Role of parental smoking and environmental tobacco smoke exposure in childhood cancer: A study using hair cotinine analysis and questionnaires

OBJECTIVES

In the etiology of childhood cancers, many genetic and environmental factors play a role. One of these factors could be cigarette smoking, and the main source of tobacco smoke exposure of children is parental smoking. However, establishing a causal relationship between parental smoking and childhood cancers has proven challenging due to difficulties in accurately detecting tobacco smoke exposure METHODS: To address this issue, we used hair cotinine analysis and a questionnaire to get information about tobacco smoke exposures of pediatric cancer patients and healthy children. A total of 104 pediatric cancer patients and 99 healthy children participated in our study. Parental smoking behaviors (pre-conceptional, during pregnancy, and current smoking) and environmental tobacco smoke (ETS) exposures of children are compared.

RESULTS

We have found no differences between two groups by means of maternal smoking behaviors. However, the rates of paternal pre-conceptional smoking and smoking during pregnancy were significantly low in cancer patients (p < .05). These data suggest that social desirability bias among fathers of cancer patients may have contributed to this discrepancy. According to questionnaire, cancer patients had significantly lower ETS exposures than healthy children (p < .05). However, ETS exposure assessment through cotinine analysis demonstrated that cancer patients had higher exposure to ETS compared to healthy children (p < .001).

CONCLUSION

Our findings provide evidence supporting the potential role of smoking as a risk factor for childhood cancers. This study also revealed that questionnaires could cause biases. We suggest that cotinine analysis along with validated questionnaires can be used to prevent biases in studies of tobacco smoke in the etiology of childhood cancers.

Cucurbitacin B and erastin co-treatment synergistically induced ferroptosis in breast cancer cells via altered iron-regulating proteins and lipid peroxidation

Ferroptosis is a unique type of cell death which co-exists with elevated iron, suppressed antioxidative function and increased lipid peroxidation. Recent studies have shown that cancer cells are particularly susceptible to the compounds with ferroptotic activities. Cucurbitacin B (CuB) is a triterpenoid with potent biological properties. It has been demonstrated to induce apoptosis and inhibit metastasis in cancer cells. However, the underlying mechanism of the compound is still not fully understood. In the present study, we investigated the ferroptotic effect of CuB in breast cancer cells and evaluated the impact of its combination with erastin, a ferroptosis inducer. In this regard, MTT assay was performed to analyze cell viability. Lipid peroxidation, oxidative stress and the cellular antioxidant capacity were determined with relevant kits. The expression of ferroptotic proteins were analyzed by western blotting. The results indicated that the combined treatment of CuB and erastin activated the ferroptotic pathways significantly in MCF-7 and MDA-MB-231 breast cancer cells. More importantly, the combination treatment altered the expression of iron-related proteins IREB2 and FPN1. In conclusion, this study demonstrated the ferroptotic potential of CuB in breast cancer cells for the first time, and revealed its impact on the expression of iron-regulating proteins.

In silico approach reveals N-(5-phenoxythiophen-2-yl)-2-(arylthio)acetamides as promising selective SIRT2 inhibitors: the case of structural optimization of virtual screening-derived hits

Epigenetic modifications play an essential role in tumor suppression and promotion. Among the diverse range of epigenetic regulators, SIRT2, a member of NAD+-dependent protein deacetylates, has emerged as a crucial regulator of cellular processes, including cell cycle progression, DNA repair, and metabolism, impacting tumor growth and survival. In the present work, a series of N-(5-phenoxythiophen-2-yl)-2-(arylthio)acetamide derivatives were identified following a structural optimization of previously reported virtual screening hits, accompanied by enhanced SIRT2 inhibitory potency. Among the compounds, ST44 and ST45 selectively inhibited SIRT2 with IC50 values of 6.50 and 7.24 μM, respectively. The predicted binding modes of the two compounds revealed the success of the optimization run. Moreover, ST44 displayed antiproliferative effects on the MCF-7 human breast cancer cell line. Further, the contribution of SIRT2 inhibition in this effect of ST44 was supported by western blotting, affording an increased α-tubulin acetylation. Furthermore, molecular dynamics (MD) simulations and binding free energy calculations using molecular mechanics/generalized born surface area (MM-GBSA) method evaluated the accuracy of predicted binding poses and ligand affinities. The results revealed that ST44 exhibited a remarkable level of stability, with minimal deviations from its initial docking conformation. These findings represented a significant improvement over the virtual screening hits and may contribute substantially to our knowledge for further selective SIRT2 drug discovery.Communicated by Ramaswamy H. Sarma.

