Upward-directed exit-site of the swan-neck catheter and "Easy-to-disinfect the backside area of exit-site" may prevent PD complications

BACKGROUND

Upward-directed exit-site has been believed to be the worst for frequent ESI by an old retrospective study using straight catheters. No comparison study of 3 exit-site directions using swan-neck catheter has been performed regarding which direction is the best for our endpoints, Easy-to-see the backside area of exit-site: ESBE, Easy-to-disinfect the backside area of exit-site: EDBE, reduction of both exit-site infection (ESI), symptomatic catheter dislocation and peritonitis.

METHODS

We assessed the relationship of exit-site direction with our endpoints in a quantitative cross-sectional, multicentered questionnaire survey. Patients who received either non-surgical catheter implantation or exit-site surgery were excluded.

RESULTS

The numbers (percentage) of exit-site directions in included 291 patients were upward 79 (26.0), lateralward 108 (37.5) and downward 105 (36.5). Cochran-Armitage analysis showed a significant step-ladder increase in the prevalence of ESI as the direction changed from upward to lateralward to downward (0.15 ± 0.41, 0.25 ± 0.54, 0.38 ± 0.69 episodes/patient-year, p = 0.03). Multivariable regression analysis revealed the upward exit-site independently associates with both higher frequency of ESBE (OR 5.55, 95% CI 2.23-16.45, p < 0.01) and reduction of prevalence of ESI (OR 0.55, 95%CI 0.27-0.98, p = 0.04). Positive association between the prevalence of symptomatic catheter dislocation and ESI (OR 2.84, 95% CI 1.27-7.82, p = 0.01), and inverse association between EDBE and either prevalence of symptomatic catheter dislocation (OR 0.27, 95% CI 0.11-0.72) or peritonitis (OR 0.48, 95% CI 0.23-0.99) observed.

CONCLUSION

Upward-directed swan-neck catheter exit-site may be the best for both ESBE and prevention of ESI. EDBE may reduce catheter dislocation and peritonitis. Symptomatic catheter dislocation may predict ESI.

Regulatory T-cells activated in metastatic draining lymph nodes possibly suppress cancer immunity in cancer tissues of head and neck squamous cell cancer

Regulatory T cells (Tregs) play an important role in creating an immunosuppressive microenvironment in cancer tissues. However, the mechanisms by which Tregs are activated and suppress cancer immunity remain unclear. To elucidate these mechanisms, we performed a T cell receptor (TCR) repertoire analysis of Tregs and conventional T cells in peripheral blood, draining lymph nodes (DLNs), and cancer tissues of patients with head and neck squamous cell cancer (HNSCC). We found that the TCR repertoire was skewed in cancer tissue and metastatic DLNs (M-DLNs) compared with non-metastatic DLNs, and TCR repertoire similarities in Tregs and CD8+ T cells between M-DLNs and cancer tissue were high compared with those at other sites. These results suggest that Tregs and CD8+ T cells are activated in M-DLNs and cancer tissues by cancer antigens, such as neoantigens, and shared antigens and Tregs suppress CD8+ T cell function in a cancer antigen-specific manner in M-DLNs and cancer tissue. Moreover, M-DLNs might be a source of Tregs and CD8+ T cells recruited into the cancer tissue. Therefore, targeting Tregs in M-DLNs in an antigen-specific manner is expected to be a novel immunotherapeutic strategy for HNSCCs.

Hypoxia-related carbonic anhydrase 9 induces serpinB9 expression in cancer cells and apoptosis in T cells via acidosis

Hypoxia is a common feature of solid tumors. However, the impact of hypoxia on immune cells within tumor environments remains underexplored. Carbonic anhydrase 9 (CA9) is a hypoxia-responsive tumor-associated enzyme. We previously noted that regardless of human CA9 (hCA9) expression, hCA9-expressing mouse renal cell carcinoma RENCA (RENCA/hCA9) presented as a "cold" tumor in syngeneic aged mice. This study delves into the mechanisms behind this observation. Gene microarray analyses showed that RENCA/hCA9 cells exhibited elevated mouse serpinB9, an inhibitor of granzyme B, relative to RENCA cells. Corroborating this, RENCA/hCA9 cells displayed heightened resistance to antigen-specific cytotoxic T cells compared with RENCA cells. Notably, siRNA-mediated serpinB9 knockdown reclaimed this sensitivity. In vivo tests showed that serpinB9 inhibitor administration slowed RENCA tumor growth, but this effect was reduced in RENCA/hCA9 tumors, even with adjunctive immune checkpoint blockade therapy. Further, inducing hypoxia or introducing the mouse CA9 gene upregulated serpinB9 expression, and siRNA-mediated knockdown of the mouse CA9 gene inhibited the hypoxia-induced induction of serpinB9 in the original RENCA cells. Supernatants from RENCA/hCA9 cultures had lower pH than those from RENCA, suggesting acidosis. This acidity enhanced serpinB9 expression and T cell apoptosis. Moreover, coculturing with RENCA/hCA9 cells more actively prompted T cell apoptosis than with RENCA cells. Collectively, these findings suggest hypoxia-associated CA9 not only boosts serpinB9 in cancer cells but also synergistically intensifies T cell apoptosis via acidosis, characterizing RENCA/hCA9 tumors as "cold."

Tracing Photoinduced Hydrogen Migration in Alcohol Dications from Time-Resolved Molecular-Frame Photoelectron Angular Distributions

The recent implementation of attosecond and few-femtosecond X-ray pump/X-ray probe schemes in large-scale free-electron laser facilities has opened the way to visualize fast nuclear dynamics in molecules with unprecedented temporal and spatial resolution. Here, we present the results of theoretical calculations showing how polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) can be used to visualize the dynamics of hydrogen migration in methanol, ethanol, propanol, and isopropyl alcohol dications generated by X-ray irradiation of the corresponding neutral species. We show that changes in the PA-MFPADs with the pump-probe delay as a result of intramolecular photoelectron diffraction carry information on the dynamics of hydrogen migration in real space. Although visualization of this dynamics is more straightforward in the smaller systems, methanol and ethanol, one can still recognize the signature of that motion in propanol and isopropyl alcohol and assign a tentative path to it. A possible pathway for a corresponding experiment requires an angularly resolved detection of photoelectrons in coincidence with molecular fragment ions used to define a molecular frame of reference. Such studies have become, in principle, possible since the first XFELs with sufficiently high repetition rates have emerged. To further support our findings, we provide experimental evidence of H migration in ethanol-OD from ion-ion coincidence measurements performed with synchrotron radiation.

A multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan

BACKGROUND

This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications.

METHODS

Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest.

RESULTS

Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines.

CONCLUSION

PD catheter placement in Japan was proven to be safe and appropriate.

Artesunate and cisplatin synergistically inhibit HNSCC cell growth and promote apoptosis with artesunate‑induced decreases in Rb and phosphorylated Rb levels

In the treatment of head and neck cancer, cisplatin is often used as a therapeutic agent; however, its efficacy is limited and it can cause renal dysfunction as an adverse effect. For this reason, the use of cisplatin is limited in elderly patients with reduced renal function. Recently, artemisinin, which was developed as an antimalarial drug, was found to have antitumor effects and is effective in combination with other anticancer drugs. In the present study, the antitumor effects of artemisinin and its derivatives as well as their combination with cisplatin and iron on head and neck squamous cell carcinoma cell lines, were investigated. Cell viability was determined by a cell viability assay, the cell cycle was analyzed by flow cytometry, cell death was assessed with annexin V and propidium iodide staining, and western blotting was used to analyze retinoblastoma protein (Rb), phosphorylated (p‑)Rb, and other cell cycle‑associated molecules. A total of four artemisinin compounds were examined and it was found that artesunate and dihydroartemisinin had a significant inhibitory effect on growth. It was also identified that the combination of artesunate, cisplatin, and iron inhibited cell proliferation and caused S/G2‑M cell cycle arrest. In addition, western blotting of Rb, a molecule involved in the cell cycle, showed that artesunate induced the loss of not only Rb but also p‑Rb. These results suggested that artesunate is a useful drug in combination with cisplatin.

Moyamoya disease-specific extracellular vesicle-derived microRNAs in the cerebrospinal fluid revealed by comprehensive expression analysis through microRNA sequencing

PURPOSE

To examine the specific changes that occur in the expression levels of extracellular vesicle-derived microRNAs (miRNAs) in intracranial cerebrospinal fluid (CSF) in moyamoya disease.

METHODS

Patients with arteriosclerotic cerebral ischemia were used as controls to eliminate the effects of cerebral ischemia. Intracranial CSF was collected from moyamoya disease and control patients during bypass surgery. Extracellular vesicles (EVs) were extracted from the CSF. Comprehensive expression analysis of miRNAs extracted from EVs by next-generation sequencing (NGS) and validation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed.

RESULTS

Experiments were conducted on eight cases of moyamoya disease and four control cases. In the comprehensive miRNA expression analysis, 153 miRNAs were upregulated, and 98 miRNAs were downregulated in moyamoya disease compared to the control cases (q-value < 0.05 and |log2 fold change|> 1). qRT-PCR performed on the four most variable miRNAs (hsa-miR-421, hsa-miR-361-5p, hsa-miR-320a, and hsa-miR-29b-3p) associated with vascular lesions among the differentially expressed miRNAs gave the same results as miRNA sequencing. On gene ontology (GO) analysis for the target genes, cytoplasmic stress granule was the most significant GO term.

