Integrated genome-wide methylation and expression analyses provide predictors of diagnosis and early response to antidepressant in panic disorder.

BACKGROUND: We investigated differentially methylated and expressed genes between panic disorder (PD) and healthy controls (HCs) to determine whether DNA methylation and expression level of candidate genes can be used as biomarkers for diagnosis and early response. METHODS: Illumina infiniun Methylation EPIC (850 k) Beadchip for genome-wide methylation screening and mRNA sequencing was conducted in a discovery set (30 patients with PD and 30 matched HCs). The candidate gene loci methylation and expression were verified in an independent validation sample (101 PD patients and 107 HCs). RESULTS: In the discovery set, there were 3613 differentially methylated cytosine phosphate guanosine sites and these differential methylation positions were located within 1938 unique genes, including 1758 hypermethylated genes, 150 hypomethylated genes, and the coexistence of hypermethylation and hypomethylation sites were found in 30 genes. There were 1111 differential transcripts in PD compared to normal controls (850 down-regulated and 261 up-regulated). Further, 212 differentially expressed genes were screened (40 up-regulated and 172 down-regulated). In the validation set, compared with HCs, there was no significant difference in DNA methylation level of Casitas B-lineage lymphoma (CBL) gene loci (cg07123846). The expression level of CBL gene in PD patients was lower (vs. HCs). After four weeks' treatment, the baseline expression level of CBL gene in the responders was higher than nonresponders. LIMITATIONS: The sample size was limited. We only chose CBL as a candidate gene. Follow-up periods were short. CONCLUSIONS: There are differences in genome-wide DNA methylation and mRNA expression between PD patients and HCs. The changes in expression level of CBL gene may be an important molecular marker for PD diagnosis and early response.

Overexpression of circ PTK2 suppresses the progression of nonalcoholic fatty liver disease via the miR-200c/SIK2/PI3K/Akt axis.

Excessive hepatic lipid accumulation is involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). A previous study showed that the circular RNA (circRNA) PTK2 was significantly downregulated in NAFLD mice. However, the detailed function of circ PTK2 in NAFLD remains unclear. A high-fat diet (HFD) was used to establish a mouse model of NAFLD, and free fatty acid (FFA) treatment was used to establish an in vitro model of NAFLD. Oil red O staining was used to evaluate lipid accumulation. The pathological changes in mice were observed by HE staining. Western blotting and RT-qPCR were applied to assess protein and mRNA levels, respectively. A dual luciferase reporter assay and RIP were used to explore the relationship among circ PTK2, miR-200c and SIK2. Circ PTK2 and SIK2 were downregulated and miR-200c was upregulated in NAFLD. Upregulation of circ PTK2 reversed lipid accumulation in FFA-treated HepG2 cells. Moreover, circ PTK2 bound to miR-200c, and SIK2 was identified as the direct target of miR-200c. Moreover, the miR-200c inhibitor-induced decrease in lipid accumulation was reversed by SIK2 knockdown. Furthermore, the impact of circ PTK2 overexpression on PI3K/Akt signaling was partially reversed by SIK2 silencing. Circ PTK2 overexpression alleviates NAFLD development via the miR-200c/SIK2/PI3K/Akt axis. Thus, our work might provide new methods for NAFLD treatment.

Associations of DNA methylation of HPA axis-related genes and neuroendocrine abnormalities in panic disorder.

OBJECTIVE: The purpose of this study was to investigate the role of aberrant DNA methylation of hypothalamic-pituitary-adrenal (HPA) axis-related genes (CRHR1, CRHR2, CRH, FKBP5, HSP90AA1, NR3C1, and POMC) in panic disorder (PD) development. We investigated the correlation among gene methylation levels, adrenocorticotropic hormone (ACTH), cortisol, and PD severity in patients. METHODS: We compared the methylation levels of HPA axis-related genes between 178 patients with PD and 184 healthy controls using MethylTarget. We then measured ACTH and cortisol levels using chemiluminescence. Disease severity was assessed using the Panic Disorder Severity Scale. RESULTS: Compared with healthy controls, patients with PD displayed significantly higher levels of ACTH and cortisol, and significantly reduced methylation levels of CRHR1, FKBP5, HSP90AA1, and NR3C1 after correcting for multiple testing using the false discovery method. A significant positive correlation was observed between the methylation of CRHR1, CRHR2, and NR3C1 and ACTH levels in patients with PD, and methylation levels of CRHR1 and NR3C1 were significantly positively related to cortisol levels. In addition, a negative correlation was observed between PD severity and the methylation of CRH, CRHR1, CRHR2, and HSP90AA1. CONCLUSION: Aberrant methylation of HPA axis-related genes may predict PD development and impact ACTH and cortisol levels.

