Targeting IL-8 and Its Receptors in Prostate Cancer: Inflammation, Stress Response, and Treatment Resistance.

This review delves into the intricate roles of interleukin-8 (IL-8) and its receptors, CXCR1 and CXCR2, in prostate cancer (PCa), particularly in castration-resistant (CRPC) and metastatic CRPC (mCRPC). This review emphasizes the crucial role of the tumour microenvironment (TME) and inflammatory cytokines in promoting tumour progression and response to tumour cell targeting agents. IL-8, acting through C-X-C chemokine receptor type 1 (CXCR1) and type 2 (CXCR2), modulates multiple signalling pathways, enhancing the angiogenesis, proliferation, and migration of cancer cells. This review highlights the shift in PCa research focus from solely tumour cells to the non-cancer-cell components, including vascular endothelial cells, the extracellular matrix, immune cells, and the dynamic interactions within the TME. The immunosuppressive nature of the PCa TME significantly influences tumour progression and resistance to emerging therapies. Current treatment modalities, including androgen deprivation therapy and chemotherapeutics, encounter persistent resistance and are complicated by prostate cancer's notably "immune-cold" nature, which limits immune system response to the tumour. These challenges underscore the critical need for novel approaches that both overcome resistance and enhance immune engagement within the TME. The therapeutic potential of inhibiting IL-8 signalling is explored, with studies showing enhanced sensitivity of PCa cells to treatments, including radiation and androgen receptor inhibitors. Clinical trials, such as the ACE trial, demonstrate the efficacy of combining CXCR2 inhibitors with existing treatments, offering significant benefits, especially for patients with resistant PCa. This review also addresses the challenges in targeting cytokines and chemokines, noting the complexity of the TME and the need for precision in therapeutic targeting to avoid side effects and optimize outcomes.

Attenuating Adaptive VEGF-A and IL8 Signaling Restores Durable Tumor Control in AR Antagonist-Treated Prostate Cancers.

Inhibiting androgen signaling using androgen signaling inhibitors (ASI) remains the primary treatment for castrate-resistant prostate cancer. Acquired resistance to androgen receptor (AR)-targeted therapy represents a major impediment to durable clinical response. Understanding resistance mechanisms, including the role of AR expressed in other cell types within the tumor microenvironment, will extend the clinical benefit of AR-targeted therapy. Here, we show the ASI enzalutamide induces vascular catastrophe and promotes hypoxia and microenvironment adaptation. We characterize treatment-induced hypoxia, and subsequent induction of angiogenesis, as novel mechanisms of relapse to enzalutamide, highlighting the importance of two hypoxia-regulated cytokines in underpinning relapse. We confirmed AR expression in CD34+ vascular endothelium of biopsy tissue and human vascular endothelial cells (HVEC). Enzalutamide attenuated angiogenic tubule formation and induced cytotoxicity in HVECs in vitro, and rapidly induced sustained hypoxia in LNCaP xenografts. Subsequent reoxygenation, following prolonged enzalutamide treatment, was associated with increased tumor vessel density and accelerated tumor growth. Hypoxia increased AR expression and transcriptional activity in prostate cells in vitro. Coinhibition of IL8 and VEGF-A restored tumor response in the presence of enzalutamide, confirming the functional importance of their elevated expression in enzalutamide-resistant models. Moreover, coinhibition of IL8 and VEGF-A resulted in a durable, effective resolution of enzalutamide-sensitive prostate tumors. We conclude that concurrent inhibition of two hypoxia-induced factors, IL8 and VEGF-A, prolongs tumor sensitivity to enzalutamide in preclinical models and may delay the onset of enzalutamide resistance. IMPLICATIONS: Targeting hypoxia-induced signaling may extend the therapeutic benefit of enzalutamide, providing an improved treatment strategy for patients with resistant disease.

Establishing a Primary Care Alliance for Conducting Cancer Prevention Clinical Research at Community Sites.

