More expression of BDNF associates with lung squamous cell carcinoma and is critical to the proliferation and invasion of lung cancer cells.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) has been reported to promote tumorigenesis and progression in several human malignancies. The purpose of this study was to explore the function of BDNF in lung squamous cell carcinoma (SCC) and adenocarcinoma (ADC). METHODS: The expression of BDNF was examined in 110 samples of lung SCC and ADC by immunohistochemistry. The protein level of BDNF was examined in 25 lung SCC or ADC samples and paired non-tumors by western blot. BDNF expression was also evaluated in human bronchial epithelial cells (HBE) and 4 lung cancer cell lines using western blot. Three BDNF mRNA variants containing exons IV, VI and IX were evaluated in HBE, two SCC (SK, LK2) and two ADC (A549, LTE) cell lines by RT-PCR. The expression and secretion of BDNF were also determined in cells using western blot and ELISA. Then the shRNA specific for BDNF was transfected into LK2 or A549 cells to further elucidate the BDNF knockdown on cell proliferation, apoptosis and invasion, which were confirmed by MTT, flow cytometry and transwell examinations. RESULTS: 71.8 % (79 out of 110) of lung SCC and ADC samples were detected positive BDNF, and high expression of BDNF was significantly correlated with histological type and T stage. Compared with non-tumorous counterparts, BDNF was apparently overexpressed in SCC and ADC tissues. In cell studies, the extensive expression and secretion of BDNF were demonstrated in lung cancer cells compared with HBE cells. Interestingly, the expressions of BDNF mRNA variant IV and VI were identical in all cells examined. However, more expression of BDNF mRNA variant IX was found in SK and LK2 cells. The apoptotic cells were increased, and the cell proliferation and invasion were both attenuated once the expression of BDNF was inhibited. When retreated by rhBDNF, BDNF knockdown cells showed less apoptotic or more proliferative and invasive. CONCLUSIONS: Our data show that BDNF probably facilitates the tumorigenesis of lung SCC and ADC. The expression of BDNF mRNA variant IX is probably more helpful to the upregulation of BDNF in SCC, and intervening the production of BDNF could be a possible strategy to lung cancer therapy.

The Hedgehog signalling pathway mediates drug response of MCF-7 mammosphere cells in breast cancer patients.

BCSCs (breast cancer stem cells) have been shown to be resistant to chemotherapy. However, the mechanisms underlying BCSC-mediated chemoresistance remain poorly understood. The Hh (Hedgehog) pathway is important in the stemness maintenance of CSCs. Nonetheless, it is unknown whether the Hh pathway is involved in BCSC-mediated chemoresistance. In the present study, we cultured breast cancer MCF-7 cells in suspension in serum-free medium to obtain BCSC-enriched MCF-7 MS (MCF-7 mammosphere) cells. We showed that MCF-7 MS cells are sensitive to salinomycin, but not paclitaxel, distinct from parent MCF-7 cells. The expression of the critical components of Hh pathway, i.e., PTCH (Patched), SMO (Smoothened), Gli1 and Gli2, was significantly up-regulated in MCF-7 MS cells; salinomycin, but not paclitaxel, treatment caused a remarkable decrease in expression of those genes in MCF-7 MS cells, but not in MCF-7 cells. Salinomycin, but not paclitaxel, increased apoptosis, decreased the migration capacity of MCF-7 MS cells, accompanied by a decreased expression of c-Myc, Bcl-2 and Snail, the target genes of the Hh pathway. The salinomycin-induced cytotoxic effect could be blocked by Shh (Sonic Hedgehog)-mediated Hh signalling activation. Inhibition of the Hh pathway by cyclopamine could sensitize MCF-7 MS cells to paclitaxel. In addition, salinomycin, but not paclitaxel, significantly reduced the tumour growth, accompanied by decreased expression of PTCH, SMO, Gli1 and Gli2 in xenograft tumours. Furthermore, the expression of SMO and Gli1 was positively correlated with the expression of CD44+ / CD24-, and the expression of SMO and Gli1 in CD44+ / CD24- tissues was associated with a significantly shorter OS (overall survival) and DFS (disease-free survival) in breast cancer patients receiving chemotherapy.

