P2Y12 protects platelets from apoptosis via PI3k-dependent Bak/Bax inactivation

BACKGROUND

Platelet ADP receptor P2Y(12) is well studied and recognized as a key player in platelet activation, hemostasis and thrombosis. However, the role of P2Y(12) in platelet apoptosis remains unknown.

OBJECTIVES

To evaluate the role of the P2Y(12) receptor in platelet apoptosis.

METHODS

We used flow cytometry and Western blotting to assess apoptotic events in platelets treated with ABT-737 or ABT-263, and stored at 37°C, combined with P2Y(12) receptor antagonists or P2Y(12) -deficient mice.

RESULTS

 P2Y(12) activation attenuated apoptosis induced by ABT-737 in human and mouse platelets in vitro, evidenced by reduced phosphatidylserine (PS) exposure, diminished depolarization of mitochondrial inner transmembrane potential (ΔΨm) and decreased caspase-3 activation. Through increasing the phosphorylation level of Akt and Bad, and changing the interaction between different Bcl-2 family proteins, P2Y(12) activation inactivated Bak/Bax. This antiapoptotic effect could be abolished by P2Y(12) antagonism or PI3K inhibition. We also observed the antiapoptotic effect of P2Y(12) activation in platelets stored at 37°C. P2Y(12) activation improved the impaired activation responses of apoptotic platelets stressed by ABT-737. In platelets from mice dosed with ABT-263 in vivo, clopidogrel or deficiency of P2Y(12) receptor enhanced apoptosis along with increased Bak/Bax activation.

CONCLUSIONS

This study demonstrates that P2Y(12) activation protects platelets from apoptosis via PI3k-dependent Bak/Bax inactivation, which may be physiologically important to counter the proapoptotic challenge. Our findings that P2Y(12) blockade exaggerates platelet apoptosis induced by ABT-263 (Navitoclax) also imply a novel drug interaction of ABT-263 and P2Y(12) antagonists.

Fine mapping and characterization of BPH27, a brown planthopper resistance gene from wild rice (Oryza rufipogon Griff.)

The brown planthopper (Nilaparvata lugens Stål; BPH) is one of the most serious rice pests worldwide. Growing resistant varieties is the most effective way to manage this insect, and wild rice species are a valuable source of resistance genes for developing resistant cultivars. BPH27 derived from an accession of Guangxi wild rice, Oryza rufipogon Griff. (Accession no. 2183, hereafter named GX2183), was primarily mapped to a 17-cM region on the long arm of the chromosome four. In this study, fine mapping of BPH27 was conducted using two BC(1)F(2) populations derived from introgression lines of GX2183. Insect resistance was evaluated in the BC(1)F(2) populations with 6,010 individual offsprings, and 346 resistance extremes were obtained and employed for fine mapping of BPH27. High-resolution linkage analysis defined the BPH27 locus to an 86.3-kb region in Nipponbare. Regarding the sequence information of rice cultivars, Nipponbare and 93-11, all predicted open reading frames (ORFs) in the fine-mapping region have been annotated as 11 types of proteins, and three ORFs encode disease-related proteins. Moreover, the average BPH numbers showed significant differences in 96-120 h after release in comparisons between the preliminary near-isogenic lines (pre-NILs, lines harboring resistance genes) and BaiR54. BPH growth and development were inhibited and survival rates were lower in the pre-NIL plants compared with the recurrent parent BaiR54. The pre-NIL exhibited 50.7% reductions in population growth rates (PGR) compared to BaiR54. The new development in fine mapping of BPH27 will facilitate the efforts to clone this important resistant gene and to use it in BPH-resistance rice breeding.

