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Background Individuals can test positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by molecular assays following the resolution of their clinical disease. Recent studies indicate that SARS-CoV-2 antigen–based tests are likely to be positive early in the disease course, when there is an increased likelihood of high levels of infectious virus. Methods Upper respiratory specimens from 251 participants with coronavirus disease 2019 symptoms (≤7 days from symptom onset) were prospectively collected and tested with a lateral flow antigen test and a real-time polymerase chain reaction (rt-PCR) assay for detection of SARS-CoV-2. Specimens from a subset of the study specimens were utilized to determine the presence of infectious virus in the VeroE6TMPRSS2 cell culture model. Results The antigen test demonstrated a higher positive predictive value (90%) than rt-PCR (70%) when compared to culture-positive results. The positive percentage agreement for detection of infectious virus for the antigen test was similar to rt-PCR when compared to culture results. Conclusions The correlation between SARS-CoV-2 antigen and SARS-CoV-2 culture positivity represents a significant advancement in determining the risk for potential transmissibility beyond that which can be achieved by detection of SARS-CoV-2 genomic RNA. SARS-CoV-2 antigen testing can facilitate low-cost, scalable, and rapid time-to-result, while providing good risk determination of those who are likely harboring infectious virus, compared to rt-PCR., Antigen-based, real-time polymerase chain reaction (rt-PCR)–based, and VeroE6TMPRSS2 cell culture–based testing was conducted using upper respiratory specimens from COVID-19–symptomatic individuals. Using VeroE6TMPRSS2 culture as reference, antigen-based testing had similar positive percentage agreement but better positive predictive value, compared to rt-PCR, for detecting infectious virus.

BACKGROUNDWhile most children who contract COVID-19 experience mild disease, high-risk children with underlying conditions may develop severe disease, requiring interventions. Kinetics of antibodies transferred via COVID-19 convalescent plasma early in disease have not been characterized.METHODSIn this study, high-risk children were prospectively enrolled to receive high-titer COVID-19 convalescent plasma (1:320 anti-spike IgG; Euroimmun). Passive transfer of antibodies and endogenous antibody production were serially evaluated for up to 2 months after transfusion. Commercial and research ELISA assays, virus neutralization assays, high-throughput phage-display assay utilizing a coronavirus epitope library, and pharmacokinetic analyses were performed.RESULTSFourteen high-risk children (median age, 7.5 years) received high-titer COVID-19 convalescent plasma, 9 children within 5 days (range, 2-7 days) of symptom onset and 5 children within 4 days (range, 3-5 days) after exposure to SARS-CoV-2. There were no serious adverse events related to transfusion. Antibodies against SARS-CoV-2 were transferred from the donor to the recipient, but antibody titers declined by 14-21 days, with a 15.1-day half-life for spike protein IgG. Donor plasma had significant neutralization capacity, which was transferred to the recipient. However, as early as 30 minutes after transfusion, recipient plasma neutralization titers were 6.2% (range, 5.9%-6.7%) of donor titers.CONCLUSIONConvalescent plasma transfused to high-risk children appears to be safe, with expected antibody kinetics, regardless of weight or age. However, current use of convalescent plasma in high-risk children achieves neutralizing capacity, which may protect against severe disease but is unlikely to provide lasting protection.Trial registrationClinicalTrials.gov NCT04377672.FundingThe state of Maryland, Bloomberg Philanthropies, and the NIH (grants R01-AI153349, R01-AI145435-A1, K08-AI139371-A1, and T32-AI052071).

Supplemental material, sj-docx-1-wso-10.1177_17474930221137019 for The global burden of cerebral small vessel disease in low- and middle-income countries: A systematic review and meta-analysis by Bonnie Yin Ka Lam, Yuan Cai, Rufus Akinyemi, Geert Jan Biessels, Hilde van den Brink, Christopher Chen, Chin Wai Cheung, King Ngai Chow, Henry Kwun Hang Chung, Marco Duering, Siu Ting Fu, Deborah Gustafson, Saima Hilal, Vincent Ming Ho Hui, Rajesh Kalaria, SangYun Kim, Maggie Li Man Lam, Frank Erik de Leeuw, Ami Sin Man Li, Hugh Stephen Markus, Anna Marseglia, Huijing Zheng, John O’Brien, Leonardo Pantoni, Perminder Singh Sachdev, Eric E Smith, Joanna Wardlaw and Vincent Chung Tong Mok in International Journal of Stroke

