SEC22B inhibition attenuates colorectal cancer aggressiveness and autophagic flux under unfavorable environment.

Autophagy has bidirectional functions in cancer by facilitating cell survival and death in a context-dependent manner. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are a large family of proteins essential for numerous biological processes, including autophagy; nevertheless, their potential function in cancer malignancy remains unclear. Here, we explored the gene expression patterns of SNAREs in tissues of patients with colorectal cancer (CRC) and discovered that SEC22B expression, a vesicle SNARE, was higher in tumor tissues than in normal tissues, with a more significant increase in metastatic tissues. Interestingly, SEC22B knockdown dramatically decreased CRC cell survival and growth, especially under stressful conditions, such as hypoxia and serum starvation, and decreased the number of stress-induced autophagic vacuoles. Moreover, SEC22B knockdown successfully attenuated liver metastasis in a CRC cell xenograft mouse model, with histological signs of decreased autophagic flux and proliferation within cancer cells. Together, this study posits that SEC22B plays a crucial role in enhancing the aggressiveness of CRC cells, suggesting that SEC22B might be an attractive therapeutic target for CRC.

A Genome-Wide Screen Reveals That Endocytic Genes Are Important for Pma1p Asymmetry during Cell Division in Saccharomyces cerevisiae.

An asymmetry in cytosolic pH between mother and daughter cells was reported to underlie cellular aging in the budding yeast Saccharomyces cerevisiae; however, the underlying mechanism remains unknown. Preferential accumulation of Pma1p, which pumps cytoplasmic protons out of cells, at the plasma membrane of mother cells, but not of their newly-formed daughter cells, is believed to be responsible for the pH increase in mother cells by reducing the level of cytoplasmic protons. This, in turn, decreases the acidity of vacuoles, which is well correlated with aging of yeast cells. In this study, to identify genes that regulate the preferential accumulation of Pma1p in mother cells, we performed a genome-wide screen using a collection of single gene deletion yeast strains. A subset of genes involved in the endocytic pathway, such as VPS8, VPS9, and VPS21, was important for Pma1p accumulation. Unexpectedly, however, there was little correlation between deletion of each of these genes and the replicative lifespan of yeast, suggesting that Pma1p accumulation in mother cells is not the key determinant that underlies aging of mother cells.

The Small-Molecule Wnt Inhibitor ICG-001 Efficiently Inhibits Colorectal Cancer Stemness and Metastasis by Suppressing MEIS1 Expression.

Recurrence and metastasis remain major obstacles in colorectal cancer (CRC) treatment. Recent studies suggest that a small subpopulation of cells with a self-renewal ability, called cancer stem-like cells (CSCs), promotes recurrence and metastasis in CRC. Unfortunately, no CSC inhibitor has been demonstrated to be more effective than existing chemotherapeutic drugs, resulting in a significant unmet need for effective CRC therapies. In this study, transcriptomic profiling of metastatic tumors from CRC patients revealed significant upregulation in the Wnt pathway and stemness genes. Thus, we examined the therapeutic effect of the small-molecule Wnt inhibitor ICG-001 on cancer stemness and metastasis. The ICG-001 treatment efficiently attenuated self-renewal activity and metastatic potential. Mechanistically, myeloid ecotropic viral insertion site 1 (MEIS1) was identified as a target gene of ICG-001 that is transcriptionally regulated by Wnt signaling. A series of functional analyses revealed that MEIS1 enhanced the CSC behavior and metastatic potential of the CRC cells. Collectively, our findings suggest that ICG-001 efficiently inhibits CRC stemness and metastasis by suppressing MEIS1 expression. These results provide a basis for the further clinical investigation of ICG-001 as a targeted therapy for CSCs, opening a new avenue for the development of novel Wnt inhibitors for the treatment of CRC metastasis.

Peroxiredoxin II Is Essential for Maintaining Stemness by Redox Regulation in Liver Cancer Cells.

