The effect of warfarin therapy on breast, colorectal, lung, and prostate cancer survival: a population-based cohort study using the Clinical Practice Research Datalink

PURPOSE: Pre-clinical studies suggest that oral anticoagulant agents, such as warfarin, may inhibit metastases and potentially prolong survival in cancer patients. However, few population-based studies have examined the association between warfarin use and cancer-specific mortality.

METHODS: Using prescribing, cause of death, and cancer registration data from the UK Clinical Practice Research Datalink, four population-based cohorts were constructed, comprising breast, colorectal, lung, and prostate cancer patients diagnosed between 1 January 1998, and the 31 December 2010. Comparing pre-diagnostic warfarin users to non-users, multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer-specific mortality.

RESULTS: Overall, 16,525 breast, 12,902 colorectal, 12,296 lung, and 12,772 prostate cancers were included. Pre-diagnostic warfarin use ranged from 2.4 to 4.7 %. There was little evidence of any strong association between warfarin use pre-diagnosis and cancer-specific mortality in prostate (adjusted HR 1.03, 95 % CI 0.84-1.26), lung (adjusted HR 1.06, 95 % CI 0.96-1.16), breast (adjusted HR 0.81, 95 % CI 0.62-1.07), or colorectal (adjusted HR 0.88, 95 % CI 0.77-1.01) cancer patients. Dose-response analyses did not reveal consistent evidence of reductions in users of warfarin defined by the number of prescriptions used and daily defined doses.

CONCLUSIONS: There was little evidence of associations between pre-diagnostic use of warfarin and cancer-specific mortality in lung, prostate, breast, or colorectal cancer patients.

Interactions of a non-thermal atmospheric pressure plasma effluent with PC-3 prostate cancer cells

The effect of a radio-frequency driven, microscale non thermal atmospheric pressure plasma jet operated in helium with vol. 0.3% molecular oxygen gas admixture, on PC-3 prostate cancer cells has been investigated. The viability of cells exposed to the plasma was found to decrease with increasing plasma exposure time, with apoptosis through caspase and PARP cleavage being observed. High concentrations of nitrite and nitrate were detected in growth media exposed to the plasma and were found to increase in a time dependent manner post exposure. This indicates a slow release of reactive nitrogen species into the growth media, which is likely to influence cellular response to plasma exposure.

Tumor-derived CXCL8 signaling augments stroma-derived CCL2-promoted proliferation and CXCL12-mediated invasion of PTEN-deficient prostate cancer cells

Impaired PTEN function is a genetic hallmark of aggressive prostate cancers (CaP) and is associated with increased CXCL8 expression and signaling. The current aim was to further characterize biological responses and mechanisms underpinning CXCL8-promoted progression of PTEN-depleted prostate cancer, focusing on characterizing the potential interplay between CXCL8 and other disease-promoting chemokines resident within the prostate tumor microenvironment. Autocrine CXCL8-stimulation (i) increased expression of CXCR1 and CXCR2 in PTEN-deficient CaP cells suggesting a self-potentiating signaling axis and (ii) induced expression of CXCR4 and CCR2 in PTEN-wild-type and PTEN-depleted CaP cells. In contrast, paracrine CXCL8 signaling induced expression and secretion of the chemokines CCL2 and CXCL12 from prostate stromal WPMY-1 fibroblasts and monocytic macrophage-like THP-1 cells. In vitro studies demonstrated functional co-operation of tumor-derived CXCL8 with stromal-derived chemokines. CXCL12-induced migration of PC3 cells and CCL2-induced proliferation of prostate cancer cells were dependent upon intrinsic CXCL8 signaling within the prostate cancer cells. For example, in co-culture experiments, CXCL12/CXCR4 signaling but not CCL2/CCR2 signaling supported fibroblast-mediated migration of PC3 cells while CXCL12/CXCR4 and CCL2/CCR2 signaling underpinned monocyte-enhanced migration of PC3 cells. Combined inhibition of both CXCL8 and CXCL12 signaling was more effective in inhibiting fibroblast-promoted cell motility while repression of CXCL8 attenuated CCL2-promoted proliferation of prostate cancer cells. We conclude that tumor-derived CXCL8 signaling from PTEN-deficient tumor cells increases the sensitivity and responsiveness of CaP cells to stromal chemokines by concurrently upregulating receptor expression in cancer cells and inducing stromal chemokine synthesis. Combined chemokine targeting may be required to inhibit their multi-faceted actions in promoting the invasion and proliferation of aggressive CaP.

Repurposing medicinal compounds for blood cancer treatment

Drug development is being continuously scrutinised for its lack of productivity. Novel drug development is associated with high costs, high failure rates and lengthy development process. These downfalls combined with a huge demand in blood cancer for new therapeutic treatments have led many to consider the method of drug repurposing. Finding new therapeutic indications for already established drug substances is known as redirecting, repositioning, reprofiling, or repurposing of drugs. Off-patent and on-patent drugs can be screened for additional targets and new indications thus bringing them to clinical trials at a faster pace. This approach offers smaller research groups, such as those that are academic based, into the drug development industry. Drug repurposing can make use of previously published data concerning dosage, toxicology and mechanism of activity.

