Differential expression of hypoxia inducible factor-1 alpha and tumor cell proliferation between squamous cell carcinomas and adenocarcinomas among operable non-small cell lung carcinomas

This study aimed to evaluate whether the elevated level of hypoxia-inducible factor-1alpha (HIF-1alpha) correlated with histologic types, angiogenesis, tumor cell proliferation, and clinical parameters in common non-small cell lung carcinomas (NSCLCs). We performed immunohistochemical stains using paraffin-embedded tissue blocks from 84 cases of operable NSCLC [No. of squamous cell carcinoma (SCC), 45; No. of adenocarcinoma (AC), 39]. HIF-1alpha expression was related with histologic types (66.7% in SCCs vs 20.5% in ACs, p<0.001), but not with lymph node status, tumor stage, vascular endothelial growth factor expression, microvessel density (MVD), and proliferating cell nuclear antigen (PCNA) index (p>0.05, respectively). As for the histologic types, MVD and PCNA index were significantly higher in SCCs than in ACs (p=0.009 and p=0.016, respectively). Among HIF-1alpha positive carcinomas, MVD was significantly higher in HIF-1alpha positive SCCs than in HIF-1alpha positive ACs (p=0.023). The overall survival curves were not associated with HIF-1alpha expression or any other histologic parameters (p>0.05). These findings suggest that HIF-1alpha expression in NSCLCs may play a differential role according to histologic types, but its prognostic significance is indeterminate.     

Promotion of airway anastomotic microvascular regeneration and alleviation of airway ischemia by deferoxamine nanoparticles

Airway tissue ischemia and hypoxia in human lung transplantation is a consequence of the sacrifice of the bronchial circulation during the surgical procedure and is a major risk factor for the development of airway anastomotic complications. Augmented expression of hypoxia-inducible factor (HIF)-1α promotes microvascular repair and alleviates allograft ischemia and hypoxia. Deferoxamine mesylate (DFO) is an FDA-approved iron chelator which has been shown to upregulate cellular HIF-1α. Here, we developed a nanoparticle formulation of DFO that can be topically applied to airway transplants at the time of surgery. In a mouse orthotopic tracheal transplant (OTT) model, the DFO nanoparticle was highly effective in enhancing airway microvascular perfusion following transplantation through the production of the angiogenic factors, placental growth factor (PLGF) and stromal cell-derived factor (SDF)-1. The endothelial cells in DFO treated airways displayed higher levels of p-eNOS and Ki67, less apoptosis, and decreased production of perivascular reactive oxygen species (ROS) compared to vehicle-treated airways. In summary, a DFO formulation topically-applied at the time of surgery successfully augmented airway anastomotic microvascular regeneration and the repair of alloimmune-injured microvasculature. This approach may be an effective topical transplant-conditioning therapy for preventing airway complications following clinical lung transplantation.     

Hypoxia-inducible factor-2alpha is involved in enhanced apoptosis in the placenta from pregnancies with fetal growth restriction

The aim of the present study is to investigate whether hypoxia-inducible factors (HIF-1alpha, HIF-2alpha, HIF-1beta) are involved in enhanced apoptosis in the human placenta from pregnancies with fetal growth restriction (FGR). Placental samples were obtained from women with normal term pregnancy (n = 18) or from pregnancy with FGR (n = 12). Placenta apoptosis was assessed by the terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) staining. The expressions of HIF-1alpha, HIF-2alpha, and HIF-1beta were examined by immunohistochemical analysis. Enhanced apoptosis was observed in the placenta from pregnancies with FGR compared with normal term placenta. The apoptosis index in FGR group (1.45 +/- 1.26%) was significantly higher than that in the normal control group (0.18 +/- 0.16%; P < 0.01). There were no significant differences in the intensity of the staining for HIF-1alpha and HIF-1beta expressions between two groups, while HIF-2alpha was overexpressed in the placenta from pregnancies with FGR group (P < 0.05). The upregulation of HIF-2alpha protein expression in the placenta from pregnancies with FGR may, at least in part, be involved in the increased placental apoptosis.     