Redox regulation in cancer stem cells (CSCs) is viewed as a good target for cancer therapy because redox status plays an important role in cancer stem-cell maintenance. Here, we investigated the role of Peroxiredoxin II (Prx II), an antioxidant enzyme, in association with maintenance of liver CSCs. Our study demonstrates that Prx II overexpressed in liver cancer cells has high potential for self-renewal activity. Prx II expression significantly corelated with expression of epithelial-cell adhesion molecules (EpCAM) and cytokerain 19 in liver cancer tissues of hepatocellular carcinoma (HCC) patients. Downregulation of Prx II in Huh7 cells with treatment of siRNA reduced expression of EpCAM and CD133 as well as Sox2 in accordance with increased ROS and apoptosis, which were reversed in Huh7-hPrx II cells. Huh7-hPrx II cells exhibited strong sphere-formation activity compared with mock cells. Vascular endothelial growth factor (VEGF) exposure enhanced sphere formation, cell-surface expression of EpCAM and CD133, and pSTAT3 along with activation of VEGF receptor 2 in Huh7-hPrx II cells. The result also emerged in Huh7-H-ras(G12V) and SK-HEP-1-H-ras(G12V) cells with high-level expression of Prx II. Prx II was involved in regulation of VEGF driving cancer stem cells through VEGFR-2/STAT3 signaling to upregulate Bmi1 and Sox2. In addition, knockdown of Prx II in Huh7-H-ras(G12V) cells showed significant reduction in cell migration in vitro and in tumorigenic potential in vivo. Taken together, all the results demonstrated that Prx II plays a key role in the CSC self-renewal of HCC cells through redox regulation. Stem Cells 2016;34:1188-1197.

Roles of Wnt Target Genes in the Journey of Cancer Stem Cells.

The importance of Wnt/ß-catenin signaling in cancer stem cells (CSCs) has been acknowledged; however, the mechanism through which it regulates the biological function of CSCs and promotes cancer progression remains elusive. Hence, to understand the intricate mechanism by which Wnt controls stemness, the specific downstream target genes of Wnt were established by analyzing the genetic signatures of multiple types of metastatic cancers based on gene set enrichment. By focusing on the molecular function of Wnt target genes, the biological roles of Wnt were interpreted in terms of CSC dynamics from initiation to metastasis. Wnt signaling participates in cancer initiation by generating CSCs from normal stem cells or non-CSCs and augmenting persistent growth at the primary region, which is resistant to anti-cancer therapy. Moreover, it assists CSCs in invading nearby tissues and in entering the blood stream, during which the negative feedback of the Wnt signaling pathway maintains CSCs in a dormant state that is suitable for survival. When CSCs arrive at distant organs, another burst of Wnt signaling induces CSCs to succeed in re-initiation and colonization. This comprehensive understanding of Wnt target genes provides a plausible explanation for how Wnt allows CSCs variation during cancer progression.

TGF-ß Type I Receptor Kinase Inhibitor EW-7197 Suppresses Cholestatic Liver Fibrosis by Inhibiting HIF1α-Induced Epithelial Mesenchymal Transition.

BACKGROUND/AIMS: Hypoxia is an environmental factor that aggravates liver fibrosis. HIF1α activates hepatic stellate cells (HSCs) and increases transforming growth factor-ß (TGF-ß) signaling and the epithelial mesenchymal transition (EMT), accelerating the progression of fibrosis. We evaluated the anti-fibrotic therapeutic potential of a small-molecule inhibitor of TGF-ß type I receptor kinase, EW-7197, on HIF1α-derived TGF-ß signaling in cholestatic liver fibrosis. METHODS: We used a bile duct ligation (BDL)-operated rat model to characterize the role of HIF1α-derived TGF-ß signaling in liver fibrosis. Cellular assays were performed in LX-2 cells (human immortalized HSCs). The anti-fibrotic effects of EW-7197 in liver tissues and HSCs were investigated via biochemical assays, immunohistochemistry (IHC), immunofluorescence (IF), chromatin immunoprecipitation (ChIP) assays, real-time PCR, and western blotting. RESULTS: In our BDL rat model, orally administered EW-7197 inhibited fibrosis and attenuated HIF1α-induced activation of HSCs and EMT in vivo. In addition, EW-7197 inhibited HIF1α-derived HSC activation and expression of EMT markers in LX-2 cells in vitro. CONCLUSION: This study suggests that EW-7197 exhibits potential as a treatment for liver fibrosis because it inhibits HIF1α-induced TGF-ß signaling.

