Stromal FOXF2 suppresses prostate cancer progression and metastasis by enhancing antitumor immunity

Cancer-associated fibroblasts (CAFs) mediate an immunosuppressive effect, but the underlying mechanism remains incompletely defined. Here we show that increasing prostatic stromal Foxf2 suppresses the growth and progression of both syngeneic and autochthonous mouse prostate cancer models in an immunocompetent context. Mechanistically, Foxf2 moderately attenuates the CAF phenotype and transcriptionally downregulates Cxcl5, which diminish the immunosuppressive myeloid cells and enhance T cell cytotoxicity. Increasing prostatic stromal Foxf2 sensitizes prostate cancer to the immune checkpoint blockade therapies. Augmenting lung stromal Foxf2 also mediates an immunosuppressive milieu and inhibits lung colonization of prostate cancer. FOXF2 is expressed higher in the stroma of human transition zone (TZ) than peripheral zone (PZ) prostate. The stromal FOXF2 expression level in primary prostate cancers inversely correlates with the Gleason grade. Our study establishes Foxf2 as a stromal transcription factor modulating the tumor immune microenvironment and potentially explains why cancers are relatively rare and indolent in the TZ prostate.

Paracrine Wnt signaling is necessary for prostate epithelial proliferation

INTRODUCTION

The Wnt proteins play key roles in the development, homeostasis, and disease progression of many organs including the prostate. However, the spatiotemporal expression patterns of Wnt proteins in prostate cell lineages at different developmental stages and in prostate cancer remain inadequately characterized.

METHODS

We isolated the epithelial and stromal cells in the developing and mature mouse prostate by flow cytometry and determined the expression levels of Wnt ligands. We used Visium spatial gene expression analysis to determine the spatial distribution of Wnt ligands in the mouse prostatic glands. Using laser-capture microscopy in combination with gene expression analysis, we also determined the expression patterns of Wnt signaling components in stromal and cancer cells in advanced human prostate cancer specimens. To investigate how the stroma-derived Wnt ligands affect prostate development and homeostasis, we used a Col1a2-CreERT2 mouse model to disrupt the Wnt transporter Wntless specifically in prostate stromal cells.

RESULTS

We showed that the prostate stromal cells are a major source of several Wnt ligands. Visium spatial gene expression analysis revealed a distinct spatial distribution of Wnt ligands in the prostatic glands. We also showed that Wnt signaling components are highly expressed in the stromal compartment of primary and advanced human prostate cancer. Blocking stromal Wnt secretion attenuated prostate epithelial proliferation and regeneration but did not affect cell survival and lineage maintenance.

DISCUSSION

Our study demonstrates a critical role of stroma-derived Wnt ligands in prostate development and homeostasis.

De novo induction of lineage plasticity from human prostate luminal epithelial cells by activated AKT1 and c-Myc

Neuroendocrine prostate cancer (NEPC) is an aggressive variant of prostate cancer that either develops de novo or arises from prostate adenocarcinoma as a result of treatment resistance. Although the prostate basal cells have been shown to directly generate tumor cells with neuroendocrine features when transduced with oncogenic signaling, the identity of the cell-of-origin for de novo NEPC remains unclear. We show that the TACSTD2^high human prostate luminal epithelia cells highly express SOX2 and are relatively enriched in the transition zone prostate. Both TACSTD2^high and TACSTD2^low luminal cells transduced by activated AKT and c-Myc can form organoids containing versatile clinically relevant tumor cell lineages with regard to the expression of AR and the neuroendocrine cell markers Synaptophysin and Chromogranin A. Tumor organoid cells derived from the TACSTD2^high luminal cells are more predisposed to neuroendocrine differentiation along passaging and are relatively more castration-resistant. Knocking down TACSTD2 and SOX2 both attenuate neuroendocrine differentiation of tumor organoid cells. This study demonstrates de novo neuroendocrine differentiation of the human prostate luminal epithelial cells induced by caAKT and c-Myc and reveals an impact of cellular status on initiation of lineage plasticity.

The Sca-1+ and Sca-1- mouse prostatic luminal cell lineages are independently sustained

The phenotypic and functional heterogeneity of the mouse prostate epithelial cell lineages remains incompletely characterized. We show that the Sca-1⁺ luminal cells at the mouse proximal prostate express Sox2. These cells are replicative quiescent, castration resistant, and do not possess secretory function. We use the Probasin-CreER^T2 and Sox2-CreER^T2 models in concert with a fluorescent reporter line to label the Sca-1^- and Sca-1⁺ luminal cells, respectively. By a lineage tracing approach, we show that the two luminal cell populations are independently sustained. Sox2 is dispensable for the maintenance of the Sca-1⁺ luminal cells but is essential for their facultative bipotent differentiation capacity. The Sca-1⁺ luminal cells share molecular features with the human TACSTD2⁺ luminal cells. This study corroborates the heterogeneity of the mouse prostate luminal cell lineage and shows that the adult mouse prostate luminal cell lineage is maintained by distinct cellular entities rather than a single progenitor population.

Spatially Restricted Stromal Wnt Signaling Restrains Prostate Epithelial Progenitor Growth through Direct and Indirect Mechanisms

Cell-autonomous Wnt signaling has well-characterized functions in controlling stem cell activity, including in the prostate. While niche cells secrete Wnt ligands, the effects of Wnt signaling in niche cells per se are less understood. Here, we show that stromal cells in the proximal prostatic duct near the urethra, a mouse prostate stem cell niche, not only produce multiple Wnt ligands but also exhibit strong Wnt/β-catenin activity. The non-canonical Wnt ligand Wnt5a, secreted by proximal stromal cells, directly inhibits proliefration of prostate epithelial stem or progenitor cells whereas stromal cell-autonomous canonical Wnt/β-catenin signaling indirectly suppresses prostate stem or progenitor activity via the transforming growth factor β (TGFβ) pathway. Collectively, these pathways restrain the proliferative potential of epithelial cells in the proximal prostatic ducts. Human prostate likewise exhibits spatially restricted distribution of stromal Wnt/β-catenin activity, suggesting a conserved mechanism for tissue patterning. Thus, this study shows how distinct stromal signaling mechanisms within the prostate cooperate to regulate tissue homeostasis.

