Identification of the interplay between SOX9 and S100P in the metastasis and invasion of colon carcinoma

SOX9 knockout decreases stemness properties in colorectal cancer cells

Background

Colorectal cancer (CRC) is a leading cause of death worldwide. SRY-box transcription factor 9 (SOX9) participates in organogenesis and cell differentiation in normal tissues but has been involved in carcinogenesis development. Cancer stem cells (CSCs) are a small population of cells present in solid tumors that contribute to increased tumor heterogeneity, metastasis, chemoresistance, and relapse. CSCs have properties such as self-renewal and differentiation, which can be modulated by many factors. Currently, the role of SOX9 in the maintenance of the stem phenotype has not been well elucidated, thus, in this work we evaluated the effect of the absence of SOX9 in the stem phenotype of CRC cells.

Methods

We knockout (KO) SOX9 in the undifferentiated CRC cell line HCT116 and evaluated their stemness properties using sphere formation assay, differentiation assay, and immunophenotyping.

Results

SOX9-KO affected the epithelial morphology of HCT116 cells and stemness characteristics such as its pluripotency signature with the increase of SOX2 as a compensatory mechanism to induce SOX9 expression, the increase of KLF4 as a differentiation feature, as well as the inhibition of the stem cell markers CD44 and CD73. In addition, SOX9-KO cells gain the epithelial-mesenchymal transition (EMT) phenotype with a significant upregulation of CDH2. Furthermore, our results showed a remarkable effect on first- and second-sphere formation, being SOX9-KO cells less capable of forming high-size-resistant spheres. Nevertheless, CSCs surface markers were not affected during the differentiation assay.

Conclusions

Collectively, our findings supply evidence that SOX9 promotes the maintenance of stemness properties in CRC-CSCs.

Dialog beyond the Grave: Necrosis in the Tumor Microenvironment and Its Contribution to Tumor Growth

Damage-associated molecular patterns (DAMPs) are endogenous molecules released from the necrotic cells dying after exposure to various stressors. After binding to their receptors, they can stimulate various signaling pathways in target cells. DAMPs are especially abundant in the microenvironment of malignant tumors and are suspected to influence the behavior of malignant and stromal cells in multiple ways often resulting in promotion of cell proliferation, migration, invasion, and metastasis, as well as increased immune evasion. This review will start with a reminder of the main features of cell necrosis, which will be compared to other forms of cell death. Then we will summarize the various methods used to assess tumor necrosis in clinical practice including medical imaging, histopathological examination, and/or biological assays. We will also consider the importance of necrosis as a prognostic factor. Then the focus will be on the DAMPs and their role in the tumor microenvironment (TME). We will address not only their interactions with the malignant cells, frequently leading to cancer progression, but also with the immune cells and their contribution to immunosuppression. Finally, we will emphasize the role of DAMPs released by necrotic cells in the activation of Toll-like receptors (TLRs) and the possible contributions of TLRs to tumor development. This last point is very important for the future of cancer therapeutics since there are attempts to use TLR artificial ligands for cancer therapeutics.

Transcriptional Regulation of Liver-Type OATP1B3 (Lt-OATP1B3) and Cancer-Type OATP1B3 (Ct-OATP1B3) Studied in Hepatocyte-Derived and Colon Cancer-Derived Cell Lines

Due to alternative splicing, the SLCO1B3 gene encodes two protein variants; the hepatic uptake transporter liver-type OATP1B3 (Lt-OATP1B3) and the cancer-type OATP1B3 (Ct-OATP1B3) expressed in several cancerous tissues. There is limited information about the cell type-specific transcriptional regulation of both variants and about transcription factors regulating this differential expression. Therefore, we cloned DNA fragments from the promoter regions of the Lt-SLCO1B3 and the Ct-SLCO1B3 gene and investigated their luciferase activity in hepatocellular and colorectal cancer cell lines. Both promoters showed differences in their luciferase activity depending on the used cell lines. We identified the first 100 bp upstream of the transcriptional start site as the core promoter region of the Ct-SLCO1B3 gene. In silico predicted binding sites for the transcription factors ZKSCAN3, SOX9 and HNF1α localized within these fragments were further analyzed. The mutagenesis of the ZKSCAN3 binding site reduced the luciferase activity of the Ct-SLCO1B3 reporter gene construct in the colorectal cancer cell lines DLD1 and T84 to 29.9% and 14.3%, respectively. In contrast, using the liver-derived Hep3B cells, 71.6% residual activity could be measured. This indicates that the transcription factors ZKSCAN3 and SOX9 are important for the cell type-specific transcriptional regulation of the Ct-SLCO1B3 gene.

Oncogenic Functions and Clinical Significance of Circular RNAs in Colorectal Cancer

Colorectal cancer (CRC) is ranked as the second most commonly diagnosed disease in females and the third in males worldwide. Therefore, the finding of new more reliable biomarkers for early diagnosis, for prediction of metastasis, and resistance to conventional therapies is an important challenge in overcoming the disease. The current review presents circular RNAs (circRNAs) with their unique features as potential prognostic and diagnostic biomarkers in CRC. The review highlights the mechanism of action and the role of circRNAs with oncogenic functions in the CRC as well as the association between their expression and clinicopathological characteristics of CRC patients. The comprehension of the role of oncogenic circRNAs in CRC pathogenesis is growing rapidly and the next step is using them as suitable new drug targets in the personalized treatment of CRC patients.