EW-7197 inhibits hepatic, renal, and pulmonary fibrosis by blocking TGF-ß/Smad and ROS signaling.

Fibrosis is an inherent response to chronic damage upon immense apoptosis or necrosis. Transforming growth factor-beta1 (TGF-ß1) signaling plays a key role in the fibrotic response to chronic liver injury. To develop anti-fibrotic therapeutics, we synthesized a novel small-molecule inhibitor of the TGF-ß type I receptor kinase (ALK5), EW-7197, and evaluated its therapeutic potential in carbon tetrachloride (CCl4) mouse, bile duct ligation (BDL) rat, bleomycin (BLM) mouse, and unilateral ureteral obstruction (UUO) mouse models. Western blot, immunofluorescence, siRNA, and ChIP analysis were carried out to characterize EW-7197 as a TGF-ß/Smad signaling inhibitor in LX-2, Hepa1c1c7, NRK52E, and MRC5 cells. In vivo anti-fibrotic activities of EW-7197 were examined by microarray, immunohistochemistry, western blotting, and a survival study in the animal models. EW-7197 decreased the expression of collagen, α-smooth muscle actin (α-SMA), fibronectin, 4-hydroxy-2, 3-nonenal, and integrins in the livers of CCl4 mice and BDL rats, in the lungs of BLM mice, and in the kidneys of UUO mice. Furthermore, EW-7197 extended the lifespan of CCl4 mice, BDL rats, and BLM mice. EW-7197 blocked the TGF-ß1-stimulated production of reactive oxygen species (ROS), collagen, and α-SMA in LX-2 cells and hepatic stellate cells (HSCs) isolated from mice. Moreover, EW-7197 attenuated TGF-ß- and ROS-induced HSCs activation to myofibroblasts as well as extracellular matrix accumulation. The mechanism of EW-7197 appeared to be blockade of both TGF-ß1/Smad2/3 and ROS signaling to exert an anti-fibrotic activity. This study shows that EW-7197 has a strong potential as an anti-fibrosis therapeutic agent via inhibition of TGF-ß-/Smad2/3 and ROS signaling.

The novel IGF-IR/Akt-dependent anticancer activities of glucosamine.

BACKGROUND: Recent studies have shown that glucosamine inhibits the proliferation of various human cancer cell lines and downregulates the activity of COX-2, HIF-1α, p70S6K, and transglutaminase 2. Because the IGF-1R/Akt pathway is a common upstream regulator of p70S6K, HIF-1α, and COX-2, we hypothesized that glucosamine inhibits cancer cell proliferation through this pathway. METHODS: We used various in vitro assays including flow cytometry assays, small interfering RNA (siRNA) transfection, western blot analysis, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, reverse transcription-polymerase chain reaction, and in vivo xenograft mouse model to confirm anticancer activities of glucosamine and to investigate the molecular mechanism. RESULTS: We found that glucosamine inhibited the growth of human non-small cell lung cancer (NSCLC) cells and negatively regulated the expression of IGF-1R and phosphorylation of Akt. Glucosamine decreased the stability of IGF-1R and induced its proteasomal degradation by increasing the levels of abnormal glycosylation on IGF-1R. Moreover, picropodophyllin, a selective inhibitor of IGF-1R, and the IGF-1R blocking antibody IMC-A12 induced significant cell growth inhibition in glucosamine-sensitive, but not glucosamine-resistant cell lines. Using in vivo xenograft model, we confirmed that glucosamine prohibits primary tumor growth through reducing IGF-1R signalling and increasing ER-stress. CONCLUSIONS: Taken together, our results suggest that targeting the IGF-1R/Akt pathway with glucosamine may be an effective therapeutic strategy for treating some type of cancer.

The dysadherin/FAK axis promotes individual cell migration in colon cancer.

