Beta-blockade enhances anthracycline control of metastasis in triple-negative breast cancer

Neurobiology of cancer: Adrenergic signaling and drug repurposing

Cancer neuroscience, as an emerging converging discipline, provides us with new perspectives on the interactions between the nervous system and cancer progression. As the sympathetic nervous system, in particular adrenergic signaling, plays an important role in the regulation of tumor activity at every hierarchical level of life, from the tumor cell to the tumor microenvironment, and to the tumor macroenvironment, it is highly desirable to dissect its effects. Considering the far-reaching implications of drug repurposing for antitumor drug development, such a large number of adrenergic receptor antagonists on the market has great potential as one of the means of antitumor therapy, either as primary or adjuvant therapy. Therefore, this review aims to summarize the impact of adrenergic signaling on cancer development and to assess the status and prospects of intervening in adrenergic signaling as a therapeutic tool against tumors.

Calcium Channel Blocker Lacidipine Promotes Antitumor Immunity by Reprogramming Tryptophan Metabolism

Dysfunction of calcium channels is involved in the development and progression of some cancers. However, it remains unclear the role of calcium channel inhibitors in tumor immunomodulation. Here, calcium channel blocker lacidipine is identified to potently inhibit the enzymatic activity and expression of indoleamine 2,3-dioxygenase 1 (IDO1), a rate-limiting enzyme in tryptophan metabolism. Lacidipine activates effector T cells and incapacitates regulatory T cells (Tregs) to augment the anti-tumor effect of chemotherapeutic agents in breast cancer by converting immunologically "cold" into "hot" tumors. Mechanistically, lacidipine targets calcium channels (CaV1.2/1.3) to inhibit Pyk2-JAK1-calmodulin complex-mediated IDO1 transcription suppression, which suppresses the kynurenine pathway and maintains the total nicotinamide adenine dinucleotide (NAD) pool by regulating NAD biosynthesis. These results reveal a new function of calcium channels in IDO1-mediated tryptophan metabolism in tumor immunity and warrant further development of lacidipine for the metabolic immunotherapy in breast cancer.

Metabolic reprogramming and therapeutic resistance in primary and metastatic breast cancer

Metabolic alterations, a hallmark of cancer, enable tumor cells to adapt to their environment by modulating glucose, lipid, and amino acid metabolism, which fuels rapid growth and contributes to treatment resistance. In primary breast cancer, metabolic shifts such as the Warburg effect and enhanced lipid synthesis are closely linked to chemotherapy failure. Similarly, metastatic lesions often display distinct metabolic profiles that not only sustain tumor growth but also confer resistance to targeted therapies and immunotherapies. The review emphasizes two major aspects: the mechanisms driving metabolic resistance in both primary and metastatic breast cancer, and how the unique metabolic environments in metastatic sites further complicate treatment. By targeting distinct metabolic vulnerabilities at both the primary and metastatic stages, new strategies could improve the efficacy of existing therapies and provide better outcomes for breast cancer patients.

Targeted intervention in nerve-cancer crosstalk enhances pancreatic cancer chemotherapy

Nerve-cancer crosstalk has gained substantial attention owing to its impact on tumour growth, metastasis and therapy resistance. Effective therapeutic strategies targeting tumour-associated nerves within the intricate tumour microenvironment remain a major challenge in pancreatic cancer. Here we develop Escherichia coli Nissle 1917-derived outer membrane vesicles conjugated with nerve-binding peptide NP41, loaded with the tropomyosin receptor kinase (Trk) inhibitor larotrectinib (Lar@NP-OMVs) for tumour-associated nerve targeting. Lar@NP-OMVs achieve efficient nerve intervention to diminish neurite growth by disrupting the neurotrophin/Trk signalling pathway. Moreover, OMV-mediated repolarization of M2-like tumour-associated macrophages to an M1-like phenotype results in nerve injury, further accentuating Lar@NP-OMV-induced nerve intervention to inhibit nerve-triggered proliferation and migration of pancreatic cancer cells and angiogenesis. Leveraging this strategy, Lar@NP-OMVs significantly reduce nerve infiltration and neurite growth promoted by gemcitabine within the tumour microenvironment, leading to augmented chemotherapy efficacy in pancreatic cancer. This study sheds light on a potential avenue for nerve-targeted therapeutic intervention for enhancing pancreatic cancer therapy.

