Prognostic value of hypoxia-inducible factor-1 alpha in nasopharyngeal carcinoma: a meta-analysis

Dynamic contrast-enhanced magnetic resonance imaging in cervical cancer: correlation between quantitative parameters and molecular markers hypoxia-inducible factors-1-alpha, vascular endothelial growth factor, and Ki-67

AIM

To investigate whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has the potential to non-invasively detect microenvironmental condition by quantitatively measuring blood perfusion, vessel wall permeability, and vascularity, and to elucidate the possible correlations between DCE-MRI quantitative parameters and the expression level of hypoxia, vascularity, and cell proliferation related molecular biomarkers.

MATERIALS AND METHODS

In this prospective single center clinical study, 58 patients diagnosed with cervical cancer underwent DCE-MRI before anticancer treatment were enrolled. Ktrans, Kep, Ve, and Vp were generated from Extended Toft's model. Then patients conducted colposcopy biopsy within 1 week after DCE-MRI. Pretreatment expression levels of HIF-1α, VEGF and Ki-67 were assessed and scored by immunohistochemistry on colposcopy obtained tumor specimens.

RESULTS

In HIF-1α low-expression group, Ktrans (p=0.031) and Kep (p=0.012) values were significantly higher than the high-expression group. In VEGF high-expression group, Ktrans (p=0.044) and Ve values (p=0.021) were significantly higher than the low-expression group. In Ki-67 high-expression group, Ktrans (p=0.026) and Kep (p=0.033) were significantly higher than the low-expression group. Multiple linear regression analyses and Pearson correlation revealed that Ktrans independently negatively correlated with HIF-1α expression, Ve independently positively correlated with VEGF, and Kep independently positively correlated with Ki-67. The area under the ROC curves of Ktrans for HIF-1α, Ve for VEGF, and Kep for Ki-67 were 0.728, 0.743, 0.730, respectively.

CONCLUSION

Our results suggest that DCE-MRI quantitative parameters could be potentially used as imaging markers for non-invasively detecting microenvironmental hypoxia, vascularity and proliferation in cervical cancer patients.

Semisynthesis and anti-cancer properties of novel honokiol derivatives in human nasopharyngeal carcinoma CNE-2Z cells

In this study, 21 new honokiol derivatives were synthesised, and their anti-cancer properties were investigated. Among these, compound 1g exhibited the most potent cytotoxic activity against human nasopharyngeal carcinoma CNE-2Z cells, human gastric cancer SGC7901 cells, human breast cancer MCF-7 cells, and mouse leydig testicular cancer I-10 lines with IC50 values of 6.04, 7.17, 6.83, and 5.30 μM, respectively. Compared to the parental compound, 1g displayed up to 5.18-fold enhancement of the cytotoxic effect on CNE-2Z cells. We further demonstrated that 1g inhibited cell growth, suppressed migration and invasion, and induced apoptosis of CNE-2Z cells by down-regulating HIF-1α, MMP-2, MMP-9, Bcl-2, Akt and up-regulating Bax protein levels. Transfection of CNE-2Z cells with HIF-1α siRNA reduced cell migration and invasion. In addition, in vivo experiments confirmed that 1g inhibited tumour growth in CNE-2Z cell-xenografted nude mice with low toxicity. Thus, our data suggested that 1g was a potent and safe lead compound for nasopharyngeal carcinoma therapy.

Hypoxia-induced degradation of PICK1 by RBCK1 promotes the proliferation of nasopharyngeal carcinoma cells

AIMS

Hypoxia is an important feature of nasopharyngeal carcinoma (NPC). "Protein interacting with PRKCA 1" (PICK1) is commonly downregulated in human malignancies and is functionally related to poor prognosis. However, there is a limited understanding of the upstream mechanisms regulating PICK1 currently.

