Interactions between BRD4S, LOXL2, and MED1 drive cell cycle transcription in triple-negative breast cancer

Triple-negative breast cancer (TNBC) often develops resistance to single-agent treatment, which can be circumvented using targeted combinatorial approaches. Here, we demonstrate that the simultaneous inhibition of LOXL2 and BRD4 synergistically limits TNBC proliferation in vitro and in vivo. Mechanistically, LOXL2 interacts in the nucleus with the short isoform of BRD4 (BRD4S), MED1, and the cell cycle transcriptional regulator B-MyB. These interactions sustain the formation of BRD4 and MED1 nuclear transcriptional foci and control cell cycle progression at the gene expression level. The pharmacological co-inhibition of LOXL2 and BRD4 reduces BRD4 nuclear foci, BRD4-MED1 colocalization, and the transcription of cell cycle genes, thus suppressing TNBC cell proliferation. Targeting the interaction between BRD4S and LOXL2 could be a starting point for the development of new anticancer strategies for the treatment of TNBC.

Identification of a Molecularly-Defined Subset of Breast and Ovarian Cancer Models that Respond to WEE1 or ATR Inhibition, Overcoming PARP Inhibitor Resistance

PURPOSE

PARP inhibitors (PARPi) induce synthetic lethality in homologous recombination repair (HRR)-deficient tumors and are used to treat breast, ovarian, pancreatic, and prostate cancers. Multiple PARPi resistance mechanisms exist, most resulting in restoration of HRR and protection of stalled replication forks. ATR inhibition was highlighted as a unique approach to reverse both aspects of resistance. Recently, however, a PARPi/WEE1 inhibitor (WEE1i) combination demonstrated enhanced antitumor activity associated with the induction of replication stress, suggesting another approach to tackling PARPi resistance.

EXPERIMENTAL DESIGN

We analyzed breast and ovarian patient-derived xenoimplant models resistant to PARPi to quantify WEE1i and ATR inhibitor (ATRi) responses as single agents and in combination with PARPi. Biomarker analysis was conducted at the genetic and protein level. Metabolite analysis by mass spectrometry and nucleoside rescue experiments ex vivo were also conducted in patient-derived models.

RESULTS

Although WEE1i response was linked to markers of replication stress, including STK11/RB1 and phospho-RPA, ATRi response associated with ATM mutation. When combined with olaparib, WEE1i could be differentiated from the ATRi/olaparib combination, providing distinct therapeutic strategies to overcome PARPi resistance by targeting the replication stress response. Mechanistically, WEE1i sensitivity was associated with shortage of the dNTP pool and a concomitant increase in replication stress.

CONCLUSIONS

Targeting the replication stress response is a valid therapeutic option to overcome PARPi resistance including tumors without an underlying HRR deficiency. These preclinical insights are now being tested in several clinical trials where the PARPi is administered with either the WEE1i or the ATRi.

High p16 expression and heterozygous RB1 loss are biomarkers for CDK4/6 inhibitor resistance in ER+ breast cancer

CDK4/6 inhibitors combined with endocrine therapy have demonstrated higher antitumor activity than endocrine therapy alone for the treatment of advanced estrogen receptor-positive breast cancer. Some of these tumors are de novo resistant to CDK4/6 inhibitors and others develop acquired resistance. Here, we show that p16 overexpression is associated with reduced antitumor activity of CDK4/6 inhibitors in patient-derived xenografts (n = 37) and estrogen receptor-positive breast cancer cell lines, as well as reduced response of early and advanced breast cancer patients to CDK4/6 inhibitors (n = 89). We also identified heterozygous RB1 loss as biomarker of acquired resistance and poor clinical outcome. Combination of the CDK4/6 inhibitor ribociclib with the PI3K inhibitor alpelisib showed antitumor activity in estrogen receptor-positive non-basal-like breast cancer patient-derived xenografts, independently of PIK3CA, ESR1 or RB1 mutation, also in drug de-escalation experiments or omitting endocrine therapy. Our results offer insights into predicting primary/acquired resistance to CDK4/6 inhibitors and post-progression therapeutic strategies.

Preclinical In Vivo Validation of the RAD51 Test for Identification of Homologous Recombination-Deficient Tumors and Patient Stratification

PARP inhibitors (PARPi) are approved drugs for platinum-sensitive, high-grade serous ovarian cancer (HGSOC) and for breast, prostate, and pancreatic cancers (PaC) harboring genetic alterations impairing homologous recombination repair (HRR). Detection of nuclear RAD51 foci in tumor cells is a marker of HRR functionality, and we previously established a test to detect RAD51 nuclear foci. Here, we aimed to validate the RAD51 score cut off and compare the performance of this test to other HRR deficiency (HRD) detection methods. Laboratory models from BRCA1/BRCA2-associated breast cancer, HGSOC, and PaC were developed and evaluated for their response to PARPi and cisplatin. HRD in these models and patient samples was evaluated by DNA sequencing of HRR genes, genomic HRD tests, and RAD51 foci detection. We established patient-derived xenograft models from breast cancer (n = 103), HGSOC (n = 4), and PaC (n = 2) that recapitulated patient HRD status and treatment response. The RAD51 test showed higher accuracy than HRR gene mutations and genomic HRD analysis for predicting PARPi response (95%, 67%, and 71%, respectively). RAD51 detection captured dynamic changes in HRR status upon acquisition of PARPi resistance. The accuracy of the RAD51 test was similar to HRR gene mutations for predicting platinum response. The predefined RAD51 score cut off was validated, and the high predictive value of the RAD51 test in preclinical models was confirmed. These results collectively support pursuing clinical assessment of the RAD51 test in patient samples from randomized trials testing PARPi or platinum-based therapies.

SIGNIFICANCE

This work demonstrates the high accuracy of a histopathology-based test based on the detection of RAD51 nuclear foci in predicting response to PARPi and cisplatin.