IntroductionCOVID-19 large scale immunization in the US has been associated with infrequent breakthrough positive molecular testing. Whether a positive test is associated with a high viral RNA load, specific viral variant, recovery of infectious virus, or symptomatic infection is largely not known.MethodsIn this study, we identified 133 SARS-CoV-2 positive patients who had received two doses of either Pfizer-BioNTech (BNT162b2) or Moderna (mRNA-1273) vaccines, the 2nd of which was received between January and April of 2021. The positive samples were collected between January and May of 2021 with a time that extended from 2 to 100 days after the second dose. Samples were sequenced to characterize the whole genome and Spike protein changes and cycle thresholds that reflect viral loads were determined using a single molecular assay. Local SARS-CoV-2 IgG antibodies were examined using ELISA and specimens were grown on cell culture to assess the recovery of infectious virus as compared to a control unvaccinated cohort from a matched time frame.ResultsOf 133 specimens, 24 failed sequencing and yielded a negative or very low viral load on the repeat PCR. Of 109 specimens that were used for further genome analysis, 68 (62.4%) were from symptomatic infections, 11 (10.1%) were admitted for COVID-19, and 2 (1.8%) required ICU admission with no associated mortality. The predominant virus variant was the alpha (B.1.1.7), however a significant association between lineage B.1.526 and amino acid change S: E484K with positives after vaccination was noted when genomes were compared to a large control cohort from a matched time frame. A significant reduction of the recovery of infectious virus on cell culture as well as delayed time to the first appearance of cytopathic effect was accompanied by an increase in local IgG levels in respiratory samples of vaccinated individuals but upper respiratory tract IgG levels were not different between symptomatic or asymptomatic infections.ConclusionsVaccination reduces the recovery of infectious virus in breakthrough infections accompanied by an increase in upper respiratory tract local immune responses.FundingNational Institute of Health (The Johns Hopkins Center of Excellence in Influenza Research and Surveillance, HHSN272201400007C), Johns Hopkins University, Maryland Department of Health, Centers for Disease Control and Prevention.

BACKGROUND AND AIM: Fine particulate matter (PM2.5) exposure is associated with increased risk of numerous adverse health outcomes. Prior research shows that PM2.5 is disproportionately concentrate...

BackgroundThe emerging SARS-CoV-2 variant of concern (VOC) B.1.6.17.2 (Delta) quickly displaced the B.1.1.7 (Alpha) and is associated with increases in COVID-19 cases nationally. The Delta variant has been associated with greater transmissibility and higher viral RNA loads in both unvaccinated and fully vaccinated individuals. Data is lacking regarding the infectious virus load in Delta infected individuals and how that compares to individuals infected with other SARS-CoV-2 lineages.MethodsWhole genome sequencing of 2,785 clinical isolates was used to characterize the prevalence of SARS-CoV-2 lineages circulating in the National Capital Region between January and July 2021. Clinical chart reviews were performed for the Delta, Alpha, and B.1.2 (a control predominant lineage prior to both VOCs) variants to evaluate disease severity and outcome and Cycle threshold values (Cts) were compared. The presence of infectious virus was determined using Vero-TMPRSS2 cells and anti-SARS-CoV-2 IgG levels were determined from upper respiratory specimen. An analysis of infection in unvaccinated and fully vaccinated populations was performed.ResultsThe Delta variant displaced the Alpha variant to constitute 88.2% of the circulating lineages in the National Capital Region by July, 2021. The Delta variant associated with increased breakthrough infections in fully vaccinated individuals that were mostly symptomatic when compared to the Alpha breakthrough infections, though it is important to note there was a significantly longer period of time between vaccination and infection with Delta infections. The recovery of infectious virus on cell culture was significantly higher with the Delta variant compared to Alpha in both vaccinated and unvaccinated groups. The impact of vaccination on reducing the recovery of infectious virus from clinical samples was only observed with Alpha variant infections but was strongly associated with low localized SARS-CoV-2 IgG for both variants. A comparison of Ct values showed a significant decrease in the Delta compared to Alpha with no significant differences between unvaccinated and vaccinated groups.ConclusionsOur data indicate that the Delta variant is associated with increased infectious virus loads when compared to the Alpha variant and decreased upper respiratory antiviral IgG levels. Measures to reduce transmission in addition to increasing vaccinations rates have to be implemented to reduce Delta variant spread.FundingNIH/NIAID Center of Excellence in Influenza Research and Surveillance contract HHS N2772201400007C, Johns Hopkins University, Maryland department of health, Centers for Disease Control and Prevention contract 75D30121C11061.

