Molecular subtypes of lung adenocarcinoma present distinct immune tumor microenvironments.

Overcoming resistance to immune checkpoint inhibitors is an important issue in patients with non-small-cell lung cancer (NSCLC). Transcriptome analysis shows that adenocarcinoma can be divided into three molecular subtypes: terminal respiratory unit (TRU), proximal proliferative (PP), and proximal inflammatory (PI), and squamous cell carcinoma (LUSQ) into four. However, the immunological characteristics of these subtypes are not fully understood. In this study, we investigated the immune landscape of NSCLC tissues in molecular subtypes using a multi-omics dataset, including tumor-infiltrating leukocytes (TILs) analyzed using flow cytometry, RNA sequences, whole exome sequences, metabolomic analysis, and clinicopathologic findings. In the PI subtype, the number of TILs increased and the immune response in the tumor microenvironment (TME) was activated, as indicated by high levels of tertiary lymphoid structures, and high cytotoxic marker levels. Patient prognosis was worse in the PP subtype than in other adenocarcinoma subtypes. Glucose transporter 1 (GLUT1) expression levels were upregulated and lactate accumulated in the TME of the PP subtype. This could lead to the formation of an immunosuppressive TME, including the inactivation of antigen-presenting cells. The TRU subtype had low biological malignancy and "cold" tumor-immune phenotypes. Squamous cell carcinoma (LUSQ) did not show distinct immunological characteristics in its respective subtypes. Elucidation of the immune characteristics of molecular subtypes could lead to the development of personalized immune therapy for lung cancer. Immune checkpoint inhibitors could be an effective treatment for the PI subtype. Glycolysis is a potential target for converting an immunosuppressive TME into an antitumorigenic TME in the PP subtype.

Investigating the immunological function of alpha-2-glycoprotein 1, zinc-binding in regulating tumor response in the breast cancer microenvironment.

BACKGROUND: Alpha-2-glycoprotein 1, zinc-binding (ZAG), a secreted protein encoded by the AZGP1 gene, is structurally similar to HLA class I. Despite its presumed immunological function, little is known about its role in tumor immunity. In this study, we thus aimed to determine the relationship between the expression of AZGP1/ZAG and the immunological profiles of breast cancer tissues at both the gene and protein level. METHODS: Using a publicly available gene expression dataset from a large-scale breast cancer cohort, we conducted gene set enrichment analysis (GSEA) to screen the biological processes associated with AZGP1. We analyzed the correlation between AZGP1 expression and immune cell composition in breast cancer tissues, estimated using CIBERSORTx. Previously, we evaluated the infiltration of 11 types of immune cells for 45 breast cancer tissues using flow cytometry (FCM). ZAG expression was evaluated by immunohistochemistry on these specimens and analyzed for its relationship with immune cell infiltration. The action of ZAG in M1/M2 polarization models using primary cultures of human peripheral blood mononuclear cells (PBMC)-derived macrophage (Mφ) was analyzed based on the expression of M1/M2 markers (CD86, CD80/CD163, MRC1) and HLA class I/II by FCM. RESULTS: AZGP1 expression was negatively correlated with multiple immunological processes and specific immune cell infiltration including Mφ M1 using GSEA and CIBERSORTx. ZAG expression was associated with decreased infiltration of monocytes/macrophages, non-classical monocytes, and myeloid-derived suppressor cells in tumor tissues assessed using FCM. In in vitro analyses, ZAG decreased the expression of CD80, CD163, MRC1, and HLA classes I/II in the M1 polarization model and the expression of CD163 and MRC1 in the M2 polarization model. CONCLUSION: ZAG is suggested to be a novel immunoregulatory factor affecting the Mφ phenotype in breast cancer tissues.

Interleukin-4 induced 1-mediated resistance to an immune checkpoint inhibitor through suppression of CD8+ T cell infiltration in melanoma.

