The potential role of nicotine in breast cancer initiation, development, angiogenesis, invasion, metastasis, and resistance to therapy

Disease burden of breast cancer and risk factors in Europe 44 countries, 1990-2019: findings of the global burden of disease study 2019

Background

Breast cancer (BC) represents a significant health challenge in Europe due to its elevated prevalence and heterogeneity. Despite notable progress in diagnostic and treatment methods, the region continues to grapple with rising BC burdens, with comprehensive investigations into this matter notably lacking. This study explores BC burden and potential contributing risk factors in 44 European countries from 1990 to 2019. The aim is to furnish evidence supporting the development of strategies for managing BC effectively.

Methods

Disease burden estimates related to breast cancer from the Global Burden of Disease 2019(GBD2019) across Eastern, Central, and Western Europe were examined using Joinpoint regression for trends from 1990 to 2019. Linear regression models examined relationships between BC burden and Socio-demographic Index (SDI), healthcare access and quality (HAQ), and BC prevalence. We utilized disability-adjusted life year(DALY) proportions for each risk factor to depict BC risks.

Results

In Europe, the BC burden was 463.2 cases per 100,000 people in 2019, 1.7 times the global burden. BC burden in women was significantly higher and increased with age. Age-standardized mortality and DALY rates of BC in Europe in 2019 decreased by 23.1%(average annual percent change: AAPC -0.92) and 25.9%(AAPC -1.02), respectively, compared to 1990, in line with global trends. From 1990 to 2019, age-standardized DALY declined faster in Western Europe (-34.8%, AAPC -1.49) than in Eastern Europe (-9.4%, AAPC -0.25) and Central Europe (-15.0%, AAPC -0.56). Monaco, Serbia, and Montenegro had the highest BC burden in Europe in 2019. BC burden was negatively correlated with HAQ. In addition, Alcohol use and Tobacco were significant risk factors for DALY. High fasting plasma glucose and obesity were also crucial risk factors that cannot be ignored in DALY.

Conclusion

The burden of BC in Europe remains a significant health challenge, with regional variations despite an overall downward trend. Addressing the burden of BC in different regions of Europe and the increase of DALY caused by different risk factors, targeted prevention measures should be taken, especially the management of alcohol and tobacco should be strengthened, and screening services for BC should be popularized, and medical resources and technology allocation should be optimized.

Nicotine promotes Staphylococcus aureus-induced osteomyelitis by activating the Nrf2/Slc7a11 signaling axis

Although smoking is a significant risk factor for osteomyelitis, there is limited experimental evidence that nicotine, a key tobacco constituent, is associated with this condition, leaving its mechanistic implications uncharacterized. This study revealed that nicotine promotes Staphylococcus aureus-induced osteomyelitis by increasing Nrf2 and Slc7a11 expression in vivo and in vitro. Inhibition of Slc7a11 using Erastin augmented bacterial phagocytosis/killing capabilities and fortified antimicrobial responses in an osteomyelitis model. Moreover, untargeted metabolomic analysis demonstrated that Erastin mitigated the effects of nicotine on S. aureus-induced osteomyelitis by altering glutamate/glutathione metabolism. These findings suggest that nicotine aggravates S. aureus-induced osteomyelitis by activating the Nrf2/Slc7a11 signaling pathway and that Slc7a11 inhibition can counteract the detrimental health effects of nicotine.

Potential Role of Nrf2, HER2, and ALDH in Cancer Stem Cells: A Narrative Review

Cancer is one of the main causes of death among humans, second only to cardiovascular diseases. In recent years, numerous studies have been conducted on the pathophysiology of cancer, and it has been established that this disease is developed by a group of stem cells known as cancer stem cells (CSCs). Thus, cancer is considered a stem cell disease; however, there is no comprehensive consensus about the characteristics of these cells. Several different signaling pathways including Notch, Hedgehog, transforming growth factor-β (TGF-β), and WNT/β-catenin pathways cause the self-renewal of CSCs. CSCs change their metabolic pathways in order to access easy energy. Therefore, one of the key objectives of researchers in cancer treatment is to destroy CSCs. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays an essential role in the protection of CSCs from reactive oxygen species (ROS) and chemotherapeutic agents by regulating antioxidants and detoxification enzymes. Human epidermal growth factor receptor 2 (HER2) is a member of the tyrosine kinase receptor family, which contributes to the protection of cancer cells against treatment and implicated in the invasion, epithelial-mesenchymal transition (EMT), and tumorigenesis. Aldehyde dehydrogenases (ALDHs) are highly active in CSCs and protect the cells against damage caused by active aldehydes through the regulation of aldehyde metabolism. On the other hand, ALDHs promote the formation and maintenance of tumor cells and lead to drug resistance in tumors through the activation of various signaling pathways, such as the ALDH1A1/HIF-1α/VEGF axis and Wnt/β-catenin, as well as changing the intracellular pH value. Given the growing body of information in this field, in the present narrative review, we attempted to shed light on the function of Nrf2, HER2, and ALDH in CSCs.

