ZFX Mediates Non-canonical Oncogenic Functions of the Androgen Receptor Splice Variant 7 in Castrate-Resistant Prostate Cancer.

Androgen receptor splice variant 7 (AR-V7) is crucial for prostate cancer progression and therapeutic resistance. We show that, independent of ligand, AR-V7 binds both androgen-responsive elements (AREs) and non-canonical sites distinct from full-length AR (AR-FL) targets. Consequently, AR-V7 not only recapitulates AR-FL's partial functions but also regulates an additional gene expression program uniquely via binding to gene promoters rather than ARE enhancers. AR-V7 binding and AR-V7-mediated activation at these unique targets do not require FOXA1 but rely on ZFX and BRD4. Knockdown of ZFX or select unique targets of AR-V7/ZFX, or BRD4 inhibition, suppresses growth of castration-resistant prostate cancer cells. We also define an AR-V7 direct target gene signature that correlates with AR-V7 expression in primary tumors, differentiates metastatic prostate cancer from normal, and predicts poor prognosis. Thus, AR-V7 has both ARE/FOXA1 canonical and ZFX-directed non-canonical regulatory functions in the evolution of anti-androgen therapeutic resistance, providing information to guide effective therapeutic strategies.

Real-World Incidence and Severity of Hypertension Caused by Abiraterone Acetate in Patients With Metastatic Prostate Cancer.

BACKGROUND: Abiraterone acetate (AA) is used in treatment of patients with metastatic prostate cancer. Despite the survival advantage, AA is associated with hypertension due to mineralocorticoid excess syndrome. OBJECTIVE: We conducted a single-center retrospective analysis to evaluate the real-world incidence and severity of AA-induced hypertension. METHODS: Electronic health records were used to collect baseline characteristics and prostate cancer history. Patient data, including blood pressure at each 4 (±2)-week interval, were collected for 24 weeks after the initiation of AA therapy. The primary endpoint was the incidence and severity of AA-induced hypertension. The secondary endpoints include effect of different prednisone dosing regimens and prostate cancer types on hypertensive incidence and the impact of clinical pharmacists' involvement in managing AA-induced hypertension. RESULTS: A total of 142 patients who met our inclusion criteria received AA for metastatic prostate cancer, 73 (51.4%) with metastatic castration-resistant prostate cancer (mCRPC), and 69 (48.6%) with metastatic castration-sensitive prostate cancer (mCSPC). Of all, 43.7% experienced all-grade hypertension, and 28.2% experienced grade 3-4 hypertension. There was no difference in incidence of hypertension between patients receiving 5 mg of prednisone daily and those receiving 5 mg of prednisone twice daily. All-grade hypertension occurred in 39.7% of mCRPC and 47.8% of mCSPC patients (P = 0.33). Thirty-two percent of patients were actively managed by a clinical pharmacist and had an overall trend of reduced hypertension severity after 12 weeks. CONCLUSION AND RELEVANCE: This single-center, retrospective cohort study found that real-world metastatic prostate cancer patients who received AA had substantially higher incidence and severity of hypertension compared with clinical trials regardless of prednisone dose. In patients with mCRPC and mCSPC, the role of prednisone dose in hypertension incidence and severity warrants further investigation. Overall, results indicate the need for closely monitoring hypertension and optimization of anti-hypertensive therapy by multidisciplinary teams in metastatic prostate cancer patients receiving AA.

Quality of life in the year after new diagnosis with advanced prostate cancer for Black and White individuals living in the US.

