Abstract P2-11-09: A p53-based strategy for protecting normal breast tissue from chemotherapy-induced damage in breast conserving therapy

Introduction: Currently, the global rate of breast conserving therapy (BCT) increased steadily. Most patients with BCT are treated with chemotherapy. However, most chemotherapeutical drugs that kill cancer cells also cause undesirable injuries to normal breast tissues. Normal breast tissue damage will further cause destruction of female secondary sex characteristics, and ultimately affect the quality of patients' lives. Therefore, it is urgent to protect the normal breast tissues for BCT patients during chemotherapy. More and more evidence shows that chemotherapy-induced normal tissue damage is mainly caused by the activation of p53 pathway, which is separate from the tumor suppressor pathway of p53. Previous studies found that use of low-dose arsenic (LDA) could temporarily and reversibly suppresses p53 activation. There are recent studies showing LDA selectively protect bone marrow and gastrointestinal tract during cancer treatment. Therefore, we hypothesize that use of LDA to temporary inhibit p53 activity will be a new strategy to protect the breast normal tissues for breast conserving patients.

Methods: Human breast epithelial cell line, MCF-10A, and three breast cancer cell lines MCF-7 (estrogen receptor and E6 expressed), MDA-MB-231 (triple negative and p53 mutated) and BT-474 (HER2 overexpressed and p53 mutated), were tested in this study. All cells were pretreated with either PBS or 100nM sodium arsenite for 12 hours, followed by 375 μM 5-fluorouracil (5-FU) or DMSO for 24, 48 and 72 hours. Cellular viability was determined by MTT assay and cell morphology was recorded under a light microscope.

Results: Morphology changes after 5-FU treatment include: the cell density decreased, the cells became rounded in shape, the cell membrane atrophied, the cell nuclei underwent pyknosis, and the cells formed a globule with nuclear and cytoplasmic fragments surrounded by the cell membrane. LDA pretreated-MCF10A cells showed significant reduced growth inhibition by 5-FU at all detected time pointes as demonstrated by MTT assay and morphology observation. Interestingly, LDA treatment had negligible effect on survival in breast cancer cells.

Table 1. Cell growth evaluated by MTT assay.Time after 5-FU treatment(h)Cell lineControl (%)LDA (%)5-FU (%)LDA+5-FU (%)24MCF-10A10099.3051.3878.28 MCF-710097.3268.5165.64 MDA-MB-23110094.9669.5669.13 BT-47410098.7971.5071.5948MCF-10A10097.3729.1347.74 MCF-710091.7649.9148.95 MDA-MB-23110093.769.048.81 BT-47410092.0460.4361.0072MCF-10A10096.3418.3443.64 MCF-710091.0142.0039.40 MDA-MB-23110093.596.445.39 BT-47410091.4635.7636.95

Conclusion: Temporary LDA pretreatment selectively protected normal tissue cells, but not tumor cells from toxicity of 5-FU chemotherapy. Our findings indicated that LDA pretreatment is a potential strategy to protect normal breast tissue during chemotherapy for BCT patients.

RL and HS contributed equally to this work.

Citation Format: Long M, Huang Y, Liu R, Liu R, Su H. A p53-based strategy for protecting normal breast tissue from chemotherapy-induced damage in breast conserving therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-11-09.

Kinematic Analysis of 7-DOF Manipulators

This article presents a kinematic analysis of seven-degree-of- freedom serial link spatial manipulators with revolute joints. To uniquely determine the joint angles for a given end-effector position and orientation, the redundancy is parameterized by a scalar variable that defines the angle between the arm plane and a reference plane. The forward kinematic mappings from joint space to end-effector coordinates and arm angle and the augmented Jacobian matrix that gives end-effector and arm angle rates as functions of joint rates are presented. Conditions under which the augmented Jacobian becomes singular are also given and are shown to correspond to the arm being either at a kinematically singular configuration or at a nonsingular configuration for which the arm angle ceases to parameterize the redundancy.