Background Long-term exposure to fine particulate matter (PM2.5) has been associated with neurodegenerative diseases, including disease aggravation in Parkinson's disease (PD), but associations with specific PM2.5 components have not been evaluated. Objective To characterize the association between specific PM2.5 components and PD first hospitalization, a surrogate for disease aggravation. Methods We obtained data on hospitalizations from the New York Department of Health Statewide Planning and Research Cooperative System (2000–2014) to calculate annual first PD hospitalization counts in New York State per county. We used well-validated prediction models at 1 km2 resolution to estimate county level population-weighted annual black carbon (BC), organic matter (OM), nitrate, sulfate, sea salt (SS), and soil particle concentrations. We then used a multi-pollutant mixed quasi-Poisson model with county-specific random intercepts to estimate rate ratios (RR) of one-year exposure to each PM2.5 component and PD disease aggravation. We evaluated potential nonlinear exposure–outcome relationships using penalized splines and accounted for potential confounders. Results We observed a total of 197,545 PD first hospitalizations in NYS from 2000 to 2014. The annual average count per county was 212 first hospitalizations. The RR (95% confidence interval) for PD aggravation was 1.06 (1.03, 1.10) per one standard deviation (SD) increase in nitrate concentrations and 1.06 (1.04, 1.09) for the corresponding increase in OM concentrations. We also found a nonlinear inverse association between PD aggravation and BC at concentrations above the 96th percentile. We found a marginal association with SS and no association with sulfate or soil exposure. Conclusion In this study, we detected associations between the PM2.5 components OM and nitrate with PD disease aggravation. Our findings support that PM2.5 adverse effects on PD may vary by particle composition.

SummaryBackgroundThere is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses.MethodsWe describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape.FindingsWe found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape.InterpretationOur results highlight the need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered.FundingThe work was partially funded by The Saban Research Institute at Children’s Hospital Los Angeles intramural support for COVID-19 Directed Research (X.G. and J.D.B.), the Johns Hopkins Center of Excellence in Influenza Research and Surveillance HHSN272201400007C (A.P.), NIH/NIAID R01AI127877 (S.D.B.), NIH/NIAID R01AI130398 (S.D.B.), NIH 1U54CA260517 (S.D.B.), an endowment to S.D.B. from the Crown Family Foundation, an Early Postdoc.Mobility Fellowship Stipend to O.F.W. from the Swiss National Science Foundation (SNSF), and a Coulter COVID-19 Rapid Response Award to S.D.B. L.G. is a SHARE Research Fellow in Pediatric Hematology-Oncology.

With the prevalence of digital devices and internet access, telemedicine (visiting physicians through real-time telecommunication) is becoming an important mode of service. In this work, we study whether the adoption of telemedicine has an impact on physicians' behavior in terms of scheduling related follow-up visits. To answer this question, we use a changes-in-changes (CIC) model to estimate the effect of adopting telemedicine on the length of the interval between two related visits, namely, the related visit interval (RVI). Our results show that physicians schedule related visits with shorter RVIs in the short term after adopting telemedicine. As a result, physicians can admit more patients to their panel as they adopt telemedicine for a longer time. Thus, in the long run, adoption of telemedicine results in experiencing a heavier workload and scheduling related visits with longer RVIs. The adoption effect is also spilled over to the scheduling decision made during in-office visits with a decrease in RVI length in the short term and an increase in the long term. Furthermore, we show that physicians tend to schedule more frequent follow-up visits after a telemedicine visit due to the uncertainty in a patient’s health status in a remote visit. This study sheds light on the benefits and unintended consequences of adopting telemedicine as this mode of service becomes more widely utilized.