PURPOSE: To assess differences in baseline and longitudinal quality of life among Black and White individuals in the US with advanced prostate cancer. METHODS: Secondary analysis of data from the International Registry for Men with Advanced Prostate Cancer (IRONMAN) including US participants newly diagnosed with advanced prostate cancer and identifying their race as Black or White from 2017 to 2023. Participants completed the EORTC QLQ-C30 Quality of Life (QoL) Survey at study enrollment and every 3 months thereafter for up to 1 year of follow-up reporting 15 scale scores ranging from 0 to 100 (higher functioning and lower symptom scores represent better quality of life). Linear mixed effects models with race and month of questionnaire completion were fit for each scale, and model coefficients were used to assess differences in baseline and longitudinal QoL by race. RESULTS: Eight hundred and seventy-nine participants were included (20% identifying as Black) at 38 US sites. Compared to White participants at baseline, Black participants had worse constipation (mean 6.3 percentage points higher; 95% CI 2.9-9.8), financial insecurity (5.7 (1.4-10.0)), and pain (5.1 (0.9-9.3)). QoL decreased over time similarly by race; most notably, role functioning decreased by 0.7 percentage points (95% CI -0.8, -0.5) per month. CONCLUSION: There are notable differences in quality of life at new diagnosis of advanced prostate cancer for Black and White individuals, and quality of life declines similarly in the first year for both groups. Interventions that address specific aspects of quality of life in these patients could meaningfully improve the overall survivorship experience.

Cistrome analysis of YY1 uncovers a regulatory axis of YY1:BRD2/4-PFKP during tumorigenesis of advanced prostate cancer.

Castration-resistant prostate cancer (CRPC) is a terminal disease and the molecular underpinnings of CRPC development need to be better understood in order to improve its treatment. Here, we report that a transcription factor Yin Yang 1 (YY1) is significantly overexpressed during prostate cancer progression. Functional and cistrome studies of YY1 uncover its roles in promoting prostate oncogenesis in vitro and in vivo, as well as sustaining tumor metabolism including the Warburg effect and mitochondria respiration. Additionally, our integrated genomics and interactome profiling in prostate tumor show that YY1 and bromodomain-containing proteins (BRD2/4) co-occupy a majority of gene-regulatory elements, coactivating downstream targets. Via gene loss-of-function and rescue studies and mutagenesis of YY1-bound cis-elements, we unveil an oncogenic pathway in which YY1 directly binds and activates PFKP, a gene encoding the rate-limiting enzyme for glycolysis, significantly contributing to the YY1-enforced Warburg effect and malignant growth. Altogether, this study supports a master regulator role for YY1 in prostate tumorigenesis and reveals a YY1:BRD2/4-PFKP axis operating in advanced prostate cancer with implications for therapy.

CD8+ T Cells Impact Rising PSA in Biochemically Relapsed Cancer Patients Using Immunotherapy Targeting Tumor-Associated Antigens.

The management of men with prostate cancer (PCa) with biochemical recurrence following local definitive therapy remains controversial. Early use of androgen deprivation therapy (ADT) leads to significant side effects. Developing an alternative, clinically effective, and well-tolerated therapy remains an unmet clinical need. INO-5150 is a synthetic DNA therapy that includes plasmids encoding for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA), and INO-9012 is a synthetic DNA plasmid encoding for interleukin-12 (IL-12). This phase 1/2, open-label, multi-center study enrolled men with PCa with rising PSA after surgery and/or radiation therapy. Patients were enrolled into one of four treatment arms: arm A, 2 mg of INO-5150; arm B, 8.5 mg of INO-5150; arm C, 2 mg of INO-5150 + 1 mg of INO-9012; and arm D, 8.5 mg of INO-5150 + 1 mg of INO-9012. Patients received study drug with electroporation on day 0 and on weeks 3, 12, and 24, and they were followed for up to 72 weeks. Sixty-two patients were enrolled. Treatment was well tolerated. 81% (50/62) of patients completed all visits. 85% (53/62) remained progression-free at 72 weeks. PSA doubling time (PSADT) was increased when assessed in patients with day 0 PSADT ≤12 months. Immunogenicity was observed in 76% (47/62) of patients by multiple assessments. Analysis indicated that CD38 and perforin co-positive CD8 T cell frequency correlated with attenuated PSA rise (p = 0.05, n = 50).

Rapamycin enhances growth inhibition on urothelial carcinoma cells through LKB1 deficiency-mediated mitochondrial dysregulation.

