The mutual determination of self-efficacy to cope with cancer and cancer-related coping over time: a prospective study in women with breast cancer

OBJECTIVE

The aim of this study was to examine the longitudinal impact of self-efficacy to cope with cancer on the cancer-related coping reactions of breast cancer patients and vice versa.

DESIGN AND MAIN OUTCOMES MEASURES

Data from the BOUNCE Project (https://www.bounce-project.eu/) were used to address the hypotheses. Participants (N = 403) were enrolled in the study a few weeks after surgery or biopsy. Coping self-efficacy was assessed at baseline and six months later (M6). Cancer-related coping was assessed three (M3) and nine months (M9) after baseline. The analyses were performed using structural equation modeling with Mplus 8.6.

RESULTS

Baseline coping self-efficacy predicted all M3 coping reactions, while M6 coping self-efficacy also predicted changes in all but one M9 coping reaction. Moreover, one of the M3 coping reactions, that is, hopelessness/helplessness, predicted the changes in M6 coping self-efficacy. The relation between coping self-efficacy and one coping reaction (i.e. cognitive avoidance) was rather weak. Stability paths from M3 to M9 coping reactions were moderate to high.

CONCLUSION

The relationship between self-efficacy to cope with cancer and cancer-related coping is complex. New theoretical models are needed to more accurately describe the diverse aspects of this association.

Changes over time in self-efficacy to cope with cancer and well-being in women with breast cancer: a cross-cultural study

OBJECTIVE

This study aimed to examine whether self-efficacy to cope with cancer changes over time in patients with breast cancer and whether these potential changes are similar across patients. It also aimed to examine whether these trajectories are related to patient psychological well-being and overall quality of life.

METHODS

Participants (N = 404) from four countries (i.e. Finland, Israel, Italy, and Portugal) were enrolled in the study few weeks after breast surgery or biopsy. Self-efficacy to cope with cancer was assessed at baseline, six and 12 months later. Well-being indices were assessed at baseline, 12 and 18 months later.

RESULTS

Using Latent Class Growth Analysis, two groups of patients were identified. The majority of patients reported high levels of self-efficacy to cope, which increased over time. For almost 15% of the patients, however, self-efficacy declined over time. Diminishing levels of self-efficacy to cope predicted worse levels of well-being. The pattern of self-efficacy changes and their relationships to well-being was consistent across countries.

CONCLUSION

Monitoring self-efficacy to cope with cancer is probably important in order to detect alarming changes in its levels, as a declining self-efficacy to cope may serve as a signal of the need for intervention to prevent adaptation difficulties.

Abuse among Portuguese older people at a time of economic crisis recovery: findings from the Harmed study

This study aimed to assess the prevalence of abuse against Portuguese older people after an economic crisis and to assess how it has influenced health. A cross-sectional study was carried out including 677 older adults (≥60 years) during 2017. Results show that overall, 23.9% of older people reported being a victim of abuse in the last 12 months. The prevalence of psychological abuse was 19.9%, financial abuse 5.8%, physical abuse 2.5% and sexual abuse 1.9%. Older people who report abuse were more likely to have perceived insufficient income and low social support. The abuse was also significantly associated with poor health status and depressive symptoms. Even in an auspicious period, more than a fifth of older people experiences abuse which is associated with social and health vulnerabilities. These results support that an investment should be made in terms of policies toward an age-friendly environment.

Absence of HIF1A Leads to Glycogen Accumulation and an Inflammatory Response That Enables Pancreatic Tumor Growth

Cancer cells respond to hypoxia by upregulating the hypoxia-inducible factor 1α (HIF1A) transcription factor, which drives survival mechanisms that include metabolic adaptation and induction of angiogenesis by VEGF. Pancreatic tumors are poorly vascularized and severely hypoxic. To study the angiogenic role of HIF1A, and specifically probe whether tumors are able to use alternative pathways in its absence, we created a xenograft mouse tumor model of pancreatic cancer lacking HIF1A. After an initial delay of about 30 days, the HIF1A-deficient tumors grew as rapidly as the wild-type tumors and had similar vascularization. These changes were maintained in subsequent passages of tumor xenografts in vivo and in cell lines ex vivo. There were many cancer cells with a "clear-cell" phenotype in the HIF1A-deficient tumors; this was the result of accumulation of glycogen. Single-cell RNA sequencing (scRNA-seq) of the tumors identified hypoxic cancer cells with inhibited glycogen breakdown, which promoted glycogen accumulation and the secretion of inflammatory cytokines, including interleukins 1β (IL1B) and 8 (IL8). scRNA-seq of the mouse tumor stroma showed enrichment of two subsets of myeloid dendritic cells (cDC), cDC1 and cDC2, that secreted proangiogenic cytokines. These results suggest that glycogen accumulation associated with a clear-cell phenotype in hypoxic cancer cells lacking HIF1A can initiate an alternate pathway of cytokine and DC-driven angiogenesis. Inhibiting glycogen accumulation may provide a treatment for cancers with the clear-cell phenotype. SIGNIFICANCE: These findings establish a novel mechanism by which tumors support angiogenesis in an HIF1α-independent manner.

An Inhibitor of the Pleckstrin Homology Domain of CNK1 Selectively Blocks the Growth of Mutant KRAS Cells and Tumors

Cnk1 (connector enhancer of kinase suppressor of Ras 1) is a pleckstrin homology (PH) domain-containing scaffold protein that increases the efficiency of Ras signaling pathways, imparting efficiency and specificity to the response of cell proliferation, survival, and migration. Mutated KRAS (mut-KRAS) is the most common proto-oncogenic event, occurring in approximately 25% of human cancers and has no effective treatment. In this study, we show that selective inhibition of Cnk1 blocks growth and Raf/Mek/Erk, Rho and RalA/B signaling in mut-KRAS lung and colon cancer cells with little effect on wild-type (wt)-KRAS cells. Cnk1 inhibition decreased anchorage-independent mut-KRas cell growth more so than growth on plastic, without the partial "addiction" to mut-KRAS seen on plastic. The PH domain of Cnk1 bound with greater affinity to PtdIns(4,5)P2 than PtdIns(3,4,5)P3, and Cnk1 localized to areas of the plasma membranes rich in PtdIns, suggesting a role for the PH domain in the biological activity of Cnk1. Through molecular modeling and structural modification, we identified a compound PHT-7.3 that bound selectively to the PH domain of Cnk1, preventing plasma membrane colocalization with mut-KRas. PHT-7.3 inhibited mut-KRas, but not wild-type KRas cancer cell and tumor growth and signaling. Thus, the PH domain of Cnk1 is a druggable target whose inhibition selectively blocks mutant KRas activation, making Cnk1 an attractive therapeutic target in patients with mut-KRAS-driven cancer. SIGNIFICANCE: These findings identify a therapeutic strategy to selectively block oncogenic KRas activity through the PH domain of Cnk1, which reduces its cell membrane binding, decreasing the efficiency of Ras signaling and tumor growth.

Abstract 2428: Redox regulation of β-catenin in colorectal cancer

Colorectal cancer (CRC) is the second most newly diagnosed cancer in the United States. β-catenin is the downstream effector of the Wnt/β-catenin signaling pathway. Loss of function (LOF) mutations on adenomatous polyposis coli (APC), a critical member of the β-catenin degradation complex leads to constitutively elevated β-catenin as an early oncogenic event in 85% of CRCs and is associated with decreased CRC patient survival. Increased level of β-catenin augments the nuclear accumulation of β-catenin, where it acts a co-activator of a number of transcription factors leading to the expression of downstream target genes that promote cancer cell proliferation, survival, and migration. There is no effective therapy for β-catenin as a cause of cancer. In addition to CRC, elevated levels of Wnt signaling have been reported in leukemia, melanoma, and breast cancers highlighting the need for novel therapies that attenuate aberrant β-catenin mediated transcription. Here we report on the redox dependency of the Wnt/β-catenin signaling pathway, identified through a forward genetic screen in Drosophila, and identify thioredoxin reductase-1 (TXNR1) as a potential target for the inhibition of aberrant β-catenin transcriptional activity through in vivo studies with the APCmin/+ mouse model. Drosophila harboring a mutation in their thioredoxin reductase (trxr-1) gene and a partial lethality phenotype were used in an enhancer/suppressor forward genetic screen. Increased lethality was observed when the trxr-1 mutation (trxr-1481) was combined with heterozygous mutations and deletions in wnt2, while wnt2 deletion and mutations alone had no effect on lethality. To test the translational value of these findings, APCmin/+ mice were treated with PX-12, a human TXNR1 inhibitor, daily by gavage from day 40 to time of death. We observed a dose dependent reduction in the number and size of intestinal polyps by PX-12 treatment, and an increased survival in treated mice. Furthermore, mechanistic studies utilizing human CRC cell lines harboring LOF mutations to the β-catenin degradation complex revealed β-Catenin mediated transcription, as measured by TOP Flash luciferase assay, was diminished when TXNR1 was silenced by siRNA. Additionally, we observed decreased β-catenin protein level in CRC cell lines treated with PX-12 or siRNA targeting TXNRD1 and its functional partner thioredoxin (TXN). The addition of the pan caspase inhibitor ZVAD but not the proteasome inhibitor MG132 was able to stabilize β-catenin protein upon treatment with PX-12 suggesting β-catenin destabilization is occurring via a caspase dependent mechanism. These results suggest a conserved mechanism for the redox regulation of β-catenin involving TXNR1; furthermore, inhibition of TXNR1 activity destabilizes β-catenin protein and decreases β-catenin mediated transcription in human CRC cell lines and inhibits intestinal neoplasia development in an experimental mouse model for CRC.

