Arsenic, tobacco use, and lung cancer: An occupational cohort with 27 follow-up years.

BACKGROUND: We explored the shape of the exposure-response relationship of arsenic-related lung cancer and the interaction between arsenic and tobacco use. METHODS: A total of 3278 tin miners with at least 10 years of arsenic exposure were enrolled since 1992 and followed up for 27 years. After excluding radon-exposed miners and former smokers, 1620 miners were included into the sub-cohort. Lung cancer risks were estimated by modeling total exposure and intensity of arsenic exposure. RESULTS: The cohort experienced 73,866 person-years and 414 lung cancer cases. Firstly, the ERR/mg/m3-year was 0.0033 (95% CI: 0.0014-0.0045) in arsenic concentration <3 mg/m3 and 0.0056 (95% CI: 0.0035-0.0073) in arsenic concentration ≥3 mg/m3. After adjusting for cumulative arsenic exposure, and the ERR/mg/m3 increased with increasing intensity (0.129 (95% CI: 0.039, 0.189)). Secondly, an unique aspect of this population was the early age at first arsenic exposure for workers. Results showed that lung cancer incidence risk from exposed in childhood (<13 years) was non-significantly greater than those in other age groups (13-17 and ≥ 18 years). Finally, the most likely joint effects of inhaled arsenic and tobacco use was sub-multiplicative. CONCLUSION: This study enlightened us that for fixed cumulative arsenic exposure, higher concentration over shorter duration might be more deleterious than lower concentration over longer duration. Substantial reductions in the lung cancer burden of smokers exposed to arsenic could be achieved by reductions in either exposure.

Quantitative evaluation of radon, tobacco use and lung cancer association in an occupational cohort with 27 follow-up years.

BACKGROUND: Occupational radon cohorts provide important information about exposure at residential level, which are difficult to observe prospectively. However, evidence about radon-related lung cancer risks from initial exposure in childhood or interaction between radon and smoking is still limited. METHODS: A total of 6017 tin miners with at least 10 years of underground radon exposure were enrolled beginning in 1992 and followed for up to 27 years. Lung cancer risks were estimated by modeling total and intensity of radon exposure. RESULTS: A total of 933 lung cancer cases occurred in this cohort over 89,092 person-years of follow up. Excess relative risk increased by 0.96% per cumulative working level month (WLM). A unique aspect of this population was the early age at first radon exposure for workers. Results showed that lung cancer risk from initial radon exposure in childhood (<13 years old) was greater than risk when first exposure occurred at later ages (13-17, 18-24, and ≥ 25 years old). Moreover, risk declined with years since last exposure and attained age, but increased with age at last exposure. Importantly, these patterns were stable after adjustment for tobacco use or arsenic exposure. For joint effects of radon and other agents, our results support sub-multiplicative as the most likely model for interaction between radon and tobacco use or arsenic exposure. CONCLUSION: This study highlights the possible importance of radon exposure in childhood in cancer etiology and suggests another potential strategy to mitigate the global lung cancer burden.

The lncRNA XIST exhibits oncogenic properties via regulation of miR-449a and Bcl-2 in human non-small cell lung cancer.

Long non-coding RNAs (lncRNAs) are associated with the occurrence, development and prognoses of non-small cell lung cancer (NSCLC). In the present study, we investigated the functional mechanisms of the lncRNA XIST in two human NSCLC cell lines, A549 and NCI-H1299. In all the 5 NSCLC cell lines (NL9980, NCI-H1299, NCI-H460, SPC-A-1 and A549) tested, the expression levels of XIST were significantly elevated, as compared with those in normal human bronchial epithelial cell line BEAS-2B. In A549 and NCI-H1299 cells, knockdown of XIST by siRNA significantly inhibited the cell proliferation, migration and invasion, and promoted cell apoptosis. Furthermore, XIST knockdown elevated the expression of E-cadherin, and suppressed the expression of Bcl-2. Moreover, knockdown of XIST significantly suppressed the tumor growth in NSCLC A549 xenograft mouse model. Bioinformatic analysis and luciferase reporter assays revealed that XIST was negatively regulated by miR-449a. We further identified reciprocal repression between XIST and miR-449a, which eventually influenced the expression of Bcl-2: XIST functioned as a miRNA sponge of miR-449a, which was a negative regulator of Bcl-2. These data show that expression of the lncRNA XIST is associated with an increased growth rate and metastatic potential in NSCLC A549 and NCI-H1299 cells partially through miR-449a, and suggest that XIST may be a potential prognostic factor and therapeutic target for patients with NSCLC.