Rapamycin, a mammalian target of rapamycin (mTOR) inhibitor, has significant potential for application in the treatment of urothelial carcinoma (URCa) of the bladder. Previous studies have shown that regulation of the AMP-activated serine/threonine protein kinase (AMPK)-mTOR signaling pathway enhances apoptosis by inducing autophagy or mitophagy in bladder cancer. Alteration of liver kinase B1 (LKB1)-AMPK signaling leads to mitochondrial dysfunction and the accumulation of autophagy-related proteins as a result of mitophagy, resulting in enhanced cell sensitivity to drug treatments. Therefore, we hypothesized that LKB1 deficiency in URCa cells could lead to increased sensitivity to rapamycin by inducing mitochondrial defect-mediated mitophagy. To test this, we established stable LKBI-knockdown URCa cells and analyzed the effects of rapamycin on their growth. Rapamycin enhanced growth inhibition and apoptosis in stable LKB1-knockdown URCa cells and in a xenograft mouse model. In spite of the stable downregulation of LKB1 expression, rapamycin induced AMPK activation in URCa cells, causing loss of the mitochondrial membrane potential, ATP depletion, and ROS accumulation, indicating an alteration of mitochondrial biogenesis. Our findings suggest that the absence of LKB1 can be targeted to induce dysregulated mitochondrial biogenesis by rapamycin treatment in the design of novel therapeutic strategies for bladder cancer.

Depletion of NBR1 in urothelial carcinoma cells enhances rapamycin-induced apoptosis through impaired autophagy and mitochondrial dysfunction.

Rapamycin is well-recognized in the clinical therapeutic intervention for patients with cancer by specifically targeting mammalian target of rapamycin (mTOR) kinase. Rapamycin regulates general autophagy to clear damaged cells. Previously, we identified increased expression of messenger RNA levels of NBR1 (the neighbor of BRCA1 gene; autophagy cargo receptor) in human urothelial cancer (URCa) cells, which were not exhibited in response to rapamycin treatment for cell growth inhibition. Autophagy plays an important role in cellular physiology and offers protection against chemotherapeutic agents as an adaptive response required for maintaining cellular energy. Here, we hypothesized that loss of NBR1 sensitizes human URCa cells to growth inhibition induced by rapamycin treatment, leading to interruption of protective autophagic activation. Also, the potential role of mitochondria in regulating autophagy was tested to clarify the mechanism by which rapamycin induces apoptosis in NBR1-knockdown URCa cells. NBR1-knockdown URCa cells exhibited enhanced sensitivity to rapamycin associated with the suppression of autophagosomal elongation and mitochondrial defects. Loss of NBR1 expression altered the cellular responses to rapamycin treatment, resulting in impaired ATP homeostasis and an increase in reactive oxygen species (ROS). Although rapamycin treatment-induced autophagy by adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in NBR1-knockdown cells, it did not process the conjugated form of LC3B-II after activation by unc-51 like autophagy-activating kinase 1 (ULK1). NBR1-knockdown URCa cells exhibited rather profound mitochondrial dysfunctions in response to rapamycin treatment as evidenced by Δψm collapse, ATP depletion, ROS accumulation, and apoptosis activation. Therefore, our findings provide a rationale for rapamycin treatment of NBR1-knockdown human urothelial cancer through the regulation of autophagy and mitochondrial dysfunction by regulating the AMPK/mTOR signaling pathway, indicating that NBR1 can be a potential therapeutic target of human urothelial cancer.

Dacomitinib, but not lapatinib, suppressed progression in castration-resistant prostate cancer models by preventing HER2 increase.

