Purpose Inherited variability in the prognosis of lung cancer patients treated with platinum-based chemotherapy has been widely investigated. However, the overall contribution of genetic variation to platinum response is not well established. To identify novel candidate SNPs/genes, we performed a genome-wide association study (GWAS) for cisplatin cytotoxicity using lymphoblastoid cell lines (LCLs), followed by an association study of selected SNPs from the GWAS with overall survival (OS) in lung cancer patients. Experimental Design GWAS for cisplatin were performed with 283 ethnically diverse LCLs. 168 top SNPs were genotyped in 222 small cell and 961 non-small cell lung cancer (SCLC, NSCLC) patients treated with platinum-based therapy. Association of the SNPs with OS was determined using the Cox regression model. Selected candidate genes were functionally validated by siRNA knockdown in human lung cancer cells. Results Among 157 successfully genotyped SNPs, 9 and 10 SNPs were top SNPs associated with OS for patients with NSCLC and SCLC, respectively, although they were not significant after adjusting for multiple testing. Fifteen genes, including 7 located within 200 kb up or downstream of the four top SNPs and 8 genes for which expression was correlated with three SNPs in LCLs were selected for siRNA screening. Knockdown of DAPK3 and METTL6, for which expression levels were correlated with the rs11169748 and rs2440915 SNPs, significantly decreased cisplatin sensitivity in lung cancer cells. Conclusions This series of clinical and complementary laboratory-based functional studies identified several candidate genes/SNPs that might help predict treatment outcomes for platinum-based therapy of lung cancer.

Gene expression microarrays are widely used to investigate molecular targets in cancers, including lung cancer. In this study, we analyzed online non-small cell lung cancer (NSCLC) microarray databases, to screen the key genes and pathways related to NSCLC by bioinformatics analyses. And then, the expression levels of two selected genes in the down-regulated co-pathways, myosin light chain kinase (MYLK) and myosin regulatory light chain 9 (MYL9), were determined in tumor, paired paraneoplastic, and normal lung tissues. First, gene set enrichment analysis and meta-analysis were conducted to identify key genes and pathways that contribute to NSCLC carcinogenesis. Second, using the total RNA and protein extracted from lung cancer tissues (n = 240), adjacent non-cancer tissues (n = 240), and normal lung tissues (n = 300), we examined the MYLK and MYL9 expression levels by quantitative real-time PCR and Western blot. Finally, we explored the correlations between mRNA and protein expressions of these two genes and the clinicopathological parameters of NSCLC. Fifteen up-regulated and nine down-regulated co-pathways were observed. A number of differentially expressed genes (CALM1, THBS1, CSF3, BMP2, IL6ST, MYLK, ROCK2, IL3RA, MYL9, PPP2CA, CSF2RB, CNAQ, GRIA2, IL10RA, IL10RB, IL11RA, LIFR, PLCB4, and RAC3) were identified (P < 0.01) in the down-regulated co-pathways. The expression levels of MYLK and MYL9, which act downstream of the vascular smooth muscle contraction signal pathway and focal adhesion pathway, were significantly lower in cancer tissue than those in the paraneoplastic and normal tissues (P < 0.05). Moreover, the expression levels of these two genes in stages III and IV NSCLC were significantly increased, when compared to stages I and II, and expressions levels in NSCLC with lymphatic metastasis were higher than that without lymphatic metastasis (P < 0.05). Additionally, significant lower expression levels of the two genes were found in smokers than in nonsmokers (P < 0.05). In contrast, gender, differentiated degrees, and pathohistological type appeared to have no impact on these gene expressions (P > 0.05). These findings suggested that low MYLK and MYL9 expressions might be associated with the development of NSCLC. These genes may be also relevant to NSCLC metastasis. Future investigations with large sample sizes needed to verify these findings.

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID) show indisputable promise as cancer chemoprevention agents. However, studies have been inconsistent as to whether aspirin has a protective effect in development of pancreatic cancer. To further evaluate the association between aspirin, NSAID and acetaminophen use with pancreatic cancer risk, we utilized a clinic-based case-control study of 904 rapidly ascertained histologically or clinically documented pancreatic ductal adenocarcinoma cases, and 1,224 age- and sex-matched healthy controls evaluated at Mayo Clinic from April 2004 to September 2010. Overall, there is no relationship between non-aspirin NSAID or acetaminophen use and risk of pancreatic cancer. Aspirin use ≥ 1 day/month was associated with a significantly decreased risk of pancreatic cancer (odds ratio (OR) = 0.74, 95% confidence intervals (CI): 0.60, 0.91, P = 0.005), compared with never or < 1 day/month. Analysis by frequency and frequency-dosage of use categories showed reduced risk (P = 0.007 and 0.022, respectively). This inverse association was also found for those who took low-dose aspirin for heart disease prevention (OR = 0.67, 95% CI: 0.49, 0.92, P = 0.013). In subgroup analyses, the association between aspirin use and pancreatic cancer was not significantly affected by pancreatic cancer stage, smoking status or body mass index. Our data suggest that aspirin use, but not non-aspirin NSAID use, is associated with lowered risk of developing pancreatic cancer.

