Orally administered nicotine effects on rat urinary bladder proliferation and carcinogenesis

RB1 Mutations Induce Smoking-Related Bladder Cancer by Modulating the Cytochrome P450 Pathway

Cigarette smoking causes multiple cancers by directly influencing mutation burden of driver mutations. However, the mechanism between somatic mutation caused by cigarette smoking and bladder tumorigenesis remains elusive. Smoking-related mutation profile of bladder cancer was characterized by The Cancer Genome Atlas cohort. Integraticve OncoGenomics database was utilized to detect the smoking-related driver genes, and its biological mechanism predictions were interpreted based on bulk transcriptome and single-cell transcriptome, as well as cell experiments. Cigarette smoking was associated with an increased tumor mutational burden under 65 years old (p = 0.031), and generated specific mutational signatures in smokers. RB1 was identified as a differentially mutated driver gene between smokers and nonsmokers, and the mutation rate of RB1 increased twofold after smoking (p = 0.008). RB1 mutations and the 4-aminobiphenyl interference could significantly decrease the RB1 expression level and thus promote the proliferation, invasion, and migration ability of bladder cancer cells. Enrichment analysis and real-time quantitative PCR (RT-qPCR) data showed that RB1 mutations inhibited cytochrome P450 pathway by reducing expression levels of UGT1A6 and AKR1C2. In addition, we also observed that the component of immunological cells was regulated by RB1 mutations through the stronger cell-to-cell interactions between epithelial scissor+ cells and immune cells in smokers. This study highlighted that RB1 mutations could drive smoking-related bladder tumorigenesis through inhibiting cytochrome P450 pathway and regulating tumor immune microenvironment.

The role of β2-AR/PI3K/AKT pathway in the proliferation, migration and invasion of THLE-2 cells induced by nicotine

Nicotine, the primary constituent of tobacco, is one of the important factors that induce the occurrence of hepatocellular carcinoma (HCC). The β2-adrenergic receptor (β2-AR) is implicated in the growth and advancement of tumors. However, the role of β2-AR and its mediated cascades in nicotine-induced HCC remains unclear. This present study aims to observe the effects of nicotine on the proliferation, migration, and invasion of immortalized human liver epithelial (THLE-2) cells, as well as to explore the underlying mechanisms of action. The results of cell counting kit-8 (CCK-8) assay showed that 0.3125 μM nicotine had the ability to promote the proliferation of THLE-2 cells with a significant time-dependent manner. Therefore, THLE-2 cells were mainly selected for chronic treatment with 0.3125 μM nicotine in the later stage to cause transformation. After 30 passages of THLE-2 cells with 0.3125 μM nicotine treatment, chronic exposure to nicotine significantly enhanced the proliferation, metastasis, and invasion of cells. Besides, it also upregulated the intracellular levels of β2-AR, phosphoinositide 3-kinase (PI3K), AKT, matrix metalloproteinase-2 (MMP-2) and Cyclin D1, as well as downregulated the expression of p53. More importantly, the β2-AR/PI3K/AKT pathway was found to mediate the expression of MMP-2, Cyclin D1, and p53 in THLE-2 cells, playing a crucial role in their proliferation, migration, and invasion after continuous exposure to nicotine. Simply put, it demonstrated the role of β2-AR/PI3K/AKT pathway in the transformation of THLE-2 cells induced by nicotine. This study could provide valuable insights into the relationship between nicotine and HCC. Additionally, it lays the groundwork for investigating potential anticancer treatments for liver cancer linked to tobacco consumption.

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.

Recent advances in the understanding of urothelial tumorigenesis

INTRODUCTION

Patients with non-muscle-invasive bladder tumor suffer from disease recurrence following transurethral surgery even with intravesical pharmacotherapy, while muscle-invasive disease is often deadly. It is therefore critical to elucidate the underlying molecular mechanisms responsible for not only bladder tumor progression but also its tumorigenesis. Indeed, various molecules and/or signaling pathways have been suggested to contribute to the pathogenesis of bladder cancer.

AREAS COVERED

We summarize the progress during the last few years on the initiation or development, but not progression, of urothelial cancer. The clinical implications of these available data, including prognostic significance and possible application for the prevention of the recurrence of non-muscle-invasive bladder tumors, are also discussed.

