Effects of thiostrepton alone or in combination with selumetinib on triple-negative breast cancer metastasis

OBJECTIVE

FoxM1 transcription factor contributes to tumor metastasis and poor prognosis in many cancers including triple-negative breast cancer (TNBC). In this study, we examined the effects of FoxM1 inhibitor Thiostrepton (THIO) alone or in combination with MEK inhibitor Selumetinib (SEL) on metastatic parameters in vitro and in vivo.

METHODS

Cell viability was determined by MTT assay. Immunoblotting and immunohistochemistry was used to assess metastasis-related protein expressions in 4T1 cells and its allograft tumor model in BALB/c mice. In vivo uPA activity was determined by enzymatic methods.

RESULTS

Both inhibitors were effective on the expressions of FoxM1, ERK, p-ERK, Twist, E-cadherin, and Vimentin alone or in combination in vitro. THIO significantly decreased 4T1 cell migration and changed the cell morphology from mesenchymal-like to epithelial-like structure. THIO was more effective than in combination with SEL in terms of metastatic protein expressions in vivo. THIO alone significantly inhibited mean tumor growth, decreased lung metastasis rate and tumor foci, however, no significant changes in these parameters were observed in the combined group. Immunohistochemically, FoxM1 expression intensity was decreased with THIO and its combination with SEL in the tumors.

CONCLUSIONS

This study suggests that inhibiting FoxM1 as a single target is more effective than combined treatment with MEK in theTNBC allograft model. The therapeutic efficacy of THIO should be investigated with further studies on appropriate drug delivery systems.

Correction to: Comparison of 2D vena contracta area with 3D planimetric mitral valve area in rheumatoid mitral valve disease

In the original publication of the article one co-author, A. Zencirci, was listed by mistake. Dr. A. Zencirci has not contributed to this article and therefore, the author list has been updated. The author name A. Zencirci has been removed. All authors have agreed to the updated author list.

Flavopiridol's effects on metastasis in KRAS mutant lung adenocarcinoma cells

BACKGROUND

There is still no clinically approved agent for mutant KRAS, which is the most common alteration in non-small-cell lung cancer (NSCLC). Flavopiridol is a semisynthetic flavonoid that inhibits cell growth through cyclin-dependent kinases in G1/S or G2/M of the cell cycle and induces apoptosis. In this study, we evaluated its effect on cellular apoptosis, survival, and metastasis mechanisms on KRAS mutant A549, Calu-1, and H2009 cell lines.

METHODS

The cytotoxic effects of flavopiridol on NSCLC cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability test. The cells were treated with 200 and 400 nM flavopiridol, and, then, apoptosis, survival, and metastasis-related protein expressions were determined by Western blot analysis. The antimetastatic effects of flavopiridol were assessed by wound healing and Galectin-3 activity assay.

RESULTS

Flavopiridol drastically affected toxicity in all KRAS mutant NSCLC cells at nanomolar concentrations. Also, it could efficiently inhibit wound healing and Galectin-3 activity in all the cells tested. However, the metastasis-related protein expressions did not reflect these obvious effects on blotting. p-Erk was activated as a cellular survival mechanism to escape apoptosis in all the cells tested.

CONCLUSION

Although there are many mechanisms that still need to be elucidated, flavopiridol can be used as a metastasis inhibitor and an apoptosis inducer in KRAS mutant NSCLC.

Flavopiridol's antiproliferative effects in glioblastoma multiforme

AIM OF STUDY

Glioblastoma multiforme (GBM) is largely refractory to surgical operation, radiotherapy, and chemotherapy in use today. Remaining lifetime accounting for the GBM-affected patients varies between 12 and 16 months generally. The most frequently altered genes in GBM are p53, epidermal growth factor receptor, PTEN, and cyclin-dependent kinase inhibitor 2A. Our aim is to investigate the antiproliferative and apoptotic effects of flavopiridol, a cyclin-dependent kinases and specific phosphokinase inhibitor, on glioblastoma cell lines having different genetic profiles: U87MG, U118MG, and T98G.

MATERIALS AND METHODS

Cell viability and IC50 values were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, protein expressions were determined by Western blot and caspase activities were analyzed by activity kit.

RESULTS

Western blot analysis showed down-regulation of the cyclin D1, c-Myc, and p53 protein activities, and up-regulation of p27KIP1 activity after flavopiridol treatment. Additionally, flavopiridol diminished p-Akt protein levels generally which induces inhibition of proliferation.

CONCLUSION

The present study demonstrated that flavopiridol did not induce caspase-3/7 activation, BIM, and BAX pro-apoptotic proteins but it leads to the expression changes of various proteins that inhibit proliferation and eternity in glioblastoma cell lines which have different genetic alterations.

Influence of influenza vaccination on recurrent hospitalization in patients with heart failure

BACKGROUND

The current study aimed to evaluate the influence of regular annual influenza vaccinations on cardiovascular (CV) death and heart failure-related hospitalizations (HFrH) in stable outpatients with heart failure with reduced ejection fraction.

