Transcription Factor SOX18 Promotes Clear Cell Renal Cell Carcinoma Progression and Alleviates Cabozantinib-Mediated Inhibitory Effects

The Transcription Factor SOX18 Inhibitor Small Molecule 4 Is a Potential Treatment of Cancer-Induced Lymphatic Metastasis and Lymphangiosarcoma

BACKGROUND

Malignant tumors release growth factors, promoting lymphangiogenesis in primary tumors and draining sentinel lymph nodes, ultimately facilitating lymph node metastasis. As a malignant lymphatic tumor entity, lymphangiosarcomas are characterized by low survival rates and limited treatment options. The transcription factor SOX18 plays a crucial role in both lymphatic endothelial cell differentiation and cancer-induced lymphangiogenesis.

AIMS

In this in vitro study, we investigated the potential therapeutic effect of a small molecule called Sm4, which inhibits SOX18, on lymphatic endothelial and lymphangiosarcoma cells in vitro.

METHODS AND RESULTS

Human dermal lymphatic endothelial cells (HDLECs), lymphangiosarcoma cells (MO-LAS), and other endothelial cell lines were cultured. We found that Sox18 exhibited high mRNA expression levels in both HDLEC and MO-LAS. Sm4 treatment decreased the Sox18 expression level at the mRNA and protein levels in both HDLEC and MO-LAS significantly, a phenomenon confirmed through immunofluorescence images. Additionally, Sm4 treatment suppressed the expression of key lymphatic phenotype markers (Prox1, Flt4, and Lyve1) and hindered migration in both HDLEC and MO-LAS, all while maintaining cell viability.

CONCLUSION

These findings suggest that targeting SOX18 with Sm4 may hold potential as a therapeutic strategy for lymphangiosarcoma and cancer-induced lymphatic metastasis. Further in vitro studies are warranted to investigate the mechanisms and conduct dose-response analyses to evaluate Sm4's potential as a targeted therapy for lymphangiosarcoma and cancer-induced lymphangiogenesis in the future.

Hyperthermia inhibits cellular function and induces immunogenic cell death in renal cell carcinoma

BACKGROUND

In recent years, hyperthermia has been widely applied as a novel strategy for cancer treatment due to its multiple antitumour effects. In particular, the potential influences of hyperthermia on the tumour immune microenvironment may improve the efficacy of immunotherapies. However, the effect of hyperthermia on renal cell carcinoma (RCC) has not been well characterized until now.

METHODS

In the present study, we primarily evaluated the effects of hyperthermia on cellular function via cellular proliferation, migration, invasion and apoptosis assays. In addition, the influence of hyperthermia on the immunogenicity of RCC cells was analysed using flow cytometry analysis, enzyme-linked immunosorbent assays, and immunofluorescent (IF) staining.

RESULTS

Our results demonstrate that hyperthermia significantly inhibits RCC cell proliferation, migration, and invasion and promotes cell apoptosis. In addition, we verified that hyperthermia improves the immunogenicity of RCC cells by inducing immunogenic cell death.

CONCLUSION

Our findings suggest that hyperthermia is a promising therapeutic strategy for RCC.

Targeting SOX18 Transcription Factor Activity by Small-Molecule Inhibitor Sm4 in Non-Small Lung Cancer Cell Lines

The transcription factor SOX18 has been shown to play a crucial role in lung cancer progression and metastasis. In this study, we investigated the effect of Sm4, a SOX18 inhibitor, on cell cycle regulation in non-small cell lung cancer (NSCLC) cell lines LXF-289 and SK-MES-1, as well as normal human lung fibroblast cell line IMR-90. Our results demonstrated that Sm4 treatment induced cytotoxic effects on all three cell lines, with a greater effect observed in NSCLC adenocarcinoma cells. Sm4 treatment led to S-phase cell accumulation and upregulation of p21, a key regulator of the S-to-G2/M phase transition. While no significant changes in SOX7 or SOX17 protein expression were observed, Sm4 treatment resulted in a significant upregulation of SOX17 gene expression. Furthermore, our findings suggest a complex interplay between SOX18 and p21 in the context of lung cancer, with a positive correlation observed between SOX18 expression and p21 nuclear presence in clinical tissue samples obtained from lung cancer patients. These results suggest that Sm4 has the potential to disrupt the cell cycle and target cancer cell growth by modulating SOX18 activity and p21 expression. Further investigation is necessary to fully understand the relationship between SOX18 and p21 in lung cancer and to explore the therapeutic potential of SOX18 inhibition in lung cancer.

