Sudden Unexpected Postnatal Collapse: Review and Management

Sudden unexpected postnatal collapse (SUPC) of healthy newborns is a catastrophic event caused by cardiorespiratory collapse in a healthy newborn. The most common cause of SUPC is poor positioning of the newborn during skin-to-skin contact or breastfeeding when the newborn is not being observed by a health professional, attentive parent, or caretaker. Maternal/newborn health care professionals need to know about the essential information, definitions, incidence, risk factors, clinical presentation, outcomes, and prevention and management strategies to minimize the occurrence and impact of SUPC. A sample SUPC hospital policy is included in the manuscript.

Prevalence, predictors and outcomes of thyroid dysfunction in patients with acute myocardial infarction: the ThyrAMI-1 study

PURPOSE

Thyroid dysfunction in patients with cardiac disease is associated with worse outcomes. This study aimed to evaluate the prevalence and analyse predictors and outcomes of thyroid dysfunction in patients presenting with an acute myocardial infarction (AMI).

METHODS

A prospective multicentre observational study of patients recruited from six acute hospitals within the North of England. Consecutive patients without previous thyroid disease presenting with both ST-elevation AMI (STEMI) and non-ST-elevation AMI (NSTEMI) were recruited to the Thyroxine in Acute Myocardial Infarction 1 (ThyrAMI-1) cohort study between December 2014 and 2016. Thyroid profile, standard biochemistry measurements and demographic information were obtained within 12 h of admission to hospital. Multivariable logistic regression analyses were performed to assess the predictors of thyroid dysfunction and Cox proportional hazards analyses were utilised to compare all-cause mortality by categories of thyroid dysfunction up to June 2019.

RESULTS

Of the 1802 participants analysed, 1440 (79.9%) were euthyroid, 312 (17.3%) had subclinical hypothyroidism (SCH), 22 (1.2%) had subclinical hyperthyroidism (SHyper) and 25 (1.3%) had low T3 syndrome (LT3S). Predictors for SCH were increasing age, female sex, higher thyroid peroxidase antibody (TPOAb) levels, higher serum creatinine levels and early morning sampling time (between 00:01-06:00 h). The predictors of SHyper were lower body mass index and afternoon sampling time (between 12:01 and 18:00 h). Predictors of LT3S were increasing age, higher creatinine levels and presence of previous ischaemic heart disease. Compared to the euthyroid group, patients with LT3S had higher all-cause mortality; adjusted hazard ratio (95% CI) of 2.02 (1.03-3.95), p = 0.04, whereas those with SCH and SHyper did not exhibit significantly increased mortality; adjusted hazard ratios (95% CI) of 1.05 (0.74-1.49), p = 0.79 and 0.27 (0.04-1.95), p = 0.19, respectively.

CONCLUSIONS

Thyroid dysfunction is common in AMI patients on admission to hospital and our data provide an understanding regarding which factors might influence thyroid dysfunction in these patients. Furthermore, the negative association between LT3S and increased mortality post-AMI has once again been highlighted by this study. More research is required to assess if treatment of thyroid dysfunction improves clinical outcomes.

Targeting Hypoxia Sensitizes TNBC to Cisplatin and Promotes Inhibition of Both Bulk and Cancer Stem Cells

Development of targeted therapies for triple-negative breast cancer (TNBC) is an unmet medical need. Cisplatin has demonstrated its promising potential for the treatment of TNBC in clinical trials; however, cisplatin treatment is associated with hypoxia that, in turn, promotes cancer stem cell (CSC) enrichment and drug resistance. Therapeutic approaches to attenuate this may lead to increased cisplatin efficacy in the clinic for the treatment of TNBC. In this report we analyzed clinical datasets of TNBC and found that TNBC patients possessed higher levels of EGFR and hypoxia gene expression. A similar expression pattern was also observed in cisplatin-resistant ovarian cancer cells. We, thus, developed a new therapeutic approach to inhibit EGFR and hypoxia by combination treatment with metformin and gefitinib that sensitized TNBC cells to cisplatin and led to the inhibition of both CD44+/CD24− and ALDH+ CSCs. We demonstrated a similar inhibition efficacy on organotypic cultures of TNBC patient samples ex vivo. Since these drugs have already been used frequently in the clinic; this study illustrates a novel, clinically translatable therapeutic approach to treat patients with TNBC.

The plasma peptides of breast versus ovarian cancer

Background

There is a need to demonstrate a proof of principle that proteomics has the capacity to analyze plasma from breast cancer versus other diseases and controls in a multisite clinical trial design. The peptides or proteins that show a high observation frequency, and/or precursor intensity, specific to breast cancer plasma might be discovered by comparison to other diseases and matched controls. The endogenous tryptic peptides of breast cancer plasma were compared to ovarian cancer, female normal, sepsis, heart attack, Alzheimer's and multiple sclerosis along with the institution-matched normal and control samples collected directly onto ice.

Methods

Endogenous tryptic peptides were extracted from individual breast cancer and control EDTA plasma samples in a step gradient of acetonitrile, and collected over preparative C18 for LC-ESI-MS/MS with a set of LTQ XL linear quadrupole ion traps working together in parallel to randomly and independently sample clinical populations. The MS/MS spectra were fit to fully tryptic peptides or phosphopeptides within proteins using the X!TANDEM algorithm. The protein observation frequency was counted using the SEQUEST algorithm after selecting the single best charge state and peptide sequence for each MS/MS spectra. The observation frequency was subsequently tested by Chi Square analysis. The log₁₀ precursor intensity was compared by ANOVA in the R statistical system.

Results

Peptides and/or phosphopeptides of common plasma proteins such as APOE, C4A, C4B, C3, APOA1, APOC2, APOC4, ITIH3 and ITIH4 showed increased observation frequency and/or precursor intensity in breast cancer. Many cellular proteins also showed large changes in frequency by Chi Square (χ² > 100, p < 0.0001) in the breast cancer samples such as CPEB1, LTBP4, HIF-1A, IGHE, RAB44, NEFM, C19orf82, SLC35B1, 1D12A, C8orf34, HIF1A, OCLN, EYA1, HLA-DRB1, LARS, PTPDC1, WWC1, ZNF562, PTMA, MGAT1, NDUFA1, NOGOC, OR1E1, OR1E2, CFI, HSA12, GCSH, ELTD1, TBX15, NR2C2, FLJ00045, PDLIM1, GALNT9, ASH2L, PPFIBP1, LRRC4B, SLCO3A1, BHMT2, CS, FAM188B2, LGALS7, SAT2, SFRS8, SLC22A12, WNT9B, SLC2A4, ZNF101, WT1, CCDC47, ERLIN1, SPFH1, EID2, THOC1, DDX47, MREG, PTPRE, EMILIN1, DKFZp779G1236 and MAP3K8 among others. The protein gene symbols with large Chi Square values were significantly enriched in proteins that showed a complex set of previously established functional and structural relationships by STRING analysis. An increase in mean precursor intensity of peptides was observed for QSER1 as well as SLC35B1, IQCJ-SCHIP1, MREG, BHMT2, LGALS7, THOC1, ANXA4, DHDDS, SAT2, PTMA and FYCO1 among others. In contrast, the QSER1 peptide QPKVKAEPPPK was apparently specific to ovarian cancer.

