolism, which may be reflected in alterations in lipid droplet dynamics. β-adrenoceptors have also been shown to participate in breast cancer carcinogenesis. Since lipid droplets may be seen as a hallmark of cancer, the present study aimed to investigate the role of β-adrenoceptors in the regulation of lipid droplet dynamics in MCF-7 breast cancer cells. Cells were treated for up to 72 h with adrenaline (an endogenous adrenoceptor agonist), isoprenaline (a non-selective β-adrenoceptor agonist) and salbutamol (a selective β₂-selective agonist), and their effects on lipid droplets were evaluated using Nile Red staining. Adrenaline or isoprenaline, but not salbutamol, caused a lipid-accumulating phenotype in the MCF-7 cells. These effects were significantly reduced by selective β₁- and β₃-antagonists (10 nM atenolol and 100 nM L-748,337, respectively), indicating a dependence on both β₁- and β₃-adrenoceptors. These effects were dependent on the cAMP signalling pathway, involving both protein kinase A (PKA) and cAMP-dependent guanine-nucleotide-exchange (EPAC) proteins: treatment with cAMP-elevating agents (forskolin or 8-Br-cAMP) induced lipid droplet accumulation, whereas either 1 µM H-89 or 1 µM ESI-09 (PKA or EPAC inhibitors, respectively) abrogated this effect. Taken together, the present results demonstrate the existence of a β-adrenoceptor-mediated regulation of lipid droplet dynamics in breast cancer cells, likely involving β₁- and β₃-adrenoceptors, revealing a new mechanism by which adrenergic stimulation may influence cancer cell metabolism.

Pathological changes in GPCR signal organisation: Opportunities for targeted therapies for triple negative breast cancer

Triple negative breast cancer (TNBC) has the poorest prognosis compared to other breast cancer subtypes, due to a historical lack of targeted therapies and high rates of relapse. Greater insight into the components of signalling pathways in TNBC tumour cells has led to the clinical evaluation, and in some cases approval, of targeted therapies. In the last decade, G protein-coupled receptors, such as the β₂-adrenoceptor, have emerged as potential new therapeutic targets. Here, we describe how the β₂-adrenoceptor accelerates TNBC progression in response to stress, and the unique signalling pathway activated by the β₂-adrenoceptor to drive the invasion of an aggressive TNBC tumour cell. We highlight evidence that supports an altered organisation of GPCRs in tumour cells, and suggests that activation of the same GPCR in a different cellular location can control unique cell responses. Finally, we speculate how the relocation of GPCRs to the "wrong" place in tumour cells presents opportunities to develop targeted anti-cancer GPCR drugs with greater efficacy and minimal adverse effects.

Resistance to Trastuzumab

Simple Summary

Trastuzumab is a humanized antibody that has significantly improved the management and treatment outcomes of patients with cancers that overexpress HER2. Many research groups, both in academia and industry, have contributed towards understanding the various mechanisms engaged by trastuzumab to mediate its anti-tumor effects. Nevertheless, data from several clinical studies have indicated that a significant proportion of patients exhibit primary or acquired resistance to trastuzumab therapy. In this article, we discuss underlying mechanisms that contribute towards to resistance. Furthermore, we discuss the potential strategies to overcome some of the mechanisms of resistance to enhance the therapeutic efficacy of trastuzumab and other therapies based on it.

Abstract

One of the most impactful biologics for the treatment of breast cancer is the humanized monoclonal antibody, trastuzumab, which specifically recognizes the HER2/neu (HER2) protein encoded by the ERBB2 gene. Useful for both advanced and early breast cancers, trastuzumab has multiple mechanisms of action. Classical mechanisms attributed to trastuzumab action include cell cycle arrest, induction of apoptosis, and antibody-dependent cell-mediated cytotoxicity (ADCC). Recent studies have identified the role of the adaptive immune system in the clinical actions of trastuzumab. Despite the multiple mechanisms of action, many patients demonstrate resistance, primary or adaptive. Newly identified molecular and cellular mechanisms of trastuzumab resistance include induction of immune suppression, vascular mimicry, generation of breast cancer stem cells, deregulation of long non-coding RNAs, and metabolic escape. These newly identified mechanisms of resistance are discussed in detail in this review, particularly considering how they may lead to the development of well-rationalized, patient-tailored combinations that improve patient survival.