Controlled clockwise and anticlockwise rotational switching of a molecular motor

The design of artificial molecular machines often takes inspiration from macroscopic machines. However, the parallels between the two systems are often only superficial, because most molecular machines are governed by quantum processes. Previously, rotary molecular motors powered by light and chemical energy have been developed. In electrically driven motors, tunnelling electrons from the tip of a scanning tunnelling microscope have been used to drive the rotation of a simple rotor in a single direction and to move a four-wheeled molecule across a surface. Here, we show that a stand-alone molecular motor adsorbed on a gold surface can be made to rotate in a clockwise or anticlockwise direction by selective inelastic electron tunnelling through different subunits of the motor. Our motor is composed of a tripodal stator for vertical positioning, a five-arm rotor for controlled rotations, and a ruthenium atomic ball bearing connecting the static and rotational parts. The directional rotation arises from sawtooth-like rotational potentials, which are solely determined by the internal molecular structure and are independent of the surface adsorption site.

Post-treatment human papillomavirus status and recurrence rates in patients treated with loop electrosurgical excision procedure conization for cervical intraepithelial neoplasia

PURPOSE OF INVESTIGATION

The aim of the study was to evaluate the rate of human papillomavirus (HPV) infection clearance after loop electrosurgical excision (LEEP) procedure conization for cervical intraepithelial neoplasia (CIN) and the factors related to such clearance and to assess the relation between HPV and recurrence.

MATERIALS AND METHODS

A total 141 patients who underwent LEEP owing to high-risk human papillomavirus (HR-HPV) associated with CIN were involved this study. All patients with negative margins on LEEP specimens were followed up with HPV testing and cervical smear after three, six, nine, and 12 months post-treatment. If necessary, cervical biopsy under colposcopy was performed.

RESULTS

LEEP can effectively eliminate HPV infection. Most patients cleared HPV infection within six months. The persistent HPV infection rates were 44.6%,10.6%, 5.7%, and 2.1% after three, six, nine, and 12 months, respectively. The clearance rates were significantly slower in patients with HPV 16 infection, and not differ significantly by age, parity, and pathologic degree. Patients with persistent HR-HPV infection after treatment had a significantly higher risk for recurrence/residual after LEEP compared to patients with negative HPV infection.

CONCLUSION

The authors concluded that patients who were positive for HPV infection, especially for HPV 16, should be followed up closely after treatment.

Effects of constant and cyclic heat stress on muscle metabolism and meat quality of broiler breast fillet and thigh meat

This study investigated the effects of constant and cyclic heat stress on muscle metabolism and meat quality of broiler breast fillet and thigh meat from 4 to 6 wk of age. Male Arbor Acres (AA) broilers (n = 270, 4 wk old) were raised under different temperature conditions: standard (temperature was 23°C); constant high temperature (temperature was 34°C); and cyclic high temperature (temperature was 36°C from 1000 h to 1600 h and 23°C from 1600 h to 1000 h). On d 42, broilers were stunned and sampled. The results showed that chronic high temperature significantly decreased the proportion of breast muscle and significantly increased the proportion of thigh muscle (P < 0.05). The moisture concentration was significantly higher in the breast muscle of the birds exposed to constant high temperature (P < 0.05), whereas the protein content was significantly lower (P < 0.05) and fat deposition was significantly higher (P < 0.05) in the breast muscle of the birds exposed to constant or diurnal cyclic high temperature than those grown under standard temperature. The breast and thigh muscle of the birds grown under constant high temperature had significantly higher lightness, cook loss, and shear force (P < 0.05) and significantly lower initial pH (pH(i)), ultimate pH (pH(u)), and redness compared with those grown under standard temperature (P < 0.05). The pH(i), pH(u), and redness were significantly lower (P < 0.05) while the lightness and shear force were significantly higher for the breast muscle of the chickens raised under diurnal cyclic high temperature (P < 0.05) than those grown under standard temperature. In contrast, lightness and yellowness of thigh muscle were significantly higher (P < 0.05) in the chickens grown under diurnal cyclic high temperature than under standard temperature. Breast and thigh muscle of broilers exposed to constant high temperature produced higher (P < 0.05) lactic acid and pyruvate kinase activities than those exposed to the standard temperature. These results indicated that chronic heat stress significantly increased lactate production, reduced meat pH value by accelerating meat glycolysis, and eventually reduced meat quality.