Citation Format: Alejandro D. Campos, Brian James, Petrus De Jong, Robert Lemos, Nikolas Marino, Garth Powis. Redox regulation of β-catenin in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2428.

Abstract 2916: Targeting lysophospholipid metabolism inhibits pancreatic cancer cell proliferation under nutrient-limiting conditions

Patients with pancreatic ductal adenocarcinoma (PDAC) have a poor prognosis, and more effective systemic treatments for patients with local progression or metastasis (85% of cases) are needed. The pancreatic tumor microenvironment provides a rich source for novel drug targets. We aimed to identify and validate novel metabolic drug targets that are unique to hypoxic PDAC cells. Using bulk RNA sequencing in combination with metabolomics analyses in vitro, we previously found that PDAC cells negate the loss of intracellular unsaturated fatty acids in hypoxia by orchestrating the release of lysophospholipids (lyso-PLs) by cancer-associated fibroblasts, which are then taken up and stored in intracellular lipid droplets in hypoxic cancer cells. To confirm the relevance of these findings in vivo, we performed 3' droplet based single-cell RNA sequencing (scRNA-seq) combined with metabolomics analyses of intracellular and extracellular (tumor interstitial fluid) metabolites of MIAPaCa2 and patient-derived xenografts (PDX). Identification of cell lineages and subpopulations with hypoxic gene signatures was performed to correlate changes in metabolite levels with metabolic gene expression in vivo. This approach confirmed differential expression of lipid droplet-associated enzymes in hypoxic areas of the tumor, including lyso-PL acyl transferases (LPCAT1, LPCAT3), and phospholipases (LYPLA1, PLA2G15). We found that resistance of PDAC cell lines to pharmacologic treatment with inhibitors of fatty acid desaturases (FADS), reminiscent of hypoxia and nutrient starvation in vivo, was mediated by uptake of lyso-PLs from the medium. Importantly, genetic knockdown of LPCAT and LYPLA isoforms reversed the resistance to FADS inhibitors in culture in vitro and in vivo. Clinical relevance was demonstrated by mRNA expression analysis of PDAC patients from The Cancer Genome Atlas (TCGA) database, which showed that the expression of lyso-PL metabolizing genes is correlated with a significant worse prognosis (log-rank test, P=0.008). We are currently developing pharmacologic approaches to target LPCAT and LYPLA enzymes in hypoxic cancer cells as a novel approach for PDAC patients with unresectable disease.

Citation Format: Petrus R. de Jong, Marco Maruggi, Alejandro D. Campos, Morgan A. Brand, Robert Lemos, David A. Scott, Sally A. Litherland, J. Pablo Arnoletti, Brian P. James, Garth Powis. Targeting lysophospholipid metabolism inhibits pancreatic cancer cell proliferation under nutrient-limiting conditions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2916.

Cirurgia paliativa do ombro em paralisia obstétrica do plexo braquial

A paralisia obstétrica do plexo braquial é rara originando disfunção grave e défice marcado da rotação externa e da abdução do ombro. Reviram-se retrospectivamente 11 casos de paralisia obstétrica do plexo braquial (sete com paralisia alta e quatro com paralisia completa) tratados cirurgicamente pela técnica de L’Épiscopo modificada por Hoffer. Estes resultados foram padronizados segundo o tipo de lesão (grupo A – lesão alta; grupo B – lesão completa) e a idade (grupo I ≤ 4 anos; grupo II > 4 anos). O seguimento médio foi de 35 meses. A idade média aquando da cirurgia era de 6,5 anos (r= 2–11). Todos, excepto um, apresentaram melhoria funcional, com aumento da pontuação média de Mallet de 4,6 pontos. Os dois subtipos de paralisia tiveram pontuação média de Mallet sobreponível (grupo A – 4.6; grupo B – 4.7); a idade aquando da cirurgia não influenciou o resultado clínico (pontuação média (grupo I) – 4.8; (grupo II) – 4.4). Não foram registadas complicações. A técnica de L’Épiscopo modificada por Hoffer é eficaz no tratamento paliativo do ombro em paralisia obstétrica do plexo braquial, permitindo recuperação da abdução e rotação externa do ombro. Está indicada em paralisias altas e completas, quando associada a outras cirurgias de recuperação da função do cotovelo, punho e/ou mão. Idade superior a 4 anos não contra-indica a cirurgia desde que sejam excluídas alterações da articulação glenoumeral.

[Ankle arthroscopy in treatment of Bosworth fracture]

The Bosworth fracture is a pattern of fracture-dislocation of the ankle joint with fixed dislocation of the proximal part of the fibula behind the posterior malleolus. It is a rare injury, which requires high index of suspicion for diagnosis. Fixed dislocation of the fibula does not allow for closed reduction, so open reduction and fixation of fibula or tibia is required. We present a case report of a patient who suffered a Bosworth fracture, with associated medial malleolus fracture. She underwent surgical treatment with open reduction and internal fixation of the fibula and tibia. We also performed anterior arthroscopy of the ankle, to evaluate the tibiofibular syndesmosis, remove loose osteochondral fragments, and perform debridement and microfracture of unstable chondral lesions of the talus. One year after injury, she remains with occasional pain and a normal range of motion comparing to the contralateral ankle joint. Bosworth fracture is a serious and rare injury, which requires early diagnosis and urgent surgical treatment. Performing ankle arthroscopy in the acute treatment of the Bosworth fracture allows for diagnosis and treatment of associated intra-articular injuries, as well as assisting with adequate fracture reduction and evaluation of the tibiofibular syndesmosis stability.

Definition of a Novel Feed-Forward Mechanism for Glycolysis-HIF1α Signaling in Hypoxic Tumors Highlights Aldolase A as a Therapeutic Target

The hypoxia-inducible transcription factor HIF1α drives expression of many glycolytic enzymes. Here, we show that hypoxic glycolysis, in turn, increases HIF1α transcriptional activity and stimulates tumor growth, revealing a novel feed-forward mechanism of glycolysis-HIF1α signaling. Negative regulation of HIF1α by AMPK1 is bypassed in hypoxic cells, due to ATP elevation by increased glycolysis, thereby preventing phosphorylation and inactivation of the HIF1α transcriptional coactivator p300. Notably, of the HIF1α-activated glycolytic enzymes we evaluated by gene silencing, aldolase A (ALDOA) blockade produced the most robust decrease in glycolysis, HIF-1 activity, and cancer cell proliferation. Furthermore, either RNAi-mediated silencing of ALDOA or systemic treatment with a specific small-molecule inhibitor of aldolase A was sufficient to increase overall survival in a xenograft model of metastatic breast cancer. In establishing a novel glycolysis-HIF-1α feed-forward mechanism in hypoxic tumor cells, our results also provide a preclinical rationale to develop aldolase A inhibitors as a generalized strategy to treat intractable hypoxic cancer cells found widely in most solid tumors. Cancer Res; 76(14); 4259-69. ©2016 AACR.