In September 2020, the National Cancer Institute convened the first PARTNRS Workshop as an initiative to forge partnerships between oncologists, primary care professionals, and non-oncology specialists for promoting patient accrual into cancer prevention trials. This effort is aimed at bringing about more effective accrual methods to generate decisive outcomes in cancer prevention research. The workshop convened to inspire solutions to challenges encountered during the development and implementation of cancer prevention trials. Ultimately, strategies suggested for protocol development might enhance integration of these trials into community settings where a diversity of patients might be accrued. Research Bases (cancer research organizations that develop protocols) could encourage more involvement of primary care professionals, relevant prevention specialists, and patient representatives with protocol development beginning at the concept level to improve adoptability of the trials within community facilities, and consider various incentives to primary care professionals (i.e., remuneration). Principal investigators serving as liaisons for the NCORP affiliates and sub-affiliates, might produce and maintain "Prevention Research Champions" lists of PCPs and non-oncology specialists relevant in prevention research who can attract health professionals to consider incorporating prevention research into their practices. Finally, patient advocates and community health providers might convince patients of the benefits of trial-participation and encourage "shared-decision making."

Clinical and functional characterization of CXCR1/CXCR2 biology in the relapse and radiotherapy resistance of primary PTEN-deficient prostate carcinoma.

Functional impairment of the tumour suppressor PTEN is common in primary prostate cancer and has been linked to relapse post-radiotherapy (post-RT). Pre-clinical modelling supports elevated CXC chemokine signalling as a critical mediator of PTEN-depleted disease progression and therapeutic resistance. We assessed the correlation of PTEN deficiency with CXC chemokine signalling and its association with clinical outcomes. Gene expression analysis characterized a PTEN LOW/CXCR1HIGH/CXCR2HIGH cluster of tumours that associates with earlier time to biochemical recurrence [hazard ratio (HR) 5.87 and 2.65, respectively] and development of systemic metastasis (HR 3.51). In vitro, CXCL signalling was further amplified following exposure of PTEN-deficient prostate cancer cell lines to ionizing radiation (IR). Inhibition of CXCR1/2 signalling in PTEN-depleted cell-based models increased IR sensitivity. In vivo, administration of a CXCR1/2-targeted pepducin (x1/2pal-i3), or CXCR2-specific antagonist (AZD5069), in combination with IR to PTEN-deficient xenografts attenuated tumour growth and progression compared to control or IR alone. Post-mortem analysis confirmed that x1/2pal-i3 administration attenuated IR-induced CXCL signalling and anti-apoptotic protein expression. Interventions targeting CXC chemokine signalling may provide an effective strategy to combine with RT in locally advanced prostate cancer patients with known presence of PTEN-deficient foci.

Cytoplasmic FLIP(S) and nuclear FLIP(L) mediate resistance of castrate-resistant prostate cancer to apoptosis induced by IAP antagonists.

Expression of tumor necrosis factor-α (TNFα) in the serum of prostate cancer patients is associated with poorer outcome and progression to castrate-resistant (CRPC) disease. TNFα promotes the activity of NFκB, which regulates a number of anti-apoptotic and proinflammatory genes, including those encoding the inhibitor of apoptosis proteins (IAPs); however, in the presence of IAP antagonists, TNFα can induce cell death. In the presence of recombinant or macrophage-derived TNFα, we found that IAP antagonists triggered degradation of cIAP1 and induced formation of Complex-IIb, consisting of caspase-8, FADD and RIPK1 in CRPC models; however, no, or modest levels of apoptosis were induced. This resistance was found to be mediated by both the long (L) and short (S) splice forms of the caspase-8 inhibitor, FLIP, another NFκB-regulated protein frequently overexpressed in CRPC. By decreasing FLIP expression at the post-transcriptional level in PC3 and DU145 cells (but not VCaP), the Class-I histone deacetylase (HDAC) inhibitor Entinostat promoted IAP antagonist-induced cell death in these models in a manner dependent on RIPK1, FADD and Caspase-8. Of note, Entinostat primarily targeted the nuclear rather than cytoplasmic pool of FLIP(L). While the cytoplasmic pool of FLIP(L) was highly stable, the nuclear pool was more labile and regulated by the Class-I HDAC target Ku70, which we have previously shown regulates FLIP stability. The efficacy of IAP antagonist (TL32711) and Entinostat combination and their effects on cIAP1 and FLIP respectively were confirmed in vivo, highlighting the therapeutic potential for targeting IAPs and FLIP in proinflammatory CRPC.