Neuroimmune crosstalk and its impact on cancer therapy and research

Cancer is a major health problem as it is the first or second leading cause of death worldwide. The global cancer burden is expected to rise 47% relative to 2020 cancer incidence. Recently, the fields of neuroscience, neuroimmunology and oncology have elaborated the neuroimmune crosstalk role in tumor initiation, invasion, progression, and metastases. The nervous system exerts a broad impact on the tumor microenvironment by interacting with a complex network of cells such as stromal, endothelial, malignant cells and immune cells. This communication modulates cancer proliferation, invasion, metastasis, induce resistance to apoptosis and promote immune evasion. This paper has two aims, the first aim is to explain neuroimmune crosstalk in cancer, tumor innervation origin and peripheral nervous system, exosomes, and miRNA roles. The second aim is to elaborate neuroimmune crosstalk impact on cancer therapy and research highlighting various potential novel strategies such as use of immune checkpoint inhibitors and anti-neurogenic drugs as single agents, drug repurposing, miRNA-based and si-RNA-based therapies, tumor denervation, cellular therapies, and oncolytic virus therapy.

β-blockers and breast cancer survival by molecular subtypes: a population-based cohort study and meta-analysis

Background

The association between use of β-blockers and breast cancer (BC) prognosis has been investigated in several observational studies, with conflicting results. We performed a nationwide cohort study and a meta-analysis to investigate the association, and assess if it varied between molecular subtypes of BC.

Methods

We identified women aged ≥50 years with BC diagnosed between 2004 and 2018 in Norway. We used Cox regression models to estimate the association between β-blocker use at diagnosis and BC-specific survival, overall and by molecular subtype. We performed a meta-analysis of observational studies that reported molecular subtype-specific estimates of this association.

Results

We included 30,060 women, of which 4461 (15%) used β-blockers. After a median follow-up of 5.1 years, 2826 (9%) died of BC. Overall, β-blocker use was not associated with BC-specific survival (hazard ratio [HR] = 1.07; 95% confidence interval [CI]: 0.97–1.19). We found an association only in triple-negative BC (TNBC) patients (HR = 0.66; 95% CI: 0.47–0.91). This was confirmed in the meta-analysis: β-blocker use was associated with progression/recurrence-free (HR = 0.58; 95% CI: 0.38–0.89) and BC-specific survival (HR = 0.74; 95% CI: 0.55–1.00) in TNBC patients only.

Conclusion

In our cohort of BC patients and in the meta-analysis, β-blocker use was associated with prolonged BC-specific survival only in TNBC patients.

Contribution of adrenergic mechanisms for the stress-induced breast cancer carcinogenesis

Breast cancer is the most common and deadliest type of cancer in women. Stress exposure has been associated with carcinogenesis and the stress released neurotransmitters, noradrenaline and adrenaline, and their cognate receptors, can participate in the carcinogenesis process, either by regulating tumor microenvironment or by promoting systemic changes. This work intends to provide an overview of the research done in this area and try to unravel the role of adrenergic ligands in the context of breast carcinogenesis. In the initiation phase, adrenergic signaling may favor neoplastic transformation of breast epithelial cells whereas, during cancer progression, may favor the metastatic potential of breast cancer cells. Additionally, adrenergic signaling can alter the function and activity of other cells present in the tumor microenvironment towards a protumor phenotype, namely macrophages, fibroblasts, and by altering adipocyte's function. Adrenergic signaling also promotes angiogenesis and lymphangiogenesis and, systemically, may induce the formation of preneoplastic niches, cancer-associated cachexia and alterations in the immune system which contribute for the loss of quality of life of breast cancer patients and their capacity to fight cancer. Most studies points to a major contribution of β₂ -adrenoceptor activated pathways on these effects. The current knowledge of the mechanistic pathways activated by β₂ -adrenoceptors in physiology and pathophysiology, the availability of selective drugs approved for clinical use and a deeper knowledge of the basic cellular and molecular pathways by which adrenergic stimulation may influence cancer initiation and progression, opens the possibility to use new therapeutic alternatives to improve efficacy of breast cancer treatments.

