Survival of patients with ruptured gastrointestinal stromal tumour treated with adjuvant imatinib in a randomised trial.

BACKGROUND: Patients with ruptured gastrointestinal stromal tumour (GIST) have poor prognosis. Little information is available about how adjuvant imatinib influences survival. METHODS: We explored recurrence-free survival (RFS) and overall survival (OS) of patients with ruptured GIST who participated in a randomised trial (SSG XVIII/AIO), where 400 patients with high-risk GIST were allocated to adjuvant imatinib for either 1 year or 3 years after surgery. Of the 358 patients with confirmed localised GIST, 73 (20%) had rupture reported. The ruptures were classified retrospectively using the Oslo criteria. RESULTS: Most ruptures were major, four reported ruptures were reclassified unruptured. The 69 patients with rupture had inferior RFS and OS compared with 289 patients with unruptured GIST (10-year RFS 21% vs. 55%, OS 59% vs. 78%, respectively). Three-year adjuvant imatinib did not significantly improve RFS or OS of the patients with rupture compared with 1-year treatment, but in the largest mutational subset with KIT exon 11 deletion/indel mutation OS was higher in the 3-year group than in the 1-year group (10-year OS 94% vs. 54%). CONCLUSIONS: About one-fifth of ruptured GISTs treated with adjuvant imatinib did not recur during the first decade of follow-up. Relatively high OS rates were achieved despite rupture. CLINICAL TRIAL REGISTRATION: NCT00116935.

Hypoxia-inducible factor (HIF)-prolyl hydroxylase 3 (PHD3) maintains high HIF2A mRNA levels in clear cell renal cell carcinoma.

Most clear cell renal cell carcinomas (ccRCCs) have inactivation of the von Hippel-Lindau tumor suppressor protein (pVHL), resulting in the accumulation of hypoxia-inducible factor α-subunits (HIF-α) and their downstream targets. HIF-2α expression is particularly high in ccRCC and is associated with increased ccRCC growth and aggressiveness. In the canonical HIF signaling pathway, HIF-prolyl hydroxylase 3 (PHD3) suppresses HIF-2α protein by post-translational hydroxylation under sufficient oxygen availability. Here, using immunoblotting and immunofluorescence staining, qRT-PCR, and siRNA-mediated gene silencing, we show that unlike in the canonical pathway, PHD3 silencing in ccRCC cells leads to down-regulation of HIF-2α protein and mRNA. Depletion of other PHD family members had no effect on HIF-2α expression, and PHD3 knockdown in non-RCC cells resulted in the expected increase in HIF-2α protein expression. Accordingly, PHD3 knockdown decreased HIF-2α target gene expression in ccRCC cells and expression was restored upon forced HIF-2α expression. The effect of PHD3 depletion was pinpointed to HIF2A mRNA stability. In line with these in vitro results, a strong positive correlation of PHD3 and HIF2A mRNA expression in ccRCC tumors was detected. Our results suggest that in contrast to the known negative regulation of HIF-2α in most cell types, high PHD3 expression in ccRCC cells maintains elevated HIF-2α expression and that of its target genes, which may enhance kidney cancer aggressiveness.

ROTS: reproducible RNA-seq biomarker detector-prognostic markers for clear cell renal cell cancer.

Recent comprehensive assessments of RNA-seq technology support its utility in quantifying gene expression in various samples. The next step of rigorously quantifying differences between sample groups, however, still lacks well-defined best practices. Although a number of advanced statistical methods have been developed, several studies demonstrate that their performance depends strongly on the data under analysis, which compromises practical utility in real biomedical studies. As a solution, we propose to use a data-adaptive procedure that selects an optimal statistic capable of maximizing reproducibility of detections. After demonstrating its improved sensitivity and specificity in a controlled spike-in study, the utility of the procedure is confirmed in a real biomedical study by identifying prognostic markers for clear cell renal cell carcinoma (ccRCC). In addition to identifying several genes previously associated with ccRCC prognosis, several potential new biomarkers among genes regulating cell growth, metabolism and solute transport were detected.

Hypoxia inducible prolyl hydroxylase PHD3 maintains carcinoma cell growth by decreasing the stability of p27.

