ObjectiveTo study the effect of Tangeretin on non-small cell lung cancer (NSCLC) and the tumor stemness, and to find the molecular mechanism of its effect. MethodsWe used cell counting and cell cloning experiments to study the effect of Tangeretin on the proliferation of NSCLC cells in vitro. The effect of Tangeretin on the invasion of NSCLC cells was detected by transwell assay. We detected the effect of Tangeretin on the proliferation of NSCLC cells in vivo by nude mouse tumor-bearing experiment. The effect of Tangeretin on tumor stemness of NSCLC cells was detected by self-renew assay, and CD133 and Nanog protein expressions. The expressions of PI3K/AKT/mTOR signaling pathway-related proteins were detected by Western blotting (WB). ResultsTangeretin had a good inhibitory effect on the proliferation of NSCLC cells in vivo and in vitro. Cell counting experiment, clonal formation experiment and nude mouse tumor-bearing experiment showed that Tangeretin could inhibit the proliferation activity, clonal formation ability, and tumor size of NSCLC cells in vivo. Self-renew experiments showed that Tangeretin could inhibit the self-renew ability of NSCLC cells. WB experiments showed that Tangeretin inhibited the expressions of tumor stemness markers CD133 and Nanog in NSCLC cells. Tangeretin could inhibit the activation of PI3K/AKT/mTOR signaling pathway-related proteins in NSCLC cells, and the activation of PI3K/AKT/mTOR signaling pathway could partially remit the inhibitory effect of Tangeretin on tumor stemness of NSCLC cells. ConclusionTangeretin can inhibit the tumor stemness of NSCLC cells, which may be related to the regulation of PI3K/AKT/mTOR signaling pathway.
ObjectiveTo understand the research status of phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signaling pathway in the thyroid cancer (TC), as well as its role in the occurrence, cell differentiation, invasion, and metastasis of the TC, so as to find potential targets for treatment of TC. MethodThe literature about the research of PI3K/AKT signaling pathway in the TC was searched and summarized. ResultsThe PI3K/AKT signaling pathway was abnormally activated directly or indirectly in the TC, resulting in inhibition of cell apoptosis, malignant proliferation, accelerated cycle progression, invasion, and metastasis, etc., which promoted the occurrence and development of the TC. There were also some tumor suppressor genes, microRNAs, long chain non-coding RNAs, etc., which indirectly inhibited the activation of PI3K/AKT signaling pathway, or directly acted on it inhibiting its activity to inhibit the occurrence and development of the TC. ConclusionsFor the TC, some proteins, genes, microRNAs, and long chain non-coding RNAs directly or indirectly activate the PI3K/AKT signaling pathway through different targets to promote the occurrence and development of TC. At the same time, many targets inhibit the activation of the PI3K/AKT signaling pathway, which inhibits the malignant proliferation, invasion, and metastasis of TC. At present, there have been studies trying to use PI3K/AKT signaling pathway as a breakthrough for the treatment of TC. In-depth exploration of the role of PI3K/AKT signaling pathway in different TC is of great significance to find new targets for the treatment of TC.
Objective To investigate the effect of Wnt/β-catenin signal pathway on the apoptosis in steroid-induced avascular necrosis of femoral head (SANFH) in rats. Methods Seventy-two male Sprague Dawley rats (weighing, 200-230 g) were randomly divided into the control group (group A, n=24), the model group (group B, n=24), and the intervening group (group C, n=24). The rats in groups B and C were injected with lipopolysaccharide and methylprednisolone (MPS) to establish the SANFH model. The rats in group C were injected intramuscularly with human recombinant secreted frizzled related protein 1 (SFRP1) [1 μg/(kg·d)] at the first time of MPS administration for 30 days. The rats in group A received saline injection at the same injection time of group B. The general condition of rats in groups B and C was observed during modeling and after modeling. At 2, 4, and 8 weeks after last injection of MPS, 8 rats were sacrificed to harvest the femoral head. Histological staining was performed to evaluate osteonecrosis. Apoptosis was detected via TUNEL staining. The expressions of Wnt/β-cate nin pathway signaling molecules (activated β-catenin and c-Myc) were detected by immunohistochemistry and Western blot. Results Six rats were added in groups B and C because of 6 deaths. The other rats survived to the end of experiment. Normal bone structure was observed in group A; osteonecrosis of bone structure disturbance and disruption of the trabecula were found with time in groups B and C. Group C had the highest empty lacuna rate and apoptosis rate, followed by groups B and A, showing significant difference between groups (P < 0.05). The expression levels of activated β-catenin and c-Myc were significantly lower in group C than groups A and B (P < 0.05), and in group B than group A (P < 0.05). Conclusion Wnt/β-catenin signal pathway is involved in the pathogenesis in early SANFH model and its possible mechanism is to affect the cell cycle and cell apoptosis by the regulation of c-Myc expression.
