Epigenetic regulation of LINC01270 in breast cancer progression by mediating LAMA2 promoter methylation and MAPK signaling pathway.

Application of long non-coding RNAs (lncRNAs) for modulation of breast cancer (BC) has attracted much attention. Here, we probed into the role and underlying mechanism of long intergenic non-coding RNA 01270 (LINC01270) in BC. With the help of bioinformatics tools, we identified laminin subunit alpha 2 (LAMA2) as a BC-related differentially expressed gene to discern the effect of LAMA2 in BC cells. LAMA2 was initially poorly expressed while LINC01270 was highly expressed in BC. BC cells were subsequently treated with sh-LINC01270 or/and sh-LAMA2 for exploration of their regulatory mechanism in BC, which unfolded that LINC01270 inhibition up-regulated LAMA2 and inactivated the MAPK signaling pathway to suppress malignant characteristics of BC cells. Functional assays demonstrated that LINC01270 bound to DNMT1, DNMT3a, and DNMT3b promoted the methylation of CpG islands in LAMA2 promoter and inhibited the LAMA2 expression. Moreover, our data suggested that LAMA2 suppressed MAPK signaling pathway to inhibit BC cell malignant characteristics. The in vitro results were re-produced with the help of the in vivo experimentations. In conclusion, LINC01270 silencing inhibited the methylation of LAMA2 promoter to suppress the activation of MAPK signaling pathway, which subsequently restrained the BC progression. 1, Overexpression of LAMA2 inhibits malignant features of BC cells. 2, LINC01270 promotes LAMA2 promoter methylation by recruiting DNMTs to the LAMA2 promoter region. 3, 5-aza-dc reverses the promotion of LAMA2 promoter methylation by LINC01270. 4, LAMA2 inhibits malignant features of BC cells by suppressing the activation of MAPK signaling pathway.

MicroRNA-4500 Inhibits Migration, Invasion, and Angiogenesis of Breast Cancer Cells via RRM2-Dependent MAPK Signaling Pathway.

With the consideration of the dynamic role of microRNAs (miRNAs) in breast cancer, miRNAs may serve as therapeutic targets, helping to prevent development of therapy resistance, maintain stable disease, and prohibit metastatic spread. We identified the differentially expressed breast cancer-related gene ribonucleotide reductase subunit M2 (RRM2) as the study focus through microarray expression profiles. Next, the upstream regulatory microRNA (miR)-4500 of RRM2 was predicted using bioinformatics website analysis, and their binding was verified by a dual luciferase reporter gene assay. The regulatory effects of miR-4500 on breast cancer cell proliferation, apoptosis, migration, invasion, and capillary-like tube formation of endothelial cells were assessed by gain- and loss-of-function experiments. The experimental data revealed that miR-4500 was downregulated, whereas RRM2 was upregulated in breast cancer cells. Mechanistic analysis revealed that miR-4500 downregulated the RRM2 expression to inactivate the mitogen-activated protein kinase (MAPK) signaling pathway. Furthermore, miR-4500 exerted anti-tumor effects by targeting RRM2 through suppression of the MAPK signaling pathway in vitro, evidenced by attenuated cancer cell migration and invasion and capillary-like tube formation of endothelial cells. The in vivo experiments further corroborated in vitro results. Collectively, overexpressed miR-4500 could downregulate RRM2 and inhibit activation of the MAPK signaling pathway, thus attenuating breast cancer cell proliferation, invasion, migration, and angiogenesis and promoting breast cancer cell apoptosis.

Microarray-based analysis of whole-genome DNA methylation profiling in early detection of breast cancer.

Emerging evidence indicated that changes in DNA methylation early in breast cancer (BC) development might be clinically relevant for therapeutic decisions. Through analysis of whole-genome gene expression microarray and DNA methylation microarray, we explored genes with abnormal DNA methylation in BC for early detection. Firstly, human BC tissues and adjacent non-cancerous tissues were collected from nine BC patients. Gene expression microarray sequencing was conducted for identifying differentially expressed genes and DNA methylation microarray sequencing for differentially methylated genes in BC. Differentially expressed genes and methylated genes in BC were further explored using the Cancer Genome Atlas database. The correlation between DNA methylation and gene expression was illustrated by multiple comparisons. In other 60 clinical samples, methylation specific polymerase chain reaction (PCR) and reverse transcription quantitative PCR were applied for the methylation of HOXA4 and IGF1 genes in BC and adjacent non-cancerous tissues. In total, 1680 upregulated genes and 1249 downregulated genes were determined in BC. Chromosome 16 and 17 showed more differentially methylated genes, and DNA methylation level was increased in BC tissues in each gene region. Chromosome 19 showed more differentially methylated genes, and DNA methylation level was increased in BC tissues in the exoniensis 1, untranslated region-5 and transcriptional start site 200 gene regions. In other 60 clinical samples, HOXA4 and IGF1 in BC tissues presented increased DNA methylation and decreased gene expression in BC. MCF7 cells treated with RG108 showed decreased HOXA4 and IGF1 expressions. It was estimated that HOXA4 and IGF1 were identified with increased DNA methylation and decreased gene expression in BC, which may serve as biomarkers in early BC detection.