Positive Impact of a Pilot Pharmacist-Run Diabetes Pharmacotherapy Clinic in Solid-Organ Transplant Recipients.

PURPOSE: Post-transplant diabetes mellitus (PTDM) can lead to significant morbidity and cardiovascular death with a functioning graft. A paucity of literature exists regarding glycemic control in solid-organ transplant (SOT) recipients, including pharmacist management of PTDM. This study aimed to assess the impact of pharmacist interventions on diabetes management in a pharmacist-run PTDM clinic. METHODS: This was a single-center, prospective, observational study of 24 adult SOT recipients enrolled in a pilot pharmacist-managed PTDM clinic from 1 January to 30 June 2015. RESULTS: Improvements were realized in markers of glycemic control, including changes in A1C, average daily self-monitoring of blood glucose (SMBG) results, fasting SMBG results, and pre-lunch SMBG results from enrollment through at least 3 months of follow-up. Median A1C decreased significantly from 8.05% (interquartile range [IQR] 6.33-11.75) at baseline to 6.45% (IQR 6.05-7.3) at the last follow-up encounter (P = 0.0010). Average daily SMBG results decreased significantly from a median of 191 mg/dL (IQR 138-232 mg/dL) at baseline to 125 mg/dL (IQR 111-167 mg/dL) at the final encounter (P = 0.0023). Median fasting and pre-lunch SMBG results decreased significantly from 153 mg/dL (IQR 117-208 mg/dL) at baseline to 120 mg/dL (IQR 102-134 mg/dL) (P = 0.0064) and from 212 mg/dL (IQR 159-258 mg/dL) to 122 mg/dL (IQR 110-169 mg/dL) (P = 0.0161), respectively. Changes from baseline in other SMBG values, lipid levels, and BMI were not statistically significant. CONCLUSION: The results of our study demonstrate that a pharmacist-managed PTDM clinic can significantly affect glycemic control in SOT recipients.

A gene signature associated with PTEN activation defines good prognosis intermediate risk prostate cancer cases.

Accurate identification of intermediate risk (Gleason 3 + 4 = 7) prostate cancer patients with low risk of disease progression is an unmet challenge in treatment decision making. Here we describe a gene signature that could guide clinicians in the selection of patients with intermediate stage clinically localized prostate cancer for active surveillance. We examined six major drivers of aggressive disease - PTEN, MYC, RB1, TP53, AURKA, AR - by immunohistochemistry in a focused (N = 69) cohort predominantly consisting of intermediate risk prostate cancer. Fuzzy clustering and unsupervised hierarchical clustering were utilized to determine the correlation of gene expression and methylation values with immunohistochemical expression. From the immunohistochemistry observation, we found that intermediate risk prostate cancer cases could be classified as 'complex' (differential expression of more than one driver) or 'simple' (differential expression of only one). Focussing on the 'simple' cases, expression and methylation profiling generated signatures which correlated tightly only with differential PTEN expression and not with any of the other drivers assessed by immunohistochemistry. From this, we derived a geneset of 35 genes linked to high PTEN expression. Subsequently we determined its prognostic significance in intermediate-risk cases extracted from three publicly available clinical datasets (Total N = 215). Hence, this study shows that, by using immunohistochemistry as an upfront stratifier of intermediate risk prostate cancers, it is possible to identify through differential gene expression profiling a geneset with prognostic power across multiple cohorts. This strategy has not been used previously and the signature has the potential to impact on treatment decisions in patients for whom decision making is currently empirical at best.

