The accumulation of tumour-associated macrophages (TAMs) in the hypoxic tumour microenvironment (TME) is associated with malignant progression in cancer. However, the mechanisms by which the hypoxic TME facilitates TAM infiltration are not fully understood. This study showed that high ZEB1 expression in hypoxic cervical cancer cell islets was positively correlated with CD163
Cancer-secreted exosomal miRNAs are emerging mediators of cancer-stromal cross-talk in the tumor environment. Our previous miRNAs array of cervical squamous cell carcinoma (CSCC) clinical specimens identified upregulation of miR-221-3p. Here, we show that miR-221-3p is closely correlated with peritumoral lymphangiogenesis and lymph node (LN) metastasis in CSCC. More importantly, miR-221-3p is characteristically enriched in and transferred by CSCC-secreted exosomes into human lymphatic endothelial cells (HLECs) to promote HLECs migration and tube formation in vitro, and facilitate lymphangiogenesis and LN metastasis in vivo according to both gain-of-function and loss-of-function experiments. Furthermore, we identify vasohibin-1 (VASH1) as a novel direct target of miR-221-3p through bioinformatic target prediction and luciferase reporter assay. Re-expression and knockdown of VASH1 could respectively rescue and simulate the effects induced by exosomal miR-221-3p. Importantly, the miR-221-3p-VASH1 axis activates the ERK/AKT pathway in HLECs independent of VEGF-C. Finally, circulating exosomal miR-221-3p levels also have biological function in promoting HLECs sprouting in vitro and are closely associated with tumor miR-221-3p expression, lymphatic VASH1 expression, lymphangiogenesis, and LN metastasis in CSCC patients. In conclusion, CSCC-secreted exosomal miR-221-3p transfers into HLECs to promote lymphangiogenesis and lymphatic metastasis via downregulation of VASH1 and may represent a novel diagnostic biomarker and therapeutic target for metastatic CSCC patients in early stages.
Abstract The activation of stromal fibroblasts into cancer-associated fibroblasts (CAFs) has been suggested to promote primary tumor growth and progression; however, the mechanisms underlying the crosstalk between tumors and fibroblasts that drives stromal heterogeneity remain unknown. Here, we show that high Wnt2B levels were positively correlated with the number of CAFs in cervical cancer (CC). More importantly, Wnt2B was characteristically enriched in CC cell-secreted exosomes and transferred into fibroblasts to promote fibroblast activation via Wnt/β-catenin signaling, and inhibiting exosomal release or the Wnt/β-catenin signaling pathway diminished the activation induced by exosomal Wnt2B. Moreover, circulating exosomal Wnt2B also promoted CAF conversion in vitro and its expression was significantly higher in CC patients. In conclusion, our findings indicate that CC cell-derived Wnt2B can induce the activation of fibroblasts into CAFs, mainly via exosome-dependent secretion, thus providing directions for the development of diagnostic and therapeutic targets for CC progression.
To investigate the correlation between tumor-associated macrophages (TAMs) and the development of high risk human papilloma virus (hr-HPV)-related cervical cancer.A total of 112 cases of cervical tissue were collected, including 16 normal cervical tissues, 55 cervical intraepithelial neoplasia (CIN) tissues and 41 squamous cervical cancer (SCC) tissues. The expression of CD163+ macrophages in the cervical tissues was detected by immunohistochemical method, and the results were analyzed in relation with the clinical data of the patients.Immunohistochemical analysis showed that the cell density of CD163+ macrophages increased progressively with the increase in the tissue malignancy, in the order of normal cervical tissue, CIN Ⅰ, CIN Ⅱ-Ⅲ, and SCC. Correlation analysis revealed a positive relationship between CD163+ macrophage density and tissue malignancy (P=0.000). The density of CD163+ macrophages was significantly upregulated in HR-HPV-positive SCC tissue (P < 0.05). CD163+ macrophages were positively correlated with cervical lymph node metastasis (P=0.005) and FIGO stage (P=0.004) of SCC.The expression of CD163+ macrophages is positively correlated with malignant transformation of cervical tissues, and hr-HPV infection is significantly correlated with CD163 expression level in the macrophages. CD163+ macrophages can be used as predictors of the occurrence and progression of cervical cancer caused by hr-HPV infection.