BACKGROUND: Despite overexpression of the ErbB (EGFR/HER2/ErbB3/ErbB4) family in castration-resistant prostate cancer (CRPC), some inhibitors of this family, including the dual EGFR/HER2 inhibitor lapatinib, failed in Phase II clinical trials. Hence, we investigated mechanisms of lapatinib resistance to determine whether alternate ErbB inhibitors can succeed. METHODS: The CWR22 human tumour xenograft and its CRPC subline 22Rv1 and sera from lapatinib-treated CRPC patients from a previously reported Phase II trial were used to study lapatinib resistance. Mechanistic studies were conducted in LNCaP, C4-2 and 22Rv1 cell lines. RESULTS: Lapatinib increased intratumoral HER2 protein, which encouraged resistance to this treatment in mouse models. Sera from CRPC patients following lapatinib treatment demonstrated increased HER2 levels. Investigation of the mechanism of lapatinib-induced HER2 increase revealed that lapatinib promotes HER2 protein stability, leading to membrane localisation, EGFR/HER2 heterodimerisation and signalling, elevating cell viability. Knockdown of HER2 and ErbB3, but not EGFR, sensitised CRPC cells to lapatinib. At equimolar concentrations, the recently FDA-approved pan-ErbB inhibitor dacomitinib decreased HER2 protein stability, prevented ErbB membrane localisation (despite continued membrane integrity) and EGFR/HER2 heterodimerisation, thereby decreasing downstream signalling and increasing apoptosis. CONCLUSIONS: Targeting the EGFR axis using the irreversible pan-ErbB inhibitor dacomitinib is a viable therapeutic option for CRPC.

The immunotherapeutic effects of recombinant Bacillus Calmette-Guérin resistant to antimicrobial peptides on bladder cancer cells.

PURPOSE: Although Mycobacterium bovis Bacillus Calmette-Guérin (BCG) is the most widely used bladder cancer immunotherapy, innate immune responses involving antimicrobial peptides (AMPs) cause BCG failure and unwanted side effects. Here, we generated genetically modified BCG strains with improved immunotherapeutic effects by adding genes that confer evasion of AMPs. MATERIALS AND METHODS: We constructed recombinant BCG (rBCG) strains expressing Streptococcal inhibitor of complement (Sic), which confers resistance to human α-defensin-1 and cathelicidin, and d-alanyl carrier protein ligase (dltA), which confers resistance to cationic AMPs. Sic and dltA were separately cloned into the pMV306 plasmid and introduced into BCG via electroporation. Then, the efficacy of the rBCGs was tested in a growth inhibition assay using two bladder cancer cell lines (5637, T24). RESULTS: We confirmed the presence of cDNA segments corresponding to the Sic and dltA genes in total mRNA of the rBCG strains containing Sic (rBCG-Sic) and dltA (rBCG-dltA), and these rBCGs showed higher survival against AMPs. The growth inhibitory effects of rBCGs on bladder cancer cells were significantly enhanced compared to those of the parent BCG, and THP-1 migration also increased. After 8 h of infection, the levels of internalization were higher in rBCG-infected bladder cancer cells than in BCG-infected cells, and cells infected with rBCGs showed increased release of antitumor cytokines, such as IL-6/12, TNF-α, and INF-γ, resulting in inhibition of bacterial killing and immune modulation via antimicrobial peptides. CONCLUSIONS: rBCG-Sic and rBCG-dltA can effectively evade BCG-stimulated AMPs, and may be significantly improved immunotherapeutic tools to treat bladder cancer.

Targeting the Hepatocyte Growth Factor and c-Met Signaling Axis in Bone Metastases.

Bone metastasis is the terminal stage disease of prostate, breast, renal, and lung cancers, and currently no therapeutic approach effectively cures or prevents its progression to bone metastasis. One of the hurdles to the development of new drugs for bone metastasis is the complexity and heterogeneity of the cellular components in the metastatic bone microenvironment. For example, bone cells, including osteoblasts, osteoclasts, and osteocytes, and the bone marrow cells of diverse hematopoietic lineages interact with each other via numerous cytokines and receptors. c-Met tyrosine kinase receptor and its sole ligand hepatocyte growth factor (HGF) are enriched in the bone microenvironment, and their expression correlates with the progression of bone metastasis. However, no drugs or antibodies targeting the c-Met/HGF signaling axis are currently available in bone metastatic patients. This significant discrepancy should be overcome by further investigation of the roles and regulation of c-Met and HGF in the metastatic bone microenvironment. This review paper summarizes the key findings of c-Met and HGF in the development of novel therapeutic approaches for bone metastasis.

