Chemokines and chemokine receptors, has been shown to be involved in metastatic process of prostate cancer (PCa). In this study, we have show that primary PCa tissues and cell lines (LNCaP and PC3) express CXCR5, a specific chemokine receptor for the CXCL13. Expression of CXCR5 was significantly higher (P < 0.001) in PCa cases than compared to normal match (NM) tissues. CXCR5 intensity correlated (R2 = 0.97) with Gleason score. While prostate tumor tissues with Gleason scores ≥ 7, displayed predominantly nuclear CXCR5 expression patterns, PCa specimens with Gleason scores ≤ 6 showed predominantly membrane and cytoplasmic expression patterns that were comparable to benign prostatic hyperplasia (BPH). Similar to tissue expression, PCa cell lines expressed significantly more CXCR5 than normal prostatic epithelial cells (PrECs) and CXCR5 expression was distributed among intracellular and extracellular compartments. Functional in vitro assays showed higher migratory and invasive potentials toward CXCL13, an effect that was CXCR5-mediated. In both PCa cell lines, CXCL13 treatment increased the expression of collagenase-1 or matrix metalloproteinase-1 (MMP-1), collagenase-3 (MMP-13), stromelysin-1 (MMP-3), stromalysin-2 (MMP-10), and stromelysin-3 (MMP-11). These data demonstrate the clinical and biological relevance of the CXCL13-CXCR5 pathway and its role in PCa cell invasion and migration.
chemokine; prostate cancer; tissue expression
Viral hepatitis and aflatoxin B1 (AFB1) exposure are common risk factors for hepatocellular carcinoma (HCC). The incidence of HCC in individuals co-exposed to hepatitis C (HCV) or B virus and AFB1 is greater than could be explained by the additive effect, yet the mechanisms are poorly understood due to lack of an animal model. This study investigated the outcomes and mechanisms of combined exposure to HCV and AFB1. We hypothesized that HCV transgenic (HCV-Tg; expressing core, E1, E2, and p7, nucleotides 342–2771) mice will be prone to hepatocarcinogenesis when exposed to AFB1. Neonatal (7 days old) HCV-Tg or C57BL/6J wild-type mice were exposed to AFB1 (6 μg/g bw) or tricaprylin vehicle (15 μl/g bw) and male offspring were followed for up to 12 months. No liver lesions were observed in vehicle-treated wild type or HCV-Tg mice. Tumors (adenomas or carcinomas) and preneoplastic lesions (hyperplasia or foci) were observed in 22.5% (9 of 40) of AFB1-treated wild-type mice. In HCV-Tg, the incidence of tumorous or pre-tumorous lesions was significantly elevated (50%, 18 of 36), with the difference largely due to a 2.5-fold increase in the incidence of adenomas (30.5% vs 12.5%). While oxidative stress and steato-hepatisis were observed in both AFB1-treated groups, molecular changes indicative of the enhanced inflammatory response and altered lipid metabolism were more pronounced in HCV-Tg mice. In summary, HCV proteins core, E1, E2 and p7 are sufficient to reproduce the co-carcinogenic effect of HCV and AFB1 which is a known clinical phenomenon.
Novelty and impact
This work establishes a model for studies of the mechanisms of co-carcinogenesis of HCV and AFB1 and indicates a crucial role for direct viral protein effects in the synergy between these factors. A number of molecular pathways known to play a role in liver carcinogenesis were investigated and the data shows that the HCV structural proteins and AFB1 react synergistically to increase steatosis and tumor incidence whereby HCV and AFB1 may operate to increase liver cancer incidence through different mechanisms. In addition, while tumor occurrence may be also linked to lipid peroxidation consequently to AFB1 exposure, we posit that the conventional explanations (e.g., oxidative stress, lipid accumulation) do not appear to be the cause of the synergy and other more specific, but as yet unidentified effects are likely to be responsible.
aflatoxin B1; hepatitis C virus; liver; mouse
Although numerous studies have assessed the effect of foods and nutrients on colorectal carcinogenesis, few studies have investigated human eating behavior in relation to risk of colorectal cancer. In the present study, we assessed whether the reported behavior of eating anything at anytime influenced colorectal cancer risk and related plasma biomarkers. We prospectively followed 55,540 women in the Nurses’ Health Study who were aged 48 to 73 years, had no history of cancer, ulcerative colitis, or diabetes, and responded to the item “I eat anything I want, anytime I want” in the 1994 questionnaire. Blood samples were collected in 1989–1990 and analyzed for 1,994 women. During 12 years of follow-up, 552 colorectal cancer cases were documented. After adjusting for age, smoking, body mass index, physical activity, red and processed meat, and other known risk factors for colorectal cancer, women who reported eating anything at anytime experienced an increased risk of colorectal cancer (relative risk [RR]=1.28, 95% confidence interval [CI]=1.06–1.56) compared with those who did not report this behavior. In addition, reporting eating anything at anytime was associated with higher fasting plasma levels of insulin (P=0.04) and C-peptide (P=0.05). In conclusion, reports of eating anything at anytime are associated with an increased risk of colorectal cancer in this large prospective cohort study, independent of other potential risk factors for colorectal cancer.