[Kaup index in 16 887 singleton neonates with a gestational age of 27-42 weeks in Shenzhen, China].

OBJECTIVE: To study the Kaup index (KI), an index used to evaluate body burliness and nutritional status, of neonates with a gestational age (GA) of 27-42 weeks at birth, and to establish the percentile curves of KI. METHODS: Cross-sectional cluster sampling was performed from April 2013 to September 2015 to select 16 887 singleton neonates with a GA of 27-42 weeks in two hospitals in Shenzhen, China. Body weight and body length were measured to calculate KI. The percentile curves of KI were plotted in these neonates. RESULTS: Mean KIs and corresponding standard deviations were obtained for singleton neonates with a gestational age of 27-42 weeks (in male, female, and mixed groups), and the 3rd-97th percentile curves of KI were plotted. The singleton neonates with a GA of 27 weeks had the lowest 50th percentile value of KI, and KI gradually increased with GA. Boys had a higher 50th percentile value of KI than girls in each GA group. In all groups except the 33-week GA group, boys had a higher mean KI than girls, and there was a significant difference in the mean KI between boys and girls in the GA groups of 34 and 36-40 weeks (P<0.05). CONCLUSIONS: KI of neonates at birth increases with GA, suggesting that body density and body burliness increase with GA. Boys have better body burliness than girls at birth. The percentile curves of KI plotted for singleton neonates with a GA of 27-42 weeks (in male, female, and mixed groups) can provide a reference for evaluating the body burliness and nutritional status of neonates at birth in Shenzhen.

[Intrauterine growth status of twin neonates with a gestational age of 27-40 weeks].

OBJECTIVE: To establish the intrauterine growth curve of twin neonates, and to investigate the intrauterine growth status of twin neonates. METHODS: Cross-sectional cluster sampling was performed for an on-the-spot investigation of 1 296 live twin neonates who were born in two hospitals in Shenzhen between April 2013 and September 2015. The Lambda-Mu-Sigma method was used for the curve fitting of body weight, body length, head circumference, chest circumference, and crown-rump length. RESULTS: The means and 3rd-97th percentile intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length were obtained for the 1 296 twin neonates with a gestational age of 27-40 weeks. The curve values of the 1 296 twin neonates for body weight, body length, head circumference, chest circumference, and crown-rump length were all lower than those of singleton neonates in Shenzhen that had been reported, and the difference increased with increasing gestational age. CONCLUSIONS: The intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length of twin neonates with a gestational age of 27-40 weeks in Shenzhen obtained in this study can provide a reference for evaluating the intrauterine growth status of twin neonates among the current population in Shenzhen.

[Differences in intrauterine growth levels between full-term neonates born to primiparous or multiparous women].

OBJECTIVE: To establish the intrauterine growth percentile curves of full-term neonates with different gestational ages (GAs) born to primiparous or multiparous women, and to investigate the influence of parity on intrauterine growth potential. METHODS: Cross-sectional cluster sampling was performed from April 2013 to September 2015 to measure physical growth in full-term singleton infants with a GA of 37-41 weeks in two hospitals in Shenzhen, China. The Lambda-Mu-Sigma method was used for curve fitting. RESULTS: The mean values of birth weight, body length, head circumference, chest circumference, and crown-rump length were obtained in 14 529 full-term infants. The 10th, 25th, 50th, 75th, and 90th percentile curves of the five indices were established. The full-term infants born to multiparous women had similar patterns and growth trends of the five percentile curves of the above five indices to those born to primiparous women, while the full-term infants with a GA of 37-41 weeks born to multiparous women had higher mean values and percentile curve values of the above five indices than those born to primiparous women. In the group with a GA of 41 weeks, there was no significant difference in the crown-rump length between the infants born to primiparous women and those born to multiparous women, but there were significant differences in the means of the above five indices in all the other GA groups between the two group infants (P<0.05). CONCLUSIONS: Full-term infants with a GA of 37-41 weeks born to multiparous women have higher intrauterine growth levels of birth weight, body length, head circumference, chest circumference, and crown-rump length than those born to primiparous women, suggesting that parity is an important influencing factor for intrauterine growth potential.