SOX9 is associated with advanced T-stages of clinical stage II colon cancer in young Mexican patients

Colorectal cancer (CRC) is one of the most common malignancies worldwide and includes colon cancer (CC) and rectal cancer (RC). Regarding CC, the development of novel molecular biomarkers for the accurate diagnosis and prognosis, as well as the identification of novel targets for therapeutic intervention, are urgently needed. SRY-related high-mobility group box 9 (SOX9), a transcription factor, is involved in development, and has been associated with the progression of human cancer. However, its underlying clinical and functional effects in CRC have not been fully understood. Therefore, the present study aimed to evaluate the clinical and functional relevance of SOX9 expression in CC. The expression of SOX9 in tumor tissues was evaluated in 97 biopsies from Mexican patients with CC with early-stage I and II disease by immunohistochemistry (IHC). In addition, SOX9 silencing in the HCT116 cell line was performed using specific small interfering RNAs, while downregulation efficiency was verified by reverse transcription-quantitative PCR and immunofluorescence. Spheroid-formation assay was carried out using ultra-low attachment plates. The IHC results showed that SOX9 was upregulated in patients with stage II (91%) and advanced T3 stage (67%) CC. Interestingly, higher SOX9 expression was associated with clinical stage, tumor size and tumor location. Furthermore, increased SOX9 expression was found in relapsed cases with local tumors; however, it was not associated with increased survival probability. Additionally, functional analysis indicated that SOX9 silencing significantly attenuated the sphere-formation capability of HCT116 cells. The present study was the first to evaluate the expression levels of SOX9 in Mexican patients diagnosed with early-stage CC. The aforementioned findings indicated that high SOX9 expression could play an important role in tumorigenesis and be associated with advanced T-stages of clinical-stage II patients, but not with relapse-free survival.

Prognostic Value of S100P Expression in Patients With Digestive System Cancers: A Meta-Analysis

Background

Digestive system cancers (DSCs) are associated with high morbidity and mortality. S100P has been reported as a prognostic biomarker in DSCs, but its prognostic value remains controversial. Accordingly, we conducted a meta-analysis to investigate whether S100P is correlated with overall survival (OS) of patients with DSCs. The relationship between S100P and clinicopathological features was also evaluated.

Methods

We systematically searched PubMed, Embase, Web of Science and Cochrane Library for eligible studies up to January 2020. In total, 16 publications with 1,925 patients were included.

Results

S100P overexpression was associated with poor OS of patient with DSCs (HR=1.54, 95% CI: 1.14–2.08, P=0.005). When stratified by anatomic structure, S100P overexpression was associated with poor prognosis in non-gastrointestinal tract cancers (HR=1.98, 95% CI: 1.44–2.72, P<0.001) but not in gastrointestinal tract cancers (HR=1.09, 95% CI: 0.66–1.81, P=0.727). When stratified by tumor type, S100P overexpression predicted poor OS in cholangiocarcinoma (HR=2.14, 95% CI: 1.30–3.50, P=0.003) and hepatocellular carcinoma (HR=1.91, 95% CI: 1.22–2.99, P =0.005) but not in gastric cancer (HR=0.97, 95% CI: 0.65–1.45, P=0.872), colorectal cancer (HR=1.18, 95% CI: 0.32–4.41, P=0.807), gallbladder cancer (HR=1.40, 95% CI: 0.84-2.34, P=0.198), and pancreatic cancer (HR=1.92, 95% CI: 0.99–3.72, P=0.053). Furthermore, high S100P expression was significantly associated with distant metastasis (OR=3.58, P=0.044), advanced clinical stage (OR=2.03, P=0.041) and recurrence (OR=1.66, P=0.007).

Conclusion

S100P might act as a prognostic indicator of non-gastrointestinal tract cancers.

S100P as a novel biomarker of microvascular invasion and portal vein tumor thrombus in hepatocellular carcinoma

BACKGROUND

Portal vein tumor thrombus (PVTT) and microvascular invasion (MVI) are types of intrahepatic vascular metastasis of hepatocellular carcinoma (HCC) and are highly correlated with poor prognosis. However, the underlying biomarkers of PVTT and MVI are unclear.

METHODS

We identified a PVTT/MVI-associated gene S100P by cDNA microarray analysis, and assess the potential value of serum S100P measurement in the differential diagnosis of HCC and prediction of MVI status with large retrospective and perspective cohort studies.

RESULTS

The mRNA and protein of S100P was increased in HCCs with PVTT or MVI. High S100P immunostaining in tumors was correlated with inferior tumor-free survival. Serum S100P values discriminated patients with HCCs from those with benign liver tumors, and it showed predictive potential of MVI status in both retrospective and perspective cohorts. S100P may regulate HCC tumorigenicity and invasive ability; S100P also was associated with up-regulation of CD44, which may mediate HCC cell adhesion to form PVTT/MVI.

CONCLUSIONS

Serum S100P may be a novel differential diagnostic marker for HCC and a potential predictor of MVI status pre-surgery for HCC patients. S100P overexpression in HCC is highly correlated with the formation of PVTT and MVI, which may make S100P as a potential therapeutic target for HCC metastasis.

Hsa_circ_0020095 Promotes Oncogenesis and Cisplatin Resistance in Colon Cancer by Sponging miR-487a-3p and Modulating SOX9

Objectives

Colon cancer (CC) currently ranks as the third most common human cancer worldwide with an increasing incidence and a poor prognosis. Recently, circular RNAs have been reported to regulate the progression of diverse human cancers. However, the role of circRNA hsa_circ_0020095 in CC remains largely unclear.

Methods

Expression levels of the related circRNAs, microRNAs and mRNA in CC tissues and cells were determined. The impacts of circ_0020095 or miR-487a-3p on CC cells were examined at the indicated times after transfection. Meanwhile, a luciferase-reporter experiment was employed to validate the interplay between miR-487a-3p and circ_002009695 or SOX9. Moreover, the in vivo tumor growth assay was applied to further evaluate the effects of circ_0020095 knockdown on CC progression.

Results

We demonstrated that circ_0020095 was highly expressed in CC tissues and cells. The proliferation, migration, invasion, and cisplatin resistance of CC were suppressed by silencing circ_0020095 in vitro and in vivo or by ectopic expression of miR-487a-3p in vitro. Mechanistically, circ_0020095 could directly bind to miR-487a-3p and subsequently act as a miR-487a-3p sponge to modulate the activity by targeting the 3′-UTR of SOX9. Interestingly, overexpression of circ_0020095 dramatically reversed the suppressive effects of miR-487a-3p mimics on CC cells.

Conclusion

Circ_0020095 functions as an oncogene to accelerate CC cell proliferation, invasion, migration and cisplatin resistance through the miR-487a-3p/SOX9 axis, which could be a promising target for CC treatment.

