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Leptin influences estrogen metabolism and increases DNA adduct formation in breast cancer cells
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作者 Samia Shouman Mohamed Wagih Marwa Kamel 《Cancer Biology & Medicine》 SCIE CAS CSCD 2016年第4期505-513,共9页
Objective: The elevated incidence of obesity has been paralleled with higher risks of breast cancer. High adiposity increases leptin secretion from adipose tissue, which in turn increases cancer cell proliferation. Th... Objective: The elevated incidence of obesity has been paralleled with higher risks of breast cancer. High adiposity increases leptin secretion from adipose tissue, which in turn increases cancer cell proliferation. The interplay between leptin and estrogen is one of the mechanisms through which leptin influences breast carcinogenesis. An unbalanced estrogen metabolism increases the formations of catechol estrogen quinones, DNA adducts, and cancer mutations. This study aims to investigate the effect of leptin on some estrogen metabolic enzymes and DNA adduction in breast cancer cells.Methods: High performance liquid chromatography(HPLC) was performed to analyze the DNA adducts 4-OHE1[E2]-1-N3 adenine and 4-OHE1[E2]-1-N7 guanine. Reporter gene assay, real time reverse transcription polymerase chain reaction(real time RT-PCR), and Western blot were used to assess the expression of estrogen metabolizing genes and enzymes: Cytochrome P-4501B1(CYP1B1), Nicotinamide adenine dinucleotide phosphate-quinone oxidoreductase1(NQO1), and Catechol-O-methyl transferase(COMT).Results: Leptin significantly increased the DNA adducts 4-OHE1[E2]-1-N3 adenine and 4-OHE1[E2]-1-N7 guanine.Furthermore, leptin significantly upregulated CYP1B1 promoter activity and protein expression. The luciferase promoter activities of NQO1 and m RNA levels were significantly reduced. Moreover, leptin greatly reduced the reporter activities of the COMT-P1 and COMT-P2 promoters and diminished the protein expression of COMT.Conclusions: Leptin increases DNA adduct levels in breast cancer cells partly by affecting key genes and enzymes involved in estrogen metabolism. Thus, increased focus should be directed toward leptin and its effects on the estrogen metabolic pathway as an effective approach against breast cancer. 展开更多
关键词 Breast cancer LEPTIN estrogen metabolism DNA adducts
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Optimal Deep Transfer Learning Based Colorectal Cancer Detection and Classification Model
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作者 Mahmoud Ragab Maged Mostafa Mahmoud +2 位作者 Amer H.Asseri Hani Choudhry Haitham A.Yacoub 《Computers, Materials & Continua》 SCIE EI 2023年第2期3279-3295,共17页
Colorectal carcinoma(CRC)is one such dispersed cancer globally and also prominent one in causing cancer-based death.Conventionally,pathologists execute CRC diagnosis through visible scrutinizing under the microscope t... Colorectal carcinoma(CRC)is one such dispersed cancer globally and also prominent one in causing cancer-based death.Conventionally,pathologists execute CRC diagnosis through visible scrutinizing under the microscope the resected tissue samples,stained and fixed through Haematoxylin and Eosin(H&E).The advancement of graphical processing systems has resulted in high potentiality for deep learning(DL)techniques in interpretating visual anatomy from high resolution medical images.This study develops a slime mould algorithm with deep transfer learning enabled colorectal cancer detection and classification(SMADTL-CCDC)algorithm.The presented SMADTL-CCDC technique intends to appropriately recognize the occurrence of colorectal cancer.To accomplish this,the SMADTLCCDC model initially undergoes pre-processing to improve the input image quality.In addition,a dense-EfficientNet technique was employed to extract feature vectors from the pre-processed images.Moreover,SMA with Discrete Hopfield neural network(DHNN)method was applied for the recognition and classification of colorectal cancer.The utilization of SMA assists in appropriately selecting the parameters involved in the DHNN approach.A wide range of experiments was implemented on benchmark datasets to assess the classification performance.A comprehensive comparative study highlighted the better performance of the SMADTL-CDC model over the recent approaches. 展开更多
关键词 Colorectal cancer deep transfer learning slime mould algorithm hyperparameter optimization biomedical imaging
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Anti-nitric oxide production, anti-proliferation and antioxidant effects of the aqueous extract from Tithonia diversifolia 被引量:1
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作者 Poonsit Hiransai Jitbanjong Tangpong +5 位作者 Chuthamat Kumbuar Namon Hoonheang Onrunee Rodpech Padchara Sangsuk Urairat Kajklangdon Waraphorn Inkaow 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2016年第11期950-956,共7页
Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of... Objective: To determine the cytotoxicity, reduction in nitric oxide production and antioxidative activity of the aqueous leaf extract from Tithonia diversifolia(T. diversifolia) in an in vitro model.Methods: Leaves of T. diversifolia were collected from natural habitats and extracted with distilled water using the decoction method. The cytotoxic effect of the extract in terms of cell viability was determined using RAW264.7 cells and human peripheral blood mononuclear cells(PBMCs) via the mitochondrial respiration method using the MTT reagent. The effect of the extract on lipopolysaccharide(LPS)-induced nitric oxide production in RAW264.7 cells was measured using the Griess reagent. The chemical antioxidant was evaluated by ABTS- and DPPH-radical scavenging assays.Results: The half-maximal cytotoxic concentration values were 145.87 mg/m L and73.67 mg/m L for human PBMCs and RAW264.7 cells, respectively. In the presence of phytohemagglutinin-M, the IC_(50) on PBMCs proliferation was 4.42 mg/m L. The noncytotoxic range of the extracts inhibited LPS-induced nitrite production in RAW264.7 cells with an IC_(50) value of 11.63 mg/m L. To determine the anti-oxidative properties, the N-acetyl cysteine equivalent antioxidant capacity of the extract was(32.62 ± 1.87) and(20.99 ± 2.79)mg N-acetyl cysteine/g extract, respectively determined by the ABTS-radical and DPPHradical assay. However, the extract did not confer death protection in a hydrogen peroxideinduced RAW264.7 co-culturing model.Conclusions: Our study demonstrated the immunomodulation caused by the aqueous leaf extract of T. diversifolia, resulting from the inhibition of phytohemagglutinin-Minduced PBMCs proliferation and LPS-induced nitric oxide production in RAW264.7macrophages. Although the anti-oxidative activity was presented in the chemical-based anti-oxidant assay, the extract cannot protect cell death from stress conditions. 展开更多
关键词 Tithonia diversifolia Anti-nitric oxide production ANTI-PROLIFERATION ANTIOXIDANT
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