Inflammatory potential of diet and risk of mortality in normal-weight adults with central obesity.

BACKGROUND & AIMS: Inflammatory potential of diet may contribute to poor health outcomes in individuals with metabolic disorders. In a representative sample of the U.S. population, we investigated the association between consuming a pro-inflammatory diet and mortality risk in adults with normal range of body mass index (BMI) but with central obesity. METHODS: This prospective cohort study included 3521 adults 20-90 years of age with normal BMI who participated in the National Health and Nutrition Examination Survey III, 1988-1994 and did not have a history of cardiovascular disease (CVD) or cancer and did not change their dietary intake in the year preceding baseline measurements. Mortality from all causes, CVD, and cancer was ascertained from the National Death Index. Normal-weight central obesity (NWCO, n = 1777) was defined as those with BMI 18.5 to <25 kg/m2 and waist-to-hip ratio (WHR) ≥0.85 in women and ≥0.90 in men. Severe central obesity was defined as WHR ≥0.92 in women and ≥1.00 in men. The dietary inflammatory index (DII®) was computed based on baseline dietary intake using 24-h dietary recalls, and associations with mortality were estimated using multivariable Cox proportional hazards regression. RESULTS: In individuals with NWCO, DII score (i.e., more pro-inflammatory diet) was associated with increased risk of CVD mortality (HRT3 vs T1, 1.89 [95% CI, 1.01-3.53], P trend = 0.04; HR 1 SD increase 1.29 [95% CI, 1.06-1.57]). This association was stronger with more severe central obesity (HRT3 vs T1, 2.79 [95% CI, 1.10-7.03], P trend = 0.03; HR 1 SD increase 1.52 [95% CI, 1.05-2.21]). DII score was not associated with increased risk of mortality in normal-weight individuals without central obesity or with risk of cancer mortality in either group. CONCLUSION: Among individuals in the normal-weight range of BMI, a pro-inflammatory diet assessed by high DII scores was associated with increased risk of CVD mortality in those with central obesity.

Engineered red blood cells carrying PCSK9 inhibitors persistently lower LDL and prevent obesity.

Low plasma levels of Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) are associated with decreased low-density lipoprotein (LDL) cholesterol and a reduced risk of cardiovascular disease. PCSK9 binds to the epidermal growth factor-like repeat A (EGFA) domain of LDL receptors (LDLR), very low-density lipoprotein receptors (VLDLR), apolipoprotein E receptor 2 (ApoER2), and lipoprotein receptor-related protein 1 (LRP1) and accelerates their degradation, thus acting as a key regulator of lipid metabolism. Antibody and RNAi-based PCSK9 inhibitor treatments lower cholesterol and prevent cardiovascular incidents in patients, but their high-cost hampers market penetration. We sought to develop a safe, long-term and one-time solution to treat hyperlipidemia. We created a cDNA encoding a chimeric protein in which the extracellular N- terminus of red blood cells (RBCs) specific glycophorin A was fused to the LDLR EGFA domain and introduced this gene into mouse bone marrow hematopoietic stem and progenitor cells (HSPCs). Following transplantation into irradiated mice, the animals produced RBCs with the EGFA domain (EGFA-GPA RBCs) displayed on their surface. These animals showed significantly reduced plasma PCSK9 (66.5% decrease) and reduced LDL levels (40% decrease) for as long as 12 months post-transplantation. Furthermore, the EGFA- GPA mice remained lean for life and maintained normal body weight under a high-fat diet. Hematopoietic stem cell gene therapy can generate red blood cells expressing an EGFA-glycophorin A chimeric protein as a practical and long-term strategy for treating chronic hyperlipidemia and obesity.

Falsely Elevated 25-Hydroxy-Vitamin D Levels in Patients with Hypercalcemia.