Benzyl isothiocyanate induces protective autophagy in human lung cancer cells through an endoplasmic reticulum stress-mediated mechanism.

Isothiocyanates, such as allyl isothiocya¬nate (AITC), benzyl isothiocyanate (BITC), phenethyl isothio¬cyanate (PEITC) and sulforaphane (SFN), are natural compounds abundant in cruciferous vegetables, which have substantial chemopreventive activities against various human malignancies. However, the mechanisms underlying the inhibition of tumor cell growth by isothiocyanates are not fully understood. Since autophagy has dual functions in cancer, in the present study we investigated the effects of BITC on autophagy induction in human lung cancer cells in vitro and in vivo. BITC (1-100 µmol/L) dose-dependently inhibited the growth of 3 different human lung cancer cell lines A549 (adenocarcinoma), H661 (large cell carcinoma) and SK-MES-1 (squamous cell carcinoma) with IC50 values of 30.7±0.14, 15.9±0.22 and 23.4±0.11 µmol/L, respectively. BITC (10-40 µmol/L) induced autophagy in the lung cancer cells, evidenced by the formation of acidic vesicular organelles (AVOs), the accumulation of LC3-II, the punctate pattern of LC3, and the expression of Atg5. Pretreatment with the autophagy inhibitor 3-MA (5 mmol/L) significantly enhanced the BITC-caused growth inhibition in the lung cancer cells. Furthermore, BITC (20-40 µmol/L) activated ER stress, as shown by the increased cytosolic Ca2+ level and the phosphorylation of the ER stress marker proteins PERK and eIF2α in the lung cancer cells. Pretreatment with the ER stress inhibitor 4-PBA (5 mmol/L) attenuated the autophagy induction and potentiated the BITC-induced cell growth inhibition. In nude mice bearing A549 xenografts, administration of BITC (100 mg·kg-1·d-1, ip) for 8 weeks markedly suppressed the lung tumor growth, and significantly enhanced both autophagy and ER stress in the tumor tissues. Our results demonstrate that BITC inhibits human lung cancer cell growth in vitro and in vivo. In addition, BITC induces autophagy in the lung cancer cells, which protects the cancer cells against the inhibitory action of BITC; the autophagy induction is mediated by the ER stress response.

HapMap-based study on the association between MPO and GSTP1 gene polymorphisms and lung cancer susceptibility in Chinese Han population.

AIM: Myeloperoxidase (MPO) and glutathione S-transferase pi 1 (GSTP1) are important carcinogen-metabolizing enzymes. The aim of this study was to investigate the association between the common polymorphisms of MPO and GSTP1 genes and lung cancer risk in Chinese Han population. METHODS: A total of 266 subjects with lung cancer and 307 controls without personal history of the disease were recruited in this case control study. The tagSNPs approach was used to assess the common polymorphisms of MOP and GSTP1 genes and lung cancer risk according to the disequilibrium information from the HapMap project. The tagSNP rs7208693 was selected as the polymorphism site for MPO, while the haplotype-tagging SNPs rs1695, rs4891, rs762803 and rs749174 were selected as the polymorphism sites for GSTP1. The gene polymorphisms were confirmed using real-time PCR, cloning and sequencing. RESULTS: The four GSTP1 haplotype-tagging SNPs rs1695, rs4891, rs762803 and rs749174, but not the MPO tagSNP rs7208693, exhibited an association with lung cancer susceptibility in smokers in the overall population and in the studied subgroups. When Phase 2 software was used to reconstruct the haplotype for GSTP1, the haplotype CACA (rs749174+rs1695 + rs762803+rs4891) exhibited an increased risk of lung cancer among smokers (adjust odds ratio 1.53; 95%CI 1.04-2.25, P=0.033). Furthermore, diplotype analyses demonstrated that the significant association between the risk haplotype and lung cancer. The risk haplotypes co-segregated with one or more biologically functional polymorphisms and corresponded to a recessive inheritance model. CONCLUSION: The common polymorphisms of the GSTP1 gene may be the candidates for SNP markers for lung cancer susceptibility in Chinese Han population.