Effect of the donor´s age and type of extender (egg yolk versus clarified egg yolk) over the sperm quality of Majorera bucks preserved at 4 ºC: in vitro results and fertility trials

This study assessed the effect of donor´s age and two different extenders in the sperm quality of chilled semen in Majorera bucks. In experiment 1, semen was individually processed from 5 young (10–12 months old) and 4 mature (3–5 years old) bucks and then was diluted in two different extenders: EY (Tris‐glucose, 12% egg yolk) and CEY (Tris‐glucose, 12% clarified egg yolk) and cooled at 4°C; semen quality (sperm motility, percentages of alive spermatozoa, acrosome status and abnormal spermatozoa) was evaluated at 24, 48, 72 and 96 hr after cooling. In experiment II, 72 Majorera goats were assigned to four experimental groups: for groups 24‐EY (n = 18) and 24‐CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 24 hr, respectively, while for groups 72‐EY (n = 18) and 72‐CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 72 hr, respectively. In vitro results confirmed that only ejaculate volume and sperm concentration were significantly different between young and mature bucks. In addition, semen quality was similar between both diluents, presenting values for the first 48 hr similar to that recorded in fresh samples. The fertility rate was around 70% after 24 hr (4°C) in both groups, but the kidding rate was significantly lower (44.4%, p < .05) in goats inseminated with EY diluent preserved for 72 hr. Our results showed that the semen samples may be stored at 4°C in media with egg yolk or clarified egg yolk, and, therefore, the use of clarified egg yolk may represent a valid alternative to chill semen samples. Finally, young bucks (older than 10–12 months) of Majorera breed could be successfully used in breeding programmes with similar efficacy to older males.

PI3K activation promotes resistance to eribulin in HER2-negative breast cancer

BACKGROUND

Eribulin is a microtubule-targeting agent approved for the treatment of advanced or metastatic breast cancer (BC) previously treated with anthracycline- and taxane-based regimens. PIK3CA mutation is associated with worse response to chemotherapy in oestrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic BC. We aimed to evaluate the role of phosphoinositide 3-kinase (PI3K)/AKT pathway mutations in eribulin resistance.

METHODS

Resistance to eribulin was evaluated in HER2- BC cell lines and patient-derived tumour xenografts, and correlated with a mutation in the PI3K/AKT pathway.

RESULTS

Eleven out of 23 HER2- BC xenografts treated with eribulin exhibited disease progression. No correlation with ER status was detected. Among the resistant models, 64% carried mutations in PIK3CA, PIK3R1 or AKT1, but only 17% among the sensitive xenografts (P = 0.036). We observed that eribulin treatment induced AKT phosphorylation in vitro and in patient tumours. In agreement, the addition of PI3K inhibitors reversed primary and acquired resistance to eribulin in xenograft models, regardless of the genetic alterations in PI3K/AKT pathway or ER status. Mechanistically, PI3K blockade reduced p21 levels likely enabling apoptosis, thus sensitising to eribulin treatment.

CONCLUSIONS

PI3K pathway activation induces primary resistance or early adaptation to eribulin, supporting the combination of PI3K inhibitors and eribulin for the treatment of HER2- BC patients.

Genetic Alterations in the PI3K/AKT Pathway and Baseline AKT Activity Define AKT Inhibitor Sensitivity in Breast Cancer Patient-derived Xenografts

PURPOSE

AZD5363/capivasertib is a pan-AKT catalytic inhibitor with promising activity in combination with paclitaxel in triple-negative metastatic breast cancer harboring PI3K/AKT-pathway alterations and in estrogen receptor-positive breast cancer in combination with fulvestrant. Here, we aimed to identify response biomarkers and uncover mechanisms of resistance to AZD5363 and its combination with paclitaxel.

EXPERIMENTAL DESIGN

Genetic and proteomic markers were analyzed in 28 HER2-negative patient-derived xenografts (PDXs) and in patient samples, and correlated to AZD5363 sensitivity as single agent and in combination with paclitaxel.

RESULTS

Four PDX were derived from patients receiving AZD5363 in the clinic which exhibited concordant treatment response. Mutations in PIK3CA/AKT1 and absence of mTOR complex 1 (mTORC1)-activating alterations, for example, in MTOR or TSC1, were associated with sensitivity to AZD5363 monotherapy. Interestingly, excluding PTEN from the composite biomarker increased its accuracy from 64% to 89%. Moreover, resistant PDXs exhibited low baseline pAKT S473 and residual pS6 S235 upon treatment, suggesting that parallel pathways bypass AKT/S6K1 signaling in these models. We identified two mechanisms of acquired resistance to AZD5363: cyclin D1 overexpression and loss of AKT1 p.E17K.

CONCLUSIONS

This study provides insight into putative predictive biomarkers of response and acquired resistance to AZD5363 in HER2-negative metastatic breast cancer.

Recovery of niobium and tantalum by solvent extraction from Sn-Ta-Nb mining tailings

The slag from the extraction processes of metals from their ores may contain valuable components that, if adequately recovered, can be reintroduced in the technological life cycle. This is the case for the material obtained in Penouta mines in the North of Spain. These mineral sites are a main source of tin obtained from cassiterite. The mineral is submitted to a pyrometallurgical process to separate tin, however cassiterite is not the only mineral present in the veins, and large amounts of other minerals are normally discarded, constituting the slag. In the present case, besides cassiterite, one of the most abundant minerals in the ore is columbo tantalite, the source of the strategic coltan. In this work the raw material (slag) has been treated by acid leaching, using HF/H₂SO₄ as the leaching agent. Then liquid–liquid extraction of Nb and Ta was performed, with Cyanex®923 extractant, so that both metals were obtained separately. Then they were precipitated from the corresponding aqeuous solution, and calcined in order to yield Nb₂O₅ of 98.5% purity and tantalum salt, after calcination and purification, of 97.3% purity. The process described in this work opens a possibility to produce high quality materials that are considered critical by the EU from alternative sources exempt of criticality factors.

The slag from the extraction processes of metals from their ores may contain valuable components that, if adequately recovered, can be reintroduced in the technological life cycle.

