Experience using donor human milk: A single-center cohort study in Japan.

BACKGROUND: Donor human milk (DHM) became available in Japan when the first human milk bank was established in 2017. This study investigated the effects of DHM on enteral nutrition (EN) in very low birth weight (VLBW) infants in the single center in Japan. METHODS: Seventy-six VLBW infants hospitalized between April 2017 and March 2020 at Showa University Hospital were included in the study. We retrospectively evaluated age (hours) at which EN was initiated and age (days) until complete feeding (EN > 100 mL/kg/day) was achieved. We compared the DHM and non-DHM groups, or the early human milk (EHM) and non-EHM groups. The EHM group was defined as those in which EN was initiated with the mother's own milk or DHM within 12 h of birth. RESULTS: In 30 extremely low birth weight (ELBW) infants, EN was initiated at significantly earlier postnatal hours in the DHM group compared to those in the non-DHM group. Complete feeding was achieved at significantly earlier ages in the EHM group after adjusting for gastrointestinal complications and gestational age. Additionally, the changes in body weight z-scores from birth to term-equivalent age were significantly greater in the EHM group after adjusting for exclusive breastfeeding and small for gestational age, compared to the non-EHM group. Statistical significance was not noted in 46 subjects (birth weight, 1000-1500 g). CONCLUSION: The use of DHM may contribute to earlier initiation and achievement of EN, resulting in greater early postnatal growth in ELBW infants in Japan.

Changes in overweight/obesity and central obesity status from preadolescence to adolescence: a longitudinal study among schoolchildren in Japan.

BACKGROUND: Little is known about changes in overweight/obesity and central obesity status among schoolchildren from preadolescence to adolescence in Japan, where waist circumference (WC) is generally not measured in annual health examinations at elementary and junior high schools. This study examined changes of overweight/obesity and central obesity status among schoolboys and schoolgirls from preadolescence to adolescence in Japan. METHODS: Study subjects were fourth-grade school children (9 or 10 years of age) from all four of Ina town's elementary schools in Japan. Measurement of each participant's height, weight, and WC were made at baseline and 3 years later. Childhood overweight/obesity was determined according to the age- and sex-specific body mass index cut-off points proposed by the International Obesity Task Force. Central obesity was defined as waist-to-height ratio ≥ 0.5. Kappa (κ) statistic was calculated to examine the tracking of overweight/obesity and central obesity. RESULTS: Data from 1436 participants (boys: n = 720, girls: n = 716) were analyzed. Overweight/obesity status tracked substantially from fourth grade to seventh grade in both boys (κ = 0.614, P value < 0.001) and girls (κ = 0.619, P value < 0.001). Among participants who were overweight/obese in fourth grade, 55.2% of boys and 63.2% of girls were still overweight/obese in seventh grade. Tracking of central obesity from fourth graders to seventh graders was substantial in boys (κ = 0.651, P value < 0.001) and moderate in girls (κ = 0.544, P value < 0.001). Among participants who had central obesity in fourth grade, 54.1% of boys and 52.6% of girls still had central obesity in seventh grade. CONCLUSIONS: The present study showed that the tracking of overweight/obesity from preadolescence to adolescence was substantial in boys and girls. Moreover, more than half of those who had central obesity in preadolescence had central obesity in adolescence. This study suggests that it is important to implement a primary prevention program for overweight/obesity and central obesity in elementary schools before fourth grade.

Survey of a nutrition management method for very low birthweight infants: Status before wide use of breast milk banks in Japan.

BACKGROUND: The importance of breast-feeding for very low birthweight (VLBW) infants has been pointed out. Some overseas studies suggested that the standardization of enteral nutrition (EN) leads to improved prognosis in VLBW infants. In Japan, however, physicians in charge of infants are responsible for making nutrition management decisions on an individual basis. We conducted an online survey to clarify the course of nutrition management of VLBW infants currently implemented in Japan. METHODS: We mailed a notice to 300 representative neonatologists throughout Japan requesting their participation in the online survey. On the survey website, neonatologists responded to questions regarding the nutritional strategy for five birthweight groups (less than 500 g, 500-749 g, 750-999 g, 1,000-1,249 g and 1,250-1,499 g). RESULTS: Responses were recieved from 137 neonatologists. The first choice for EN up to 1 week after birth was breast milk regardless of birthweight (92.0% for 1,250-1,499 g to 95.6% for 500-999 g). More than 30% of the respondents answered that they fast infants who weigh <750 g at birth or feed them with other mothers' breast milk until their own mother's milk becomes available. The lower the birthweight, the later EN is started, and the greater the number of days to establish EN. CONCLUSION: The lower the birthweight, the more difficult it is to feed infants their own mother's milk and the later the EN is started. If donor milk is supplied in a stable manner, it takes fewer days to establish EN.