MAIN METHODS

PICK1 and HIF-1α expression levels were analyzed by Immunohistochemistry (IHC), western blotting, and quantitative real-time PCR assay. Protein stability and ubiquitin assays were used to investigate PICK1 protein degradation. Immunofluorescence and co-immunoprecipitation assays were used to demonstrate the interaction between RBCK1 and PICK1. Gene knockdown by siRNA transfection was used to investigate the role of HIF-1α and RBCK1 in hypoxia-induced PICK1 degradation. Cell Counting Kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) assays and subcutaneous xenograft nude models were used to explore the roles of RBCK1 and PICK1 in NPC cell proliferation.

KEY FINDINGS

PICK1 expression in NPC tissue was negatively relative to that of HIF-1α. HIF-1α downregulated PICK1 expression by facilitating its ubiquitination by the E3 ligases RANBP2-type and C3HC4-type zinc finger containing 1 (RBCK1), thereby enhancing proteasome-mediated PICK1 degradation. RBCK1 knockdown inhibited NPC cell proliferation, which was ameliorated by double knockdown of RBCK1/PICK1.

SIGNIFICANCE

These data provide evidence for an NPC cell adaptation mechanism to hypoxia, where HIF-1α regulates RBCK1, which targets PICK1 for degradation to promote cell proliferation.

Aberrant miR-874-3p/leptin/EGFR/c-Myc signaling contributes to nasopharyngeal carcinoma pathogenesis

Background

Leptin is important in physiological and pathological functions in various cancers, however, the significance and mechanisms of leptin in nasopharyngeal carcinoma remain ambiguous.

Methods

Leptin expression was analyzed by QPCR, immunohistochemistry, Western blotting, and TCGA database. The impact of gain- or loss-of-function of leptin were determined by MTT, colony formation, wound healing, and Transwell assays in NPC cells, and by a xenograft tumor model. Leptin-modulated glucose consumption and lactate production were assessed by ELISA. Furthermore, leptin-regulated signaling pathways were examined by QPCR and Western blotting assays. The immunoprecipitation assay was conducted to determine interaction between leptin and EGFR. In addition, miR-874-3p-regulated leptin expression was evaluated using bioinformatics, QPCR, luciferase assay, AGO2-RIP assay, and Western blotting.

Results

In this study, we found that leptin was highly expressed in the sera and tumor tissues of patients with NPC, and elevated leptin expression was associated with advanced clinical features and poor prognosis. Functional assays demonstrated that leptin remarkably promoted NPC cell growth, motility, and glycolysis in vitro and in vivo. Mechanistically, leptin associated with EGFR, resulting in enhanced cell growth through the regulation of cell-cycle related markers, glycolysis-related genes, and EGFR/AKT/c-Myc signaling. Moreover, leptin potentiated the invasive capacity of NPC cells by promoting EMT. We further explored that miR-874-3p influenced leptin-mediated NPC progression. Overexpression of miR-874-3p prevented cell growth, motility, glucose consumption, and lactate production in NPC cells, whereas miR-874-3p inhibition had the opposite effects. AGO-RIP assays confirmed that Argonaute 2 (AGO2), a protein associated with miR-874-3p, regulated leptin expression in NPC cells. The rescue assays indicated that inhibition of leptin suppressed the effects of miR-874-3p inhibitor. In clinical specimens, miR-874-3p was negatively correlated with leptin.

Conclusions

Leptin may serve as a novel prognostic factor and potential therapeutic target for patients with NPC. In addition, a newly discovered regulatory axis of leptin/EGFR/AKT/c-Myc can provide a novel therapeutic strategy for NPC.

Prognostic Biomarkers for Survival in Nasopharyngeal Carcinoma: A Systematic Review of the Literature

This systematic review aims to identify prognostic molecular biomarkers which demonstrate strong evidence and a low risk of bias in predicting the survival of nasopharyngeal carcinoma (NPC) patients. The literature was searched for on PubMed to identify original clinical studies and meta-analyses which reported associations between molecular biomarkers and survival, including ≥150 patients with a survival analysis, and the results were validated in at least one independent cohort, while meta-analyses must include ≥1000 patients with a survival analysis. Seventeen studies fulfilled these criteria-two studies on single nucleotide polymorphisms (SNPs), three studies on methylation biomarkers, two studies on microRNA biomarkers, one study on mutational signature, six studies on gene expression panels, and three meta-analyses on gene expressions. The comparison between the hazard ratios of high-risk and low-risk patients along with a multivariate analysis are used to indicate that these biomarkers have significant independent prognostic values for survival. The biomarkers also indicate a response to certain treatments and whether they could be used as therapeutic targets. This review highlights that patients' genetics, epigenetics, and signatures of cancer and immune cells in the tumor microenvironment (TME) play a vital role in determining their survival.

