Effect of Focal Zone Size on Treatment Outcomes and Renal Injury Following Extracorporeal Shockwave Lithotripsy of Renal Calculi: A Prospective Randomized Study.

Background: The narrower focal zone (FZ) size of modern lithotripter was considered as one of the factors that resulted in suboptimal treatment result of extracorporeal shockwave lithotripsy (SWL). Therefore, we investigate the efficacy and safety of standard narrow or extended (FZ) sizes in SWL for patients with renal stones. Materials and Methods: In this prospective study conducted between April 2018 and October 2022, patients with renal stones were randomized to receive SWL with either standard or extended FZ. Treatment was delivered using a Modulith SLX-F2 lithotripter with a maximum of 3000 shocks at 1.5 Hz. The primary outcome was treatment success 12 weeks after a single SWL session, defined as the absence of a stone or stone fragment <4 mm on computed tomography. Secondary outcomes included the incidence of perinephric hematoma, stone-free rate (SFR), and changes in the urinary levels of acute renal injury markers. Results: A total of 320 patients were recruited, and 276 patients were randomized into the two groups. The two groups had similar baseline parameters. The treatment success rate was significantly better for standard FZ (74.3%) than the extended FZ group (59.3%) (p = 0.009). Standard FZ also had a significantly better SFR (Grade-A, 36.8% vs 23.0%, p = 0.013) and less pain after treatment. Both groups had similar perinephric hematoma formation rates, unplanned hospital admission rates, and changes in urinary acute renal injury markers. Conclusions: The standard narrow FZ has better treatment efficacy and similar safety compared with the extended FZ during SWL for renal stones. This clinical trial has been registered in the public domain (CCRBCTR) under trial number CUHK_CCRB00510.

Ambient fine particulate matter inhibits 15-lipoxygenases to promote lung carcinogenesis.

BACKGROUND: Epidemiological observations have demonstrated that ambient fine particulate matter with dp < 2.5 µm (PM2.5) as the major factor responsible for the increasing incidence of lung cancer in never-smokers. However, there are very limited experimental data to support the association of PM2.5 with lung carcinogenesis and to compare PM2.5 with smoking carcinogens. METHODS: To study whether PM2.5 can contribute to lung tumorigenesis in a way similar to smoking carcinogen 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) via 15-lipoxygenases (15-LOXs) reduction, normal lung epithelial cells and cancer cells were treated with NNK or PM2.5 and then epigenetically and post-translationally examined the cellular and molecular profiles of the cells. The data were verified in lung cancer samples and a mouse lung tumor model. RESULTS: We found that similar to smoking carcinogen NNK, PM2.5 significantly enhanced cell proliferation, migration and invasion, but reduced the levels of 15-lipoxygenases-1 (15-LOX1) and 15-lipoxygenases-2 (15-LOX2), both of which were also obviously decreased in lung cancer tissues. 15-LOX1/15-LOX2 overexpression inhibited the oncogenic cell functions induced by PM2.5/NNK. The tumor formation and growth were significantly higher/faster in mice implanted with PM2.5- or NNK-treated NCI-H23 cells, accompanied with a reduction of 15-LOX1/15-LOX2. Moreover, 15-LOX1 expression was epigenetically regulated at methylation level by PM2.5/NNK, while both 15-LOX1 and 15-LOX2 could be significantly inhibited by a set of PM2.5/NNK-mediated microRNAs. CONCLUSION: Collectively, PM2.5 can function as the smoking carcinogen NNK to induce lung tumorigenesis by inhibiting 15-LOX1/15-LOX2.

Estrogen receptor alpha promotes smoking-carcinogen-induced lung carcinogenesis via cytochrome P450 1B1.

UNLABELLED: Smoking carcinogen N-nitrosamines such as 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) require metabolic activation to exert their genotoxicity. The first activation step is mainly catalyzed by cytochrome P450 (CYP) family. Estrogen receptor α (ERα) plays a role in lung pathology. The association between them is unknown. In this study, we explored the relationship and function of CYP1B1 and ERα in NNK-induced lung tumorigenesis. CYP1B1 and ERα expression was analyzed in human lung cancer tissues and NNK-induced lung tumor of A/J mice. Cell lines NCI-H23 and NCI-H460 were employed to further study the responsible mechanisms using various cellular and molecular approaches. Our in vivo experiments demonstrated that CYP1B1 and ERα were over-expressed at the early stage of NNK-induced lung tumorigenesis. Microarray analysis found that ERα was involved in the extracellular-signal-regulated kinase (ERK)/MAPK pathway. NNK activated RAS/ERK/AP1 as it remarkably increased the levels of p-ERK, c-Fos, and c-Jun but inhibited multiple negative regulators of Ras/ERK/AP1, Pdcd4, Spry1, Spry2, and Btg2 through up-regulating miR-21. Both CYP1B1 siRNA and ERK-specific inhibitor U0126 suppressed NNK-mediated ERα up-regulation, suggesting that ERα was downstream of CYP1B1 and ERK. ERK inactivation led to the accumulation of CYP1B1, indicating that CYP1B1 was upstream of ERK activation. Inhibition of ERK or ERα decreased NNK-induced cell proliferation. Blockage of CYP1B1 or ERα induced apoptosis of lung cancer cells. Collectively, NNK-mediated ERα induction is via CYP1B1 and ERK and contributes to the lung carcinogenesis. The inhibition of CYP1B1, ERK, or ERα may arrest the lung cancer cell growth, implicating a pivotal strategy for the treatment of lung cancer. KEY MESSAGES: Smoking carcinogen NNK requires metabolic activation to exert their genotoxicity. CYP1B1 is the enzyme to catalyze NNK. NNK activates CYP1B1 and ERK to induce ERα. Inhibition of CYP1B1, ERK, or ERα arrests the lung cancer cell growth.