Eating behavior; colorectal cancer; cohort study
Smoking adversely affects hematopoietic stem cell transplantation outcome. We asked whether smoking affected outcome of newly diagnosed acute myeloid leukemia (AML) patients treated with chemotherapy. Data were collected on 280 AML patients treated with high-dose cytarabine and idarubicin-containing regimens at Roswell Park Cancer Institute who had smoking status data at diagnosis. Patients’ gender, age, AML presentation (de novo vs. secondary), white blood cell (WBC) count at diagnosis, karyotype and smoking status (never vs. ever) were analyzed. Among the 161 males and 119 females with a median follow-up of 12.9 months, 101 (36.1%) had never smoked and 179 (63.9%) were ever smokers. The proportion of patients between never and ever smokers was similar with respect to age, AML presentation, WBC count at diagnosis or karyotype based on univariate analysis of these categorical variables. Never smokers had a significantly longer overall survival (60.32 months) compared to ever smokers (30.89; p=0.005). In multivariate analysis incorporating gender, age, AML presentation, WBC count, karyotype, and smoking status as covariates, age, karyotype and smoking status retained prognostic value for overall survival. In summary, cigarette smoking has a deleterious effect on overall survival in AML.
We characterized the effects of a newly developed STAT3 inhibitor, LLL12 in multiple myeloma (MM) cells. LLL12 specifically inhibited STAT3 phosphorylation, nuclear localization, DNA binding activity, down-regulated STAT3 downstream genes, and induced apoptosis in MM cells. Importantly, LLL12 significantly inhibited STAT3 phosphorylation, induced apoptosis in primary MM cells which came from patients that were clinically resistant to lenalidomide and bortezomib. LLL12 is a potent inhibitor of cell proliferation with IC50 values ranging between 0.26μM and 1.96μM in MM and primary MM cells. LLL12 also inhibited STAT3 phosphorylation induced by interleukin-6 (IL-6) and interferon-α but not STAT1, STAT2, STAT4, and STAT6 phosphorylation induced by interferon-α, interferon-γ, and interleukin-4 indicating the selectivity of LLL12 for STAT3. The selectively of LLL12 on STAT3 was further demonstrated on 21 protein kinases, which LLL12 had IC50 values 73.92μM. In addition, the pre-treatment of LLL12 blocked the promotion of the cell proliferation and resistance to lenalidomide by IL-6. Furthermore, LLL12 significantly blocked tumor growth of MM cells in mouse model. Our results indicate that LLL12 blocks constitutive STAT3 and IL-6 induced STAT3 signaling and may be a potential therapeutic agent for MM.
STAT3; multiple myeloma; small molecule inhibitors
Body mass index (BMI) has been positively associated with thyroid cancer risk in several studies, but the underlying mechanisms remain unclear. We examined the associations for waist and hip circumference and weight change during adulthood with thyroid cancer risk among 125,347 men and 72,363 women in the NIH-AARP Diet and Health Study who completed a second mailed questionnaire in 1996–97. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated separately by sex and adjusted for race/ethnicity, education, and smoking status. During follow-up (median=10.1 years), 106 men and 105 women were diagnosed with a first primary thyroid cancer, as identified through linkage to state cancer registries. Having a large waist circumference (above the clinical cutpoint for normal: >102 cm in men and >88 cm in women) was associated with increased risk in both men (HR=1.79, 95% CI: 1.21–2.63) and women (HR=1.54, 95% CI: 1.05–2.26). Having both a large waist and BMI in the obese range (≥30 kg/m2) approximately doubled the risk of thyroid cancer (HR in men=2.13, 95% CI: 1.18–3.85; HR in women=1.91, 95% CI: 1.31–3.25) compared to having a normal waist circumference/normal BMI (18.5–24.9 kg/m2). We also observed a positive association for weight gain between ages 18–35 in men (gained ≥10.0 kg versus lost/gained <5 kg, HR=1.49, 95% CI: 0.93–2.39, P-trend=0.03), but the association was less pronounced in women. No clear association for weight gain in later life was observed. These results support a potential role for hormonal and metabolic parameters common to central adiposity in thyroid carcinogenesis.
