Targeting PI3K/AKT/mTOR-mediated autophagy for tumor therapy.

Autophagy is a highly conserved catabolic process and participates in a variety of cellular biological activities. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, as a critical regulator of autophagy, is involved in the initiation and promotion of a series of pathological disorders including various tumors. Autophagy also participates in regulating the balance between the tumor and the tumor microenvironment. Natural products have been considered a treasure of new drug discoveries and are of great value to medicine. Mounting evidence has suggested that numerous natural products are targeting PI3K/AKT/mTOR-mediated autophagy, thereby suppressing tumor growth. Furthermore, autophagy plays a "double-edged sword" role in different tumors. Targeting PI3K/AKT/mTOR-mediated autophagy is an important therapeutic strategy for a variety of tumors, and plays important roles in enhancing the chemosensitivity of tumor cells and avoiding drug resistance. Therefore, we summarized the roles of PI3K/AKT/mTOR-mediated autophagy in tumorigenesis, progression, and drug resistance of tumors, which may be utilized to design preferably therapeutic strategies for various tumors.

[Pirfenidone Inhibits Cytokines/chemokines Release from Alveolar Macrophages].

Objective To investigate the effect of pirfenidone on cytokine/chemokine production by alveolar macrophages(AMs)in patients with idiopathic nonspecific interstitial pneumonia(iNSIP)or idiopathic pulmonary fibrosis(IPF).Methods We prospectively enrolled 10 iNSIP patients,11 IPF patients,and 8 non-interstitial lung disease(non-ILD)patients(control group)from our center from January 2015 to December 2018.AMs from bronchoalveolar lavage fluid(BALF)were cultured with or without lipopolysaccharide(LPS)stimulation.The production of Th1 cytokines [soluble tumor necrosis factor receptor(sTNFR)-1,sTNFR-2,and interleukin(IL)-1ß],Th2 cytokines [IL-10 and granulocyte-macrophage colony-stimulating factor(GM-CSF)],angiogenic chemokines [IL-18 and macrophage inflammatory protein(MIP)-1ß],and angiostatic chemokines [interferon-gama inducible monokines(MIG)and interferon-gama inducible protein(IP-10)] in the culture supernatants were measured by a bead-based assay,Luminex.The effect of pirfenidone on the cytokine/chemokine production was tested at various concentrations(0,0.03,0.10,0.30 mg/ml).Results The spontaneous and LPS-stimulated release of TNF-α,sTNFR-1,sTNFR-2,IL-1ß,IL-10,MIP-1ß,MIG,and IP-10 by AMs were significantly increased in iNSIP and IPF groups compared with control group(all P<0.05),but no difference in IL-18 was seen among three groups(all P>0.05).MIG and IP-10 were significantly higher in iNSIP group than in IPF group(both P<0.05).Pirfenidone suppressed the spontaneous and LPS-stimulated AMs release of all studied cytokine/chemokine in iNSIP and IPF in a dose-dependent manner at concentrations of 0.10 and 0.30 mg/ml,and no difference was observed between iNSIP and IPF groups(both P>0.05).Conclusion Pirfenidone can markedly suppress cytokine/chemokine expression in iNSIP and IPF patients,but the difference is not significant between these two groups of patients.

The miR-15a/16 gene cluster in human cancer: A systematic review.

MicroRNAs (miRNAs) are an important class of endogenous small noncoding single-stranded RNAs that suppress the expression of their target genes through messenger RNA (mRNA) degradation to inhibit transcription and translation. MiRNAs play a crucial regulatory role in many biological processes including proliferation, metabolism, and cellular malignancy. miR-15a/16 is an important tumor suppressor gene cluster with a variety of factors that regulate its transcriptional activity. It has been discovered that a relative reduction of miR-15a/16 expression in various cancers is closely related to the occurrence and progression of tumors. miR-15a/16 takes part in a wide array of biological processes including tumor cell proliferation, apoptosis, invasion, and chemoresistance by binding to the 3'-untranslated region of its target gene's mRNA. In this review, we will examine the complex regulatory network of miR-15a/16 gene expression and its biological functions in human cancers to further elucidate the molecular mechanisms of its antitumor effects.

