Inhibition of Sonic Hedgehog Signaling Pathway by Thiazole Antibiotic Thiostrepton Attenuates the CD44+/CD24-Stem-Like Population and Sphere-Forming Capacity in Triple-Negative Breast Cancer.

BACKGROUND/AIM: Triple-negative breast cancer (TNBC) represents a particular clinical challenge because these cancers do not respond to endocrine therapy or other available targeted agents. The lack of effective agents and obvious targets are major challenges in treating TNBC. In this study we explored the cytostatic effect of thiazole ring containing antibiotic drug thiostrepton on TNBC cell lines and investigated the molecular mechanism. METHODS: Cell viability was measured by MTT assay. Cell surface marker was monitored by FCM. Western blot was applied to assess the protein expression levels of target genes. RESULTS: We found that thiostrepton remarkably suppressed the CD44+/CD24- stem-like population and sphere forming capacity of TNBC cell lines. Notably, we showed for the first time that thiostrepton exerted its pharmacological action by targeting sonic hedgehog (SHH) signaling pathway. Thiostrepton repressed SHH ligand expression and reduced Gli-1 nuclear localization in TNBC cell line. Furthermore, the downstream target of SHH signaling undergone dose-dependent, rapid, and sustained loss of mRNA transcript level after thiostrepton treatment. Finally, we showed that SHH ligand was essential for maintaining CD44+/CD24- stem-like population in TNBC cell line. CONCLUSION: We conclude that thiostrepton suppresses the CD44+/CD24- stem-like population through inhibition of SHH signaling pathway. Our results give a new insight into the mechanism of thiostrepton anti-tumor activity and suggest thiostrepton as a promising agent that targets hedgehog signaling pathway in TNBC.

[Association of L-selectin gene polymorphism with susceptibility to coronary heart disease].

OBJECTIVE: To investigate the possible association between L-selectin gene P213S polymorphism and coronary heart disease (CHD) in Chinese population. METHODS: In total 212 CHD patients diagnosed by angiography and 230 healthy controls were studied. The genotype and allele frequencies of L-selectin gene polymorphism were assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The frequency of the L-selectin gene 213P allele in CHD patients was significantly higher than that in the control group (77.59% vs 69.35%, P=0.006). Compared with the SS genotype, PP homozygote had a significantly increased CHD risk (OR=2.70 and OR=2.15 using unadjusted and adjusted Logistic regression models, respectively). No association was found between the severity of CHD and the Lselectin gene P213S polymorphism CONCLUSION: Our findings suggest that L-selectin gene 213P mutant allele might contribute to susceptibility of Chinese individuals to contract CHD.

[Association of C-159T polymorphism in promoter region of CD14 and coronary heart disease].

OBJECTIVE: To investigate the distribution of CD14 promoter gene -159(C>T) polymorphism in Hubei Han population of China and analyze the association of CD14 polymorphisms with coronary heart disease (CHD). METHODS: Genotypes of CD14 were typed in 162 CHD patients and 196 controls by polymerase chain reaction-restriction fragment length polymorphism. Selected coronary angiography was performed in 162 CHD patients. RESULTS: CD14 promoter -159 genotype frequencies of CC, CT and TT were 27.4%, 45.6%, 27.0% and 14.8%, 46.5%, 38.7% in normal control group and CHD group respectively. Genotype distribution was in accordance with Hardy-Weinberg equilibrium. There existed statistically significant difference in frequencies of allele and genotype in CD14 C-159T polymorphism between CHD group and control group (Genotype: Chi2=0.654, P < 0.05, CT vs CC, OR=1.245, 95%CI: 1.001-1.473, TT vs CC, OR=2.374, 95%CI 2.012-2.649; Allele: Chi2=0.547, P < 0.05, T vs C, Chi2=0.547, P < 0.05, OR=3.105, 95%CI: 2.493-3.539). The distributions of allele and genotype in CD14 -159(C>T) were of statistically significant difference between non-myocardial infarction subgroup and myocardial infarction subgroup (Genotype: Chi2=0.782, P < 0.05, CT vs CC, OR=2.375, 95%CI: 2.017-2.689, TT vs CC, OR=3.459, 95%CI: 3.003-3.846. Allele: Chi2=2.374, P < 0.05, T vs C, Chi2=2.374, P < 0.05, OR=4.011, 95%CI: 3.814-4.279). However, no statistically significant difference was found among the subgroups of oneìtwo and three stenosed vessels. CONCLUSION: The T allele of the C-159T polymorphism of CD14 gene may be a risk factor for myocardial infarction.