Pinocytosis as the Biological Mechanism That Protects Pgp Function in Multidrug Resistant Cancer Cells and in Blood–Brain Barrier Endothelial Cells

Cancer is the second leading cause of death worldwide. Chemotherapy has shown reasonable success in treating cancer. However, multidrug resistance (MDR), a phenomenon by which cancerous cells become resistant to a broad range of functionally and structurally unrelated chemotherapeutic agents, is a major drawback in the effective use of chemotherapeutic agents in the clinic. Overexpression of P-glycoprotein (Pgp) is a major cause of MDR in cancer as it actively effluxes a wide range of structurally and chemically unrelated substrates, including chemotherapeutic agents. Interestingly, Pgp is also overexpressed in the endothelial cells of blood–brain barrier (BBB) restricting the entry of 98% small molecule drugs to the brain. The efficacy of Pgp is sensitive to any impairment of the membrane structure. A small increase of 2% in the membrane surface tension, which can be caused by a very low drug concentration, is enough to block the Pgp function. We demonstrate in this work by mathematical equations that the incorporation of drugs does increase the surface tension as expected, and the mechanism of endocytosis dissipates any increase in surface tension by augmenting the internalisation of membrane per unit of time, such that an increase in the surface tension of about 2% can be dissipated within only 4.5 s

Possible hypocholesterolemic effect of ginger and rosemary oils in rats

Background: Hypercholesterolemia is a major risk factor for development of atherosclerosis. The present study was conducted to evaluate the potential effect of ginger oil alone or combined with rosemary oil as hypocholesterolemic agent in rats fed high fat diet.Materials and methods: Healthy female albino rats (n=80) weighting about (150-180 g) were included in this study divided into two equal groups; Group (I): were fed on the basal diet. Group (I) were divided into 4 subgroups each 10: Group (Ia): negative control. Group (Ib): Rats received i.p 2.5 g/Kg b.w of ginger oil. Group (Ic): rats received i.p 2.5 g/Kg b.w of rosemary oil. Group (Id): Rats received i.p 5 g/Kg b.w mixture of ginger oil and rosemary oil (1:1). The second main groups; Group (II): high fat diet (HFD) were fed on the basal diet plus cholesterol (1%), bile salt (0.25%) and animal fat (15%) to induce hypercholesterolemia for six weeks. Group (II) was divided into 4subgroups: Group (IIa): HFD. Group (IIb): HFD were treated with i.p 2.5 g/Kg b.w ginger oil. Group (IIc): (n=10) HFD were treated with i.p 2.5 g/Kg b.w rosemary oil. Group (IId): (n=10) HFD were treated with i.p 5 g/Kg b.w mixture of oils.Results: It was found that HFD rats showed a significant elevation in glucose, total cholesterol, triglyceride, GOT, GPT, alkaline phosphatase and a reduction in serum HDL-c compared with negative control. Treatment with ginger oil, rosemary oil and their mixture modulated the elevation of these parameters. Histopathological examination of the liver tissue of HFD rats showed a lipid deposition and macrophage infiltration and stenosis of hepatic vein. Treatment with mixture oils preserves normal structure of liver.Conclusion: It was concluded that, hypocholesterolemic effect was related to the active oil content as Rosemary oil contain - α-pinene, Camphor, cineole, borneol and Ginger oil contain Linalool, Terpineol ,Borneol , Eucalyptol.Keywords: Ginger Oil, Rosemary Oil, Rats, Hypocholesterolemi

Insights into N-calls of mitochondrial DNA sequencing using MitoChip v2.0

Developments in DNA resequencing microarrays include mitochondrial DNA (mtDNA) sequencing and mutation detection. Failure by the microarray to identify a base, compared to the reference sequence, is designated an 'N-call.' This study re-examined the N-call distribution of mtDNA samples sequenced by the Affymetrix MitoChip v.2.0, based on the hypothesis that N-calls may represent insertions or deletions (indels) in mtDNA.We analysed 16 patient mtDNA samples using MitoChip. N-calls by the proprietary GSEQ software were significantly reduced when either of the freeware on-line algorithms ResqMi or sPROFILER was utilized. With sPROFILER, this decrease in N-calls had no effect on the homoplasmic or heteroplasmic mutation levels compared to GSEQ software, but ResqMi produced a significant change in mutation load, as well as producing longer N-cell stretches. For these reasons, further analysis using ResqMi was not attempted. Conventional DNA sequencing of the longer N-calls stretches from sPROFILER revealed 7 insertions and 12 point mutations. Moreover, analysis of single-base N-calls of one mtDNA sample found 3 other point mutations.Our study is the first to analyse N-calls produced from GSEQ software for the MitoChipv2.0. By narrowing the focus to longer stretches of N-calls revealed by sPROFILER, conventional sequencing was able to identify unique insertions and point mutations. Shorter N-calls also harboured point mutations, but the absence of deletions among N-calls suggests that probe confirmation affects binding and thus N-calling. This study supports the contention that the GSEQ is more capable of assigning bases when used in conjunction with sPROFILER