A RAD51 assay feasible in routine tumor samples calls PARP inhibitor response beyond BRCA mutation

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are effective in cancers with defective homologous recombination DNA repair (HRR), including BRCA1/2-related cancers. A test to identify additional HRR-deficient tumors will help to extend their use in new indications. We evaluated the activity of the PARPi olaparib in patient-derived tumor xenografts (PDXs) from breast cancer (BC) patients and investigated mechanisms of sensitivity through exome sequencing, BRCA1 promoter methylation analysis, and immunostaining of HRR proteins, including RAD51 nuclear foci. In an independent BC PDX panel, the predictive capacity of the RAD51 score and the homologous recombination deficiency (HRD) score were compared. To examine the clinical feasibility of the RAD51 assay, we scored archival breast tumor samples, including PALB2-related hereditary cancers. The RAD51 score was highly discriminative of PARPi sensitivity versus PARPi resistance in BC PDXs and outperformed the genomic test. In clinical samples, all PALB2-related tumors were classified as HRR-deficient by the RAD51 score. The functional biomarker RAD51 enables the identification of PARPi-sensitive BC and broadens the population who may benefit from this therapy beyond BRCA1/2-related cancers.

RAD51 foci as a functional biomarker of homologous recombination repair and PARP inhibitor resistance in germline BRCA-mutated breast cancer

Background

BRCA1 and BRCA2 (BRCA1/2)-deficient tumors display impaired homologous recombination repair (HRR) and enhanced sensitivity to DNA damaging agents or to poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi). Their efficacy in germline BRCA1/2 (gBRCA1/2)-mutated metastatic breast cancers has been recently confirmed in clinical trials. Numerous mechanisms of PARPi resistance have been described, whose clinical relevance in gBRCA-mutated breast cancer is unknown. This highlights the need to identify functional biomarkers to better predict PARPi sensitivity.

Patients and methods

We investigated the in vivo mechanisms of PARPi resistance in gBRCA1 patient-derived tumor xenografts (PDXs) exhibiting differential response to PARPi. Analysis included exome sequencing and immunostaining of DNA damage response proteins to functionally evaluate HRR. Findings were validated in a retrospective sample set from gBRCA1/2-cancer patients treated with PARPi.

Results

RAD51 nuclear foci, a surrogate marker of HRR functionality, were the only common feature in PDX and patient samples with primary or acquired PARPi resistance. Consistently, low RAD51 was associated with objective response to PARPi. Evaluation of the RAD51 biomarker in untreated tumors was feasible due to endogenous DNA damage. In PARPi-resistant gBRCA1 PDXs, genetic analysis found no in-frame secondary mutations, but BRCA1 hypomorphic proteins in 60% of the models, TP53BP1-loss in 20% and RAD51-amplification in one sample, none mutually exclusive. Conversely, one of three PARPi-resistant gBRCA2 tumors displayed BRCA2 restoration by exome sequencing. In PDXs, PARPi resistance could be reverted upon combination of a PARPi with an ataxia-telangiectasia mutated (ATM) inhibitor.

Conclusion

Detection of RAD51 foci in gBRCA tumors correlates with PARPi resistance regardless of the underlying mechanism restoring HRR function. This is a promising biomarker to be used in the clinic to better select patients for PARPi therapy. Our study also supports the clinical development of PARPi combinations such as those with ATM inhibitors.

Abstract 150: Identification of determinants of sensitivity to AKT inhibition using breast cancer (BC) patient-derived tumor xenografts (PDX)

The antitumor activity of AKT inhibitors is being investigated for the treatment of BC with activation of the PI3K/AKT pathway. Putative predictive biomarkers that are being tested in ongoing trials are PTEN loss/mutation (mut) (around 40% of triple negative BC) and AKT1 mutation (4-5% ER+/HER2- BC). The BEECH trial is evaluating the activity of the pan-AKT1/2/3 inhibitor (AKTi) AZD5363 in combination with the antimicrotubule agent paclitaxel in HER2-negative (HER2-) metastatic BC. We aimed to identify response biomarkers to the single agent AKTi and its degree of synergy in combination with paclitaxel, using HER2- patient-derived tumor xenografts (PDX).

Fifteen PDX have been established from BC patients receiving standard treatment at our Hospital, as well as from those participating in the BEECH trial, when sample was available, by implanting their tumor biopsies at baseline, on-treatment and at progression. The antitumor activity of AZD5363 as single agent and in combination with paclitaxel has been measured in these PDX. Genotyping and protein levels have been analyzed by exome sequencing, capture-based sequencing, Western blot and immunohistochemistry (IHC).

AZD5363 monotherapy results in disease stabilization or tumor regression in 3 out of 15 PDX (2/9 ER-/HER2- and 1/6 ER+/HER2-). We found a positive association between high levels of pAKT S473 by Western blot and antitumor response. Interestingly, the two ER-/HER2- responding PDX harbor a PTEN frameshift mutation or gene loss concomitant with an activating mutation within the PI3K pathway (PIK3CA or PIK3R1). The ER+/HER2- PDX responder harbors an AKT1-p.E17K mutation. AZD5363 plus paclitaxel, at a clinically relevant dose, results in disease stabilization in 2/11 PDX that progress to either single agent (1/7 ER-/HER2- and 1/4 ER+/HER2-); the latter PDX being derived from the baseline tumor biopsy of a BEECH trial patient who benefited from this combination for one year.

Altogether these results suggest that double-altering events in the PI3K pathway, including PTEN loss/mut and a second PI3K-pathway alteration in ER-/HER2- tumors, or AKT1-p.E17K in ER+/HER2- tumors, and consequent high pAkt S473 levels could be associated with intrinsic sensitivity to AKT inhibition. The predictive value of these alterations as determinants of response to AKTi deserves further investigation.