TRAF4 participates in Wnt/ß-catenin signaling in breast cancer by upregulating ß-catenin and mediating its translocation to the nucleus.

Tumor necrosis factor receptor-associated factor 4 (TRAF4) is upregulated in various subtypes of breast cancers and cell lines; however, the precise functions of TRAF4 are poorly understood. Our objective was to investigate its relationship with ß-catenin. TRAF4 participates in several signaling pathways, such as NF-κB and JNK signaling pathways. In this study, we identified ß-catenin as a TRAF4-binding protein, have shown that TRAF4 enhanced expression of ß-catenin, and found that TRAF4 mediated the translocation of ß-catenin from the cytoplasm to the nucleus, thereby facilitating activation of the Wnt signaling pathway in breast cancer.

MiR-181a enhances drug sensitivity in mitoxantone-resistant breast cancer cells by targeting breast cancer resistance protein (BCRP/ABCG2).

Breast cancer resistance protein (BCRP)/ATP-binding cassette subfamily G member 2 (ABCG2) mediates multidrug resistance (MDR) in breast cancers. In this study, we aimed to investigate the role of microRNAs in regulation of BCRP expression and BCRP-mediated drug resistance in breast cancer cells. Microarray analysis was performed to determine the differential expression patterns of miRNAs that target BCRP between the MX-resistant breast cancer cell line MCF-7/MX and its parental MX-sensitive cell line MCF-7. MiR-181a was found to be the most significantly down-regulated miRNA in MCF-7/MX cells. Luciferase activity assay showed that miR-181a mimics inhibited BCRP expression by targeting the 3' untranslated region (UTR) of the BCRP mRNA. Overexpression of miR-181a down-regulated BCRP expression, and sensitized MX-resistant MCF-7/MX cells to MX. In a nude mouse xenograft model, intratumoral injection of miR-181a mimics inhibited BCRP expression, and enhanced the antitumor activity of MX. In addition, miR-181a inhibitors up-regulated BCRP expression, and rendered MX-sensitive MCF-7 cells resistant to MX. These findings suggest that miR-181a regulates BCRP expression via binding to the 3'-UTR of BCRP mRNA. MiR-181a is critical for regulation of BCRP-mediated resistance to MX. MiR-181a may be a potential target for preventing and reversing drug resistance in breast cancer.

Evaluation of transmission-blocking potential of Pv22 using clinical Plasmodium vivax infections and transgenic Plasmodium berghei.

Antigens expressed during the sexual development of malaria parasites are transmission-blocking vaccine (TBV) targets. Pb22, a protein expressed and localized to the plasma membrane of gametes and ookinetes in Plasmodium berghei, is an excellent TBV candidate. Here, we evaluated the TB potential of the Plasmodium vivax ortholog Pv22 using a transgenic P. berghei parasite line and P. vivax clinical isolates. The full-length recombinant Pv22 (rPv22) protein was produced and used to immunize mice and rabbits to obtain antibodies. We generated a transgenic P. berghei line (TrPv22Pb) by inserting the pv22 gene into the pb22 locus and showed that Pv22 expression completely rescued the defects in male gametogenesis of the pb22 deletion parasite. Since Pv22 in the transgenic parasite showed similar expression and localization patterns to Pb22, we used the TrPv22Pb parasite as a surrogate to evaluate the TB potential of Pv22. In mosquito feeding assays, mosquitoes feeding on rPv22-immunized mice infected with TrPv22Pb parasites showed a 49.3-53.3 % reduction in the oocyst density compared to the control group. In vitro assays showed that the rPv22 immune sera significantly inhibited exflagellation and ookinete formation of the TrPv22Pb parasites. In a direct membrane feeding assay using three clinical P. vivax isolates, the rabbit anti-rPv22 antibodies also significantly decreased the oocyst density by 53.7, 30.2, and 26.2 %, respectively. This study demonstrated the feasibility of using transgenic P. berghei parasites expressing P. vivax antigens as a potential tool to evaluate TBV candidates. However, the much weaker TB activity of Pv22 obtained from two complementary assays suggest that Pv22 may not be a promising TBV candidate for P. vivax.