Conclusion

There was striking agreement between the breast cancer plasma peptides and proteins discovered by LC-ESI-MS/MS with previous biomarkers from tumors, cells lines or body fluids by genetic or biochemical methods. The results indicate that variation in plasma peptides from breast cancer versus ovarian cancer may be directly discovered by LC-ESI-MS/MS that will be a powerful tool for clinical research. It may be possible to use a battery of sensitive and robust linear quadrupole ion traps for random and independent sampling of plasma from a multisite clinical trial.

The plasma peptides of ovarian cancer

Background

It may be possible to discover new diagnostic or therapeutic peptides or proteins from blood plasma by using liquid chromatography and tandem mass spectrometry to identify, quantify and compare the peptides cleaved ex vivo from different clinical populations. The endogenous tryptic peptides of ovarian cancer plasma were compared to breast cancer and female cancer normal controls, other diseases with their matched or normal controls, plus ice cold plasma to control for pre-analytical variation.

Methods

The endogenous tryptic peptides or tryptic phospho peptides (i.e. without exogenous digestion) were analyzed from 200 μl of EDTA plasma. The plasma peptides were extracted by a step gradient of organic/water with differential centrifugation, dried, and collected over C18 for analytical HPLC nano electrospray ionization and tandem mass spectrometry (LC–ESI–MS/MS) with a linear quadrupole ion trap. The endogenous peptides of ovarian cancer were compared to multiple disease and normal samples from different institutions alongside ice cold controls. Peptides were randomly and independently sampled by LC–ESI–MS/MS. Precursor ions from peptides > E4 counts were identified by the SEQUEST and X!TANDEM algorithms, filtered in SQL Server, before testing of frequency counts by Chi Square (χ²), for analysis with the STRING algorithm, and comparison of precursor intensity by ANOVA in the R statistical system with the Tukey-Kramer Honestly Significant Difference (HSD) test.

Results

Peptides and/or phosphopeptides of common plasma proteins such as HPR, HP, HPX, and SERPINA1 showed increased observation frequency and/or precursor intensity in ovarian cancer. Many cellular proteins showed large changes in frequency by Chi Square (χ² > 60, p < 0.0001) in the ovarian cancer samples such as ZNF91, ZNF254, F13A1, LOC102723511, ZNF253, QSER1, P4HA1, GPC6, LMNB2, PYGB, NBR1, CCNI2, LOC101930455, TRPM5, IGSF1, ITGB1, CHD6, SIRT1, NEFM, SKOR2, SUPT20HL1, PLCE1, CCDC148, CPSF3, MORN3, NMI, XTP11, LOC101927572, SMC5, SEMA6B, LOXL3, SEZ6L2, and DHCR24. The protein gene symbols with large Chi Square values were significantly enriched in proteins that showed a complex set of previously established functional and structural relationships by STRING analysis. Analysis of the frequently observed proteins by ANOVA confirmed increases in mean precursor intensity in ZFN91, TRPM5, SIRT1, CHD6, RIMS1, LOC101930455 (XP_005275896), CCDC37 and GIMAP4 between ovarian cancer versus normal female and other diseases or controls by the Tukey–Kramer HSD test.

Conclusion

Here we show that separation of endogenous peptides with a step gradient of organic/water and differential centrifugation followed by random and independent sampling by LC–ESI–MS/MS with analysis of peptide frequency and intensity by SQL Server and R revealed significant difference in the ex vivo cleavage of peptides between ovarian cancer and other clinical treatments. There was striking agreement between the proteins discovered from cancer plasma versus previous biomarkers discovered in tumors by genetic or biochemical methods. The results indicate that variation in plasma proteins from ovarian cancer may be directly discovered by LC–ESI–MS/MS that will be a powerful tool for clinical research.

Electronic supplementary material

The online version of this article (10.1186/s12014-018-9215-z) contains supplementary material, which is available to authorized users.

The plasma peptidome

Background

It may be possible to discover new diagnostic or therapeutic peptides or proteins from blood plasma using LC–ESI–MS/MS to identify, with a linear quadrupole ion trap to identify, quantify and compare the statistical distributions of peptides cleaved ex vivo from plasma samples from different clinical populations.

Methods

A systematic method for the organic fractionation of plasma peptides was applied to identify and quantify the endogenous tryptic peptides from human plasma from multiple institutions by C18 HPLC followed nano electrospray ionization and tandem mass spectrometry (LC–ESI–MS/MS) with a linear quadrupole ion trap. The endogenous tryptic peptides, or tryptic phospho peptides (i.e. without exogenous digestion), were extracted in a mixture of organic solvent and water, dried and collected by preparative C18. The tryptic peptides from 6 institutions with 12 different disease and normal EDTA plasma populations, alongside ice cold controls for pre-analytical variation, were characterized by mass spectrometry. Each patient plasma was precipitated in 90% acetonitrile and the endogenous tryptic peptides extracted by a stepwise gradient of increasing water and then formic acid resulting in 10 sub-fractions. The fractionated peptides were manually collected over preparative C18 and injected for 1508 LC–ESI–MS/MS experiments analyzed in SQL Server R.

Results

Peptides that were cleaved in human plasma by a tryptic activity ex vivo provided convenient and sensitive access to most human proteins in plasma that show differences in the frequency or intensity of proteins observed across populations that may have clinical significance. Combination of step wise organic extraction of 200 μL of plasma with nano electrospray resulted in the confident identification and quantification ~ 14,000 gene symbols by X!TANDEM that is the largest number of blood proteins identified to date and shows that you can monitor the ex vivo proteolysis of most human proteins, including interleukins, from blood. A total of 15,968,550 MS/MS spectra ≥ E4 intensity counts were correlated by the SEQUEST and X!TANDEM algorithms to a federated library of 157,478 protein sequences that were filtered for best charge state (2+ or 3+) and peptide sequence in SQL Server resulting in 1,916,672 distinct best-fit peptide correlations for analysis with the R statistical system. SEQUEST identified some 140,054 protein accessions, or some ~ 26,000 gene symbols, proteins or loci, with at least 5 independent correlations. The X!TANDEM algorithm made at least 5 best fit correlations to more than 14,000 protein gene symbols with p-values and FDR corrected q-values of ~ 0.001 or less. Log₁₀ peptide intensity values showed a Gaussian distribution from E8 to E4 arbitrary counts by quantile plot, and significant variation in average precursor intensity across the disease and controls treatments by ANOVA with means compared by the Tukey–Kramer test. STRING analysis of the top 2000 gene symbols showed a tight association of cellular proteins that were apparently present in the plasma as protein complexes with related cellular components, molecular functions and biological processes.