Impact of a pharmacist-led vaccine recommendation program for pediatric kidney transplant candidates.

Pediatric transplant recipients commonly have deficient vaccination status at the time of transplantation. Utilizing transplant pharmacists to improve vaccination rates has not previously been described. This single-center, retrospective study evaluated the impact of transplant pharmacist interventions on the completion rate of vaccination schedules at time of kidney transplant. Patients who received pharmacist-led vaccination recommendations prior to transplant were compared to patients without pharmacist recommendations. Forty-seven pediatric patients were included: 24 intervention patients and 23 control patients. The median percentage of up-to-date vaccinations at time of transplant was significantly higher in intervention group (91%; IQR 86%-100%) vs. control group (80%; IQR 71%-80%) (P<.0001). The median change in up-to-date vaccinations from time of evaluation to time of transplant was also significantly higher in the intervention group (7.5%) compared to the control group (0%) (P<.0001). There was no difference in live vaccination rates. No patients in either group were readmitted for a vaccine-preventable disease within 6 months post-transplant. With pharmacist intervention, significantly more patients were up to date with vaccination schedules at the time of transplant. These results suggest that a transplant pharmacist may serve as a valuable resource to increase vaccination schedule compliance between time of evaluation and transplantation.

PTEN deficiency promotes macrophage infiltration and hypersensitivity of prostate cancer to IAP antagonist/radiation combination therapy.

PTEN loss is prognostic for patient relapse post-radiotherapy in prostate cancer (CaP). Infiltration of tumor-associated macrophages (TAMs) is associated with reduced disease-free survival following radical prostatectomy. However, the association between PTEN loss, TAM infiltration and radiotherapy response of CaP cells remains to be evaluated. Immunohistochemical and molecular analysis of surgically-resected Gleason 7 tumors confirmed that PTEN loss correlated with increased CXCL8 expression and macrophage infiltration. However PTEN status had no discernable correlation with expression of other inflammatory markers by CaP cells, including TNF-α. In vitro, exposure to conditioned media harvested from irradiated PTEN null CaP cells induced chemotaxis of macrophage-like THP-1 cells, a response partially attenuated by CXCL8 inhibition. Co-culture with THP-1 cells resulted in a modest reduction in the radio-sensitivity of DU145 cells. Cytokine profiling revealed constitutive secretion of TNF-α from CaP cells irrespective of PTEN status and IR-induced TNF-α secretion from THP-1 cells. THP-1-derived TNF-α increased NFκB pro-survival activity and elevated expression of anti-apoptotic proteins including cellular inhibitor of apoptosis protein-1 (cIAP-1) in CaP cells, which could be attenuated by pre-treatment with a TNF-α neutralizing antibody. Treatment with a novel IAP antagonist, AT-IAP, decreased basal and TNF-α-induced cIAP-1 expression in CaP cells, switched TNF-α signaling from pro-survival to pro-apoptotic and increased radiation sensitivity of CaP cells in co-culture with THP-1 cells. We conclude that targeting cIAP-1 can overcome apoptosis resistance of CaP cells and is an ideal approach to exploit high TNF-α signals within the TAM-rich microenvironment of PTEN-deficient CaP cells to enhance response to radiotherapy.

PTEN mRNA detection by chromogenic, RNA in situ technologies: a reliable alternative to PTEN immunohistochemistry.