A new HIF-1α/RANTES-driven pathway to hepatocellular carcinoma mediated by germline haploinsufficiency of SART1/HAF in mice

The hypoxia-inducible factor (HIF), HIF-1, is a central regulator of the response to low oxygen or inflammatory stress and plays an essential role in survival and function of immune cells. However, the mechanisms regulating nonhypoxic induction of HIF-1 remain unclear. Here, we assess the impact of germline heterozygosity of a novel, oxygen-independent ubiquitin ligase for HIF-1α: hypoxia-associated factor (HAF; encoded by SART1). SART1(-/-) mice were embryonic lethal, whereas male SART1(+/-) mice spontaneously recapitulated key features of nonalcoholic steatohepatitis (NASH)-driven hepatocellular carcinoma (HCC), including steatosis, fibrosis, and inflammatory cytokine production. Male, but not female, SART1(+/-) mice showed significant up-regulation of HIF-1α in circulating and liver-infiltrating immune cells, but not in hepatocytes, before development of malignancy. Additionally, Kupffer cells derived from male, but not female, SART1(+/-) mice produced increased levels of the HIF-1-dependent chemokine, regulated on activation, normal T-cell expressed and secreted (RANTES), compared to wild type. This was associated with increased liver-neutrophilic infiltration, whereas infiltration of lymphocytes and macrophages were not significantly different. Neutralization of circulating RANTES decreased liver neutrophilic infiltration and attenuated HCC tumor initiation/growth in SART1(+/-) mice.

CONCLUSION

This work establishes a new tumor-suppressor role for HAF in immune cell function by preventing inappropriate HIF-1 activation in male mice and identifies RANTES as a novel therapeutic target for NASH and NASH-driven HCC.

HNF4α is a therapeutic target that links AMPK to WNT signalling in early-stage gastric cancer

BACKGROUND

Worldwide, gastric cancer (GC) is the fourth most common malignancy and the most common cancer in East Asia. Development of targeted therapies for this disease has focused on a few known oncogenes but has had limited effects.

OBJECTIVE

To determine oncogenic mechanisms and novel therapeutic targets specific for GC by identifying commonly dysregulated genes from the tumours of both Asian-Pacific and Caucasian patients.

METHODS

We generated transcriptomic profiles of 22 Caucasian GC tumours and their matched non-cancerous samples and performed an integrative analysis across different GC gene expression datasets. We examined the inhibition of commonly overexpressed oncogenes and their constituent signalling pathways by RNAi and/or pharmacological inhibition.

RESULTS

Hepatocyte nuclear factor-4α (HNF4α) upregulation was a key signalling event in gastric tumours from both Caucasian and Asian patients, and HNF4α antagonism was antineoplastic. Perturbation experiments in GC tumour cell lines and xenograft models further demonstrated that HNF4α is downregulated by AMPKα signalling and the AMPK agonist metformin; blockade of HNF4α activity resulted in cyclin downregulation, cell cycle arrest and tumour growth inhibition. HNF4α also regulated WNT signalling through its target gene WNT5A, a potential prognostic marker of diffuse type gastric tumours.

CONCLUSIONS

Our results indicate that HNF4α is a targetable oncoprotein in GC, is regulated by AMPK signalling through AMPKα and resides upstream of WNT signalling. HNF4α may regulate 'metabolic switch' characteristic of a general malignant phenotype and its target WNT5A has potential prognostic values. The AMPKα-HNF4α-WNT5A signalling cascade represents a potentially targetable pathway for drug development.

Abstract A2-29: A PDK1 inhibitors that has antitumor activity in a vemurafenib resistant BRAF(V600E)::NRAS(G12V) melanoma PDX

Phosphatidylinositol 3-kinase/phosphatidylinositide-dependent protein kinase 1 (PDPK1)/Akt signaling is activated in many cancers, and is associated with mutational loss of PTEN function, or activation of Phosphatidylinositide-3-kinase (PI3K). Activation of the PDPK1 signaling pathway contributes to proliferation and survival pathways in tumor cells. In a mouse Braf(V600E)::Pten(-/-) melanoma model genetic inactivation of PDKP1 delays the development of pigmented lesions and melanoma. We have found that the PDPK1 inhibitor PHT-427 has antitumor activity in BRAF(V600E)::NRAS(G12V) melanoma patient derived xenografts (PDX) grown in immune deficient mice.

Pleckstrin homology (PH) domains are 100-120 amino acid domains found in more than 250 human proteins that bind phosphatidylinositide (Ptdlns) lipids in cell membranes. The phosphorylation of Ptdins, and the consequent binding of PH domain containing proteins is found in many signal transduction pathways critical for cell growth, survival, angiogenesis, and metastasis. Though the primary amino acid sequences of PH domains are not highly conserved, PH domains do have a highly conserved tertiary structure. This structural conservation of PH domains combined with the role PH domains play in signal transduction make them promising targets for small molecule inhibitors. PHT-427 was designed to bind PH domains, and experiments show that PHT-427 binds with the highest affinity to the PH domain of PDKP1.

We wanted to test the antitumor activity of PHT-427 in human melanoma PDX models of varying genetic background. About 50% of melanoma tumors are driven by the BRAF(V600E) mutation, and these tumors are effectively targeted with BRAF inhibitors, such as vemurafenib. Unfortunately, these tumors usually develop resistance to vemurafenib, and the disease progresses. Additionally, 40-50% of melanoma tumors do not carry the BRAF(V600E) mutation, indicating the need to target additional pathways in melanoma. We sequenced human PDX samples on the Ion Proton sequencer, using the 409 gene Comprehensive Cancer Panel from Life Technologies. Compared to xenografts, PDXs are closer to the tumor biology of the patient, having a higher degree of molecular subtypes and intratumor heterogeneity, and a mixture of human and mouse stroma. The TMAP alignment program that works with Ion Torrent sequence data cannot handle a combined human-mouse reference genome, we developed a set of scripts we call Graft Extraction Out of REcipient Genome (GEORGE). Sequence reads aligned to the hg19 human reference, and mm10 mouse reference are evaluated by GEORGE and assigned to either the human, or mouse genome. In this project, only human assigned reads were used for variant calling. We sequence 14 melanoma samples, and five samples carried BRAF(V600E). We tested the antitumor activity of PHT-427 in four PDX samples with various BRAF and NRAS mutational statuses. We found that PHT-427 had antitumor activity in a vemurafenib resistant BRAF(V600E)::NRAS(G12V) mutant PDX sample.

Citation Format: Brian P. James, Robert Lemos, Jr., Stacey Bagby, Steven Robinson, William Robinson, John Tentler, S. Gail Eckhardt, D. Lynn Kirkpatrick, Garth Powis. A PDK1 inhibitors that has antitumor activity in a vemurafenib resistant BRAF(V600E)::NRAS(G12V) melanoma PDX. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A2-29.

Hypoxia-induced SUMOylation of E3 ligase HAF determines specific activation of HIF2 in clear-cell renal cell carcinoma

Clear-cell renal cell cancer (CRCC) is initiated typically by loss of the tumor-suppressor VHL, driving constitutive activation of hypoxia-inducible factor-1 (HIF1) and HIF2. However, whereas HIF1 has a tumor-suppressor role, HIF2 plays a distinct role in driving CRCC. In this study, we show that the HIF1α E3 ligase hypoxia-associated factor (HAF) complexes with HIF2α at DNA to promote HIF2-dependent transcription through a mechanism relying upon HAF SUMOylation. HAF SUMOylation was induced by hypoxia, whereas HAF-mediated HIF1α degradation was SUMOylation independent. HAF overexpression in mice increased CRCC growth and metastasis. Clinically, HAF overexpression was associated with poor prognosis. Taken together, our results show that HAF is a specific mediator of HIF2 activation that is critical for CRCC development and morbidity.

[Impact of foot reconstruction surgery on the daily life of patients with cerebrovascular accident sequelae]

OBJECTIVE

The equinovarus deformity of the foot and digital scrolling is very common among people with sequelae from cerebrovascular accidents. The aim of this study was focused on changes produced by surgical correction of the deformity in terms of comfort, balance, independence and ability to move freely within the context of the daily life of the patient.

MATERIAL AND METHODS

The data was evaluated using a retrospective survey and a prospective analysis of gait habits using a recording walking device (WalkinSense(®)) before and after surgery. All the 15 patients enrolled in the study were submitted to similar surgical procedures of lengthening and tendon transfers.

