ABSTRACT
ObjectiveTo study the effect of Xianlian Jiedu prescription （XLJDP） on the activation of nuclear transcription factor-κB （NF-κB） signaling pathway induced by bromodomain-containing protein 4 （Brd4） in hypoxic microenvironment and to explore its mechanism in inhibiting the proliferation of colorectal cancer HT-29 cells. MethodThe human colorectal cancer HT-29 cells were cultured in a hypoxic incubator or normoxia incubator and treated with XLJDP at 0.8，1，1.2，1.6，3.2，6.4，and 12.8 g·L-1 for 48 h， respectively. Following the detection of cell vitality using methyl thiazolyl tetrazolium （MTT） colorimetry， the effects of XLJDP （1.25，2.5，and 5 g·L-1） on the cell mitochondrial membrane potential were determined using a fluorescent probe （JC-1）， and the apoptosis of colorectal cancer HT-29 cells was detected by flow cytometry. The cell colony formation assay and 5-ethynyl-2'-deoxyuridine （EDU） staining were conducted to test the proliferation of colorectal cancer HT-29 cells. The Western blot was carried out to measure the expression levels of Brd4 and its downstream relevant proteins such as c-Myc and hexamethylene bisacetamide-inducible protein 1 （HEXIM1）， as well as the effects of XLJDP on related proteins in the NF-κB signaling pathway. ResultCompared with the blank control group， XLJDP at 0.8，1，1.2，1.6，3.2，6.4，and 12.8 g·L-1 inhibited the vitality of colorectal cancer HT-29 cells （P<0.05 ， P<0.01）， with the median inhibitory concentration （IC50） under the hypoxic condition higher than that under the normoxia condition. Compared with the blank control group， XLJDP at 1.25，2.5，and 5 g·L-1 significantly decreased the mitochondria membrane potential， enhanced the apoptosis （P<0.05，P<0.01）， and lowered the number of cell colonies and also the EDU-positive cells （P<0.05， P<0.01）. The results of Western blot showed that compared with the blank control group， XLJDP at 1.25，2.5，and 5 g·L-1 down-regulated Brd4， c-Myc， p-NF-κB p65， and p-IκBα protein expression to varying degrees and up-regulated the expression of HEXIM1 （P<0.05， P<0.01）. ConclusionIn the hypoxic microenvironment， XLJDP inhibits the proliferation of colorectal cancer HT-29 cells regulated by Brd4， which may be related to its inhibition of the activation of NF-κB signaling pathway.
ABSTRACT
Rheumatoid arthritis (RA) is a systemic autoimmune disease whose development is closely related to the hypoxic mi-croenvironment of joints. Hypoxia-inducible factor-1 a (HIF-la) is a nuclear transcription factor that regulates cellular responses to hypoxia and plays an important role in promoting synovial inflammation, angiogenesis, pannus formation, cartilage destruction and bone erosion. In addition to regulation by oxygen receptors, its expression is regulated by multiple signal transduction pathways, including PI3K/Akt, Ras-Raf-MEK-ERK, JAK/STAT and NF-kB , etc. This article provides an overview of the signaling pathways involved in the regulation of HIF-la expres-sion, in order to provide new ideas and evidence for the treatment of RA and the search for new disease modifying antirheumatic drugs.
ABSTRACT
Hypoxia is one of the most important characteristics of malignant tumor microenvironment, and its degree is closely related to the development and prognosis of the tumor. Hypoxia promotes neovascularization in tumor microenvironment, which leads to changes of energy metabolism and the formation of drug tolerance in tumor. Studies in recent years have shown that TCM can interfere with the occurrence and development of hypoxia tumor microenvironment in certain aspects, thus inhibiting tumor growth. This article summarized recent studies on the etiology, pathogenesis, and TCM intervention for the occurrence and development of hypoxia tumor microenvironment in terms of spleen deficiency, blood stasis, and phlegm retention, and provided a reference for clinical intervention of tumors and research and development of new drugs.
ABSTRACT
Objective Drug resistance is a major problem for the successful chemotherapeutic treatment and prognosis of cervi -cal cancer .The article investigated the role of Twist on cisplatin resistance of Hela cervical cancer cells in hypoxia microenvironment and its possible mechanism to provide an experimental basis to improve the therapeutic efficacy for cervical cancer . Methods Hela Cells were divided into two groups, normal oxygen group A (no CoCl2) and hypoxia group A (addition of 150μmol/L CoCl2 medium).6 hours later, different degrees(10-3, 10-4, 10-5, 10-6, 10-7 mol/L) of cisplatin (10 -3 , 10 -4 , 10 -5 , 10 -6 , 10 -7 mol/L) were added into two groups .24 hours later , MTT were added to measure IC 50 and growth inhibition ratio .CoCl2 were used to mimic hypoxia environ-ment.The working concentration and the treatment duration of Cispla-tin was optimized by MTT method.The expressions of Twist and MDR1 in normal oxygen group , cisplatin group , hypoxic group B and hypoxic cisplatin group B were determined by immunofluores-cence and western blot . Results The IC50 values were 10 -5.3 mol/L and 10 -4.5 mol/L of cisplatin respectively in normal oxygen group and hypoxia group, and there was significantly difference between them (P<0.05).The optimized working concentration and work time of cisplatin was 10 -5 mol/L and 24 h.Compare to the normal oxygen group (13.08 ±2.39, 29.57 ±12.80), the expres-sions of Twist (20.81 ±2.07, 24.25 ±4.51, 33.14 ±4.24) and MDR1 (35.26 ±8.41, 60.13 ±22.32, 76.00 ±9.96) was signifi-cantly higher than those in other three groups and which were the highest in hypoxic cisplatin group (P<0.05).There were significant positive correlations among them in hypoxic group and hypoxic cisplatin group (r =0.686,P <0.05;r =0.546,P <0.05). Conclusion The hypoxia microenvironment may be related to the cisplatin resistance of Hela cervical cancer cells .The possible mechanism is hypoxia activates Twist and upregulates MDR 1 expression , resulting in cisplatin resistance of Hela cells .