METHODS

The Turkish research team-HF (TREAT-HF) is a network undertaking multicenter, observational cohort studies in HF. This study is a subgroup analysis of TREAT-HF outpatient cohorts who completed a questionnaire on influenza vaccination status and for whom follow-up data were available. A total of 656 patients with available follow-up data for CV death and HFrH including recurrent hospitalization were included in the study. Patients were classified into two groups: those who received regular influenza vaccination (40 %) and those who did not receive vaccination.

RESULTS

During a mean follow-up of 15 ±6 months, 113 (18 %) patients had CV death and 471 (72 %) patients had at least one HFrH. The CV death rate was similar in both groups of patients (16 vs. 19 %, p = 0.37), whereas, HFrH and recurrent HFrH were significantly less frequently encountered in patients who received regular influenza vaccination than in those who did not receive vaccination (43 vs. 92 % and 16 vs. 66 %, p < 0.001, respectively). In a multivariate Cox proportional hazards model - in addition to a few clinical factors - vaccination status (HR = 0.30, 95 % CI = 0.17-0.51, p < 0.001) and graduation from university (HR = 0.35, 95 % CI = 0.17-0.72, p = 0.004) remained independently associated with the risk of recurrent HFrH.

CONCLUSION

Regular influenza vaccination does not influence CV deaths; however, it decreases HFrH including recurrent episodes of HFrH in outpatients with heart failure with reduced ejection fraction.

HDAC inhibitors, MS-275 and salermide, potentiates the anticancer effect of EF24 in human pancreatic cancer cells

Histone deacetylases (HDACs) play a major role in the regulation of chromatin structure and gene expression by changing acetylation status of histone and non-histone proteins. MS-275 (entinostat, MS) is a well-known benzamide-based HDACI and Salermide (SAL), a reverse amide compound HDACI, have antiproliferative effects on several human cancer cells. In this study, we aimed to investigate the effects of HDACIs (MS and SAL) alone and/or combined use with EF24 (EF), a novel synthetic curcumin analog, on human pancreatic cancer cell line (BxPC-3). In vitro, BxPC-3 cells were exposed to varying concentrations of MS, SAL with or without EF, and their effects on cell viability, acetylated Histone H3 and H4 levels, cytotoxicity, and cleaved caspase 3 levels, and cell cycle distribution were measured. The viability of BxPC-3 cells decreased significantly after treatment with EF, MS and SAL treatments. MS and SAL treatment increased the acetylation of histone H3 and H4 in a dose dependent manner. MS and SAL alone or combined with EF were increased the number of cells in G1 phase. In addition, treatment with agents significantly decreased the ratio of cell in G2/M phase. There were significant dose-dependent increases at cleaved Caspase 3 levels after MS treatment but not after SAL treatment. Our results showed that HDAC inhibitors (MS and SAL), when combined with EF, may effectively reduce pancreatic cancer cell (BxPC-3) progression and stop the cell cycle at G1 phase. Further molecular analyses are needed to understand the fundamental molecular consequences of HDAC inhibition in pancreas cancer cells.

Flavopiridol Induces Apoptosis via Mitochondrial Pathway in B16F10 Murine Melanoma Cells and a Subcutaneous Melanoma Tumor Model

Flavopiridol is a cyclin-dependent kinase (CDK) inhibitor that promotes cell cycle arrest. We aimed to examine the anti-proliferative effects of the flavopiridol and oxaliplatin combination on p16INK4A deficient melanoma cells B16F10 and also its apoptotic effects on a subcutaneously injected B16F10 allograft melanoma tumor model. Flavopiridol and oxaliplatin treated B16F10 cell viability was determined by MTT assay. C57BL6 mice were injected with B16F10 cells and treated with flavopiridol after tumor implantation. BRAF and BCL2L1 mRNA expression levels were measured using reverse transcription-polymerase chain reaction (RT-PCR). Caspase 9 and caspase 3/7 activity were determined by activity assay kits. Proliferating cell nuclear antigen (PCNA) and B-cell lymphoma 2 (BCL-2) protein expression levels were analyzed immunohistochemically. Flavopiridol and oxaliplatin decreased cell death. Flavopiridol enhanced caspase 3/7 and caspase 9 activities in vitro and in vivo in a dose dependent manner via the mitochondrial apoptotic pathway. Even though there was a significant increase in Bcl-2 staining, PCNA staining was decreased in flavopiridol-administered mice. Decreased PCNA expression showed antiproliferative effects of flavopiridol which might be the result of cell-cycle arrest. Flavopiridol can be used as a cell cycle inhibitor.

SOX2 expression is an early event in a murine model of EGFR mutant lung cancer and promotes proliferation of a subset of EGFR mutant lung adenocarcinoma cell lines

OBJECTIVES

Primary and acquired resistance to EGFR TKIs in EGFR mutant lung cancer occurs primarily through secondary mutations in EGFR or Met amplification. Drug resistance can also be mediated by expression of pluripotency transcription factors, such as OCT4, SOX2 and NANOG that decrease terminal differentiation. In this study, we investigated the expression and role of SOX2 in model systems of EGFR mutant tumors.