Phase II trial of palbociclib in patients with metastatic urothelial cancer after failure of first-line chemotherapy.

BACKGROUND: The majority of urothelial cancers (UC) harbor alterations in retinoblastoma (Rb) pathway genes that can lead to loss of Rb tumour suppressor function. Palbociclib is an oral, selective inhibitor of CDK 4/6 that restores Rb function and promotes cell cycle arrest. METHODS: In this phase II trial, patients with metastatic platinum-refractory UC molecularly selected for p16 loss and intact Rb by tumour immunohistochemistry received palbociclib 125 mg p.o. daily for 21 days of a 28-day cycle. Primary endpoint was progression-free survival at 4 months (PFS4) using a Simon's two-stage design. Next-generation sequencing including Rb pathway alterations was conducted. RESULTS: Twelve patients were enrolled and two patients (17%) achieved PFS4 with insufficient activity to advance to stage 2. No responses were seen. Median PFS was 1.9 months (95% CI 1.8-3.7 months) and median overall survival was 6.3 months (95% CI 2.2-12.6 months). Fifty-eight percent of patients had grade ≥3 hematologic toxicity. There were no CDKN2A alterations found and no correlation of Rb pathway alterations with clinical outcome. CONCLUSIONS: Palbociclib did not demonstrate meaningful activity in selected patients with platinum-refractory metastatic UC. Further development of palbociclib should only be considered with improved integral biomarker selection or in rational combination with other therapies.

Cabozantinib-induced serum creatine kinase elevation and musculoskeletal complaints.

Cabozantinib is a multikinase inhibitor approved for the treatment of metastatic medullary thyroid cancer and advanced renal cell carcinoma (RCC) in patients who have received prior anti-angiogenic therapy. While associations between serum creatine kinase (CK) elevations and other tyrosine kinase inhibitors used for the treatment of solid malignancies have been previously reported, we report a case of cabozantinib-associated CK elevation that was associated with musculoskeletal complaints by an RCC patient. Nine days following initiation of cabozantinib, the patient reported muscle cramps and serum CK had increased from levels 12 months earlier that were within normal limits to a grade 1 elevation of 244 units/L. Despite a dose reduction, her CK continued to rise over the next 2 months, leading to a peak CK of 914 units/L. Due to this grade 3 elevation, cabozantinib was permanently discontinued, and her CK subsequently returned to a grade 1 elevation within one week and then to baseline within 3 weeks. The temporal relationship between drug exposure and CK increase strongly suggests causality. To the authors' knowledge, this is the first reported case of CK elevation attributed to cabozantinib, but cabozantinib-induced CK elevations could be under-reported, and providers should monitor for musculoskeletal complaints during cabozantinib therapy.

Combined Poly(Lactide-Co-Glycolide) Microspheres Containing Diphtheria Toxoid for a Single-shot Immunization.

To develop a single-shot vaccine containing diphtheria toxoid (DT) with a sufficient immune response, poly(lactide-co-glycolide) (PLGA) microspheres were prepared by water-in-oil-in-water double emulsification and solvent extraction techniques using low or high-molecular-weight PLGA (LMW-MS or HMW-MS). Stearic acid (SA) was introduced to HMW-MS (HMW/SA-MS) as a release modulator. Mean particle sizes (dvs, µm) varied between the prepared microspheres, with LMW-MS, HMW-MS, and HMW/SA-MS having the sizes of 29.83, 110.59, and 69.5 µm, respectively; however, the protein entrapment and loading efficiency did not vary, with values of 15.2-16.8 µg/mg and 61-75%, respectively. LMW-MS showed slower initial release (~ 2 weeks) but faster and higher release of antigen during weeks 3~7 than did HMW-MS. HMW/SA-MS showed rapid initial release followed by a continuous release over an extended period of time (~ 12 weeks). Mixed PLGA microspheres (MIX-MS), a combination of HMW/SA-MS and LMW-MS (1:1), demonstrated a sufficient initial antigen release and a subsequent boost release in a pulsatile manner. Serum antibody levels were measured by ELISA after DT immunization of Balb/c mice, and showed a greater response to MIX-MS than to alum-adsorbed DT (control). A lethal toxin challenge test with MIX-MS (a DT dose of 18 Lf) using Balb/c mice revealed complete protection, indicating a good candidate delivery system for a single-shot immunization.