Angiogenin is up-regulated in the nucleus and cytoplasm in human primary breast carcinoma and is associated with markers of hypoxia but not survival

Angiogenin, a 14.2 kD polypeptide that was originally noted for its angiogenic activity, is now increasingly recognized to have a multiplicity of biological roles in both physiological and pathological conditions. In breast cancer, there are conflicting studies questioning the role of angiogenin. Here, the pattern of expression of angiogenin during the transition from normal breast tissue to ductal carcinoma in situ and invasive carcinoma is reported together with the correlates between the level of angiogenin in 239 invasive carcinomas and standard clinicopathological parameters, hypoxia-inducible factor (HIF)-1 alpha and the HIF-1 alpha target gene DEC-1. This study shows that angiogenin expression is up-regulated in the cytoplasmic and nuclear compartments in in situ carcinoma and invasive carcinoma compared with normal breast tissue and that angiogenin expression in invasive carcinomas is significantly positively associated with high tumour grade (p = 0.03), positive oestrogen receptor (ER) status (p = 0.01), HIF-1 alpha (p = 0.001) and DEC 1 (p = 0.001), but not with patient age (p = 0.8), tumour size (p = 0.25), lymph node status (p = 0.69), epidermal growth factor receptor (p = 0.56) or microvessel density (p = 0.32). No difference in relapse-free (p = 0.26) or overall (p = 0.63) survival was observed in patients stratified by angiogenin expression. This study suggests that angiogenin may be important in breast cancer progression and that, through its relationship with ER, it may be a target for tamoxifen.     

Expression of HIF-1 and ubiquitin in conventional renal cell carcinoma: relationship to mutations of the von Hippel-Lindau tumor suppressor gene

Conventional clear cell renal cell carcinomas (cRCC) have mutations of the von Hippel-Lindau (VHL) tumor suppressor gene at 3p25 in approximately 50% of cases. The VHL gene normally regulates ubiquitin-mediated proteolysis of hypoxia-inducible factor 1alpha (HIF-1alpha); in cell lines, VHL inactivation blocks HIF-1alpha proteolysis, resulting in increased HIF-1 expression. This study was undertaken to investigate the relationship between VHL mutations and the expression of ubiquitin and HIF-1alpha in cRCC. Eleven cRCC were studied with microsatellite analysis for 3p deletions and with sequencing for VHL mutations. Immunohistochemistry was performed for HIF-1alpha and ubiquitin. Deletions at 3p25 were found in 10 tumors, and VHL mutations were identified in 6 of these cases. There was staining for ubiquitin and HIF-1alpha in all tumors with VHL mutations. Among the five cases without VHL mutations, staining for ubiquitin or HIF-1alpha was not present in three cases but was present in two tumors, both of which had 3p deletions. The findings support a role for VHL mutations promoting cRCC development by an impairment of HIF-1alpha proteolysis. The findings also suggest that a 3p tumor suppressor gene other than VHL may also influence HIF-1alpha degradation and that there is an additional tumorigenic pathway for cRCC that does not involve VHL or HIF-1.     

Expression of hypoxia-inducible factors is correlated with the presence of a fibrotic focus and angiogenesis in pancreatic ductal adenocarcinomas