Conclusions

The random and independent sampling of pre-fractionated blood peptides by LC-ESI-MS/MS with SQL Server-R analysis revealed the largest plasma proteome to date and was a practical method to quantify and compare the frequency or log₁₀ intensity of individual proteins cleaved ex vivo across populations of plasma samples from multiple clinical locations to discover treatment-specific variation using classical statistics suitable for clinical science. It was possible to identify and quantify nearly all human proteins from EDTA plasma and compare the results of thousands of LC–ESI–MS/MS experiments from multiple clinical populations using standard database methods in SQL Server and classical statistical strategies in the R data analysis system.

Electronic supplementary material

The online version of this article (10.1186/s12014-018-9211-3) contains supplementary material, which is available to authorized users.

Dual inhibition of Wnt and Yes-associated protein signaling retards the growth of triple-negative breast cancer in both mesenchymal and epithelial states

Triple‐negative breast cancer (TNBC), the most refractory subtype of breast cancer to current treatments, accounts disproportionately for the majority of breast cancer‐related deaths. This is largely due to cancer plasticity and the development of cancer stem cells (CSCs). Recently, distinct yet interconvertible mesenchymal‐like and epithelial‐like states have been revealed in breast CSCs. Thus, strategies capable of simultaneously inhibiting bulk and CSC populations in both mesenchymal and epithelial states have yet to be developed. Wnt/β‐catenin and Hippo/YAP pathways are crucial in tumorigenesis, but importantly also possess tumor suppressor functions in certain contexts. One possibility is that TNBC cells in epithelial or mesenchymal state may differently affect Wnt/β‐catenin and Hippo/YAP signaling and CSC phenotypes. In this report, we found that YAP signaling and CD44^high/CD24^−/lowCSCs were upregulated while Wnt/β‐catenin signaling and ALDH+ CSCs were downregulated in mesenchymal‐like TNBC cells, and vice versa in their epithelial‐like counterparts. Dual knockdown of YAP and Wnt/β‐catenin, but neither alone, was required for effective suppression of both CD44^high/CD24^−/low and ALDH+ CSC populations in mesenchymal and epithelial TNBC cells. These observations were confirmed with cultured tumor fragments prepared from patients with TNBC after treatment with Wnt inhibitor ICG‐001 and YAP inhibitor simvastatin. In addition, a clinical database showed that decreased gene expression of Wnt and YAP was positively correlated with decreased ALDH and CD44 expression in patients’ samples while increased patient survival. Furthermore, tumor growth of TNBC cells in either epithelial or mesenchymal state was retarded, and both CD44^high/CD24^−/low and ALDH+ CSC subpopulations were diminished in a human xenograft model after dual administration of ICG‐001 and simvastatin. Tumorigenicity was also hampered after secondary transplantation. These data suggest a new therapeutic strategy for TNBC via dual Wnt and YAP inhibition.

Abstract P6-12-11: A randomized, double-blind, placebo-controlled window of opportunity trial evaluating clinical effects of high dose vitamin D in patients with breast cancer

This abstract was withdrawn by the authors.

Strategies for obtaining bone biopsy specimens from breast cancer patients - Past experience and future directions

Background

Cancer and its treatment can have multiple effects on the bone. Despite the widespread use of in vivo and in vitro models, it is still necessary to understand these effects in humans. Obtaining human bone biopsies is technically challenging and in this article we review the experiences from the Ottawa Bone Oncology Program.

Methods

A series of bone biopsy studies in breast cancer patients with and without bone metastasis have been performed. We reviewed the results of these studies and present them in a descriptive manner. We discuss lessons learned from each project and how they have affected future directions for research.

Results

Since 2009, 5 studies have been performed accruing 97 breast cancer patients. Study endpoints have ranged from comparing the yield of malignant cells from CT-guided versus standard iliac crest biopsies, to studies assessing the feasibility of micro-CT analysis on Jedhadi trephines to evaluate bisphosphonate effects on bone micro-architecture. More recently, we have assessed the feasibility of performing repeat bone biopsies in the same patient as well as evaluating the practicality of obtaining bone tissue at the time of orthopaedic surgery.

Conclusion

Human bone tissue is an important biological resource. Our experience suggests that obtaining bone biopsies is feasible and can yield adequate amount of tumour cells for many studies. However, these remain technically challenging specimens to obtain and given the rapid advances in cancer therapeutics and the use of potent adjuvant bone-targeted agents, more centres need to be involved in these types of studies.

Both bulk and cancer stem cell subpopulations in triple-negative breast cancer are susceptible to Wnt, HDAC, and ERα coinhibition

Development of targeted therapies for triple-negative breast cancer (TNBC, a more aggressive subtype) is an unmet medical need. We analyzed data from 887 patients with invasive breast cancer and observed that increased Wnt and histone deacetylase (HDAC) activities are associated with estrogen receptor 1 (ESR1) and progesterone receptor (PGR) repression, poor survival, and increased relapse. The inverse correlation between Wnt signaling and repression of ESR1 and PGR expression was found to be magnified in cancer stem cell (CSC) subpopulations in TNBC cell lines. Cosuppression of Wnt, HDAC, and ESR1 using clinically relevant low-dose inhibitors effectively repressed both bulk and CSC subpopulations and converted CSCs to non-CSCs in TNBC cells without affecting MCF-10A mammary epithelial cells.

Future directions for bone metastasis research - highlights from the 2015 bone and the Oncologist new updates conference (BONUS)

In an era of reduced peer-reviewed grant funding, performing academic bone oncology-related research has become increasingly challenging. Over the last 10 years we have held an annual meeting to bring together clinicians, clinician/scientists and basic biomedical researchers interested in the effects of cancer and its treatment on skeletal tissues. In the past these "Bone and the Oncologist New Updates Conference (BONUS)" meetings have served as critical catalyst for initiating productive research collaborations between attendees. The 2015 BONUS meeting format focused on potential key research themes that could form the basis of a coordinated national research strategy to tackle unmet clinical and research needs related to complications associated with cancer metastasis to bone. The three themes planned for discussion were: Is bone metastases-related pain the main issue facing patients? Are there new therapeutic targets for patients with bone metastases? How do we more firmly link basic science with clinical practice? We present a summary of lectures and commentaries from the attendees to serve as an example that other similarly motivated groups can model and share their experiences. It is our hope that these presentations will result in comments, feedback and suggestions from all those researchers interested in this important area.