CONCLUSIONS

This study is the first comprehensive expression analysis of EV-derived miRNAs in the CSF of moyamoya disease patients using NGS. The miRNAs identified here may be related to the etiology and pathophysiology of moyamoya disease.

Pilot study of plasma creatine riboside as a potential biomarker for cervical cancer

This pilot study aimed primarily to evaluate plasma levels of a novel metabolite, creatine riboside, in patients with cervical cancer (discovery and validation cohorts, n = 11 for each) compared with non-cancer subjects (controls, n = 30). We found that the pre-treatment plasma creatine riboside level was significantly higher in the discovery cohort than in controls. The cut-off value determined from the discovery cohort distinguished 90.9% of the patients in the validation cohort from controls. Unbiased principal component analysis of plasma metabolites in high-creatine riboside samples demonstrated enrichment of pathways involved in arginine and creatine metabolism. These data indicate the potential utility of plasma creatine riboside as a biomarker of cervical cancer.

Long noncoding RNA profile of the intracranial artery in patients with moyamoya disease

OBJECTIVE

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive stenosis of the internal carotid artery (ICA) and secondary formation of collateral vessels. Revascularization surgery is performed in patients with MMD to prevent stroke; however, the pathogenesis of MMD remains unknown. Recently, long noncoding RNAs (lncRNAs) have been found to play a key role in gene regulation and are implicated in various vascular diseases. However, the lncRNA expression profile in MMD lesions has not been investigated. In this study the authors aimed to determine the characteristics of lncRNA expression in MMD lesions.

METHODS

The authors collected microsamples of the middle cerebral artery (MCA) from patients with MMD (n = 21) and patients with control conditions (n = 11) who underwent neurosurgical treatment. Using microarray experiments, the authors compared the profiles of lncRNA expression in the MCAs of the MMD and control patient groups and identified differentially expressed lncRNAs (fold change > 2, q < 0.05). In addition, the neighboring coding genes, whose transcription can be regulated in cis by the identified differentially expressed lncRNAs, were investigated and Gene Ontology (GO) analysis was applied to predict associated biological functions.

RESULTS

The authors detected 308 differentially expressed lncRNAs (fold change > 2, q < 0.05), including 306 upregulated and 2 downregulated lncRNAs in the MCA from patients with MMD. Regarding the prediction of biological function, GO analyses with possible coding genes whose transcription was regulated in cis by the identified differentially expressed lncRNAs suggested involvement in the antibacterial humoral response, T-cell receptor signaling pathway, positive regulation of cytokine production, and branching involved in blood vessel morphogenesis.

CONCLUSIONS

The profile of lncRNA expression in MMD lesions was different from that in the normal cerebral artery, and differentially expressed lncRNAs were identified. This study provides new insights into the pathophysiology of MMD.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Interleukin-6 blockade reduces salt-induced cardiac inflammation and fibrosis in subtotal nephrectomized mice

Cardiovascular disease is the most common comorbidity in patients with chronic kidney disease (CKD), affecting both their prognosis and quality of life. Cardiac fibrosis is common in patients with CKD with left ventricular diastolic dysfunction, and it is associated with increased risk of heart failure and mortality. Recent evidence suggests that high salt intake activates immune responses associated with local accumulation of sodium. We reported that high salt intake promotes cardiac inflammation in subtotal nephrectomized (Nx) mice. We investigated the effects of administration of MR16-1, a rat anti-mouse monoclonal interleukin (IL)-6 receptor antibody, in Nx mice with salt loading (Nx-salt). Expression of monocyte chemoattractant protein-1, tumor necrosis factor-α, IL-1β, and IL-6 mRNAs and macrophage infiltration was significantly reduced in the heart of Nx-salt mice treated with MR16-1 (Nx-salt-MR16-1) compared with Nx-salt mice treated with control rat rat IgG1 (Nx-salt-rat IgG1). Correspondingly, cardiac fibrosis was significantly attenuated in Nx-salt-MR16-1 mice compared with Nx-salt-rat IgG1 mice. Furthermore, in the heart of Nx-salt-MR16-1 mice, expression of mRNA for nicotinamide adenine dinucleotide phosphate oxidase-2, an oxidative stress marker, was significantly downregulated compared with Nx-salt-rat IgG1 mice. Increases in cardiac metabolites, including histidine and γ-butyrobetaine, were also reversed by IL-6 blockade treatment. In conclusion, IL-6 blockade exerts anti-inflammatory, antifibrotic, and partial antioxidative effects in the heart of Nx-salt mice.NEW & NOTEWORTHY In the present study, IL-6 blockade exerted anti-inflammatory, antifibrotic, and partial antioxidative effects on the hearts of mice with CKD on a high-salt diet. Therefore, IL-6 potentially mediates cardiac fibrosis induced by high salt intake in patients with CKD, a finding with therapeutic implications. Of note, the next therapeutic implication may simply be the reinforcement of low-salt diets or diuretics and further research on the anti-inflammatory effects of these measures rather than IL-6 blockade with high-salt diet.

Renal thrombotic microangiopathy and nephrotic proteinuria induced by intravitreal injection of aflibercept for diabetic macular edema

BACKGROUND

Vascular endothelial growth factor inhibitors (VEGFIs) are used to treat malignant neoplasms and ocular diseases by inhibiting angiogenesis. Systemic use of VEGFIs has various side effects, including hypertension, proteinuria, and thrombotic microangiopathy, but adverse events due to intravitreal injection of VEGFIs have not been fully clarified. Although age-related macular degeneration was initially the most common target of intravitreal injection of VEGFIs, it has also been applied sporadically for diabetic macular edema in recent years. Proteinuria following intravitreal injection of VEGFIs would be reversible. In patients with diabetes mellitus (DM), however, it would be difficult to determine whether kidney damage arises from the clinical course of DM or from intravitreal injection of VEGFIs for diabetic macular edema.

CASE PRESENTATION

A 55-year-old woman with a 20-year history of type 2 DM began intravitreal injection of VEGFI (aflibercept, 2 mg every 4 weeks) for treatment of diabetic macular edema 2 years previously. She presented with leg edema, hypertension, and nephrotic-range proteinuria 14 months after the first injection. Histological examination of renal biopsy specimens revealed diabetic nephropathy with renal thrombotic microangiopathy probably associated with intravitreal injection of VEGFI. The patient's nephrotic syndrome completely improved at 6 months after simply discontinuing aflibercept.

CONCLUSIONS

This is a precious report of pathologically investigated renal thrombotic microangiopathy leading to nephrotic syndrome due to intravitreal injection of aflibercept for diabetic macular edema in a patient with type 2 DM. Renal function and proteinuria should be monitored in diabetic patients who receive intravitreal injection of a VEGFI. If kidney damage develops independent of the clinical course of DM during intravitreal injection of a VEGFI, renal biopsy should be performed and intravitreal VEGFI injection discontinued.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

Temporary central venous catheter at hemodialysis initiation and reasons for use: a cross-sectional study

Background

Creating permanent vascular access (VA) is recommended before hemodialysis initiation in patients with end-stage renal disease (ESRD). Although many patients are still introduced to hemodialysis with temporary central venous catheters (CVCs), the reasons for their use remain unclear. We aimed to clarify the characteristics of Japanese patients introduced to hemodialysis using temporary CVCs, the reasons for their use, and whether this rate can be reduced in the future.

Methods

We conducted this cross-sectional study in an acute care general hospital in Japan. We enrolled 393 patients aged ≥ 18 years who received a permanent VA creation for initiating hemodialysis. We classified participants into the temporary CVC group or the permanent VA group according to the VA type at hemodialysis initiation and compared their backgrounds. We identified why permanent VA could not be used at hemodialysis initiation for patients in the temporary CVC group.

Results

Of the 393 patients, 137 (35%) initiated hemodialysis with a temporary CVC, and arteriovenous fistulas (AVFs) were created as the first VA in all patients during hospitalization following hemodialysis initiation. The remaining 256 patients (65%) initiated hemodialysis via AVF cannulation. The duration of predialysis nephrology care was significantly shorter in the temporary CVC group than that in the permanent VA group. The median time from AVF creation to the first successful cannulation was also shorter in the temporary CVC group (8 vs. 66 days, P < 0.001), but the estimated glomerular filtration rate values at hemodialysis initiation did not differ. Reasons for temporary CVC use were varied and complex. Problems on the part of healthcare providers, patient behavioral issues, and characteristics of causative kidney disease itself were underlying reasons. Delayed referral to a nephrologist was less frequent than expected (16%) and the most commonly reported reason (20%) was that a nephrologist was unable to predict the timing of hemodialysis initiation.

Conclusions

Patients with ESRD should be referred to a nephrologist earlier for AVF creation. However, given the already relatively high rate of hemodialysis initiation with permanent VA in Japan, we considered it surprisingly difficult to further reduce the temporary CVC usage rate in Japan.

Transcriptome-wide analysis of intracranial artery in patients with moyamoya disease showing upregulation of immune response, and downregulation of oxidative phosphorylation and DNA repair

OBJECTIVE

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive occlusion of the internal carotid artery and the secondary formation of collateral vessels. Patients with MMD have ischemic attacks or intracranial bleeding, but the disease pathophysiology remains unknown. In this study, the authors aimed to identify a gene expression profile specific to the intracranial artery in MMD.

