Expression of Hypoxia-Inducible Factor-1α Protein Predicts Survival in Patients with Transitional Cell Carcinoma of the Upper Urinary Tract

METTL4-mediated nuclear N6-deoxyadenosine methylation promotes metastasis through activating multiple metastasis-inducing targets

BACKGROUND

DNA N6-methyldeoxyadenosine (6mA) is rarely present in mammalian cells and its nuclear role remains elusive.

RESULTS

Here we show that hypoxia induces nuclear 6mA modification through a DNA methyltransferase, METTL4, in hypoxia-induced epithelial-mesenchymal transition (EMT) and tumor metastasis. Co-expression of METTL4 and 6mA represents a prognosis marker for upper tract urothelial cancer patients. By RNA sequencing and 6mA chromatin immunoprecipitation-exonuclease digestion followed by sequencing, we identify lncRNA RP11-390F4.3 and one novel HIF-1α co-activator, ZMIZ1, that are co-regulated by hypoxia and METTL4. Other genes involved in hypoxia-mediated phenotypes are also regulated by 6mA modification. Quantitative chromatin isolation by RNA purification assay shows the occupancy of lncRNA RP11-390F4.3 on the promoters of multiple EMT regulators, indicating lncRNA-chromatin interaction. Knockdown of lncRNA RP11-390F4.3 abolishes METTL4-mediated tumor metastasis. We demonstrate that ZMIZ1 is an essential co-activator of HIF-1α.

CONCLUSIONS

We show that hypoxia results in enriched 6mA levels in mammalian tumor cells through METTL4. This METTL4-mediated nuclear 6mA deposition induces tumor metastasis through activating multiple metastasis-inducing genes. METTL4 is characterized as a potential therapeutic target in hypoxic tumors.

Bladder cancer cell lines adapt their aggressiveness profile to oxygen tension

During the process of tumor growth, cancer cells will be subjected to intermittent hypoxia. This results from the delay in the development of the vascular network in relation to the proliferation of cancer cells. The hypoxic nature of a tumor has been demonstrated as a negative factor for patient survival. To evaluate the impact of hypoxia on the survival and migration properties of low and high-grade bladder cancer cell lines, two low-grade (MGHU-3 and SW-780) and two high-grade (SW-1710 and T24) bladder cancer cell lines were cultured in normoxic (20% O₂) or hypoxic atmospheric conditions (2% O₂). The response of bladder cancer cell lines to hypoxic atmospheric cell culture conditions was examined under several parameters, including epithelial-mesenchymal transition, doubling time and metabolic activities, thrombospondin-1 expression, whole Matrix Metallo-Proteinase activity, migration and resistance to oxidative stress. The low-grade cell line response to hypoxia was heterogeneous even if it tended to adopt a more aggressive profile. Hypoxia enhanced migration and pro-survival properties of MGHU-3 cells, whereas these features were reduced for the SW-780 cell line cultured under low oxygen tension. The responses of tested high-grade cell lines were more homogeneous and tended to adopt a less aggressive profile. Hypoxia drastically changed some of the bladder cancer cell line properties, for example matrix metalloproteinases expression for all cancer cells but also switch in glycolytic metabolism of low grade cancer cells. Overall, studying bladder cancer cells in hypoxic environments are relevant for the translation from in vitro findings to in vivo context.

Reduction in mitochondrial oxidative stress mediates hypoxia-induced resistance to cisplatin in human transitional cell carcinoma cells

Tumor hypoxia is known to promote the acquisition of more aggressive phenotypes in human transitional cell carcinoma (TCC), including drug resistance. Accumulating evidence suggests that mitochondria play a central role in the chemoresistance of TCC. However, the role of mitochondria in the hypoxia-induced drug resistance in TCC remains elusive. The present study investigated the function of mitochondria in the drug resistance using a TCC cell line under hypoxic conditions. In vitro hypoxia (0.1% O₂, 48 h) was achieved by incubating TCC cells in air chamber. Mitochondrial events involving hypoxia-induced drug resistance were assessed. Hypoxia significantly reduced the cisplatin-induced apoptosis of TCC cells. Additionally, hypoxia substantially decreased the level of mitochondrial reactive oxygen species (ROS) generated by cisplatin treatment. Analogously, elimination of mitochondrial ROS significantly rescued cells from cisplatin-induced apoptosis. Hypoxia enhanced mitochondrial hyperpolarization, which was not related to ATP production or the reversal of ATP synthase activity. The mitochondrial DNA (mtDNA) amplification efficiency data illustrated that hypoxia significantly prevented oxidative damage to the mitogenome. Moreover, transmission electron microscopy revealed that cisplatin-induced disruption of the mitochondrial ultrastructure was abated under hypoxic conditions. Notably, depletion of mtDNA by ethidium bromide abrogated hypoxia-induced resistance to cisplatin. Taken together, the present study demonstrated that TCC cells exposed to hypoxic conditions rendered mitochondria less sensitive to oxidative stress induced by cisplatin treatment, leading to enhanced drug resistance.

Hypoxic environment may enhance migration/penetration of endocrine resistant MCF7- derived breast cancer cells through monolayers of other non-invasive cancer cells in vitro

The response of cancer cells to hypoxic conditions found within the interior of a tumor mass is mediated through the hypoxia inducible factor (HIF) cascade and is thought to promote metastasis. However, given their distant proximity from blood vessels as compared to normoxic cells at the vascularised tumor periphery, it is uncertain if these cells can migrate through the tumor mass to gain access. Hypoxia was simulated by exposure to cobalt chloride or deferoxamine in normal (MCF10A) and cancerous [estrogen receptor (ER)−ve (pII), and ER +ve (YS1.2/ EII)] cells. In this report, HIF1α expression and localization was measured using western blotting, ELISA, and immunofluorescence, cell proliferation by MTT assay, motility and invasion by wound healing, live cell imaging, matrigel and co-culture in chambered slides. We found that the expression and nuclear translocation of HIF1α was significantly elevated by hypoxia, which inhibited cell proliferation, but significantly increased motility of pII cells and their penetration into and through a dense layer of adjacent EII cells, as well as their selective emergence out of a co-culture. These data suggest that endocrine resistant pII cancer cells, having undergone epithelial to mesenchymal transition are able to penetrate through other cell layers, with possible enhancement in response to hypoxia.

Volumetric imaging: a potential tool to stage upper tract urothelial carcinoma

PURPOSE

To investigate whether volumetric imaging of tumor vasculature can be used to phenotypically characterize advanced upper tract urothelial carcinoma, and if this technique can distinguish aggressive invasive tumors from non-aggressive superficial ones.

METHODS

In a pilot study, two TaG1 and two T3G3 formalin-fixed paraffin-embedded (FFPE) tumor samples were examined using the DIPCO pipeline (Tanaka et al. in Nature Biomed Eng 1(10):796-806. https://doi.org/10.1038/s41551-017-0139-0 , 2017). Briefly, punch biopsies of FFPE tumors were deparaffinized, cleared, immunolabeled with the vessel marker CD34 and imaged with a light-sheet microscope. Thereafter, the three-dimensional (3D) vasculature of the tumors was analyzed and characterized using a specialized image processing software.

RESULTS

We found that T3G3 tumors had increased CD34 density kurtosis and skewness compared to TaG1 tumors. This suggests that analysis of the 3D vasculature can distinguish between high-grade invasive and low-grade superficial tumors.