[A standardization study of Meta-analyses on nephropathy published in Chinese journals].

OBJECTIVE: To evaluate the standardization of Meta-analyses on nephropathy published in Chinese journals. METHODS: By searching in WANFANG, VIP, CNKI databases and Chinese Biomedical Literature Database (CBM) as well as related Chinese journals, eligible Meta-analyses were enrolled and analyzed according to the PRISMA(Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement and the MOOSE (Meta-analysis of Observational Studies in Epidemiology) Checklist. RESULTS: A total of 217 Meta-analyses were enrolled with 166 on randomized controlled trials (RCT) and 51 on observational studies. Based on the PRSIMA Statement, of the 166 Meta-analyses on RCT, 51.8% (86 papers) were found with the complete research hypothesis, 13.9% (23) with the literature screening flow chart, 15.7% (26) with the subgroup analysis, 53.0% (88) with the publication bias analysis and 28.3% (47) with the sensitivity analysis. According to the MOOSE Checklist, of the 51 Meta-analyses on observational studies, only 9.8% (5) had done the statistical stability calculation, 54.9% (28) with the outlook of application, 45.1% (23) with the limitation of the study, 2.0% (1) with the quantitative analysis on potential bias and 17.6% (9) with the suggestion for future studies. CONCLUSIONS: Unclear hypothesis, limited methodological description, lack of in-depth analysis on heterogeneity and bias are the common defects in Meta-analyses published in Chinese journals on nephrology.

Effect of Arsenic Exposure and Cigarette Smoking on Total and Cause-Specific Mortality: An Occupational Cohort With 27 Follow-up Years.

BACKGROUND: The relationship between arsenic exposure and all-cause mortality and the joint effects of arsenic exposure and smoking have been poorly described in previous studies. METHODS: After 27 years of follow-up, a total of 1738 miners were included in the analysis. Different statistical methods were used to explore the relationship between arsenic exposure and smoking and the risk of all-cause mortality and various causes of death. RESULTS: A total of 694 deaths occurred during the 36,199.79 person-years of follow-up. Cancer was the leading cause of death, and arsenic-exposed workers had significantly higher mortality rates for all-cause, cancer, and cerebrovascular disease. All-cause, cancer, cerebrovascular disease, and respiratory disease increased with cumulative arsenic exposure. CONCLUSIONS: We demonstrated the negative effects of smoking and arsenic exposure on all-cause mortality. More effective actions should be taken to reduce arsenic exposure in miners.

Additional new species of the genus Hexarhopalus Fairmaire, 1891 (Coleoptera, Tenebrionidae: Cnodalonini) from China.

Three new species of the genus Hexarhopalus Fairmaire, 1891, all of the nominate subgenus, are described and figured from China: Hexarhopalus (Hexarhopalus) ferreri sp. nov. from Yunnan, H. (H.) tianbaoyanensis sp. nov. from Fujian, and H. (H.) yeziyangi sp. nov. from Jiangxi.

Effect of Time Since Smoking Cessation on Lung Cancer Incidence: An Occupational Cohort With 27 Follow-Up Years.

Background: This special cohort reveals the effect of smoking cessation in occupational miners exposed to radon and arsenic. Methods: A total of 9,134 tin miners with at least 10 years of underground radon and arsenic exposure were enrolled beginning in 1992 and followed for up to 27 years. Detailed smoking information was collected at baseline, and information on smoking status was consecutively collected from 1992 to 1996. The Cox proportional hazards model was used to explore the relationship between time since smoking cessation and lung cancer. Results: A total of 1,324 lung cancer cases occurred in this cohort over 167,776 person-years of follow-up. Among populations exposed to radon and arsenic, miners after quitting smoking for 10 years or more had almost halved their lung cancer risk [adjusted hazard ratio (HR) = 0.55, 95% CI: 0.38-0.79], compared with current smokers. Among miners after quitting smoking for 5 years or more, lung cancer incidence approximately halved (HR = 0.52, 95% CI: 0.30-0.92) for squamous cell lung carcinoma, while it showed no significant decline for adenocarcinoma (HR = 0.79, 95% CI: 0.34-1.85). Conclusion: Smoking cessation for 10 years or more halved lung cancer incidence among miners exposed to radon and arsenic, and the benefit was more pronounced among squamous cell lung carcinoma.