Suicidality in patients with primary diagnosis of panic disorder: A single-rate meta-analysis and systematic review.

BACKGROUND: This study investigated the lifetime suicide attempt and ideation rates among patients with panic disorder (PD). METHODS: Online databases regarding lifetime suicide attempt and ideation rates in patients with PD were searched up to May 2021. RESULTS: The suicide attempt and ideation rates were 0.17 (95% CI: 0.16, 0.18) and 0.23 (95% CI: 0.22, 0.25). The suicide attempt rates among female and male patients were 0.17 (95% CI: 0.14, 0.20) and 0.15 (95% CI: 0.12, 0.19). When PD was comorbid with anxiety, depression, substance abuse, and personality disorders, the suicide attempt rates increased to 0.23 (95% CI: 0.20, 0.26), 0.23 (95% CI: 0.18, 0.27), 0.25 (95% CI: 0.20, 0.31), and 0.25 (95% CI: 0.23, 0.28), respectively. LIMITATIONS: The suicide attempt and ideation by age, suicide ideation by sex, and suicide ideation by comorbidity with other mental disorders were passed in our meta-analysis as sample size was small. Stratification analysis on ethnicity, marital status, education levels, resident location, and severity of PD should be considered in the future. CONCLUSION: The lifetime suicide ideation and attempt rates in patients with PD were higher than general populations but lower than patients with bipolar or depression. The lifetime suicide attempt rate in female patients was slightly higher than male patients. When PD was comorbid with one other mental illness, the lifetime suicide attempt rate increased by about 50%.

Anlotinib Combined with S-1 in Third- or Later-Line Stage IV Non-Small Cell Lung Cancer Treatment: A Phase II Clinical Trial.

LESSONS LEARNED: The combination of anlotinib and S-1 exhibited good antitumor activity in third- or later-line treatment for stage IV non-small cell lung cancer (NSCLC). Combination therapy of anlotinib with S-1 has manageable toxicities in patients with NSCLC. BACKGROUND: This study aimed to evaluate the efficacy and safety of anlotinib combined with S-1 as a third- or later-line treatment for patients with stage IV non-small cell lung cancer (NSCLC). Anlotinib was approved in 2018 by the Chinese Food and Drug Administration (FDA) as a third-line treatment for patients with refractory advanced NSCLC and is under study in the U.S. and Europe. METHODS: Simon's phase II clinical trial design with an α error of 5% and a power ß of 80% was used, anticipating a 10% objective response rate (ORR) of anlotinib and a 30% ORR of anlotinib combined with S-1; the required sample size was 29. A total of 29 patients were enrolled in the clinical trial. Patients were treated with anlotinib plus S-1 over a 21-day treatment course until disease progression or unacceptable toxic effects. If the efficacy was assessed as stable disease, partial response, or complete response after six cycles, anlotinib was maintained until disease progression or death. The primary endpoint was the objective response rate. Somatic mutations were not required for study enrollment. RESULTS: The median follow-up time was 11.1 months. Objective responses were observed in 11 of 29 (37.9%) patients making up the intention-to-treat population, which reached the target primary endpoint of 30% ORR. The median overall and progression-free survival were 16.7 and 5.8 months, respectively. The most common grade 3 adverse events (AEs) were gastrointestinal, including nausea, vomiting and diarrhea, fatigue, and hypertension. No grade 4 treatment-related AEs or treatment-related deaths occurred. CONCLUSION: The combination of anlotinib with S-1 in the third- or later-line treatment of stage IV NSCLC shows promising antitumor activity and manageable toxicity in patients with NSCLC; phase III trials will be planned in the future.

Clinical Application of Oral Meglumine Diatrizoate Esophagogram in Screening for Esophageal Fistula During Radiotherapy or Chemoradiotherapy for Esophageal Cancer.