METHODS

This was a single-center, prospectively sampled, retrospective cohort study. Microsamples of the middle cerebral artery (MCA) were collected from patients with MMD (n = 11) and from control patients (n = 9). Using microarray techniques, transcriptome-wide analysis was performed.

RESULTS

Comparison of MCA gene expression between patients with MMD and control patients detected 62 and 26 genes whose expression was significantly (p < 0.001 and fold change > 2) up- or downregulated, respectively, in the MCA of MMD. Gene set enrichment analysis of genes expressed in the MCA of patients with MMD revealed positive correlations with genes involved in antigen processing and presentation, the dendritic cell pathway, cytokine pathway, and interleukin-12 pathway, and negative correlations with genes involved in oxidative phosphorylation and DNA repair. Microarray analysis was validated by quantitative polymerase chain reaction.

CONCLUSIONS

Transcriptome-wide analysis showed upregulation of genes for immune responses and downregulation of genes for DNA repair and oxidative phosphorylation within the intracranial artery of patients with MMD. These findings may represent clues to the pathophysiology of MMD.

Tumor-infiltrating FoxP3+ T cells are associated with poor prognosis in oral squamous cell carcinoma

OBJECTIVES

Squamous cell carcinoma is the most common malignancy in the oral cavity. Moreover, human papillomavirus (HPV) infection has been recently implicated in the onset of oral squamous cell carcinoma (OSCC). Regulatory T cells (Tregs) are Forkhead box P3 (FoxP3) positive and are normally involved in the mechanism by which organisms escape attacks from their own immune system; however, in tumors, these cells are known to suppress antitumor immunity and block the attack against tumors. The present study evaluated the associations of the number of Tregs and HPV infection with prognoses in patients with OSCC.

MATERIAL AND METHODS

Samples from 106 patients diagnosed with OSCC were evaluated by immunohistochemical staining for the identification of FoxP3+ Tregs and HPV. The relationship between the observed number of Foxp3-positive cells, the presence/absence of HPV infection and associations with clinicopathological indicators were analyzed.

RESULTS

Tissues were classified into high (High) and low (Low) Treg count groups, with 69 patients classified as High and 37 classified as Low. The prognoses were significantly better in the Low group compared with the High group (p = 0.04). FoxP3 expression may have had some effect on nodal metastases (p = 0.09). HPV antigens were detected in 65 patients, but there were no significant associations with prognosis (p = 0.34). HPV-infected tumors were more common in the gums and tongues than in the lips, cheeks, and floor of the mouth (p = 0.05).

CONCLUSIONS

These results indicate that Tregs in tumor sites are associated with worsened prognoses of patients with OSCC and suggest potential therapies targeting Tregs in OSCC.

Improving function of cytotoxic T-lymphocytes by transforming growth factor-β inhibitor in oral squamous cell carcinoma

Immunotherapy with immune‐checkpoint therapy has recently been used to treat oral squamous cell carcinomas (OSCCs). However, improvements in current immunotherapy are expected because response rates are limited. Transforming growth factor‐β (TGF‐β) creates an immunosuppressive tumor microenvironment (TME) by inducing the production of regulatory T‐cells (Tregs) and cancer‐associated fibroblasts and inhibiting the function of cytotoxic T‐lymphocytes (CTLs) and natural killer cells. TGF‐β may be an important target in the development of novel cancer immunotherapies. In this study, we investigated the suppressive effect of TGF‐β on CTL function in vitro using OSCC cell lines and their specific CTLs. Moreover, TGFB1 mRNA expression and T‐cell infiltration in 25 OSCC tissues were examined by in situ hybridization and multifluorescence immunohistochemistry. We found that TGF‐β suppressed the function of antigen‐specific CTLs in the priming and effector phases in vitro. Additionally, TGF‐β inhibitor effectively restored the CTL function, and TGFB1 mRNA was primarily expressed in the tumor invasive front. Interestingly, we found a significant negative correlation between TGFB1 mRNA expression and the CD8⁺ T‐cell/Treg ratio and between TGFB1 mRNA expression and the Ki‐67 expression in CD8⁺ T‐cells, indicating that TGF‐β also suppressed the function of CTLs in situ. Our findings suggest that the regulation of TGF‐β function restores the immunosuppressive TME to active status and is important for developing new immunotherapeutic strategies, such as a combination of immune‐checkpoint inhibitors and TGF‐β inhibitors, for OSCCs.

T-cell responses and combined immunotherapy against human carbonic anhydrase 9-expressing mouse renal cell carcinoma

Renal cell carcinoma (RCC) is known to respond to immune checkpoint blockade (ICB) therapy, whereas there has been limited analysis of T-cell responses to RCC. In this study, we utilized human carbonic anhydrase 9 (hCA9) as a model neoantigen of mouse RENCA RCC. hCA9-expressing RENCA RCC (RENCA/hCA9) cells were rejected in young mice but grew in aged mice. CD8⁺ T cells were the primary effector cells involved in rejection in young mice, whereas CD4⁺ T cells participated at the early stage. Screening of a panel of hCA9-derived peptides revealed that mouse CD8⁺ T cells responded to hCA9_288-296 peptide. Mouse CD4⁺ T cells responded to lysates of RENCA/hCA9, but not RENCA cells, and showed reactivity to hCA9 _276-290, which shares three amino acids with hCA9 _288-296 peptide. Immunohistochemistry analysis revealed that few T cells infiltrated RENCA/hCA9 tissues in aged mice. ICB therapy of anti-PD-1/anti-CTLA-4 antibodies promoted T-cell infiltration into tumor tissues, whereas no definite antitumor effect was observed. However, additional combination with cyclophosphamide or axitinib, a vascular endothelial growth factor receptor inhibitor, induced complete regression in half of the RENCA/hCA9-bearing aged mice with increased expression of PD-L1 in tumor tissues. These results indicate that hCA9 can be a useful model neoantigen to investigate antitumor T-cell responses in mice with RCC, and that RENCA/hCA9 in aged mice can serve as a non-inflamed 'cold' tumor model facilitating the development of effective combined immunotherapies for RCC.

First case report of monoclonal IgG3-heavy-chain glomerulonephritis with microtubular structures

Our patient was a 69-year-old woman admitted to our hospital for heavy proteinuria and hematuria. A renal biopsy showed findings similar to those of membranoproliferative glomerulonephritis associated with nodular lesions, and immunofluorescence showed marked deposits of IgG, C1q, and C3 on the peripheral capillary walls. IgG3 alone was observed on IgG subclass staining with no κ or λ light chains, and Congo red staining was negative. These findings suggested IgG3-heavy-chain deposition disease (HCDD). However, we did not find a deletion of the first heavy-chain constant domain, which is commonly observed in HCDD. Electron microscopy showed randomly arranged subendothelial microtubular structures with diameters of 70-90 nm. Altogether, the diagnosis of HCDD could not be made, although monoclonal IgG3 deposits in glomeruli were observed. This is the first case report of monoclonal IgG3-heavy-chain glomerulonephritis with subendothelial-based, randomly arranged microtubular structures with diameters of 70-90 nm.

Identification of cisplatin-resistant factor by integration of transcriptomic and proteomic data using head and neck carcinoma cell lines

Cisplatin is an important drug for the treatment of head and neck squamous cell carcinoma (HNSCC). Determining chemoresistant factors prior to treatment will lead to great benefits for clinicians and patients. Here, we evaluated chemoresistant factors by integrating proteomic and transcriptomic data using HNSCC cell lines to identify a more precise chemoresistant factor in HNSCC. We used four HNSCC cell lines: cisplatin-sensitive, acquired cisplatin resistance, naturally cisplatin-resistant, and acquired 5-FU resistance. Proteomic analysis was performed using iTRAQ, tandem mass spectrometry, and liquid chromatography-electrospray ionization-tandem mass spectrometry. Transcriptomic analysis was performed using microarrays. By integrating these independent data, common factors were addressed and functional analysis was performed using small interfering RNAs (siRNAs) to change the chemosensitivity. Using iTRAQ analysis, 7 proteins were identified as specific for cisplatin chemoresistance factors. Transcriptomic analysis revealed hundreds of potential candidate factors. By combining and integrating these data, S100A2 was identified as a potential cisplatin-specific chemoresistance factor. Functional analysis with siRNA revealed that the expression of S100A2 was reduced and cisplatin sensitivity recovered in the acquired and naturally cisplatin-resistant cell lines, but not in the cisplatin-sensitive cell lines. S100A2 was identified as a cisplatin-specific chemoresistance factor by integrating the transcriptomic and proteomic results obtained using HNSCC cell lines. This is a novel technique that allows for a precise identification, also known as a comprehensive analysis. Our findings indicate that these proteins could be used as biomarkers of HNSCC treatments, providing physicians with new treatment strategies for patients with HNSCC, showing chemoresistance.