Immunohistochemical staining for phosphatase and tensin homolog (PTEN) does not have either an acceptable standard protocol or concordance of scoring between pathologists. Evaluation of PTEN mRNA with a unique and verified sequence probe may offer a realistic alternative providing a robust and reproducible protocol. In this study, we have evaluated an in situ hybridization (ISH) protocol for PTEN mRNA using RNAScope technology and compared it with a standard protocol for PTEN immunohistochemistry (IHC). PTEN mRNA expression by ISH was consistently more sensitive than PTEN IHC, with 56% of samples on a mixed-tumor tissue microarray (TMA) showing high expression by ISH compared with 42% by IHC. On a prostate TMA, 49% of cases showed high expression by ISH compared with 43% by IHC. Variations in PTEN mRNA expression within malignant epithelium were quantifiable using image analysis on the prostate TMAs. Within tumors, clear overexpression of PTEN mRNA on malignant epithelium compared with benign epithelium was frequently observed and quantified. The use of SpotStudio software in the mixed-tumor TMA allowed for clear demonstration of varying levels of PTEN mRNA between tumor samples by the mRNA methodology. This was evident by the quantifiable differences between distinct oropharyngeal tumors (up to 3-fold increase in average number of spots per cell between 2 cases). mRNA detection of PTEN or other biomarkers, for which optimal or standardized immunohistochemical techniques are not available, represents a means by which heterogeneity of expression within focal regions of tumor can be explored with more confidence.

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.

Rationale and Means to Target Pro-Inflammatory Interleukin-8 (CXCL8) Signaling in Cancer.

It is well established that chronic inflammation underpins the development of a number of human cancers, with pro-inflammatory signaling within the tumor microenvironment contributing to tumor progression and metastasis. CXCL8 is an ELR+ pro-inflammatory CXC-chemokine which mediates its effects via signaling through two G protein-coupled receptors, CXCR1 and CXCR2. Elevated CXCL8-CXCR1/2 signaling within the tumor microenvironment of numerous cancers is known to enhance tumor progression via activation of signaling pathways promoting proliferation, angiogenesis, migration, invasion and cell survival. This review provides an overview of established roles of CXCL8-CXCR1/2 signaling in cancer and subsequently, discusses the possible strategies of targeting CXCL8-CXCR1/2 signaling in cancer, covering indirect strategies (e.g., anti-inflammatories, NFκB inhibitors) and direct CXCL8 or CXCR1/2 inhibition (e.g., neutralizing antibodies, small molecule receptor antagonists, pepducin inhibitors and siRNA strategies). Reports of pre-clinical cancer studies and clinical trials using CXCL8-CXCR1/2-targeting strategies for the treatment of inflammatory diseases will be discussed. The future translational opportunities for use of such agents in oncology will be discussed, with emphasis on exploitation in stratified populations.

Intravenous sodium bicarbonate therapy in severely acidotic diabetic ketoacidosis.

BACKGROUND: The use of intravenous bicarbonate in diabetic ketoacidosis (DKA) may be considered for patients with a pH less than 6.9 according to the American Diabetes Association. The impact of this therapy on resolution of acidosis in patients with DKA is unclear. OBJECTIVE: To determine whether the use of intravenous bicarbonate therapy was associated with improved outcomes in patients with severe DKA who were seen in the emergency department. METHODS: This review was conducted from 2007 to 2011 in the emergency department of a tertiary teaching hospital. Adults diagnosed with DKA with an initial pH less than 7.0 were included. Patients were stratified into 2 groups based on receipt of intravenous bicarbonate. The primary study outcome was time to resolution of acidosis, defined as return to pH greater than 7.2. Secondary outcomes included length of stay; continuous infusion insulin use; and intravenous fluid, po tas si um, and insulin requirements within the first 24 hours of hospital admission, beginning upon admittance to the emergency department. We also conducted a subgroup analysis of patients with an initial pH less than 6.9. RESULTS: There was no significant difference in time to resolution of acidosis (8 hours vs 8 hours; p = 0.7) or time to hospital discharge (68 hours vs 61 hours; p = 0.3) between patients who received intravenous bicarbonate (n = 44) compared with those who did not (n = 42). The median dose of intravenous bicarbonate was 100 mEq (100-150) for patients who received intravenous bicarbonate. Insulin and fluid requirements in the first 24 hours were significantly higher in patients who received intravenous bicarbonate compared with those who did not (100 units vs 86 units; p = 0.04 and 7.6 L vs 7.2 L; p = 0.01, respectively). There was no significant difference in hours of continuous insulin infusion (27 hours vs 26 hours; p = 0.09) or potassium requirements in the first 24 hours of hospital stay (135 mEq vs 120 mEq; p = 0.84). CONCLUSIONS: Intravenous bicarbonate therapy did not decrease time to resolution of acidosis or time to hospital discharge for patients with DKA with an initial pH less than 7.0.