CONCLUSIONS

Volumetric imaging of tumor samples may represent novel methodology that can complement conventional histopathology. Volumetric imaging enabled us to differentiate between invasive and non-invasive upper tract urothelial carcinoma. The method is of particular interest in diagnostic work-up of patients with upper tract urothelial carcinoma as previous findings indicate that volumetric imaging of vascular patterns could be used to differentiate superficial and invasive urothelial carcinoma, irrespective of if the tumor sample was deep or superficial. However, further and more extensive studies are required before this method can be applied clinically.

Tissue-based molecular markers in upper tract urothelial carcinoma and their prognostic implications

Upper tract urothelial carcinoma (UTUC) is a rare and aggressive disease that is associated with high rates of recurrence and death. Radical nephroureterectomy (RNU) with excision of the bladder cuff is considered the standard of care for high-risk UTUC, whereas kidney-sparing techniques can be indicated for select patients with low-risk disease. There is a significant lack of clinical and pathological prognostic factors for stratifying patients with regard to making treatment decisions. Incorporation of tissue-based molecular markers into prognostic tools could help accurately stratify patients for clinical decision-making in this heterogeneous disease. Although the number of studies on tissue-based markers in UTUC has risen dramatically in the past several years-many of which are based on single centers and small cohorts, with a low level of evidence-many discrepancies remain between their results. Nevertheless, certain biomarkers are promising tools, necessitating prospective multi-institution studies to validate their function.

Prostaglandin receptors induce urothelial tumourigenesis as well as bladder cancer progression and cisplatin resistance presumably via modulating PTEN expression

Background:

We investigated the role of prostaglandin receptors (e.g. prostaglandin E2 receptor 2 (EP2), EP4) and the efficacy of celecoxib in urothelial tumourigenesis and cancer progression.

Methods:

We performed immunohistochemistry in bladder cancer (BC) tissue microarrays, in vitro transformation assay in a normal urothelial SVHUC line, and western blot/reverse transcription–polymerase chain reaction/cell growth assays in BC lines.

Results:

EP2/EP4 expression was elevated in BCs compared with non-neoplastic urothelial tissues and in BCs from those who were resistant to cisplatin-based neoadjuvant chemotherapy. Strong positivity of EP2/EP4 in non-muscle-invasive tumours or positivity of EP2/EP4 in muscle-invasive tumours strongly correlated with disease progression or disease-specific mortality, respectively. In SVHUC cells, exposure to a chemical carcinogen 3-methylcholanthrene considerably increased and decreased the expression of EP2/EP4 and phosphatase and tensin homologue (PTEN), respectively. Treatment with selective EP2/EP4 antagonist or celecoxib also resulted in prevention in 3-methylcholanthrene-induced neoplastic transformation of SVHUC cells. In BC lines, EP2/EP4 antagonists and celecoxib effectively inhibited cell viability and migration, as well as augmented PTEN expression. Furthermore, these drugs enhanced the cytotoxic activity of cisplatin in BC cells. EP2/EP4 and PTEN were also elevated and reduced, respectively, in cisplatin-resistant BC sublines.

Conclusions:

EP2/EP4 activation correlates with induction of urothelial cancer initiation and outgrowth, as well as chemoresistance, presumably via downregulating PTEN expression.

Prognostic microRNAs in upper tract urothelial carcinoma: multicenter and international validation study

Objective

To validate previously discovered miRNAs (miR-31-5p and miR-149-5p) as prognostic factors for UTUC in an independent cohort of UTUC patients.

Patients and Methods

Multicenter, international and retrospective study of formalin-fixed paraffin-embedded tissue samples from 103 UTUC patients (45 progressing and 58 non-progressing) who underwent radical nephroureterectomy. Total RNA was isolated and reverse transcribed. The expression of target miRNAs (miR-31-5p and miR-149-5p) and the endogenous control miR-218-5p was evaluated in all samples by reverse transcription quantitative PCR. Normalized miRNA expression values were evaluated by multivariate forward stepwise Cox regression analysis. Kaplan Meier curves were used to discriminate between two groups of patients with a different probability of tumour progression.

Results

The mean age (range) of the series was 67 (33-94) years. Overall, 45 patients (43.7%) developed tumour progression and 32 patients (31.2%) died, 20 of these (62.5%) due to their UTUC, after a median follow-up of 36 months. The mean time for tumour progression and cancer-specific survival were 15 and 20 months, respectively. Five year tumour progression free survival and cancer-specific survival were 58% for ≤ pT2, 36% for pT3 and 0% for pT4 and 67.8% for ≤ pT2, 50.6% for pT3 and 0% for pT4, respectively. In the multivariate analysis, expression of miR-31-5p was found to be an independent prognostic factor of tumour progression (HR 1.1; 95% CI 1.039-1.273; p=0.02). Kaplan Meier curve shows that miR-31-5p expression values are able to discriminate between two groups of UTUC patients with a different probability of tumour progression (p=0.007).

Conclusions

We have been able to validate our previous results in an independent multicentre international cohort of UTUC patients, suggesting that miRNA-31-5p could be a useful prognostic marker of UTUC progression. The application of miRNA expression values to clinical practice could refine the currently used clinicopathological-based approach for predicting UTUC patients’ outcome.

Increased nucleophosmin expression is a strong predictor of recurrence and prognosis in patients with N0M0 upper tract urothelial carcinoma undergoing radical nephroureterectomy

PURPOSE

We aimed to evaluate whether increased nucleophosmin expression predicts recurrence and survival in upper tract urothelial carcinoma (UTUC).

METHODS

Specimens from 101 patients with N0M0 UTUC undergoing radical nephroureterectomy were evaluated. Nucleophosmin expression was determined immunohistochemically and categorized into two groups according to nucleophosmin staining intensity. The association between nucleophosmin expression and various clinicopathological factors including Ki-67 expression was analyzed. Multivariate analyses were performed to identify the independent predictors of extraurothelial recurrence and cancer-specific survival.

RESULTS

High nucleophosmin expression was significantly correlated with tumor location, pT ≥3, lymphovascular invasion, lymph node metastasis, and high Ki-67 expression. Patients whose tumors demonstrated high nucleophosmin expression had a significantly higher rate of extraurothelial recurrence and a lower survival rate than those with low nucleophosmin expression. Multivariate analysis showed that pT ≥3, lymph node metastasis, high nucleophosmin expression, and high Ki-67 expression were independent predictors of extraurothelial recurrence. When patients were stratified into three groups according to the number of risk factors, the 2-year extraurothelial recurrence-free survival rates were 92.9% in patients with 0 or 1 risk factor, 76.5% in patients with 2 risk factors, and 9.1% in patients with 3 or 4 risk factors. Regarding cancer-specific survival, lymphovascular invasion and high nucleophosmin expression were independent predictors.

CONCLUSIONS

Increased nucleophosmin expression was a strong predictor of extraurothelial recurrence and cancer-specific survival in patients with N0M0 UTUC undergoing radical nephroureterectomy. Our risk stratification models integrating nucleophosmin expression may provide valuable information on disease recurrence and prognosis.

