[Enhancement of Antitumor Effect by the Combined Use of Anti-EGFR Antibody(Necitumumab)and PD-1 Inhibitor].

Necitumumab enhances antitumor immunity by decreasing the PD-L1 expression; it is expected to improve the prognosis of patients treated with an immune checkpoint inhibitor(ICI)by inhibiting the IL-8 expression. Since the combined effect of necitumumab and PD-L1 inhibitor was confirmed in an in vivo study conducted in transgenic mice, further antitumor effects can be expected by the combined use of necitumumab and ICI.

Binding affinities of paclitaxel and docetaxel for generic and nanoparticle albumin-bound paclitaxel-derived albumin from human serum.

Nanoparticle albumin-bound (nab)-paclitaxel is a 130-nm formulation containing human serum albumin (HSA). The clinical efficacy of this formulation is considered to depend on its affinity for HSA. The high pressure employed during the manufacture of nab-paclitaxel HSA (nab HSA) may influence its conformation and/or oligomerization, and ultimately its affinity for HSA. Therefore, studies are required to evaluate whether the affinity of paclitaxel for nab HSA is similar to that of generic HSA (control HSA). In the present study, nab HSA was isolated from nab-paclitaxel by gel filtration, and the binding affinities (KDs) were determined by surface plasmon resonance. Furthermore, the affinity of docetaxel for nab HSA and control HSA was measured, as their binding sites are similar. Paclitaxel showed KDs of 8.93±8.60 and 7.39±5.81 µM for nab HSA and control HSA, respectively, whereas the corresponding KDs for docetaxel were 44.3±9.50 and 55.9±2.28 µM, respectively. This suggests that the paclitaxel binding site was not modified during the nab-paclitaxel manufacturing process. Additionally, nab HSA likely does not affect paclitaxel and blood HSA binding, as evidenced by the similar affinities of paclitaxel and docetaxel for nab HSA and control HSA. In conclusion, the binding affinities of paclitaxel and docetaxel for nab HSA and control HSA were found to be comparable. Additionally, the manufacturing process did not influence the paclitaxel binding affinity for nab HSA. These results also suggest that nab HSA may not affect the clinical effectiveness of nab-paclitaxel.

Involvement of non­triple helical type VI collagen α1 chain, NTH α1(VI), in the proliferation of cancer cells.

It has been reported that a polypeptide encoded by collagen type VI alpha 1 chain (COL6A1), one of the three α chains of type VI collagen, is strongly associated with the migration and invasion of highly metastatic human pancreatic cancer BxPC­M8 cells and excessive proliferation of LNCaP cells. We previously reported that non­triple helical type VI collagen α1 chain, NTH α1(VI), a non­triple helical polypeptide encoded by COL6A1, is not derived from type VI collagen and exists in cancer cell­conditioned media. Therefore, NTH α1(VI) may be involved in cancer cell migration, invasion, and proliferation. The active entity that promotes cellular behaviors in cancer remains unclear. Thus, we predicted that NTH α1(VI) has cancer­promoting activity, such as the ability to induce cell proliferation. This study was conducted to examine whether NTH α1(VI) and/or its derived peptides are involved in cancer cell proliferation. Highly metastatic human pancreatic S2­VP10 cells were used to explore the potential of COL6A1 knockdown in reducing cell proliferation. Moreover, S2­VP10 conditioned medium was assessed after molecular size­fractionation to determine whether the inhibitory effect of COL6A1 knockdown could be rescued by the medium. We showed that S2­VP10­conditioned medium contained COL6A1 polypeptide, but not COL6A2, suggesting that COL6A1 in the conditioned medium of S2­VP10 cells reflects the presence of NTH α1(VI). COL6A1 knockdown repressed S2­VP10 cell proliferation and this repression was rescued using the conditioned medium of S2­VP10 cells. The fraction of conditioned medium containing peptides smaller than 10 kDa rescued the inhibitory effect; however, the fraction containing polypeptides larger than 10 kDa, including NTH α1(VI), did not show rescue activity, indicating that NTH α1(VI) fragmentation is necessary for enhanced cancer cell proliferation. In conclusion, fragmentation of NTH α1(VI) into peptides <10 kDa is required for its cancer cell proliferation­promoting activity.

Identification of a common epitope in the sequences of COL4A1 and COL6A1 recognized by monoclonal antibody #141.

Identification of a type IV collagen α1 polypeptide in non-triple helical form [NTH α1(IV)], possibly involved in angiogenesis, introduces the further possibility of the existence of non-triple helical forms of other collagen chains. We previously reported that an anti-NTH α1(IV) monoclonal antibody #141 recognizes not only NTH α1(IV) but also a novel non-triple helical collagen polypeptide NTH α1(VI) encoded by COL6A1. In this study, we identified the recognition sequence in order to better understand the properties of antibody #141 and provide clues regarding the biological function of the two non-triple helical molecules. Additionally, we determined the common epitope between COL4A1 and COL6A1 as PXXGXPGLRG, with surface plasmon resonance analyses revealing KD values for the COL4A1 epitope as 5.56±1.81×10-9 M and for the COL6A1 epitope as 7.15±0.44×10-10 M. The specific recognition of NTH α1(IV) and NTH α1(VI) by antibody #141 can be explained by the common epitope sequence. Moreover, epitope localization supports previous finding that NTH α1(IV) and NTH α1(VI) differ in conformation from the α1 chains in triple-helical type IV and type VI collagen. These findings suggest that antibody #141 might be useful for diagnosis of type VI collagen myopathies.