[A study of Ververck index in 16 865 singleton neonates with a gestational age of 27-42 weeks in Shenzhen, China].

OBJECTIVE: Ververck index (VI) reflects thoracic development, body type, and nutritional status. This study aimed to investigate the VI of singleton neonates with a gestational age (GA) of 27-42 weeks at birth, and to establish percentile curves of VI of the neonates. METHODS: Cross-sectional cluster sampling was performed between April 2013 and September 2015. Body weight, body length, and chest circumference were measured for 16 865 singleton neonates with a GA of 27-42 weeks in two hospitals in Shenzhen, China. VI was calculated and the percentile curves of VI were plotted for the neonates. RESULTS: Mean VIs were obtained for singleton neonates with a gestational age of 27-42 weeks (in three groups of male, female, and both sexes), and related 3rd-97th percentile curves were plotted. As for the 50th percentile curve, the singleton neonates with a GA of 27 weeks had the lowest 50th percentile value of VI, which gradually increased with the increase in GA. The singleton neonates with a GA of 42 weeks had the highest 50th percentile value of VI. Girls had a slightly higher 50th percentile value of VI than boys in all GA groups. CONCLUSIONS: VI of neonates increases with the increase in GA. Female neonates may have a slightly better thoracic development, body type, and nutritional status than male neonates at birth. The percentile curves of VI plotted for singleton neonates with a GA of 27-42 weeks (in three groups of male, female, and both sexes) can provide a basis for evaluating thoracic development, body type, and nutritional status of neonates at birth in Shenzhen, China.

[Intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length in 16 887 neonates with a gestational age of 27-42 weeks in Shenzhen, China].

OBJECTIVE: To establish the intrauterine growth curves of neonates in Shenzhen, China and to investigate the intrauterine growth of neonates in Shenzhen. METHODS: Cross-sectional cluster sampling was performed for an on-the-spot investigation of 16 887 neonates (9 418 males and 7 469 females) with a gestational age of 27-42 weeks who were born in two hospitals in Shenzhen from April 2013 to September 2015. The Lambda Mu Sigma (LMS) method was used for the curve fitting of body weight, body length, head circumference, chest circumference, and crown-rump length. RESULTS: The 3rd-97th percentile intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length were plotted for the neonates with a gestational age of 27-42 weeks who were divided into three groups (male, female, and mixed). The male neonates had significantly higher curves for the five indices than the female counterparts. The pattern and changing trend of body weight curves of these neonates were basically consistent with those in China Neonatal Network. CONCLUSIONS: The percentile intrauterine growth curves for body weight, body length, head circumference, chest circumference, and crown-rump length in neonates with a gestational age of 27-42 weeks in Shenzhen which has been established can provide a reference for clinical practice in the department of neonatology.

[Study on height-weight indices in newborns of different gestational ages].

OBJECTIVE: To establish height-weight indices in newborns of different gestational ages and to provide reference data for evaluation of intrauterine fetal growth. METHODS: The weight, height, crown-rump length, head circumference, and chest circumference of 8 357 newborns were measured in Maternal and Child Health Care Hospital of Bao'an District of shenzhen between 2005 and 2006, with the method of fact-finding investigation with cross-sectional cluster sampling, to establish the height-weight indices in newborns of different gestational ages. RESULTS: Five gender-specific height-weight indices (Quetelet Index, QI; Kaup Index, KI; Rohrer Index, RI; Livi Index, LI; Polock Index, PI) in newborns of different gestational ages (28-44 weeks of gestation) in three different groups (boys+girls, boys, and girls) were established in Shenzhen, China, and were expressed as mean gestational weeks±SD. The five indices above all increased with increasing gestational age, and the highest values appeared at 41-43 gestational weeks, suggesting that body density and enrichment degree increased constantly with increasing gestational age. Three indices (QI, KI and PI) were higher in boys than in girls (P<0.05). CONCLUSIONS: With the increasing gestational age, the body density and enrichment degree of newborns increase, and the enrichment degree in boys is better than that in girls.