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.

Harnessing brain-body communication to understand cancer

Solid tumors that arise in the body interact with neurons, which influences cancer progression and treatment response. Here, we discuss key questions in the field, including defining the nature of interactions between tumors and neural circuits and defining how neural signals shape the tumor microenvironment. This information will allow us to optimally target neural signaling to improve outcomes for cancer patients.

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.

Regulating tumor innervation by nanodrugs potentiates cancer immunochemotherapy and relieve chemotherapy-induced neuropathic pain

Sympathetic nerves play a pivotal role in promoting tumor growth through crosstalk with tumor and stromal cells. Chemotherapy exacerbates the infiltration of sympathetic nerves into tumors, thereby providing a rationale for inhibiting sympathetic innervation to enhance chemotherapy. Here, we discovered that doxorubicin increases the density and activity of sympathetic nerves in breast cancer mainly by upregulating the expression of nerve growth factors (NGFs) in cancer cells. To address this, we developed a combination therapy by co-encapsulating small interfering RNA (siRNA) and doxorubicin within breast cancer-targeted poly (lactic-co-glycolic acid) (PLGA) nanoparticles, aiming to suppress NGF expression post-chemotherapy. Incorporating NGF blockade into the nanoplatform for chemotherapy effectively mitigated the chemotherapy-induced proliferation of sympathetic nerves. This not only bolstered the tumoricidal activity of chemotherapy, but also amplified its stimulatory impact on the antitumor immune response by increasing the infiltration of immunostimulatory cells into tumors while concurrently reducing the frequency of immunosuppressive cells. Consequently, the combined nanodrug approach, when coupled with anti-PD-L1 treatment, exhibited a remarkable suppression of primary and deeply metastatic tumors with minimal systematic toxicity. Importantly, the nanoplatform relieved chemotherapy-induced peripheral neuropathic pain (CIPNP) by diminishing the expression of pain mediator NGFs. In summary, this research underscores the significant potential of NGF knockdown in enhancing immunochemotherapy outcomes and presents a nanoplatform for the highly efficient and low-toxicity treatment of breast cancer.

The intersection of the nervous system and breast cancer

Breast cancer (BC) represents a paradigm of heterogeneity, manifesting as a spectrum of molecular subtypes with divergent clinical trajectories. It is fundamentally characterized by the aberrant proliferation of malignant cells within breast tissue, a process modulated by a myriad of factors that govern its progression. Recent endeavors outline the interplay between BC and the nervous system, illuminate the complex symbiosis between neural structures and neoplastic cells, and elucidate nerve dependence as a cornerstone of BC progression. This includes the neural modulations on immune response, neurovascular formation, and multisystem interactions. Such insights have unveiled the critical impact of neural elements on tumor dynamics and patient prognosis. This revelation beckons a deeper exploration into the neuro-oncological interface, potentially unlocking novel therapeutic vistas. This review endeavors to delineate the intricate mechanisms between the nervous system and BC, aiming to accentuate the implications and therapeutic strategies of this intersection for tumor evolution and the formulation of innovative therapeutic approaches.