Synergy of arsenic with smoking in causing cardiovascular disease mortality: A cohort study with 27 follow-up years in China.

Background: To explore the patterns of the exposure-response relationship between arsenic exposure and cardiovascular disease (CVD) mortality and investigate the effect of cigarette smoking on the association. Methods: Seven thousand seven hundred thirty-five tin miners with at least 10 years of arsenic exposure were enrolled since 1992 and followed up for 27 years. Each individual's air arsenic exposure at workplace was calculated by time weighted average arsenic concentration × exposure months. Detailed information on smoking was collected at baseline, and information on smoking status was collected for five consecutive years from 1992 to 1996. Hazard ratio (HR) and 95% confidence interval (CI) for the risk of CVD were estimated using Cox proportional hazards models. Results: A total of 1,046 CVD deaths occurred in this cohort over 142,287.7 person-years of follow up. We firstly reported that for equal cumulative exposure, participants exposed to higher concentrations over shorter duration had a higher risk of CVD mortality than those exposed to lower concentration over longer duration. The HR and 95% CI were 1.38 (95%CI: 1.03-1.85) in participants exposed to arsenic concentration (45.5-99.5 mg/m3), 1.29 (95%CI: 1.02-1.67) in 99.5-361.0 mg/m3. Further, participants with age at first exposure <18 years had a significantly higher risk of morality from CVD, cerebrovascular and heart diseases than those with ≥18 years. Finally, all synergy indices were greater than 1 (range, 1.11-2.39), indicating that the joint effect of arsenic exposure and cigarette smoking on CVD mortality was greater than the sum of their individual effect. Conclusions: Exposure to air arsenic at workplace is adversely associated with mortality from CVD, especially among smokers younger than 18 years and smokers.

Membrane localization of beta-amyloid 1-42 in lysosomes: a possible mechanism for lysosome labilization.

beta-Amyloid peptide (Abeta42) is the core protein of amyloid plaque in Alzheimer disease. The intracellular accumulation of Abeta42 in the endosomal/lysosomal system has been under investigation for many years, but the direct link between Abeta42 accumulation and dysfunction of the endosomal/lysosomal system is still largely unknown. Here, we found that both in vitro and in vivo, a major portion of Abeta42 was tightly inserted into and a small portion peripherally associated with the lysosomal membrane, whereas its soluble portion was minimal. We also found that the Abeta42 molecules inserted into the membrane tended to form multiple oligomeric aggregates, whereas Abeta40 peptides formed only dimers. Neutralizing lysosomal pH in differentiated PC12 cells decreased the lysosomal membrane insertion of Abeta42 and moderated Abeta42-induced lysosomal labilization and cytotoxicity. Our findings, thus, suggest that the membrane-inserted portion of Abeta42 accumulated in lysosomes may destabilize the lysosomal membrane and induce neurotoxicity.

A small molecule inhibits Akt through direct binding to Akt and preventing Akt membrane translocation.

The Akt pathway is frequently hyperactivated in human cancer and functions as a cardinal nodal point for transducing extracellular and intracellular oncogenic signals and, thus, presents an exciting target for molecular therapeutics. Here we report the identification of a small molecule Akt/protein kinase B inhibitor, API-1. Although API-1 is neither an ATP competitor nor substrate mimetic, it binds to pleckstrin homology domain of Akt and blocks Akt membrane translocation. Furthermore, API-1 treatment of cancer cells results in inhibition of the kinase activities and phosphorylation levels of the three members of the Akt family. In contrast, API-1 had no effects on the activities of the upstream Akt activators, phosphatidylinositol 3-kinase, phosphatidylinositol-dependent kinase-1, and mTORC2. Notably, the kinase activity and phosphorylation (e.g. Thr(P)(308) and Ser(P)(473)) levels of constitutively active Akt, including a naturally occurring mutant AKT1-E17K, were inhibited by API-1. API-1 is selective for Akt and does not inhibit the activation of protein kinase C, serum and glucocorticoid-inducible kinase, protein kinase A, STAT3, ERK1/2, or JNK. The inhibition of Akt by API-1 resulted in induction of cell growth arrest and apoptosis selectively in human cancer cells that harbor constitutively activated Akt. Furthermore, API-1 inhibited tumor growth in nude mice of human cancer cells in which Akt is elevated but not of those cancer cells in which it is not. These data indicate that API-1 directly inhibits Akt through binding to the Akt pleckstrin homology domain and blocking Akt membrane translocation and that API-1 has anti-tumor activity in vitro and in vivo and could be a potential anti-cancer agent for patients whose tumors express hyperactivated Akt.