Non-Cell-Autonomous Regulation of Prostate Epithelial Homeostasis by Androgen Receptor

Prostate inflammation has been suggested as an etiology for benign prostatic hyperplasia (BPH). We show that decreased expression of the androgen receptor (AR) in luminal cells of human BPH specimens correlates with a higher degree of regional prostatic inflammation. However, the cause-and-effect relationship between the two events remains unclear. We investigated specifically whether attenuating AR activity in prostate luminal cells induces inflammation. Disrupting luminal cell AR signaling in mouse models promotes cytokine production cell-autonomously, impairs epithelial barrier function, and induces immune cell infiltration, which further augments local production of cytokines and chemokines including Il-1 and Ccl2. This inflammatory microenvironment promotes AR-independent prostatic epithelial proliferation, which can be abolished by ablating IL-1 signaling or depleting its major cellular source, the macrophages. This study demonstrates that disrupting luminal AR signaling promotes prostate inflammation, which may serve as a mechanism for resistance to androgen-targeted therapy for prostate-related diseases.

Notch promotes tumor metastasis in a prostate-specific Pten-null mouse model

Although Notch signaling is deregulated in prostate cancer, the role of this pathway in disease development and progression is not fully understood. Here, we analyzed 2 human prostate cancer data sets and found that higher Notch signaling correlates with increased metastatic potential and worse disease survival rates. We used the Pten-null mouse prostate cancer model to investigate the function of Notch signaling in the initiation and progression of prostate cancer. Disruption of the transcription factor RBPJ in Pten-null mice revealed that endogenous canonical Notch signaling is not required for disease initiation and progression. However, augmentation of Notch activity in this model promoted both proliferation and apoptosis of prostate epithelial cells, which collectively reduced the primary tumor burden. The increase in cellular apoptosis was linked to DNA damage-induced p53 activation. Despite a reduced primary tumor burden, Notch activation in Pten-null mice promoted epithelial-mesenchymal transition and FOXC2-dependent tumor metastases but did not confer resistance to androgen deprivation. Notch activation also resulted in transformation of seminal vesicle epithelial cells in Pten-null mice. Our study highlights a multifaceted role for Notch signaling in distinct aspects of prostate cancer biology and supports Notch as a potential therapeutic target for metastatic prostate cancer.

Clinical Characteristics of Epidermoid Cysts of the External Auditory Canal

Background and Objectives

The epidermoid cyst is a common benign disease of the skin caused by inflammation of hair cortex follicles and proliferation of epidermal cells within the dermis or superficial subcutaneous tissue. The purpose of this study was to investigate the characteristics of epidermoid cysts of the external auditory canal (EAC) by analyzing the clinical and radiologic features.

Subjects and Methods

The clinical records were retrospectively reviewed for patients diagnosed with epidermoid cyst of the EAC from March 2004 to December 2013. The epidermoid cysts were diagnosed clinically by endoscopy and microscopy examinations and by temporal bone CT images, and were confirmed by histopathologic examination. Characteristics of epidermoid cysts in bony EAC and cartilaginous EAC were compared.

Results

Eight patients had an epidermoid cyst in the bony EAC and nine patients had one in the cartilaginous EAC. Swelling and otalgia were common symptoms, but 47% of cysts were found incidentally. The mean age of patients was 49.6 years (age range, 26-67 years) in the bony EAC cases and 26.1 years (age range, 6-57 years) in the cartilaginous EAC cases. The mean size of the epidermoid cyst was 3.50 mm (size range, 2-7 mm) in the bony EAC cases and 9.55 mm (size range, 2-20 mm) in the cartilaginous EAC cases.

Conclusions

Comparison of epidermoid cysts of the bony EAC and the cartilaginous EAC revealed that epidermoid cysts of the bony EAC is usually found incidentally, arose in older patients and had smaller size.

High fat diet promotes prostatic basal-to-luminal differentiation and accelerates initiation of prostate epithelial hyperplasia originated from basal cells

Recent lineage tracing studies showed that the prostate basal and luminal cells in adult mice are two independent lineages under the physiological condition, but basal cells are capable of generating luminal progenies during bacterial infection-induced prostatitis. Because acute bacterial infection in human prostate tissues is relatively rare, the disease relevance of the bacterial infection-induced basal-to-luminal differentiation is uncertain. Herein we employ a high fat diet-induced sterile prostate inflammation model to determine whether basal-to-luminal differentiation can be induced by inflammation irrespective of the underlying etiologies. A K14-CreER model and a fluorescent report line are utilized to specifically label basal cells with the green fluorescent protein. We show that high fat diet promotes immune cell infiltration into the prostate tissues and basal-to-luminal differentiation. Increased cell proliferation accompanies basal-to-luminal differentiation, suggesting a concurrent regulation of basal cell proliferation and differentiation. This study demonstrates that basal-to-luminal differentiation can be induced by different types of prostate inflammation evolved with distinct etiologies. Finally, high fat diet also accelerates initiation and progression of prostatic intraepithelial neoplasia that are originated from basal cells with loss-of-function of the tumor suppressor Pten. Because prostate cancer originated from basal cells tends to be invasive, our study also provides an alternative explanation for the association between obesity and aggressive prostate cancer.