Perivascular M2 Macrophages Stimulate Tumor Relapse after Chemotherapy

Tumor relapse after chemotherapy-induced regression is a major clinical problem, because it often involves inoperable metastatic disease. Tumor-associated macrophages (TAM) are known to limit the cytotoxic effects of chemotherapy in preclinical models of cancer. Here, we report that an alternatively activated (M2) subpopulation of TAMs (MRC1(+)TIE2(Hi)CXCR4(Hi)) accumulate around blood vessels in tumors after chemotherapy, where they promote tumor revascularization and relapse, in part, via VEGF-A release. A similar perivascular, M2-related TAM subset was present in human breast carcinomas and bone metastases after chemotherapy. Although a small proportion of M2 TAMs were also present in hypoxic tumor areas, when we genetically ablated their ability to respond to hypoxia via hypoxia-inducible factors 1 and 2, tumor relapse was unaffected. TAMs were the predominant cells expressing immunoreactive CXCR4 in chemotherapy-treated mouse tumors, with the highest levels expressed by MRC1(+) TAMs clustering around the tumor vasculature. Furthermore, the primary CXCR4 ligand, CXCL12, was upregulated in these perivascular sites after chemotherapy, where it was selectively chemotactic for MRC1(+) TAMs. Interestingly, HMOX-1, a marker of oxidative stress, was also upregulated in perivascular areas after chemotherapy. This enzyme generates carbon monoxide from the breakdown of heme, a gas known to upregulate CXCL12. Finally, pharmacologic blockade of CXCR4 selectively reduced M2-related TAMs after chemotherapy, especially those in direct contact with blood vessels, thereby reducing tumor revascularization and regrowth. Our studies rationalize a strategy to leverage chemotherapeutic efficacy by selectively targeting this perivascular, relapse-promoting M2-related TAM cell population.

Treatment choices for patients with invasive lobular breast cancer: a doctor survey

RATIONALE, AIMS AND OBJECTIVES

Invasive lobular breast cancer (ILC) has distinct features that present challenges for management. We surveyed doctors regarding management approaches, opinions on quality of evidence supporting their practice, and future research needs.

METHODS

An online questionnaire was developed and circulated to breast cancer surgical, radiation and medical oncologists.

RESULTS

The questionnaire was completed by 88/428 doctors (20.6%); 22/56 (39.3%) surgeons, 21/64 (32.8%) radiation oncologists and 45/308 (14.6%) medical oncologists. The majority (65%) of surgeons were comfortable treating ILC patients using the same surgical management as patients with invasive ductal cancers (IDC). Furthermore, 25% would perform a similar surgery but would obtain larger gross margins. There was equipoise for radiation oncologists regarding whether or not ILC was an independent risk factor for local-regional recurrence after either breast-conserving surgery or mastectomy. Of those radiation oncologists who believe ILC is an independent risk factor for recurrence after mastectomy, 44.4% would offer radiation in the absence of usual indications. Medical oncologists approached systemic therapy for ILC patients similarly to those with comparable IDCs. Areas identified as most controversial and requiring future research were preoperative magnetic resonance imaging, radiotherapy post-mastectomy and the responsiveness of ILC to adjuvant chemotherapy compared with endocrine therapy.

CONCLUSIONS

There is a variation in doctors' beliefs, management and opinions regarding the quality of evidence for the management of ILC. Clinical trials specifically assessing the management of ILC are required to guide clinical practice.

Invasive Pleomorphic Lobular Carcinoma of the Breast: Pathologic, Clinical, and Therapeutic Considerations

Pleomorphic lobular carcinoma is an uncommon form of breast cancer and a subtype of invasive lobular carcinoma. It has unique histopathologic features that translate to a more aggressive phenotype with an associated poor prognosis. Unlike classical invasive lobular carcinoma, it can lose estrogen and progesterone receptor expression and demonstrate HER-2/neu amplification. It remains to be determined, however, whether the pleomorphic histology independently predicts a worse outcome or whether other known associated negative prognostic factors such as larger tumor size, increased metastatic disease, and associated worse molecular subtypes commonly present in pleomorphic carcinoma account for the poor prognosis. Here we present an updated review of the unique pathologic and clinical features of pleomorphic lobular carcinoma needed to guide management for women with this subtype of cancer.

Neoadjuvant endocrine therapy and window of opportunity trials: new standards in the treatment of breast cancer?

Until recently, the use of neoadjuvant endocrine therapy was mainly restricted to those patients whose general frailty or comorbidities were contraindications to surgery. There is now increased evidence that certain patient populations (i.e. older patients with hormone-receptor positive disease) can gain as good a pathologic response, with considerably less toxicity, from neoadjuvant endocrine therapy than from neoadjuvant chemotherapy. Optimization of neoadjuvant endocrine therapy is therefore an important therapeutic goal. However, possibly of greater importance in the overall management of breast cancer, is the increased interest in exploring the effects of brief periods of endocrine therapy on in vivo biomarkers, in so called window of opportunity trials. These trials can not only be used to identify the mechanisms of action of novel agents but also to predict optimal subsequent adjuvant therapy for individual patients. While this paper will briefly review the history of neoadjuvant endocrine therapy, more emphasis will be on the evaluation of pivotal window of opportunity trials that will likely lead to a long awaited paradigm shift in the management of breast cancer.

Abstract P5-21-09: Oncologist treatment choices in patients with early stage invasive lobular breast carcinoma - a survey

Introduction: Invasive lobular carcinoma (ILC) is common and accounts for 5-15% of all breast cancers. ILC has distinct clinical and histological features that separate it from invasive ductal carcinoma (IDC) with regards to its breast imaging characteristics, patterns of recurrence and sensitivity to systemic therapy. ILC presents challenges to the physician in many aspects of local-regional and systemic therapy choices. We surveyed breast cancer physicians on their beliefs and practice patterns on issues around the management of ILC.

Methods: A questionnaire was developed and circulated electronically using a modified Dillman technique to surgical, radiation, and medical oncologists across Canada and Ireland.

Results: The questionnaire was completed by 91 of 429 physicians (21% response rate). Response rate by specialty was 25/69 (36%), 21/54 (41%) and 45/306 (13%) for surgical, radiation and medical oncologists respectively. Most surgeon responders (77%) would feel "uncomfortable making treatment decisions for ILC with a mammogram alone" and 100% would be "more comfortable with an MRI". Although 55% reported treating ILC as they would IDC, 22% of surgeons will purposefully obtain larger gross margins intra-operatively. Some radiation oncologists believe ILC is an independent risk factor for local-regional recurrence after breast conserving surgery (49%), and after mastectomy (29%). 33% of radiation oncologists would offer radiation therapy after mastectomy specifically because of the ILC subtype even in the absence of usual indications for radiotherapy. Most medical oncologists treat ILC comparably to IDC with the factors having the largest influence on systemic treatment decisions being tumour stage, hormone receptor status and HER-2 status. 51% of medical oncologists treat ILC with adjuvant chemotherapy as they do for IDC at least ‘most of the time’, while 40% use neoadjuvant chemotherapy as frequently as they do for IDC at least ‘most of the time’. 75% of medical oncologists manage the hormonal treatment of ILC as they do IDC ‘most of the time’ or ‘always’.

Conclusions: There remains significant clinical equipoise in the local-regional and systemic management of ILC. This survey has demonstrated wide variations in both beliefs and practices of management for ILC. Clinical guidance, developed on clinical trials specifically assessing the management of ILC, is required.