Epinephrine promotes breast cancer metastasis through a ubiquitin-specific peptidase 22-mediated lipolysis circuit

Chronic stress-induced epinephrine (EPI) accelerates breast cancer progression and metastasis, but the molecular mechanisms remain unclear. Herein, we found a strong positive correlation between circulating EPI levels and the tumoral expression of ubiquitin-specific peptidase 22 (USP22) in patients with breast cancer. USP22 facilitated EPI-induced breast cancer progression and metastasis by enhancing adipose triglyceride lipase (ATGL)-mediated lipolysis. Targeted USP22 deletion decreased ATGL expression and lipolysis, subsequently inhibiting EPI-mediated breast cancer lung metastasis. USP22 acts as a bona fide deubiquitinase for the Atgl gene transcription factor FOXO1, and EPI architects a lipolysis signaling pathway to stabilize USP22 through AKT-mediated phosphorylation. Notably, USP22 phosphorylation levels are positively associated with EPI and with downstream pathways involving both FOXO1 and ATGL in breast cancers. Pharmacological USP22 inhibition synergized with β-blockers in treating preclinical xenograft breast cancer models. This study reveals a molecular pathway behind EPI's tumor-promoting effects and provides a strong rationale for combining USP22 inhibition with β-blockers to treat aggressive breast cancer.

Why do patients with cancer die?

Cancer is a major cause of global mortality, both in affluent countries and increasingly in developing nations. Many patients with cancer experience reduced life expectancy and have metastatic disease at the time of death. However, the more precise causes of mortality and patient deterioration before death remain poorly understood. This scarcity of information, particularly the lack of mechanistic insights, presents a challenge for the development of novel treatment strategies to improve the quality of, and potentially extend, life for patients with late-stage cancer. In addition, earlier deployment of existing strategies to prolong quality of life is highly desirable. In this Roadmap, we review the proximal causes of mortality in patients with cancer and discuss current knowledge about the interconnections between mechanisms that contribute to mortality, before finally proposing new and improved avenues for data collection, research and the development of treatment strategies that may improve quality of life for patients.

Beta-blocker use and breast cancer outcomes: a meta-analysis

PURPOSE

Beta blockers (BBs) are commonly used cardiovascular medications, and their association with breast cancer outcomes has been examined in several previous observational studies and meta-analyses. In this study, an updated meta-analysis was undertaken to ascertain the association between BBs and both breast cancer death (BCD) and breast cancer recurrence (BCR).

METHODS

Articles were sourced from various databases up until the 14th of August 2023. Effect estimates were pooled using the random effects model, and the Higgins I2 statistic was computed to ascertain heterogeneity. Subgroup analyses were conducted by the potential for immortal time bias (ITB), the exposure period (prediagnosis vs postdiagnosis), and type of BB (selective vs non-selective). Publication bias was assessed using funnel plots and Egger's regression tests.

RESULTS

Twenty-four studies were included. Pooled results showed that there was no statistically significant association between BB use and both BCD (19 studies, hazard ratio = 0.90, 95% CI 0.78-1.04) and BCR (16 studies, HR = 0.87, 95% CI 0.71-1.08). After removing studies with ITB, the associations were attenuated towards the null. There was no effect modification for either outcome when stratifying by the exposure period or type of BB. There was clear evidence of publication bias for both outcomes.

CONCLUSION

In this meta-analysis, we found no evidence of an association between BB use and both BCD and BCR. Removing studies with ITB attenuated the associations towards the null, but there was no effect modification by the exposure period or type of BB.

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.

The Neuroimmune Axis and Its Therapeutic Potential for Primary Liver Cancer

The autonomic nervous system plays an integral role in motion and sensation as well as the physiologic function of visceral organs. The nervous system additionally plays a key role in primary liver diseases. Until recently, however, the impact of nerves on cancer development, progression, and metastasis has been unappreciated. This review highlights recent advances in understanding neuroanatomical networks within solid organs and their mechanistic influence on organ function, specifically in the liver and liver cancer. We discuss the interaction between the autonomic nervous system, including sympathetic and parasympathetic nerves, and the liver. We also examine how sympathetic innervation affects metabolic functions and diseases like nonalcoholic fatty liver disease (NAFLD). We also delve into the neurobiology of the liver, the interplay between cancer and nerves, and the neural regulation of the immune response. We emphasize the influence of the neuroimmune axis in cancer progression and the potential of targeted interventions like neurolysis to improve cancer treatment outcomes, especially for hepatocellular carcinoma (HCC).

