Cten promotes Epithelial–Mesenchymal Transition (EMT) in colorectal cancer through stabilisation of Src

Kaempferol inhibited invasion and metastasis of gastric cancer cells by targeting AKT/GSK3β pathway based on network pharmacology and molecular docking

This study aims to explore the mechanisms of the inhibitory effect of kaempferol on the invasion and metastasis of gastric cancer (GC) cells through network pharmacology prediction and experimental verification. It identifies core targets via PPI network analysis and finds that kaempferol binds to these targets well. In vitro experiments showed that kaempferol could inhibit the proliferation, colony formation, migration and invasion of GC cells. Western blotting indicated kaempferol may reduce AKT and GSK3β phosphorylation, leading to lower expression of invasion-related genes SRC, MMP9, CXCR4, KDR, and MMP2. Overall, kaempferol may prevent migration and invasion of GC cells via the AKT/GSK3β signaling pathway.

Development and functional validation of a disulfidoptosis-related gene prognostic model for lung adenocarcinoma based on bioinformatics and experimental validation

Background

Disulfidoptosis is increasingly linked to cancer progression, yet its immunological impacts and prognostic value in lung adenocarcinoma (LUAD) remain poorly understood. This study aims to delineate the predictive significance of disulfidoptosis-related genes (DRGs) in LUAD, their potential as therapeutic targets, and their interaction with the tumor microenvironment.

Methods

We analyzed the expression profiles of 23 DRGs and survival data, performing consensus clustering to identify molecular subtypes. Survival analysis and gene set variation analysis (GSVA) were used to explore cluster differences. Key DRGs were selected for Cox and LASSO regression to develop a prognostic model. Tensin4 (TNS4), a key gene in the model, was further evaluated through immunohistochemistry (IHC) in LUAD and normal tissues and gene knockdown experiments in vitro.

Results

Two clusters were identified, with 225 differentially expressed genes. A six-gene signature was developed, which classified LUAD patients into high- and low-risk groups, showing significant survival differences. The risk score independently predicted LUAD prognosis and correlated with immunotherapy responses. IHC showed elevated TNS4 levels in LUAD tissues, while in vitro TNS4 knockdown reduced both cell proliferation and migration.

Conclusion

This study highlights the role of DRGs in LUAD, with a validated gene signature offering new avenues for targeted therapies, potentially improving LUAD treatment outcomes.

Chitosan and hyaluronic acid in colorectal cancer therapy: A review on EMT regulation, metastasis, and overcoming drug resistance

Up to 90% of cancer-related fatalities could be attributed to metastasis. Therefore, understanding the mechanisms that facilitate tumor cell metastasis is beneficial for improving patient survival and results. EMT is considered the main process involved in the invasion and spread of CRC. Essential molecular components like Wnt, TGF-β, and PI3K/Akt play a role in controlling EMT in CRC, frequently triggered by various factors such as Snail, Twist, and ZEB1. These factors affect not only the spread of CRC but also determine the reaction to chemotherapy. The influence of non-coding RNAs, especially miRNAs and lncRNAs, on the regulation of EMT is clear in CRC. Exosomes, involved in cell-to-cell communication, can affect the TME and metastasis of CRC. Pharmacological substances and nanoparticles demonstrate promise as efficient modulators of EMT in CRC. Chitosan and HA are two major carbohydrate polymers with considerable potential in inhibiting CRC. Chitosan and HA can be employed to modify nanoparticles to enhance cargo transport for reducing CRC. Additionally, chitosan and HA-modified nanocarriers, which can be utilized as potential approaches in suppressing EMT and reversing drug resistance in CRC, can inhibit EMT and chemoresistance, crucial components in tumorigenesis.

Tensin 4 facilitates aerobic glycolysis, migration and invasion of colorectal cancer cells through the β‑catenin/c‑Myc signaling pathway

