Long noncoding RNAs and their possible roles in tumorigenesis and drug resistance in cancer chemotherapy

Cancer is still one of the most important diseases that have a high mortality rate around the world. The management of cancer involves many procedures, which include surgery, radiotherapy, and chemotherapy. Drug resistance in cancer chemotherapy is considered one of the most important problems in clinical oncology. A good understanding of the tumorigenesis process and the mechanisms of developing chemotherapy resistance in cancer cells will help achieve significant advances in cancer treatment protocols. In recent years, there has been an increasing interest in long noncoding RNAs (lncRNAs). LncRNAs are no longer just a transcriptional noise, and many investigations proved their possible roles in regulating mandatory cellular functions. A lot of newly published studies confirmed the implication of lncRNAs in the tumor formation process and the multiple drug resistance in cancer chemotherapy. The main aim of this review is to focus on the lncRNAs' functions in the cell, their possible roles in the tumor formation process, and their roles in the development of chemotherapy resistance in different cancer cells.

Benzimidazolium Salts Bearing Nitrile Moieties: Synthesis, Enzyme Inhibition Profiling, and Molecular Docking Analysis for Carbonic Anhydrase and Acetylcholinesterase

This report presents the synthesis and characterization of a range of benzimidazolium salts featuring 3-cyanopropyl groups on the 1st nitrogen atom and varied alkyl groups on the 3rd nitrogen atom within the benzimidazole structure. Benzimidazolium salts were synthesized by N-alkylation of 1-alkyl benzimidazole with 3-cyanopropyl-bromide. The new salts were characterized by 1 H and 13 C-NMR, FT-IR spectroscopic and elemental analysis techniques. In this study, the enzyme inhibition abilities of seven nitrile substituted benzimidazolium salts were investigated against acetylcholinesterase (AChE) and carbonic anhydrase isoenzymes I and II (hCA I and hCA II). They showed a highly potent inhibition effect on AChE, hCA I and hCA II (Ki values are in the range of 26.71-119.09 nM for AChE, 19.77 to 133.68 nM for hCA I and 13.09 to 266.38 nM for hCA II). Reflecting the binding mode of the synthesized cyanopropyl series, the importance of the 2,3,5,6-tetramethylbenzyl, 3-methylbenzyl and 3-benzyl groups for optimal interactions with target proteins, evaluated by molecular docking studies. At the same time, the docking findings support the inhibition constants (Ki ) values of the related compounds in this study. Potential compounds were also evaluated by their pharmacokinetic properties were predicted.

Superior photo-induced antibacterial/antibiofilm activities of ZnPcs/TiO2 and computational simulation studies

Bacteria can form biofilms on any surface, which causes biofilm-associated infections and bacterial resistance to antibiotics. Thus, it is important to design new-generation non-chemotherapeutic nanoagents for effective antibacterial and antibiofilm strategies. Herein, the effects of the anchoring groups, which are imidazole and carboxylic acid, of zinc phthalocyanines (ZnPcs) sensitized TiO₂ on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated under light-emitting diode (LED) irradiation. The photocatalytic antibacterial activities of ZnPc-1/TiO₂ and ZnPc-2/TiO₂ on the bacterial strains were examined by monitoring the optical density value at 600 nm (OD_600 nm). Glutathione (GSH) oxidation assay was used to measure the reactive oxygen species (ROS) generation activity of the compounds. Bacterial damages were imaged by scanning electron microscopy (SEM). According to our photocatalytic antibacterial mechanism, photogenerated electrons are transferred from Pcs to TiO₂ and then react with O₂, thus creating ROS, which causes damage to bacterial membrane, protein and biofilm destruction as well. Further, computational simulation analysis was used to show the interaction patterns of ZnPc-1 and ZnPc-2 with penicillin binding protein 2a (PBP2a) of S. aureus and FimH lectin protein (PDB:4XO8) of E. coli to elucidate the dark molecular antibacterial mechanism of the compounds. The obtained results from computational studies showed that ZnPc-2 binds firmly through bonds with the 1MWT protein from S. aureus. On the other hand, ZnPc-1 binds firmly through bonds with the 4XO8 protein from E. coli. From combining experimental and computational results, we can conclude that this strategy can be applied to different types of bacterial infections.