Citation Format: Albert Gris-Oliver, Mafalda Oliveira, Marta Guzman, Olga Rodríguez, Judit Grueso, Maurizio Scaltriti, William J. Howat, J Carl Barrett, Javier Cortés, José Baselga, Gaia Schiavon, Barry R. Davies, Cristina Saura, Violeta Serra. Identification of determinants of sensitivity to AKT inhibition using breast cancer (BC) patient-derived tumor xenografts (PDX) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 150. doi:10.1158/1538-7445.AM2017-150

Failure of Bacillus Calmette-Guérin therapy in non-muscle-invasive bladder cancer: Definition and treatment options

Adjuvant intravesical bacillus Calmette- Guérin (BCG) therapy is the standard conservative adjuvant treatment and the most effective regimen for patients with high-risk non-muscle-invasive bladder cancer (NMIBC). The term "BCG failure" is generally used to refer to recurrence or progression following BCG therapy, as experienced by many patients. However, the term has been defined inconsistently, and several studies have indicated that patients with a particular pattern of BCG failure have a worse prognosis. There are many different treatment options for patients who experience BCG failure.

OBJECTIVE

To summarize the different current definitions of BCG failure and the present treatment options available for patients with high-risk NMIBC who experience BCG failure.

EVIDENCE SYNTHESIS

Overall, the failure rate in response to BCG is about 40-50%. Most guidelines recommend that patients failing BCG should be offered radical cystectomy (RC). The significant potential for progression specific to high-risk NMIBC leads some clinicians to argue that immediate RC should be considered the preferred first-line treatment in high-risk patients, bearing in mind that it achieves a long-term survival rate in excess of 90% with ongoing improvements in morbidity. While other salvage intravesical treatments have to be considered oncologically inferior to RC, several therapies are now available if the patient is unfit to undergo RC or if bladder preservation is the objective, and some agents have shown promise in the context of BCG failure.

CONCLUSIONS

The definition, prediction, and treatment of BCG failure remain topics of debate. Patients with BCG failure need carefully selected, individualized therapy in experienced hands. Stratification of patients with BCG failure into groups can identify those with a better or worse prognosis. RC should be the selected option if a patient experiences BCG failure, but several promising intravesical salvage options are available for those cases in which the patient is unfit for surgery or bladder preservation is preferred. Currently data are still inadequate to allow formulation of definitive recommendations, and larger and higher quality studies of salvage intravesical therapies are urgently required.

MEK plus PI3K/mTORC1/2 Therapeutic Efficacy Is Impacted by TP53 Mutation in Preclinical Models of Colorectal Cancer

PURPOSE

PI3K pathway activation occurs in concomitance with RAS/BRAF mutations in colorectal cancer, limiting the sensitivity to targeted therapies. Several clinical studies are being conducted to test the tolerability and clinical activity of dual MEK and PI3K pathway blockade in solid tumors.

EXPERIMENTAL DESIGN

In the present study, we explored the efficacy of dual pathway blockade in colorectal cancer preclinical models harboring concomitant activation of the ERK and PI3K pathways. Moreover, we investigated if TP53 mutation affects the response to this therapy.

RESULTS

Dual MEK and mTORC1/2 blockade resulted in synergistic antiproliferative effects in cell lines bearing alterations in KRAS/BRAF and PIK3CA/PTEN. Although the on-treatment cell-cycle effects were not affected by the TP53 status, a marked proapoptotic response to therapy was observed exclusively in wild-type TP53 colorectal cancer models. We further interrogated two independent panels of KRAS/BRAF- and PIK3CA/PTEN-altered cell line- and patient-derived tumor xenografts for the antitumor response toward this combination of agents. A combination response that resulted in substantial antitumor activity was exclusively observed among the wild-type TP53 models (two out of five, 40%), but there was no such response across the eight mutant TP53 models (0%). Interestingly, within a cohort of 14 patients with colorectal cancer treated with these agents for their metastatic disease, two patients with long-lasting responses (32 weeks) had TP53 wild-type tumors.

CONCLUSIONS

Our data support that, in wild-type TP53 colorectal cancer cells with ERK and PI3K pathway alterations, MEK blockade results in potent p21 induction, preventing apoptosis to occur. In turn, mTORC1/2 inhibition blocks MEK inhibitor-mediated p21 induction, unleashing apoptosis. Clin Cancer Res; 21(24); 5499-510. ©2015 AACR.

Mercury leaching from hazardous industrial wastes stabilized by sulfur polymer encapsulation

European Directive 2013/39/EU records mercury as a priority hazardous substance. Regulation n° 2008/1102/EC banned the exportation of mercury and required the safe storage of any remaining mercury compounds. The present work describes the encapsulation of three wastes containing combinations of HgS, HgSe, HgCl2, HgO2, Hg3Se2Cl2, HgO and Hg(0), according to patent of Spanish National Research Council WO2011/029970A2. The materials obtained were subjected to leaching tests according to standards UNE-EN-12457 and CEN/TS 14405:2004. The results are compared with the criteria established in the Council Decision 2003/33/EC for the acceptance of waste at landfills. The Hg concentrations of all leachates were <0.01mgHg/kg for a liquid/solid ratio of 10l/kg. All three encapsulated materials therefore meet the requirements for storage in inert waste landfills.

Synthesis and photophysical and supramolecular study of π-conjugated (diethylene glycol methyl ether) benzoateethynylene oligomers and polymers

The strong π–π interaction that governs (diethylene glycol methyl ether) benzoateethynylene macromolecules was evidenced by X-ray scattering and HRTEM.

