Protein 4.1N is required for the formation of the lateral membrane domain in human bronchial epithelial cells

Plasmon Coupling Enhanced Micro-Spectroscopy and Imaging for Sensitive Discrimination of Membrane Domains of a Single Cell

Different cell membrane domains play different roles in many cell processes, and the discrimination of these domains is of considerable importance for the elucidation of cellular functions. However, the strategies available for distinguishing these cell membrane domains are limited. A novel technique called plasmon coupling enhanced micro-spectroscopy and imaging to discriminate basal and lateral membrane domains of a single cell combines the application of an additional plasmonic silver film for surface plasmon (SP) excitation to selectively excite and enhance the basal membranes in the near-field with directional enhanced microscopic imaging and spectroscopy. The SP and critical evanescent fields are induced upon excitation through a silver-coated semitransparent coverslip at the surface plasmon resonance and critical angles, respectively. The basal and lateral membrane domains located within the SP and critical evanescent fields can be selectively excited and distinguished by adjusting the incident angle of laser irradiation. Moreover, the brighter images and more intense spectra of membrane-targeting fluorescence-Raman probes under directional excitation than in conventional EPI mode allow clear identification of the membrane domains.

4.1N-Mediated Interactions and Functions in Nerve System and Cancer

Scaffolding protein 4.1N is a neuron-enriched 4.1 homologue. 4.1N contains three conserved domains, including the N-terminal 4.1-ezrin-radixin-moesin (FERM) domain, internal spectrin–actin–binding (SAB) domain, and C-terminal domain (CTD). Interspersed between the three domains are nonconserved domains, including U1, U2, and U3. The role of 4.1N was first reported in the nerve system. Then, extensive studies reported the role of 4.1N in cancers and other diseases. 4.1N performs numerous vital functions in signaling transduction by interacting, locating, supporting, and coordinating different partners and is involved in the molecular pathogenesis of various diseases. In this review, recent studies on the interactions between 4.1N and its contactors (including the α7AChr, IP3R1, GluR1/4, GluK1/2/3, mGluR8, KCC2, D2/3Rs, CASK, NuMA, PIKE, IP6K2, CAM 1/3, βII spectrin, flotillin-1, pp1, and 14-3-3) and the 4.1N-related biological functions in the nerve system and cancers are specifically and comprehensively discussed. This review provides critical detailed mechanistic insights into the role of 4.1N in disease relationships.

βII spectrin (SPTBN1): biological function and clinical potential in cancer and other diseases

βII spectrin, the most common isoform of non-erythrocyte spectrin, is a cytoskeleton protein present in all nucleated cells. Interestingly, βII spectrin is essential for the development of various organs such as nerve, epithelium, inner ear, liver and heart. The functions of βII spectrin include not only establishing and maintaining the cell structure but also regulating a variety of cellular functions, such as cell apoptosis, cell adhesion, cell spreading and cell cycle regulation. Notably, βII spectrin dysfunction is associated with embryonic lethality and the DNA damage response. More recently, the detection of altered βII spectrin expression in tumors indicated that βII spectrin might be involved in the development and progression of cancer. Its mutations and disorders could result in developmental disabilities and various diseases. The versatile roles of βII spectrin in disease have been examined in an increasing number of studies; nonetheless, the exact mechanisms of βII spectrin are still poorly understood. Thus, we summarize the structural features and biological roles of βII spectrin and discuss its molecular mechanisms and functions in development, homeostasis, regeneration and differentiation. This review highlight the potential effects of βII spectrin dysfunction in cancer and other diseases, outstanding questions for the future investigation of therapeutic targets. The investigation of the regulatory mechanism of βII spectrin signal inactivation and recovery may bring hope for future therapy of related diseases.

Identification and Functional Analysis of EPOR+ Tumor-Associated Macrophages in Human Osteosarcoma Lung Metastasis

Background

Tissue-resident macrophages can be educated to tumor-associated macrophages (TAMs) by the tumor microenvironment and many types of macrophages express erythropoietic receptor (EPOR); However, little is known about the expression of EPOR on TAMs and the identity of EPOR⁺ TAMs in osteosarcoma lung metastasis has thus far remained elusive.