Abstract P5-03-12: Selenocystine inhibits triple-negative breast cancer cell proliferation by inducing cell apoptosis and S-phase arrest

Introduction: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited effective treatment options. New therapeutic approaches are urgently needed to improve the prognosis of TNBC. Reactive oxygen species (ROS) are inherent byproducts of oxidative metabolism, and forced stimulation of glucose oxidation in cancer cells raises oxidative stress and sensitizes cells to different stresses. Therefore, targeting the antioxidant capacity of cancer cells has become a promising anticancer strategy. As a redox modulator, selenocystine (SeC) has received a great deal of attention and has been shown effective against human melanoma, hormone receptor-positive breast cancer, and cancers of liver, lung and cervical in vitro. However, whether SeC exerts an anticancer effect on TNBC cells has never been explored.

Methods: The dose-response effects and time course of effects of SeC on three different TNBC cell lines, MDA-MB-231, MDA-MB-436 and MDA-MB-468, were investigated in this study. Cellular viability was determined by the CCK-8 assay and cell morphology were recorded under a light microscope. Cellular apoptosis was detected using Annexin V/PI staining assay and cell cycle distribution was analyzed by flow cytometry.

Results: SeC induced cell growth inhibition in all three TNBC cell lines. For 24, 48 and 72 hours of SeC treatments, the IC50 values were 40.8, 12.8 and 9.2 μM for MDA-MB-231 cells; 14.6, 5.4 and 3.0 μM for MDA-MB-436 cells; and 69.6, 29.3 and 19.9 μM for MDA-MB-468 cells. The changes of cellular morphology of TNBC cells in response to SeC treatment were similar to those cells undergoing apoptotic pathway. This result was confirmed by Annexin V/PI staining assays (Table 1). Cell cycle analysis further revealed that SeC also induced S-phase arrest in a dose-dependent manner (Table 2).

Conclusion: In summary, SeC inhibited TNBC cell viability in a dose- and time-dependent manner which was attributed to the induction of apoptosis and S-phase arrest. Our finding indicates that SeC is a potential therapeutic agent for TNBC.

Table 1. Apoptotic rate of TNBC cells after SeC treatment.Conc.(μM)MDA-MB-231MDA-MB-436MDA-MB-46805.8 %18.1 %26.7 %1025.5 %45.8 %60.7 %2040.1 %67.1 %70.9 %4054.7 %70.7 %74.5 %

Table 2. SeC induces S-phase arrest in TNBC cells in a dose-dependent manner. Conc.(μM)G0/G1 (%)S (%)G2/M (%)MDA-MB-231016.655.927.5 1050.139.310.6 2045.548.16.4 4041.753.05.3MDA-MB-436042.127.630.3 1036.335.028.7 2034.340.725.0 4032.445.422.2MDA-MB-468059.123.717.2 1054.929.315.8 2050.135.714.2 4043.843.113.1

Citation Format: Long M, Qiu W, Wu J, Liu R, Su H. Selenocystine inhibits triple-negative breast cancer cell proliferation by inducing cell apoptosis and S-phase arrest. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-03-12.

Subclinical hypothyroidism and the associations with macrovascular complications and chronic kidney disease in patients with Type 2 diabetes

AIMS

The prevalence of subclinical hypothyroidism (SCH) is high among patients with diabetes, although the relationship between SCH and diabetic vascular complications is unknown. This study aimed to determine the relationship between SCH and vascular complications in patients with Type 2 diabetes.

METHODS

In this cross sectional study, 991 patients with Type 2 diabetes were screened for thyroid function at their admission to the Second Affiliated Hospital of Chongqing Medical University. We compared the prevalence of coronary heart disease (CHD), ischaemic stroke and chronic kidney disease (CKD) with the prevalence of euthyroidism and SCH.

RESULTS

Among the 991 patients, 126 (12.7%) patients had SCH. The prevalence of CHD was significantly higher in the SCH group than in the euthyroid group (22.2% and 15.0%, respectively; P = 0.039). In the logistic regression analyses, SCH was associated with CHD [odds ratio (OR): 1.993; 95% confidence interval (CI): 1.135-3.497; P = 0.016]. This association was stronger in patients aged ≥ 65 years than in younger patients [2.474 (1.173-5.220); P = 0.017]. No significant association was found between SCH and ischaemic stroke. Patients with severe SCH had a high risk of CKD [1.842 (1.120-3.029); P = 0.016].

CONCLUSIONS

This study provides evidence that SCH in patients with Type 2 diabetes is associated with a high prevalence of CHD (and CKD in severe SCH), although not with ischaemic stroke.

Validity and reliability of eye healthcare professionals in the assessment of glaucoma - a systematic review

OBJECTIVE(S)

To explore the validity and reliability of eye healthcare professionals with different levels of training in diagnosing and/or identifying glaucomatous progression.

