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Endometrial cancer screening is crucial for clinical treatment. Currently, cytopathologists analyze cytopathology images is considered a popular screening method, but manual diagnosis is time-consuming and laborious. Deep learning can provide objective guidance efficiency. But endometrial cytopathology images often come from different medical centers with different staining styles. It decreases the generalization ability of deep learning models in cytopathology images analysis, leading to poor performance. This study presents a robust automated screening framework for endometrial cancer that can be applied to cytopathology images with different staining styles, and provide an objective diagnostic reference for cytopathologists, thus contributing to clinical treatment. We collected and built the XJTU-EC dataset, the first cytopathology dataset that includes segmentation and classification labels. And we propose an efficient two-stage framework for adapting different staining style images, and screening endometrial cancer at the cellular level. Specifically, in the first stage, a novel CM-UNet is utilized to segment cell clumps, with a channel attention (CA) module and a multi-level semantic supervision (MSS) module. It can ignore staining variance and focus on extracting semantic information for segmentation. In the second stage, we propose a robust and effective classification algorithm based on contrastive learning, ECRNet. By momentum-based updating and adding labeled memory banks, it can reduce most of the false negative results. On the XJTU-EC dataset, CM-UNet achieves an excellent segmentation performance, and ECRNet obtains an accuracy of 98.50%, a precision of 99.32% and a sensitivity of 97.67% on the test set, which outperforms other competitive classical models. Our method robustly predicts endometrial cancer on cytopathologic images with different staining styles, which will further advance research in endometrial cancer screening and provide early diagnosis for patients. The code will be available on GitHub. [ABSTRACT FROM AUTHOR]

Background: In the study, we aimed to evaluate the ability of micro‐histology combined with cytology to improve the quality of slides and diagnose endometrial lesions. Methods: Endometrial specimens were collected from Li Brushes. Every specimen was prepared for micro‐histological and cytological slides, using cell block (CB) and liquid‐based cytology (LBC) technologies. Semi‐quantitative scoring system was used to evaluate the qualities of slides. CB slides were assessed by 5‐category scoring system. Diagnostic accuracy was calculated in LBC, CB, and LBC + CB groups based on the histological gold standard. Endometrial atypical hyperplasia, and endometrial cancer were considered positive, whereas others were considered negative. Results: A total of 167 patients were enrolled. CB slides were inferior to LBC slides only in cellularity (p < 0.001), but superior in the other six parameters (all p < 0.001). The satisfaction rate of micro‐histology accounted for 92.3%. The accuracy index in the CB group was higher than in the LBC group in terms of sensitivity (85.5% vs. 82.7%) and specificity (98.9% vs. 95.7%). The sensitivity and specificity in the LBC + CB group were increased to 94.2% and 99.0%, respectively. Conclusions: The quality of micro‐histological slides was higher than that of cytological slides. By combining micro‐histology with cytology, higher accuracy was achieved for endometrial lesions diagnosis. [ABSTRACT FROM AUTHOR]

Intratumor heterogeneity (ITH) is a barrier to effective therapy. However, it is largely unknown how ITH is established at the onset of tumor progression, such as in colorectal cancer (CRC). Here, we integrate single‐cell RNA‐seq and functional validation to show that asymmetric division of CRC stem‐like cells (CCSC) is critical for early ITH establishment. We find that CCSC‐derived xenografts contain seven cell subtypes, including CCSCs, that dynamically change during CRC xenograft progression. Furthermore, three of the subtypes are generated by asymmetric division of CCSCs. They are functionally distinct and appear at the early stage of xenografts. In particular, we identify a chemoresistant and an invasive subtype, and investigate the regulators that control their generation. Finally, we show that targeting the regulators influences cell subtype composition and CRC progression. Our findings demonstrate that asymmetric division of CCSCs contributes to the early establishment of ITH. Targeting asymmetric division may alter ITH and benefit CRC therapy. Synopsis: Asymmetric division of colorectal cancer stem‐like cells contributes to the early establishment of intratumor heterogeneity. Targeting asymmetric division may alter intratumor heterogeneity and benefit colorectal cancer therapy. CCSC‐derived xenografts contain seven cell subtypes, which dynamically change during CRC xenograft progression.Three functionally distinct subtypes are generated by asymmetric division of CCSCs at an early xenograft stage.One subtype derived from CCSCs by asymmetric division is chemoresistant and highly invasive.Targeting regulators that control the generation of these subtypes affects xenograft composition and CRC progression. [ABSTRACT FROM AUTHOR]