PRG4 expression in myxoid liposarcoma maintains tumor cell growth through suppression of an antitumor cytokine IL-24.

PRG4 is one of the downstream molecules of the myxoid liposarcoma (MLS)-specific fusion oncoproteins TLS-CHOP and EWS-CHOP. Exogenous PRG4 expression increases the tumorigenicity of cells injected in nude mice. The molecular functions of PRG4 in tumorigenesis and/or tumor progression of MLS cells, however, still remain unclear. In this report, we demonstrated that siRNA-mediated knockdown of PRG4 suppressed the growth of the MLS-derived cell lines 1955/91 and 2645/94. In addition, PRG4 knockdown promoted adipocytic differentiation in 1955/91 cells. Thus, PRG4 may play essential roles in MLS cell growth and have potential as a therapeutic target. On the other hand, our previous study has revealed that TLS-CHOP suppresses expression of an anti-tumor cytokine IL-24, contributing to tumor cell survival. In this study, we found that double knockdown of PRG4 and IL-24 did not inhibit MLS cell growth, and single knockdown of PRG4 remarkably increased IL-24 expression. These results suggest that the growth inhibitory effect of PRG4 knockdown is caused by induction of IL-24 expression, and PRG4 may contribute to maintain MLS cell growth through repression of IL-24 expression.

Trps1 deficiency inhibits the morphogenesis of secondary hair follicles via decreased Noggin expression.

A representative phenotype of patients with tricho-rhino-phalangeal syndrome (TRPS) is sparse hair. To understand the developmental defects of these patient's hair follicles, we analyzed the development of hair follicles histologically and biochemically using Trps1 deficient (KO) mice. First, we compared the numbers of primary hair follicles in wild-type (WT) and KO embryos at different developmental stages. No differences were observed in the E14.5 skins of WT and KO mice. However, at later time points, KO fetal skin failed to properly develop secondary hair follicles, and the number of secondary hair follicles present in E18.5 KO skin was approximately half compared to that of WT skin. Sonic hedgehog expression was significantly decreased in E17.5 KO skin, whereas no changes were observed in Eda/Edar expression in E14.5 or E17.5 skins. In addition, Noggin expression was significantly decreased in E14.5 and E17.5 KO skin compared to WT skin. In parallel with the suppression of Noggin expression, BMP signaling was promoted in the epidermal cells of KO skins compared to WT skins as determined by immunohistochemistry for phosphorylated Smad1/5/8. The reduced number of secondary hair follicles was restored in skin graft cultures treated with a Noggin and BMP inhibitor. Furthermore, decreased cell proliferation, and increased apoptosis in KO skin was rescued by Noggin treatment. Taken together, we conclude that hair follicle development in Trps1 KO embryos is impaired directly or indirectly by decreased Noggin expression.

Smad3 plays an inhibitory role in phosphate-induced vascular smooth muscle cell calcification.

