Microstructural Characterization and Magnetic, Dielectric, and Transport Properties of Hydrothermal La2FeCrO6 Double Perovskites.

Double perovskite La2FeCrO6 (LFCO) powders were synthesized via the hydrothermal method, which crystallized in an orthorhombic (Pnma) structure and exhibited a spherical morphology with an average particle size of 900 nm. Fourier transform infrared spectroscopy demonstrated the presence of fingerprints of vibrational modes of [FeO6] and [CrO6] octahedra in the powders. The XPS spectra revealed dual oxide states of Fe (Fe2+/Fe3+) and Cr (Cr3+/Cr4+) elements, and the oxygen element appeared as lattice oxygen and defect oxygen, respectively. The LFCO powders exhibited weak ferromagnetic behavior at 5 K with a Curie temperature of 200 K. Their saturation magnetization and coercive field were measured as 0.31 µB/f.u. and 8.0 kOe, respectively. The Griffiths phase was observed between 200 K and 223 K. A butterfly-like magnetoresistance (MR)-magnetic field (H) curve was observed in the LFCO ceramics at 5 K with an MR (5 K, 6 T) value of -4.07%. The temperature dependence of resistivity of the LFCO ceramics demonstrated their semiconducting nature. Electrical transport data were fitted by different conduction models. The dielectric behaviors of the LFCO ceramics exhibited a strong frequency dispersion, and a dielectric abnormality was observed around 260 K. That was ascribed to the jumping of electrons trapped at shallow levels created by oxygen vacancies. The dielectric loss showed relaxation behavior between 160 K and 260 K, which was attributed to the singly ionized oxygen vacancies.

Microstructural Characterization of the Sol-Gel-Derived Sr2CrReO6 Powders and Their Magnetic and Electrical Transport Properties.

The double-perovskite (DP) Sr2CrReO6 (SCRO) oxide has gained much attention due to its high Curie temperature (∼635 K), high spin polarization, and strong spin-orbit coupling, which provides promising potential for room-temperature spintronic devices. In this work, we report on microstructures of a set of sol-gel-derived SCRO DP powders and their magnetic and electrical transport properties. The SCRO powders crystallize into a tetragonal crystal structure (space group of I4/m). X-ray photoemission spectroscopy spectra verify that the rhenium ions possess variable valences (Re4+ and Re6+) in the SFRO powders while chromium ions are presented as Cr3+. Ferrimagnetic behavior was observed in the SFRO powders at 2 K, and the saturation magnetization was evaluated to be 0.72 µB/f.u. and the coercive field to be 7.54 kOe. The Curie temperature was derived from susceptibility measurements to be 656 K at 1 kOe. Such ferrimagnetic behavior stems from the Cr3-Re4+(Re6+) super exchange interaction via intervening oxygen. Electrical transport measurements revealed that the SFRO ceramic grains were semiconducting and the electrical transport process was governed by the small polarons hopping with variable ranges. The hopping paths for these small polarons are provided by the hetero-valent Re ions in the SCRO ceramics. Negative magnetoresistance (MR) was observed in the SCRO ceramics, and the plot of MR vs magnetic field (H) exhibited a butterfly-like shape. The MR (2 K, 6 T) was measured to be -5.3%, due to the intergranular magneto-tunneling effect. The present results demonstrate a unique combination of high-temperature ferrimagnetism and intrinsic semiconducting nature of the sol-gel-derived SCRO oxides, which are highly attractive for oxide spintronics.

The Interaction of Apelin and FGFR1 Ameliorated the Kidney Fibrosis through Suppression of TGFß-Induced Endothelial-to-Mesenchymal Transition.