Hypoxia and Its Influence on Radiotherapy Response of HPV-Positive and HPV-Negative Head and Neck Cancer

Head and neck squamous cancers are a heterogeneous group of cancers that arise from the upper aerodigestive tract. Etiologically, these tumors are linked to alcohol/tobacco abuse and infections with high-risk human papillomavirus (HPV). HPV-positive HNSCCs are characterized by a different biology and also demonstrate better therapy response and survival compared to alcohol/tobacco-related HNSCCs. Despite this advantageous therapy response and the clear biological differences, all locally advanced HNSCCs are treated with the same chemo-radiotherapy schedules. Although we have a better understanding of the biology of both groups of HNSCC, the biological factors associated with the increased radiotherapy response are still unclear. Hypoxia, i.e., low oxygen levels because of an imbalance between oxygen demand and supply, is an important biological factor associated with radiotherapy response and has been linked with HPV infections. In this review, we discuss the effects of hypoxia on radiotherapy response, on the tumor biology, and the tumor microenvironment of HPV-positive and HPV-negative HNSCCs by pointing out the differences between these two tumor types. In addition, we provide an overview of the current strategies to detect and target hypoxia.

DCE-MRI quantitative transport mapping for noninvasively detecting hypoxia inducible factor-1α, epidermal growth factor receptor overexpression, and Ki-67 in nasopharyngeal carcinoma patients

BACKGROUND

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has the potential to noninvasively detect expression of hypoxia inducible factor-1-alpha (HIF-1α), epidermal growth factor receptor (EGFR), and Ki-67 in nasopharyngeal carcinoma (NPC) by quantitatively measuring tumor blood flow, vascularity, and permeability.

PURPOSE

We aim to explore the utility of DCE-MRI in detecting HIF-1α, EGFR, and Ki-67 expression levels using traditional Kety's/Tofts' modeling and quantitative transport mapping (QTM).

MATERIALS AND METHODS

Eighty-nine NPC patients underwent DCE-MRI before treatment were enrolled. DCE-MRI was processed to generate the following kinetic parameters: |u| and D from the QTM model, tumor blood flow (TBF) from Kety's model, and K^trans, V_e, and K_ep from Tofts' model. Pretreatment levels of HIF-1α, EGFR, and Ki-67 were assessed by immunohistochemistry and classified into low and high expression groups.

RESULTS

|u| (p < 0.001) and TBF (p = 0.015) values were significantly higher in the HIF-1α high-expression group compared to low-expression group. Only K^trans (p = 0.016) was significantly higher in the EGFR high-expression group. Only |u| (p < 0.001) values were significantly higher in the Ki-67 high-expression group compared to low-expression group. Multiple linear regression analyses showed that |u| independently correlated with HIF-1α and Ki-67 expression, and K^trans independently correlated with EGFR. The areas under the ROC curves of |u| for HIF-1α and Ki-67, and K^trans for EGFR were 0.83, 0.74, and 0.70, respectively.

CONCLUSION

|u| and K^trans derived from DCE-MRI may be considered as noninvasive imaging markers for detecting hypoxia and proliferation in NPC patients.

Lost in application: Measuring hypoxia for radiotherapy optimisation

The history of radiotherapy is intertwined with research on hypoxia. There is level 1a evidence that giving hypoxia-targeting treatments with radiotherapy improves locoregional control and survival without compromising late side-effects. Despite coming in and out of vogue over decades, there is now an established role for hypoxia in driving molecular alterations promoting tumour progression and metastases. While tumour genomic complexity and immune profiling offer promise, there is a stronger evidence base for personalising radiotherapy based on hypoxia status. Despite this, there is only one phase III trial targeting hypoxia modification with full transcriptomic data available. There are no biomarkers in routine use for patients undergoing radiotherapy to aid management decisions, and a roadmap is needed to ensure consistency and provide a benchmark for progression to application. Gene expression signatures address past limitations of hypoxia biomarkers and could progress biologically optimised radiotherapy. Here, we review recent developments in generating hypoxia gene expression signatures and highlight progress addressing the challenges that must be overcome to pave the way for their clinical application.