Symptomatic hypercalcemia is a commonly encountered clinical scenario. Though it is important to collect detailed history to find clinical clues connecting to the etiology of hypercalcemia, the diagnostic workup of hypercalcemia depends heavily on laboratory analysis. Accurate measurement of the parathyroid hormone and vitamin D levels is essential. However, commercial laboratory measurement of vitamin D levels can be erroneous in the setting of abundant paraprotein in the serum. One of the most common conditions that can cause an increased amount of paraproteins is multiple myeloma. We report 2 cases of falsely elevated 25-hydroxy-vitamin D levels in patients presenting with hypercalcemia and an underlying diagnosis of MM.

Dietary inflammatory potential and risk of mortality in metabolically healthy and unhealthy phenotypes among overweight and obese adults.

BACKGROUND & AIMS: This study was designed to investigate the association between the dietary inflammatory index (DII®) scores, metabolic phenotypes, and risk of mortality risk in overweight/obese individuals from a representative sample of the U.S. METHODS: Data from 3733 overweight/obese adults (BMI ≥ 25 kg/m2) aged 20-90 years from the National Health and Nutrition Examination Survey III, 1988-1994 were analyzed; these participants were followed for mortality through December 31, 2011. DII scores were computed based on baseline dietary intake using 24-h dietary recalls. Metabolically unhealthy status was defined as having 2 or more of these metabolic abnormalities: high glucose, insulin resistance, elevated blood pressure, triglycerides, C-reactive protein levels, or low high-density lipoprotein-cholesterol values. RESULTS: In metabolically unhealthy overweight/obese (MUO) individuals, DII score was associated with increased risk of all-cause mortality (HRTertile 3 vs Tertile 1 1.44; 95% CI 1.11-1.86 Ptrend = 0.008; HR1SD increase 1.08; 95% CI 0.99-1.18). Additionally, a stronger association with cardiovascular mortality was observed (HRT3 vs T1 3.29; 95% CI 2.01-5.37 Ptrend < 0.001; HR1SD increase 1.40; 95% CI 1.18-1.66), after adjusting for potential confounders. Furthermore, when analyses were restricted to obese individuals (BMI ≥ 30 kg/m2), the association was more pronounced, especially for cardiovascular mortality (HRT3 vs T1 5.55; 95% CI 2.11-14.57 Ptrend = 0.006; HR1SD increase 1.74; 95% CI 1.21-2.50). No association was observed between DII score and risk of mortality in individuals with metabolically healthy overweight/obese (MHO) phenotype, or for cancer mortality in either MHO or MUO phenotype. CONCLUSIONS: A pro-inflammatory diet appears to increase risk of all-cause and cardiovascular mortality in the MUO phenotype, but not among the MHO phenotype.

Genomic characterization of clonal evolution during oropharyngeal carcinogenesis driven by human papillomavirus 16.

Secondary prevention via earlier detection would afford the greatest chance for a cure in premalignant lesions. We investigated the exomic profiles of non-malignant and malignant changes in head and neck squamous cell carcinoma (HNSCC) and the genomic blueprint of human papillomavirus (HPV)-driven carcinogenesis in oropharyngeal squamous cell carcinoma (OPSCC). Whole-exome (WES) and whole-genome (WGS) sequencing were performed on peripheral blood and adjacent non-tumor and tumor specimens obtained from eight Korean HNSCC patients from 2013 to 2015. Next-generation sequencing yielded an average coverage of 94.3× for WES and 35.3× for WGS. In comparative genomic analysis of non-tumor and tumor tissue pairs, we were unable to identify common cancer-associated early mutations and copy number alterations (CNA) except in one pair. Interestingly, in this case, we observed that non-tumor tonsillar crypts adjacent to HPV-positive OPSCC appeared normal under a microscope; however, this tissue also showed weak p16 expression. WGS revealed the infection and integration of high-risk type HPV16 in this tissue as well as in the matched tumor. Furthermore, WES identified shared and tumor-specific genomic alterations for this pair. Clonal analysis enabled us to infer the process by which this transitional crypt epithelium (TrCE) evolved into a tumor; this evolution was accompanied by the subsequent accumulation of genomic alterations, including an ERBB3 mutation and large-scale CNAs, such as 3q27-qter amplification and 9p deletion. We suggest that HPV16-driven OPSCC carcinogenesis is a stepwise evolutionary process that is consistent with a multistep carcinogenesis model. Our results highlight the carcinogenic changes driven by HPV16 infection and provide a basis for the secondary prevention of OPSCC. [BMB Reports 2018; 51(11): 584-589].