Potentiation of inflammatory CXCL8 signalling sustains cell survival in PTEN-deficient prostate carcinoma.

BACKGROUND: Inflammation and genetic instability are enabling characteristics of prostate carcinoma (PCa). Inactivation of the tumour suppressor gene phosphatase and tensin homolog (PTEN) is prevalent in early PCa. The relationship of PTEN deficiency to inflammatory signalling remains to be characterised. OBJECTIVE: To determine how loss of PTEN functionality modulates expression and efficacy of clinically relevant, proinflammatory chemokines in PCa. DESIGN, SETTING, AND PARTICIPANTS: Experiments were performed in established cell-based PCa models, supported by pathologic analysis of chemokine expression in prostate tissue harvested from PTEN heterozygous (Pten(+/-)) mice harbouring inactivation of one PTEN allele. INTERVENTIONS: Small interfering RNA (siRNA)- or small hairpin RNA (shRNA)-directed strategies were used to repress PTEN expression and resultant interleukin-8 (CXCL8) signalling, determined under normal and hypoxic culture conditions. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Changes in chemokine expression in PCa cells and tissue were analysed by real-time polymerase chain reaction (PCR), immunoblotting, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry; effects of chemokine signalling on cell function were assessed by cell cycle analysis, apoptosis, and survival assays. RESULTS AND LIMITATIONS: Transient (siRNA) or prolonged (shRNA) PTEN repression increased expression of CXCL8 and its receptors, chemokine (C-X-C motif) receptor (CXCR) 1 and CXCR2, in PCa cells. Hypoxia-induced increases in CXCL8, CXCR1, and CXCR2 expression were greater in magnitude and duration in PTEN-depleted cells. Autocrine CXCL8 signalling was more efficacious in PTEN-depleted cells, inducing hypoxia-inducible factor-1 (HIF-1) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription and regulating genes involved in survival and angiogenesis. Increased expression of the orthologous chemokine KC was observed in regions displaying atypical cytologic features in Pten(+/-) murine prostate tissue relative to normal epithelium in wild-type PTEN (Pten(WT)) glands. Attenuation of CXCL8 signalling decreased viability of PCa cells harbouring partial or complete PTEN loss through promotion of G1 cell cycle arrest and apoptosis. The current absence of clinical validation is a limitation of the study. CONCLUSIONS: PTEN loss induces a selective upregulation of CXCL8 signalling that sustains the growth and survival of PTEN-deficient prostate epithelium.

Retrospective analysis of levetiracetam compared to phenytoin for seizure prophylaxis in adults with traumatic brain injury.

BACKGROUND: Phenytoin is standard of care for seizure prophylaxis following traumatic brain injury (TBI). Levetiracetam, an alternative antiepileptic drug, is utilized for seizure prophylaxis despite limited data supporting its use. OBJECTIVE: Our primary outcome was post-TBI seizure activity measured by electroencephalogram (EEG) for levetiracetam versus phenytoin. Secondary outcomes were length of intensive care unit (ICU) stay, requirement for additional antiepileptic drugs (AED), and drug and monitoring costs. METHODS: A retrospective review was performed of patients admitted to neurosurgical or surgical trauma ICU. Adult patients with at least 1 day of EEG monitoring were included. Patients were excluded if they had history of epilepsy, prior TBI, less than 48 hours of AED therapy, or additional AED prior to EEG monitoring. RESULTS: A total 90 patients met inclusion criteria, with 18 receiving levetiracetam and 72 receiving phenytoin. Prevalence of EEG-confirmed seizure activity was similar between the levetiracetam and phenytoin groups (28% vs 29%; P = .99). ICU length of stay (13 vs 18 days; P = .28), time to EEG-confirmed seizure activity (4 vs 6 days; P = .24), and duration of seizure prophylaxis (9 vs 14 days; P = .18) were also similar. The median daily cost of levetiracetam therapy was $43 compared to $55 for phenytoin therapy and monitoring (P = .08). When all anticonvulsant therapy and monitoring were included, costs were lower for the levetiracetam group ($45 vs $83; P = .02). CONCLUSION: Levetiracetam may provide an alternative treatment option for seizure prevention in TBI patients in the ICU. Total antiepileptic drug and monitoring costs were lower for levetiracetam patients.