Citation Format: Carmel Jacobs, Mark Clemons, Mohamed FK Ibrahim, Christina Addison, Jean-Michel Caudrelier, Ian D Graham, Brain Hutton, Angel Arnaout. Oncologist treatment choices in patients with early stage invasive lobular breast carcinoma - a survey [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-21-09.

Bone-targeted therapy for metastatic breast cancer-Where do we go from here? A commentary from the BONUS 8 meeting

The annual Bone and The Oncologist New Updates (BONUS 8) conference focuses on the current understanding and dilemmas in the treatment and prevention of bone metastasis in cancer, as well as novel research on bone homeostasis and cancer-induced bone loss. We present commentaries from experts for their own take on where they feel the field of bone-targeted therapies for metastatic breast cancer is moving, or needs to move, if we are to make further progress.

De-escalated administration of bone-targeted agents in patients with breast and prostate cancer-A survey of Canadian oncologists

Objective

Questions remain regarding the optimal use of bone-targeted agents in patients with metastatic bone disease. The purpose of this study was to assess current clinical practice regarding the use and administration of bone-targeted agents by Canadian oncologists in patients with metastatic breast and prostate cancer.

Methods

A survey was designed to explore; bone-targeted agent use in metastatic bone disease, variability in the choice and the frequency of administration of these agents. Opinions were sought on potential outcomes for future trials.

Results

A total of 193 clinicians were contacted and 90 completed our survey (response rate 49% after adjustment for inactivity). Survey respondents were medical oncologists (71.1%), radiation oncologists (21.1%) and urologists (7.8%). The findings suggest that once bone-targeted agents are started they are rarely discontinued. More agents are used in breast cancer than in prostate cancer. There was considerable interest in performing studies of de-escalated therapy in both breast and prostate cancer. Physicians requested (86%) that the primary study endpoint be the occurrence of skeletal related events and not biomarker driven.

Conclusions

Despite clinical practice guidelines and widespread use, significant areas of clinical equipoise with respect to use of bone-targeted agents exist. Findings from this survey suggest that physicians are interested in de-escalated therapy for both breast and prostate patients. However, the use of multiple agents in breast cancer and the desire for skeletal related events to be the primary endpoint means that very large randomized studies will be required.

Time to put an end to the "one size fits all" approach to bisphosphonate use in patients with metastatic breast cancer?

Bisphosphonates emerged as an effective treatment for metastatic bone disease in the mid-1990s, and in a relatively short time, they have become an integral component in the palliative care of a range of common malignancies that spread to bone[...].

Abstract P3-13-05: Evaluating efficacy of de-escalated bisphosphonate therapy in metastatic breast cancer patients at low-risk of skeletal related events. TRIUMPH: A pragmatic multicentre trial

Background: Optimal bisphosphonate (BP) dosing intervals for breast cancer patients (pts) with bone metastases (BM) remain unknown. BP are usually prescribed q3-4 wk regardless of individual pt risk for skeletal related events (SREs). Recent evidence (Amadori J Clin Oncol, 2012 suppl; abstr 9005) shows that q12 wk BP is as effective as q4 wk in pts previously treated with &gt;9 cycles of q4 wk therapy. Hence, further evaluation of modified BP dosing strategies is warranted. The objective of the current study was to show in women with biochemically defined low-risk bone disease that IV BP use every q12 wk for 1 year is sufficient to maintain stability of the bone turnover [measured by serum c-telopeptide (CTx) or bone specific alkaline phosphatase (BSAP)].

Methods: Eligible pts with BM, who had received &gt;3 months of q3-4 wk IV BP and no systemic treatment change within 4 wks of study entry were enrolled. Low risk was defined as serum CTx &lt;600 ng/L. Biochemical failure was defined as CTx levels &gt;600 ng/L at baseline, weeks 6, 12, 24, 36 or 48. Evaluation of palliative benefit of 12-wk IV BP therapy was measured by SREs, analgesic use, and self-reported pain (BPI and FACT-BP).

Results: Between Oct. 2010-Sept. 2011, 85 pts consented to screening, with 13 found ineligible. In the 71 accrued pts baseline characteristics were: mean age 60 (SD 13), median time from breast cancer diagnosis to development of bone metastases 4 months (IQR 82), median duration of prior BP therapy 14 months (IQR 19), and mean number of SREs/yr prior to entering study 0.35 (SD 0.76). Baseline median CTx was 120 ng/L (IQR 240) and BSAP 9.2 IU/L (IQR 3). To date: 26/71 pts (36%) remain on study. Reasons for coming off study include; study completion (18), elevation of CTx &gt;600ng/L (10), or on study SRE (3). An elevation of CTx between baseline and wk 6 was significantly associated with coming off study early (p = 0.008). For pts who had had an SRE before study entry the odds ratios for coming off study early due to an on study SRE or elevated CTx was 1.005 (CI 1.002–1.009; p = 0.007) and for coming off early for an SRE was 0.0245 (CI 0.061–0.094; p = 0.046) respectively. Of the 8/13 pts who were ineligible due to baseline CTx &gt;600ng/L, 6 had an SRE within 1 year of screening.

Conclusion: De-escalating BP therapy to 12 weekly in low risk pts has advantages for both the pt and the health care system. Individual risk of SREs is highly variable, however baseline serum CTx levels &lt;600 ng/L is associated with a low risk of subsequent SREs. While larger trials are required to assess whether increasing CTx with de-escalated therapy will lead to higher rates of SREs or not (Coleman et al. J Clin Oncol 2012 suppl; abstr 511). However, the results of this study and Amadori et al. would suggest that de-escalated BP treatment will likely become a new standard of care after a limited period of q 4wk treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-13-05.

An adenoviral vector expressing interleukin-4 modulates tumorigenicity and induces regression in a murine breast-cancer model

Anti-tumor activity of a recombinant adenovirus expressing murine IL-4 (AdCAIL-4) was investigated in a murine model of mammary adenocarcinoma. Primary tumor cells derived from mammary adenocarcinomas induced in transgenic mice by the middle T antigen gene of polyomavirus were infected with AdCAIL-4 and injected into syngeneic non-tumor bearing recipients. Expression of IL-4 by AdCAIL-4 transduced tumor cells significantly prolonged survival of all animals and prevented tumor development in 61% of recipient mice. When tumor bearing animals were injected intra-tumorally with AdCAIL-4, all animals survived at least 8 to 10 weeks longer than controls, and 50% of treated animals underwent complete tumor regression. Both en: vivo and in vivo treatment with AdCAIL-4 resulted in infiltration by eosinophils in and around the tumor site. Animals which had undergone complete tumor regression were protected from a second challenge suggesting that immunotherapy with Ad vectors expressing cytokines may protect from metastatic disease.