[Analysis of sensitivity and specificity of sputum cytology screening for lung cancer with different positive criteria].

OBJECTIVE: To discuss the effect of different positive criteria on the sensitivity and specificity of sputum cytology screening for lung cancer among Yunnan tin miners. METHODS: 9223 Yunnan tin miners who received at least one annual sputum cytology screening for lung cancer during the period between 1992 and 1999 were recruited in the study. At time of enrollment, all participants were aged over 40 years old, had at least 10 years of employment as an underground miner and(or) smelter, and had not been diagnosed with malignancy. In our study, a true positive was categorized as having at least one prior positive sputum screening and a diagnosis of lung cancer, while a true negative, by our definition, signified negative sputum examinations and no diagnosis of lung cancer during the follow up time. Based on different positive criteria, sensitivity and specificity of sputum cytology were computed and receiver operating characteristic (ROC) curve analysis was conducted. Z statistic was used to test the differences of the area under ROC based on Hanley and McNeil method. RESULTS: By the end of following up on December 31, 2001, a total 500 lung cancer cases were diagnosed among 9223 participants: most were squamous cell carcinoma (55.8% (222/398)) and central lung cancers (68.5% (316/461)). 150 lung cancer cases had a previous positive sputum screening result. When positive criteria were taken as grave atypical metaplasia, moderate atypical metaplasia and slight atypical metaplasia, the corresponding sensitivities were 30.0% (150/500), 36.4% (182/500), 53.0% (265/500) respectively; while the corresponding specificities were 98.9% (8628/8723), 95.1% (8611/8723), 77.9% (7033/8723) respectively. The areas under ROC curve according to different positive criterias were 0.645 (95%CI: 0.635 - 0.654), 0.657 (95%CI: 0.668 - 0.667), 0.655 (95%CI: 0.645 - 0.664) respectively. There were no significant differences found in the comparisons between grave and moderate atypical metaplasia, grave and slight atypical metaplasia, moderate and slight atypical metaplasia(Z statistics were 0.780, 0.645, 0.209 respectively, all P values > 0.05). CONCLUSION: While the standard of positive criteria for diagnosis of lung cancer decreased, the sensitivity of sputum cytology screening increased and the specificity decreased. Since there were no significant differences of accuracy for different positive criteria.

DNA Repair Gene Polymorphisms in the Nucleotide Excision Repair Pathway and Lung Cancer Risk: A Meta-analysis.

OBJECTIVE: A number of studies have reported the association of "XPA", "XPC", "XPD/ERCC2" gene polymorphisms with lung cancer risk. However, the results were conflict. To clarify the impact of polymorphisms of "XPA", "XPC", "XPD/ERCC2", on lung cancer risk, a meta-analysis was performed in this study. METHODS: The electronic databases PubMed and Embase were retrieved for studies included in this meta-analysis by "XPA", "XPC", "XPD/ERCC2", "lung", "cancer/neoplasm/tumor/carcinoma", "polymorphism" (An upper date limit of October, 31, 2009). A meta-analysis was performed to evaluate the relationship among XPA, XPC and XPD polymorphism and lung cancer risks. RESULTS: A total of 31 publications retrieved from Pubmed and Embase included in this study. XPC A939C CC genotype increased lung cancer risk in total population (recessive genetic model: OR=1.23, 95% CI:1.05-1.44; homozygote comparison: OR=1.21,95%CI:1.02-1.43and CC vs. CA contrast: OR=1.25,95%CI:1.06-1.48), except in Asians. XPD A751C, 751C allele and CC genotype also increased lung cancer risk in total population and in Caucasians (recessive genetic model: Total population: OR=1.20, 95%CI:1.07-1.35). No significant correlation was found between XPD A751C and lung cancer risk in Asians and African Americans. XPD G312A AA genotype increased lung cancer risk in total population, in Asians and Caucasians(recessive genetic model: Total population: OR=1.20, 95%CI: 1.06-1.36). No significant association was found between XPA G23A, XPC C499T, XPD C156A and lung cancer risk. CONCLUSION: Our results suggest that the polymorphisms in XPC and XPD involve in lung cancer risks. XPA polymorphisms is less related to lung cancer risk.

