Hypoxia-inducible factor 1α (HIF-1α) plays an important role in tumor growth and metastasis. Genetic variations of HIF1A gene have been shown to influence the developing risk and prognosis in many types of human malignancies. However, their association with clinical outcomes of hepatocellular carcinoma (HCC) patients remains unclear. To investigate the predictive role of single nucleotide polymorphisms (SNPs) in HIF1A gene in HCC patients’ outcomes, we genotyped three functional SNPs (rs2057482, rs1957757 and rs2301113) in HIF1A gene and assessed their associations with clinicopathological parameters and prognosis of 492 surgical HCC patients. The patients with variant alleles (CT+TT) of SNP rs2057482 had a significantly lower recurrence risk when compared with patients with the CC genotype. In stratified analysis, the protective effect of rs2057482 CT+TT genotype was more evident in patients with adverse strata, compared with patients with favorable strata. Additionally, strong joint predictive effect between rs2057482 genotypes and AFP level, stage or differentiation were observed. Functional assay also indicated the significant effect of rs2057482 on gene expression. In conclusion, SNP rs2057482 in HIF1A gene is significantly associated with clinical outcomes of Chinese HCC patients after surgery, especially in those with aggressive status, which warrants further validation in other patient populations.

Tumor necrosis factor-α has been proven an effective anticancer agent in preclinical studies. However, the translation of TNFα from research to clinic has been blocked by significant systemic toxicity and limited efficacy at maximal tolerated dose, which need urgently to be solved. The level of cytosolic Ca2+ was assessed by Fura-2 in HCC cells. After changing cytosolic Ca2+ level by using agonists or inhibitors, cell apoptosis was detected by flow cytometry. We also detected the effect of ionomycin or parvalbumin on the anti-tumor activity of TNFα in a mice model. Lastly, we studied the roles of cytosolic Ca2+ in the mitochondrial-dependent intrinsic apoptosis pathway. Here, we demonstrated that TNFα induced extracellular Ca2+ influx into cytoplasm through transient receptor potential channel in HCC cells. Both cytosolic Ca2+ scavenger and Ca2+-binding protein PV effectively desensitized hepatocellular carcinoma cells to TNFα, whereas combination ionomycin or 1,4,5-inositol triphosphate significantly sensitized HCC cells to TNFα, indicating that the increased level of cytosolic Ca2+ was positively correlated with the TNFα-induced cell apoptosis in vitro. In a nude mice xenograft model, our data revealed that TNFα combined with ionomycin remarkably synergized the anti-tumor effect of TNFα. Furthermore, we found that TNFα-mediated extracellular Ca2+ influx accelerated TNFα-induced extrinsic apoptosis through activating calpain/IAP/caspase3 pathway. Our study provides the evidence supporting a novel mechanism by which TNFα induces extracellular Ca2+ influx to enhance cell apoptosis and suggests that increasing the level of cytosolic Ca2+ might be an alternative strategy to improve the pro-apoptotic activity of TNFα in HCC cells, although suitable chemical or biological reagents need to be further tested.

Increasing evidence suggests that alterations in mitochondrial DNA (mtDNA) content may be implicated in the tumorigenesis of several malignancies. However, the association between mtDNA content in peripheral blood lymphocytes (PBLs) and glioma risk has not been investigated. Real-time PCR was used to examine the mtDNA content in PBLs of 414 glioma patients and 414 matched controls in a hospital-based case–control study. The association between mtDNA content and glioma risk was evaluated using an unconditional multivariate logistic regression model. We found that glioma patients exhibited a significantly higher median mtDNA content than healthy controls (0.99 vs. 0.71, P < 0.001). Unconditional multivariate logistic regression analysis adjusting for age, gender, smoking status, and family cancer history showed that there was an S-shaped association between mtDNA content and glioma risk. Higher mtDNA content was significantly associated with an elevated risk of glioma. Compared with the first quartile, the odds ratio (95% confidence interval) for subjects in the second, third, and fourth quartiles of mtDNA content were 0.90 (0.52-1.53), 3.38 (2.15-5.31), and 5.81 (3.74-9.03), respectively (P for nonlinearity = 0.009). Stratified analysis showed that the association between mtDNA content and glioma risk was not modulated by major host characteristics. Our findings demonstrate for the first time that a higher mtDNA content in PBLs is associated with an elevated risk of glioma, which warrants further investigation in larger populations.

The KRAB‐type zinc‐finger protein Apak was recently identified as a negative regulator of p53‐mediated apoptosis. However, the mechanism of this selective regulation is not fully understood. Here, we show that Apak recognizes the TCTTN2−30TTGT consensus sequence through its zinc‐fingers. This sequence is specifically found in intron 1 of the proapoptotic p53 target gene p53AIP1 and largely overlaps with the p53‐binding sequence. Apak competes with p53 for binding to this site to inhibit p53AIP1 expression. Upon DNA damage, Apak dissociates from the DNA, which abolishes its inhibitory effect on p53‐mediated apoptosis. There is a [Hot off the Press][1] (April 2012) associated with this Scientific Report. [1]: http://dx.doi.org/10.1038/embor.2012.33