TGF-α and amphiregulin levels in non-small cell lung cancer (NSCLC) patients (pts) treated with erlotinib/placebo in the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) BR.21

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Background: In BR.21, erlotinib prolonged survival of previously treated NSCLC pts. We examined the predictive/ prognostic effects of the EGFR ligands, TGFa and amphiregulin(Am). Methods: Plasma was collected prior to treatment in consenting pts. TGFa and Am were analyzed by ELISA (R&D Systems). Samples were blinded, measured in duplicate and ligand concentrations determined following interpolation of a standard curve generated from known quantities of recombinant proteins. Sensitivity was ∼3pg/ml. Cutoff points for TGFa were <10 (low) and ≥10 (high); for Am <1.5 (low) vs 1.5–10 (intermediate) vs >10 (high). Standard statistical methods were used to correlate biomarker data with baseline characteristics and outcomes. Results: In 731 randomized pts, 539 were evaluable for both markers; there was a significant interaction (p=0.03) between the evaluable and inevaluable cohorts (erlotinib benefit favoring the evaluable cohort); evaluable pts were more likely to be male, > 60 and to have EGFR amplification. Baseline high TGFa was associated with poorer ECOG PS (p=0.03) while high Am was associated with worse PS (p<0.0001), anemia (p<0.0001), non response to prior therapies (p=0.01) and no-prior platinum therapy (p=0.02). Although TGFa was not prognostic for OS (HR=1.0, p=0.99), high Am was (HR: Middle vs low: 0.94, 95% C.I 0.49 -1.81; high vs.low: 2.04, 95% C.I 1.43 - 2.91; p=0.0002). High TGFa was a poor prognostic factor for PFS (HR 1.4, p=0.07) as was elevated Am (HR: Middle vs low: 1.02, 95% C.I 0.56 -1.85; high vs. low: 1.67, 95% C.I 1.19 - 2.35, p=0.01). In multivariate analyses including both ligands, high Am remained prognostic, but neither ligand was predictive. Conclusions: High levels of baseline Am appears to be a poor prognostic factor, while low levels of TGFa showed a trend to predict benefit from erlotinib in univariate analyses. [Table: see text]

[Table: see text]

Benchmarking best practice for external ventricular drainage

Sharing of best practice and use of all available evidence is important in developing effective clinical guidelines for nursing practice. This can be achieved through benchmarking. Sharing of good practice and achieving consensus guidelines can avoid repetition of effort by nurses engaged in similar fields of practice. The Pan London Neuroscience Practice Development Forum was established in 1998 to share best practice within the field of neuroscience nursing across London. The Pan London Forum has now achieved consensus and developed evidence-based clinical guidelines for the management of external ventricular drainage. Within the scope of this article, the principles of external ventricular drainage will be highlighted, before identifying the evidence base for nursing management of patients. Approaches for troubleshooting common problems will also be discussed and the benchmarked clinical guidelines will be presented.

The use of ambulatory blood pressure monitoring in managing hypertension according to different treatment guidelines

OBJECTIVE

To investigate the use of ambulatory blood pressure monitoring (ABPM) in identifying and managing a group of patients referred to a tertiary centre for the assessment of their blood pressure and to illustrate the importance of introducing standardised ABPM treatment guidelines.

PATIENTS AND METHODS

We examined 2000 sequential ABP recordings, 1557 were first time referrals from General Practitioners, Consultants and other hospitals. All patients were referred with suspected hypertension, resistant hypertension, white coat hypertension and for investigations of secondary hypertension. Fully trained nurse specialists fitted the monitors in the hypertension clinic and recordings were performed for 24 h. The data was then analysed and stratified according to treatment guidelines and categorised according to different definitions.

RESULTS

The group of first time referrals (n = 1557) showed an even sex distribution of 789 men and 768 women, mean age 53 +/- 13.8 (12-88 years). Of this group 542 patients (35%) exhibited a white coat effect (WCE), 526 (34%) had a daytime ABP < or =139/89 mm Hg. Of these 81 (15%) had a high clinic blood pressure (ie, white coat hypertension (WCH)) according to our definition. Thirty-five of these patients were not on treatment but may have had it initiated on the basis of their clinic pressures. According to the British Hypertension Society (BHS) guidelines on clinic readings 772 (45%) of our patients would be classified as hypertensive or inadequately treated, 509 (33%) borderline and 326 (21%) as normal. Using daytime ABP levels according to O'Brien: 1031 (67%) would be defined as abnormal, 192 (12%) as borderline and 334 (21%) as normal.

CONCLUSION

These results illustrates how patient management may differ markedly when treating in accordance either with the BHS guidelines for clinic readings or the suggested levels for ABP. More patients had abnormal blood pressure levels according to ABPM, even though it is superior in detecting WCE and WCH. Clear guidelines for ABPM treatment levels need to be established.

Clinical features, anthropometric characteristics, and racial influences on the 'white-coat effect' in a single-centre cohort of 1553 consecutive subjects undergoing routine ambulatory blood pressure monitoring

BACKGROUND

Patients with high office blood pressures but relatively normal readings during daytime ambulatory monitoring have been the subject of much investigation and debate. This clinical finding in part depends on an alerting reaction to the circumstances of the clinical measurement, often described as the 'white-coat effect' (WCE). Little is known of the characteristics of patients that are associated with the white coat effect in a large population of routinely referred patients.

OBJECTIVE

To relate the size of the WCE (defined as the difference between office and ambulatory daytime readings) to clinical features that may influence this phenomenon.

METHODS

We categorized 1553 consecutive subjects (51.3% men, aged 17-88 years), who had been referred to a single centre for the assessment of suspected hypertension prospectively into three groups: those aged <40, 40-59, and >/=60 years.

RESULTS

WCE on systolic blood pressure (SBP) increased significantly with advancing age and was correlated positively to body mass index (BMI), age and treatment. We found significant correlations to sex (higher in women) and race. WCE on diastolic blood pressure (DBP) decreased slightly with advancing age and was correlated positively to BMI and significantly to race and sex. We found no correlation to age or treatment. Caucasians had a greater WCE than did non-Caucasians (P<0. 001 for SBP and DBP) and hypertensives had greater WCE than did normotensives (P<0.0001 for SBP and DBP). Multiple linear regression analysis showed that age and BMI are the most important factors influencing WCE on SBP and DBP.

CONCLUSIONS

Factors such as race, age and BMI may exert important influences on the size of WCE possibly via effects on sympathetic nervous system activity.

Genomic studies of the Lucké tumor herpesvirus (RaHV-1)

Ranid herpesvirus 1 (RaHV-1) is the etiological agent of the Lucké renal adenocarcinoma of the North American leopard frog Rana pipiens. Construction of cosmid libraries containing RaHV-1 DNA inserts allowed the derivation of a BamHI map for the viral genome. Summation of fragment sizes indicates that the genome is 217 kbp in size, a value in accordance with the most recent published estimate (220 kbp) obtained by field-inversion gel electrophoresis. The DNA sequence of the 39,757-bp insert in 1 cosmid (cos54) was determined and was predicted to contain 21 complete and 3 partial genes. In all, 12 genes have distant counterparts in a fish herpesvirus (ictalurid herpesvirus 1) and are present in 2 blocks, 1 of which is relatively inverted. This indicates that RaHV-1 belongs to the fish virus lineage of the herpesvirus family rather than to the lineage populated by mammalian and avian viruses. The remaining 12 genes in cos54 lack counterparts in any other herpesvirus. One of these encodes a putative DNA (cytosine-5) methyltransferase. This raises the possibility that biological processes induced in the host by RaHV-1 might involve methylation of cellular DNA by the viral enzyme.