The molecular mechanism of chronic stress affecting the occurrence and development of breast cancer and potential drug therapy

According to the 2020 data released by the International Agency for Research on Cancer, breast cancer has surpassed lung cancer as the world's most newly diagnosed first-time cancer. Compared with patients with other types of cancer, those with breast cancer experience greater mental stress and more severe psychological impacts because of the life-threatening diagnosis, physical changes, treatment side effects, and family and social life dysfunctions. These usually manifest as anxiety, depression, nervousness, and insomnia, all of which elicit stress responses. Particularly under chronic stress, the continuous release of neurotransmitters from the neuroendocrine system can have a highly profound impact on the occurrence and prognosis of breast cancer. However, because of the complex mechanisms underlying chronic stress and the variability in individual tolerance, evidence of the role of chronic stress in the occurrence and evolution of breast cancer remains unclear. This article reviewed previous research on the correlation between chronic stress and the occurrence and development of breast cancer, particularly the molecular mechanism through which chronic stress promotes breast cancer via neurotransmitters secreted by the nervous system. We also review the progress in the development of potential drugs or blockers for the treatment of breast cancer by targeting the neuroendocrine system.

Stress and cancer: mechanisms, significance and future directions

The notion that stress and cancer are interlinked has dominated lay discourse for decades. More recent animal studies indicate that stress can substantially facilitate cancer progression through modulating most hallmarks of cancer, and molecular and systemic mechanisms mediating these effects have been elucidated. However, available clinical evidence for such deleterious effects is inconsistent, as epidemiological and stress-reducing clinical interventions have yielded mixed effects on cancer mortality. In this Review, we describe and discuss specific mediating mechanisms identified by preclinical research, and parallel clinical findings. We explain the discrepancy between preclinical and clinical outcomes, through pointing to experimental strengths leveraged by animal studies and through discussing methodological and conceptual obstacles that prevent clinical studies from reflecting the impacts of stress. We suggest approaches to circumvent such obstacles, based on targeting critical phases of cancer progression that are more likely to be stress-sensitive; pharmacologically limiting adrenergic-inflammatory responses triggered by medical procedures; and focusing on more vulnerable populations, employing personalized pharmacological and psychosocial approaches. Recent clinical trials support our hypothesis that psychological and/or pharmacological inhibition of excess adrenergic and/or inflammatory stress signalling, especially alongside cancer treatments, could save lives.

Neuroimmunology of cancer and associated symptomology

Evolutionarily the nervous system and immune cells have evolved to communicate with each other to control inflammation and host responses against injury. Recent findings in neuroimmune communication demonstrate that these mechanisms extend to cancer initiation and progression. Lymphoid structures and tumors, which are often associated with inflammatory infiltrate, are highly innervated by multiple nerve types (e.g. sympathetic, parasympathetic, sensory). Recent preclinical and clinical studies demonstrate that targeting the nervous system could be a therapeutic strategy to promote anti-tumor immunity while simultaneously reducing cancer-associated neurological symptoms, such as chronic pain, fatigue, and cognitive impairment. Sympathetic nerve activity is associated with physiological or psychological stress, which can be induced by tumor development and cancer diagnosis. Targeting the stress response through suppression of sympathetic activity or activation of parasympathetic activity has been shown to drive activation of effector T cells and inhibition of myeloid derived suppressor cells within the tumor. Additionally, there is emerging evidence that sensory nerves may regulate tumor growth and metastasis by promoting or inhibiting immunosuppression in a tumor-type specific manner. Since neural effects are often tumor-type specific, further study is required to optimize clinical therapeutic strategies. This review examines the emerging evidence that neuroimmune communication can regulate anti-tumor immunity as well as contribute to development of cancer-related neurological symptoms.

Role of the nervous system in cancers: a review

Nerves are important pathological elements of the microenvironment of tumors, including those in pancreatic, colon and rectal, prostate, head and neck, and breast cancers. Recent studies have associated perineural invasion with tumor progression and poor outcomes. In turn, tumors drive the reprogramming of neurons to recruit new nerve fibers. Therefore, the crosstalk between nerves and tumors is the hot topic and trend in current cancer investigations. Herein, we reviewed recent studies presenting direct supporting evidences for a better understanding of nerve-tumor interactions.

miR-21 modulates cisplatin resistance of gastric cancer cells by inhibiting autophagy via the PI3K/Akt/mTOR pathway