Meta-analytic review of online guided self-help interventions for depressive symptoms among college students.

OBJECTIVE: This meta-analysis examines the effect of online guided self-help interventions for depressive symptoms among college students. METHODS: We searched studies through PubMed, Embase, Web of Science, PsycINFO, and Cochrane Central. Effect estimates were reported as standardized mean differences (SMD) and data were pooled using random-effects models. Subgroup analyses were conducted to investigate the differential effects of these interventions by sample type, level of contact, use of incentive, length of intervention, and program content. RESULTS: 24 comparisons (n = 3074) deriving from 19 trials were included in the meta-analysis. Intervention participants (n = 1620) indicated significant reductions in depressive symptoms at post-intervention compared to non-active control conditions (n = 1454). The weighted effect size was 0.46 (95% CI: 0.28-0.64), which dropped to 0.36 (95% CI: 0.26-0.45) after an outlier was removed. Subgroup analyses showed that the effects were significant among interventions using both selective and universal samples; among interventions of shorter (≤4 weeks), moderate (4-8 weeks), and greater length (≥8 weeks); among interventions with high, moderate, and low levels of contact; among interventions with and without incentive; and among interventions employing cognitive-behavioral therapy (CBT) and third-wave CBT. CONCLUSION: This meta-analysis reinforces evidence to support the effectiveness of online guided self-help interventions in reducing depressive symptoms among college students. However, because of the generally variable and limited quality of current evidence, further research applying rigorous methods is needed to confirm and extend the findings of this meta-analysis.

TrkB is highly expressed in NSCLC and mediates BDNF-induced the activation of Pyk2 signaling and the invasion of A549 cells.

BACKGROUND: Aberrant regulation in the invasion of cancer cells is closely associated with their metastatic potentials. TrkB functions as a receptor tyrosine kinase and is considered to facilitate tumor metastasis. Pyk2 is a non-receptor tyrosine kinase and integrates signals in cell invasion. However, little is known about the expression of TrkB in NSCLC and whether Pyk2 is involved in TrkB-mediated invasion of A549 cells. METHODS: The expression of TrkB was investigated in NSCLC by immunohistochemical staining. Both HBE and A549 cells were treated with BDNF. The expression of TrkB, Pyk2 and ERK phosphorylations were assessed by western blot. Besides, A549 cells were transfected with TrkB-siRNA or Pyk2-siRNA, or treated with ERK inhibitor where indicated. Transwell assay was performed to evaluate cell invasion. RESULTS: 40 cases (66.7%) of NSCLC were found higher expression of TrkB and patients with more TrkB expression had significant metastatic lymph nodes (p = 0.028). BDNF facilitated the invasion of A549 cells and the activations of Pyk2 in Tyr402 and ERK. However, the effects of BDNF were not observed in HBE cells with lower expression of TrkB. In addition, the increased Pyk2 and ERK activities induced by BDNF were significantly inhibited by blocking TrkB expression, so was the invasion of A549 cells. Knockdown studies revealed the essential role of Pyk2 for BDNF-induced cell invasion, since the invasion of A549 cells was abolished by Pyk2-siRNA. The application of ERK inhibitor also showed the suppressed ERK phosphorylation and cell invasion. CONCLUSION: These data indicated that higher expression of TrkB in NSCLC was closely correlated with lymph node metastasis, and BDNF probably via TrkB/Pyk2/ERK promoted the invasion of A549 cells.

[The study about expression of Gli2 in vein grafts].

