Reduced BCL2 and CCND1 mRNA expression in human cervical cancer HeLa cells treated with a combination of everolimus and paclitaxel.

AIM OF THE STUDY: Cervical cancer is the second most common malignancy in women worldwide. Everolimus displays direct effects on growth and proliferation of cancer cells via inhibition of mammalian target of rapamycin (mTOR) protein, which is known to be associated with drug resistance. In this study, we aimed to investigate the effects of everolimus, gemcitabine, and paclitaxel in terms of cell viability and mRNA expression levels of GRP78, CCND1, CASP2, and BCL2 genes. MATERIAL AND METHODS: HeLa cells were treated with different doses of everolimus, gemcitabine, and paclitaxel. Cell viability was assessed using MTT assay, and obtained dose response curves were used for the calculations of inhibitory concentration (IC) values. At the end of the treatment times with selected doses, RNA isolation and cDNA synthesis were performed. Finally, GRP78, CCND1, CASP2, and BCL2 genes mRNA expression levels were analysed using quantitative PCR. RESULTS: The IC50 value of everolimus was 0.9 µM for 24-hour treatment. Moreover, the IC50 value of gemcitabine and paclitaxel was found to be around 18.1 µM and 7.08 µM, respectively. Everolimus, gemcitabine, and paclitaxel treatments alone did not change the GRP78, CCND1, BCL2 and CASP2 mRNA expression levels significantly. However, combined treatment of everolimus and paclitaxel significantly reduced BCL2 and CCND1 mRNA expression (p < 0.05). In contrast, this combination did not change GRP78 and CASP2 mRNA expression levels (p > 0.05). CONCLUSIONS: Down-regulation of CCND1 and BCL2 expression may be an important mechanism by which everolimus increases the therapeutic window of paclitaxel in cervical cancers.

Evaluation of the effects of the flavonoid apigenin on apoptotic pathway gene expression on the colon cancer cell line (HT29).

Apigenin (4',5,7-trihydroxyflavone) is one of the leading components supporting targeted treatment options. We explored the cytotoxic and apoptotic effects of various doses of apigenin administered alone and together with 5-fluorouracil (5-FU)-a chemotherapeutic agent with high cytotoxicity-for different incubation periods, on morphologic, DNA, RNA (messenger RNA [mRNA]), and protein levels on the p53 mutant HT29 human colon adenocarcinoma cell line. Treatment with apigenin alone for a 72-hour incubation at 90-µM dose resulted in an apoptotic percentage of 24.92% (P=.001). A higher percentage (29.13%) was observed after treatment with the same dose of apigenin plus 5-FU for the same incubation period (P=.001). These results were confirmed as mRNA and protein expression levels of caspase-3 increased 2.567-fold and mRNA expression levels of caspase-8 increased 3.689-fold compared with the control group. On the other hand, mRNA expression levels of mammalian target of rapamycin (mTOR) and cyclin D1 (CCND1) decreased by 0.423-fold and 0.231-fold, respectively. To our knowledge this is the first study showing that treatment with apigenin alone results in cell cycle arrest through activation of caspase cascade and stimulation of apoptosis in HT29 cells. It also shows that use of apigenin plus 5-FU further increases this effect. This study draws attention to the probable clinical effectiveness of apigenin plus a chemotherapeutic agent with high cytotoxicity. It also highlights the induction of desirable apoptotic effects by targeting the caspase cascade pathway through administration of reduced doses for shorter incubation periods.

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.

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.