Targeting nerve growth factor-mediated osteosarcoma metastasis: mechanistic insights and therapeutic opportunities using larotrectinib

Osteosarcoma (OS) therapy presents numerous challenges, due largely to a low survival rate following metastasis onset. Nerve growth factor (NGF) has been implicated in the metastasis and progression of various cancers; however, the mechanism by which NGF promotes metastasis in osteosarcoma has yet to be elucidated. This study investigated the influence of NGF on the migration and metastasis of osteosarcoma patients (88 cases) as well as the underlying molecular mechanisms, based on RNA-sequencing and gene expression data from a public database (TARGET-OS). In osteosarcoma patients, the expression of NGF was significantly higher than that of other growth factors. This observation was confirmed in bone tissue arrays from 91 osteosarcoma patients, in which the expression levels of NGF and matrix metallopeptidase-2 (MMP-2) protein were significantly higher than in normal bone, and strongly correlated with tumor stage. In summary, NGF is positively correlated with MMP-2 in human osteosarcoma tissue and NGF promotes osteosarcoma cell metastasis by upregulating MMP-2 expression. In cellular experiments using human osteosarcoma cells (143B and MG63), NGF upregulated MMP-2 expression and promoted wound healing, cell migration, and cell invasion. Pre-treatment with MEK and ERK inhibitors or siRNA attenuated the effects of NGF on cell migration and invasion. Stimulation with NGF was shown to promote phosphorylation along the MEK/ERK signaling pathway and decrease the expression of microRNA-92a-1-5p (miR-92a-1-5p). In in vivo experiments involving an orthotopic mouse model, the overexpression of NGF enhanced the effects of NGF on lung metastasis. Note that larotrectinib (a tropomyosin kinase receptor) strongly inhibited the effect of NGF on lung metastasis. In conclusion, it appears that NGF promotes MMP-2-dependent cell migration by inhibiting the effects of miR-92a-1-5p via the MEK/ERK signaling cascade. Larotrectinib emerged as a potential drug for the treatment of NGF-mediated metastasis in osteosarcoma.

Role of Exosomes in Cancer and Aptamer-Modified Exosomes as a Promising Platform for Cancer Targeted Therapy

Exosomes are increasingly recognized as important mediators of intercellular communication in cancer biology. Exosomes can be derived from cancer cells as well as cellular components in tumor microenvironment. After secretion, the exosomes carrying a wide range of bioactive cargos can be ingested by local or distant recipient cells. The released cargos act through a variety of mechanisms to elicit multiple biological effects and impact most if not all hallmarks of cancer. Moreover, owing to their excellent biocompatibility and capability of being easily engineered or modified, exosomes are currently exploited as a promising platform for cancer targeted therapy. In this review, we first summarize the current knowledge of roles of exosomes in risk and etiology, initiation and progression of cancer, as well as their underlying molecular mechanisms. The aptamer-modified exosome as a promising platform for cancer targeted therapy is then briefly introduced. We also discuss the future directions for emerging roles of exosome in tumor biology and perspective of aptamer-modified exosomes in cancer therapy.

Schwann cells in pancreatic cancer: Unraveling their multifaceted roles in tumorigenesis and neural interactions

Pancreatic ductal adenocarcinoma (PDAC), characterized by heightened neural density, presents a challenging prognosis primarily due to perineural invasion. Recognized for their crucial roles in neural support and myelination, Schwann cells (SCs) significantly influence the process of tumorigenesis. This review succinctly outlines the interplay between PDAC and neural systems, positioning SCs as a nexus in the tumor-neural interface. Subsequently, it delves into the cellular origin and influencers of SCs within the pancreatic tumor microenvironment, emphasizing their multifaceted roles in tumor initiation, progression, and modulation of the neural and immune microenvironment. The discussion encompasses potential therapeutic interventions targeting SCs. Lastly, the review underscores pressing issues, advocating for sustained exploration into the diverse contributions of SCs within the intricate landscape of PDAC, with the aim of enhancing our understanding of their involvement in this complex malignancy.

