In vitro study of radiosensitization by β-Elemene in A549 cell line from adenocarcinoma of lung

Objective: To explore the effect and possible mechanism in vitro of radiosensitization by β-Elemene in A549 cell line from adenocarcinoma of lung. Methods: The A549 cell line from adenocarcinoma of lung was chosen for the study to determine the inhibition ratio by using MTT assay. Morphologic change, growth curve, cloning efficiency, divisional index were observed. Change of cell cycle and apoptosis rate were analyzed by FCM and the expressions of gene P53 and Bcl-2 were detected. Results: Reproductive activity of the group which was under irradiation and β-Elemene was significantly sup-pressed and its cloning efficiency and divisional index also declined. The apoptosis rate of the group which was under irradia-tion and β-Elemene was significantly higher at 48 h and 72 h, which was analyzed by FCM. The expression of P53 without Bcl-2 was observed in the group under irradiation and β-Elemene and the group under β-Elemene only at the 48th hour point, while the expression of Bcl-2 without p53 was observed in the group under irradiation only and the control group. Conclusion: β-Elemene is good at radiosensitization and its mechanism may be relevant to the up-regulation of P53, down-regulation of Bcl-2 and inducing apoptosis.     

Inhibition of HIF-1α by PX-478 enhances the anti-tumor effect of gemcitabine by inducing immunogenic cell death in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the worst prognoses among all the malignancies. Now, gemcitabine (Gem) is the first line chemotherapeutic drug for advanced pancreatic cancer. However, Gem is usually ineffective to the PDAC because of high degree of drug resistance. Hypoxia and immune suppressive milieu are the best-described hallmarks of PDAC; therefore, we investigated the impact of hypoxia inducible factor-1 (HIF-1) inhibitor, PX-478, in combination with Gem on the induction of immunogenic cell death (ICD). We verified that combined treatment with Gem/PX-478 significantly enhanced the anti-tumor effect and increased proportion of tumor infiltrating T-lymphocytes in Panc02-bearing immune-competent but not in immune-deficient mice. Vaccination using Panc02 cell line treated with single agent or in combination showed significant anti-tumor effects. Pancreatic cell lines treated with Gem and PX-478 can induce an increase in eIF2α phosphorylation was correlated with down-regulation of HIF-1α and elicited exposure of CRT and release of HMGB1 and ATP. Only co-treated cells induced DC maturation/phagocytosis and IFN-γ secretion by cytotoxic T lymphocytes. Altogether, combined treatment with Gem/PX-478 showed significantly inhibition on tumor growth and anti-tumor immunization. We propose that inhibition HIF-1α elicits Gem-induced immune response and eliminates PDAC cells by inducing ICD.     

HIF-1α effects on angiogenic potential in human small cell lung carcinoma

Background

Hypoxia-inducible factor-1 alpha (HIF-1α) maybe an important regulatory factor for angiogenesis of small cell lung cancer (SCLC). Our study aimed to investigate the effect of HIF-1α on angiogenic potential of SCLC including two points: One is the effect of HIF-1α on the angiogenesis of SCLC in vivo. The other is the regulation of angiogenic genes by HIF-1α in vitro and in vivo.

Methods

In vivo we used an alternative method to study the effect of HIF-1a on angiogenic potential of SCLC by buliding NCI-H446 cell transplantation tumor on the chick embryo chorioallantoic membrane (CAM) surface. In vitro we used microarray to screen out the angiogenic genes regulated by HIF-1a and tested their expression level in CAM transplantation tumor by RT-PCR and Western-blot analysis.

Results

In vivo angiogenic response surrounding the SCLC transplantation tumors in chick embryo chorioallantoic membrane (CAM) was promoted after exogenous HIF-1α transduction (p < 0.05). In vitro the changes of angiogenic genes expression induced by HIF-1α in NCI-H446 cells were analyzed by cDNA microarray experiments. HIF-1α upregulated the expression of angiogenic genes VEGF-A, TNFAIP6, PDGFC, FN1, MMP28, MMP14 to 6.76-, 6.69-, 2.26-, 2.31-, 4.39-, 2.97- fold respectively and glycolytic genes GLUT1, GLUT2 to2.98-, 3.74- fold respectively. In addition, the expression of these angiogenic factors were also upregulated by HIF-1α in the transplantion tumors in CAM as RT-PCR and Western-blot analysis indicated.

Conclusions

These results indicated that HIF-1α may enhance the angiogenic potential of SCLC by regulating some angiogenic genes such as VEGF-A, MMP28 etc. Therefore, HIF-1α may be a potential target for the gene targeted therapy of SCLC.     