Tensin 4 (TNS4) is overexpressed in multiple cancers, including colorectal cancer (CRC), and is associated with a poor prognosis of patients with CRC. However, the role and underlying mechanisms of TNS4 in CRC have yet to be elucidated. The expression of TNS4 in CRC tissues were analyzed by immunohistochemistry. Cell migration and invasion were assessed in vitro using Transwell assay. Western blot and reverse transcription (RT)-quantitative (q)PCR were used to investigate the molecular mechanisms by which TNS4 regulates aerobic glycolysis, migration and invasion of CRC cells. The present study demonstrated that TNS4 was highly expressed in the cancer tissues of patients with CRC and significantly associated with the tumor-node-metastasis stages. TNS4 silencing led to a significant decrease in glucose consumption and lactate production in CRC cells, and knockdown of TNS4 suppressed the migration and invasion of CRC cells via aerobic glycolysis through the β-catenin/c-Myc pathway. Notably, treatment with DASA-58, an activator of glycolysis, or SKL2001, an activator of β-catenin/c-Myc signaling, significantly reversed the effect of TNS4 knockdown on aerobic glycolysis, migration and invasion of CRC cells. Collectively, these results suggest that TNS4 may act as a novel regulator of aerobic glycolysis, migration and invasion of CRC cells by modulating β-catenin/c-Myc signaling, providing a new potential biomarker and therapeutic target in CRC.

CTEN-induced TGF-β1 expression facilitates EMT and enhances paclitaxel resistance in bladder cancer cells

OBJECTIVES

To investigate the role of C-terminal tensin-like (CTEN) in mediating chemotherapy resistance via epithelial-mesenchymal transition (EMT) in bladder cancer (BC) cells, through the regulation of transforming growth factor-β1 (TGF-β1) expression.

METHODS

Lentiviral vectors were used to create CTEN overexpression and knockdown constructs, which were then introduced into paclitaxel-resistant BC cell lines. The effects of CTEN manipulation on cell proliferation and drug sensitivity was assessed using the CCK-8 assay, and apoptosis was evaluated by flow cytometry. The expression levels of CTEN, TGF-β1, and EMT markers were quantified by RT-qPCR and Western blot analysis. The interaction between CTEN and TGF-β1 and its effect on TGF-β1 methylation were studied using bisulfite sequencing PCR and co-immunoprecipitation.

RESULTS

Overexpression of CTEN in BC cells was associated with decreased paclitaxel efficacy, reduced apoptosis, and elevated levels of TGF-β1 and EMT-related proteins. CTEN was found to bind TGF-β1, inhibiting its methylation and thereby promoting TGF-β1 upregulation. This increase in TGF-β1 expression facilitated the EMT process and enhanced drug resistance in BC cells.

CONCLUSIONS

The induction of TGF-β1 expression by CTEN promotes EMT and increases chemotherapy resistance in BC cells. Targeting CTEN or the EMT pathway could improve chemosensitivity in treatment-resistant BC, suggesting a novel therapeutic strategy to enhance chemotherapy effectiveness.

Role of Post-Translational Modifications in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive tract. CRC metastasis is a multi-step process with various factors involved, including genetic and epigenetic regulations, which turn out to be a serious threat to CRC patients. Post-translational modifications (PTMs) of proteins involve the addition of chemical groups, sugars, or proteins to specific residues, which fine-tunes a protein's stability, localization, or interactions to orchestrate complicated biological processes. An increasing number of recent studies suggest that dysregulation of PTMs, such as phosphorylation, ubiquitination, and glycosylation, play pivotal roles in the CRC metastasis cascade. Here, we summarized recent advances in the role of post-translational modifications in diverse aspects of CRC metastasis and its detailed molecular mechanisms. Moreover, advances in drugs targeting PTMs and their cooperation with other anti-cancer drugs, which might provide novel targets for CRC treatment and improve therapeutic efficacy, were also discussed.

Unraveling the function of epithelial-mesenchymal transition (EMT) in colorectal cancer: Metastasis, therapy response, and revisiting molecular pathways

Colorectal cancer (CRC) is a dangerous form of cancer that affects the gastrointestinal tract. It is a major global health concern, and the aggressive behavior of tumor cells makes it difficult to treat, leading to poor survival rates for patients. One major challenge in treating CRC is the metastasis, or spread, of the cancer, which is a major cause of death. In order to improve the prognosis for patients with CRC, it is necessary to focus on ways to inhibit the cancer's ability to invade and spread. Epithelial-mesenchymal transition (EMT) is a process that is linked to the spread of cancer cells, also known as metastasis. The process transforms epithelial cells into mesenchymal ones, increasing their mobility and ability to invade other tissues. This has been shown to be a key mechanism in the progression of colorectal cancer (CRC), a particularly aggressive form of gastrointestinal cancer. The activation of EMT leads to increases in the spread of CRC cells, and during this process, levels of the protein E-cadherin decrease while levels of N-cadherin and vimentin increase. EMT also contributes to the development of resistance to chemotherapy and radiation therapy in CRC. Non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), play a role in regulating EMT in CRC, often through their ability to "sponge" microRNAs. Anti-cancer agents have been shown to suppress EMT and reduce the progression and spread of CRC cells. These findings suggest that targeting EMT or related mechanisms may be a promising approach for treating CRC patients in the clinic.

