Production of Carcinogenic Acetaldehyde by Oral Microbiome

Oral cancer is the seventh most common cancer worldwide and its incidence is increasing. The most important risk factors for oral cancer are chronic alcohol consumption and tobacco smoking, up to 80 % of oral carcinomas are estimated to be caused by alcohol and tobacco. They both trigger an increased level of salivary acetaldehyde, during and after consumption, which is believed to lead to carcinogenesis. Acetaldehyde has multiple mutagenic features and it has recently been classified as a Group 1 carcinogen for humans by the International Agency for Research on Cancer. Acetaldehyde is metabolized from ethanol by microbes of oral microbiota. Some oral microbes possess alcohol dehydrogenase enzyme (ADH) activity, which is the main enzyme in acetaldehyde production. Many microbes are also capable of acetaldehyde production via alcohol fermentation from glucose. However, metabolism of ethanol into acetaldehyde leads to production of high levels of this carcinogen. Acetaldehyde is found in saliva during and after alcohol consumption. In fact, rather low ethanol concentrations (2-20mM) derived from blood to saliva are enough for microbial acetaldehyde production. The high acetaldehyde levels in saliva after alcohol challenge are explained by the lack of oral microbiota and mucosa to detoxify acetaldehyde by metabolizing it into acetate and acetyl coenzymeA. The aim of this thesis project was to specify the role of oral microbes in the in vitro production of acetaldehyde in the presence of ethanol. In addition, it was sought to establish whether microbial metabolism could also produce acetaldehyde from glucose. Furthermore, the potential of xylitol to inhibit ethanol metabolism and acetaldehyde production was explored. Isolates of oral microbes were used in the first three studies. Acetaldehyde production was analyzed after ethanol, glucose and fructose incubation with gas chromatography measurement. In studies I and III, the ADH enzyme activity of some microbes was measured by fluorescence. The effect of xylitol was analyzed by incubating microbes with ethanol and xylitol. The fourth study was made ex vivo and microbial samples obtained from different patient groups were analyzed. This work has demonstrated that isolates of oral microbiota are able to produce acetaldehyde in the presence of clinically relevant ethanol and glucose concentrations. Significant differences were found between microbial species and isolates from different patient groups. In particular, the ability of candidal isolates from APECED patients to produce significantly more acetaldehyde in glucose incubation compared to healthy and cancer patient isolates is an interesting observation. Moreover, xylitol was found to reduce their acetaldehyde production significantly. Significant ADH enzyme activity was found in the analyzed high acetaldehyde producing streptococci and candida isolates. In addition, xylitol was found to reduce the ADH enzyme activity of C. albicans. Some results from the ex vivo study were controversial, since acetaldehyde production did not correlate as expected with the amount of microbes in the samples. Nevertheless, the samples isolated from patients did produce significant amounts of acetaldehyde with a clinically relevant ethanol concentration.

Mammalian RAD51 paralogs protect nascent DNA at stalled forks and mediate replication restart

Mammalian RAD51 paralogs are implicated in the repair of collapsed replication forks by homologous recombination. However, their physiological roles in replication fork maintenance prior to fork collapse remain obscure. Here, we report on the role of RAD51 paralogs in short-term replicative stress devoid of DSBs. We show that RAD51 paralogs localize to nascent DNA and common fragile sites upon replication fork stalling. Strikingly, RAD51 paralogs deficient cells exhibit elevated levels of 53BP1 nuclear bodies and increased DSB formation, the latter being attributed to extensive degradation of nascent DNA at stalled forks. RAD51C and XRCC3 promote the restart of stalled replication in an ATP hydrolysis dependent manner by disengaging RAD51 and other RAD51 paralogs from the halted forks. Notably, we find that Fanconi anemia (FA)-like disorder and breast and ovarian cancer patient derived mutations of RAD51C fails to protect replication fork, exhibit under-replicated genomic regions and elevated micro-nucleation. Taken together, RAD51 paralogs prevent degradation of stalled forks and promote the restart of halted replication to avoid replication fork collapse, thereby maintaining genomic integrity and suppressing tumorigenesis.