Protective effect of myricetin, apigenin, and hesperidin pretreatments on cyclophosphamide-induced immunosuppression

Aim: Major side effects of cyclophosphamide administration are immunosuppression and myelosuppression. The immunomodulatory effects of plant bioactive compounds on chemotherapy drug-induced immunosuppression may have significant effects in cancer treatment. For this reason, we investigated the immunomodulatory effect of myricetin, apigenin, and hesperidin in cyclophosphamide-induced immunosuppression in rats.Methods: In our study, a total of 64 rats were used, and divided into eight equal groups. These groups were: control, cyclophosphamide, cyclophosphamide + myricetin (100 mg/kg), cyclophosphamide + myricetin (200 mg/kg), cyclophosphamide + apigenin (100 mg/kg), cyclophosphamide + apigenin (200 mg/kg), cyclophosphamide + hesperidin (100 mg/kg), and cyclophosphamide + hesperidin (200 mg/kg). Myricetin, apigenin, and hesperidin pretreatments were performed for 14 d, while cyclophosphamide application (200 mg/kg) was performed only on the 4th day of the study. Levels of humoral antibody production, quantitative hemolysis, macrophage phagocytosis, splenic lymphocyte proliferation, and natural killer cell cytotoxicity were determined. In addition, we measured pro-inflammatory cytokines, and followed lipid peroxidation and antioxidant markers and examined the histology of bone marrow, liver and spleen in all groups.Results: During cyclophosphamide treatment, all three phytochemicals increased the levels of humoral antibody production, quantitative hemolysis, macrophage phagocytosis, splenic lymphocyte proliferation, antioxidant markers, and natural killer cell cytotoxicity. Moreover, the agents decreased the levels of pro-inflammatory cytokines and mediators, reduced lipid peroxidation markers, and reduced tissue damage in liver, spleen, and bone marrow.Conclusion: Our study demonstrated that myricetin, apigenin, and hesperidin can reduce the immunosuppressive effect of cyclophosphamide by enhancing both innate and adaptive immune responses, and these compounds may be useful immunomodulatory agents during cancer chemotherapy.

Enzyme activity and genetic polymorphisms in patients with type II diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) has become more and more common and has a high morbidity and mortality rate worldwide. It is a multifactorial chronic disease affected by both genetic and environmental factors.

OBJECTIVES

To evaluate the association between antioxidant enzyme activities and their genetic variations and the level of malondialdehyde (MDA) in type II diabetes patients living in the Adıyaman province in the southeast part of Turkey.

MATERIAL AND METHODS

One hundred patients diagnosed with type II DM (T2DM) and 100 healthy controls were included in the study. Malondialdehyde levels and antioxidant enzyme activities were measured spectrophometrically. DNA isolation was performed and genotyping was carried out using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Our results revealed no significant differences in genotype distributions and allele frequencies of all polymorphisms between groups (p > 0.05). Significantly elevated MDA levels and a significant reduction in catalase (CAT) and paraoxonase (PON) enzyme activities were observed in patients compared to the control group in terms of study groups and genetic variations (p < 0.05). Moreover, CAT activity was reduced in TT genotype in terms of CAT -262 C/T polymorphism in patients (p < 0.05). Paraoxonase activity was observed to be lower in MM genotype in both groups (p < 0.05).

CONCLUSIONS

CAT -262 C/T polymorphism may be one of the factors that lead to severe clinical situation in DM. Our results suggest that TT genotype may be more prone to lipid peroxidation.