Resistance to cisplatin (DDP) remains a major obstacle in the control of gastric cancer (GC) progression. A previous study revealed that microRNA-21 (miR-21) contributes to DDP resistance in GC cells via the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. The aim of the current study was to explore the mechanisms underlying the cytoprotective function of miR-21. In this study, DDP-resistant GC cells were obtained by continuous exposure of human gastric adenocarcinoma cells to increasing concentrations of DDP. Western blot analysis was used to evaluate activation of the PI3K/Akt/mechanistic target of rapamycin kinase (mTOR) pathway. The level of miR-21 was altered by transfection of miR-21 mimic and inhibitor. Autophagy was assessed by detecting autophagosome formation, Beclin-1 and LC3 expression. An Annexin V-propidium iodide assay was performed to estimate the survival and death of GC cells. GC cells became refractory to the growth inhibition and apoptosis induced by DDP treatment, activation of Akt and mTOR were increased in DDP-resistant GC cells. Inhibition of autophagy decreased the sensitivity of GC cells to DDP, and autophagy induction produced the opposite effect. DDP-resistant GC cells expressed higher levels of miR-21 compared with the parent cells. Transfection of GC cells with miR-21 mimics contributed to restored DDP resistance by suppressing autophagy, while miR-21 inhibitor sensitized DDP-resistant GC cells by promoting autophagy. In conclusion, the results demonstrated that miR-21 is associated with DDP resistance in GC cells by inhibiting autophagy via the PI3K/Akt/mTOR pathway, and autophagy inducers could be therapeutic targets for the effective treatment of DDP resistance in GC.

Stress reduction strategies in breast cancer: review of pharmacologic and non-pharmacologic based strategies

Breast cancer is the most common cancer diagnosed in women. It is associated with multiple symptoms in both patients and caregivers, such as stress, anxiety, depression, sleep disturbance, and fatigue. Stress appears to promote cancer progression via activation of the sympathetic nervous system releasing epinephrine and norepinephrine as well as activation of hypothalamic-pituitary-adrenal axis releasing cortisol. These stress hormones have been shown to promote the proliferation of cancer cells. This review focuses on stress-reducing strategies which may decrease cancer progression by abrogating these pathways, with a main focus on the β-adrenergic signaling pathway. Patients utilize both non-pharmacologic and pharmacologic strategies to reduce stress. Non-pharmacologic stress-reduction strategies include complementary and alternative medicine techniques, such as meditation, yoga, acupuncture, exercise, use of natural products, support groups and psychology counseling, herbal compounds, and multivitamins. Pharmacologic strategies include abrogating the β2-adrenergic receptor signaling pathway to antagonize epinephrine and norepinephrine action on tumor and immune cells. β-Blocker drugs may play a role in weakening the pro-migratory and pro-metastatic effects induced by stress hormones in cancer and strengthening the anti-tumor immune response. Preclinical models have shown that non-selective β1/2-blocker use is associated with a decrease in tumor growth and metastases and clinical studies have suggested their positive impact on decreasing breast cancer recurrence and mortality. Thus, non-pharmacological approaches, along with pharmacological therapies part of clinical trials are available to cancer patients to reduce stress, and have promise to break the cycle of cancer and stress.

Functionalized silk spheres selectively and effectively deliver a cytotoxic drug to targeted cancer cells in vivo

Background

Chemotherapy is often a first-line therapeutic approach for the treatment of a wide variety of cancers. Targeted drug delivery systems (DDSs) can potentially resolve the problem of chemotherapeutic drug off-targeting effects. Herein, we examined in vivo models to determine the efficacy of Her2-targeting silk spheres (H2.1MS1) as DDSs for delivering doxorubicin (Dox) to Her2-positive and Her2-negative primary and metastatic mouse breast cancers.

Results

The specific accumulation of H2.1MS1 spheres was demonstrated at the site of Her2-positive cancer. Dox delivered only by functionalized H2.1MS1 particles selectively inhibited Her2-positive cancer growth in primary and metastatic models. Moreover, the significant effect of the Dox dose and the frequency of treatment administration on the therapeutic efficacy was indicated. Although the control MS1 spheres accumulated in the lungs in Her2-positive metastatic breast cancer, the Dox-loaded MS1 particles did not treat cancer. Histopathological examination revealed no systemic toxicity after multiple administrations and at increased doses of Dox-loaded silk spheres. Although the studies were performed in immunocompetent mice, the H2.1MS1 silk spheres efficiently delivered the drug, which exerted a therapeutic effect.

Conclusion

Our results indicated that functionalized silk spheres that enable cell-specific recognition, cellular internalization, and drug release represent an efficient strategy for cancer treatment in vivo.