Abstract P2-10-15: Evaluation of Prognostic and Predictive Performance of Breast Cancer Index and Its Components in Hormonal Receptor-Positive Breast Cancer Patients: A TransATAC Study

Background: The Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial compared the efficacy and safety of 5 years of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with localized HR+ breast cancer. At a median follow-up of 10 years, a statistically significant improvement with anastrozole vs. tamoxifen for disease-free survival, time to recurrence and time to distant recurrence was observed. The HOXB13:IL17BR gene expression ratio (H/I) quantifies recurrence risk in ER positive (ER+) breast cancer patients and is predictive of benefit from endocrine therapy. Molecular Grade Index (MGI) is a five-gene index that provides quantitative and objective molecular assessment of tumor grade and proliferative status. Breast Cancer Index (BCI) combines H/I and MGI into a continuous risk model that provides a likelihood of distant recurrence in patients treated with endocrine therapy, and efficacy from neoadjuvant chemotherapy. In the current analysis, evaluation of the prognostic and predictive performance of BCI, H/I and MGI in the ATAC study cohort was conducted.

Methods: Under the TransATAC protocol, formalin-fixed, paraffin-embedded (FFPE) blocks of primary tumor were collected from HR+ patients from each monotherapy arm. The current study examined samples collected from the United Kingdom, which constituted 79% of the collection. RNA extracted from 1102 samples from the TransATAC study was amplified, converted to cDNA and subjected to RT-PCR with primers and probes to HOXB13, IL17BR, BUB1A, CENPA, NEK2, RACGAP1 and RRM2. H/I, MGI and BCI were calculated and risk groups were determined using pre-specified cutpoints.

Results: Of 1102 tumor specimens assayed, 29 failed QC criteria, leaving 1073 samples for analysis. Detailed results on the prognostic and predictive performance of BCI, H/I and MGI will be presented. Data on whether BCI and its components provided independent prognostic information in the presence of classical variables, their prognostic value for risk of late recurrence, interaction by treatment arms, and comparative performance vs other models will also be discussed.

Discussion: The ATAC trial has established the long-term efficacy and safety of anastrozole over tamoxifen as initial adjuvant treatment for post-menopausal early stage breast cancer patients. Continued efforts are needed to improve on quantification of residual risk in patients who were treated with endocrine therapy to guide decision-making in selecting additional adjuvant chemotherapy and/or administering extended endocrine treatment. This study will help to establish the strategy to more effectively select patients for adjuvant therapies.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-15.

Abstract P1-07-13: Prognostic relevance of statistically standardized estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in tamoxifen(TAM)-treated NCIC CTG MA.14 patients

Background: Poor inter-laboratory comparability of common clinically used breast cancer biomarkers led to a proposal of statistical standardization (SS) of laboratory results, similar to bone mineral density (BMD) z-scores. This analysis is the first utilization of SS in a trial where all women received TAM.

Methods: MA.14 allocated 667 postmenopausal women to TAM +/− Octreotide LAR (OCT) based on locally determined ER/PR, without HER2 status. At 9.8 yrs median follow-up, the secondary endpoint of relapse-free survival (RFS) had a non-significant hazard ratio (HR) for TAM-OCT to TAM of 0.87 (95% CI 0.63–1.21; p = 0.40). 299 patients who were representative of MA.14 patients by treatment and stratification factors (exact Fisher p-values=0.19–0.90) had their tumors centrally assessed for ER, PR, and HER2 by RT-PCR. Continuous values were used for SS of each biomarker. Univariate (uni) assessment used similar categorizations as those for BMD, assigning ER/PR/HER2 values by number of standard deviations (SD) about the mean (Group 1, z-score ≥1.0 SD below mean; Group 2, z-score &lt;1.0 SD below mean; Group 3, z-score ≤1.0 SD above mean; Group 4, z-score &gt;1.0 SD above mean). A log-rank statistic was used to test for differences between SS biomarker groups with K-M plots for graphical description. Multivariate (multi) effects of SS biomarkers and baseline patient characteristics on RFS were examined with exploratory (un)stratified Cox step-wise forward regression, adding a factor if likelihood ratio criterion was p ≤ 0.05. Sensitivity analyses used a prior external HER2+ cut-point of ≥1.32 SD.