Arterial medial calcification is a major complication in patients with chronic kidney disease and diabetes. It has been hypothesized that a high concentration of inorganic phosphate (Pi) induces calcification in vascular smooth muscle cells (vSMCs). However, the role of transforming growth factor-ß (TGF-ß)/Smad3 signaling in Pi-induced vascular calcification remains controversial. The aim of this study was to investigate the possible involvement of Smad3 in Pi-induced vascular calcification. We compared the degree of Pi-induced vSMC calcification between vSMCs isolated from wild-type (Smad3(+/+)) and Smad3-deficient (Smad3(-/-)) mice. We found that vSMCs from Smad3(+/+) mice had less calcium (Ca) than those from Smad3(-/-) mice when they were exposed to high concentrations of Pi and Ca (Pi+Ca). The phosphorylation of Smad3 was induced in Smad3(+/+) vSMCs by exposure to Pi+Ca. The concentration of extracellular pyrophosphate (ePPi) was lower in Smad3(-/-) vSMCs than in Smad3(+/+) vSMCs and was significantly increased in Smad3(+/+) vSMCs by treatment with TGF-ß1. Also, the addition of a small amount of PPi to culture medium significantly decreased the deposition of Ca in both Smad3(+/+) and Smad3(-/-) vSMCs. Ectonucleotide phosphatase/phosphodiesterase1 (Enpp1) was decreased at the mRNA, protein, and enzymatic activity levels in Smad3(-/-) vSMCs compared with Smad3(+/+) vSMCs. A ChIP assay showed that phosphorylated Smad3 directly binds to the Enpp1 gene. Furthermore, the calcification of aortic segments was attenuated by treatment with TGF-ß1 only in Smad3(+/+) mice. Taken together, we conclude that Pi-induced vSMC calcification is suppressed by Smad3 via an increase in ePPi.

Loss of Dec1 inhibits alcohol-induced hepatic lipid accumulation and circadian rhythm disorder.

Chronic alcohol exposure increases liver damage such as lipid accumulation and hepatitis, resulting in hepatic cirrhosis. Chronic alcohol intake is known to disturb circadian rhythms in humans and animals. DEC1, a basic helix-loop-helix transcription factor, plays an important role in the circadian rhythm, inflammation, immune responses, and tumor progression. We have previously shown that Dec1 deficiency inhibits stresses such as periodontal inflammation and perivascular fibrosis of the heart. However, the significance of Dec1 deficiency in chronic alcohol consumption remains unclear. In the present study, we investigated whether the biological stress caused by chronic alcohol intake is inhibited in Dec1 knockout mice. We treated control and Dec1 knockout mice for three months by providing free access to 10% alcohol. The Dec1 knockout mice consumed more alcohol than control mice, however, we observed severe hepatic lipid accumulation and circadian rhythm disturbance in control mice. In contrast, Dec1 knockout mice exhibited little effect on these outcomes. We also investigated the expression of peroxisome proliferator-activated receptors (PPARs) and AMP-activated protein kinase (AMPK), which are involved in the regulation of fatty acid metabolism. Immunohistochemical analysis revealed increases of phosphorylation AMPK and PPARa but decreases PPARg in Dec1 knockout mice compared to that in control mice. This indicates a molecular basis for the inhibition of hepatic lipid accumulation in alcohol-treated Dec1 knockout mice. These results suggest a novel function of Dec1 in alcohol-induced hepatic lipid accumulation and circadian rhythm disorders.

Suppression of antitumor cytokine IL­24 by PRG4 and PAI­1 may promote myxoid liposarcoma cell survival.

Suppression of the antitumor cytokine interleukin-24 (IL-24) is critical for the survival of myxoid liposarcoma (MLS) cells. It has been previously demonstrated by the authors that an MLS-specific chimeric oncoprotein, translocated in liposarcoma-CCAAT/enhancer-binding protein homologous protein (TLS-CHOP), supresses IL24 mRNA expression via induction of proteoglycan 4 (PRG4) to sustain MLS cell proliferation. However, IL-24 has also been revealed to be suppressed by the ubiquitin-proteasome system in human ovarian and lung cancer cells. Therefore, the aim of the present study was to elucidate the mechanism of IL-24 suppression in MLS cells. The results revealed that the proteasome inhibitor, MG-132, induced cell death in MLS cells in vitro; this effect was reduced following IL-24 knockdown. This indicated that proteasomal degradation of IL-24 may be an important process for MLS cell survival. In addition, it was also previously revealed by the authors that knockdown of plasminogen activator inhibitor-1 (PAI-1), a TLS-CHOP downstream molecule, suppressed the growth of MLS cells, thus instigating the investigation of the effect of PAI-1 on IL-24 expression in MLS cells. Double knockdown of PAI-1 and IL-24 negated the growth-suppressive effect of PAI-1 single knockdown in MLS cells. Interestingly, PAI-1 single knockdown did not increase the mRNA expression of IL24, but it did increase the protein abundance of IL-24, indicating that PAI-1 suppressed IL-24 expression by promoting its proteasomal degradation. Moreover, treatment of MLS cells with a PAI-1 inhibitor, TM5275, induced IL-24 protein expression and apoptosis. Collectively, the results of the present as well as previous studies indicated that IL-24 expression may be suppressed at the transcriptional level by PRG4 and at the protein level by PAI-1 in MLS cells. Accordingly, PAI-1 may represent an effective therapeutic target for MLS treatment.