CLINICAL RELEVANCE

Substantial pressure is being placed on our current eye healthcare workforce by chronic diseases such as glaucoma. Shared care schemes and role expansion of professionals other than ophthalmologists are being proposed to alleviate this pressure. A sound evidence base is imperative to determine whether other allied health professionals are skilled and clinically competent, when it comes to taking on these new roles in glaucoma management.

METHODS

A systematic review of research articles identified in MEDLINE, CINAHL, Embase, Scopus and Cochrane Library was performed. Studies which investigated rater reliability of various health professionals in diagnosing and/or identifying glaucoma progression against a reference standard were included.

RESULTS

Of the 4088 publications identified by the initial database search, 32 met the inclusion criteria. The majority of studies demonstrated positive results, with most finding moderate to substantial agreement for inter- and intra-rater reliability across all testing modalities. The eye health professionals with ophthalmology training consistently attained the greatest agreement. When allied health professionals with different levels of training were compared, those who had completed residency training were significantly better than those who had not.

CONCLUSION

The studies included in this review show promising results, including those raters without ophthalmology training. A lack of power calculations, unequal sample sizes in some studies and the diversity of the testing procedures used make it difficult to make sound inferences.

Antimicrobial and disinfectant resistance of Escherichia coli isolated from giant pandas

AIMS

The study aims to demonstrate the antimicrobial and disinfectant resistance phenotypes and genotypes of Escherichia coli isolates obtained from giant pandas (Ailuropoda melanoleuca).

METHODS AND RESULTS

Antimicrobial testing was performed according to the standard disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of antimicrobial and disinfectant resistance genes and further analysed for genetic relatedness by pulse-field gel electrophoresis (PFGE). Results showed that 46·6% of the isolates were resistant to at least one antimicrobial. Escherichia coli isolates showed resistance to fewer antimicrobials as panda age increased. Among antimicrobial-resistant E. coli isolates, the antimicrobial resistance genes blaCTX-M (88·2%) and sul1 (92·3%) were most prevalent. The disinfectant resistance genes emrE, ydgE/ydgF, mdfA and sugE(c) were commonly present (68·2-98·9%), whereas qac and sugE(p) were relatively less prevalent (0-21·3%). The frequencies of resistance genes tended to be higher in E. coli isolated in December than in July, and PFGE profiles were also more diverse in isolates in December. The qacEΔ1 and sugE(p) genes were higher in adolescent pandas than in any other age groups. PFGE revealed that antimicrobial resistance correlated well with sampling time and habitat.

CONCLUSIONS

This study demonstrated that antimicrobial and disinfectant resistance was common in giant panda-derived E. coli, and the antimicrobial resistance was associated with sampling time and habitat. Escherichia coli could serve as a critical vector in spreading disinfectant and antimicrobial resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The study highlights the need for regularly monitoring the antimicrobial and disinfectant resistance in bacteria from giant pandas.

Morphologic control of Sb-rich Sb2Se3 to adjust its catalytic hydrogenation properties for p-nitrophenol

Sb-rich Sb₂Se₃ with hollow sphere morphology is an efficient catalyst for the hydrogenation of p-nitrophenol.

Five days of head-down-tilt bed rest induces noninflammatory shedding of L-selectin

Head-down-tilt bed rest (HDTBR) is a popular model, simulating alterations of gravitation during space missions. The aim of this study was to obtain a better insight into the complexly orchestrated regulations of HDTBR-induced immunological responses, hypothesizing that artificial gravity can mitigate these HDTBR-related physiological effects. This crossover-designed 5 days of HDTBR study included three protocols with no, or daily 30 min of centrifugation or 6 × 5 min of centrifugation. Twelve healthy, male participants donated blood pre-HDTBR, post-HDTBR, and twice during HDTBR. Cellular immune changes were assessed either by enumerative and immune cell phenotyping assays or by functional testing of responses to either recall antigens or receptor-dependent activation by chemotactic agents N-formyl-methionyl-leucyl-phenylalanine (fMLP) and with TNF-α. The expression of the adhesion molecule L-selectin (CD62L) on the surface of granulocytes and its shedding into plasma samples were measured. In parallel, other humoral factor, such as interleukin-6 and interleukin-8, parameters of endothelial damage (glycocalyx) were determined. Hematocrit and hemoglobin were significantly increased during HDTBR. Although immune functional tests did not indicate a change in the immune performance, the expression of CD62L on resting granulocytes was significantly shed by 50% during HDTBR. Although the latter is normally associated to an activation of inflammatory innate immune responses and during interaction of granulocytes with the endothelium, CD62L shedding was, however, not related either to a systemic inflammatory alteration or to shedding of the endothelial glycocalyx during bed rest. This suggests a noninflammatory or “mechanical” shedding related to fluid shifts during head-down intervention and not to an acute inflammatory process.