Stressed out neutrophils drive metastasis

Stress hormones can contribute to cancer progression, but how immune cells play a role in this process is unclear. In a recent study in Cancer Cell, He et al. showed that glucocorticoids potentiate metastasis by skewing neutrophils toward pro-tumorigenic functions.

Next Directions in the Neuroscience of Cancers Arising outside the CNS

SUMMARY

The field of cancer neuroscience has begun to define the contributions of nerves to cancer initiation and progression; here, we highlight the future directions of basic and translational cancer neuroscience for malignancies arising outside of the central nervous system.

Psychosocial stressors and breast cancer gene expression in the Black Women's Health Study

PURPOSE

Prior studies indicate that the physiologic response to stress can affect gene expression. We evaluated differential gene expression in breast cancers collected from Black women with high versus low exposure to psychosocial stressors.

METHODS

We analyzed tumor RNA sequencing data from 417 Black Women's Health Study breast cancer cases with data on early life trauma and neighborhood disadvantage. We conducted age-adjusted differential gene expression analyses and pathway analyses. We also evaluated Conserved Transcriptional Response to Adversity (CTRA) contrast scores, relative fractions of immune cell types, T cell exhaustion, and adrenergic signaling. Analyses were run separately for estrogen receptor positive (ER+; n = 299) and ER- (n = 118) cases.

RESULTS

Among ER+ cases, the top differentially expressed pathways by stress exposure were related to RNA and protein metabolism. Among ER- cases, they were related to developmental biology, signal transduction, metabolism, and the immune system. Targeted analyses indicated greater immune pathway enrichment with stress exposure for ER- cases, and possible relevance of adrenergic signaling for ER+ cases. CTRA contrast scores did not differ by stress exposure, but in analyses of the CTRA components, ER- breast cancer cases with high neighborhood disadvantage had higher pro-inflammatory gene expression (p = 0.039) and higher antibody gene expression (p = 0.006) compared to those with low neighborhood disadvantage.

CONCLUSION

There are multiple pathways through which psychosocial stress exposure may influence breast tumor biology. Given the present findings on inflammation and immune response in ER- tumors, further research to identify stress-induced changes in the etiology and progression of ER- breast cancer is warranted.

Nerve Growth Factor and the Role of Inflammation in Tumor Development

Nerve growth factor (NGF) plays a dual role both in inflammatory states and cancer, acting both as a pro-inflammatory and oncogenic factor and as an anti-inflammatory and pro-apoptotic mediator in a context-dependent way based on the signaling networks and its interaction with diverse cellular components within the microenvironment. This report aims to provide a summary and subsequent review of the literature on the role of NGF in regulating the inflammatory microenvironment and tumor cell growth, survival, and death. The role of NGF in inflammation and tumorigenesis as a component of the inflammatory system, its interaction with the various components of the respective microenvironments, its ability to cause epigenetic changes, and its role in the treatment of cancer have been highlighted in this paper.

Efficacy and safety of chlorpromazine as an adjuvant therapy for glioblastoma in patients with unmethylated MGMT gene promoter: RACTAC, a phase II multicenter trial

Introduction

Drug repurposing is a promising strategy to develop new treatments for glioblastoma. In this phase II clinical trial, we evaluated the addition of chlorpromazine to temozolomide in the adjuvant phase of the standard first-line therapeutic protocol in patients with unmethylated MGMT gene promoter.

Methods

This was a multicenter phase II single-arm clinical trial. The experimental procedure involved the combination of CPZ with standard treatment with TMZ in the adjuvant phase of the Stupp protocol in newly-diagnosed GBM patients carrying an unmethylated MGMT gene promoter. Progression-free survival was the primary endpoint. Secondary endpoints were overall survival and toxicity.

Results

Forty-one patients were evaluated. Twenty patients (48.7%) completed 6 cycles of treatment with TMZ+CPZ. At 6 months, 27 patients (65.8%) were without progression, achieving the primary endpoint. Median PFS was 8.0 months (95% CI: 7.0-9.0). Median OS was 15.0 months (95% CI: 13.1-16.9). Adverse events led to reduction or interruption of CPZ dosage in 4 patients (9.7%).