EXPERT OPINION

Bladder cancer is a heterogeneous group of neoplasms. The establishment of personalized therapeutic options based on the molecular profile in each case should thus be considered. On that account, further accumulation of data on urothelial tumorigenesis is warranted to identify promising targets for the prevention of postoperative tumor recurrence or tumor development in otherwise high-risk patients.

Environmental exposure to microcystin-LR increases the risks of urinary bladder proliferation and carcinogenesis: Evidence from case control, animal, and in vitro studies

To date, no reported studies have explored the impacts of microcystin-LR (MC-LR) on bladder tissues, and even the occurrence of bladder cancer. The current study explores the role of MC-LR in the development of bladder cancer through human observation and experimental research. In the population study, the odds ratio of bladder cancer for MC-LR was 6.073 (95 % CI, 2.117-17.422) after adjusting interference confounders. MC-LR is mainly located in the nucleus of epithelial cells in bladder cancer tissues instead of normal tissues. A positive association was observed between MC-LR and advanced tumor stage in serum and tissues. The animal study confirmed that prolonged MC-LR treatment promoted the bladder cancer phenotype accompanied by urinary bladder proliferation. In vitro, we indicated that MC-LR activated the PI3K/AKT/GSK3β/Cyclin D1 and JAK2/STAT3/Bcl2 signaling pathways to induce the growth of SV-HUC-1 cells. Moreover, MC-LR promoted the angiogenesis of SV-HUC-1 cells through PI3K/AKT/mTOR/HIF-1α/VEGF pathway. Our study provided the first evidence that prolonged MC-LR treatment increases the incidence of bladder cancer from human investigations, mice models, and in vitro studies, implying the profound importance of the investigation of MC-LR for public health.

Inflammatory reflex disruption in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China, in late 2019 and caused coronavirus disease 2019 (COVID-19), which is still a global pandemic. In most infected people, SARS-CoV-2 can only cause moderate symptoms, while in other patients, it leads to severe illness and eventually death. Although the main clinical manifestation of COVID-19 is often seen in the lungs, this disease affects almost all body organs. The excessive and prolonged release of inflammatory cytokines that may occur in COVID-19 patients, known as cytokine storms, stimulates undesired immune responses and can cause various tissues damage. In the current review article, we focus on the potential advantages of the intrinsic cholinergic anti-inflammatory pathway (CAP) as the efferent arm of inflammatory reflex in COVID-19 management. Considering this endogenous protective mechanism against chronic inflammation, we focused on the effects of SARS-CoV-2 in the destruction of this anti-inflammatory system. Several studies indicated the interaction of SARS-CoV-2 with the alpha7 subtype of the nicotinic acetylcholine receptor as the effector molecule of the inflammatory reflex. On the other hand, neurological manifestations have increasingly been identified as significant extrapulmonary manifestations of COVID-19. The rational connection between these findings and COVID-19 pathogenesis may be an important issue in both our understanding and dealing with this disease. COVID-19 is deeply rooted in our daily life and requires an urgent need for the establishment of effective therapeutic options, and all the possible treatments must be considered for the control of such inflammatory conditions.

Short-term whole body cigarette smoke exposure induces regional differences in cellular response in the mouse larynx

The larynx is an essential organ in the respiratory tract and necessary for airway protection, respiration, and phonation. Cigarette smoking is a significant risk factor associated with benign and malignant laryngeal diseases. Despite this association, the underlying mechanisms by which cigarette smoke (CS) drives disease development are not well elucidated. In the current study, we developed a short-term murine whole body inhalation model to evaluate the first CS-induced cellular responses in the glottic [i.e. vocal fold (VF)] and subglottic regions of the larynx. Specifically, we investigated epithelial cell proliferation, cell death, surface topography, and mucus production, at various time points (1 day, 5 days, 10 days) after ∼ 2 h exposure to 3R4F cigarettes (Delivered dose: 5.6968 mg/kg per cigarette) and following cessation for 5 days after a 5 day CS exposure (CSE). CSE elevated levels of BrdU labeled proliferative cells and p63 labeled epithelial basal cells on day 1 in the VF. CSE increased proliferative cells in the subglottis at days 5, 10 and following cessation in the subglottis. Cleaved caspase-3 apoptotic activity was absent in VF at all time points and increased at day 1 in the subglottis. Evaluation of the VF surface by scanning electron microscopy (SEM) revealed significant epithelial microprojection damage at day 10 and early signs of necrosis at days 5 and 10 post-CSE. SEM visualizations additionally indicated the presence of deformed cilia at days 5 and 10 after CSE and post-cessation in the respiratory epithelium lined subglottis. In terms of mucin content, the impact of short-term CSE was observed only at day 10, with decreasing acidic mucin levels and increasing neutral mucin levels. Overall, these findings reveal regional differences in murine laryngeal cellular responses following short-term CSE and provide insight into potential mechanisms underlying CS-induced laryngeal disease development.