Dysregulation of cancer cell motility is a key driver of invasion and metastasis. High dysadherin expression in cancer cells is correlated with invasion and metastasis. Here, we found the molecular mechanism by which dysadherin regulates the migration and invasion of colon cancer (CC). Comprehensive analysis using single-cell RNA sequencing data from CC patients revealed that high dysadherin expression in cells is linked to cell migration-related gene signatures. We confirmed that the deletion of dysadherin in tumor cells hindered local invasion and distant migration using in vivo tumor models. In this context, by performing cell morphological analysis, we found that aberrant cell migration resulted from impaired actin dynamics, focal adhesion turnover and protrusive structure formation upon dysadherin expression. Mechanistically, the activation of focal adhesion kinase (FAK) was observed in dysadherin-enriched cells. The dysadherin/FAK axis enhanced cell migration and invasion by activating the FAK downstream cascade, which includes the Rho family of small GTPases. Overall, this study illuminates the role of dysadherin in modulating cancer cell migration by forcing actin dynamics and protrusive structure formation via FAK signaling, indicating that targeting dysadherin may be a potential therapeutic strategy for CC patients.

Aerosol-Synthesized Surfactant-Free Single-Walled Carbon Nanotube-Based NO2 Sensors: Unprecedentedly High Sensitivity and Fast Recovery.

This study pioneers a chemical sensor based on surfactant-free aerosol-synthesized single-walled carbon nanotube (SWCNT) films for detecting nitrogen dioxide (NO2). Unlike conventional CNTs, the SWCNTs used in this study exhibit one of the highest surface-to-volume ratios. They show minimal bundling without the need for surfactants and have the lowest number of defects among reported CNTs. Furthermore, the dry-transferrable and facile one-step lamination results in promising industrial viability. When applied to devices, the sensor shows excellent sensitivity (41.6% at 500 ppb), rapid response/recovery time (14.2/120.8 s), a remarkably low limit of detection (below ≈0.161 ppb), minimal noise, repeatability for more than 50 cycles without fluctuation, and long-term stability for longer than 6 months. This is the best performance reported for a pure CNT-based sensor. In addition, the aerosol SWCNTs demonstrate consistent gas-sensing performance even after 5000 bending cycles, indicating their suitability for wearable applications. Based on experimental and theoretical analyses, the proposed aerosol CNTs are expected to overcome the limitations associated with conventional CNT-based sensors, thereby offering a promising avenue for various sensor applications.

Tumor Immune Microenvironment Biomarkers for Recurrence Prediction in Locally Advanced Rectal Cancer Patients after Neoadjuvant Chemoradiotherapy.

BACKGROUND/OBJECTIVES: The tumor microenvironment (TME) has emerged as a significant prognostic factor. This study aimed to identify prognostic factors by combining clinicopathologic parameters and the TME biomarkers in patients who underwent surgery following neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC). METHODS: CD8+ T cells, CXCR3, CXCL10, and α-smooth muscle actin (α-SMA) were analyzed via immunohistochemical staining. We also incorporated AI-powered digital pathology to assess the spatial TME. The associations between these biomarkers, clinicopathologic parameters, and survival outcomes were evaluated. RESULTS: CD8+ T cell expression, CXCR3 expression in tumor-infiltrating lymphocytes (TILs), and immune phenotypes were correlated. LARC patients with a high expression of CD8+ T cells, CXCR3 in TILs, and an inflamed phenotype had a significantly better prognosis than their counterparts did. In the multivariate analysis, the expression of CD8+ T cells and the inflamed/immune-excluded phenotype were significant tumor immune microenvironment (TiME) biomarkers for recurrence-free survival (RFS) but not for overall survival (OS). Notably, patients with the immune-desert phenotype had a poor prognosis regardless of pathologic stage, even if postoperative chemotherapy was administered (p < 0.001). CONCLUSIONS: CD8+ T cells and AI-powered immune phenotypes, alongside clinical factors, can guide personalized treatment in LARC patients receiving nCRT. A therapeutic strategy to modify the TiME after nCRT could help reduce recurrence after surgery.

Loss of Mel-18 enhances breast cancer stem cell activity and tumorigenicity through activating Notch signaling mediated by the Wnt/TCF pathway.