Nuclear-localized CTEN is a novel transcriptional regulator and promotes cancer cell migration through its downstream target CDC27

C-terminal tensin-like (CTEN) is a tensin family protein typically localized to the cytoplasmic side of focal adhesions, and primarily contributes to cell adhesion and migration. Elevated expression and nuclear accumulation of CTEN have been reported in several types of cancers and found to be associated with malignant behaviors. However, the function of nuclear CTEN remains elusive. In this study, we report for the first time that nuclear CTEN associates with chromatin DNA and occupies the region proximal to the transcription start site in several genes. The mRNA expression level of CTEN positively correlates with that of one of its putative target genes, cell division cycle protein 27 (CDC27), in a clinical colorectal cancer dataset, suggesting that CTEN may play a role in the regulation of CDC27 gene expression. Furthermore, we demonstrated that CTEN is recruited to the promoter region of the CDC27 gene and that the mRNA expression and promoter activity of CDC27 are both reduced when CTEN is downregulated. In addition, we found that enhanced nuclear accumulation of CTEN in HCT116 cells by overexpression of CTEN fused with nuclear localization signals increases CDC27 transcript levels and promoter activity. The increased nuclear-localized CTEN also significantly promotes cell migration, and the migratory ability is suppressed when CDC27 is knocked down. These results demonstrate that nuclear CTEN regulates CDC27 expression transcriptionally and promotes cell migration through CDC27. Our findings provide new insights into CTEN moonlighting in the nucleus as a DNA-associated protein and transcriptional regulator involved in modulating cancer cell migration.

Immunohistochemical Expression of Tensin-4/CTEN in Squamous Cell Carcinoma in Dogs

C-terminal tensin-like (tensin-4/TNS4/CTEN) is the fourth member of the tensin family, frequently described as displaying oncological functions, including cellular migration, invasion, adhesion, growth, metastasis, epithelial to mesenchymal transition, and apoptosis, in several different types of cancer. To investigate, for the first time, the clinical significance of CTEN in squamous cell carcinoma (SCC) of dogs, we studied a total of 45 SCC sections from various dog breeds. The mean age of the affected dogs was 8.9 ± 3.6 years. Immunohistochemistry confirmed strong cytoplasmatic CTEN expression in the basal layer of the epidermis next to the tumor. We detected high CTEN expression associated with the highest grade of the tumor (grade III) and observed 100% of immunopositivity for this tumor grading (p < 0.0001). These data suggest that CTEN is an oncogene in SCC of dogs and a promising biomarker and a therapeutic target for dogs affected by SCC.

Mining TCGA and GEO databases for the prediction of poor prognosis in lung adenocarcinoma based on up-regulated expression of TNS4

To investigate the clinical significance of Tensin4 (TNS4) in human cancers, particularly lung cancer, we mined the Cancer Genome Atlas database for lung adenocarcinoma (TCGA-LUAD) and the Gene Expression Omnibus database to predict poor prognosis based on the up-regulated expression of TNS4 in LUAD. The correlation between the clinical pathologic features of patients and TNS4 gene expression was analyzed using the Wilcoxon signed-rank test. Cox regression analysis was used to evaluate the association of clinicopathologic characteristics with the overall survival (OS) of cancer patients using TCGA data. The relationship between TNS4 expression and cancer patient survival was evaluated with Kaplan-Meier survival curves and meta-analyses. GO and KEGG were also included in the data mining methods. The expression level of TNS4 in LUAD tissue was higher than that in adjacent normal tissue (P < .001). According to the Kaplan-Meier survival curve, LUAD patients with high TNS4 expression had worse prognosis than those with low TNS4 expression (P < .001 for OS; P = .028 for progression-free survival). A positive correlation between TNS4 expression and poor OS was found with both univariate and multivariate analyses. Increased TNS4 expression in LUAD was closely correlated with a higher disease stage (P = .007), positive lymph nodes (P = .005), and larger tumor size (P = .002). Moreover, meta-analysis including seven independent datasets showed LUAD patients with higher TNS4 had poorer OS (combined hazard ratio = 1.27, 95% confidence interval 1.16-1.39). In the high-TNS4 population, regulation of the actin cytoskeleton, extracellular matrix receptor interactions, and focal adhesion were differentially enriched. Integrin α6β4 and laminin-5 genes were also associated with TNS4. TNS4 expression may be a potential biomarker for predicting poor survival in LUAD. Moreover, the correlation between TNS4 and integrin α6β4 may be attributed to the role of TNS4 in LUAD.