Results: 292 patient samples passing internal analytical quality control were included in this analysis. Uni analyses indicated SS ER was not associated with RFS (p = 0.31). SS PR had a significant uni effect on RFS [p = 0.03; Group 4 compared to Group 1, HR of 0.33 (95% CI 0.12–0.90); Group 3 compared to Group 1, HR of 0.42 (95% CI 0.21–0.83); and Group 2 compared to Group 1 HR of 0.70 (95%CI 0.36–1.37)]. SS HER2 also had a significant uni effect on RFS [p = 0.004; Group 4 compared to Group 1, HR of 0.90 (95% CI 0.37–2.16)]; Group 3 compared to Group 1, HR of 0.39 (95% CI 0.18–0.84); and, Group 2 compared to Group 1, HR of 0.34 (95% CI 0.16–0.70)]. Multi stratified/unstratified Cox models indicated T1 tumours (p = 0.02/p = 0.0002) and higher SS PR (p = 0.02/0.01) were associated with significantly longer RFS; other unstratified results showed that N-ve patients had better RFS (p &lt; .0001), while local ER/PR status did not impact RFS (p &gt; 0.05). The HER2+ cut-point of ≥1.32 SD indicated directionally worse RFS (uni p-value=0.05; multi p-value=0.06).

Discussion: In MA.14, all women received TAM. Local ER/PR status using categorical or semi-quantitative values did not impact RFS. A statistically standardized approach using continuous centralized ER, PR, HER2 by RT-PCR demonstrated that increasing PR values were associated with better RFS. Evaluation in other trials may provide support for this methodology.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-13.

Abstract P1-03-03: milk deposition in women's mammary duct has been a potential risk factor of breast tumor

Background: According to the pathology and general resection specimens, so many patients have breast tumors together with deposited milk. Therefore, we performed this retrospective study to determine the distribution and characteristics of breast diseases in women undergoing mammary ductoscopy and explore the clinical values and implications of mammary ductoscopy in the management of the breast diseases.

Materials & Methods: Total of 10,082 women(20,082 breasts) with a mean age of 39.2 years old (ranging from 12 to 84 years old) underwent mammary ductoscopy from 2002 to 2011. We studied NSND in contrast with SND duct, specially focused on the situation of duct with intraductal mass. Comparing with the pathology, we studied the relationship between duct milk deposition and epithelial hyperplasia.

Results: From this study we concluded that duct milk deposition was a common disease in 25–59 years old women, it occupied 42.89% cases of the mammary ductal disease and almost 46% are NSND. The character of deposited milk became solid from liquid with the age growing up. Duct milk deposition 476/1431(33.26%)was mostly associated with intraductal masses(total 1431 cases), followed by duct dilatation 517/1431(36.13%). Pathology of patients diagnosed by FDS for duct milk deposition are epithelial hyperplasia(100%), adenosis(86.5%), chronic inflammation(8.8%), metaplasia(16.9), florid hyperplasia(10.8%), tumor-like hyperplasia (57.2%), intraductal tumor or fibroadenoma (27.8%), dysplasia (3.0%), breast cancer (11.7%).

Abstract OT2-2-03: Dovitinib (TKI258) or placebo in combination with fulvestrant in postmenopausal, endocrine-resistant HER2–/HR+ breast cancer: a phase II study

Background: Overcoming endocrine resistance is a critical goal in the treatment of hormone receptor-positive (HR+) breast cancer. Molecular mechanisms associated with endocrine resistance include adaptive cross-talk between the estrogen receptor and the fibroblast growth factor receptor (FGFR). Up to 8% of HR+/ human epidermal growth factor receptor 2 negative (HER2–) breast cancer patients have amplification of the FGFR1 gene, which is associated with resistance to endocrine therapy. In preclinical models, resistance to endocrine therapy can be overcome via FGFR1 inhibition. Dovitinib is a potent oral inhibitor of receptor tyrosine kinases, including FGFR, vascular endothelial growth factor receptor (VEGFR), and platelet derived growth factor receptor (PDGFR), that demonstrated antitumor activity in heavily pretreated breast cancer patients with FGF-pathway amplification (FGFR1, FGFR2, or ligand FGF3; Andre et al, ASCO 2011). Dovitinib may reverse resistance to endocrine therapy related to FGF-pathway amplification and may also inhibit angiogenesis, which plays an essential role in breast cancer development. Dovitinib is studied here in combination with fulvestrant to determine if it can improve outcomes in postmenopausal patients with endocrine resistant HER2−/HR+ breast cancer.