MATERIALS AND METHODS

Immunoblotting or immunohistochemistry was used to assess expression of pluripotency transcription factors in lungs of transgenic mice or in human NSCLC cell lines. Expression of SOX2 was reduced by shRNA knockdown, and response to erlotinib and cellular proliferation were assessed.

RESULTS AND CONCLUSION

Induction of mutant EGFR in transgenic CCSP-rtTA/TetO-EGFR(L858R/T790M) mice correlated with increased OCT4 and SOX2 expression in lung tissue prior to tumor development. Established lung tumors retained SOX2 expression. To assess a role for SOX2 in tumorigenesis, a panel of NSCLC cell lines with activating EGFR mutations was assessed for SOX2 expression. Two of six cell lines with mutant EGFR showed detectable SOX2 levels, suggesting SOX2 expression did not correlate with EGFR mutation status. To assess the role of SOX2 in these cell lines, HCC827 and H1975 cells were infected with lentivirus containing SOX2 shRNA. Knockdown of SOX2 decreased proliferation in both cell lines and increased sensitivity to erlotinib in HCC827 cells. Because constitutive activation of the PI3K/Akt pathway is associated with EGFR TKI resistance, cells were treated with PI3K/AKT inhibitors and expression of SOX2 was examined. PI3K/Akt inhibitors decreased SOX2 expression in a time-dependent manner. These data suggest targeting SOX2 may provide therapeutic benefit in the subset of EGFR-mutant tumors with high constitutive levels of SOX2, and that until more direct means of inhibiting SOX2 are developed, PI3K/Akt inhibitors might be useful to inhibit SOX2 in EGFR TKI resistant tumors.

Metabolic syndrome and long-term cardiovascular outcomes in NSTEMI with unstable angina

BACKGROUND AND AIM

Metabolic syndrome (MS) is associated with cardiovascular mortality and morbidity in patients with acute coronary syndrome. The purpose of this study was to evaluate the impact of MS on long-term clinical outcomes in patients with pure non-ST segment myocardial infarction (NSTEMI) or unstable angina pectoris (USAP).

METHODS AND RESULTS

We prospectively enrolled 310 consecutive NSTEMI/USAP patients (74 females; mean age, 59.3 ± 11.9 years). The study population was divided into two groups: MS(+) and MS(-). The clinical outcomes of the patients were followed for up to 3 years. Increased 3-year cardiovascular mortality and reinfarction were observed in the MS(+) group, as compared to the MS(-) group (15 vs. 3.4%, p = 0.001, and 22.2 vs. 8.3%, p = 0.001, respectively). Hospitalization rates for heart failure and stroke were not significantly different between the two groups on follow-up. By a Cox multivariate analysis, a significant association was noted between MS and the adjusted risk of 3-year cardiovascular mortality (odds ratio 3.4, 95% confidence interval, 1.24-9.1, p = 0.02).

CONCLUSION

These results suggest that MS is associated with an increased risk of 3-year cardiovascular mortality and reinfarction in patients with NSTEMI/USAP.

Abstract 5255: The comparison between MAPK and PI3K signaling pathway inhibition in KRAS mutant NSCLC cell lines

Introduction: KRAS mutations are found 15-25% of patients with lung adenocarcinoma and they lead to constitutive activation of KRAS signaling pathway that results in sustained cell proliferation. Currently, there are no direct anti-KRAS therapies available. Therefore, it is rational to target the downstream molecules of KRAS signaling pathway. MAPK signaling pathway (RAF-MEK-ERK) and the PI3K pathway (PI3K-AKT-mTOR PI3K/Akt) are the activated pathways by KRAS signaling and crucial for cell survival and proliferation in non-small cell lung cancer (NSCLC). Here, we examined the inhibition of both these pathways combination and alone and analyzed the anti-proliferative and apoptotic events in KRAS mutant NCSLC cell lines, A549 and Calu-1.

Materials and Methods: Cytotoxicity was determined by MTT assay after the cells were treated with LY294002 (PI3K inhibitor), U0126 (MEK inhibitor) and RAD001 (mTOR inhibitor) for 24 hour. The expression levels of p-EGFR, EGFR, p-ERK, ERK, AKT, p-AKT, p53, cyclinD1, c-myc, p27kip1, BAX, BIM and GAPDH were detected by Western blot after 6 and 24 hour treatment.

Results: In proliferation assays, combination of RAD001 (100nM) with U0126 (10uM) and LY294002 (10uM) resulted in higher cytotoxic activity than single agents alone at 24 hour in both cell lines. Western blots revealed that U0126 directly inhibited the phosphorylation of ERK at 6 and 24 hour, followed by inhibiting the activations of its downstream molecules, including cyclinD1 and c-myc but increased the expression of p27kip1, BAX and BIM at 6 and 24 hour. On the other hand, LY294002 downregulated p-AKT signaling only at 6 hour, but not in 24 hour. However, LY294002 and RAD001 combination was effective on cyclinD1 and c-myc expression at 24 hour which can correlate with their cytotoxic effect. Although PI3K/mTOR inhibition is more effective in cytotoxicity, MEK/mTOR inhibition markedly decreases cell proliferation protein marker expressions.

