Biomedical subjects

Min Xiao

Publications and source records attributed to Min Xiao.

At least 19 recordsLinked to original sources

PubMed2026

DNA hypermethylation of abscisic-acid-related genes helps enhance the cold tolerance of tetraploid rice.

Polyploid plants exhibit enhanced stress resistance and superior adaptability to extreme environments, but the underlying molecular mechanisms remain incompletely understood. Here we confirm that tetraploid rice exhibits stronger cold tolerance than diploid rice. This improved tolerance is mediated by reduced malondialdehyde accumulation, elevated antioxidant enzyme activity, and epigenetic regulation of genes involved in abscisic acid (ABA) biosynthesis and signaling. Under cold stress, tetraploid rice induces stress-responsive genes (especially in the ABA pathway) more rapidly and to higher levels than diploid rice. This enhanced gene expression coincides with increased endogenous ABA accumulation. Furthermore, polyploidization and cold stress synergistically induce high methylation at CG, CHG, and CHH sites in genes and transposons (TEs). Notably, the methylation level of class II TEs in tetraploid rice is significantly higher than in diploid rice under low temperatures. To suppress TE activation in gene promoter regions under cold stress, tetraploid rice enhances the methylation level of ABA pathway-related gene promoters, thereby silencing TEs and maintaining genome stability. Collectively, these results enrich the theoretical understanding of the strong stress tolerance in polyploid plants and provide theoretical support for breeding cold-tolerant polyploid rice varieties.

ABA↗

PubMed2026

miR-2116-5p functions as a tumor suppressor in lung adenocarcinoma by targeting ADAM12 and serves as a prognostic biomarker.

BACKGROUND: MicroRNAs play key roles in tumor progression. miR-2116-5p is downregulated in lung adenocarcinoma (LUAD), and this study investigated its prognostic value and functional role in the disease. MATERIALS AND METHODS: A total of 125 LUAD patients contributed tissue samples. miR-2116-5p and ADAM12 expression in tissues and cell lines were detected by RT‑qPCR. Clinicopathological correlations of miR-2116-5p were analyzed using the chi-square test. Kaplan‑Meier and Cox regression were employed to assess prognostic significance. CCK‑8, Transwell, and dual‑luciferase reporter assays were performed to investigate miR‑2116-5p function and its targeting of ADAM12. Rescue experiments validated the functional involvement of ADAM12. RESULTS: Significant downregulation of miR-2116-5p was observed in LUAD tissues and cell lines. Low expression was markedly linked to lymph node metastasis (P = 0.013) and advanced TNM stage (P = 0.002). Patients exhibiting reduced miR-2116-5p levels showed worse overall survival, and it was identified as an independent prognostic factor (HR = 2.521, 95% CI: 1.129-5.628, P = 0.020). Functional experiments showed that increasing miR-2116-5p expression suppressed LUAD cell proliferation, migration, and invasion, whereas its knockdown promoted these processes. ADAM12 was confirmed as a direct target, with expression inversely correlated in LUAD tissues (r = -0.749, P < 0.001). ADAM12 overexpression effectively counteracted the ability of miR-2116-5p to suppress proliferation, migration, and invasion. CONCLUSION: miR‑2116-5p suppresses LUAD progression by targeting ADAM12, suggesting it may serve as a prognostic biomarker and therapeutic target.

Humans↗

PubMed2025

Lactate dehydrogenase a is a crucial biomarker that affects the prognosis, chemotherapy effect, and immune infiltration of breast cancer.