BACKGROUND: Hypoxia can halt cell cycle progression of several cell types at the G1/S interface. The arrest needs to be overcome by cancer cells. We have previously shown that the hypoxia-inducible cellular oxygen sensor PHD3/EGLN3 enhances hypoxic cell cycle entry at the G1/S boundary. METHODS: We used PHD3 knockdown by siRNA and shRNA in HeLa and 786-0 renal cancer cells. Flow cytometry with cell synchronization was used to study cell growth at different cell cycle phases. Total and phosphospecific antibodies together with cycloheximide chase were used to study p27/CDKN1B expression and fractionations for subcellular protein localization. RESULTS: Here we show that PHD3 enhances cell cycle by decreasing the expression of the CDK inhibitor p27/CDKN1B. PHD3 reduction led to increased p27 expression under hypoxia or VHL mutation. p27 was both required and sufficient for the PHD3 knockdown induced cell cycle block. PHD3 knockdown did not affect p27 transcription and the effect was HIF-independent. In contrast, PHD3 depletion increased the p27 half-life from G0 to S-phase. PHD3 depletion led to an increase in p27 phosphorylation at serine 10 without affecting threonine phosphorylation. Intact serine 10 was required for normal hypoxic and PHD3-mediated degradation of p27. CONCLUSIONS: The data demonstrates that PHD3 can drive cell cycle entry at the G1/S transition through decreasing the half-life of p27 that occurs by attenuating p27S10 phosphorylation.

p62/SQSTM1 regulates cellular oxygen sensing by attenuating PHD3 activity through aggregate sequestration and enhanced degradation.

The hypoxia-inducible factor (HIF) prolyl hydroxylase PHD3 regulates cellular responses to hypoxia. In normoxia the expression of PHD3 is low and it occurs in cytosolic aggregates. SQSTM1/p62 (p62) recruits proteins into cytosolic aggregates, regulates metabolism and protein degradation and is downregulated by hypoxia. Here we show that p62 determines the localization, expression and activity of PHD3. In normoxia PHD3 interacted with p62 in cytosolic aggregates, and p62 was required for PHD3 aggregation that was lost upon transfer to hypoxia, allowing PHD3 to be expressed evenly throughout the cell. In line with this, p62 enhanced the normoxic degradation of PHD3. Depletion of p62 in normoxia led to elevated PHD3 levels, whereas forced p62 expression in hypoxia downregulated PHD3. The loss of p62 resulted in enhanced interaction of PHD3 with HIF-α and reduced HIF-α levels. The data demonstrate p62 is a critical regulator of the hypoxia response and PHD3 activity, by inducing PHD3 aggregation and degradation under normoxia.

Reasons for Treatment Discontinuation and Their Effect on Outcomes of Immunotherapy in Southwest Finland: A Retrospective, Real-World Cohort Study.

Immune checkpoint inhibitors (ICI) have improved survival in several cancer types. Still, most patients develop disease progression during or after treatment. We evaluated the reasons for treatment discontinuation and their effect on treatment outcomes in adult patients with advanced cancer with ICI in the first or later treatment lines in Southwest Finland between 1 January 2015 and 31 December 2021. Baseline characteristics and treatment outcomes were retrospectively obtained from the electronic medical records. There were 317 patients with 15 different cancer types, most commonly non-small cell lung cancer, melanoma, and kidney cancer, treated with ICI outside clinical trials. During follow-up, 94% of the patients had discontinued treatment. A total of 62% was due to disease progression, 17% due to immune-related adverse events (irAEs), 12% after achieving disease control or radiological response, and 9% due to poor performance status. The median progression-free survival (mPFS) was 5.4 months and the median overall survival (mOS) was 20.3 months in the whole cohort. Longer mPFS and mOS were observed in patients who discontinued ICI due to irAEs (24.3 and 49.2 months) and after disease control (49.7 months and not reached). In total, 46% of the patients who discontinued ICI after irAEs or disease control remained alive and progression-free during follow-up.

Low nuclear expression of HIF-hydroxylases PHD2/EGLN1 and PHD3/EGLN3 are associated with poor recurrence-free survival in clear cell renal cell carcinoma.