Application of RT-PCR in formalin-fixed and paraffin-embedded lung cancer tissues.

AIM: To analyze gene expression in formalin-fixed, paraffin-embedded lung cancer tissues using modified method. METHODS: Total RNA from frozen tissues was extracted using TRIZOL reagent. RNA was extracted from formalin-fixed, paraffin-embedded tissues by digestion with proteinase K before the acid-phenol:chloroform extraction and carrier precipitation. We modified this method by using a higher concentration of proteinase K and a longer digestion time, optimized to 16 hours. RT-PCR and real-time RT-PCR were used to check reproducibility and the concordance between frozen and paraffin-embedded samples. RESULTS: The results showed that the RNA extracted from the paraffin-embedded lung tissues had high quality with the most fragment length between 28S and 18S bands (about 1000 to 2000 bases). The housekeeping gene GUSB exhibited low variation of expression in frozen and paraffin-embedded lung tissues, whereas PGK1 had the lowest variation in lymphoma tissues. Furthermore, real-time PCR analysis of the expression of known prognostic genes in non-small cell lung carcinoma (NSCLC) demonstrated an extremely high correlation (r>0.880) between the paired frozen and formalin-fixed, paraffin-embedded specimens. CONCLUSION: This improved method of RNA extraction is suitable for real-time quantitative RT-PCR, and may be used for global gene expression profiling of paraffin-embedded tissues.

A pooled analysis of molecularly targeted agents for treatment of metastatic oesophago-gastric cancer in elderly patients.

INTRODUCTION: The aim of the present study was to assess the efficacy of molecularly targeted agents (MTAs) in the treatment of elderly patients with metastatic oesophago-gastric cancer (mOGC). MATERIAL AND METHODS: We systematically searched electronic databases and abstracts presented at American Society of Clinical Oncology (ASCO) meetings up to January 31, 2017. Hazard ratios (HRs) were used to estimate overall survival (OS) and progression-free survival (PFS). Subgroup analysis and publication bias were also evaluated. All statistical analysis was conducted using Comprehensive Meta Analysis software (Version 2.0). RESULTS: A total of 2,149 elderly patients with mOGC from thirteen trials were included. Compared to non-MTA-containing regimens, OS was significantly improved in the MTA-containing regimens (HR = 0.86, 95% CI: 0.75-0.99, p = 0.037), but not for PFS (HR = 1.05, 95% CI: 0.85-1.30, p = 0.67). In addition, subgroup analysis indicated that MTA-containing regimens as second-line therapy in elderly mOGC patients significantly improved PFS (HR = 0.58; 95% CI: 0.39-0.85, p = 0.005) and OS (HR = 0.82, 95% CI: 0.70-0.96, p = 0.016), but did not significantly improve PFS (HR = 1.36; 95% CI: 1.06-1.76, p = 0.017) and OS (HR = 0.98, 95% CI: 0.77-1.27, p = 0.90) for MTA-containing regimens as first-line therapy in these patients. No publication bias was detected by Begg's and Egger's tests for OS and PFS. CONCLUSIONS: Our results indicate that the MTA-containing therapies significantly improve OS but not for PFS in elderly mOGC patients. Sub-group analysis shows that improved efficacy is only observed in the second-line setting and not in the first-line setting. Our findings support the use of angiogenesis as second-line treatment for elderly mOGC patients.

Performance of lung cancer screening with low-dose CT in Gejiu, Yunnan: A population-based, screening cohort study.