Mel-18 has been proposed as a negative regulator of Bmi-1, a cancer stem cell (CSC) marker, but it is still unclear whether Mel-18 is involved in CSC regulation. Here, we examined the effect of Mel-18 on the stemness of human breast CSCs. In Mel-18 small hairpin RNA (shRNA)-transduced MCF-7 cells, side population (SP) cells and breast CSC surface marker (CD44(+)/CD24(-)/ESA(+))-expressing cells, which imply a CSC population, were enriched. Moreover, the self-renewal of CSCs was enhanced by Mel-18 knockdown, as measured by the ability for tumorsphere formation in vitro and tumor-initiating capacity in vivo. Similarly, Mel-18 overexpression inhibited the number and self-renewal activity of breast CSCs in SK-BR-3 cells. Furthermore, our data showed that Mel-18 blockade up-regulated the expression of the Wnt/TCF target Jagged-1, a Notch ligand, and consequently activated the Notch pathway. Pharmacologic inhibition of the Notch and Wnt pathways abrogated Mel-18 knockdown-mediated tumorsphere formation ability. Taken together, our findings suggest that Mel-18 is a novel negative regulator of breast CSCs that inhibits the stem cell population and in vitro and in vivo self-renewal through the inactivation of Wnt-mediated Notch signaling.

Apoptotic effect of tolfenamic acid on MDA-MB-231 breast cancer cells and xenograft tumors.

Recent studies have indicated that non-steroidal anti-inflammatory drug (NSAID), particularly tolfenamic acid, can inhibit proliferation and induce apoptosis invarious cancer cells. Breast cancer represents one-third of all cancers diagnosed in women and is the second leading cause of cancer death in Western European and North American women. In the present study, we investigated the apoptotic effect of tolfenamic acid in MDA-MB-231 estrogen receptor-negative human breast carcinoma cells and in a xenograft tumor model. Treatment of cells with tolfenamic acid significantly decreased cell viability in a concentration-dependent manner. Notably, tolfenamic acid increased apoptosis-related proteins, such as p53 and p21, within 48 h. Furthermore, in vivo experiments showed that tolfenamic acid treatment resulted in a significant reduction in tumor volume over 5 weeks. Immunohistochemistry results showed that apoptosis-related protein induction by tolfenamic acid was significantly higher in the 50 mg/kg-treated group compared to the control group. Together, these results indicate that tolfenamic acid induces apoptosis in MDA-MB-231 breast cancer cells and tumor xenograft model and it may be a potential chemotherapeutic agent against breast cancer.

Machine learning with in silico analysis markedly improves survival prediction modeling in colon cancer patients.

BACKGROUND: Predicting the survival of cancer patients provides prognostic information and therapeutic guidance. However, improved prediction models are needed for use in diagnosis and treatment. OBJECTIVE: This study aimed to identify genomic prognostic biomarkers related to colon cancer (CC) based on computational data and to develop survival prediction models. METHODS: We performed machine-learning (ML) analysis to screen pathogenic survival-related driver genes related to patient prognosis by integrating copy number variation and gene expression data. Moreover, in silico system analysis was performed to clinically assess data from ML analysis, and we identified RABGAP1L, MYH9, and DRD4 as candidate genes. These three genes and tumor stages were used to generate survival prediction models. Moreover, the genes were validated by experimental and clinical analyses, and the theranostic application of the survival prediction models was assessed. RESULTS: RABGAP1L, MYH9, and DRD4 were identified as survival-related candidate genes by ML and in silico system analysis. The survival prediction model using the expression of the three genes showed higher predictive performance when applied to predict the prognosis of CC patients. A series of functional analyses revealed that each knockdown of three genes reduced the protumor activity of CC cells. In particular, validation with an independent cohort of CC patients confirmed that the coexpression of MYH9 and DRD4 gene expression reflected poorer clinical outcomes in terms of overall survival and disease-free survival. CONCLUSIONS: Our survival prediction approach will contribute to providing information on patients and developing a therapeutic strategy for CC patients.

Piperlongumine induces apoptosis and autophagy via the PI3K/Akt/mTOR pathway in KB human cervical cancer cells.