Abstract 924: Predictive biomarker identification for combined anti-mTOR and anti-IGF-1R treatment in luminal B breast cancer

Luminal B breast cancer is one of the most aggressive subtypes of breast cancer for which effective treatments are needed. Recently, a phase I clinical study revealed that blockade of mTOR and IGF-1R has potential clinical activity in this cancer subtype. However, biomarkers to predict patient's response to the combination are still needed. Previous exploratory studies in ovarian cancer have associated low RAS-pathway activity, as determined by a RAS gene expression signature score, and high levels of IGF-1R axis genes with response to this combination therapy. In the present study we evaluated low RAS signature/high IGF-1/high IGF-1R as potential predictive biomarkers for anti-mTOR and anti-IGF-1R combination therapy in luminal B breast cancer patient-derived xenografts (PDX) treated with the allosteric mTOR inhibitor ridaforolimus and the monoclonal antibody against IGF-1R, dalotuzumab. Expression array analysis revealed that our 6 luminal B PDXs exhibited a low RAS signature score, compared to 6 HER2 and triple negative PDXs. Overall, luminal B PDXs expressed higher IGF-1R as compared to the other breast cancer subtypes with some variability among the different luminal models. Low expression of human IGF-pathway ligands IGF-1 and IGF-2 among the luminal PDXs, compared to luminal B breast cancers, suggested to us the need of exogenous IGF-1 ligand supplementation to derive IGF-1R feedback activation and combinatorial antitumor response. Accordingly, three high IGF-1R-PDXs treated with the anti-mTOR and anti-IGF-1R combination therapy supplemented with recombinant human IGF-1 exhibited statistically significant anti-tumor response as compared to single agents, whereas two low IGF-1R-expressing PDXs did not. As anticipated, ridaforolimus induced the IGF-1R-axis by increasing the levels of the adapter protein IRS-1, which potentiated Akt signaling. Hence, in vitro knockdown of IRS-1 promoted the antiproliferative activity of ridaforolimus in patient-derived tumor cells. In conclusion, our results demonstrate that baseline IGF-pathway expression, namely IGF-1, IGF-1R and IRS-1, predict benefit to combined anti-mTOR and anti-IGF-1R treatment in breast cancer and supports further exploration in luminal B breast cancers that derived benefit from this combination.

Citation Format: Martin A. Rivas, Yasir H. Ibrahim, Olga Rodríguez, Pilar Antón, Patricia Cozar, Patricia Gómez-Pardo, Claudia Aura, Brian B. Haines, Sriram Sathyanarayanan, Theresa Zhang, Violeta Serra, José Baselga. Predictive biomarker identification for combined anti-mTOR and anti-IGF-1R treatment in luminal B breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 924. doi:10.1158/1538-7445.AM2014-924

Second transurethral resection and prognosis of high-grade non-muscle invasive bladder cancer in patients not receiving bacillus Calmette-Guérin

OBJECTIVE

To define the natural history of T1G3 bladder tumor not receiving intravesical Bacillus Calmette-Guerin (BCG) and assess the diagnostic and therapeutic value of a second transurethral resection (Re-TUR) in these patients.

PATIENTS AND METHODS

Retrospective study on the natural history of 210 patients treated at two institutions for T1G3 bladder carcinoma without associated CIS. In no case was BCG administered; 79 (37.6%) received TUR alone, and 131 (62.4%) Re-TUR 4 to 6 weeks later; 23 (12.4%) underwent cystectomy for tumor progression.

RESULTS

Median follow-up was 55 (78 IQR) months, male/female ratio 8/1, and mean age 70.6+11.8 (range 37-93). 19.5% were free of recurrence at 10 years, and 61.9% free of progression. Independent prognostic factors for progression were solid pattern (HR: 2.71; P=.0004), multiplicity (HR: 2.26; P=.003), and recurrence at 3 months (HR: 3.4; P=.003). Cancer-specific survival was 81.5% at 5 and 69% at 10 years. Independent predictors of survival were: progression during the first year (HR: 17.9; P<.0001), solid pattern (HR: 2.13; P=.02), multiplicity (HR: 2.05; P=.03), and age>65 years (HR: 2.9; P=.03). Re-TUR avoided under-staging (7.4%), detected T1G3 residual disease (10.7%), reduced recurrence rate at 3 months (11.4 to 4.6%; P=.06), and rate of progression on the 1st year (13.9 to 3.8%; P=.0075). However, in these patients the risk remains and no differences were detected in the long term in terms of recurrence (log-rank, P=.14), progression (P=.91), or cancer death (P=.21) in patients treated with Re-TUR.

CONCLUSION

The recurrence in the first 3 months of a T1G3 tumor not receiving BCG is the main risk factor for progression, and progression of this type of tumors within the first year is the main factor of cancer death. The Re-TUR improves both variables but it does not change the long-term prognosis.

Evaluation and clinical analyses of downstream targets of the Akt inhibitor GDC-0068

PURPOSE

The oncogenic PI3K/Akt/mTOR pathway is an attractive therapeutic target in cancer. However, it is unknown whether the pathway blockade required for tumor growth inhibition is clinically achievable. Therefore, we conducted pharmacodynamic studies with GDC-0068, an ATP competitive, selective Akt1/2/3 inhibitor, in preclinical models and in patients treated with this compound.

EXPERIMENTAL DESIGN

We used a reverse phase protein array (RPPA) platform to identify a biomarker set indicative of Akt inhibition in cell lines and human-tumor xenografts, and correlated the degree of pathway inhibition with antitumor activity. Akt pathway activity was measured using this biomarker set in pre- and post-dose tumor biopsies from patients treated with GDC-0068 in the dose escalation clinical trial.

RESULTS

The set of biomarkers of Akt inhibition is composed of 10 phosphoproteins, including Akt and PRAS40, and is modulated in a dose-dependent fashion, both in vitro and in vivo. In human-tumor xenografts, this dose dependency significantly correlated with tumor growth inhibition. Tumor biopsies from patients treated with GDC-0068 at clinically achievable doses attained a degree of biomarker inhibition that correlated with tumor growth inhibition in preclinical models. In these clinical samples, compensatory feedback activation of ERK and HER3 was observed, consistent with preclinical observations.

CONCLUSION

This study identified a set of biomarkers of Akt inhibition that can be used in the clinical setting to assess target engagement. Here, it was used to show that robust Akt inhibition in tumors from patients treated with GDC-0068 is achievable, supporting the clinical development of this compound in defined patient populations.