Identification of Downstream Genes of the mTOR Pathway that Predict Recurrence and Progression in Non-Muscle Invasive High-Grade Urothelial Carcinoma of the Bladder.

Microarray analysis was used to investigate the lack of identified mammalian target of rapamycin (mTOR) pathway downstream genes to overcome cross-talk at non-muscle invasive high-grade (HG)-urothelial carcinoma (UC) of the bladder, gene expression patterns, gene ontology, and gene clustering by triple (p70S6K, S6K, and eIF4E) small interfering RNAs (siRNAs) or rapamycin in 5637 and T24 cell lines. We selected mTOR pathway downstream genes that were suppressed by siRNAs more than 2-fold, or were up-regulated or down-regulated by rapamycin more than 2-fold. We validated mTOR downstream genes with immunohistochemistry using a tissue microarray (TMA) of 125 non-muscle invasive HG-UC patients and knockout study to evaluate the synergistic effect with rapamycin. The microarray analysis selected mTOR pathway downstream genes consisting of 4 rapamycin up-regulated genes (FABP4, H19, ANXA10, and UPK3A) and 4 rapamycin down-regulated genes (FOXD3, ATP7A, plexin D1, and ADAMTS5). In the TMA, FABP4, and ATP7A were more expressed at T1 and FOXD3 was at Ta. ANXA10 and ADAMTS5 were more expressed in tumors ≤ 3 cm in diameter. In a multivariate Cox regression model, ANXA10 was a significant predictor of recurrence and ATP7A was a significant predictor of progression in non-muscle invasive HG-UC of the bladder. In an ATP7A knock-out model, rapamycin treatment synergistically inhibited cell viability, wound healing, and invasion ability compared to rapamycin only. Activity of the ANXA10 and ATP7A mTOR pathway downstream genes might predict recurrence and progression in non-muscle invasive HG-UC of the bladder. ATP7A knockout overcomes rapamycin cross-talk.

Posterior reversible encephalopathy syndrome induced by enzalutamide in a patient with castration-resistant prostate cancer.

Posterior reversible encephalopathy syndrome (PRES) is a clinical/radiological syndrome characterized by symptoms that can include seizure, headache, impaired vision and hypertension, and can be confirmed by magnetic resonance imaging. Numerous reports have emerged that describe PRES in cancer patients. The list of medications linked to PRES can include traditional cytotoxic chemotherapeutics (e.g., cisplatin, cyclophosphamide, and high-dose corticosteroids), newer agents that target the vascular endothelial growth factor pathway (e.g., bevacizumab, sunitinib, and pazopanib), and supportive care mediations (e.g., granulocyte colony stimulating factors and erythropoietin). We report, for the first time, a case of PRES that is secondary to treatment with enzalutamide, a potent androgen receptor antagonist used in the treatment of metastatic castration-resistant prostate cancer. Enzalutamide is approved for the treatment of both docetaxel-pretreated and chemotherapy-naïve metastatic castration-resistant prostate cancer. Enzalutamide has been previously linked to the increased risk of seizures. Clinicians should be aware that, in rare cases, patients treated with enzalutamide could potentially be at risk for PRES. If symptoms suggestive of PRES arise in patients receiving enzalutamide, the drug should be discontinued immediately and the diagnostic process should be initiated.

Transcriptional and posttranslational regulation of insulin-like growth factor binding protein-3 by Akt3.