Natural products are continuously being researched to develop safe and effective treatment options for cervical cancer, the fourth most common cancer in women. Piperlongumine (PL), an amide alkaloid mainly present in long pepper, exhibits neuroprotective and anti-cancer properties. However, the specific effect of PL in cervical cancer and the relationship between the anti-cancer pathway and autophagy remain unclear. Therefore, we aimed to investigate PL-induced apoptosis in KB human cervical cancer cells and the relationship between apoptosis and autophagy therein. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound-healing assays showed that PL treatment suppressed KB cell viability and proliferation. Apoptosis was identified through 4',6-diamidino-2-phenylindole and annexin V-propidium iodide staining, increased cleaved-poly (ADP-ribose) polymerase and Bcl-2 associated X levels, and decreased B cell lymphoma 2 levels. Acridine orange staining and increased microtubule-associated protein 1A/1B-light chain 3-II and Beclin-1 levels confirmed autophagy. We determined that KB cell-related autophagy exerted cytoprotective effects using the autophagy inhibitors 3-methyladenine and hydroxychloroquine. PL treatment promoted apoptosis by inhibiting the phosphatidylinositol-3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin pathway in KB cells; inhibiting the pathway using PI3K inhibitors increased autophagy. We suggest that PL is a potential natural anticancer agent for cervical cancer treatment.

Dysadherin expression promotes the motility and survival of human breast cancer cells by AKT activation.

High dysadherin expression has been recognized as a biological predictor of metastasis and poor prognosis for many different cancer types; however, the molecular mechanisms of how dysadherin affects cancer progression are still poorly understood. In this study, we examined whether AKT signaling could link dysadherin expression with downstream events that promote the metastatic potential of human breast cancer cells. Immunohistochemical analysis of breast cancer tissues showed that dysadherin expression was highly associated with elevated expression of phospho-AKT. The introduction of dysadherin cDNA into BT-474, MCF-7 and T-47D breast cancer cell lines enhanced their levels of AKT phosphorylation, while knockdown of dysadherin in MDA-MB-231 and Hs578T breast cancer cell lines suppressed AKT phosphorylation. Treatment with the AKT inhibitor triciribine suppressed dysadherin-mediated pro-metastatic effects, including epithelial-mesenchymal transition, cell motility and drug resistance. These findings suggest that dysadherin might contribute to breast cancer progression through AKT activation.

Inhibition of Wnt1 expression reduces the enrichment of cancer stem cells in a mouse model of breast cancer.

Breast cancer is the leading cause of deaths from cancer in women. Cancer recurrence is the most common cause of mortality in breast cancer patients. The cancer stem cell (CSC) hypothesis proposes that CSCs are the center of cancer development and recurrence. Targeting CSCs, in combination with standard chemotherapy, may prevent cancer recurrence and improve long-term survival. Stem cells can be enriched in non-adherent sphere cultures. To identify molecular targets in breast CSCs, we evaluated the transcription levels of stem cell-related genes in 4T1 mouse mammary cancer cells grown as spheres or in a monolayer culture. The most differentially expressed gene was found to be wingless-type MMTV integration site family member 1 (Wnt1) in the 4T1 sphere culture. Functionally, knockdown of Wnt1 in breast cancer cell lines suppressed the in vitro properties of the stem-like cells, including their sphere-forming ability and ALDH activity, whereas the addition of recombinant Wnt1 to breast cancer cell lines enhanced the in vitro properties of these stem-like cells. In addition, knockdown of Wnt1 in 4T1 cells affected the properties of the stem-like cells in vivo, including their tumorigenic potential and tumor initiation ability. Collectively, these results suggest that Wnt1 expression may give rise to the properties of CSCs in breast tumors. Therefore, targeting Wnt1-associated signaling proteins may provide an effective therapeutic approach for the treatment of advanced breast cancer.

DCLK1 promotes colorectal cancer stemness and aggressiveness via the XRCC5/COX2 axis.