Myricetin inhibits angiotensin converting enzyme and induces nitric oxide production in HUVEC cell line

Nitric oxide is known as relaxing factor because it acts as a vasodilator, increases blood flow, and inhibits platelet aggregation and adhesion, on the other hand nitric oxide can modulate cellular and physiological processes to limit oxidative injury, limiting processes such as leukocyte adhesion. As the complete mechanism of myricetin and its cardiovascular benefits is not completely understood, the aim of this study was to investigate the antihypertensive activity of myricetin in human umbilical vein endothelial cell (HUVEC). Angiotensin converting enzyme (ACE) activity, nitric oxide production, reactive oxygen species (ROS) scavenger activity, cellular calcium concentration, and endothelial nitric oxide synthase (eNOS) activity and protein expression was investigated in HUVEC treated with different concentration of myricetin (1-60 µM). Myricetin increased nitric oxide production in HUVEC through decreased ROS levels and increased nitric oxide production and eNOS activation. Activation of eNOS enzyme was achieved by an increase of cellular calcium concentration. At the same examined concentration of myricetin, the activity of ACE was significantly inhibited. These findings indicate that myricetin may be helpful for lowering blood pressure; this could be achieved through dietary intervention or by the production of new antihypertensive treatments from a natural product.

Histopathologic evaluation of Ecballium elaterium applied to nasal mucosa in a rat rhinosinusitis model

This study aimed to evaluate the antimicrobial effects of the medicinal plant Ecballium elaterium, which is topically applied as a traditional medicine for the treatment of rhinosinusitis. Pure and extract forms of E elaterium were applied to the nasal cavity of rats for the treatment of Streptococcus-pneumoniae -induced rhinosinusitis. The nasal mucosa, soft palate, and trachea of the rats were harvested in the first hour, third day, and third week for histopathologic evaluation. This experiment revealed the anti-inflammatory effects of E elaterium and showed that it reduced fibrosis. The anti-inflammatory effect of all forms of E elaterium was found to reach its maximum level on the third day, decreasing by the third week. We also observed that the pure form of E elaterium caused severe epithelium loss in the first hour after application. The mechanism of the anti-inflammatory effect of different levels of extract forms needs to be further analyzed with different doses and duration of treatment.

Effects of silica nanoparticles on isolated rat uterine smooth muscle

In spite of their widespread use, toxicity of silica nanoparticles (SiO₂ NPs) to mammalian has not been extensively investigated. In the present study, it is aimed to investigate the effects and the mechanism of action of 20 nm sized SiO₂ NPs on isolated uterine smooth muscle. A total number of 84 preparations of uterine strips were used in the experiments. Study was designed as four groups: group I (control), group II (0.2 mM SiO₂ NPs), group III (0.4 mM SiO₂ NPs) and group IV (0.8 mM SiO₂ NPs). Spontaneous contractions were recorded using mechanical activity recording system. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) levels were measured using the spectrophotometric methods. Apoptosis of the cells was detected using immunofluorescence staining assay. SiO₂ NP distribution and ultrastructural changes were determined by transmission electron microscopy. In groups II-IV, the frequency of contraction was significantly lower than that of the group I, whereas the contraction energy significantly decreased only in group IV. SOD and GSH-Px activities were significantly lower in experimental groups compared to the control group. MDA level and apoptotic cells were significantly higher in all SiO₂ groups compared to the control group. Numerous SiO₂ NPs in cytoplasm and connective tissue were observed in all dose groups. These findings showed that 20 nm sized SiO₂ NPs enter the connective tissue and cytoplasm of uterine muscle cells and cause oxidative stress and apoptosis leading to impaired uterine contractile activity.

Effects of Hypericum perforatum on an Experimentally Induced Diabetic Wound in a Rat Model

OBJECTIVE

The aim of this study was to investigate the probable effects of Hypericum perforatum (HP) on wound healing in diabetic rats.

MATERIALS AND METHODS

Thirty-five male Wistar rats were divided evenly into 5 groups. Diabetes formation was induced by intraperitoneal streptozotocin (60 mg/kg) administration for groups 1 (HP extract in olive oil), 2 (HP extract in ethanol), 3 (povidone-iodine application), and 4 (diabetic rats without any applied medication); group 5 was the control. Dorsal dermoepidermal incision was performed on each rat after 48 hours. The aforementioned solutions were applied only to groups 1, 2, and 3; groups 4 and 5 did not receive solution applications. At the end of the 7-day period, the cutaneous tissue was resected from the center of the incised and sutured region and divided into 3 pieces for biomechanical, biochemical, and histopathological assessments.