Simple Summary: The soaring demand for endometrial cancer screening has exposed a huge shortage of cytopathologists worldwide. Deep learning algorithms, based on convolutional neural networks, have been successfully applied to the classification and segmentation of medical images. The aim was to establish an artificial intelligence system that automatically recognizes and diagnoses pathological images of endometrial cell clumps (ECCs). Total 39,000 ECCs (26,880 for training, 11,520 for testing and 600 malignant for verification) patches were obtained by the segmentation network. The training set reached 100% accuracy, the testing set gained 93.5% accuracy, 92.2% specificity, and 92.0% sensitivity. Therefore, an artificial intelligence system was successfully built to classify malignant and benign ECCs for reducing pathologists' workload, providing decision-making assistance and promoting the development of endometrial cancer screening. Objectives: The soaring demand for endometrial cancer screening has exposed a huge shortage of cytopathologists worldwide. To address this problem, our study set out to establish an artificial intelligence system that automatically recognizes and diagnoses pathological images of endometrial cell clumps (ECCs). Methods: We used Li Brush to acquire endometrial cells from patients. Liquid-based cytology technology was used to provide slides. The slides were scanned and divided into malignant and benign groups. We proposed two (a U-net segmentation and a DenseNet classification) networks to identify images. Another four classification networks were used for comparison tests. Results: A total of 113 (42 malignant and 71 benign) endometrial samples were collected, and a dataset containing 15,913 images was constructed. A total of 39,000 ECCs patches were obtained by the segmentation network. Then, 26,880 and 11,520 patches were used for training and testing, respectively. On the premise that the training set reached 100%, the testing set gained 93.5% accuracy, 92.2% specificity, and 92.0% sensitivity. The remaining 600 malignant patches were used for verification. Conclusions: An artificial intelligence system was successfully built to classify malignant and benign ECCs. [ABSTRACT FROM AUTHOR]

Background: Understanding the relationship between Alzheimer's disease (AD) and intestinal flora is still a major scientific topic that continues to advance.Objective: To determine characterized changes in the intestinal microbe community of patients with mild AD.Methods: Comparison of the 16S ribosomal RNA (rRNA) high-throughput sequencing data was obtained from the Illumina MiSeq platform of fecal microorganisms of the patients and healthy controls (HC) which were selected from cohabiting caregivers of AD patients to exclude environmental and dietary factors.Results: We found that the abundance of several bacteria taxa in AD patients was different from that in HC at the genus level, such as Anaerostipes, Mitsuokella, Prevotella, Bosea, Fusobacterium, Anaerotruncus, Clostridium, and Coprobacillus. Interestingly, the abundance of Akkermansia, an emerging probiotic, increased significantly in the AD group compared with that in the HC group. Meanwhile, the quantity of traditional probiotic Bifidobacteria of the AD group also rose.Conclusion: These alterations in fecal microbiome of the AD group indicate that patients with mild AD have unique gut microbial characteristics. These specific AD-associated intestinal microbes could serve as novel potential targets for early intervention of AD. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) metastasizes mainly to the liver, which accounts for the majority of CRC‐related deaths. Here it is shown that metastatic cells undergo specific chromatin remodeling in the liver. Hepatic growth factor (HGF) induces phosphorylation of PU.1, a pioneer factor, which in turn binds and opens chromatin regions of downstream effector genes. PU.1 increases histone acetylation at the DPP4 locus. Precise epigenetic silencing by CRISPR/dCas9KRAB or CRISPR/dCas9HDAC revealed that individual PU.1‐remodeled regulatory elements collectively modulate DPP4 expression and liver metastasis growth. Genetic silencing or pharmacological inhibition of each factor along this chromatin remodeling axis strongly suppressed liver metastasis. Therefore, microenvironment‐induced epimutation is an important mechanism for metastatic tumor cells to grow in their new niche. This study presents a potential strategy to target chromatin remodeling in metastatic cancer and the promise of repurposing drugs to treat metastasis. [ABSTRACT FROM AUTHOR]