Targeting c-Met in the treatment of urologic neoplasms: Current status and challenges

At present, studies have found that c-Met is mainly involved in epithelial-mesenchymal transition (EMT) of tumor tissues in urologic neoplasms. Hepatocyte growth factor (HGF) combined with c-Met promotes the mitosis of tumor cells, and then induces motility, angiogenesis, migration, invasion and drug resistance. Therefore, c-Met targeting therapy may have great potential in urologic neoplasms. Many strategies targeting c-Met have been widely used in the study of urologic neoplasms. Although the use of targeting c-Met therapy has a strong biological basis for the treatment of urologic neoplasms, the results of current clinical trials have not yielded significant results. To promote the application of c-Met targeting drugs in the clinical treatment of urologic neoplasms, it is very important to study the detailed mechanism of c-Met in urologic neoplasms and innovate c-Met targeted drugs. This paper firstly discussed the value of c-Met targeted therapy in urologic neoplasms, then summarized the related research progress, and finally explored the potential targets related to the HGF/c-Met signaling pathway. It may provide a new concept for the treatment of middle and late urologic neoplasms.

The Cellular and Molecular Landscape of Synchronous Pediatric Sialoblastoma and Hepatoblastoma

Sialoblastoma (SBL) is an infrequent embryonal malignant tumor originating from the salivary gland, resembling primitive salivary gland anlage, whereas hepatoblastoma (HB) is the most common pediatric liver malignancy. The simultaneous occurrence of both tumors is extremely rare. Here we reported a case of a 6-month-old infant diagnosed with synchronous SBL and HB. The patient received neoadjuvant chemotherapy followed by surgical resection. Fresh tissues of both tumors were collected before and after chemotherapy, which were further profiled by whole exome sequencing (WES) and single-cell RNA sequencing (scRNA-seq). WES analysis revealed potential somatic driver mutation PIK3CA p.Glu454Lys for SBL and canonical mutation CTNNB1 p.Ser45Pro for HB. No shared somatic variants or common copy number alterations were found between SBL and HB primary tumor samples. Though scRNA-seq, single-cell atlases were constructed for both tumors. SBL may recapitulate a pre-acinar stage in the development of salivary gland, including basaloid, duct-like, myoepithelial-like, and cycling phenotypes. In the meantime, HB was composed of tumor cells resembling different stages of the liver, including hepatocyte-like, hepatic progenitor-like, and hepatoblast-like cells. After chemotherapy, both tumors were induced into a more mature phenotype. In terms of transcriptional signatures, SBL and HB showed enhanced expression of epithelial markers KRT8, KRT18, and essential embryo development genes SDC1, MDK, indicating the disruption of normal embryo epithelium development. Finally, heterozygous deleterious germline mutation BLM and FANCI were identified which could predispose the patient to higher cancer risk. It partially explained the reason for the co-occurrence of SBL and HB. Taken together, we provided valuable resources for deciphering cellular heterogeneity and adaptive change of tumor cells after chemotherapy for synchronous SBL and HB, providing insights into the mechanisms leading to synchronous pediatric tumors.