Both epithelial-to-mesenchymal (EMT) and endothelial-to-mesenchymal (EndMT) transitions have shown to contribute to the development and progression of kidney fibrosis. It has been reported that apelin, a regulatory peptide, alleviates EMT by inhibiting the transforming growth factor ß (TGFß) pathway in renal diseases. Additionally, fibroblast growth factor receptor 1 (FGFR1) has been shown to be a key inhibitor of EndMT through suppression of the TGFß/Smad pathway. In this study, we found that apelin and FGFR1 were spatially close to each other and that the apelin and FGFR1 complex displayed inhibitory effects on TGFß/Smad signaling as well as associated EndMT in diabetic kidney fibrosis. In cultured human dermal microvascular endothelial cells (HMVECs), we found that the anti-EndMT and anti-TGFß/Smad effects of apelin were dampened in FGFR1-deficient cells. Either siRNA- or an inhibitor-mediated deficiency of apelin induced the Smad3 phosphorylation and EndMT. Streptozotocin-induced CD-1 diabetic mice displayed EndMT and associated kidney fibrosis, which were restored by apelin treatment. The medium from apelin-deficient endothelial cells stimulated TGFß/Smad-dependent EMT in cultured HK2 cells. In addition, depletion of apelin and the FGFR1 complex impaired CEBPA expression, and TGFß-induced repression of CEBPA expression contributed to the initiation of EndMT in the endothelium. Collectively, these findings revealed that the interaction between apelin and FGFR1 displayed renoprotective potential through suppression of the TGFß/Smad/CEBPA-mediated EndMT/EMT pathways.

Circ_100395 impedes malignancy and glycolysis in papillary thyroid cancer: Involvement of PI3K/AKT/mTOR signaling pathway.

Circular RNAs (circRNAs) play critical roles in cancer procession, including papillary thyroid cancer (PTC). Despite of published reports regarding the abnormal downregulation of circ_100395 in PTC, the role and regulatory mechanism of which are still undiscovered. Circ_100395 expression was examined via qRT-PCR. Cell growth was detected by the CCK-8 and colony formation, BrdU incorporation and flow cytometry assays. Cell migration and invasion were measured using transwell assays. Aerobic glycolysis was analyzed by the glucose uptake and lactate production. Immunoblotting was performed to evaluate the associated proteins. Decreased circ_100395 expression was shown in PTC tissues and cell lines. Circ_100395 overexpression significantly reduced aerobic glycolysis and the survival, migration and invasion abilities and downregulated phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, which were reversed by the PI3K activator 740Y-P. Our data demonstrated that circ_100395 may play an anti-oncogenic role in PTC cells through the inhibition of PI3K/AKT/mTOR signaling pathway.

Circ_0000267 promotes gastric cancer progression via sponging MiR-503-5p and regulating HMGA2 expression.

BACKGROUND: Circular RNAs (circRNAs) are a class of newly discovered RNAs that attach great importance to modulate gene expression and biological function. Nonetheless, in gastric cancer (GC), the expression and function of circRNA are much less explored. In this study, circ_0000267 expression in GC was investigated and the function and mechanism of circ_0000267 was probed. MATERIALS AND METHODS: Quantitative real-time PCR (qRT-PCR) was employed to detect circ_0000267, miR-503-5p, and HMGA2 expression. Immunohistochemistry and western blot were adopted to detect HMGA2 and epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin and N-cadherin) expression in GC tissues and cells, respectively. GC cell lines with circ_0000267 overexpressed and knocked down were constructed, and CCK-8 assay, BrdU assay, scratch healing assay, and transwell assay were employed to assess the effect of circ_0000267 on the proliferation and metastasis of GC cells. Besides, dual-luciferase reporter gene assay was adopted to verify the targeting relationship between circ_0000267 and miR-503-5p. RESULTS: Circ_0000267 showed a significant upregulation in GC tissues and cell lines, and its high expression level was extremely linked to the increased tumor diameter and local lymph node metastasis. Circ_0000267 overexpression accelerated GC cell proliferation, metastasis, and EMT processes, while knocking down circ_0000267 led to the opposite effect. From the perspective of mechanism, circ_0000267 promoted the progression of GC through adsorbing miR-503-5p and upregulating HMGA2 expression. CONCLUSION: Circ_0000267 is an oncogenic circRNA that affects the progression of GC, which participates in promotion of GC proliferation, migration, invasion, and EMT via modulating the miR-503-5p/HMGA2 axis.

[Advances in copepod resting egg ecology in estuarine and coastal waters].

Copepods are the key group in aquatic ecosystems, and play an important role in energy flow, the cycle of materials and information transfer. This paper summarized the distribution and composition of the copepods that spawn resting eggs in the estuarine and coastal marine areas. It also reviewed the survival time, hatching rates, abundance of resting eggs in the sediments, and the potential recruitment into the plankton population as correlated with environmental factors. The prospects of copepod resting egg ecology were also proposed in order to provide new ideas for future research.

XRCC1 polymorphisms and lung cancer risk in Caucasian populations: a meta-analysis.