PURPOSE: Lactate dehydrogenase A (LDHA) is a key node in tumor growth, metabolism, and invasion and is upregulated across multiple cancers. However, the molecular mechanisms by which LDHA influences breast cancer (BC) remain unclear. We analyzed public datasets and an institutional cohort to clarify the relationship between LDHA and BC, with the aim of informing future therapeutic strategies. PATIENTS AND METHODS: Using The Cancer Genome Atlas (TCGA), we assessed LDHA expression in BC and examined its associations with tumor mutational burden (TMB), immune cell infiltration, immune checkpoint molecules, and drug sensitivity. We integrated multiple databases and used Kaplan-Meier analyses to evaluate prognostic value. To explore biological functions of LDHA, we performed Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). We then analyzed BC patients receiving neoadjuvant chemotherapy (NAC) at Harbin Medical University Cancer Hospital to test the relationship between serum lactate dehydrogenase (LDH) and pathological complete response (pCR). Finally, we used National Health and Nutrition Examination Survey (NHANES) data to examine the association between serum LDH and mortality. RESULTS: LDHA was upregulated in BC tissues, and higher expression was significantly associated with worse overall survival (OS), recurrence-free survival (RFS), and distant metastasis-free survival (DMFS). Functional analyses indicated enrichment of metabolic pathways, such as glycolysis. LDHA expression correlated with multiple immune cell populations, suggesting involvement in the tumor immune microenvironment. Lower LDHA expression was associated with greater sensitivity to several chemotherapeutic agents. In our institutional cohort, patients with lower serum LDH were more likely to achieve pCR, and LDH was an independent predictor of pCR. In NHANES, elevated serum LDH was linked to increased mortality risk. CONCLUSION: Our findings suggest that LDHA expression and serum LDH levels are promising prognostic biomarkers for survival and may predict chemotherapy response in BC patients. These results highlight the clinical relevance of LDHA-mediated metabolic pathways. However, as a correlational study, our findings warrant further validation through functional experiments to confirm LDHA's role as a potential therapeutic target.

Humans↗

PubMed2006

Multi-dark-state resonances in cold multi-Zeeman-sublevel atoms.

We present our experimental and theoretical studies of multi-dark-state resonances (MDSRs) generated in a unique cold rubidium atomic system with only one coupling laser beam. Such MDSRs are caused by different transition strengths of the strong coupling beam connecting different Zeeman sublevels. Controlling the transparency windows in such an electromagnetically induced transparency system can have potential applications in multiwavelength optical communication and quantum information processing.

Journal Article↗

PubMed2006

Immobilization of UDP-galactose 4-epimerase from Escherichia coli on the yeast cell surface.

UDP-galactose 4-epimerase (EC 5.1.3.2, Gal E) from Escherichia coli catalyzes the reversible reaction between UDP-galactose and UDP-glucose. In this study, the Gal E gene from E. coli, coding UDP-galactose 4-epimerase, was cloned into pYD1 plasmid and then transformed into Saccharomyces cerevisiae EBY100 for expression of Gal E on the cell surface. Enzyme activity analyses with EBY100 cells showed that the enzyme displayed on the yeast cell surface was very active in the conversion between UDP-Glc and UDP-Gal. It took about 3 min to reach equilibrium from UDP-galactose to UDP-glucose.

Cloning, Molecular↗

PubMed2006

Notch1 signaling promotes primary melanoma progression by activating mitogen-activated protein kinase/phosphatidylinositol 3-kinase-Akt pathways and up-regulating N-cadherin expression.

Cellular signaling mediated by Notch receptors results in coordinated regulation of cell growth, survival, and differentiation. Aberrant Notch activation has been linked to a variety of human neoplasms. Here, we show that Notch1 signaling drives the vertical growth phase (VGP) of primary melanoma toward a more aggressive phenotype. Constitutive activation of Notch1 by ectopic expression of the Notch1 intracellular domain enables VGP primary melanoma cell lines to proliferate in a serum-independent and growth factor-independent manner in vitro and to grow more aggressively with metastatic activity in vivo. Notch1 activation also enhances tumor cell survival when cultured as three-dimensional spheroids. Such effects of Notch signaling are mediated by activation of the mitogen-activated protein kinase (MAPK) and Akt pathways. Both pathways are activated in melanoma cells following Notch1 pathway activation. Inhibition of either the MAPK or the phosphatidylinositol 3-kinase (PI3K)-Akt pathway reverses the Notch1 signaling-induced tumor cell growth. Moreover, the growth-promoting effect of Notch1 depends on mastermind-like 1. We further showed that Notch1 activation increases tumor cell adhesion and up-regulates N-cadherin expression. Our data show regulation of MAPK/PI3K-Akt pathway activities and expression of N-cadherin by the Notch pathway and provide a mechanistic basis for Notch signaling in the promotion of primary melanoma progression.