BACKGROUND: Hypoxia inducible factors, HIF-1α and HIF-2α, and their main regulators, the prolyl hydroxylase domain proteins (PHDs), mediate cellular response to hypoxia and contribute to tumor progression in clear cell renal cell carcinoma (ccRCC). These biomarkers may improve the value of traditional histopathological features in predicting disease progression after nephrectomy for localized ccRCC and guide patient selection for adjuvant treatments. PATIENTS AND METHODS: In this study, we analyzed the associations of PHD2 and PHD3 with histopathological tumor features and recurrence-free survival (RFS) in a retrospective cohort of 173 patients who had undergone surgery for localized ccRCC at Helsinki University Hospital (HUH), Finland. An external validation cohort of 191 patients was obtained from Turku University Hospital (TUH), Finland. Tissue-microarrays (TMA) were constructed using the primary tumor samples. Clinical parameters and follow-up information from 2006 to 2019 were obtained from electronic medical records. The cytoplasmic and nuclear expression of PHD2, and PHD3 were scored based on immunohistochemical staining and their associations with histopathological features and RFS were evaluated. RESULTS: Nuclear PHD2 and PHD3 expression in cancer cells were associated with lower pT-stage and Fuhrman grade compared with negative nuclei. Patients with positive nuclear expression of PHD2 and PHD3 in cancer cells had favorable RFS compared with patients having negative tumors. The nuclear expression of PHD2 was independently associated with a decreased risk of disease recurrence or death from RCC in multivariable analysis. These results were observed in both cohorts. CONCLUSIONS: The absence of nuclear PHD2 and PHD3 expression in ccRCC was associated with poor RFS and the nuclear expression of PHD2 predicted RFS regardless of other known histopathological prognostic factors. Nuclear PHD2 and PHD3 are potential prognostic biomarkers in patients with localized ccRCC and should be further investigated and validated in prospective studies.

Interaction with ErbB4 promotes hypoxia-inducible factor-1α signaling.

The receptor-tyrosine kinase ErbB4 was identified as a direct regulator of hypoxia-inducible factor-1α (HIF-1α) signaling. Cleaved intracellular domain of ErbB4 directly interacted with HIF-1α in the nucleus, and stabilized HIF-1α protein in both normoxic and hypoxic conditions by blocking its proteasomal degradation. The mechanism of HIF stabilization was independent of VHL and proline hydroxylation but dependent on RACK1. ErbB4 activity was necessary for efficient HRE-driven promoter activity, transcription of known HIF-1α target genes, and survival of mammary carcinoma cells in vitro. In addition, mammary epithelial specific targeting of Erbb4 in the mouse significantly reduced the amount of HIF-1α protein in vivo. ERBB4 expression also correlated with the expression of HIF-regulated genes in a series of 4552 human normal and cancer tissue samples. These data demonstrate that soluble ErbB4 intracellular domain promotes HIF-1α stability and signaling via a novel mechanism.

The regulation, localization, and functions of oxygen-sensing prolyl hydroxylase PHD3.

The prolyl 4-hydroxylase domain protein 3 (PHD3) belongs to 2-oxoglutarate and iron-dependent dioxygenases. Together with the two closest paralogues, PHD1 and PHD2, these enzymes have been identified as cellular oxygen sensors that can mark the hypoxia-inducible factor α (HIF-α) for von Hippel-Lindau protein-mediated proteasomal destruction. Although having overlapping functions with PHD1 and PHD2, PHD3 markedly differs from the two isoforms. PHD3 shows a different expression pattern and subcellular localization as well as activity under low oxygen tension. Moreover, it has the widest range of non-HIF targets underlying its diverse functions. The functions of PHD3 differ depending on the cell type and also partially on the microenvironmental conditions it is expressed at. Under normoxia, PHD3 has been shown to be proapoptotic, but under hypoxia, it can have cell survival or proliferation-supporting functions. Here we discuss the regulation, targets, and functions of PHD3.

Bexmarilimab-induced macrophage activation leads to treatment benefit in solid tumors: The phase I/II first-in-human MATINS trial.