X-ray repair cross-complementing group 1 (XRCC1) plays an important role in the base excision repair. Many studies have reported the association of XRCC1 Arg399Gln, Arg194Trp and Arg280His polymorphisms with lung cancer risk, but the results remained controversial. In this meta-analysis, we performed a meta-analysis of ten published case-control studies in Caucasian populations to investigate the associations between lung cancer risk and XRCC1 Arg399Gln (2187 cases and 3453 controls from ten studies), Arg194Trp (857 cases and 2108 controls from six studies) and Arg280His (894 cases and 1133 controls from five studies). The results in total population showed that XRCC1 codon 399 polymorphism (OR=0.93, 95% CI=0.82-1.04) and codon 194 (OR=0.94, 95% CI=0.73-1.21) was significantly associated with lung cancer risk. However, no association was found between lung cancer risk and codon 280 (OR=1.17, 95% CI=0.89-1.54). In conclusion, this meta-analysis has demonstrated that codon 399 and codon 194 might have contributed to individual susceptibility to lung cancer in Caucasian populations. To further evaluate effect of XRCC1 polymorphisms, large studies with thousands of subjects are required to get conclusive results.

Screening feature genes of lung carcinoma with DNA microarray analysis.

Lung carcinoma is the most common and aggressive malignant tumor with poor clinical outcome. Identification of new marker of lung cancer is essential for the diagnosis and prognosis of the disease. To identify differentially expressed genes (DEGs) and find associated pathways that may function as targets of lung cancer. Gene expression profiling of GSE40791 were downloaded from GEO (Gene Expression Omnibus), including 100 normal specimens and 94 lung cancer samples. The DEGs were screened out by LIMMA package in R language. Besides, novel genes associated with lung cancer were identified by co-expression analysis. Then, GO enrichment and transcription binding site analysis were performed on these DEGs, and novel genes were predicted using DAVID. Finally, PPI network was constructed by String software in order to get the hub codes involved in cancer carcinoma. A total of 541 DEGs were filtered out between normal samples and patients with lung carcinoma, including 155 up-regulated genes and 386 down-regulated genes. Additionally, nine novel genes, CA4, CDC20, CHRDL1, DLGAP5, EMCN, GPM6A, NUSAP1, S1PR1 and TCF21, were figured out. The transcription biding site analysis showed that these genes were regulated by LHX3, HNF3B, CDP, HFH1, FOXO4, STAT, SOX5, MEF2, FOXO3 and SRY. Hub codes as BUB1B, MAD2L and TOP2A may play as target genes in lung carcinoma in the result of PPI network analysis. Newly predicted genes and hub codes can perform as target genes for diagnose and clinical therapy of lung cancer.

Effect of HER-2/neu over-expression on prognosis in gastric cancer: a meta-analysis.

BACKGROUND: Her-2/neu is the most frequently studied molecular target in gastric cancer but its prognostic impact is still equivocal. We therefore conducted a meta-analysis to more precisely estimate its prognostic significance. METHODS: Published studies that investigated between Her-2/neu status and survival were identified. Meta-analysis was performed by Dersimonian-Laird model. Pooled hazard ratio (HR) and its 95% confidence interval (95%CI) were calculated to evaluate the risk of disease. RESULTS: A total of 19 studies were analyzed by meta-analysis method, cumulative 4342 cases were included. Pooled data of 15 studies using univariate analysis showed worse survival of patient with her-2/neu (+) (pooled HR=1.59, 95%CI: 1.20-2.12), which maintained in 7 studies of multivariate analysis (pooled HR=1.58, 95%CI: 1.18-2.12). The Q statistic test for 15 studies of univariate analysis and for 7 studies of multivariate analysis showed they had heterogeneity (Q=26.98, p=0.019, Q=17.76, p=0.007, respectively). CONCLUSION: HER-2/neu over-expression is related to poor prognosis of gastric cancer but has a modest effect on survival in gastric cancer as an independent prognosis factor.

[Increased coronin-1C expression is related to hepatocellular carcinoma invasion and metastasis].