OBJECTIVE: To study the expression of cell cycle related factor Gli2 in autogenous vein graft and its relation with neointima formation. METHOD: Autogenous vein graft model were established in 36 male wistar rats of 8 weeks old, 140 g, by transplanting the left jugular vein to intra renal abdominal aorta with microsurgical technique. Graft veins were harvest at 14, 28 days after transplantation. The IF and W-B were used to detect the protein expression in the vein graft. At the same time Gli2- mRNA was measured by RT-PCR. RESULTS: Immunofluorescent staining showed that the Gli2+ cells was only 3.2% ± 0.4% in the normal vein, but was much more in the vein graft after surgery, was 41.3% ± 0.6%, 58.3 ± 0.6% respectively; The expression of Gli2 and PCNA were both elevated in the vein graft. There is a positive correlation between them which indicated by W-B, the relation index was 0.826; the Gli2 mRNA content was also increased in vein graft, was 8.9, 13.6 fold compared with normal vein as 1 respectively. CONCLUSION: Gli2 is upregulated in autogenous vein grafts and may correlated with the proliferation of vascular smooth muscle cells.

[The expression of sonic hedgehog in rat vein grafts].

OBJECTIVE: To study the expression of cell cycle related factor sonic hedgehog (SHH) in autogenous vein graft and its relation with neointima formation. METHODS: Autogenous vein graft model were established in 24 male Wistar rats of 8 weeks old and 140 g weight, by transplanting the left jugular vein to intra renal abdominal aorta with microsurgical technique. Graft veins were harvested at 14 d and 28 d after transplantation. The immunohistochemistry and Western blot were used to detect the SHH and PCNA expression in the vein graft. At the same time SHH mRNA was measured by quantitative real-time PCR. The opposite normal veins served as control. RESULTS: Histological staining showed that the percent of SHH+ cells was only (2.0 +/- 0.5)% in the normal vein, but was much more in the vein graft after surgery, as (39.4 +/- 0.4)% and (63.0 +/- 0.3)% respectively (P < 0.01). The expression of SHH and PCNA were both elevated in the vein graft. There was a positive correlation between them which indicated by Western blot (r = 0.808, P < 0.01). The SHH mRNA content also increased in vein graft to 9.5 and 23.8 folds of that in control. CONCLUSION: SHH is upregulated in autogenous vein grafts and may correlated with the proliferation of vascular smooth muscle cells.

Resilience-oriented cognitive behavioral interventions for depressive symptoms in children and adolescents: A meta-analytic review.

OBJECTIVE: The study aimed to evaluate whether resilience-oriented cognitive behavioral interventions (CBIs) which teach cognitive, problem-solving, and social skills are effective for addressing depressive symptoms in the school setting and to investigate factors that could moderate the intervention effects. METHOD: Electronic databases Medline, PsycINFO and Cochrane Central were searched to identify potentially relevant trials. The difference of change from baseline in depressive symptoms between intervention and control condition was assessed. Mean effect sizes (Hedges'g) were calculated using random-effects models. Study-specific characteristics relevant to participant demographics (age, gender, and risk status), intervention conditions (program type, intervention duration, group leader type, and use of homework), and study features (sample size, and methodological quality) were evaluated as potential moderators of the effect size. RESULTS: 38 controlled studies were identified, including 24,135 individuals. At post-intervention, the mean effect size was considered significantly small (Hedges'g = 0.13) and subgroup analyses revealed significant effect sizes for programs administered to both universal and targeted samples, programs both with and without homework, and programs led by school personnel. The mean effect size was largely maintained at 6 months follow-up and subgroup analyses indicated significant effect sizes for programs administered to targeted samples, programs based on Penn Resiliency Program, programs with homework, and programs led by professional interventionists. CONCLUSION: This study reinforces the efficacy of resilience-oriented CBIs for addressing depressive symptoms in the school setting. Although more research is needed to confirm and extend the findings of this study, our findings suggest a range of directions in particular for further investigation.

Association between polymorphisms in DNA repair genes and survival of non-smoking female patients with lung adenocarcinoma.