RSK3/4 mediate resistance to PI3K pathway inhibitors in breast cancer

The PI3K signaling pathway regulates diverse cellular processes, including proliferation, survival, and metabolism, and is aberrantly activated in human cancer. As such, numerous compounds targeting the PI3K pathway are currently being clinically evaluated for the treatment of cancer, and several have shown some early indications of efficacy in breast cancer. However, resistance against these agents, both de novo and acquired, may ultimately limit the efficacy of these compounds. Here, we have taken a systematic functional approach to uncovering potential mechanisms of resistance to PI3K inhibitors and have identified several genes whose expression promotes survival under conditions of PI3K/mammalian target of rapamycin (PI3K/mTOR) blockade, including the ribosomal S6 kinases RPS6KA2 (RSK3) and RPS6KA6 (RSK4). We demonstrate that overexpression of RSK3 or RSK4 supports proliferation upon PI3K inhibition both in vitro and in vivo, in part through the attenuation of the apoptotic response and upregulation of protein translation. Notably, the addition of MEK- or RSK-specific inhibitors can overcome these resistance phenotypes, both in breast cancer cell lines and patient-derived xenograft models with elevated levels of RSK activity. These observations provide a strong rationale for the combined use of RSK and PI3K pathway inhibitors to elicit favorable responses in breast cancer patients with activated RSK.

Preparation and characterization of activated carbon from the char produced in the thermolysis of granulated scrap tyres

The char produced in the thermolysis of granulated scrap tyres has few market outlets, reducing the economic viability of the thermolytic process. This paper reports the potential of this char as a low-cost precursor of porous carbons. The tyre-derived char was demineralized in either alkaline or acidic media to reduce its ash, zinc, sulfur, and silica contents. The lowest impurity content was achieved with an HNO3/H2O treatment. The resulting demineralized char was then subjected to activation by KOH or CO2. The Brunauer-Emmett-Teller (BET)-specific surface area of the activated carbon produced by the KOH treatment was 242 m2/g, whereas that of the CO2-activated carbon was 720 m2/g. The textural properties of the latter product were similar to those of some commercial activated carbons. The use of tyre-derived char as a precursor of porous carbons could render the thermolytic treatment of scrap tyres more economically attractive.

IMPLICATIONS

Char produced in thermolysis of granulated scrap tyres has a few market outlets; in this paper an alternative for its use is presented. The char was converted into activated carbon with textural properties similar to those of some commercial activated carbons. This process could render the thermolytic treatment of scrap tyres more economically attractive.

Access and success with less: improving productivity in broad-access postsecondary institutions

Achieving national goals for increased college completion in a time of scarce resources will require the postsecondary institutions that enroll the majority of undergraduates--community colleges and less-selective public universities--to graduate more students at a lower cost. Davis Jenkins and Olga Rodriguez examine research on how these "broad-access" institutions can do so without sacrificing access or quality. Research indicates that the strategies broad-access institutions have relied on in the past to cut costs--using part-time instructors and increasing student-faculty ratios--may in fact reduce productivity and efficiency. The limited evidence available suggests that some of the most popular strategies for improving student success are not cost-effective. New strategies to cut costs and improve college success are therefore imperative. Some believe that redesigning courses to make use of instructional technologies will lead to better outcomes at lower cost, although the evidence is mixed. Recently, a growing number of institutions are going beyond redesigning courses and instead changing the way they organize programs and supports along the student's "pathway" through college. These efforts are promising, but their effects on cost per completion are not yet certain. Meager funding has so far hampered efforts by policy makers to fund colleges based on outcomes rather than how many students they enroll, but some states are beginning to increase the share of appropriations tied to outcomes. Jenkins and Rodriquez argue that as policy makers push colleges to lower the cost per graduate, they must avoid providing incentives to lower academic standards. They encourage policy makers to capitalize on recent research on the economic value of postsecondary education to measure quality, and urge colleges and universities to redouble efforts to define learning outcomes and measure student mastery.

PI3K inhibition impairs BRCA1/2 expression and sensitizes BRCA-proficient triple-negative breast cancer to PARP inhibition

PARP inhibitors are active in tumors with defects in DNA homologous recombination (HR) due to BRCA1/2 mutations. The phosphoinositide 3-kinase (PI3K) signaling pathway preserves HR steady state. We hypothesized that in BRCA-proficient triple-negative breast cancer (TNBC), PI3K inhibition would result in HR impairment and subsequent sensitization to PARP inhibitors. We show in TNBC cells that PI3K inhibition leads to DNA damage, downregulation of BRCA1/2, gain in poly-ADP-ribosylation, and subsequent sensitization to PARP inhibition. In TNBC patient-derived primary tumor xenografts, dual PI3K and PARP inhibition with BKM120 and olaparib reduced the growth of tumors displaying BRCA1/2 downregulation following PI3K inhibition. PI3K-mediated BRCA downregulation was accompanied by extracellular signal-regulated kinase (ERK) phosphorylation. Overexpression of an active form of MEK1 resulted in ERK activation and downregulation of BRCA1, whereas the MEK inhibitor AZD6244 increased BRCA1/2 expression and reversed the effects of MEK1. We subsequently identified that the ETS1 transcription factor was involved in the ERK-dependent BRCA1/2 downregulation and that knockdown of ETS1 led to increased BRCA1/2 expression, limiting the sensitivity to combined BKM120 and olaparib in 3-dimensional culture.

SIGNIFICANCE

Treatment options are limited for patients with TNBCs. PARP inhibitors have clinical activity restricted to a small subgroup of patients with BRCA mutations. Here, we show that PI3K blockade results in HR impairment and sensitization to PARP inhibition in TNBCs without BRCA mutations, providing a rationale to combine PI3K and PARP inhibitors in this indication. Our findings could greatly expand the number of patients with breast cancer that would benefit from therapy with PARP inhibitors. On the basis of our findings, a clinical trial with BKM120 and olaparib is being initiated in patients with TNBCs.