Proteome Profiling of Urinary Exosomes Identifies Alpha 1-Antitrypsin and H2B1K as Diagnostic and Prognostic Biomarkers for Urothelial Carcinoma

MALDI-TOF spectrometry has not been used for urinary exosome analysis. We used it for determining UC biomarkers. From 2012 to 2015, we enrolled 129 consecutive patients with UC and 62 participants without UC. Exosomes from their urine were isolated, and analyzed through MALDI-TOF spectrometry. Immunohistochemical (IHC) analysis of another 122 UC and 26 non-UC tissues was conducted to verify the discovered biomarkers. Two peaks at m/z 5593 (fragmented peptide of alpha-1-antitrypsin; sensitivity, 50.4%; specificity, 96.9%) and m/z 5947 (fragmented peptide of histone H2B1K sensitivity, 62.0%; specificity, 92.3%) were identified as UC diagnosis exosome biomarkers. UC patients with detectable histone H2B1K showed 2.29- and 3.11-fold increased risks of recurrence and progression, respectively, compared with those with nondetectable histone H2B1K. Verification results of IHC staining revealed significantly higher expression of alpha 1-antitrypsin (p = 0.038) and H2B1K (p = 0.005) in UC tissues than in normal tissues. The expression of alpha 1-antitrypsin and H2B1K in UC tissues was significantly correlated with UC grades (p < 0.05). Urinary exosome proteins alpha 1-antitrypsin and histone H2B1K, which are identified through MALDI-TOF analysis, could facilitate rapid diagnosis and prognosis of UC.

Prognostic Genetic Signatures in Upper Tract Urothelial Carcinoma

Urothelial carcinoma is a highly heterogeneous disease that can arise throughout the entire urothelial lining from the renal pelvis to the proximal urethra. Upper tract urothelial carcinoma (UTUC) is rare, and while it shares many similarities with urothelial carcinoma of bladder (UCB), there are also significant differences between UTUC and UCB regarding clinical management and outcomes. No major advances have been made recently in the development of new systemic therapies for urothelial carcinoma, partly due to the lack of understanding of underlying molecular pathogenetic mechanisms. In the past decade, the emergence of next-generation sequencing has greatly enabled genomic characterization of tumor samples. Researchers are currently exploring a personalized approach to augment traditional clinical decision-making based on genetic alterations. In the present review, we summarize current genomic advances in UTUC and discuss the potential implications of these developments for developing prognostic and predictive biomarkers.

The clinical and therapeutic uses of MDM2 and PSMA and their potential interaction in aggressive cancers

Prostate-specific membrane antigen (PSMA) overexpression is observed in the neovasculature of solid tumors, but not in the vasculature of normal tissues. Increased PSMA expression is positively associated with tumor stage and grade, although its function in cancer remains unclear. Mouse double minute 2 (MDM2) is a negative regulator of the p53 tumor suppressor and is reported to regulate VEGF expression and angiogenesis. Both proteins have been considered as biomarkers and therapeutic targets for advanced solid tumors. Our work and a recent microarray-based gene profiling study suggest there could be signaling interplay between MDM2 and PSMA. We herein review the mechanisms underlining the outgrowth of tumors associated with PSMA and MDM2, their potential interaction and how this may be applied to anticancer therapeutics.

Identification of circulating microRNA signatures for upper tract urothelial carcinoma detection

The involvement of circulating microRNAs (miRNAs) in cancer and their potential as diagnostic and prognostic biomarkers are becoming increasingly known. However, the significance of circulating miRNAs in upper tract urothelial carcinoma (UTUC) has remained to be investigated. The present study performed a genome‑wide serum miRNA analysis using a deep sequencing platform for initial screening. Subsequently, serum samples of 46 UTUC patients and 30 cancer‑free individuals with hematuria were subjected to a quantitative reverse‑transcription polymerase chain reaction analysis. The expression of thirteen miRNAs (miR‑664a‑3p, miR‑423‑5p, miR‑431‑5p, miR‑191‑5p, miR‑92a‑3p, miR‑22‑3p, miR‑26a‑5p, miR‑33b‑3p, miR‑16‑5p, let‑7a‑5p, let‑7b‑5p, let‑7f‑5p and let‑7c) was significantly different in serum from UTUC patients compared with that in control samples. Receiver operator characteristic analysis showed that 10 miRNAs (miR‑664a‑3p, miR‑431‑5p, miR‑423‑5p, miR‑191‑5p, miR‑33b‑3p, miR‑26a‑5p, miR‑22‑3p, miR‑16‑5p, let‑7b‑5p and let‑7c) had the potential to distinguish individuals with UTUC from the controls (areas under the curve >0.8). The present study provided the first evidence for the potential use of circulating miRNAs as biomarkers for UTUC diagnosis, which remains to be verified by further studies.

Targeting Hypoxia-Inducible Factor 1α in a New Orthotopic Model of Glioblastoma Recapitulating the Hypoxic Tumor Microenvironment

Tissue hypoxia and necrosis represent pathophysiologic and histologic hallmarks of glioblastoma (GBM). Although hypoxia inducible factor 1α (HIF-1α) plays crucial roles in the malignant phenotypes of GBM, developing HIF-1α-targeted agents has been hampered by the lack of a suitable preclinical model that recapitulates the complex biology of clinical GBM. We present a new GBM model, MGG123, which was established from a recurrent human GBM. Orthotopic xenografting of stem-like MGG123 cells reproducibly generated lethal tumors that were characterized by foci of palisading necrosis, hypervascularity, and robust stem cell marker expression. Perinecrotic neoplastic cells distinctively express HIF-1α and are proliferative in both xenografts and the patient tissue. The xenografts contain scattered hypoxic foci that were consistently greater than 50 μm distant from blood vessels, indicating intratumoral heterogeneity of oxygenation. Hypoxia enhanced HIF-1α expression in cultured MGG123 cells, which was abrogated by the HIF-1α inhibitors digoxin or ouabain. In vivo, treatment of orthotopic MGG123 xenografts with digoxin decreased HIF-1α expression, vascular endothelial growth factor mRNA levels, and CD34-positive vasculature within the tumors, and extended survival of mice bearing the aggressive MGG123 GBM. This preclinical tumor model faithfully recapitulates the GBM-relevant hypoxic microenvironment and stemness and is a suitable platform for studying disease biology and developing hypoxia-targeted agents.

Transcriptional upregulation of HIF-1α by NF-κB/p65 and its associations with β-catenin/p300 complexes in endometrial carcinoma cells

The hypoxia-inducible factor (HIF)-1α, which has a major role in cell adaptation to hypoxia, is mainly regulated at post-translational levels. Recently, HIF-1α mRNA was also shown to be upregulated by several signal pathways under normoxic conditions. Here we focused on relationships of HIF-1α with NF-κB and β-catenin signaling in endometrial carcinomas (Em Cas). Long-term exposure of Ishikawa cells to cobalt chloride (CoCl2), which is known to mimic the effect of hypoxia, caused a decrease in the growth, along with increased HIF-1α protein but not mRNA expression. In contrast, short-term exposure resulted in a rapid and transient increase in HIF-1α mRNA expression along with stabilization of nuclear NF-κB/p65 (p65). Transfection of p65 increased HIF-1α expression through activation of the promoter, whereas overexpression of HIF-1α also activated NF-κB-dependent transcription, indicating the existence of a positive feedback loop. In addition, HIF-1α was indirectly associated with nuclear β-catenin through interactions with p300, leading to slight enhancement of both HIF-1α- and β-catenin-mediated transcriptional activity. In clinical samples, biphasic upregulation of HIF-1α expression was observed in normal endometrial glandular components during the menstrual cycle, with the labeling indices showing significantly higher values in the early secretory stage. Significantly higher values for phosphorylated p65 and nuclear β-catenin were also observed in HIF-1α-positive than -negative lesions of Em Cas, in contrast to significantly lower Ki-67 status. These data therefore suggest that transcriptional associations with HIF-1α and NF-κB, as well as β-catenin/p300 complexes, may contribute to modulation of changes in tumor cell kinetics in response to a hypoxic condition in Em Cas.