Abstract Background Suicide and major depressive disorders (MDD) are strongly associated, and genetic factors are responsible for at least part of the variability in suicide risk. We investigated whether variation at the tryptophan hydroxylase-2 (TPH2) gene rs7305115 SNP may predispose to suicide attempts in MDD. Methods We genotyped TPH2 gene rs7305115 SNP in 215 MDD patients with suicide and matched MDD patients without suicide. Differences in behavioral and personality traits according to genotypic variation were investigated by logistic regression analysis. Results There were no significant differences between MDD patients with suicide and controls in genotypic (AG and GG) frequencies for rs7305115 SNP, but the distribution of AA genotype differed significantly (14.4% vs. 29.3%, p < 0.001). The G-allele frequency was significantly higher in cases than control group (58.1% vs.45.6%, p < 0.001), but the A-allele carrier indicated a decreased trend in MDD with suicide behaviors than control group (41.9% vs.54.4%, p < 0.001). The multivariate logistic regression analysis indicated that TPH2 rs7305115 AA (OR 0.33, 95% CI 0.22-0.99), family history of suicide (OR 2.98, 95% CI 1.17-5.04), negative life events half year ago (OR 6.64, 95% CI 2.48-11.04) and hopelessness (OR 7.68, 95% CI 5.79-13.74) were significantly associated with the suicide behaviors in MDD patients. Conclusions The study suggested that hopelessness, negative life events and family history of suicide were risk factors of attempted suicide in MDD while the TPH2 rs7305115A remained a significant protective predictor of suicide attempts.

Obesity and its related complications pose an increasing threat to human health; however, targetable obesity‐related membrane receptors are not yet elucidated. Here, the membrane receptor CD146 is demonstrated to play an essential role in obesity. In particular, CD146 acts as a new adipose receptor for angiopoietin‐like protein 2 (ANGPTL2), which is thought to act on endothelial cells to activate adipose inflammation. ANGPTL2 binds to CD146 to activate cAMP response element‐binding protein (CREB), which then upregulates CD146 during adipogenesis and adipose inflammation. CD146 is present in preadipocytes and mature adipocytes, where it is mediated by its ligands ANGPTL2 and galectin‐1. In preadipocytes, CD146 ablation suppresses adipogenesis, whereas the loss of CD146 in mature adipocytes suppresses lipid accumulation and enhances energy expenditure. Moreover, anti‐CD146 antibodies inhibit obesity by disrupting the interactions between CD146 and its ligands. Together, these findings demonstrate that ANGPTL2 directly affects adipocytes via CD146 to promote obesity, suggesting that CD146 can be a potential target for treating obesity. [ABSTRACT FROM AUTHOR]