Lung cancer is the leading cause of cancer mortality for men and women in the United States and is a growing worldwide problem. Protection against lung cancer is associated with higher dietary intake of fruits and vegetables, according to recent large epidemiologic studies. One strategy for lung cancer chemoprevention focuses on the use of agents to modulate the metabolism and disposition of tobacco, environmental and endogenous carcinogens through upregulation of detoxifying phase II enzymes. We summarize the substantial evidence that suggests that induction of phase II enzymes, particularly the glutathione S-transferases, plays a direct role in chemoprotection against lung carcinogenesis. The engagement of the Keap1–Nrf2 complex regulating the antioxidant response element (ARE) signaling pathway has been identified as a key molecular target of chemopreventive phase II inducers in several systems. Monitoring of phase II enzyme induction has led to identification of novel chemopreventive agents such as the isothiocyanate sulforaphane, and the 1,2-dithiole-3-thiones. However, no agents have yet demonstrated clear benefit in human cell systems, or in clinical trials. Alternative strategies include: (a) using intermediate cancer biomarkers for the endpoint in human trials; (b) high-throughput small molecule discovery approaches for induced expression of human phase II genes; and (c) integrative approaches that consider pharmacogenetics, along with pharmacokinetics and pharmacodynamics in target lung tissue. These approaches may lead to a more effective strategy of tailored chemoprevention efforts using compounds with proven human activity.

Antimicrobial peptides are small-molecule proteins that are usually encoded by multiple-gene families. They play crucial roles in the innate immune response, but reports on the functional divergence of antimicrobial peptide gene families are rare. In this study, 14 paralogs of antimicrobial peptides belonging to cecropin, moricin and gloverin families were recombinantly expressed in pET expression systems. By antimicrobial activity tests, peptides representing paralogs in the same family of cecropin and moricin families, displayed remarkable differences against 10 tested bacteria. The evolutionary rates were relatively fast in the two families, which presented obvious functional divergence among paralogs of each family. Four peptides of gloverin family had similar antimicrobial spectrum and activity against tested bacteria. The gloverin family showed similar antimicrobial function and slow evolutionary rates. By induced transcriptional activity, genes encoding active antimicrobial peptides were upregulated at obviously different levels when silkworm pupae were infected by three types of microbes. Association analysis of antimicrobial activities and induced transcriptional activities indicated that the antimicrobial activities might be positively correlated with induced transcriptional activities in the cecropin and moricin families. These results suggest that representative BmcecB6, BmcecD and Bmmor as the major effector genes have broad antimicrobial spectrum, strong antimicrobial activity and high microbe-induced expression among each family and maybe play crucial roles in eliminating microbial infection.

The insect midgut epithelium is generally lined with a unique chitin and protein structure, the peritrophic membrane (PM), which facilitates food digestion and protects the gut epithelium. PM proteins are important determinants for PM structure and formation. In this study, the silkworm Bombyx mori midgut PM protein BmCDA7 was identified by proteomic tools. The full-length BmCDA7 cDNA is 1357 bp; the deduced protein is composed of 379 amino acid residues and includes a 16 amino acid residue signal peptide, a putative polysaccharide deacetylase-like domain and 15 cysteine residues present in three clusters. The heterologously expressed proteins of the BmCDA7 gene in yeast displayed chitin deacetylase activity. Expression of B. mori BmCDA7 was detected in the midgut at both the transcriptional and translational levels. The BmCDA7 gene was expressed by the newly hatched silkworm larvae until day seven of the fifth instar and was expressed at a high level in the newly exuviated larvae of different instars. The functions and regulatory mechanism of BmCDA7, however, need further investigation.

Objectives To further elucidate anti-cancer mechanisms of metformin again pancreatic cancer, we evaluated inhibitory effects of metformin on pancreatic tumorigenesis in a genetically-engineered mouse model, and investigated its possible anti-inflammatory and anti-angiogenesis effects. Methods Six-week old LSL-KrasG12D/+;Trp53F2-10 mice (10 per group) were administered once daily intraperitoneally with saline (control) for one week or metformin (125 mg/kg) for one week (Met_1wk) or three weeks (Met_3wk) prior to tumor initiation. All mice continued with their respective injections for six weeks post-tumor initiation. Molecular changes were evaluated by quantitative polymerase chain reaction (PCR), immunohistochemistry, and Western blotting. Results At euthanasia, pancreatic tumor volume in Met_1wk (median, 181.8 mm3) and Met_3wk (median, 137.9 mm3) groups was significantly lower than the control group (median, 481.1 mm3) (P = 0.001 and 0.0009, respectively). No significant difference was observed between Met_1wk and Met_3wk groups (P = 0.51). These results were further confirmed using tumor weight and tumor burden measurements. Furthermore, metformin treatment decreased the phosphorylation of nuclear factor κB (NFκB) and signal transducer and activator of transcription 3 (STAT3) as well as the expression of Sp1 transcription factor and several NFκB-regulated genes. Conclusions Metformin may inhibit pancreatic tumorigenesis by modulating multiple molecular targets in inflammatory pathways.

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