Constitutive and treatment-induced CXCL8-signalling selectively modulates the efficacy of anti-metabolite therapeutics in metastatic prostate cancer.

BACKGROUND: The current study was undertaken to characterize the effect of anti-metabolites on inducing CXCL8 signaling and determining whether the constitutive and/or drug-induced CXCL8 signaling in metastatic prostate cancer (CaP) cells modulates their sensitivity to this class of agent. METHODS: The response of metastatic CaP cells to 5-Fluorouracil (5-FU), Pemetrexed or Tomudex was determined using cell count assays, flow cytometry and PARP cleavage analysis. Quantitative-PCR, ELISA and immunoblots were employed to determine effects of drugs or CXCL8 administration on target gene/protein expression. RESULTS: Administration of 5-FU but not pemetrexed potentiated CXCL8 secretion and increased CXCR1 and CXCR2 gene expression in metastatic PC3 cells. Consistent with this, the inhibition of CXCL8 signaling using a CXCR2 antagonist, AZ10397767, increased the cytotoxicity of 5-FU by 4-fold (P<0.001), and increased 5-FU-induced apoptosis in PC3 cells (P<0.01). In contrast, while administration of AZ10397767 had no effect on the sensitivity of pemetrexed, the CXCR2 antagonist exerted the greatest effect in increasing the sensitivity of PC3 cells to Tomudex, a directed thymidylate synthase (TS) inhibitor. Subsequent experiments confirmed that administration of recombinant human CXCL8 increased TS expression, a response mediated in part by the CXCR2 receptor. Moreover, siRNA-mediated knockdown of the CXCL8-target gene Bcl-2 increased the sensitivity of PC3 cells to 5-FU. CONCLUSIONS: CXCL8 signaling provides a selective resistance of metastatic prostate cancer cells to specific anti-metabolites by promoting a target-associated resistance, in addition to underpinning an evasion of treatment-induced apoptosis.

Elevation of c-FLIP in castrate-resistant prostate cancer antagonizes therapeutic response to androgen receptor-targeted therapy.

PURPOSE: To characterize the importance of cellular Fas-associated death domain (FADD)-like interleukin 1ß-converting enzyme (FLICE) inhibitory protein (c-FLIP), a key regulator of caspase-8 (FLICE)-promoted apoptosis, in modulating the response of prostate cancer cells to androgen receptor (AR)-targeted therapy. EXPERIMENTAL DESIGN: c-FLIP expression was characterized by immunohistochemical analysis of prostatectomy tissue. The functional importance of c-FLIP to survival and modulating response to bicalutamide was studied by molecular and pharmacologic interventions. RESULTS: c-FLIP expression was increased in high-grade prostatic intraepithelial neoplasia and prostate cancer tissue relative to normal prostate epithelium (P < 0.001). Maximal c-FLIP expression was detected in castrate-resistant prostate cancer (CRPC; P < 0.001). In vitro, silencing of c-FLIP induced spontaneous apoptosis and increased 22Rv1 and LNCaP cell sensitivity to bicalutamide, determined by flow cytometry, PARP cleavage, and caspase activity assays. The histone deacetylase inhibitors (HDACi), droxinostat and SAHA, also downregulated c-FLIP expression, induced caspase-8- and caspase-3/7-mediated apoptosis, and increased apoptosis in bicalutamide-treated cells. Conversely, the elevated expression of c-FLIP detected in the CRPC cell line VCaP underpinned their insensitivity to bicalutamide and SAHA in vitro. However, knockdown of c-FLIP induced spontaneous apoptosis in VCaP cells, indicating its relevance to cell survival and therapeutic resistance. CONCLUSION: c-FLIP reduces the efficacy of AR-targeted therapy and maintains the viability of prostate cancer cells. A combination of HDACi with androgen deprivation therapy may be effective in early-stage disease, using c-FLIP expression as a predictive biomarker of sensitivity. Direct targeting of c-FLIP, however, may be relevant to enhance the response of existing and novel therapeutics in CRPC.