The spike D614G mutation increases SARS-CoV-2 infectivity, viral load, and transmission but the molecular mechanism underlying these effects remains unclear. We report here that spike is trafficked to lysosomes and that the D614G mutation enhances the lysosomal sorting of spike and the lysosomal accumulation of spike-positive punctae in SARS-CoV-2-infected cells. Spike trafficking to lysosomes is an endocytosis-independent, V-ATPase-dependent process, and spike-containing lysosomes drive lysosome clustering but display poor lysotracker labeling and reduced uptake of endocytosed materials. These results are consistent with a lysosomal pathway of coronavirus biogenesis and raise the possibility that a common mechanism may underly the D614G mutation’s effects on spike protein trafficking in infected cells and the accelerated entry of SARS-CoV-2 into uninfected cells.

Mutations of SMC5/6 components cause developmental defects, including primary microcephaly. To model neurodevelopmental defects, we engineered a mouse wherein Smc5 is conditionally knocked out (cKO) in the developing neocortex. Smc5 cKO mice exhibited neurodevelopmental defects due to neural progenitor cell (NPC) apoptosis, which led to reduction in cortical layer neurons. Smc5 cKO NPCs formed DNA bridges during mitosis and underwent chromosome missegregation. SMC5/6 depletion triggers a CHEK2-p53 DNA damage response, as concomitant deletion of the Trp53 tumor suppressor or Chek2 DNA damage checkpoint kinase rescued Smc5 cKO neurodevelopmental defects. Further assessment using Smc5 cKO and auxin-inducible degron systems demonstrated that absence of SMC5/6 leads to DNA replication stress at late-replicating regions such as pericentromeric heterochromatin. In summary, SMC5/6 is important for completion of DNA replication prior to entering mitosis, which ensures accurate chromosome segregation. Thus, SMC5/6 functions are critical in highly proliferative stem cells during organism development.

