Down-regulation of SOX18 inhibits laryngeal carcinoma cell proliferation, migration, and invasion through JAK2/STAT3 signaling

TGF-β1-Induced SOX18 Elevation Promotes Hepatocellular Carcinoma Progression and Metastasis Through Transcriptionally Upregulating PD-L1 and CXCL12

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is characterized by an immune-suppressive microenvironment, which contributes to tumor progression, metastasis, and immunotherapy resistance. Identification of HCC-intrinsic factors regulating the immunosuppressive microenvironment is urgently needed. Here, we aimed to elucidate the role of SYR-Related High-Mobility Group Box 18 (SOX18) in inducing immunosuppression and to validate novel combination strategies for SOX18-mediated HCC progression and metastasis.

METHODS

The role of SOX18 in HCC was investigated in orthotopic allografts and diethylinitrosamine/carbon tetrachloride-induced spontaneous models by using murine cell lines, adeno-associated virus 8, and hepatocyte-specific knockin and knockout mice. The immune cellular composition in the HCC microenvironment was evaluated by flow cytometry and immunofluorescence.

RESULTS

SOX18 overexpression promoted the infiltration of tumor-associated macrophages (TAMs) and regulatory T cells (Tregs) while diminishing cytotoxic T cells to facilitate HCC progression and metastasis in cell-derived allografts and chemically induced HCC models. Mechanistically, transforming growth factor-beta 1 (TGF-β1) upregulated SOX18 expression by activating the Smad2/3 complex. SOX18 transactivated chemokine (C-X-C motif) ligand 12 (CXCL12) and programmed death ligand 1 (PD-L1) to induce the immunosuppressive microenvironment. CXCL12 knockdown significantly attenuated SOX18-induced TAMs and Tregs accumulation and HCC dissemination. Antagonism of chemokine receptor 4 (CXCR4), the cognate receptor of CXCL12, or selective knockout of CXCR4 in TAMs or Tregs likewise abolished SOX18-mediated effects. TGFβR1 inhibitor Vactosertib or CXCR4 inhibitor AMD3100 in combination with anti-PD-L1 dramatically inhibited SOX18-mediated HCC progression and metastasis.

CONCLUSIONS

SOX18 promoted the accumulation of immunosuppressive TAMs and Tregs in the microenvironment by transactivating CXCL12 and PD-L1. CXCR4 inhibitor or TGFβR1 inhibitor in synergy with anti-PD-L1 represented a promising combination strategy to suppress HCC progression and metastasis.

Downregulation of ITGA5 inhibits lymphangiogenesis and cell migration and invasion in male laryngeal squamous cell carcinoma

ITGA5, a fibronectin receptor was highly expressed in laryngeal squamous cell carcinoma (LSCC) samples and was related to poor survival. However, the potential mechanism remains unclear. To elucidate the regulatory role of ITGA5 in LSCC progression, we investigated the effect of ITGA5 expression on lymphangiogenesis, migration, and invasion of LSCC cells in vitro and in vivo using immunohistochemistry, siRNA transfection, qRT-PCR, western blotting, enzyme-linked immunosorbent assay, flow cytometry, transwell co-culture, tube formation, cell migration, and invasion assays, and a subcutaneous graft tumor model. The expression of ITGA5 was higher in the LSCC tissues and linked to lymph node metastasis and T staging. Moreover, ITGA5 expression was significantly positively correlated with VEGF-C expression, and the lymphatic vessel density of patients with high ITGA5 expression was noticeably higher than that of patients with low ITGA5 expression. Additionally, it was found in vitro that downregulation of ITGA5 expression not only inhibited the expression and secretion of VEGF-C, but also suppressed the tube-forming ability of human lymphatic endothelial cells (HLECs) and the migration and invasion ability of LSCC cells, while exogenous VEGF-C supplementation reversed these phenomena. Furthermore, a tumor xenograft assay showed that si-ITGA5 restrained the growth and metastasis of TU212-derived tumors in vivo. Our findings suggested that ITGA5 induces lymphangiogenesis and LSCC cell migration and invasion by enhancing VEGF-C expression and secretion.

Downregulation of miR-19a inhibits the proliferation and promotes the apoptosis of osteosarcoma cells by regulating the JAK2/STAT3 pathway

Osteosarcoma is a malignant tumor derived from the skeletal system, often occurring in bone tissues, and it is the most common malignant tumor in the skeletal system, with more than 90% of cases being highly malignant. The present study was designed to explore the regulatory effects of microRNA (miR)-19a on the proliferation and apoptosis of osteosarcoma cells, and its influence on the activation of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. The expression of miR-19a in adult SaOS-2 osteosarcoma cells was downregulated via lentiviral transfection, and the cells were divided into a control group, NC-inhibitor group and miR-19a-inhibitor group. The expression of miR-19a in each group was detected via quantitative polymerase Chain reaction (qPCR). Next, the cell proliferation and apoptosis levels in each group were detected via methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively, and the level of reactive oxygen species (ROS) in cells was further determined. Moreover, the expression levels of apoptosis-related proteins and JAK2/STAT3 signaling pathway-related proteins were detected through western blotting. The expression level of miR-19a in the miR-19a-inhibitor group was significantly lower than that in the control group and NC-inhibitor group (P<0.01). Downregulation of miR-19a significantly reduced the proliferation ability (P<0.01), increased the apoptosis level of SaOS-2 cells (P<0.01), and significantly increased the ROS level in cells (P<0.01). Downregulation of miR-19a also promote cleaved caspase-3/caspase-3 expression in the OS cells (P<0.01) and inhibited Bcl-2/Bax expression (P<0.01). Additionally, downregulation of miR-19a markedly lowered the protein expression levels of phosphorylated (p-)JAK2, p-STAT3 and myeloid cell leukemia-1 (Mcl-1) in the cells (P<0.01). To conclude, downregulation of miR-19a can inhibit the JAK2/STAT3 signaling pathway in SaOS-2 cells, promote the expression of apoptosis-related proteins, and increase the ROS level in cells, thereby promoting apoptosis and inhibiting cell proliferation.