Elevated snoRNA biogenesis is essential in breast cancer

Hyperactive ribosomal biogenesis is widely observed in cancer, which has been partly attributed to the increased rDNA transcription by Pol I in cancer. However, whether small nucleolar RNAs (snoRNAs), a class of non-coding RNAs crucial in ribosomal RNA (rRNA) maturation and functionality, are involved in cancer remains elusive. We report that snoRNAs and fibrillarin (FBL, an enzymatic small nucleolar ribonucleoprotein, snoRNP) are frequently overexpressed in both murine and human breast cancer as well as in prostate cancers, and significantly, that this overexpression is essential for tumorigenicity in vitro and in vivo. We demonstrate that when the elevated snoRNA pathway is suppressed, the tumor suppressor p53 can act as a sentinel of snoRNP perturbation, the activation of which mediates the growth inhibitory effect. On the other hand, high level of FBL interferes with the activation of p53 by stress. We further show that p53 activation by FBL knockdown is not only regulated by the ribosomal protein-MDM2-mediated protein stabilization pathway, but also by enhanced PTB-dependent, cap-independent translation. Together, our data uncover an essential role of deregulated snoRNA biogenesis in tumors and a new mechanism of nucleolar modulation of p53.

We are all in this together: working towards a holistic understanding of self-harm

Self-harm is a widespread and controversial issue in contemporary society. Statistics are based on reported incidents and therefore do not accurately reveal prevalence, as self-harm is often a hidden behaviour. This highlights the essential need for practitioners and society to work towards reducing the stigma surrounding self-harm. This paper goes some way towards understanding the impact of self-harm on individuals and communities. It begins by exploring terminologies and definitions of self-harm and discusses the importance of sensitivity in language use relating to self-harm. It continues by examining types of self-harm and subsequently presents life experiences that may contribute to the onset of self-harm. The paper elucidates the cultural, historical and religious origins of self-harm, indicating the ways in which self-harm has evolved with us as part of our humanity. Moreover, literature relating to the significance of stigma and attitudes is examined, followed by issues around psychiatric diagnoses pertaining to self-harm. The paper concludes by synthesizing literature relevant to the relationship between self-harm and suicide.

Alterations of fatty acid β-oxidation capability in the liver of ketotic cows

Dairy cows are highly susceptible to ketosis after parturition. In the present study, we evaluated the expression of fatty acid β-oxidation-related enzymes in the liver of ketotic (n=6) and nonketotic (n=6) cows. Serum levels of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and glucose were determined by using standard biochemical techniques. The mRNA abundance and protein content of acyl-CoA synthetase long-chain (ACSL), carnitine palmitoyltransferase I (CPT I), carnitine palmitoyltransferase II (CPT II), acyl-CoA dehydrogenase long chain (ACADL), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS), and acetyl-CoA carboxylase (ACC) were evaluated by real-time PCR and ELISA. We found that serum glucose levels were lower in ketotic cows than in nonketotic cows, but serum BHBA and NEFA concentrations were higher. Messenger RNA and protein levels of ACSL were significantly higher in livers of ketotic cows than those in nonketotic cows. In contrast, mRNA levels of CPT I and mRNA and protein levels of CPT II, ACADL, HMGCS, and ACC were decreased in the liver of ketotic cows. Serum NEFA concentration positively correlated with ACSL protein levels and negatively correlated with protein levels of CPT II, HMGCS, ACADL, and ACC. In addition, serum BHBA concentration negatively correlated with protein levels of CPT II, HMGCS, and ACADL. Overall, fatty acid β-oxidation capability was altered in the liver of ketotic compared with nonketotic cows. Furthermore, high serum NEFA and BHBA concentrations play key roles in affecting pathways of fatty acid metabolism in the liver.