Background: MRG001 is an antibody drug conjugate (ADC), which is composed of a chimeric anti-CD20 monoclonal antibody conjugated via a valine citrulline linker to monomethyl auristatin E (MMAE), an anti-microtubulin agent. In preclinical studies, MRG001 demonstrated significant tumor growth inhibition in rituximab-resistant non-Hodgkin's lymphoma (NHL) models. MRG001 is being evaluated in a first-in-human, open-label, multicenter Phase I study for the safety, tolerability, pharmacokinetics (PK) and preliminary antitumor activity in patients with CD20-positive relapsed or refractory (R/R) B-cell NHL. Methods: MRG001 was evaluated as a monotherapy for the treatment of patients with confirmed CD20-positive R/R B-cell NHL. The study consists of Phase Ia dose escalation and Ib dose expansion. In the Phase Ia dose-escalation study utilizing a "3+3" design, patients with pathologically confirmed R/R NHL received single agent MRG001 intravenously once every 3 weeks (Q3W) for a maximum of 6 treatment cycles. Six dose levels ranging from 0.15 to 2.5 mg/kg were evaluated for safety, PK and preliminary antitumor activity to determine the MTD/RP2D. Results: From June 25, 2019 to May 31, 2021, a total of 21 subjects with DLBCL (n=8), FL (n=12), and MZL (n=1) who met the eligibility criteria had received at least two cycles of MRG001. As of May 31, 2021, 18 subjects were off treatment and 3 subjects were still on treatment. There were 3 subjects enrolled into the 0.15, 0.3 , 0.6, 1.2 and 2.5 mg/kg cohort respectively, and 6 subjects enrolled into the 1.8 mg/kg cohort. Of the 21 subjects enrolled, 12 subjects were male and 9 subjects were female, with age ranging from 27 to 75 years old. Among the 18 subjects who were off treatment, 5 had completed 6 cycles of treatment, and 13 had drug discontinuation (12 due to progression of disease and 1 subject due to withdrawal of the informed consent for personal reasons). Commonly observed drug-related TEAEs were decreased white blood cell/neutrophil/lymphocyte counts, ALT/AST elevation, pyrexia, hypertension, increased LDH, QT prolongation, and thrombocytopenia.TEAEs (29 cases) ≥ Grade 3 were reported in 9 subjects, including 23 drug-related TEAEs in 8 subjects. The most commonly reported Grade 3 or above TRAEs were leukopenia/neutropenia, lymphopenia, hypertension, and ALT elevation. In the 2.5 mg/kg cohort, two subjects experienced drug-related toxicities that met the DLT definition per protocol, including 1 subject with Grade 3 hyperlipidemia and 1 subject with Grade 4 neutropenia that lasted 5 days. There was no death due to AEs. PK samples of total antibody, MRG001 and MMAE were measured at predefined time points and the results showed that the C max and AUC of total antibody, MRG001 and MMAE increased with dose level increase. The T max of MMAE was non-linear to dose level increase, similar trends could be observed in two other parameters including C max and AUC 0-t, which suggested that MMAE was continuously released from MRG001. Among 21 pts who had at least one tumor assessment, 1 CR (5%), 4 PR (19%), 9 SD (43%), and 7 PD (33%). The investigator assessed ORR was 24% and the DCR was 67%. In the starting dose 0.15 mg/kg cohort, one subject with FL acheived PR. Among six subjects (4 with DLBCL and 2 with FL) enrolled in the 1.8 mg/kg cohort, one DLBCL subject achieved CR and another subject with DLBCL achieved PR, ORR was 33.33% (2 out of 6). Three subjects were enrolled in the 2.5 mg/kg cohort, two subjects with FL had PR, both of them had DLT on cycle 1 and had dose reduction to 1.8 mg/kg from cycle 2, ORR was 66.7% (2 out of 3). Conclusion: The dose escalation study of MRG001 has shown manageable safety profiles and encouraging preliminary antitumor activity in patients with NHL. Based on the safety, tolerability, and pharmacokinetic parameters of MRG001, 1.8 mg/kg was determined to be the RP2D and further investigation of MRG001 in patients with NHL is warranted. Disclosures Peng: Lepu Biopharma Co., Ltd.: Current Employment. Sun: Shanghai Miracogen Inc.: Current Employment. Sun: Shanghai Miracogen Inc.: Current Employment. Li: Shanghai Miracogen Inc.: Current Employment.

Summary Background There is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses. Methods We describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape. Findings We found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape. Interpretation Our results highlight the need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered. Funding The work was partially funded by The Saban Research Institute at Children’s Hospital Los Angeles intramural support for COVID-19 Directed Research (X.G. and J.D.B.), the Johns Hopkins Center of Excellence in Influenza Research and Surveillance HHSN272201400007C (A.P.), NIH/NIAID R01AI127877 (S.D.B.), NIH/NIAID R01AI130398 (S.D.B.), NIH 1U54CA260517 (S.D.B.), an endowment to S.D.B. from the Crown Family Foundation, an Early Postdoc.Mobility Fellowship Stipend to O.F.W. from the Swiss National Science Foundation (SNSF), and a Coulter COVID-19 Rapid Response Award to S.D.B. L.G. is a SHARE Research Fellow in Pediatric Hematology-Oncology.

Introduction Hyperlipidaemia is a recognized complication of HIV antiretroviral therapy. The interactions among HIV, viral hepatitis, antiretroviral therapies and lipids are poorly understood. Methods Ontario HIV Treatment Network Cohort Study participants with at least one lipid level after highly active antiretroviral therapy (HAART) initiation were assessed. Hepatitis B virus (HBV)- and hepatitis C virus (HCV)-coinfected patients were identified by serology or chart review. HCV antiviral recipients, diabetics and those on lipid-lowering drugs at baseline were excluded from the study. Factors associated with a decreased risk of grade 3 or 4 hyperlipidaemia or lipid-lowering drug use were assessed by multivariate logistic regression. Results A total of 1587 HIV-monoinfected, 190 HIV/HBV-coinfected and 255 HIV/HCV-coinfected patients were evaluated. Most were male (85–92% for the 3 groups evaluated: HIV, HIV/HBV, HIV/HCV). The median [interquartile range (IQR)] age at HAART initiation was 48 (44–56) years and was similar between groups. The median (IQR) CD4 count at HAART initiation was 245 (120–370) cells/μL in HIV-monoinfected participants, 195 (110–330) cells/μL in HIV/HBV-coinfected participants and 268 (140–409) cells/μL in HIV/HCV-coinfected participants. Factors associated with a decreased risk of grade 3 or 4 hyperlipidaemia or lipid-lowering drug use included HIV/HCV coinfection [odds ratio (OR) 0.46; 95% confidence interval (CI) 0.34, 0.61; P