Late effects of cancer and cancer treatment-the perspective of the patient

PURPOSE: Understanding the experience of late effects from the perspective of cancer survivors is essential to inform patient-centred care. This study investigated the nature and onset of late effects experienced by survivors and the manner in which late effects have affected their lives.

METHODS: Sixteen purposively selected cancer survivors participated in a qualitative interview study. The data were analysed inductively using a narrative schema in order to derive the main themes that characterised patients' accounts of late effects.

RESULTS: Individual survivors tended to experience more than one late effect spanning a range of physical and psychological effects. Late effects impacted on relationships, working life, finances and the ability to undertake daily activities. Survivors reported experiencing psychological late effects from around the end of treatment whereas the onset of physical effects occurred later during the post-treatment period. Late effects were managed using formal health services, informal social support and use of 'wellbeing strategies'. Survivors engaged in a process of searching for reasons for experiencing late effects and struggled to make sense of their situation. In particular, a process of 'peer-patient comparison' was used by survivors to help them make sense of, or cope with, their late effects. There appeared to be an association between personal disposition and adaptation and adjustment to the impact of late effects.

CONCLUSIONS: Cancer survivors identified potential components for supported self-management or intervention programmes, as well as important considerations in terms of peer comparisons, personal disposition and making sense of experienced late effects.

A feasibility study of auricular therapy and self-administered acupressure for insomnia following cancer treatment

Introduction: Many cancer patients experience sleeping difficulties which can persist several years after the completion of cancer treatment. Previous research suggests that acupuncture, and variants of acupuncture (acupressure, auricular therapy) may be effective treatment options for sleep disturbance. However, current evidence is limited for cancer patients.

Methods: Feasibility study with 3 arms. Seven cancer patients with insomnia randomised to receive either auricular therapy (attaching semen vaccariae seeds to ear acupoints) (n=4), self-acupressure (n=1) or no treatment (n=2). Participants assigned to receive auricular therapy or self-acupressure stimulated the acupoints each night an hour before retiring to bed. The duration of participant involvement was 5 weeks. Subjective sleep quality was measured at baseline and post-treatment using the Pittsburgh Sleep Quality Index (PSQI). The impact of treatment on concerns of importance to the participants themselves was measured using the Measure Yourself Concerns and Wellbeing (MYCaW). Each participant also completed a treatment log book.

Results: All participants completed their treatment. All auricular therapy and self-acupressure participants recorded clinically significant improvements in global PSQI scores. In the auricular therapy arm mean global PSQI reduced from 12.5 at baseline to 8 following completion of treatment. In the self-acupressure arm PSQI reduced from 15 to 11. While in the no treatment arm the mean PSQI score was 14.5 at both baseline and follow up.

Conclusions: Despite the limited sample size, both auricular therapy and self-acupressure may represent potentially effective treatments for cancer patients with insomnia. The positive findings suggest further research is warranted into both treatment modalities.

Gene expression and epigenetic discovery screen reveal methylation of SFRP2 in prostate cancer

Aberrant activation of Wnts is common in human cancers, including prostate. Hypermethylation associated transcriptional silencing of Wnt antagonist genes SFRPs (Secreted Frizzled-Related Proteins) is a frequent oncogenic event. The significance of this is not known in prostate cancer. The objectives of our study were to (i) profile Wnt signaling related gene expression and (ii) investigate methylation of Wnt antagonist genes in prostate cancer. Using TaqMan Low Density Arrays, we identified 15 Wnt signaling related genes with significantly altered expression in prostate cancer; the majority of which were upregulated in tumors. Notably, histologically benign tissue from men with prostate cancer appeared more similar to tumor (r = 0.76) than to benign prostatic hyperplasia (BPH; r = 0.57, p < 0.001). Overall, the expression profile was highly similar between tumors of high (≥ 7) and low (≤ 6) Gleason scores. Pharmacological demethylation of PC-3 cells with 5-Aza-CdR reactivated 39 genes (≥ 2-fold); 40% of which inhibit Wnt signaling. Methylation frequencies in prostate cancer were 10% (2/20) (SFRP1), 64.86% (48/74) (SFRP2), 0% (0/20) (SFRP4) and 60% (12/20) (SFRP5). SFRP2 methylation was detected at significantly lower frequencies in high-grade prostatic intraepithelial neoplasia (HGPIN; 30%, (6/20), p = 0.0096), tumor adjacent benign areas (8.82%, (7/69), p < 0.0001) and BPH (11.43% (4/35), p < 0.0001). The quantitative level of SFRP2 methylation (normalized index of methylation) was also significantly higher in tumors (116) than in the other samples (HGPIN = 7.45, HB = 0.47, and BPH = 0.12). We show that SFRP2 hypermethylation is a common event in prostate cancer. SFRP2 methylation in combination with other epigenetic markers may be a useful biomarker of prostate cancer.