Cell proliferation of rat bladder urothelium induced by nicotine is suppressed by the NADPH oxidase inhibitor, apocynin

Tobacco smoking is a major risk factor for human cancers including urinary bladder carcinoma. In a previous study, nicotine enhanced rat urinary bladder carcinogenesis in a two-stage carcinogenesis model. Nicotine also induced cytotoxicity in the bladder urothelium in a short-term study. In the present study, male rats were treated with nicotine (40 ppm) in drinking water co-administered with the NADPH oxidase inhibitor, apocynin (0, 250 or 750 mg/kg) in diet for 4 weeks. The apocynin treatment induced no clinical toxic effects. Reduction of reactive oxygen species (ROS) by apocynin was confirmed by immunohistochemistry of 8-OHdG in the bladder urothelium. Incidences of simple hyperplasia, cell proliferation and apoptosis were reduced by apocynin treatment in the bladder urothelium. However, despite reduction of cell proliferation (labeling index), apocynin did not affect the incidence of simple hyperplasia, apoptosis, or ROS generation in the kidney pelvis urothelium, in addition to 8-OHdG positivity induced by nicotine being lower. In vitro, apocynin (500 μM) reduced ROS generation, but induced cell proliferation in bladder cancer cell lines (T24 and UMUC3 cells). These data suggest that oxidative stress may play a role in the cell proliferation of the bladder urothelium induced by nicotine.

Antimicrobial Peptide-Loaded Nanoparticles as Inhalation Therapy for Pseudomonas aeruginosa Infections

INTRODUCTION

Antibiotic-resistant bacteria kill 25,000 people every year in the EU. Patients subject to recurrent lung infections are the most vulnerable to severe or even lethal infections. For these patients, pulmonary delivery of antibiotics would be advantageous, since inhalation can achieve higher concentration in the lungs than iv administration and can provide a faster onset of action. This would allow for the delivery of higher doses and hence reduce the number of treatments required. We report here about a new nanosystem (M33-NS) obtained by capturing SET-M33 peptide on single-chain dextran nanoparticles. SET-M33 is a non-natural antimicrobial peptide synthesized in branched form. This form gives the peptide resistance to degradation in biological fluids. SET-M33 has previously shown efficacy in vitro against about one hundred of Gram-negative multidrug and extensively drug-resistant clinical isolates and was also active in preclinical infection models of pneumonia, sepsis and skin infections.

METHODS

The new nanosystem was evaluated for its efficacy in bacteria cells and in a mouse model of pneumonia. Toxicity and genotoxicity were also tested in vitro. Biodistribution and pharmacokinetic studies in healthy rats were carried out using a radiolabeled derivative of the nanosystem.

RESULTS

The M33-nanosystem, studied here, showed to be effective against Pseudomonas aeruginosa in time-kill kinetic experiments. Cytotoxicity towards different animal cell lines was acceptable. Lung residence time of the antimicrobial peptide, administered via aerosol in healthy rats, was markedly improved by capturing SET-M33 on dextran nanoparticles. M33-NS was also efficient in eradicating pulmonary infection in a BALB/c mouse model of pneumonia caused by P. aeruginosa.

DISCUSSION

This study revealed that the encapsulation of the antimicrobial peptide in dextran nanoparticles markedly improved lung residence time of the peptide administered via aerosol. The result has to be considered among the aims of the development of a new therapeutic option for patients suffering recurrent infections, that will benefit from high local doses of persistent antimicrobials.