Cuproptosis as the new kryptonite of cancer: a copper-dependent novel cell death mechanism with promising implications for the treatment of hepatocellular carcinoma

Copper is an essential element for critical cellular functions such as mitochondrial respiration, cholesterol biosynthesis and immune response. Altered copper homeostasis has been associated with various disorders, including cancer. The copper overload is known to contribute to tumorigenesis, angiogenesis and metastasis, and recently it has been suggested that the elevated level of this element may also create vulnerability to a novel cell death mechanism, named cuproptosis. Excessive amount of copper in mitochondria binds to lipoylated enzymes of the TCA cycle and forms insoluble oligomers. The aggregation of these oligomers and subsequent iron-sulfur cluster protein loss results in proteotoxic stress and eventual cell death. Hepatocellular carcinoma is a common malignancy with a low survival rate, despite the available treatment options. The discovery of cuproptosis led many researchers to explore its potential use in hepatocellular cancer therapy due to the rich mitochondria content of hepatic cells. In this regard, a number of genomic studies were conducted to discover several cuproptosis-related genes and explored their association with prognosis, survival and immunotherapy response. This review brings together the available data on the relationship between cuproptosis and hepatocellular cancer for the first time, and highlights some of the potential biomarkers or target molecules that may be useful in the treatment.

Effects of pyrrolopyrimidine derivatives on cancer cells cultured in vitro and potential mechanism

In this study, the anticancer activities of some pyrrolopyrimidine derivatives were evaluated. Compound 3 is the most cytotoxic compound on MCF-7 cancer cells with an IC50 value of 23.42 µM. Also, compound 3 induced apoptosis and the ROS(+) cell population in MCF-7 cells. Moreover, it significantly reduced MMP-9 activity, having 42.16 ± 5.10% and 58.28 ± 1.96% inhibitory activities at 10 µM and 50 µM concentrations, respectively. Molecular docking results supported the activity, showing key hydrogen bonds with the binding site of MMP-9. Therefore, compound 3 might be a lead compound for the development of potent MMP-9 inhibitors.

Alpha-lipoic acid induced apoptosis of PC3 prostate cancer cells through an alteration on mitochondrial membrane depolarization and MMP-9 mRNA expression

Cancer has become an important cause of mortality and morbidity in the world. Over the past decades, biomedical research revealed insights into the molecular events and signaling pathways involved in carcinogenesis and cancer progression. Matrix metalloproteinases (MMPs) are a diverse family of enzymes that can degrade various components of the extracellular matrix and are considered as potential diagnostic and prognostic biomarkers for many cancer types and cancer stages. Recently, studies on the role of natural-origin active substances in the prevention of cancer development gained importance. Among them, the α-lipoic acid, which is commonly found in plants, displayed potent anti-proliferative effects on cancer cell lines. However, the effect of the compound on the induction of apoptosis and mRNA expression of MMPs in human prostate cancer cells remains unclear. The present study aimed to evaluate the anti-proliferative and apoptotic activity of α-lipoic acid in human PC3 prostate carcinoma cells considering different concentrations and exposure durations. The findings showed that, α-lipoic acid significantly decreased PC3 cell viability with an IC₅₀ value of 1.71 mM at 48 h (p < 0.05). Additionally, the compound significantly increased Annexin-V binding in cells compared to control and induced a significant alteration in mitochondrial membrane potential and caspase levels (p < 0.05). Furhermore, the RT-PCR analyses have revealed that α-lipoic acid reduced MMP-9 mRNA expression in PC3 cells compared to the control (p < 0.05). In conclusion, this study highlights that α-lipoic acid induced apoptosis in human PC3 prostate cancer cells and inhibited the MMP-9 gene at the mRNA level, which is known to play a role in metastasis development.