Impairment of Hypoxia-Induced CA IX by Beta-Blocker Propranolol-Impact on Progression and Metastatic Potential of Colorectal Cancer Cells

The coexistence of cancer and other concomitant diseases is very frequent and has substantial implications for treatment decisions and outcomes. Beta-blockers, agents that block the beta-adrenergic receptors, have been related also to cancers. In the model of multicellular spheroids formed by colorectal cancer cells we described a crosstalk between beta-blockade by propranolol and tumour microenvironment. Non-selective beta-blocker propranolol decreased ability of tumour cells to adapt to hypoxia by reducing levels of HIF1α and carbonic anhydrase IX in 3D spheroids. We indicated a double action of propranolol in the tumour microenvironment by inhibiting the stability of HIF1α, thus mediating decrease of CA IX expression and, at the same time, by its possible effect on CA IX activity by decreasing the activity of protein kinase A (PKA). Moreover, the inhibition of β-adrenoreceptors by propranolol enhanced apoptosis, decreased number of mitochondria and lowered the amount of proteins involved in oxidative phosphorylation (V-ATP5A, IV-COX2, III-UQCRC2, II-SDHB, I-NDUFB8). Propranolol reduced metastatic potential, viability and proliferation of colorectal cancer cells cultivated in multicellular spheroids. To choose the right treatment strategy, it is extremely important to know how the treatment of concomitant diseases affects the superior microenvironment that is directly related to the efficiency of anti-cancer therapy

β2-AR activation promotes cleavage and nuclear translocation of Her2 and metastatic potential of cancer cells

Prolonged hypersecretion of catecholamine induced by chronic stress may correlate with malignant progression of cancer. β2‐adrenergic receptor (β2‐AR) overexpressed in certain cancer cells may translate the signals from neuroendocrine system to malignant signals by interacting with oncoproteins, such as Her2. In the present study, we demonstrate that catecholamine stimulation activates the expression and proteolytic activity of ADAM10 by modulating the expression of miR‐199a‐5p and SIRT1 and also confirm that catecholamine induction triggers the activities of γ‐secretase, leading to shedding of Her2 extracellular domain (ECD) by ADAM10 and subsequent intramembranous cleavage of Her2 intracellular domain (ICD) by presenilin‐dependent γ‐secretase, nuclear translocation of Her2 ICD, and enhanced transcription of tumor metastasis‐associated gene COX‐2. Chronic stimulation of catecholamine strongly promotes the invasive activities of cancer cells in vitro and spontaneous tumor lung metastasis in mice. Furthermore, nuclear localization of Her2 was significantly correlated with overexpression of β2‐AR in human breast cancer tissues, indicating that catecholamine‐induced β2‐AR activation plays decisive roles in tumor metastasis. Our data also reveal that an unknown mechanism by which the regulated intramembrane proteolysis (RIP) initiated by β2‐AR‐mediated signaling controls a novel Her2‐mediated signaling transduction.

β2-AR blockade potentiates MEK1/2 inhibitor effect on HNSCC by regulating the Nrf2-mediated defense mechanism

The β2-Adrenergic receptor (β2-AR) is a G protein-coupled receptor (GPCR), involved in the development of many cancers, among which HNSCC. In this contest, β2-AR signaling interacts with different pathways, such as PI3K and MAPK, commonly activated by TK receptors. For this reason, TK blockade is one of the most adopted therapeutic strategies in HNSCC patients. In our study we investigated the effects of the β2-AR blocking in HNSCC cell lines, using the selective inhibitor ICI118,551 (ICI), in combination with the MAPK inhibitor U0126. We found that ICI leads to the blocking of p38 and NF-kB oncogenic pathways, strongly affecting also the ERK and PI3K pathways. Cotreatment with U0126 displays a synergic effect on cell viability and pathway alteration. Interestingly, we found that the β2-AR blockade affects Nrf2-Keap1 stability and its nuclear translocation leading to a drastic ROS increase and oxidative stress. Our results are confirmed by a TCGA dataset analysis, showing that NFE2L2 gene is commonly overexpressed in HNSC, and correlated with a lower survival rate. In our system, the PI3K pathway inhibition culminated in the blocking of pro-survival autophagy, a mechanism normally adopted by cancer cells to became less responsive to the therapies. The mTOR expression, commonly upregulated in HNSC, was reduced in patients with disease-recurrence. It is well known that mTOR has a strong autophagy inhibition effect, therefore its downregulation promoted pro-survival autophagy, with a related increase recurrence rate. Our findings highlight for the first time the key role of β2-AR and related pathway in HNSCC cell proliferation and drug resistance, proposing it as a valuable therapeutic molecular target.