Methods

EPOR-eGFPcre mice were used to determine the expression of EPOR on lung tissue-resident macrophages. Flow cytometry, RT-PCR, and Western blot were examined to define the identity of EPOR⁺ TAMs in 106 osteosarcoma lung metastasis specimens. Moreover, the clinicopathologic factors and prognosis of patients with CD163⁺EPOR⁺ macrophages were compared.

Results

We found that a subpopulation of mouse lung tissue-resident macrophages express EPOR and EPO enhances the proliferation of EPOR⁺ macrophages in mouse lung. A subpopulation of CD163⁺ macrophages expresses EPOR in human osteosarcoma lung metastasis specimens. CD163⁺EPOR⁺TAMs increase 2.5 times in human osteosarcoma lung metastasis tissues; CD206, CD163, and PD1, which are known to have a significant role in TAM function had high expression in CD163⁺EPOR⁺ TAMs compared with CD163⁺EPOR^- TAMs. Furthermore, CD163⁺EPOR⁺ TAMs had higher M2 marker and cytokine expression in osteosarcoma tissues compared with para-osteosarcoma tissues. EPO enhanced the expression of M2 cytokines in primary CD163⁺EPOR⁺ TAMs. Importantly, the percentage of CD163⁺EPOR⁺ TAMs had a positive linear association with malignant phenotypes as well as poor disease-free survival and overall survival time.

Conclusions

We have characterized TAMs expressing EPOR and CD163⁺EPOR⁺ macrophages as TAMs in osteosarcoma lung metastasis patients, which are highly associated with tumor aggressiveness.

PD1+ tumor associated macrophages predict poor prognosis of locally advanced esophageal squamous cell carcinoma

Aim: Tumor associated macrophages are the most abundant cancer immune cells. However, little was known about the identity of CD68⁺PD1⁺ macrophages as well as the contributions in the prognosis of esophageal squamous cell carcinoma (ESCC). Methods & methods: Immunofluorescence, flowcytometry and RT-PCR were used to analysis PD1⁺ macrophages in ESCC. Results: CD68⁺PD1⁺ macrophages which can express higher M2 markers in cancer tissues, increased about 4.2-times compared with para-cancer tissues. Additionally, PD1^high macrophages were significantly correlated with more malignant phenotypes and poor prognosis. PD1 treatment can enhance phagocytosis of cultured macrophages and redirect this macrophage to M1-like phenotype. Conclusion: Thus, our findings overall indicate that CD68⁺PD1⁺ macrophages are tumor associated macrophagess in ESCC, which can forecast the prognosis of ESCC.

Deguelin attenuates non-small cell lung cancer cell metastasis through inhibiting the CtsZ/FAK signaling pathway

Lung cancer is the leading cause of cancer-related death among both men and women every year, mainly due to metastasis. Although natural compound deguelin has been reported to inhibited cell migration and invasion in various cancer cells, the details of this regulation progress remain to be fully elucidated. In this study, we investigated the underlying mechanism of deguelin-suppressed metastasis of non-small cell lung cancer (NSCLC) cells. Our results demonstrate that deguelin inhibits NSCLC cell migration, invasion, and metastasis both in vitro and in vivo. These inhibitory effects of deguelin were mediated by suppressing of Cathepsin Z (CtsZ) expression and interrupting the interaction of CtsZ with integrin β3. Moreover, deguelin inhibits the activation of CtsZ downstream FAK/Src/Paxillin signaling. Knockdown of CtsZ mimicked the effect of deguelin on NSCLC cells migration and invasion. Our study reveals that deguelin exerts its anti-metastatic effect both in vitro and in vivo is partly dependent on the suppression of CtsZ signaling. Deguelin would be a potential anti-metastasis agent against NSCLC.