Accumulated unfolded proteins in the endoplasmic reticulum (ER) trigger the unfolded protein response (UPR) to increase ER protein folding capacity. ER proteostasis and UPR signaling need to be regulated in a precise and timely manner. Here, we identify phosphorylation of protein disulfide isomerase (PDI), one of the most abundant and critical folding catalysts in the ER, as an early event during ER stress. The secretory pathway kinase Fam20C phosphorylates Ser357 of PDI and responds rapidly to various ER stressors. Phosphorylation of Ser357 induces an open conformation of PDI and turns it from a "foldase" into a "holdase", which is critical for preventing protein misfolding in the ER. Phosphorylated PDI also binds to the lumenal domain of IRE1α, a major UPR signal transducer, and attenuates excessive IRE1α activity. Importantly, PDI‐S359A knock‐in mice display enhanced IRE1α activation and liver damage under acute ER stress. We conclude that the Fam20C‐PDI axis constitutes a post‐translational response to maintain ER proteostasis and plays a vital role in protecting against ER stress‐induced cell death. Synopsis: Endoplasmic reticulum (ER) proteostasis and unfolded protein response (UPR) signaling need to be regulated in a precise and timely manner. Here, phosphorylation of protein disulfide isomerase (PDI) by secretory pathway kinase Fam20C turns PDI activity from "foldase" into "holdase", thereby protecting mouse liver from ER stress‐induced cell death. Fam20C phosphorylates ER‐associated PDI on Serine 357 rapidly after ER stress.Ser357 phosphorylation induces a functional switch that transforms PDI from a 'foldase' into a 'holdase' chaperone.Phosphorylated PDI safeguards ER proteostasis and attenuates excessive activity of UPR transducer IRE1α.PDI phosphorylation is critical for preventing liver damage under ER stress in vivo. [ABSTRACT FROM AUTHOR]

The reaction mechanism between silacyclopropenylidene and three-membered heterocyclic compounds (azirane and oxirane) has been systematically investigated at the B3LYP/6-311+G* level of theory in order to better understand the reactivity of unsaturated cyclic silylene. Geometry optimizations and vibrational analyses have been conducted for the stationary points on the potential energy surface of the system. Calculations show that the Si-spiroheterocyclic intermediate and four-membered heterocyclic silylene compound could be produced through the insertion process and subsequent dissociation process between silacyclopropenylidene and three-membered heterocyclic compounds. For the insertion process, it is easier for silacyclopropenylidene to insert into C-N bond of azirane than into C-O bond of oxirane. This study is helpful to understand the reactivity of silacyclopropenylidene, the evolution of silicon-bearing molecules in space, and to offer an alternative approach to the formation of enlarged heterocyclic silylene compound. [ABSTRACT FROM AUTHOR]

The aim of this study is to examine the immunocytochemical expression of p53, Ki-67, and CA125 in endometrial brush samples for endometrial cancer. Forty-four patients were recruited with liquid-based cytology preparations during a 5-month period. Both the histological and cytological samples were assessed by histology based on hematoxylin and eosin (H&E), and the expression of p53, CA125, and Ki-67 in endometrial cells was examined by immunocytochemistry. The percentage and intensity of endometrial cells were scored on a scale of 0–3. The final score was calculated by the addition of all partial scores, and then Probit model was used to predict the possibility for malignant lesions. The mean immunoreactivity score of the three immunocytochemical biomarkers (p53, CA125, and Ki-67) in the positive group (including atypical hyperplastic cells and malignant cells) was significantly higher than in the negative group (benign cells and non-atypical hyperplastic cells). The possibility value of the positive group was also significantly higher than the negative group (P < 0.05). The cutoff value of the possibility value was 0.754, the sensitivity and specificity of which were 86.4 and 95.5%. The assessment of p53, CA125, and Ki-67 combined with the prediction model is valuable for the detection of endometrial cancer and atypical hyperplasia in endometrial cytology. [ABSTRACT FROM AUTHOR]

Objective: To study whether dysregulation of insulin-like growth factors (IGFs) and IGF signaling are common molecular changes in symptomatic leiomyomas (fibroids) and whether IGFs are associated with large fibroids. Design: Examination of IGFs and IGF pathway genes in a large cohort of fibroids at transcriptional and translational levels. Mechanisms leading to alterations of IGFs and related genes were also analyzed. Setting: University clinical research laboratory. Patient(s): Hysterectomies for symptomatic fibroids were collected: 180 cases from paraffin-embedded tissues and 50 cases from fresh-frozen tissues. Intervention(s): Tissue microarray and immunohistochemistry, DNA methylation analysis, reverse-transcriptase polymerase chain reaction, and Western blot. Main Outcome Measurement(s): Transcription and translation analyses of IGF-1/2, p-AKT, p-S6K, and TSC1/2 in fibroids and matched myometrium. Result(s): Insulin-like growth factors and downstream effectors were dysregulated in approximately one third of fibroids. All except for IGF-2 seemed to be abnormally regulated at translation levels. Up-regulation of IGF-2 messenger RNAs was contributed by all four alternating slicing promoters. There was a positive correlation of IGF-1 and p-AKT over-expression with fibroid size. Insulin-like growth factor 1 but not IGF-2 levels directly correlated with activation of p-AKT and p-S6K. Conclusion(s): Altered expressions of IGFs and their related downstream proteins were found in one third of fibroids. Large fibroids show high levels of IGF-1 and p-AKT activity compared with small ones. [Copyright &y& Elsevier]