Inhibitory effects of epigallocatechin-3-gallate on cell proliferation and the expression of HIF-1α and P-gp in the human pancreatic carcinoma cell line PANC-1

The aim of this study was to verify the inhibitory effects of epigallocatechin-3-gallate (EGCG) on cell proliferation and the expression of hypoxia-inducible factor 1 (HIF-1α) and multidrug resistance protein 1 (MDR1/P-gp) in the human pancreatic carcinoma cell line PANC-1, thereby, reversing drug resistance of pancreatic carcinoma and improving its sensitivity to cancer chemotherapy. The human pancreatic carcinoma cell line PANC-1 was incubated under hypoxic conditions with different concentrations of epigallocatechin-3-gallate (EGCG) for indicated hours. The effects of EGCG on the mRNA or protein expression of HIF-1α and MDR1 were determined by RT-PCR or western blotting. Cellular proliferation and viability assays were measured using Cell Counting Kit-8. Western blotting revealed that EGCG inhibits the expression of the HIF-1α protein in a dose-dependent manner, while RT-PCR showed that it does not have any effects on HIF-1α mRNA. In addition, EGCG attenuated the mRNA and protein levels of P-gp in a dose-dependent manner, reaching a peak at the highest concentration. Furthermore, EGCG inhibited the proliferation of PANC-1 cells in a concentration- and time-dependent manner. The attenuation of HIF-1α and the consequently reduced P-gp could contribute to the inhibitory effects of EGCG on the proliferation of PANC-1 cells.     

Effect of 125I seed brachytherapy and radiotherapy on the growth of transplanted human lung cancer cell line A549 in nude mice and the impact of HIF-1α expression after therapy

Objective To study the inhibitory effects of radiotherapy and 125I seed brachytherapy on the growth of transplanted human lung cancer cell line A549 in nude mice and the impact of HIF-1αexpression after therapy.Methods Forty nude mice bearing human lung cancer cell line A549 were randomly divided into control group,radiotherapy group,125I seed brachytherapy group and radiotherapy + 125I seed group when tumor volume achieved (300±50) mm3.The tumor growth was observed and the alteration of tumor size was calculated at different time.On 15th day,the expression of HIF-1α was detected by immunohistochemistry and western blot.Results When eighth day after treatment,compared with the control group,the tumor volume of the combined treatment group was significantly smaller (t = 46.4,P ＜0.05).After fifteenth day after treatment,compared with control group,the group of radiotherapy,125I seed brachytherapy and radiotherapy + 125I seed gained the tumor control rate of 45.9 %,44.4 %,69.4 % respectively.Compared with other groups,the change of expression of HIF-1α in the combined treatment group was not significant (P ＞0.05).Conclusion Radiotherapy combined with 125I seed brachytherapy can inhibit the growth of transplanted human lung cancer cell line A549 in nude mice,and the tumor regression can be observed in early stage.But in our study,the expression of HIF-1α in tumors cannot be inhibited by 125I seed.     

Effect of 125I seed brachytherapy and radiotherapy on the growth of transplanted human lung cancer cell line A549 in nude mice and the impact of HIF-1α expression after therapy

Objective To study the inhibitory effects of radiotherapy and 125I seed brachytherapy on the growth of transplanted human lung cancer cell line A549 in nude mice and the impact of HIF-1αexpression after therapy.Methods Forty nude mice bearing human lung cancer cell line A549 were randomly divided into control group,radiotherapy group,125I seed brachytherapy group and radiotherapy + 125I seed group when tumor volume achieved (300±50) mm3.The tumor growth was observed and the alteration of tumor size was calculated at different time.On 15th day,the expression of HIF-1α was detected by immunohistochemistry and western blot.Results When eighth day after treatment,compared with the control group,the tumor volume of the combined treatment group was significantly smaller (t = 46.4,P ＜0.05).After fifteenth day after treatment,compared with control group,the group of radiotherapy,125I seed brachytherapy and radiotherapy + 125I seed gained the tumor control rate of 45.9 %,44.4 %,69.4 % respectively.Compared with other groups,the change of expression of HIF-1α in the combined treatment group was not significant (P ＞0.05).Conclusion Radiotherapy combined with 125I seed brachytherapy can inhibit the growth of transplanted human lung cancer cell line A549 in nude mice,and the tumor regression can be observed in early stage.But in our study,the expression of HIF-1α in tumors cannot be inhibited by 125I seed.     