HIF-1α is a crucial factor in the development of peritoneal dissemination via natural metastatic routes in scirrhous gastric cancer

The molecular mechanisms underlying the peritoneal dissemination of gastric cancer remain unclear. Using in vivo metastatic models, this study attempted to clarify the role of hypoxia inducible factor (HIF)-1α in the development of peritoneal dissemination of gastric cancer. HIF-1α knockdown (KD) cells were established in the scirrhous gastric cancer cell line 58As9. Using KD and control (SC) cells, the presence of peritoneal dissemination was assessed in orthotopic implantation (o.i.) and intraperitoneal injection (i.p.) models. A series of in vitro analyses were also conducted. Finally, tumor angiogenesis was immunohistochemically analyzed. In the o.i. model, peritoneal dissemination was more frequently observed in the SC mice (93%) compared to the KD mice (13%) (P<0.001). In the i.p. model, peritoneal dissemination occurred at a high rate in both types of mice; however, a greater number of nodules was observed in the KD mice (P=0.017). The in vitro assays showed that HIF-1α exerts unfavorable effects on anoikis resistance and adhesion to extracellular matrix. Angiogenesis and vascular invasion were more aggressive in the SC gastric tumors. Vascular invasion was present in the intratumoral regions of the disseminated nodules in the SC o.i., but not the i.p., mice. HIF-1α was found to be crucial for the development of peritoneal dissemination in o.i. model, which mimics natural metastasis. In contrast, HIF-1α played an inhibitory role in suppressing peritoneal dissemination in the i.p. model. These results indicate that peritoneal dissemination in o.i. mice may not act through a seeding mechanism. An immunohistochemical analysis demonstrated HIF-1α-activated angiogenesis and vascular invasion in stomach tumors. Furthermore, the results showed that the disseminated nodules observed in SC o.i. mice were formed via extravasation of cancer cells. We provide a possible mechanism in which peritoneal dissemination of gastric cancer develops via a vascular network whereby HIF-1α activates tumor angiogenesis.

Prognostic significance of Bcl-xL expression and efficacy of Bcl-xL targeting therapy in urothelial carcinoma

BACKGROUND

Bcl-xL has an important role in the control of cell death through its inhibition of apoptosis. The aim of this study was to investigate the clinicopathological significance of Bcl-xL in upper urinary tract urothelial carcinoma (UTUC) and the therapeutic effect of targeting Bcl-xL protein in urothelial carcinoma (UC) cells.

METHODS

We evaluated the immunohistochemical expression of Bcl-xL in 175 UTUC patients to determine the clinical role of Bcl-xL expression in clinical outcome. We used bafilomycin A1 (BMA) as a specific inhibitor of Bcl-xL to examine the biological effects in UC cells in vitro and in vivo.

RESULTS

Immunohistochemical analysis of Bcl-xL expression revealed that patients with a high Bcl-xL score had a significantly lower 5-year cancer-specific survival (CSS) rate (53.2%) than those with a low Bcl-xL score (77.2%) (P=0.0011). Multivariate analysis indicated that a high Bcl-xL score was an independent prognostic factor of CSS (P=0.023). BMA inhibited UMUC-3 cell proliferation in vitro by induction of apoptosis. Treatment with BMA significantly inhibited tumour growth in UMUC-3 tumours in this mouse xenograft model accompanied by an elevated apoptosis induction.

CONCLUSION

Bcl-xL appears to be a significant molecular marker for the prognosis of UTUCs. Targeting Bcl-xL may be a promising therapeutic strategy for patients with UC.

Molecular aspects of upper tract urothelial carcinoma

OBJECTIVES

Primary upper tract urothelial carcinoma (UTUC) is a relatively rare tumor with up to 60% of cases being muscle invasive at presentation. In this article we review the molecular biology of UTUC, an understanding of which may help to address some of the dilemmas surrounding the diagnosis and treatment of this disease and ultimately lead to the introduction of personalized treatment plans.

METHODS

The literature search on the molecular aspects of UTUC was performed using the National Library of Medicine database.

RESULTS

UTUC and urothelial carcinomas of the bladder share many common biological pathways. UTUC are more commonly associated with conditions such as Balkan Endemic Nephropathy and Hereditary Non Polyposis Colon Cancer (HNPCC), the molecular basis of which is now being understood. A large number of potential biomarkers have been studied to help identify robust prognostic markers in UTUC.

CONCLUSION

Advances in our understanding of the biology of UTUC is may in the future help to identify novel druggable targets, clinically applicable biomarkers and guide treatment of the rare but lethal condition.

Distinct patterns and behaviour of urothelial carcinoma with respect to anatomical location: how molecular biomarkers can augment clinico-pathological predictors in upper urinary tract tumours

PURPOSE

Upper urinary tract urothelial carcinoma (UTUC) shares many similarities with bladder-UC, but there is strong evidence on a clinical, aetiological, epidemiological and genetic level that key differences exist. In this review, we aim to highlight how UTUC differs from bladder-UC and report on the utility of molecular markers in the diagnosis and management of UTUC.

MATERIALS AND METHODS

A systematic literature search was conducted using the Medline and Embase databases and specific keyword combinations: 'urothelial carcinoma', 'bladder cancer', 'transitional cell carcinoma', 'upper tract', 'upper urinary tract', 'genetics', 'prognosis' and 'biomarkers'.

RESULTS

UTUC has specific acquired (e.g. Balkans nephropathy, phenacetin abuse) and genetic hereditary non-polyposis colorectal cancer risk factors compared with bladder-UC. In general, the molecular biology of UC is broadly similar, irrespective of location in the urinary tract. However, there are distinct genetic (microsatellite instability) and epigenetic (hypermethylation) differences between some UTUC and bladder-UC. Clinical-pathological variables (e.g. hydronephrosis, tumour architecture, tumour location, stage and grade) have independent predictive power in UTUC, but tissue and urinary biomarkers can improve the clinical prediction of recurrence, invasion and survival in UTUC, though the evidence level is weak.

CONCLUSIONS

UTUC shares many similarities with bladder-UC, but there is strong evidence that they should be considered as distinct urothelial entities. Prospective multi-institutional studies investigating molecular markers are urgently needed to augment clinic-pathological predictors in UTUC.

Up-regulation of hypoxia inducible factor-1α by cobalt chloride correlates with proliferation and apoptosis in PC-2 cells

Background

The exact mechanism of the effects of hypoxia on the proliferation and apoptosis in carcinoma cells is still conflicting. This study investigated the variation of hypoxia-inducible factor-1α(HIF-1α) expression and the apoptosis effect of hypoxia stimulated by cobalt chloride (CoCl₂) in pancreatic cancer PC-2 cells.