Efficient adenovirus-mediated gene expression in malignant human plasma cells: relative lymphoid cell resistance

Although adenoviruses offer several potential advantages as gene transfer vectors, some hematopoietic cells, particularly lymphoid cells, are considered relatively resistant to adenovirus-mediated gene transfer. To examine the role of adenovirus-mediated gene transfer in the lymphoid malignancy multiple myeloma (MM), we used E1- and E3-deleted adenoviral vectors to infect myeloma and lymphoma cell lines and subsequently primary bone marrow plasma cells and lymphocytes from patients with MM. Adenoviral vectors expressing LacZ or luciferase (AdCA18) reporter genes were used initially. Subsequently, we studied adenoviral vectors expressing genes of potential value in therapeutic immunomodulation, i.e., CD80 (AdB7-1) and interleukin-2 (AdIL-2). A human plasma cell line (OCI-My5) infected with LacZ or AdB7-1 vectors expressed the corresponding gene product in 95% and 85% of exposed cells, respectively. Time course experiments indicated that maximum expression of adenoviral transgenes in plasma cells was reached 3 days after infection. IL-2 was detected in the supernatant of AdIL-2-infected plasma cells, was functional, and could be detected for at least 30 days after infection. In contrast, three lymphoma cell lines (OCI-Ly2, OCI-Ly13.2, and OCI-Ly17) were significantly less sensitive to adenovirus infection, with relatively low efficiencies of gene transfer even using high adenoviral titers: Surface CD80 expression (13-25% of infected cells) and positive LacZ staining (0-5% of infected cells). Indeed, expression of luciferase was 96-168 times higher in AdCA18-infected OCI-My5 cells than in the OCI-Ly2 lymphoma cell line. Similar patterns were observed in primary plasma cells and lymphocytes from 19 MM patient bone marrow samples. After infection with AdB7-1, increased levels of CD80 expression on CD38 bright bone marrow plasma cells were observed in 84% of patients, with a 33% average increase in the number of plasma cells expressing CD80. In contrast, although increased CD80 expression was also detected on AdB7-1-infected CD19+ B lymphocytes from 63% of the MM patients, an average of only 14% of the infected lymphocytes demonstrated increased expression of CD80. Circulating T lymphocytes could not be transduced with AdB7-1. The relative resistance of B and T lymphocytes to adenovirus-mediated gene transfer warrants further investigation. Adenoviral vectors can efficiently infect malignant plasma cells and may be useful vehicles for therapeutic gene transfer.

Intradermal transgenic expression of granulocyte-macrophage colony-stimulating factor induces neutrophilia, epidermal hyperplasia, Langerhans' cell/macrophage accumulation, and dermal fibrosis

Granulocyte-macrophage colony-stimulating factor (GM-CSF), a pleiotropic cytokine, is up-regulated in a number of chronic skin inflammatory diseases, particularly atopic dermatitis. However, its role in these conditions remains largely unclear. To explore its function, we have established a rat intradermal transgene model by using a replication-deficient adenoviral vector expressing GM-CSF. Intradermal GM-CSF gene transfer led to a prolonged compartmentalized expression of transgene protein in the dermis. This expression induced an unexpectedly wide spectrum of pathologies in both epidermis and dermis, including neutrophilia, epidermal hyperplasia (acanthosis), an increased number of epidermal Langerhans' cells, accumulation of MHC II-positive macrophages, as well as mild eosinophilia in the dermis at earlier stages and upper dermal fibrosis at later stages. These findings thus identify GM-CSF as a potent multifunctional cytokine at skin site that is capable of evolving numerous inflammatory processes ranging from the early acute neutrophilia to later chronic fibrotic responses, and also suggest the important role of this cytokine in the development and perpetuation of pathologic changes in chronic skin inflammatory conditions including chronic atopic dermatitis. In addition, our study presents a novel model of adult normal animals that is useful for identifying and studying key cytokines involved in inflammatory skin diseases.

The published DNA sequence of human cytomegalovirus strain AD169 lacks 929 base pairs affecting genes UL42 and UL43

Compared with the published DNA sequence (M. S. Chee, et al. Curr. Top. Microbiol. Immunol. 154:125-170, 1990), most isolates of human cytomegalovirus strain AD169 contain an additional 929 bp after nucleotide 54612. This results in a changed reading frame for the 5'-terminal 50 codons of gene UL42 and expansion of gene UL43 (a US22 family member) from 187 (3'-truncated) to 423 (full-length) codons. The UL42 and UL43 gene products are nonessential for growth in culture.

Intramarrow cytokine gene transfer by adenoviral vectors in dogs

Daily systemic administration of hematopoietic growth factors can be associated with dose-limiting systemic side effects. To overcome this, we have investigated hematopoietic cytokine gene transfer to the marrow cavity of dogs by direct intramarrow injection of adenoviral vectors. In marrow culture, replication-deficient (E1-deleted) adenoviral vectors were able to transduce marrow stromal cells, demonstrating 30-fold greater expression than from other marrow cell types. High-level (ng/ml) cytokine production from transduced stromal cells persisted for 14 days in culture. Because adenovectors could efficiently transduce marrow stromal cells in culture, we investigated if stromal cells could also be transduced in vivo following direct intramarrow vector injection. Adenovectors with genes for interleukin 6 (IL-6) and Lac Z (beta-galactosidase) were injected directly into the marrow cavity of dogs resulting in protein expression localized to within the treated marrow. To evaluate this approach further in dogs, we constructed a vector expressing biologically active canine granulocyte-macrophage colony stimulating factor (GM-CSF). 293 cells infected with ADGM-CSF demonstrated prevalent GM-CSF mRNA by Northern blot and 135 +/- 30 ng/ml of protein as measured by enzyme-linked immunosorbent assay (ELISA). In vitro bioactivity of protein expressed was confirmed by canine GM colony-forming assay (CFU-GM). In vivo high-level protein production was noted in supernatants of marrow aspirates 72 hr following direct intramarrow administration of ADGM-CSF (baseline mean +/- SEM, 27 +/- 22 ng/ml, 72-hr sample 921 +/- 461 ng/ml). A localized myeloid expansion of marrow and significant peripheral leukocytosis (neutrophilia) were noted in all ADGM-CSF-treated dogs. Peripheral blood changes lasted for up to 3 weeks in dogs following single intramarrow injection. Thus, adenoviral cytokine expression from the marrow of a single large bone (ilium) led to compartmentalized expression of growth factor and an increase of hematopoiesis sufficient to cause peripheral blood changes in a large animal model.