DEAD-box helicase DP103 defines metastatic potential of human breast cancers

Despite advancement in breast cancer treatment, 30% of patients with early breast cancers experience relapse with distant metastasis. It is a challenge to identify patients at risk for relapse; therefore, the identification of markers and therapeutic targets for metastatic breast cancers is imperative. Here, we identified DP103 as a biomarker and metastasis-driving oncogene in human breast cancers and determined that DP103 elevates matrix metallopeptidase 9 (MMP9) levels, which are associated with metastasis and invasion through activation of NF-κB. In turn, NF-κB signaling positively activated DP103 expression. Furthermore, DP103 enhanced TGF-β-activated kinase-1 (TAK1) phosphorylation of NF-κB-activating IκB kinase 2 (IKK2), leading to increased NF-κB activity. Reduction of DP103 expression in invasive breast cancer cells reduced phosphorylation of IKK2, abrogated NF-κB-mediated MMP9 expression, and impeded metastasis in a murine xenograft model. In breast cancer patient tissues, elevated levels of DP103 correlated with enhanced MMP9, reduced overall survival, and reduced survival after relapse. Together, these data indicate that a positive DP103/NF-κB feedback loop promotes constitutive NF-κB activation in invasive breast cancers and activation of this pathway is linked to cancer progression and the acquisition of chemotherapy resistance. Furthermore, our results suggest that DP103 has potential as a therapeutic target for breast cancer treatment.

Diagnostic value of increased sensitivity by massively parallel sequencing

Routine molecular diagnostics modalities are unable to confidently detect low frequency mutations (<5-15%) that may indicate response to targeted therapies. We confirm the presence of a low frequency NRAS mutation in a rectal cancer patient using massively parallel sequencing when previous Sanger sequencing results proved negative and Q-PCR testing inconclusive. There is increasing evidence that these low frequency mutations may confer resistance to anti-EGFR therapy. In view of negative/inconclusive Sanger sequencing and Q-PCR results for NRAS mutations in a KRAS wt rectal case, the diagnostic biopsy and 4 distinct subpopulations of cells in the resection specimen after conventional chemo/radiotherapy were massively parallel sequenced using the Ion Torrent PGM. DNA was derived from FFPE rectal cancer tissue and amplicons produced using the Cancer Hotspot Panel V2 and sequenced using semiconductor technology. NRAS mutations were observed at varying frequencies in the patient biopsy (12.2%) and all four subpopulations of cells in the resection with an average frequency of 7.3% (lowest 2.6%). The results of the NGS also provided the mutational status of 49 other genes that may have prognostic or predictive value, including KRAS and PIK3CA. NGS technology has been postulated in diagnostics because of its capability to generate results in large panels of clinically meaningful genes in a cost-effective manner. This case illustrates another potential advantage of this technology: its use for detecting low frequency mutations that may influence therapeutic decisions in cancer treatment.

Tanztherapie in der Psychoonkologie : Auswirkungen der Intervention auf die gesundheitsbezogene Lebensqualität