OBJECTIVE: To search for hepatocellular carcinoma (HCC) invasion related biomarkers using the cell membrane proteomics approaches, and to validate the markers using experimental and clinical specimens. METHODS: The HCCLM9 and MHCC97L cells with a similar genetic background and remarkably different metastasis behaviors were used for comparative membrane proteome profiling using sodium dodecyl sulfate polyacrylamide gel electrophoresis and electrospray ionization mass spectrometry technologies. Candidate protein makers were further validated by western blot on cells, immunohistochemistry (IHC) on animal tumor tissues, and tissue micro-array on clinical specimens. RESULTS: The membrane proteins of MHCC97L and HCCLM9 cells were compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses. 14 proteins were identified by ESI-MS/MS among the differential bands. Coronin-1C was overexpressed in HCCLM9 (7.31+/-0.73) versus MHCC97L (2.84+/-0.99) validated by western blot. Elevated coronin-1C expression was observed in liver cancer tissues of HCCLM9 nude mice. IHC study in 115 human HCC specimens demonstrated that patients with higher coronin-1C expression had more advanced stage. CONCLUSION: The study suggests that coronin-1C could be a potential molecule to predict HCC invasive behavior.

Coronin-1C is a novel biomarker for hepatocellular carcinoma invasive progression identified by proteomics analysis and clinical validation.

BACKGROUND: To better search for potential markers for hepatocellular carcinoma (HCC) invasion and metastasis, proteomic approach was applied to identify potential metastasis biomarkers associated with HCC. METHODS: Membrane proteins were extracted from MHCC97L and HCCLM9 cells, with a similar genetic background and remarkably different metastasis potential, and compared by SDS-PAGE and identified by ESI-MS/MS. The results were further validated by western blot analysis, immunohistochemistry (IHC) of tumor tissues from HCCLM9- and MHCC97L-nude mice, and clinical specimens. RESULTS: Membrane proteins were extracted from MHCC97L and HCCLM9 cell and compared by SDS-PAGE analyses. A total of 14 differentially expressed proteins were identified by ESI-MS/MS. Coronin-1C, a promising candidate, was found to be overexpressed in HCCLM9 cells as compared with MHCC97L cells, and validated by western blot and IHC from both nude mice tumor tissues and clinical specimens. Coronin-1C level showed an abrupt upsurge when pulmonary metastasis occurred. Increasing coronin-1C expression was found in liver cancer tissues of HCCLM9-nude mice with spontaneous pulmonary metastasis. IHC study on human HCC specimens revealed that more patients in the higher coronin-1C group had overt larger tumor and more advanced stage. CONCLUSIONS: Coronin-1C could be a candidate biomarker to predict HCC invasive behavior.

Quantum dots-based immunofluorescence technology for the quantitative determination of HER2 expression in breast cancer.

HER2 detection is important for breast cancer (BC) treatment and prognosis, but the detection methods currently used have some disadvantages. Quantum dots (QDs)-based probes provide a potentially important new method for HER2 detection in clinical practice. This potential is examined in this paper. A QDs HER2 probe kit and QDs image acquisition and analysis software were developed and applied to 94 clinical samples of BC. Compared to conventional immunohistochemistry techniques, this method provided a superior accurate and sensitive method for the detection of HER2 in clinical breast cancer diagnosis.

Evaluation of tumor markers biochip C12 system in the diagnosis of gastric cancer and the strategies for improvement: analysis of 100 cases.

BACKGROUND/AIMS: A C12 biochip system using 12 tumor markers has been developed in China for serum diagnosis of common cancers. This work is to evaluate this C12 system in the diagnosis of gastric cancer. METHODOLOGY: Sera from 100 gastric carcinoma patients were screened for 12 tumor markers including carcinoembryonic antigen, alpha-fetoprotein, carbohydrate antigen 19-9, carbohydrate antigen 242, cancer antigen 15-3, cancer antigen 125, prostate specific antigen, free-PSA, neuron-specific enolase, human chorionic gonagotropin-beta, human growth hormone, and ferritin, using the C12 biochip system. The most relevant tumor marker and the contribution of the tumor markers to the improvement of diagnosis were determined. RESULTS: The overall diagnostic rate of C12 biochip system was 37%, and 7.8%, 29.4%, 35.5% and 50%, respectively, for stages I, II, III and IV patients. The differences in diagnostic rates between stage I (7.8%) and stage IV (50%) reached statistical significance (chi-square test, Chi2=7.20, p<0.01). Among all the 12 markers, carbohydrate antigen 19-9 had the highest positive rate up to 23%, against which any form of combinations of 5 most relevant tumor markers (2, 3, 4 or 5 markers combined) could not significantly improve the diagnostic rate. CONCLUSIONS: The C12 biochip system has some value in the diagnosis of advanced stage gastric cancer, but less sensitive in early gastric cancer.