Prostate stem cell antigen mRNA in blood is a predictor of survival after radical prostatectomy in patients with high-risk prostate cancer.

OBJECTIVES: To investigate whether the preoperative detection of prostate stem cell antigen (PSCA) mRNA in blood has predictive value for biochemical recurrence, overall survival, and cancer-specific survival after radical prostatectomy in patients with high-risk prostate cancer. RESULTS: Median age was 67 years (interquartile range: 63-71), and median follow-up was 41 months (interquartile range: 25-65). PSCA mRNA was detected in 151 patients (51.1%). Biochemical recurrence was developed in 101 patients (34.2%), and all-cause mortality and prostate cancer-specific mortality occurred in 17 (5.7%) and 8 (2.7%) patients, respectively. Kaplan-Meier analysis revealed significant differences in biochemical recurrence, overall survival, and cancer-specific survival according to PSCA mRNA positivity. Cox regression hazards model analysis showed that PSCA mRNA positivity was an independent predictor of biochemical recurrence, overall survival, and cancer-specific survival. CONCLUSIONS: PSCA mRNA in the peripheral blood was related to poor prognosis. Detection of PSCA mRNA by polymerase chain reaction in peripheral blood can be used to predict survival after radical prostatectomy in patients with high-risk prostate cancer. Future study with larger cohort and long-term follow-up is required to confirm this finding. MATERIALS AND METHODS: A total of 295 patients with high-risk prostate cancer scheduled to undergo radical prostatectomy were prospectively enrolled from 2008 to 2016. Nested reverse transcription polymerase chain reaction was used to detect cells with PSCA mRNA in peripheral blood. The predicting ability of PSCA mRNA positivity for biochemical recurrence, overall survival, and cancer-specific survival after radical prostatectomy was evaluated.

Ad5/35E1aPSESE4: A novel approach to marking circulating prostate tumor cells with a replication competent adenovirus controlled by PSA/PSMA transcription regulatory elements.

Circulating tumor cells serve as useful biomarkers with which to identify disease status associated with survival, metastasis and drug sensitivity. Here, we established a novel application for detecting PSA/PSMA-positive prostate cancer cells circulating in peripheral blood employing an adenovirus called Ad5/35E1aPSESE4. Ad5/35E1aPSESE4 utilized PSES, a chimeric enhancer derived from PSA/PSMA promoters that is highly active with and without androgen. A fluorescence signal mediated by GFP expression upon Ad5/35E1aPSESE4 infection was selectively amplified in PSA/PSMA-positive prostate cancer cells in vitro and ex vivo. Furthermore, for the in vivo model, blood drawn from TRAMP was tested for CTCs with Ad5/35E1aPSESE4 infection and was positive for CTCs at week 16. Validation was performed on patient blood at various clinical stages and found out 1-100 CTCs expressing GFP upon Ad5/35E1aPSESE4 infection. Interestingly, CTC from one patient was confirmed to be sensitive to docetaxel chemotherapeutic reagent and to abundantly express metastasis-related genes like MMP9, Cofilin1, and FCER1G through RNA-seq. Our study established that the usage of Ad5/35E1aPSESE4 is effective in marking PSA/PSMA-positive prostate cancer cells in patient blood to improve the efficacy of utilizing CTCs as a biomarker.

Genomic Copy Number Variations Characterize the Prognosis of Both P16-Positive and P16-Negative Oropharyngeal Squamous Cell Carcinoma After Curative Resection.