Four methylation-driven genes detected by linear discriminant analysis model from early-stage colorectal cancer and their methylation levels in cell-free DNA

The process of colorectal cancer (CRC) formation is considered a typical model of multistage carcinogenesis in which aberrant DNA methylation plays an important role. In this study, 752 methylation-driven genes (MDGs) were identified by the MethylMix package based on methylation and gene expression data of CRC in The Cancer Genome Atlas (TCGA). Iterative recursive feature elimination (iRFE) based on linear discriminant analysis (LDA) was used to determine the minimum MDGs (iRFE MDGs), which could distinguish between cancer and cancer-adjacent tissues. Further analysis indicated that the changes in methylation levels of the four iRFE MDGs, ADHFE1-Cluster1, CNRIP1-Cluster1, MAFB, and TNS4, occurred in adenoma tissues, while changes did not occur until stage IV in cell-free DNA. Furthermore, the methylation levels of iRFE MDGs were correlated with the genes involved in the reprogramming process of somatic cells to pluripotent stem cells, which is considered the common signature of cancer cells and embryonic stem cells. The above results indicated that the four iRFE MDGs may play roles in the early stage of colorectal carcinogenesis and highlighted the complicated relationship between tissue DNA and cell-free DNA (cfDNA).

Identification of an Immune-Related BAT Signature for Predicting Adjuvant Chemotherapy Response and Overall Survival in Patients with Resected Ductal Adenocarcinoma of the Pancreas

BACKGROUND

Adjuvant chemotherapy (ACT) is widely accepted in patients with pancreatic ductal adenocarcinoma (PDAC) after surgery; however, effective models for predicting ACT response are scarce. Thus, the objective of this study was to develop a novel signature for predicting its response and overall survival (OS) in resected PDAC patients.

METHODS

A total of 50 PDAC patients with the transcriptome expression profiles, information about chemotherapy, and relevant clinical data were retrieved from the Cancer Genome Atlas (TCGA), and twenty-nine patients with tissue specimens and clinical data from our hospital were included as a validation. A novel gene signature was developed using bioinformatic differentially expressed genes (DEGs) analysis, Lasso-penalized Cox regression, and multivariate Cox regression studies.

RESULTS

Between chemotherapy-resistant and chemotherapy-sensitive cohorts, 569 DEGs were identified, with 490 upregulated and 79 downregulated genes mainly specialized in the regulation of peptide/protein/hormone secretion, calcium ion homeostasis, and T cell activation regulation in biological processes. After Lasso-penalized Cox and multivariate Cox regression analysis, BAT (BCHE, ADH1A, and TNS4) signature was established to predict ACT response and OS. Moreover, BAT signature was verified as an independent risk factor for ACT response (p = 0.042) and OS (median OS: 17.5 months vs. 34.8 months, p = 0.040) and significantly associated with immune infiltrations (p < 0.05). Then, this signature was further validated as the independent risk factor for recurrence-free survival (RFS) in PDAC patients receiving postoperative ACT (median RFS: 9.0 months vs. not reached, p = 0.014), and tumor-infiltrating CD4+ and CD8+ T cells were further validated to be significantly decreased in tissues with higher BAT signature scores (p = 0.015 and 0.021, respectively).

CONCLUSION

The BAT signature is a novel formulated and independent risk factor for predicting ACT response and long-term survival in patients with resected PDAC. This signature could comprehensively reflect local immune-related response, tumor purity, potential biological behavior, and chemo drug susceptibility.

Increased tensin 4 expression is related to the histological type of gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common malignant tumors worldwide. Tensin 4 (TNS4) is an adhesive protein belonging to the tensin family. This protein is located in focal adhesion sites. The TNS4 gene is considered an oncogene in numerous cancers. This protein plays an important role in adhesion, migration and proliferation of cells.