Concerns on liquid mercury and mercury-containing wastes: a review of the treatment technologies for the safe storage

Due to the adverse effects of mercury on human health and the environment, restrictive legislations and world-wide common efforts are now under way to reduce both the supply and demand of mercury. As a result, all excess Hg must be stored in safe conditions in secure places. This paper is an attempt to review the various treatment technologies types of liquid mercury (Hg(0)) and mercury-containing wastes, which can be used to store these residues in a safe way. The different treatments were classified as a function of the waste treated. The main treatments described are amalgamation, formation of sulfides, thermal treatments, vitrification, soil washing, sulfur polymer stabilization solidification, chemically bonded phosphate ceramics and other encapsulation processes, being highlighted the stabilization/solidification processes that are the treatments that provide better results, according to the consulted bibliography.

Patterns of iodine intake and urinary iodine concentrations during pregnancy and blood thyroid-stimulating hormone concentrations in the newborn progeny

BACKGROUND

Appropriate maternal intake of iodine during pregnancy is essential for maternal thyroxine production and thyroid status of the fetus. It should be possible to enhance iodine intake during pregnancy by using iodine fortified salt or taking iodine supplements. In the present report we determined the status of iodine nutrition in pregnant women who were stratified on the basis of their history of taking or not taking iodized salt or iodine supplements. The study was performed in Toledo (Spain), a region in which prior studies have noted borderline iodine sufficiency. Iodine nutrition was assessed by measuring urinary iodine concentration (UIC) and neonatal thyrotropin (TSH).

METHODS

UIC was measured in 525 pregnant women. They were grouped according to their history of iodine intake. Diet Group 1 patients (n = 69) did not take iodized salt or iodine supplements during pregnancy. Diet Group 2 patients (n = 75) took iodized salt but not iodine supplements during pregnancy. Diet Group 3 patients (n = 381) took iodine supplements during pregnancy. Plasma determinations included TSH, free thyroxine, thyroid peroxidase antibody, and thyroglobulin antibody. UIC was measured in a single urine sample from all the pregnant women. Neonatal TSH was measured in capillary spot blood from all the neonates as part of a screening for congenital metabolic abnormalities.

RESULTS

The median UIC in all subjects was 164 μg/L (interquartile range [IR]: 116-245). The median UICs in Diet Groups 1, 2, and 3 were 134.5 (IR: 90-196), 146 (IR: 103-205), and 183 (IR: 124-261) μg/L, respectively (p = not significant [NS] for Diet Group 1 vs. 2; p < 0.01 for Diet Group 2 vs. 3; all other comparisons NS). The median (IR) TSH of the neonates in all Diet Groups was 1.0 (IR: 0.7-1.6) μU/mL. Only 2 neonates had blood TSH concentrations >5 mU/L. Neonatal blood TSH concentrations were similar in all Diet Groups.

CONCLUSIONS

In a region with a history of borderline iodine deficiency the UICs were below 150 μg/L in a substantial percentage of pregnant women who did not take iodine supplements, regardless of whether or not they took iodized salt. Our results support the use of iodine supplements from the start of the pregnancy, or even before pregnancy in women who live in regions with a history of even small degrees of iodine deficiency. In addition, neonate TSH screening is not the best tool to assess whether the iodine status in populations is ideal.

Use of linezolid in critically ill patients admitted to intensive care units

All indications of linezolid (LZD) in Intensive Care Units (ICU) were included as cases in an observational, prospective and multicentre study. One hundred thirty-nine indications were analyzed. In most cases (92.7%), treatment for nosocomial infections was indicated. The most frequent infection was pneumonia (42.7%), followed by catheter-related bacteraemias (CRB). A total of 58.7% of the indications were empirical and in 45.7% of the cases the cultures confirmed infection by gram-positive cocci (GPC). In 43 cases (31.2%), the indication was made as a rescue measure (mainly due to clinical failure) in patients previously treated with glycopeptides. Of isolated GPC, 70.2% were methicillin-resistant. The cure rate of the population per intent-to-treat was 73.2%. Only one case of thrombocytopenia was recorded. Conclusions. LZD is used with a high degree of diagnostic safety. In the ICU, it is primarily indicated to treat pneumonias and CRB with good clinical and microbiological response. This antibiotic has acted as a good therapeutic resource against clinical failure in infections treated with glycopeptides.

[Practical guideline for the management of adverse events associated with BCG installations]

OBJECTIVES

Morbidity secondary to intravesical Bacillus Calmette-Guèrin (BCG) may present both locally and systemically. Most patients suffer a self-limited irritative voiding syndrome. Often, there are not unified criteria for the management of BCG side effects. After treating more than 500 patients with BCG we developed a practical guideline for the management of its morbidity. We present clearly and schematically the practice guideline we follow in our Center when the patient presents symptoms and morbidity secondary to BCG intravesical installations.

METHODS

We analyze and describe, following the literature and our own experience, the management of adverse events experienced by patients treated with intravesical BCG, since the initial implementation of the protocol for its indication in patients with high risk non-muscle invasive bladder tumors and/or CIS.

RESULTS

Irritative voiding symptoms are among the most frequent symptoms, generally self-limited; but if they persist (> 48 hours) will have the urologist treat them depending on intensity and duration. Macroscopic hematuria is not unfrequent and diminishes with an expectant approach and water intake. But, it may also be a urinary tract infection or residual tumor. A febrile syndrome, if present, is usually self-limited to the first 24-48 hours and below 38.5 degrees C without general status affectation. In cases of persistence and/or sepsis, tuberculostatic treatment and/or corticoids should be started. Other clinical pictures may appear, such as orchyoepididymitis, arthritis, etc.

CONCLUSIONS

Proper diagnosis and treatment of adverse events after BCG therapy are basic to allow intravesical immunotherapy be properly prescribed and managed by urologists, enabling a proper treatment of patients and avoiding the possibility of more severe complications.