Objective To investigate the role of AKT/FOXOs /atrogin-1/MuRF1 signaling pathway in skeletal muscle atrophy in rats with chronic obstructive pulmonary diseases( COPD) .Methods Passive cigarette smoking was used to establish COPD model. The protein expression of atrogin-1, MuRF1, FOXO-1, phosohorylated-AKT and total AKT were measured by Western blot. The mRNA expression of atrogin-1, MuRF1 and FOXO-1 were measured by reverse transcription-polymerase chain reaction( RT-PCR) . Results Compared with the control group, the mRNA expressions of atrogin-1, MuRF1 and FOXO-1 significantly increased in extensor digitorum longus ( EDL) of the COPD group (Plt;0.05 ) . Meanwhile the protein expression of atrogin-1 and MuRF1 significantly increased in the COPD group(Plt;0.05) , while the protein expression of FOXO-1 was not significantly different between two groups(Pgt;0.05) . In addition, , the protein expression of phosohorylated-AKTand the ratio of phosohorylated-AKT to total AKT significantly increased in EDL of the COPD group(Plt;0.05) . Conclusion The mRNA and protein expression of AKT/FOXOs/ atrogin-1 /MuRF1 in skeletal muscle are significantly increased in COPD rats, suggesting that AKT/FOXOs/ atrogin-1 /MuRF1 signalling pathway plays a crucial role in skeletal muscle atrophy of COPD.
Continuous activation of Janus kinase (JAK)- signal transduction and activator of transcription (STAT) signaling pathway is prevalent in leukemia cells, and it has been found that this pathway plays an important role in acute leukemia (AL). JAK2/JAK1 gene mutations are found in both acute myelocytic leukemia and acute lymphoblastic leukemia and may have implications for the treatment and overall prognosis of the disease. Among the STAT family members, STAT3 and STAT5 proved to be key factors in AL. These gene mutations may provide new targets and new ideas for the treatment of AL. This article provides a review of the research progress of JAK-STAT signaling pathway, related gene mutations and AL.
Objective To review the research progress of hair follicle stem cell(FSC) in wound healing and correlative signals. Methods The advances in the FSC location, characters, relations with wound repair and correlative singals were introduced based on the recent related literature. Results FSC played an important role in hair follicle cycle and wound healing. The correlative signals maybe Wnt, bone morphogenetic protein/transforming growth factor β, Norch, Shh and fibroblast growth factor. Conclusion The multipotency and plasticity of FSC offer a new way in regeneration medicine and the signals in cell proliferation and differentiation will be the new focus in future research.
Objective To explore the protective effect of rapamycin on brain tissues injury in severe acute pancreatitis (SAP) and its possible mechanism in experimental rats. Methods Ninety SPF males SD rats were randomly divided into 3 groups by random envelope opening method: sham operation group (SO group), SAP group, and rapamycin group (RAPA group), then the rats of each group were divided into 24 h, 36 h, and 48 h 3 subgroups by random number table method. Rats in each group underwent laparotomy, the model was prepared by retrograde injection of solutions into biliopancreatic duct, rat of the SO group was injected with 0.9% normal saline (2 mL/kg), rats of the SAP group and the RAPA group were injected with 5% sodium taurocholate solution (2 mL/kg), but rat of the RAPA group was injected with rapamycin (1 mg/kg) at 30 min before narcosis. All survival rats in each subgroup were killed at 24 h, 36 h, and 48 h respectively, then the pancreas and brain tissues of rats were collected, pancreas and brain tissues were stained by hematoxylin-eosin staining, brain tissues were stained by Luxol fast blue additionally, pathological changes of brain tissues were scored under light microscope. The protective effect of rapamycin on brain tissues injury was determined by comparing the differences in the degree of brain tissues among 3 groups. The phosphorylated mammaliantarget of rapamycin (p-mTOR) and phosphorylated ribosomal 40S small subunitS6 protein kinase (p-S6K1) expression levels in brain tissues were detected by Western blot. In addition, the correlations between the expression levels of p-mTOR and p-S6K1 in brain tissues and the degree of brain tissues injury were analyzed to further explore the possible mechanism of rapamycin’s protective effect on brain tissues injury in SAP. Results① At the point of 24 h, 36 h, and 48 h, the order of the relative expression levels of p-mTOR and p-S6K1 in brain tissues of three groups were all as follows: the SO group < the RAPA group < the SAP group (P<0.05). ② At the point of 24 h, 36 h, and 48 h, the order of brain histological score in three groups were all as follows: the SO group < the RAPA group < the SAP group (P<0.05). ③ The relative expression levels of p-mTOR and p-S6K1 in brain tissues were positively correlated with pathological scores of brain tissues (r=0.99, P<0.01; r=0.97, P<0.01). ConclusionRapamycin plays a protective role in pancreatic brain tissues injure by down-regulating the expression levels of p-mTOR and p-S6K1 in mTOR signaling pathway.