Abstract A36: Notch signaling promotes tumor metastasis in the Pten null mouse model for prostate cancer

The role of Notch signaling in prostate cancer remains inconclusive. We show that a higher Notch signature score is significantly correlated with higher disease grade, metastatic potential and higher probability of lethal outcome in two published human prostate cancer datasets. We employ genetic approaches to investigate the role of Notch signaling in initiation and progression of prostate cancer in a Pten null mouse model. Notch signaling is dispensable for disease initiation and progression in this model. Elevated Notch activity in the Pten null model promotes both epithelial proliferation and apoptosis, which collectively results in a reduction of primary tumor burdens. Despite reduced primary tumor burdens, Notch activation drives epithelial-mesenchymal-transition and promotes distal tumor metastases at full penetrance. Our study reveals distinct impacts of Notch signaling on cancer cell proliferation, survival and metastasis in the context of Pten loss, and highlights a multifaceted and pleiotropic role of Notch in regulating the different aspects of prostate cancer cell biology.

Citation Format: Oh-Joon Kwon, Li Zhang, Wang Jianghua, Chad Creighton, Michael Ittmann, Li Xin. Notch signaling promotes tumor metastasis in the Pten null mouse model for prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference: Developmental Biology and Cancer; Nov 30-Dec 3, 2015; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(4_Suppl):Abstract nr A36.

Identification of a novel HLA-C*03 variant allele, C*03:280 by sequence-based typing

The new allele, HLA-C*03:280 differs from C*03:04:01 by one nucleotide substitution at codon 35 (CGG→CAG).

Stem Cell Antigen-1 Identifies a Distinct Androgen-Independent Murine Prostatic Luminal Cell Lineage with Bipotent Potential

Recent lineage tracing studies support the existence of prostate luminal progenitors that possess extensive regenerative capacity, but their identity remains unknown. We show that Sca-1 (stem cell antigen-1) identifies a small population of murine prostate luminal cells that reside in the proximal prostatic ducts adjacent to the urethra. Sca-1(+) luminal cells do not express Nkx3.1. They do not carry the secretory function, although they express the androgen receptor. These cells are enriched in the prostates of castrated mice. In the in vitro prostate organoid assay, a small fraction of the Sca-1(+) luminal cells are capable of generating budding organoids that are morphologically distinct from those derived from other cell lineages. Histologically, this type of organoid is composed of multiple inner layers of luminal cells surrounded by multiple outer layers of basal cells. When passaged, these organoids retain their morphological and histological features. Finally, the Sca-1(+) luminal cells are capable of forming small prostate glands containing both basal and luminal cells in an in vivo prostate regeneration assay. Collectively, our study establishes the androgen-independent and bipotent organoid-forming Sca-1(+) luminal cells as a functionally distinct cellular entity. These cells may represent a putative luminal progenitor population and serve as a cellular origin for castration resistant prostate cancer.

PTEN is required to maintain luminal epithelial homeostasis and integrity in the adult mammary gland

In the mammary gland, PTEN loss in luminal and basal epithelial cells results in differentiation defects and enhanced proliferation, leading to the formation of tumors with basal epithelial characteristics. In breast cancer, PTEN loss is associated with a hormone receptor-negative, basal-like subtype that is thought to originate in a luminal epithelial cell. Here, we show that luminal-specific PTEN loss results in distinct effects on epithelial homeostasis and mammary tumor formation. Luminal PTEN loss increased proliferation of hormone receptor-negative cells, thereby decreasing the percentage of hormone receptor-positive cells. Moreover, luminal PTEN loss led to misoriented cell divisions and mislocalization of cells to the intraluminal space of mammary ducts. Despite their elevated levels of activated AKT, Pten-null intraluminal cells showed increased levels of apoptosis. One year after Pten deletion, the ducts had cleared and no palpable mammary tumors were detected. These data establish PTEN as a critical regulator of luminal epithelial homeostasis and integrity in the adult mammary gland, and further show that luminal PTEN loss alone is not sufficient to promote the progression of mammary tumorigenesis.

Prostate epithelial stem and progenitor cells

The classic androgen ablation and replacement experiment demonstrates that prostate epithelia possess extensive regenerative capacities and implies the existence of the prostate stem/progenitor cells. These cells may serve as the cells of origin for prostate cancer and their intrinsic property may dictate the clinical behaviors of the resulting diseases. Therefore, detailed characterization of these cells will potentially benefit disease prevention, diagnosis and prognosis. In this review, we describe several major in vitro and in vivo approaches that have been employed in the studies of the prostate stem cell activities, summarize the major progress that has been made during the last two decades regarding the identity of prostate stem/progenitor cells and their niches, and discuss some remaining outstanding questions in the field.

Changes in serum immunomolecules during antibiotic therapy for Mycobacterium avium complex lung disease

Little information is available regarding changes in immune status for patients with Mycobacterium avium complex (MAC) lung disease during antibiotic therapy. Serum immunomolecules from 42 patients with MAC lung disease were assayed comparatively using an array-based system according to (i) patients with MAC lung disease at the time of diagnosis versus healthy controls and (ii) alterations after 12 months of antibiotic therapy in the MAC lung disease group. In addition, cytokine analyses were performed to determine whether cytokine responses were associated specifically with the disease phenotype, treatment outcome and aetiological agent. Notably, the serum concentrations of type 1 cytokine-associated molecules, such as CD40L, interferon (IFN)-γ, interleukin (IL)-8 and IL-23, were decreased significantly in patients at the time of diagnosis, suggesting that these molecules may serve as indicators of host susceptibility to MAC disease. Although the overall serum level of T helper type 1 (Th1)-related molecules, such as CD40L and IFN-γ, was restored after treatment, Th17-related cytokines, such as IL-17 and IL-23, were down-regulated significantly at 12 months post-treatment compared to pretreatment. Furthermore, these cytokine patterns differed among patient subgroups. Decreased serum concentrations of IL-17 and/or IL-23 were associated with failure of sputum conversion, the fibrocavitary disease phenotype and M. intracellulare lung disease. Thus, the reciprocal balance between Th1 and Th17 immunity during antibiotic therapy for MAC lung disease is critical for dictating the treatment response. In conclusion, a low level of Th1-related immunomolecules may perpetuate MAC lung disease, and the serum concentrations of Th17-related cytokines can reflect the treatment outcome, disease phenotype and aetiological agent.