Ephedrine causes retinal damage in SD rats associating with JAK2/STAT3 pathway

PURPOSE

Ephedrine has various side effects in the cardiovascular and nervous systems. However, the cellular mechanism of toxicity remains unknown, specifically on the retina. This study was to investigate effects of ephedrine on the retina and explore the underlying mechanisms.

METHODS

Sprague Dawley rats were treated with ephedrine (n = 10) or saline (n = 10) by oral gavage for seven days. The retinal morphology was evaluated by Toluidine blue staining. Apoptosis-related markers were detected in the retinal lysate. Enzyme-linked immunosorbent assays were used to measure neurotransmitters and oxidative stress markers. Real-time PCR and western blot were used to measure gene and protein expression, respectively.

RESULTS

Our results demonstrated that ephedrine induced apoptosis in the retina, increased dopamine level as well as oxidative stress, and down-regulated the Jak2/Stat3 gene expression as well as protein expression of p-JAK2/p-STAT3.

CONCLUSIONS

Our study indicated that ephedrine treatment caused retinal damage in SD rats, which may be associated with the JAK2/STAT3 pathway.

Significance of SOX18 expression in nonmelanoma skin cancers for prediction of high-risk patients: a preliminary study

BACKGROUND

SOX18 is an integral transcription factor that is involved in endothelial cells differentiation during both angiogenesis and lymphangiogenesis. Therefore, it has been implicated in tumor progression and metastasis.

OBJECTIVE

To study SOX18 expression in nonmelanoma skin cancers (NMSCs) in comparison to seborrheic keratosis (SK) and normal control skin, and to assess its probable role in tumor evolution and progression.

PATIENTS AND METHODS

This study was conducted on 60 specimens of NMSCs: 30 basal cell carcinomas (BCC) and 30 squamous cell carcinomas (SCC), 30 specimens of SK, and 30 normal skin specimens. All were examined for immunohistochemical expression of SOX18 antibody. Additionally, morphometric assessment of vessel density (blood & lymphatic) in each specimen was estimated.

RESULTS

Significant SOX18 overexpression was observed in all studied cutaneous tumors in comparison to control skin. The highest score of SOX18 expression was detected in SCC, then BCC, and the least expression was reported in SK with significant difference between them. Furthermore, significant upregulation of SOX18 expression was observed in high-risk types of both BCC and SCC compared to low-risk types. Stromal vessel density showed significant differences between the studied tumors with the highest mean value in SCC, followed by BCC and then SK. Positive correlation between SOX18 expression in the studied tumors and their vessel density was detected.

CONCLUSIONS

SOX18 may have a potential role in the evolution as well as progression of NMSCs, possibly through induction of both angiogenesis and lymphangiogenesis. Furthermore, it could be beneficial for prediction of NMSC patients with poor prognosis.

Long noncoding RNA LINC01194 enhances the malignancy of laryngeal squamous cell carcinoma by sponging miR-655 to increase SOX18 expression

Long noncoding RNAs (lncRNAs) have undergone a comprehensive study for their involvements in tumor treatments. The purpose of our study was to explore the biological effects and regulatory mechanisms of lncRNA LINC01194 (LINC01194) in laryngeal squamous cell carcinoma (LSCC). The levels of LINC01194 in 105 LSCC patients were detected by RT-qPCR. The diagnostic and prognostic value of LINC01194 in LSCC patients were statistically analyzed. The potential functions of LINC01194 in proliferation, apoptosis, and metastasis of LSCC cells were evaluated. The interaction among LINC01194, miR-655 and SOX18 was explored by bioinformatics analysis, luciferase reporter assays and biotinylated RNA pull-down. We found that the expression levels of LINC01194 were highly expressed in LSCC, which was negatively correlated with the clinical outcome of LSCC patients. The area under the ROC curve for LINC01194 was up to 0.8388. Functional assays indicated that LINC01194 knockdown distinctly inhibited LSCC cells proliferation, induced apoptosis, and also attenuated LSCC cells migration and invasion in vitro. Furthermore, we elucidated that LINC01194 promoted SOX18 expression in LSCC cells via functioning as a molecular sponge for miR-655. Overall, based on our findings, LINC01194 served as a tumor promoter and potentially represents a novel prognostic indicator and therapeutic target in LSCC.