Hedgehog-responsive PDGFRa(+) fibroblasts maintain a unique pool of alveolar epithelial progenitor cells during alveologenesis

The lung alveolus is lined with alveolar type 1 (AT1) and type 2 (AT2) epithelial cells. During alveologenesis, increasing demand associated with expanding alveolar numbers is met by proliferating progenitor AT2s (pAT2). Little information exists regarding the identity of this population and their niche microenvironment. We show that during alveologenesis, Hedgehog-responsive PDGFRa(+) progenitors (also known as SCMFs) are a source of secreted trophic molecules that maintain a unique pAT2 population. SCMFs are in turn maintained by TGFβ signaling. Compound inactivation of Alk5 TβR2 in SCMFs reduced their numbers and depleted the pAT2 pool without impacting differentiation of daughter cells. In lungs of preterm infants who died with bronchopulmonary dysplasia, PDGFRa is reduced and the number of proliferative AT2s is diminished, indicating that an evolutionarily conserved mechanism governs pAT2 behavior during alveologenesis. SCMFs are a transient cell population, active only during alveologenesis, making them a unique stage-specific niche mesodermal cell type in mammalian organs.

The lymphatic vasculature: An active and dynamic player in cancer progression

The lymphatic vasculature has been widely described and explored for its key functions in fluid homeostasis and in the organization and modulation of the immune response. Besides transporting immune cells, lymphatic vessels play relevant roles in tumor growth and tumor cell dissemination. Cancer cells that have invaded into afferent lymphatics are propagated to tumor‐draining lymph nodes (LNs), which represent an important hub for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites. In recent years many studies have reported new mechanisms by which the lymphatic vasculature affects cancer progression, ranging from induction of lymphangiogenesis to metastatic niche preconditioning or immune modulation. In this review, we provide an up‐to‐date description of lymphatic organization and function in peripheral tissues and in LNs and the changes induced to this system by tumor growth and progression. We will specifically focus on the reported interactions that occur between tumor cells and lymphatic endothelial cells (LECs), as well as on interactions between immune cells and LECs, both in the tumor microenvironment and in tumor‐draining LNs. Moreover, the most recent prognostic and therapeutic implications of lymphatics in cancer will be reported and discussed in light of the new immune‐modulatory roles that have been ascribed to LECs.

SOX18 enhances the proliferation and migration of airway smooth muscle cells induced by tumor necrosis factor-α via the regulation of Notch1 signaling

Childhood asthma is a frequent chronic disease of pediatric populations. The excessive proliferation and migration of airway smooth muscle cells contribute to airway remodeling during asthma pathogenesis. Sex-determining region on the Y chromosome-related high mobility group box 18 (SOX18) has been reported to be over-expressed in asthma. However, whether SOX18 plays a role in modulating the airway remodeling of asthma is not fully understood. The purposes of this work were to assess the potential role of SOX18 in modulating airway remodeling using tumor necrosis factor-α (TNF-α)-stimulated airway smooth muscle cells in vitro. Our results showed that SOX18 expression was increased following TNF-α stimulation in airway smooth muscle cells. The silencing of SOX18 markedly prohibited the proliferation and migration of airway smooth muscle cells induced by TNF-α, whilst the over-expression of SOX18 produced the opposite effects. Further investigation revealed that SOX18 promoted the expression of Notch1, and enhanced the activation of Notch1 signaling in airway smooth muscle cells stimulated by TNF-α. The inhibition of Notch1 markedly diminished SOX18-over-expression-evoked promotion effects on TNF-α-induced proliferation and migration of airway smooth muscle cells. In addition, the reactivation of Notch1 signaling markedly reversed the SOX18-silencing-induced suppressive effect on the TNF-α-induced proliferation and the migration of airway smooth muscle cells. In summary, the findings of this work demonstrate that SOX18 regulates the proliferation and migration of airway smooth muscle cells induced by TNF-α via the modulation of Notch1 signaling. This study indicates a potential role for SOX18 in promoting airway remodeling during asthma pathogenesis.

Association between copy-number alteration of +20q, -14q and -18p and cross-sensitivity to tyrosine kinase inhibitors in clear-cell renal cell carcinoma

Background

We aim to explore association between copy number alteration (CNA) and sensitivity to common tyrosine kinase inhibitors (TKIs) used in clear-cell renal cell carcinoma (ccRCC) treatment.