Recently increasing high-risk HPV+ OSCC exhibits unique clinical and molecular characteristics compared to HPV-unrelated (HPV-) counterpart. Genomic copy number variations (CNVs), unique in HPV+ OSCCs, and their role for the prognosis prediction remains poorly studied. Here, we analyzed the distinct genomic copy number variations (CNVs) in human papillomavirus-related (HPV+) oropharyngeal squamous cell carcinoma (OSCC) and their role as a prognosticator after curative resection. For 58 consecutive, Korean OSCC patients that underwent surgery-based treatment with median 10 years of follow-up, HPV-related markers, and genome-wide CNV analysis were analyzed. Clinical associations between the CNV profile and survival analyses were followed. p16 expression predicted the overall survival (OS) (hazard ratio [HR] = 0.27, confidence interval [CI]: 0.39-0.80, P = 0.0006) better than HPV L1 PCR (HR = 0.83, CI: 0.66-1.29, P = 0.64), smoking, or other variables. Although the overall number of CNVs was not significantly different, 30 loci showed unique CNV patterns between the p16+ and p16- groups. A region containing PRDM2 was amplified only in the p16+ group, whereas EGFR and 11q13.3 showed increased amplification in p16- counterpart. Loss of a locus containing FGF18 led to a worse, but gain of region including CDK10 and RAD18 led to better overall survival (OS) in all OSCC patients. Meanwhile, subgroup analysis of p16+ OSCC revealed that amplification of regions harboring HRAS and loss of locus bearing KDR led to better OS. p16+ OSCC exhibit distinct CNV patterns compared with p16- counterpart. Specific patterns of CNVs predict better survival, especially in p16+ OSCC. This might allow better insights of the outcome after curative resection for HPV+ and HPV- OSCC.

The Quantified Level of Circulating Prostate Stem Cell Antigen mRNA relative to GAPDH Level Is a Clinically Significant Indictor for Predicting Biochemical Recurrence in Prostate Cancer Patients after Radical Prostatectomy.

The study quantified the relative absolute PSCA level in relation to the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) level in the peripheral blood of 478 hormone-naive prostate cancer (PC) patients who underwent radical prostatectomy from 2005 to 2012 and evaluated its prognostic significance as a risk factor for predicting biochemical recurrence (BCR), compared to known parameters. Nested real-time polymerase chain reaction (RT-PCR) and gel electrophoresis detected PSCA levels and measured the PSCA/GAPDH ratio. Clinicopathological data from the institutional database were examined to determine the adequate cut-off level to predict postoperative BCR. A total of 110 patients had a positive PSCA result (23.0%) via RT-PCR (mean blood ratio 1.1 ± 0.4). The BCR was significantly higher in the PSCA-positive detection group (p = 0.009). A multivariate model was created to show that a PSCA/GAPDH ratio between 1.0 and 1.5 (HR 12.722), clinical T2c stage (HR 0.104), preoperative PSA (HR 1.225), extraprostatic capsule extension (HR 0.006), lymph node dissection (HR 16.437), and positive resection margin (HR 27.453) were significant predictive factors for BCR (p < 0.05). The study showed successful quantification of PSCA with its significance for BCR-related risk factor; however, further studies are needed to confirm its clinical predictive value.

Human papillomavirus-related cell cycle markers can predict survival outcomes following a transoral lateral oropharyngectomy for tonsillar squamous cell carcinoma.

OBJECTIVES: To identify the prognostic implications of human papillomavirus (HPV)-related cell cycle marker profiles in patients who have received a transoral lateral oropharyngectomy (TLO) as a primary treatment for tonsillar squamous cell carcinoma (TSCC). PATIENTS AND METHODS: Immunohistochemical profiles of HPV-related cell cycle markers, including p16, pRb, cyclin D1, p53, and the HPV DNA status of 42 consecutive TSCC patients who underwent TLO-based treatments were analyzed. The prognostic value of each marker was evaluated. RESULTS: Univariate analysis indicated that high p16, low pRb, and low p53 expression levels are significantly associated with a good disease-free and overall survival outcome. Clinicopathological parameters and the HPV DNA status did not show prognostic significance. When adjusted for age, overall stage and treatment strategy, a high p16 and low pRb level remained an effective prognostic marker for good survival outcomes. A high p16/low pRb combination showed superior survival prediction ability over high p16 or low pRb alone. CONCLUSION: HPV-related cell cycle markers may also be good indicators for predicting survival after TLO for TSCC. The de-escalation TLO surgery approach would be more effective if performed under the stringent guidance of these markers.