ZBTB20 regulates WNT/CTNNB1 signalling pathway by suppressing PPARG during hepatocellular carcinoma tumourigenesis

Background & Aims

Zinc finger and BTB domain containing 20 (ZBTB20) has been implicated as a potential oncogene in liver cancer. However, knockout studies have shown it to be a transcriptional repressor of the alpha-foetoprotein (Afp) gene in adult liver, and reduced levels of ZBTB20 allow for upregulation of AFP with increased tumour severity in certain cases of hepatocellular carcinoma (HCC). As there are many discrepancies in the literature regarding its role in liver tumourigenesis, the aim of this study was to elucidate the role of ZBTB20 in HCC tumourigenesis.

Methods

A reverse genetic study using the Sleeping Beauty (SB) transposon system in mice was performed to elucidate the role of ZBTB20 in HCC tumourigenesis. In vitro ZBTB20 gain- and loss-of-function experiments were used to assess the relationship amongst ZBTB20, peroxisome proliferator activated receptor gamma (PPARG) and catenin beta 1 (CTNNB1).

Results

Transgenic overexpression of ZBTB20 in hepatocytes and in the context of transformation related protein (T r p53) inactivation induced hepatic hypertrophy, activation of WNT/CTNNB1 signalling, and development of liver tumours. In vitro overexpression and knockout experiments using CRISPR/Cas9 demonstrated the important role for ZBTB20 in downregulating PPARG, resulting in activation of the WNT/CTNNB1 signalling pathway and its downstream effectors in HCC tumourigenesis.

Conclusions

These findings demonstrate a novel interaction between ZBTB20 and PPARG, which leads to activation of the WNT/CTNNB1 signalling pathway in HCC tumourigenesis.

Lay summary

ZBTB20 has been implicated as a potential oncogene in liver cancer. Herein, we uncover its important role in liver cancer development. We show that it interacts with PPARG to upregulate the WNT/CTNNB1 signalling pathway, leading to tumourigenesis.

MYEOV increases HES1 expression and promotes pancreatic cancer progression by enhancing SOX9 transactivity

Emerging evidence indicates that myeloma overexpressed (MYEOV) is an oncogene and plays crucial roles in multiple human cancers. However, its roles in the development of pancreatic ductal adenocarcinoma (PDAC) remain elusive. Here, we provide evidence of essential roles of MYEOV in the development and progression of PDAC. In tumor specimens derived from pancreatic cancer patients, MYEOV was overexpressed and associated with poor prognosis. In addition, MYEOV expression in PDAC was upregulated through promoter hypomethylation. MYEOV depletion impaired metastatic ability and proliferation of PDAC cells both in vitro and in vivo, whereas its overexpression had the opposite effect. Mechanistic investigations revealed that MYEOV interacted with SRY-Box Transcription Factor 9 (SOX9), a well-known oncogenic transcription factor in PDAC. This interaction occurred mainly in the nuclei of PDAC cells and increased transcriptional activity of SOX9. Furthermore, MYEOV promoted the expression of Hairy and enhancer of split homolog-1 (HES1), a SOX9 target gene, by enhancing SOX9 DNA-binding ability to the HES1 enhancer without affecting the protein level and subcellular localization of SOX9. HES1 knockdown partly abrogated the oncogenic effect of MYEOV. Our findings suggest that MYEOV could be a potential prognostic biomarker and therapeutic target for PDAC.

Receptor for Advanced Glycation End Products Acts as a Fuel to Colorectal Cancer Development

Receptor for advanced glycation end-products (RAGE) is a multiligand binding and single-pass transmembrane protein taken in diverse chronic inflammatory conditions. RAGE behaves as a pattern recognition receptor, which binds and is engaged in the cellular response to a variety of damage-associated molecular pattern molecules, as well as HMGB1, S100 proteins, and AGEs (advanced glycation end-products). The RAGE activation turns out to a formation of numerous intracellular signaling mechanisms, resulting in the progression and prolongation of colorectal carcinoma (CRC). The RAGE expression correlates well with the survival of colon cancer cells. RAGE is involved in the tumorigenesis, which increases and develops well in the stressed tumor microenvironment. In this review, we summarized downstream signaling cascade activated by the multiligand activation of RAGE, as well as RAGE ligands and their sources, clinical studies, and tumor markers related to RAGE particularly in the inflammatory tumor microenvironment in CRC. Furthermore, the role of RAGE signaling pathway in CRC patients with diabetic mellitus is investigated. RAGE has been reported to drive assorted signaling pathways, including activator protein 1, nuclear factor-κB, signal transducer and activator of transcription 3, SMAD family member 4 (Smad4), mitogen-activated protein kinases, mammalian target of rapamycin, phosphoinositide 3-kinases, reticular activating system, Wnt/β-catenin pathway, and Glycogen synthase kinase 3β, and even microRNAs.

SOX9 has distinct regulatory roles in alternative splicing and transcription

SOX9 is known as a crucial transcription factor for various developmental processes and for tissue homeostasis. We examined here its potential role in alternative splicing by analyzing global splicing changes, using RNA-seq of colon tumor cells. We show that SOX9 knockdown alters the splicing of hundreds of genes without affecting their expression levels, revealing that SOX9 controls distinct splicing and transcriptional programs. SOX9 does not affect splicing patterns through the control of splicing factors expression. We identify mutants that uncouple SOX9 splicing function from its transcriptional activity. We demonstrate that SOX9 binds to RNA and associates with several RNA-binding proteins, including the core exon junction complex component Y14. Half of SOX9 splicing targets are also modulated by Y14 and are no longer regulated by SOX9 upon Y14 depletion. Altogether, our work reveals that SOX9 is a moonlighting protein which modulates either transcription or splicing of distinct sets of targets.