Pretreatment Photopenia on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scans Predicts Poor Prognosis in Nasopharyngeal Cancer Patients Undergoing Concurrent Chemoradiotherapy

OBJECTIVES

To investigate the influence of pretreatment primary tumor or nodal photopenia (PP) on 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT), an indicator of tumor ischemia, on survival results of nasopharyngeal cancers (NPCs) treated with concurrent chemoradiotherapy (C-CRT).

METHODS

The pre-C-CRT FDG PET-CT scans of 104 patients with NPC (cT1-4 N0-3 M0) were retrospectively examined to determine the presence of PP (PP+). Our primary endpoint was the influence of PP+ on overall survival (OS), while the progression-free survival (PFS) and locoregional PFS (LRPFS) constituted the secondary endpoints.

RESULTS

The PP+ was detected in 29 (27.9%): nine (8.7%), seven (6.7%), and 13 (12.5%) in the primary tumor alone, primary tumor plus neck nodes, and neck nodes alone, respectively. Because the PP+ cases were small by count per location, all comparative analyses were performed according to overall PP+/ PP- status instead of per detected site. At a median follow-up of 67.8 months (range, 9 to 130 months), the median survival times were not reached (NR) for the entire population, while 5-year OS, LRPFS, and PFS rates were 73.3%, 68.2%, and 63.4%, respectively. Comparatively the PP+ patients exhibited significantly poorer median OS (49.8 months vs. NR, P<0.001), LRPFS (40.7 months vs. NR, P=0.001), and PFS (31.8 months vs. NR, P=0.002) durations than their PP- counterparts. Furthermore, the PP+ retained its independent prognostic significance in multivariate analysis (P<0.001).

CONCLUSION

Present results uncovered the pre-C-CRT PP as an independent predictor of poor prognosis for NPC patients, which underscore the requirement for the fortification of the local and systemic treatments in hypoxic NPCs.

Long non-coding RNA HOXA-AS2 promotes the expression levels of hypoxia-inducible factor-1α and programmed death-ligand 1, and regulates nasopharyngeal carcinoma progression via miR-519

Nasopharyngeal carcinoma (NPC) is a rare malignancy arising from the nasopharyngeal epithelium and belongs to the group of head and neck cancer types, which are usually associated with viral and/or environmental influences, as well as heredity causes. A recent study reported that the long non-coding RNA (lncRNA) HOXA cluster antisense RNA 2 (HOXA-AS2) may be a prognostic biomarker in NPC; however, the specific mechanisms underlying NCP progression are yet to be determined. The aim of the present study was to investigate the biological role of HOXA-AS2 in NPC. In the present study, the gene expression levels of HOXA-AS2, miR-519, hypoxia-inducible factor (HIF-1α) and programmed death-ligand 1 (PD-L1) were detected using reverse transcription-quantitative PCR (RT-qPCR) analysis and western blotting. Bioinformatics analysis and a dual luciferase reporter assay were performed to predict and confirm the direct interactions between HOXA-AS2 and microRNA (miR)-519, as well as between miR-519 and HIF-1α. A MTT assay was used to detect the cell viability, while cell migratory and invasive abilities were assessed using wound healing and Transwell assays. HOXA-AS2 and HIF-1α were found to be significantly upregulated in NPC tumor tissues, as well as in NPC cell lines. The overexpression of HOXA-AS2 significantly enhanced NPC progression, including the cell proliferative, migratory and invasive abilities. HOXA-AS2 was identified to directly bind to miR-519, whereas a miR-519 inhibitor significantly rescued the HOXA-AS2 knockdown-attenuated progression of NPC. Moreover, miR-519 could bind to HIF-1α and PD-L1. Overexpression of HIF-1α and PD-L1 significantly promoted NPC progression and partially recovered the phenotype of NPC cells attenuated by HOXA-AS2 knockdown. In conclusion, the present study demonstrated that HOXA-AS2/miR-519/HIF-1α and/or HOXA-AS2/miR-519/PD-L1 may be a novel mechanism regulating the progression of NPC, which may facilitate the development of targeted clinical therapy.