Insulin-like growth factor (IGF)-dependent and -independent antitumor activities of insulin-like growth factor binding protein-3 (IGFBP-3) have been proposed in human non-small cell lung cancer (NSCLC) cells. However, the mechanism underlying regulation of IGFBP-3 expression in NSCLC cells is not well understood. In this study, we show that activation of Akt, especially Akt3, plays a major role in the mRNA expression and protein stability of IGFBP-3 and thus antitumor activities of IGFBP-3 in NSCLC cells. When Akt was activated by genomic or pharmacologic approaches, IGFBP-3 transcription and protein stability were decreased. Conversely, suppression of Akt increased IGFBP-3 mRNA levels and protein stability in NSCLC cell lines. Characterization of the effects of constitutively active form of each Akt subtype (HA-Akt-DD) on IGFBP-3 expression in NSCLC cells and a xenograft model indicated that Akt3 plays a major role in the Akt-mediated regulation of IGFBP-3 expression and thus suppression of Akt effectively enhances the antitumor activities of IGFBP-3 in NSCLC cells with Akt3 overactivation. Collectively, these data suggest a novel function of Akt3 as a negative regulator of IGFBP-3, indicating the possible benefit of a combined inhibition of IGFBP-3 and Akt3 for the treatment of patients with NSCLC.

Arrays of High-Aspect Ratio Microchannels for High-Throughput Isolation of Circulating Tumor Cells (CTCs).

Microsystem-based technologies are providing new opportunities in the area of in vitro diagnostics due to their ability to provide process automation enabling point-of-care operation. As an example, microsystems used for the isolation and analysis of circulating tumor cells (CTCs) from complex, heterogeneous samples in an automated fashion with improved recoveries and selectivity are providing new opportunities for this important biomarker. Unfortunately, many of the existing microfluidic systems lack the throughput capabilities and/or are too expensive to manufacture to warrant their widespread use in clinical testing scenarios. Here, we describe a disposable, all-polymer, microfluidic system for the high-throughput (HT) isolation of CTCs directly from whole blood inputs. The device employs an array of high aspect ratio (HAR), parallel, sinusoidal microchannels (25 µm × 150 µm; W × D; AR = 6.0) with walls covalently decorated with anti-EpCAM antibodies to provide affinity-based isolation of CTCs. Channel width, which is similar to an average CTC diameter (12-25 µm), plays a critical role in maximizing the probability of cell/wall interactions and allows for achieving high CTC recovery. The extended channel depth allows for increased throughput at the optimized flow velocity (2 mm/s in a microchannel); maximizes cell recovery, and prevents clogging of the microfluidic channels during blood processing. Fluidic addressing of the microchannel array with a minimal device footprint is provided by large cross-sectional area feed and exit channels poised orthogonal to the network of the sinusoidal capillary channels (so-called Z-geometry). Computational modeling was used to confirm uniform addressing of the channels in the isolation bed. Devices with various numbers of parallel microchannels ranging from 50 to 320 have been successfully constructed. Cyclic olefin copolymer (COC) was chosen as the substrate material due to its superior properties during UV-activation of the HAR microchannels surfaces prior to antibody attachment. Operation of the HT-CTC device has been validated by isolation of CTCs directly from blood secured from patients with metastatic prostate cancer. High CTC sample purities (low number of contaminating white blood cells, WBCs) allowed for direct lysis and molecular profiling of isolated CTCs.

Rac1 promotes kidney collecting duct repair by mechanically coupling cell morphology to mitotic entry.

Prolonged obstruction of the ureter, which leads to injury of the kidney collecting ducts, results in permanent structural damage, while early reversal allows for repair. Cell structure is defined by the actin cytoskeleton, which is dynamically organized by small Rho guanosine triphosphatases (GTPases). In this study, we identified the Rho GTPase, Rac1, as a driver of postobstructive kidney collecting duct repair. After the relief of ureteric obstruction, Rac1 promoted actin cytoskeletal reconstitution, which was required to maintain normal mitotic morphology allowing for successful cell division. Mechanistically, Rac1 restricted excessive actomyosin activity that stabilized the negative mitotic entry kinase Wee1. This mechanism ensured mechanical G2-M checkpoint stability and prevented premature mitotic entry. The repair defects following injury could be rescued by direct myosin inhibition. Thus, Rac1-dependent control of the actin cytoskeleton integrates with the cell cycle to mediate kidney tubular repair by preventing dysmorphic cells from entering cell division.