The biocompatibility of quantum dot probes used for the targeted imaging of hepatocellular carcinoma metastasis.

Semiconductor quantum dots (QDs) have several photo-physical advantages over organic dyes making them good markers in biomedical application. We used CdSe/ZnS QDs with maximum emission wavelength of 590nm (QD590) linked to alpha-fetoprotein (AFP) monoclonal antibody (Ab) to detect AFP in cytoplasm of human hepatocellular carcinoma (HCC) cell line HCCLM6. For the in vivo studies, we used QD-AFP-Ab probes for targeted imaging of human HCC xenograft growing in nude mice by injecting them into the tail vein. In addition, the cytotoxicity in vitro, the acute toxicity in vivo, the hemodynamics and tissue distribution of these probes were also investigated. The results in vitro and in vivo indicate that our QD-based probes have good stability, specificity and biocompatibility for ultrasensitive fluorescence imaging of molecular targets in our liver cancer model system.

Intraperitoneal chemotherapy with hydroxycamptothecin reduces peritoneal carcinomatosis: results of an experimental study.

PURPOSE: We studied the efficacy and safety of intraperitoneal chemotherapy with hydroxycamptothecin (HCPT) for the treatment of peritoneal carcinomatosis in animal model. METHODS: Highly metastatic human hepatocellular carcinoma (HCC) cell line HCCLM3 was injected into the peritoneal cavity of 30 nude mice to construct a model of intraperitoneal carcinomatosis, which were randomized into a treatment group and a control group of 15 mice in each group. The former received intraperitoneal injections of HCPT at the dose of 2 mg/kg body weight for 7 days every other week, on weeks 2, 4 and 6; and the latter received the same dose schedule treatment of 0.9% sodium chloride solution. The mice were observed for 8 weeks. Body weight changes, intraperitoneal carcinomatosis, hematological and biochemical parameters were evaluated. RESULTS: On day 56, 14 mice in the treatment group were still alive, compared against 5 in the control group, and the mean survival time was 55 +/- 1 days [95% confidence interval (CI) 54-57 days] versus 43 +/- 4 days (95% CI 34-51 days) (P = 0.002). The tumor weight in the treatment group (0.8 +/- 0.8 g) was significantly smaller than the control group (2.0 +/- 0.8 g) (P = 0.00028). No bloody ascites or diffuse peritoneal carcinomatosis were observed in the treatment group, as compared with 4 mice (26.7%) that developed bloody ascites and 6 mice (40%) which developed diffuse peritoneal carcinomatosis in the control group (P < 0.001). The treatment group had a significantly lower peripheral white blood cell count [(3.18 +/- 1.72) x 10(9) l(-1)] than the control group [(5.08 +/- 2.03) x 10(9 )l(-1)] (P < 0.05), significantly lower serum alpha fetoprotein level (101.22 +/- 20.12 microg/l) than the control group (244.87 +/- 30.24 microg/l) (P < 0.05), and significantly lower serum gamma glutamyl transpeptidase level (12.45 +/- 2.26 U/l) than the control group (20.75 +/- 3.87 U/l) (P < 0.05). No obvious treatment related toxicities were observed. CONCLUSIONS: Intraperitoneal injection of HCPT could inhibit tumor progression, reduce the extent of peritoneal carcinomatosis and improve survival of tumor bearing mice.

[In-vivo targeted imaging of hepatocellular carcinoma in nude mice using quantum dot probes].