Monotherapy or combination therapy? The Pseudomonas aeruginosa conundrum.

Abstract The use of combination antibiotic therapy for severe pseudomonal infections is a standard practice in many hospitals; however, the data supporting its use are somewhat unclear. Possible benefits of combination therapy for Pseudomonas aeruginosa infections include in vitro antibiotic synergy, prevention of the emergence of bacterial resistance while receiving therapy, and improved adequacy of empiric therapy. Unfortunately, the potential disadvantages are also considerable, the most worrisome of which are drug toxicity and creation of multidrug-resistant organisms in the environment. Many in vitro and animal studies have attempted to shed light on this clinically challenging issue; however, these studies have often yielded conflicting results and used different study methods, which limits the clinical utility of the results. Clinical studies have also attempted to clarify this issue, particularly in patients with serious pseudomonal infections such as bacteremia and ventilator-associated pneumonia, but again, often resulted in conflicting conclusions. Thus, we performed a MEDLINE search (1950-May 2010) of clinical and in vitro studies evaluating the use of antibiotic combination therapy and monotherapy for bacteremia and pneumonia due to P. aeruginosa. Although a clear answer still eludes this controversy, combination therapy for seriously ill patients suspected of having pseudomonal infection has been shown, with considerable evidence, to improve the likelihood of an active agent being included in the initial antibiotic regimen of these patients. The clinical status of the patient and true likelihood of encountering a multidrug-resistant organism should be evaluated before deciding on empiric combination therapy. Future research may be able to better identify which patient populations might receive the most benefit from combination therapy rather than using combination therapy for everyone at risk for these infections.

Pravastatin versus simvastatin for prevention of contrast-induced nephropathy.

Contrast-induced nephropathy (CIN) is associated with long-term morbidity, mortality, and increased health care costs. It has been suggested that statins have pleiotropic effects countering inflammatory and oxidative stress involved in CIN. Several studies support this theory; however, previously published studies have not evaluated the potential differences between statins in reducing the incidence of CIN. The purpose of this retrospective, single-center trial was to compare the incidence of CIN in patients receiving simvastatin or pravastatin therapy undergoing percutaneous coronary intervention (PCI). A total of 261 patients were included (145 received simvastatin and 116 received pravastatin) with the majority undergoing elective PCI. The population was predominantly male (65%), Hispanic (65%), and diabetic (62%), with a mean age of 59 years and a low-density lipoprotein (LDL) of 85 mg/dL. No significant differences were found between groups for risk factors or prophylactic strategies (eg, hydration). Contrast-induced nephropathy occurred in 26 patients (17.9%) in the simvastatin group versus 10 (8.6%) in the pravastatin group (P < .05). No patients required dialysis as a result of contrast administration. Acute kidney injury (AKI) occurred in 21 patients (14.5%) in the simvastatin group compared to 8 (6.9%) in the pravastatin group (P < .05). In multivariate analysis, the difference between statins remained an independent predictor for the development of CIN. In conclusion, patients on pravastatin had a significantly lower incidence of CIN compared to patients on simvastatin.