POSSIBLE REGULATION OF LDL-RECEPTOR BY NARINGENIN IN HEPG2 HEPATOMA CELL LINE

Background: High plasma concentration of low-density lipoprotein cholesterol (LDL-c) plays a significant role in the incidence of atherosclerosis and coronary heart diseases (CHD). Materials and Methods: The purpose of this study was to investigate the mechanism by which citrus flavonoids, naringenin regulate the LDL receptor (LDLr) gene in human liver using the human hepatoma cell line, HepG2 as a model. Results: Time-course transient transfection of HepG2 cells with luciferase reporter-gene constructs incorporating the promoters of SREBP-1a,-1c, -2 and LDLr, revealed that in lipoprotein-deficient medium (LPDM), only SREBP-1a promoter activity was increased significantly after 4h exposure to 200μM naringenin respectively. However, after 24h incubation with 200μM naringenin the gene expression activities of all the SREBP-1a, -1c, -2 and LDLr promoterconstructs were increased significantly. The effects of both 200μM naringenin on elevating LDLr mRNA are possibly due to regulation of gene transcription by SREBP-la and SREBP-2. However, the suppression effect of 200μM naringenin on hepatic SREBP-1c mRNA expression is likely associated with the reduction in mRNA expression of both acetyl-CoA carboxylase and fatty acid synthase in human hepatoma HepG2 cells. It was found that, 200μM naringenin was likely to stimulate LDLr gene expression via increase phosphorylation of PI3K and ERK1/2 which enhance the transcription factors SREBP-1a and SREBP-2 mRNA levels and increased their protein maturation in human hepatoma HepG2 cell. Conclusion: Diets supplemented with naringenin could effectively reduce mortality and morbidity from coronary heart diseases and as cardio-protective effects in humans

Association of mutation and expression of the brother of the regulator of imprinted sites (BORIS) gene with breast cancer progression

INTRODUCTION: The BORIS, 11 zinc-finger transcription factors, is a member of the cancer-testis antigen (CTA) family. It is mapped to chromosome number 20q13.2 and this region is genetically linked to the early onset of breast cancer. The current study analyzed the correlation between BORIS mutations and the expression of the protein in breast cancer cases. MATERIALS AND METHODS: A population-based study including a total of 155 breast cancer tissue samples and an equal number of normal adjacent tissues from Indian female breast cancer patients was carried out. Mutations of the BORIS gene were detected by polymerase chain reaction-single standard confirmation polymorphisms (PCR-SSCP) and automated DNA sequencing and by immunohistochemistry for BORIS protein expression were performed. The observed findings were correlated with several clinicopathological parameters to find out the clinical relevance of associations. RESULTS: Of all the cases 16.12% (25/155) showed mutations in the BORIS gene. The observed mutations present on codon 329 are missense, leading to Val\u3e Ile (G\u3eA) change on exon 5 of the BORIS gene. A significant association was observed between mutations of the BORIS gene and some clinicopathological features like nodal status (p = 0.013), estrogen receptor (ER) expression (p = 0.008), progesterone receptor (PR) expression (p = 0.039), clinical stage (p = 0.010) and menopausal status (p = 0.023). The protein expression analysis showed 20.64% (32/155) samples showing low or no expression (+), 34.19% (53/155) with moderate expression (++), and 45.17% (70/155) showing high expression (+++) of BORIS protein. A significant association was observed between the expression of BORIS protein and clinicopathological features like clinical stage (p = 0.013), nodal status (p = 0.049), ER expression (p = 0.039), and PR expression (p = 0.027). When mutation and protein expression were correlated in combination with clinicopathological parameters a significant association was observed in the category of high (+++) level of BORIS protein expression (p = 0.017). CONCLUSION: The BORIS mutations and high protein expression occur frequently in carcinoma of the breast suggesting their association with the onset and progression of breast carcinoma. Further, the BORIS has the potential to be used as a biomarker

Inosine Triphosphate Pyrophosphatase (ITPase): Functions, Mutations, Polymorphisms and Its Impact on Cancer Therapies

Inosine triphosphate pyrophosphatase (ITPase) is an enzyme encoded by the ITPA gene and functions to prevent the incorporation of noncanonical purine nucleotides into DNA and RNA. Specifically, the ITPase catalyzed the hydrolysis of (deoxy) nucleoside triphosphates ((d) NTPs) into the corresponding nucleoside monophosphate with the concomitant release of pyrophosphate. Recently, thiopurine drug metabolites such as azathioprine have been included in the lists of ITPase substrates. Interestingly, inosine or xanthosine triphosphate (ITP/XTP) and their deoxy analogs, deoxy inosine or xanthosine triphosphate (dITP/dXTP), are products of important biological reactions such as deamination that take place within the cellular compartments. However, the incorporation of ITP/XTP, dITP/dXTP, or the genetic deficiency or polymorphism of the ITPA gene have been implicated in many human diseases, including infantile epileptic encephalopathy, early onset of tuberculosis, and the responsiveness of patients to cancer therapy. This review provides an up-to-date report on the ITPase enzyme, including information regarding its discovery, analysis, and cellular localization, its implication in human diseases including cancer, and its therapeutic potential, amongst others