The cost-effectiveness of ambulatory blood pressure monitoring

Some people's blood pressure is elevated simply by being in a clinical environment. Twenty-four hour monitoring gives a more accurate average blood pressure reading. The initial costs of ABPM are recouped in less than two years.

Multiple interactions control the intracellular localization of the herpes simplex virus type 1 capsid proteins

Herpes simplex virus type 1 (HSV-1) capsid assembly takes place in the nucleus of infected cells. However, when each of the outer capsid shell proteins, VP5, VP23 and VP26, is expressed in the absence of any other HSV-1 proteins, it does not localize to the nucleus but is distributed throughout the cell. We have previously shown that the HSV-1 capsid scaffolding protein, preVP22a, can relocate VP5 into the nucleus but does not influence the distribution of VP23. We now demonstrate that the outer capsid shell protein, VP19C, is able to relocate both VP5 and VP23 separately into the nucleus. However, nuclear localization of VP26 is only observed when VP5 is present together with either VP19C or preVP22a. Thus, pair-wise interactions involving all of the abundant capsid proteins have now been identified. Electron microscope examination of insect cells coinfected with recombinant baculoviruses expressing VP19C and VP5 reveals the presence of 70 nm diameter 'capsid-like' structures, suggesting that these two proteins can form the basic capsid shell.

Localization of the herpes simplex virus type 1 major capsid protein VP5 to the cell nucleus requires the abundant scaffolding protein VP22a

The intracellular distributions of three herpes simplex virus type 1 (HSV-1) capsid proteins, VP23, VP5 and VP22a, were examined using vaccinia virus and plasmid expression systems. During infection of cells with HSV-1 wild-type virus, all three proteins were predominantly located in the nucleus, which is the site of capsid assembly. However, when expressed in the absence of any other HSV-1 proteins, although VP22a was found exclusively in the nucleus as expected, VP5 and VP23 were distributed throughout the cell. Thus nuclear localization is not an intrinsic property of these proteins but must be mediated by one or more HSV-1-induced proteins. Co-expression experiments demonstrated that VP5 was efficiently transported to the nucleus in the presence of VP22a, but the distribution of VP23 was unaffected by the presence of either or both of the other two proteins.

Noninfectious L-particles supply functions which can facilitate infection by HSV-1

The tegument of herpes simplex virus contains proteins important for the efficient initiation of infection. L-particles are noninfectious virion-related particles that lack the nucleocapsid but do contain tegument and envelope. Their ability to deliver functional proteins into cells was compared to that of virions by testing the biological activities of two tegument proteins which are present in both types of particle. Results indicated that L-particles are as efficient as virions in supplying these in a fully functional state. Thus, L-particles are biologically competent and have the potential to participate in the early stages of virus infection.

A C-terminal alpha-helix plus basic region motif is the major structural determinant of p53 tetramerization

The p53 gene product has been implicated in both human and animal tumorigenesis. p53 forms heterologous complexes with the transforming proteins encoded by several different DNA tumor viruses. p53 also assembles into stable homo-oligomers. We demonstrate that the major structural determinant for the tetramerization of p53 is an alpha-helical plus basic region motif near the C-terminus of the protein. A monomeric p53 mutant adopts a conformation distinct from both 'wild-type' and 'mutant' form as defined by PAb1620 and PAb240 monoclonal antibody recognition. Nevertheless, monomeric and dimeric mutant p53 proteins retain the ability to suppress SV40 origin-directed DNA replication in vivo. Thus, p53-p53 interaction and expression of the PAb1620 epitope is not a prerequisite for such activity. We present data suggesting that suppression of replication by p53 may occur by a mechanism that is independent of detectable p53-T antigen association.

Assembly of enveloped tegument structures (L particles) can occur independently of virion maturation in herpes simplex virus type 1-infected cells

Cells infected with a number of alphaherpesviruses produce non-infectious virion-related particles, termed L particles, in addition to infectious virions. L particles consist of the tegument and envelope components, but lack the virus capsid and DNA. Using a herpes simplex virus type 1 (HSV-1) temperature-sensitive mutant, ts1201, which fails to produce mature virions, we show that L particle production is independent of virion formation. Moreover, the quantity and protein composition of L particles generated by this mutant at the non-permissive temperature are indistinguishable from those produced in wild-type HSV-1 infections. Electron microscopy studies suggest that the processes governing the assembly of tegument and envelope components into L particles are similar to those involved in virion maturation.

A human tumour-derived mutant p53 protein induces a p34cdc2 reversible growth arrest in fission yeast

We have expressed wild-type and human tumour-derived mutant p53 cDNA genes in the fission yeast Schizosaccharomyces pombe. In the case of one mutant this resulted in a growth arrest of recipient yeast cells. In contrast, wild-type p53 and three other mutant proteins tested did not block outgrowth of colonies. Human and yeast cdc2 acted as functionally equivalent extragenic suppressors of the mutant-induced growth arrest allowing the establishment of viable p53 expressor strains. In cotransformation assays the mutant allele was found to be dominant over wt p53. Our results provide the first evidence of a functional relationship between p53 and p34cdc2 in an in-vivo system and suggest that the wide variety of mutant proteins present in human tumours may fall into functionally distinct subclasses.

Herpes simplex virus type 1 UL28 gene product is important for the formation of mature capsids

The herpes simplex virus type 1 temperature-sensitive (ts) DNA-positive mutant ts1203 has been characterized. The ts lesion in ts1203 was located by marker rescue within the coding region of gene UL28. Nuclei of cells infected with ts1203 at the non-permissive temperature (NPT) contained large numbers of capsids with a uniform morphology. These capsids lacked DNA but had a defined internal structure. No full capsids were detected at the NPT, suggesting that ts1203 was unable to package viral DNA. In this respect ts1203 is similar to ts1201 which has a defect in gene UL26. The capsids made by ts1203 at the NPT, however, contained a more compact internal structure than those of ts1201. In addition, ts1203 capsids were dispersed throughout the nucleus whereas ts1201 capsids were frequently found clustered together in large arrays. Southern blot and sedimentation analyses of viral DNA confirmed that ts1203 had an encapsidation defect and showed that most of the mutant DNA at the NPT was of a high Mr. The effect of the ts1203 mutation could not be reversed in the absence of de novo protein synthesis by transferring mutant-infected cells from the NPT to the permissive temperature.

p53 interacts with p34cdc2 in mammalian cells: implications for cell cycle control and oncogenesis

The p53 gene product has been implicated in both human and animal tumorigenesis. p53 complexes with the transforming proteins encoded by several different DNA tumour viruses. We demonstrate that human p53 is phosphorylated by the mammalian p34cdc2 kinase in vitro and coprecipitates with p34cdc2 in vivo. Our observations suggest that phosphorylation of p53 by p34cdc2 kinase may regulate the known activities of p53 in the initiation steps of DNA replication in mammalian cells.