Up-regulated long noncoding RNA AB073614 modulates the tumor cell proliferation, invasion and migration in human colorectal cancer

Colorectal cancer (CRC) is a common cancer and the function of long noncoding RNA (lncRNA) AB073614 in CRC mainly unclear. Here, the expression of lncRNA AB073614 in CRC tissues was evaluated by quantitative real-time PCR (qRT-PCR). CCK-8 assays were conducted to explore the impact of AB073614 on cell proliferation. The effects of AB073614 on cell migration, invasion and apoptosis were evaluated by a Transwell in vitro assay. Apoptosis-related molecular marker expression levels were detected by Western blot analysis. In the present study, we confirmed that AB073614 was significantly upregulated in CRC tissues. A difference analysis in the lncRNA AB073614 expression in CRC patient group suggested that the expression of lncRNA AB073614 was independently associated with higher possibilities of high grade (P = 0.0005), tumor size (> 5 cm) (P = 0.0001), distant metastasis (P = 0.0009), and differentiation level (P = 0.0037). In vitro studies demonstrated that the knockdown of {"type": "entrez-nucleotide", "attrs":{"text": "AB073614", "term_id": "51555790", "term_text": "AB073614"}}AB073614 suppressed SW480 cell proliferation. Meanwhile, the overexpression of {"type": "entrez-nucleotide", "attrs":{"text": "AB073614", "term_id": "51555790", "term_text": "AB073614"}}AB073614 in SW480 cells accelerated cell growth and invasion, and suppressed cell apoptosis. In conclusion, our results suggest that AB073614 may function as a tumor promoter in CRC. Our findings may provide a therapeutic approach for the future treatment of CRC.

SOX9 promotes nasopharyngeal carcinoma cell proliferation, migration and invasion through BMP2 and mTOR signaling

SRY-related high-mobility-group box 9 (SOX9) is a member of the SOX family of transcription factors. Accumulating evidence has shown that SOX9 plays a significant role in various malignancies. However, the role of SOX9 in nasopharyngeal carcinoma (NPC) remains unknown. In the present study, up-regulation of SOX9 was observed in both NPC tissues and different NPC cells. Overexpression of SOX9 promoted NPC cell proliferation, migration and invasion. Conversely, knock down of SOX9 inhibited NPC proliferation, colony formation, migration and invasion. Mechanistically, SOX9 bound directly to the promoter region of BMP2 and increased BMP2 expression. In addition, overexpression of SOX9 activated the mTOR pathway partly through BMP2. Collectively, these results identify a novel role for SOX9 as a potential therapeutic marker for the prevention and treatment of NPC.

Expression and Clinical Relevance of SOX9 in Gastric Cancer

Gastric cancer is one of the most frequent tumours and the third leading cause of cancer-related death worldwide. The investigation of new biomarkers that can predict patient outcome more accurately and allow better treatment and follow-up decisions is of crucial importance. SOX9 (sex-determining region Y (SRY)-box 9) is a regulator of cell fate decisions in embryogenesis and adulthood. Here, we sought to ascertain the relevance of SOX9 transcription factor as a prognostic marker in gastric cancer. SOX9 expression was analyzed by immunohistochemistry in 333 gastric adenocarcinoma cases, and its association with clinicopathological and follow-up data was evaluated. SOX9 nuclear expression was absent in 17% of gastric cancer cases and predicted worse disease-free survival (P = 0.03). SOX9 expression was associated with lower risk of relapse in Cox univariable analysis (HR = 0.58; 95% CI = 0.35-0.97; P = 0.04). The prognostic value of SOX9 was more pronounced in tumours with expansive growth (P = 0.01) or with venous invasion (P = 0.02). Two validation cohorts from the Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG) confirmed that low SOX9 expression was significantly associated with poor patient outcome. In conclusion, we have identified SOX9 as a biomarker of disease relapse in gastric cancer patients. Further experiments are needed to elucidate its biological relevance at the cellular level.

SOX9 Stem-Cell Factor: Clinical and Functional Relevance in Cancer

Transcriptional and epigenetic embryonic programs can be reactivated in cancer cells. As result, a specific subset of undifferentiated cells with stem-cells properties emerges and drives tumorigenesis. Recent findings have shown that ectoderm- and endoderm-derived tissues continue expressing stem-cells related transcription factors of the SOX-family of proteins such as SOX2 and SOX9 which have been implicated in the presence of cancer stem-like cells (CSCs) in tumors. Currently, there is enough evidence suggesting an oncogenic role for SOX9 in different types of human cancers. This review provides a summary of the current knowledge about the involvement of SOX9 in development and progression of cancer. Understanding the functional roles of SOX9 and clinical relevance is crucial for developing novel treatments targeting CSCs in cancer.

The role of SOX family members in solid tumours and metastasis

Cancer is a heavy burden for humans across the world with high morbidity and mortality. Transcription factors including sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are thought to be involved in the regulation of specific biological processes. The deregulation of gene expression programs can lead to cancer development. Here, we review the role of the SOX family in breast cancer, prostate cancer, renal cell carcinoma, thyroid cancer, brain tumours, gastrointestinal and lung tumours as well as the entailing therapeutic implications. The SOX family consists of more than 20 members that mediate DNA binding by the HMG domain and have regulatory functions in development, cell-fate decision, and differentiation. SOX2, SOX4, SOX5, SOX8, SOX9, and SOX18 are up-regulated in different cancer types and have been found to be associated with poor prognosis, while the up-regulation of SOX11 and SOX30 appears to be favourable for the outcome in other cancer types. SOX2, SOX4, SOX5 and other SOX members are involved in tumorigenesis, e.g. SOX2 is markedly up-regulated in chemotherapy resistant cells. The SoxF family (SOX7, SOX17, SOX18) plays an important role in angio- and lymphangiogenesis, with SOX18 seemingly being an attractive target for anti-angiogenic therapy and the treatment of metastatic disease in cancer. In summary, SOX transcription factors play an important role in cancer progression, including tumorigenesis, changes in the tumour microenvironment, and metastasis. Certain SOX proteins are potential molecular markers for cancer prognosis and putative potential therapeutic targets, but further investigations are required to understand their physiological functions.