Conclusion: These findings suggest that the combination of MEK and mTOR inhibitors and PI3K and mTOR inhibitors compared with either drug alone can inhibit cell proliferation, induce apoptosis and effect downstream signaling pathways. Also, in molecular level, U0126/RAD001 combination is a better option than LY294002/RAD001 combination in A549 and Calu-1 cells.

Citation Format: Irem Dogan, Ayla Cihan, Abdullah Ekmekci. The comparison between MAPK and PI3K signaling pathway inhibition in KRAS mutant NSCLC cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5255. doi:10.1158/1538-7445.AM2013-5255

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Investigation of ocular neovascularization-related genes and oxidative stress in diabetic rat eye tissues after resveratrol treatment

Changes in vascular endothelial growth factor (VEGF), angiotensin-converting enzyme (ACE), matrix metalloproteinase (MMP)-9, and endothelial nitric oxide synthase (eNOS) mRNA expression profiles and oxidative stress in the eye tissue microenviroment may have important roles in ocular neovascularization and permeability in proliferative diabetic retinopathy. The present study investigated the effects of resveratrol (RSV) treatment on the mRNA expression profile of VEGF, ACE, MMP-9, and eNOS, which are associated with vascular neovascularization, and glutathione, protein carbonyl, and nitrite-nitrate levels, which are markers of oxidative stress in eyes of diabetic rats. Twenty-four Wistar albino male rats were divided into four groups. After diabetes induction with streptozotocin (10 mg/kg/day) RSV was administered to the RSV and diabetes mellitus (DM) + RSV groups for 4 weeks. The mRNA levels were measured by quantitative real-time polymerase chain reaction assay, and biochemical estimations were determined with spectrophotometric assays in eye homogenates. The mRNA expression levels of VEGF, ACE, and MMP-9 were increased in the DM group compared with the control group, and RSV treatment decreased their mRNA levels. Expression of eNOS mRNA was increased in the RSV and DM groups and decreased in the DM + RSV group. Nitrite-nitrate levels and protein carbonyl content were increased and glutathione levels were decreased in the DM group compared with controls. Consequently, these data suggest that RSV suppressed the expression of eNOS, which is actively involved in the inflammation and healing process in chronic diabetes. Although oxidative stress was increased in eye tissue from diabetic rats, mRNA levels of VEGF, MMP-9, and ACE genes associated with vascular remodeling did not change in diabetic eyes.

Polymorphisms in the vitamin D receptor gene and risk of lung cancer

BACKGROUND

Differences between the individual variations in DNA may modulate lung cancer process. Many studies reported that Vitamin D Receptor (VDR) gene polymorphisms may influence the cancer risk due to their antiproliferative, antiangiogenic, antimetastatic and apoptotic effects.

MATERIAL/METHODS

The genotype and haplotype frequencies of three polymorphisms of VDR, i.e. TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232), were studied using PCR-RFLP in 137 patients with lung cancer and 156 controls.

RESULTS

Differences were observed in genotype (P=0.024) and allele (P=0.011) frequencies of TaqI polymorphism due to the "T" allele. Furthermore, compared with the "tt" genotype, the odds ratio for the "TT" genotype increased 2.24 times (95%CI=1.05-4.77, P=0.037). Comparing cases and controls, smoking habit (P=0.012) and gender distribution (P=0.005) were found to increase the risk of lung cancer in patients with "TT" homozygotes, demonstrating the role of gene-environment interaction in lung cancer. In addition, when age and gender within the case group only were evaluated in relation to genotype, the adjusted odds ratios for the "TT" genotype increased 2.20 times (95%CI=1.01-4.78, P=0.047) for age and 2.24 times (95%CI=1.05-4.80, P=0.037) for gender. However, no differences were observed for the distribution of variant genotypes of the BsmI and ApaI polymorphisms (P>0.05). To evaluate the joint effects of these polymorphisms, haplotype analysis was performed which showed that the haplotype baT was associated with higher lung cancer risk compared with the most common haplotype BAt (P=0.026).

CONCLUSIONS

This is perhaps the first study suggesting that TaqI polymorphism of the VDR gene might be a risk factor for lung cancer and that age, gender, and smoking habit could have an impact on lung cancer risk.

Endothelial function and endothelial nitric oxide synthase intron 4a/b polymorphism in primary hyperparathyroidism

BACKGROUND AND AIM

Patients with symptomatic primary hyperparathyroidism (pHT) have increased cardiovascular morbidity and mortality. Endothelial nitric oxide synthase (eNOS) intron 4a/b polymorphism is associated with coronary artery disease and hypertension in various populations. Our aim is to evaluate endothelial function in patients with pHT during pre-operative hypercalcemic and post-operative normocalcemic periods and to determine whether intron 4a/b polymorphism of eNOS gene influences endothelial function.