Background: This study aimed to investigate the specificity and sensitivity of oral meglumine diatrizoate esophagogram in screening for esophageal fistula during radiotherapy or chemoradiotherapy for esophageal cancer and determine if early detection and intervention could improve the prognosis of esophageal fistulas. Methods: Esophageal cancer patients undergoing radiotherapy or chemoradiotherapy were included. Weekly oral meglumine diatrizoate esophagograms were performed to screen for esophageal fistulas during radiotherapy. When an esophageal fistula was detected, fibroesophagoscopy and computed tomography (CT) were used for confirmation; once confirmed, radiotherapy was discontinued, and the patient received intervention. The esophagogram results were reviewed weekly to assess the recovery of the esophageal fistula. If the fistula was healed, the patient resumed and completed radiotherapy. Results: A total of 206 patients with cancer of the esophagus undergoing chemotherapy/radiotherapy were included. During radiotherapy, 10 cases of esophageal fistula were detected or suspected based on the oral meglumine diatrizoate esophagography findings, and eight of those cases were confirmed by CT and esophagoscopy. All patients with esophageal fistula received intervention; among them, 62.5% (5/8) recovered after 1 to 2 weeks of treatment and continued radiotherapy to completion. The sensitivity and specificity of oral meglumine diatrizoate esophagography in screening for esophageal fistulas during radiotherapy or chemoradiotherapy were 100 and 98.9%, respectively. The median survival period of patients with esophageal fistulas was 6.4 months. Conclusion: Oral meglumine diatrizoate esophagography has high sensitivity and specificity in screening for esophageal fistulas during radiotherapy or chemoradiotherapy with minimal side effects. Early diagnosis and timely intervention can significantly improve the prognosis and prolong the survival period of patients. Trial Registration: Chictr.org.cn, Identifier: ChiCTR-DDD-17012617. Registered on September 7, 2017. The first participant was enrolled on September 25, 2017. http://www.chictr.org.cn/showproj.aspx?proj=21526.

Anlotinib Combined with S-1 in the Third-Line Treatment of Stage IV Non-Small Cell Lung Cancer: Study Protocol for Phase II Clinical Trial.

BACKGROUND: A proportion of patients with stage IV non-small-cell lung cancer (NSCLC) is predicted to receive third-line treatment. However, currently no standard third-line treatment for NSCLC is available. Anlotinib is an oral, multi-targeted tyrosine kinase (TK) receptor inhibitor, which was approved as a third-line treatment for stage IV NSCLC in China on May 9, 2018. Nevertheless, The objective response rate of patients treated with anlotinib was merely 9.2% and the overall survival was only 3 months compared with the patients treated with placebo. Previous studies have shown that cancer treatment with a combination of chemotherapy with TK receptor inhibitors is effective and safe well tolerated. Therefore, the combination of anlotinib with other chemotherapeutic agents may be an effective treatment strategy for patients with stage IV NSCLC. Oral S-1 is a third-generation fluorouracil derivative; it showed good efficacy and caused relatively low toxicity in patients with NSCLC. METHODS: The purpose of this trial is to evaluate the efficacy and safety of anlotinib combined with S-1 as the third-line treatment for patients with stage IV NSCLC. This is a prospective, phase II clinical trial. We will enroll29 patients with stage IV NSCLC treated with anlotinib plus S-1. Tumors will be assessed using computed tomography prior to treatment, after two, four, and six cycles of treatment, and during follow-up every 3 months until disease progression or death. The primary endpoint is the objective response rate (ORR). The secondary endpoints are progression-free survival, duration of response, proportion of disease control, and safety. DISCUSSION: The expected outcome of this study is that anlotinib combined with S-1 has tolerable toxicity and better ORR than anlotinibmonotherapy. The results may indicate additional treatment options for patients with stage IV NSCLC.
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Sera total oxidant/antioxidant status in lung cancer patients.

We investigated oxidative stress parameters in the sera of patients with lung cancer and healthy individuals to evaluate their correlations with lung cancer.Ninety-four lung cancer patients and 64 healthy controls were enrolled after obtaining informed consent. Their sera oxidative stress parameters were measured.Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were significantly different between patients and healthy groups (all P < .001). TAS gradually decreased and TOS and OSI gradually increased from stage I to III, but it did not reach statistical significance (all P > .05). TAS and OSI were significantly different between the nonsmoking and smoking groups, radiotherapy and without radiotherapy groups, chemotherapy and without chemotherapy groups (P < .05), but not TOS (P > .05). In a receiver operating characteristic curve analysis comparing patients with lung cancer with healthy controls, the Youden indices of TOS, TAS, and OSI were 0.541, 0.532, and 1, respectively.The oxidative stress may be correlation with lung cancer staging. Smoking, surgery, radiotherapy, and chemotherapy showed correlation with parts oxidative stress parameters.