Human papillomavirus in oropharyngeal squamous cell carcinomas in Korea: use of G1 cycle markers as new prognosticators.

BACKGROUND: Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (SCC) exhibits distinct patterns worldwide, but its prevalence has not been extensively evaluated in Korea. The E7 oncogene-mediated carcinogenesis and its meaning are yet to be uncovered for oropharyngeal SCCs. METHODS: In a Korean oropharyngeal SCC cohort, epidemiological indicators, HPV, and G1 cell cycle marker expressions were correlated with survival. RESULTS: Among 93 surgically treated patients with oropharyngeal SCCs, 49.5% were HPV+, which were significantly younger, and predominantly nonsmoking. They demonstrated better survival than HPV- (94% vs 60%). Patients who were HPV+ with oropharyngeal SCCs expressed higher p16, cyclin-dependent kinase 4 (cdk4), and lower pRb. The p16 (hazard ratio [HR] 2.39), pRb (HR 2.13), and CCND1 (HR 2.09) correlated with survival. Notably, combined markers like p16/cdk4 ratio (HR 2.47) and cdk4+CCND1 sum (HR 2.65) were more significantly correlated. CONCLUSION: Incidence of HPV-related oropharyngeal SCC in Korea is similar to U.S.-European data. HPV presence correlates with improved survival. Expression ratios of G1 markers may predict survival of oropharyngeal SCCs better than each marker alone.

Prostate specific membrane antigen mRNA in blood as a potential predictor of biochemical recurrence after radical prostatectomy.

We investigated whether the detection of prostate specific membrane antigen (PSMA) in blood preoperatively has predictive value for biochemical recurrence (BCR) after radical prostatectomy in patients with prostate cancer. All 134 patients scheduled to receive radical prostatectomy for prostate cancer were prospectively enrolled. The authors used nested reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect PSMA mRNA-bearing cells in peripheral blood, and analyzed the ability of PSMA mRNA positivity to predict BCR after surgery. PSMA-mRNA was detected in 24 (17.9%) patients by RT-PCR. Over a median follow-up of 20 months (range, 3 to 46 months), BCR developed in 15 patients (11.2%) and median time to BCR was 7 months (range, 3 to 25 months). Kaplan-Meier analysis revealed a significant difference between those positive or negative for PSMA in terms of recurrence-free actuarial probability (log rank P=0.0039). Multivariate analysis showed that positivity for PSMA mRNA (HR: 3.697, 95% CI 1.285-10.634, P=0.015) and a biopsy Gleason score of >or=7 (HR: 4.500, 95% CI 1.419-14.274, P=0.011) were independent preoperative predictors of BCR. The presence of PSMA mRNA in peripheral blood can be used to predict BCR after radical prostatectomy.

Alpha-tocopheryl succinate potentiates the paclitaxel-induced apoptosis through enforced caspase 8 activation in human H460 lung cancer cells.

Paclitaxel is one of the chemotherapeutic drugs widely used for the treatment of nonsmall cell lung cancer (NSCLC) patients. Here, we tested the ability of alpha-tocopheryl succinate (TOS), another promising anticancer agent, to enhance the paclitaxel response in NSCLC cells. We found that sub-apoptotic doses of TOS greatly enhanced paclitaxel-induced growth suppression and apoptosis in the human H460 NSCLC cell lines. Our data revealed that this was accounted for primarily by an augmented cleavage of poly(ADP-ribose) polymerase (PARP) and enhanced activation of caspase-8. Pretreatment with z-VAD-FMK (a pan-caspase inhibitor) or z-IETD-FMK (a caspase-8 inhibitor) blocked TOS/paclitaxel cotreatment-induced PARP cleavage and apoptosis, suggesting that TOS potentiates the paclitaxel-induced apoptosis through enforced caspase 8 activation in H460 cells. Furthermore, the growth suppression effect of TOS/paclitaxel combination on human H460, A549 and H358 NSCLC cell lines were synergistic. Our observations indicate that combination of paclitaxel and TOS may offer a novel therapeutic strategy for improving paclitaxel drug efficacy in NSCLC patient therapy as well as for potentially lowering the toxic side effects of paclitaxel through reduced drug dosage.