Combining T-cell-based immunotherapy with venetoclax elicits synergistic cytotoxicity to B-cell lines in vitro

Alterations of B-cell lymphoma 2 (BCL-2) family proteins contribute to the survival of B-cell malignancies. Recently, venetoclax, a BCL-2 inhibitor, was approved for B-cell chronic lymphocytic leukemia therapy and is being investigated in clinical trials for a variety of hematologic cell malignancies. Furthermore, combination therapy with other molecularly targeted drugs was reported to be more effective than monotherapy. However, combining venetoclax with immunotherapy based on T-cells has not been tested. Because both venetoclax and granzyme B activate the mitochondrial apoptosis pathway by targeting different BCL-2 family molecules, it is possible that combinations of venetoclax with immunotherapy will be effective treatments. We examined the effect of combining venetoclax with immunotherapy using an in vitro model system involving cytomegalovirus (CMV) pp65 antigen-specific cytotoxic T-cells (CMV-CTLs) as the effector cells and CMVpp65 antigen-expressing B-cell lines as the target cells. Cytotoxicity of CMV-CTLs to the target B-cell lines was enhanced by venetoclax with combination index values of 0.47-0.83. This suggests that venetoclax synergizes with T-cell-based immunotherapy to affect B-cell malignancies. Interestingly, venetoclax synergized not only with antigen-specific cytotoxicity but also with nonspecific cytotoxicity. Importantly, CMV-CTLs could be expanded in the presence of venetoclax at the maximum concentration (5 μM) that induced apoptosis in resting CMV-CTLs. B-cell lymphoma-extra large (BCL-xL) expression in CMV-CTLs increased transiently after activation by CMVpp65-transfected B-cell lines, indicating that the expression of BCL-xL was important for the effectiveness of combination treatment with venetoclax. These findings suggest that T-cell-based immunotherapy combined with venetoclax is effective against B-cell malignancies.

Abstract 1071: Targeting A2aR in mouse Pten-deficient prostate cancer

Inactivation of PTEN occurs frequently in advanced human prostate cancer and can promote an immunosuppressive tumor microenvironment (TME). Extracellular adenosine can be produced by tumors which can in turn modulate anti-inflammatory and immunosuppressive effects via interactions with the A2a receptor (A2aR). Here, we used a transgenic mouse model of Pten-deficient prostate cancer to characterize adenosine-mediated immunosuppression in the TME and evaluate the effects of A2aR blockade. Transcriptomic analysis of normal wildtype prostate and Pten-deficient prostate tumors revealed enriched signatures for genes downregulated after a A2aR knockdown or upregulated after A2aR stimulation. Moreover, androgen withdrawal led to increased expression of the A2aR-stimulated responsive genes Cxcl2/3/5, Il1b, S100a8, Ptgs2 and Thbs1. Immunohistochemical staining of CD73, the ecto-enzyme responsible for producing extracellular adenosine, showed heterogeneous staining ranging from negative to focally strong in epithelial cancer cells and was strongly expressed in immune cells. A2aR was also strongly expressed on immune infiltrates. We used the oral A2aR antagonist AZD4635 to determine the immunosuppressive activity of extracellular adenosine and evaluate its antitumor activity in the context of castration-naïve (CNPC), castration-sensitive (CSPC) and castration-resistant (CRPC) prostate cancer. Four weeks of treatment with AZD4635 led to a 12.1% (P=0.140) reduction of tumor burden compared to control mice. Notably a subset of these mice (4/8) had tumor reductions greater than 20%. For the CSPC/CRPC models, mice were orchidectomized and treated with apalutamide with or without AZD4635 for four or eight weeks to represent CSPC or CRPC phenotypes, respectively. In these settings, treatment with AZD4635 improved the reduction of tumor burden by 16.4% (P=0.165) and 16.8% (P=0.123) in CSPC and CRPC, respectively. Despite similar reduction rates between the cohorts, a greater proportion of AZD4635 treated mice were below the median distribution in the CRPC setting compared to the CSPC setting, 50% (4/8) vs 70% (7/10), respectively. Immunophenotyping showed an increase in the abundance of dendritic cells in tumors and tumor draining lymph nodes of AZD4635-treated mice in the CPNC setting. Whereas a shift in M2 to M1 macrophage, decrease of PD1hi CD8 T cells and an increase in genes related to cytotoxic lymphocyte activity (Gzma, Gzmb, Prf1, Klrg1, and B3gat1) were observed in AZDD4635 treated mice in the CRPC setting. Decreased expressions of immunosuppressive genes related to T regulatory cells (Ctla4, Il2ra, Itga2, Tigit, Foxp3) were noted in both CSPC and CRPC settings. Our findings show that targeting extracellular adenosine with AZD4635 is effective in a subset of mouse Pten-deficient tumors and provides evidence that suggests context-specific immune modulating activity by extracellular adenosine in prostate cancer.

Citation Format: Marco A. De Velasco, Yurie Kura, Noriko Sako, Naomi Ando, Kazuko Sakai, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuhiro Yoshikawa, Alwin Schuller, Kazuto Nishio, Hirotsugu Uemura. Targeting A2aR in mouse Pten-deficient prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1071.

Abstract 3416: Androgen deprivation following JAK1/2 and PD-L1 inhibition improves antitumor efficacy in mouse models of Pten-deficient prostate cancer

Recently, the tumor suppressor PTEN has been shown to function as an immune modulator and its inactivation is associated with mediating tumor immune evasion. We previously examined the effects of programmed death-ligand 1 (PD-L1) immune checkpoint blockade (ICB) in transgenic mouse models of Pten-null prostate cancer. However, anti-PD-L1 monotherapy was largely ineffective in immunologically cold castration-naïve tumors from intact mice but showed some activity when administered to castrated mice. Our previous immune profiling studies also revealed that while androgen withdrawal increased tumor inflammation, it also mediated the recruitment and accumulation of immunosuppressive cells such as regulatory T cells, M2-polarized macrophages and myeloid-derived suppressor cells (MDSCs). Interleukin-6 (IL-6)/signal transducer and activator of transcription-3 (STAT3) signaling is a key immune modulating pathway that is upregulated in both intact and androgen deprived tumors. Here, we evaluate the effectiveness of targeting PD-L1 and JAK/STAT signaling in preclinical models of Pten-null prostate cancer. Intact tumor bearing conditional Pten-knockout were treated for four weeks with an a-PD-L1 blocking antibody (clone D265A, mouse/IgG1 kappa) and/or the JAK1/2 inhibitor, AZD1480. Pharmacological treatments targeting PD-L1 and JAK1/2 (PJ) combinations were also evaluated as concurrent therapy with androgen deprivation (AD) by orchidectomy (PJ+AD), and as sequential therapy; two weeks AD followed by PJ (AD&gt;PJ), and one week of PT followed by AD (PJ&gt;AD). Combined PD-L1/JAK followed by AD was the only treatment combination that improved antitumor immune responses over monotherapy. Notably, flow cytometry studies showed that combined PD-L1/JAK potently abrogated PD-L1 expression in circulating dendritic cells in all settings. Evidence for enhanced antitumor immune response in PJ&gt;AD was supported by increased numbers circulating effector memory CD8 T cells and CD355+CD8+ T cells (CD355 Class I MHC-restricted T cell-associated molecule (CRTAM) a marker for activated CD8 T cell), and increased CD8 T cell infiltration in tumors and a reduction of CD25+CD4+ regulatory T cells. The efficacy of the PJ&gt;AD treatment combination was further tested and confirmed in a subcutaneous syngeneic allograft model using mice grafted with tumor blocks from Pten-deficient castration-resistant prostate cancer tumors. Together these results indicate that pretreatment with combined PD-L1/JAK blockade can decrease the immunosuppressive effects of androgen withdrawal and have the potential to restore antitumor immune activity in Pten-deficient prostate cancer.

Citation Format: Marco A. De Velasco, Yurie Kura, Naomi Ando, Noriko Sako, Kazuko Sakai, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Androgen deprivation following JAK1/2 and PD-L1 inhibition improves antitumor efficacy in mouse models of Pten-deficient prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3416.

Abstract 3341: Systemic targeted JAK1/2 therapy for mouse Pten-deficient prostate cancer model influences the diversity and composition of the gut microbiome

Modulation of immune response by gut microbiota is believed to play a key role in determining response to anticancer therapy. Conversely, anticancer therapies have the potential to alter resident microbiota and the implications are unknown. We previously showed the antitumor efficacy of targeted JAK1/2 inhibition in a preclinical mouse model of prostate cancer and are now exploring its effectiveness as an immune modulator in prostate cancer therapy. We have also shown that androgen withdrawal can turn a poorly inflamed tumor into an inflamed tumor. In this follow-up study, we examine the effects of targeted JAK1/2 cancer therapy on the gut microbiome. For this we utilize 16S rDNA amplicon sequencing to profile the fecal microbiota (proximal and distal colon) of normal wildtype (WT) and tumor bearing conditional Pten-knockout (KO) mice treated for four weeks with the JAK1/2 inhibitor AZD1480 alone or in combination with orchidectomy. Mice treated with AZD1480 had lower tumor burden compared to control mice. Alpha diversity of fecal microbiota was greater in castrated KO mice compared intact WT and KO mice and mice receiving AZD1480 tended to have lower diversity regardless of castration status. Significant compositional differences were observed between the colonic microbiota of all experimental groups. Overall, mice treated with AZD1480, regardless of castration status resulted in decreased abundance of Clostridiaceae, F16, Gemellaceae, Odoribacteraceae, Rikenellaceae, and Lactobacillaceae and an increase of Paraprevotellaceae, Porphyromonadaceae, Verrucomicrobiaceae, Bifidobacteriaceae bacterial families. In the castration-naïve prostate cancer setting, enrichments of Akkermansia, Coprobacillus, Prevotella and Dehalobacterium and decreases of Lactococcus, Bacilli, Gemella, Lactobacillus, Desulfovibrio, and Odoribacter. Bifidobacterium, Desulfovibrio, Allobaculum, and Lactococcus were enriched in androgen deprived AZD1480-treated mice while Ruminococcus, and unclassified Clostridiaceae and F16 were decreased. We further used weighted correlation network analysis (WGCNA) to identify relevant networks of fecal microbiota associated with systemic targeted JAK1/2 inhibition. Using this approach, we have identified clusters of highly correlated taxa in the context of poorly inflamed and inflamed prostate tumors. Our findings show that systemic anticancer therapies can modify host microbiomes and provides insights into interactions between tumor, host microbiomes and immune modulating cancer therapies.