Endothelin-1, an important mitogen of smooth muscle cells of spontaneously hypertensive rats.

OBJECTIVE: To study the features of vascular smooth muscle cell (VSMC) proliferation induced by endothelin-1 (ET-1). METHODS: VSMCs of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats were cultured and treated with ET-1. Basic fibroblast growth factor (bFGF) gene expression was measured using both Northern blot and an enzyme-linked immunoassay. RESULTS: ET-1 resulted in an increase in bFGF transcripts at 8 - 24 h; bFGF levels were significantly higher in VSMCs treated with ET-1 than in those not treated. However, VSMCs growth responses in SHR and WKY were different. Smooth muscle cells of SHR were hyper-responsive to ET-1. Maximal bFGF mRNA levels were elevated 3.5-fold at 4 h of stimulation in WKY and 8-fold at 8h in SHR4. Moreover, the proliferation of VSMCs induced by ET-1 was inhibited by antisense phosphorothioate oligodeoxynucleotides (10 micromol/L AS-bFGF) but not sense bFGF oligomers at the same concentrations, being reduced by 80% in SHR and 40% in WKY vs control, respectively. Furthermore, the effect of AS-bFGF oligomers on SHR SMC proliferation is significantly greater than on WKY SMC proliferation. CONCLUSION: ET-1 may be required for exaggerated vascular growth responses in SHR and bFGF may be involved.

[CALM-AF10 fusion transcripts in primary leukemia with t(10;11) and in vitro chemotherapy sensitivity of leukemic cells with t(10;11)].

In order to determine the involvement of CALM-AF10 fusion transcripted in primary leukaemias with t(10;11) and its chemotherapy sensitivity in vitro, the AF10-CALM fusion transcripts were detected by reverse transcription-polymerase chain reaction (RT-PCR), and the chemotherapy sensitivity testing in vitro was undergone by MTT assay in five t(10;11) leukemia samples from patients with ALL, AML and lymphoblastic lymphoma. The results showed that five different-sized AF10-CALM product and four different-sized CALM-AF10 products were detected. The chemotherapy sensitivity of leukemic cells with t(10;11) in vitro to drugs is lower than that of leukemic cells without t(10;11). 3 out of 5 cases of t(10;11) leukemia were sensitive to chemotherapeutic drugs, while 31 out of 36 cases of leukemia without t(10;11) were sensitive at same condition. There were significant differences (P < 0.01), consistent with clinical features of patients. Apoptosis rate of leukemic cells with t(10;11) induced by chemotherapeutic drugs was lower than that of leukemic cells without t(10;11), (16.37 +/- 2.56)%, and (33.75 +/- 5.59)%, respectively (P < 0.01). It is concluded that the CALM-AF10 fusion transcripts are a common features and are involved in the pathogenesis of haematological malignancies with t(10;11), and are associated with a poor prognosis.

Probucol inhibits oxidized-low density lipoprotein-induced adhesion of monocytes to endothelial cells in vitro.

AIM: To investigate the mechanism by which probucol (PBC) affected adhesion of monocytes to human umbilical vein endothelial cells (HUVEC). METHODS: Effects of PBC on expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, a nd E-selectin in human umbilical vein endothelial cells were examined. Moreover, the inhibitory effect of PBC were compared with that of monoclonal antibodies (mAbs) to ICAM-1, VCAM-1, P-selectin, and E-select in on adhesion induced by oxidized-low density lipoprotein(Ox-LDL). RESULTS: PBC at 10 to 80 micromol/L inhibited Ox-LD L-induced adhesion index from 16.7 % to 7.0 % (P < 0.01) and Ox-LDL-induced expression of ICAM-1 (75 %) and P-selectin (72 %). mAbs to ICAM -1 or P-selectin, when used alone, could only slightly reduce the adhesion of monocyte to HUVEC. When both monoclonal antibodies were used in combination, the adhesion was markedly inhibited from 16.7 % to 11.3 % (P < 0.01), but the effect was still weaker than that of PBC (average 9.3 %). CONCLUSION: PBC exerts its inhibitory effect on the adhesion of monocyte to HUVEC by inhibiting the expression of ICAM-1 and P-selectin.