Thromboxane A2 receptor α promotes tumor growth through an autoregulatory feedback pathway.

Tobacco smoking can cause a number of cancers. The role of thromboxane synthase (TxAS) in smoking-related cancers is largely unknown. In this study, 37 pairs of tumor and non-tumor lung tissues of non-small-cell lung cancer, 5 lung cancer cell lines, and a mouse tumor model were used to study TxAS and its related molecules. A mouse model of smoking carcinogen 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK)-induced lung tumor showed an increase in TxAS. Thromboxane A2 receptor (TP) was aberrant in lung cancer tissues of smokers. TxAS and TP were increased in lung tissues of NNK-treated mice. The in vitro studies showed that TPα rather than TPß promoted tumor growth, and NNK increased TPα. NNK-induced TxAS, which depended on activation of cyclooxygenase-2 (COX-2), ERK and NF-κB, could be inhibited by miR-34b/c. TPα played a positive role in NNK-induced COX-2/ERK/NF-κB activation, leading to the upregulation of TxAS expression and thromboxane A2 (TxA2) synthesis. The newly synthesized TxA2 could further activate TPα, forming an autoregulatory feedback loop for TPα activation. Collectively, NNK promotes lung tumor growth via inducing TxAS and TPα, which constitutes an auto-positive feedback loop to exaggerate the growth. This study suggests that TPα and TxAS are the ideal targets against smoking-related lung cancer.

Anticancer efficacy of 5F in NNK-induced lung cancer development of A/J mice and human lung cancer cells.

The mechanism responsible for the apoptotic effect induced by ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) is not fully understood and its in vivo effect has not been tested. In this study, the effect and mechanism of 5F was investigated in cigarette smoking carcinogen 4-methylnitrosamino-1-3-pyridyl-butanone (NNK)-induced mouse lung tumor model and in cultured lung cancer cells NCI-H23 and CRL-2066. 5F were given to mice after they were treated with NNK for 18 weeks. The effect of 5F on the lung tumor formation was examined, and its side effect was monitored. Cell proliferation and apoptosis were determined through expression of PCNA, Bcl-2, Bax, and TUNEL assay in in vivo animal model. 5F significantly inhibited the NNK-induced lung tumors by inducing apoptosis and suppressing cell proliferation in vivo with minimal side effects. Cell culture experiments showed that 5F translocated Bax into the mitochondria, downregulated Bcl-2, activated caspase-9 and caspase-3, released cytochrome c into the cytosol, and translocated AIF from the mitochondria to the nucleus, which leading to G2-M cell cycle arrest and cell apoptosis. 5F also activated ERK1/2 and the inhibition of ERK1/2 suppressed 5F-mediated changes in apoptotic molecules. In addition to ERK1/2, 5F activated Akt. The inhibition of Akt further facilitated the apoptosis induced, suggesting that Akt activation was anti-apoptotic rather than pro-apoptotic. Collectively, 5F is effective against lung cancer in vivo with minimal side effects. It induces apoptosis in lung cancer through the mitochondrial-mediated pathway, in which the activation of ERK is critical.

Roles of peroxisome proliferator-activated receptor-alpha and -gamma in the development of non-small cell lung cancer.

Peroxisome proliferator-activated receptor (PPAR)-α and PPARγ participate in cell proliferation and apoptosis. Few studies have simultaneously investigated both PPARα and PPARγ in lung cancers in vivo. The roles of PPARα and -γ were investigated in the development of pulmonary tumors induced in the adult A/J mouse by treatment with 4-(methylnitrosamino)-l-(3-pyridyl)-lbutanone (NNK). Compared with the normal lung tissues, PPARγ expression was much higher in the NNK-induced lung tumor tissues. However, PPARγ transcriptional activity, and the levels of two major endogenous PPARγ ligands, 13-hydroxyoctadecadienoic acid and 15-hydroxyeicosatetraenoic acid, were significantly lower in the NNK-treated lung tissues. The ligand changes in mice were confirmed in human lung cancer tissues. Along with the alteration of PPARγ and its endogenous ligands, the level of PPARα and its activity were increased in the NNK-induced mouse lung tumors. Treatment of mice with the synthetic PPARγ ligand, pioglitazone, significantly inhibited the formation of mouse lung tumors induced by NNK. Our study demonstrated that the reduction of endogenous PPARγ ligands and increased PPARα occurred before the formation of lung tumors, indicating that the molecular changes play a role in lung carcinogenesis. The results suggest that the enhancement of PPARγ activity with its ligands, and the suppression of PPARα with its inhibitors, may prevent the formation of lung tumors, as well as accelerate the therapy of lung cancer. Our findings may also reveal the possibility of using the level of endogenous PPARγ ligands and the activities of PPARγ or PPARα as tumor markers for lung cancer.