Long-lasting immunosuppressive effects of tacrolimus-loaded micelle NK61060 in preclinical arthritis and colitis models.

AIM: Tacrolimus (TAC) is an important drug for inflammatory diseases. However, TAC has several limitations, such as variable trough concentrations among individuals and a high medication frequency. In this study, we created NK61060, a novel micellar TAC formulation, to circumvent these disadvantages. MATERIALS & METHODS: Immunosuppressive activity of NK61060 was determined in the collagen-induced arthritis rat model, mannan-induced arthritis mouse model and dextran sodium sulfate-induced colitis mouse model. The pharmacokinetics and toxicology of NK61060 were evaluated in those models. RESULTS: In arthritis and colitis models, NK61060 exhibited superior immunosuppressive activity compared with that of TAC. Pharmacokinetic and toxicological analyses indicated that NK61060 had a wider safety margin and could be administered at a reduced medication frequency. CONCLUSION: NK61060 mitigates the trough concentration variability and the medication frequency and it may be a safer and more effective option for use in clinical settings. Further studies are needed to determine its clinical usefulness.

Type VI collagen α1 chain polypeptide in non-triple helical form is an alternative gene product of COL6A1.

Expression of type IV collagen α1 chain in non-triple helical form, NTH α1(IV), is observed in cultured human cells, human placenta and rabbit tissues. Biological functions of NTH α1(IV) are most likely to be distinct from type IV collagen, since their biochemical characteristics are quite different. To explore the biological functions of NTH α1(IV), we prepared some anti-NTH α1(IV) antibodies. In the course of characterization of these antibodies, one antibody, #141, bound to a polypeptide of 140 kDa in size in addition to NTH α1(IV). In this study, we show evidence that the 140 kDa polypeptide is a novel non-triple helical polypeptide of type VI collagen α1 chain encoded by COL6A1, or NTH α1(VI). Expression of NTH α1(VI) is observed in supernatants of several human cancer cell lines, suggesting that the NTH α1(VI) might be involved in tumourigenesis. Reactivity with lectins indicates that sugar chains of NTH α1(VI) are different from those of the α1(VI) chain in triple helical form of type VI collagen, suggesting a synthetic mechanism and a mode of action of NTH α1(VI) is different from type VI collagen.

Preparation and partial characterization of monoclonal antibodies specific for the nascent non-triple helical form of the type IV collagen alpha 1 chain.

This report describes the preparation and partial characterization of monoclonal antibodies that are reactive specifically with the nascently produced non-triple helical form of the type IV collagen α1 chain, designated as NTH α1(IV). These antibodies were nonreactive with the α1 chain of the type IV collagen in the triple-helical conformation. Three antibodies, #141, #179 and #370, with different epitopes in NTH α1(IV) were found to be reactive with the nascent polypeptide secreted from human normal cells and a human carcinoma cell line. The antibodies with different epitopes may provide a key method for elucidating the physiological function and tissue distribution of NTH α1(IV), which is distinct from the chain derived from triple-helical type IV collagen.

Characterization of the Growth of Deep and Subcortical White Matter Hyperintensity on MR Imaging: A Retrospective Cohort Study.

PURPOSE: In elderly patients, deep and subcortical white matter hyperintense lesions are frequently observed on MRI; however, the growth process of these lesions is unclear. The aims of this retrospective cohort study were to elucidate the growth characteristics of deep and subcortical white matter hyperintense lesions, and to insight their etiology. MATERIALS AND METHODS: We enrolled 103 patients (1610 lesions) whose deep and subcortical white matter hyperintense lesions were monitored for 3 or more years by MRI examination. The area of each hyperintense lesion was measured using a tracing method in the first and last MRI examinations. The annual rate of increase in the area of each lesion was calculated, and using the Pearson product-moment correlation coefficient the correlation between the annual rate of increase in area and the interval between the first and last MRI examinations was determined. RESULTS: The paired t-test showed a significant increase in the mean area of all the deep and subcortical white matter hyperintense lesions between the first and last MRI examinations (P < 0.001). However, hyperintense lesions had decreased in the area or disappeared in 227 (14.1%) lesions in the last MRI examination, particularly in patients with diabetes. The mean annual rate of increase in area of all hyperintense lesions was 0.013 ± 0.021 cm2 per year. The annual rate of increase in area and the interval between the first and last MRI examinations showed a weak negative correlation (r = -0.121; P < 0.01). CONCLUSION: Decrease in the area and the disappearance of the subcortical white matter hyperintense lesions, and a decline in the annual rate of increase in the lesion area with time suggest that the interstitial fluid accumulation associated with dysfunctional drainage around the vessels may be involved in the possible etiologies of deep and subcortical white matter hyperintense lesions.