Cancer cells adopt multiple strategies to escape tumor surveillance by the host immune system and aberrant amino acid metabolism in the tumor microenvironment suppresses the immune system. Among the amino acid-metabolizing enzymes is an L-amino-acid oxidase called interleukin-4 induced 1 (IL4I1), which depletes essential amino acids in immune cells and is associated with a poor prognosis in various cancer types. Although IL4I1 is involved in immune metabolism abnormalities, its effect on the therapeutic efficacy of immune checkpoint inhibitors is unknown. In this study, we established murine melanoma cells overexpressing IL4I1 and investigated their effects on the intratumor immune microenvironment and the antitumor efficacy of anti-programmed death-ligand 1 (PD-L1) antibodies (Abs) in a syngeneic mouse model. As a result, we found that IL4I1-overexpressing B16-F10-derived tumors showed resistance to anti-PD-L1 Ab therapy. Transcriptome analysis revealed that immunosuppressive genes were globally upregulated in the IL4I1-overexpressing tumors. Consistently, we showed that IL4I1-overexpressing tumors exhibited an altered subset of lymphoid cells and particularly significant suppression of cytotoxic T cell infiltration compared to mock-infected B16-F10-derived tumors. After treatment with anti-PD-L1 Abs, we also found a more prominent elevation of tumor-associated macrophage (TAM) marker, CD68, in the IL4I1-overexpressing tumors than in the mock tumors. Consistently, we confirmed an enhanced TAM infiltration in the IL4I1-overexpressing tumors and a functional involvement of TAMs in the tumor growth. These observations indicate that IL4I1 reprograms the tumor microenvironment into an immunosuppressive state and thereby confers resistance to anti-PD-L1 Abs.

Pathological complete response to neoadjuvant chemotherapy may improve antitumor immune response via reduction of regulatory T cells in muscle-invasive bladder cancer.

The prognosis for patients who achieve a pathologic complete response in bladder cancer is excellent, but the association between their prognosis and the tumor microenvironment is unclear. We investigated the tumor immune microenvironment of those with pathological complete response after platinum-based neoadjuvant chemotherapy for cT2-4aN0M0 bladder cancer using multiplex fluorescence immunohistochemistry. Our retrospective study included 12 patients with pathological complete response who underwent radical cystectomy following neoadjuvant chemotherapy for cT2-4aN0M0 muscle-invasive bladder cancer. We assessed the density of several immune cell types in pretreatment and posttreatment tissues via multiplex fluorescence immunohistochemical analysis. The median age was 67 years; 10 patients were male. Nine (75%) and 3 (25%) patients were cT2 and cT3, respectively. The 5-year progression-free and overall survivals were 90% and 100%, respectively. The densities of regulatory T cells (Treg; CD3+CD4+FoxP3+ cell) were significantly decreased and almost disappeared in the tumor microenvironment of posttreatment tissue compared with pretreatment tissue. Other immune cells, such as effector T cells or M2 macrophages, were not significantly changed between posttreatment and pretreatment tissues. In pathological complete response, Tregs in the tumor immune microenvironment were significantly decreased after platinum-based chemotherapy for muscle-invasive bladder cancer. The temporary arresting of immune response in the tumor microenvironment may reflect a favorable prognosis due to the decrease of Tregs with tumor shrinkage and improve the host tumor immune response.

Tumor-infiltrating Leukocyte Profiling Defines Three Immune Subtypes of NSCLC with Distinct Signaling Pathways and Genetic Alterations.

Resistance to immune checkpoint blockade remains challenging in patients with non-small cell lung cancer (NSCLC). Tumor-infiltrating leukocyte (TIL) quantity, composition, and activation status profoundly influence responsiveness to cancer immunotherapy. This study examined the immune landscape in the NSCLC tumor microenvironment by analyzing TIL profiles of 281 fresh resected NSCLC tissues. Unsupervised clustering based on numbers and percentages of 30 TIL types classified adenocarcinoma (LUAD) and squamous cell carcinoma (LUSQ) into the cold, myeloid cell-dominant, and CD8+ T cell-dominant subtypes. These were significantly correlated with patient prognosis; the myeloid cell subtype had worse outcomes than the others. Integrated genomic and transcriptomic analyses, including RNA sequencing, whole-exome sequencing, T-cell receptor repertoire, and metabolomics of tumor tissue, revealed that immune reaction-related signaling pathways were inactivated, while the glycolysis and K-ras signaling pathways activated in LUAD and LUSQ myeloid cell subtypes. Cases with ALK and ROS1 fusion genes were enriched in the LUAD myeloid subtype, and the frequency of TERT copy-number variations was higher in LUSQ myeloid subtype than in the others. These classifications of NSCLC based on TIL status may be useful for developing personalized immune therapies for NSCLC. Significance: The precise TIL profiling classified NSCLC into novel three immune subtypes that correlates with patient outcome, identifying subtype-specific molecular pathways and genomic alterations that should play important roles in constructing subtype-specific immune tumor microenvironments. These classifications of NSCLC based on TIL status are useful for developing personalized immune therapies for NSCLC.