Citation Format: Marco A. De Velasco, Kazuko Sakai, Yurie Kura, Naomi Ando, Noriko Sako, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Systemic targeted JAK1/2 therapy for mouse Pten-deficient prostate cancer model influences the diversity and composition of the gut microbiome [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3341.

Abstract 3340: Prostate cancer alters gut microbiota in mice

Commensal gut bacteria are essential for maintaining intestinal homeostasis, however, aging, environmental factors and pathological conditions can cause changes in microbial composition resulting in dysbiosis. Specific microbial communities can alter host immune functions and are implicated in promoting carcinogenesis, tumor progression and therapeutic resistance. In this study we use a genetically engineered mouse model of prostate cancer to characterize changes in gut microbiota. 16S marker sequencing data was used to perform a comprehensive profile of the fecal microbiomes of conditional Pten-knockout mice harboring prostate tumors versus wildtype mice with normal prostate. Unsupervised clustering of microbiota was performed by hierarchical clustering. Community composition (beta diversity) was determine by principal components analysis, principal coordinates analysis (PCoA) and Adonis (permutational manova (PERMANOVA)) and the Shannon index was used to determine alpha diversity. The linear discriminant analysis effect size method was used to identify features associated with cancer and multiple linear regression was performed to determine relevant features of fecal bacteria collected from the proximal and distal colon. Predictive biomarkers associated with prostate cancer were identified with the Wilcoxon rank test. Weighted correlation network analysis (WGCNA) was performed to identify clusters of taxa associated with the presence of prostate cancer. Taxon set enrichment analysis (TSEA) was carried out to identify taxon sets associated with host genetic variations, and host intrinsic and extrinsic factors. Overall, the presence of prostate cancer did not affect diversity, however, significant compositional differences were observed between the cohorts (Bray-Curtis Adonis, P=0.003). At the family level S24_7, Odoribacteraceae, and Peptococcaceae were associated with cancer bearing mice while Bifidobacteriaceae, Peptostreptococcaceae, Coriobacteriaceae, Ruminococcaceae and Erysipelotrichaceae were associated with healthy mice (P&lt;0.05). Prevotella, Lactobacillus reuteri and various unclassified Clostridiales, S24_7 and Rikenellaceae were identified as predictive biomarkers associated with cancer. Clusters of highly correlated taxa were identified in both cohorts and their functional influences are summarized. Overall, our study provides an in-depth overview of fecal microbiome in the context of mouse prostate cancer and provides the foundation to further investigate the interactions with disease progression and cancer therapy.

Citation Format: Marco A. De Velasco, Kazuko Sakai, Yurie Kura, Eri Banno, Naomi Ando, Noriko Sako, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Prostate cancer alters gut microbiota in mice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3340.

Immune-checkpoint molecules on regulatory T-cells as a potential therapeutic target in head and neck squamous cell cancers

Immune-checkpoint inhibitors improve the survival of head and neck squamous cell carcinoma (HNSCC) patients. Although recent studies have demonstrated that the tumor immune microenvironment (TIME) has critical roles in immunotherapy, the precise mechanisms involved are unclear. Therefore, further investigations of TIME are required for the improvement of immunotherapy. The frequency of effector regulatory T-cells (eTregs) and the expression of immune-checkpoint molecules (ICM) on eTregs and conventional T-cells (Tconvs) both in peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL) from HNSCC patients were analyzed by flow cytometry and their distributions were evaluated by multi-color immunofluorescence microscopy. High frequency eTreg infiltration into HNSCC tissues was observed and high expressions of CD25, FOXP3, stimulatory-ICM (4-1BB, ICOS, OX40 and GITR) and inhibitory-ICM (programmed cell death-1 [PD-1] and cytotoxic T-lymphocyte-associated protein-4 [CTLA-4]) were found on invasive eTregs. In contrast, the expression of stimulatory-ICM on Tconvs was low and the expression of inhibitory-ICM was high. In addition, ICM-ligands (programmed cell death-1 [PD-L1], galectin-9 and CEACAM-1) were frequently expressed on cancer cells. PD-L1 and galectin-9 were also expressed on macrophages. PD-1⁺ T-cells interacted with PD-L1⁺ cancer cells or PD-L1⁺ macrophages. This suggested that in TIL, eTregs are highly activated, but Tconvs are exhausted or inactivated by eTregs and immune-checkpoint systems, and ICM and eTregs are strongly involved in the creation of an immunosuppressive environment in HNSCC tissues. These suggested eTreg targeting drugs are expected to be a combination partner with immune-checkpoint inhibitors that will improve immunotherapy of HNSCC.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

P977Selective liner ablation according to the type of tachycardia induced after pulmonary vein isolation in single-procedure for long-standing persistent atrial fibrillation

Background

The most effective approach for long-standing persistent atrial fibrillation (LSPAF) ablation remained undetermined. Here, we hypothesized that selective linear ablation (SLA) according to the type of tachycardia induced by burst atrial pacing (BAP) after pulmonary venous isolation (PVI) in single-procedure reduces the recurrence.

Methods

A cohort of 66 LSPAF patients (Mean age 71.0±8.2 years, AF duration 40.5±58.8 months) who underwent PVI in single-procedure between April 2016 and November 2018 was evaluated.

Results

Any sustained atrial tachycardia (AT) or AF were not inducible by BAP after PVI in 21 patients (Non-inducible group, 31.8%, 71.3±7.9 years, 34.4±54.2 months). These patients underwent cavo-tricuspid isthmus (CTI) ablation after PVI. Forty-one patients underwent selective liner ablation according to the type of tachycardia induced by BAP after PVI (SLA group, 62.1%, 71.2±8.3 years, 39.3±55.6 months). Maccroreentry ATs (6 common atrial flutter, 5 AT originating from left atrial anterior wall, 2 peri-mitral atrial flutter, 1 roof-dependent atrial flutter) were induced by BAP in 14 patients of SLA group (73.2±19.7 years, 51.7±83.5 months). RF applications created the complete linear lesions to terminate maccroreentry ATs. Sustained AF was induced by BAP after PVI in 27 patients of SLA group (70.2±9.2 years, 32.9±31.2 months). These patients underwent posterior wall isolation (PWI) and CTI ablation. Unmappable AT was induced by BAP after PVI in 4 patients (Non-SLA group, 6.1%, 67.0±9.7 years, 84.5±105.6 months). These patients underwent PWI, CTI and mitral isthmus ablation on an empirical basis instead of SLA. Using a 90-day blanking period, the single-procedure Kaplan-Meier estimates of AT or AF event-free survival were 79% at 12 months. During follow-up (14.5±8.0 months), although 19 /21 (90.5%) of Non-inducible group patients and 33/41 (80.5%) of SLA group patients did not experience AT or AF recurrence, all of Non-SLA group patients experienced AF recurrence. There was no difference between Non-inducible group and SLA group in predicting recurrence of AT or AF (p=0.3). However, there was a difference when compared with Non-SLA group (each p<0.001). Non-SLA group was an independent powerful predictor resulting in recurrence of AF after adjusting for potential confounding factors (adjusted hazard ratio = 7.17; 95% confidence interval; 2.2–23.1, p=0.001, Wald χ2=10.9). Furthermore, in Kaplan-Meier survival curves for predicting AT or AF recurrence, Non-SLA group was the significant predictive marker of AT or AF recurrence (Log-Lank χ2=18.0, p<0.001).

Kaplan-Meier survival curves

Conclusions

In LSPAF patients without inducibility of any tachycardia after PVI, sinus rhythm was highly maintained without stepwise ablation other than CTI ablation. SLA reduced recurrence of AF in LSPAF patients with AT and AF induced after PVI. In addition, nonselective liner ablations for unmappable AT after PVI were less effective in LSPAF patients.

Increased infiltration of CCR4-positive regulatory T cells in prostate cancer tissue is associated with a poor prognosis

BACKGROUND

Regulatory T cells (Tregs) play important roles in the suppression of immune responses, including antitumor immune responses. C-C chemokine receptor 4 (CCR4) is highly expressed on effector Tregs, and anti-CCR4 antibody is attracting attention as a novel immunotherapeutic agent for solid tumors. This study aimed to evaluate the expression of CCR4-positive Tregs (CCR4+Tregs) in prostate cancer and estimate the clinical potential of CCR4-targeting therapy for prostate cancer.

METHODS

A total of 15 radical prostatectomy (RP) specimens and 60 biopsy specimens from individuals diagnosed with prostate cancer were analyzed to evaluate the infiltration of CCR4+Tregs in prostate cancer. The relationships between the number of CCR4+Tregs and clinical parameters were investigated in RP and biopsy specimens. Moreover, the total number of Tregs, CCR4+Tregs, and T cells and the ratio of CCR4+Tregs to Tregs and T cells in biopsy specimens were compared between patients with poor prognosis who progressed to castration-resistant prostate cancer (CRPC) within 12 months (n = 13) and those with good prognosis who were stable with hormone-sensitive prostate cancer over 12 months (n = 47). Furthermore, biopsy specimens were divided into two groups: low and high CCR4+Treg expression groups and the prognosis was compared between them.