Safety and efficacy of pulsed low-dose rate radiotherapy for local recurrent esophageal squamous cell carcinoma after radiotherapy: Study protocol for a prospective multi-center phase II trial.

INTRODUCTION: Re-irradiation after radiotherapy is a common treatment for locally recurrent esophageal cancer. However, the side effects of re-irradiation are serious. The most serious adverse reactions of re-irradiation include esophageal perforation and hemorrhage caused by esophageal perforation. Studies have shown that pulsed low-dose rate radiotherapy (PLDR) induces a hypersensitivity effect on tumor tissue and a hyper-repair effect on normal tissue, which can simultaneously reduce damage on the normal tissue and increase the therapeutic effect on the tumor. The objective of this study is to explore whether PLDR can reduce rate of esophageal perforation and improve efficacy in patients with recurrent esophageal squamous cell carcinoma (ESCC) after radiotherapy. METHODS AND ANALYSIS: This study is a prospective, multi-center, open, single-arm clinical trial designed to enroll 27 patients with locally recurrent ESCC after radiotherapy with or without chemotherapy. Re-irradiation will be performed using intensity modulated radiation therapy in 50 Gy/25 fractions. The strategy of PLDR includes dividing 2 Gy into 10 fractions, and administering each irradiating dose of 20 cGy at an interval of 3 minutes before the next low-dose irradiation. The actual dose rate of administration each time will be 16.67 cGy /minute. The primary endpoint in this study is the rate of esophageal perforation. The secondary endpoints are the objective remission rate, the palliative effect on quality of life and pain, and the time of disease progression. The observation time is 2 years after the end of the study. TRIAL REGISTRATION: Clinical trial number: ChiCTR1900020609.

Clinical observation of the reduced glutathione in the treatment of diabetic chronic kidney disease.

BACKGROUND: Diabetic chronic kidney disease (CKD) has become the main cause of death in diabetic patients, but its pathogenesis has not yet been clear. OBJECTIVE: To investigate the effects of reduced glutathione (GSH) on oxidative stress (OS), angiogenesis factors and lymphocyte subsets in diabetic CKD patients. METHODS: A total of 130 subjects were retrospectively studied. The subjects were divided into the control group (45 cases), treatment group (45 cases, treated with reduced GSH), and a healthy control group (40 cases). The levels of superoxide dismutase (SOD), advanced oxidation protein products (AOPP), malondialdehyde (MDA), endostatin (ES), and vascular endothelial growth factor (VEGF), and the percentages of lymphocyte subsets were detected. RESULTS: After treatment, the indexes of OS and angiogenesis and the percentage of CD3- CD19+ B cells were obviously decreased, and the percentages of T cell subsets and natural killer (NK) cell subsets were markedly increased in the treatment group compared with the control group. AOPP was positively correlated with angiogenesis indexes, MDA and CD3- CD19+ B cells, and negatively correlated with SOD and other lymphocyte subsets. SOD was inversely associated with angiogenesis indexes and MDA, and positively associated with lymphocyte subsets. Moreover, MDA had a positive correlation with angiogenesis indexes, B and T cell subsets, and a negative correlation with NK cell subsets. AOPP, MDA, SOD, VEGF, CD3+ T cells, CD3+ CD8+ T cells, CD3- CDl6+ CD56+ NK cells, and CD3- CDl6+ CD56+ NK T cells were the risk factors of diabetic CKD. CONCLUSION: GSH could inhibit OS and abnormal angiogenesis, and improve cellular immune response in CKD patients.

Clinical application of oral meglumine diatrizoate esophagogram in screening esophageal fistula during radiotherapy for esophageal cancer.