Correlation between volume and morphological changes in the hippocampal formation in Alzheimer's disease: rounding of the outline of the hippocampal body on coronal MR images.

INTRODUCTION: The aim of this study was to investigate whether the outline of the hippocampal body becomes rounded on coronal magnetic resonance imaging (MRI) as the volume of the hippocampal formation decreases in Alzheimer's disease (AD). METHODS: Institutional review board approval of the study protocol was obtained, and all subjects provided informed consent for the mini-mental state examination (MMSE) and MRI. The MRI and MMSE were prospectively performed in all 103 subjects (27 men and 76 women; mean age ± standard deviation, 77.7 ± 7.8 years) who had AD or were concerned about having of dementia and who consulted our institute over 1 year. The subjects included 14 non-dementia cases (MMSE score ≥ 28) and 89 AD cases (MMSE score ≤ 27). The total volume of the bilateral hippocampal formation (VHF) was assessed with a tracing method, and the ratio of the VHF to the intracranial volume (RVHF) and the rounding ratio (RR) of the hippocampal body (mean ratio of its short dimension to the long dimension in the bilateral hippocampal body) were calculated. Using Spearman's correlation coefficient, the correlations between RR and VHF and between RR and RVHF were assessed. RESULTS: Correlation coefficients between RR and VHF and between RR and RVHF were -0.419 (p < 0.01) and -0.418 (p < 0.01), respectively. There was a significant negative correlation between RR and the volume of the hippocampal formation. CONCLUSION: The outline of the body of the hippocampal formation becomes rounded on coronal images as its volume decreases in AD.

Smaller brain size likely in young adults (<40 years old) with depressive symptoms compared to healthy controls: a retrospective study.

PURPOSE: The aim of this study was to determine whether the brain size of young patients with depressive symptoms is smaller than that of healthy controls using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively evaluated brain size by calculating the ratio of the brain area to that of the skull (the brain-to-skull ratio) on routine MRI scans including the splenium of the corpus callosum obtained from 19 patients <40 years old with depressive symptoms in 2009. The controls were 12 healthy individuals <40 years old who underwent MRI for medical examinations. RESULTS: The mean brain-to-skull ratio of the control group was 0.850 ± 0.022 (range 0.822-0.889), and that of the patient group was 0.819 ± 0.041 (range 0.756-0.878). An unpaired t-test showed a significant difference in the brain-to-skull ratios between these groups (P = 0.011). In particular, in 7 of the 19 patients with longer duration of illness and more severe symptoms, the brainto-skull ratio was 89%-92% of the mean ratio of the control group. CONCLUSION: The brain size of young patients with depressive symptoms appears to be smaller than that of healthy controls.

Large-scale proteomic analysis of tyrosine-phosphorylation induced by T-cell receptor or B-cell receptor activation reveals new signaling pathways.

Activation of the T-cell receptor (TCR) and that of the B-cell receptor (BCR) elicits tyrosine-phosphorylation of proteins that belongs to similar functional categories, but result in distinct cellular responses. Large-scale analyses providing an overview of the signaling pathways downstream of TCR or BCR have not been described, so it has been unclear what components of these pathways are shared and which are specific. We have now performed a systematic analysis and provide a comprehensive list of tyrosine-phosphorylated proteins (PY proteome) with quantitative data on their abundance in T cell, B cell, and nonlymphoid cell lines. Our results led to the identification of novel tyrosine-phosphorylated proteins and signaling pathways not previously implicated in immunoreceptor signal transduction, such as clathrin, zonula occludens 2, eukaryotic translation initiation factor 3, and RhoH, suggesting that TCR or BCR signaling may be linked to downstream processes such as endocytosis, cell adhesion, and translation. Thus comparative and quantitative studies of tyrosine-phosphorylation have the potential to expand knowledge of signaling networks and to promote understanding of signal transduction at the system level.

Expression profiling to predict postoperative prognosis for estrogen receptor-negative breast cancers by analysis of 25,344 genes on a cDNA microarray.

Estrogen receptor (ER) status is an essential determinant of clinical and biological behavior of human breast cancers. While ER-positive breast cancers respond well to adjuvant hormone therapy, ER-negative tumors are generally resistant. To date, no attempts have succeeded in finding molecular markers for classifying ER-negative breast cancers with respect to postoperative prognosis. To identify a set of prognostic markers for this type of cancer, we used a cDNA microarray consisting of 25,344 human genes to investigate expression profiles of ten primary breast cancers from patients who had died of breast cancer within 5 years after surgery (5y-D) and 10 from patients who had survived disease-free for more than 5 years (5y-S). Sets of genes characterizing each group were identified by Mann-Whitney and random-permutation tests. We documented 71 genes with higher expression in the 5y-D group than in the 5y-S group, and 15 with higher expression in the 5y-S group than in the 5y-D group. Semi-quantitative RT-PCR experiments were carried out to confirm the results of the microarray analysis. We established a scoring system for predicting postoperative prognosis of ER-negative breast cancers on the basis of aberrant gene expression. The list of genes reported here provides valuable information with regard to progression of breast cancer and is a source of possible target molecules for development of novel drugs to treat patients with ER-negative breast cancers.