RESULTS

The use of technical aids to correct the deformity and to aid in walking, as well as painful calluses and difficulties with the shoes and walking on uneven surfaces, decreased significantly. Quantitative analysis of the gait showed that after surgery the patient started to move with smaller steps, although with a higher cadence. Gait analysis also revealed a decrease in the amount of gait segments and speed.

DISCUSSION AND CONCLUSIONS

The results showed a positive development in terms of indicators of comfort, balance, independence and self-image through surgery. However the new way of walking seems to be more tiring for the patients, which could justify a decrease in the number of gait segments and speed.

Abstract 5534: Metformin increases AMPKα activity by inhibition of AMPKα and cell cycle proliferation in Asian gastric cancer

The LKB1/AMPK signaling pathway has been well elucidated and recent evidence suggests its involvement in cancer cell biology, demonstrating that the reinforcement of the tumor suppressive functions of LKB1/AMPK is a valuable therapeutic strategy for cancers. Interest in metformin as a novel anticancer agent for breast cancer and other solid tumors continue to grow, currently being investigated in several cancer types in both neoadjuvant and metastatic settings. The biological effect of metformin on cancer cells is driven by its ability to activate AMPK through upstream kinase LKB1, tumor suppressor gene in epithelial tissues. Metformin increases intracellular AMP level, which allosterically activates AMPK. We have previously identified the AMPKα as a modulator in gastric cancer (GC) and through experimental evidence. We show the impact of LKB1/AMPK modulation of HNF4α, a dramatic suppression of cancer cell growth.

GC samples were collected and sequenced on SOLiD v 3.0 for both WT-seq and small RNA-seq. Computational analysis showed that 356 out of 18,890 genes were identified as GC related differentially expressed genes in the five-group comparison (normal, tumor stage I, II, III or IV). 28 genes were identified as stage-specific differentially expressed genes, and 13 out of the 28 genes were within the network between HNF4α and HNF1α. In order to test the anti-proliferation activity of metformin in GC cell lines associated with activation of PRKAA1, PRKAA2 and LKB1, and by HNF4α suppression, 4 GC cell lines (NCI-N87, AGS, HS 746T and MKN 45) were treated with metformin. Both PRKAA1/2 showed increased gene expression level when the cells were treated with 10mM of metformin. As for STK11 (LKB1 gene) and HNF4A gene expression level, LKB1 increased and HNF4A decreased with metformin treatment on all four cell lines. Metformin treated NCI-N87 and AGS show that it is involved in cell cycle arrest. Western-blot analysis shows, decreased protein expression of Cyclin A/B and D1 on metformin treated. Lastly, NCI-N87 xenograft study show metformin treated suppression of tumor progression compared to non-treated mouse. During the 28 day treatment of metformin, PRKAA1 and PRKAA2 expression level increased compared to the untreated with. Consistent with in vitro assay, LKB1 level was elevated in the metformin treated tumor compared to the non-treated, and HNF4α level decreased over time in the metformin treated tumor.

Study shows that AMPK is a strong therapeutic tumor suppressor target and that metformin is a potential drug for Asian early gastric cancer patient. In our research in progress, we observe potential relationships between the Wnt pathway and AMPKα in light of WNT druggability with metformin. In conclusion LKB1/AMPK by HNF4α inhibition suggests metformin could be a candidate for gastric cancer treatment, probably in combination with conventional chemotherapy and/or as a maintenance therapy.

Citation Format: Hae Rim Jung, Hae Ryung Chang, Hye-Hyun Seo, Robert Lemos, Hee Seo Park, Han Liang, Garth Powis, Yon Hui Kim. Metformin increases AMPKα activity by inhibition of AMPKα and cell cycle proliferation in Asian gastric cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5534. doi:10.1158/1538-7445.AM2013-5534

Resistance to BRAF inhibition in BRAF-mutant colon cancer can be overcome with PI3K inhibition or demethylating agents

PURPOSE

Vemurafenib, a selective inhibitor of BRAF(V600), has shown significant activity in BRAF(V600) melanoma but not in less than 10% of metastatic BRAF(V600) colorectal cancers (CRC), suggesting that studies of the unique hypermethylated phenotype and concurrent oncogenic activation of BRAF(mut) CRC may provide combinatorial strategies.

EXPERIMENTAL DESIGN

We conducted comparative proteomic analysis of BRAF(V600E) melanoma and CRC cell lines, followed by correlation of phosphoinositide 3-kinase (PI3K) pathway activation and sensitivity to the vemurafenib analogue PLX4720. Pharmacologic inhibitors and siRNA were used in combination with PLX4720 to inhibit PI3K and methyltransferase in cell lines and murine models.

RESULTS

Compared with melanoma, CRC lines show higher levels of PI3K/AKT pathway activation. CRC cell lines with mutations in PTEN or PIK3CA were less sensitive to growth inhibition by PLX4720 (P = 0.03), and knockdown of PTEN expression in sensitive CRC cells reduced growth inhibition by the drug. Combined treatment of PLX4720 with PI3K inhibitors caused synergistic growth inhibition in BRAF-mutant CRC cells with both primary and secondary resistance. In addition, methyltransferase inhibition was synergistic with PLX4720 and decreased AKT activation. In vivo, PLX4720 combined with either inhibitors of AKT or methyltransferase showed greater tumor growth inhibition than PLX4720 alone. Clones with acquired resistance to PLX4720 in vitro showed PI3K/AKT activation with EGF receptor (EGFR) or KRAS amplification.

CONCLUSIONS

We show that activation of the PI3K/AKT pathway is a mechanism of both innate and acquired resistance to BRAF inhibitors in BRAF(V600E) CRC and suggest combinatorial approaches to improve outcomes in this poor prognosis subset of patients.

The promise of patient-derived xenografts: the best laid plans of mice and men

Compared with xenografts from previously established cell lines, patient-derived xenografts may more faithfully recapitulate the molecular diversity, cellular heterogeneity, and histology seen in patient tumors, although other limitations of murine models remain. The ability of these models to inform clinical development and answer mechanistic questions will determine their ultimate use.

Abstract 970: Multi-layer and integrative analysis of the whole transcriptome in Asian gastric cancer: AMPKβ modulation in cancer progression

We performed whole-transcriptome profiling of gastric cancer_the most common cancer in developing countries and the second leading cause of cancer deaths in the world. Applying a innovative SOLiD RNA-Seq approach to 24 gastric tumor samples and 6 noncancerous samples, we generated 3.0 billion short reads to quantitatively measure the abundance of mRNAs and small non-coding RNAs. We then developed a multi-layer analysis to identify differentially expressed mRNAs and microRNAs, and novel single-nucleotide mutations candidates associated with gastric cancer. With the insights from the multi-layer analysis, we experimentally demonstrated a critical role for AMPKβ modulation in gastric cancer progression. This work provides a multi-faceted portrait of the Asian gastric cancer transcriptome, which facilitates the elucidation of molecular mechanisms of gastric carcinogenesis and the development of targeted therapies. By integrating data obtained on the expression of both mRNa and miRNa molecules, we were able to identify certain gene signatures uniquely expressed in gastric cancer. This gene signatures along with gastric cancer-related therapeutic target gene signature, showed molecular changes as robust biological markers. Integration of differentially expressed mRNAs and microRNA profiles allowed us to identify potential miRNA drivers of disease progression. We demonstrated the translational relevance of AMPKβ as a potential therapeutic target for treatment and for prediction of early stage gastric cancer. This work lays a critical foundation for the identification of molecular mechanisms of gastric carcinogenesis and the development of related targeted therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 970. doi:1538-7445.AM2012-970

Abstract 3941: HAF promotes the switch from HIF-1α to HIF-2α signaling during chronic hypoxia and promotes stem cell characteristics