Cell signaling and epigenetic regulation of nicotine-induced carcinogenesis

Nicotine, a naturally occurring tobacco alkaloid responsible for tobacco addiction, has long been considered non-carcinogenic. However, emerging evidence suggests that nicotine may possess carcinogenic properties in mice and could be a potential carcinogen in humans. This review aims to summarize the potential molecular mechanisms underlying nicotine-induced carcinogenesis, with a specific focus on epigenetic regulation and the activation of nicotinic acetylcholine receptors (nAChRs) in addition to genotoxicity and excess reactive oxygen species (ROS). Additionally, we explore a novel hypothesis regarding nicotine's carcinogenicity involving the downregulation of stem-loop binding protein (SLBP), a critical regulator of canonical histone mRNA, and the polyadenylation of canonical histone mRNA. By shedding light on these mechanisms, this review underscores the need for further research to elucidate the carcinogenic potential of nicotine and its implications for human health.

The Association between the Extent of the Osteoarthritic Meniscus Degeneration and Cigarette Smoking-A Pilot Study

Background and Objectives: The negative effects of smoking on the musculoskeletal system were presented by many authors, although the relationship between smoking and osteoarthritis remains unclear. The aim of this paper was to investigate the negative effects of smoking on meniscal tissue in osteoarthritic knees by microscopic examination, by adapting the Bonar scoring system and its modifications. Materials and Methods: The study involved 34 patients with varus knees, from whom 65 samples of knee menisci were obtained. The mean age in the studied group was 65.385 years. The smoking status of the patients concluded that there were 13 smokers and 21 nonsmokers. Results: Among smokers, the mean classical Bonar score was 8.42 and the mean modified Bonar score was 6.65, while nonsmokers were characterized by scores of 8.51 and 7.35, respectively. There was a statistically significant negative correlation between the number of cigarettes and the collagen in the medial meniscus (p = 0.0197). Moreover, in the medial meniscus, the modified Bonar score correlated negatively with the number of cigarettes (p = 0.0180). Similarly, such a correlation was observed between the number of cigarettes and the modified Bonar score in the lateral meniscus (p = 0.04571). Furthermore, no correlation was identified between the number of cigarettes and the classical Bonar score in the lateral meniscus. There was a statistically significant difference in the collagen variable value between the smokers and nonsmokers groups (p = 0.04525). Conclusions: The microscopic investigation showed no differences in the menisci of smokers and nonsmokers, except for the collagen, which was more organized in smokers. Moreover, the modified Bonar score was correlated negatively with the number of cigarettes, which supports the role of neovascularization in meniscus pathology under the influence of tobacco smoking.

Correlation of PTEN signaling pathway and miRNA in breast cancer

Breast cancer (BC) is one of the most common cancers among women and can be fatal if not diagnosed and treated on time. Various genetic and environmental factors play a significant role in the development and progression of BC. Within the body, different signaling pathways have been identified that contribute to cancer progression, or conversely, cancer prevention. Phosphatase and tensin homolog (PTEN) is one of the proteins that prevent cancer by inhibiting the oncogenic PI3K/Akt/mTOR signaling pathway. MicroRNAs (miRNAs) are molecules with about 18 to 28 base pairs, which regulate about 30% of human genes after transcription. miRNAs play a key role in the progression or prevention of cancer through different signaling pathway and mechanisms, e.g., apoptosis, angiogenesis, and proliferation. miRNAs, which are upstream mediators of PTEN, can reinforce or suppress the effect of PTEN signaling on BC cells, and suppressing the PTEN signaling, linked to weakness of the cancer cells to chemotherapeutic drugs. However, the precise mechanism and function of miRNAs on PTEN in BC are not yet fully understood. Therefore, in the present study, has been focused on miRNAs regulating PTEN function in BC.

The global, regional, and national disease burden of breast cancer attributable to tobacco from 1990 to 2019: a global burden of disease study

OBJECTIVE

Tobacco has been identified as a significant contributory element to the development of breast cancer. Our objective was to evaluate the spatiotemporal trends of tobacco-related breast cancer at the global, regional, and national scales during 1990-2019.

METHODS

We extracted data on mortality, disability adjusted of life years (DALYs), age-standardized mortality rate (ASMR), and age-standardized DALYs rate (ASDR) from the Global Burden of Disease (GBD) study 2019. Estimated annual percentage change (EAPC) was computed to assess the temporal change in ASDR and ASMR.