Inhibition of tumour angiogenesis and growth by small hairpin HIF-1α and IL-8 in hepatocellular carcinoma

BACKGROUND & AIMS

Hypoxia-inducible factor-1α (HIF-1α), a key transcription factor in the cellular response to hypoxia, and interleukin 8 (IL-8), a key mediator of angiogenesis, are important in cancerous tumour growth. In this study, we evaluated the effects of HIF-1α and IL-8 knockdown on angiogenesis and tumour growth in hepatocellular carcinoma (HCC).

METHODS

Hepatocellular carcinoma cell lines were infected with adenoviruses expressing small-hairpin RNA (shRNA) specific for HIF-1α or IL-8, cultured under hypoxic conditions (1% O2), and examined for their levels of HIF-1α, IL-8, and angiogenesis factors using immunoblot. The effects of adenovirus-mediated shRNA-induced HIF-1α and IL-8 knockdown on tumour growth and angiogenesis were also investigated in a subcutaneous Hep3B-tumour mouse model.

RESULTS

Hypoxia-inducible factor-1α knockdown directly repressed tumour growth, whereas IL-8 knockdown indirectly repressed tumour growth. Combined knockdown of HIF-1α and IL-8 increased survival rates of mice. HIF-1α and IL-8 knockdown also decreased microvessel density and tumour volume in vivo. Similarly, HIF-1α and IL-8 knockdown inhibited the angiogenic effects of HCC cell-conditioned media on tube formation and invasion by endothelial cells in vitro.

CONCLUSION

These findings indicate that shRNA-induced HIF-1α and IL-8 knockdown inhibit angiogenesis and tumour growth in HCC. Further development of HIF-1α and IL-8 shRNA technologies could lead to effective therapies for HCC.

Inorganic nanovehicle targets tumor in an orthotopic breast cancer model

The clinical efficacy of conventional chemotherapeutic agent, methotrexate (MTX), can be limited by its very short plasma half-life, the drug resistance, and the high dosage required for cancer cell suppression. In this study, a new drug delivery system is proposed to overcome such limitations. To realize such a system, MTX was intercalated into layered double hydroxides (LDHs), inorganic drug delivery vehicle, through a co-precipitation route to produce a MTX-LDH nanohybrid with an average particle size of approximately 130 nm. Biodistribution studies in mice bearing orthotopic human breast tumors revealed that the tumor-to-liver ratio of MTX in the MTX-LDH-treated-group was 6-fold higher than that of MTX-treated-one after drug treatment for 2 hr. Moreover, MTX-LDH exhibited superior targeting effect resulting in high antitumor efficacy inducing a 74.3% reduction in tumor volume compared to MTX alone, and as a consequence, significant survival benefits. Annexin-V and propidium iodine dual staining and TUNEL analysis showed that MTX-LDH induced a greater degree of apoptosis than free MTX. Taken together, our data demonstrate that a new MTX-LDH nanohybrid exhibits a superior efficacy profile and improved distribution compared to MTX alone and has the potential to enhance therapeutic efficacy via inhibition of tumor proliferation and induction of apoptosis.

Toxocariasis as a cause of new pulmonary infiltrates

SETTING

Patients with new pulmonary infiltrates on chest computed tomography (CT) scans at a tertiary centre in South Korea.

OBJECTIVE

To demonstrate associations among radiological changes, blood eosinophilia (E) and Toxocara (T) seropositivity.

DESIGN

We retrospectively reviewed blood eosinophilia, Toxocara seropositivity, history of raw meat intake and radiological features, and divided study patients into four groups according to blood eosinophilia and Toxocara seropositivity.

RESULTS

Among 150 patients, 62 were E- and T-positive (E+T+), 45 were E-negative and T-positive (E-T+), 7 were E-positive and T-negative (E+T-), and 36 were E- and T-negative (E-T-). History of raw meat intake was found in 95 (63%) patients. The type and number of lesions on CT did not show any significant differences among the four groups. Among 119 patients who were not diagnosed with a specific disease, transient or migrating lesions were seen in 93% of E+T+, 93% of E-T+, 80% of E+T- and 52% of E-T- patients (P < 0.0001). Furthermore, the frequencies of migrating or new lesions and improvement were significantly higher in the Toxocara-positive group (88/95, 93%) than in the Toxocara-negative group (14/24, 58%; P = 0.002).

CONCLUSION

Transient and migratory pulmonary infiltrates on chest CT scans were associated with blood eosinophilia and Toxocara seropositivity. Clinicians should consider asymptomatic toxocariasis as a cause of unexplained new pulmonary infiltrates in countries with dietary habits of raw meat intake.

The impact of post-transplant hemoglobin level on renal allograft outcome

BACKGROUND

Anemia is a common complication of chronic renal disease and renal transplantation. Early post-transplant anemia is the consequence of blood loss, immunosuppressant therapy, and failure to produce sufficient erythropoietin. Late post-transplant anemia has been attributed to drug therapy, renal dysfunction, and infection. The effect of post-transplant anemia on renal allograft survival and acute rejection rates is not established. The aim of this study was to examine the impact of post-transplant anemia on renal function and allograft outcomes.