thyroid cancer; anthropometry; obesity; prospective study
Urinary metabolites of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides, termed total NNAL, have recently been shown to be good predictors of lung cancer risk, years prior to diagnosis. We sought to determine the contribution of several genetic polymorphisms to total NNAL output and inter-individual variability. The study subjects were derived from the Harvard/Massachusetts General Hospital Lung cancer case-control study. We analyzed 87 self-described smokers (35 lung cancer cases and 52 controls), with urine samples collected at time of diagnosis and (1992–1996). We tested 82 tagging SNPs in 16 genes related to the metabolism of NNK to total NNAL. Using weighted case status least squares regression, we tested for the association of each SNP with square-root (sqrt) transformed total NNAL (pmol per mg creatinine), controlling for age, sex, sqrt packyears and sqrt nicotine (ng per mg creatinine). After a sqrt transformation, nicotine significantly predicted a 0.018 (0.014, 0.023) pmol/mg creatinine unit increase in total NNAL for every ng/mg creatinine increase in nicotine at p<10E-16. Three HSD11B1 SNPs and AKR1C4 rs7083869 were significantly associated with decreasing total NNAL levels: HSD11B1 rs2235543 (p= 4.84E-08) and rs3753519 (p= 0.0017) passed multiple testing adjustment at FDR q=1.13E-05 and 0.07 respectively, AKR1C4 rs7083869 (p=0.019) did not, FDR q=0.51. HSD11B1 and AKR1C4 enzymes are carbonyl reductases directly involved in the single step reduction of NNK to NNAL. The HSD11B1 SNPs may be correlated with the functional variant rs13306401 and the AKR1C4 SNP is correlated with the enzyme activity reducing variant rs17134592, L311V.
NNK; NNAL; tobacco specific nitrosamine; genetic polymorphism; HSD11B1
Circulating micro-RNA (miR) profiles have been proposed as promising diagnostic and prognostic biomarkers for cancer, including lung cancer. We have developed methods to accurately and reproducibly measure microRNA levels in serum and plasma. Here we study paired serum and plasma samples from 220 patients with early stage NSCLC and 220 matched controls. We use qRT-PCR to measure the circulating levels of 30 different miRs that have previously been reported to be differently expressed in lung cancer tissue. Duplicate RNA extractions were performed for 10% of all samples and microRNA measurements were highly correlated among those duplicates. This demonstrates high reproducibility of our assay. The expression of miR-146b, miR-221, let-7a, miR-155, miR-17-5p, miR-27a and miR-106a were significantly reduced in the serum of NSCLC cases while miR-29c was significantly increased. No significant differences were observed in plasma of patients compared to controls. Overall, expression levels in serum did not correlate well with levels in plasma. In secondary analyses, reduced plasma expression of let-7b was modestly associated with worse cancer-specific mortality in all patients and reduced serum expression of miR-223 was modestly associated with cancer-specific mortality in stage IA/B patients. MiR profiles also showed considerable differences comparing African American and European Americans. In summary, we found significant differences in miR expression when comparing cases and controls and find evidence that expression of let-7b is associated with prognosis in NSCLC.
Cancer of the oral cavity is a serious disease, affecting about 30,000 individuals in US annually. There are several animal models of oral cancer, but each has certain disadvantages. As a new model, we investigated whether topical application of the tobacco smoke carcinogen, dibenzo[a,l]pyrene (DB[a,l]P) is mutagenic and carcinogenic in the oral cavity of the B6C3F1 lacI and B6C3F1 mouse, respectively. B6C3F1 lacI mice received DB[a,l]P (0, 3, 6, 12 nmol) 3× per week. B6C3F1 mice received the same doses and also 24 nmol. At 38 weeks mutagenesis was measured in oral tissues in lacI mice. For the high dose group, the mutant fraction (MF) in upper mucosa and tongue increased about twofold relative to that in vehicle-alone. The increases were statistically significant. The mutational profile in the DB[a,l]P-induced mutants was compared with that induced by benzo[a]pyrene (BaP) in oral tissue. BaP is mutagenic in many tissues when administered by gavage. The mutational profile for DB[a,l]P was more similar to that reported for p53 mutations in head and neck cancers than was that of BaP. At 47 weeks, oral squamous cell carcinomas (OSCC) were found in 31% of the high-dose B6C3F1 group. Elevations of p53 and COX-2 protein were observed in tumor and dysplastic tissue. As DB[a,l]P induces mutations and tumors in the oral cavity, and has a mutational profile in oral tissue similar to that found in p53 in human OSCC, the treatment protocol described here may represent a new and relevant model for cancer of the oral cavity.