MicroRNAs that target Ca(2+) transporters are involved in vascular smooth muscle cell calcification.

The role of microRNAs (miRNAs) in vascular calcification is currently unclear. To examine how miRNAs are involved in vascular smooth muscle cell (VSMC) calcification, we explored the alteration of miRNAs in VSMC calcification in vitro and in vivo. Klotho homozygous mutant mice (kl/kl) display vascular calcification and have perturbations of calcium handling. We therefore hypothesized that the calcium perturbations in VSMCs could be mediated by miRNAs. Using an miRNA array analysis, we demonstrated that miRNAs are aberrantly expressed in the aortic media of 3-week-old kl/kl mice compared with wild-type (WT) mice. The expression levels of miR-135a(*), miR-762, miR-714, and miR-712(*) in the aortic media of kl/kl mice were significantly higher than in WT mice. We used quantitative real-time reverse transcriptase polymerase chain reaction to further confirm that these miRNAs were increased in the aortic media of kl/kl mice and in cultured VSMCs treated with high phosphate and calcium. A search of the miRNA database indicated that the Ca(2+) efflux proteins NCX1, PMCA1, and NCKX4 frequently appeared as potential targets of these miRNAs. The transfection of miRNA mimics into cultured VSMCs reduced the protein levels of each potential target. Conversely, miRNA inhibitors reduced phosphate and calcium-induced VSMC calcification. Furthermore, these inhibitors decreased the intracellular Ca(2+) concentration in cultured VSMCs after treatment with phosphate and calcium. Our results suggest that increased expression of miR-135a(*), miR-762, miR-714, and miR-712(*) in VSMCs may be involved in VSMC calcification by disrupting Ca(2+) efflux proteins.

Identification of a novel role of Septin 10 in paclitaxel-resistance in cancers through a functional genomics screen.

Paclitaxel (also known as taxol) is a member of the taxane class of anticancer agents, which has a well-known mechanism that blocks cell mitosis and kills tumor cells, that is often used in clinics to treat cancer. However, some carcinomas such as breast, ovarian and non-small-cell lung cancers are often resistant to paclitaxel treatment. In this study, we used a lentiviral siRNA library against the entire human genomes to identify genes associated with sensitivity to paclitaxel. We isolated two paclitaxel-resistant clones carrying the siRNA specific to septin 10 (SEPT10) and to budding uninhibited by benzimidazoles 3. The relation of budding uninhibited by benzimidazoles 3 to paclitaxel sensitivity has already been established, but that of SEPT10 remains unknown. Interestingly, overexpression of SEPT10 increased cells' sensitivity to paclitaxel; we also found that SEPT10 is an important regulator for microtubule stability. Furthermore, we found that paclitaxel-resistant tumors had decreased expression of SEPT10. Thus, SEPT10 may be a novel candidate molecule that acts as a good indicator of paclitaxel-resistant carcinomas.

TLS-CHOP represses miR-486 expression, inducing upregulation of a metastasis regulator PAI-1 in human myxoid liposarcoma.

Myxoid liposarcomas (MLSs) are characterized by t(12;16)(q13;p11) translocation and expression of TLS-CHOP chimeric oncoprotein. However, the molecular functions of TLS-CHOP have not been fully understood. On the other hand, microRNAs (miRNAs) comprise an abundant class of endogenous small non-coding RNAs that negatively regulate the expression of their target genes, and are involved in many biological processes. It is now evident that dysregulation of miRNAs is an important step in the development of many cancers. To our knowledge, however, there have been no reports of the miRNAs involved in MLS tumorigenesis and development. In this study, we have found that miR-486 expression was repressed in TLS-CHOP-expressed NIH3T3 fibroblasts and MLS tissues, and exogenous overexpression of miR-486 repressed growth of MLS cells. Thus, downregulation of miR-486 may be an important process for MLS. In addition, we have identified plasminogen activator inhibitor-1 (PAI-1) as a novel target gene of miR-486. PAI-1 is a unique type of serine protease inhibitor and is known to be one of the key regulators of tumor invasion and metastasis. Furthermore, knockdown of PAI-1 by a specific small interfering RNA (siRNA) inhibited growth of MLS cells, suggesting that increased expression of PAI-1 by miR-486 repression is critical for survival of MLS cells. Collectively, these results suggest a novel essential molecular mechanism that TLS-CHOP activates PAI-1 expression by repression of miR-486 expression in MLS tumorigenesis and development.