SUBJECTS AND METHODS

Forty patients with pHT (age 48.48+/-11.64 yr) were examined pre-operatively and reexamined 5.8+/-1.9 months after parathyroidectomy. Forty-three healthy subjects (age 47.13+/-8.14 yr) were served as control group. Endothelial function was determined by flow-mediated dilation of brachial artery (FMD). eNOS4a/b polymorphism was detected by polymerase chain reaction.

RESULTS

FMD was significantly lower in patients pre-operatively compared with controls (8.48+/-1.78% vs 19.49+/-2.34%, p<0.001). FMD improved significantly after parathyroidectomy (16.19+/-2.16%, p<0.001 compared with pre-operative measurements), but was still significantly lower than controls (p<0.001). The distribution of eNOS4a/b genotype frequencies was not significantly different between patients and controls. Logistic regression analysis showed that increased serum calcium (>2.47 mmol/l) and PTH concentrations (>7.75 pmol/l) were significant independent predictors of lower FMD (<16.7%). ENOS4a/b polymorphism did not enter in this model.

CONCLUSION

Impaired endothelial function in patients with pHT improves after successful parathyroid surgery. No compelling data are evident to suggest that eNOS4a/b polymorphism modifies the endothelial function in patients with pHT.

Association of genetic polymorphisms in vitamin D receptor gene and susceptibility to sporadic prostate cancer

Genetic and environmental factors are involved in prostate cancer (PCa) etiology. Single nucleotide polymorphisms (SNPs) may contribute to the PCa pathogenesis. The goal of this study is to determine the role of vitamin D receptor (VDR) gene polymorphisms and haplotypes in the development and progression of sporadic PCa. One hundred and thirty-three PCa patients and 157 age-matched healthy controls were genotyped for the Apa I (rs7975232), Bsm I (rs1544410) and Taq I (rs731236) polymorphisms in VDR gene by using polymerase chain reaction-restriction fragment length polymorphism. An association was observed between the Apa I polymorphism and PCa predisposition (P = 0.03). When compared with AA genotype, there was a highly notable difference in the frequencies of the Aa (P = 0.02), aa (P = 0.026) and Apa I ''a'' allele carriers (Aa + aa) (P = 0.009) genotypes. Furthermore, we found a statistical difference in the allele frequencies of the Apa I polymorphism between the sporadic PCa patients and control subjects (P = 0.013). The genotype distribution for the Bsm I and Taq I polymorphisms were similar between cases and controls (P > 0.05). No clinically significant relationship was found between the three-locus haplotypes and development of sporadic PCa. The genotype frequencies for the three polymorphisms of the VDR gene within subgroups of PCa (defined by tumor stage, Gleason score, PSA levels) were also analyzed, but no statistically noteworthy difference was observed (P > 0.05). As far as we know, this is the first study which investigates the relationship between VDR genotypes and sporadic PCa in the Turkish population. Our findings suggest that the VDR ApaI (rs7975232) polymorphism may play a role in the development of sporadic PCa.

Single nucleotide polymorphisms in the hypoxia-inducible factor-1alpha (HIF-1alpha) gene in human sporadic breast cancer

BACKGROUND

DNA sequence variations in hypoxia-inducible factor-1alpha (HIF-1alpha) gene, which have been demonstrated to be correlated with tumor angiogenesis, may yield changes both in the production outcomes and in the activities of the gene. In this study, we investigated the relationship between three single nucleotide polymorphisms (SNPs) [C1772T and G1790A in exon 12 and C111A in exon 2 of the HIF-1alpha gene] in the HIF-1alpha gene coding regions and development of sporadic breast cancer in the Turkish population. These three polymorphisms result in an amino acid change from proline 582 to serine, from alanine 588 to threonine and from serine 28 to tyrosine, respectively.

METHODS

Genomic DNA was isolated from 102 sporadic breast cancer patients and 102 healthy female controls. All three HIF-1alpha gene regions were amplified by PCR, and genotypes were determined by RFLP and DNA sequencing.

RESULTS

There were no significant differences between patients and controls in terms of the distribution of C1772T and G1790A polymorphisms of HIF-1 gene (p >0.05). As for HIF-1alpha C111A polymorphism, we did not find CA and AA variants of the gene in either controls or patients. Multivariable logistic regression analysis was performed between CC and CT + TT genotypes of C1772T polymorphism. No significant differences were found between these two genotypes in terms of clinicopathological characteristics of the patients including age at enrollment, age at menarche and first delivery, number of full-term pregnancies, body mass index, use of oral contraceptives and postmenopausal hormones, family history of breast and ovarian cancers, menopausal status, histopathological features, oophorectomy, smoking habits, and alcohol consumption (p >0.05).

CONCLUSIONS

Our results suggest that none of the polymorphisms studied in the HIF-1alpha gene influence susceptibility to sporadic breast cancer. The present study is the first case-control study that investigates the association of HIF-1alpha polymorphisms with sporadic breast cancer in the Turkish population.