Expression of MDR1, HIF-1α and MRP1 in sacral chordoma and chordoma cell line CM-319

Background

Chordoma was a typically slow-growing tumor. The therapeutic approach to chordoma had traditionally relied mainly on surgical therapy. And the main reason for therapeutic failure was resistance to chemotherapy and radiotherapy. However the refractory mechanism was not clear. The aim of this study was to investigate the expression of three genes (MDR1, HIF-1α and MRP1) associated with resistance to chemotherapy and radiotherapy in chordoma and chordoma cell line CM-319.

Materials and methods

Using immunohistochemical techniques, the expression of MDR1, HIF-1α and MRP1 was investigated in 50 chordoma specimen. Using RT-PCR and Western blot, the expression of MDR1, HIF-1α and MRP1 was investigated in chordoma and chordoma cell line CM-319.

Results

Expression of MDR1, HIF-1α and MRP1 was observed in 10%, 80% and 74% of all cases, respectively. Expression of MRP1 was correlated with HIF-1α. On the other hand, expression of MDR1 was not correlated with the expression of HIF-1α or MRP1. The expression of HIF-1α and MRP1 was observed, but MDR1 was not observed in chordoma and CM-319.

Conclusion

Expression of HIF-1α and MRP1 was observed in most chordoma specimen and CM-319 cell line; expression of HIF-1α correlated with MRP1. HIF-1α and MRP1 may play a role in the multidrug resistance of chordoma to chemotherapy.     

Conditional Ror1 knockout reveals crucial involvement in lung adenocarcinoma development and identifies novel HIF-1α regulator

We previously reported that ROR1 is a crucial downstream gene for the TTF-1/NKX2-1 lineage-survival oncogene in lung adenocarcinoma, while others have found altered expression of ROR1 in multiple cancer types. Accumulated evidence therefore indicates ROR1 as an attractive molecular target, though it has yet to be determined whether targeting Ror1 can inhibit tumor development and growth in vivo. To this end, genetically engineered mice carrying homozygously floxed Ror1 alleles and an SP-C promoter–driven human mutant EGFR transgene were generated. Ror1 ablation resulted in marked retardation of tumor development and progression in association with reduced malignant characteristics and significantly better survival. Interestingly, gene set enrichment analysis identified a hypoxia-induced gene set (HALLMARK_HYPOXIA) as most significantly downregulated by Ror1 ablation in vivo, which led to findings showing that ROR1 knockdown diminished HIF-1α expression under normoxia and clearly hampered HIF-1α induction in response to hypoxia in human lung adenocarcinoma cell lines. The present results directly demonstrate the importance of Ror1 for in vivo development and progression of lung adenocarcinoma, and also identify Ror1 as a novel regulator of Hif-1α. Thus, a future study aimed at the development of a novel therapeutic targeting ROR1 for treatment of solid tumors such as seen in lung cancer, which are frequently accompanied with a hypoxic tumor microenvironment, is warranted.     

Prostate cancer cell malignancy via modulation of HIF-1α pathway with isoflurane and propofol alone and in combination

Background:

Surgery is considered to be the first line treatment for solid tumours. Recently, retrospective studies reported that general anaesthesia was associated with worse long-term cancer-free survival when compared with regional anaesthesia. This has important clinical implications; however, the mechanisms underlying those observations remain unclear. We aim to investigate the effect of anaesthetics isoflurane and propofol on prostate cancer malignancy.

Methods:

Prostate cancer (PC3) cell line was exposed to commonly used anaesthetic isoflurane and propofol. Malignant potential was assessed through evaluation of expression level of hypoxia-inducible factor-1α (HIF-1α) and its downstream effectors, cell proliferation and migration as well as development of chemoresistance.

Results:

We demonstrated that isoflurane, at a clinically relevant concentration induced upregulation of HIF-1α and its downstream effectors in PC3 cell line. Consequently, cancer cell characteristics associated with malignancy were enhanced, with an increase of proliferation and migration, as well as development of chemoresistance. Inhibition of HIF-1α neosynthesis through upper pathway blocking by a PI-3K-Akt inhibitor or HIF-1α siRNA abolished isoflurane-induced effects. In contrast, the intravenous anaesthetic propofol inhibited HIF-1α activation induced by hypoxia or CoCl₂. Propofol also prevented isoflurane-induced HIF-1α activation, and partially reduced cancer cell malignant activities.