Macrophage Clever-1 contributes to impaired antigen presentation and suppression of anti-tumor immunity. This first-in-human trial investigates the safety and tolerability of Clever-1 blockade with bexmarilimab in patients with treatment-refractory solid tumors and assesses preliminary anti-tumor efficacy, pharmacodynamics, and immunologic correlates. Bexmarilimab shows no dose-limiting toxicities in part I (n = 30) and no additional safety signals in part II (n = 108). Disease control (DC) rates of 25%-40% are observed in cutaneous melanoma, gastric, hepatocellular, estrogen receptor-positive breast, and biliary tract cancers. DC associates with improved survival in a landmark analysis and correlates with high pre-treatment intratumoral Clever-1 positivity and increasing on-treatment serum interferon γ (IFNγ) levels. Spatial transcriptomics profiling of DC and non-DC tumors demonstrates bexmarilimab-induced macrophage activation and stimulation of IFNγ and T cell receptor signaling selectively in DC patients. These data suggest that bexmarilimab therapy is well tolerated and show that macrophage targeting can promote immune activation and tumor control in late-stage cancer.

Prognostic Factors for Localized Clear Cell Renal Cell Carcinoma and Their Application in Adjuvant Therapy.

Approximately 20% of patients with renal cell carcinoma (RCC) present with primarily metastatic disease and over 30% of patients with localized RCC will develop distant metastases later, after complete resection of the primary tumor. Accurate postoperative prognostic models are essential for designing personalized surveillance programs, as well as for designing adjuvant therapy and trials. Several clinical and histopathological prognostic factors have been identified and adopted into prognostic algorithms to assess the individual risk for disease recurrence after radical or partial nephrectomy. However, the prediction accuracy of current prognostic models has been studied in retrospective patient cohorts and the optimal set of prognostic features remains unclear. In addition to traditional histopathological prognostic factors, novel biomarkers, such as gene expression profiles and circulating tumor DNA, are extensively studied to supplement existing prognostic algorithms to improve their prediction accuracy. Here, we aim to give an overview of existing prognostic features and prediction models for localized postoperative clear cell RCC and discuss their role in the adjuvant therapy trials. The results of ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic factors and biomarkers that help to define patients at high risk for disease recurrence.

Hypoxia-activated Smad3-specific dephosphorylation by PP2A.

The transforming growth factor-beta (TGF-beta) maintains epithelial homeostasis and suppresses early tumor formation, but paradoxically at later stages of tumor progression, TGF-beta promotes malignancy. TGF-beta activates phosphorylation of Smad2 and -3 effectors. Smad2 and -3 are known to have different functions, but differential regulation of their phosphorylation has not been described. Here we show that upon hypoxia, the TGF-beta-induced phosphorylation of Smad3 was inhibited, although Smad2 remained phosphorylated. The inhibition of Smad3 phosphorylation was not due to TGF-beta receptor inactivation. We show that Smad3 was dephosphorylated by PP2A (protein phosphatase 2A) specifically under hypoxic conditions. The hypoxic Smad3 dephosphorylation required intact expression of the essential scaffold component PR65 of PP2A. PP2A physically interacted with Smad3 that occurred only in hypoxia. Accordingly, Smad3-associated PP2A activity was found under hypoxic conditions. Hypoxia attenuated the nuclear accumulation of TGF-beta-induced Smad3 but did not affect Smad2. Moreover, the influence of TGF-beta on a set of Smad3-activated genes was attenuated by hypoxia, and this was reversed by chemical PP2A inhibition. Our data demonstrate the existence of a Smad3-specific phosphatase and identify a novel role for PP2A. Moreover, our data implicate a novel mechanism by which hypoxia regulates growth factor responses.

Retention of prolyl hydroxylase PHD2 in the cytoplasm prevents PHD2-induced anchorage-independent carcinoma cell growth.

Cellular oxygen tension is sensed by a family of prolyl hydroxylases (PHD1-3) that regulate the degradation of hypoxia-inducible factors (HIF-1alpha and -2alpha). The PHD2 isoform is considered as the main downregulator of HIF in normoxia. Our previous results have shown that nuclear translocation of PHD2 associates with poorly differentiated tumor phenotype implying that nuclear PHD2 expression is advantageous for tumor growth. Here we show that a pool of PHD2 is shuttled between the nucleus and the cytoplasm. In line with this, accumulation of wild type PHD2 in the nucleus was detected in human colon adenocarcinomas and in cultured carcinoma cells. The PHD2 isoforms showing high nuclear expression increased anchorage-independent carcinoma cell growth. However, retention of PHD2 in the cytoplasm inhibited the anchorage-independent cell growth. A region that inhibits the nuclear localization of PHD2 was identified and the deletion of the region promoted anchorage-independent growth of carcinoma cells. Finally, the cytoplasmic PHD2, as compared with the nuclear PHD2, less efficiently downregulated HIF expression. Forced HIF-1alpha or -2alpha expression decreased and attenuation of HIF expression increased the anchorage-independent cell growth. However, hydroxylase-inactivating mutations in PHD2 had no effect on cell growth. The data imply that nuclear PHD2 localization promotes malignant cancer phenotype.