Methods

PC-2 cells were cultured with different concentration (50-200 μmol/L) of CoCl₂ after 24-120 hours to simulate hypoxia in vitro. The proliferation of PC-2 cells was examined by MTT assay. The cellular morphology of PC-2 cells were observed by light inverted microscope and transmission electron microscope(EM). The expression of HIF-1α on mRNA and protein level was measured by semi-quantitive RT-PCR and Western blot analysis. Apoptosis of PC-2 cells were demonstrated by flow cytometry with Annexin V-FITC/PI double staining.

Results

MTT assay showed that the proliferation of PC-2 cells were stimulated in the first 72 h, while after treated over 72 h, a dose- dependent inhibition of cell growth could be observed. By using transmission electron microscope, swollen chondrosomes, accumulated chromatin under the nuclear membrane and apoptosis bodies were observed. Flow cytometer(FCM) analysis showed the apoptosis rate was correlated with the dosage of CoCl₂. RT-PCR and Western blot analysis indicated that hypoxia could up-regulate the expression of HIF-1α on both mRNA and protein levels.

Conclusion

Hypoxic microenvironment stimulated by CoCl₂ could effectively induce apoptosis and influence cell proliferation in PC-2 cells, the mechanism could be related to up-expression of HIF-1α.

Role of chemotherapy in upper urinary tract urothelial cell cancers

Urothelial cancers of the upper urinary tract are uncommon and often treated in a similar fashion to lower urinary tract urothelial malignancies. Currently, there are no clear guidelines on the use of systemic chemotherapy for upper urinary tract urothelial cancers either in the perioperative setting or in cases of advanced disease. The aim of this article is to review the key studies in upper urinary tract cancers to help develop an understanding about the optimal management and suggest areas for future research.

Expression of p53 in upper urinary tract urothelial carcinoma

The management of upper urinary tract urothelial carcinoma (UUT-UC) is controversial. Radical nephroureterectomy is a major undertaking and has obvious shortcomings in the presence of renal impairment and solitary kidneys, whereas endoscopic management can be associated with a risk of disease progression. There is a pressing need for reliable predictive biomarkers to refine patient selection for renal conservation. p53 is the most frequently investigated molecular marker in UUT-UC. Of the 24 papers published on the subject, expression of p53 is a significant univariate prognostic marker in 12 publications, representing seven unique cohorts. However, multivariate analysis demonstrates that p53 expression is of independent prognostic significance in only five studies, all of which contain potential statistical bias. The currently available data do not, therefore, support a role for p53 in this regard, and suggest a need for prospective large-scale collaborative studies using standardized methods of p53 detection and statistical analysis.

Prognostic factors for upper urinary tract urothelial carcinoma

Upper urinary tract urothelial carcinoma (UTUC) is a rare disease, which means there are little evidence-based data available to guide clinical decision-making. Although diagnosis and treatment of UTUC have improved significantly over the last 5 years, accurate risk stratification remains a challenge owing to the difficulty of clinical staging. A number of potential prognostic factors have been identified, encompassing clinical characteristics, pathological factors and molecular markers. Tumor stage and lymph node status are the most important predictors of survival in patients with UTUC. Preoperative evaluation for hydronephrosis can identify patients at risk of non-organ-confined disease. In the subgroup of patients with stage ≥pT2 disease, a longer interval between diagnosis and radical nephroureterectomy is associated with a higher risk of disease recurrence and cancer-specific mortality. Extensive tumor necrosis, sessile tumor architecture and lymphovascular invasion are independent predictors of clinical outcomes for patients with UTUC treated with radical nephroureterectomy. The incorporation of such prognosticators into clinical prediction models might help to guide decision-making with regard to timing of surveillance, type of treatment, performance of lymphadenectomy, and consideration of neoadjuvant or adjuvant systemic therapies.

The emerging role of hypoxia, HIF-1 and HIF-2 in multiple myeloma

Hypoxia is an imbalance between oxygen supply and demand, which deprives cells or tissues of sufficient oxygen. It is well-established that hypoxia triggers adaptive responses, which contribute to short- and long-term pathologies such as inflammation, cardiovascular disease and cancer. Induced by both microenvironmental hypoxia and genetic mutations, the elevated expression of the hypoxia-inducible transcription factor-1 (HIF-1) and HIF-2 is a key feature of many human cancers and has been shown to promote cellular processes, which facilitate tumor progression. In this review, we discuss the emerging role of hypoxia and the HIFs in the pathogenesis of multiple myeloma (MM), an incurable hematological malignancy of BM PCs, which reside within the hypoxic BM microenvironment. The need for current and future therapeutic interventions to target HIF-1 and HIF-2 in myeloma will also be discussed.

Association of tumor necrosis with pathological features and clinical outcome in 754 patients undergoing radical nephroureterectomy for upper tract urothelial carcinoma: an international validation study

PURPOSE

Tumor necrosis is associated with a poor oncological outcome in patients with upper tract urothelial carcinoma and other malignancies. We validated the association of tumor necrosis with pathological features and clinical outcomes in a large international cohort of patients with upper tract urothelial carcinoma treated with radical nephroureterectomy.

MATERIAL AND METHODS

This retrospective study included 754 patients treated with radical nephroureterectomy at a total of 9 centers. Tumor necrosis was scored as greater than 10% of tumor area based on microscopic evaluation.

RESULTS

Tumor necrosis was present in 165 specimens (21.9%). The prevalence of tumor necrosis increased with advancing pathological stage, including 7%, 10.6% and 50% for T1, T2 and T3-4, respectively (p <0.001). Tumor necrosis was associated with features of aggressive upper tract urothelial carcinoma, such as high grade, lymph node metastasis, lymphovascular invasion, sessile tumor architecture and concomitant carcinoma in situ (p <0.002). Median followup in censored patients was 40 months (IQR 18 to 75). On univariate Cox regression analysis tumor necrosis was significantly associated with disease recurrence and cancer specific mortality (HR 2.4 and 2.7, p <0.001). However, on multivariate Cox regression analysis including patient age, stage, grade, lymph node status, lymphovascular invasion and adjuvant chemotherapy tumor necrosis was not associated with disease recurrence (HR 1.1, p = 0.49) or cancer specific mortality (HR 1.1, p = 0.51). Excluding 63 patients who received adjuvant chemotherapy and/or 49 with positive lymph nodes did not substantially change these results.

CONCLUSIONS

In this large, multicenter international study tumor necrosis was associated with pathological features of biologically aggressive upper tract urothelial carcinoma. However, tumor necrosis was not an independent predictor of clinical outcomes.