MATERIALS AND METHODS

We included 411 patients who underwent living or deceased donor renal transplantations in our center from April 1990 to March 2010. The patients were divided into 2 groups according to their postoperative hemoglobin level at 1 month: anemic group (<12.0 g/dL in men, <11.0 g/dL in women) and nonanemic group (≥ 12.0 g/dL in men, ≥ 11.0 g/dL in women). The outcome measures included postoperative serum creatinine levels at 12 and 36 months, acute and chronic rejection rates, as well as long-term graft survival.

RESULTS

The acute and chronic rejection rates were significantly higher in the anemic group: 28.1% versus 19.7% (P = .000) and 24.1% versus 19.7% (P = .027), respectively. Postoperative serum creatinine levels at 12 and 36 months were not significantly different in patients with functioning grafts regardless of their anemia status (P = .530 and P = .430, respectively). Graft survival was lower with anemia: 85.4% versus 93.8% at 5 years, and 74.8% versus 83.5% at 10 years (P = .040).

CONCLUSIONS

Post-transplant anemia was associated with poorer renal function at 12 months, higher acute rejection rates, and worse long-term renal allograft outcomes compared with subjects displaying normal hemoglobin levels.

Therapeutic targeting of chitosan-PEG-folate-complexed oncolytic adenovirus for active and systemic cancer gene therapy

Adenovirus (Ad)-based cancer therapies have shown much promise. However, until now, Ad has only been delivered directly to primary tumors because the therapeutic efficacy of systemic delivery is limited by the immune response of the host, short blood circulation times, and non-specific liver uptake of Ad. In order to circumvent the issues regarding systemic delivery and to increase the safety and efficacy of Ad therapies, the surface of oncolytic Ad was coated with cationic polymer chitosan via ionic crosslinking (Ad/chitosan), after which polyethylene glycol (PEG) and/or folic acid (FA) was chemically conjugated onto the surface of Ad/chitosan, generating Ad/chitosan-FA, Ad/chitosan-PEG, and Ad/chitosan-PEG-FA nanocomplex. The FA-coordinated Ad nanocomplexes (Ad/chitosan-FA & Ad/chitosan-PEG-FA) elicited folate receptor (FR)-selective cancer cell killing efficacy. In vivo administration of Ad/chitosan-PEG or Ad/chitosan-PEG-FA into mice demonstrated that PEGylation greatly increased blood circulation time, resulting in 9.0-fold and 48.9-fold increases at 24h after injection compared with naked Ad, respectively. In addition, generation of Ad-specific neutralizing antibodies in mice treated with Ad/chitosan-PEG-FA was markedly decreased by 75.3% compared with naked Ad. The quantitative polymerase chain reaction assay results showed a 285.0-fold increase in tumor tissues and a 378-fold reduction of Ad/chitosan-PEG-FA in liver tissues compared with naked Ad. Bioluminescence imaging study further supported the enhanced tumor-to-liver ratio of Ad/chitosan-PEG-FA. Consequently, systemic delivery of Ad/chitosan-PEG-FA significantly inhibited the growth of FR-positive tumor, decreasing 52.8% compared to the naked Ad-treated group. Importantly, PEGylated oncolytic Ad nanocomplexes showed no elevation of both alanine transaminase and aspartate transaminase levels, demonstrating that systemically delivered Ad-related hepatic damage can be completely eliminated with PEG conjugation. In sum, these results demonstrate that conjugation of chitosan-PEG-FA to oncolytic Ad significantly improves antitumor efficacy and safety profiles, suggesting that Ad/chitosan-PEG-FA has potential as a therapeutic agent to target FR-positive cancer via systemic administration.

A new HLA-C*07:244 allele identified by sequence-based typing in a Korean individual

The C*07:244 changes single nucleotide of C*07:02:01 at codon 75 (CGA → CAA), Arg to Gln.

A proteoliposome containing apolipoprotein A-I mutant (V156K) enhances rapid tumor regression activity of human origin oncolytic adenovirus in tumor-bearing zebrafish and mice

We recently reported that the efficiency of adenoviral gene delivery and virus stability are significantly enhanced when a proteoliposome (PL) containing apolipoprotein (apo) A-I is used in an animal model. In the current study, we tested tumor removal activity of oncolytic adenovirus (Ad) using PL-containing wildtype (WT) or V156K. Oncolytic Ad with or without PL was injected into tumors of zebrafish and nude mice as a Hep3B tumor xenograft model. The V156K-PL-Ad-injected zebrafish, group showed the lowest tumor tissue volume and nucleic acids in the tumor area, whereas injection of Ad alone did not result in adequate removal of tumor activity. Reactive oxygen species (ROS) contents increased two-fold in tumor-bearing zebrafish; however, the V156K-PL-Ad injected group showed a 40% decrease in ROS levels compared to that in normal zebrafish. After reducing the tumor volume with the V156K-PL-Ad injection, the swimming pattern of the zebrafish changed to be more active and energetic. The oncolytic effect of PL-Ad containing either V156K or WT was about two-fold more enhanced in mice than that of Ad alone 34 days after the injection. Immunohistochemical analysis revealed that the PL-Ad-injected groups showed enhanced efficiency of viral delivery with elevated Ad-E1A staining and a diminished number of proliferating tumor cells. Thus, the antitumor effect of oncolytic Ad was strongly enhanced by a PL-containing apoA-I and its mutant (V156K) without causing side effects in mice and zebrafish models.

A new HLA-B*40:186 allele identified by sequence-based typing in a Korean individual

The new allele B*40:186 shows a one nucleotide substitution compared with B*40:01:02 at codon 56 (GGG → AGG) resulting in coding change, Gly to Arg.