A three-feature prediction model for metastasis-free survival after surgery of localized clear cell renal cell carcinoma.

After surgery of localized renal cell carcinoma, over 20% of the patients will develop distant metastases. Our aim was to develop an easy-to-use prognostic model for predicting metastasis-free survival after radical or partial nephrectomy of localized clear cell RCC. Model training was performed on 196 patients. Right-censored metastasis-free survival was analysed using LASSO-regularized Cox regression, which identified three key prediction features. The model was validated in an external cohort of 714 patients. 55 (28%) and 134 (19%) patients developed distant metastases during the median postoperative follow-up of 6.3 years (interquartile range 3.4-8.6) and 5.4 years (4.0-7.6) in the training and validation cohort, respectively. Patients were stratified into clinically meaningful risk categories using only three features: tumor size, tumor grade and microvascular invasion, and a representative nomogram and a visual prediction surface were constructed using these features in Cox proportional hazards model. Concordance indices in the training and validation cohorts were 0.755 ± 0.029 and 0.836 ± 0.015 for our novel model, which were comparable to the C-indices of the original Leibovich prediction model (0.734 ± 0.035 and 0.848 ± 0.017, respectively). Thus, the presented model retains high accuracy while requiring only three features that are routinely collected and widely available.

Systemic Blockade of Clever-1 Elicits Lymphocyte Activation Alongside Checkpoint Molecule Downregulation in Patients with Solid Tumors: Results from a Phase I/II Clinical Trial.

PURPOSE: Macrophages are critical in driving an immunosuppressive tumor microenvironment that counteracts the efficacy of T-cell-targeting therapies. Thus, agents able to reprogram macrophages toward a proinflammatory state hold promise as novel immunotherapies for solid cancers. Inhibition of the macrophage scavenger receptor Clever-1 has shown benefit in inducing CD8+ T-cell-mediated antitumor responses in mouse models of cancer, which supports the clinical development of Clever-1-targeting antibodies for cancer treatment. PATIENTS AND METHODS: In this study, we analyzed the mode of action of a humanized IgG4 anti-Clever-1 antibody, FP-1305 (bexmarilimab), both in vitro and in patients with heavily pretreated metastatic cancer (n = 30) participating in part 1 (dose-finding) of a phase I/II open-label trial (NCT03733990). We studied the Clever-1 interactome in primary human macrophages in antibody pull-down assays and utilized mass cytometry, RNA sequencing, and cytokine profiling to evaluate FP-1305-induced systemic immune activation in patients with cancer. RESULTS: Our pull-down assays and functional studies indicated that FP-1305 impaired multiprotein vacuolar ATPase-mediated endosomal acidification and improved the ability of macrophages to activate CD8+ T-cells. In patients with cancer, FP-1305 administration led to suppression of nuclear lipid signaling pathways and a proinflammatory phenotypic switch in blood monocytes. These effects were accompanied by a significant increase and activation of peripheral T-cells with indications of antitumor responses in some patients. CONCLUSIONS: Our results reveal a nonredundant role played by the receptor Clever-1 in suppressing adaptive immune cells in humans. We provide evidence that targeting macrophage scavenging activity can promote an immune switch, potentially leading to intratumoral proinflammatory responses in patients with metastatic cancer.

The role of HIF prolyl hydroxylases in tumour growth.