RESULTS

There was a higher expression of CCR4+Tregs in RP specimens with a higher (≥8) Gleason score than in those with a lower (<8) Gleason score (P = .041). In biopsy specimens, 65.9% Tregs were positive for CCR4. The number of CCR4+Tregs positively correlated with clinical stage (P < .001) and Gleason score (P = .006). The total number of Tregs and CCR4+Tregs significantly increased in the poor prognosis group compared with that in the good prognosis group (P = .024 and .01, respectively). Furthermore, patients with lower CCR4+Treg expression levels showed a significantly longer time to progression to CRPC (not reached vs 27.3 months; P < .001) and median survival time (not reached vs 69.0 months; P = .014) than those with higher expression levels.

CONCLUSIONS

CCR4+Tregs are highly infiltrated in the prostate tissue of patients with poor prognosis with potential to progress to CRPC. Furthermore, the degree of infiltration of CCR4+Tregs is related to the prognosis of prostate cancer.

Targeting castration-resistant prostate cancer with androgen receptor antisense oligonucleotide therapy

Sustained therapeutic responses from traditional and next-generation antiandrogen therapies remain elusive in clinical practice due to inherent and/or acquired resistance resulting in persistent androgen receptor (AR) activity. Antisense oligonucleotides (ASO) have the ability to block target gene expression and associated protein products and provide an alternate treatment strategy for castration-resistant prostate cancer (CRPC). We demonstrate the efficacy and therapeutic potential of this approach with a Generation-2.5 ASO targeting the mouse AR in genetically engineered models of prostate cancer. Furthermore, reciprocal feedback between AR and PI3K/AKT signaling was circumvented using a combination approach of AR-ASO therapy with the potent pan-AKT inhibitor, AZD5363. This treatment strategy effectively improved treatment responses and prolonged survival in a clinically relevant mouse model of advanced CRPC. Thus, our data provide preclinical evidence to support a combination strategy of next-generation ASOs targeting AR in combination with AKT inhibition as a potentially beneficial treatment approach for CRPC.

Abstract 5023: Immunomodulation of the multi-tyrosine kinase inhibitor TAS-115 in a mouse model of prostate cancer

Increasingly, immunotherapeutic agents are making their way into the clinic for the management of cancer, however, not all patients respond to single agent treatments. Susceptibility to immunotherapy is highly dependent on a tumor’s immune composition. Agents that are able modulate the tumor’s microenvironment (TME) to improve the balance between cytotoxic T cells and immunosuppressive cells such as myeloid-derived suppressor cells (MDSCs) M2-polarized macrophages and T regulatory cells (Tregs) are highly sought. We previously evaluated the preclinical activity of the multikinase inhibitor TAS-115 on mouse model of prostate cancer and showed that its antitumor effect was due in large part to its influence on the TME. In this study we examine the consequences of TAS-115 administration alone or in combination with androgen withdrawal via surgical castration or anti-androgen therapy with apalutamide, and focus on its influence on antitumor immunity. Pten/Trp53-double knockout mice were treated with TAS-115 alone or in combination with surgical castration or apalutamide for 4 weeks. Overall, TAS-115 reduced prostate tumor burden by 10.5%, however, 37.5% (3/5) of mice experienced no response (7.5%), while reductions of 14% and 27% were observed in 25% (2/8), 37.5% (3/5) of the remaining mice, respectively. A similar trend was noted in mice treated with the TAS/apalutamide combination but TAS plus surgical castration. Changes in cancer cell proliferation and apoptosis were insignificant with TAS-115 treatment, however, 2 of 4 TAS-115-responsive mice used for immunohistochemical (IHC) analysis showed a ~3-fold increased cleaved caspase-3 expression over non responsive mice. All TAS-115-treated mice showed reduced levels of phosphorylated STAT-3. Flow cytometric analysis of dissociated tumor samples revealed a reduction of tumor associated macrophages (TAMs) particularly when TAS-115 was given in combination with castration or apalutamide. Further analysis by IHC and qRT-PCR showed a M2-M1 polarization switch after TAS-115 therapy accompanied with decreased accumulation of monocytic MDSCs. An increase in tumor infiltrating neutrophils was also observed in mice receiving TAS-115. Although overall T cell infiltration was not improved TAS-115, there was an enhanced of activated CD8+ T cells, which was especially evident in responders. However, Treg infiltration was also increased after the administration of TAS-115. Overall our findings suggest that TAS-115 induced the reduction of immunosuppressive MDSCs and TAMs and may have induced an M2-M1 switch to provide a less immunosuppressive tumor microenvironment resulting in improved T cell mediated responses and provides evidence to support further investigation into using molecular targeting agents such TAS-115 as immune-modulators in combination with other immunotherapies to enhance or restore cytotoxic T cell activity.

Citation Format: Marco A. De Velasco, Yurie Kura, Noriko Sato, Naomi Ando, Kazuko Sakai, Kazuhiro Yoshimura, Masahiro Nozawa, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Immunomodulation of the multi-tyrosine kinase inhibitor TAS-115 in a mouse model of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5023.

Abstract 3951: Apalutamide reworks the immune composition of prostate tumors

Prostate cancers depend on androgen receptor (AR) signaling for survival making it a major therapeutic target. Apalutamide is an oral nonsteroidal AR antagonist that is currently indicated for the treatment of patients with non-metastatic castration-resistant prostate cancer. Apalutamide hinders AR-mediated transcriptional activity by impeding AR nuclear translocation and binding to DNA in cancer cells. AR is also expressed by stromal and immune cells and can modulate innate and adaptive immune responses, moreover, androgen ablation can both hinder and enhance antitumor immunity. Thus far, success from immune checkpoint blockade monotherapy has been lacking in prostate cancer patients and novel strategies using of other modalities are being investigated. Here, we characterize the effect of apalutamide therapy on antitumor immunity in a preclinical mouse model of prostate cancer to assess its value as potential partner for combination with immunotherapy. Conditional prostate-specific Pten-knockout mice were treated with apalutamide (30 mg/kg/d, 5 days on/2 days off) or vehicle for a period of 4 or 8 weeks to coincide with androgen sensitivity and the shift towards castration resistance. Tumor reductions after 4 or 8 weeks of treatment with apalutamide were 38.2% (P&lt;0.01) and 46.2% (P&lt;0.001), respectively. Flow cytometric analysis of tumor tissues revealed 1.3 (P=0.033) and 1.9 (P&lt;0.001) -fold increases of leukocyte (CD45+) infiltration in mice treated with apalutamide for 4 or 8 weeks, respectively. CD8+ T cell infiltration was 2.7-fold higher at 8 weeks, however, tumor reactive PD1+/CD8 T cells were 2-3-fold greater for apalutamide-treated mice at weeks 4 and 8. Quantitative immunohistochemical analysis confirmed increased intraepithelial CD8+ T and granzyme B-positive cells. Apalutamide treatment was also associated with increased peritumoral T regulatory cells and intraepithelial neutrophils. Immuno-profiling using a qRT-PCR-based panel of immune-relevant genes associated apalutamide therapy with an increased IFN-γ inflammatory signature, antigen presentation/dendritic cell, natural killer cell, T regulatory cell, tumor associated macrophage, and myeloid-derived suppressor cells (MDSC). These data also revealed a trend towards decreased CD8 T cell activation at week 8 accompanied by increased expression of the immunological checkpoints Ctla4, Tim3, and 2b4. In conclusion, our findings suggests that apalutamide-induced tumor cell death attracted phagocytes (macrophages and dendritic cells) that led to a innate and adaptive immune cell responses. While, cytotoxic T cell activity was improved, it was limited by the development of an immunosuppressive tumor microenvironment replete with MDSCs and T regulatory cells. Nevertheless, treatment with apalutamide turned immunologically “cold” tumors into more immunologically reactive tumors that may become more susceptible to targeted immunotherapy.

Citation Format: Marco A. De Velasco, Yurie Kura, Naomi Ando, Noriko Sato, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuko Sakai, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Apalutamide reworks the immune composition of prostate tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3951.

Abstract 1613: Dietary isoflavone decreases prostate cancer progression and improves survival in conditional Pten/Trp53-deficient mice

Epidemiological data has shown that dietary practices can greatly influence cancer rates. Men in East Asian countries, men have significantly lower prostate cancer rates compared to their counterparts the US and Europe. Soybeans are a versatile and rich source of protein and its products constitute a rich portion of Asian diets. Recent interest in healthy eating has expanded the consumption of soy products which also provide a rich source of naturally occurring isoflavones and 17β-estradiol. In this study, we used roasted soybean flour (kinako), which contains high levels isoflavones glycosides and estradiol, as dietary soy source to determine the influence of isoflavones rich diets on prostate cancer. Six-week old conditional Pten/Trp53 double knockout mice were randomized and fed plain AIN-93M (Control) diets or a diets supplemented with kinako ad libitum. Concentrations of kinako were adjusted to for daily intakes of aglycone isoflavones (genistein, daidzein, and glycetein) of 400 (LDI) and 800 (HDI) mg. Mice were sacrificed at 16 and 20 weeks (n=6 mice/group) or maintained for survival assessment (n=8 mice/group). Dietary intake of kinako-supplemented diets did not influence the onset of prostatic intraepithelial neoplasia or tumor burden at the early stages. However, tumors from mice fed the HDI diet experienced reduced tumor proliferation rates. Moreover, mice fed LDI and HDI diets showed reduced androgen receptor (AR) protein expression levels as well as mRNA levels for the AR target genes Fkbp5, Nk3x3.1 and Timp4. Interestingly, mice on the LDI diet, but not the HDI, experienced longer times to disease progression (median times 264, 299 and 250 days for Control, LDI and HDI, respectively, P=0.663), tumor doubling (median times 14, 27 and 14 days for Control, LDI and HDI, respectively, P=0.083), cumulative survival (median times 292, 348 and 320 days for Control, LDI and HDI, respectively, P=0.199), and overall survival times (median times 28, 43 and 35 days for Control, LDI and HDI, respectively, P=0.324). The metastatic incidence was 33%, 14% and 14% for Control, LDI and HDI groups, respectively, P=0.631. We also investigated whether dietary intervention with kinako would impact previously stablished tumors. For this we fed kinako supplemented diets to conditional Pten-knockout mice with established tumors but no changes were observed in tumor burden, proliferation, apoptosis and AR activity. Together our data shows that long-term continuous ingestion of a diet rich in isoflavones may be necessary in order suppress tumor growth. Interestingly, this protective effect appears to be lost with high-doses of the dietary isoflavones. Further studies will need to be performed in order to decipher complex dynamic interplay between survival pathways isoflavones chemoprevention.