The five Ferulago species inhibited cell proliferation and induced apoptosis of A549, MCF-7, PC3 and SW480 cancer cells in vitro

In this study, it was aimed to evaluate the cytotoxic and apoptotic activities of ethanolic extracts prepared from the roots of 5 Ferulago species [F. humilis Boiss., F. macrosciadia Boiss. & Balansa, F. sandrasica Peşmen & Quézel, F. silaifolia (Boiss.) Boiss., F. trojana Akalın & Pimenov] on various human cancer cell lines. The cytotoxicity analyses against human lung (A549), breast (MCF-7), prostate (PC3) and colon (SW480) cancer cell lines were determined by MTT test; while the apoptotic effect was evaluated by Annexin V binding assay. All studied extracts showed concentration-dependent cytotoxic activity with an IC50 value ranging from 0.416 to 5.336 mg/mL. The studied Ferulago species significantly induced apoptosis of cancer cells, while F. macrosciadia had the highest apoptotic activity on MCF-7 cells with 21.79 ± 1.63% apoptotic cell population (p < 0.0001). In addition, felamedin and prantschimgin content of the extracts, which are common coumarins in Ferulago species, were evaluated by HPLC. According to HPLC analysis, the highest amount of felamedin content was found in F. trojana, while the highest content of prantschimgin was found in F. sandrasica among the studied Ferulago species. This preliminary research has revealed that the studied Ferulago species have promising effects on various cancer cell lines. Further studies are planned to determine the compounds responsible for the effect and underlying mechanism.

Mitochondrial transplantation: Effects on chemotherapy in prostate and ovarian cancer cells in vitro and in vivo

Prostate and ovarian cancers affect the male and female reproductive organs and are among the most common cancers in developing countries. Previous studies have demonstrated that cancer cells have a high rate of aerobic glycolysis that is present in nearly all invasive human cancers and persists even under normoxic conditions. Aerobic glycolysis has been correlated with chemotherapeutic resistance and tumor aggressiveness. These data suggest that mitochondrial dysfunction may confer a significant proliferative advantage during the somatic evolution of cancer. In this study we investigated the effect of direct mitochondria transplantation on cancer cell proliferation and chemotherapeutic sensitivity in prostate and ovarian cancer models, both in vitro and in vivo. Our results show that the transplantation of viable, respiration competent mitochondria has no effect on cancer cell proliferation but significantly decreases migration and alters cell cycle checkpoints. Our results further demonstrate that mitochondrial transplantation significantly increases chemotherapeutic sensitivity, providing similar apoptotic levels with low-dose chemotherapy as that achieved with high-dose chemotherapy. These results suggest that mitochondria transplantation provides a novel approach for early prostate and ovarian cancer therapy, significantly increasing chemotherapeutic sensitivity in in vitro and in vivo murine models.

Increased endoglin levels correlated with angiogenesis-associated angiopoietin-2 in haemophilia patients

INTRODUCTION

Haemophilia is a bleeding disorder that occurs due to the deficiency of coagulation factors, and the angiogenesis process is an important process underlying the pathophysiology of haemophilic arthropathy. The role of the new adipocytokine endoglin (ENG) in patients with haemophilia is not yet known.

AIM

The aim of this study is to evaluate the association between ENG protein and angiogenesis-related cytokines in patients with haemophilia for the first time.

METHODS

Plasma protein levels and mRNA expressions of ENG and various angiogenesis-associated cytokines were compared in blood samples collected from 28 patients with haemophilia A or B and 29 healthy volunteers. The relationship between the cytokines and ENG were determined by correlation analysis.

RESULTS

Plasma ENG levels and angiogenic markers were found to be significantly higher in patients with haemophilia compared to controls. Real-time PCR studies showed that mRNA expressions of ENG, vascular endothelial growth factor A, hypoxia-inducible factor A, and prostaglandin E2 increased in patients with haemophilia. Correlation analysis showed a significant positive correlation between ENG and angiopoietin-2 levels in the haemophilia group. Besides, a significant decrease in annexin-V binding to platelets in haemophilia patients compared to control was found to be related to the bleeding profiles in the patients.

CONCLUSIONS

This study determined that ENG protein may be involved in the formation of angiogenesis in haemophilia patients and its effects may be related to angiogenetic marker angiopoietin-2 in this process. Our findings contribute to the literature during the determination of target proteins in haemophilia treatment.