INTRODUCTION: Esophageal fistula is a serious and common complication of radiotherapy for esophageal cancer. Therefore, early diagnosis and treatment is necessary. Because of side effect of barium esophagography, it cannot be used to screening esophageal fistula during radiotherapy. Meglumine diatrizoate is an ionic contrast agent, its adverse reactions were rarely seen when it was used in the body cavity. The purpose of this trial is identified the sensitivity and specificity of oral meglumine diatrizoate in an esophagogram for screening esophageal fistula during radiotherapy. METHODS/DESIGN: This trial was a prospective, multicenter, diagnostic clinical trial. A total of 105 patients with esophageal cancer will swallowed meglumine diatrizoate and underwent a radiographic examination weekly during radiotherapy, medical personnel observed the esophageal lesions to determine whether an esophageal fistula formed. If an esophageal fistula was observed, esophagofiberoscopy and/or computer tomography was used to further confirm the diagnosis. And the sensitivity and specificity of meglumine diatrizoate should be calculated for screening esophageal fistula during radiotherapy. DISCUSSION: To our knowledge, this study protocol is the first to identify the sensitivity and specificity of oral meglumine diatrizoate in an esophagogram for screening esophageal fistula during radiotherapy. If oral meglumine diatrizoate can be used to screening esophageal fistula, more patients will benefit from early detection and treatment.

Attitudes of radiation oncologists to percutaneous endoscopic gastrostomy in patients with head and neck cancer and eating difficulties: A survey in China.

Objective To investigate the attitudes of radiation oncologists towards using percutaneous endoscopic gastrostomy (PEG) to solve nutritional problems in patients with head and neck cancer (HNC) undergoing radiotherapy. Methods A self-reported questionnaire was developed and used to assess the willingness of radiation oncologists from 26 hospitals throughout several provinces in China to use the nutritional method. Results Of the 433 radiation oncologists who were contacted and returned questionnaires, 361 were completed correctly and used in the study (83.4% completion rate). Years of working and degree of understanding PEG were significantly related to the willingness of oncologists to use PEG in patients with HNC. Radiation oncologists who were willing to accept PEG training were more willing to use PEG. Main reasons for unwillingness to use PEG were poor understanding of the operation or cost and fear of side effects causing medical disputes. Conclusions The findings of the survey suggest that attitudes of radiation oncologists in China towards using PEG in patients with HNC requiring nutritional support may be improved by providing accessible training in the technique.

Total Oxidant/Antioxidant Status in Sera of Patients with Esophageal Cancer.

BACKGROUND Oxidative stress parameters such as total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) have been studied in breast, thyroid, and simple esophageal cancers (EC). We evaluated these parameters in patients with EC and analyzed their correlations with treatment outcomes. MATERIAL AND METHODS Serum TOS, TAS, and OSI in 92 patients with EC at different clinical stages and in 64 healthy people (controls) were measured. RESULTS Serum TOS, TAS, and OSI were significantly different between patients with EC and healthy controls (all p<0.001); however, there were no significant differences across different clinical stages (all p>0.05). These factors are not correlated with smoking or drinking history (all p>0.05). Patients with EC with higher TOS and OSI and lower TAS had better responses to chemotherapy and/or radiotherapy, but there was no significant correlation with different responses (all p>0.05). In a receiver operating characteristic curve analysis comparing patients with EC with healthy controls, the Youden indices were 0.391, 0.886, and 1, respectively. CONCLUSIONS Serum TOS, TAS, and OSI were significantly different between patients with EC and healthy controls. In patients with EC, these factors were not correlated with smoking or drinking history or with clinical stage. Patients with EC with higher TOS and OSI and lower TAS had a trend towards better outcomes but it did not reach significance. Serum TOS and OSI are potential diagnostic biomarkers that can be used to identify cases of EC.

Significance of Serum Total Oxidant/Antioxidant Status in Patients with Colorectal Cancer.

Oxidative stress is involved in a variety of diseases. Prospective studies investigating the relationship between oxidative stress biomarkers and the status and development of colorectal cancer (CRC) are scarce; previous studies have failed to establish a relationship between the serum total oxidant/antioxidant status and CRC. Therefore, we compared the total serum oxidant/antioxidant levels of CRC patients and healthy subjects, and analyzed their clinical significance in the CRC. Fasting blood samples from 132 CRC patients and 64 healthy subjects were collected. Oxidative stress parameters, including total oxidant status (TOS) and total antioxidant status (TAS), were measured, and the oxidative stress index (OSI) was calculated. The TOS and OSI levels increased significantly (P<0.001) and the TAS level significantly decreased (P<0.001) in the CRC group compared to those in the healthy control group. Oxidative stress parameters differed significantly depending on the patient's smoking and drinking status (P<0.05). The preoperative and postoperative levels of TOS, TAS, and OSI did not differ significantly between primary sites (colon/rectum) and clinical stages (P>0.05).However, the levels of TOS, TAS, and OSI were significantly different between patients with no metastasis and those with metastases to two organs (P<0.05) Finally, the parameters are affected by smoking and drinking, and subsequent research should be conducted excluding the relevant influencing factors.