DB[a,l]P; oral cancer; mutagenesis; mutational profile; tobacco smoking
Glutathione-S-transferases (GST) are upregulated in malignant gliomas and contribute to their chemoresistance. The nitric oxide (NO) donor PABA/NO generates NO upon selective enzymatic activation by GST-π inducing selective biological effects in tumors. Tumor cell killing and chemosensitization were observed in a variety of tumors after exposure to GST-activated NO donor drugs. In this project, cytotoxic and chemosensitizing effects of PABA/NO in combination with carboplatin (CPT) and temozolomide (TMZ) were studied in human U87 glioma cells in vitro and in vivo. U87 glioma cells were exposed to PABA/NO alone or in combination with CPT or TMZ for 24h. Cell viability was assessed by MTT assay after 24h incubation and 48h after drug removal. The antiproliferative effect of PABA/NO was assessed in an intracranial U87 glioma nude rat model comparing subcutaneous administration and intratumoral delivery by convection-enhanced delivery (CED). PABA/NO monotherapy showed a strong dose-dependent growth-inhibitory effect in U87 glioma cells in vitro, and a strong synergistic effect was observed after concomitant treatment with TMZ, but not with CPT. Systemic and intratumoral PABA/NO administration significantly reduced cell proliferation but this did not result in prolonged survival in nude rats with intracranial U87 gliomas. PABA/NO has potent antiproliferative effects, sensitizes U87 glioma cells to TMZ in vitro and shows some in vivo efficacy. Further studies are still required to consolidate the role of NO donor therapy in glioma treatment.
nitric oxide; glioma; glutathione-S-transferase; PABA/NO; chemosensitization; temozolomide; carboplatin
Cytochrome P450 1A2 (CYP1A2) is hypothesized to catalyze the activation of arylamines, known human bladder carcinogens present in cigarette smoke. The relationship between CYP1A2 phenotype and bladder cancer risk was examined in a case-control study involving 519 patients and 514 controls in Shanghai, China. Both CYP1A2 and N-acetyltransferase 2 (NAT2) phenotypic status were determined by a caffeine-based urinary assay. The present study showed that among smokers at urine collection, bladder cancer patients had statistically significantly higher CYP1A2 phenotype scores compared with control subjects (P = 0.001). The odds ratios (95% confidence intervals) of bladder cancer for the 2nd, 3rd, and 4th quartiles of the CYP1A2 score were 1.31 (0.53–3.28), 2.04 (0.90–4.60) and 2.82 (1.32–6.05), respectively, relative to the lowest quartile (P for trend = 0.003). NAT2 slow acetylation phenotype was associated with a statistically significant 40% increased risk of bladder cancer, and the relationship was independent of subjects’ smoking status. Subjects possessing the NAT2 slow acetylation phenotype and the highest tertile of CYP1A2 scores showed the highest risk for bladder cancer. Their odds ratios (95% confidence intervals) was 2.13 (1.24–3.68) relative to their counterparts possessing the NAT2 rapid acetylation phenotype and the lowest tertile of CYP1A2 scores. The findings of the present study demonstrate that CYP1A2 phenotype may be an important contributing factor in the development of smoking-related bladder cancer in humans.
It is well accepted that near-infrared (NIR) lasers are appropriate to ablate benign lesions and induce irreversible thermal injury in deeply seated blood vessels. At this wavelength, the laser light penetrates deep (3–5 mm) into the skin. However, many researchers have reported noticeable pain, extending from mild to severe, during and immediately following NIR laser treatment. Intravenous administration of an exogenous chromophore (indocyanine green, ICG, dye) can effectively convert NIR laser light into heat. In this approach the presence of ICG has shown to enhance thermal injury of blood vessels in the treatment of healthy tissues. However, the effectiveness of thermal injury on the regression of cutaneous carcinomas during ICG/NIR laser therapy has not been assessed. The purpose of this study was to evaluate the potential benefit of using ICG/NIR laser therapy to regress superficial carcinoma with thermal injury. Two groups of A/J mice with subcutaneous mammary adenocarcinoma tumors (7–9 mm) were irradiated with a 808-nm NIR laser preceded by tail vein injection of ICG dye or sterile saline. Histological evaluation of the subcutaneous tissue revealed minor thermal damage and necrosis in the laser/saline group and substantial damage (up to 100% necrosis) in the laser/ICG group. The laser/ICG-treated group showed a steady reduction in tumor volume compared to the laser/saline group: 48% by Day 5 (P=0.045) and 69%–70% by Days 8, 9, and 10 (P values 0.0005 or less).
The vascular targeted ICG–NIR laser therapy appears to have potential for treating superficial tumors.