Ferroptosis: A Trusted Ally in Combating Drug Resistance in Cancer

Ferroptosis, which is an iron-dependent, non-apoptotic cell death mechanism, has recently been proposed as a novel approach in cancer treatment. Bearing distinctive features and its exclusive mechanism have put forward the potential therapeutic benefit of triggering this newly discovered form of cell death. Numerous studies have indicated that apoptotic pathways are often deactivated in resistant cells, leading to a failure in therapy. Hence, alternative strategies to promote cell death are required. Mounting evidence suggests that drug-resistant cancer cells are particularly sensitive to ferroptosis. Given that cancer cells consume a higher amount of iron than healthy ones, ferroptosis not only stands as an excellent alternative to trigger cell death and reverse drug-resistance, but also provides selectivity in therapy. This review focuses specifically on overcoming drug-resistance in cancer through activating ferroptotic pathways and brings together the relevant chemotherapeutics-based and nanotherapeutics-based studies to offer a perspective for researchers regarding the potential use of this mechanism in developing novel therapeutic strategies.

The Trinity of Matrix Metalloproteinases, Inflammation, and Cancer: A Literature Review of Recent Updates

The critical link between cancer and inflammation has been known for many years. This complex network was further complexed by revealing the association of the matrix metalloproteinase family members with inflammatory cytokines, which were previously known to be responsible for the development of metastasis. This article summarizes the current studies which evaluate the relationship between cancer and inflammatory microenvironment as well as the roles of MMPs on invasion and metastasis together.

Investigation of molecular mechanisms underlying the antiproliferative effects of colchicine against PC3 prostate cancer cells

This work examined the cytotoxic effects of colchicine on PC3 cells and elucidated the possible underlying mechanisms of its cytotoxicity. The cells were exposed to colchicine at different concentrations ranging from 1 to 100 ng/mL for 24 h, and it showed considerable cytotoxicity with an IC₅₀ value of 22.99 ng/mL. Mechanistic studies also exhibited that colchicine treatment results in cell cycle arrest at the G2/M phase as well as decreased mitochondrial membrane potential and increased early and late apoptotic cells. The apoptotic and DNA-damaging effects of colchicine have also been verified by fluorescence imaging and ELISA experiments, and they revealed that while colchicine treatment significantly modulated expression as increases in Bax, cleaved caspase 3, cleaved PARP, and 8-hydroxy-desoxyguanosine levels and as a decrease of BCL-2 protein expression. Besides, colchicine treatment significantly increased the total oxidant (TOS) level, which is a signal of oxidative stress and potential cause of DNA damage. Finally, the results of quantitative real-time PCR experiments demonstrated that colchicine treatment concentration-dependently suppressed MMP-9 mRNA expression. Overall, colchicine provides meaningful cytotoxicity on PC3 cells due to induced oxidative stress, reduced mitochondrial membrane potential, increased DNA damage, and finally increased apoptosis in PC3 cells. Nevertheless, further research needs to be conducted to assess the potential of colchicine as an anticancer drug for the treatment of prostate cancer.

Hit-to-lead optimization on aryloxybenzamide derivative virtual screening hit against SIRT

Sirtuins (SIRTs) are a class of nicotinamide adenine dinucleotide (NAD⁺)-dependent protein histone deacetylases (HDACs) that are evolutionarily conserved from bacteria to mammals. This group of enzymes catalyses the reversible deacetylation of lysine residues in the histones or non-histone substrates using NAD⁺ as a cosubstrate. Numerous studies have demonstrated that the aberrant enzymatic activity of SIRTs has been linked to various diseases like diabetes, cancer, and neurodegenerative disorders. Previously, we performed a pharmacophore-based virtual screening campaign and an aryloxybenzamide derivative (1) displaying SIRT1/2 inhibitory effect was identified as a hit compound. In the current study, the hit-to-lead optimization on the hit compound was explored in order to improve the SIRT binding and inhibition. Fourteen compounds, ten of which were new, have been synthesized and subjected to in vitro biological evaluation for their inhibitory activity against SIRT1-3. By the structural modifications performed, a significant improvement was observed in selective SIRT1 inhibition for ST01, ST02, and ST11 compared to that of the hit compound. The highest SIRT2 inhibitory activity was observed for ST14, which was designed according to compatibility with pharmacophore model developed for SIRT2 inhibitors and thus, providing the interactions required with key residues in SIRT2 active site. Furthermore, ST01, ST02, ST11, and ST14 were subjected to in vitro cytotoxicity assay against MCF-7 human breast cancer cell line to determine the influence of the improvement in SIRT1/2 inhibition along with the structural modifications on the cytotoxic properties of the compounds. The cytotoxicity of the compounds was found to be correlated with their SIRT inhibitory profiles indicating the effects of SIRT1/2 inhibition on cancer cell viability. Overall, this study provides structural insights for further inhibitor improvement.