AIMS: To study the expression of hypoxia-regulated markers in pancreatic ductal adenocarcinomas (PA) in relationship to the presence of a fibrotic focus, angiogenesis quantification and clinical outcome. METHODS AND RESULTS: The expression of hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, carbonic anhydrase 9 (CA9) and vascular endothelial growth factor (VEGF) was immunohistochemically detected in 50 PA and correlated with tumour characteristics, microvascular density (MVD) and survival. HIF-1alpha was expressed within tumour cells in 68%, HIF-2alpha in 46%, CA9 in 78% and VEGF in 52% of the cases. Stromal expression was also noted for HIF-2alpha and CA9 in, respectively, 42% and 48% of the cases. Tumour CA9 expression was associated with that of VEGF (P=0.004) and that of stromal HIF-2alpha (P=0.013), with the presence of a fibrotic focus (P=0.046) and with an increased MVD (P=0.034). Tumour VEGF expression correlated with the presence of a fibrotic focus (P=0.039) and a greater MVD (P=0.047). Both the presence of a fibrotic focus (P=0.0002) and high tumour CA9 expression (P=0.029) were associated with reduced overall survival. CONCLUSION: The strong association of the presence of a fibrotic focus with CA9 expression and lower survival demonstrates that hypoxia-driven angiogenesis plays an important role in the progression of PA.     

Expression of hypoxia-inducible factor 1alpha in mononuclear phagocytes infected with Leishmania amazonensis

Increasing evidence indicates that hypoxia-inducible factor 1alpha (HIF-1alpha) can be upregulated in different cell types by nonhypoxic stimuli such as growth factors, cytokines, nitric oxide, lipopolysaccharides and a range of infectious microorganisms. In this study, the ability of the following mononuclear phagocytes to express HIF-1alpha is reported: mouse macrophages (mMPhi), human macrophages (hMPhi) and human dendritic cells (DC), parasitized in vitro with Leishmania amazonensis; as assessed by immunofluorescence microscopy. A logical explanation for HIF-1alpha expression might be that the mononuclear phagocytes became hypoxic after L. amazonensis infection. Using the hypoxia marker pimonidazole, observation revealed that L. amazonensis-infected cells were not hypoxic. In addition, experiments using a HIF-1alpha inhibitor, CdCl(2), to treat L. amazonensis-infected macrophage cultures showed reduced parasite survival. These studies indicated that HIF-1alpha could play a role in adaptative and immune responses of mononuclear phagocytes presenting infection by the parasite L. amazonensis.     

Thymidine phosphorylase and hypoxia-inducible factor 1-α expression in clinical stage II/III rectal cancer: association with response to neoadjuvant chemoradiation therapy and prognosis

The aim of this study was to determine whether pretreatment status of thymidine phosphorylase (TP), and hypoxia-inducible factor alpha (HIF-1α) could predict pathologic response to neoadjuvant chemoradiation therapy with oxaliplatin and capecitabine (XELOXART) and outcomes for clinical stage II/III rectal cancer patients. A total of 180 patients diagnosed with clinical stage II/III rectal cancer received XELOXART. The status of TP, and HIF-1α were determined in pretreatment biopsies by immunohistochemistry (IHC). Tumor response was assessed in resected regimens using the tumor regression grade system and TNM staging system. 5-year disease free survival (DFS) and 5-year overall survival (OS) were evaluated with the Kaplan-Meier method and were compared by the log-rank test. Over expression of TP and low expression of HIF-1α were associated with pathologic response to XELOXART and better outcomes (DFS and OS) in clinical stage II/III rectal cancer patients (P < 0.05). Our result suggested that pretreatment status of TP and HIF-1α were found to predict pathologic response and outcomes in clinical stage II/III rectal cancer received XELOXART. Additional well-designed, large sample, multicenter, prospective studies are needed to confirm the result of this study.     

缺氧诱导因子1α在妊高征和正常妊娠胎盘组织中的差异表达

目的:探讨缺氧诱导因子1α(HIF-1α)蛋白及其mRNA在妊高征和正常妊娠胎盘组织中的表达的差异。方法:应用Westernblot检测10例妊高征和10例年龄匹配的正常妊娠的胎盘组织中HIF-1α蛋白表达的水平;应用实时定量PCR,检测两种组织中HIF-1αmRNA表达的水平。结果:与正常妊娠胎盘组织相比较,妊高征胎盘组织中HIF-1α蛋白和mRNA的表达水平明显增加(P<0.05)。结论:HIF-1α在妊高征胎盘组织中表达增高,可能与妊高征的病因及病理生理有关。