Background: For women with intrauterine devices (IUDs), it is difficult to sample the endometrium when abnormal uterine bleeding occurs or when regular screening of endometrial cancer is proposed. The purpose of this study is to evaluate the validity of endometrial sampling using Li Brush in IUD users. Methods: This study was a prospective cohort study and conducted in two parts. Part I was to assess the impact of Li Brush on the position of IUDs. Transvaginal ultrasound was used to locate IUDs before and after sampling. Part II was to explore the diagnostic accuracy of Li Brush in detecting endometrial lesions. IUD users with irregular uterine bleeding were recruited in the IUD group and IUD non-users who arranged for dilatation and curettage (D&C) were recruited in the control group. The endometrium was sampled by Li Brush for cells and by D&C for tissues in both groups. The satisfactoriness of sampling and validity of Li Brush were evaluated. Results: Seventeen cases in part I confirmed no significant difference in the position of IUDs before and after sampling ( p = 0.20). 112 IUD users and 139 IUD non-users were recruited in part II. Li Brush achieved 94.64 and 92.09% satisfactory sampling rates in the IUD group and control group, respectively, without statistically significant difference between the two groups ( p = 0.42). The Sensitivity and specificity of Li Brush for detection of endometrial lesions in IUD group were 95.35 and 87.76% respectively. Conclusions: Li Brush used for endometrial biopsy did not affect the position of IUDs and had high yield of satisfactory samples and good validity for endometrial diagnoses. It was feasible to screen endometrial lesions by Li Brush for women with IUDs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Han, Ma, Zhao, Liu, Wang, Feng, Zhang, Wang, Wang, Yin, Liang, Hou, Shi and Li.)

Objectives: To compare the effectiveness between Qi brush and Cervex-Brush® Combi for the diagnosis of cervical lesions. Methods: After we registered a random-control clinical trial on the Chinese Clinical Trial Registry (No. XJTU1AF2017LSK-25), cervical cell samples were successively collected with both Qi brush and Cervex-Brush® Combi before undergoing colposcope. Colposcopy with biopsy was performed later. Histological diagnosis was regarded as the gold standard in this study. The following indices of the two brushes were compared: sampling degree of satisfaction and presence rate of metaplastic cells, together with sensitivity (Se), specificity (Sp), false positives (FP), false negatives (FN), positive predictive value (PPV), and negative predictive value (NPV). The kappa value was used to measure the inter-rater agreement of the Qi brush and Cervex-Brush® Combi in diagnosing cervical lesions. Results: In total, 74 patients were enrolled in this study. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Qi brush were 57.14, 86.84, 76.19, and 73.33%, respectively. For the Cervex-Brush® Combi, they were 26.92, 88.89, 63.63, and 62.75%, respectively. In addition, the Qi brush had a higher satisfied sampling rate (89.19%) than the Cervex-Brush® Combi (83.78%), and the P -value was 0.336 using Chi-square test. The kappa value was 0.444, which indicated a medium agreement between these two brushes, and the sensitivity of the Qi brush was higher than that of the Cervex-Brush® Combi, with significant statistical difference ( P = 0.039<0.05). Conclusions: The Qi brush was more effective than the Cervex-Brush® Combi for sampling and also had a slightly higher accuracy in diagnosing in cytology. In terms of social and economic benefits, the Qi brush may be a better cervical cytology collector., (Copyright © 2020 Zou, Tuo, Wu, Liu, Feng, Zhao, Han, Wang, Wang, Hou, Shi and Li.)