Animals↗

PubMed2006

Inhibition of endothelial cell proliferation by Notch1 signaling is mediated by repressing MAPK and PI3K/Akt pathways and requires MAML1.

The requirement for Notch signaling in vasculogenesis and angiogenesis is well documented. In a previous study, we showed that activation of the Notch pathway in endothelial cells induces differentiation-associated growth arrest; however, the underlying mechanism remains to be elucidated. Here, we show that activation of the Notch pathway by either stimulation of cell surface Notch receptors with crosslinked soluble delta-like 4 (sDll4)/Jagged1 (sJag1) or constitutive expression of the Notch1 intracellular domain (N(IC)) suppresses endothelial cell proliferation. This suppression is mediated by the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt pathways. Following Notch1 activation, both pathways were suppressed in endothelial cells, and alterations in MAPK or PI3K/Akt pathway activity reversed Notch1-induced growth inhibition. Furthermore, we found the effect of Notch1 on endothelial cells to require Mastermind-like (MAML). Overexpression of a dominant-negative mutant of MAML1 antagonized the effects of activated Notch1 on the MAPK and PI3K/Akt pathways. Ectopic expression of Hairy/Enhancer of Split 1 (HES1) consistently reproduced the inhibitory effect of N(IC) on endothelial cell proliferation. Together, our data demonstrate that the Notch/MAML-HES signaling cascade can regulate both MAPK and PI3K/Akt pathways, which suggests a molecular mechanism for the inhibitory effect of Notch signaling on endothelial cell proliferation.

Cell Proliferation↗

PubMed2006

[Geometric active contour model with color and intensity priors for medical image segmentation].

A new algorithm using the geometric active contour model with the fusion of color and intensity priors to segment medical images is presented in this paper. The prior knowledge used here are firstly defined in different color spaces and represented as thresholds searched by the genetic algorithm. Then the prior knowledge is merged into active contour model with its contour evolution by the level set technique. The experiments on clinical marrow images and mammograms have successfully demonstrated its superiority of the proposed algorithm over the existing active contour models which deal with image gradient information.

Algorithms↗

PubMed2006

[Application of glycosyl fluorides in the study on glycosidases].

Glycosyl fluorides are becoming increasingly important molecules for the study on glycosidases. Firstly, glycosyl fluorides act as substrates for glycosidases hydrolysis. Scecondly, the installation of fluorine elsewhere on the carbohydrate ring modifies the properties of the glycosyl fluoride so that the resultant compounds act as mechanism-based inhibitors to label enzymes in the active site, allowing identification of the catalytic nucleophile. Furthermore, glycosyl fluorides also act as donors for transglycosylation by retaining glycolides. Finally, glycosyl fluorides of the wrong anomeric configuration could be used by retaining glycosidase mutants such as glycosynthases and thioglycosynthases to synthesize carbohydrate with high yields(normally 60% to approximately 90%). Fundamental and applied research in biology, glycobiology and nanobiotechnology would benefit from the possibility of synthesizing tailor-made oligo-/poly-saccharides.

Animals↗

PubMed2006

[An epidemiological study on domestic violence in Hunan, China].