Most solid tumors and their metastases experience periods of hypoxia, which promotes tumor progression and resistance to therapy. Hypoxia is also an important micro-environmental factor supporting the maintenance of pluripotent cancer stem/progenitor cells (CSCs) within the stem cell niche. The clinical relevance of CSCs is underscored by their resistance to cytotoxic therapies, invasive potential and role in tumor recurrence. Critical mediators of the hypoxia response are the hypoxia-inducible factors HIF-1α and HIF-2α. Although they have some overlapping functions, the HIFs are generally non-redundant whereby HIF-1α regulates the acute metabolic changes required for hypoxic survival, whereas HIF-2α promotes the adaptation to chronic hypoxia, including the maintenance of CSCs. However, the mechanism determining selectivity for HIF-1α versus HIF-2α activation is unclear. Here we describe a new mechanism for the switch between HIF-1α and HIF-2α dependent transcription during chronic hypoxia by the hypoxia associated factor (HAF). HAF is overexpressed in a number of tumor types and is an E3 ubiquitin ligase that ubiquitinates HIF-1α independently of oxygen and pVHL, thus targeting HIF-1α for proteasomal degradation. HAF also binds to HIF-2α but at a different site than it binds to HIF-1α, increasing HIF-2α transactivation without causing its degradation. Hence HAF switches cellular dependence from HIF-1α towards HIF-2α, resulting in the activation of HIF-2α specific target genes (MMP9, OCT3/4)and the simultaneous inhibition of HIF-1α specific target genes (CA-IX, DDIT4). HAF itself is hypoxia regulated - decreasing during acute hypoxia, but increasing with hypoxic duration. Hence HAF is a key determinant of HIF-2 versus HIF-1 activation in response to hypoxia. Using cell-free recombinant proteins and in vitro binding assays, we show that HAF binding to HIF-2α requires a novel eukaryotic post-translational modification of HIF-2α within a unique region of HIF-2 that is absent from HIF-1. HAF binding to HIF-2α is increased in cells exposed to prolonged hypoxia and promotes the transcription of HIF-2α target genes important in CSC maintenance such as OCT3/4 and SOX2. HAF levels are elevated in CD133+ U87 glioblastoma stem/progenitor cells and HAF knockdown decreases neurosphere formation suggesting a key role for HAF in the maintenance of the stem cell phenotype. The HAF-induced switch to HIF-2α dependent transcription promotes invasion and enriches the proportion of stem/progenitor CD133+ U87 cells. This increases the rate of tumor take and increases tumor morbidity in vivo. Funded by NIH CA095060, CA17094, CA098920

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3941. doi:1538-7445.AM2012-3941

Metastatic carcinoma as an unusual cause of failure in total hip arthroplasty

Evaluation of osteolysis after total hip arthroplasty remains a challenge. It may reflect a myriad of problems: from wear-debris induced lesions to infection, metabolic bone disease or even malignant infiltration. We present the clinical, radiographic and pathological features of a 64-year-old woman in whom loosening and failure of total hip arthroplasty occurred secondary to a periacetabular metastasis from a previously undiagnosed lung carcinoma.

Clinical and radiological results following radial osteotomy in patients with Kienböck’s disease

Radial osteotomy is currently advocated for patients with Lichtman’s stages II and IIIA of Kienböck’s disease; its place in the treatment of patients with stage IIIB disease remains controversial. The purpose of this study was to evaluate the medium-term results of this procedure and to compare the outcome in patients with stage IIIB disease and those with earlier stages (II and IIIA). A total of 18 patients (18 osteotomies) were evaluated both clinically and radiologically at a mean follow-up of 10.3 years (4 to 18). Range of movement, grip strength and pain improved significantly in all patients; the functional score (Nakamura Scoring System (NSSK)) was high and self-reported disability (Disabilities of Arm, Shoulder and Hand questionnaire) was low at the final follow-up in all patients evaluated. Patients with stage IIIB disease, however, had a significantly lower grip strength, lower NSSK scores and higher disability than those in less advanced stages. Radiological progression of the disease was not noted in either group, despite the stage. Radial osteotomy seems effective in halting the progression of disease and improving symptoms in stages II, IIIA and IIIB. Patients with less advanced disease should be expected to have better clinical results.

Abstract A213: Topical PHT-427, a dual AKT/PDPK1 PH domain inhibitor, for treatment of primary and metastatic skin cancer

Epicutaneous (topical) therapy with molecularly targeted agents is an attractive modality for treatment of basal cell carcinoma (BCC), early UVB induced squamous cell carcinoma (SCC) and cutaneous metastatic disease (CMD) associated with metastatic breast cancer. There is evidence that Akt and PDKP1 play complimentary yet independent roles in PI3K pathway signaling associated with driving the growth of BCC, UVB induced SCC, and breast CMD. Both Akt and PDPK1 possess a pleckstrin homology (PH) domain, a highly conserved three-dimensional superfold with a high affinity for binding phosphatidylinositol-3-phosphates, causing Akt and PDPK1 to translocation to the plasma membrane where Akt is activated. Through reiterative molecular docking and structure refinement using a proprietary computational platform, we have identified PHT-427 as an agent that binds to the PH domains of Akt and PDPK1, inhibiting their activity. PHT-427 has antitumor activity when administered orally but importantly also following epicutaneous administration. We evaluated the antitumor potential of epicutaneous PHT-427 against CMD in an intradermal breast xenograft model and in an early UVB induced skin cancer model in mice. For the CMD investigation MCF-7 human breast cancer (mutant PIK3CA) was injected intradermally in the flank of female nu/nu mice. Groups of 5 mice were treated twice a day for 10 days with vehicle or 0.1ml PH-427 (50 mg/mL) applied to a 1 cm patch of skin over the tumor. The mice were euthanized 4 hr after the last application and blood, tumor and overlying skin were removed for analyzes. Topical PHT-427 produced 89% inhibition of tumor growth (3/5 no measurable tumor) with no change in body weight or skin toxicity and inhibited targets in skin and tumor. Levels of PHT-427 by HPL-MS were detected in the skin at the site of application, in tumor and in plasma. To evaluate the activity PHT-427 in early UVB induced skin cancer female SKH-1 hairless mice were exposed to UVB irradiation to induce Akt and the production of skin tumors. The mice were treated epicutaneously with PHT-427 or vehicle 3 times a week for 4 weeks at which point animals were sacrificed and skin, tumors and blood were obtained. In this study topical PHT-427 significantly reduced tumor incidence, tumor burden and tumor multiplicity. Following treatment with PHT-427 80% of mice were tumor free and those with tumors averaged fewer than 1 per mouse and those were < 1mm in size while 59% of untreated group had tumors, with 1.6 tumors per mouse and the majority > 1mm in size. There was no change in body weight and no apparent skin toxicity. Thus, topical application of PHT-427 can deliver active drug to skin and tumor, inhibiting AKT and PDPK1, both of which drive the PI3K pathway important in UVB induced SCC and breast CMD, with significant inhibition of tumor growth without adverse effects on normal skin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A213.

Artoplastia trapeziometacarpiana tipo «ball-and-socket». Resultados a médio prazo

O objectivo deste estudo foi determinar os resultados a médio prazo de uma artroplastia retentiva da base do polegar utilizada para o tratamento da artrose trapezio-metacarpiana (TMC).

Reavaliamos clínica e radiograficamente 20 polegares (20 doentes) com um seguimento médio de 45 meses (R = 57-30).

Utilizando a pontuação de Buck-Gramko concluímos que funcionalmente 19 dos 20 doentes apresentavam um resultado considerado bom ou excelente. A avaliação da força e da mobilidade revelou resultados muito aproximados dos obtidos na mão não intervencionada.

A revisão radiográfica demonstrou a existência de áreas de osteólise rodeando o componente trapeziano em 2 casos, e extensas ossificações envolvendo a neo-articulação em dois casos adicionais.

Na nossa série registamos a presença de 4 complicações: duas fracturas do trapézio, uma luxação e uma perturbação sensitiva transitória.

A prótese trapézio-metacarpiana tem vindo a ganhar progressivamente mais adeptos, pois é clinicamente uma solução muito vantajosa devolvendo ao paciente uma articulação livre de dor, móvel e estável que lhe permite o rápido regresso a bons níveis de actividade e bem estar.

Contudo os achados radiográficos da nossa série levam-nos a recomendar a manutenção de uma atitude prudente e vigilante sobre estes casos que tem vindo a ser submetidos a artroplastias da TMC.

Shoulder arthrodesis in adult brachial plexus injury: what is the optimal position?

Brachial plexus injuries are a major indication for shoulder arthrodesis. However, there is no consensus concerning the optimal position of the glenohumeral joint for fusion. Between 1997 and 2008, 19 shoulder arthrodeses were performed using pelvic reconstruction plates. The radiographic and functional characteristics of 13 patients of mean age 46 years were examined at a mean of 101 months after arthrodesis. Arthrodeses showed 30° mean angle of abduction, 32° forward flexion and 44° internal rotation of the humerus with respect to the scapula. Abduction >35° and forward flexion ≥30° seem to offer slightly better functional results. Internal rotation ≤45° significantly relates to better ability of the hand to reach the face (p = 0.012). Neither abduction >35° nor forward flexion ≥30° showed a higher prevalence of periscapular pain. Abduction around 35° and forward flexion around 30° are needed for good functional results. Internal rotation should not exceed 45°.

