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There is limited knowledge about cancer patients' experiences of uncertainty while waiting for genome sequencing results, and whether prolonged uncertainty contributes to psychological factors in this context. To investigate uncertainty in patients with a cancer of likely hereditary origin while waiting for genome sequencing results, we collected questionnaire and interview data at baseline, and at three and 12 months follow up (prior to receiving results). Participants (N = 353) had negative attitudes towards uncertainty (M = 4.03, SD 0.68) at baseline, and low levels of uncertainty at three (M = 8.23, SD 7.37) and 12 months (M = 7.95, SD 7.64). Uncertainty about genome sequencing did not change significantly over time [t(210) = 0.660, p = 0.510]. Greater perceived susceptibility for cancer [r(348) = 0.14, p < 0.01], fear of cancer recurrence [r(348) = 0.19, p < 0.01], perceived importance of genome sequencing [r(350) = 0.24, p < 0.01], intention to change behavior if a gene variant indicating risk is found [r(349) = 0.29, p < 0.01], perceived ability to cope with results [r(349) = 0.36, p < 0.01], and satisfaction with decision to have genome sequencing [r(350) = 0.52, p < 0.01] were significantly correlated with negative attitudes towards uncertainty at baseline. Multiple primary cancer diagnoses [B = −2.364 [−4.238, −0.491], p = 0.014], lower perceived ability to cope with results [B = −0.1.881 [−3.403, −0.359], p = 0.016] at baseline, greater anxiety about genome sequencing (avoidance) [B = 0.347 [0.148, 0.546], p = 0.0012] at 3 months, and greater perceived uncertainty about genome sequencing [B = 0.494 [0.267, 0.721] p = 0.000] at 3 months significantly predicted greater perceived uncertainty about genome sequencing at 12 months. Greater perceived uncertainty about genome sequencing at 3 months significantly predicted greater anxiety (avoidance) about genome sequencing at 12 months [B = 0.291 [0.072, 0.509], p = 0.009]. Semi-structured interviews revealed that while participants were motivated to pursue genome sequencing as a strategy to reduce their illness and risk uncertainty, genome sequencing generated additional practical, scientific and personal uncertainties. Some uncertainties were consistently discussed over the 12 months, while others emerged over time. Similarly, some uncertainty coping strategies were consistent over time, while others emerged while patients waited for their genome sequencing results. This study demonstrates the complexity of uncertainty generated by genome sequencing for cancer patients and provides further support for the inter-relationship between uncertainty and anxiety. Helping patients manage their uncertainty may ameliorate psychological morbidity.

Limited research has indicated that despite their overwhelming interest in tumor molecular profiling (MP),11 Abbreviations: Accessibility and Remoteness Index of Australia (ARIA): an indication of the proximity of service centers relative to where the participant lives. Eastern Cooperative Oncology Group (ECOG): A performance status measure to quantify cancer patients' general well-being and activities of daily life. Molecular Therapeutics (MoST) Program: A research program which forms a component of the Australian Genomic Cancer Medicine Program. The Psychosocial Issues in Genomic Oncology (PiGeOn) Project: a longitudinal, mixed methods psychosocial sub-study of the MoST Program which aims to examine the psychosocial, behavioral and ethical impact of MP. Tumor molecular profiling (MP): a form of genomic testing, that involves characterization of tumor-derived DNA and RNA. cancer patients have poor knowledge about MP. The current study aimed to investigate demographic and psychological predictors of knowledge and perceived importance of MP in an advanced cancer patient cohort. Eligible participants had advanced solid cancers of any histological type with sufficient accessible tissue for MP and were enrolled in the Molecular Screening and Therapeutics (MoST) Program. A questionnaire was completed by 1074 participants (91% response rate) after consent, prior to undergoing MP. Overall, participants had poor to moderate knowledge of MP, yet perceived MP to have high importance. Higher education, speaking English at home, and greater satisfaction with the decision to undergo MP were associated with higher knowledge scores. More negative attitudes towards uncertainty, greater self-efficacy to cope with results, and lower perceived likelihood of cancer progression were associated with greater perceived importance of MP. Less educated participants and those who do not speak English at home will need clear explanations, visual aids and ample opportunity to ask questions about MP at the time of their decision-making. Clinicians also need to consider psychological factors relevant to patients' decision to pursue MP. Given the increased awareness of and demand for cancer genomic information and the rapidly changing nature of the actionability of MP, these findings will help inform an important ongoing debate on how to facilitate ethical and informed consent and manage patient expectations about personalized treatments.