A specific inhibitor of polo-like kinase 1, GSK461364A, suppresses proliferation of Raji Burkitt's lymphoma cells through mediating cell cycle arrest, DNA damage, and apoptosis

Polo-like kinase 1 (PLK1) is a prominent mediatory player during the cell cycle, mitosis, and cytokinesis in eukaryotic cells. Besides its physiological roles, PLK1 expression is upregulated in a wide range of human malignant tumors and its overexpression worsens prognosis, therefore, specific inhibition of PLK1 in tumor cells is a fascinating approach for the development of novel chemotherapeutics. The present study elucidated the potential cytotoxic effects of a PLK1 inhibitor, GSK461364A, in five cancer cell lines including Raji, K562, PC3, MCF-7, MDA-MB-231, along with noncancerous L929 cells by XTT assay. The cells were treated for 24 h with GSK461364A at different concentrations ranged between 0.5 and 40 μM and significant cytotoxicity was observed in all treated groups with the IC50 values between 2.36 and 4.08 μM. GSK461364A was also found to be safer with lower cytotoxicity against L929 cells and the IC50 value was found to be greater than 40 μM. Raji cells were identified as the most sensitive cell line against GSK461364A with the lowest IC50 values, hence it was selected for further studies to evaluate the underlying mechanism of cytotoxic activity. The treatment of Raji cells with GSK461364A caused a cell cycle arrest at the G2/M phase, also altered TOS, which is an indicator of oxidative stress, and DNA damage response, significantly. The Annexin V binding assay revealed that GSK461364A treatment significantly increased in the percentage of early and late apoptotic cells. Fluorescence imaging also showed that GSK461364A treatment significantly induced apoptosis of Raji cells. The apoptotic effect of the compound has also been confirmed by increased expressions of Bax and cleaved caspase 3 and along with the decreased expression of BCL-2. The results demonstrated that GSK461364A induced anticancer effects which was mainly promoted by cell cycle arrest, oxidative stress, DNA damage, and finally apoptosis in Burkitt's lymphoma cells. Taken together, the present results emphasized that GSK461364A could be a useful therapeutic agent in patients with Burkitt's lymphoma. However, further studies are required to consolidate the anticancer activity of this promising compound.

Seseli petraeum M. Bieb. (Apiaceae) Significantly Inhibited Cellular Growth of A549 Lung Cancer Cells through G0/G1 Cell Cycle Arrest

Seseli L. is an important genus of the Apiaceae family, with a large number of aromatic species. It is used in traditional medicine extensively, but there is quite limited information on their phytochemicals and biological activities. Seseli petraeum M. Bieb. grows in Northern Anatolia, and there are no phytochemical studies on this species. In the present study, we aimed to investigate the effect of the extracts of S. petraeum on A549 lung cancer cell proliferation. For this purpose, the antiproliferative effect was determined via MTT assay, and the extracts obtained from the root of S. petraeum showed a significant inhibitory effect on cell proliferation. The hexane extract of the root exhibited potent inhibition on A549 cancer cell growth at the 24th hour with 3.432 mg/mL IC50 value. The results also showed that the hexane extract had displayed cytotoxic effect through an arrest at the G0/G1 phase of the cell cycle and induced apoptosis as well as DNA damage of A549 cells. Consequently, this study demonstrated the antiproliferative potential of the extracts from S. petraeum, especially hexane extract from the roots. Further studies are required to identify the mechanisms underlying these effects.

Potentiation of the Effect of Lonidamine by Quercetin in MCF-7 human breast cancer cells through downregulation of MMP-2/9 mRNA Expression

Combination therapies are becoming increasingly important to develop an effective treatment in cancer. Lonidamine is frequently used in cancer treatment, but it's often preferred to be used in combination with other drugs because of its side effects. In the present study, the efficacy of the combination of lonidamine with quercetin, a flavonoid of natural origin, on human MCF-7 breast cancer cells was evaluated. The results showed that the combined use of the compounds significantly increased cytotoxicity compared to administration alone (p<0.0001). In addition, while lonidamine induced a cell cycle arrest in the G2/M phase, administration of quercetin and its combination with lonidamine arrested the cell division at S point, indicating the synergistic strength of quercetin on cytotoxicity. The combination of quercetin and lonidamine significantly induced apoptosis of MCF-7 cells (p<0.0001) and increased caspase levels (p<0.0001). In this study, the combination of quercetin and lonidamine has been evaluated for the first time and the combination treatment decreased MMP-2/-9 mRNA expression more potently than the effects of the compounds alone. The results showed that lonidamine was more effective when combined with quercetin, and their combination may be a candidate for a novel strategy of treatment for breast cancer.