Apolipoprotein E gene polymorphism in nonalcoholic fatty liver disease

The aim of this study was to evaluate the relationship between apolipoprotein E gene polymorphism and nonalcoholic fatty liver disease. The study group consisted of 237 nonalcoholic fatty liver disease patients who were detected by ultrasonography and 201 controls with ultrasonographically normal livers. DNA amplifications were performed by polymerase chain reaction technique and apolipoprotein E genotypes were evaluated after digestion with CfoI restriction enzyme. Serum levels of glucose, lipids, lipoproteins, and apolipoproteins were measured in all subjects. Additionally, viral hepatitis markers, liver enzymes, and body mass index were assessed. Patients were found to have significantly higher triglyceride, glucose, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyltransferase levels and lower high-density lipoprotein cholesterol and apolipoprotein (a) levels than controls (P<0.05). There were no statistically significant differences in genotypes and allele frequencies between all patients and controls. Comparing nonobese patients with controls, the frequencies of allele epsilon2 and genotype epsilon2epsilon3 were statistically significantly different in the controls (P=0.04 and P=0.01, respectively). In conclusion, occurrence of the epsilon2 allele and epsilon2epsilon3 genotype may be protective against development of nonalcoholic fatty liver disease.

Lack of association between -460 C/T and 936 C/T of the vascular endothelial growth factor and angiopoietin-2 exon 4 G/A polymorphisms and ovarian, cervical, and endometrial cancers

Tumor growth, which employs a number of regulators, requires the formation of new blood vessels. The most important regulators are vascular endothelial growth factor (VEGF) and angiopoietin-2 (ANGPT-2). DNA sequence variations in VEGF and ANGPT-2 genes may lead to altered productions and/or activities of these genes. In this study, we aimed to determine the polymorphic effects of the changes in the VEGF -460 C/T, VEGF 936 C/T, and ANGPT-2 exon 4 G/A, which we perceive as risk factors in the progress and metastasis of cancer, on the gynecologic cancer patients in the Turkish population. Forty-seven ovarian, 32 cervical, and 21 endometrial cancer patients and 106 healthy controls were studied. The genomic DNA was extracted from the whole blood by using DNA extraction techniques. DNA samples were analyzed by polymerase chain reaction and restriction fragment length polymorphism. There were no significant differences between any of the three types of gynecologic cancer patients and controls in terms of the distribution of VEGF -460, VEGF 936, and ANGPT-2 genotypes and alleles (p > 0.05). Odds ratios (ORs) were calculated by logistic regression analysis in comparison with the most common homozygote genotype observed in the studied population. No evidence of a relationship that would constitute a risk factor (p > 0.05) was found between genotype and allele frequencies of patients and controls for VEGF -460, VEGF 936, and ANGPT-2 genes. A multivariable logistic regression analysis with the involvement of covariant factors, such as the history of gynecologic cancer and/or other cancer types in the family, stages of tumor, smoking habits, and existence of other diseases, did not change the results. The present study is the first case-control study of VEGF and ANGPT-2 polymorphisms in relation to ovarian, cervical, and endometrial cancers.

An investigation of relationships between hypoxia-inducible factor-1 alpha gene polymorphisms and ovarian, cervical and endometrial cancers

BACKGROUND

DNA sequence variations in HIF-1 alpha gene might yield changes both in the production outcomes and in the activities of the gene. Overexpression of the HIF-1 alpha subunit, resulting from intratumoral hypoxia and genetic alterations, has been demonstrated in common human cancers and is correlated with tumor angiogenesis and patient mortality. In this study, we aimed to determine how the three single nucleotide polymorphisms (SNPs, C1772T and G1790A exon 12, C111A exon 2) in the HIF-1 alpha gene coding regions affect the ovarian, cervical and endometrial cancer patients in the Turkish population. A study on this relationship has not been conducted to date.

METHOD

102 gynecologic cancer patients and 107 healthy controls were studied. Genotypes of the three polymorphisms were analyzed by PCR-RFLP.

RESULTS

There was no significant difference between ovarian cancer patients and controls in terms of the distribution of C1772T genotypes and alleles (P>0.05). However, there was a highly significant increase in the frequency of both CT 1772 and TT 1772 genotypes in patients with cervical and endometrial cancers compared with healthy controls. In fact, 1772T allele-carriers (CT+TT genotypes) showed an association with the risk of cervical and endometrial cancers compared to the wild type (OR=3.84, 95% CI: 1.65-8.93; OR=7.41, 95% CI: 2.33-23.59, respectively). C1772T polymorphism was not associated with family history concerning gynecologic and/or other cancer types, stages (I-IV) and grades of tumor, smoking habits and existence of other diseases that generate a hypoxic microenvironment even after multivariable logistic regression analysis. As for HIF-1 alpha G1790A genotypes, the frequencies of G alleles were 98% in ovarian patients and 100% in the control group. We found no significant difference in the genotype distribution and allele frequencies between the ovarian patients and healthy control subjects. There were no GA and AA genotypes among the cervical and endometrial cancer patients. As for HIF-1 alpha C111A polymorphism, we did not find CA and AA variants of the gene in controls or in any of the three types of patients.

CONCLUSION

Our results suggest that the C1772T polymorphism of the HIF-1 alpha may be associated with cervical and endometrial cancers.