IGFBP7 promoter methylation and gene expression analysis in prostate cancer

PURPOSE: IGFBP7 belongs to a family of insulin-like growth factor-1 regulatory binding proteins. IGFBP7 hypermethylation is associated with its down-regulation in various carcinomas. In prostate cancer IGFBP7 down-regulation has been widely reported but to our knowledge the mechanisms behind this event are unknown. We performed a denaturing high performance liquid chromatography screening and validation strategy to profile the methylation status of IGFBP7 in prostate cancer.

MATERIALS AND METHODS: We combined denaturing high performance liquid chromatography and bisulfite sequencing to examine IGFBP7 methylation in a panel of prostate cancer cell lines. Quantitative methylation specific polymerase chain reaction was used to determine methylation levels in prostate tissue specimens of primary prostate cancer, histologically benign prostate adjacent to tumor, high grade prostatic intraepithelial neoplasia and benign prostatic hyperplasia. IGFBP7 gene expression was measured by quantitative methylation specific polymerase chain reaction in cell lines and tissue specimens.

RESULTS: IGFBP7 was methylated in the 4 prostate cancer cell lines DU145, LNCaP, PC-3 and 22RV1. Quantitative methylation specific polymerase chain reaction analysis revealed that promoter methylation was associated with decreased IGFBP7 expression. Quantitative methylation specific polymerase chain reaction showed that IGFBP7 methylation was more frequently detected in prostate cancer (60% (31/52)) and high grade prostatic intraepithelial neoplasia (40% (6/15)) samples compared to histologically benign prostate adjacent to tumor (10%) and benign prostatic hyperplasia (0%) samples.

CONCLUSIONS: To our knowledge this is the first report of aberrant IGFBP7 promoter hypermethylation and concurrent IGFBP7 gene silencing in prostate cancer cell lines. Results demonstrate that CpG methylation of IGFBP7 may represent a novel biomarker of prostate cancer and pre-invasive neoplasms. Thus, future examination of IGFBP7 methylation and expression in a larger patient cohort, including bodily fluids, is justified to further evaluate its role in a diagnostic and prognostic setting.

The role of secreted frizzled-related protein 2 expression in prostate cancer

AIMS: Improved prostate cancer (PCa)-specific biomarkers are urgently required to distinguish between indolent and aggressive disease, in order to avoid overtreatment. In this study, we investigated the prostatic tissue expression of secreted frizzled-related protein (SFRP)-2.

METHODS AND RESULTS: Following immunohistochemical analysis on PCa tissue microarrays with samples from 216 patients, strong/moderate SFRP-2 expression was observed in epithelial cells of benign prostatic hyperplasia, and negative/weak SFRP-2 expression was observed in the majority of tumour epithelia. However, among Gleason grade 5 carcinomas, 40% showed strong/moderate SFRP-2 expression and 60% showed negative SFRP-2 expression in epithelial cells. Further microscopic evaluation of Gleason grade 5 tumours revealed different morphological patterns, corresponding with differential SFRP-2 expression. The first subgroup (referred to as Type A) appeared to have a morphologically solid growth pattern, whereas the second subgroup (referred to as Type B) appeared to have a more diffuse pattern. Furthermore, 100% (4/4) of Type A patients experienced biochemical recurrence, as compared with 0% (0/6) of Type B patients.

CONCLUSIONS: These results imply: (i) that there is a loss of SFRP-2 expression from benign to malignant prostate glands; and (ii) differential SFRP-2 expression among two possible subgroups of Gleason grade 5 tumours.

Docetaxel maintains its cytotoxic activity under hypoxic conditions in prostate cancer cells

OBJECTIVE: The efficacy of docetaxel has recently been shown to be increased under hypoxic conditions through the down-regulation of hypoxia-inducible-factor 1α (HIF1A). Overexpression of the hypoxia-responsive gene class III β-tubulin (TUBB3) has been associated with docetaxel resistance in a number of cancer models. We propose that administration of docetaxel to prostate patients has the potential to reduce the hypoxic response through HIF1A down-regulation and that TUBB3 down-regulation participates in sensitivity to docetaxel.

METHODS: The cytotoxic effect of docetaxel was determined in both 22Rv1 and DU145 prostate cancer cell lines and correlated with HIF1A expression levels under aerobic and hypoxic conditions. Hypoxia-induced chemoresistance was investigated in a pair of isogenic docetaxel-resistant PC3 cell lines. Basal and hypoxia-induced TUBB3 gene expression levels were determined and correlated with methylation status at the HIF1A binding site.

RESULTS: Prostate cancer cells were sensitive to docetaxel under both aerobic and hypoxic conditions. Hypoxic cytotoxicity of docetaxel was consistent with a reduction in detected HIF1A levels. Sensitivity correlated with reduced basal and hypoxia-induced HIF1A and TUBB3 expression levels. The TUBB3 HIF1A binding site was hypermethylated in prostate cell lines and tumor specimens, which may exclude transcription factor binding and induction of TUBB3 expression. However, acquired docetaxel resistance was not associated with TUBB3 overexpression.

CONCLUSION: These data suggest that the hypoxic nature of a tumor may have relevance as regard to their response to docetaxel. Further investigation into the nature of this relationship may allow identification of novel targets to improve tumor control in prostate cancer patients.