We studied the association of once-daily dosing with self-reported adherence among participants of the Ontario Cohort Study who were currently taking ART and who had completed a 90-min interviewer-administered questionnaire. Suboptimal adherence was defined as missing ≥1 dose of ART in the 4 days prior to the interview. Participants (n = 779) were 85% male, 69% men having sex with men, 67% white, median age 48 years (IQR 42-54), median years of ART 9 (IQR 5-13) and median CD4 count 463 cells/mm(3) (IQR 320-638). Fifteen percent of participants reported suboptimal adherence in the 4 days prior to the interview. In a multivariable logistic regression model, participants on once daily regimens were half as likely to miss a dose during the 4 days prior to the interview. Other independent correlates of suboptimal adherence were younger age, lower positive social interaction and increased frequency of consuming > 6 alcoholic drinks on one occasion.

Studies have reported that soy isoflavones inhibit growth in a number of carcinoma cell lines. The overexpression of Akt, a prosurvival pathway, and vimentin, a mesenchymal marker, in urological carcinomas has been associated with tumor progression and poor prognosis. Our study investigated the effects of a soy isoflavone concentrate (ISF) on the expression of Akt and vimentin in a) cultured human prostate cancer cells and b) xenograft tumors in mice. METHODS: Human prostate cancer PC-3 cells, which are androgen-insensitive and do not express p53 or PTEN, were grown in culture. Hypoxia exposure was at 1% oxygen vs room air for 48 hours. Akt, phosphorylated-Akt (phosAkt), carbonic anhydrase IX (CAIX) and vimentin expression in cells was measured by Western immunoblot analysis. Male nude mice on a soy-free control diet were injected with PC-3 cells into the hind flank. On day 5, half the mice were placed on a diet containing 0.5% soy isoflavone concentrate (ISF). Tumor size was monitored biweekly. Resected tumors were fixed in formalin and paraffin-embedded. Immunohistochemical (IHC) analysis of tumors used antibodies against PCNA, TUNEL, CAIX, Akt, phosAkt, and vimentin. RESULTS: In culture, PC-3 cells constitutively express high levels of Akt and vimentin proteins, which is not altered by hypoxia; in contrast, phosAkt and CAIX proteins are highly expressed only under hypoxic conditions. ISF caused dose-dependent inhibition of DNA synthesis and cell viability without evidence of apoptotic cell death. In culture, ISF decreased the constitutive expression of vimentin, as well as the hypoxia-mediated induction of pAkt and CAIX. In mice, the soy ISF diet significantly inhibited xenograft tumor growth. At 39 days, median tumor size was 862 mm3 in soy-free controls, and 520 mm3 in mice on the ISF diet (p=0.02). IHC analysis of tumors shows that ISF decreased the expression of nuclear PCNA, while TUNEL positive apoptotic cells was increased 4-fold. The ISF diet markedly suppressed levels of total Akt and activated phosAkt. In contrast, staining for CAIX protein was not different in control vs ISF-tumors. Vimentin was clearly expressed in PC-3 tumors and was increased by exposure to irradiation (IR, 2Gy). Interestingly, ISF suppressed IR-induced vimentin expression. Thus, soy ISF treatment inhibited PC-3 cell proliferation both in vitro and in vivo, but different mechanisms are involved in the regulation of expression of the dominant Akt prosurvival signaling pathway, as well as a major mesenchymal marker vimentin. CONCLUSIONS: Together, data indicate that a soy ISF diet strongly inhibits the growth of prostate xenograft tumors which is mediated by differential effects on hypoxia-regulated genes in the tumor microenvironment. (Supported by NIH CA102386 and the Maren Foundation) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2886.