OBJECTIVE: To investigate the prevalence of domestic violence (DV) in Hunan. METHODS: Using a multi-stage sampling strategy, 9451 households involving 32 720 persons in urban, rural and industrial areas in Hunan, China were studied. Multiform clue investigation and face-to-face interviews were combined to investigate the prevalence of DV. RESULTS: A lifetime prevalence of DV was reported by 1533 households (16.2%). A total of 1098 households (11.6%) reported at least one incident of DV in the previous year. Both lifetime and 12-month prevalence of DV varied significantly by geographic setting (P < 0.01). The lifetime prevalence abuse rates were: spousal 10.2%, child abuse 7.8%, and elder 1.5%. With regard to household structure, the lifetime prevalence of DV was highest among those remarried families (21.0%), followed by married couples with one child and extended families with several generations living together (20.1% and 20.0%, respectively). The highest rate of spousal abuse was found among remarried families (14.7%), while child and elder abuse was most prevalent among extended families (12.4% and 4.1%, respectively). CONCLUSIONS: The findings suggested that although the prevalence of DV in Hunan was modest compared to Western countries, it remained a serious public health problem affecting over 1 in 10 households. Furthermore, the prevalence of various types of DV varied by geographic setting and family structure, suggesting that diverse geographic setting and family constellations carried different risk and protective features.

Aged↗

PubMed2005

Activation of Notch1 signaling is required for beta-catenin-mediated human primary melanoma progression.

Notch is a highly conserved transmembrane receptor that determines cell fate. Notch signaling denotes cleavage of the Notch intracellular domain, its translocation to the nucleus, and subsequent activation of target gene transcription. Involvement of Notch signaling in several cancers is well known, but its role in melanoma remains poorly characterized. Here we show that the Notch1 pathway is activated in human melanoma. Blocking Notch signaling suppressed whereas constitutive activation of the Notch1 pathway enhanced primary melanoma cell growth both in vitro and in vivo yet had little effect on metastatic melanoma cells. Activation of Notch1 signaling enabled primary melanoma cells to gain metastatic capability. Furthermore, the oncogenic effect of Notch1 on primary melanoma cells was mediated by beta-catenin, which was upregulated following Notch1 activation. Inhibiting beta-catenin expression reversed Notch1-enhanced tumor growth and metastasis. Our data therefore suggest a beta-catenin-dependent, stage-specific role for Notch1 signaling in promoting the progression of primary melanoma.

Animals↗

PubMed2005

Chaos in an electromagnetically induced transparent medium inside an optical cavity.

We theoretically predict and experimentally demonstrate chaotic behaviors in a system comprising of three-level atoms inside an optical ring cavity. This electromagnetically induced transparency (EIT) system is driven to chaos through period-doubling route by reducing the frequency detuning of the coupling laser beam. The chaos occurs in a different parametric regime as previously predicted and is believed to be caused by the enhanced dispersion and nonlinearity due to induced atomic coherence in such EIT system.

Journal Article↗

PubMed2005

Dynamical hysteresis in a three-level atomic system.

We have experimentally investigated dynamical hysteresis behavior by changing the sweeping frequency of the cavity input field in the optical bistability of rubidium atoms (in a three-level atomic-type configuration) inside an optical cavity. The shape, width (or area), and direction of the hysteresis cycle are sensitive functions of the sweeping frequency for such an optical bistable system.

Journal Article↗

PubMed2005

All-optical switching and routing based on an electromagnetically induced absorption grating.

An electromagnetically induced absorption grating is formed in a three-level atomic vapor under the condition of electromagnetically induced transparency in which the strong coupling beam is replaced by a standing wave. The transmission and reflection behaviors of the weak probe beam are greatly modified at certain frequencies near the two-photon resonance. An all-optical two-port signal router-all-optical switch is demonstrated.

Journal Article↗

PubMed2005

Photoluminescence intermittency of InGaAs/GaAs quantum dots confined in a planar microcavity.

Photoluminescence intermittency, or "blinking", was observed in semiconductor InGaAs/GaAs quantum dots (QDs) inside a planar microcavity. Most of the blinking QDs were found around defect sites such as dislocation lines naturally formed in the GaAs barrier layers, and the carrier traps responsible for blinking had an excitation threshold of approximately 1.53 eV. The blinking properties of epitaxial QDs and colloidal nanocrystal QDs were also compared by performing laser intensity dependent measurements and statistics of the "on" and "off" time distributions.

Journal Article↗

PubMed2005

[Research progresses on deformable model in medical image processing].