RESULTS

Ultimate stress and toughness significantly decreased in groups 3, 4, and 5 compared to group 1. There was a significant difference between groups 2 and 3 for the same parameters (P < .05). Compared with group 4, tissue malondialdehyde levels were found to be lower in the HP groups (P < .05). Histopathological evaluation revealed the fibroblast count was reduced considerably in the HP-applied rats compared with other groups (P < .05).

CONCLUSION

Application of HP may be recommended as effective on wound healing in diabetic rats, but further investigation is needed to adapt the findings for clinical use.

Out-of-Reference Range Thyroid-Stimulating Hormone Levels in Levothyroxine-Treated Primary Hypothyroid Patients: A Multicenter Observational Study

OBJECTIVE

Although levothyroxine (LT4) replacement therapy for hypothyroidism has been established as safe, inexpensive and effective, many studies from different countries reported out-of-reference range thyroid-stimulating hormone (TSH) values for the hypothyroid patients under LT4 treatment. The aim of this study was to determine TSH levels of primary hypothyroid patients under LT4 treatment and to assess self-reported compliance with daily LT4 intake in tertiary care centers in Turkey.

DESIGN

In this cross-sectional, observational study, adult patients with primary hypothyroidism, receiving LT4 treatment for at least 6 months, were included. The patients were from 12 tertiary care centers in 9 cities of Turkey. TSH and free T4 levels were recorded from patient files and self-reported compliance with daily LT4 intake was assessed by interviewing the subjects at the last visit.

RESULTS

A total of 1,755 subjects (46 ± 13 years; F/M: 89.9/10.1%) with primary hypothyroidism were enrolled. Of the hypothyroid subjects, 44.8% had out-of-reference range serum TSH levels. TSH values were over the reference range (TSH > 4 mIU/L) in 26.2% and were under the reference range (TSH < 0.5 mIU/L) in 18.6% of the patients. Total duration of LT4 treatment was 5.9 ± 4.7 years and mean dose was 1.2 ± 0.6 μg/kg/day. Non-compliant patients (31.1%) had higher TSH levels (6.9 ± 16 vs 3.8 ± 0.9 mIU/L, P = 0.01) compared to compliant patients.

CONCLUSION

The results of this study revealed that nearly half of the hypothyroid patients had out-of-reference range serum TSH values, despite under LT4 treatment. Compliance with LT4 treatment seems to be one of the major determinants to reach the target TSH levels in hypothyroid patients.

[Investigation of the association between chronic hepatitis B and C infections and TNF-α (-308) gene polymorphism]

Cytokines and genetic factors play important roles in the pathogenesis of chronic hepatitis B (CHB) and chronic hepatitis C (CHC) infections. Variations in cytokine genes may effect the gene expression and may lead to changes in the clinical manifestations of diseases. One of the single nucleotide polymorphisms in the promoter region of tumor necrosis factor-alpha (TNF-α) gene is the polymorphism at -308. position which was investigated in many studies by means of its relationship between CHB and CHC infections, however their results are incompatible. Furthermore, there is no sufficient data on this subject in our country. This study was aimed to determine the relationship between TNF-α(-308) gene polymorphism with CHB and CHC infections. A total of 271 patients with chronic hepatitis and 181 healthy subjects were included in the study. Of them 167 were CHB cases (67 female, 100 male; age range 18-74 years, mean age: 40.23 ± 13.09) and 95 controls for CHB group (46 female, 49 male; mean age: 36.41 ± 15.0 years), while 104 were CHC cases (63 female, 41 male; age range: 25-79 years, mean age: 52.8 ± 12.6) and 86 controls for CHC group (41 female, 45 male; mean age: 36.4 ± 14.9 years). After the isolation of genomic DNA from blood samples of the patient and control groups, TNF-α(-308)G/A (rs 1800629) polymorphism was investigated by using the real-time polymerase chain reaction from the obtained DNAs. Among CHB group, TNF-α(-308) GG, GA, AA genotypes were detected in 126 (75.4%), 38 (22.8%) and 3 (1.8%) of the patients, respectively, while these numbers were 84 (88.4%), 11 (11.6%) and 0 (0%) in control group, respectively. Among CHC group, TNF-α(-308) GG, GA, AA genotypes were detected in 37 (35.6%), 28 (26.9%) and 39 (37.5%) of the patients, respectively, while these numbers were 38 (44.2%), 8 (9.3%) and 40 (46.5%) in control group, respectively. The frequency of GA genotype was significantly higher in both patient groups compared to the control groups (p=0.024 for CHB and p= 0.006 for CHC). When the distribution of allele frequencies of TNF-α(-308)G/A polymorphism was evaluated in the patients and control groups, it was noted that G allele was found to be high in CHB patients comparing with controls (94.2% vs 86.8%), however A allele was identified to be lower than controls (5.8% vs 13.2%) (p= 0.008). In contrast, there was no significant difference in terms of allele frequency compared with CHC patients and the control group (p= 0.969). In conclusion, our data in accordance with the results of many studies in literature, determined that TNF-α(-308) polymorphisms can influence the chronicity of hepatitis B and C infections. Further studies on this subject would contribute to the elucidation of the molecular mechanisms of chronic hepatitis B and C diseases.