Multi-omics analyses identify HSD17B4 methylation-silencing as a predictive and response marker of HER2-positive breast cancer to HER2-directed therapy

HER2-positive breast cancers that achieve pathological complete response (pCR) after HER2-directed therapy consistently have good survival. We previously identified HSD17B4 methylation as a marker for pCR by methylation screening. Here, we aimed to identify a new marker by conducting a multi-omics analysis of materials prepared by laser capture microdissection, and adding 71 new samples. In the screening set (n = 36), mutations, methylation, and expression were analyzed by targeted sequencing, Infinium 450 K, and expression microarray, respectively, and 15 genes were identified as differentially expressed and eight genomic regions as differentially methylated between cancer samples with and without pCR. In a validation set (n = 47), one gene showed differential expression, and one region had differential methylation. Further, in the re-validation set (n = 55), all new samples, only HSD17B4 methylation was significantly different. The HSD17B4 methylation was at the transcriptional start site of its major variant, and was associated with its silencing. HSD17B4 was highly expressed in the vast majority of human cancers, and its methylation was present only in breast cancers and one lymphoblastic leukemia cell line. A combination of estrogen receptor-negative status and HSD17B4 methylation showed a positive predictive value of 80.0%. During HER2-directed neoadjuvant therapy, HSD17B4 methylation was the most reliable marker to monitor response to the therapy. These results showed that HSD17B4 methylation is a candidate predictive and response marker of HER2-positive breast cancer to HER2-directed therapy.

MicroRNA-21-Enriched Exosomes as Epigenetic Regulators in Melanomagenesis and Melanoma Progression: The Impact of Western Lifestyle Factors

DNA mutation-induced activation of RAS-BRAF-MEK-ERK signaling associated with intermittent or chronic ultraviolet (UV) irradiation cannot exclusively explain the excessive increase of malignant melanoma (MM) incidence since the 1950s. Malignant conversion of a melanocyte to an MM cell and metastatic MM is associated with a steady increase in microRNA-21 (miR-21). At the epigenetic level, miR-21 inhibits key tumor suppressors of the RAS-BRAF signaling pathway enhancing proliferation and MM progression. Increased MM cell levels of miR-21 either result from endogenous upregulation of melanocytic miR-21 expression or by uptake of miR-21-enriched exogenous exosomes. Based on epidemiological data and translational evidence, this review provides deeper insights into environmentally and metabolically induced exosomal miR-21 trafficking beyond UV-irradiation in melanomagenesis and MM progression. Sources of miR-21-enriched exosomes include UV-irradiated keratinocytes, adipocyte-derived exosomes in obesity, airway epithelium-derived exosomes generated by smoking and pollution, diet-related exosomes and inflammation-induced exosomes, which may synergistically increase the exosomal miR-21 burden of the melanocyte, the transformed MM cell and its tumor environment. Several therapeutic agents that suppress MM cell growth and proliferation attenuate miR-21 expression. These include miR-21 antagonists, metformin, kinase inhibitors, beta-blockers, vitamin D, and plant-derived bioactive compounds, which may represent new options for the prevention and treatment of MM.

The Influence of Pre-Existing Beta-Blockers Use on Survival Outcomes in HER2 Positive Advanced Breast Cancer: Pooled Analysis of Clinical Trial Data

Introduction: Beta-blockers (BB) are commonly used to manage cardiovascular disease and may have benefits in controlling complications of anti-HER2 therapies. This study aimed to evaluate the association of pre-existing BB use with survival outcomes in patients initiating anti-HER2 therapy for advanced breast cancer (ABC). Materials and Methods: Data from clinical trials EMILIA, TH3RESA, MARIANNE, and CLEOPATRA was pooled. Cox proportional analysis was used to assess the association between pre-existing BB use with survival outcomes in patients initiating anti-HER2 therapies. Results: Of the 2,777 patients with HER2 positive ABC, 266 were using a BB at the time of anti-HER2 therapy initiation. BB use was associated with worse overall survival (OS) (adjusted HR = 1.27, 95% CI: 1.04-1.55). Sensitivity analysis in patients with pre-existing cardiovascular disease (CVD) also indicated that BB use was associated with worse OS (1.29, 1.02-1.63). Conclusion: In large high-quality data, BB use at the time of anti-HER2 therapy initiation for ABC was independently associated with worse OS, regardless of CVD status. The finding is contrary to pre-study hypotheses and findings in other BC subtypes. Future research should aim to gain a deeper understanding of the effects of BBs on specific BC subtypes, cancer types, and cancer treatments.

