Role of the SOX18 protein in neoplastic processes

The role of SOX18 in nasopharyngeal carcinoma: implications for prognosis and therapy

OBJECTIVE

To investigate the cellular function of SOX18 in nasopharyngeal carcinoma (NPC) by analyzing its effects on tumor cell proliferation, apoptosis, migration and invasion, and to verify its expression and prognostic significance by clinical samples, thereby providing a basis for precise diagnosis and treatment.

METHODS

SOX18 expression was analyzed in NPC cell lines and clinical samples. Gene silencing techniques were utilized to reduce SOX18 expression in NPC cells, followed by assays to evaluate cell proliferation, apoptosis, migration, and invasion. Additionally, changes in the Wnt/β-catenin signaling pathway were examined.

RESULTS

High SOX18 expression was correlated with poor survival in NPC patients. Silencing SOX18 significantly inhibited cell proliferation, increased apoptosis, and suppressed migration and invasion capabilities. Furthermore, SOX18 silencing downregulated key genes and proteins associated with the Wnt/β-catenin signaling pathway.

CONCLUSION

SOX18 plays a critical role in NPC progression by affecting key cellular behaviors. Targeting SOX18 may offer new therapeutic strategies and improve prognostic assessments for NPC patients, highlighting its potential as a valuable molecular marker for cancer treatment.

Regulatory T cells crosstalk with tumor cells and endothelium through lymphotoxin signaling

Regulatory T cells (Tregs) with multifaceted functions suppress anti-tumor immunity by signaling surrounding cells. Here we report Tregs use the surface lymphotoxin (LT)α1β2 to preferentially stimulate LT beta receptor (LTβR) nonclassical NFκB signaling on both tumor cells and lymphatic endothelial cells (LECs) to accelerate tumor growth and metastasis. Selectively targeting LTβR nonclassical NFκB pathway inhibits tumor growth and migration in vitro. Leveraging in vivo Treg LTα1β2 interactions with LTβR on tumor cells and LECs, transfer of wild type but not LTα-/- Tregs promotes B16F10 melanoma growth and tumor cell-derived chemokines in LTβR-/- mice; and increases SOX18 and FLRT2 in lymphatic vessels of LTβR-/- melanoma. Blocking the nonclassical pathway suppresses tumor growth and lymphatic metastasis by reducing chemokine production, restricting Treg recruitment to tumors, and retaining intratumoral IFNγ+ CD8 T cells. Our data reveals that Treg LTα1β2 promotes LTβR nonclassical NFκB signaling in tumor cells and LECs providing a rational strategy to prevent Treg promoted tumor growth and metastasis.

[Effects of propranolol on the biological behavior of human umbilical vein endothelial cells and the expression of SOX18, MMP-7, and VEGFA]

OBJECTIVES

To investigate the effects of propranolol on the proliferation, apoptosis, migration, and tube formation ability of human umbilical vein endothelial cells (HUVEC), as well as its impact on the expression of sex-determining region Y-box 18 (SOX18), matrix metalloproteinase-7 (MMP-7), and vascular endothelial growth factor A (VEGFA).

METHODS

HUVEC were treated with different concentrations of propranolol, and cell viability was assessed using the CCK-8 method to determine the optimal concentration and treatment duration. The experiment consisted of a control group and groups treated with different concentrations of propranolol (50, 100, 150 μmol/L). Apoptosis, migration, and tube formation of HUVEC were observed using flow cytometry, wound healing assays, and tube formation assays. Western blot and real-time quantitative PCR were used to detect the expression levels of SOX18, MMP-7, and VEGFA proteins and mRNA.

RESULTS

Compared to the control group, the apoptosis rate in the propranolol treatment groups increased significantly (P<0.05), and it rose significantly with increasing drug concentration (P<0.05). The wound healing rate decreased in the propranolol treatment groups, and both the number of tube formation nodes and total tube length were reduced (P<0.05). The expression levels of SOX18, MMP-7, and VEGFA proteins and mRNA were downregulated in the propranolol treatment groups (P<0.05).

CONCLUSIONS

Propranolol can inhibit the proliferation, migration, and tube formation ability of HUVEC and promote cell apoptosis, resulting in decreased expression levels of SOX18, MMP-7, and VEGFA.

SOX18 meditates the resistance of Bmi1-expressing cells to cetuximab in HNSCC

OBJECTIVE

Head and neck squamous cell carcinoma (HNSCC) is the most common type of malignancy in the head and neck region worldwide. The therapeutic strategies for HNSCC remain unsatisfying and limited. Here, we found a population of resistant Bmi1-expressing cells in the presence of cetuximab treatment and reported a novel role of SRY-box transcription factor 18 (SOX18), a member of the SOX family, in promoting HNSCC resistance to cetuximab. This study aimed to investigate the regulatory mechanism of Sox18 in Bmi1-positive cells and to search for better therapeutic targets.

METHODS

We successfully obtained Bmi1CreER, RosatdTomato, and RosaDTA mice and identified Bmi1-expressing cells through lineage tracing. SOX18 expression in HNSCC and normal tissues was analyzed by immunohistochemistry, colocalization of Sox18, and Bmi1-expressing cells was analyzed by immunofluorescence, and SOX18 expression in SCC9 cell lines was quantified by western blotting and quantitative real-time PCR. The investigation of the mechanism of SOX18-mediated cetuximab resistance in Bmi1-positive cells was based on the analysis of single-cell RNA-seq data obtained from the Gene Expression Omnibus (GEO) database. Western blotting was performed to verify the results obtained from the single-cell RNA-seq analysis.

