Antisense oligonucleotide of hypoxia-inducible factor-1alpha suppresses growth and tumorigenicity of lung cancer cells A549

PHD3 affects gastric cancer progression by negatively regulating HIF1A

Prolyl hydroxylase 3 (PHD3) is widely accepted as a tumor suppressor; however, the expression of PHD3 in various cancer types remains controversial. The present study aimed to investigate the association between PHD3 expression and the clinicopathological features of gastric cancer using reverse transcription‑quantitative polymerase chain reaction and immunohistochemistry. The effects of PHD3 in gastric cancer cell lines were assessed using western blot analysis and transwell migration assays. The present results revealed that PHD3 expression was increased in adjacent non‑cancerous tissue compared with in gastric cancer tissue, and PHD3 overexpression was correlated with the presence of well‑differentiated cancer cells, early cancer stage classification and the absence of lymph node metastasis. In vitro experiments demonstrated that PHD3 may act as a negative regulator of hypoxia‑inducible factor‑1α and vascular endothelial growth factor, both of which participate in tumor angiogenesis. In conclusion, the present results suggested that PHD3 may act as a tumor suppressor in gastric cancer. Therefore, the targeted regulation of PHD3 may have potential as a novel therapeutic approach for the treatment of patients with gastric cancer.

SOCS3 blocks HIF-1α expression to inhibit proliferation and angiogenesis of human small cell lung cancer by downregulating activation of Akt, but not STAT3

Suppressor of cytokine signaling 3 (SOCS3) is a major negative regulator of signal transducer and activator of transcription 3 (STAT3) during tumorigenesis. Previous studies have indicated that SOCS3 also regulates other signaling pathways, such as PI3K/Akt. However, little is known about the specific molecular mechanisms by which SOCS3 regulates the proliferation and angiogenesis of small cell lung cancer (SCLC) cells. The present study investigated the effect of SOCS3 upregulation on the expression of hypoxia-inducible factor-1α (HIF-1α) and how this affects the proliferation and angiogenesis of SCLC cells. It was investigated whether this interaction is associated with STAT3 or the Akt signaling pathway. The results of the present study revealed that SOCS3 negatively regulates proliferation and angiogenesis of NCI-H446 cells and that HIF-1α is required in this process. The results also suggested a suppressive role of SOCS3 in Akt signaling, but not STAT3 signaling to block HIF-1α expression and a previously unidentified regulatory mechanism for Akt function. In conclusion, the present study suggested that SOCS3 targets the Akt signaling pathway to inhibit HIF-1α expression and affect the growth and angio-genesis of SCLC cells, and may therefore be considered as a potential novel therapeutic for the treatment of SCLC.

Polymorphisms of HIF1A gene are associated with prognosis of early stage non-small-cell lung cancer patients after surgery

Hypoxia-inducible factor 1α (HIF1α) activates the transcription of genes that are involved in angiogenesis and cell survival. Over-expression of HIF1α caused by intratumoral hypoxia and its genetic alterations are associated with increased mortality in several cancer types including non-small-cell lung cancer (NSCLC). The aim of this study was to investigate the predictive role of single nucleotide polymorphisms (SNPs) in HIF1A gene in NSCLC outcomes. We genotyped two functional SNPs (rs2057482 and rs2301113) in HIF1A gene and assessed their associations with clinicopathological parameters and prognosis of 494 NSCLC patients by Cox proportional hazard model. There was no significant association between the SNPs and clinical outcomes of NSCLC for overall analysis. However, in stratified analysis for NSCLC patients at early stage (I/II), we observed a protective effect conferred by variant genotype of rs2057482 on overall survival (OS) (HR 0.42, 95% CI 0.22-0.80) and recurrence-free survival (RFS) (HR 0.60, 95 % CI 0.36-0.97) in a dominant model. Additionally, multivariate Cox analysis based on dominant model indicated that significant increased death and recurrence risks were observed in patients with early T-stage (T1 and T2) tumors, who carrying variant-containing genotype of rs2301113, as well as in patients without lymph node involvement (N0 stage) for rs2057482. Genetic variations on HIF1A gene are significantly associated with NSCLC outcomes in patients with early stage disease.

Inhibitory effect of hypoxia inducible factor-1 antisense oligonucleotide on growth of human hepatocellular carcinoma cells

OBJECT

To observe the inhibitory effect of Hypoxia inducible factor-1 antisense oligonuclecotide on growth of human hepatocellular carcinoma cells and gene expression of HIF-1, in order to seek a new gene therapy for hepatocellular carcinoma.

METHODS

Six Hypoxia inducible factor-1 antisense oligonuclecotides with various concentrations (0.2 micromol/l, 0.4 micromol/l, and 0.8 micromol/l) were transformed into HepG2 cells by lipofectamine reagent. 72 h after transfection, MTS assay was used to detect cellular proliferation. In addition, Hypoxia inducible factor-1 antisense oligonuclecotide2 with various concentrations (0.2, 0.4, 0.8, and 1.0 micromol/l) were transformed into HepG2 cells. About 48 h after transfection, reverse transcription-polymerase chain reaction assay and Western Blot assay were employed to detect the expression of Hypoxia inducible factor-1 gene and the synthesis of Hypoxia inducible factor-1 protein respectively.

RESULTS

HepG2 cell growth was inhibited by 6 Hypoxia inducible factor-1 antisense oligonuclecotides at various concentrations. Among them, Hypoxia inducible factor-1 antisense oligonuclecotide2 showed the most effective inhibition ability (P < 0.01), the inhibitory rate was 89.66% at the concentration of 1.0 micromol/l. About 48 h after transfection, Hypoxia inducible factor-1 mRNA expression was downregulated and Hypoxia inducible factor-1 protein synthesis was decreased by antisense oligonuclecotide2.

CONCLUSIONS

The hepatocellular carcinoma cell proliferation was inhibited by Hypoxia inducible factor-1 antisense oligonuclecotide. Moreover, the gene expression and protein synthesis of Hypoxia inducible factor-1 were reduced by Hypoxia inducible factor-1 antisense oligonuclecotide. The findings suggested that antisense technique targeting Hypoxia inducible factor-1 might be an effective gene therapy of human hepatocellular carcinoma.