Recent development of recycling lead from scrap CRTs: A technological review.

Cathode ray tubes (CRTs) contain numerous harmful substances with different functions. Lead is found in the funnel glass of CRTs. Improperly treated toxic lead may pose significant risks to human health and the environment. This paper reviews and summarizes existing technological processes on the recycling of lead from waste CRTs, including pyrometallurgy, hydrometallurgy, and product-regeneration. The present situation, advantages, and disadvantages of these techniques are described in detail. Generally, pyrometallurgy shows better practicability in recovery lead from waste CRT than hydrometallurgy and hydrometallurgy, in view of environmental impact, energy-consumption, product formats and safety and maturity of technology. Moreover, the gaps in the existing technologies were identified and recommendations for future research were provided.

Inhibition of 12-lipoxygenase reduces proliferation and induces apoptosis of hepatocellular carcinoma cells in vitro and in vivo.

BACKGROUND: 12-lipoxygenase (12-LOX) has been reported to be an important gene in cancer cell proliferation and survival, and tumor metastasis. However, its role in hepatocellular carcinoma (HCC) cells remains unknown. METHODS: Expression of 12-LOX was assessed in a diethyl-nitrosamine-induced rat HCC model, and in SMMC-7721, HepG2 and L-02 cells using immunohistochemical staining and reverse transcriptase-polymerase chain reaction (RT-PCR). GST-π and Ki-67 were determined in vivo by immunohistochemical staining. Apoptosis was evaluated by TUNEL assay. Cell viability and apoptosis were determined by MTT assay and flow cytometry, respectively. Apoptosis-related proteins in SMMC-7721 and HepG2 cells were detected by Western blotting. RESULTS: Immunohistochemical staining and RT-PCR showed that 12-LOX was over-expressed in rat HCC and two HCC cell lines, while the expression was inhibited by baicalein, a specific inhibitor of 12-LOX. Baicalein inhibited cell proliferation and induced apoptosis in rat HCC and both cell lines in a dose- and time-dependent manner. Our in vivo study demonstrated that baicalein also reduced neoplastic nodules. Mechanistically, baicalein reduced Bcl-2 protein expression coupled with a slight increase of the expression of Bax and activation of caspase-3. Furthermore, baicalein inhibited the activation of ERK-1/2 (phosphorylated). Interestingly, the effects of baicalein were reversed by 12(S)-HETE, a metabolite of 12-LOX. CONCLUSIONS: Inhibition of 12-LOX leads to reduced numbers of HCC cells, partially caused by increased apoptosis. 12-LOX may be a potential molecular target for HCC prevention and treatment.

5-Lipoxygenase contributes to the progression of hepatocellular carcinoma.

5-Lipoxygenase (5-LOX) has been implicated in the development and progression of lung, pancreatic and esophageal cancers. However, its role in hepatocellular carcinoma (HCC) remains unclear. This study aimed to explore the role of 5-LOX in the pathogenesis of HCC. The expression of 5-LOX was detected in human HCC, HepG2 cells and diethylnitrosamine (DEN)-induced rat HCC using immunohistochemistry (IHC) staining or reverse transcriptase-polymerase chain reaction. Apoptosis in rat HCC was evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) assay. Cell viability and apoptosis were determined in HepG2 cells by MTT assay and flow cytometry, respectively. IHC staining showed that the 5-LOX protein was highly expressed in human HCC, HepG2 cells and rat HCC, but not in the normal liver tissues. 5-LOX mRNA expression in human and rat HCC was also significantly increased compared to normal liver tissues. Zileuton, a 5-LOX inhibitor, reduced the nodule incidence and the mean number of nodules per nodule-bearing liver in DEN-induced rats. Further study using TUNEL assay showed that zileuton treatment induced apoptosis in the liver as the result of inhibition on 5-LOX levels. This result is consistent with our observation of significantly higher apoptotic indices in rats treated with DEN/zileuton, which were significantly higher compared to those from the control groups. In addition, zileuton reduced cell viability and induced apoptosis in a concentration- and time-dependent manner as detected using HepG2 cells in our in vitro analysis. In conclusion, 5-LOX is expressed in HCC, and the inhibition of 5-LOX blocks the development of HCC via the induction of apoptosis in tumor cells.