Effect of butyrate on the heregulin/ErbB-mediated proliferation of human colorectal cancer cells.

The expression of ErbB proteins, together with heregulin, was found to be increased in colon cancer cells compared with normal mucosa, and heregulin-stimulated activation of ErbB signaling was observed to contribute to the proliferation of colon cancer cells. Butyrate produced during the fermentation of fiber by intestinal bacteria is known to exert diverse anticancer effects, including the induction of differentiation, cell cycle arrest and growth suppression in human colon cancer cells. In this study, we investigated whether butyrate affects the heregulin/ErbB-mediated proliferation of colon cancer cells. The growth of human CaCo-2 and SNU-C4 colon cancer cells, which express ErbB1-4 proteins, was stimulated by heregulin in a concentration-dependent manner. Pretreatment with sodium butyrate abolished heregulin-stimulated proliferation in both cell lines. Although butyrate did not alter ErbB protein expression and activation, it did block the prolonged activation of Akt and Erk1/2, which are known to be important ErbB downstream molecules mediating heregulin-stimulated proliferation. Our data suggest that the inhibitory effects of butyrate on the heregulin-stimulated proliferation of colorectal cancer cells are, in part, associated with the suppression of the Akt and Erk signaling pathway. Butyrate may act as a preventive and therapeutic agent in the progression of colorectal cancer through the regulation of heregulin-stimulated mitogenic signaling.

Alpha-tocopheryl succinate sensitizes human colon cancer cells to exisulind-induced apoptosis.

Sulindac sulfone (also known as exisulind) and its chemical derivatives are promising anticancer agents capable of inducing apoptosis in a variety of malignant cell types with minimal toxicity to normal cells. Here, we tested the ability of alpha-tocopheryl succinate (TOS), another promising anticancer agent, to sensitize colon cancer cells to exisulind-induced apoptosis. We found that sub-apoptotic doses of TOS greatly enhanced exisulind-induced growth suppression and apoptosis in the HCT116, LoVo and SNU-C4 human colon cancer cell lines. Our results revealed that this was accounted for primarily by an augmented cleavage of poly(ADP-ribose) polymerase (PARP) and enhanced activation of caspase-8, -9 and -3. Pretreatment with z-VAD-FMK (a pan-caspase inhibitor), z-IETD-FMK (a caspase-8 inhibitor) or z-LEHD-FMK (a caspase-9 inhibitor) blocked TOS and exisulind cotreatment-induced PARP cleavage and apoptosis. Furthermore, TOS/exisulind cotreatment induced JNK phosphorylation, while pretreatment with SP600151 (a JNK inhibitor) partially blocked cotreatment-induced caspase-dependent PARP cleavage and apoptosis. Taken together, these findings indicate that TOS sensitizes human colon cancer cells to exisulind-induced apoptosis. Apoptotic synergy induced by exisulind plus TOS seems likely to be mediated through a mechanism involving activation of caspases and JNK.

Role of p21CIP1 as a determinant of SC-560 response in human HCT116 colon carcinoma cells.

SC-560, a structural analogue of celecoxib, induces growth inhibition in a wide range of human cancer cells in a cyclooxygenase (COX)-independent manner. Since SC-560 suppresses the growth of cancer cells mainly by inducing cell cycle arrest, we sought to examine the role of p21CIP1, a cell cycle regulator protein, in the cellular response against SC-560 by using p21(+/+) and p21(-/-) isogenic HCT116 colon carcinoma cells. In HCT116 (p21(+/+)) cells, SC-560 dose-dependently induced growth inhibition and cell cycle arrest at the G1 phase without significant apoptosis induction. SC-560-induced cell cycle arrest was accompanied by upregulation of p21CIP1. However, the extent of SC-560-induced accumulation at the G1 phase was approximately equal in the p21(+/+) and the p21(-/-) cells. Nonetheless, the growth inhibition by SC-560 was increased in p21(-/-) cells than p21(+/+)cells. SC-560-induced reactive oxygen species (ROS) generation did not differ between p21(+/+) and p21(-/-) cells but the subsequent activation of apoptotic caspase cascade was more pronounced in p21(-/-) cells compared with p21(+/+) cells. These results suggest that p21CIP1 blocks the SC-560-induced apoptotic response of HCT116 cells. SC-560 combined with other therapy that can block p21 CIP1 expression or function may contribute to the effective treatment of colon cancer.