Clinicopathological and immunohistochemical evaluation of lonidamine-entrapped lipid-polymer hybrid nanoparticles in treatment of benign prostatic hyperplasia: An experimental rat model

Benign prostatic hyperplasia (BPH) is a progressive proliferative disease, the incidence of which is constantly increasing due to aging of population. In this research, a hexokinase-II enzyme inhibiting agent, lonidamine - the use of which is limited in BPH treatment due to high hepatic toxicity observed after three months of treatment - was selected as an active agent, based on its mechanism of action in treating BPH. The aim of this study was to evaluate in vivo therapeutic efficacy and hepatic toxicity of lipid-polymer hybrid nanoparticles of lonidamine in a rat BPH model created in rat prostates. After local injections of hybrid nanoparticles of lonidamine were administered to the rat prostates, hyperplasic structures of prostates were evaluated in terms of prostatic index values, immunohistochemical evaluations, and histopathological findings. Liver blood enzyme values were also determined to specify hepatic toxicity. Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) reaction and histopathological methods to determine intravital degenerative destruction in liver. Through this study, lonidamine-loaded hybrid nanoparticles were found to reduce the hepatic toxicity and increase therapeutic efficiency of lonidamine. Therefore, lonidamine-entrapped hybrid nanoparticles may provide a promising, and very safe, drug delivery strategy in the treatment of BPH.

Synthesis and anticancer activity of some pyrimidine derivatives with aryl urea moieties as apoptosis-inducing agents

A new series of pyrimidine derivatives containing aryl urea moieties was designed and synthesized. The anticancer activities of all compounds were evaluated in vitro against colon and prostat cancer cell lines by MTT assay. Among these compounds, 4b exhibited the highest cytotoxic activity against SW480 cancer cell line with IC₅₀ value of 11.08 µM. Mechanistic studies showed that compound 4b arrested cell cycle at G2/M phase and induced apoptosis through upregulating Bax, Ikb-α and cleaved PARP and downregulating Bcl-2 expression levels. Moreover, compound 4b induced loss of mitochondrial membrane potential in SW480 cells. These results suggest that pyrimidine with urea moieties could be a template for designing new anticancer agents.

Evaluation of hair cotinine and toxic metal levels in children who were exposed to tobacco smoke

Tobacco or tobacco products (TTP) are harmful because they contain nicotine and some heavy metals. In this study, it was aimed to evaluate whether the responses of parents to questionnaires were compatible with the hair cotinine levels of their children, and to investigate whether exposure to environmental tobacco smoke (ETS) and living conditions increased the levels of cotinine, lead (Pb), arsenic (As), and cadmium (Cd) in the hair samples of the children. Questionnaires were administered to the parents questioning household consumption of TTP and living conditions. Children were grouped as "exposed to ETS" (E-ETS) and "not exposed to ETS" (NE-ETS). This grouping was performed through a questionnaire-based evaluation, and a hair cotinine cut-off value-based evaluation. According to the questionnaire-based evaluation, there were no significant differences in hair Pb, As, and Cd levels between the groups (P-values: .337, .994, and .825, respectively). The hair cotinine of the E-ETS group was higher (0.24 ± 0.21 vs 0.22 ± 0.15 ng/mg), but the difference was not statistically significant (P = .317). According to the cotinine evaluation, cotinine, Pb, and As levels were statistically higher in the E-ETS group (P < .001, <.001, and .036, respectively), but there was no statistical difference between the groups in terms of Cd levels (P = .238). Our results showed that exposure to ETS increased the levels of cotinine, Pb, and As in the hair samples of children, and the questionnaire responses of the parents about their smoking habits might not be compatible with the hair cotinine levels of the children.