The effect of donor-recipient relationship on long-term outcomes of living related donor renal transplantation

BACKGROUND

Presensitization to human leukocyte antigen (HLA) tends to decrease renal graft survival. During the pregnancy, fetal blood is frequently exposed to the maternal circulation possibly inducing maternal immunization to paternal HLA inherited by the fetus. In this way, pregnancy may occasionally present a hazard to renal graft survival. In this study, we compared retrospectively graft survivals according to living related donor-recipient pairs.

MATERIALS AND METHODS

From July 1979 to January 2011, 374 patients underwent living related renal transplantation sharing at least one HLA haplotype with their donor. We compared acute rejection and complication rates as well as long-term graft survival according to the donor-recipient paring: child-to-mother, child-to-father, mother-to-child, father-to-child, and one haplotype-matched siblings. All patients received immunosuppressive therapy, consisting of a calcineurin inhibitor, mycophenolate mofetil, or azathioprine and prednisolone.

RESULTS

Twenty-one cases (5.6%) were child-to-father paring; 28 (7.5%), child-to-mother; 179 (47.9%), one-haplotype-matched siblings; 46 (12.3%), father-to-child; and 100 (26.7%), mother-to-child paring. Child-to-father pairing displayed the best graft survival; child-to-mother (hazard ratio [HR] = 1.709, P = .662) and one-haplotype-matched siblings (HR = 6.589, P = .062) showed no significant difference. Father-to-child pares experienced poorer outcomes than child-to-father pairs (HR = 11.579, P = .017) and mother-to-child, the poorest graft survival (HR 17.188, P = .005).

CONCLUSION

Pregnancy continues to be a significant source of presensitization in the course of gestation and after parturition. Graft failure can result from an anamnestic reaction subsequent to intrauterine exposure of the mother to HLA of a fetus due to sensitization.

The role of the altruistic unbalanced chain in exchange living donor renal transplantation: single-center experience

BACKGROUND

The exchange donor program in renal transplantation is an efficient solution for recipients with a blood type or crossmatch-incompatible donor. However, this program has some difficulties to define unacceptable human leukocyte antigen matches, deteriorating clinical potential recipient condition, and withdrawal of donor consent. We analyzed the outcomes of exchange donor renal transplantation through the altruistic unbalanced chain.

METHODS

Among 152 cases of exchange donor renal transplantation from 1991 to 2010 in our hospital, we performed 58 procedures through altruistic unbalanced chains. We compared their outcomes with the direct and balanced chain group. We analyzed retrospectively whether this program expanded the donor pool, seeking better immunologic, size, and age matching.

RESULTS

The graft survival and acute rejection rates did not differ significantly in the two groups. Of 152 cases, 58 (38.2%) renal transplantations were performed through an unbalanced chain. Seventeen waiting list recipients were transplanted through an altruistic unbalanced chain. In blood type O recipients (n = 32), the causes of registration in the exchange program were ABO incompatibility (93.3%), and positive crossmatch (6.7%). Nine altruistic blood type O donors and 9 (28.1%) type O recipients underwent transplantations through this chain.

CONCLUSIONS

We suggest the altruistic unbalanced chain may expand the donor pool with advantages for difficult-to-match pairs. The disadvantages of type O recipients may be overcome through the use of an unbalanced chain. The altruistic unbalanced exchange transplantation program can help easy-to-match subjects, shortening the waiting periods.

The utilization and advantages of an exchange donor program in living donor renal transplantation: a single-center experience

INTRODUCTION

The availability of donors is a major limiting factor in living donor renal transplantation. Approximately one third of patients with end-stage renal disease have willing potential living donors who are blood type or cross-match incompatible. The living donor kidney exchange has become an efficient solution for recipients in this situation. We analyzed the outcome and advantages of an exchange donor program compared with ABO-incompatible transplantation and desensitized protocol transplantation for highly sensitized patients.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 152 exchange donor cases from 1991 to 2010. We analyzed the risk factors, outcomes, matching factors, complication rates, and acute rejection rates of this program compared with other alternative strategies.

RESULTS

In our center, 22% of total living donor kidney transplantations were performed through an exchange program and an expanded donor pool. The graft survival, complication, and acute rejection rates were not significantly different compared with the alternatives. The severe complication rates were lower than with the alternatives and the immunosuppressant protocol and preoperative preparation were simpler. Blood type O recipients who registered in the exchange program showed no significant differences from the living related groups (P = .45), which were similar to the proportions for other ABO types. Upon multivariate analysis, an acute rejection episode and use of mycophenolate mofetil (MMF) were significant factors associated with graft survival (P = .015 and P = .007; odds ratio [OR] 5.968 and 7.324; 95% confidence interval [CI] .003-.533 and .098-.690).

CONCLUSION

Although exchange donor programs are not the sole solution, they show several advantages, such as the prescription of standard immunosuppression, simple preoperative preparation, low cost, and modest rates of severe complications compared with ABO-incompatible transplantation or desensitized protocols.