Cytotoxicity of standardized curcuminoids mixture against epithelial ovarian cancer cell line SKOV-3

Herbal medicine has been in use for centuries for a wide variety of ailments; however, the efficacy of its therapeutic agents in modern medicine is currently being studied. Curcuminoids are an example of natural agents, widely used due to their potential contribution in the prevention and treatment of cancer. In this study, the three main compounds of curcuminoids-curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin-were determined by reversed-phase high performance liquid chromatography (HPLC) to quantify total content in a mixture. Subsequently, the effect of the three curcuminoids, employed as one sample, was evaluated, to study the proliferation, apoptosis, cell cycle, and migration of the human ovarian cancer cell line SKOV-3. The results reveal that curcuminoids inhibit the proliferation of SKOV-3 cells with concentration- and time-dependent mechanisms. The morphological analysis of the treated SKOV-3 cells showed a typical apoptotic phenotype-cell shrinkage and membrane blebbing in a dose-dependent manner. In addition, flow cytometry demonstrated an increase in apoptosis with an IC50 of 30 mu M curcuminoids. The migration of SKOV-3 cells was also inhibited, reflected by a decrease in wound area. Furthermore, the curcuminoids were found to have no stimulation effect on the expression of cytokines TNF-alpha and IL-10. These results suggest that a curcuminoid mixture can effectively suppress epithelial cancer cell growth in vitro by inducing cellular changes and apoptosis.Deanship of Scientific Research (DSR) at King Abdulaziz University (KAU), Jeddah, S

Cytotoxicity of standardized curcuminoids mixture against epithelial ovarian cancer cell line SKOV-3

Herbal medicine has been in use for centuries for a wide variety of ailments; however, the efficacy of its therapeutic agents in modern medicine is currently being studied. Curcuminoids are an example of natural agents, widely used due to their potential contribution in the prevention and treatment of cancer. In this study, the three main compounds of curcuminoids-curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin-were determined by reversed-phase high performance liquid chromatography (HPLC) to quantify total content in a mixture. Subsequently, the effect of the three curcuminoids, employed as one sample, was evaluated, to study the proliferation, apoptosis, cell cycle, and migration of the human ovarian cancer cell line SKOV-3. The results reveal that curcuminoids inhibit the proliferation of SKOV-3 cells with concentration- and time-dependent mechanisms. The morphological analysis of the treated SKOV-3 cells showed a typical apoptotic phenotype-cell shrinkage and membrane blebbing in a dose-dependent manner. In addition, flow cytometry demonstrated an increase in apoptosis with an IC50 of 30 mu M curcuminoids. The migration of SKOV-3 cells was also inhibited, reflected by a decrease in wound area. Furthermore, the curcuminoids were found to have no stimulation effect on the expression of cytokines TNF-alpha and IL-10. These results suggest that a curcuminoid mixture can effectively suppress epithelial cancer cell growth in vitro by inducing cellular changes and apoptosis.Deanship of Scientific Research (DSR) at King Abdulaziz University (KAU), Jeddah, S

Targeting microRNA/UHRF1 pathways as a novel strategy for cancer therapy

Ubiquitin-like containing plant homeodomain and RING finger domains 1 (UHRF1) is an anti-apoptotic protein involved in the silencing of several tumor suppressor genes (TSGs) through epigenetic modifications including DNA methylation and histone post-translational alterations, and also epigenetic-independent mechanisms. UHRF1 overexpression is observed in a number of solid tumors and hematological malignancies, and is considered a primary mechanism in inhibiting apoptosis. UHRF1 exerts its inhibitory activity on TSGs by binding to functional domains and therefore influences several epigenetic actors including DNA methyltransferase, histone deacetylase 1, histone acetyltransferase Tat-interacting protein 60 and histone methyltransferases G9a and Suv39H1. UHRF1 is considered to control a large macromolecular protein complex termed epigenetic code replication machinery, in order to maintain epigenetic silencing of TSGs during cell division, thus enabling cancer cells to escape apoptosis. MicroRNAs (miRNAs) are able to regulate the expression of its target gene by functioning as either an oncogene or a tumor suppressor. In the present review, the role of tumor suppressive miRNAs in the regulation of UHRF1, and the importance of targeting the microRNA/UHRF1 pathways in order to induce the reactivation of silenced TSGs and subsequent apoptosis are discussed