Expressions of hypoxia-inducible factor-1α and hexokinase-II in gastric adenocarcinoma: the impact on prognosis and correlation to clinicopathologic features

The impact of hypoxia-inducible factor (HIF)-1α and hexokinase-II (HK-II) expression on prognosis of gastric adenocarcinoma patients has not been clearly established. We identified all patients in Cancer Center of Sun Yat-Sen University who were diagnosed as gastric adenocarcinoma and underwent radical gastrectomy between January 1999 and December 2001. We used immunohistochemistry to determine the expressions of HIF-1α protein and HK-II in the surgical sections. We identified 188 patients with gastric adenocarcinoma for the final analysis. The positive rate of HIF-1α and HK-II were 110/188 (54.6%) and 40/188 (21.3%), respectively. Both HIF-1α and HK-II were all positively correlated with tumor size, lower differentiation, and tumor stage. Univariate analysis showed that advanced tumor stages (P < 0.001), tumor size (P = 0.003), HIF-1α expression (P < 0.001), and HK-II expression (P < 0.001) were all significantly associated with shorter survival. The multivariate Cox analysis revealed that tumor stage (P < 0.001), HIF-1α expression (P < 0.001), and HK-II expression (P = 0.002) remained independent prognostic variables for survival. In addition, there was a positive correlation of HIF-1α protein expression and HK-II (P = 0.022). Both HIF-1α and HK-II were overexpressed in gastric adenocarcinoma. The multivariate Cox analysis revealed that both of them were independent factors on survival of gastric adenocarcinoma patients.

HIF-1alpha is an unfavorable determinant of relapse in gastric cancer patients who underwent curative surgery followed by adjuvant 5-FU chemotherapy

Among several chemotherapeutic agents, 5-fluorouracil (5-FU) has been widely used as a key drug in adjuvant chemotherapy for gastric cancer. However, no reliable marker, which predicts the response to 5-FU in an adjuvant setting, has been identified. Hypoxia-induced drug resistance, via upregulation of HIF-1alpha, is a major obstacle in the development of effective cancer therapy. However, few clinical studies have so far assessed the relationship between the HIF-1alpha expression and the chemo-resistance of gastric cancer patients in an adjuvant setting. We established 2 HIF-1alpha knockdown gastric cancer cell lines in order to clarify the role of HIF-1alpha in chemo-resistance against 5-FU. Furthermore, expression of HIF-1alpha was immunohistochemically assessed in 91 resected specimens. Sixty-four of 91 patients received 5-FU adjuvant chemotherapy after surgery. HIF-1alpha expression was associated with the significantly shorter relapse-free survival and disease-specific survival in the 64 patients of adjuvant group (p = 0.026, 0.014, respectively), but not in the 27 of surgery group. Multivariate analysis showed that HIF-1alpha was an independent risk factor for relapse in 64 patients in the adjuvant group (p = 0.029). In conclusion, the current study confirmed, for the first time that HIF-1alpha expression is an independent risk factor for relapse in high-risk gastric cancer patients who underwent curative surgery followed by adjuvant 5-FU chemotherapy. A favorable effect of 5-FU might therefore be expected in patients that do not express HIF-1alpha, whereas, other types of chemotherapy or additional treatments, such as HIF-1alpha inhibitors, should be considered in patients that do express HIF-1alpha.

Hypoxia response pathway in border cell migration

Cell invasion and metastasis mark the most lethal phase of cancer, but little is known about the key molecular events that initiate this crucial turning point. Low oxygen, or hypoxia, is thought to be one trigger for metastasis. Hypoxic conditions within the tumor mass are thought to activate signaling pathways that stimulate invasiveness of cancer cells spreading the disease. However, the molecular basis of this process is not well understood. A recent study used Drosophila ovarian border cell migration to model the type of cell migration that occurs in tumors in response to oxygen deprivation through the activation of the hypoxia response pathway (Doronkin et al. Oncogene. 2009). This model organism approach revealed a highly sophisticated mechanism of control of cell migration that is regulated by multiple genetic inputs tied to the hypoxic response. Genetic manipulations with the components of the HIF-1 (hypoxia-inducible factor 1) pathway were able to either inhibit or block the migration of border cells or cause unprecedented acceleration of their migration. The HIF-1-mediated transcriptional cascade appears to be the major regulator of border cell locomotion. Based on the similarity of the fly and human HIF-1 pathways, this model organism study might lead to improvements in understanding hypoxia-induced metastasizing of human cancers. This article discusses new findings in the context of their relevance to cancer metastasis and speculates on the potential regulatory mechanisms and future research directions.

Hypoxia-inducible factor 1α expression is a prognostic biomarker in patients with astrocytic tumors associated with necrosis on MR image

Hypoxia-inducible factor (HIF)-1α and HIF-2α expression were investigated immunohistochemically as determinants of prognosis in 42 cases of astrocytic tumors associated with necrosis grade on magnetic resonance (MR) imaging. Expression of HIF-1α was determined immunohistologically. The degree of necrosis on MR images was divided into four grades. Kaplan-Meier analysis revealed a significant effect of necrosis grade on MR images on cumulative overall survival. Median survival times were 26, 14, and 13 months for patients with necrosis grades 1, 2, and 3, respectively (not defined for grade 0). Kaplan-Meier analysis revealed a significant effect of HIF-1α expression on cumulative overall survival. Median survival time of patients with HIF-1α expression was 17 months, whereas it was 80 months for patients without HIF-1α expression. However, overexpression of HIF-2α did not correlate with malignant features, for example angiogenesis or necrosis, and had no impact on overall survival of patients with glial tumors. In conclusion, HIF-1α, but not HIF-2α, is a useful prognostic factor in astrocytic tumor associated with necrosis on MR images.

Glucose-regulated protein 78 expression in urothelial carcinoma of the upper urinary tract

OBJECTIVE

To examine glucose-regulated protein 78 (GRP78; a major molecular chaperone at the endoplasmic reticulum, strongly expressed in several tumours) expression in urothelial carcinoma (UC) of the upper urinary tract (UUT) and to evaluate the diagnostic and progressive importance of GRP78 expression in UC-UUT.

PATIENTS AND METHODS

We investigated GRP78 expression (using immunohistochemistry) in 126 UC-UUTs to assess its relevance to progression. GRP78 overexpression was recognised in 23 (18.3%) of tumour samples.

RESULTS

There was no association between GRP78 overexpression and clinicopathological findings, except for an association with low grade in invasive tumours. GRP78 overexpression significantly improved the disease-free survival rate in all patients (according to univariate and multivariate analyses), but did not alter the overall survival rate.

CONCLUSION

The detection of GRP78 overexpression would appear to provide valuable information for the prognosis of UC-UUT.

Soluble elastin decreases in the progress of atheroma formation in human aorta

BACKGROUND

The serum levels of soluble elastin increase in patients with aortic dissection, but its distribution and characteristics are unclear.

METHODS AND RESULTS

The 173 aortic specimens were categorized into 4 groups under microscopy (non-atherosclerotic aorta, n=13; fiber-rich plaque, n=77; lipid-rich plaque, n=66; ruptured plaque, n=17). Soluble elastin was abundant within the intima of both the non-atherosclerotic aorta and fiber-rich plaque, rather than in the media, and was decreased within the intima of lipid-rich and ruptured plaques. Soluble elastin levels decreased with progress of atherosclerosis (6.0 +/-0.3 microg/mg protein in non-atherosclerotic aorta; 5.8 +/-0.2 microg/mg protein in fiber-rich plaque; 4.9 +/-0.2 microg/mg protein in lipid-rich plaque; 2.8 +/-0.4 microg/mg protein in ruptured plaque, P<0.05). As well, both matrix metalloprotease-9 activity and elastin mRNA expression showed inverse distribution against soluble elastin (r=0.437, P<0.0001; r=0.186, P<0.05, respectively). Multivariable analysis revealed a decrease in the level of soluble elastin in ruptured plaque (2.8 +/-0.4 microg/mg protein in ruptured plaque, n=18; 5.5 +/-0.2 microg/mg protein in non-ruptured plaque, n=155, P<0.01). Furthermore, western blot showed soluble elastin consists of heterogeneous molecular pattern proteins.