Das Ziel der vorliegenden Arbeit ist es zu prüfen, ob Tanztherapie einen Effekt auf dieLebensqualität bei Brustkrebspatientinnen hat. Brustkrebs ist die häufigste Krebserkrankungbei Frauen in Deutschland. Verbesserte Behandlungsformen und Früherkennungsmaßnahmenführen zu einem Anstieg der Überlebensrate. Dennoch bedingen ein langerBehandlungsweg und Unsicherheit über den Verlauf der Krankheit hohe Belastungen undUnsicherheiten. Nebenwirkungen und Langzeitfolgen der Interventionen beeinflussen zudemdie gesundheitsbezogene Lebensqualität. Körper und Psyche werden stark beansprucht undleiden. Die Psychoonkologie stellt dabei einen Teil des Behandlungsweges dar. Sie bildetesich aus der Erkenntnis heraus, dass die Krebserkrankung nicht nur den Körper beeinflusst,sondern den gesamten Menschen mit seiner seelischen und geistigen Verfassung. DieTanztherapie ist eine Maßnahme im Kanon der psychoonkologischen Betreuung. Sie vereintkörperliche Betätigung und kreative Ausdrucksmöglichkeiten. Psyche und Körper werden beidieser Therapieform angesprochen. Im Gruppensetting fließt zudem die soziale Komponentemit ein. Die These lautet demnach, dass Tanztherapie positive Auswirkungen auf diegesundheitsbezogenen Lebensqualität hat. Denn Körper, Psyche und soziales Umfeld sindTeile der Lebensqualität. Das methodische Vorgehen dieser Arbeit setzte sich aus demRecherchieren von relevanten Studien, Reviews und Metaanalysen zusammen. Es wurdendie Datenbanken Google Scholar, PubMed, PsyCONTENT und Springer Link bis zum Jahre2014 durchsucht. Schlüsselworte waren dabei Tanztherapie, Psychoonkologie, Krebspatient,Lebensqualität, gesundheitsbezogene Lebensqualität, künstlerische Therapie,dance/movement therapy, cancer patient, quality of life, health related quality of life.

Compositional Data in Biomedical Research

Modern methods of compositional data analysis are not well known in biomedical research. Moreover, there appear to be few mathematical and statistical researchers working on compositional biomedical problems. Like the earth and environmental sciences, biomedicine has many problems in which the relevant scienti c information is encoded in the relative abundance of key species or categories. I introduce three problems in cancer research in which analysis of compositions plays an important role. The problems involve 1) the classi cation of serum proteomic pro les for early detection of lung cancer, 2) inference of the relative amounts of di erent tissue types in a diagnostic tumor biopsy, and 3) the subcellular localization of the BRCA1 protein, and it's role in breast cancer patient prognosis. For each of these problems I outline a partial solution. However, none of these problems is \solved". I attempt to identify areas in which additional statistical development is needed with the hope of encouraging more compositional data analysts to become involved in biomedical research

Apoyo social e ideación suicida en pacientes con cáncer

El diagnóstico de cáncer ha sido asociado con un alto riesgo de presentar ideación suicida en comparación con la población no oncológica, sin embargo se ha considerado al apoyo social como un factor protector para la ocurrencia de esta conducta. La presente investigación tuvo como objetivo identificar la relación entre el apoyo social percibido y la ideación suicida en 90 pacientes oncológicos adultos en Bogotá, bajo la hipótesis de que a mayor apoyo social percibido, menor presencia de ideación suicida. Se midió la variable de apoyo social a través del cuestionario Duke UNC y la ideación suicida a través de cuatro instrumentos: Escala de Ideación Suicida (SSI), Escala de Desesperanza de Beck (BHS), el ítem 9 del Inventario de Depresión de Beck (BDI-IA) y una entrevista semiestructurada. Los resultados mostraron que no existe relación entre el apoyo social percibido y la ideación suicida. Por otro lado se identificó una prevalencia de suicidio entre 5,6% y 22,77%, confirmando que el paciente con cáncer considera el suicidio y es fundamental evaluar esta variable en esta población. Se considera importante continuar con la realización de investigaciones que permitan generalizar los resultados a la población oncológica colombiana.

Families as carers-information needs in a cultural context

While the important role of family as a carer has been increasingly recognised in healthcare service provision, particularly for patients with acute or chronic illnesses, the carer’s information needs have not been well understood and adequately supported by current health information systems. In order to effectively provide continuous and home-based care for the patient, a family relative as the primary carer needs sufficient access to medical knowledge and patient’s health information. There are two challenges. First, being a family relative, the primary carer is often a non-medical practitioner. Second, in Australia, many primary carers are family relatives of patients from a non-English speaking background. They are often seen as interpreters in clinical consultation sessions. Their roles and responsibilities as an interpreter and a carer are often mixed and blurry.
Therefore, their information needs are often seen as secondary to the patient or neglected. The primary carer’s information needs are currently not yet well understood.