AIM

To evaluate expression of TNS4 protein in GC tissues and analysis of the clinical and histopathological parameters as well as the overall survival rate of patients.

METHODS

The expression of TNS4 was assessed in 89 patients using immunohistochemistry.

RESULTS

Positive expression of TNS4 was observed in 49 of 89 patients (55.06%). Higher TNS4 expression was more common in GC tumors with a diameter ≥ 5 cm (P = 0.040). We demonstrated that an increase in TNS4 expression was more frequent in tumors of the histological type without mucinous components than in tumors from mucosal cancers (P = 0.023). Furthermore, TNS4 expression was higher in moderately differentiated tumors than in poorly differentiated and non-differentiated tumors (P = 0.002). Increased TNS4 expression was also noted in the intestinal type of GC according to Lauren’s classification (P = 0.020). No statistically significant correlation was found between the expression of TNS4 and the overall survival rate of patients.

CONCLUSION

TNS4 expression was significantly higher in tumors with a diameter ≥ 5 cm of the moderately differentiated intestinal type (according to Lauren’s classification) of GC without a mucinous component. Therefore, increased TNS4 expression is related to the histological type of GC with a better prognosis.

CTEN Inhibits Tumor Angiogenesis and Growth by Targeting VEGFA Through Down-Regulation of β-Catenin in Breast Cancer

C-terminal tensin-like (CTEN) belongs to the tensin gene family, which encodes proteins that localize to focal adhesions and modulate integrin function. Accumulating studies have reported that CTEN expression can be upregulated or downregulated in different types of cancers, suggesting that CTEN has both oncogenic and tumor suppressor functions. In this study, by analyzing the expression level of CTEN in the human breast cancer (BRCA) samples from the clinically annotated genomic database, The Cancer Genome Atlas, we found that CTEN was downregulated in different BRCA subclasses, including luminal, human epidermal growth factor receptor 2 positive and triple-negative BRCA. Consistently, the protein level of CTEN was also reduced in BRCA based on the Proteomic Tumor Analysis Consortium. In contrast, vascular endothelial growth factor A (VEGFA), a signal protein that stimulates the formation of blood vessels, was upregulated in BRCA. CTEN overexpression in human umbilical vein endothelial cells and MCF7 significantly suppressed the expression of VEGFA, inhibited cell proliferation, migration, and tube formation in vitro. Mechanistically, CTEN bind to casitas B-lineage lymphoma (c-Cbl), an E3 ubiquitin-protein ligase, and decreased the β-catenin expression. In turn, the downregulation of β-catenin reduced the expression of VEGFA. Rescuing β-catenin expression effectively ameliorated the effect of CTEN overexpression in cell proliferation, migration, and tube formation. In conclusion, CTEN inhibited tumor angiogenesis by targeting VEGFA through c-Cbl-mediated down-regulation of β-catenin and may serve as a tumor suppressor in BRCA.

[Value of prediction models for prognosis prediction of colorectal cancer: an analysis based on TCPA database]

OBJECTIVE

To assess the value of the combination of multiple proteins in predicting the prognosis of colorectal cancer (CRC) through bioinformatics analysis.

OBJECTIVE

The protein expression and clinical data were downloaded from TCPA database. Perl and R were used to screen the prognostic-related proteins, and through Cox analysis, the proteins that served as independent prognostic factors of CRC were identified to build the prediction model. Survival analyses were conducted for each of the proteins included in the prediction model and the risk score of the model, and risk curves was drawn for the risk score and the patients' survival status to verify the performance of the model. Independent prognosis analysis and ROC analysis were used to assess the value and advantages of the model in prognosis prediction. The interactions between the proteins included in the model and the differential expressions of the key genes related with the proteins were analyzed.

OBJECTIVE

Six proteins were screened for model construction. Compared with a single gene, the model showed much greater prognostic value for CRC. Independent prognostic analysis showed that the risk score of the prediction model was significantly related with the prognosis (P < 0.001), and the model could be used as an independent risk factor for prognostic assessment of the patients. ROC analysis showed that the model had good specificity and sensitivity for prognostic prediction (AUC=0.734). Protein interactions showed that BID, SLC1A5 and SRC_pY527 were significantly correlated with other proteins (P < 0.001), and SLC1A5 and SRC_pY527 had the most significant interactions with other proteins (P < 0.001). Except for those of INPP4B, the key genes related with the proteins in the prediction model had significant differential expressions at the mRNA level in CRC (P < 0.05).