The Association of 5α-Reductase II (SRD5A2) and 17 Hydroxylase (CYP17) Gene Polymorphisms with Prostate Cancer Patients in The Turkish Population

To date, research has led to the invention of multiple genes and their single nucleotide polymorphisms (SNPs) and environmental factors that influence the prostate cancer (PCa) pathogenesis. Therefore, the genes involved in these pathways are candidates for PCa predisposition. It is thought that polymorphisms of 5alpha-reductase II (SRD5A2) and 17 hydroxylase (CYP17) genes are likely to increase susceptibility. The aim of this study was to investigate the risk association of SRD5A2 and CYP17 gene polymorphisms in the development and progression of PCa in the Turkish population. In this study, 100 PCa patients and 105 healthy controls were studied. SRD5A2 and CYP17 gene polymorphisms were determined by real-time PCR and polymerase chain reaction-restriction length polymorphisms (PCR-RFLP) techniques. First, the AT and TT genotypes of SRD5A2 gene at codon 49 were not observed. Second, there was no significant association between the polymorphisms at codon 89 and the risk of PCa. Third, in the CYP17 gene, the A1A1 genotype is more common (46%) in cases than controls (32.4%). The odds ratios (ORs) of the A1A1 genotype was found at 1.69 (95% confidence interval [CI], 0.77-3.74) compare with the A2A2 genotype. Genotyping results of the SRD5A2 and CYP17 genes were also analyzed in relation to prostate-specific antigen (PSA) levels, Gleason score (GS), and tumor stage, but no statistically significant difference was observed (P > 0.05). Finally, we conclude that there was no evidence of an association between CYP17 (P = 0.134) and SRD5A2 (P = 0.784) polymorphism and PCa risk in the Turkish population.

No association between polymorphism in the vascular endothelial growth factor gene at position -460 and sporadic prostate cancer in the Turkish population

The development and progression of prostate cancer (PCa) has biologically and genetically remained a mystery. A man's risk of developing PCa is influenced by both genetic and environmental factors. Angiogenic cytokines like vascular endothelial growth factor (VEGF) play a pivotal role in tumor angiogenesis. Single nucleotide polymorphisms in angiogenesis-dependent genes affect the sensibility of cancer development and progression. Therefore, we hypothesized a potential association between DNA sequence variations in VEGF -460 gene region and sporadic PCa patients in the Turkish population. 133 sporadic PCa patients and 157 healthy controls were studied. Genotypes were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. The distribution of genotype and allele frequencies of the polymorphism did not yield a statistically significant difference between patients and controls (P>0.05). Furthermore, classification of patients by tumor-lymph nodes-metastasis (TNM), Gleason Scores (GS) and serum prostate-specific antigen (PSA) levels did not show significant differences among the VEGF -460 C>T genotypes (P>0.05). This is the first demonstration showing that the VEGF -460 C>T polymorphism in men is not associated with sporadic PCa in the Turkish population.

Effects of diethylstilbestrol in human lymphocytes in vitro: A dose and time-dependent study on genotoxic, cytotoxic and apoptotic effects

Most of the biological, chemical or physical agents that cause cell death in certain doses and time of exposure may induce either apoptosis or necrosis. This study explores in what ways the genotoxic, cytotoxic and apoptotic effects of diethylstilbestrol (DES), a chemical agent currently used in the treatment of various types of cancer, on the human lymphocytes depend upon the dose and the exposure time. For this purpose, firstly it aims to determine in what dosages and durations of DES treatment, genotoxicity and cytotoxicity in human lymphocytes occur in vitro. Secondly, it explores the effects of DES on sister-chromatid exchanges (SCEs) and apoptosis and their relation with the nitric oxide (NO) levels. Finally, it investigates whether different dosages of DES and duration of treatment with it are correlated with each other. In so doing, we investigated the relationship among the viability, necrosis and apoptosis rates of human lymphocytes which were treated with five different DES concentrations (1, 5, 10, 15 and 20 microM) for 24, 48 and 72 h, DNA fragmentation analysis of these cells, their mean SCE values and NO levels. We concluded that 5 microM DES at 24 h is the most effective dosage that induces typical features of apoptosis in human lymphocytes. Despite the fact that there are many other studies on the effects of DES on the cancer cells, we thought it might be worth looking into the effects of DES on human lymphocytes in vitro. We meant the present study to contribute to the research done in the field of cancer treatment.

An in vitro study of cytotoxic effects of gossypol on human epidermoid larynx carcinoma cell line (HEp-2)

AIM

The study was aimed on an evaluation of the effect of gossypol at concentration of 25-150 microM on the level of apoptosis in the human epidermoid larynx carcinoma cell line, HEp-2, in vitro.

METHODS

To determine the apoptotic effects of gossypol on growth of human epidermoid larynx carcinoma cell lines (HEp-2 cells), morphological evaluation of the cells and DNA fragmentation analysis were used.

RESULTS

6 h incubation of HEp-2 cells with gossypol at concentrations of 50 microM and 75 microM resulted in the increase of apoptosis rate by 26 and 23%, respectively.

CONCLUSION

This preliminary study may constitute a base for in vivo studies of anticancer properties of gossypol.