Tumour hypoxia is a well-known microenvironmental factor that causes cancer progression and resistance to cancer treatment. This involves multiple mechanisms of which the best-understood ones are mediated through transcriptional gene activation by the hypoxia-inducible factors (HIFs). HIFs in turn are regulated in response to oxygen availability by a family of iron- and 2-oxoglutarate-dependent dioxygenases, the HIF prolyl hydroxylases (PHDs). PHDs inactivate HIFs in normoxia by activating degradation of the HIF-alpha subunit but release HIF activation in poorly oxygenated conditions. The function of HIF in tumours is fairly well characterized but our understanding on the outcome of PHDs in tumours is much more limited. Here we review the function of PHDs on the HIF system, the expression of PHDs in human tumours as well as their putative function in cancer. The PHDs may have either tumour promoting or suppressing activity. Their outcome in cancer depends on the cell and cancer type-specific expression and on the availability of diverse natural PHD inhibitors in tumours. Moreover, besides the action of PHDs on HIF, recent data suggest PHD function in non-HIF signalling. Together the data illustrate a complex operation of the oxygen sensors in cancer.

Survival Outcomes Associated With 3 Years vs 1 Year of Adjuvant Imatinib for Patients With High-Risk Gastrointestinal Stromal Tumors: An Analysis of a Randomized Clinical Trial After 10-Year Follow-up.

Importance: Adjuvant imatinib is associated with improved recurrence-free survival (RFS) when administered after surgery to patients with operable gastrointestinal stromal tumor (GIST), but its influence on overall survival (OS) has remained uncertain. Objective: To evaluate the effect of adjuvant imatinib on OS of patients who have a high estimated risk for GIST recurrence after macroscopically complete surgery. Design, Setting, and Participants: In this open-label, randomized (1:1), multicenter phase 3 clinical trial conducted in Finland, Germany, Norway, and Sweden, 400 patients who had undergone macroscopically complete surgery for GIST with a high estimated risk for recurrence according to the modified National Institutes of Health Consensus Criteria were enrolled between February 2004 and September 2008. Data for this follow-up analysis were analyzed from September to November, 2019. Interventions: Imatinib 400 mg/d administered orally for either 12 months or 36 months after surgery. Main Outcomes And Measures: The primary end point was RFS; the secondary objectives included OS and treatment safety. Results: The intention-to-treat cohort consisted of 397 patients (12-month group, 199; 36-month group, 198; 201 men and 196 women; median [IQR] age, 62 (51-69) years and 60 (51-67) years, during a median follow-up time of 119 months after the date of randomization, 194 RFS events and 96 OS events were recorded in the intention-to-treat population. Five-year and 10-year RFS was 71.4% and 52.5%, respectively, in the 36-month group and 53.0% and 41.8% in the 12-month group (hazard ratio [HR], 0.66; 95% CI, 0.49-0.87; P = .003). In the 36-month group, 5-year OS and 10-year OS rates were 92.0% and 79.0%, respectively, and in the 12-month group 85.5% and 65.3% (HR, 0.55; 95% CI, 0.37-0.83; P = .004). The results were similar in the efficacy population, from which 15 patients who did not have GIST in central pathology review and 24 patients who had intra-abdominal metastases removed at surgery were excluded (36-month group, 10-year OS 81.6%; 12-month group, 66.8%; HR, 0.50; 95% CI, 0.32-0.80; P = .003). No new safety signals were detected. Conclusions and Relevance: Three years of adjuvant imatinib is superior in efficacy compared with 1 year of imatinib. Approximately 50% of deaths may be avoided during the first 10 years of follow-up after surgery with longer adjuvant imatinib treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT00116935.

Overall Survival and Metastasis Resections in Patients with Metastatic Colorectal Cancer Using Electronic Medical Records.

PURPOSE: Treatment for patients with metastatic colorectal cancer is chemotherapy commonly combined with monoclonal antibodies against vascular endothelial growth factor (bevacizumab) or epidermal growth factor receptor (cetuximab or panitumumab), the efficacy of which has been proven in randomized controlled trials. The objective of the current retrospective study was to analyze the impact of targeted therapy, adverse events, and dose reduction on overall survival (OS) and metastasis resection rates. METHODS: A hospital-based electronic informatics center was used to gather clinical data and outcome information in a "real-life" setting in a single academic hospital. A total of 178 patients were included in 2010-2013. RESULTS: In patients whose tumors expressed the KRAS wild type, the longest median OS was observed with irinotecan-based chemotherapy combined with bevacizumab (38 months), or with cetuximab (41 months). In the KRAS-mutated group, the longest median OS was observed with oxaliplatin with or without bevacizumab (34 months). Beneficial liver metastasis resections were observed in 12 out of 20 patients. Patients with KRAS wild-type tumors who received cetuximab were the most likely to undergo surgery. Age was a negative predictor of OS. Patients whose chemotherapy dose was reduced to below 80% had lower OS compared to those remaining above 80%. Treatment delays in chemotherapy did not affect OS. Pulmonary embolism and infections were common but did not have an impact on OS. CONCLUSIONS: A hospital-based electronic informatics center provides comparable OS results, even though adverse events were frequently observed in the present study.