Conclusions:

Our findings suggest that modulation of HIF-1α activity by anaesthetics may affect cancer recurrence following surgery. If our data were to be extrapolated to the clinical setting, isoflurane but not propofol should be avoided for use in cancer surgery. Further work involving in vivo models and clinical trials is urgently needed to determine the optimal anaesthetic regimen for cancer patients.     

Stem cell factor/c-kit signaling enhances invasion of pancreatic cancer cells via HIF-1α under normoxic condition

The SCF/c-kit signaling plays an important role in invasion of c-kit-expressing tumor cells, however, the molecular mechanisms have not been studied yet. Using a pancreatic cancer model, we demonstrate that SCF/c-kit binding up-regulates the expression of invasion-related genes through the accumulation of HIF-1α. Furthermore, the expression of HIF-1α induced by SCF is not dependent on the oxygen level, but rather on both the PI3K/Akt and Ras/MEK/ERK signaling pathways. In conclusion, under normoxic conditions, SCF/c-kit binding increases expression of HIF-1α through the PI3K/Akt and Ras/MEK/ERK pathways, and the accumulation of HIF-1α up-regulates expression of invasion-related genes that augment the invasiveness of pancreatic cancer, a fatal cancer. Therefore, our results suggest that the inhibition of both c-kit and HIF-1α may be an effective strategy for pancreatic cancer therapy.     

Role of HIF-1α in response of tumors to a combination of hyperthermia and radiation in vivo

Purpose: Mild temperature hyperthermia (MTH) increases blood flow and oxygenation in tumours. On the other hand, high-dose-per-fraction irradiation damages blood vessels, decreases blood flow and increases hypoxia in tumours. The radiation-induced hypoxia in tumours activates hypoxia-inducible factor-1α (HIF-1α) and its target genes, such as vascular endothelial growth factor (VEGF), promoting revascularization and recurrence. In the present study, we examined the hypothesis that MTH inhibits radiation-induced upregulation of HIF-1α and its target genes by increasing tumour oxygenation.

Materials and methods: FSaII fibrosarcoma tumours grown subcutaneously in the legs of C3H mice were used. Tumours were irradiated with 15?Gy using a ⁶⁰Co irradiator or heated at 41?°C for 30?min using an Oncothermia heating unit. Blood perfusion and hypoxia in tumours were assessed with Hoechst 33342 and pimonidazole staining, respectively. Expression levels of HIF-1α and VEGF were determined using immunohistochemical techniques. Apoptosis of tumour cells was quantitated via TUNEL staining and the effects of treatments on tumour growth rate were assessed by measuring tumour diameters.

Results: Irradiation of FSaII tumours with a single dose of 15?Gy led to significantly decreased blood perfusion, increased hypoxia and upregulation of HIF-1α and VEGF. On the other hand, MTH at 41?°C for 30?min increased blood perfusion and tumour oxygenation, thereby suppressing radiation-induced HIF-1α and VEGF in tumours, leading to enhanced apoptosis of tumour cells and tumour growth delay.

Conclusion: MTH enhances the anti-tumour effect of high-dose irradiation, at least partly by inhibiting radiation-induced upregulation of HIF-1α.     

Berberine enhances radiosensitivity of esophageal squamous cancer by targeting HIF-1α in vitro and in vivo

Radiation therapy is an important treatment approach for esophageal squamous cell carcinoma (ESCC). However, how to promote radiation sensitivity in ESCC remains a challenge. This study aimed to evaluate the effects of berberine, a common used Chinese medicine, on the radiosensitivity of ESCC. ECSS cell line ECA109 and TE13 were subjected to hypoxia and/or ionizing radiation (IR), in the presence or absence of berberine treatment. Cell growth and survival, and apoptosis were evaluated. In addition, ECA109 cells were xenografted into nude mice and subjected to IR and/or berberine treatment. The expression of HIF-1α and VEGF was detected by western blot and immunohistochemical analysis. Our results showed that berberine increased radiosensitivity of ESCC cells and xenografts, and this was associated with the inhibition of HIF-1α and VEGF expression. These data suggest that berberine may be a potential radiotherapy sensitization drugs due to its significant anti-hypoxia activity.     