Indocyanine green; near infrared (NIR) laser; adenocarcinoma; thermal imaging
HtrA1, a member of serine protease family, has been previously found to be involved in resistance to chemotherapy in ovarian cancer although the underlying mechanism is not clear. Using mixture-based oriented peptide library approach, we previously identified X-linked inhibitor of apoptosis protein (XIAP), a member of the inhibitor of apoptosis proteins (IAPs) family as a potential substrate of HtrA1. The aim of this work is to investigate the link between HtrA1 and XIAP proteins and their relationships with chemoresistance in ovarian cancer. Our results showed that recombinant XIAP was degraded by purified wild type HtrA1 but not mutant HtrA1 in vitro. Consistent with the in vitro data, co-immunoprecipitation assays showed that HtrA1 and XIAP formed a protein complex in vivo. Ectopic expression of HtrA1 led to decreased level of XIAP in OV167 and OV202 ovarian cancer cells, while knockdown of HtrA1 resulted in increased level of XIAP in SKOV3 ovarian cancer cells. Furthermore, over-expression of HtrA1 in OV202 cells promoted cell sensitivity to cisplatin-induced apoptosis which could be reversed by increased expression of XIAP. The cleavage of XIAP induced by HtrA1 was enhanced by cisplatin treatment. Taken together, our experiments have identified XIAP as a novel substrate of HtrA1 and the degradation of XIAP by HtrA1 contributes to cell response to chemotherapy, suggesting that restoring the expression of HtrA1 may be a promising treatment strategy for ovarian cancer.
HtrA1; XIAP; apoptosis; chemoresistance; ovarian cancer
Reduced levels of global DNA methylation, assessed in peripheral blood, have been associated with bladder cancer risk in European and American populations. Similar data are lacking in Asian populations where genetic differences, lifestyle factors, and different environmental exposures may affect DNA methylation and its risk relationship with bladder cancer. The association between global DNA methylation measured at long interspersed nuclear element (LINE-1) repeat regions through bisulfite pyrosequencing in lymphocyte DNA and bladder cancer risk was examined in a case-control study of 510 bladder cancer patients and 528 healthy control subjects in Shanghai, China. In an initial analysis restricted to control subjects, LINE-1 methylation was elevated among men, those who frequently consumed cruciferous vegetables, and those with a null genotype for either glutathione S-transferase M1 (GSTM1) or GSTT1. In contrast, reduced LINE-1 methylation was found in current smokers with a high cytochrome P450 1A2 (CYP1A2) phenotype index. In a case-control analysis, there was no significant association of LINE-1 methylation with case status, although reduced LINE-1 methylation was associated with increased risk of bladder cancer among never smokers (P for trend = 0.03); analysis by tertile revealed odds ratios (ORs) of 1.91 (lowest tertile; 95% CI = 1.17–3.13) and 1.34 (middle tertile; 95% CI = 0.79–2.28) when compared to the highest tertile. This association was strongest among nonsmokers null for either the GSTM1 or GSTT1 genotype (P for trend = 0.006). Further research is needed to understand the relationships between methyl group availability and LINE-1 methylation in relation to bladder cancer risk.
Epithelial cancer cells are likely to undergo epithelial mesenchymal transition (EMT) prior to entering the peripheral circulation. By undergoing EMT, circulating tumor cells (CTCs) lose epithelial markers and may escape detection by conventional methods. Therefore, we conducted a pilot study to investigate mRNA transcripts of EMT-inducing transcription factors (TFs) in tumor cells from the peripheral blood (PB) of primary breast cancer (PBC) patients.
Peripheral blood mononuclear cells were isolated from 52 stages I–III PBC patients and 30 healthy donors (HD) and sequentially depleted of EpCAM+ cells and CD45+ leukocytes, henceforth referred to as CD45−. The expression levels of EMT-inducing TFs (TWIST1, SNAIL1, SLUG, ZEB1, and FOXC2) in the CD45− cells were determined using qRT-PCR. The highest level of expression by the CD45− cell fraction of HD was used as “cut off” to determine if samples from PBC patients overexpressed any EMT-inducing TFs. In total, 15.4% of PBC patients overexpressed at least one of the EMT-inducing TF transcripts. Overexpression of any EMT-inducing TF transcripts was more likely to be detected in PBC patients who received neoadjuvant therapies (NAT) than patients who received no NAT (P = 0.003). Concurrently, CTCs were detected in 7 out of 38 (18.4%) patients by CellSearch® and 15 out of 42 (35.7%) patients by AdnaTest™. There was no association between the presence of CTCs measured by CellSearch® or AdnaTest™.
In summary, our results demonstrate that CTCs with EMT phenotype may occur in the peripheral circulation of PBC patients and NAT is unable to eliminate CTCs undergoing EMT.