S100A4-MYH9 Axis Promote Migration and Invasion of Gastric Cancer Cells by Inducing TGF-β-Mediated Epithelial-Mesenchymal Transition

Driver genes conducing to peritoneal metastasis in advanced gastric cancer remain to be clarified. S100A4 is suggested to evolve in metastasis of gastrointestinal cancer, we aim to explore the role of S100A4 plays in metastasis of advanced gastric cancer and the potential mechanism. Transfection of siRNA or cDNA was applied to alter the expression of protein S100A4 and MYH9, investigation of the expression of epithelial and mesenchymal transition (EMT) associated markers was followed. Cell migration assay was used to screen the alteration of migration ability regulated by S100A4 and MYH9. IHC analysis for tissue sample microarray was performed to reveal their relationship with clinical pathological parameters and potential capacity of predicting survival. Consistent overexpression of S100A4 and MYH9 were found in peritoneal metastasis and primary site compared with adjacent normal tissue. Low expression of S100A4 led to increased epithelial markers as wells as decline of mesenchymal makers, while overexpression of S100A4 led to inverse impact. S100A4 expression was closely correlated with increased migration ability and EMT process induced by TGF-β stimulation. Interference of S100A4 led to downregulation of MYH9 and inactivation of Smad pathway through participating in EMT process, which could be reversed by overexpression of MYH9. Moreover, co-expression of S100A4 and MYH9 was identified in tissue microarray and confirmed by immunofluorescence assay. In conclusion, overexpression of S100A4 and downstream molecular MYH9 in advanced gastric cancer predicted poor prognosis; oncogene S100A4 facilitate EMT process induced by TGF-β stimulation, suggesting a potential target in management of peritoneal metastasis of gastric cancer.

TGF-β1-SOX9 axis-inducible COL10A1 promotes invasion and metastasis in gastric cancer via epithelial-to-mesenchymal transition

Molecular biomarkers that predict disease progression might promote drug development and therapeutic strategies in aggressive cancers, such as gastric cancer (GC). High-throughput mRNA sequencing (RNA-seq) revealed that collagen type X alpha 1 (COL10A1) is a disease progression-associated gene. Analysis of 103 GC patients showed that high COL10A1 mRNA expression was associated with GC metastasis and reduced survival. We analyzed the COL10A1 promoter using the UCSC genome website and JASPAR database, and we found potential SOX9 binding site. Here, we demonstrated that SOX9 and COL10A1 were both up-regulated in GC. We observed a positive correlation between the expression patterns of SOX9 and COL10A1 in GC cells and tissues. The results of electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP) assay and promoter reporter indicated that SOX9 could directly bind to the COL10A1 gene promoter and activate its transcription. Biological function experiments showed that COL10A1 regulated the migration and invasion of GC cells. Knockdown COL10A1 inhibited lung and abdominal cavity metastasis in a nude mouse model. Moreover, transforming growth factor-β1 (TGF-β1) treatment up-regulated the phosphorylation of Smad2 and increased SOX9 and COL10A1 expression. COL10A1 was confirmed to be a potential inducer of epithelial-to-mesenchymal transition (EMT). SOX9 was essential for COL10A1-mediated EMT, and cell migration, invasion and metastasis. Co-expression of SOX9 and COL10A1 was associated with tumor progression and was strongly predictive of overall survival in GC patients. In summary, this study elucidated the mechanistic link between COL10A1 and the TGF-β1-SOX9 axis. These findings indicated that COL10A1 might play a crucial role in GC progression and serve as a potential biomarker and therapeutic target in GC patients.

S100P enhances the motility and invasion of human trophoblast cell lines

S100P has been shown to be a marker for carcinogenesis where its expression in solid tumours correlates with metastasis and a poor patient prognosis. This protein's role in any physiological process is, however, unknown. Here we first show that S100P is expressed both in trophoblasts in vivo as well as in some corresponding cell lines in culture. We demonstrate that S100P is predominantly expressed during the early stage of placental formation with its highest expression levels occurring during the first trimester of gestation, particularly in the invading columns and anchoring villi. Using gain or loss of function studies through overexpression or knockdown of S100P expression respectively, our work shows that S100P stimulates both cell motility and cellular invasion in different trophoblastic and first trimester EVT cell lines. Interestingly, cell invasion was seen to be more dramatically affected than cell migration. Our results suggest that S100P may be acting as an important regulator of trophoblast invasion during placentation. This finding sheds new light on a hitherto uncharacterized molecular mechanism which may, in turn, lead to the identification of novel targets that may explain why significant numbers of confirmed human pregnancies suffer complications through poor placental implantation.

The HER4-YAP1 axis promotes trastuzumab resistance in HER2-positive gastric cancer by inducing epithelial and mesenchymal transition

Trastuzumab is the only target to be approved as the first-line treatment of HER2 positive metastatic gastric cancer, but ubiquitous resistance decreases its therapeutic benefit. In this study, we found HER4, phosphorylation HER4 (p-HER4) and the mesenchymal marker Vimentin increased in trastuzumab-resistant cells (MKN45TR and NCI-N87TR), while epithelial markers expressions in trastuzumab-resistant cell lines and animal models decreased. Additionally, silencing HER4 prevented the epithelial-mesenchymal transition and led to decreased proliferation and migration in vitro and in vivo. The expression of YAP1, a vital downstream interacted target of HER4, decreased when HER4 was knocked down. Interestingly, stimulation of NRG1 could compromise the inhibitory impact and rescue cell survival; whereas, transfection of siYAP1 sensitized trastuzumab-treated cells. Expression analysis of the proteins in patient-derived xenograft model (PDX) mice showed that HER4, p-HER4, YAP1, and Vimentin were clearly upregulated in the trastuzumab-resistant mice compared to mice without trastuzumab resistance. However, HER2 and E-cadherin were downregulated in response to continuous treatment with trastuzumab. These findings elucidated that the central role of the HER4-YAP1 axis in trastuzumab resistance of HER2-positive gastric cancer cells through induction of EMT. Hence, regulating the HER4-YAP1 axis might be a promising strategy for clinical interventions in patients with HER2-positive gastric cancer.