CONCLUSIONS

Both the synthesis and degradation of elastin may be enhanced in active atherosclerotic lesions.

Antisense hypoxia-inducible factor-1alpha augments transcatheter arterial embolization in the treatment of hepatocellular carcinomas in rats

Transcatheter arterial embolization (TAE) is a standard treatment for unresectable hepatic malignancies. It blocks the arterial blood supply to the tumor, but blockade of the blood supply can be short-lived as collateral blood vessels develop, leading to the failure of TAE. Here we report that intraportal delivery of adeno-associated viral (AAV) vectors expressing antisense hypoxia-inducible factor-1alpha (HIF-1alpha) (AAV-ASHIF) augments TAE to combat hepatocellular carcinoma (HCC). Intraportal delivery of AAV-ASHIF led to long-term localized expression of transgenic ASHIF in rat liver, and suppressed the growth of CBRH7919 HCC tumors established in rat liver by inhibiting the formation of neovessels and tumor cell proliferation. TAE therapy caused the necrosis and shrinkage of liver tumors; however, neovessels quickly formed and the residual tumors underwent rapid expansion. TAE enhanced tumor and liver hypoxia, which in turn upregulated expression of HIF-1alpha, vascular endothelial growth factor, glucose transporter-1, lactate dehydrogenase A, and proliferating cell nuclear antigen. Intraportal injection of AAV-ASHIF augmented the therapeutic effects of TAE and diminished its undesirable effects, resulting in extensive tumor cell death and suppression of the growth of liver tumors. In conclusion, this study has revealed that HIF-1 impedes the response of liver tumors to TAE. Antisense HIF-1alpha therapy is warranted as an approach for enhancing the efficacy of TAE to treat unresectable liver cancers.

Hypoxia-inducible factor-1alpha suppresses squamous carcinogenic progression and epithelial-mesenchymal transition

Hypoxia-inducible factor-1 (HIF-1) is a known cancer progression factor, promoting growth, spread, and metastasis. However, in selected contexts, HIF-1 is a tumor suppressor coordinating hypoxic cell cycle suppression and apoptosis. Prior studies focused on HIF-1 function in established malignancy; however, little is known about its role during the entire process of carcinogenesis from neoplasia induction to malignancy. Here, we tested HIF-1 gain of function during multistage murine skin chemical carcinogenesis in K14-HIF-1alpha(Pro402A564G) (K14-HIF-1alphaDPM) transgenic mice. Transgenic papillomas appeared earlier and were more numerous (6 +/- 3 transgenic versus 2 +/- 1.5 nontransgenic papillomas per mouse), yet they were more differentiated, their proliferation was lower, and their malignant conversion was profoundly inhibited (7% in transgenic versus 40% in nontransgenic mice). Moreover, transgenic cancers maintained squamous differentiation whereas epithelial-mesenchymal transformation was frequent in nontransgenic malignancies. Transgenic basal keratinocytes up-regulated the HIF-1 target N-myc downstream regulated gene-1, a known tumor suppressor gene in human malignancy, and its expression was maintained in transgenic papillomas and cancer. We also discovered a novel HIF-1 target gene, selenium binding protein-1 (Selenbp1), a gene of unknown function whose expression is lost in human cancer. Thus, HIF-1 can function as a tumor suppressor through transactivation of genes that are themselves targets for negative selection in human cancers.

Prognostic value of apoptosis-related markers in urothelial cancer of the upper urinary tract

We investigated the expression of apoptosis-related markers and their association with the clinical outcomes of patients with urothelial carcinoma of the upper urinary tract. A total of 112 patients with urothelial carcinoma of the upper urinary tract that had surgery from March 1998 to July 2005 were included in the study. Tissue microarray slides were used for immunohistochemistry, and immunohistochemical staining was performed to investigate the association of apoptosis-related markers with clinical outcome. Apoptosis was confirmed by the TdT-mediated DUTP nick-end labeling method to obtain the apoptotic index. Survival analysis was performed according to the Kaplan-Meier method, and the Cox proportional hazard regression model was used to compare the relative influence of different prognostic factors. Among the 112 patients, 32 (28.6%) had altered expression of p53, 30 (26.8%) of bcl-2, 62 (55.4%) of bax, 27 (24.1%) of caspase-3, and 23 (20.5%) of survivin. The expression of p53 and caspase-3 was associated with the pathologic grade (P = .035 and P = .004, respectively). Altered expression of caspase-3 was associated with the pathologic stage (P = .016). The multivariate analysis showed that the expression of survivin (hazard ratio 2.91, 95% confidence interval 1.07-7.90, P = .036) and the apoptotic index (AI) (3.35, 1.06-10.56, P = .039), as well as the T and N stages (P = .043 and P = .010, respectively) were significantly associated with the disease-specific survival. Our results suggest that survivin expression and a high apoptotic index were poor prognostic factors for survival in patients with urothelial carcinoma of the upper urinary tract. These results may help to identify a subset of patients who require adjuvant therapy or closer follow-up.

Tumor necrosis is associated with increased alphavbeta3 integrin expression and poor prognosis in nodular cutaneous melanomas

Background

Tumor necrosis and apoptotic activity are considered important in cancer progression, but these features have not been much studied in melanomas. Our hypothesis was that rapid growth in cutaneous melanomas of the vertical growth phase might lead to tissue hypoxia, alterations in apoptotic activity and tumor necrosis. We proposed that these tumor characteristics might be associated with changes in expression of cell adhesion proteins leading to increased invasive capacity and reduced patient survival.

Methods

A well characterized series of nodular melanoma (originally 202 cases) and other benign and malignant melanocytic tumors (109 cases) were examined for the presence of necrosis, apoptotic activity (TUNEL assay), immunohistochemical expression of hypoxia markers (HIF-1 α, CAIX, TNF-α, Apaf-1) and cell adhesion proteins (α_vβ₃ integrin, CD44/HCAM and osteopontin). We hypothesized that tumor hypoxia and necrosis might be associated with increased invasiveness in melanoma through alterations of tumor cell adhesion proteins.

Results

Necrosis was present in 29% of nodular melanomas and was associated with increased tumor thickness, tumor ulceration, vascular invasion, higher tumor proliferation and apoptotic index, increased expression of α_vβ₃ integrin and poor patient outcome by multivariate analysis. Tumor cell apoptosis did also correlate with reduced patient survival. Expression of TNF-α and Apaf-1 was significantly associated with tumor thickness, and osteopontin expression correlated with increased tumor cell proliferation (Ki-67).

Conclusion

Tumor necrosis and apoptotic activity are important features of melanoma progression and prognosis, at least partly through alterations in cell adhesion molecules such as increased α_vβ₃ integrin expression, revealing potentially important targets for new therapeutic approaches to be further explored.