Initial lactate level and mortality in septic shock patients with hepatic dysfunction

An elevated serum lactate level is associated with morbidity and mortality in patients with severe sepsis and septic shock. In patients with hepatic dysfunction, however an elevated serum lactate level may be due to either impaired lactate clearance or excessive production. Thus, we evaluated whether the initial serum lactate level was also associated with mortality in septic shock patients with hepatic dysfunction. A retrospective observational study enrolled 307 patients with septic shock admitted to the intensive care unit (ICU) between May 2007 and July 2009. Hepatic dysfunction was defined as a serum total bilirubin > 34.2 micromol/l (2 mg/dl). Selected patients were divided into high (> or = 4 mmol/l) and low (< 4 mmol/l) lactate groups, according to the initial serum lactate level. Of 307 patients with septic shock, 118 (38%) patients with hepatic dysfunction were eligible for this study. The median lactate levels were 5.9 (interquartile range 4.7 to 9.0) and 2.6 (interquartile range 1.7 to 3.2) mmol/l for the high and low lactate groups respectively (P < 0.001). The initial serum lactate level was strongly associated with in hospital mortality in a univariate analysis (P < 0.001). After adjusting for potential confounding factors, the initial serum lactate level remained significantly associated with in-hospital mortality (odds ratio 1.281, 95% confidence interval 1.097 to 1.496, P = 0.002). In conclusion, the serum lactate level could be useful in predicting the outcome of patients with septic shock regardless of hepatic dysfunction.

Allele frequencies of human leukocyte antigen-G in a Korean population

The human leukocyte antigen (HLA)-G is a nonclassical major histocompatibility complex class I molecule with relatively limited polymorphism. The differences in allele frequency according to ethnicity and country have not been studied enough, so far. Therefore, fundamental data including allele frequencies and polymorphism are needed for studies on immunological function of HLA-G in each population. We investigated allele frequencies and 14-bp polymorphism of the HLA-G in Koreans. HLA-G alleles and 14-bp polymorphisms were determined by sequence-based typing analysis of exons 2-4 and polymerase chain reaction of exon 8 in 200 unrelated individuals. Genotyping analysis identified eight different HLA-G alleles, which indicates that the Korean population presents limited HLA-G allelic polymorphism. HLA-G*01:01:01:01 and G*01:04:01 were frequent alleles (42.5% and 34.0%), and allelic frequencies were similar to those of other Asian populations. The 14-bp deletion alleles are higher (78%) in Koreans, although the frequencies of the 14-bp insertion/deletion polymorphism have been known to be nearly equal in many Caucasian populations. HLA-G*01:01:08 was reported strong linkage disequilibrium with the 14-bp deletion in a previous report; the same allele was accompanied with 14-bp insertion in our study. There are a few studies investigating allele frequencies, and most of them were studied before high-resolution method era. This is the first study regarding HLA-G genotypes in Korean, which were identified by high-resolution method. From this study, we identified HLA-G frequencies of a Korean population and expect this study could help further investigations for immunological and clinical implications of HLA-G.

A hypoxia- and {alpha}-fetoprotein-dependent oncolytic adenovirus exhibits specific killing of hepatocellular carcinomas

PURPOSE

Oncolytic adenoviruses (Ad) constitute a new promising modality of cancer gene therapy that displays improved efficacy over nonreplicating Ads. We have previously shown that an E1B 19-kDa-deleted oncolytic Ad exhibits a strong cell-killing effect but lacks tumor selectivity. To achieve hepatoma-restricted cytotoxicity and enhance replication of Ad within the context of tumor microenvironment, we used a modified human α-fetoprotein (hAFP) promoter to control the replication of Ad with a hypoxia response element (HRE).

EXPERIMENTAL DESIGN

We constructed Ad-HRE(6)/hAFPΔ19 and Ad-HRE(12)/hAFPΔ19 that incorporated either 6 or 12 copies of HRE upstream of promoter. The promoter activity and specificity to hepatoma were examined by luciferase assay and fluorescence-activated cell sorting analysis. In addition, the AFP expression- and hypoxia-dependent in vitro cytotoxicity of Ad-HRE(6)/hAFPΔ19 and Ad-HRE(12)/hAFPΔ19 was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cytopathic effect assay. In vivo tumoricidal activity on subcutaneous and liver orthotopic model was monitored by noninvasive molecular imaging.

RESULTS

Ad-HRE(12)/hAFPΔ19 exhibited enhanced tumor selectivity and cell-killing activity when compared with Ad-hAFPΔ19. The tumoricidal activity of Ad-HRE(12)/hAFPΔ19 resulted in significant inhibition of tumor growth in both subcutaneous and orthotopic models. Histologic examination of the primary tumor after treatment confirmed accumulation of viral particles near hypoxic areas. Furthermore, Ad-HRE(12)/hAFPΔ19 did not cause severe inflammatory immune response and toxicity after systemic injection.

CONCLUSIONS

The results presented here show the advantages of incorporating HREs into a hAFP promoter-driven oncolytic virus. This system is unique in that it acts in both a tissue-specific and tumor environment-selective manner. The greatly enhanced selectivity and tumoricidal activity of Ad-HRE(12)/hAFPΔ19 make it a promising therapeutic agent in the treatment of liver cancers.

A new HLA-B*5124 variant, B*512402 allele, identified by sequence-based typing

A novel human leukocyte antigen-B allele, officially named B*512402, was identified in a Korean bone marrow donor. The B*512402 allele shows two nucleotide substitutions compared with B*512401 in exon 3 at codons 135 (GCG --> GCC) and 138 (ACC --> ACG) without any amino acid substitution.