Transportable system enabling multiple irradiation studies under simultaneous hypoxia in vitro.

BACKGROUND: Cells in solid tumours are variably hypoxic and hence resistant to radiotherapy - the essential role of oxygen in the efficiency of irradiation has been acknowledged for decades. However, the currently available methods for performing hypoxic experiments in vitro have several limitations, such as a limited amount of parallel experiments, incapability of keeping stable growth conditions and dependence on CO2 incubator or a hypoxia workstation. The purpose of this study was to evaluate the usability of a novel portable system (Minihypoxy) in performing in vitro irradiation studies under hypoxia, and present supporting biological data. MATERIALS AND METHODS: This study was conducted on cancer cell cultures in vitro. The cells were cultured in normoxic (~ 21% O2) or in hypoxic (1% O2) conditions either in conventional hypoxia workstation or in the Minihypoxy system and irradiated at dose rate 1.28 Gy/min ± 2.9%. The control samples were sham irradiated. To study the effects of hypoxia and irradiation on cell viability and DNA damage, western blotting, immunostainings and clonogenic assay were used. The oxygen level, pH, evaporation rate and osmolarity of the culturing media on cell cultures in different conditions were followed. RESULTS: The oxygen concentration in interest (5, 1 or 0% O2) was maintained inside the individual culturing chambers of the Minihypoxy system also during the irradiation. The radiosensitivity of the cells cultured in Minihypoxy chambers was declined measured as lower phosphorylation rate of H2A.X and increased clonogenic capacity compared to controls (OER~ 3). CONCLUSIONS: The Minihypoxy system allows continuous control of hypoxic environment in multiple wells and is transportable. Furthermore, the system maintains the low oxygen environment inside the individual culturing chambers during the transportation and irradiation in experiments which are typically conducted in separate facilities.

Overexpression and nuclear translocation of hypoxia-inducible factor prolyl hydroxylase PHD2 in head and neck squamous cell carcinoma is associated with tumor aggressiveness.

PURPOSE: Hypoxia in tumors is associated with poor prognosis and resistance to treatment. The outcome of hypoxia is largely regulated by the hypoxia-inducible factors (HIF-1alpha and HIF-2alpha). HIFs in turn are negatively regulated by a family of prolyl hydroxylases (PHD1-3). The PHD2 isoform is the main down-regulator of HIFs in normoxia and mild hypoxia. This study was designed to analyze the correlation of the expression and subcellular localization of PHD2 with the pathologic features of human carcinomas and HIF-1alpha expression. EXPERIMENTAL DESIGN: The expression of PHD2 was studied from paraffin-embedded normal tissue (n = 21) and head and neck squamous cell carcinoma (HNSCC; n = 44) by immunohistochemistry. Further studies included PHD2 mRNA detection and HIF-1alpha immunohistochemistry from HNSCC specimens as well as PHD2 immunocytochemistry from HNSCC-derived cell lines. RESULTS: In noncancerous tissue, PHD2 is robustly expressed by endothelial cells. In epithelium, the basal proliferating layer also shows strong expression, whereas the more differentiated epithelium shows little or no PHD2 expression. In HNSCC, PHD2 shows strongly elevated expression both at the mRNA and protein level. Moreover, PHD2 expression increases in less differentiated phenotypes and partially relocalizes from the cytoplasm into the nucleus. Endogenously high nuclear PHD2 is seen in a subset of HNSCC-derived cell lines. Finally, although most of the tumor regions with high PHD2 expression show down-regulated HIF-1alpha, regions with simultaneous HIF-1alpha and PHD2 expression could be detected. CONCLUSIONS: Our results show that increased levels and nuclear translocation of the cellular oxygen sensor, PHD2, are associated with less differentiated and strongly proliferating tumors. Furthermore, they imply that even the elevated PHD2 levels are not sufficient to down-regulate HIF-1alpha in some tumors.