Genotoxicity and repair capability of Mus musculus DNA following the oral exposure to Tramadol

Tramadol is an analgesic and psychoactive drug that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior. The aim of present study was to analyze the genotoxicity and repair capability of DNA after Tramadol exposure in albino mice (Mus musculus). For this purpose, forty mice were divided equally into four groups as; a control group (without drug) and three treatment groups that were treated with three doses of Tramadol as minimum dose group, Intermediate dose group and maximum dose group, corresponding to 25 mg/kg, 50 mg/kg and 75 mg/kg of body weight respectively. The dose was given orally for 15 days. After 15 days peripheral blood was drawn from half mice of each group and subjected to comet assay. While the remaining half mice were given a recovery period of 15 days and same procedure was used for blood collection and comet assay. Significant difference in various comet parameters was observed among control and exposed groups. Maximum damage was observed at highest concentration 75 mg/kg of Tramadol and minimum damage was observed at dose 25 mg/kg of Tramadol, while results of repaired mice group showed that repair capability of Tramadol was minor and recovery of Tramadol required a lot of time. It can be concluded that Tramadol cause genotoxicity that is dose dependent and has low repair capability.

Cotinine, a major nicotine metabolite, induces cell proliferation on urothelium in vitro and in vivo

Tobacco smoking is a major risk factor for human cancers including urinary bladder carcinoma. In a previous study, nicotine enhanced rat urinary bladder carcinogenesis using a rat urinary bladder two-stage carcinogenesis model. In the present study, nicotine metabolites (cotinine, trans-3'-hydroxy cotinine and N'-nitrosonornicotine) were evaluated in a cell proliferation assay using urinary bladder urothelial cell lines. Cotinine (0.1 to 1 mM) induced the highest cell proliferation compared to the others, including nicotine, in three bladder cancer cell lines (RT4, T24 and UMUC3 cells). By Western blot, cotinine induced phosphorylation of Stat3 and expression of cyclin D1 in UMUC3 cells. The cell proliferation induced by cotinine was blocked by inhibitors of nicotinic receptors (10 nM SR16584 or 10 μM methyllycaconitine citrate) and Stat3 (100 nM stattic). In an in vivo study, cotinine (13, 40 and 120 ppm) in drinking water also induced cell proliferation and simple hyperplasia in urinary bladder and renal pelvis urothelium of rats, but to a lesser degree compared to nicotine (40 ppm). Cytotoxicity detected by scanning electron microscopy and apoptosis in the bladder urothelium were induced by nicotine but not cotinine. These data suggest that cotinine is able to induce urothelial cell proliferation both in vitro and in vivo, and high urinary concentrations may enhance urothelial carcinogenesis.

Serum level and single-nucleotide polymorphisms of toll-like receptor-7 among urinary bladder cancer Iraqi patients

Background

Toll-like receptor 7 (TLR7), a member of TLR family, plays a pivotal role in pathogenesis of different malignancies. Among these is urinary bladder cancer (UBC), which has not been extensively studied. Therefore, it was aimed to determine TLR7 serum level in UBC patients and evaluate its association with some demographic and clinicopathological characteristics. In addition, four TLR7 single-nucleotide polymorphisms (SNPs: rs179018, rs179019, rs179020, and rs179021) were investigated to determine their susceptibility role in UBC and inspect SNP’s impact on TLR7 level. Sixty-six UBC Iraqi patients were enrolled in this case-control study. Two control samples were also involved, 40 urinary tract infection (UTI) patients, and 48 healthy control subjects.

Results

Male gender, older age, and cigarette-smoking are risk factors for UBC. TLR7 level showed a significant decreased median in UBC patients compared to UTI patients or control (1.4 vs. 8.1 and 9.5 ng/ml, respectively; p < 0.001). The decrease was more pronounced in males, age group ≥ 48 years, cigarette-smokers, alcohol non-consumers, clinical stages I–II, and superficial tumor, as well as patients with family history of cancer and untreated patients. Mitomycin C and Bacillus Calmette–Guérin therapies tended to increase TLR7 level. Among the four investigated SNPs, only rs179019 C allele showed significantly uncorrected increased frequency in UBC males compared to control males (p = 0.038), while among UTI females, C allele frequency maintained a significantly corrected decreased frequency compared to control females (p = 0.005). Some SNPs influenced serum level of TLR7, but a significant impact was recorded for rs179019 in UTI females (p = 0.006).

Conclusions

Downregulation of TLR7 is suggested to have a role in etiology and pathogenesis of UBC, especially the male, elderly and smoker patients. Mitomycin C and Bacillus Calmette–Guérin may enhance TLR7 production in the blood of UBC patients. TLR7 SNPs are suggested to influence susceptibility to develop UBC, and their potential in impacting TLR7 serum level is augmented.