Differential immunohistochemical expression of DEC1, CK­1ε, and CD44 in oral atypical squamous epithelium and carcinoma in situ.

Presence of nuclear atypia during histological investigation is often a cause of concern for pathologists while identifying tumor and non­tumor cells in a biopsy sample of oral mucosa. Nuclear atypia is observed in severe inflammation, ulcers and reactive changes. Therefore, additional methods, such as immunohistochemistry, may help precise diagnosis. When the atypia is suggestive of tumorous or reactive origin, the lesion is diagnosed as atypical squamous epithelium (ASE). When there is severe nuclear atypia in the mucosa, such as in disorders of nuclear polarity, large nuclei, and clear nucleolus, the lesion is diagnosed as carcinoma in situ (CIS). However, it is not easy to distinguish ASE and CIS using hematoxylin and eosin staining. The present study aimed to distinguish ASE from CIS using immunohistochemistry. A total of 32 biopsy samples of either ASE or CIS cases were selected and the level of casein kinase 1ε (CK­1ε), differentiated embryonic chondrocyte gene 1 (DEC1), proliferating cell nuclear antigen (PCNA) and CD44, which are four protein markers which have been previously linked to cancer progression, were analyzed. CK­1ε and CD44 expression was higher in CIS samples than in ASE samples. However, DEC1 expression was lower in CIS samples than in ASE samples. PCNA expression was not markedly different between the two groups. Additionally, it was found that DEC1­overexpressing cells had decreased levels of CK­1ε and CD44 compared with control cells, while CK­1ε­overexpressing cells had relatively unchanged levels of CD44, DEC1 and PCNA. These results suggested that DEC1 negatively regulates the expression of CK­1ε and CD44. Thus, DEC1, CK­1ε, and CD44 were identified as mechanistically linked and clinically relevant protein biomarkers, which could help distinguish ASE and CIS.

Summer Hospitalization and Bronchial Asthma Make Treatment of Respiratory Syncytial Virus Infection Difficult: A Retrospective Study in Japan.

In recent years, epidemics of respiratory syncytial virus (RSV) have been seen in the summer in Japan. Patients hospitalized in the summer used a high-flow oxygen administration device more frequently than patients hospitalized in the winter. This study was a retrospective study to examine the variables associated with duration of oxygen therapy and severe cases. Subjects were pediatric patients diagnosed with RSV infection and hospitalized for treatment during the 5 years from April 2014 to March 2019. Data from 292 patients were analyzed. Duration of oxygen therapy was significantly associated with bronchial asthma (partial regression coefficient: 0.897, P = .004). Hospitalization in summer was significantly associated with severe condition (adjusted odds ratio: 4.07, 95% confidence interval: 1.16-14.27). The present study showed that bronchial asthma is a risk factor for prolonged oxygen therapy and infection in summer is a risk factor for progression to severe condition in cases of RSV infection.

Loss of Smad3 gives rise to poor soft callus formation and accelerates early fracture healing.