circulating tumor cells; epithelial-mesenchymal transition; primary breast cancer; neoadjuvant therapy
Pregnancy reduces maternal risk of breast cancer in the long-term, but the biological determinants of the protection are unknown. Animal experiments suggest that estrogens and progesterone could be involved, but direct human evidence is scant. A case-control study (536 cases, 1,049 controls) was nested within the Finnish Maternity Cohort. Eligible were primiparous women, who delivered at term a singleton offspring before age 40. For each case, two individually matched controls by age (±6 months) and date of sampling (±3 months) were selected. Estradiol, estrone, and progesterone in first-trimester serum were measured by High Performance Liquid Chromatography Tandem Mass Spectrometry and sex-hormone binding globulin (SHBG) by immunoassay. Odds ratios (OR) and 95% confidence intervals (CI) were estimated through conditional logistic regression. In the whole study population, there was no association of breast cancer with any of the studied hormones. In analyses stratified by age at diagnosis, however, estradiol concentrations were positively associated with risk of breast cancer before age 40 (upper quartile OR, 1.81; CI, 1.08-3.06), but inversely associated with risk in women who were diagnosed ≥age 40 (upper quartile OR, 0.64; CI, 0.40-1.04), pinteraction 0.004. Risk estimates for estrone mirrored those for estradiol, but were less pronounced. Progesterone was not associated with risk of subsequent breast cancer. Our results provide initial evidence that concentrations of estrogens during the early parts of a primiparous pregnancy are associated with maternal risk of breast cancer and suggest that the effect may differ for tumors diagnosed before and after age 40.
breast cancer; pregnancy; estrogens; progesterone; nested case-control study
There is little information regarding associations between suspected bladder cancer risk factors and tumor subtypes at diagnosis. Some, but not all, studies have found that bladder cancer among smokers is often more invasive than it is among nonsmokers. This population-based case-control study was conducted in Los Angeles, California, involving 1,586 bladder cancer patients and their individually matched controls. Logistic regression was used to conduct separate analyses according to tumor subtypes defined by stage and grade. Cigarette smoking increased risk of both superficial and invasive bladder cancer, but the more advanced the stage, the stronger the effect. The odds ratios associated with regular smokers were 2.2 (95% confidence intervals, 1.8-2.8), 2.7 (2.1-3.6) and 3.7 (2.5-5.5) for low-grade superficial, high-grade superficial and invasive tumors respectively. This pattern was consistently observed regardless of the smoking exposure index under examination. Women had higher risk of invasive bladder cancer than men even they smoked comparable amount of cigarettes as men. There was no gender difference in the association between smoking and risk of low-grade superficial bladder cancer. The heterogeneous effect of cigarette smoking was attenuated among heavy users of NSAIDs. Our results indicate that cigarette smoking was more strongly associated with increased risk of invasive bladder cancer than with low-grade superficial bladder cancer.
cigarette smoking; bladder cancer; tumor subtypes; non-steroidal anti-inflammatory drugs; Los Angeles
Overweight and obesity are inversely related to the risk of breast cancer among premenopausal women. We assessed the association between adult weight change since age 18 years with the risk of breast cancer among premenopausal women to explore whether weight gain was associated with a decrease in risk and weight loss was associated with an increase in risk. A total of 56,223 premenopausal participants in the Nurses' Health Study and 109,385 premenopausal participants in the Nurses' Health Study II were prospectively followed for up for 28 years and 14 years, respectively, and weight change since age 18 years was assessed biennially. The incidence of invasive breast cancer was assessed throughout follow-up. Weight loss of 5kg or more since age 18, maintained for at least 4 years, was related to lower incidence of premenopausal breast cancer, compared to maintaining a stable weight, but this relation was of borderline statistical significance (covariate-adjusted HR=0.75; 95% CI 0.52-1.09). Weight gain since age 18 years was also inversely related to breast cancer incidence among premenopausal women (covariate-adjusted p for trend=0.01), but the association weakened after controlling for weight at age 18 and did not reach statistical significance (p for trend=0.08). Although obesity and breast cancer among premenopausal women are inversely related, weight loss since age 18 years did not increase and weight gain did not significantly decrease the risk of premenopausal breast cancer among participants in the large prospective cohorts of NHS and NHS II.
Breast cancer; premenopausal; weight gain; weight loss; BMI
We previously reported an inverse association between sleep duration and breast cancer risk in the prospective, population-based Singapore Chinese Health Study (SCHS) cohort (Wu et al., Carcinogenesis 2008;29:1244–8). Sleep duration was significantly positively associated with 6-sulfatoxymelatonin (aMT6s) levels determined in a spot urine, but aMT6s levels in breast cancer cases were lacking (Wu et al., Carcinogenesis 2008;29:1244–8). We updated the sleep duration–breast cancer association with 14 years of follow-up of 34,028 women in the SCHS. In a nested case–control study conducted within the SCHS, randomly timed, prediagnostic urinary aMT6s concentrations were compared between 248 incident breast cancer and 743 individually matched cohort controls. Three female controls were individually matched to each case on age at baseline interview (within 3 years), dialect group, menopausal status, date of baseline interview (within 2 years), date of urine sample collection (within 6 months) and timing of urine collection during the day (within 1 hr). Cox proportional hazards and conditional regression models with appropriate adjustment for confounders were used to examine the sleep– and aMT6s–breast cancer relationships. Breast cancer risk was not significantly associated with sleep duration; adjusted odds ratio (OR) for 9+ vs. ≤6 hr is 0.89 [95% confidence interval (95% CI) 5 0.64–1.22]. Prediagnostic aMT6s levels did not differ between breast cancer cases and matched controls; adjusted OR for highest versus lowest quartiles is 1.00 (95% CI 5 0.64-1.54). We conclude that sleep duration is not significantly associated with breast cancer risk reduction. Melatonin levels derived from randomly timed spot urine are unrelated to breast cancer. Randomly timed, spot urine-derived melatonin levels are noninformative as surrogates of nocturnal melatonin production.
