RESUMO
This study mainly explores the role of myeloid differentiation primary response protein 88 (MyD88) in tumorigenesis and development, to identify active compounds targeting MyD88. CRISPR/Cas9 system and xenograft tumor model were used to detect the effect of MyD88 deletion on tumor growth, and the experimental animal ethics review number was PZSHUTCM200828006. Microscale thermophoresis technology (MST) was used to identify compounds directly bind to MyD88 and further detect the impact of candidate small molecules on cell proliferation. Results showed that depletion of MyD88 significantly inhibited xenograft tumor growth of colon cancer, pancreatic cancer and skin cancer and the activity of NF-κB signaling pathway. MST showed that nordihydroguaiaretic acid (NDGA) bound to MyD88, with the binding dissociation constant Kd of 14.61 µmol·L-1. NDGA inhibited NF-κB reporting system activation and phosphorylation of p65, the key factor in NF-κB signal pathway. In addition, the results of colony formation assay showed that NDGA suppressed the proliferation of tumor cells. The above results show that, MyD88 is a potential therapeutic target for colon cancer, pancreatic cancer and skin cancer, NDGA directly binds to MyD88 and inhibits the activity of NF-κB signaling pathway, as well as inhibits the proliferation of pancreatic cancer, skin cancer and colon cancer cells.
RESUMO
Huachansu is a traditional Chinese medicine widely used in the clinic for cancer therapy, while the underlying mechanism is not fully clarified. This study was to investigate the targets and mechanisms of cinobufagin (CBG), an active component of Huachansu, in terms of blocking mitosis of cancer cells. Propidium iodide (PI) DNA staining was used to analyze the effect of CBG on cell cycle. The effect of CBG on mitosis of cancer cells was examined by α-tubulin and pericentrin staining after synchronization by a double thymidine block. Tubulin turbidity, tubulin polymerization and α-tubulin immunofluorescence assays were used to evaluate the effect of CBG on microtubule polymerization. CRISPR/Cas9 gene-editing technology was used to knockout microtubule-severing protein Katanin regulatory subunit B1 (KATNB1) in HCT116 cells, and the inhibitory effect of CBG on wild-type cells and knockout cells was measured by CCK-8. The engagement of CBG with KATNB1 was measured by CETSA and DARTS assays. The effect of CBG on KATNB1 protein and mRNA level was examined by Western blot and real-time PCR, respectively. Our data showed that CBG arrested HCT116 cell cycle at the G2/M phase, disrupted mitosis and induced centriole overduplication. CBG significantly inhibited tubulin polymerization in vitro and in vivo. The cytotoxicity of CBG inhibition on HCT116 was significantly attenuated upon KATNB1 depletion. Moreover, CBG bound to KATNB1 and decreased its protein level, while mutated KATNB1 weakened this effect. In conclusion, CBG inhibited microtubule polymerization via targeting KATNB1, thereby disrupting mitosis in cancer cells.
RESUMO
<p><b>OBJECTIVE</b>To investigate hereditary susceptibility to coronary heart disease (CHD) in apolipoprotein E(apo E) and apo B polymorphisms of youths.</p><p><b>METHODS</b>Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to analyze apoE, apoB Xba I, apoB 3' variable number of tandem repeat (VNTR) genotypes for 244 healthy Han students (among them were 109 students with positive CHD family history).</p><p><b>RESULTS</b>The allele frequencies of apo e4, XbaI x(+), 3'VNTR-B(hypervariable element, HVE>38) in the positive group were obviously higher than those in the negative group(P<0.05), and were significantly correlated with the increase in TC, LDL-C, apoB100 levels (P<0.05).</p><p><b>CONCLUSION</b>The alleles for apo e4, XbaI x(+), 3'VNTR-B may be the important genetic markers of Han CHD.</p>