Discussion

The addition of CPZ to standard TMZ in the first-line treatment of GBM patients with unmethylated MGMT gene promoter was safe and led to a longer PFS than expected in this population of patients. These findings provide proof-of-concept for the potential of adding CPZ to standard TMZ treatment in GBM patients with unmethylated MGMT gene promoter.

Clinical trial registration

https://clinicaltrials.gov/study/NCT04224441, identifier NCT04224441.

The Beta2-adrenergic agonist salbutamol synergizes with paclitaxel on cell proliferation and tumor growth in triple negative breast cancer models

PURPOSE

Globally breast cancer accounts for 24.5% in incidence and 15.5% in cancer deaths in women. The triple-negative subtype lacks any specific therapy and is treated with chemotherapy, resulting in significant side-effects. We aimed to investigate if the dose of chemotherapeutic drugs could be diminished by co-administering it with the β2-agonist salbutamol.

METHODS

Cell proliferation was measured by thymidine incorporation; gene expression, by real-time PCR and protein phosphorylation by WB. Apoptosis was assessed by acridine orange / ethidium bromide and TUNEL tests. Public patient databases were consulted. Cells were inoculated to nude mice and their growth assessed.

RESULTS

The β2-agonist salbutamol synergizes in MDA-MB-231 cells in vitro with paclitaxel and doxorubicin on cell proliferation through ADRB2 receptors, while the β-blocker propranolol does not. The expression of this receptor was assessed in patient databases and other cell lines. Triple negative samples had the lowest expression. Salbutamol and paclitaxel decreased MDA-MB-231 cell proliferation while their combination further inhibited it. The pathways involved were analyzed. When these cells were inoculated to nude mice, paclitaxel and salbutamol inhibited tumor growth. The combined effect was significantly greater. Paclitaxel increased the expression of MDR1 while salbutamol partially reversed this increase.

CONCLUSION

While the effect of salbutamol was mainly on cell proliferation, suboptimal concentrations of paclitaxel provoked a very important enhancement of apoptosis. The latter enhanced transporter proteins as MDR1, whose expression were diminished by salbutamol. The expression of ADRB2 should be assessed in the biopsy or tumor to eventually select patients that could benefit from salbutamol repurposing.

Low-dose aspirin, statins, and metformin and survival in patients with breast cancers: a Norwegian population-based cohort study

BACKGROUND

Previous studies assessed the prognostic effect of aspirin, statins, and metformin in breast cancer (BC) patients, with inconclusive results.

METHODS

We performed a nationwide population-based cohort study to evaluate if post-diagnostic use of low-dose aspirin, statins, and metformin was associated with BC-specific survival. Women aged ≥ 50 years and diagnosed with BC in 2004-2017, who survived ≥ 12 months after diagnosis (follow-up started 12 months after diagnosis), were identified in the Cancer Registry of Norway. The Norwegian Prescription Database provided information on prescriptions. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between post-diagnostic use and BC-specific survival, overall and by oestrogen receptor (ER) status.

RESULTS

A total of 26,190 patients were included. Of these, 5324 (20%), 7591 (29%), and 1495 (6%) were post-diagnostic users of low-dose aspirin, statins, and metformin, respectively. The median follow-up was 6.1 years, and 2169 (8%) patients died from BC. HRs for use, compared to no use, were estimated at 0.96 (95% CI 0.85-1.08) for low-dose aspirin (ER+: HR = 0.97, 95% CI 0.83-1.13; ER-: HR = 0.97, 95% CI 0.73-1.29, p value for interaction = 0.562), 0.84 (95% CI 0.75-0.94) for statins (ER+: HR = 0.95, 95% CI 0.82-1.09; ER-: HR = 0.77, 95% CI 0.60-1.00, p value for interaction = 0.259), and 0.70 (95% CI 0.51-0.96) for metformin (compared to use of non-metformin antidiabetics) (ER+: HR = 0.67, 95% CI 0.45-1.01; ER-: HR = 1.62, 95% CI 0.72-3.62, p value for interaction = 0.077).