Expression of hormone receptors is associated with specific immunological profiles of the breast cancer microenvironment.

BACKGROUND: Elucidating the unique immunoregulatory mechanisms in breast cancer microenvironment may help develop new therapeutic strategies. Some studies have suggested that hormone receptors also have immune regulatory functions, but their mechanisms are not fully understood. In this study, we have comprehensively analyzed the relationship between the expressions of estrogen (ER), progesterone (PgR), and androgen receptors (AR), and the immunological profile in breast cancer. METHODS: Using publicly available gene expression profile datasets, METABRIC and SCAN-B, the associations between the expressions of hormone receptors and the immune cell compositions in breast cancer tissue, estimated by CIBERSORTx algorithm, were analyzed. We histologically evaluated tumor-infiltrating lymphocytes (hTIL), PD-L1 (hPD-L1) expression, and the infiltration of 11 types of immune cells by flow cytometry (FCM) for 45 breast cancer tissue samples. The relationships between them and the expressions of ER, PgR, and AR of tumor tissues, evaluated immunohistochemically, were analyzed. RESULTS: Expressions of ESR1, PGR, and AR were negatively correlated with overall immune composition. Expressions of ER and AR, but not that of PgR, were inversely associated with hTIL and hPD-L1 expression. FCM analysis showed that the expressions of ER and AR, but not that of PgR, were associated with decreased total leukocyte infiltration. Both CIBERSORTx and FCM analysis showed that ER expression was associated with reduced infiltration of macrophages and CD4+ T cells and that of AR with reduced macrophage infiltration. CONCLUSION: Hormone receptor expression correlates with specific immunological profiles in the breast cancer microenvironment both at the gene and protein expression levels.

Immunological profiles of the breast cancer microenvironment represented by tumor-infiltrating lymphocytes and PD-L1 expression.

Tumor-infiltrating lymphocytes (TILs) and programmed cell death 1 ligand 1 (PD-L1) are established prognostic and predictive biomarkers for certain breast cancer subsets. However, their association with the immune response complexity is not fully understood. Therefore, we analyzed the association between the immune cell fractions in breast cancer tissues and histologically assessed TIL (hTIL) and PD-L1 (hPD-L1). Forty-five tumor and eighteen blood samples were collected from patients with breast cancer. Total leukocyte counts, frequency of 11 immune cell populations, and PD-L1 expression in each cell fraction were evaluated by flow cytometry. TILs and PD-L1 were assessed by hematoxylin and eosin staining and immunohistochemistry, respectively. A higher hTIL score showed association with increased leukocyte infiltration, higher CD4+ and CD8+ T cell proportions, and lower natural killer and natural killer T cell proportions. PD-L1 was highly expressed in nonclassical monocytes, monocyte/macrophages, myeloid-derived suppressor cells, myeloid dendritic cells, dendritic cells, and other lineages in tumors. hPD-L1 positivity reflected PD-L1 expression accurately in these fractions, as well as increased leukocyte infiltration in tumors. These results indicate that hTILs reflect differences in the immune responses in the tumor microenvironment, and certain immune cell fractions are favorably expressed in the PD-L1 pathway in breast cancer microenvironments.

Immune microenvironment, homologous recombination deficiency, and therapeutic response to neoadjuvant chemotherapy in triple-negative breast cancer: Japan Breast Cancer Research Group (JBCRG)22 TR.