Telomerase is a ribonucleoprotein complex that maintains the length and integrity of telomeres, and thereby enables cellular proliferation. Understanding the regulation of telomerase in hematopoietic cells is relevant to the pathogenesis of leukemia, in which telomerase is constitutively activated, as well as bone marrow failure syndromes that feature telomerase insufficiency. Past studies showing high levels of telomerase in human erythroblasts and a prevalence of anemia in disorders of telomerase insufficiency provide the rationale for investigating telomerase regulation in erythroid cells. Here it is shown for the first time that the telomerase RNA-binding protein dyskerin (encoded by DKC1) is dramatically upregulated as human hematopoietic stem and progenitor cells commit to the erythroid lineage, driving an increase in telomerase activity in the presence of limiting amounts of TERT mRNA. It is also shown that upregulation of DKC1 was necessary for expansion of glycophorin A+ erythroblasts and sufficient to extend telomeres in erythroleukemia cells. Chromatin immunoprecipitation and reporter assays implicated GATA1-mediated transcriptional regulation of DKC1 in the modulation of telomerase in erythroid lineage cells. Together these results describe a novel mechanism of telomerase regulation in erythroid cells which contrasts with mechanisms centered on transcriptional regulation of TERT that are known to operate in other cell types. This is the first study to reveal a biological context in which telomerase is upregulated by DKC1 and to implicate GATA1 in telomerase regulation. The results from this study are relevant to hematopoietic disorders involving DKC1 mutations, GATA1 deregulation and/or telomerase insufficiency.

Abstract Protein colocalisation is often studied using pixel intensity-based coefficients such as Pearson, Manders, Li or Costes. However, these methods cannot be used to study object-based colocalisations in biological systems. Therefore, a novel method is required to automatically identify regions of fluorescent signal in two channels, identify the co-located parts of these regions, and calculate the statistical significance of the colocalisation. We have developed MatCol to address these needs. MatCol can be used to visualise protein and/or DNA colocalisations and fine tune user-defined parameters for the colocalisation analysis, including the application of median or Wiener filtering to improve the signal to noise ratio. Command-line execution allows batch processing of multiple images. Users can also calculate the statistical significance of the observed object colocalisations compared to overlap by random chance using Student’s t-test. We validated MatCol in a biological setting. The colocalisations of telomeric DNA and TRF2 protein or TRF2 and PML proteins in >350 nuclei derived from three different cell lines revealed a highly significant correlation between manual and MatCol identification of colocalisations (linear regression R2 = 0.81, P

Summary: Acquisition of replicative immortality is currently regarded as essential for malignant transformation. This is achieved by activating a telomere lengthening mechanism (TLM), either telomerase or alternative lengthening of telomeres, to counter normal telomere attrition. However, a substantial proportion of some cancer types, including glioblastomas, liposarcomas, retinoblastomas, and osteosarcomas, are reportedly TLM-negative. As serial samples of human tumors cannot usually be obtained to monitor telomere length changes, it has previously been impossible to determine whether tumors are truly TLM-deficient, there is a previously unrecognized TLM, or the assay results are false-negative. Here, we show that a subset of high-risk neuroblastomas (with ∼50% 5-year mortality) lacked significant TLM activity. Cancer cells derived from these highly aggressive tumors initially had long telomeres and proliferated for >200 population doublings with ever-shorter telomeres. This indicates that prevention of telomere shortening is not always required for oncogenesis, which has implications for inhibiting TLMs for cancer therapy. : Dagg et al. find that a subset of highly malignant neuroblastomas (survival ∼50% despite intensive treatment) lack an effective telomere length maintenance mechanism. Their cells undergo continuous telomere shortening throughout >200 population doublings, challenging the concept that activation of a mechanism to prevent telomere shortening is essential for oncogenesis. Keywords: telomeres, ever-shorter telomeres, telomerase, alternative lengthening of telomeres, neuroblastoma

Here we describe a method for growing fibroblasts from human skin explants that increases the number of cells obtained by up to two orders of magnitude, thus increasing the amount of material available for research and diagnostic purposes and potentially for cell-based therapies. Explants can be transferred sequentially up to 80 times, if required, at which point the explants appear to be completely depleted of fibroblasts. Utilizing skin samples obtained from 16 donors, aged 18-66 years old, the first 20 transfers produced cultures with lifespan and growth characteristics that were all very similar to each other, but the cultures derived from later transfers had a decreasing replicative capacity. Final cumulative population doublings did not correlate with donor age, but correlated positively with the telomere length at early passage. We also demonstrated that explants can be transduced directly by lentiviral infection, and that cryopreserved tissue can be explanted successfully using this procedure.

Alternative Lengthening of Telomeres (ALT) is a non-telomerase mechanism of telomere lengthening that occurs in about 10% of cancers overall and is particularly common in astrocytic brain tumors and specific types of sarcomas. Somatic cell hybridization analyses have previously shown that normal telomerase-negative fibroblasts and telomerase-positive immortalized cell lines contain repressors of ALT activity, indicating that activation of ALT results from loss of one or more unidentified repressors. More recently, ATRX or DAXX was shown to be mutated both in tumors with telomere lengths suggestive of ALT activity and in ALT cell lines. Here, an ALT cell line was separately fused to each of four telomerase-positive cell lines, and four or five independent hybrid lines from each fusion were examined for expression of ATRX and DAXX and for telomere lengthening mechanism. The hybrid lines expressed either telomerase or ALT, with the other mechanism being repressed. DAXX was expressed normally in all parental cell lines and in all of the hybrids. ATRX was expressed normally in each of the four telomerase-positive parental cell lines and in every telomerase-positive hybrid line, and was abnormal in the ALT parental cells and in all but one of the ALT hybrids. This correlation between ALT activity and loss of ATRX expression is consistent with ATRX being a repressor of ALT.