RESULTS

In 2019, the deaths and DALYs attributed to tobacco-related breast cancer were estimated to be 35,439 (95% UI: 22,179-48,119) and 1,060,590 (95% UI: 622,550-1,462,580), respectively. These figures accounted for 5.1% and 5.2% of the total burden of breast cancer. ASMR and ASDR increased in low SDI regions, remained stable in low-middle and middle SDI regions and declined in high and high-middle SDI regions. The burden of breast cancer attributable to tobacco varied notably among regions and nations. Oceania, Southern Latin America, and Central Europe were the GBD regions with the highest number of ASMR and DALYs. There was a positive relationship between age-standardized rate and SDI value in 2019 across 204 nations or territories. A negative association was observed between the EAPC in ASMR or ASDR and the human development index (HDI) in 2019 (R = -0.55, p < 0.01 for ASMR; R = -0.56, p < 0.01 for ASDR).

CONCLUSION

Tobacco is one important and modifiable risk factor for breast cancer. The heterogeneity in both the spatial and temporal distribution can be attributed to factors such as aging, population growth, and SDI. These findings substantiate the necessity of expediting the enforcement of tobacco-free legislation in order to safeguard populations from the detrimental effects of tobacco.

The nuclear factor erythroid 2-related factor 2/p53 axis in breast cancer

One of the most important factors involved in the response to oxidative stress (OS) is the nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of components such as antioxidative stress proteins and enzymes. Under normal conditions, Kelch-like ECH-associated protein 1 (Keap1) keeps Nrf2 in the cytoplasm, thus preventing its translocation to the nucleus and inhibiting its role. It has been established that Nrf2 has a dual function; on the one hand, it promotes angiogenesis and cancer cell metastasis while causing resistance to drugs and chemotherapy. On the other hand, Nrf2 increases expression and proliferation of glutathione to protect cells against OS. p53 is a tumour suppressor that activates the apoptosis pathway in aging and cancer cells in addition to stimulating the glutaminolysis and antioxidant pathways. Cancer cells use the antioxidant ability of p53 against OS. Therefore, in the present study, we discussed function of Nrf2 and p53 in breast cancer (BC) cells to elucidate their role in protection or destruction of cancer cells as well as their drug resistance or antioxidant properties.

ADP-Ribosylation Factor 6 Pathway Acts as a Key Executor of Mesenchymal Tumor Plasticity

Despite the "big data" on cancer from recent breakthroughs in high-throughput technology and the development of new therapeutic modalities, it remains unclear as to how intra-tumor heterogeneity and phenotypic plasticity created by various somatic abnormalities and epigenetic and metabolic adaptations orchestrate therapy resistance, immune evasiveness, and metastatic ability. Tumors are formed by various cells, including immune cells, cancer-associated fibroblasts, and endothelial cells, and their tumor microenvironment (TME) plays a crucial role in malignant tumor progression and responses to therapy. ADP-ribosylation factor 6 (ARF6) and AMAP1 are often overexpressed in cancers, which statistically correlates with poor outcomes. The ARF6-AMAP1 pathway promotes the intracellular dynamics and cell-surface expression of various proteins. This pathway is also a major target for KRAS/TP53 mutations to cooperatively promote malignancy in pancreatic ductal adenocarcinoma (PDAC), and is closely associated with immune evasion. Additionally, this pathway is important in angiogenesis, acidosis, and fibrosis associated with tumor malignancy in the TME, and its inhibition in PDAC cells results in therapeutic synergy with an anti-PD-1 antibody in vivo. Thus, the ARF6-based pathway affects the TME and the intrinsic function of tumors, leading to malignancy. Here, we discuss the potential mechanisms of this ARF6-based pathway in tumorigenesis, and novel therapeutic strategies.

Nicotine: From Discovery to Biological Effects

Nicotine, the primary psychoactive agent in tobacco leaves, has led to the widespread use of tobacco, with over one billion smokers globally. This article provides a historical overview of tobacco and discusses tobacco dependence, as well as the biological effects induced by nicotine on mammalian cells. Nicotine induces various biological effects, such as neoangiogenesis, cell division, and proliferation, and it affects neural and non-neural cells through specific pathways downstream of nicotinic receptors (nAChRs). Specific effects mediated by α7 nAChRs are highlighted. Nicotine is highly addictive and hazardous. Public health initiatives should prioritize combating smoking and its associated risks. Understanding nicotine's complex biological effects is essential for comprehensive research and informed health policies. While potential links between nicotine and COVID-19 severity warrant further investigation, smoking remains a significant cause of morbidity and mortality globally. Effective public health strategies are vital to promote healthier lifestyles.