BACKGROUND: Excision repair cross-complementing group 1 (ERCC1) and group 2 (ERCC2), and X-ray repair cross-complementing group 1 (XRCC1) proteins play important roles in the repair of DNA damage and adducts. Single nucleotide polymorphisms (SNPs) of DNA repair genes are suspected to influence treatment effect and survival of cancer patients. This study aimed to investigate the relationship between polymorphisms in ERCC2, ERCC1 and XRCC1 genes and survival of non-smoking female patients with lung adenocarcinoma. METHODS: We used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to evaluate SNPs in ERCC2, ERCC1 and XRCC1 genes among 257 patients. RESULTS: The overall median survival time (MST) was 13.07 months. Increasing numbers of either ERCC1 118 or XRCC1 399 variant alleles were associated with shorter survival of non-smoking female lung adenocarcinoma patients (Log-rank P < 0.001). The adjusted hazard ratios (HRs) for individuals with CT or TT genotype at ERCC1 Asn118Asn were 1.48 and 2.67 compared with those with CC genotype. For polymorphism of XRCC1 399, the HRs were 1.28 and 2.68 for GA and AA genotype. When variant alleles across both polymorphisms were combined to analysis, the increasing number of variant alleles was associated with decreasing overall survival. Using the stepwise Cox regression analysis, we found that the polymorphisms in ERCC1 and XRCC1, tumor stage and chemotherapy or radiotherapy status independently predicted overall survival of non-smoking female patients with lung adenocarcinoma. CONCLUSIONS: Genetic polymorphisms in ERCC1 and XRCC1 genes might be prognostic factors in non-smoking female patients with lung adenocarcinoma.

[The sonic hedgehog induce vascular adventitial fibroblasts phenotypic modulation, proliferation and migration].

OBJECTIVE: To study the effect of shh on the migration, proliferation and phenotypic modulation of vascular adventitial fibroblasts. METHOD: Cultivate the vascular adventitial fibroblast in vitro. Use immunofluorescent, laser confocal microscopy, Western-blot and real-time PCR to detect the expression of mRNA and protein of related index. Estimate cell proliferation according to the expression of Ki67 and cell proliferation curve. Application of wound healing test to estimate migration of fibroblast. The expression of alpha-actin is thought to be marker of phenotypic modulation of fibroblast. RESULT: The expression of shh was detected in vascular adventitial fibroblast in vitro. After addition of exogenous shh (3.5 microg/ml), there were more Ki67(+) cells and the wounding area which was covered by cells became larger. The expression of alpha-actin was detected. After addition of cyclopamine (40 micromol/L), there were less Ki67(+) cells and the wounding area which was covered by cells became smaller. CONCLUSION: Shh can promote proliferation, migration and phenotypic modulation of vascular adventitial fibroblasts.

XRCC1 polymorphisms, cooking oil fume and lung cancer in Chinese women nonsmokers.

X-ray repair cross-complementing group 1 (XRCC1) is one of the major DNA repair proteins involved in the base excision repair (BER) and single-strand break repair (SSBR) pathway. Single nucleotide polymorphisms (SNPs) in XRCC1 may alter protein function and repair capacity, thus lead to genetic instability and carcinogenesis. To establish our understanding of possible relationships between XRCC1 polymorphisms (5'UTR -77T>C, Arg194Trp, Arg280His and Arg399Gln) and the susceptibility to lung cancer among women nonsmokers, we performed a hospital-based case-control study of 350 patients with newly diagnosed lung cancer and 350 cancer-free controls, frequency matched by age. Our results showed that exposure to cooking oil fume was associated with increased risk of lung cancer in Chinese women nonsmokers [odds ratio (OR)=2.51, 95% confidence interval (CI) [1.80-3.51], P<0.001]. Individuals with homozygous XRCC1 399Gln/Gln genotype (OR=1.75, 95% CI [1.02-3.01]) and XRCC1 -77 combined TC and CC genotype (OR=1.66, 95% CI [1.13-2.42]) showed a slightly higher risk for lung cancer overall. In the subgroup of adenocarcinoma cases, adjusted ORs were increased for individuals with homozygous XRCC1 399Gln/Gln genotype (OR=2.62, 95% CI [1.44-4.79]) and XRCC1 -77 combined TC and CC genotype (OR=1.85, 95% CI [1.19-2.86]). Haplotype analysis showed that T-Trp-Arg-Gln haplotypes were associated with an increased risk of lung cancer among women nonsmokers (OR=2.26, 95% CI [1.38-3.68]), however, we did not observe a statistically significant joint effect of cooking oil fume and 399Gln or -77C variant allele on lung cancer among women nonsmokers. In conclusion, XRCC1 Arg399Gln and T-77C polymorphisms may alter the risk of lung cancer in women nonsmokers in China.