RESULTS

In our study, we demonstrated that Bmi1-expressing cells were resistant to cetuximab treatment and that depletion of Bmi1-expressing cells improved cetuximab efficacy in HNSCC. We then discovered that Sox18 mediated the stem cell-like properties of Bmi1-expressing cells and promoted cellular cetuximab resistance through an oxidative phosphorylation pathway. There was a significant downregulation of key genes in the oxidative phosphorylation pathway in Sox18 knockout cell lines.

CONCLUSIONS

Taken together, the findings of our study suggest that Sox18 mediates the resistance of Bmi1-expressing cells to cetuximab in HNSCC via the oxidative phosphorylation pathway.

Epitenon-derived cells comprise a distinct progenitor population that contributes to both tendon fibrosis and regeneration following acute injury

Flexor tendon injuries are common and heal poorly owing to both the deposition of function- limiting peritendinous scar tissue and insufficient healing of the tendon itself. Therapeutic options are limited due to a lack of understanding of the cell populations that contribute to these processes. Here, we identified a bi-fated progenitor cell population that originates from the epitenon and goes on to contribute to both peritendinous fibrosis and regenerative tendon healing following acute tendon injury. Using a combination of genetic lineage tracing and single cell RNA-sequencing (scRNA-seq), we profiled the behavior and contributions of each cell fate to the healing process in a spatio-temporal manner. Branched pseudotime trajectory analysis identified distinct transcription factors responsible for regulation of each fate. Finally, integrated scRNA-seq analysis of mouse healing with human peritendinous scar tissue revealed remarkable transcriptional similarity between mouse epitenon- derived cells and fibroblasts present in human peritendinous scar tissue, which was further validated by immunofluorescent staining for conserved markers. Combined, these results clearly identify the epitenon as the cellular origin of an important progenitor cell population that could be leveraged to improve tendon healing.

The Impact of Transcription Factor Prospero Homeobox 1 on the Regulation of Thyroid Cancer Malignancy

Transcription factor Prospero homeobox 1 (PROX1) is continuously expressed in the lymphatic endothelial cells, playing an essential role in their differentiation. Many reports have shown that PROX1 is implicated in cancer development and acts as an oncoprotein or suppressor in a tissue-dependent manner. Additionally, the PROX1 expression in many types of tumors has prognostic significance and is associated with patient outcomes. In our previous experimental studies, we showed that PROX1 is present in the thyroid cancer (THC) cells of different origins and has a high impact on follicular thyroid cancer (FTC) phenotypes, regulating migration, invasion, focal adhesion, cytoskeleton reorganization, and angiogenesis. Herein, we discuss the PROX1 transcript and protein structures, the expression pattern of PROX1 in THC specimens, and its epigenetic regulation. Next, we emphasize the biological processes and genes regulated by PROX1 in CGTH-W-1 cells, derived from squamous cell carcinoma of the thyroid gland. Finally, we discuss the interaction of PROX1 with other lymphatic factors. In our review, we aimed to highlight the importance of vascular molecules in cancer development and provide an update on the functionality of PROX1 in THC biology regulation.

Novel Biomarkers of Early Atherosclerotic Changes for Personalised Prevention of Cardiovascular Disease in Cervical Cancer and Human Papillomavirus Infection

Cervical cancer is associated with a causative role of human papillomavirus (HPV), which is a highly prevalent infection. Recently, women with a genital HPV infection were found to have increased incidence of cardiovascular diseases (CVD), including severe cardiovascular events such as myocardial infarction and stroke. The pathomechanisms of this relation are not yet fully understood, and may significantly affect the health of a large part of the population. Accelerated atherosclerosis is assumed to play a key role in the pathophysiology of this relationship. To identify high-risk groups of the population, it is necessary to stratify the CVD risk. Current algorithms, as widely used for the estimation of CVD risk, seem to be limited by the individual misclassification of high-risk subjects. However, personalised prediction of cardiovascular events is missing. Regarding HPV-related CVD, identification of novel sensitive biomarkers reflecting early atherosclerotic changes could be of major importance for such personalised cardiovascular risk prediction. Therefore, this review focuses on the pathomechanisms leading to HPV-related cardiovascular diseases with respect to atherosclerosis, and the description of potential novel biomarkers to detect the earliest atherosclerotic changes important for the prevention of CVD in HPV infection and cervical cancer.

R-propranolol is a small molecule inhibitor of the SOX18 transcription factor in a rare vascular syndrome and hemangioma

Propranolol is an approved non-selective β-adrenergic blocker that is first line therapy for infantile hemangioma. Despite the clinical benefit of propranolol therapy in hemangioma, the mechanistic understanding of what drives this outcome is limited. Here, we report successful treatment of pericardial edema with propranolol in a patient with Hypotrichosis-Lymphedema-Telangiectasia and Renal (HLTRS) syndrome, caused by a mutation in SOX18. Using a mouse pre-clinical model of HLTRS, we show that propranolol treatment rescues its corneal neo-vascularisation phenotype. Dissection of the molecular mechanism identified the R(+)-propranolol enantiomer as a small molecule inhibitor of the SOX18 transcription factor, independent of any anti-adrenergic effect. Lastly, in a patient-derived in vitro model of infantile hemangioma and pre-clinical model of HLTRS we demonstrate the therapeutic potential of the R(+) enantiomer. Our work emphasizes the importance of SOX18 etiological role in vascular neoplasms, and suggests R(+)-propranolol repurposing to numerous indications ranging from vascular diseases to metastatic cancer.