Smad3 is an intracellular signaling molecule in the transforming growth factor ß (TGF-ß) pathway that serves as a regulator of chondrogenesis and osteogenesis. To investigate the role of the TGF-ß/Smad3 signaling in the process of fracture healing, an open fracture was introduced in mouse tibiae, and the histology of the healing process was compared between wild-type (WT) and Smad3-null (KO) mice. In KO mice, the bone union formed more rapidly with less formation of cartilage in the callus and eventually the fracture was repaired more rapidly than in WT mice. Alkaline phosphatase staining showed that osteoblastic differentiation in the fracture callus was promoted in KO mice. Additionally, TRAP staining and the TUNEL assay revealed that the induction of osteoclasts and apoptotic cells was significantly promoted in the healing callus of KO mice. Sox9 expression clearly decreased at both mRNA and protein levels in the early stage of fracture in KO mice. In contrast, the expression of genes for osteogenesis and osteoclast formation increased from day 5 until day 14 post-fracture in KO mice compared to WT mice. From these results, we concluded that the loss of TGF-ß/Smad3 signaling promoted callus formation by promoting osteogenesis and suppressing chondrogenesis, which resulted in faster fracture healing.

Aberrant expression of the P2 promoter-specific transcript Runx1 in epiphyseal cartilage of Trps1-null mice.

Tricho-rhino-phalangeal syndrome (TRPS) is an autosomal dominant skeletal disorder caused by mutations of the Trps1 gene, which encodes a GATA type transcriptional repressor. To investigate the genes that act downstream of Trps1, we performed a DNA array using ATDC5 cells. One of the target genes identified from the DNA array was Runx1, which is essential for hematopoiesis and like Runx2 plays a significant role in chondrogenesis. A luciferase promoter assay and a chromosome immunoprecipitation assay showed that Runx1 expression in mouse epiphyseal cartilage was repressed by Trps1 binding to the GATA domain of the P2 promoter; the proximal segment of two promoters of the Runx1 gene. The aberrant expression of P2 transcripts was detected in growth plate chondrocytes from Trps1-null mice by in situ hybridization. In conclusion, Trps1 binds to the P2 promoter of the Runx1 gene and down-regulates Runx1 expression, which is necessary for normal cartilage formation.

Trps1 haploinsufficiency promotes renal fibrosis by increasing Arkadia expression.

Mutations in TRPS1 cause tricho-rhino-pharyngeal syndrome (TRPS). Trps1 is essential for nephron development, acting downstream of Bmp7. Because Bmp7 counteracts epithelial-to-mesenchymal transition (EMT) and reverses chronic renal injury, we examined the function of Trps1 in renal fibrosis. Immunohistochemistry revealed Trps1 expression in proximal tubular epithelial cells of mice. Unilateral ureteral obstruction reduced mRNA and protein expression of Trps1 in wild-type and heterozygous Trps1-knockout (Trps1(+/-)) mice. Trps1 haploinsufficiency promoted tubulointerstitial fibrosis via increased phosphorylation of Smad3 and decreased Smad7 protein. In primary culture, Trps1 deficiency promoted TGF-beta1-mediated EMT in proximal tubule cells. Trps1(+/-)-derived cells had higher levels of phosphorylated Smad3, and TGF-beta1 induced a time-dependent decrease in Smad7 protein in wild-type and Trps1(+/-) kidneys. In addition, compared with wild-type cells, Trps1(+/-) cells had double the amount of the E3 ubiquitin ligase Arkadia, and TGF-beta1 induced further Arkadia expression. Furthermore, knockdown of Arkadia inhibited TGF-beta1-induced EMT in Trps1(+/-) cells. Collectively, these data suggest that Trps1 haploinsufficiency enhances TGF-beta1-induced EMT and tubulointerstitial fibrosis by modulating the amount of Smad7 through Arkadia/ubiquitin-mediated degradation.

WAPL induces cervical intraepithelial neoplasia modulated with estrogen signaling without HPV E6/E7.