A national survey on the practice and outcomes of mechanical ventilation in Korean intensive care units

A study was undertaken to describe the practice and outcomes of mechanical ventilation throughout Korea. This prospective cohort study was conducted over a three-month period enrolling patients (n = 519) who received mechanical ventilation for more than 72 hours in 21 university hospital intensive care units throughout Korea. The most common indication for mechanical ventilation was acute respiratory failure. The most common cause of acute-on-chronic respiratory failure was tuberculous lung disease. The most common initial mode for ventilation was volume-controlled ventilation. The mean tidal volume of acute respiratory distress syndrome patients was 7.6 ml/kg of the predicted body weight and the mean positive end-expiratory pressure was 9.4 cmH20. The weaning success rate at 28 days was 50.3%. Pressure support and the T-piece were most commonly used as initial and final weaning modes respectively. Preventive measures against deep vein thrombosis during mechanical ventilation were performed more frequently in intensive care units with full-time critical care physicians than those without such physicians. Multivariate analysis showed that the APACHE II score, indication for mechanical ventilation, respiratory rate at 72 hours, enteral feeding and prophylaxis of deep vein thrombosis were prognostic factors for survival. In Korean intensive care units, tuberculous lung disease remains an important cause for mechanical ventilation. The practice of mechanical ventilation in Korean intensive care units in general appeared to comply with the current international recommendations with regard to lung protection and weaning. However, intensive care units lacking critical care physicians seemed to be adopting fewer ancillary measures, such as deep vein thrombosis prophylaxis.

Direct application of the PCR restriction analysis method for identifying NTM species in AFB smear-positive respiratory specimens

The early differentiation of Mycobacterium tuberculosis from non-tuberculous mycobacteria (NTM) and the identification of NTM species are crucial for the proper management of patients with smear-positive sputum. We evaluated the usefulness of a polymerase chain reaction restriction analysis (PRA) method based on the rpoB gene for identifying NTM species in a study of 121 smear-positive respiratory specimens with presumed NTM. The PRA method amplified mycobacterial DNA in 72 specimens (60%) and differentiated NTM species correctly in 68 (94%). The PRA method could be a useful and rapid method for identifying NTM species in smear-positive respiratory specimens when urgent clinical decisions are required.

Vitamin D-receptor polymorphisms and non-tuberculous mycobacterial lung disease in Korean patients

This study investigated the potential role of vitamin D-receptor (VDR) gene polymorphisms in susceptibility to lung disease caused by non-tuberculous mycobacteria (NTM). TaqI and FokI polymorphisms were compared in 124 patients and 127 controls. The genotype, allele and haplotype frequencies did not differ between patients and controls. TaqI and FokI polymorphisms of the VDR gene do not appear to be responsible for host susceptibility to NTM lung disease, at least in this Korean population. An association cannot, however, be completely ruled out, as only two single nucleotide polymorphisms of the VDR gene were studied in this report.

A new HLA-B*40 variant, B*4073, identified by sequence-based typing in the Korean population

A novel human leukocyte antigen-B*40 (HLA-B*40) allele was identified in the Korean population and designated HLA-B*4073. The HLA-B*4073 allele shows one nucleotide difference from B*400102 in exon 2 at nucleotide position 299 (A-->T), resulting in an amino acid change, Glu76Val.

Safety and usefulness of bronchoscopy in ventilator-dependent patients with severe thrombocytopenia

Flexible bronchoscopy is a useful diagnostic procedure in patients with respiratory failure due to unexplained pulmonary infiltrates, but its safety and usefulness in ventilator-dependent patients with severe thrombocytopenia have not been established. A retrospective review of the medical records of all patients who underwent bronchoscopy while receiving mechanical ventilation support at Samsung Medical Centre, Seoul, Korea between January 2002 and July 2006 was conducted. The medical records of 37 patients with severe thrombocytopenia (platelet count <50,000 /microl) at the time of bronchoscopy were analysed. Mean platelet count was 27,300+/-12,500 /microl. The most common underlying condition was haematologic malignancy, which occurred in 21(56.7%) patients, followed by severe sepsis in five (13.6%) and post-liver transplantation complications and autoimmune disease in four each (10.8%). The procedures performed were bronchoalveolar lavage in 33 patients, washing in three and transbronchial lung biopsy in five. Two patients died within 24 hours of completing the procedure. In patients surviving longer than 24 hours, there was no significant decline in oxygenation index (PaO2/FiO2), sequential organ failure assessment score or simplified acute physiological score II after the procedure. Lung compliance significantly decreased at two hours post-bronchoscopy but recovered to the pre-bronchoscopy level by 24 hours. Intensive care unit mortality was 51.4% (19 of 37 patients). Bronchoscopy was helpful in confirming the diagnosis in 17 patients (45.9%). Therapeutic modifications were made in 14 patients (37.8%) after bronchoscopy. Severe thrombocytopenia per se should not preclude bronchoscopy, even in patients receiving mechanical ventilation.

A cyclic RGD-coated peptide nanoribbon as a selective intracellular nanocarrier

We have synthesized a peptide-based supramolecular building block consisting of a cyclic Arg-Gly-Asp (cRGD) peptide segment and a beta-sheet-forming peptide segment. The block peptide was shown to self-assemble into a cRGD-coated nanoribbon structure, as revealed by circular dichroism (CD), dynamic light scattering (DLS), and transmission electron microscopy (TEM) studies. We have shown that this cRGD-coated nanoribbon can encapsulate hydrophobic guest molecules and deliver them into cells. Colocalization of the nanoribbon with LysoTracker and the selective intracellular delivery results suggests that the cRGD-coated nanoribbon is likely to be internalized into the cells through integrin receptors.

A new HLA-A*24 variant, A*2475, identified by sequence-based typing in the Korean population

A novel human leukocyte antigen (HLA) A*24 allele was identified in the Korean population and designated HLA-A*2475. The HLA-A*2475 allele shows one nucleotide difference from A*24020101 in exon 3 at nucleotide position 575 (T-->C), resulting in an amino acid change, Leu168Arg.

Identification of a new HLA-A*24 variant, A*2474, by sequence-based typing in the Korean population

A novel human leukocyte antigen, A*24 (HLA-A*24), was identified in the Korean population. HLA-A*2474 allele shows one nucleotide difference from A*24020101 in exon 2 at nucleotide position 186 (C --> A), resulting in an amino acid change, Ser38Arg.