Citation Format: Yasunori Mori, Marco A. De Velasco, Yurie Kura, Eri Banno, Naomi Ando, Noriko Sato, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuko Sakai, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Dietary isoflavone decreases prostate cancer progression and improves survival in conditional Pten/Trp53-deficient mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1613.

Abstract 4996: A real-time PCR-based approach to quantitatively assess tumor immune profiles and immune responses

Exciting breakthroughs in tumor immunology have led to the discovery and development of several promising immunotherapeutic strategies for cancer patients. Thus far, immune checkpoint inhibitors have been the most encouraging for solid tumors, however, treatment responses are observed in only a subset of patients and these appear to be primarily dependent on a tumor’s baseline immune profile. Additionally, tumors respond differently to immunotherapy and criteria to assess treatment responses are still being refined. We have identified a set of immune-related genes and developed a scoring system to profile the tumor’s immune status and assess immunological responses. In this study, we used a qRT-PCR-based approach to assess this panel and determine baseline tumor immune-profiles in an immunocompetent mouse model of Pten-null prostate cancer. We also assessed and compared tumor immune responses following androgen withdrawal (via surgical castration) and anti-PD-L1 immune checkpoint blockade. A total of 96 genes were selected for this focused panel which consisted of cell-type, immuno-responsive and housekeeping control genes. Core modules were designated based on functional gene associations which included antigen presentation, tumor inflammation, effector cells, immunomodulatory cells, immunosuppressive signaling and immune checkpoints. Core modules were further subdivided in to appropriately relevant sub-modules. A score for each submodule was calculated and a weighed score was then assigned for each core module. Tumor immunophenotypes based on core and sub-core immune scores (IS) were corroborated with immunohistochemical and/or flow cytometric analyses. Mouse castration-naïve prostate tumors exhibited low scores indicating a ‘”cold tumor” phenotype with little variation between individual mice. Androgen withdrawal induced cancer cell death in these tumors that in turn promoted immune cell infiltration. Core and sub-core IS of individual mice identified varied signatures reminiscent of immune excluded and inflamed “hot tumor” phenotypes. Short-term treatment with anti-PD-L1 blockade (clone D265A, mouse/IgG1 kappa) elicited an increased immune response signature in tumors from surgically castrated mice, but not in tumors from intact mice. Notably, discernable differences were noted among individual responders supporting the notion that responses to immune checkpoint may indeed be dependent on baseline tumor immune-profiles. In summary, androgen withdrawal appears to promote a “hotter” immunological phenotype in this model of prostate cancer, that is increased further by PD-L1 inhibition. Moreover, this investigation provides proof of concept evidence for a qRT-PCR-based biomarker approach for immuno-oncology.

Citation Format: Marco A. De Velasco, Yurie Kura, Noriko Sato, Naomi Ando, Kazuko Sakai, Yasunori Mori, Barry R. Davies, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. A real-time PCR-based approach to quantitatively assess tumor immune profiles and immune responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4996.

Targeting lactate dehydrogenase‑A promotes docetaxel‑induced cytotoxicity predominantly in castration‑resistant prostate cancer cells

Docetaxel (DOC) is one of the most effective chemotherapeutic agents against castration‑resistant prostate cancer (CRPC). Despite an impressive initial clinical response, the majority of patients eventually develop resistance to DOC. In tumor metabolism, where tumors preferentially utilize anaerobic metabolism, lactate dehydrogenase (LDH) serves an important role. LDH controls the conversion of pyruvate to lactate, with LDH‑A, one of the predominant isoforms of LDH, controlling this metabolic process. In the present study, the role of LDH‑A in drug resistance of human prostate cancer (PC) was examined by analyzing 4 PC cell lines, including castration‑providing strains PC3, DU145, LNCaP and LN‑CSS (which is a hormone refractory cell line established from LNCaP). Sodium oxamate (SO) was used as a specific LDH‑A inhibitor. Changes in the expression level of LDH‑A were analyzed by western blotting. Cell growth and survival were evaluated with a WST‑1 assay. Cell cycle progression and apoptotic inducibility were evaluated by flow cytometry using propidium iodide and Annexin V staining. LDH expression was strongly associated with DOC sensitivity in PC cells. SO inhibited growth of PC cells, which was considered to be caused by the inhibition of LDH‑A expression. Synergistic cytotoxicity was observed by combining DOC and SO in LN‑CSS cells, but not in LNCaP cells. This combination treatment induced additive cytotoxic effects in PC‑3 and DU145 cells, caused cell cycle arrest in G2‑M phase and increased the number of cells in the sub‑G1 phase of cell cycle in LN‑CSS cells. SO promoted DOC induced apoptosis in LN‑CSS cells, which was partially caused by the inhibition of DOC‑induced increase in LDH‑A expression. The results strongly indicated that LDH‑A serves an important role in DOC resistance in advanced PC cells and inhibition of LDH‑A expression promotes susceptibility to DOC, particularly in CRPC cells. The present study may provide valuable information for developing targeted therapies for CRPC in the future.

HOXA10 expression profiling in prostate cancer

BACKGROUND

HOX genes encode transcription factors that play key roles in modulating normal tissue morphogenesis, differentiation and homeostasis. Disruption of normal HOX gene expression occurs frequently in human cancers and is associated with both tumor promoting and suppressing activities. Among these is, HOXA10, a pleiotropic gene that is critical for normal prostate development. In this study we characterized HOXA10 expression in human and mouse PCa to gain insights into its clinical significance.

METHODS

A meta-analysis of HOXA10 mRNA expression was carried out across several publicly available data sets. Expression of HOXA10 protein expression was assessed by immunohistochemistry (IHC) using human radical prostatectomy (RP) cases. We correlated HOXA10 expression to clinicopathological features and investigated its relationship to biochemical recurrence (BCR) after RP by the Kaplan-Meier method. HOXA10 mRNA and IHC protein expression was also examined in a mouse model of Pten-null PCa.

RESULTS

A meta-analysis of HOXA10 gene expression indicated dysregulated expression of HOXA10 in human PCa. IHC profiling of HOXA10 revealed inverse correlations between HOXA10 expression and Gleason pattern, Gleason score, and pathological stage (P < 0.01). Patients with low expression profiles of HOXA10 were associated with a higher risk of BCR, (OR, 3.54; 95%CI, 1.21-16.14; P = 0.049) whereas patients with high HOXA10 expression experienced longer times to BCR (P = 0.045). However, HOXA10 was not an independent predictor of BCR (OR, 1.52; 95%CI, 0.42-5.54; P = 0.52). Evaluation of expression patterns of HOXA10 in mouse prostate tumors mimicked that of humans.

CONCLUSIONS

Our findings show that HOXA10 expression is inversely associated with tumor differentiation and high HOXA10 expression is associated with improved BCR-free survival. This study provides human and mouse evidence to suggest tumor suppressive roles for HOXA10 in the context of prostate cancer.

CCR4 Expression in Tumor-Infiltrating Regulatory T Cells in Patients with Squamous Cell Carcinoma of the Lung: A Prognostic Factor for Relapse and Survival

To clarify the prognostic impact of tumor-infiltrating effector regulatory T cells (eTregs) in non-small cell lung cancer (NSCLC), eTregs were evaluated by immunohistochemical detection of CCR4 and Foxp3 in 108 consecutive surgical NSCLC tumors. Multivariate analysis showed that a high ratio of CCR4⁺ eTregs to total Tregs (≥40%) was the only independent risk factor for relapse-free survival (odds ratio [OR]: 6.54, 95% confidence interval: 1.67-25.7, p = .007) and overall survival (OR: 3.76, p = .037) in lung squamous cell carcinoma (SqCC). These results highlight the prognostic importance of the balance of tumor-infiltrating Tregs in resected lung SqCC.

Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu-A spinning top-shaped rubble pile

The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present Hayabusa2 observations of Ryugu's shape, mass, and geomorphology. Ryugu has an oblate "spinning top" shape, with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates a high-porosity (>50%) interior. Large surface boulders suggest a rubble-pile structure. Surface slope analysis shows Ryugu's shape may have been produced from having once spun at twice the current rate. Coupled with the observed global material homogeneity, this suggests that Ryugu was reshaped by centrifugally induced deformation during a period of rapid rotation. From these remote-sensing investigations, we identified a suitable sample collection site on the equatorial ridge.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

Systemic transduction of p16INK4a antitumor peptide inhibits lung metastasis of the MBT-2 bladder tumor cell line in mice

p16^INK4a (p16) is a key molecule in bladder tumor (BT) development. We previously reported that a p16 antitumor peptide inhibited the growth of subcutaneous BT grafts in mice through restoration of p16 function using a Wr-T peptide transporter system. In the present study, the efficacy of mouse p16 peptide administration in a mouse lung metastasis model for BT and also the toxicity of peptides by cardiac peptide injection were evaluated. Mouse lung metastases were developed by tail vein injection of a p16-deficient MBT-2 cell line. Six-week-old C3H/He female mice were divided into three groups: A control group (n=12) receiving no treatment; a group treated once on the 3rd experimental day (n=12); and a group treated three times on the 3rd, 5th and 7th experimental days (n=10) with an injection of a mixture of 80 nmol mouse p16 peptide and 50 nmol Wr-T into the tail vein. At the 14th experimental day, the lung metastases were histologically evaluated. Lung metastases were observed in 100% (12/12), 41.7% (5/12) and 30% (3/10) of the aforementioned three groups, respectively. The number and area of metastatic lung tumors were significantly different between control and treatment groups (control vs. triple treatment group for the number and area, P=0.0029 and P=0.0296, respectively). Immunohistochemistry demonstrated that phosphorylated retinoblastoma (Rb) protein was decreased in lung tumors of the treatment groups, compared with the control group. The toxicity of p16 peptide transduction was evaluated by using low-dose treatment (three dosages) and high-dose treatment (two dosages) on three male and three female C3H/He mice in early and late experimental phases. In low and high dose groups, no notable change was determined in body weight or blood analyses in early or late phases following mouse p16 peptide administration. In addition, no notable change was observed histologically in bone marrow of treatment groups. To conclude, systemic p16 peptide administration decreased lung tumor development in a mouse metastatic BT model without severe adverse events, as assessed by blood analyses and histological evaluation.

Generation of PTEN‑knockout (‑/‑) murine prostate cancer cells using the CRISPR/Cas9 system and comprehensive gene expression profiling

Phosphatase and tensin homolog (PTEN) deficiency is associated with development, progression, and metastasis of various cancers. However, changes in gene expression associated with PTEN deficiency have not been fully characterized. To explore genes with altered expression in PTEN‑deficient cells, the present study generated a PTEN‑knockout cell line (ΔPTEN) from a mouse prostate cancer‑derived cell line using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‑associated protein 9 (CRISPR/Cas9) gene editing system. Following transfection of the CRISPR/Cas9 construct, DNA sequencing was performed to identify deletion of the Pten locus and PTEN inactivation was verified by western blotting. The ΔPTEN cell line exhibited enhanced RAC‑alpha serine/threonine‑protein kinase phosphorylation and cyclin D1 expression. In addition, an increase in cell proliferation and colony formation was observed in the ΔPTEN cell line. Gene expression profiling experiments were analyzed with microarray and microRNA (miRNA) arrays. In the microarray analysis, 111 genes exhibited ≥10‑fold increased expression compared with the parent strain and mock cell line and 23 genes were downregulated. The only miRNA with increased expression of 10‑fold or more was mmu‑miR‑210‑3p. Genes with enhanced expression included genes involved in the development, progression, and metastasis of cancer such as Tet methylcytosine dioxygenase 1, twist family BHLH transcription factor 2, C‑fos‑induced growth factor and Wingless‑Type MMTV Integration Site Family, Member 3, and genes involved in immunosuppression such as Arginase 1. The results of the present study suggest that PTEN deficiency mobilizes a variety of genes critical for cancer cell survival and host immune evasion.

Abstract 947: Influence of abiraterone therapy on anti-tumor immunity in genetically engineered mouse prostate cancer models

Recent evidence has suggested that androgen deprivation therapies (ADTs) can influence tumor immune responses via androgen receptor (AR) regulation. On one hand, reports have indicated that certain ADTs can compromise T cell immune responses and enhance PD-L1 immune suppression, while others indicate that ADT can enhance anti-tumor responses via modulation of the apoptotic pathway. Abiraterone is a steroidal CYP17 inhibitor approved for the treatment of late-stage metastatic castration-resistant prostate cancer. In this study we use genetically engineered mouse models of prostate cancer (GEMMs-PCa) to investigate the antitumor activity of abiraterone and its influence on tumor immunity. In a mouse Pten-deficient prostate cancer model, chronic treatment with abiraterone acetate (40 mg/kg/d, 5 days on, 2 days off) reduced prostate tumor burden by 13.1% ± 9.0 (P=0.499) after four weeks of dosing and 30.5% ± 8.1 (P=0.0275) after eight weeks. Downregulation of classical mouse Ar-responsive genes (Fkbp5, Nkx3.1, Msmb and Timp4) confirmed the inhibition AR transcriptional activity after abiraterone therapy. In a model of advanced prostate cancer, driven by the conditional inactivation of Pten and Trp53, treatment with abiraterone after surgical castration modestly improved median overall survival from 7 days to 16 days vs. castration alone (P=0.240, n=8 mice/group). qRT-PCR-based analysis of a panel of 54 immune-responsive genes, revealed distinct expression signatures in abiraterone-treated tumors compared to tumors from orchidectomized mice. Relative to orchidectomized mice, tumors from abiraterone treated mice consistently demonstrated reduced mRNA levels of the T regulatory cell gene markers Cd4, Foxp3, Cd4, Tgfb1 and Il10. Furthermore, mRNA expression levels of representative immune checkpoint genes Cd274, Pdcd1lg2, Pdcd1 and Ctla4 were also lower in abiraterone treated mice. Follow-up immunohistochemical analysis showed a 1.8-fold increase of tumor infiltrating granzyme B-positive cells in tumors of mice treated with abiraterone compared to surgical castration. Our results show that abiraterone suppressed AR transcriptional activity and reduced tumor growth and progression in GEMMs-PCa. Our data also suggests that abiraterone induces lesser immunosuppressive responses than surgical castration and supports further investigation into developing rational combinations of ADT and immunotherapy in order to enhance therapeutic responses for patients suffering with prostate cancer.

Citation Format: Eri Banno, Marco A. De Velasco, Yurie Kura, Naomi Ando, Noriko Sato, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuko Sakai, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Influence of abiraterone therapy on anti-tumor immunity in genetically engineered mouse prostate cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 947.

Abstract 1715: Treatment-dependent effects of androgen receptor signaling suppression on immune modulation in mouse Pten-deficient prostate cancer

Androgen-deprivation therapy (ADT) is the mainstay treatment for advanced metastatic prostate cancer. Treatments targeting androgen receptor (AR) signaling by androgen withdrawal or AR antagonists have been implemented in clinical practice, and clinical trials evaluating treatment combinations with immunotherapy are ongoing. However, AR expression is not limited to prostate epithelial cells and is expressed in several cell types including stromal and immune cells. Preclinical studies have shown that ADT can positively or negatively influence antitumor immunity depending on the treatment approach. To gain insights into the influence of ADT on tumor immunity, we compared surgical castration (Cast), AR-antisense oligonucleotide (ISIS581088, ISI), nonsteroidal antiandrogen (apalutamide, Apa) and hormonal antiandrogen (chlormadinone acetate, CMA) treatments in a mouse model of Pten-deficient prostate cancer. Conditional PSACre/Ptenf/f mice were treated for eight weeks and the antitumor activity and effects on immune organs were assessed. Compared to control mice, treatments with Cast, ISI, Apa and CMA significantly reduced tumor growth by 69.8%, 65.0%, 37.8%, and 40.8%, respectively, P&lt;0.001. A significant enlargement of the thymus was seen in Cast (125 %) and Apa (45.8%)-treated mice whereas significant involution occurred after ISI (-73.3%) and CMA (-60.0%) treatments. Enlargement of spleen was noted in Cast (201.2%, P=0.009) ISI (96.3%, P=0.004) and Apa (55%, P=0.256)-treated mice. Draining lymph nodes were significantly larger in mice treated with ISI (48%, P=0.027), whereas their size decreased after treatment with Apa (-31.6%) and CMA (-15.4%). Focused gene expression profiling of immune and AR responsive genes by qRT-PCR array was performed on prostate tumor samples. Functional enrichment analysis of differentially expressed genes indicated distinct patterns of expression between treatments. Overall, the expression signatures of Cast and ISI were more closely concordant than those of Apa and CMA. Notably, genes associated with abnormal immune tolerance were enriched in Cast, Apa and CMA treatment groups. Genes associated with abnormal T-cell proliferation and PD-1 signaling were enriched in castrated mice. Our study shows that the AR signaling axis influences immune modulation and its effects on tumor immunity vary greatly depending on the pharmacologic approach for AR signaling inhibition. Rational combinations of ADT and immunotherapy will have to be carefully characterized and optimized in order to achieve their full therapeutic potential.

Citation Format: Marco A. De Velasco, Yurie Kura, Naomi Ando, Kazuko Sakai, Barry R. Davies, Youngsoo Kim, A. Robert MacLeod, Masahiro Nozawa, Kazuhiro Yoshimura, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. Treatment-dependent effects of androgen receptor signaling suppression on immune modulation in mouse Pten-deficient prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1715.