Serum proteomics analysis of candidate predictive biomarker panel for the diagnosis of trastuzumab-based therapy resistant breast cancer

Human epidermal growth factor receptor 2 (HER2)-positive is a particularly aggressive type of the breast cancer. Trastuzumab-based therapy is a standard treatment for HER2-positive breast cancer, but some patients are resistant to the therapy. Serum proteins have been used to predict therapeutic benefit for various cancers, but whether serum proteins can serve as biomarkers for HER2-positive breast cancer remains unclear. Using an isobaric Tandem Mass Tag (TMT) label-based quantitative proteomic, we discovered 18 differentially expressed proteins in the serum of trastuzumab-based therapy resistant patients before therapy. Then, four proteins were selected and validated using an LC-MS/MS-based multiple reaction monitoring quantification method, and it was confirmed that three proteins (SRGN, LDHA and CST3) were correlated with trastuzumab-based therapy resistance. Finally, the trastuzumab-based therapy resistance diagnostic score was calculated and acquired by means of a logistic regression pattern based on the level of these three proteins. In summary, we develop a serum-based protein signature that potentially predicts the therapeutic effects of trastuzumab-based therapy for HER2-positive breast cancer patients.

Overcoming trastuzumab resistance in HER2-positive breast cancer using combination therapy

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) comprises around 20-30% of all BC subtypes and is correlated with poor prognosis. For many years, trastuzumab, a monoclonal antibody, has been used to inhibit the HER2 activity. Though, the main resistance to trastuzumab has challenged the use of this drug in the management of HER2-positive BC. Therefore, the determination of resistance mechanisms and the incorporation of new agents may lead to the development of a better blockade of the HER family receptor signaling. During the last few years, some therapeutic drugs have been developed for treating patients with trastuzumab-resistant HER2-positive BC that have more effective influences in the management of this condition. In this regard, the present study aimed at reviewing the mechanisms of trastuzumab resistance and the innovative therapies that have been investigated in trastuzumab-resistant HER2-positive BC subjects.

Prognostic and Predictive Impact of Beta-2 Adrenergic Receptor Expression in HER2-Positive Breast Cancer

BACKGROUND

Beta-2 adrenergic receptor (ADRB2) mediates proliferation and treatment resistance in preclinical models of human epidermal growth factor receptor 2 positive (HER2+) breast cancer. We evaluated ADRB2 gene expression as a prognostic and predictive biomarker in patients with HER2+ early breast cancer.

METHODS

ADRB2 expression was retrieved from HER2+ patients enrolled in the FinHer study (N = 202), and 2 public datasets containing data from patients with HER2+ early breast cancer: one including patients who did not receive systemic treatment (disease-free survival [DFS] dataset; n = 175) and another including patients who received neoadjuvant treatment (pathologic complete response [pCR] dataset; n = 207). Survival was estimated with Kaplan-Meier method and Cox regression was used for uni-multivariate analyses. ADRB2 expression was correlated with several gene signatures.

RESULTS

ADRB2 high expression was associated with improved DFS rates in HER2+ patients (hazard ratio [HR] 0.52; 95% confidence interval [CI] 0.32-0.84; P = .0068). No association between ADRB2 expression and pCR was observed (odds ratio 1.14; 95% CI, 0.63-2.10; P = .67). No association between ADRB2 and relapse-free survival (RFS) was observed in HER2+ patients enrolled in the FinHer study (HR 0.93; 95% CI, 0.69-1.25; P = .61). ADRB2 was associated with a low expression of angiogenesis-related (vascular endothelial growth factor -0.38, P < .001) and proliferation-related (aurora kinase A -0.36, P < .001; genomic grade index -0.028, P < .001; signal transducers and activators of transcription -0.17, P < .001) genes; and a high expression of immune-related genes (Perez +0.45, P < .001; STAT1 +0.28, P < .001; immune response gene expression module +0.29, P < .001).

CONCLUSIONS

Opposing our initial hypothesis, a high ADRB2 expression may be a favorable prognostic factor in patients with HER2+ early breast cancer. This association appears to be mediated by antiproliferative, antiangiogenic, and immunogenic effects of ADRB2.

Propranolol: What is BLOCKing Its Clinical Investigation in Breast Cancer?

Presurgical propranolol modulates biomarkers associated with breast cancer progression. β-adrenergic signaling promotes invasion, epithelial-to-mesenchymal transition phenotype, and immune cell infiltration into the tumor microenvironment. Blockade of the β-adrenergic receptor signaling with propranolol, along with potential future combinatorial strategies, holds promise for reducing breast cancer progression and metastasis.See related article by Hiller et al., p. 1803.