Abstract MicroRNAs have implicated in the relapse and metastasis of cervical cancer, which is the leading cause of cervical cancer-related mortality. However, the underlying molecular mechanisms need further elucidation. Our present study revealed that miR-221-3p is transcriptionally promoted in metastatic cervical cancer tissues compared with non-metastatic cervical cancer tissues. Forced overexpression of miR-221-3p facilitated EMT and promoted cell migration and invasion in vitro and lymphatic metastasis in vivo . Twist homolog 2 (TWIST2) was found to be a key transcription factor binding to the promoter of miR-221-3p. Inhibitors of miR-221-3p drastically reduced the induction of EMT and decreased cell migration and invasion mediated by TWIST2. By combined computational and experimental approaches, THBS2 was recognized to be an important downstream target gene of miR-221-3p. In cervical cancer tissues, especially with lymphatic metastasis, miR-221-3p and TWIST2 were increased and THBS2 was decreased, suggesting that TWIST2 induces miR-221-3p expression and consequently suppresses its direct target THBS2 in lymphatic metastasis CC. Our findings uncover a mechanistic role for miR-221-3p in lymph node metastasis, suggesting that miR-221-3p is upregulated by the transcription factor TWIST2 and downregulates its target THBS2, which may potentially promote lymph node metastasis in cervical cancer.
Antigen-specific stem-like memory CD8+ T cells (Tscm) have a series of stem cell characteristics, including long-term survival, self-renewal, anti-apoptosis and persistent differentiation into cytotoxic T cells. The effective induction of tumor-specific CD8+ Tscm could persistently eradicate tumor in pro-tumor hostile microenvironment. This study was to investigate the role of CD40 in HPV16-specific CD8+ Tscm induction and its anti-tumor function. We found that CD40 activation accelerated vaccine-induced HPV16 E7-specific CD8+ Tscm formation. Comparing to other HPV-specific CD8+ T cells, CD8+ Tscm were found to be stronger and long-term anti-tumor function, in vivo and vitro, even in the adoptive cellular transferring model. Furthermore, high frequencies of Tscm might prevent the HPV infection to move on to the development of cancer. And the CD40 effect on Tscm involved Wnt/β-catenin activation. Our study suggest that CD40 activation supports the generation of tumor-specific CD8+ Tscm, thus providing new insight into cancer immunotherapy.
With increasing ambient wind speed, eddy currents appear near condenser cells, affecting the thermal-flow performance of a direct air-cooled condenser. To examine the impact of ambient wind on the eddy-current distribution of an air-cooling island, a 2 × 600 MW direct air-cooling unit in North China was studied. To compare a series of different inlet wind speeds, the temperature and pressure distribution and the mechanism of and variation in eddy currents were studied. Moreover, the effects of ambient wind speed on the inlet flow rate of an axial-flow fan cluster were examined. Numerical results show that with increasing ambient speed, the chance of hot-air plume generation increases, resulting in a reduction in heat-transfer volume and efficiency. Additionally, more negative-pressure areas are created near the condenser cells. Vortices appear in the condenser-cell flow field, gradually becoming larger. The mass-flow rate of the axial flow fan cluster exhibits a downward trend with increasing ambient speed.
Abstract Clinical response to immunotherapy is closely associated with the immunosuppressive tumour microenvironment (TME), and influenced by the dynamic interaction between tumour cells and lymphatic endothelial cells (LECs). Here, we show that high levels of miR-142-5p positively correlate with indoleamine 2,3-dioxygenase (IDO) expression in tumour-associated lymphatic vessels in advanced cervical squamous cell carcinoma (CSCC). The miR-142-5p is transferred by CSCC-secreted exosomes into LECs to exhaust CD8 + T cells via the up-regulation of lymphatic IDO expression, which was abrogated by an IDO inhibitor. Mechanistically, miR-142-5p directly down-regulates lymphatic AT-rich interactive domain-containing protein 2 (ARID2) expression, inhibits DNA methyltransferase 1 (DNMT1) recruitment to interferon (IFN)-γ promoter, and enhances IFN-γ transcription by suppressing promoter methylation, thereby leading to elevated IDO activity. Furthermore, increased serum exosomal miR-142-5p levels and the consequent IDO activity positively correlate with CSCC progression. In conclusion, exosomes secreted by CSCC cells deliver miR-142-5p to LECs and induce IDO expression via ARID2–DNMT1–IFN-γ signalling to suppress and exhaust CD8 + T cells. Our study suggests that LECs act as an integral component of the immune checkpoint(s) in the TME and may serve as a potential new target for CSCC diagnosis and treatment.
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