Rationale: Doublecortin-like kinase 1 (DCLK1) is a serine/threonine kinase that selectively marks cancer stem-like cells (CSCs) and promotes malignant progression in colorectal cancer (CRC). However, the exact molecular mechanism by which DCLK1 drives the aggressive phenotype of cancer cells is incompletely determined. Methods: Here, we performed comprehensive genomics and proteomics analyses to identify binding proteins of DCLK1 and discovered X-ray repair cross-complementing 5 (XRCC5). Thus, we explored the biological role and downstream events of the DCLK1/XRCC5 axis in human CRC cells and CRC mouse models. Results: The results of comprehensive bioinformatics analyses suggested that DCLK1-driven CRC aggressiveness is linked to inflammation. Mechanistically, DCLK1 bound and phosphorylated XRCC5, which in turn transcriptionally activated cyclooxygenase-2 expression and enhanced prostaglandin E2 production; these events collectively generated the inflammatory tumor microenvironment and enhanced the aggressive behavior of CRC cells. Consistent with the discovered mechanism, inhibition of DCLK1 kinase activity strongly impaired the tumor seeding and growth capabilities in CRC mouse models. Conclusion: Our study illuminates a novel mechanism that mediates the pro-inflammatory function of CSCs in driving the aggressive phenotype of CRC, broadening the biological function of DCLK1 in CRC.

Dysadherin awakens mechanical forces and promotes colorectal cancer progression.

Rationale: Dysadherin is a tumor-associated, membrane-embedded antigen found in multiple types of cancer cells, and associated with malignant behavior of cancer cells; however, the fundamental molecular mechanism by which dysadherin drives aggressive phenotypes of cancer is not yet fully determined. Methods: To get a mechanistic insight, we explored the physiological relevance of dysadherin on intestinal tumorigenesis using dysadherin knockout mice and investigated its impact on clinicopathological features in patients with advanced colorectal cancer (CRC). Next, to discover the downstream signaling pathways of dysadherin, we applied bioinformatic analysis using gene expression data of CRC patient tumors and dysadherin knockout cancer cells. Additionally, comprehensive proteomic and molecular analyses were performed to identify dysadherin-interacting proteins and their functions. Results: Dysadherin deficiency suppressed intestinal tumorigenesis in both genetic and chemical mouse models. Moreover, increased dysadherin expression in cancer cells accounted for shorter survival in CRC patients. Comprehensive bioinformatics analyses suggested that the effect of dysadherin deletion is linked to a reduction in the extracellular matrix receptor signaling pathway. Mechanistically, the extracellular domain of dysadherin bound fibronectin and enhanced cancer cell adhesion to fibronectin, facilitating the activation of integrin-mediated mechanotransduction and leading to yes-associated protein 1 activation. Dysadherin-fibronectin interaction promoted cancer cell growth, survival, migration, and invasion, effects collectively mediated the protumor activity of dysadherin. Conclusion: Our results highlight a novel function of dysadherin as a driver of mechanotransduction that stimulates CRC progression, providing a potential therapy strategy for CRC.

Myricetin induces apoptosis and autophagy in human gastric cancer cells through inhibition of the PI3K/Akt/mTOR pathway.

Myricetin, a natural flavonoid present in berries, nuts, and green tea, is well-known for its anticancer properties. Even though several previous studies have reported the anticancer effects induced by myricetin, these effects have not yet been confirmed in the adenocarcinoma gastric cell line (AGS). Moreover, the exact mechanisms of myricetin-induced apoptosis and autophagy have not been clearly identified either. Therefore, in this study, we aimed to examine the role of myricetin in inducing apoptosis and autophagy in AGS gastric cancer cells. First, the survival rate of AGS gastric cancer cells was assessed using the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) cell viability assay. Thereafter, the rate of apoptosis was analyzed using4',6-diamidino-2-phenylindole (DAPI) staining as well as annexin V and propidium iodide (PI) staining, and the expression of the proteins associated with apoptosis, PI3K/Akt/mTOR pathway, and autophagy was examined by western blotting. We observed that myricetin reduced the survival rate of AGS gastric cancer cells by inhibiting the PI3K/Akt/mTOR pathway, thereby inducing apoptosis and autophagy. Similar results were also obtained in vivo, and tumor growth was inhibited. Therefore, in the AGS gastric cancer cells, myricetin seems to inhibit the PI3K/Akt/mTOR pathway, which in turn leads to apoptosis in vitroand in vivo, cell-protective autophagy, as well as inhibition of cancer cell proliferation. These results indicate the potential of myricetin as a natural anticancer agent.