Interplay between Trx-1 and S100P promotes colorectal cancer cell epithelial-mesenchymal transition by up-regulating S100A4 through AKT activation

We previously reported a novel positive feedback loop between thioredoxin‐1 (Trx‐1) and S100P, which promotes the invasion and metastasis of colorectal cancer (CRC). However, the underlying molecular mechanisms remain poorly understood. In this study, we examined the roles of Trx‐1 and S100P in CRC epithelial‐to‐mesenchymal transition (EMT) and their underlying mechanisms. We observed that knockdown of Trx‐1 or S100P in SW620 cells inhibited EMT, whereas overexpression of Trx‐1 or S100P in SW480 cells promoted EMT. Importantly, S100A4 and the phosphorylation of AKT were identified as potential downstream targets of Trx‐1 and S100P in CRC cells. Silencing S100A4 or inhibition of AKT phosphorylation eliminated S100P‐ or Trx‐1‐mediated CRC cell EMT, migration and invasion. Moreover, inhibition of AKT activity reversed S100P‐ or Trx‐1‐induced S100A4 expression. The expression of S100A4 was higher in human CRC tissues compared with their normal counterpart tissues and was significantly correlated with lymph node metastasis and poor survival. The overexpression of S100A4 protein was also positively correlated with S100P or Trx‐1 protein overexpression in our cohort of CRC tissues. In addition, overexpression of S100P reversed the Trx‐1 knockdown‐induced inhibition of S100A4 expression, EMT and migration and invasion in SW620 cells. The data suggest that interplay between Trx‐1 and S100P promoted CRC EMT as well as migration and invasion by up‐regulating S100A4 through AKT activation, thus providing further potential therapeutic targets for suppressing the EMT in metastatic CRC.

Pinin facilitated proliferation and metastasis of colorectal cancer through activating EGFR/ERK signaling pathway

Increasing emphasis has been put on the influence of desmosome related proteins on progress of colorectal cancer (CRC). Pinin (PNN) is a desmosome-associated molecule that has been reported its overexpression could increase desmoglein 2 (DSG2) and E-cadherin (E-ca) levels. However, it was documented that DSG2 and E-ca had opposite functions in CRC. Thus, we attempted to elucidate function and mechanism of PNN in CRC. Herein, we revealed that overexpression of PNN was significantly correlated with the aggressive characteristics and indicated poor overall survival of CRC patients. In addition, the proliferation, invasion in vitro, and tumorigenic growth, metastasis in vivo were also promoted by the up-regulation of PNN. It was also verified that up-regulation of PNN increased the expression of DSG2 and activated the EGFR/ERK signaling pathway. Our findings suggested that PNN, as a valuable marker of prognosis, has important influence on the progression of CRC.

Cancer-associated S100P protein binds and inactivates p53, permits therapy-induced senescence and supports chemoresistance

S100P belongs to the S100 family of calcium-binding proteins regulating diverse cellular processes. Certain S100 family members (S100A4 and S100B) are associated with cancer and used as biomarkers of metastatic phenotype. Also S100P is abnormally expressed in tumors and implicated in migration-invasion, survival, and response to therapy. Here we show that S100P binds the tumor suppressor protein p53 as well as its negative regulator HDM2, and that this interaction perturbs the p53-HDM2 binding and increases the p53 level. Paradoxically, the S100P-induced p53 is unable to activate its transcriptional targets hdm2, p21^WAF, and bax following the DNA damage. This appears to be related to reduced phosphorylation of serine residues in both N-terminal and C-terminal regions of the p53 molecule. Furthermore, the S100P expression results in lower levels of pro-apoptotic proteins, in reduced cell death response to cytotoxic treatments, followed by stimulation of therapy-induced senescence and increased clonogenic survival. Conversely, the S100P silencing suppresses the ability of cancer cells to survive the DNA damage and form colonies. Thus, we propose that the oncogenic role of S100P involves binding and inactivation of p53, which leads to aberrant DNA damage responses linked with senescence and escape to proliferation. Thereby, the S100P protein may contribute to the outgrowth of aggressive tumor cells resistant to cytotoxic therapy and promote cancer progression.

CUL4A promotes proliferation and metastasis of colorectal cancer cells by regulating H3K4 trimethylation in epithelial-mesenchymal transition

Increasing evidence suggests that CUL4A, a ubiquitin ligase, is involved in the promotion of cancer malignancy and correlated with worse clinical prognosis in several kinds of human cancers. Although its effect and mechanism on the progression of colorectal cancer (CRC) remain unknown. Our clinical data show that CUL4A protein is overexpressed, positively associated with lymph nodes status, differentiation degree, tumor size, and poor prognosis in 80 CRC patients. CUL4A overexpression promotes cell proliferation and colony formation of CRC cells. Knockdown of CUL4A inhibits cell proliferation and migration. CUL4A can significantly promote the in vitro migration of CRC cells via induction of the epithelial–mesenchymal transition process. And the modulation of CUL4A expression altered the level of H3K4 trimethylation at the E-cadherin, N-cadherin, and vimentin gene promoters, which in turn transcriptionally regulated their expression. Moreover, knockdown of CUL4A also decreased the tumor volume and tumor weight in vivo. Together, our results reveal that CUL4A plays as an oncogene in CRC and may become a potential therapeutic target in the treatment of colorectal cancer.

Cdk3-promoted epithelial-mesenchymal transition through activating AP-1 is involved in colorectal cancer metastasis

Cyclin dependent kinase-3 (Cdk3) is a positive regulator of the G1 mammalian cell cycle phase. Cdk3 is involved in cancer progression, but very little is known about its mechanism in cancer development and progression. Herein, we found that Cdk3 increased colorectal cancer metastasis through promoting epithelial-mesenchymal transition (EMT) shift. Cdk3 was found to highly express in metastatic cancer and induce cell motility and invasion. Cdk3 was shown to phosphorylate c-Jun at Ser 63 and Ser 73 in vitro and ex vivo. Cdk3-phosphorylated c-Jun at Ser 63 and Ser 73 resulted in an increased AP-1 activity. Ectopic expression of Cdk3 promoted colorectal cancer from epithelial to mesenchymal transition conjugating AP-1 activation, while AP-1 inhibition dramatically decreased Cdk3-increased EMT shift. These results showed that the Cdk3/c-Jun signaling axis mediating epithelial-mesenchymal transition plays an important role in colorectal cancer metastasis.

