Background/Aims: Targeting cancer stem cells (CSCs) is emerging as a promising method for cancer treatment. We previously indicated that knockdown of Neuropilin 1(NRP-1) could inhibit breast cancer cell proliferation. Here, we continue exploring the roles and mechanisms of VEGF-A/NRP-1 axis in breast CSCs formation. Methods: qRT-PCR was used to detect the levels of VEGF-A and NRP-1 in breast cancer sphere cells and wild-type cells. Mammospheres formation, flow cytometry, soft agar colony and tumor formation assays were performed to evaluate the effects of VEGF-A/NRP-1 on breast cancer stemness. Further HUVECs tube formation, cell invasion assays were carried out to detect the effects of VEGF-A/NRP-1 on breast cancer spheres-induced angiogenesis. Finally, Annexin V/PI apoptosis and CCK8 assays were used to detect the effects of VEGF-A/NRP-1 on chemoresistance. Results: Overexpression of VEGF-A or NRP-1 conferred CSCs-related traits in MCF-7 cells, while knockdown of VEGF-A or NRP-1 reduced CSCs-related traits in MDA-MB-231 cells in vitro and in vivo. Notably, VEGF-A acted in a NRP-1 dependent way. Mechanistically, the VEGF-A/NRP-1 axis conferred CSCs phenotype via activating Wnt/β-catenin pathway. Conclusion: our results suggest that VEGF-A/NRP-1 axis could confer CSCs-related traits and chemoresistance.

Abstract. Previous studies have demonstrated that pluripotency-associated transcription factors, such as Oct3/4, Nanog and Sox2, play a crucial role in the development and malignant progression of various types of tumors. Breast cancer is the most frequent cancer among females, being a heterogeneous disease, with distinct morphologies, metastatic behavior and therapeutic responses. The expression of Oct3/4, Nanog and Sox2 in 3 human breast cancer cell lines, MCF7, T-47D and MDA-MB-231, was determined. The expression of Oct3/4, Nanog and Sox2 mRNA was determined by reverse transcription polymerase chain reaction (RT-PCR) and protein expression was detected by immunocytohistochemistry. RT-PCR revealed that all three human breast cancer cell lines tested expressed evident Oct3/4, Nanog and Sox-2 mRNA at various levels. Higher levels of Oct3/4 were identified in MCF7 and MDA-MB-231 cells compared with T-47D cells. Higher levels of Nanog were observed in MCF7 and T-47D cells compared with MDA-MB-231 cells and the highest expression of Sox-2 was detected in MCF7 cells. The nuclear localization of Oct3/4, Nanog and Sox-2 was confirmed by immunostaining. Oct3/4, Nanog and Sox2 were expressed in human breast cancer cell lines. Further studies are required to characterize the role of Oct3/4, Nanog and Sox2 in human breast cancer.

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Since most of the contact conduction type of heart sound sensors don’t take into account the acoustic signal attenuation problem caused by the heart sound signal transmitting to a sensor whose filling materials’ impedance is different to human soft tissue, the signal-to-noise ratio (SNR) of the heart sound sensors is not very well. Human heart is immersed in blood. If the sensor’s core sensitive element can be immersed in fluid, the attenuation of heart sound signal may be decreased greatly. Inspired by the principle of hydroacoustic signal’s detection, this paper proposes the design of heart sound sensor based on the bionic vector hydrophone. Then theoretical analysis and finite element method (FEM) simulation about the sensor have been carried out. Combined sensitivity with resonant frequency, the optimum dimension of the sensor’s structure has been determined. The sensor’s micro-structure has been fabricated by using Micro-Electro-Mechanical System (MEMS) technology and coupling encapsulated by choosing a kind of medical coupling agent as the filling material. Finally, the performance of the proposed sensor is tested. The fact is that the proposed sensor can work well with either healthy people or patients with heart disease. The obtained data clearly show that: the SNR of the proposed heart sound sensor is superior to 3200-type of 3M Littmann 8.2 dB.