Since cervical cancer still afflicts women around the world, it is necessary to understand the underlying mechanism of cervical cancer development. Infection with HPV is essential for the development of cervical intraepithelial neoplasia (CIN). In addition, estrogen receptor signaling is implicated in the development of cervical cancer. Previously, we have isolated human wings apart-like (WAPL), which is expected to cause chromosomal instability in the process of HPV-infected precancerous lesions to cervical cancer. However, the role of WAPL in the development of CIN is still unknown. In this study, in order to elucidate the role of WAPL in the early lesion, we established WAPL overexpressing mice (WAPL Tg mice) and HPV E6/E7 knock-in (KI) mice. WAPL Tg mice developed CIN lesion without HPV E6/E7. Interestingly, in WAPL Tg mice estrogen receptor 1 (ESR1) showed reduction as compared with the wild type, but cell growth factors MYC and Cyclin D1 controlled by ESR1 expressed at high levels. These results suggested that WAPL facilitates sensitivity of ESR1 mediated by some kind of molecule, and as a result, affects the expression of MYC and Cyclin D1 in cervical cancer cells. To detect such molecules, we performed microarray analysis of the uterine cervix in WAPL Tg mice, and focused MACROD1, a co-activator of ESR1. MACROD1 expression was increased in WAPL Tg mice compared with the wild type. In addition, knockdown of WAPL induced the downregulation of MACROD1, MYC, and Cyclin D1 but not ESR1 expression. Furthermore, ESR1 sensitivity assay showed lower activity in WAPL or MACROD1 downregulated cells than control cells. These data suggested that WAPL increases ESR1 sensitivity by activating MACROD1, and induces the expression of MYC and Cyclin D1. Therefore, we concluded that WAPL not only induces chromosomal instability in cervical cancer tumorigenesis, but also plays a key role in activating estrogen receptor signaling in early tumorigenesis.

Heterochromatin protein 1gamma epigenetically regulates cell differentiation and exhibits potential as a therapeutic target for various types of cancers.

Heterochromatin protein 1 (HP1) is a chromosomal protein that participates in both chromatin packaging and gene silencing. Three HP1 isoforms (alpha, beta, and gamma) occur in mammals, but their functional differences are still incompletely understood. In this study, we found that HP1gamma levels are decreased during adipocyte differentiation, whereas HP1alpha and beta levels are expressed constitutively during adipogenesis in cultured preadipocyte cells. In addition, ectopic overexpression of HP1gamma inhibited adipogenesis. Furthermore, we did not detect any HP1gamma protein in the differentiated cells of various normal human tissues. These results suggest that the loss of HP1gamma is required for cell differentiation to occur. On the other hand, the methylation levels of lysine 20 (K20) on histone H4 showed a significant correlation with HP1gamma expression in both these preadipocyte cells and normal tissue samples. However, all cancer tissues examined were positive for HP1gamma but were often negative for trimethylated histone H4 K20. Thus, a dissociation of the correlation between HP1gamma expression and histone H4 K20 trimethylation may reflect the malfunction of epigenetic control. Finally, suppression of HP1gamma expression restrained cell growth in various cancer-derived cell lines, suggesting that HP1gamma may be an effective target for gene therapy against various human cancers. Taken together, our results demonstrate the novel function of HP1gamma in the epigenetic regulation of both cell differentiation and cancer development.

SNAIL induces epithelial-to-mesenchymal transition in a human pancreatic cancer cell line (BxPC3) and promotes distant metastasis and invasiveness in vivo.

SNAIL, a potent repressor of E-cadherin expression, plays a key role in inducing epithelial-to-mesenchymal transition (EMT) in epithelial cells. During EMT, epithelial cells lose cell polarity and adhesion, and undergo drastic morphological changes acquiring highly migratory abilities. Although there is increasing evidence that EMT is involved in the progression of some human cancers, its significance in the progression of pancreatic cancer remains elusive. In Panc-1, a well-known human pancreatic cancer cell line in which EMT is triggered by TGF-ß1 treatment, SNAIL and vimentin are highly expressed, whereas E-cadherin expression is scant. In contrast, another human pancreatic cancer cell line, BxPC3, in which SNAIL expression is not detected, has high levels of E-cadherin expression and does not undergo EMT upon TGF-ß1 treatment. After transfecting the SNAIL gene into BxPC3, however, the cells undergo EMT with remarkable alterations in cell morphology and molecular expression patterns without the addition of any growth factors. Furthermore, in an orthotopic transplantation model using SCID mice, SNAIL-transfected BxPC3 displayed highly metastatic and invasive activities. In the immunohistochemical analysis of the tumor derived from the SNAIL-expressing BxPC3, alterations suggestive of EMT were observed in the invasive tumor front. SNAIL enabled BxPC3 to undergo EMT, endowing it with a highly malignant potential in vivo. These results indicate that SNAIL-mediated EMT may be relevant in the progression of pancreatic cancer, and SNAIL could be a molecular target for a pancreatic cancer intervention.