Hypoxia Attenuates Trastuzumab Uptake and Trastuzumab-Emtansine (T-DM1) Cytotoxicity through Redistribution of Phosphorylated Caveolin-1

The antibody-drug conjugate trastuzumab-emtansine (T-DM1) offers an additional treatment option for patients with HER2-amplified tumors. However, primary and acquired resistance is a limiting factor in a significant subset of patients. Hypoxia, a hallmark of cancer, regulates the trafficking of several receptor proteins with potential implications for tumor targeting. Here, we have investigated how hypoxic conditions may regulate T-DM1 treatment efficacy in breast cancer. The therapeutic effect of T-DM1 and its metabolites was evaluated in conjunction with biochemical, flow cytometry, and high-resolution imaging studies to elucidate the functional and mechanistic aspects of hypoxic regulation. HER2 and caveolin-1 expression was investigated in a well-annotated breast cancer cohort. We find that hypoxia fosters relative resistance to T-DM1 in HER2⁺ cells (SKBR3 and BT474). This effect was not a result of deregulated HER2 expression or resistance to emtansine and its metabolites. Instead, we show that hypoxia-induced translocation of caveolin-1 from cytoplasmic vesicles to the plasma membrane contributes to deficient trastuzumab internalization and T-DM1 chemosensitivity. Caveolin-1 depletion mimicked the hypoxic situation, indicating that vesicular caveolin-1 is indispensable for trastuzumab uptake and T-DM1 cytotoxicity. In vitro studies suggested that HER2 and caveolin-1 are not coregulated, which was supported by IHC analysis in patient tumors. We find that phosphorylation-deficient caveolin-1 inhibits trastuzumab internalization and T-DM1 cytotoxicity, suggesting a specific role for caveolin-1 phosphorylation in HER2 trafficking. IMPLICATIONS: Together, our data for the first time identify hypoxic regulation of caveolin-1 as a resistance mechanism to T-DM1 with potential implications for individualized treatment of breast cancer.

β-Adrenergic Signaling in Lung Cancer: A Potential Role for Beta-Blockers

Lung cancer results in more patient deaths each year than any other cancer type. Additional treatment strategies are needed to improve clinical responses to approved treatment modalities and prevent the emergence of resistant disease. Catecholamines including norepinephrine and epinephrine are elevated as a result of chronic stress and mediate their physiological effects through activation of adrenergic receptors on target tissues. Lung cancer cells express β-adrenergic receptors (β-ARs), and numerous preclinical studies indicate that β2-AR signaling on lung cancer cells facilities cellular programs including proliferation, motility, apoptosis resistance, epithelial-to-mesenchymal transition, metastasis, and the acquisition of an angiogenic and immunosuppressive phenotype. Here, we review the preclinical and clinical evidence supporting a potential role for beta-blockers in improving the clinical outcome of lung cancer patients. Graphical Abstract Catecholamines including norepinephrine and epinephrine act of β-ARs expressed on NSCLC tumor cells and activate pathways regulating tumor progression.

The beta adrenergic receptor antagonist propranolol alters mitogenic and apoptotic signaling in late stage breast cancer

Background

Substantial evidence supports the use of inexpensive β-AR antagonists (beta blockers) against a variety of cancers, and the β-AR antagonist propranolol was recently approved by the European Medicines Agency for the treatment of soft tissue sarcomas. Prospective and retrospective data published by our group and others suggest that non-selective β-AR antagonists are effective at reducing proliferative rates in breast cancers, however the mechanism by which this occurs is largely unknown.

Methods

In this study, we measured changes in tumor proliferation and apoptosis in a late stage breast cancer patient treated with neoadjuvant propranolol. We expounded upon these clinical findings by employing an in vitro breast cancer model, where we used cell-based assays to evaluate propranolol-mediated molecular alterations related to cell proliferation and apoptosis.

Results

Neoadjuvant propranolol decreased expression of the pro-proliferative Ki-67 and pro-survival Bcl-2 markers, and increased pro-apoptotic p53 expression in a patient with stage III breast cancer. Molecular analysis revealed that β-AR antagonism disrupted cell cycle progression and steady state levels of cyclins. Furthermore, propranolol treatment of breast cancer cells increased p53 levels, enhanced caspase cleavage, and induced apoptosis.

Conclusion

Collectively, these data provide support for the incorporation of β-AR antagonists into the clinical management of breast cancer, and elucidate a partial molecular mechanism explaining the efficacy of β-AR antagonists against this disease.