sleep duration; spot urinary melatonin; breast cancer; prospective; Singaporean Chinese
Certain classes of vitamins and nutrients found in fruits and vegetables have been of particular interest in relation to cancer prevention, owing to their potential anti-carcinogenic properties. We examined the association between certain fruits, vegetables, carotenoids, and vitamin A and breast cancer risk in a large population based case-control study of women residing in the states of Massachusetts, New Hampshire, and Wisconsin. The study was comprised of 5,707 women with incident invasive breast cancer (2,363 premenopausal women and 3,516 postmenopausal women) and 6,389 population controls (2,594 premenopausal women and 3,516 postmenopausal women). In an interview women were asked about their intake of carotenoid rich fruits and vegetables five years prior to a referent date. An inverse association was observed among premenopausal women was for high levels of vitamin A (OR: 0.82, 95%CI: 0.68–0.98, p for trend = 0.01), β-carotene (OR: 0.81, 95% CI 0.68–0.98, p for trend = 0.009), α-carotene (OR: 0.82, 95% CI: 0.68–0.98, p for trend = 0.07), and lutein/zeaxanthin (OR: 0.83, 95% CI 0.68 – 0.99, p for trend = 0.02). An inverse association was not observed among postmenopausal women. Among premenopausal women who reported ever smoking, these results were stronger than among never smokers, although tests for interaction were not statistically significant. Results from this study are comparable to previous prospective studies and suggest that a high consumption of carotenoids may reduce the risk of pre but not post menopausal breast cancer, particularly among smokers.
breast cancer; nutrition; carotenoids; epidemiology
Bone morphogenetic proteins (BMP) are part of the TGF-β-signaling pathway; genetic variation in these genes may be involved in colorectal cancer. In this study we evaluated the association between genetic variation in BMP1 (11 tagSNPs), BMP2 (5 tagSNPs), BMP4 (3 tagSNPs), BMPR1A (9 tagSNPs), BMPR1B (21 tagSNPs), BMPR2 (11 tagSNPs), and GDF10 (7 tagSNPs) with risk of colon and rectal cancer and tumor molecular phenotype. We used data from population-based case-control studies (colon cancer n=1574 cases, 1970 controls; rectal cancer n=791 cases, 999 controls). We observed that genetic variation in BMPR1A, BMPR1B, BMPR2, BMP2, and BMP4 was associated with risk of developing colon cancer, with 20 to 30% increased risk for most high-risk genotypes. A summary of high-risk genotypes showed over a twofold increase in colon cancer risk at the upper risk category (OR 2.49 95% CI 1.95, 3.18). BMPR2, BMPR1B, BMP2, and GDF10 were associated with rectal cancer. BMPR2 rs2228545 was associated with an almost twofold increased risk of rectal cancer. The risk associated with the highest category of the summary score for rectal cancer was 2.97 (95% CI 1.87, 4.72). Genes in the BMP-signaling pathway were consistently associated with CIMP+ status in combination with both KRAS-mutated and MSI tumors. BMP genes interacted statistically significantly with other genes in the TGF-β-signaling pathway, including TGFβ1, TGFβR1, Smad 3, Smad 4, and Smad 7. Our data support a role for genetic variation in BMP-related genes in the etiology of colon and rectal cancer. One possible mechanism is via the TGF-β-signaling pathway.
bone morphogenetic protein; TGF-β; CIMP+; MSI+; genes; colon cancer; rectal cancer; GDF10
Retinoblastoma (RB) is an important ocular malignancy of childhood. It has been commonly accepted for some time that knockout of the two alleles of the RB1 gene is the principal molecular target associated with the occurrence of RB. In this paper, we examine the validity of the two-hit theory for retinoblastoma by comparing the fit of a stochastic model with two or more mutational stages. Unlike many such models, our model assumes a fully stochastic stem cell compartment, which is crucial to its behavior. Models are fitted to a population-based dataset comprising 1,553 cases of retinoblastoma for the period 1962–2000 in Great Britain (England, Scotland, Wales). The population incidence of retinoblastoma is best described by a fully stochastic model with two stages, although models with a deterministic stem cell compartment yield equivalent fit; models with three or more stages fit much less well. The results strongly suggest that knockout of the two alleles of the RB1 gene is necessary and may be largely sufficient for the development of retinoblastoma, in support of Knudson’s two-hit hypothesis.