BACKGROUND: Triple-negative breast cancer (TNBC) is a biologically diverse disease, with characteristics such as homologous recombination deficiency (HRD), gene mutation, and immune reactions. Japan Breast Cancer Research Group 22 is a multicenter trial examining TNBC's response to neoadjuvant chemotherapy (NAC) according to the HRD status. This translational research investigated the clinical significance of the immune microenvironment of TNBC in association with HRD, tumor BRCA1/2 (tBRCA1/2) mutation, and response to NAC. METHODS: Patients aged below 65 years with high HRD or germline BRCA1/2 (gBRCA1/2) mutation randomly received paclitaxel + carboplatin (group A1) or eribulin + carboplatin (A2), followed by anthracycline. Patients aged below 65 years with low HRD or those aged 65 years or older without gBRCA1/2 mutation randomly received eribulin + cyclophosphamide (B1) or eribulin + capecitabine (B2); nonresponders to the first four cycles of the therapy received anthracycline. A pathological complete response (pCR) was defined as the absence of residual cancer cells in the tissues. Pretreatment biopsy specimens were stained by multiplexed fluorescent immunohistochemistry using antibodies against CD3, CD4, CD8, Foxp3, CD204, and pan-cytokeratin. Immune cells with specific phenotypes were counted per mm2 in cancer cell nests (intratumor) and stromal regions. The immune cell densities were compared with clinicopathological and genetic factors including tumor response. RESULTS: This study analyzed 66 samples. T1 tumors had a significantly higher density of intratumoral CD8+ T cells than T2 or larger tumors. The tBRCA1/2 mutation or HRD status was not associated with the density of any immune cell. The density of intratumoral and stromal CD4+ T cells was higher in patients showing pCR than in those without pCR. In a multivariate analysis, intratumoral and stromal CD4+ T cell density significantly predicted pCR independent of age, chemotherapy dose, HRD status, and treatment groups (P = 0.009 and 0.0057, respectively). In a subgroup analysis, the predictive value of intratumoral and stromal CD4+ T cell density persisted in the platinum-containing chemotherapy group (A1+A2) but not in the non-platinum-containing group (B1+B2). CONCLUSIONS: Intratumoral and stromal CD4+ T cell density was an independent predictor of pCR in patients with TNBC. A larger study is warranted to confirm the results. TRIAL REGISTRATION: UMIN000023162.

Comprehensive biomarker analysis from phase II study of nivolumab in patients with thymic carcinoma.

In a phase II trial of nivolumab in advanced thymic carcinoma (UMIN000022007), long SD (SD for more than 24 weeks) was seen in three patients and irAE (Gr2 or higher) was seen in four patients among 15 patients. Here, we report preplanned comprehensive biomarker analyses. We obtained tumor samples for immunohistochemistry, peripheral blood mononuclear cells (PBMCs), plasma and serum for pharmacokinetic analysis of nivolumab and cytokine evaluations, and whole blood for immuno pharmacogenomic (PGx) analysis. PD-L1 expression on tumor cells were not associated with therapeutic efficacy, but FOXP3 expression in tumor area and stroma, CD204 expression in stroma, and MHC class I in tumor area were all low among long SD patients. PBMC of long SD patients presented with larger number of naïve/memory cells prior to treatment, suggesting priming after nivolumab administration. Immuno-PGx analysis showed non-synonymous SNVs in ITGAX and PDCD1 had some correlation with PFS. Concentration of nivolumab in blood during the treatment was not related to PFS, with their overall trend towards decreased nivolumab concentration in patients with irAEs. Low immunogenicity of thymic carcinoma demonstrated in our study may require the activation of immune systems via a combination of immune checkpoint blockades.

Pretreatment tumour immune microenvironment predicts clinical response and prognosis of muscle-invasive bladder cancer in the neoadjuvant chemotherapy setting.

BACKGROUND: We examined the relationship between the tumour microenvironment and the clinical efficacy of neoadjuvant chemotherapy in patients with cT2-4aN0M0 bladder cancer using multiplex fluorescence immunohistochemistry. METHODS: The study retrospectively evaluated 51 patients who underwent radical cystectomy following neoadjuvant chemotherapy for cT2-4aN0M0 muscle-invasive bladder cancer. Patients were divided into responders (

Transient Depletion of CD4+ Cells Induces Remodeling of the TCR Repertoire in Gastrointestinal Cancer.