Objective To explore mechanism of gastric bypass in treating obesity with type 2 diabetes mellitus (T2DM) and its relationship with c-Jun N-terminal kinase (JNK) signaling pathway. Methods The INS-1 cells were divided into 4 groups according to the different treatment: control group (complete medium), high glucose group (30 mmol/L glucose medium), exendin-4 group (high glucose+100 nmol/L exendin-4), and JNK agonist group (high glucose+100 nmol/L exendin-4+JNK agonist). When these cells were cultured on day 7, the cell activity was assessed by the MTT staining. The cell apoptosis was determined by the fluorescence microscopy analysis after the Hoechst/PI staining and flow cytometric assay after the Annexin V-FITC/PI staining. The expressions of the human immunoglobulin binding protein (Bip), CCAAT/enhancer-binding protein homologous protein (CHOP), P-SAPK/JNK, and caspase-3 protein were detected by the Western blot. Results Compared with the control group, the cell activities were significantly decreased (P<0.05), the cell apoptosis rates and the P-SAPK/JNK and caspase-3 protein expression levels were significantly increased (P<0.01) in the high glucose group and the JNK agonist group, but the Bip and CHOP protein expression levels were significantly increased (P<0.01) in the high glucose group. Compared with the high glucose group, the cell activity was significantly increased (P<0.05), the cell apoptosis rate and the Bip, CHOP, P-SAPK/JNK, and caspase-3 protein expression levels were significantly decreased (P<0.01) in the exendin-4 group, the Bip and CHOP protein expression levels were significantly decreased (P<0.01) in the JNK agonist group. Compared with the exendin-4 group, the cell activity was significantly decreased (P<0.05), the cell apoptosis rate and the P-SAPK/JNK and caspase-3 protein expression levels were significantly increased (P<0.01) in the JNK agonist group. Conclusion Gastric bypass can inhibit endoplasmic reticulum stress of pancreatic islet β-cells by regulating secretion of glucagon like peptide-1, thereby inhibiting JNK signaling pathway, protecting pancreatic islet β-cells and inhibiting apoptosis, so as to achieve effect of treating T2DM.
In this study, we aim to investigat the effect of microgravity on osteoblast differentiation in osteoblast-like cells (MC3T3-E1). In addition, we explored the response mechanism of nuclear factor-kappa B (NF-κB) signaling pathway to " zero-g” in MC3T3-E1 cells under the simulated microgravity conditions. MC3T3-E1 were cultured in conventional (CON) and simulated microgravity (SMG), respectively. Then, the expression of the related osteoblastic genes and the specific molecules in NF-κB signaling pathway were measured. The results showed that the mRNA and protein levels of alkaline phosphatase (ALP), osteocalcin (OCN) and type Ⅰ collagen (CoL-Ⅰ) were dramatically decreased under the simulated microgravity. Meanwhile, the NF-κB inhibitor α (IκB-α) protein level was decreased and the expressions of phosphorylation of IκB-α (p-IκB-α), p65 and phosphorylation of p65 (p-p65) were significantly up-regulated in SMG group. In addition, the IL-6 content in SMG group was increased compared to CON. These results indicated that simulated microgravity could activate the NF-κB pathway to regulate MC3T3-E1 cells differentiation.
ObjectiveTo summarize the mechanism of long non-coding RNA (lncRNA) in signal pathways related to osteogenic differentiation. Methods Relevant domestic and foreign researches in recent years were consulted. The characteristics and biological functions of lncRNA were introduced, and the specific mechanism of lncRNA regulating related signal pathways in osteogenic differentiation was elaborated. Results The exertion and maintenance of normal function of bone requires the closed coordination of transcription networks and signal pathways. However, most of these signal pathways or networks are dysregulated under pathological conditions that affect bone homeostasis. lncRNA can regulate the differentiation of various bone cells by activating or inhibiting signal pathways to achieve the balance of bone homeostasis, thereby reversing the pathological state of bones and achieving the purpose of treating bone metabolic diseases. Conclusion At present, the research on the mechanism of lncRNA regulating various osteogenic differentiation pathways is still in the early stage. Its in-depth regulator mechanism, especially the cross-talk of complex signal pathways needs to be further studied. And how to apply these molecular targets to clinical treatment is also a big challenge.