α7 nicotinic acetylcholine receptor interaction with G proteins in breast cancer cell proliferation, motility, and calcium signaling

Chronic smoking is a primary risk factor for breast cancer due to the presence of various toxins and carcinogens within tobacco products. Nicotine is the primary addictive component of tobacco products and has been shown to promote breast cancer cell proliferation and metastases. Nicotine activates nicotinic acetylcholine receptors (nAChRs) that are expressed in cancer cell lines. Here, we examine the role of the α7 nAChR in coupling to heterotrimeric G proteins within breast cancer MCF-7 cells. Pharmacological activation of the α7 nAChR using choline or nicotine was found to increase proliferation, motility, and calcium signaling in MCF-7 cells. This effect of α7 nAChR on cell proliferation was abolished by application of Gαi/o and Gαq protein blockers. Specifically, application of the Gαi/o inhibitor pertussis toxin was found to abolish choline-mediated cell proliferation and intracellular calcium transient response. These findings were corroborated by expression of a G protein binding dominant negative nAChR subunit (α7345-348A), which resulted in significantly attenuating calcium signaling and cellular proliferation in response to choline. Our study shows a new role for G protein signaling in the mechanism of α7 nAChR-associated breast cancer growth.

NFR2/ABC transporter axis in drug resistance of breast cancer cells

Breast cancer is one of the most serious malignancies among women, accounting for about 12% of all cancers. The inherent complexity and heterogeneity of breast cancer results in failure to respond to treatment in the advanced stages of the disease. Breast cancer is caused by several genetic and environmental factors. One of the significant factors involved in the development of breast cancer is oxidative stress, which is generally regulated by nuclear factor erythroid 2-related factor 2 (NRF2). The level of NRF2 expression is low in healthy cells, which maintains the balance of the antioxidant system; however, its expression is higher in cancer cells, which have correlation characteristics such as angiogenesis, stem cell formation, drug resistance, and metastasis. Drug resistance increases with the upregulation of NRF2 expression, which contributes to cell protection. NRF2 controls this mechanism by increasing the expression of ATP-binding cassettes (ABCs). Considering the growing number of studies in this field, we aimed to investigate the relationship between NRF2 and ABCs, as well as their role in the development of drug resistance in breast cancer.

β-Caryophyllene Counteracts Chemoresistance Induced by Cigarette Smoke in Triple-Negative Breast Cancer MDA-MB-468 Cells

Exposure to cigarette smoke (CS) has been associated with an increased risk of fatal breast cancers and recurrence, along with chemoresistance and chemotherapy impairment. This strengthens the interest in chemopreventive agents to be exploited both in healthy and oncological subjects to prevent or repair CS damage. In the present study, we evaluated the chemopreventive properties of the natural sesquiterpene β-caryophyllene towards the damage induced by cigarette smoke condensate (CSC) in triple negative breast cancer MDA-MB-468 cells. Particularly, we assessed the ability of the sesquiterpene to interfere with the mechanisms exploited by CSC to promote cell survival and chemoresistance, including genomic instability, cell cycle progress, autophagy/apoptosis, cell migration and related pathways. β-Caryophyllene was found to be able to increase the CSC-induced death of MDA-MB-468 cells, likely triggering oxidative stress, cell cycle arrest and apoptosis; moreover, it hindered cell recovery, autophagy activation and cell migration; at last, a marked inhibition of the signal transducer and activator of transcription 3 (STAT3) activation was highlighted: this could represent a key mechanism of the chemoprevention by β-caryophyllene. Although further studies are required to confirm the in vivo efficacy of β-caryophyllene, the present results suggest a novel strategy to reduce the harmful effect of smoke in cancer patients and to improve the survival expectations in breast cancer women.

Epithelial-Mesenchymal Transition-Mediated Tumor Therapeutic Resistance

Cancer is one of the world’s most burdensome diseases, with increasing prevalence and a high mortality rate threat. Tumor recurrence and metastasis due to treatment resistance are two of the primary reasons that cancers have been so difficult to treat. The epithelial–mesenchymal transition (EMT) is essential for tumor drug resistance. EMT causes tumor cells to produce mesenchymal stem cells and quickly adapt to various injuries, showing a treatment-resistant phenotype. In addition, multiple signaling pathways and regulatory mechanisms are involved in the EMT, resulting in resistance to treatment and hard eradication of the tumors. The purpose of this study is to review the link between EMT, therapeutic resistance, and the molecular process, and to offer a theoretical framework for EMT-based tumor-sensitization therapy.