The protective role of ascorbic acid (vitamin C) against chlorpyrifos-induced oxidative stress in Oreochromis niloticus

Ability of ascorbic acid (vitamin C) to attenuate oxidative damage was evaluated in liver and brain tissues of Oreochromis niloticus (O. niloticus) experimentally exposed to sublethal concentrations of chlorpyrifos (CPF). O. niloticus was exposed to sublethal concentrations of CPF at 12 μg/L (CPF1) and 24 μg/L (CPF2) for 96 h. The fish of vitamin C (Vit C) and CPF2 + Vit C groups were fed with Vit C supplemented diet (200 mg Vit C/100 g feed). A significant increase in thiobarbituric acid-reactive substances (TBARS) level (P < 0.05) was observed in brain of CPF-exposed fish although liver TBARS level was not changed compared to control group. This result showed that lipid peroxidation (LPO) was elevated in brain of fish exposed to CPF. Glutathione peroxidase (GSH-Px) activity in liver and brain tissues was significantly elevated (P < 0.05) by exposure to CPF1 and CPF2. Catalase (CAT) activity was significantly increased (P < 0.05) in liver but decreased in brain of treated fish by CPF2 concentration. Superoxide dismutase (SOD) activity was decreased in liver, but increased in brain by exposure to CPF1 and CPF2 concentrations. Levels of TBARS were increased in brain of CPF-treated animals, but tended to decrease by the effect of Vit C. Vit C treatment for CPF-intoxicated animals normalized the otherwise raised activities of GSH-Px, CAT, and SOD within normal limits. The results clearly indicate that exposure to CPF caused a dose-dependent increase in oxidative stress brain and to a lesser extend in liver of fish and the ability of Vit C to attenuate CPF-induced oxidative damage.

The association between cyclooxygenase-2 (COX-2/PTGS2) gene polymorphism and osteoarthritis

OBJECTIVES

This study aims to investigate the relationship between the risk for the development of osteoarthritis and Cyclooxygenase-2 (COX 2) -765G>C gene polymorphism.

PATIENTS AND METHODS

We included a total of 100 osteoarthritis patients (18 males, 82 females; mean age 60.4±8.4 years; range 41 to 81 years) who were treated in the Physical Therapy Clinic and 100 healthy subjects without a history of arthritis (40 males, 60 females; mean age 30.9±7.5 years; range 16 to 48 years) in our study between September 2006 and May 2008. The frequency of -765G>C gene polymorphism in the COX-2 promoter region was investigated in the osteoarthritis patients and the control group without a history of arthritis using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The data were analysed with chi-square and logistic regression analysis.

RESULTS

The frequencies of -765G>C polymorphism for GG, GC and CC genotypes were found to be 54%, 35%, and 11% in the control group and 48%, 34% and 18% in the osteoarthritis group, respectively.

CONCLUSION

Based on the data obtained, it can be stated that there is no significant relation between COX-2 -765G>C polymorphism and osteoarthritis disease. Furthermore, this study presents the first results of COX-2 promoter variant in Turkish patients with osteoarthritis.