CONCLUSION

We found evidence supporting an association between post-diagnostic use of statins and metformin and survival, in patients with BC. Our findings indicate potential differences according to ER status.

Using administrative healthcare data to evaluate drug repurposing opportunities for cancer: the possibility of using beta-blockers to treat breast cancer

Introduction: Cancer registries and hospital electronic medical records are commonly used to investigate drug repurposing candidates for cancer. However, administrative data are often more accessible than data from cancer registries and medical records. Therefore, we evaluated if administrative data could be used to evaluate drug repurposing for cancer by conducting an example study on the association between beta-blocker use and breast cancer mortality. Methods: A retrospective cohort study of women aged ≥50 years with incident breast cancer was conducted using a linked dataset with statewide hospital admission data and nationwide medication claims data. Women receiving beta blockers and first-line anti-hypertensives prior to and at diagnosis were compared. Breast cancer molecular subtypes and metastasis status were inferred by algorithms from commonly prescribed breast cancer antineoplastics and hospitalization diagnosis codes, respectively. Subdistribution hazard ratios (sHR) and corresponding 95% confidence intervals (CIs) for breast cancer mortality were estimated using Fine and Gray's competing risk models adjusted for age, Charlson comorbidity index, congestive heart failure, myocardial infraction, molecular subtype, presence of metastasis at diagnosis, and breast cancer surgery. Results: 2,758 women were hospitalized for incident breast cancer. 604 received beta-blockers and 1,387 received first-line antihypertensives. In total, 154 breast cancer deaths were identified over a median follow-up time of 2.7 years. We found no significant association between use of any beta-blocker and breast-cancer mortality (sHR 0.86, 95%CI 0.58-1.28), or when stratified by beta-blocker type (non-selective, sHR 0.42, 95%CI 0.14-1.25; selective, sHR 0.95, 95%CI 0.63-1.43). Results were not significant when stratified by molecular subtypes (e.g., triple negative breast cancer (TNBC), any beta blocker, sHR 0.16, 95%CI 0.02-1.51). Discussion: It is possible to use administrative data to explore drug repurposing opportunities. Although non-significant, an indication of an association was found for the TNBC subtype, which aligns with previous studies using registry data. Future studies with larger sample size, longer follow-up are required to confirm the association, and linkage to clinical data sources are required to validate our methodologies.

SGLT2 Inhibitors as Potential Anticancer Agents

Sodium-glucose cotransporter 2 (SGLT2) serves as a critical glucose transporter that has been reported to be overexpressed in cancer models, followed by increased glucose uptake in both mice and humans. Inhibition of its expression can robustly thwart tumor development in vitro and in vivo. SGLT2 inhibitors are a comparatively new class of antidiabetic drugs that have demonstrated anticancer effects in several malignancies, including breast, liver, pancreatic, thyroid, prostate, and lung cancers. This review aims to assess the extent of SGLT involvement in different cancer cell lines and discuss the pharmacology, mechanisms of action, and potential applications of SGLT2 inhibitors to reduce tumorigenesis and its progression. Although these agents display a common mechanism of action, they exhibit distinct affinity towards the SGLT type 2 transporter compared to the SGLT type 1 transporter and varying extents of bioavailability and half-lives. While suppression of glucose uptake has been attributed to their primary mode of antidiabetic action, SGLT2 inhibitors have demonstrated several mechanistic ways to combat cancer, including mitochondrial membrane instability, suppression of β-catenin, and PI3K-Akt pathways, increase in cell cycle arrest and apoptosis, and downregulation of oxidative phosphorylation. Growing evidence and ongoing clinical trials suggest a potential benefit of combination therapy using an SGLT2 inhibitor with the standard chemotherapeutic regimen. Nevertheless, further experimental and clinical evidence is required to characterize the expression and role of SGLTs in different cancer types, the activity of different SGLT subtypes, and their role in tumor development and progression.