OBJECTIVE: To explore in-vivo targeted imaging techniques for liver cancer detection using quantum dots (QDs) labeled probes in a nude mouse model of human hepatocellular carcinoma. METHODS: Mercaptoacetic acid (MAA) modified QDs were linked to mouse-anti-human alpha-fetoprotein (AFP) monoclonal antibody to form water soluble QD-AFP-Ab probes, which were validated by spectra analyses and transmission electron microscope. The probes were firstly used to detect AFP antigen in human hepatocellular carcinoma cell line HCCLM6 in-vitro by one-step immunofluorescence method. In-vivo tumor xenografts and lung metastases models were then established by inoculation of HCCLM6 cells subcutaneously and into the tail vein of nude mice, respectively. QD-AFP-Ab probes were injected into the tail vein of the tumor bearing mice for live animal fluorescence imaging. Spectra of tumor and normal tissue were analyzed under illumination of Ti: sapphire laser. Serum levels of alanine amino transferase, aspartate amino transferase, blood urea nitrogen and creatinine were determined by conventional biochemical analysis. The liver, spleen, lungs, kidneys, heart and brain of the experimental nude mice were investigated for nonspecific uptake of the probes by confocal microscope. RESULTS: The QD-AFP-Ab probes had broad excitation spectra and high fluorescence intensity. They could specifically and efficiently recognize AFP antigen in hepatocellular carcinoma cells. Tumor targeting imaging using these probes were successful without any acute toxicity to the experimental animals. Spectra analysis showed that the probes per field were lower in the centre than the periphery of the tumor. Non-specific uptake of QD-AFP-Ab probes occurred mainly in the liver, spleen and lungs. CONCLUSIONS: QD-AFP-Ab probes have good optical properties and biocompatibility for in-vivo targeted imaging of hepatocellular carcinoma. Such approach promises to be highly desirable for molecular targeted research of liver cancer.

Immunofluorescence detection with quantum dot bioconjugates for hepatoma in vivo.

The use of highly specific and highly sensitive immunofluorescent probes is a promising approach for biomedical imaging in living tissue. We focus on immunofluorescence with quantum dot bioconjugates for hepatoma detection in vivo. We synthesized specific immunofluorescent probes by linking quantum dots to AFP (alpha-fetoprotein) antibody for specific binding AFP-an important marker for hepatocellular carcinoma cell lines. In in vivo studies, the characteristic quantum dot (QD) fluorescent property is exhibited by the QDs-Anti-AFP probes in tumor and they demonstrate active tumor targeting and spectroscopic hepatoma imaging with an integrated fluorescence imaging system. We investigate the inhomogeneous distribution of the QDs-Anti-AFP probes in tumor by using a site-by-site measurement method to test their ability for distribution studies of cancer cells. These results demonstrate the practicality of QD bioconjugates as attractive fluorescent probes for biomedical detection.

Fluorescence analysis with quantum dot probes for hepatoma under one- and two-photon excitation.

A new class of fluorescent probe produced by conjugating semiconductor quantum dots (QDs) with protein molecule is proposed as an alternative to conventional organic labels. However the fluorescence characteristics of the QD bioconjugates are not clear while they are excitied with one- or two-photon laser pulse. We synthesized specific immunofluorescent probes by linking QDs to alpha fetoprotein (AFP) antibody for specific binding alpha-fetoprotein -an important marker for hepatocellular carcinoma cell lines, and archived specific fluorescence detection with the QDs-Anti-AFP in nude mice. Then, we have analyzed the fluorescence characteristics of QDs-Anti-AFP and original QDs both under one- and two-photon excitations. The results demonstrated that QDs-Anti-AFP's fluorescent spectral and lifetime haven't varied much from that of original QDs. Moreover, QDs-Anti-AFP have exhibited higher fluorescence efficiency than QDs under two-photon examination.

[Quantum dots and their applications in cancer research].

Quantum dots are semiconductor nanocrystals with physical dimensions smaller than the exciton Bohr radius. As their fluorescence emissions are size-tunable, we can acquire any spectrum from ultraviolet (UV) to near-infrared by changing the particles' radiuses. The large Stokes shifts of quantum dots can be used to further improve detection sensitivity. The luminescence intensity is high and stable. Single quantum dots have longer excited state lifetimes, and they appear 10-20 times brighter than organic fluorescent dyes. And they have good biocompatibility because quantum dots with appropriate shells don't interfere with physiological processes, such as growth, development, signaling and motility. With the development of optical labeling and imaging technology, many present conventional biomedical methods have limitations in microcosmic direct real-time researches of bio-molecular interactions and early diagnosis of malignant tumors. The invention of quantum dots and their biomedical applications make them as good markers for tumor cell tracing and targeting in cancer research, such as prostate cancer, mammary cancer, cervical cancer, basal cell carcinoma, liver cancer, and melanoma. The current research is focused on tumor markers imaging and molecular interaction based on tangible carriers such as cells and tissues. The next research orientation would be to tap the potential of this highly sensitive technology to image tumor biomarkers in serum and other body fluids, so as to increase the early diagnosis rate of malignant tumors.