The hypoxia-associated factor switches cells from HIF-1α- to HIF-2α-dependent signaling promoting stem cell characteristics, aggressive tumor growth and invasion

Most solid tumors and their metastases experience periods of low oxygen or hypoxia, which is of major clinical significance as it promotes both tumor progression and resistance to therapy. Critical mediators of the hypoxic response are the hypoxia-inducible factors HIF-1α and HIF-2α. The HIFs are nonredundant and regulate both overlapping and unique downstream target genes. Here, we describe a novel mechanism for the switch between HIF-1α- and HIF-2α-dependent transcription during tumor hypoxia caused by the hypoxia associated factor (HAF). HAF is overexpressed in a variety of tumors and its levels are decreased during acute hypoxia, but increased following prolonged hypoxia. We have previously identified HAF as an E3 ubiquitin ligase that binds and ubiquitinates HIF-1α by an oxygen and pVHL-independent mechanism, thus targeting HIF-1α for proteasomal degradation. Here, we show that HAF also binds to HIF-2α, but at a different site than HIF-1α, and increases HIF-2α transactivation without causing its degradation. HAF, thus, switches the hypoxic response of the cancer cell from HIF-1α-dependent to HIF-2α-dependent transcription and activates genes involved in invasion such as MMP9, PAI-1, and the stem cell factor OCT-3/4. The switch to HIF-2α-dependent gene expression caused by HAF also promotes an enriched tumor stem cell population, resulting in highly aggressive tumors in vivo. Thus, HAF, by causing a switch from a HIF-1α- to HIF-2α-dependent response to hypoxia, provides a mechanism for more aggressive growth of tumors under prolonged hypoxia.

Abstract 4481: Topical application of the dual PDPK1/AKT inhibitor PHT-427 inhibits signaling and growth of human breast cancer cutaneous metastases in mice

Despite advances in the treatment of breast cancer between 10 to 15% of patients develop cutaneous metastatic disease (CMD) most frequently on the face, neck and chest wall, usually in later stages of the disease as a harbinger of metastasis that will occur in other organs 1 to 3 years later. CMD is not life threatening but can significantly impact patients’ quality of life and is a cause of anxiety, pain, discomfort, and a portal for infection. CMD could also be a seed for metastases at other sites. Surgery or radiotherapy is used for single or localized CMD. Topical (epicutaneous) therapy with molecularly targeted agents provides an attractive modality for treatment of more widespread breast CMD. PHT-427 is a dual pleckstrin homology (PH) domain inhibitor of PDPK and AKT, two key enzymes of PI3K signaling that is frequently activated in breast cancer. We report here PHT-427's topical activity in CMD. MCF-7 human breast cancer (mutant PIK3CA) 106 cells in 20 μI were injected intradermaly in the flank of estradiol pelleted female nu/nu mice. When tumors reached 40-200 mm3 groups of 5 mice were treated twice a day with 0.1 ml vehicle or vehicle with 50 mg/ml PH-427, applied to a 1 cm patch of skin over the tumor. Mice were housed individually with collars to prevent them ingesting applied drug. After 10 days mice were euthanized 4 hr after the last application and blood, tumor and overlying skin were removed for analyses. Topical PHT-427 gave 89 % inhibition of tumor growth (p = 0.017, 3/5 no measurable tumor). There was no change in body weight and no apparent skin toxicity. Western blotting showed that PHT-427 inhibited p-AKT Thr308/Ser473 in skin and tumor, and decreased total AKT in skin but not tumor. p-PDPK1 Ser241 was inhibited in tumor but not skin, as was the downstream target pPKC Thr410 and pMAPK Thr202/Tyr204. Measurement of PHT-427 by HPL-MS showed very high levels in the skin at the site of application, levels of ∼50 μg/g in tumor and 5.5 μg/ml in plasma. In vitro levels of PHT-427 of 5 μg/ml are required for killing of sensitive cell lines. Thus, topical application of PHT-427 can deliver active drug levels to skin and tumor, inhibiting PDPK1 and AKT, and significantly inhibiting tumor growth without adverse effects on normal skin. Topical PHT-427 could have use in skin conditions driven by PDPK/AKT such as prevention of sun damage and skin cancer, and in the personalized therapy of breast CMD.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4481. doi:10.1158/1538-7445.AM2011-4481

HIF-1-dependent stromal adaptation to ischemia mediates in vivo tumor radiation resistance

PURPOSE

Hypoxia-inducible factor 1 (HIF-1) promotes cancer cell survival and tumor progression. The specific role played by HIF-1 and tumor-stromal interactions toward determining tumor resistance to radiation treatment remains undefined. We applied a multimodality preclinical imaging platform to mechanistically characterize tumor response to radiation, with a focus on HIF-1-dependent resistance pathways.

METHODS

C6 glioma and HN5 human squamous carcinoma cells were stably transfected with a dual HIF-1 signaling reporter construct (dxHRE-tk/eGFP-cmvRed2XPRT). Reporter cells were serially interrogated in vitro before and after irradiation as monolayer and multicellular spheroid cultures and as subcutaneous xenografts in nu/nu mice.

RESULTS

In vitro, single-dose irradiation of C6 and HN5 reporter cells modestly impacted HIF-1 signaling in normoxic monolayers and inhibited HIF-1 signaling in maturing spheroids. In contrast, irradiation of C6 or HN5 reporter xenografts with 8 Gy in vivo elicited marked upregulation of HIF-1 signaling and downstream proangiogenic signaling at 48 hours which preceded recovery of tumor growth. In situ ultrasound imaging and dynamic contrast-enhanced (DCE) MRI indicated that HIF-1 signaling followed acute disruption of stromal vascular function. High-resolution positron emission tomography and dual-contrast DCE-MRI of immobilized dorsal skin window tumors confirmed postradiotherapy HIF-1 signaling to spatiotemporally coincide with impaired stromal vascular function. Targeted disruption of HIF-1 signaling established this pathway to be a determinant of tumor radioresistance.

CONCLUSIONS

Our results illustrate that tumor radioresistance is mediated by a capacity to compensate for stromal vascular disruption through HIF-1-dependent proangiogenic signaling and that clinically relevant vascular imaging techniques can spatially define mechanisms associated with tumor irradiation.

Radiosensitization and stromal imaging response correlates for the HIF-1 inhibitor PX-478 given with or without chemotherapy in pancreatic cancer

Growing tumors are hypoxic and respond to microenvironmental stress through increased expression of the hypoxia inducible factor-1alpha (HIF-1alpha) transcription factor, resulting in an adaptive switch to glycolytic metabolism, angiogenic signaling, survival, and metastasis. HIF-1alpha expression is associated with tumor resistance to cytotoxic therapy and inferior patient outcomes. Pancreatic cancer is the most hypoxic of all solid tumors and remains refractory to current chemoradiotherapy. We have seen nuclear HIF-1alpha in 88% of human pancreatic ductal carcinoma but in only 16% of normal pancreas. Stroma adjacent to the pancreatic ductal carcinoma also showed HIF-1alpha in 43% of cases. We investigated the novel selective HIF-1alpha inhibitor PX-478 on in vitro and in vivo radiation response of human pancreatic cancer models. Inhibition of HIF-1alpha by PX-478 increased cell killing by radiation. In mice with Panc-1, CF-PAC-1, or SU.86.86 pancreatic xenografts, concurrent administration of PX-478 potentiated the antitumor effects of fractionated radiation, with or without combined treatment with 5-fluorouracil or gemcitabine. Alternative sequencing of PX-478 with fractionated radiotherapy suggests optimal radiosensitization with concurrent or neoadjuvant administration of drug. Early tumor responses to combined PX-478/radiation treatment could be rapidly and repeatedly quantified by vascular imaging biomarkers. Dual-tracer dynamic contrast enhanced-magnetic resonance imaging and ultrasound imaging discriminated response to combined treatment prior to detection of differences in anatomic tumor size at 10 days posttreatment. Therefore, PX-478 is a mechanistically appealing and potentially clinically relevant enhancer of pancreatic cancer radiosensitivity, inhibiting tumor and stromal HIF-1 proangiogenic signaling and reducing the innate radiation resistance of hypoxic tumor cells.