Inactivation of Cryptosporidium parvum oocysts in water using ultrasonic treatment

Ultrasound in a liquid phase cause mass and heat transfer across the liquid through cavitational processes which act as nanoreactors to generate unstable mechanical equilibrium. The effect of 1 MHz ultrasound on the inactivation of Cryptosporidium parvum was investigated. Continuous irradiation of ultrasound (20 min) increased temperature due to cavitational phenomena. Ultrasound irradiation of liquid containing C. parvum showed significant quantitative changes in pH, temperature and inactivation of C. parvum (102.7 oocysts killed/s) with a minimum energy consumption (0.05 oocysts/s).

[Cervical adenopathy presentation of adenocarcinoma of prostate]

The metastases of prostate cancer shows the regional lymphatic dissemination, being the cervical lymphatic metastases to infrequent and little reported in Literature. In the present work we contributed a new observation of this organization. We displayed a clinical case with lateral mass cervical left, abdominal pain and diarrheic. When making biopsy of cervical adenopathy reported adenocarcinoma prostate metastases. Colonoscopy with biopsy was made whose results were carcinoma little differentiated infiltrated necrotic center to rectum. The complementary studies demonstrated bilateral aortic adenopathys without injuries in thorax. Within the diagnosis differential of the cervical adenopathys in neck in adult men it must consider the prostate carcinoma, because in an early diagnosis and adapting treatment it can prolong the survive.

Cutaneous metastases in renal cell carcinoma

Cutaneous metastases from a renal cell carcinoma are rarely diagnosed during life. We report a case of renal carcinoma metastatic to the skin that occurred 18 months after kidney removal. The cutaneous metastasis was excised. Cutaneous metastases from urological tumors are uncommon and occur in 1% of the patients, and their clinical appearance may mimic other common dermatological disorders affecting patients with advanced malignancies.

How effective is pre-release nematode control in farm-reared red-legged partridges Alectoris rufa?

Game bird farming is associated with high parasite levels that reduce farm productivity, reduce survival after releasing, and may pose a health risk for natural populations. The efficacy of albendazole (orally, 20 mg kg− 1) was evaluated in farmed red-legged partridges naturally infected with the nematodes Aonchotheca caudinflata and Heterakis gallinarum. In treated birds body condition improved, nematode egg deposition was reduced and the proportion of gravid A. caudinflata females was reduced, but not the overall worm burdens. Albendazole was found to be 36.8% and 17.1% effective against A. caudinflata and H. gallinarum, respectively. These results indicate that the anthelmintic treatment used normally in Spanish partridge farms is not effective enough to avoid the introduction of parasites into the field after release.

Changes in parasite transmission stage excretion after pheasant release

The production of parasite transmission stages was investigated in the faeces of 77 farm-bred ring-necked pheasants (Phasianus colchicus). Coccidian oocysts (Eimeria sp.), and nematode eggs (Heterakis sp., and Capillaria-like eggs) were recovered before and after release but all birds were treated prior to release. Treatment with fenbendazole significantly reduced the abundance of transmission-stage excretion for all parasites, and reduced the prevalence in the case of Eimeria sp. and Heterakis sp. Nonetheless, a significant increase in the excretion abundance for all parasites and in the prevalence of Eimeria sp. and Heterakis sp. was found after release. Eggs of Ascaridia sp. were found only after releasing, suggesting infection ocurred in the wild. A negative relationship was found between the pheasant body condition and Heterakis excretion abundance and a higher abundance of Capillaria sp. eggs in female birds. No significant relationship was found between parasite excretion abundance and pheasant survival. Despite this, results suggest that an increase in the excretion of parasite transmission stages follows the release of captive pheasants into the wild. This can in part explain restocking failures, but also means that autochtonous free-living birds may become exposed to new and potentially harmful pathogens. To avoid these risks it is proposed that improved prophylactic measures should be taken.

[Prevalence of metallo-beta-lactamase in carbapenem resistant Pseudomonas aeruginosa at a university hospital of Buenos Aires City]

The present study was conducted to estimate the prevalence of metallo-beta-lactamases in 91 consecutive carbapenem resistant Pseudomonas aeruginosa isolates, recovered from inpatients at Hospital de Clínicas in Buenos Aires. Both, phenotypic and genotypic methods detected the presence of carbapenemases in 10 (11%) isolates, corresponding to VIM-11 in 7/10 and VIM-2 in the others. Codifying genes were all included in class 1 integrons, upstream genes coding for aminoglycoside modifying enzymes. One hundred percent sensitivity and specificity was achieved by the metallo-beta-lactamases phenotypic screening method using EDTA (1 micromol) disks in the Pseudomonas aeruginosa isolates included in this study. Sensitivity to aztreonam in carbapenem resistant isolates was suspicious of the presence of these enzymes.

A novel mutation (K317M) in the MAPT gene causes FTDP and motor neuron disease

BACKGROUND

Frontotemporal dementia with parkinsonism is often linked to chromosome 17 and is related to mutations in the MAPT gene. In some families the genetic basis is still unknown. The authors report two pedigrees with FTDP-17 harboring a novel mutation (K317M) in exon 11 in the MAPT gene.

METHODS

The authors identified two apparently unrelated pedigrees with an autosomal dominant neurodegenerative condition. Thirteen patients were examined and eight autopsies were performed.

RESULTS

Mean age at onset was 48 years. Mean disease duration was 6 years. Dysarthria often heralded the disease. All cases had parkinsonism and pyramidalism and half of them had amyotrophy. Behavioral or personality changes were not a prominent feature. Cognitive decline appeared late in the evolution. Neuropathologically, a massive degeneration of the substantia nigra without Lewy bodies was a constant finding. A variable degree of frontotemporal atrophy was found. Corticospinal tract degeneration and anterior horn neuron loss were present in six of seven autopsies in which the spinal cord was examined. An extensive deposition of abnormal tau protein in a mixed pattern (neuronal, glial) was observed. Pick's bodies were not seen. Biochemical analysis of tau revealed two bands of 64 and 68 kDa.

CONCLUSION

Genetic analysis revealed the same novel mutation (K317M) in exon 11 of the MAPT gene in both pedigrees. A common haplotype between members of the two pedigrees suggests that they belong to the same family.