Methods: This is a multicenter, randomized, double-blind, placebo-controlled, phase II trial that will enroll postmenopausal HER2–/HR+ locally advanced or metastatic breast cancer patients (N ≈ 150) progressing within 12 months of completion of adjuvant endocrine therapy or after ≤ 1 prior endocrine therapy in the advanced setting. Patients prospectively undergo molecular screening to enrich for FGF amplification (FGFR1, FGFR2, or FGF3 amplification by qualitative polymerase chain reaction (qPCR); 45 amplified and 30 nonamplified patients per arm). Patients are randomized 1:1 (stratified by FGF-amplification and presence of visceral disease) to receive fulvestrant intramuscularly (500 mg q4w [with an additional dose 2 weeks after the initial dose]) in combination with oral dovitinib (500 mg, 5 days on/2 days off) or placebo until disease progression, unacceptable toxicity, death or discontinuation due to any reason (eg, withdrawal). Crossover is not permitted. The primary endpoint is progression-free survival, with tumor assessments performed q8w. Secondary endpoints include overall response rate per RECIST v1.1, duration of response, overall survival, Eastern Cooperative Oncology Group performance status and patient-reported outcome scores over time, and safety. Additionally, the pharmacodynamic effect of dovitinib on FGFR-associated angiogenic pathways in tumor specimens and potential predictive biomarkers of response to dovitinib will be explored.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT2-2-03.

Abstract P4-06-18: Targeting basal-like breast cancer through downstream effectors of oncogene cooperation

Basal-like breast cancer is a highly aggressive and lethal form of cancer, not amenable to treatment by molecularly targeted agents or conventional chemotherapy effective against other forms of breast cancer. Thus, discovery of novel intervention targets regulating tumorigenesis in basal-like breast cancer cells is critical. The success of molecularly targeted therapies against some forms of cancer has led to a search for additional cancer cell-specific targets that will permit effective tumor inhibition with minimal damage to normal cells. These efforts are largely focused on identification of novel oncogenes and tumor suppressors by genome sequencing or synthetic lethalities found via genome-wide RNAi screens. We employ a novel approach to identify cancer cell vulnerabilities among genes disregulated downstream of cooperating oncogenic mutations, which drive malignant transformation in large part through synergistic modulation of non-mutated downstream effector genes, the ‘cooperation response genes’ (CRGs) [McMurray et al., Nature, 19 June 2008]. After assessing how common was CRG disregulation in different epithelial cancers, via comparative genomic analysis of CRG expression patterns in tumor vs. normal tissue, we found that 34 CRGs (∼35%) were significantly disregulated in breast cancer. Because of the need for novel intervention targets in basal-like breast cancer, we focused our functional analysis there. We have tested a subset of CRGs disregulated in breast tumors for their contribution to malignancy in basal-like breast cancer cells, re-setting CRG levels toward normal cell levels by stable cDNA expression or shRNA-mediated knock-down and testing tumor formation capacity of perturbed cells. Our studies reveal that CRGs play an essential role in controlling tumor formation of basal-like breast cancer cells, with significant reductions in tumor volume, and in some cases reduced tumor incidence, upon CRG modulation. Disruption of cell behavior appears to be limited to cancer cells, as non-transformed mammary cells harboring analogous perturbations retain capacity to form acinar structures in 3D culture. Several FDA approved pharmacological agents, identified to reverse the CRG expression pattern, display inhibitory effects on basal-like breast cancer cell lines, with minimal effects on non-transformed cells. CRGs thus represent cancer cell-specific vulnerabilities in basal-like breast cancer, providing novel and unexpected opportunities for intervention against this difficult-to-target disease.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-06-18.