Elucidation of individual Notch protein biology in specific cancer is crucial to develop safe, effective, and tumor-selective Notch-targeting therapeutic reagents for clinical use [1]. Here, we explored the Notch4 function in triple-negative breast cancer (TNBC). We found that silencing Notch4 enhanced tumorigenic ability in TNBC cells via upregulating Nanog expression, a pluripotency factor of embryonic stem cells. Intriguingly, silencing Notch4 in TNBC cells suppressed metastasis via downregulating Cdc42 expression, a key molecular for cell polarity formation. Notably, downregulation of Cdc42 expression affected Vimentin distribution, but not Vimentin expression to inhibit EMT shift. Collectively, our results show that silencing Notch4 enhances tumorigenesis and inhibits metastasis in TNBC, indicating that targeting Notch4 may not be a potential strategy for drug discovery in TNBC.

Cerebrospinal fluid-touching neurons (CSF-cNs) exist in the region surrounding the central canal of the spinal cord, which locate in the adult neurogenic niche. Previous research showed that CSF-cNs expressed the molecular markers of immature neural cells in vivo. Here, we explored the potential of CSF-cNs as neural stem cell in intro. We first found that PKD2L1⁺ CSF-cNs, isolating by FACS using the molecular marker PKD2L1 of CSF-cNs, expressed neural stem cells markers like Nestin, Sox2, and GFAP by immunofluorescence staining. PKD2L1⁺ CSF-cNs were able to form neurospheres and passaged in vitro. Immunofluorescence staining showed that the neurospheres forming by PKD2L1⁺ CSF-cNs also expressed neural stem cell markers Nestin, Sox2 and GFAP. The neurospheres expressed proliferation markers Ki67 and PCNA by immunofluorescence staining, indicating that the neurospheres forming by PKD2L1⁺ CSF-cNs were proliferative. The neurospheres, forming by CSF-cNs, had the ability of differentiation into neurons, astrocytes, and oligodendrocytes. Collectively, our data suggested that PKD2L1⁺ CSF-cNs have the properties of neural stem cells in vitro and may provide a promising approach for the repair of spinal cord injury.

The neural stem cells (NSCs) in the ventricular-subventricular zone of the adult mammalian spinal cord may be of great benefit for repairing spinal cord injuries. However, the sources of NSCs remain unclear. Previously, we have confirmed that cerebrospinal fluid-contacting neurons (CSF-cNs) have NSC potential in vitro. In this study, we verified the NSC properties of CSF-cNs in vivo. In mouse spinal cords, Pkd2l1⁺ CSF-cNs localized around the central canal express NSC markers. In vitro, Pkd2l1⁺ CSF-cNs form a neurosphere and express NSC markers. Activation and proliferation of CSF-cNs can be induced by injection of the neurotrophic factors basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) into the lateral ventricle. Spinal cord injury (SCI) also induces NSC activation and proliferation of CSF-cNs. Collectively, our results demonstrate that Pkd2l1⁺ CSF-cNs have NSC properties in vivo and may be involved in SCI recovery.

Asian Journal of Andrology,China

Chemotherapy resistance exposes patients to side effects and delays the effect of therapy in patients. So far, there are no predictive tools to predict resistance to chemotherapy and select sensitive chemotherapeutic drugs for the patient. Here, we aim to develop an in-vitro primary cell culture model from breast cancer patients to predict sensitivity to chemotherapy. We created the primary breast cancer cell medium BCMI and culture system with higher efficiency of the model establishment. Immunofluorescence staining of ERa, PR and HER2 were done to identify the primary breast cancer cell from the counterpart breast cancer patient. The killing assay showed that these primary breast cancer cells responded differently to doxorubicin and pirarubicin treatment. These results indicate that our established primary breast cancer cell model holds great promise for predicting breast cancer sensitivity to chemotherapy drugs.

Activating adult neural stem cells (NSCs) located within the spinal cord niche is considered a promising therapeutic approach for treating spinal cord injury (SCI). Cerebrospinal fluid (CSF)-contacting neurons expressing Pkd2l1 exhibit phenotypic and molecular traits similar to those of adult NSCs. However, the mechanism responsible for regulating the activation of Pkd2l1⁺ CSF-cNs still needs to be discovered. This research demonstrated that Pkd2l1⁺ CSF-cNs have a high concentration of vascular endothelial growth factor receptor 3 (Vegfr3) and that SCI results in elevated Vegfr3 levels. The overexpression of Vegfr3 in Pkd2l1⁺CSF-cNs induced potential NSC activation. Blocking Vegfr3 led to a significant reduction in the percentage of active Pkd2l1⁺ CSF-cNs, suggesting that Vegfr3 is involved in controlling the shift from dormancy to activation in these cells. In vivo, the downregulation of Vegfr3 by SAR131475 inhibited Pkd2l1⁺CSF-cN proliferation and maintained self-renewal. Injection of vascular endothelial growth factor C (Vegf-C) into the lateral ventricle of adult mice confirmed the involvement of Vegfr3 in activating Pkd2l1⁺ CSF-cNs. Vegf-C administration significantly increased the number of activated Pkd2l1⁺ CSF-cNs. Mechanistically, Vegfr3 primed quiescent Pkd2l1⁺ CSF-cNs for cell cycle reentry by enabling the activation of PI3K/Akt signaling. The activation of Vegfr3 may enhance SCI outcomes by promoting neuronal survival and facilitating the recovery of motor function in mice. Together, our findings highlight that Vegfr3 is a crucial functional regulator of Pkd2l1⁺ CSF-cNs, governing the transition from NSC quiescence to activation.