Methods

CNA with related sensitivity profiles were extracted from the Genomics of Drug Sensitivity in Cancer (GDSC) dataset and was cross-referenced with common CNA in ccRCC in the Cancer Genome Atlas (TCGA) dataset. Functional annotation was profiled using GSEA and NET-GE. Target genes within cytobands of interest were screened in silico and validated in vitro using proliferation assays in A498 and 786-O ccRCC cells.

Results

Four TKIs (Sunitinib, Cabozantinib, Axitinib and Sorafenib) that were clinically used in ccRCC were selected. In silico analysis showed gain of 20q (+20q) occurred in ~ 23% of cases and was associated with resistance to all four TKIs; loss of 14q (−14q) occurred in ~ 39% of cases and was associated with resistance to Sunitinib and Sorafenib; loss of 18p (−18p) occurred in ~ 39% of cases and was associated with sensitivity to Sunitinib and Sorafenib. All 3 CNAs were associated with worsened prognosis, respectively. Candidate target genes included of RBL1 on 20q, KLHL33 on 14q and ARHGAP28 on18q. In vitro validation showed RBL1 overexpression induced resistance to Sunitinib and Cabozantinib; KLHL33 silencing induced resistance to Sunitinib; ARHGAP28 silencing induced sensitivity to Cabozantinib. Functional annotation indicated FoxO signaling, hypoxic response and Wnt pathway, and Rho-related cellular adhesion were mechanistically associated with +20q, −14q and −18p, respectively.

Conclusion

Common CNAs in ccRCC are associated with cancer-intrinsic cross-sensitivity to common TKIs. Further validation and functional analyses are therefore needed.

SOX18 exerts tumor-suppressive functions in papillary thyroid carcinoma through inhibition of Wnt/β-catenin signaling

Sex-determining region on the Y chromosome-related high mobility group box 18 (SOX18) has emerged as a key tumor-related protein in a wide range of human tumors. Yet, the involvement of SOX18 in papillary thyroid carcinoma has not been determined. This study aimed to explore the expression and biological function of SOX18 in papillary thyroid carcinoma. There was a significant decrease in SOX18 expression in papillary thyroid carcinoma tissues compared with that in normal tissues. Low expression of SOX18 was also detected in papillary thyroid carcinoma cell lines and upregulation of SOX18 effectively repressed the proliferative, colony-forming and invasive abilities of papillary thyroid carcinoma cells in vitro. In contrast, knockdown of SOX18 in papillary thyroid carcinoma cells was associated with a significant increase in cell proliferation and invasion. Further studies revealed that SOX18 upregulation was associated with the reduced nuclear accumulation of β-catenin and the downregulation of Wnt/β-catenin signaling in thyroid carcinoma cells. Moreover, inhibition of Wnt/β-catenin signaling markedly attenuated SOX18 knockdown-evoked oncogenic effects in papillary thyroid carcinoma cells. In addition, SOX18 overexpression remarkably retarded the tumor growth of papillary thyroid carcinoma cell-derived xenograft tumors in nude mice. Taken together, these results demonstrate that SOX18 suppresses the proliferation and invasion of papillary thyroid carcinoma by inhibiting Wnt/β-catenin signaling. Our study reveals a tumor-suppressive role of SOX18 in papillary thyroid carcinoma and suggests that SOX18 is an attractive candidate target for treatment of papillary thyroid carcinoma.

Mini-Review: Cabozantinib in the Treatment of Advanced Renal Cell Carcinoma and Hepatocellular Carcinoma

Cabozantinib is an oral, tyrosine-kinase inhibitor with potent activity against VEGFR2 and MET, along with multiple other tyrosine kinases involved in cancer development and progression. Herein, we will focus on preclinical and clinical studies leading to the approval of cabozantinib in advanced renal cell carcinoma and hepatocellular carcinoma. Covered studies include NCT01100619, CABOSUN, METEOR, NCT00940225 and the CELESTIAL trial. Finally, we review future directions of cabozantinib development by highlighting some ongoing clinical trials.