Antisense hypoxia-inducible factor 1alpha gene therapy enhances the therapeutic efficacy of doxorubicin to combat hepatocellular carcinoma

Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, is resistant to anticancer drugs. Hypoxia is a major cause of tumor resistance to chemotherapy, and hypoxia-inducible factor (HIF)-1 is a key transcription factor in hypoxic responses. We have previously demonstrated that gene transfer of an antisense HIF-1alpha expression vector downregulates expression of HIF-1alpha and vascular endothelial growth factor (VEGF), and synergizes with immunotherapy to eradicate lymphomas. The aim of the present study was to determine whether gene transfer of antisense HIF-1alpha could enhance the therapeutic efficacy of doxorubicin to combat HCC. Both antisense HIF-1alpha therapy and doxorubicin suppressed the growth of subcutaneous human HepG2 tumors established in BALB/c nude mice, tumor angiogenesis, and cell proliferation, and induced tumor cell apoptosis. The combination therapy with antisense HIF-1alpha and doxorubicin was more effective in suppressing tumor growth, angiogenesis, and cell proliferation, and inducing cell apoptosis than the respective monotherapies. Gene transfer of antisense HIF-1alpha downregulated the expression of both HIF-1alpha and VEGF, whereas doxorubicin only downregulated VEGF expression. Antisense HIF-1alpha and doxorubicin synergized to downregulate VEGF expression. Both antisense HIF-1alpha and doxorubicin inhibited expression of proliferating cell nuclear antigen, and combined to exert even stronger inhibition of proliferating cell nuclear antigen expression. Antisense HIF-1alpha therapy warrants investigation as a therapeutic strategy to enhance the efficacy of doxorubicin for treating HCC.

Overexpression of hypoxia-inducible factor-1alpha predicts an unfavorable outcome in urothelial carcinoma of the upper urinary tract

OBJECTIVES

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that plays an important role in cell hypoxia adaptation. Overexpression of HIF-1alpha subunit has been reported to be involved in the carcinogenesis, progression and metastasis of many human cancers. We evaluated the clinical significance of HIF-1alpha expression in urothelial carcinoma (UC) of the upper urinary tract.

METHODS

Ninety-eight cases (mean age = 63.5 +/- 11.7, range = 23-84 years) of renal pelvic or ureter UC were included in the present study. Those who had distant metastasis at diagnosis, other cancer, urolithiasis, incomplete clinical information or had received radiotherapy or chemotherapy before surgery were excluded. Nuclear HIF-1alpha expression were evaluated by immunohistochemistry staining on a paraffin-embedded section of the tumor and non-malignant upper urinary tract specimens and scored by two qualified pathologists. Clinical data were collected retrospectively.

RESULTS

Positive HIF-1alpha expression was found in 65 (66.3%) of the cancer specimens. No HIF-1alpha expression was found in normal urothelial specimens. Tumor HIF-1alpha expression score was significantly correlated with tumor T stage (P < 0.001), N stage (P < 0.001) and grade (P = 0.004). Tumor necrosis was associated with high tumor T stage (P < 0.001), N stage (P = 0.002) and grade (P < 0.001). Higher HIF-1alpha score (negative vs 3-5 vs 6-7) was a significant predictor for cancer-specific survival (Cox regression hazard ratio = 2.23, P = 0.004), and tumor recurrence (Cox regression hazard ratio = 1.58, P = 0.036).

CONCLUSION

Our findings indicate that HIF-1alpha immunostaining may have an important role in predicting prognosis in upper urinary tract urothelial carcinoma.

Expression of hypoxia-inducible factor-1alpha and its relationship to tumour angiogenesis and cell proliferation in cartilage tumours

We investigated the use of hypoxia-inducible factor (HIF) proteins as prognostic markers in chondrosarcoma and the relationship of HIF to the biological characteristics of cartilage tumours. The expression of HIF-1alpha, HIF-2alpha, proliferating cell nuclear antigen (PCNA) and microvessel density (MVD) were measured immunohistochemically in 29 specimens of cartilage tumour. There was no HIF-1alpha and HIF-2alpha staining in any of the nine benign cartilage tumours. In 20 specimens of chondrosarcoma, the rate of HIF-1alpha and HIF-2alpha expression was 40% and 25%, respectively. The tumour size (> or = 8 cm), histological grade (grade 2 and grade 3) surgical margin (marginal and intralesional) and HIF-1alpha expression (positive) correlated significantly with a shorter disease-free survival. There was a significant association between HIF-1alpha and the MVD and a strong trend towards a correlation between HIF-1alpha and the PCNA index or histological grade. Our findings suggest that HIF-1alpha protein may be a useful objective marker in the assessment of the prognosis in chondrosarcoma, since it plays an important role in tumour angiogenesis and cell proliferation.

Molecular and histological markers in urothelial carcinomas of the upper urinary tract

Urothelial cell carcinomas (UCCs) are one of the most common types of malignancies. Recently, different mechanisms of carcinogenesis, as well as discrepancies in the natural history of urothelial cancers of the bladder and of the upper urinary tract (UUT), have been identified. As a result several teams have focused on specific markers in UUT-UCCs, a very rare type of cancer. This review gives a brief overview on the current markers of interest. Microsatellite instabilities (MSI) are independent molecular makers for prognosis. In addition, MSI can help detect a germline mutation and therefore allows for the detection of possible hereditary cancers. The loss of proteins of the mismatch repair system can also facilitate the detection of a germline mutation but should be followed by DNA sequencing. Epithelial cadherin has been shown to be an independent marker of prognosis, as well as hypoxia-inducible factor-1alpha (HIF-1alpha) and telomerase RNA component. Furthermore HIF-1alpha is significantly associated with the grade and pattern of growth and the telomerase RNA component could possibly also be used in diagnosis. The active form of the L-type amino acid transporter 1 (LAT1) was a significant prognostic marker in univariate analysis only. There are contrasting studies on the significances of p27 and Ki-67 as prognostic markers in UUT-UCCs. MET is a factor that correlates with vascular invasion of invasive cancer and bcl-2 oncoprotein correlates with stage. The ongoing identification of these markers might help to find specific treatments tailored to the molecular pattern of each tumour. Therefore a subgroup of patients with a higher risk of recurrence could be identified as well as patients that could benefit from minimal invasive surgery.

Bladder cancer following upper tract urothelial carcinoma

Upper tract urothelial carcinoma (UTUC) is uncommon relative to primary bladder transitional cell carcinoma, with notable differences at the genetic, molecular and clinical levels. A variety of management options with similar oncologic outcomes are available for UTUC. Regardless of upper tract treatment modality, recurrence in the bladder consistently occurs in 20-50% of patients, thus presenting a significant clinical challenge. The initial intravesical relapse typically occurs within the first 2 years following upper tract therapy, but the risk is lifelong and repeat episodes are common. The identification of variables that allow accurate risk stratification of UTUC patients with regards to future bladder relapse is crucial. Unfortunately, to date, no variables have been identified that can reliably predict such bladder recurrences. A history of bladder cancer prior to UTUC resection and upper tract tumor multifocality are frequently reported clinical risk factors. Candidate molecular markers, such as E-cadherin, also hold promise for improving patient risk stratification. The impact of bladder recurrences on patient survival is still poorly defined. The risk of progression to invasive bladder disease is not well documented but appears to be an infrequent event. This article highlights important recent observations and key current issues regarding UTUC and subsequent bladder cancer. In addition, we suggest a bladder surveillance regimen following UTUC and provide recommendations for managing patients with intravesical recurrences.