Alpha-tocopheryl succinate, in contrast to alpha-tocopherol and alpha-tocopheryl acetate, inhibits prostaglandin E2 production in human lung epithelial cells.

The production of prostaglandin E2 (PGE2), a key proinflammatory mediator, is regulated by the availability of its substrate, arachidonic acid (AA), and the activity of the enzyme cyclooxygenase (COX). Increased PGE2 production and COX-2 expression have been observed frequently in specimens from lung cancer patients. Agents that decrease PGE2 production may prevent the initiation and progression of lung cancer. We, therefore, tested the effects of alpha-tocopherol (alphaTOL) analogs on PGE2 production in human lung epithelial cells. Alpha-tocopheryl succinate (alphaTOS), but not alphaTOL or alpha-tocopheryl acetate (alphaTOA), inhibited the phorbol 12-myristate 13-acetate (PMA)-stimulated PGE2 production in three human lung epithelial cell lines (BEAS-2B, H460 and A549 cells). The effect of these compounds on PGE2 production was not correlated with their antioxidant activities, since alphaTOS alone did not inhibit PMA-induced generation of reactive oxygen species. alphaTOS had no effect on PMA-induced AA release or COX-2 expression, although post-incubation with alphaTOS inhibited COX activity and prostaglandin (PGE2 and PGF(2alpha)) production in PMA-stimulated cells. alphaTOS also blocked the COX activity in A549 cells with endogenous high levels of COX enzymes in the absence of PMA stimulation. In addition, the ability of alphaTOS to inhibit COX was affected by AA concentration, suggesting that alphaTOS may compete with AA for interaction with COX proteins. These results suggest that alphaTOS inhibits COX activity, thereby inhibiting PGE2 production in human lung epithelial cells, despite the lack of antioxidant activity. Administration of alphaTOS may block inflammatory responses mediated by PGE2, thereby inhibiting the initiation and progression of lung cancer.

5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole acts in a reactive oxygen species-dependent manner to suppress human lung cancer growth.

PURPOSE: 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-trifluoromethylpyrazole (SC-560) is a structural analog of celecoxib. Recent studies suggested that SC-560 inhibits the in vivo proliferation of colon and breast cancer cells to an extent similar to that observed in celecoxib, and that SC-560 exerts their growth inhibitory effects in a cyclooxygenase-independent manner. METHODS: In the current study, we sought to investigate the mechanism by which SC-560 inhibits the growth of human lung cancer cells. RESULTS: SC-560 more potently inhibited the growth of human A549, H460, and H358 lung cancer cell lines compared with that of human BEAS-2B normal bronchial epithelial cells. SC-560-induced growth inhibition was mainly due to the induction of cell-cycle arrest at the G1 phase without apoptosis induction. SC-560 rapidly and dose-dependently induced the generation of reactive oxygen species (ROS), followed by accumulation of cells at the G1 phase. Antioxidant pretreatment blocked the cell-cycle arrest and growth inhibition induced by SC-560. Combination treatment with other ROS-inducing agents such as alpha-tocopheryl succinate (TOS) augmented cellular response against SC-560, leading to synergistic apoptosis induction and growth suppression. Our data also showed that the apoptosis induced by combination treatment with SC-560 and TOS was mediated through ROS-dependent caspase activation. CONCLUSION: Collectively, our results demonstrate that SC-560 acts in a ROS-dependent manner to induce growth suppression in human lung cancer cells.