[Correlation among expression of CD44, DNA content and apoptosis in female adenocarcinoma of the lung].

BACKGROUND: Cluster of differentiation 44 (CD44) is a family of transmembrane glycoproteins. As cell surface hyaluronate receptor, it has been found to be widely expressed in a variety of cells. The aim of this study is to assess the relationship among CD44 expression, DNA content, proliferation index (PI) and apoptosis in female adenocarcinoma of the lung. METHODS: The expression of CD44, DNA index (DI), PI and apoptotic rate were studied in 61 cases of female adenocarcinoma of the lung, paracancerous tissues and 45 cases of benign lesions by flow cytometry. RESULTS: The percent of DNA aneuploidy was 75.41% in adenocarcinoma. The expression of CD44, DI and PI in adenocarcinoma were significantly higher than those in paracancerous and benign controls (P < 0.01), however the apoptotic rate was obviously lower in adenocarcinoma than that in paracancerous and benign controls (P < 0.01). There was a positive correlation between CD44 and DI (P < 0.01), and a negative correlation between apoptosis and DI in adenocarcinoma (P < 0.01). CONCLUSIONS: The expression of CD44, DNA content, proliferation and apoptosis may play important regulating roles in oncogenesis, development and metastasis of female adenocarcinoma of the lung.

Tauroursodeoxycholic acid attenuates endoplasmic reticulum stress and protects the liver from chronic intermittent hypoxia induced injury.

Obstructive sleep apnea that characterized by chronic intermittent hypoxia (CIH) has been reported to associate with chronic liver injury. Tauroursodeoxycholic acid (TUDCA) exerts liver-protective effects in various liver diseases. The purpose of this study was to test the hypothesis that TUDCA could protect liver against CIH injury. C57BL/6 mice were subjected to intermittent hypoxia for eight weeks and applied with TUDCA by intraperitoneal injection. The effect of TUDCA on liver histological changes, liver function, oxidative stress, inflammatory response, hepatocyte apoptosis and endoplasmic reticulum (ER) stress were investigated. The results showed that administration of TUDCA attenuated liver pathological changes, reduced serum alanine aminotransferase and aspartate aminotransferase level, suppressed reactive oxygen species activity, decreased tumor necrosis factor-α and interleukin-1ß level and inhibited hepatocyte apoptosis induced by CIH. TUDCA also inhibited CIH-induced ER stress in liver as evidenced by decreased expression of ER chaperone 78 kDa glucose-related protein, unfolded protein response transducers and ER proapoptotic proteins. Altogether, the present study described a liver-protective effect of TUDCA in CIH mice model, and this effect seems at least partly through the inhibition of ER stress.

[Association of genetic polymorphism in the DNA repair gene XPD with risk of lung cancer in nonsmoking females].

BACKGROUND: Xeroderma pigmentosum group D (XPD) is one of the important DNA repair genes. XPD polymorphism at Lys751Gln site has been shown to alter XPD protein function, modulate DNA repair capacity and therefore affect cancer risk. The aim of this study is to explore the relationship between XPD polymorphism and susceptibility to lung cancer in nonsmoking female via a population-based case-control study. METHODS: There were 105 female patients who were diagnosed with lung cancer between January 2004 and December 2005 from Liaoning Tumor Hospital and 202 Hospital, and the control group included 105 healthy volunteers who were obtained from community centers at the same time. Information concerning demographic and risk factors was obtained for each case and control by a trained interviewer. XPD genotypes of cases and controls were determined by PCR-RFLP method. Two-sided Chi-Square test was used to compare the distribution of the genotypes and risk factors between cases and controls. Unconditional logistic regression analysis was performed to calculate the odds ratios (OR) with 95% confidence intervals (CI) for estimating the association between certain genotypes and lung cancer and exploring the interaction of environmental risk factors and genetic polymorphism. RESULTS: All of the subjects in this study were nonsmoking females in Shenyang. There was no significant demographic difference (age, economic level and education) between cases and controls. There was a significant difference in the frequencies of XPD polymorphism between cancer cases and controls. The frequencies of XPD 751Gln allele were 6.2% in controls and 13.8% in cases (P < 0.05). The risk of lung cancer was higher in those with the Lys/Gln or Gln/Gln genotype than in those with the Lys/Lys genotype and adjusted OR was 2.80 (95% CI: 1.21-6.48). The result showed that cooking fumes exposure was a risk factor for lung cancer (OR was 2.44). Furthermore, an interaction between environmental risk factors and the variant XPD 751Gln allele on the risk of lung cancer was observed. Individuals with both risk gen-otype and exposure to cooking fumes had a higher elevated risk of cancer than those with only one of them (adjusted OR= 6.85 ; 95% CI: 1.69-27.67; P=0.007). CONCLUSIONS: The above findings indicate that the Lys751Gln polymorphism in XPD gene is associated with the risk of lung cancer in nonsmoking females. Individuals with both XPD 751Gln allele genotype and exposure to cooking fumes have a higher elevated risk of cancer than those with only one of them in nonsmoking female population.