Clinicopathological and prognostic value of hypoxia-inducible factor-1α in breast cancer: a meta-analysis including 5177 patients

PURPOSE

Mounting studies have investigated the clinicopathological and prognostic value of hypoxia-inducible factor-1α (HIF-1α) in breast cancer (BC), yet conclusions remain controversial. Therefore, we conducted this meta-analysis to clarify this issue.

METHODS

All relevant studies were searched using Cochrane Library, Web of Science, PubMed, and EMBASE online databases. Pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were applied to evaluate the clinicopathological and prognostic value of HIF-1α, respectively. Subgroup analysis and sensitivity analysis were performed to investigate heterogeneity and stability of the results. Begg's funnel plot and Egger's test were used to examine publication bias.

RESULTS

A total of 31 eligible studies including 5177 subjects were enrolled. Of these, 25 studies assessed the prognostic role of HIF-1α and included 4546 individuals. Twenty-three studies involving 3277 individuals evaluated the clinicopathological significance of HIF-1α. High expression level of HIF-1α was correlated with poor overall survival (OS) (HR = 1.59, 95% CI = 1.40-1.80, P < 0.001), disease-free survival (DFS) (HR = 1.87, 95% CI = 1.53-2.28, P < 0.001), relapse-free survival (HR = 1.36, 95% CI = 1.07-1.73, P = 0.001), and cancer-specific survival (HR = 1.55, 95% CI = 1.10-2.19, P = 0.012). Pooled data from studies using multivariate survival analysis also showed that HIF-1α expression was associated with worse OS (HR = 1.59, 95% CI = 1.32-1.92, P < 0.001) and DFS (HR = 1.60, 95% CI = 1.39-1.84, P < 0.001). Additionally, high HIF-1α expression was associated with advanced tumor-node-metastasis stage, positive lymph-node status, negative ER status, ductal type, advanced histologic grade, high Ki67 expression, and strong VEGF expression.

CONCLUSION

HIF-1α might serve as an independent prognostic biomarker and a promising therapeutic target for BC. Future large-scale prospective randomized trials are needed to confirm our findings.

Association of hypoxia-inducible factor-1α (HIF1α) 1790G/A gene polymorphism with renal cell carcinoma and prostate cancer susceptibility: a meta-analysis

BACKGROUND

This meta-analysis was performed to evaluate the relationship between hypoxia-inducible factor-1α (HIF1α) 1790G/A gene polymorphism and the susceptibility to renal cell carcinoma (RCC) and prostate cancer (PCa).

METHODS

Association investigations were identified and included from the Embase, Cochrane Library and PubMed databases on March 1, 2018, and eligible investigations were analyzed by meta-analysis. Odds ratios (OR) were used to express the dichotomous data, and the 95% confidence intervals (CI) were also calculated.

RESULTS

In this meta-analysis, we found that the AA genotype of HIF1α 1790G/A was positively associated with the risk of RCC in overall populations, Caucasians, but not for Asians. G allele and GG genotype were not associated with the susceptibility of RCC in overall populations, Caucasians, and Asians. The G allele was negatively associated with PCa susceptibility in overall populations, Asians, but not for Caucasians. GG genotype was negatively associated with PCa susceptibility in Asians, but not for overall populations and Caucasians. HIF1α 1790G/A AA genotype was not associated with PCa susceptibility in overall populations of Caucasians or Asians.

CONCLUSION

AA genotype of HIF1α 1790G/A was positively associated with RCC risk in overall populations and Caucasians. Furthermore, the G allele was negatively associated with prostate cancer susceptibility in overall populations, Asians, and GG genotype was negatively associated with PCa susceptibility in Asians.