Antibody-mediated transient depletion of CD4+ cells enhances the expansion of tumor-reactive CD8+ T cells and exhibits robust antitumor effects in preclinical and clinical studies. To investigate the clonal T-cell responses following transient CD4+ cell depletion in patients with cancer, we conducted a temporal analysis of the T-cell receptor (TCR) repertoire in the first-in-human clinical trial of IT1208, a defucosylated humanized monoclonal anti-CD4. Transient depletion of CD4+ cells promoted replacement of T-cell clones among CD4+ and CD8+ T cells in the blood. This replacement of the TCR repertoire was associated with the extent of CD4+ T-cell depletion and an increase in CD8+ T-cell count in the blood. Next, we focused on T-cell clones overlapping between the blood and tumor in order to track tumor-associated T-cell clones in the blood. The total frequency of blood-tumor overlapping clones tended to increase in patients receiving a depleting dose of anti-CD4, which was accompanied by the replacement of overlapping clones. The greater expansion of CD8+ overlapping clones was commonly observed in the patients who achieved tumor shrinkage. These results suggested that the clonal replacement of the TCR repertoire induced by transient CD4+ cell depletion was accompanied by the expansion of tumor-reactive T-cell clones that mediated antitumor responses. Our findings propose beneficial remodeling of the TCR repertoire following transient CD4+ cell depletion and provide novel insight into the antitumor effects of monoclonal anti-CD4 treatment in patients with cancer.See related Spotlight on p. 601.

First-in-human phase 1 study of IT1208, a defucosylated humanized anti-CD4 depleting antibody, in patients with advanced solid tumors.

BACKGROUND: Transient CD4+ T cell depletion led to the proliferation of tumor-specific CD8+ T cells in the draining lymph node and increased infiltration of PD-1+CD8+ T cells into the tumor, which resulted in strong anti-tumor effects in tumor-bearing mice. This is a first-in-human study of IT1208, a defucosylated humanized anti-CD4 monoclonal antibody, engineered to exert potent antibody-dependent cellular cytotoxicity. METHODS: Patients with advanced solid tumors were treated with intravenous IT1208 at doses of 0.1 or 1.0 mg/kg. The first patient in each cohort received a single administration, and the other patients received two administrations of IT1208 on days 1 and 8. RESULTS: Eleven patients were enrolled in the 0.1 mg/kg (n = 4) and 1.0 mg/kg cohorts (n = 7). Grade 1 or 2 infusion-related reactions was observed in all patients. Decreased CD4+ T cells in peripheral blood due to IT1208 were observed in all patients and especially in those receiving two administrations of 1.0 mg/kg. CD8+ T cells increased on day 29 compared with baseline in most patients, resulting in remarkably decreased CD4/8 ratios. One microsatellite-stable colon cancer patient achieved durable partial response showing increased infiltration of both CD4+ and CD8+ T cells into tumors after IT1208 administration. Moreover, transcriptomic profiling of the liver metastasis of the patient revealed upregulation of the expression of interferon-stimulated genes, T cell activation-related genes, and antigen presentation-related genes after IT1208 administration. Two additional patients with gastric or esophageal cancer achieved stable disease lasting at least 3 months. CONCLUSIONS: IT1208 monotherapy successfully depleted CD4+ T cells with a manageable safety profile and encouraging preliminary efficacy signals, which warrants further investigations, especially in combination with immune checkpoint inhibitors.

Biomarkers for Immune Checkpoint Inhibitors in Melanoma.

Immune checkpoint inhibitors have now become a standard therapy for malignant melanoma. However, as immunotherapies are effective in only a limited number of patients, biomarker development remains one of the most important clinical challenges. Biomarkers predicting clinical benefit facilitate appropriate selection of individualized treatments for patients and maximize clinical benefits. Many biomarkers derived from tumors and peripheral blood components have recently been reported, mainly in retrospective settings. This review summarizes the recent findings of biomarker studies for predicting the clinical benefits of immunotherapies in melanoma patients. Taking into account the complex interactions between the immune system and various cancers, it would be difficult for only one biomarker to predict clinical benefits in all patients. Many efforts to discover candidate biomarkers are currently ongoing. In the future, verification, by means of a prospective study, may allow some of these candidates to be combined into a scoring system based on bioinformatics technology.