Retinoblastoma; carcinogenesis modeling; two-hit theory; stochastic MVK model; RB1 gene
The PI3 kinase/Akt pathway is commonly deregulated in human cancers, functioning in such processes as proliferation, glucose metabolism, survival and motility. We have previously described a novel function for one of the Akt isoforms (Akt3) in primary endothelial cells: the control of VEGF-induced mitochondrial biogenesis. We sought to determine if Akt3 played a similar role in carcinoma cells. Since the PI3 kinase/Akt pathway has been strongly implicated as a key regulator in ovarian carcinoma, we tested the role of Akt3 in this tumor type. Silencing of Akt3 by shRNA did not cause an overt reduction in mitochondrial gene expression in a series of PTEN positive ovarian cancer cells. Rather, we find that blockade of Akt3, results in smaller, less vascularized tumors in a xenograft mouse model that is correlated with a reduction in VEGF expression. We find that blockade of Akt3, but not Akt1, results in a reduction in VEGF secretion and retention of VEGF protein in the endoplasmic reticulum (ER). The reduction in secretion under conditions of Akt3 blockade is, at least in part, due to the down regulation of the resident golgi protein and reported tumor cell marker, RCAS1. Conversely, over-expression of Akt3 results in an increase in RCAS1 expression and in VEGF secretion. Silencing of RCAS1 using siRNA inhibits VEGF secretion. These findings suggest an important role for Akt3 in the regulation of RCAS1 and VEGF secretion in ovarian cancer cells.
Akt3; VEGF; secretion; ovarian cancer; xenograft model; angiogenesis
Although cell-based studies have shown that γ-tocotrienol (γTE) exhibits stronger anticancer activities than other forms of vitamin E including γ-tocopherol (γT), the molecular bases underlying γTE-exerted effects remains to be elucidated. Here we showed that γTE treatment promoted apoptosis, necrosis and autophagy in human prostate PC-3 and LNCaP cancer cells. In search of potential mechanisms of γTE-provoked effects, we found that γTE treatment led to marked increase of intracellular dihydroceramide and dihydrosphingosine, the sphingolipid intermediates in de novo sphingolipid synthesis pathway, but had no effects on ceramide or sphingosine. The elevation of these sphingolipids by γTE preceded or coincided with biochemical and morphological signs of cell death and was much more pronounced than that induced by γT, which accompanied with much higher cellular uptake of γTE than γT. The importance of sphingolipid accumulation in γTE-caused fatality was underscored by the observation that dihydrosphingosine and dihydroceramide potently reduced the viability of both prostate cell lines or LNCaP cells, respectively. In addition, myriosin, a specific inhibitor of de novo sphingolipid synthesis, counteracted γTE-induced cell death. In agreement with these cell-based studies, γTE inhibited LNCaP xenograft growth by 53% (P<0.05), compared with 33% (P = 0.07) by γT, in nude mice. These findings provide a molecular basis of γTE-stimulated cancer-cell death and support the notion that elevation of intracellular dihydroceramide and dihydrosphingosine is likely a novel anticancer mechanism.
sphingolipids; vitamin E; tocopherol; autophagy; apoptosis
Acheron (Achn) is a new member of the Lupus Antigen family of RNA binding proteins. Previous studies have shown that Achn controls developmental decisions in neurons and muscle. In the human mammary gland, Achn expression is restricted to ductal myoepithelial cells. Microarray analysis and immunohistochemistry have shown that Achn expression is elevated in some basal-like ductal carcinomas. To study the possible role of Achn in breast cancer, we engineered human MDA-MB-231 cells to stably express enhanced green fluorescent protein-tagged wild-type Achn (AchnWT), as well as Achn lacking either its nuclear localization signal (AchnNLS) or its nuclear export signal (AchnNES). In in vitro assays, AchnWT and AchnNES, but not AchnNLS, enhanced cell proliferation, lamellipodia formation, and invasive activity and drove expression of the elevated expression of the metastasis-associated proteins MMP-9 and VEGF. To determine if Achn could alter the behavior of human breast cancer cells in vivo, Achn-engineered MDA-MB-231 cells were injected into athymic SCID/Beige mice. AchnWT and AchnNES-expressing tumors displayed enhanced angiogenesis and an approximately five-fold increase in tumor size relative to either control cells or those expressing AchnNLS. These data suggest that Achn enhances human breast tumor growth and vascularization, and that this activity is dependent on nuclear localization.
invasion; metastasis; VEGF; MDA-MB-231 cells; xenograft; MMP9