This paper reports finding from a case study which examines an on-line diary of a husband-carer who provided support and care for his wife, who at the time of care was a lung cancer patient. The case study examines an ongoing learning process that the husband went through, identifies information needs by the carer and cultural factors which played an important role in the husband’s interpretation of information, decision making and provision of care. The finding extends a current model of the user’s information needs in the literature and suggests implications for further research into developing health information systems to meet information needs by the family carer.

Information systems and healthcare XXVIII : the information needs of family carers in collaborative healthcare

While the important role of family carers has been increasingly recognized in healthcare service provision, particularly for patients with acute or chronic illnesses, the family carer's information needs have not been well understood or adequately supported by health information systems. In this study, we explore the information needs of a family carer by analyzing the extensive online diary of a Vietnamese family carer supporting his wife, who was a lung cancer patient. The study provides a deep understanding of the information needs of the family carer and suggests a four-stage information journey model including identification, searching, interpretation and information sharing, and collaboration. A number of themes emerge from the study including the key role of the carer, information filtering by the carer, information sharing and collaboration, and the influence of Vietnamese culture. The paper concludes with a discussion of the requirements for health information systems that meet the needs of family carers.

The decision-making journey of a family carer : information and social needs in a cultural context

While the important role of family as carer has been increasingly recognised in healthcare service provision, particularly for patients with acute or chronic illnesses, the carer's information and social needs have not been well understood and adequately supported. In order to provide continuous and home-based care for the patient, and to make informed decisions about the care, a family carer needs sufficient access to medical information in general, the patient's health information specifically, and supportive care services. Two key challenges are the carer's lack of medical knowledge and the many carers with non-English speaking and different cultural backgrounds. The informational and social needs of family carers are not yet well understood. This paper analyses the web-log of a husband-carer who provided support for his wife, who at the time of care was a lung cancer patient. It examines the decision-making journey of the carer and identifies the key issues faced in terms of informational and social practices surrounding care provision.

Oncology service initiatives and research in regional Australia

OBJECTIVE: This paper reflects on the recent growth of cancer research being conducted through some of Australia's rural centres. It encompasses work being done across the fields of clinical, translational and health services research. DESIGN: This is a collaborative piece with contributions from rural health researchers, clinical and cancer services staff from several different regions. CONCLUSION: The past decade has seen an expansion in cancer research in rural and regional Australia driven in part by the recognition that cancer patients in remote areas experience poorer outcomes than their metropolitan counterparts. This work has led to the development of more effective cancer networks and new models of care designed to meet the particular needs of the rural cancer patient. It is hoped that the growth of cancer research in regional centres will, in time, reduce the disparity between rural and urban communities and improve outcomes for cancer patients across both populations.

Quantitative real-time RT-PCR and chromogenic in situ hybridization: precise methods to detect HER-2 status in breast carcinoma

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Role of natural killer cells in antitumor resistance

Natural killer cells constitute a population of lymphocytes able to non-specifically destroy virus-infected and some kinds of tumor cells. Since this lytic activity was shown by non-immunized animals the phenomenon is denominated natural killer (NK) activity and contrasts with specific cytotoxicity performed by cytolytic T lymphocytes (CTLs) because it does not depends on MHC-restricted peptides recognition. In fact, the main feature of most functional receptors of NK cells (NKRs) is their ability to be inhibited by different kinds of class I MHC antigens. In the middle of the 1950's, Burnet & Thomas forged the concept of tumor immunosurveillance and NK cells can be considered one of the main figures in this phenomenon both for effector and regulatory functions. In the present review the early studies on the biology of NK cells were revisited and both their antitumor activity and dependence on the activation by cytokines are discussed.