BACKGROUND: The performance of lung cancer screening with low-dose computed tomography (CT) (LDCT) in China is uncertain. This study aimed to evaluate the performance of LDCT lung cancer screening in the Chinese setting. METHODS: In 2014, a screening cohort of lung cancer with LDCT was established in Gejiu, Yunnan Province, a screening center of the Lung Cancer Screening Program in Rural China (LungSPRC). Participants received a baseline screening and four rounds of annual screening with LDCT in two local hospitals until June 2019. We analyzed the rates of participation, detection, early detection, and the clinical characteristics of lung cancer. RESULTS: A total of 2006 participants had complete baseline screening results with a compliance rate of 98.4%. Of these, 1411 were high-risk and 558 were nonhigh-risk participants. During this period, 40 lung cancer cases were confirmed, of these, 35 were screen-detected, four were post-screening and one was an interval case. The positive rate of baseline and annual screening was 9.7% and 9.0%, while the lung cancer detection rate was 0.4% and 0.6%, respectively. The proportion of early lung cancer increased from 37.5% in T0 to 75.0% in T4. Adenocarcinoma was the most common histological subtype. Lung cancer incidence according to the criteria of LungSPRC and National Lung Cancer Screening Trial (NLST) was 513.31 and 877.41 per 100 000 person-years, respectively. CONCLUSIONS: The program of lung cancer screening with LDCT showed a successful performance in Gejiu, Yunnan. However, further studies are warranted to refine a high-risk population who will benefit most from LDCT screening and reduce the high false positive results. KEY POINTS: This study reports the results of lung cancer screening with LDCT in Gejiu, Yunnan, a high-risk area of lung cancer, and it demonstrates that lung cancer screening with LDCT is effective in detecting early-stage lung cancer. Our program provides an opportunity to explore the performance of LDCT lung cancer screening in the Chinese context.

Are isothiocyanates potential anti-cancer drugs?

Isothiocyanates are naturally occurring small molecules that are formed from glucosinolate precursors of cruciferous vegetables. Many isothiocyanates, both natural and synthetic, display anticarcinogenic activity because they reduce activation of carcinogens and increase their detoxification. Recent studies show that they exhibit anti-tumor activity by affecting multiple pathways including apoptosis, MAPK signaling, oxidative stress, and cell cycle progression. This review summarizes the current knowledge on isothiocyanates and focuses on their role as potential anti-cancer agents.

Different BAG-1 isoforms have distinct functions in modulating chemotherapeutic-induced apoptosis in breast cancer cells.

AIM: BAG-1 is a multifunctional anti-apoptotic gene with four isoforms, and different BAG-1 isoforms have different anti-apoptotic functions. In this study, we transfected BAG-1 isoforms into the human breast cancer cell lines Hs578T (ER negative) and MCF-7 (ER positive) to study their effect on apoptosis with or without estrogens. METHODS: The constructed recombinant expression vectors carrying individual BAG-1 isoforms was used to transfect human breast cancer cell lines Hs578T (ER negative) and MCF-7 (ER positive). After stable cell lines were made, a variety of apoptosis-inducing agents, including doxorubicin, docetaxel, and 5-FU, was used to treat these cell lines with or without estrogen to test the role of BAG-1. The mechanism by which BAG-1 affected the function of Bcl-2 was exploredby using the cycloheximide chase assay. RESULTS: The BAG-1 p50 and p46 isoforms significantly enhanced the resistance to apoptosis in both cell lines according to flow cytometry analysis. BAG-1 p33 and p29 failed to protect the transfected cells from apoptosis. The cell viability assay showed that only BAG-1 p50, but not p46, p33, or p29, increased estrogen-dependent function in ER-positive cell line MCF-7. Only BAG-1 p50 dramatically increased its anti-apoptotic ability in the presence of estrogen, while estrogen has very little effect on the anti-apoptotic ability of other BAG-1 isoforms. In the detection of the expression of K-ras, Hsp70, cytochrome c, Raf-1, ER-alpha, and Bcl-2 in MCF-7 cells by Western blot, only Bcl-2 protein expression was significantly increased in MCF-7 cells transfected with BAG-1 p50 and p46, respectively. Furthermore, the cycloheximide chase assay indicated that the degradation of Bcl-2 protein was extended in the BAG-1 p50 and p46 transfected MCF-7 cells. CONCLUSION: Distinct isoforms of BAG-1 have different anti-apoptotic functions in breast cancer cells, and that the BAG-1 p50 isoform can potentiate the role of estrogen in ER-positive breast cancer.