[Dietary approach to improving the nutritional status in institutionalized elderly hemodialysis patients with a poor dietary intake: a single-arm pilot study].

OBJECTIVE: The hemodialysis (HD) diet, which is a high-calorie and high-fat regimen, may inadvertently lead to an inadequate dietary intake, resulting in undernutrition among elderly HD patients. Therefore, an attempt was made to improve the dietary intake by implementing a modified diet regimen in eligible elderly HD patients. SUBJECTS: Elderly HD patients who had ingested < 50% of the meals provided and were diagnosed with undernutrition among all elderly patients institutionalized at the special elderly nursing home annexed to Nagasaki Kidney Hospital between June and November 2012. RESULTS: Of the elderly HD patients in the nursing home (n = 27), the study included a total of 7 consecutive patients (male/female, 1/6; mean age, 84.1±6.4 years old; duration of HD, 4.3±3.8 years; geriatric nutritional index [GNRI], 83.5±8.3; normalized protein catabolic ratio [nPCR], 0.78±0.14). The modified diet regimen, which involved reducing food portion sizes and incorporating a liquid diet, led to a significant increase in their dietary intake from 48.1% at baseline to 97.1% of the meals provided 3 months after the start of the modified HD diet regimen. Their GNRI also significantly increased from 83.5±8.3 to 86.1±10.2, and their serum albumin levels significantly increased from 3.2±0.2 g/dL to 3.4±0.4 g/dL, suggesting improvements in their nutritional status. CONCLUSIONS: The attempted dietary approach for elderly HD patients was shown to potentially increase their dietary intake and improve their nutritional status without affecting the efficiency of HD being implemented.

HEG1 is a novel mucin-like membrane protein that serves as a diagnostic and therapeutic target for malignant mesothelioma.

The absence of highly specific markers for malignant mesothelioma (MM) has served an obstacle for its diagnosis and development of molecular-targeting therapy against MM. Here, we show that a novel mucin-like membrane protein, sialylated protein HEG homolog 1 (HEG1), is a highly specific marker for MM. A monoclonal antibody against sialylated HEG1, SKM9-2, can detect even sarcomatoid and desmoplastic MM. The specificity and sensitivity of SKM9-2 to MM reached 99% and 92%, respectively; this antibody did not react with normal tissues. This accurate discrimination by SKM9-2 was due to the recognition of a sialylated O-linked glycan with HEG1 peptide. We also found that gene silencing of HEG1 significantly suppressed the survival and proliferation of mesothelioma cells; this result suggests that HEG1 may be a worthwhile target for function-inhibition drugs. Taken together, our results indicate that sialylated HEG1 may be useful as a diagnostic and therapeutic target for MM.

Visualizing spatial distribution of alectinib in murine brain using quantitative mass spectrometry imaging.

In the development of anticancer drugs, drug concentration measurements in the target tissue have been thought to be crucial for predicting drug efficacy and safety. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is commonly used for determination of average drug concentrations; however, complete loss of spatial information in the target tissue occurs. Mass spectrometry imaging (MSI) has been recently applied as an innovative tool for detection of molecular distribution of pharmacological agents in heterogeneous targets. This study examined the intra-brain transitivity of alectinib, a novel anaplastic lymphoma kinase inhibitor, using a combination of matrix-assisted laser desorption ionization-MSI and LC-MS/MS techniques. We first analyzed the pharmacokinetic profiles in FVB mice and then examined the effect of the multidrug resistance protein-1 (MDR1) using Mdr1a/b knockout mice including quantitative distribution of alectinib in the brain. While no differences were observed between the mice for the plasma alectinib concentrations, diffuse alectinib distributions were found in the brain of the Mdr1a/b knockout versus FVB mice. These results indicate the potential for using quantitative MSI for clarifying drug distribution in the brain on a microscopic level, in addition to suggesting a possible use in designing studies for anticancer drug development and translational research.