Detection and Typing of Human Papillomavirus in Non-Small Cell Lung Cancer

BACKGROUND

Lung cancer is the most frequent cause of death in both men and women. Smoking is the greatest risk factor for lung cancer and the relation of human papillomavirus (HPV) infection with lung cancer has been reported. HPV can be detected in small cell lung cancer samples with the methods like in situ hybridization, polymerase chain reaction (PCR), Southern blotting, dot blotting.

OBJECTIVE

We aimed to detect and type HPV infection in non-small cell lung carcinoma tissue samples.

METHODS

Tumor samples from 40 patients were collected during surgery and PCR and restriction fragment length polymorphism (RFLP) were used in order to detect HPV infection in the samples.

RESULTS

Two HPV DNA were detected among 40 of the patients, revealing a low frequency of HPV in the samples.

CONCLUSIONS

HPV can be regarded as an environmental factor in tumor development. There might be a relationship between HPV infection and some non-small cell lung cancers, especially in the smoking group.

Apoptosis and nitric oxide release induced by thalidomide, gossypol and dexamethasone in cultured human chronic myelogenous leukemic K-562 cells

The effects of different dosages of thalidomide, gossypol and dexamethasone on the levels of apoptosis and nitric oxide (NO) production were studied in a human chronic myelogenous leukemic cell line, K-562. Increases in the levels of apoptosis were induced by both 15 and 30 microM of thalidomide but only 15 microM significantly increased NO production. All dosages of gossypol used increased the production of NO and all dosages except 200 microM raised the level of apoptosis. After dexamethasone treatment the level of NO either decreased or stayed constant. Thus, some dosages of thalidomide and gossypol concomitantly raise the levels of apoptosis and NO production, but dexamethasone, though it induced apoptosis, had no significant effect on NO production.

L-arginine and mitomycin C-induced nitric oxide release and apoptosis in human lymphocytes

Nitric oxide (NO) is a free radical that is produced by a number of mammalian cell types from L-arginine and a critical mediator that acts in many tissues to regulate a diverse range of physiological processes. The major metabolic end product for NO is nitrate (NO(3)) and nitrite (NO(2)), which are stable metabolites within tissue, plasma, and urine. Measurements of nitrate and nitrite values reveal alterations in NO production. Endogenously generated or exogenously applied NO causes DNA cleavage by endonuclease activation. We investigated the effect of L-arginine and mitomycin C (MMC) on cultured lymphocytes of healthy individuals. We observed chromosome breaks, apoptotic cells and increased NO levels after L-arginine and MMC addition. In conclusion, our results confirmed that NO may be the cause of apoptotic cell death in L-arginine added lymphocyte culture.

The expression of common fragile sites in peripheral blood lymphocytes of breast and colorectal cancer patients with aphidicolin

The frequency and distribution of aphidicolin induced common fragile sites was evaluated on chromosomes of peripheral blood lymphocytes in 10 breast and 10 colorectal cancer patients, and 10 healthy controls to determine correlation between specific fragile sites and cancer breakpoints. Fifty complete metaphases were screened from each culture and the results were evaluated by Student's t-test. The total number of fragile sites was found as 933 in breast cancer patients, 950 in colorectal cancer patients and 501 in control group. Both the number of aberrations per cell and number of aberrations per damaged cell were significantly higher in the patient groups. These findings indicate that genetic instability in the breast and colorectal cancer patients increased and fragile sites may play a critical role in the pathogenesis of breast and colorectal cancer.

Gossypol induced apoptosis in the human promyelocytic leukemia cell line HL 60

In human promyelocytic leukemia cell line HL60, apoptosis was induced by treatment with gossypol that is an inhibitor of protein kinase C. Gossypol acetic acid was added to HL 60 cells at 50, 100, 150 and 200 microM concentrations for six hours. Morphological features of apoptosis as well as internucleosomal DNA fragmentation were evaluated by light microscope, agarose gel electrophoresis and spectrofluorometric quantitation. Our results indicated that with the effective concentrations of gossypol (50 and 100 microM), apoptosis was induced in HL 60 cells.

In vitro effects of prostaglandin E1 and indomethacin on mitomycin C-induced sister-chromatid exchanges in mitogen-stimulated human lymphocytes

In this study, the individual and combined effects of prostaglandin E1 (PGE1) and Indomethacin on mitomycin C (MMC)-induced SCEs in human lymphocytes was investigated in vitro. All MMC-treated cultures showed a great increase of SCEs (approximately two-fold), indicating its ability to induce mutations. SCE data showed that MMC-induced SCEs were reduced significantly in the presence of PGE1 in pooled analysis of six experiments (60.55% reduction of SCEs at 10(-6) M, 34.13% reduction of SCEs at 10(-9) M). In contrast the presence of indomethacin in the medium during MMC treatment of cells failed to show a significant reduction of SCEs in pooled analysis (21.17%). However, individual analyses revealed only two of six donors with a significant SCE response. Thus, the findings suggest that PGE1 can modify the DNA damaging effect of carcinogens and thereby may prevent the initiation of the carcinogenic process.