Expression of T cell factor-4 in non-small-cell lung cancer.

BACKGROUND: T cell factor-4 (TCF-4) plays an important role in development and carcinogenesis. Recently, the role of TCF-4 has been described in colon cancer and other cancers. However, whether TCF-4 plays a similar role in lung cancer is unknown. To answer this question, we studied the expression of TCF-4 protein and mRNA in non-small-cell lung cancer (NSCLC) and the relation of TCF-4 expression pattern to histological type and cell differentiation. METHODS: Tissue samples from sixty cases of pathologically diagnosed NSCLC and eight normal tissue samples were obtained between September 2001 and March 2003. Immunohistochemistry was used to investigate the distribution of TCF-4 protein. The staining patterns of the tumors were divided into 4 categories: nuclear staining alone or nuclear staining greater than cytoplasmic staining; cytoplasmic staining or cytoplasmic staining greater than nuclear staining; equal nuclear and cytoplasmic staining; no nuclear staining or cytoplasmic staining. The integrated optical density (OD) values of all sections were analyzed by UIC MetaMorph image analysis software. The expression of TCF-4 mRNA was detected by one-step reverse transcription-polymerase chain reaction (RT-PCR). The integrated density values of the PCR products were analyzed semi-quantitatively. RESULTS: Immunohistochemistry showed that there was no expression of TCF-4 in normal tissue. However, TCF-4 was expressed in 86.7% (52/60) of NSCLC samples, mainly in the nuclei of tumor cells. Furthermore, there was a significant difference in TCF-4 localization patterns between squamous cell carcinomas and adenocarcinomas (P < 0.05). The integrated OD values of TCF-4 expression was significantly higher in tumors with moderate-poor cell differentiation than in well differentiated tumors (51.63 +/- 6.67 vs 46.13 +/- 12.31, P < 0.01). There was no TCF-4 mRNA expression in normal tissue. However, 63.9% (23/36) of carcinoma samples expressed TCF-4 mRNA. TCF-4 mRNA expression was significantly higher in tumors with moderate-poor cell differentiation than in well differentiated tumors (P < 0.05). There were no significant differences in mRNA expression in comparison with histological type. CONCLUSIONS: The sub-cellular distribution of TCF-4 may correlate with NSCLC histological type. High expression of TCF-4 mRNA and protein may be associated with the degree of cell differentiation in NSCLC.

[Association of genetic polymorphism in the DNA repair gene XRCC1 with susceptibility to lung cancer in non-smoking women].