Mechanisms through Which Hypoxia-Induced Caveolin-1 Drives Tumorigenesis and Metastasis in Hepatocellular Carcinoma

In solid tumors, hypoxia triggers an aberrant vasculogenesis, enhances malignant character, and elevates metastatic risk. The plasma membrane organizing protein caveolin-1 (Cav1) is increased in a variety of cancers, including hepatocellular carcinoma (HCC), where it contributes to metastatic capability. However, the reason for elevation of Cav1 in tumor cells and the mechanistic basis for its contributions to metastatic risk are not fully understood. Here, we show that in HCC cells, hypoxia elevates expression of Cav1, which then acts through the calcium-binding protein S100P to promote metastasis. Hypoxic regions of HCC xenografts displayed elevated expression of Cav1. Hypoxia promoted HCC cell migration and invasion and distant pulmonary metastases, whereas Cav1 silencing abolished these effects. Gene expression profiling revealed that hypoxia-induced Cav1 functioned as a positive regulator of S100P via activation of the NF-κB pathway. S100P elevation under hypoxic conditions was abrogated by silencing of Cav1 or NF-κB function. Conversely, restoring S100P in Cav1-silenced cells rescued the migratory potential of HCC cells along with tumor formation and lung metastasis. In clinical specimens of HCC, we observed S100P overexpression to correlate with venous invasion, microsatellites, direct liver invasion, and absence of tumor encapsulation. Collectively, our findings demonstrated how hypoxia-induced expression of Cav1 in HCC cells enhances their invasive and metastatic potential. Cancer Res; 76(24); 7242-53. ©2016 AACR.

Genetic variants of SOX9 contribute to susceptibility of gliomas among Chinese population

Gliomas make up about 80% of all malignant brain tumors, and cause serious public health problem. Genetic factors and environmental factors jointly caused the development of gliomas, and understanding of the genetic basis is a key component of preventive oncology. However, most genetic factors underlying carcinogenesis of gliomas remain largely unclear. In current study, we systematically evaluated whether genetic variants of SOX9 gene, a transcription factor that plays a central role in the development and differentiation of tumors, contribute to susceptibility of gliomas among Chinese population using a two-stage, case-control study. Results showed that SOX9 rs1042667 was significant associated with increased gliomas risk after adjusted by age, gender, family history of cancer, smoking status and alcohol status (Allele C vs A: OR=1.25; 95% CI=1.11-1.40; P=1.2×10-4). Compared with the carriers of genotype AA, both those of genotype AC (OR=1.37; 95% CI=1.13-1.66) and CC (OR=1.53; 95% CI=1.22-1.91) had significantly increased gliomas risk. This should be the first genetic association study which aims to evaluated the association between genetic variants of SOX9 and susceptibility of gliomas. Additional functional and association studies with different ethnic groups included are needed to further confirm our results.

SOX9-regulated cell plasticity in colorectal metastasis is attenuated by rapamycin

The cancer stem cell (CSC) hypothesis proposes a hierarchical organization of tumors, in which stem-like cells sustain tumors and drive metastasis. The molecular mechanisms underlying the acquisition of CSCs and metastatic traits are not well understood. SOX9 is a transcription factor linked to stem cell maintenance and commonly overexpressed in solid cancers including colorectal cancer. In this study, we show that SOX9 levels are higher in metastatic (SW620) than in primary colorectal cancer cells (SW480) derived from the same patient. This elevated expression correlated with enhanced self-renewal activity. By gain and loss-of-function studies in SW480 and SW620 cells respectively, we reveal that SOX9 levels modulate tumorsphere formation and self-renewal ability in vitro and tumor initiation in vivo. Moreover, SOX9 regulates migration and invasion and triggers the transition between epithelial and mesenchymal states. These activities are partially dependent on SOX9 post-transcriptional modifications. Importantly, treatment with rapamycin inhibits self-renewal and tumor growth in a SOX9-dependent manner. These results identify a functional role for SOX9 in regulating colorectal cancer cell plasticity and metastasis, and provide a strong rationale for a rapamycin-based therapeutic strategy.

Upregulation of sex-determining region Y-box 9 (SOX9) promotes cell proliferation and tumorigenicity in esophageal squamous cell carcinoma

Sex-determining region Y-box 9 (SOX9), a vital transcription factor, play important roles in numerous biological and pathological processes. However, the clinical significance and biological role of SOX9 expression has not been characterized in human esophageal squamous cell cancer (ESCC). Herein, we found that SOX9 was markedly upregulated, at both mRNA and protein level, in ESCC cell lines and ESCC tissues and that SOX9 expression was significantly correlated with tumor clinical stage, T classification, N classification, M classification, pathological differentiation, and shorter overall survival. The proliferation and tumorigenicity of ESCC cells were dramatically induced by SOX9 overexpression but were inhibited by SOX9 knockdown both in vitro and in vivo. Moreover, we demonstrated that upregulation of SOX9 increased the expression of phosphorylated Akt, the cyclin-dependent kinase (CDK) regulator cyclin D1, phosphorylated forkhead box O (FOXO)1, and phosphorylated FOXO3, but SOX9 downregulation decreased their expression, whereas the levels of the CDK inhibitors p21^Cip1 and p27^Kip1 were attenuated in SOX9-transduced cells. Taken together, our results suggest that SOX9 plays an important role in promoting the proliferation and tumorigenesis of ESCC and may represent a novel prognostic marker for the disease.

Animal models of colorectal peritoneal metastasis

Colorectal cancer remains an important cause of mortality worldwide. The presence of peritoneal carcinomatosis (PC) causes significant symptoms and is notoriously difficult to treat. Therefore, informative preclinical research into the mechanisms and possible novel treatment options of colorectal PC is essential in order to improve the prognostic outlook in these patients. Several syngeneic and xenograft animal models of colorectal PC were established, studying a wide range of experimental procedures and substances. Regrettably, more sophisticated models such as those giving rise to spontaneous PC or involving genetically engineered mice are lacking. Here, we provide an overview of all reported colorectal PC animal models and briefly discuss their use, strengths, and limitations.

CD146 promotes metastasis and predicts poor prognosis of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. Recurrence and metastasis after curative resection remain critical obstacles in HCC treatment. CD146 predicted poor prognosis of a variety of cancers including melanoma, breast tumors, prostate cancer, and gastric cancer. However, the role of CD146 in HCC has not yet been systematically explored.