Correlations of 99Tcm-HL91 SPECT hypoxia imaging with HIF-1α and VEGF expression in non-small cell lung cancer

Objective 99Tcm-HL91(99Tcm labeled 4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime)is a potential noninvasive marker of tumor hypoxia.It has been reported that 99Tcm-HL91 has validity for hypoxia imaging in non-small cell lung cancer(NSCLC).The aim of this study was to evaluate the 99Tcm-HL91 SPECT hypoxia imaging of NSCLC,the expression of inducible hypoxia factor-1α (HIF-1α)and vascular endothelial growth factor(VEGF),and to analyze their correlations with clinicopathological characteristics.Methods Twenty NSCLC patients who underwent radical resection were enrolled into this study prospectively.99Tcm-HL91 SPECT scanning was performed in all patients at one or two days before surgery.After intravenous injection of approximately 740 MBq 99Tcm-HL91,anterior,posterior and lateral planar images were collected at 2,4 and 6 hours,respectively.Regions of interest (ROls)were drawn in the tumor and the contralateral normal lung tissue,and the radioactivity ratio of tumor to normal tissue(T/N)was calculated.Immunohistochemistry was used to detect the expression of HIF-1α and VEGF in sequential histological sections of specimens.Results Among the 20 NSCLC patients,13 showed positive expression of HIF-1α and 15 had positive expression of VEGF,with a positive rate of 65.0% and 75.0%,respectively.The uptake of 99Tcm-HL91 was strongly correlated with the expression status of HIF-1α.No correlation between HIF-1α and VEGF expression levels was observed.The HIF-1α expression level was not correlated with histological subtype,but with lymph node involvement.The expression levels of HIF-1α and VEGF were positively correlated with tumor stage.Conclusion The result of 99Tcm-HL91 SPECT hypoxia imaging is found to be positively correlated with expression of HIF-1α in the non-small cell lung cancer.HIF-1α expression is positively correlated with VEGF expression.Furthermore,both HIF-1α and VEGF expressions are increasing with the increase of tumor stage.     

Angelica sinensis suppresses human lung adenocarcinoma A549 cell metastasis by regulating MMPs/TIMPs and TGF-β1

In this study we investigated the potential effects of Angelica sinensis on the growth and metastasis in human lung adenocarcinoma A549 cells. In?vitro the Cck-8 assays showed that Angelica sinensis had weak antiproliferative effect on A549 cells only at high concentration. The cell adhesion assay showed that Angelica sinensis decreased the adhesive ability of A549 cells in a dose- and time-dependent manner. Transwell invasion and migration assay showed that Angelica sinensis reduced the invasive and migratory abilities of A549 cells in a dose-dependent manner. In?vivo the animal experiments showed that Angelica sinensis suppressed lung metastasis of nude mice at high concentration. Then, we attempted to clarify the mechanisms of anti-metastatic activities of Angelica sinensis. The results showed Angelica sinensis inhibited the enzymatic activity of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), it involved the down-regulation of the expressions of MMP-2 and MMP-9 at both the protein and mRNA levels, which may be associated with Angelica sinensis suppressing the expression of TGF-β1. It also involved the increase of the tissue inhibitors of metalloproteinases TIMP-2, but TIMP-1 decreased upon incubation of A549 cells with Angelica sinensis. The results suggest that Angelica sinensis might exert anti-growth and anti-metastasis activity against lung cancer cells through the decrease of MMP-2, MMP-9, TGF-β1 and TIMP-1 and increase of TIMP-2.     

Overexpression of human papillomavirus (HPV) type 16 oncoproteins promotes angiogenesis via enhancing HIF-1α and VEGF expression in non-small cell lung cancer cells

HPV-16 infection may play an important role in the development of non-small cell lung cancer (NSCLC) among never-smokers. Due to the critical role of angiogenesis in NSCLC development, we describe here the effect of HPV-16 oncoproteins on angiogenesis in NSCLC and the underlying mechanisms. We found that overexpression of HPV-16 E6 and E7 oncoproteins in NSCLC cells significantly promoted angiogenesis both in vitro and in vivo, and correspondingly, an enhanced expression of HIF-1α and VEGF, important pro-angiogenic factors in tumor angiogenesis. Meanwhile, overexpression of HPV-16 oncoproteins also led to HIF-1α-dependent increases in the secretion of several other pro-angiogenic factors, including IL-8. Our findings suggest that HPV-16 oncoproteins contribute to the development of NSCLC possibly by promoting HIF-1α/VEGF-mediated tumor angiogenesis.     

HIF-1α inhibition by siRNA or chetomin in human malignant glioma cells: effects on hypoxic radioresistance and monitoring via CA9 expression

Background  

Hypoxia induces activation of the HIF-1 pathway and is an essential characteristic of malignant gliomas. Hypoxia has been linked to tumor progression, therapy resistance and poor prognosis. However, little is known about the impact of HIF-1α inhibition on radioresistance of malignant glioma.