OBJECTIVE: To assess the relationship between the XRCC1 polymorphism and susceptibility to lung cancer in non-smoking female on the basis of a hospital-based case-control study. METHODS: Genotypes were determined by PCR-restriction fragment length polymorphism in 50 patients with lung cancer and 50 controls. The adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression model to study the relationship between different genotypes and risk of lung cancer in non-smoking women. Furthermore, a multiplicative interaction between exposure to cooking oil smoke and the variant XRCC1 399Gln allele on risk of lung adenocarcinoma was evaluated. RESULTS: Individuals carrying Gln/Gln genotype were at an increased risk to suffer from lung adenocarcinoma as compared with those with the Arg/Arg genotype (OR: 14.12; 95% CI: 2.14 approximately 92.95, adjusted for age and cooking oil smoke). The OR of lung adenocarcinoma for the variant XRCC1 399Gln allele with exposure to cooking oil smoke was 6.29 (95% CI 1.99 approximately 19.85). CONCLUSION: The above described findings indicate that Arg 399Gln polymorphism in the XRCC1 is associated with risk of lung adenocarcinoma but not with risk of squamous-cell carcinoma of the lung in non-smoking women.

[Association of genetic polymorphism in DNA repair gene XRCC1 with risk of lung adenocarcinoma in nonsmoking women].

BACKGROUND: XRCC1 polymorphism at Arg399Gln site has been shown to modulate DNA repair capacity. The aim of this study is to assess the relationship between XRCC1 polymorphism and susceptibility to lung adenocarcinoma in nonsmoking female via a hospital-based case-control study. METHODS: Cases were 126 female patients with lung adenocarcinoma from January 2002 to October 2004 in China Medical University Hospital and Liaoning Tumor Hospital. Controls were selected from patients with other pulmonary diseases in the hospitals at the same time. These controls were matched to cases on age (±5 years). Information concerning demographic and risk factors was obtained for each case and control by a trained interviewer. XRCC1 genotypes were determined by PCR-RFLP. The adjusted odds ratio (OR) and 95% confidence interval (CI) were calculated using logistic regression. RESULTS: Cases showed a higher prevalence of oil smoke compared with controls (P < 0.05). The frequencies of Arg/Arg, Arg/Gln and Gln/Gln in lung adenocarcinoma group (32.54%, 42.86%, 24.60%) were significantly different from those in controls (54.76%, 40.48%, 4.76%) (P < 0.05). The individual carrying Gln/Gln genotype was at a significantly increased risk of lung adenocarcinoma compared with those with Arg/Arg genotype (OR=8.695, 95%CI 3.343-22.614, adjusted for age and oil smoke exposure). Furthermore, the OR of lung adenocarcinoma for the variant XRCC1 399Gln allele combined with exposure to oil smoke was 5.21 (95%CI 1.85-14.70, P < 0.001). CONCLUSIONS: The results indicate that the Arg399Gln polymorphism in XRCC1 is associated with the risk of lung adenocarcinoma in nonsmoking women.

Wnt3a increases the metastatic potential of non-small cell lung cancer cells in vitro in part via its upregulation of Notch3.

Metastasis is the leading cause of death in lung cancer. Understanding the mechanisms underlying the process of metastasis is crucial for identifying novel anti-metastatic therapies. Studies indicate that the highly conserved developmental pathways, such as the Wnt and Notch signaling pathways, play important roles in the non-small cell lung cancer (NSCLC) tumorigenesis. However, the roles of both pathways in NSCLC metastasis are unclear. The present study aimed to investigate whether Wnt3a and Notch3, key components of the Wnt and Notch signaling pathways, respectively, regulate the metastatic abilities of NSCLC cells and whether there is some relationship during these regulatory events. Here, we observed that Wnt3a treatment upregulated, not only the protein expression of Notch3, but also the mRNA expression of Notch3 and its downstream genes, HES1 and HEYL. In addition, Wnt3a promoted cell invasion and anchorage-independent growth. Meanwhile, Wnt3a treatment caused epithelial­mesenchymal transition (EMT)-like morphological changes and F-actin reorganization. The western blotting data showed that Wnt3a treatment decreased the expression of E-cadherin and increased the expression of N-cadherin and vimentin. Compared with Wnt3a treatment, Notch3 shRNA transfection had opposite effects. Furthermore, Notch3 shRNA weakened the effects of Wnt3a treatment on the in vitro cell invasion and EMT. Overall, these observations suggest that Wnt3a and Notch3 may promote the metastasis of NSCLC and Notch3 upregulation is required for the Wnt3a mediated increased metastatic abilities of NSCLC.