In recent years, image processing technique based on deformable models has been widely used in the field of medical image processing and analysis. This survey demonstrates the principle of two kinds of basic deformable models, i.e. parametric deformable model and geometric deformable model. The design of model in application is also discussed. By incorporating prior knowledge and modeling global properties, several new extensions of basic deformable model are then reviewed. At last, some prospects of possible research are given.

Computer Simulation↗

PubMed2005

Transforming growth factor-beta1 gene polymorphisms associated with chronic obstructive pulmonary disease in Chinese population.

AIM: To determine the frequencies of polymorphism and haplotype in the transforming growth factor-beta 1 (TGF-beta1) gene promoter in the Chinese population and to investigate the susceptibility of this population to chronic obstructive pulmonary disease (COPD). METHODS: The target fragments of the TGF-beta1 gene promoter were amplified and analyzed by polymerase chain reaction-restriction fragment length polymorphism technique in 84 COPD patients and 97 age- and sex-matched healthy controls. The test for Hardy-Weinberg equilibrium was performed using HWE program of the LINKUTIL package and statistical analysis was carried out with the SPSS statistical package. An expectation maximization algorithm was used for the pairwise linkage disequilibrium test and haplotype analysis. RESULTS: More carriers of the -800A allele, or fewer carriers of the -509T allele, were detected in the COPD patients compared with the non-symptomatic control subjects [for the -800A allele, 29.8% vs 14.4%, respectively, Chi2=6.257, degrees of freedom (df)=1, P=0.012; for the -509T allele, 27.3% vs 44.3%, respectively, Chi2=5.582, df=1, P=0.018]. The prevalence of the -800A allele was significantly higher in the COPD patients than in control subjects (P=0.009), whereas the frequency of the -509T allele was significantly higher in control subjects than in the COPD patients (P=0.008). In addition, this distribution tendency for the -800A or -509T allele was similar in heavy smokers (smoking history >20 pack years); (number of packs of cigarettes per day multiplied by the number of years of smoking) Chi2=7.235, P=0.007, and Chi2=5.636, P=0.018, respectively). The linkage disequilibrium was found between -800 G-A and -509 C-T (D>0.60, P<0.0001), and the frequency of the AC haplotype, consisting of the least common base at -800 and the most common base at -509, was significantly higher in patients with COPD than in controls (0.056 vs 0.021, P<0.05). CONCLUSIONS: The single nucleotide polymorphism (SNP) in the TGF-beta1 gene promoter might be associated with COPD, and the -800A/-509C haplotype is possibly one of the susceptibility factors for COPD.

Aged↗

PubMed2005

[High expression of alpha-D-galactosidase gene (aga1) of Bifidobacterium breve 203 in Escherichia coli].

Alpha-D-galactosidase gene (agal) of Bifidobacterium breve 203 was cloned into temperature expression vector pBV220 and transformed into E. coli. The recombinant plasmid pBVagal was induced to express with temperature. The specific activities of recombinant enzyme Agal in E. coli DH5alpha, E. coli DH10B and E. coli BL21 were 28.08 U/mg, 19.44 U/mg and 13.85 U/mg, respectively. The recombinant plasmid pBVagal is more stable in E. coli BL21. The molecular weight of Agal as determined by SDS-PAGE was about 67 kD. The optimum pH of Agal was pH 4.0-4.4, and it was stable between pH 3.6 and 6.0 (kept at 4 degrees C overnight). The optimum temperature of Agal was 45 degrees C, and it was stable below 40 degrees C (incubated for 30 min). Km-values for p-nitrophenyl-alpha-galactopyranoside (pNPGal) and melibiose were calculated with 1.43 mmol/L and 261 mmol/L, respectively. No transgalactosylation activity was found when Agal hydrolyzed melibiose or raffinose. The results suggest that Agal is much different from reported alpha-D-galactosidase from Bi. breve 203. Agal is another kind of alpha-D-galactosidase in the same bifidobacteria strain.

Bifidobacterium↗