Artroplastia total do punho na artrite reumatóide. Resultados dos primeiros 11 doentes operados

Sendo a artrite reumatóide, a principal indicação para a artroplastia total do punho, pretendemos com o este estudo, analisar a experiência com os implantes utilizados na nossa instituição. Avaliamos retrospectivamente 12 próteses colocadas em 11 doentes, utilizando a Universal 2 em 8 casos e a ReMotion em 4. Com um seguimento médio de 33 meses (rango = 15-59), obtivemos melhoria significativa da dor em todos os doentes; registamos incremento das amplitudes articulares e força, em média de 5,8º na flexão, 15,7º na extensão, 3,3º no desvio radial, 6º no cubital, de 22º na pronação, 26º na supinação e 5,4 e 1 kg para força de preensão da mão e de pinça. O DASH, avaliado na maioria dos doentes, teve melhoria média de 19 pontos. Como complicações houve um hematoma e uma deiscência com necrose dos bordos da ferida cirúrgica; um caso revelou sinais de descelamento do componente radial, no entanto sem repercussões significativas no resultado clínico e não registamos instabilidades. Até à data, nenhum doente foi reoperado. A artroplastia total punho revelou-se um procedimento eficaz no tratamento da artrite reumatóide, com uma baixa taxa de complicações. Apesar de não possuirmos tempo de evolução a longo prazo, os implantes revelaram uma fixação estável ao osso na grande maioria dos casos.

Detection of bacterial DNA in acute and chronic cholecystitis

BACKGROUND

The incidence of bacterbilia in cholelithiasis remains controversial. The positivity of cultures ranges from 0 to 73 per cent. The aim of this study was to employ the polymerase chain reaction (PCR) to detect bacterial DNA in gallbladder bile extracted during elective laparoscopic cholecystectomy, and to compare PCR findings with those of bile culture.

METHODS

Bile samples from 84 laparoscopic cholecystectomies were collected for culture and PCR analysis.

RESULTS

Positive results for bacterbilia were found in 42 (50 per cent) of 84 patients by PCR but in only 16 patients (19 per cent) by culture (P < 0.001). Agreement between the two methods was seen in 44 samples (52 per cent), which were negative in 35 cases. Pathological examination showed chronic cholecystitis in 69 cases (82 per cent) and acute cholecystitis in 15 (18 per cent). Thirty-three (48 per cent) of the patients with chronic cholecystitis were PCR positive but only ten (14 per cent) were culture positive (P < 0.001). Only culture results correlated with findings on pathological examination (P = 0.033).

CONCLUSION

PCR is more sensitive in detecting bacterial contamination of gallbladder bile in cholecystitis than conventional culture. The clinical relevance of this high sensitivity remains unclear.

Molecular pharmacology and antitumor activity of PHT-427, a novel Akt/phosphatidylinositide-dependent protein kinase 1 pleckstrin homology domain inhibitor

Phosphatidylinositol 3-kinase/phosphatidylinositide-dependent protein kinase 1 (PDPK1)/Akt signaling plays a critical role in activating proliferation and survival pathways within cancer cells. We report the molecular pharmacology and antitumor activity of PHT-427, a compound designed to bind to the pleckstrin homology (PH) binding domain of signaling molecules important in cancer. Although originally designed to bind the PH domain of Akt, we now report that PHT-427 also binds to the PH domain of PDPK1. A series of PHT-427 analogues with variable C-4 to C-16 alkyl chain length were synthesized and tested. PHT-427 itself (C-12 chain) bound with the highest affinity to the PH domains of both PDPK1 and Akt. PHT-427 inhibited Akt and PDPK1 signaling and their downstream targets in sensitive but not resistant cells and tumor xenografts. When given orally, PHT-427 inhibited the growth of human tumor xenografts in immunodeficient mice, with up to 80% inhibition in the most sensitive tumors, and showed greater activity than analogues with C4, C6, or C8 alkyl chains. Inhibition of PDPK1 was more closely correlated to antitumor activity than Akt inhibition. Tumors with PIK3CA mutation were the most sensitive, and K-Ras mutant tumors were the least sensitive. Combination studies showed that PHT-427 has greater than additive antitumor activity with paclitaxel in breast cancer and with erlotinib in non-small cell lung cancer. When given >5 days, PHT-427 caused no weight loss or change in blood chemistry. Thus, we report a novel PH domain binding inhibitor of PDPK1/Akt signaling with significant in vivo antitumor activity and minimal toxicity.

The selective hypoxia inducible factor-1 inhibitor PX-478 provides in vivo radiosensitization through tumor stromal effects

Hypoxia inducible factor-1 (HIF-1) promotes tumor cell adaptation to microenvironmental stress. HIF-1 is up-regulated in irradiated tumors and serves as a promising target for radiosensitization. We initially confirmed that the orally bioavailable HIF-1 inhibitor PX-478 reduces HIF-1 protein levels and signaling in vitro in a dose-dependent manner and provides direct radiosensitization of hypoxic cancer cells in clonogenic survival assays using C6 glioma, HN5 and UMSCCa10 squamous cells, and Panc-1 pancreatic adenocarcinoma cell lines. However, PX-478 yields striking in vivo tumor sensitization to single-dose irradiation, which cannot be explained by incremental improvement in direct tumor cell killing. We show that PX-478 prevents postradiation HIF-1 signaling and abrogates downstream stromal adaptation in C6 and HN5 reporter xenografts as measured by serial ultrasound, vascular magnetic resonance imaging, and hypoxia response element-specific micro-positron emission tomography imaging. The primacy of indirect PX-478 in vivo effects was corroborated by our findings that (a) either concurrent or early postradiation sequencing of PX-478 provides roughly equivalent sensitization and (b) constitutive vascular endothelial growth factor expression maintains refractory tumor vessel function and progression following combined radiation and PX-478. These results confirm that disruption of postradiation adaptive HIF-1 signaling by PX-478 imparts increased therapeutic efficacy through blockade of HIF-1-dependent reconstitution of tumor stromal function. Successful translation of targeted HIF-1 radiosensitization to the clinical setting will require specific consideration of tumor microenvironmental effects and mechanisms.

In vitro and in vivo activity of novel small-molecule inhibitors targeting the pleckstrin homology domain of protein kinase B/AKT

The phosphatidylinositol 3-kinase/AKT signaling pathway plays a critical role in activating survival and antiapoptotic pathways within cancer cells. Several studies have shown that this pathway is constitutively activated in many different cancer types. The goal of this study was to discover novel compounds that bind to the pleckstrin homology (PH) domain of AKT, thereby inhibiting AKT activation. Using proprietary docking software, 22 potential PH domain inhibitors were identified. Surface plasmon resonance spectroscopy was used to measure the binding of the compounds to the expressed PH domain of AKT followed by an in vitro activity screen in Panc-1 and MiaPaCa-2 pancreatic cancer cell lines. We identified a novel chemical scaffold in several of the compounds that binds selectively to the PH domain of AKT, inducing a decrease in AKT activation and causing apoptosis at low micromolar concentrations. Structural modifications of the scaffold led to compounds with enhanced inhibitory activity in cells. One compound, 4-dodecyl-N-(1,3,4-thiadiazol-2-yl)benzenesulfonamide, inhibited AKT and its downstream targets in cells as well as in pancreatic cancer cell xenografts in immunocompromised mice; it also exhibited good antitumor activity. In summary, a pharmacophore for PH domain inhibitors targeting AKT function was developed. Computer-aided modeling, synthesis, and testing produced novel AKT PH domain inhibitors that exhibit promising preclinical properties.

In Vivo Therapeutic Silencing of Hypoxia-Inducible Factor 1 Alpha (HIF-1α) Using Single-Walled Carbon Nanotubes Noncovalently Coated with siRNA

A new approach is described for delivering small interfering RNA (siRNA) into cancer cells by noncovalently complexing unmodified siRNA with pristine single-walled carbon nanotubes (SWCNTs). The complexes were prepared by simple sonication of pristine SWCNTs in a solution of siRNA, which then served both as the cargo and as the suspending agent for the SWCNTs. When complexes containing siRNA targeted to hypoxia-inducible factor 1 alpha (HIF-1α) were added to cells growing in serum containing culture media, there was strong specific inhibition of cellular HIF-1α activity. The ability to obtain a biological response to SWCNT/siRNA complexes was seen in a wide variety of cancer cell types. Moreover, intratumoral administration of SWCNT-HIF-1α siRNA complexes in mice bearing MiaPaCa-2/HRE tumors significantly inhibited the activity of tumor HIF-1α. As elevated levels of HIF-1α are found in many human cancers and are associated with resistance to therapy and decreased patient survival, these results imply that SWCNT/siRNA complexes may have value as therapeutic agents.