OBJECTIVE

The prediction model constructed based on 6 proteins has good prognostic value for CRC. The proteins SLC1A5 and SRC_pY527 play key roles in the prognosis of CRC, and SRC_pY527 may regulate the occurrence and progression of CRC through the SRC/AKT/MAPK signal axis and thus may serve as a new therapeutic target of CRC.

Tensins - emerging insights into their domain functions, biological roles and disease relevance

Tensins are a family of focal adhesion proteins consisting of four members in mammals (TNS1, TNS2, TNS3 and TNS4). Their multiple domains and activities contribute to the molecular linkage between the extracellular matrix and cytoskeletal networks, as well as mediating signal transduction pathways, leading to a variety of physiological processes, including cell proliferation, attachment, migration and mechanical sensing in a cell. Tensins are required for maintaining normal tissue structures and functions, especially in the kidney and heart, as well as in muscle regeneration, in animals. This Review discusses our current understanding of the domain functions and biological roles of tensins in cells and mice, as well as highlighting their relevance to human diseases.

Identification of 6 Hub Proteins and Protein Risk Signature of Colorectal Cancer

Background

Colorectal cancer (CRC) is the second most common cause of cancer death in the United States and the third most common cancer globally. The incidence of CRC tends to be younger, and we urgently need a reliable prognostic assessment strategy.

Methods

Protein expression profile and clinical information of 390 CRC patients/samples were downloaded from the TCPA and TCGA database, respectively. The Kaplan-Meier, Cox regression, and Pearson correlation analysis were applied in this study.

Results

Based on the TCPA and TCGA database, we screened 6 hub proteins and first constructed protein risk signature, all of which were significantly associated with CRC patients' overall survival (OS). The risk score was an independent prognostic factor and significantly related with the size of the tumor in situ (T). 6 hub proteins were differentially expressed in cancer and normal tissues and in different CRC stages, which were validated at the ONCOMINE database. Next, 40 coexpressed proteins of 6 hub proteins were extracted from the TCPA database. In the protein-protein interaction (PPI) network, HER1, HER2, and CTNNB1 were at the center. Function enrichment analysis illustrated that 46 proteins were mainly involved in the EGFR (HER1) tyrosine kinase inhibitor resistance pathway.

Conclusion

Studies indicated that 6 hub proteins might be considered as new targets for CRC therapies, and the protein risk signature can be used to predict the OS of CRC patients.

Overexpression of CTEN is associated with gefitinib resistance in non-small cell lung cancer

COOH-terminus tensin-like molecule (CTEN) is a member of the tensin family, which is considered to be one of the novel proto-oncogenes involved in tumorigenesis and cancer progression. However, the mechanisms of CTEN in acquired resistance of non-small cell lung cancer (NSCLC) remain relatively unknown. The aim of the present study was to understand the roles of CTEN in acquired gefitinib resistance of NSCLC. The present study investigated the expression level of CTEN using reverse transcription-quantitative polymerase chain reaction and Western blot analysis. Cell Counting kit-8 and colony-formation assays were performed to evaluate the proliferative and colony-formative abilities of PC9 and PC9/GR cells in vitro. Mouse xenograft models were used to assess the growth of PC9/GR cells in vivo. A gefitinib-resistant NSCLC cell line (PC9/GR) was established, and the protein and mRNA expression levels of CTEN were observed to be higher in PC9/GR cells than in PC9 cells. Notably, the sensitivity of PC9/GR cells to gefitinib was observed to be decreased when CTEN was overexpressed, while PC9/GR cells with CTEN-downregulation showed markedly enhanced sensitivity to gefitinib. In vitro proliferation and colony formation assays revealed that increased CTEN markedly promoted the cell proliferative and colony-forming capacities of PC9 and PC9/GR cells, and CTEN-silencing inhibited the cell proliferative and colony-forming abilities of the PC9 and PC9/GR cells. Notably, deficient expression of CTEN notably retarded the growth of PC9/GR xenografts in vivo. In addition, the plasma mRNA expression of CTEN was notably elevated in patients with NSCLC with acquired gefitinib resistance. Overexpression of CTEN is associated with acquired gefitinib resistance in NSCLC. CTEN may be investigated as a potential therapeutic target for the treatment of patients with NSCLC with acquired gefitinib resistance.