Cytotoxic and Apoptotic Effects of Novel Pyrrolo[2,3-d]Pyrimidine Derivatives Containing Urea Moieties on Cancer Cell Lines

BACKGROUND

Pyrrolo[2,3-d]pyrimidines have been recently reported to have anticancer activities through inhibition of different targets such as, Epidermal Growth Factor Receptor (EGFR) tyrosine kinase, Janus Kinase (JAK), mitotic checkpoint protein kinase (Mps1), carbonic anhydrase, MDM-2. On the other hand, aryl urea moieties which are found in some tyrosine kinase inhibitors such as Sorafenib and Linifanib have aroused recent attention as responsible for anticancer activities. The aims of this paper are to synthesize pyrrolo[ 2,3-d]pyrimidine derivatives containing urea moiety and evaluate their anti-cancer activity against human lung cancer cell line (A549), prostate cancer cell line (PC3), human colon cancer cell line (SW480) and human breast cancer cell line (MCF-7).

METHODS

A series of new pyrrolo[2,3-d]pyrimidines containing urea moieties have been synthesized as Scheme 1. In vitro cytotoxicity of target compounds were evaluated against, SW480, PC3, A549 and MCF-7 human cancer cell lines using a MTT assay. In order to evaluate the mechanism of cytotoxic activity of compounds 9e, 10a and 10b, having the best cytotoxic activity, Annexin V binding assay, cell cycle analysis and western blot analysis were performed.

RESULTS

Among the target compounds, 10a (IC50 = 0.19 µM) was found to be the most potent derivative against PC3 cells. Compound 10b and 9e showed the strong cytotoxic activity against MCF-7 and A549 cells with IC50 value of 1.66 µM and 4.55 µM, respectively. Flow cytometry data suggest that the cytotoxic activity of the compounds on cancer cells might be mediated by apoptosis revealing a significant increase in the percentage of late apoptotic cells and causing a cell cycle arrest at different stages. Western blot analysis of apoptosis marker demonstrated that these compounds induce apoptosis through the intrinsic pathway.

CONCLUSION

Compound 9e displayed the strongest cytotoxicity against A549 cancer cell line, and induced late apoptosis in A549, as confirmed by cell cycle arrest in G0/G1 phase. In addition, compound 9e reduced expression of the anti-apoptotic protein Bcl-2 and enhanced expression of the pro-apoptotic protein Bax, besides increased caspase-9 and caspase-3, as well as cleavage of PARP levels. These results suggest that compound 9e showed a cytotoxic effect in A549 cells through activation of the mitochondrial apoptotic pathway. Further studies will be undertaken in our laboratory to improve cytotoxic activity of compound 9e and to identify the biological targets of 9e which are responsible for anticancer activity.

RO3280: A Novel PLK1 Inhibitor, Suppressed the Proliferation of MCF-7 Breast Cancer Cells Through the Induction of Cell Cycle Arrest at G2/M Point

BACKGROUND

As a member of serine/threonine-protein kinase, Polo.like kinase 1 (PLK1) plays crucial roles during mitosis and also contributes to DNA damage response and repair. PLK1 is aberrantly expressed in many types of tumor cells and increased levels of PLK1 are closely related to tumorigenesis and poor clinical outcomes. Therefore, PLK1 is accepted as one of the potential targets for the discovery of novel anticancer agents. The objective of this study was to assess the cytotoxic effects of a novel PLK1 inhibitor, RO3280, against MCF-7, human breast cancer cells; HepG2, human hepatocellular carcinoma cells; and PC3, human prostate cancer cells, as well as non-cancerous L929 fibroblast cells.

METHODS

Antiproliferative activity of RO3280 was examined using the XTT assay. Flow cytometry assay was performed to evaluate cell cycle distribution, apoptosis, multicaspase activity, mitochondrial membrane potential, and DNA damage response. Apoptosis with fluorescence imaging studies was also examined.

RESULTS

According to the results of XTT assay, although RO3280 displayed potent cytotoxicity in all treated cancer cells, the most sensitive cell line was identified as MCF-7 cells that were selected for further studies. The compound induced a cell cycle arrest in MCF-7 cells at G2/M phase and significantly induced apoptosis, multicaspase activity, DNA damage response, and decreased mitochondrial membrane potential of MCF-7 cells.

CONCLUSION

Overall, RO3280 induces anticancer effects promoted mainly by DNA damage, cell cycle arrest, and apoptosis in breast cancer cells. Further studies are needed to assess its usability as an anticancer agent with specific cancer types.