A novel method for evaluating antibody-dependent cell-mediated cytotoxicity by flowcytometry using cryopreserved human peripheral blood mononuclear cells.

Analyzing the cytotoxic functions of effector cells, such as NK cells against target cancer cells, is thought to be necessary for predicting the clinical efficacy of antibody-dependent cellular cytotoxicity (ADCC) -dependent antibody therapy. The (51)Cr release assay has long been the most widely used method for quantification of ADCC activity. However, the reproducibilities of these release assays are not adequate, and they do not allow evaluation of the lysis susceptibilities of distinct cell types within the target cell population. In this study, we established a novel method for evaluating cytotoxicity, which involves the detection and quantification of dead target cells using flowcytometry. CFSE (carboxyfluorescein succinimidyl ester) was used as a dye to specifically stain and thereby label the target cell population, allowing living and dead cells, as well as both target and effector cells, to be quantitatively distinguished. Furthermore, with our new approach, ADCC activity was more reproducibly, sensitively, and specifically detectable, not only in freshly isolated but also in frozen human peripheral blood mononuclear cells (PBMCs), than with the calcein-AM release assay. This assay, validated herein, is expected to become a standard assay for evaluating ADCC activity which will ultimately contribute the clinical development of ADCC dependent-antibody therapies.

Quantitative Assessment of Tissue Perfusion in Hepatocellular Carcinoma Using Perflubutane Dynamic Contrast-Enhanced Ultrasonography: A Preliminary Study.

Our purpose in this study was to assess the relationship between contrast signal intensity (CI) and concentration of perflubutane microbubbles in a phantom experiment, and to examine the feasibility of this technique for quantitative analysis of vascularity in hepatocellular carcinoma (HCC). Microbubble solutions of the perflubutane contrast agent were prepared by mixing with purified water. We examined the relationship between CI in dB units and the concentration. Moreover, seven HCC patients were examined using real-time dynamic contrast imaging. The perfusion index was calculated from time-intensity curves generated for both HCC and surrounding liver parenchyma. We observed a linear relationship between the CIdB and the concentration in the phantom study and a higher perfusion index in the HCC lesions relative to the surrounding liver parenchyma. Dynamic contrast-enhanced ultrasonography with perflubutane microbubbles, which exhibit linear and temporally stable characteristics under continuous ultrasound exposure, allows the collection of quantitative hemodynamic information regarding HCC.

Distinct pathways leading to TDP-43-induced cellular dysfunctions.

TAR DNA-binding protein of 43 kDa (TDP-43) is the major component protein of inclusions found in brains of patients with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP). However, the molecular mechanisms by which TDP-43 causes neuronal dysfunction and death remain unknown. Here, we report distinct cytotoxic effects of full-length TDP-43 (FL-TDP) and its C-terminal fragment (CTF) in SH-SY5Y cells. When FL-TDP was overexpressed in the cells using a lentiviral system, exogenous TDP-43, like endogenous TDP-43, was expressed mainly in nuclei of cells without any intracellular inclusions. However, these cells showed striking cell death, caspase activation and growth arrest at G2/M phase, indicating that even simple overexpression of TDP-43 induces cellular dysfunctions leading to apoptosis. On the other hand, cells expressing TDP-43 CTF showed cytoplasmic aggregates but without significant cell death, compared with cells expressing FL-TDP. Confocal microscopic analyses revealed that RNA polymerase II (RNA pol II) and several transcription factors, such as specificity protein 1 and cAMP-response-element-binding protein, were co-localized with the aggregates of TDP-43 CTF, suggesting that sequestration of these factors into TDP-43 aggregates caused transcriptional dysregulation. Indeed, accumulation of RNA pol II at TDP-43 inclusions was detected in brains of patients with FTLD-TDP. Furthermore, apoptosis was not observed in affected neurons of FTLD-TDP brains containing phosphorylated and aggregated TDP-43 pathology. Our results suggest that different pathways of TDP-43-induced cellular dysfunction may contribute to the degeneration cascades involved in the onset of ALS and FTLD-TDP.