Tensin4 (TNS4) is upregulated by Wnt signalling in adenomas in multiple intestinal neoplasia (Min) mice

Apc^Min/+ mice are regarded as a standard animal model of colorectal cancer (CRC). Tensin4 (TNS4 or Cten) is a putative oncogene conferring features of stemness and promoting motility. Our objective was to assess TNS4 expression in intestinal adenomas and determine whether TNS4 is upregulated by Wnt signalling. Apc^Min/+ mice (n = 11) were sacrificed at approximately 120 days old at the onset of anaemia signs. Small intestines were harvested, and Swiss roll preparations were tested for TNS4 expression by immunohistochemistry (IHC). Individual polyps were also separately collected (n = 14) and tested for TNS4 mRNA expression and Kras mutation. The relationship between Wnt signalling and TNS4 expression was tested by Western blotting in the human CRC cell line HCT116 after inhibition of β-catenin activity with MSAB or its increase by transfection with a Flag β-catenin expression vector. Overall, 135/148 (91.2%) of the total intestinal polyps were positive for TNS4 expression by IHC, whilst adjacent normal areas were negative. RT-qPCR analysis showed approximately 5-fold upregulation of TNS4 mRNA in the polyps compared to adjacent normal tissue and no Kras mutations were detected. In HCT116, β-catenin inhibition resulted in reduced TNS4 expression, and conversely, β-catenin overexpression resulted in increased TNS4 expression. In conclusion, this is the first report linking aberrant Wnt signalling to upregulation of TNS4 both during initiation of intestinal adenomas in mice and in in vitro models. The exact contribution of TNS4 to adenoma development remains to be investigated, but the Apc^Min/+ mouse represents a good model to study this.

Tensin4 promotes invasion and migration of gastric cancer cells via regulating AKT/GSK-3β/snail signaling pathway

Gastric cancer (GC) remains one of the most lethal human malignancies, and exploring novel therapeutic targets for the treatment has been a major focus. The molecular mechanism of invasion and migration of GC cells remains unclear. The present study aimed to investigate the role of Tensin 4 and the associated molecular signaling pathways in the process of invasion and metastasis of GC. The expression of Tensin 4 protein and phosphorylated AKT (p-AKT) were evaluated in GC and normal adjacent tissues of 80 patients using immunohistochemistry staining. The expression of Tensin4 mRNA was analyzed in 10 GC tissues and 3 GC cell lines (SGC7901, MKN45, and MKN28) by qPCR. Cell proliferation, migration, and invasion were assessed using CCK-8 and Transwell assays in the Tensin 4 siRNA transfected SGC7901 cells and Tensin 4 plasmid transfected MKN28 cells. Additionally, protein expressions of Tensin 4, E-cadherin, vimentin, AKT, p-AKT, GSK-3β, p-GSK-3β, and Snail were analyzed by western blotting. The results demonstrated that the expression of Tensin 4 was significantly up-regulated in the GC tissues and cell lines, especially in the SGC7901 cells. The expression of Tensin 4 positively correlated with p-AKT in GC tissues and with GC progression, and was an independent risk factor for the prognosis of GC. Tensin 4 promoted the invasion and migration abilities of GC cells, but had no significant effect on GC cell proliferation. Tensin 4 promoted the occurrence of epithelial mesenchymal transition (EMT) through up-regulating the expression of p-AKT, p-GSK-3β, and snail. Overall, this study suggests that the activation of AKT/GSK-3β/Snail signaling pathway promoted by Tensin 4 plays an important role in the progression of GC. Therefore, Tensin 4 may serve as a potential target in GC treatment.

A Novel Model of Cancer Drug Resistance: Oncosomal Release of Cytotoxic and Antibody-Based Drugs

Extracellular vesicles (EVs), such as exosomes or oncosomes, often carry oncogenic molecules derived from tumor cells. In addition, accumulating evidence indicates that tumor cells can eject anti-cancer drugs such as chemotherapeutics and targeted drugs within EVs, a novel mechanism of drug resistance. The EV-releasing drug resistance phenotype is often coupled with cellular dedifferentiation and transformation in cells undergoing epithelial-mesenchymal transition (EMT), and the adoption of a cancer stem cell phenotype. The release of EVs is also involved in immunosuppression. Herein, we address different aspects by which EVs modulate the tumor microenvironment to become resistant to anticancer and antibody-based drugs, as well as the concept of the resistance-associated secretory phenotype (RASP).