Pain and Its Association with Survival for Black and White Individuals with Advanced Prostate Cancer in the United States.

Bone pain is a well-known quality-of-life detriment for individuals with prostate cancer and is associated with survival. This study expands previous work into racial differences in multiple patient-reported dimensions of pain and the association between baseline and longitudinal pain and mortality. This is a prospective cohort study of individuals with newly diagnosed advanced prostate cancer enrolled in the International Registry for Men with Advanced Prostate Cancer (IRONMAN) from 2017 to 2023 at U.S. sites. Differences in four pain scores at study enrollment by race were investigated. Cox proportional hazards models and joint longitudinal survival models were fit for each of the scale scores to estimate HRs and 95% confidence intervals (CI) for the association with all-cause mortality. The cohort included 879 individuals (20% self-identifying as Black) enrolled at 38 U.S. sites. Black participants had worse pain at baseline compared with White participants, most notably a higher average pain rating (mean 3.1 vs. 2.2 on a 10-point scale). For each pain scale, higher pain was associated with higher mortality after adjusting for measures of disease burden, particularly for severe bone pain compared with no pain (HR, 2.47; 95% CI: 1.44-4.22). The association between pain and all-cause mortality was stronger for participants with castration-resistant prostate cancer compared with those with metastatic hormone-sensitive prostate cancer and was similar among Black and White participants. Overall, Black participants reported worse pain than White participants, and more severe pain was associated with higher mortality independent of clinical covariates for all pain scales. SIGNIFICANCE: Black participants with advanced prostate cancer reported worse pain than White participants, and more pain was associated with worse survival. More holistic clinical assessments of pain in this population are needed to determine the factors upon which to intervene to improve quality of life and survivorship, particularly for Black individuals.

A phase 1 study of a chimeric monoclonal antibody against interleukin-6, siltuximab, combined with docetaxel in patients with metastatic castration-resistant prostate cancer.

PURPOSE: Siltuximab is a chimeric, anti-interleukin-6 monoclonal antibody with potential therapeutic benefit in castration-resistant prostate cancer (CRPC) patients. We assessed the safety and tolerability of siltuximab in combination with docetaxel, the pharmacokinetics of docetaxel alone and with siltuximab, and the efficacy and pharmacodynamics of siltuximab plus docetaxel. PATIENTS AND METHODS: In an open-label, dose-escalation, multicenter, phase 1 study, patients with metastatic, progressive CRPC received docetaxel 75 mg/m(2) q3w plus siltuximab 6 mg/kg q2w (n=12), 9 mg/kg q3w (n=12), or 12 mg/kg q3w (n=15). Dose-limiting toxicity (DLT), PSA, and radiologic response according to WHO criteria were evaluated. RESULTS: DLT was reported in 1 of 11 patients receiving 6 mg/kg, 1 of 12 receiving 9 mg/kg, and in 1 of 14 receiving 12 mg/kg. Common Grade ≥ 3 adverse events were neutropenia (73 %), leukopenia (60 %), lymphopenia (30 %), dyspnea (19 %), and fatigue (14 %). Toxicities were not dose dependent. Siltuximab did not affect docetaxel pharmacokinetics. The pharmacokinetic profile for siltuximab in combination was similar to single-agent siltuximab pharmacokinetics. Twenty-three (62 %; 95 % CI 45 %, 78 %) of 37 combination-treated patients achieved a confirmed ≥ 50 % PSA decline. Of 17 patients with measurable disease at baseline, 2 confirmed and 2 unconfirmed radiologic partial responses ranging 190 to 193 days were achieved with 9- and 12-mg/kg siltuximab. C-reactive protein concentrations were suppressed throughout treatment in all patients. CONCLUSION: These results suggest that siltuximab in combination with docetaxel is safe and shows preliminary efficacy in patients with CRPC, although alternative siltuximab schedules may be better tolerated for future studies.