METHODS

To investigate the role of CD146 in HCC, we evaluated its expression in HCC tissues and HCC cell lines using real-time PCR and western blotting (WB). Second, we established HCC cell lines that stably overexpressed and interfered CD146 and explored the function of CD146 in HCC in vitro and in vivo. Third, we conducted microarray analysis to investigate the potential mechanism by identifying differentially expressed genes. Last, follow ups were conducted to help uncover the connection of CD146 expression and the prognosis of HCC patients.

RESULTS

We found that CD146 was overexpressed in HCC tissues and that high CD146 expression predicted poor overall survival time and shorter recurrence period in HCC patients. In vitro and in vivo experiments indicated that CD146 promoted migration and invasion of HCC cell lines. Further study indicated that CD146 promoted epithelial mesenchymal transition (EMT), IL-8 upregulation, and STAT1 downregulation. CD146 was upregulated in HCC tissues and cell lines.

CONCLUSIONS

CD146 promoted metastasis of HCC cells and predicted poor prognosis of HCC patients. CD146 induced EMT, and IL-8 upregulation and STAT1 downregulation may be the potential underlying mechanism. The exact mechanism still needs further investigation.

Analysis of the predictive efficiency of S100P on adverse prognosis and the pathogenesis of S100P-mediated invasion and metastasis of colon adenocarcinoma

Elevated expression of S100P has been detected in several tumor types. To analyze the potential use of S100P for the prediction of colorectal cancer (CRC) metastasis and prognosis, S100P expression was detected in 125 patients with colon adenocarcinoma by immunohistochemistry, followed by correlation and survival analysis. High S100P expression was correlated with metastasis, as demonstrated by clinically relevant data, and predicted poor survival more effectively than preoperative serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels in colon adenocarcinoma. Stable S100P knockdown CRC cell lines were established to elucidate the relationship between S100P expression and tumor progression in vitro and in vivo. S100P knockdown resulted in reductions in the invasiveness and metastasis of CRC cells. Xenograft growth in nude mice also demonstrated that down-regulated S100P dramatically inhibited peritoneal metastasis of CRC cells. S100P promoted the invasion and metastasis of CRC by activating RAGE/ERK signaling and promoting the epithelial-mesenchymal transition (EMT). RAGE was found to be crucial for S100P-mediated EMT in colon cancer. Knockdown of RAGE in S100P-overexpressing colon cancer cells dramatically suppressed EMT process. Our results indicate that overexpression of S100P is related with an invasive and metastatic phenotype of CRC which is EMT-involved and RAGE dependent.

SOX9 expression predicts relapse of stage II colon cancer patients

The aim of this study was to investigate if the protein expression of sex-determining region y-box 9 (SOX9) in primary tumors could predict relapse of stage II colon cancer patients. One hundred forty-four patients with stage II primary colon cancer were retrospectively enrolled in the study. SOX9 expression was evaluated by immunohistochemistry, and mismatch repair status was assessed by both immunohistochemistry and promoter hypermethylation assay. High SOX9 expression at the invasive front was significantly associated with lower risk of relapse when including the SOX9 expression as a continuous variable (from low to high expression) in univariate (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.56-0.94; P = .01) and multivariate Cox proportional hazards analyses (HR, 0.75; 95% CI, 0.58-0.96; P = .02), adjusting for mismatch repair deficiency and histopathologic risk factors. Conversely, low SOX9 expression at the invasive front was significantly associated with high risk of relapse, when including SOX9 expression as a dichotomous variable, in univariate (HR, 2.32; 95% CI, 1.14-4.69; P = .02) and multivariate analyses (HR, 2.32; 95% CI, 1.14-4.69; P = .02), adjusting for histopathologic risk factors and mismatch repair deficiency. In conclusion, high levels of SOX9 of primary stage II colon tumors predict low risk of relapse, whereas low levels of SOX9 predict high risk of relapse. SOX9 may have an important value as a biomarker when evaluating risk of relapse for personalized treatment.

The multiple faces of RAGE--opportunities for therapeutic intervention in aging and chronic disease

INTRODUCTION

This review focuses on the multi-ligand receptor of the immunoglobulin superfamily--receptor for advanced glycation endproducts (RAGE). The accumulation of the multiple ligands of RAGE in cellular stress milieux links RAGE to the pathobiology of chronic disease and natural aging.

AREAS COVERED

In this review, we present a discussion on the ligands of RAGE and the implications of these ligand families in disease. We review the recent literature on the role of ligand-RAGE interaction in the consequences of natural aging; the macro- and microvascular complications of diabetes; obesity and insulin resistance; autoimmune disorders and chronic inflammation; and tumors and Alzheimer's disease. We discuss the mechanisms of RAGE signaling through its intracellular binding effector molecule--the formin DIAPH1. Physicochemical evidence of how the RAGE cytoplasmic domain binds to the FH1 (formin homology 1) domain of DIAPH1, and the consequences thereof, are also reviewed.

EXPERT OPINION

We discuss the modalities of RAGE antagonism currently in preclinical and clinical studies. Finally, we present the rationale behind potentially targeting the RAGE cytoplasmic domain-DIAPH1 interaction as a logical strategy for therapeutic intervention in the pathological settings of chronic diseases and aging wherein RAGE ligands accumulate and signal.

The S100P/RAGE signaling pathway regulates expression of microRNA-21 in colon cancer cells

S100P signaling through the receptor for advanced glycation end-products (RAGE) contributes to colon cancer invasion and metastasis, but the mechanistic features of this process are obscure. Here, we investigate whether activation of S100P/RAGE signaling regulates oncogenic microRNA-21 (miR-21). We show that exogenous S100P up-regulates miR-21 levels in human colon cancer cells, whereas knockdown of S100P results in a decrease of miR-21. Furthermore, blockage of RAGE with anti-RAGE antibody suppresses S100P induction of miR-21. In addition, we found that S100P induction of miR-21 expression involves ERK and is suppressed by the MEK inhibitor U0126. Also, S100P treatment stimulates the enrichment of c-Fos, and AP-1 family members, at the miR-21 gene promoter.