The combined treatment of brassinin and imatinib synergistically downregulated the expression of MMP-9 in SW480 colon cancer cells

In cancer treatment, which is a major cause of mortality today, combination studies with clinically used chemotherapeutics are becoming increasingly important as much as investigating the effects of novel natural compounds. In this context, phytoalexins constitute an important group due to their unique structure. Brassinin is an essential indole phytoalexin and is a biosynthetic precursor for other phytoalexins. The purpose of this study was to evaluate the anticancer effects of brassinin in combination with imatinib in SW480 cells. In the study, it was observed that brassinin-imatinib combination significantly increased cytotoxicity compared with the single treatment of both compounds and inhibited cell cycle at G0/G1 phase. Annexin V binding and fluorescence imaging assays showed that the combination of brasinin-imatinib induces apoptosis in a dose-dependent manner. Furthermore, the effect of brassinin on the activity of MMP-9 in SW480 cells was evaluated for the first time, and it was detected that MMP-9 activity was significantly reduced. The combination of brassinin-imatinib was found to inhibit MMP-9 activity as well as relative MMP-9 gene expression on a higher level compared with control and compounds alone. Our findings have revealed that the combination of brassinin-imatinib synergistically induces cytotoxicity and apoptosis in SW480 cells. The findings on MMP-9 downregulation have also revealed the anti-metastatic potential of treatment.

The Cellular Uptake and Apoptotic Efficiency of Colchicine is Correlated with Downregulation of MMP-9 mRNA Expression in SW480 Colon Cancer Cells

BACKGROUND

Colchicine, a tricyclic alkaloid, is commonly used in treatment due to its antiinflammatory and anti-fibrotic effects. Besides its toxicity at high doses, colchicine is reported for its potential anticancer effects at lower concentrations. The present study aimed to evaluate the anticancer effects of colchicine in SW480 cells.

METHODS

The effect of colchicine on cell proliferation was determined by MTT assay. The cellular colchicine uptake was measured by HPLC analysis. The apoptotic effects was evaluated by annexin v binding assay and MMP-9 mRNA expression was determined by RT-PCR experiments.

RESULTS

Colchicine showed significant cytotoxicity at 10 ng/ml and higher concentrations and caused a cell cycle arrest of SW480 cells at G2/M phase. The results of HPLC analysis showed that colchicine uptake was increased in correlation with treated concentrations. Colchicine concentrations have increased the amount of apoptotic cell population. The elisa and western blot measurements showed that colchicine led to nuclear translocation of NF-κB proteins and increased caspase levels. The real time PCR experiments showed that colchicine has inhibitory effect on MMP-9 mRNA expression in a concentration dependent manner.

CONCLUSION

These results illustrated that low dose colchicine efficiently induced cell death and apoptosis of SW480 cells and the inhibition of MMP-9 mRNA levels was significantly correlated with the amount of cellular colchicine uptake, suggesting that colchicine has a potential value in the treatment of human colorectal cancer.

Decreased Spexin Levels in Patients with Type 1 and Type 2 Diabetes

BACKGROUND/AIMS

Spexin is a novel peptide which has a potential role as a biomarker of insulin resistance, diabetes, and obesity. Our aim was to measure spexin levels in lean type 1 diabetic patients and its relevance to glycemic parameters without the presence of obesity or insulin resistance.

SUBJECTS AND METHODS

This cross-sectional study included 29 type 1 and 30 type 2 diabetic patients and a control group of 23 healthy subjects with adjusted age, sex, and body mass index (BMI). Height and weight were measured using standard techniques. Glucose levels, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, serum cortisol levels, and spexin levels were measured in each patient.

RESULTS

The median fasting serum spexin levels were significantly lower in patients with type 1 and type 2 diabetes than in control subjects (p = 0.008 and p = 0.041, respectively). Spexin levels were not correlated with glycemic parameters, lipids, BMI, cortisol levels, and thyroid-stimulating hormone (p > 0.05). Only age turned out to be correlated with spexin levels in patients with type 1 diabetes when we analyzed the groups separately. Regression models, including age and diabetes duration, revealed no association between age and spexin levels. Regression models, including cortisol, BMI, and HbA1c, revealed no association with spexin levels within each group.

CONCLUSION

The presence of type 1 diabetes is associated with lower spexin levels, independent of glucose, lipid parameters, and BMI. The expression of spexin in the pancreas apart from the current glycemic control of the patients may be the main determinant of spexin levels in type 1 diabetic patients.