Peroxisome proliferator-activated receptor gamma agonist pioglitazone prevents the hyperglycemia caused by phosphatidylinositol 3-kinase pathway inhibition by PX-866 without affecting antitumor activity

The phosphatidylinositol 3-kinase (PI3K)/Akt signaling cascade is an important component of the insulin signaling in normal tissues leading to glucose uptake and homeostasis and for cell survival signaling in cancer cells. Hyperglycemia is an on-target side effect of many inhibitors of PI3K/Akt signaling including the specific PI3K inhibitor PX-866. The peroxisome proliferator-activated receptor gamma agonist pioglitazone, used to treat type 2 diabetes, prevents a decrease in glucose tolerance caused by acute administration of PX-866. Our studies have shown that pioglitazone does not inhibit the antitumor activity of PX-866 in A-549 non-small cell lung cancer and HT-29 colon cancer xenografts. In vitro studies also showed that pioglitazone increases 2-[1-(14)C]deoxy-D-glucose uptake in L-6 muscle cells and prevents inhibition of 2-deoxyglucose uptake by PX-866. Neither pioglitazone nor PX-866 had an effect on 2-deoxyglucose uptake in A-549 lung cancer cells. In vivo imaging studies using [18F]2-deoxyglucose (FDG) positron emission tomography showed that pioglitazone increases FDG accumulation by normal tissue but does not significantly alter FDG uptake by A-549 xenografts. Thus, peroxisome proliferator-activated receptor gamma agonists may be useful in overcoming the increase in blood glucose caused by inhibitors of PI3K signaling by preventing the inhibition of normal tissue insulin-mediated glucose uptake without affecting antitumor activity.

Mutations in the phosphatidylinositol-3-kinase pathway predict for antitumor activity of the inhibitor PX-866 whereas oncogenic Ras is a dominant predictor for resistance

The novel phosphatidylinositol-3-kinase (PI3K) inhibitor PX-866 was tested against 13 experimental human tumor xenografts derived from cell lines of various tissue origins. Mutant PI3K (PIK3CA) and loss of PTEN activity were sufficient, but not necessary, as predictors of sensitivity to the antitumor activity of the PI3K inhibitor PX-866 in the presence of wild-type Ras, whereas mutant oncogenic Ras was a dominant determinant of resistance, even in tumors with coexisting mutations in PIK3CA. The level of activation of PI3K signaling measured by tumor phosphorylated Ser(473)-Akt was insufficient to predict in vivo antitumor response to PX-866. Reverse-phase protein array revealed that the Ras-dependent downstream targets c-Myc and cyclin B were elevated in cell lines resistant to PX-866 in vivo. Studies using an H-Ras construct to constitutively and preferentially activate the three best-defined downstream targets of Ras, i.e., Raf, RalGDS, and PI3K, showed that mutant Ras mediates resistance through its ability to use multiple pathways for tumorigenesis. The identification of Ras and downstream signaling pathways driving resistance to PI3K inhibition might serve as an important guide for patient selection as inhibitors enter clinical trials and for the development of rational combinations with other molecularly targeted agents.

[Cervical lymphadenopathy as first manifestation of a bronchogenic cyst]

A 26-year old woman was admitted with clinical and laboratory signs and symptoms of chronic infection and multiple cervical lymphadenopathy, whose pathological studies disclosed a non-specific inflammatory reaction. Anti-tuberculosis treatment was then started, with no significant improvement. Chest CT scans was compatible with a mediastinial tumor and RMN studies revealed the presence of an infected bronchogenic cyst, which was surgically and successfully removed with complete disappearance of the infection. The authors conclude by enhancing the fact that bronchogenic cysts may course with diverse clinical manifestations and should be included in differential diagnosis of mediastinal tumors.

[Terminolateral esophagojejunostomy after gastrectomy with the biofragmentable anastomosis ring in the dog model]

INTRODUCTION

Esophagojejunostomy after total gastrectomy still remains a high risk anastomosis with a considerable morbidity and mortality. The majority of these anastomoses are performed by the intraluminal stapler technique, yet stenoses are a known late complication even after an uneventful postoperative course. In the present study, the osophagojejunostomy with the biofragmentable anastomosis ring (BAR) was examined in dogs.

METHODS

28 dogs were randomized into a group of manual suture (n = 14) and a BAR-group (n = 14). After gastrectomy, the esophagojejunostomy was performed by hand-suture with polypropylene 4-0 in the manual suture group, and with the 25/1.5 mm BAR in the BAR-group. In both groups the Roux-en-Y jejunojejunostomy was performed by hand-suture. The dogs were evaluated on postoperative days 4, 7 and 14 with regard to macroscopy, bursting strength, tissue hydroxyproline and histology.

RESULTS

There was one leakage without clinical effect in the hand-sewn group on postoperative day 4; there was no leak in the BAR-group. In observing fibre-free enteral feeding, neither functional disorders nor obstruction of the BAR were observed. The general anastomosis parameters were matchable between the groups.

CONCLUSION

The infracarinal BAR-esophagojejunostomy is comparable to the hand-sewn anastomosis in the dog-model.

Evaluation of carboxymethylcellulose, hydroxypropylmethylcellulose, and aluminum hydroxide as potential carriers for rhBMP-2

Conventional iliac crest nonvascularized corticocancelous bone grafts and bone flaps have been used to treat bony defects. However, these treatments have some limitations, namely, the availability of donor tissue, donor site morbidity, difficulty to shape the bone flap to the defect, and complexity of the surgery. The bone morphogenetic protein (rhBMP-2) is osteoinductive. However, its implantation requires a matrix (carrier) in order to define the shape of the resulting bone and to retain the protein at the site for the time required for induction to occur. When the ideal carrier is found, an unlimited supply of material would be available for all applications where bone is needed. In this in vitro study, we evaluated the suitability of some potential carriers for rhBMP-2 by measuring the alkaline phosphatase (ALP) activity of fibroblast cultures. Either rhBMP-2 or sodium carboxymethylcellulose significantly increased the ALP activity, when used alone. When sodium carboxymethylcellulose was combined with rhBMP-2, there was an increase in the ALP activity, but lower than those obtained when the products were used alone. Hydroxypropylmethylcellulose alone did not affect ALP activity. However, the combination of rhBMP-2 with hydroxypropylmethylcellulose did not increase the ALP activity, despite the presence of rhBMP-2. Aluminium hydroxide proved to be an unsuitable rhBMP-2 adsorbent.

Retinal detachment in young premature infants with acute retrolental fibroplasia. Thirty-two new cases

Experience with scleral buckling for exudative and tractional retinal detachments in very young premature infants who have acute retrolental fibroplasia (RLF) is reported. In this series, surgery was successful in 24 of 32 eyes (75%) of 23 infants, (age at surgery ranged from 1.75 months to 6 months, average age of 3 months). We attribute the 15% improvement in the success rate over our 1979 series in part to closer screening with emphasis on the examination at age 8 weeks, to earlier referral for treatment, and to our observation that these fragile eyes can withstand reoperation if buckle revision is necessary to combat persistent retinal traction. We encountered no serious complications either at surgery or immediately after surgery. We stress that (1) because of the high incidence of spontaneous remission, buckling surgery should not be performed until the detachment has progressed well posterior to the equator and remission is obviously unlikely (Grade IV or V); (2) excessive cryotherapy and undue surgical trauma should be avoided; and (3) because scleral erosion is certain as the eyes grow, the encircling band should be transected six months to one year after surgery.

[Epidermoid carcinoma of the stomach]

A case of pure squamous cell carcinoma of the stomach in a 63-year-old woman has been reported. The tumor was located in pyloric antrum and histologic examination disclosed a well differentiated squamous cell carcinoma, with many horn pearls. Histogenesis of similar cases of this unusual tumor have been briefly discussed.