Background: Endoplasmic reticulum (ER) oxidoreductin-1α (Ero1α) and protein disulfide isomerase (PDI) constitute the pivotal pathway of oxidative protein folding, and are highly expressed in many cancers. However, whether targeting the functional interplay between Ero1α and PDI could be a new approach for cancer therapy remains unknown., Methods: We performed wound healing assays, transwell migration and invasion assays and xenograft assays to assess cell migration, invasion and tumorigenesis; gel filtration chromatography, oxygen consumption assay and in cells folding assays were used to detect Ero1α-PDI interaction and Ero1α oxidase activity., Findings: Here, we report that elevated expression of Ero1α is correlated with poor prognosis in human cervical cancer. Knockout of ERO1A decreases the growth, migration and tumorigenesis of cervical cancer cells, through downregulation of the H 2 O 2 -correlated epithelial-mesenchymal transition. We identify that the conserved valine (Val) 101 of Ero1α is critical for Ero1α-PDI complex formation and Ero1α oxidase activity. Val101 of Ero1α is specifically involved in the recognition of PDI catalytic domain. Mutation of Val101 results in a reduced ER, retarded oxidative protein folding and decreased H 2 O 2 levels in the ER of cervical cancer cells and further impairs cell migration, invasion, and tumor growth., Interpretation: Our study identifies the critical residue of Ero1α for recognizing PDI, which underlines the molecular mechanism of oxidative protein folding for tumorigenesis and provides a proof-of-concept for cancer therapy by targeting Ero1α-PDI interaction. FUND: This work was supported by National Key R&D Program of China, National Natural Science Foundation of China, and Youth Innovation Promotion Association, CAS., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

Immune homeostasis is a prerequisite to protective immunity against gastrointestinal infections. In Drosophila, immune deficiency (IMD) signalling (tumour necrosis factor receptor/interleukin-1 receptor, TNFR/IL-1R in mammals) is indispensable for intestinal immunity against invading bacteria. However, how this local antimicrobial immune response contributes to inflammatory regulation remains poorly defined. Here, we show that flies lacking intestinal Bap180 (a subunit of the chromatin-remodelling switch/sucrose non-fermentable (SWI/SNF) complex) are susceptible to infection as a result of hyper-inflammation rather than bacterial overload. Detailed analysis shows that Bap180 is induced by the IMD-Relish response to both enteropathogenic and commensal bacteria. Upregulated Bap180 can feed back to restrain overreactive IMD signalling, as well as to repress the expression of the pro-inflammatory gene eiger (TNF), a critical step to prevent excessive tissue damage and elongate the lifespan of flies, under pathological and physiological conditions, respectively. Furthermore, intestinal targeting of Baf180 renders mice susceptible to a more aggressive infectious colitis caused by Citrobacter rodentium. Together, Bap180 and Baf180 serve as a conserved transcriptional repressor that is critical for the maintenance of innate immune homeostasis in the intestines.

Purpose: High-motility group AT-hook gene 1 (HMGA1) is a non-histone nuclear binding protein that is developmentally regulated. HMGA1 is significantly overexpressed in and associated with high grade and advance stage of prostate cancer (PC). The oncogenic role of HMGA1 is at least mediated through chromosomal instability and structural aberrations. However, regulation of HMGA1 expression is not well understood. Identification of microRNA-mediated HMGA1 regulation will provide a promising therapeutic target in treating PC., Experimental Design: In this study, we examined the functional relation between miR-296 and HMGA1 expression in several PC cell lines and a large PC cohort. We further examined the oncogenic property of HMGA1 regulated by miR-296., Results: Here we report that miR-296, a microRNA predicted to target HMGA1, specifically represses HMGA1 expression by promoting degradation and inhibiting HMGA1translation. Repression of HMGA1 by miR-296 is direct and sequence specific. Importantly, ectopic miR-296 expression significantly reduced PC cell proliferation and invasion, in part through the downregulation of HMGA1. Examining PC patient samples, we found an inverse correlation between HMGA1 and miR-296 expression: high levels of HMGA1 were associated with low miR-296 expression and strongly linked to more advanced tumor grade and stage., Conclusions: Our results indicate that miR-296 regulates HMGA1 expression and is associated with PC growth and invasion., (©2010 AACR.)

Overexpression of HMGA2 is common in uterine leiomyomas (ULM). The expression of HMGA2 in its malignant counterpart - uterine leiomyosarcomas (ULMS) remains undetermined. Recently it has been shown that repression of HMGA2 by microRNA let-7s is a critical molecular regulatory mechanism associated with tumour growth in many tumours and cell types, including leiomyomas. To test whether HMGA2 and let-7s play a role in ULMS, we examined the levels of endogenous HMGA2 and let-7 expression and found a significant correlation between these two molecules in a case-matched cohort of human ULMS. We found that overexpression of HMGA2 and let-7-mediated HMGA2 repression is a relevant molecular alteration in ULMS. Disrupting the control of HMGA2 and let-7 pairs promotes ULMS cell growth in vitro.

High-mobility group A2 (HMGA2) is commonly overexpressed in large leiomyomas. HMGA2 is an important regulator of cell growth, differentiation, apoptosis, and transformation. As a predicted target of Let-7 microRNAs (Let-7s), HMGA2 can be repressed by Let-7s in vitro. MicroRNA profiling analysis revealed that Let-7s were significantly dysregulated in uterine leiomyomas: high in small leiomyomas and lower in large leiomyomas. To evaluate whether Let-7 repression of HMGA2 plays a major role in leiomyomas, we analyzed the molecular relationship of HMGA2 and Let-7s, both in vitro and in vivo. We first characterized that exogenous Let-7 microRNAs could directly repress the dominant transcript of HMGA2, HMGA2a. This repression was also identified for two cryptic HMGA2 transcripts in primary leiomyoma cultures. Second, we found that the endogenous Let-7s were biologically active and played a major role in the regulation of HMGA2. Then, we illustrated that Let-7 repression of HMGA2 inhibited cellular proliferation. Finally, we examined the expression levels of Let-7c and HMGA2 in a large cohort of leiomyomas (n = 120), and we found high levels of Let-7 and low levels of HMGA2 in small leiomyomas, and low levels of Let-7 and high levels of HMGA2 in large leiomyomas. Our findings suggest that the Let-7-mediated repression of HMGA2 mechanism can be an important molecular event in leiomyoma growth.

LASS1 is the mammalian homologue of yeast longevity-assurance gene 1 (LAG1) which is differentially expressed during the yeast replicative life span and was shown to play a role in determining yeast longevity. Growth/differentiation factor 1 (GDF1) is a transforming growth factor-beta family member that was originally isolated from an mouse embryo cDNA library. GDF1 is expressed specifically in the nervous system and functions in left-right patterning of the mouse embryo. To explore the potential role of LASS1 in rat neuron aging, northern blot analysis for LASS1 mRNA was performed and detected a 2.7 kb transcript in adult rat cerebral cortex. Cloning and sequence analysis revealed that this transcript contains two nonoverlapping open reading frames (ORFs), LASS1 and GDF1, which are quite different to the predicted sequences in GenBank (accession number XM&#95;224734 and XM&#95;224733). The alignment with the rat genome database revealed this transcript matches the sequence of rat chromosome 16 genomic contig (GenBank accession number NW&#95;047470) between nucleotide positions 1935060th and 1919439th, which contains eight exons and seven introns. Multiple sequence analysis revealed high conservation of the two ORFs. The phylogenetic analysis showed very close evolutionary relationship among rat, mouse and human. It raises the possibility that this mRNA may give rise to two different proteins and the conserved bicistronic structure might be of unknown significance.